bluuebunny/crossref_metadata_2025 huggingface dataset:
Low‐Density Lipoprotein Apheresis: Clinical Results with Different Methods
Authors: Bambauer Rolf
Published: March 2003

Abstract: In 40 patients (22 women, 18 men) suffering from familial hypercholesterolemia resistant to diet and lipid lowering drugs, low‐density lipoprotein (LDL) apheresis was performed over 84.9 ± 43.2 months. Four different systems (Liposorber, 28 of 40, Kaneka, Osaka, Japan; Therasorb, 6 of 40, Baxter, Munich, Germany; Lipopak, 2 of 40, Pocard, Moscow, Russia; and Dali, 4 of 40, Fresenius, St. Wendel, Germany) were used. With all methods, average reductions of 50.6% for total cholesterol, 52.2% for LDL, 64.3% for lipoprotein (a) (Lp[a]), and 43.1% for triglycerides, and an average increase of 10.3% for high‐density lipoprotein (HDL) were reached. Severe side effects such as shock or allergic reactions were very rare (0.5%) in all methods. In the course of treatment, an improvement in general well being and increased performance were experienced by 39 of 40 patients. Assessing the different apheresis systems used, at the end of the trial, there were no significant differences with respect to the clinical outcome experienced with the patients' total cholesterol, LDL, HDL, and triglyceride concentrations. However, to reduce high Lp(a) levels, the immunoadsorption method with special Lp(a) columns (Lipopak) seems to be most effective: −59% versus –25% (Kaneka) – (Baxter), and –29% (Dali). The present data demonstrate that treatment with LDL apheresis of patients suffering from familial hypercholesterolemia resistant to maximum conservative therapy is very effective and safe even in long‐term application.
Recurrence of Left Ventricular Hypertrophy Following Cessation of Erythropoietin Therapy
Authors: Sikole Aleksandar , Polenakovic Momir , Spiroska Vera , Polenakovic Biljana , Klinkmann Horst , Scigalla Paul
Published: March 2003

Abstract: The high cardiac output state is considered a major factor for occurrence of left ventricular hypertrophy (LVH). Increased left ventricular mass is a powerful predictor of morbidity and mortality. We analyzed morphologic changes of the heart in dialysis patients during treatment with erythropoietin (EPO) and after cessation of therapy. Fourteen hemodialysis patients were treated with EPO for 1 year. They were above age 18, dialyzed 3 times per week, and with a hematocrit below 28 vol%. EPO was given subcutaneously, at a dose of 20 U/kg body weight 3 times per week, before each hemodialysis session. Anemia was corrected and hematocrit maintained between 30 and 35 vol%. When this part of the study was completed, EPO was stopped in all 14 patients. Echocardiography was performed three times: at baseline, at 12 months of therapy, and 1 year after EPO cessation. Mean hematocrit of the group at these 3 time intervals was 23.78 ± 2.11 vol%; 33.14 ± 1.95 vol%; and 25.93 ± 5.23 vol%, respectively (mean ± SD). The following echocardiographic changes occurred. End‐diastolic volume decreased from 134.8 ± 25.4 to 113.2 ± 26.4 ml and increased back to 136.2 ± 46.2 ml. Left ventricular mass decreased from 296.6 ± 62.4 to 225.2 ± 52.7 g and increased again to 311.7 ± 106 g. Cardiac output decreased from 7,295.8 ± 2,166.9 to 5,816.4 ± 1,216.2 ml/min and increased to 6,803.2 ± 1,646.5 ml/min. Total peripheral resistance increased from 1,360.8 ± 428 to 1,691.3 ± 326 and decreased again to 1,242.8 ± 303.3 dyne · s/cm5. All these changes were significant. Mean arterial pressure increased from 114.7 ± 13.9 to 119.3 ± 13.8 mm Hg and decreased to 100.5 ± 9.3 mm Hg. LVH could be affected severely by the degree of anemia in uremics and was reversible.
Bedside Testing with the New CoaguChek Pro Activated Clotting Time Assay in Dialysis
Authors: Bommer Jürgen , Schwab Michael
Published: March 2003

Abstract: The objective of this study was to assess the analytical performance of CoaguChek Pro activated clotting time (ACT) assay using 2 lots versus Hemochron Celite and glass ACT regarding ACT values and correlations versus heparin levels. Determinations were performed using 4 CoaguChek Pro meters and 1 Hemochron 801 meter. Samples were collected during hemodialysis before, after start of heparinization, and 2 h later. Agreement between CoaguChek Pro ACT and Hemochron Celite was good (r = 0.82, slope = 1.12) and moderate with Hemochron glass (r = 0.83, slope = 0.97). Agreement between both CoaguChek Pro lots was r = 0.98. Agreement between the activators, Hemochron Celite, and glass was r = 0.73. Correlation between CoaguChek Pro ACT and heparin concentration was r = 0.88 and 0.94; for Hemochron the correlation was r = 0.75 (Celite) and r = 0.73 (glass). CoaguChek Pro ACT is therefore suitable for monitoring heparin administration during dialysis.
Does Treatment Modality Have an Impact on Anemia in Patients with Chronic Renal Failure? Effect of Low‐ and High‐Flux Biocompatible Dialysis
Authors: Opatrný Karel , Reischig Tomáš , Vienken Jörg , Eiselt Jaromír , Vít Ladislav , Opatrná Sylvie , Šefrna František , Racek Jaroslav , Brown Gail S.
Published: March 2003

Abstract: Renal anemia significantly affects the morbidity and mortality of dialysis patients. The aim of the present study was to establish whether the severity of anemia and success of its treatment differs when using high‐flux (HF) or low‐flux (LF) hemodialysis. Twenty‐five patients on long‐term hemodialysis with a mean hematocrit (Hct) of 33%, Salb of 36 g/L, and Kt/Vurea of 1.5 were divided into Groups X (n = 13) and Y (n = 12) in a prospective randomized crossover study. Group X was initially treated with LF hemodialysis to be followed by HF hemodialysis for 8 weeks each time. Group Y started with 8 week HF hemodialysis and continued, after crossover, with 8 weeks of LF hemodialysis. HF and LF hemodialysis were performed with polysulfone dialyzers F 7HPS and F60S (Fresenius Medical Care, Bad Homburg, Germany). Hct values, examined at 2 week intervals, did not differ significantly between Groups X and Y during 16 weeks of the study at any measuring interval. In another analysis, all results of HF hemodialysis (first 8 weeks of Y + second 8 weeks of X) were pooled as were all data of LF hemodialysis (first 8 weeks of X + second 8 weeks of Y). No significant relationships were noted between duration of treatment with HF hemodialysis and Hct (n = 72, rS = 0.11, p = 0.36) and between duration of LF hemodialysis and Hct (n = 74, rS = 0.02, p = 0.87) in the newly formed groups. The Hct measured during HF hemodialysis and LF hemodialysis did not differ significantly. Analysis of variance did not reveal a relationship between Hct and the HF or LF membrane. As HF and LF hemodialysis differed significantly in Kt/Vurea, the variables were adjusted to identical Kt/Vurea using analysis of covariance. No relationship between Hct and dialysis membrane permeability was demonstrated even in this case. Use of biocompatible LF and HF membranes in standard hemodialysis modes under conditions of adequate dose of dialysis and the time period studied did not result in different effects on anemia.
Utility of a Peritoneal Dialysis Leukocyte Test Strip in the Diagnosis of Peritonitis
Authors: Sam Ramin , Sahani Mandeep , Ulozas Erlandas , Leehey David J. , Ing Todd S. , Gandhi Vasant C.
Published: March 2003

Abstract: Expeditious diagnosis of peritonitis remains a significant goal in the management of patients maintained on peritoneal dialysis. Several attempts to use leukocyte esterase reagent strips to diagnose peritonitis have been described. In this study we examined the usefulness of a new reagent strip, the PeriScreen Test Strip, in the diagnosis of peritonitis. A series of 72 peritoneal effluent samples obtained from 22 maintenance peritoneal dialysis patients is reported. In this study, the test strips had a sensitivity of 100% and a specificity of 98.3% as compared to an abnormal leukocyte count. Thus, in the diagnosis of peritonitis we believe that the PeriScreen Test Strip can be used as a simple bedside screening test to exclude peritonitis in peritoneal dialysis patients.
Gap Velocity Measurements of a Blood Pump Model
Authors: Chua Leok Poh , Ong Kang Shiu , Yu Ching Man Simon , Chan Weng Kong , Wong Yew Wah
Published: March 2003

Abstract: This paper presents the velocity measurements in the gap between the impeller and the pump casing of a 5:1 enlarged centrifugal blood pump model at operating condition. Both the radial and tangential velocity at the gap were measured. It was found that there was no cross flow in both the radial and tangential velocity distributions at the seven radial locations. This implies that the 0.2 mm gap in the prototype should be the optimal clearance of the pump. The vector plot of the resultant velocity showed that the double volute design of the pump, especially the splitter plate that started at θ = 180 degrees, has created a washout mechanism in the clearance gap; that is, a sector of flow ranging from θ = 100 degrees to θ = 190 degrees has directed strongly toward the eye while the rest of the flow in the gap is in a tangential direction. It is important that the blood should flow out of the gap through the eye instead of continuing to circulate in the clearance gap. This explains why the pump has minimum hemolysis and thrombus formation and is able to function with nominal efficiency as compared to other centrifugal pumps.
Left Ventricular Remodeling After Pulmonary Autograft Aortic Valve Replacement: Evaluation with Color‐Doppler Echocardiography and Magnetic Resonance Imaging
Authors: Schmid Franz X. , Keyser Andreas , Djavidani Behrus , Link Johann , Holmer Stefan , Birnbaum Dietrich E.
Published: March 2003

Abstract: The superior hemodynamic performance of the pulmonary autograft in aortic position is expected to reflect complete regression of hypertrophy and improved ventricular function. We evaluated and compared early and midterm transthoracic color‐Doppler echocardiography (TTE) and magnetic resonance imaging (MRI) assessment concerning left ventricular (LV) function, LV mass regression, and performance of the semilunar valves. A total of 42 consecutive patients, mean age 36 ± 6 years (range 15 to 56 years), were studied. TTE and MRI were performed preoperatively, at discharge, and at 6 and 12 months postoperatively. Left ventricular diameters and function and LV wall thickness and mass were assessed. There was no early and one late postoperative death. Maximum and mean LV outflow gradients were significantly reduced (p = 0.0001 and p = 0.0001, respectively). There was a significant reduction in left ventricular mass to near normal for all patients (p = 0.001) seen after 6 months. This was paralleled by significant reductions in the interventricular septum and posterior wall thickness, but difference was slight during further follow‐up. There was a strong correlation between the results ontained by TTE and MRI for LV mass and ejection fraction (r = 0.86 and 0. 87, respectively). The pulmonary autograft operation gives excellent results that are translated into greater, rapid, and near complete regression of LV hypertrophy. Magnetic resonance imaging is a sensitive and noninvasive methodology that provides reliable visualization and quantification of ventricular performance.
Long‐Term Results for Aortic Valve Replacement with Small Aortic Annulus
Authors: Yamasaki Motoshige , Sasaguri Shiro , Hosoda Yasuyuki , Takazawa Kenji , Yamamoto Taira , Hariya Akifusa
Published: March 2003

Abstract: We determined whether aortic prosthesis size influences survival and hemodynamic function. Eighty‐nine patients who underwent small aortic valve replacement were followed. The small internal orifice area index (IOAI) group was defined as having an internal orifice area/body surface area ratio of ≤1.3 cm2/m2 (n = 34). The control group was defined as having an IOAI >1.3 cm2/m2 (n = 55). The actuarial survival rate at 10 years was 74.5% in the small IOAI group and 75% in the control group (NS). Freedom from valve‐related impairment at 10 years was 87% in the small IOAI group and 85% in the control group (NS). Postoperative pressure gradients were higher in the small IOAI group (p < 0.05). Left ventricular mass index decreased in both groups (albeit nonsignificantly in the small group, but significantly decreased in the control group). The long‐term results of aortic valve replacement for patients with small aortic annulus were satisfactory. However, the postoperative pressure gradient through the prosthesis and left ventricular hypertrophy remained at a high level in the small IOAI group.
Experimental Evaluation and Early Clinical Results of a New Low‐Profile Bileaflet Aortic Valve
Authors: Walther Thomas , Lehmann Sven , Falk Volkmar , Köhler Josef , Doll Nico , Bucerius Jan , Gummert Jan , Mohr Friedrich W.
Published: March 2003

Abstract: We performed an experimental and clinical evaluation of a new low‐profile bileaflet aortic valve (Regent, St. Jude Medical Inc., St. Paul, MN, U.S.A.). Common valve sizes were experimentally tested for leakage volume, pressure drop, and transvalvular hemodynamics using a pulse duplicator. Thirty patients (mean age 60 ± 7 years, predominant valve stenosis n = 25) received the Regent prosthesis for initial clinical evaluation. In vitro evaluation revealed equivalent leakage volumes, larger performance indices (0.552 versus 0.513), and lower pressure drops in comparison to SJM hemodynamic plus valve controls. Clinically, 21 mm (n = 9), 23 mm (n = 12), and 25 mm (n = 9) valves were implanted with no significant perioperative complications. Echocardiography revealed low transvalvular flow velocities (2.2 ± 0.4 m/s) and low pressure gradients (20 ± 6 mm Hg) postoperatively and at 6 months follow‐up. In vitro testing and early clinical results are promising; however, long‐term performance has to be proven.
Tissue Engineered Heart Valves: Autologous Cell Seeding on Biodegradable Polymer Scaffold
Authors: Shinoka Toshiharu
Published: March 2003

Abstract: We previosly reported on the successful creation of tissue‐engineered valve leaflets and the implantation of these autologous tissue leaflets in the pulmonary valve position. Mixed cell populations of endothelial cells and fibroblasts were isolated from explanted ovine arteries. Endothelial cells were selectively labeled with an acetylated low‐density lipoprotein marker and separated from fibroblasts using a fluorescent activated cell sorter. A synthetic biodegradable scaffold consisting of polyglycolic acid fibers was seeded first with fibroblasts then subsequently coated with endothelial cells. Using these methods, autologous cell/polymer constructs were implanted in 6 animals. In 2 additional control animals, a leaflet of polymer was implanted without prior cell seeding. In each animal, using cardiopulmonary bypass, the right‐posterior leaflet of the pulmonary valve was resected completely and replaced with an engineered valve leaflet with (n = 6) or without (n = 2) prior cultured cell seeding. After 6 h and 1, 6, 7, 9, and 11 weeks, the animals were sacrificed and the implanted valve leaflets were examined histologically, biochemically, and biomechanically. Animals receiving leaflets made from polymer without cell seeding were sacrificed and examined in a similar fashion after 8 weeks. In the control animals, the acellular polymer leaflets were degraded completely leaving no residual leaflet tissue at 8 weeks. The tissue‐engineered valve leaflet persisted in each animal in the experimental group; 4‐hydroxyproline analysis of the constructs showed a progressive increase in collagen content. Immunohistochemical staining demonstrated elastin fibers in the matrix and factor VIII on the surface of the leaflet. The cell labeling experiments demonstrated that the cells on the leaflets had persisted from the in vitro seeding of the leaflets. In the tissue‐engineered heart valve leaflet, transplanted autologous cells generated proper matrix on the polymer scaffold in a physiologic environment at a period of 8 weeks after implantation.
Mid‐Term Results of an Endovascular Stent‐Graft by Means of Median Sternotomy for Distal Aortic Arch Aneurysm
Authors: Usui Akihiko , Ueda Yuichi , Akita Toshiaki , Takagi Yasushi , Tajima Kazuki , Nishikimi Naomichi , Ishiguchi Tsuneo
Published: March 2003

Abstract: Migration and perigraft leakage are major problems after endovascular stent graft (EVG) by means of median sternotomy for distal aortic arch aneurysm. Anchoring sutures have been applied to prevent these problems. We evaluate the mid‐term results and the efficacy of anchoring sutures. The operation was performed on 19 men and 2 women with a mean age of 70 years (range, 59–81). The aneurysms were 19 true (12 fusiform, 7 saccular), 1 chronic dissection, and 1 penetrating aortic ulcer. EGVs were implanted by way of the aortic arch under retrograde cerebral perfusion in 13 patients and selective cerebral perfusion in 8. Total arch replacement was performed in 2 patients, and aortocoronary bypass grafting in 4. Anchoring sutures to fix the EVG were applied in 9 patients. The average follow‐up period was 28 months (range, 2–56). There were no operative mortalities, but 1 paraplegia, 1 stroke, and 2 cases of temporary spinal cord dysfunction occurred. All aneurysms were thrombosed completely after surgery and reduced in diameter (66.9 ± 17.4 mm to 57.3 ± 15.7 mm, p < 0.0001). EVG‐related complications arose in 4 patients. A chronic Type B dissection revealed impending rupture because of false lumen infection 1 year after operation, and redo surgery was performed. Migration occurred in 3 patients, all with fusiform aneurysms. One of these had a graft kink 1 year later. Another showed aneurysm enlargement with serous pleural effusion 3 years after operation. The third required redo surgery because of perigraft leakage at 3 years after surgery. There were 2 late deaths caused by stroke. There were no EVG‐related complications in the 9 cases in which anchoring sutures were applied and in the 7 cases with saccular aneurysms. No spinal cord dysfunction occurred in 8 cases with low‐flow antegrade perfusion by way of both axillary arteries while the aorta was opened. Logistic regression analysis showed significant relevance to complications of large aneurysms, greater than 80 mm in diameter. A large aneurysm tends to give rise to complications involving EVG migration. Anchoring sutures of EVG may prevent EVG‐related complications.
A New Approach to Assist Postoperative Heart Failure in an Animal Model: Juxta‐Aortic Counterpulsation
Authors: Fischer Edmundo I. Cabrera , Christen Alejandra I. , Risk Marcelo R. , Pessana Franco M. , De Forteza Eduardo
Published: March 2003

Abstract: Aortic counterpulsation is a useful technique frequently used in postcardiotomy heart failure. An acute heart failure model in open chest sheep was chosen to evaluate hemodynamic improvement with a counterpulsation balloon pump in juxta‐aortic position. This was achieved with a manufactured Dacron prosthesis and a balloon pump placed between the prosthesis and the aorta. Juxta‐aortic balloon pump counterpulsation in acute experimental heart failure resulted in a significant improvement of hemodynamic parameters: increase of cardiac output (from 0.86 ± 0.04 to 1.29 ± 0.09 L/min, p < 0.05) and cardiac index (from 0.03 ± 0.01 to 0.04 ± 0.01 L/min per kg, p < 0.05), and decrease of systemic vascular resistance (from 89.76 ± 6.69 to 66.56 ± 6.02 mm Hg/L per min, p < 0.05). The extent of aortic diastolic pressure change evaluated through the diastolic and systolic areas beneath the aortic pressure curve (DABAC/SABAC) index before cardiac failure induction showed a significant increase compared with unassisted values (from 0.81 ± 0.10 to 1.12 ± 0.09, p < 0.05). Assisted values of DABAC/SABAC index after heart failure induction also showed a significant increase compared with unassisted values (from 0.78 ± 0.21 to 1.17 ± 0.38, p < 0.05). Treatment of experimental acute heart failure by juxta‐aortic balloon pump counterpulsation allows an effective hemodynamic improvement in open chest sheep.
Effect of Rotary Blood Pump Failure on Left Ventricular Energetics Assessed by Mathematical Modeling
Authors: Vandenberghe Stijn , Segers Patrick , Meyns Bart , Verdonck Pascal R.
Published: March 2003

Abstract: In this study, we used a mathematical model to study the influence of backflow through a failing rotary blood pump. We performed simulations based on animal experiments that were published earlier by Nishida et al., who used the Medos Microdiagonal pump to assess the acute effect of sudden pump failure. The mathematical model consists of validated cardiac and arterial modules and a pump module. We could evaluate the influence of pump failure with mechanoenergetic parameters and wall stress obtained from model output. Simulations were performed at baseline and after 15 min of backflow in a control group and a heart failure group. Simulation results agreed well with the experiment. Stroke volume, aortic flow, and stress time integral increased significantly because of pump failure. However, total systemic flow and arterial pressure were not altered by backflow, and a life‐threatening situation did not appear.
Effects of Scaling on Centrifugal Blood Pumps
Authors: Wong Yew Wah , Chan Weng Kong , Yu S.C.M. , Chua Leok Poh
Published: March 2003

Abstract: Experimental studies on the effects of scaling on the performance of centrifugal blood pumps were conducted in a closed‐loop test rig. For the prototype, eight different impellers of the same outer diameter of 25 mm were tested at 1,500, 2,000, and 2,500 revolutions per minute (rpm) using blood analog as fluid medium. This corresponds to Reynolds numbers (Re) of 25,900, 34,500, and 43,200, respectively. The results indicated that the nondimensional pump characteristic is a function of Re. This is understandable since the typical operating Re for centrifugal blood pumps is less than 100,000. Thus, the effects of scaling cannot be ignored for centrifugal blood pumps. Experiments on a 5× scaled‐up model have also indicated that the scaled‐up model is more efficient than the prototype model. Our results showed that in the range of Re tested, the nondimensional head versus flow curve is a function of Re to the power of approximately 0.25. It is observed that the nondimensional head versus flow is a function of diameter ratio to the power of 0.2.
Investigation on the Mechanical Properties of Contracted Collagen Gels as a Scaffold for Tissue Engineering
Authors: Feng Z. , Yamato M. , Akutsu T. , Nakamura T. , Okano T. , Umezu M.
Published: March 2003

Abstract: In this article the mechanical properties of contracted collagen gels were investigated thoroughly by means of uniaxial tensile test. Large type I collagen‐Dulbecco's Modified Eagle Medium (DMEM) gels (each was 26 ml in volume, 1.67 mg/ml collagen concentration), each populated with about 2.5 × 106 human fibroblasts, were made in 100 mm diameter plastic dishes precoated with albumin for floating the gels in DMEM. Such identically treated gels were divided into three groups for the mechanical measurements at different culture periods (2, 4, and 10 weeks). Rapid contraction occurred within the first 3 days and then the contraction went slowly in the rest period until it reached about 13% of its original size. The stress‐strain curve of the contracted collagen gels demonstrated an exponential behavior at low stress region, followed by linear region, a point of yielding, and finally an ultimate stress point at which the maximum stress was reached. The mechanical strength increased in the first few weeks and then decreased as the culture went on. It is obvious that the collagen fibrils formed and were forced to orientate to the tensile direction after the test. The stress relaxation and cyclic creep phenomena were observed. Based on the morphological analysis of transmission electron microscopy (TEM) of the gels, a nonlinear visco‐elastic‐plastic constitutive formula was proposed, which was able to reproduce the rheological phenomena of the gels. This experiment shows that the human fibroblasts significantly contracted collagen gels so as to achieve certain mechanical strength, which makes it possible to be a scaffold for tissue engineering. However, a further method to reinforce the mechanical strength by several folds must be considered. Meanwhile, the rheological phenomena should be taken into account in the fabrication and application of the structure.
Regional Vulnerability: A Conceptual Framework
Authors: Boughton David A. , Smith Elizabeth R. , O'neill Robert V.
Published: March 2003

ABSTRACT Regional vulnerability assessment, or ReVA, is an approach to place‐based ecological risk assessment that is currently under development by the Office of Research and Development of the U.S. Environmental Protection Agency (EPA). The assessment is done at the scale of EPA regions and builds on data collected for the Environmental Monitoring and Assessment Program (EMAP) of the EPA. The pilot ReVA is being developed for the U.S. mid‐Atlantic region to identify those ecosystems, together with the ecological goods and services they provide, that are most vulnerable to being lost in the next 20 years. The project is currently exploring different conceptual approaches to integrated assessment. In this article, we give an operational approach to estimating ecosystem vulnerability and discuss important issues arising from it. The first issue is estimating vulnerability at the regional scale as opposed to the more familiar local scale. The second issue is integrating information about different sorts of risks in order to prioritize them at the regional scale. The challenge of integration is considerable because of the possibility of synergistic (mutually reinforcing) interactions between different environmental stresses. Synergistic effects are often too poorly known to include, yet potentially too important to ignore. Vulnerability at the regional scale may provide a pragmatic, middle‐road approach to this problem by highlighting and characterizing geographic areas that are expected to change the most in the future. The goal is not exact predictions, but a first‐cut early warning system to identify and prioritize the risks of undesirable environmental changes over the next few decades.
Forest Health Assessment in Canada
Authors: Allen Eric
Published: March 2003

Canada's forests cover more than 418 million hectares, 45% of our land area, and represent a diverse range of ecosystems including mixed hardwood stands in southeastern Canada, temperate rain forests of British Columbia and dwarf forests of the arctic tundra. The size and diversity of the forest presents interesting challenges to forest health assessment. The Canadian Forest Service (CFS) now recognizes that “forest health” encompasses more than the incidence and distribution of insect pests and diseasecausing organisms and that forests are perceived as healthy when ecological processes are maintained and pest populations are operating within natural ranges of variability. Different stakeholders are also seen as having varying definitions of forest “health.” For example, the forest industry may focus on health as it relates to timber productivity, whereas environmental advocates may focus on ecological integrity. The assessment and reporting of forest health in Canada is currently being accomplished through cooperation among federal and provincial governments, academia, and industry. An interagency program is being developed where broad‐scale geographic coverage will be linked to national forest inventory plots, current pest conditions monitored by provincial agencies, research on specific disturbance agents carried out regionally, and an overall synthesis of national forest health undertaken by the Canadian Forest Service.
Headache in Patients With Neurofibromatosis Type 1
Authors: Clementi M. , Battistella P.A. , Rizzi L. , Boni S. , Tenconi R.
Published: March 2003

A study of headache in a homogeneously ascertained population of 181 subjects suffering from neurofibromatosis type I is described. All subjects underwent a diagnostic protocol including imaging studies (for subjects over 5 years old up until 1992). Headache data were collected by means of a questionnaire. Headache was present in 55 of 181 subjects (25 males). Overall headache frequency was 30%, which is not significantly different from the frequency of headache reported in the general population. Headache was primary in 52 cases (5 migraine and 47 tension‐type) and secondary to obstructive hydrocephalus with brain tumor‐induced intracranial hypertension in 3 with a tension‐type pattern.

It was concluded that headache is not a specific feature of neurofibromatosis ype 1, it is not significantly related to central nervous system abnormalities, and in itself, it is not an indication for neuroradiological examination.
Chronic Paroxysmal Hemicrania and Hemicrania Continua. Interval Between Indomethacin Administration and Response
Authors: Pareja Juan A. , Sjaastad Ottar
Published: March 2003

The interval between indomethacin dosage and clinical response was assessed in hemicrania continua (n=12) and chronic paroxysmal hemicrania (n=11) sufferers. The number of trials per patient ranged from I to 30. At the time of testing, the patients had "considerable" pain after discontinuation of the drug. The dosage used was the usual one for that patient at the given pain level; ie, 25 or 50 mg tid. All the patients had a complete, long‐term response to treatment. Nevertheless, the average interval between drug intake and pain relief during the present study ranged beween 30 minutes and 48 hours in both disorders. In most patients (10 in both groups), the indomethacin effect was complete within 24 hours, and frequently within 8 hours. It is suggested that interindividual differences in dosage and timing to abolish the headaches may be due to different bioavailability or individual sensitivity. Recommendations on indomethacin testing in unilateral headaches are given.
Psychosocial Functioning in Schoolchildren With Recurrent Headaches
Authors: Carlsson Jane , Larsson Bo , Mark Anders
Published: March 2003

The psychosocial functioning of 113 schoolchildren (8 to 15 years old) reporting headaches at least once a month was compared to a group of headache‐free control subjects matched for sex and age. Thirteen percent of the headache sufferers had migraine headaches, 28% had episodic tension‐type headaches, 30% had chronic tension‐type headaches, and 29% had migraine coexisting with tension‐type headaches.

Overall, the headache sufferers experienced more somatic complaints, stress, and psychological symptoms, in addition to being absent from school (due to illness), more often and reported fewer caring persons as compared to headache‐free controls. Although few differences between the four headache groups emerged in the children's psychosocial functioning levels, children with migraine coexisting with tension‐type headaches had significantly more frequent somatic complaints than those having episodic tension‐type headaches. In addition, children with migraine or migraine coexisting with tension‐type headaches were more often absent from school than those having tension‐type headaches only. A significant but weak relationship between children's headache severity and their somatic complaints was noted.
Behcet's Disease: Presentation With Sagittal Sinus Thrombosis Diagnosed Noninvasively
Authors: Swerdlow R.H. , Hanna G.R.
Published: March 2003

The standard evaluation of patients with intracranial hypertension frequently does not reveal a discrete pathophysiologic process, leading in these cases to classification of the syndrome as “benign.” We present a 35‐year‐old woman with a recent diagnosis of pseudotumor cerebri who presented with headache, emesis, and blurring of vision. Her symptoms were progressive despite two lumbar punctures that revealed normal cerebrospinal fluid under high pressure. Contrast and noncontrast CT scans were normal; both the cerebrospinal fluid and CT neuroimaging were thus consistent with benign intracranial hypertension. An MRI, however, supported the presence of sagittal sinus thrombosis, a finding which was confirmed by MR venography. Further workup for an underlying cause of sinus thrombosis disclosed symptoms and signs fulfilling the diagnostic criteria for Behcet's disease. Cerebral venous (or sinus) thrombosis should be considered in the differential diagnosis of intracranial hypertension. Behcet's disease, while extremely rare, should be considered as a potential cause of cerebral venous thrombosis. Magnetic resonance venography can serve as a useful diagnostic study in situations where confirmation or exclusion of sinus thrombosis is required.
IHS Criteria for Migraine and Tension‐Type Headache in Children and Adolescents
Authors: Wöber‐Bingöl Cicek , Wöber Christian , Wagner‐Ennsgraber Christa , Karwautz Andreas , Vesely Christine , Zebenholzer Karin , Geldner Julia
Published: March 2003

We investigated the influence of age on the IHS criteria for migraine and tension‐type headache in 437 consecutive children and adolescents and found the following age‐associated statistically significant differences: migraine duration, occurrence of migraine aura, and bilateral location of tension‐type headache were more often fulfilled by adolescents, whereas aggravation of headache by physical activity (in migrainous disorder) and photophobia (in migraine with aura) were more often fulfilled by children, Accordingly, there are only a few, differences concerning the fulfillment of the IHS criteria for migraine and tension‐type headache in children and adolescents. Independent of age, the intensity of headache and the presence or absence of nausea are most important for differentiating the two major types of idiopathic headache. The sensitivity of the IHS criteria for migraine could be increased by reducing the minimum duration of migraine and by allowing the diagnosis of migraine when severe headache is associated with nausea, even though the criteria of location, quality, and aggravation by physical activity are not fulfilled.
Exclusion of 5‐HT2A and 5‐HT2C Receptor Genes as Candidate Genes for Migraine
Authors: Buchwalder Anne , Welch Susan K. , Peroutka Stephen J.
Published: March 2003

Several lines of investigation suggest that the serotonergic system may be involved in the pathogenesis of migraine. In particular, drugs which block 5‐HT2 receptor subtypes appear to be effective migraine prophylactic agents. Therefore, chromosomal DNA regions overlapping the 5‐HT2A (13q14‐q22) and 5‐HT2c (Xq22‐25) receptor loci were analyzed for possible linkage to the clinical diagnosis of migraine. No evidence for linkage to either chromosomal region was found, although a small subset of migrainous families showed positive likelihood of odds (LOD) scores. However, a homogeneity (HOMOG) analysis provided no statistical evidence for locus heterogeneity. The coding region of the 5‐HT2A and 5‐HT2c receptor genes was also analyzed in migraine patients and unaffected controls using polmerase chain reaction and direct sequencing. No mutations were found in the deduced amino acid sequence of either receptor in the sample of migraineurs tested. These results indicate that DNA‐based mutations in the 5‐HT2A and 5‐HT2c receptors are not generally involved in the pathogenesis of migraine.
Cerebrovascular Reactivity Measured By Transcranial Doppler in Migraine
Authors: Valikovics Attila , Oláh Lászió , Fülesdi Béla , Káposzta Zoltán , Ficzere Andrea , Bereczki Dániel , Csiba László
Published: March 2003

Changes in the diameter of intracranial arteries might have a major role in the pathophysiology of migraine. Though several studies have found alterations in velocity of blood flow and in cerebral vasomotor reactivity of intracranial arteries in migraineurs in headache‐free periods, as well as during migraine attacks, the results are inconclusive. To determine if intracranial hemodynamic characteristics of patients with migraine differ from those of controls, we measured baseline velocity of blood flow by transcranial Doppler in the middle cerebral arteries in headache‐free periods in 51 migraine patients and in 101 age‐matched controls. Cerebrovascular reactivity was measured after intravenous administration of acetazolamide in 12 migrainous patients and in 19 controls. Baseline mean velocity was significantly higher in the migraine group (70 versus 65 and 72 versus 65 cm/s with P=0.02 and P=0.0007 on the left and right sides, respectively). The difference stayed significant during acetazolamide stimulation, but the course of response did not differ between controls and migraineurs. Despite statistical significance, absolute differences were small. Therefore, middle cerebral artery velocity measurements and the acetazolamide test are not useful for the diagnosis of migraine in the interictal period.
Chronic Daily Headache in Children and Adolescents: A 2‐Year Prospective Study
Authors: Gladstein Jack , Holden E. Wayne
Published: March 2003

Chronic daily headache in children and adolescents has not been well described. We analyzed data for 37 children and adolescents who presented with chronic daily headache to our Pediatric Headache Clinic over a 2‐year period. These youngsters had five distinct headache patterns; 40% of them had the “comorbid” pattern, 35% were classified with new daily persistent headache, 15% with transformed migraine, 5% with chronic tension‐type headache, and 5% could not be classified.

There were no significant differences by diagnosis in externalizing and internalizing behaviors, type A behaviors, disability, pain severity, days missed from school, and number of coping skills employed.

Children and adolescents with chronic daily headache have distinct clinical patterns, but for the most part, have similar disability. Differences between adult and childhood chronic daily headache are emphasized.
The IHS Classification Criteria for Migraine Headaches in Adolescents Need Minor Modifications
Authors: Raieli V. , Raimondo D. , Gangitano M. , D'Amelio M. , Cammalleri R. , Camarda R.
Published: March 2003

The operational and diagnostic criteria for migraine and all other headache disorders released in 1988 by the International Headache Society are universally considered reliable and exhaustive. These criteria, however, cannot be considered as satisfactory for population‐based studies on migraine prevalence, especially if adolescents are the subjects of the study.

Using these diagnostic criteria, we conducted an epidemiological study in order to assess the prevalence of migraine headache in a student population aged 11 to 14 years. Our survey made it possible to code IHS 1.1 (migraine without aura) in 2.35%, IHS 1.2 (migraine with aura) in 0.62%, IHS 1.7 (migrainous disorders not fulfilling migraine criteria) in 1.52%, and IHS 13 (headache not classifiable) in 1.38% of the examined pupils.

In adolescents, the low prevalence estimates of migraine headache coded IHS 1.1 and the relatively high prevalence estimates of headaches coded IHS 1.7 and IHS 13 have appeared to be a consequence of the rigidity of some operational diagnostic criteria of the recent IHS classification rather than of the geographical, environmental, or socioeconomical pecularities of the cohort.

Therefore, in order to improve the reliability and the exhaustiveness of the IHS classification by increasing its sensitivity, we believe that minor modifications of the diagnostic criteria are necessary. Within these revised criteria, the subitem “moderate or severe intensity” of pain headache should become mandatory, whereas the lower limit of the criterion “duration of pain” should be reduced to 1 hour.
Codeine Self‐medication in a Headache Patient
Authors: Eng Elaine Leong , Lachenmeyer Juliana
Published: March 2003

Self‐medicating behavior for the treatment of headaches is a widespread phenomenon with costly and hazardous consequences. The case presented illustrates the ramifications of such behavior and suggests an integrated approach to the management of headaches. Biological mechanisms for the aggravation of headaches by self‐medication are discussed and integrated with psychological observations. The existing epidemiologic studies of self‐medication are reviewed and reveal a need for further studies, particularly in the United States.
Sumatriptan ‐ Nonresponders: A Survey in 366 Migraine Patients
Authors: Visser WH , de Vriend RHM , Jaspers NHWM , Ferrari MD
Published: March 2003

Sumatriptan, notably after subcutaneous administration, is highly effective in the acute treatment of migraine in the majority of patients. The response is consistent within patients and over time. To determine risk factors for nonresponse to sumatriptan, we compared clinical characteristics. In responders and nonresponders and, within patients, between attacks with and without response. We found no differences at the strict level of significance (P<0.001 because of multiple comparisons), but only tendencies for differences (0.001<P<.0.05) in either the subcutaneous or oral groups. In the subcutaneous group, nonresponders had a higher body mass index, migraine onset at an earlier age, and, most importantly, they treated their migraine attacks earlier. In the oral group, nonresponders had attacks associated with more severe vomiting and photophobia, more often went to sleep or rest, and more frequently experienced initial worsening of the headache after sumatriptan administration. Within patients, no differences were found between attacks with and without response. In conclusion, we found few, If any, clinically relevant risk factors for nonresponse to sumatriptan. Administration of sumatriptan too early was the strongest indicator and should be avoided.
Migraine Patients Show Increased Platelet Vasopressin Receptors
Authors: Buschmann J. , Leppla‐Wollsiffer G. , Nemeth N. , Nelson K. , Kirsten R.
Published: March 2003

This study was designed to investigate vasopressin receptor status (Bmax and Kd) on platelets, vasopressin plasma levels, and vasopressin‐induced platelet aggregation in migraine patients (21 females and 6 males) during a headache‐free interval and in a matched control group. In the migraine group, B max was significantly higher (P = 0.02) at 53.9 ± 20.6 fmol/mg than in the control group (36.8 + 21.0 fmol/mg). A correlation between Bmax and high or low sensitivity to vasopressin as an aggregator was evident in the control group, but not in the migraine group. No differences in Kd or in plasma levels of vasopressin between the migraine and control group were apparent. Men in both groups were much less sensitive to vasopressin as a platelet aggregator than were women (P < 0.01). Whether the higher Bmax in the migraine group is a reflection of temporarily higher vasopressin levels during headache or reflects a primary increase in sensitivity to vasopressin, remains to be clarified. The higher sensitivity of platelets (as a model for vessel wall receptors) from women may indicate why many more women than men suffer from migraine. Since the Bmax of the vasopressin receptor on platelets from migraine patients is increased compared to controls, treating migraine headache with vasopressin may deserve more attention.
Neck Mobility in Different Headache Disorders
Authors: Zwart John‐Anker
Published: March 2003

The main purpose of this study was to assess neck mobility (by Cybex equipment) in different headache disordered and, in particular, cervicogenic headache, and to compare; these findings with those in controls. A total of 51 control subjects and 90 headache patients were investigated, whereof 28 patients suffered from common migraine (migraine without aura), 34 from tension‐type headache (H episodic and 25 chronic), and 28 patients from cervicogenic headache. One‐way ANOVA and post hoc Bonferroni analysis showed significant differences between those with cervicogenic headache and the other groups for rotation ( P <0.001) and flexion/extension ( P <0.001), but not for lateral neck movement ( P =NS). There were no significant differences between migraine patients, tension‐type headache patients, and controls. In all four groups, there was a significant positive correlation between active and passive neck movement for rotation ( P <0.001), flexion/extension ( P <0.001), and lateral neck movement ( P <0.001). Repeated measures analysis of variance (ANOVA) showed no significant day‐to‐day differences in 10 control subjects. In the control group (n=51), there was a significant negative correlation between age and neck movement. For rotation. Pearson's correlation coefficient was: r =‐0.71 ( P <0.001), for flexion/extension r =‐0.71 ( P <0.001), and for lateral neck movement r =‐0.67 ( P <0.001). No significant sex difference was found as for any of the neck movements. Pain at the time of investigation did not seem to influence neck mobility. Cervicogenic headache has been recognized as a pair syndrome by the International Association for the Study of Pain (IASP). Since reduced neck mobility is one of the major criteria for this diagnosis, it emphasizes the need for systematic, objective neck mobility measurements in the individual patient to substantiate the diagnosis. The technique is simple and proved reliable.
Paroxysmal Headache Caused by Colloid Cyst of the Third Ventricle: Case Report and Review of the Literature
Authors: Young William B. , Silberstein Stephen D.
Published: March 2003

Colloid cysts of the third ventricle are benign tumors that may cause brief, severe headache and, rarely, death. We present a patient with frequent, episodic, brief, severe headaches of 2 weeks' duration who suddenly became obtunded. We reviewed the literature on the symptomatology of colloid cysts and conclude that any patient: with less than a 1‐year history suggestive of a third ventricular colloid cyst causing brief, severe headaches should be aggressively investigated.
Coexistence of Migraine and Cluster Headache: Report of 10 Cases and Possible Pathogenetic Implications
Authors: D'Amico Domenico , Centonze Vincenzo , Grazzi Licia , Leone Massimo , Ricchetti Giuseppe , Bussone Gennaro
Published: March 2003

We report on 10 patients suffering from two types of primary headache, migraine and cluster, diagnosed according to IHS criteria, and selected from headache patients attending two Italian headache centers. We briefly review the literature on coexisting migraine and cluster headache, considering the time relationships between these two headaches. The present series seems not to confirm the hypothesis that migraine transforms into cluster headache since both headaches persist together in the patients. The series is of clinical interest particularly with regard to diagnosis and to treatment strategies. Furthermore, while migraine and cluster headache comorbidity must be confirmed by population‐based epidemiological studies, the possibility arises that the two conditions may be linked pathophysiologically: common genetic factors or functional alterations in the same central neurological circuits may play a role in the pathogenesis of both disorders.
Sumatriptan in the Acute Treatment of Migraine Without Aura: Efficacy of 50‐mg Dose
Authors: Moschiano Franca , D'Amico Domenico , Grazzi Licia , Leone Massimo , Bussone Gennaro
Published: March 2003

We conducted an open study on the efficacy of 50 mg of sumatriptan as an acute treatment for migraine without aura. We recruited 200 consecutive patients, with an established history of migraine without aura, presenting at a headache center. The patients were instructed to take half a 100‐mg sumatriptan tablet for their next migraine attack, and to record details of their headache in a diary. The primary outcome of the study was headache relief from one migraine attack. Attacks were moderately intense (46%), moderate to severe (7%), or severe (47%). Total or partial benefit at 2 hours from the 50‐mg dose was reported by 140 of 200 patients (70%). Thirty‐six patients received no benefit from half a tablet, and 24 did not take sumatriptan, preferring their habitual medication. Side effects were few, mild, and short lasting. We conclude that the 50‐mg oral dose is generally effective for migraine without aura attacks of both moderate and severe intensity and recommend this dose for all such patients. If, however, sumatriptan is ineffective at that dose it can be increased to a maximum of 100 mg.