The pedunculopontine tegmentum controls renal sympathetic nerve activity and cardiorespiratory activities in nembutal-anesthetized rats

Elevated renal sympathetic nerve activity (RSNA) accompanies a variety of complex disorders, including obstructive sleep apnea, heart failure, and chronic kidney disease. Understanding pathophysiologic renal mechanisms is important for determining why hypertension is both a common sequelae and a predisposing factor of these disorders. The role of the brainstem in regulating RSNA remains incompletely understood. The pedunculopontine tegmentum (PPT) is known for regulating behaviors including alertness, locomotion, and rapid eye movement sleep. Activation of PPT neurons in anesthetized rats was previously found to increase splanchnic sympathetic nerve activity and blood pressure, in addition to altering breathing. The present study is the first investigation of the PPT and its potential role in regulating RSNA. Microinjections of DL-homocysteic acid (DLH) were used to probe the PPT in 100-μm increments in Nembutal-anesthetized rats to identify effective sites, defined as locations where changes in RSNA could be evoked. A total of 239 DLH microinjections were made in 18 rats, which identified 20 effective sites (each confirmed by the ability to evoke a repeatable sympathoexcitatory response). Peak increases in RSNA occurred within 10–20 seconds of PPT activation, with RSNA increasing by 104.5 ± 68.4% (mean ± standard deviation) from baseline. Mean arterial pressure remained significantly elevated for 30 seconds, increasing from 101.6 ± 18.6 mmHg to 135.9 ± 36.4 mmHg. DLH microinjections also increased respiratory rate and minute ventilation. The effective sites were found throughout the rostal-caudal extent of the PPT with most located in the dorsal regions of the nucleus. The majority of PPT locations tested with DLH microinjections did not alter RSNA (179 sites), suggesting that the neurons that confer renal sympathoexcitatory functions comprise a small component of the PPT. The study also underscores the importance of further investigation to determine whether sympathoexcitatory PPT neurons contribute to adverse renal and cardiovascular consequences of diseases such as obstructive sleep apnea and heart failure.

Effect of first-line treatment on second primary malignancies and Richter's transformation in patients with CLL

This study aimed to assess the frequency of and the contributing factors for second primary malignancies (SPMs) and Richter's transformations (RTs) following first-line treatment of chronic lymphocytic leukemia within four phase II/III trials of the GCLLSG evaluating fludarabine (F) vs F+cyclophosphamide (FC), chlorambucil vs F, FC without or with rituximab, and bendamustine+R (BR). Among 1458 patients, 239 (16.4%) experienced either an SPM (N=191) or a RT (N=75). Solid tumors (N=115; 43.2% of all second neoplasias) appeared most frequently, followed by RTs (N=75; 28.2%). Patients showed a 1.23-fold increased risk of solid tumors in comparison to the age-matched general population from the German cancer registry. Age>65 (hazard ratio (HR) 2.1; P<0.001), male sex (HR 1.7; P=0.01), co-morbidities (HR 1.6; P=0.01) and number of subsequent treatments⩾1 (HR 12.1; P<0.001) showed an independent adverse prognostic impact on SPM-free survival. Serum thymidine kinase>10 U/l at trial enrollment (HR 3.9; P=0.02), non-response to first-line treatment (HR 3.6; P<0.001) and number of subsequent treatments⩾1 (HR 30.2; P<0.001) were independently associated with increased risk for RT.

Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications: A Scientific Statement for Healthcare Professionals From the American Heart Association

BACKGROUND

Infective endocarditis is a potentially lethal disease that has undergone major changes in both host and pathogen. The epidemiology of infective endocarditis has become more complex with today's myriad healthcare-associated factors that predispose to infection. Moreover, changes in pathogen prevalence, in particular a more common staphylococcal origin, have affected outcomes, which have not improved despite medical and surgical advances.

METHODS AND RESULTS

This statement updates the 2005 iteration, both of which were developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It includes an evidence-based system for diagnostic and treatment recommendations used by the American College of Cardiology and the American Heart Association for treatment recommendations.

CONCLUSIONS

Infective endocarditis is a complex disease, and patients with this disease generally require management by a team of physicians and allied health providers with a variety of areas of expertise. The recommendations provided in this document are intended to assist in the management of this uncommon but potentially deadly infection. The clinical variability and complexity in infective endocarditis, however, dictate that these recommendations be used to support and not supplant decisions in individual patient management.

Brown Norway and Zucker Lean rats demonstrate circadian variation in ventilation and sleep apnea

STUDY OBJECTIVES

Circadian rhythms influence many biological systems, but there is limited information about circadian and diurnal variation in sleep related breathing disorder. We examined circadian and diurnal patterns in sleep apnea and ventilatory patterns in two rat strains, one with high sleep apnea propensity (Brown Norway [BN]) and the other with low sleep apnea propensity (Zucker Lean [ZL]).

DESIGN/SETTING

Chronically instrumented rats were randomized to breathe room air (control) or 100% oxygen (hyperoxia), and we performed 20-h polysomnography beginning at Zeitgeber time 4 (ZT 4; ZT 0 = lights on, ZT12 = lights off). We examined the effect of strain and inspired gas (twoway analysis of variance) and analyzed circadian and diurnal variability.

MEASUREMENTS AND RESULTS

Strain and inspired gas-dependent differences in apnea index (AI; apneas/h) were particularly prominent during the light phase. AI in BN rats (control, 16.9 ± 0.9; hyperoxia, 34.0 ± 5.8) was greater than in ZL rats (control, 8.5 ± 1.0; hyperoxia, 15.4 ± 1.1, [strain effect, P < 0.001; gas effect, P = 0.001]). Hyperoxia reduced respiratory frequency in both strains, and all respiratory pattern variables demonstrated circadian variability. BN rats exposed to hyperoxia demonstrated the largest circadian fluctuation in AI (amplitude = 17.9 ± 3.7 apneas/h [strain effect, P = 0.01; gas effect, P < 0.001; interaction, P = 0.02]; acrophase = 13.9 ± 0.7 h; r (2) = 0.8 ± 1.4).

CONCLUSIONS

Inherited, environmental, and circadian factors all are important elements of underlying sleep related breathing disorder. Our method to examine sleep related breathing disorder phenotypes in rats may have implications for understanding vulnerability for sleep related breathing disorder in humans.

Innovative treatments for adults with obstructive sleep apnea

Obstructive sleep apnea (OSA) affects one in five adult males and is associated with significant comorbidity, cognitive impairment, excessive daytime sleepiness, and reduced quality of life. For over 25 years, the primary treatment has been continuous positive airway pressure, which introduces a column of air that serves as a pneumatic splint for the upper airway, preventing the airway collapse that is the physiologic definition of this syndrome. However, issues with patient tolerance and unacceptable levels of treatment adherence motivated the exploration of other potential treatments. With greater understanding of the physiologic mechanisms associated with OSA, novel interventions have emerged in the last 5 years. The purpose of this article is to describe new treatments for OSA and associated complex sleep apnea. New approaches to complex sleep apnea have included adaptive servoventilation. There is increased literature on the contribution of behavioral interventions to improve adherence with continuous positive airway pressure that have proven quite effective. New non-surgical treatments include oral pressure devices, improved mandibular advancement devices, nasal expiratory positive airway pressure, and newer approaches to positional therapy. Recent innovations in surgical interventions have included laser-assisted uvulopalatoplasty, radiofrequency ablation, palatal implants, and electrical stimulation of the upper airway muscles. No drugs have been approved to treat OSA, but potential drug therapies have centered on increasing ventilatory drive, altering the arousal threshold, modifying loop gain (a dimensionless value quantifying the stability of the ventilatory control system), or preventing airway collapse by affecting the surface tension. An emerging approach is the application of cannabinoids to increase upper airway tone.

Accuracy of the non-sentinel node risk score (N-SNORE) in patients with cutaneous melanoma and positive sentinel lymph nodes: a retrospective study

BACKGROUND

Sentinel node (SLN) biopsy in patients with melanoma permits identification of those at risk for further metastases in non-sentinel lymph nodes (NSLN). However, a mere 20% of SLN-positive patients have metastases in NSLN. Therefore we need criteria to predict NSLN-positivity. A new score system known as the non-sentinel risk score, (N-SNORE) based on five clinical and pathological characteristics (gender, regression in primary melanoma, proportion of SNs containing melanoma, perinodal lymphatic invasion, and SN tumor burden), was first published in 2010. In this study, the accuracy of N-SNORE was validated in melanoma patients with positive SLN.

METHODS

A total of 106 melanoma patients with positive SLN, who had undergone complete lymph node dissection (CLND) subsequently, were included in the study. The N-SNORE was calculated in all patients, and the risk was compared to the frequency of NSLN metastases. Statistical analysis of the data was performed.

RESULTS

Thirteen patients were at very low risk for NSN metastasis (score 0), 63 patients at low risk (score 1-3), 19 at intermediate risk (score 4-5), 6 at high risk (score 6-7), and 5 at very high risk (score >8). NSLN positivity rates for these 5 risk groups were 7.7%, 18.2%, 21.1%, 33.3%, and 80%, respectively. According to Fisher's exact test, the contingency coefficient was .322; the p-value was .025.

CONCLUSION

An increasing N-SNORE was clearly correlated with a higher risk of NSLN positivity. Based on the p-value and the contingency coefficient, the overall accuracy of the N-SNORE was proven on statistical calculation.

Fatigue, inflammation, and projected mortality in heart failure

BACKGROUND

Fatigue is a prominent and poorly understood symptom of heart failure with reduced ejection fraction (HFrEF). The purpose of this study was to determine whether fatigue correlated with immune biomarkers and prognosis.

METHODS/RESULTS

In patients with HFrEF (N = 59) and healthy controls (N = 25), we prospectively measured fatigue (Profile of Mood States), depressive symptoms (Patient Health Questionnaire-8), sleep quality (Pittsburgh Sleep Quality Index), and immune biomarkers (plasma C-reactive protein [CRP], tumor necrosis factor-α [TNFα], and interleukins [IL-6 and IL-10]). Seattle Heart Failure Model (SHFM) mortality risk scores were determined. Patients with HFrEF had significantly greater fatigue and depressive symptoms and poorer sleep quality compared to control subjects. When controlling for depressive symptoms, however, fatigue did not differ significantly between patients with HFrEF and controls. Patients with HFrEF had significantly lower levels of IL-10 compared to controls. Cytokines did not correlate significantly with fatigue, but fatigue was significantly associated with higher SHFM scores.

CONCLUSIONS

Depressive symptoms were an important covariate of fatigue in patients with HFrEF. Our study findings were the first to show a positive association between fatigue and the SHFM score, indicating that fatigue was associated with poorer prognosis.

Cardiovascular responses and differential changes in mitogen-activated protein kinases following repeated episodes of binge drinking

AIMS

Excessive alcohol use in the form of binge drinking is associated with many adverse medical outcomes. Using an animal model, the primary objective of this study was to determine the effects of repeated episodes of binge drinking on myocardial structure, blood pressure (BP) and activation of mitogen-activated protein kinases (MAPKs). The effects of carvedilol, a beta-adrenergic blocker, were also examined in this animal model of binge drinking.

METHODS

Rats were randomized into three groups: control, binge and binge + carvedilol (20 mg/kg). Animals received intragastric administration of 5 g ethanol/kg in the morning × 4 days (Monday-Thursday) followed by no ethanol on Friday-Sunday. Animals were maintained on the protocol for 5 weeks. BP was measured using radiotelemetry methods. Animals underwent echocardiography at baseline, 2.5 and 5 weeks. Myocardial MAPKs were analyzed at 5 weeks using western blot techniques.

RESULTS

Over the course of 5 weeks, binge drinking was associated with significant transient increases in BP that were greater at 4 and 5 weeks compared with earlier time points. Carvedilol treatment significantly attenuated the binge-induced transient increases in BP at 4 and 5 weeks. No significant changes were found in echocardiographic parameters at any time period; however, binge drinking was associated with increased phosphorylation of p38 MAPK, which was blocked by carvedilol treatment.

CONCLUSION

Repeated episodes of binge drinking result in progressive and transient increases in BP, no change in myocardial structure and differential regulation of MAPK activation.

Fatigue in Adults with Type 2 Diabetes—An Overview of Current Understanding and Management Approaches

Patients with type 2 diabetes often experience fatigue, which impacts their self-care and quality of life. There are few data supporting a relationship between fatigue and glucose homeostasis, but fatigue in type 2 diabetes has been associated with higher body mass index (BMI), depression, physical inactivity, sleep disturbances, and chronic low-grade inflammation. Although links between fatigue and inflammation are documented in other disease populations, little is known about inflammatory mechanisms specific to type 2 diabetes and associated treatment modalities for type 2 diabetes-related fatigue. Herein we review existing knowledge about fatigue in type 2 diabetes and potential pharmacologic and behavioral therapies.

The 6-min walk test: is it an effective method for evaluating heart failure therapies?

The 6-min walk (6MW) is a self-paced test for measuring functional capacity. Lower 6MW distances have been associated with adverse outcomes in patients with heart failure. The purpose of this article is to describe the history of the 6MW test and to evaluate its reliability, validity, and predictive value as well as the responsiveness of the test to therapies. In the literature we reviewed, reliability was affected by several factors including learning effects and protocol deviations. The 6MW distance was moderately correlated with peak oxygen consumption derived from cardiopulmonary exercise stress testing. In some studies the 6MW distance was predictive of hospitalization and mortality. In pharmacological and cardiac resynchronization trials the 6MW distance did not consistently detect clinical improvements. Despite limitations, the 6MW test is a viable alternative to stress testing for objectively evaluating functional capacity in some settings. We provide recommendations for using the 6MW test in future studies.

Addition of rituximab to fludarabine and cyclophosphamide in patients with chronic lymphocytic leukaemia: a randomised, open-label, phase 3 trial

BACKGROUND

On the basis of promising results that were reported in several phase 2 trials, we investigated whether the addition of the monoclonal antibody rituximab to first-line chemotherapy with fludarabine and cyclophosphamide would improve the outcome of patients with chronic lymphocytic leukaemia.

METHODS

Treatment-naive, physically fit patients (aged 30-81 years) with CD20-positive chronic lymphocytic leukaemia were randomly assigned in a one-to-one ratio to receive six courses of intravenous fludarabine (25 mg/m(2) per day) and cyclophosphamide (250 mg/m(2) per day) for the first 3 days of each 28-day treatment course with or without rituximab (375 mg/m(2) on day 0 of first course, and 500 mg/m(2) on day 1 of second to sixth courses) in 190 centres in 11 countries. Investigators and patients were not masked to the computer-generated treatment assignment. The primary endpoint was progression-free survival (PFS). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00281918.

FINDINGS

408 patients were assigned to fludarabine, cyclophosphamide, and rituximab (chemoimmunotherapy group) and 409 to fludarabine and cyclophosphamide (chemotherapy group); all patients were analysed. At 3 years after randomisation, 65% of patients in the chemoimmunotherapy group were free of progression compared with 45% in the chemotherapy group (hazard ratio 0·56 [95% CI 0·46-0·69], p<0·0001); 87% were alive versus 83%, respectively (0·67 [0·48-0·92]; p=0·01). Chemoimmunotherapy was more frequently associated with grade 3 and 4 neutropenia (136 [34%] of 404 vs 83 [21%] of 396; p<0·0001) and leucocytopenia (97 [24%] vs 48 [12%]; p<0·0001). Other side-effects, including severe infections, were not increased. There were eight (2%) treatment-related deaths in the chemoimmunotherapy group compared with ten (3%) in the chemotherapy group.

INTERPRETATION

Chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab improves progression-free survival and overall survival in patients with chronic lymphocytic leukaemia. Moreover, the results suggest that the choice of a specific first-line treatment changes the natural course of chronic lymphocytic leukaemia.

FUNDING

F Hoffmann-La Roche.

Psychometric properties of three instruments to measure fatigue with myocardial infarction

The purpose of this study was to evaluate the psychometric properties of three questionnaires to measure fatigue with myocardial infarction. The Fatigue Symptom Inventory Interference Scale, Profile of Moods States Fatigue subscale (POMS-F), and Short Form 36 (SF-36) Vitality Scale were completed during hospitalization (n = 116) and 30 days after hospital admission (n = 49). Moderate to strong correlations were found among each of these fatigue scales and between each fatigue scale and measures of other variables to include vigor, depressed mood, anxiety, and physical functioning. POMS-F scores decreased significantly at Time 2, but this decline in fatigue was not validated on the other fatigue scales. Patients' Time 1 scores reflected significantly more fatigue compared to published scores for healthy adults. The ability to discriminate between groups suggests that the instruments may be useful for identifying patients with cardiovascular risk factors who report clinically significant fatigue.

Fatigue in Adults with Type 2 Diabetes – An Overview of Current Understanding and Management Approaches

Patients with type 2 diabetes often experience fatigue, which impacts their self-care and quality of life. There are few data supporting a relationship between fatigue and glucose homeostasis, but fatigue in type 2 diabetes has been associated with higher body mass index (BMI), depression, physical inactivity, sleep disturbances and chronic low-grade inflammation. Although links between fatigue and inflammation are documented in other disease populations, little is known about inflammatory mechanisms specific to type 2 diabetes and associated treatment modalities for type 2 diabetes-related fatigue. Herein we review existing knowledge about fatigue in type 2 diabetes and potential pharmacological and behavioural therapies.

Toward a new definition of health disparity: a concept analysis

In response to federal requests for investigation into measures to eradicate health disparities, a concept analysis of the term health disparity was conducted. Health-related and multidisciplinary literature was reviewed. Multiple terms were explored alone and in combination with no limitations on search date parameters. Findings indicated several definitions of the concept,with the term health care disparity being used interchangeably with the term health disparity. New theoretical and operational definitions, antecedents, characteristics, and consequences of the concept are proffered. Model, borderline, and contrary cases are developed to illustrate the concept. Nursing implications and recommendations for future research are discussed.

Seborrhoeic keratoses in patients with internal malignancies: a case-control study with prospective accrual of patients

BACKGROUND

The association between the eruption of numerous seborrhoeic keratoses as a result of an underlying malignancy is controversially discussed. The aim of this case-control study with prospective accrual of patients was to determine whether a direct association exists between the number seborrhoeic keratoses and internal malignancies.

METHODS

The numbers and sites of seborrhoeic keratoses were counted in 150 oncological patients and 150 matched controls. Additionally, the presence or absence of pruritus, acanthosis nigricans, and the sudden appearance of seborrhoeic keratoses were assessed.

RESULTS

Seborrhoeic keratoses did not differ significantly between patients with internal malignancies and controls. Only two patients fulfilled the criteria of the Leser-Trélat sign, defined as the eruption of numerous seborrhoeic keratoses as a cutaneous marker of an underlying internal malignancy.

CONCLUSION

No association was found between seborrhoeic keratoses and cancer. Furthermore, our data did not provide support to the validity of the Leser-Trélat sign in patients with internal malignancies.

Vascular endothelial growth factor in patients with psoriatic arthritis

OBJECTIVE

To determine the levels of vascular endothelial growth factor (VEGF) in patients with active psoriatic arthritis, patients with inactive psoriatic arthritis, and healthy controls. Serum VEGF levels were correlated with clinical and laboratory features in patients with active psoriasis arthritis.

METHODS

Serum samples from 14 patients with active psoriatic arthritis, 14 patients with inactive psoriatic arthritis, and 9 healthy controls were investigated. VEGF levels in the serum were measured using a sensitive sandwich ELISA.

RESULTS

The mean serum VEGF concentration in patients with active PA was 394.4 pg/ml (394 +/- 171.8), in patients with inactive PA 200.4 pg/ml (200.4 +/- 115.7), and in healthy subjects 214.3 pg/ml (214.3 +/- 162.1). Patients with active psoriasis arthritis had significantly higher levels of VEGF compared to patients with inactive psoriasis arthritis and healthy individuals (p > 0.001). In contrast, VEGF levels were comparable in patients with inactive psoriatic arthritis and controls (p =0.659). Furthermore, in patients with psoriatic arthritis, VEGF levels were positively correlated with ESR, HAQ, PASI and VAS.

CONCLUSION

VEGF levels may be regarded as a good indicator of active psoriasis arthritis.

Enlarged parietal foramina: MR imaging features in the fetus and neonate

Enlarged parietal foramina are believed to be benign and familial and due to a variable degree of defective intramembranous ossification of the parietal bones. We report 2 patients with this condition in whom fetal and neonatal MR imaging studies illustrate the antenatal and perinatal evolution of this condition and the associated persistence of a falcine sinus. We discuss its relationship to the spectrum of cephalocoeles.

Endocarditis after valve replacement surgery. Early recognition and treatment are essential to averting deadly complications

The incidence of infective endocarditis, an inflammation of the heart valves, the endocardium, or both that's caused by bacterial, viral, or fungal agents, continues to rise despite advances in treatment. People with prosthetic valves are among those at highest risk, and mortality rates can be extremely high, especially in cases of early onset. Diagnosis is challenging, in part because signs and symptoms associated with systemic infections can mask signs of the underlying endocarditis. This article outlines the causes and effects of prosthetic valve-related endocarditis (PVE), describes its signs and symptoms, discusses the leading diagnostic tests and criteria, and addresses prevention and treatment, as well as nursing implications.

Long-term Mortality in Patients with Thrombosis of the Inferior Vena Cava, Iliac and Femoral Veins

OBJECTIVES

To assess the long-term mortality in patients with thrombosis of the vena cava, iliac and femoral veins.

DESIGN

Registry study.

MATERIALS

Between 1992 and 2000, 212 consecutive patients with acute pelvic vein thrombosis diagnosed by duplex sonography were examined by magnetic resonance imaging (MRI) to determine the most proximal extent of the thrombus. MRI revealed a thrombosis in the inferior vena cava in 46 patients (22%), in the iliac vein in 142 patients (67%), and in the femoral vein in 24 patients (11%).

METHODS

The vital status of the patients was investigated in April 2004 using the Austrian National Registry and the Cause of Death Register.

RESULTS

A total of 211 patients of the original 212 patients were monitored over a mean follow-up period of 91 months. Seventy-two of 211 patients (34%) had died. There was no significant difference in the long-term mortality, the survival period or the occurrence of fatal pulmonary embolism (PE) between previously diagnosed vena cava, iliac vein, or femoral vein thrombosis.

CONCLUSIONS

Extension of a thrombus into the inferior caval vein in patients considered to have a pelvic vein thrombosis has no impact on long-term mortality or the development of fatal PE compared to those patients with thrombus limited to more distal veins.

Age-related pituitary volumes in prepubertal children with normal endocrine function: volumetric magnetic resonance data

BACKGROUND

Evaluation of the size of the pituitary gland on magnetic resonance imaging (MRI) may be difficult, considering the wide variation in normal gland morphology. Given the paucity of age-related biometric data, our purpose was to obtain standard normal reference values for pituitary volumes in prepubertal children using three-dimensional MRI data.

METHODS

Children under the age of 10 yr undergoing brain MRI for seizures or idiopathic developmental delay and who had no endocrine abnormality were recruited prospectively over 2 yr. All MRI studies included a three-dimensional sequence. Only subjects with normal studies were included. One hundred thirty-nine children were eligible (mean age, 5.2 yr). Direct pituitary volumes were measured from contiguous 1-mm thick reconstructed coronal and sagittal images. Estimated pituitary volumes were calculated using pituitary height, width, and length.

RESULTS

Volumes obtained from reconstructions in either plane were essentially identical. There was a linear increase in log-transformed pituitary volume with age, but relatively weak correlations with height or body mass index. There was no gender difference and only weak correlations between pituitary height and pituitary volume and between estimated pituitary volume calculation and measured pituitary volume. We provide age-related reference ranges for pituitary volumes in graphical and tabular forms.

Serum level of VEGF-D in patients with primary lymphedema

Recent studies have indicated that vascular endothelial growth factor-D (VEGF-D) stimulates lymphangiogenesis in humans. Furthermore, mutations of vascular endothelial growth factor receptor 3 (VEGFR-3) have been observed in families with hereditary lymphedema. The lack of stimulation of lymphangiogenesis could lead to production of even more VEGF-D to obtain stimulation of lymphangiogenesis resulting in a high serum level of VEGF-D. The aim of the present study was to compare the serum level of VEGF-D in patients with primary lymphedema with healthy controls. In a prospective study, the serum level of VEGF-D was determined by a solid phase ELISA in patients with primary lymphedema and compared with healthy controls. In the group of patients with primary lymphedema the serum level of VEGF-D was significantly higher compared with controls (p=0.0047). The increased levels of VEGF-D observed in the present study suggest that primary lymphedema may be based on defective stimulation of VEGFR-3.