New tree-ring data from Canadian boreal and hemi-boreal forests provide insight for improving the climate sensitivity of terrestrial biosphere models.

Understanding boreal/hemi-boreal forest growth sensitivity to seasonal variations in temperature and water availability provides important basis for projecting the potential impacts of climate change on the productivity of these ecosystems. Our best available information currently comes from a limited number of field experiments and terrestrial biosphere model (TBM) simulations of varying predictive accuracy. Here, we assessed the sensitivity of annual boreal/hemi-boreal forest growth in Canada to yearly fluctuations in seasonal climate variables using a large tree-ring dataset and compared this to the climate sensitivity of annual net primary productivity (NPP) estimates obtained from fourteen TBMs. We found that boreal/hemi-boreal forest growth sensitivity to fluctuations in seasonal temperature and precipitation variables changed along a southwestern to northeastern gradient, with growth limited almost entirely by temperature in the northeast and west and by water availability in the southwest. We also found a lag in growth climate sensitivity, with growth largely determined by the climate during the summer prior to ring formation. Analyses of NPP sensitivity to the same climate variables produced a similar southwest to northeast gradient in growth climate sensitivity for NPP estimates from all but three TBMs. However, analyses of growth from tree-ring data and analyses of NPP from TBMs produced contrasting evidence concerning the key climate variables limiting growth. While analyses of NPP primarily indicated a positive relationship between growth and seasonal temperature, tree-ring analyses indicated negative growth relationships to temperature. Also, the positive effect of precipitation on NPP derived from most TBMs was weaker than the positive effect of precipitation on tree-ring based growth: temperature had a more important limiting effect on NPP than tree-ring data indicated. These mismatches regarding the key climate variables limiting growth suggested that characterization of tree growth in TBMs might need revision, particularly regarding the effects of stomatal conductance and carbohydrate reserve dynamics.

Genetic variants of antioxidant enzymes and environmental exposures as molecular biomarkers associated with the risk and aggressiveness of bladder cancer.

Bladder cancer (BC) is one of the top 10 most common tumours worldwide; however, no molecular markers are currently available for tumour management and follow-up. BC could benefit from molecular biomarkers in environmental disease, which provide mechanistic understanding of individual susceptibility to exposure-related cancers and allow characterizing genetic alterations in the molecular pathway for malignancy. This case-control study performed a molecular analysis in 99 BC and 125 controls. Buccal swabs were collected to assess SNPs in eleven genes coding for xenobiotic detoxification enzymes, cellular antioxidant defences, and hormone synthesis and signalling (NAT2 (rs1801280), GPX1 (rs1050450 and rs17650792), TXNRD1 (rs7310505), PRDX3 (rs3740562), PON1 (rs662), SOD1 (rs10432782), SOD2 (rs4880), CAT (rs1001179), CYP17A1 (rs743572) and ESR1 (rs746432)). A structured questionnaire was administered to study participants to assess environmental and dietary chemical exposures. Several miRNAs associated with BC and detoxification/antioxidant pathways were analysed in a subsample of the study population, including miR-93-5p, miR-221-3p, miR-126, miR-27a-3p, miR-193b, and miR-193a-5p. Levels of selected environmental pollutants (polycyclic aromatic hydrocarbons and endocrine disrupting chemicals) were determined in urine from a subsample of BC cases and controls. We found that CYP17A1, CAT, SOD1, ESR1, PON1, and GPX1 (rs17650792) were associated with BC risk. Furthermore, exposure to smoke and/or dust, and alcohol intake were identified as risk factors for BC. Increased urinary levels of benzo[a]pyrene and bisphenol A were observed in BC patients relative to controls, along with an increased expression of miR-193b, miR-27a and miR-93-5p in BC. Nevertheless, further studies with a larger sample size are warranted to confirm these exploratory results. This study also shows that the combination of genetic markers (PON1 and CYP17A1) and miRNA (miR-221-3p and miR-93-5p) open a new scenario in the use of non-invasive biomarkers in the stratification of BC to guide personalized medicine, which is extremely urged in the current clinical setting.

Stomatal conductance, not biochemistry, drives low temperature acclimation of photosynthesis in Populus balsamifera, regardless of nitrogen availability.

Low-temperature thermal acclimation may require adjustments to N and water use to sustain photosynthesis because of slow enzyme functioning and high water viscosity. However, understanding of photosynthetic acclimation to temperatures below 11 °C is limited. We acclimated Populus balsamifera to 6 °C and 10 °C (6A and 10A, respectively) and provided the trees with either high or low N fertilizer. We measured net CO2 assimilation (Anet ), stomatal conductance (gs ), maximum rates of Rubisco carboxylation (Vcmax ), electron transport (Jmax ) and dark respiration (Rd ) at leaf temperatures of 2, 6, 10, 14 and 18 °C, along with leaf N concentrations. The 10A trees had higher Anet than the 6A trees at warmer leaf temperatures, which was correlated with higher gs in the 10A trees. The instantaneous temperature responses of Vcmax , Jmax and Rd were similar for trees from both acclimation temperatures. While soil N availability increased leaf N concentrations, this had no effect on acclimation of photosynthesis or respiration. Our results indicate that acclimation below 11 °C occurred primarily through changes in stomatal conductance, not photosynthetic biochemistry, and was unaffected by short-term N supply. Thermal acclimation of stomatal conductance should therefore be a priority for future carbon cycle model development.

Panenteric capsule endoscopy identifies proximal small bowel disease guiding upstaging and treatment intensification in Crohn's disease: A European multicentre observational cohort study.

BACKGROUND: Endoscopically defined mucosal healing in Crohn's disease is associated with improved outcomes. Panenteric capsule endoscopy enables a single non-invasive assessment of small and large bowel mucosal inflammation. AIMS AND METHODS: This multicentre observational study of patients with suspected and established Crohn's disease examined the feasibility, safety and impact on patient outcomes of panenteric capsule endoscopy in routine clinical practice. The potential role in assessment of disease severity and extent by a comparison with existing clinical and biochemical markers is examined. RESULTS: Panenteric capsule endoscopy was performed on 93 patients (71 with established and 22 with suspected Crohn's disease). A complete examination occurred in 85% (79/93). Two cases (2.8%) of capsule retention occurred in patients with established Crohn's disease. Panenteric capsule resulted in management change in 38.7% (36/93) patients, including 64.6% (32/48) of those with an established diagnosis whose disease was active, and all three patients with newly diagnosed Crohn's disease. Montreal classification was upstaged in 33.8% of patients with established Crohn's disease and mucosal healing was demonstrated in 15.5%. Proximal small bowel disease upstaged disease in 12.7% and predicted escalation of therapy (odds ratio 40.3, 95% confidence interval 3.6-450.2). Raised C-reactive protein and faecal calprotectin were poorly sensitive in detecting active disease (0.48 and 0.59 respectively). CONCLUSIONS: Panenteric capsule endoscopy was feasible in routine practice and the ability to detect proximal small bowel disease may allow better estimation of prognosis and guide treatment intensification. Panenteric capsule endoscopy may be a suitable non-invasive endoscopic investigation in determining disease activity and supporting management decisions.

Small-calibre percutaneous nephrolithotomy (SC-PCNL). Therapeutic decision algorithm. / Nefrolitectomía percutánea de calibre reducido (NLP-CR). Algoritmo de decisión terapéutica.

INTRODUCTION: The progressive reduction in the calibre of the tract in percutaneous kidney surgery to the point of miniaturisation has expanded its use to smaller stones that until now have been treated with extracorporeal shock wave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS). OBJECTIVE: To provide an update on the various techniques of small-calibre nephrolithotomy (SC-PCNL) analyse their efficacy, safety and indications and determine their degree of implantation at this time. MATERIAL AND METHODS: We performed a review in PubMed of Spanish and English medical literature on the various techniques of SC-PCNL. RESULTS: The use of SC-PCNL has reduced the morbidity associated with standard PCNL, particularly bleeding, and has enabled tubeless nephrolithotomy with greater safety. There are various techniques with blurred terminology (Miniperc, Microperc, Mini-microperc, Ultraminiperc), which differ in terms of gauge employed and in certain technical aspects that require their indications be specified. Currently, SC-PCNL competes with techniques that are less invasive than standard PCNL such as ESWL and the RIRS in treating small stones, but the role of SC-PCNL is still not sufficiently understood and continues to be the subject of debate. CONCLUSIONS: The indications for PCNL are expanding to small stone sizes due to the miniaturisation of the technique. PCNL competes in this field with ESWL and RIRS. Larder studies are needed to establish the specific indications for PCNL in treating nephrolithiasis.

Validación psicométrica de la versión en castellano del cuestionario USS-PROM para pacientes sometidos a cirugía de uretra anterior / Psychometric validation of the Spanish version of the USS-PROM questionnaire for patients who undergo anterior urethral surgery

Objetivo: Traducir y validar en lengua castellana el cuestionario Urethral Stricture Surgery Patient-Reported Outcome Measure (USS-PROM), evaluar sus propiedades psicométricas y determinar su idoneidad para su uso clínico en nuestro medio. Adicionalmente, se valoraron los posibles cambios en la función eyaculatoria mediante el Male Sexual Health Questionnaire-Ejaculatory Dysfunction (MSHQ-EjD). Material y métodos: Se realizó una traducción sistemática de la versión británica. De forma prospectiva, entre septiembre 2014 y septiembre 2015 se incluyeron pacientes programados para cirugía de estenosis de uretra anterior. Todos los pacientes completaron el cuestionario antes y después de la cirugía. Se realizó un estudio psicométrico en profundidad del cuestionario. Resultados: Se evaluaron las respuestas de un total de 40 pacientes. El cuestionario demostró su validez presentando excelente correlación negativa entre las puntuaciones de los síntomas de vaciado y el flujo máximo (r = −0,6, p < 0,001), y mostrando también mejoría significativa en el EQ5D-visual analogue scale (VAS) y el time trade-off (TTO). Para la consistencia interna, el alfa de Cronbach fue de 0,701. Para la fiabilidad test-retest el coeficiente de correlación intraclase (CCI) global fue de 0,974 y los CCI de cada ítem por separado oscilaron entre 0,799 y 0,980. Se observaron mejoras significativas en todos los ítems de síntomas miccionales y calidad de vida relacionada con la salud (CVRS) (p < 0,001), quedando demostrada la capacidad de respuesta al cambio del cuestionario. No observamos cambios significativos en el MSHQ-EjD. Conclusiones: La versión en castellano del cuestionario USS-PROM es un instrumento válido para cuantificar los cambios en los síntomas de vaciado y la CVRS de los pacientes sometidos a cirugía de uretra anterior

Ojective: To translate into Spanish and validate the Urethral Stricture Surgery Patient-Reported Outcome Measure (USS-PROM) questionnaire, assessing its psychometric properties and determining its suitability for clinical use in our community. We also assessed the potential changes in ejaculatory function using the Male Sexual Health Questionnaire-Ejaculatory Dysfunction (MSHQ-EjD). Material and methods: A systematic translation of the British version was performed. Patients scheduled for anterior urethral stricture surgery between September 2014 and September 2015 were prospectively included in the study. All patients completed the questionnaire before and after the surgery. We conducted an in-depth psychometric study of the questionnaire. Results: We assessed the responses of a total of 40 patients. The questionnaire showed its validity, presenting an excellent negative correlation between the voiding symptom scores and the maximum flow (r = −0.6,P < .001), and also showed significant improvement in the EQ5D-VAS (visual analogue scale) and the time trade-off. For internal consistency, the Cronbach's alpha was 0.701. For the test-retest reliability, the overall intraclass correlation coefficient (ICC) was 0.974, and the ICC for each item separately ranged from 0.799 to 0.980. We observed significant improvement in all items regarding urinary symptoms and health-related quality of life (P < .001), thereby demonstrating the response capacity to changing the questionnaire. There were no significant changes in the MSHQ-EjD. Conclusions: The Spanish version of the USS-PROM questionnaire is a valid instrument for quantifying changes in voiding symptoms and the health-related quality of life of patients undergoing anterior urethral surgery

Psychometric validation of the Spanish version of the USS-PROM questionnaire for patients who undergo anterior urethral surgery. / Validación psicométrica de la versión en castellano del cuestionario USS-PROM para pacientes sometidos a cirugía de uretra anterior.

OBJECTIVE: To translate into Spanish and validate the Urethral Stricture Surgery Patient-Reported Outcome Measure (USS-PROM) questionnaire, assessing its psychometric properties and determining its suitability for clinical use in our community. We also assessed the potential changes in ejaculatory function using the Male Sexual Health Questionnaire-Ejaculatory Dysfunction (MSHQ-EjD). MATERIAL AND METHODS: A systematic translation of the British version was performed. Patients scheduled for anterior urethral stricture surgery between September 2014 and September 2015 were prospectively included in the study. All patients completed the questionnaire before and after the surgery. We conducted an in-depth psychometric study of the questionnaire. RESULTS: We assessed the responses of a total of 40 patients. The questionnaire showed its validity, presenting an excellent negative correlation between the voiding symptom scores and the maximum flow (r=-0.6, P<.001), and also showed significant improvement in the EQ5D-VAS (visual analogue scale) and the time trade-off. For internal consistency, the Cronbach's alpha was 0.701. For the test-retest reliability, the overall intraclass correlation coefficient (ICC) was 0.974, and the ICC for each item separately ranged from 0.799 to 0.980. We observed significant improvement in all items regarding urinary symptoms and health-related quality of life (P<.001), thereby demonstrating the response capacity to changing the questionnaire. There were no significant changes in the MSHQ-EjD. CONCLUSIONS: The Spanish version of the USS-PROM questionnaire is a valid instrument for quantifying changes in voiding symptoms and the health-related quality of life of patients undergoing anterior urethral surgery.

Primary health care services provided by nurse practitioners and family physicians in shared practice.

BACKGROUND: Collaborative practice involving nurse practitioners (NPs) and family physicians (FPs) is undergoing a renaissance in Canada. However, it is not understood what services are delivered by FPs and NPs working collaboratively. One objective of this study was to determine what primary health care services are provided to patients by NPs and FPs working in the same rural practice setting. METHODS: Baseline data from 2 rural Ontario primary care practices that participated in a pilot study of an outreach intervention to improve structured collaborative practice between NPs and FPs were analyzed to compare service provision by NPs and FPs. A total of 2 NPs and 4 FPs participated in data collection for 400 unique patient encounters over a 2-month period; the data included reasons for the visit, services provided during the visit and recommendations for further care. Indices of service delivery and descriptive statistics were generated to compare service provision by NPs and FPs. RESULTS: We analzyed data from a total of 122 encounters involving NPs and 278 involving FPs. The most frequent reason for visiting an NP was to undergo a periodic health examination (27% of reasons for visit), whereas the most frequent reason for visiting an FP was cardiovascular disease other than hypertension (8%). Delivery of health promotion services was similar for NPs and FPs (11.3 v. 10.0 instances per full-time equivalent [FTE]). Delivery of curative services was lower for NPs than for FPs (18.8 v. 29.3 instances per FTE), as was provision of rehabilitative services (15.0 v. 63.7 instances per FTE). In contrast, NPs provided more services related to disease prevention (78.8 v. 55.7 instances per FTE) and more supportive services (43.8 v. 33.7 instances per FTE) than FPs. Of the 173 referrals made during encounters with FPs, follow-up with an FP was recommended in 132 (76%) cases and with an NP in 3 (2%). Of the 79 referrals made during encounters with NPs, follow-up with an NP was recommended in 47 (59%) cases and with an FP in 13 (16%) (p < 0.001). INTERPRETATION: For the practices in this study NPs were underutilized with regard to curative and rehabilitative care. Referral patterns indicate little evidence of bidirectional referral (a measure of shared care). Explanations for the findings include medicolegal issues related to shared responsibility, lack of interdisciplinary education and lack of familiarity with the scope of NP practice.

The restricted cellular host range of human herpesvirus 8.

DESIGN: A selection of primary and transformed cell types were evaluated for their susceptibility to infection with human herpesvirus 8 (HHV-8)/Kaposi's sarcoma-associated herpesvirus. METHODS: Sources of HHV-8 included Kaposi's sarcoma lesion punch biopsies that were either cocultured directly with target cells or that were first cocultured with human lymphocytes to derive HHV-8-containing fluids that were inoculated onto target cells. HHV-8 was also obtained from primary effusion lymphoma-derived cell lines. Techniques to detect infection included the PCR, immunofluorescence assays and in situ hybridization. RESULTS: Susceptible cells included human umbilical cord blood mononuclear cells (UCMC), adult CD19 B cells, macrophages and certain endothelial cells of human and animal origin, including some that are transformed with human papilloma virus type 16 E6 and E7 genes. The infection of lymphocytes did not yield established lymphoblastoid cell lines (LCL) and virus infection persisted for only 4-7 days. However, long-term HHV-8 infection of UCMC could be achieved by coinfection with Epstein-Barr virus. HHV-8 could also infect UCMC LCL recently derived by Epstein-Barr virus transformation, but long-established LCL could not be infected with HHV-8. CONCLUSIONS: These data provide further biological evidence in cell culture for the limited cellular host range of HHV-8 to CD19 B cells, macrophages, and certain endothelial cells.

Glutathione-S-Transferase as a selective inhibitor of oncogenic ras-p21-induced mitogenic signaling through blockade of activation of jun by jun-N-terminal kinase.

We have identified the intracellular detoxification enzyme, glutathione-S-transferase (GST), as a potent inhibitor of the activation of jun by its kinase, jun-N-terminal kinase (JNK), in vitro. All three major isozymes (alpha, mu, and pi) bind to JNK-jun complexes and inhibit activation of jun by JNK. We now find that GST inhibits JNK-induced oocyte maturation in vivo and strongly inhibits oocyte maturation induced by oncogenic ras-p21 protein, but not by insulin-activated normal cellular p21 protein. These results correlate with the finding that oncogenic, but not insulin-activated normal, p21 induces high levels of activated JNK. GST also strongly blocks induction of oocyte maturation by protein kinase C (PKC) which is a critical downstream target of oncogenic but not normal ras-p21. Thus, we have established a new function for GST as a potent physiological inhibitor of the ras-JNK-jun pathway.

Microglial and astrocyte chemokines regulate monocyte migration through the blood-brain barrier in human immunodeficiency virus-1 encephalitis.

The numbers of immune-activated brain mononuclear phagocytes (MPs) affect the progression of human immunodeficiency virus (HIV)-1-associated dementia (HAD). Such MPs originate, in measure, from a pool of circulating monocytes. To address the mechanism(s) for monocyte penetration across the blood-brain barrier (BBB), we performed cross-validating laboratory, animal model, and human brain tissue investigations into HAD pathogenesis. First, an artificial BBB was constructed in which human brain microvascular endothelial and glial cells-astrocytes, microglia, and/or monocyte-derived macrophages (MDM)-were placed on opposite sides of a matrix-coated porous membrane. Second, a SCID mouse model of HIV-1 encephalitis (HIVE) was used to determine in vivo monocyte blood-to-brain migration. Third, immunohistochemical analyses of human HIVE tissue defined the relationships between astrogliosis, activation of microglia, virus infection, monocyte brain infiltration, and beta-chemokine expression. The results, taken together, showed that HIV-1-infected microglia increased monocyte migration through an artificial BBB 2 to 3.5 times more than replicate numbers of MDM. In the HIVE SCID mice, a marked accumulation of murine MDM was found in areas surrounding virus-infected human microglia but not MDM. For human HIVE, microglial activation and virus infection correlated with astrogliosis, monocyte transendothelial migration, and beta-chemokine expression. Pure cultures of virus-infected and activated microglia or astrocytes exposed to microglial conditioned media produced significant quantities of beta-chemokines. We conclude that microglial activation alone and/or through its interactions with astrocytes induces beta-chemokine-mediated monocyte migration in HAD.

Refinement of a rodent model of peripheral lymphedema.

A reliable, inexpensive experimental counterpart of peripheral lymphedema has been notoriously difficult to reproduce thereby stifling basic and clinical research into this frustrating clinical condition. Accordingly, in 45 adult Wistar-Fuzzy rats, we attempted to produce sustained hindlimb lymphedema by either groin nodal/lymphatic microsurgical ablation (S) (guided by visual blue dye lymphography) or limited field-groin irradiation (R) alone (4500 rads) or combined S followed by R or R followed by S with an additional non-manipulated group serving as controls. Observations were made for 30-100 days thereafter. Hindlimb volumes were determined serially using the truncated cone formula based on multiple circumferential measurements at standardized intervals along the affected hindlimb and the findings compared with similar measurements in the contralateral non-manipulated hindlimb. In randomly selected rats from each group, lymphatic drainage was assessed by lymphangioscintigraphy (LAS), soft tissue swelling by magnetic resonance imaging (MRI), and edema fluid total protein content by refractometry. Whereas S or R alone produced only transient or mild hindlimb edema without associated morbidity or mortality, S-R or R-S induced moderate to severe sustained protein-rich hindlimb lymphedema associated with 9-13% early mortality and notable late local limb morbidity. Lymphatic obstruction was documented by sustained maintenance of increased hindlimb volume, subcutaneous fluid accumulation (MRI), and impaired lymphatic drainage (LAS). This reproducible rodent model of secondary lymphedema reliably simulates a stable clinical condition for a window of up to 100 days and should thereby facilitate standardized testing of therapeutic/preventive protocols and basic research into lymphatic dynamics in secondary lymphedema.

Expression of multiple matrix metalloproteinases and urokinase type plasminogen activator in cultured Kaposi sarcoma cells.

Kaposi's sarcoma (KS) cells are considered to be of endothelial origin. KS lesions are characterized by hyperproliferation and an invasive phenotype. We have determined that KS cell cultures constitutively secrete multiple forms of several matrix metalloproteinases (MMPs) and an altered form of urokinase plasminogen activator (uPA) by zymogram and Western analysis of the culture media. MMPs are a family of secreted endoproteinases which degrade components of the extracellular matrix. Their enhanced expression and activity are strongly correlated with cellular processes involving tissue remodeling and invasion. The KS cells secrete increased levels of gelatinase A and B and a high molecular weight uPA in vitro when compared with non-KS endothelial or epithelial cells. Multiple forms of gelatinases A and B were observed on gelatin zymograms. Caseinolytic bands observed were confirmed by Western blot analysis to be due to stromelysin activity, whereas matrilysin was not detected by casein zymography. Western blot analysis also detected secretion of interstitial collagenase and high molecular weight uPA. Gelatinolytic activity with the mobility of gelatinase B was detected on gelatin zymograms, but not by Western analysis. This unusual constitutive expression pattern of MMPs and uPA by KS cells in vitro is characterized by elevated levels of gelatinase A, gelatinase B, interstitial collagenase, stromelysin and a high molecular weight form of uPA, and the lack of expression of matrilysin. These secreted MMPs, taken together, are capable of digesting a broad range of components of the extracellular matrix. This unusual pattern is likely to contribute to the characteristic hyperproliferative and invasive phenotype of KS lesions.

Cocaine enhances brain endothelial adhesion molecules and leukocyte migration.

Leukocyte infiltration of cerebral vessels in cocaine-associated vasculopathy suggests that cocaine may enhance leukocyte migration. We have investigated cocaine's effects on leukocyte adhesion in human brain microvascular endothelial cell (BMVEC) cultures and monocyte migration in an in vitro blood-brain barrier (BBB) model constructed with BMVEC and astrocytes. Cocaine (10(-5) to 10(-9) M) enhanced adhesion of monocytes and neutrophils to BMVEC. In the BBB model, cocaine (10(-4) to 10(-8) M) enhanced monocyte transmigration. Cocaine increased expression of endothelial adhesion molecules, intercellular adhesion molecule-1 (ICAM-1, CD54), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule-1 (ELAM-1) on BMVEC. The peak effect on ICAM-1 expression was between 6 and 18 h after treatment. ICAM-1 was increased by cocaine in BMVEC, but not in human umbilical vein endothelial cells, and the enhancement was greater in a coculture of BMVEC with monocytes. ICAM-1 expression was enhanced by a transcriptional mechanism. Polymyxin B inhibited up-regulation of adhesion molecules by LPS but not by cocaine. In LPS-activated BMVEC/monocyte coculture, cocaine increased secretion of tumor necrosis factor-alpha and interleukin-6. Taken together, these findings indicate that cocaine enhances leukocyte migration across the cerebral vessel wall, in particular under inflammatory conditions, but the effects are variable in different individuals. Cocaine's effects are exerted through a cascade of augmented expression of inflammatory cytokines and endothelial adhesion molecules. These could underlie the cerebrovascular complications of cocaine abuse.

CXC and CC chemokine receptors on coronary and brain endothelia.

BACKGROUND: Chemokine receptors on leukocytes play a key role in inflammation and HIV-1 infection. Chemokine receptors on endothelia may serve an important role in HIV-1 tissue invasion and angiogenesis. MATERIALS AND METHODS: The expression of chemokine receptors in human brain microvascular endothelial cells (BMVEC) and coronary artery endothelial cells (CAEC) in vitro and cryostat sections of the heart tissue was determined by light and confocal microscopy and flow cytometry with monoclonal antibodies. Chemotaxis of endothelia by CC chemokines was evaluated in a transmigration assay. RESULTS: In BMVEC, the chemokine receptors CCR3 and CXCR4 showed the strongest expression. CXCR4 was localized by confocal microscopy to both the cytoplasm and the plasma membrane of BMVEC. In CAEC, CXCR4 demonstrated a strong expression with predominantly periplasmic localization. CCR5 expression was detected both in BMVEC and CAEC but at a lower level. Human umbilical cord endothelial cells (HUVEC) expressed strongly CXCR4 but only weakly CCR3 and CCR5. Two additional CC chemokines, CCR2A and CCR4, were detected in BMVEC and CAEC by immunostaining. Immunocytochemistry of the heart tissues with monoclonal antibodies revealed a high expression of CXCR4 and CCR2A and a low expression of CCR3 and CCR5 on coronary vessel endothelia. Coronary endothelia showed in vitro a strong chemotactic response to the CC chemokines RANTES, MIP-1alpha, and MIP-1beta. CONCLUSIONS: The endothelia isolated from the brain display strongly both the CCR3 and CXCR4 HIV-1 coreceptors, whereas the coronary endothelia express strongly only the CXCR4 coreceptor. CCR5 is expressed at a lower level in both endothelia. The differential display of CCR3 on the brain and coronary endothelia could be significant with respect to the differential susceptibility of the heart and the brain to HIV-1 invasion. In addition, CCR2A is strongly expressed in the heart endothelium. All of the above chemokine receptors could play a role in endothelial migration and repair.