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1.
Plant Biol (Stuttg) ; 22(2): 212-220, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31627255

ABSTRACT

Leaf venations have elements with relatively lower elasticity than other leaf tissue components, which are thought to contribute to leaf biomechanics. A better mechanistic understanding of relationships between vein traits and leaf mechanical properties is essential for ecologically relevant interpretation of leaf structural variations. We investigated 13 major (first to third order) and minor (>third order) vein traits, six leaf mechanical properties and other structural traits across 58 woody species from a subtropical forest to elucidate how vein traits contribute to leaf biomechanics. Across species, vein dry mass density (ρv ), total vein dry mass per leaf area (VMA) and minor vein diameter (VDmin ), but not the lower-order vein density (VLA1•2 ), were positively correlated with leaf force to punch (Fp ) and force to tear (Ft ). Structural equation models showed that ρv and VDmin not only contribute to leaf mechanical properties directly (direct pathway), but also had impacts on leaf biomechanics by influencing leaf thickness and leaf dry mass per area (indirect pathway). Our study demonstrated that vein dry mass density and minor vein diameter are the key vein properties for leaf biomechanics. We also suggest that the mechanical characteristics of venations are potential factors influencing leaf mechanical resistance, structure and leaf economics spectrum.


Subject(s)
Forests , Plant Leaves , Plant Structures , Biomechanical Phenomena , Plant Leaves/anatomy & histology , Plant Leaves/physiology , Plant Structures/anatomy & histology , Plant Structures/physiology , Species Specificity
2.
Acta Neuropathol Commun ; 7(1): 168, 2019 11 04.
Article in English | MEDLINE | ID: mdl-31685033

ABSTRACT

The family of juvenile xanthogranuloma family neoplasms (JXG) with ERK-pathway mutations are now classified within the "L" (Langerhans) group, which includes Langerhans cell histiocytosis (LCH) and Erdheim Chester disease (ECD). Although the BRAF V600E mutation constitutes the majority of molecular alterations in ECD and LCH, only three reported JXG neoplasms, all in male pediatric patients with localized central nervous system (CNS) involvement, are known to harbor the BRAF mutation. This retrospective case series seeks to redefine the clinicopathologic spectrum of pediatric CNS-JXG family neoplasms in the post-BRAF era, with a revised diagnostic algorithm to include pediatric ECD. Twenty-two CNS-JXG family lesions were retrieved from consult files with 64% (n = 14) having informative BRAF V600E mutational testing (molecular and/or VE1 immunohistochemistry). Of these, 71% (n = 10) were pediatric cases (≤18 years) and half (n = 5) harbored the BRAF V600E mutation. As compared to the BRAF wild-type cohort (WT), the BRAF V600E cohort had a similar mean age at diagnosis [BRAF V600E: 7 years (3-12 y), vs. WT: 7.6 years (1-18 y)] but demonstrated a stronger male/female ratio (BRAF V600E: 4 vs WT: 0.67), and had both more multifocal CNS disease ( BRAFV600E: 80% vs WT: 20%) and systemic disease (BRAF V600E: 40% vs WT: none). Radiographic features of CNS-JXG varied but typically included enhancing CNS mass lesion(s) with associated white matter changes in a subset of BRAF V600E neoplasms. After clinical-radiographic correlation, pediatric ECD was diagnosed in the BRAF V600E cohort. Treatment options varied, including surgical resection, chemotherapy, and targeted therapy with BRAF-inhibitor dabrafenib in one mutated case. BRAF V600E CNS-JXG neoplasms appear associated with male gender and aggressive disease presentation including pediatric ECD. We propose a revised diagnostic algorithm for CNS-JXG that includes an initial morphologic diagnosis with a final integrated diagnosis after clinical-radiographic and molecular correlation, in order to identify cases of pediatric ECD. Future studies with long-term follow-up are required to determine if pediatric BRAF V600E positive CNS-JXG neoplasms are a distinct entity in the L-group histiocytosis category or represent an expanded pediatric spectrum of ECD.


Subject(s)
Brain/pathology , Erdheim-Chester Disease/diagnosis , Erdheim-Chester Disease/genetics , Proto-Oncogene Proteins B-raf/genetics , Xanthogranuloma, Juvenile/diagnosis , Xanthogranuloma, Juvenile/genetics , Algorithms , Child , Child, Preschool , Erdheim-Chester Disease/pathology , Female , Humans , Infant , Male , Mutation , Retrospective Studies , Xanthogranuloma, Juvenile/pathology
3.
Bone Marrow Transplant ; 51(10): 1313-1317, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27183095

ABSTRACT

In our study, we evaluated the safety and efficacy of Brentuximab vedotin (BV) with or without the addition of donor lymphocyte infusion (DLI) after allogeneic stem cell transplantation (allo-SCT) in 16 patients with advanced Hodgkin lymphoma (HL). Thirteen patients with relapsed HL after allo-SCT received BV as treatment for active disease. Three patients without progression of HL after allo-SCT received BV as consolidation. Twelve patients had been previously exposed to BV for treatment of relapse after autologous-SCT. Ten out of 16 patients received BV in combination with DLI. Among the 13 patients treated for active disease, CR and PR was observed in 7 and 2 patients, respectively. With a median follow-up of 13 months, 13 out of 16 patients are alive, while 3 died because of disease progression. The median PFS was 6 months. DLI-associated GVHD occurred in seven patients. Five patients with GVHD required immunosuppression, and in all cases, GVHD resolved after a short course of low dose steroids, implying that an anti-GVHD modulating effect could be induced by the concurrent administration of BV. No serious adverse event was observed in any of the patients.


Subject(s)
Hematopoietic Stem Cell Transplantation/methods , Hodgkin Disease/therapy , Immunoconjugates/administration & dosage , Adolescent , Adult , Brentuximab Vedotin , Combined Modality Therapy , Female , Graft vs Host Disease/drug therapy , Graft vs Host Disease/etiology , Hematopoietic Stem Cell Transplantation/adverse effects , Hodgkin Disease/complications , Hodgkin Disease/mortality , Humans , Immunoconjugates/adverse effects , Lymphocyte Transfusion , Male , Steroids/therapeutic use , Survival Analysis , Treatment Outcome , Young Adult
4.
Transplant Proc ; 47(10): 2881-5, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26707307

ABSTRACT

INTRODUCTION: This study aims to evaluate outcomes of bare-metal stents (BMS) versus drug-eluting stents (DES) in patients who undergo stenting for transplant renal arterial stenosis. MATERIALS AND METHODS: We retrospectively reviewed records of renal transplantation patients who underwent transplant renal arterial stenting from September 2009 to September 2013. All stents greater than 5 mm were excluded to allow for equivalent comparison between the DES and BMS groups. Statistical comparisons were performed using a two-tailed Fischer exact test, and analysis of continuous variables was analyzed using a one-way analysis of variance. RESULTS: The final study population included a total of 18 patients who received either BMS or DES (11 and 7 patients, respectively) for transplant renal arterial stenosis. The most common indications for stenting were increasing creatinine level and abnormal Doppler velocities. There were more re-interventions with BMS (n = 4/11) than DES (n = 0/7), but the trend was not statistically significant (P = .12). Three patients who received BMS had a clinically significant decrease in blood pressure versus 4 in the DES group (P = .33). Six patients who received BMS had a clinically significant decrease in creatinine level versus 3 in the DES group (P = 1.0). CONCLUSION: There is an absolute but not statistically significant difference in the incidence of restenosis requiring repeat intervention between the BMS and DES groups. No difference was detected in clinical success as measured by decreases in blood pressure or creatinine. Future larger studies are needed to corroborate these findings.


Subject(s)
Drug-Eluting Stents , Kidney Transplantation , Renal Artery Obstruction/surgery , Stents , Adult , Aged , Blood Pressure , Creatinine/analysis , Female , Humans , Male , Middle Aged , Retrospective Studies
5.
J Laryngol Otol ; 129(5): 468-72, 2015 May.
Article in English | MEDLINE | ID: mdl-25827753

ABSTRACT

OBJECTIVE: We wanted to present our experience with the extended endoscopic approach to clival pathology, focusing on cerebrospinal fluid leak and reconstruction challenges. METHODS: We examined a consecutive series of 37 patients undergoing the extended endoscopic approach for skull base tumours, 9 patients with clival pathology. Patients were examined for the incidence of post-operative cerebrospinal fluid leak in relation to tumour pathology, location, size, reconstruction and lumbar drain. RESULTS: The overall incidence of post-operative cerebrospinal fluid leak was 10.8 per cent. Seventy-five per cent of patients who had a post-operative cerebrospinal fluid leak underwent a transclival approach (p < 0.05). All patients with clival pathology who underwent an intradural dissection had a post-operative cerebrospinal fluid leak (p < 0.05). CONCLUSION: Post-operative cerebrospinal fluid leak rates after the extended endoscopic approach have improved significantly after advancements including the vascularised nasoseptal flap. Despite this, transclival approaches continue to pose much difficulty. Further investigation is necessary to develop technical improvements that can meet the unique challenges associated with this region.


Subject(s)
Cranial Fossa, Posterior/surgery , Endoscopy/adverse effects , Plastic Surgery Procedures/adverse effects , Skull Base Neoplasms/surgery , Adolescent , Adult , Aged , Cerebrospinal Fluid Leak/epidemiology , Cerebrospinal Fluid Leak/etiology , Child , Child, Preschool , Cranial Fossa, Posterior/pathology , Endoscopy/methods , Female , Humans , Male , Middle Aged , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Plastic Surgery Procedures/methods , Skull Base Neoplasms/pathology , Surgical Flaps , Young Adult
6.
Haemophilia ; 18(1): 117-21, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21545377

ABSTRACT

The risk of bleeding during dental procedures may be increased in patients with Gaucher disease. We aimed to evaluate potential coagulation and platelet function abnormalities and targeted therapy accordingly. Patients with type 1 Gaucher disease who were treated at the Oral and Maxilo-Facial surgery clinic at Sheba Medical Center between 2003 and 2010 comprised the study cohort. Data collected included disease history, enzyme treatment, platelet counts, dental therapy and outcome. Bleeding was defined as excessive bleeding during or immediately following procedure. Coagulation studies and platelet function tests including aggregometry were performed on all patients. Dental procedures (n = 14, including eight teeth extractions, two crown lengthening procedures, one cyst enucleation and three deep dental scaling) of seven patients were studied. Mean platelet count prior to procedure was 73 K ± 14.8 mm(3). Patients bleeding risk score was calculated according to previous history of bleeding tendency, degree of thrombocytopenia, presence of comorbid coagulopathy and the type of dental procedure. Two patients with highest risk score received prophylactic platelet transfusions, three patients (medium-risk) received DDAVP preprocedure and all received systemic tranexamic acid, which was the only systemic therapy for low-risk patients. Meticulous surgical local haemostasis was applied. No excessive intra-operative or postoperative bleeding occurred. Patients with Gaucher disease who have thrombocytopenia and abnormal platelet function tests may be safely treated if meticulous haemostasis is applied along with systemic therapy as required. Platelet transfusions are not mandatory and should be applied considering the procedure-related risk and the patient's calculated haematological risk for bleeding.


Subject(s)
Dental Care/adverse effects , Gaucher Disease/complications , Oral Hemorrhage/etiology , Oral Surgical Procedures/adverse effects , Thrombocytopenia/etiology , Adult , Antifibrinolytic Agents/therapeutic use , Cohort Studies , Deamino Arginine Vasopressin/therapeutic use , Female , Hemostatics/therapeutic use , Humans , Male , Middle Aged , Oral Hemorrhage/prevention & control , Platelet Function Tests , Postoperative Hemorrhage/etiology , Predictive Value of Tests , Risk Factors , Tooth Extraction/adverse effects , Young Adult
7.
Phys Rev Lett ; 106(14): 140502, 2011 Apr 08.
Article in English | MEDLINE | ID: mdl-21561175

ABSTRACT

We describe a method to enhance the sensitivity of precision measurements that takes advantage of the environment of a quantum sensor to amplify the response of the sensor to weak external perturbations. An individual qubit is used to sense the dynamics of surrounding ancillary qubits, which are in turn affected by the external field to be measured. The resulting sensitivity enhancement is determined by the number of ancillas that are coupled strongly to the sensor qubit; it does not depend on the exact values of the coupling strengths and is resilient to many forms of decoherence. The method achieves nearly Heisenberg-limited precision measurement, using a novel class of entangled states. We discuss specific applications to improve clock sensitivity using trapped ions and magnetic sensing based on electronic spins in diamond.

8.
J Neurosci Res ; 89(5): 619-27, 2011 May.
Article in English | MEDLINE | ID: mdl-21337366

ABSTRACT

To identify guidance molecules to promote long-distance growth of dopaminergic axons from transplanted embryonic ventral mesencephalon (VM) tissue, three pathways were created by expressing green fluorescent protein (GFP), glial cell line-derived neurotrophic factor (GDNF), or a combination of GDNF/GDNF receptor α1 (GFRα1) along the corpus callosum. To generate the guidance pathway, adenovirus encoding these transcripts was injected at four positions along the corpus callosum. In all groups, GDNF adenovirus was also injected on the right side 2.5 mm from the midline at the desired transplant site. Four days later, a piece of VM tissue from embryonic day 14 rats was injected at the transplant site. All rats also received daily subcutaneous injections of N-acetyl-L-cysteinamide (NACA; 100 µg per rat) as well as chondroitinase ABC at transplant site (10 U/ml, 2 µl). Two weeks after transplantation, the rats were perfused and the brains dissected out. Coronal sections were cut and immunostained with antibody to tyrosine hydroxylase (TH) to identify and count dopaminergic fibers in the corpus callosum. In GFP-expressing pathways, TH(+) fibers grew out of the transplants for a short distance in the corpus callosum. Very few TH(+) fibers grew across the midline. However, pathways expressing GDNF supported more TH(+) fiber growth across the midline into the contralateral hemisphere. Significantly greater numbers of TH(+) fibers grew across the midline in animals expressing a combination of GDNF and GFRα1 in the corpus callosum. These data suggest that expression of GDNF or a combination of GDNF and GFRα1 can support the long-distance dopaminergic fiber growth from a VM transplant, with the combination having a superior effect.


Subject(s)
Brain Tissue Transplantation/methods , Dopamine/physiology , Growth Cones/physiology , Mesencephalon/transplantation , Animals , Brain Tissue Transplantation/pathology , Cell Line, Tumor , Cells, Cultured , Female , Growth Cones/pathology , Growth Cones/ultrastructure , Mesencephalon/cytology , Mesencephalon/embryology , Neural Pathways/growth & development , Neural Pathways/metabolism , Neural Pathways/physiology , Parkinson Disease/metabolism , Parkinson Disease/pathology , Parkinson Disease/therapy , Rats , Rats, Sprague-Dawley
9.
Cancer ; 116(17): 4197-205, 2010 Sep 01.
Article in English | MEDLINE | ID: mdl-20533566

ABSTRACT

BACKGROUND: The use of central venous catheters (CVCs) has greatly improved the quality of care in children with cancer, yet these catheters may cause serious infectious and thrombotic complications. The aim of this prospective registry study was to assess the host and CVC-related risk factors for CVC-created thrombotic complications. METHODS: Patients undergoing CVC insertion for chemotherapy were followed prospectively for CVC complications. At the time of enrollment, demographic, clinical, and CVC-related data, and family history of thrombosis were collected. Survival and Cox regression analyses were performed. RESULTS: A total of 423 CVCs were inserted into 262 patients for a total of 76,540 catheter days. The incidence of CVC-related deep-vein thrombosis (DVT) was 0.13 per 1000 catheter-days (95% confidence interval [CI], 0.06-0.24). Insertion of peripherally inserted central catheters (PICCs) and insertion in an angiography suite significantly increased the risk of symptomatic CVC-related DVT. The incidence of CVC occlusion was 1.35 per 1000 catheter-days (95% CI, 1.1-1.63). Positive family history of thrombosis significantly increased the risk of CVC occlusion (hazard ratio [HR], 2.16; 95% CI, 1.2-3.8). The CVC-related risk factors were insertion of Hickman catheters, insertion in angiography suite, and proximal-tip location. Patients developing at least 1 episode of both CVC occlusion and infection had an increased risk for developing symptomatic CVC-related DVT (HR, 4.15; 95% CI, 1.2-14.4). CONCLUSIONS: Both patient-related and CVC-related factors are associated with higher risk of symptomatic thrombotic complications. These risk factors could be used in the clinical setting and in developing future studies for CVC thromboprophylaxis.


Subject(s)
Antineoplastic Agents/administration & dosage , Catheterization, Central Venous/adverse effects , Neoplasms/complications , Thrombosis/epidemiology , Adolescent , Catheterization, Central Venous/instrumentation , Child , Child, Preschool , Humans , Infant , Neoplasms/drug therapy , Risk Factors , Thrombosis/etiology
10.
Eur J Med Res ; 13(1): 31-8, 2008 Jan 23.
Article in English | MEDLINE | ID: mdl-18226995

ABSTRACT

UNLABELLED: Bone involvement is one of the most disabling complications in patients with type 1 Gaucher disease (GDI) and its pathophysiology is yet to be fully understood. It is well known that body composition is a determinant of bone mass. Previous reports indicating disturbance in glucose and lipid metabolism in GDI patients suggested a posible alteration in body composition in this group of patients. OBJECTIVE: To analyze body composition, bone mass and turnover in young adults with GDI receiving enzyme replacement therapy (ERT). POPULATION: 5 women and 4 men with GDI aged (X +/- SD) 26.9 +/- 6.9 years, receiving imiglucerase in a mean dose of 53 +/- 13 IU/kg/2weeks, during 4.9 +/- 3.9 years; and 145 sex and age matched healthy adults agreed to participate in the study. All control subjects had a body mass index (BMI) between 20 and 25 kg/m2. METHODS: Total body dual X-ray absorptiometry (DXA) was used to measure body composition and bone mass. Serum creatinine, calcium, osteocalcin (BGP), and type I collagen beta carboxy-terminal telopeptide (betaCTX) were determined in patients and controls. In addition, 25 hydroxyvitamin D (25OHD), and chitotriosidase activity were measured in patients. RESULTS: GDI patients presented statistically significant (p<0.01) lower BMI, bone mineral density (BMD), bone mineral content (BMC), lean mass (LM), and fat mass (FM), compared to controls. LM correlated positively with BMC and BMD in both groups (p<0.01). GDI patients receiving the lower dose of ERT (<60 IU/kg/2weeks) presented lower BMD values than those receiving the higher dose (> or =60 IU/kg/2weeks) (0.968 +/- 0.032 vs 1.088 +/- 0.061 g/m2, respectively, p<0.001). Mean BGP levels were similar in patients and controls, whereas betaCTX levels were higher in GDI patients (p<0.02). All patients presented deficiency levels (<30ng/ml) of 25OHD. CONCLUSIONS: Although the patients had been receiving ERT, they presented a significant diminution in all body composition parameters, the decrease was more evident in those receiving the lower dose. The reduction in bone mass was associated with an imbalance in bone turnover (increased bone resorption). The correlation between LM and bone mass, suggests that metabolic disturbance occurring in GDI patients may be indirectly responsible for bone mass reduction in GDI patients, by altering body composition.


Subject(s)
Body Composition/drug effects , Bone and Bones/drug effects , Gaucher Disease/metabolism , Glucosylceramidase/therapeutic use , Absorptiometry, Photon , Adipose Tissue/drug effects , Adult , Body Weight/drug effects , Bone Density/drug effects , Bone and Bones/metabolism , Bone and Bones/pathology , Calcium/blood , Collagen Type I/blood , Creatinine/blood , Female , Gaucher Disease/blood , Gaucher Disease/drug therapy , Glucosylceramidase/administration & dosage , Hexosaminidases/blood , Humans , Male , Middle Aged , Osteocalcin/blood , Peptides/blood , Vitamin D/analogs & derivatives , Vitamin D/blood
11.
Plant Cell Environ ; 29(1): 26-35, 2006 Jan.
Article in English | MEDLINE | ID: mdl-17086750

ABSTRACT

Vulnerability to water-stress-induced embolism and variation in the degree of native embolism were measured in lateral roots of four co-occurring neotropical savanna tree species. Root embolism varied diurnally and seasonally. Late in the dry season, loss of root xylem conductivity reached 80% in the afternoon when root water potential (psi root) was about -2.6 MPa, and recovered to 25-40% loss of conductivity in the morning when psi root was about -1.0 MPa. Daily variation in psi root decreased, and root xylem vulnerability and capacitance increased with rooting depth. However, all species experienced seasonal minimum psi root close to complete hydraulic failure independent of their rooting depth or resistance to embolism. Predawn psi root was lower than psi soil when psi soil was relatively high (> -0.7 MPa) but became less negative than psi soil, later in the dry season, consistent with a transition from a disequilibrium between plant and soil psi induced by nocturnal transpiration to one induced by hydraulic redistribution of water from deeper soil layers. Shallow longitudinal root incisions external to the xylem prevented reversal of embolism overnight, suggesting that root mechanical integrity was necessary for recovery, consistent with the hypothesis that if embolism is a function of tension, refilling may be a function of internal pressure imbalances. All species shared a common relationship in which maximum daily stomatal conductance declined linearly with increasing afternoon loss of root conductivity over the course of the dry season. Daily embolism and refilling in roots is a common occurrence and thus may be an inherent component of a hydraulic signaling mechanism enabling stomata to maintain the integrity of the hydraulic pipeline in long-lived structures such as stems.


Subject(s)
Circadian Rhythm/physiology , Plant Roots/physiology , Seasons , Trees/physiology , Tropical Climate , Water/metabolism , Xylem/physiology , Plant Leaves/physiology , Soil
12.
Phys Rev Lett ; 95(8): 082502, 2005 Aug 19.
Article in English | MEDLINE | ID: mdl-16196853

ABSTRACT

The dynamical eikonal approximation unifies the semiclassical time-dependent and eikonal methods. It allows calculating differential cross sections for elastic scattering and breakup in a quantal way by taking into account interference effects. Good agreement is obtained with experiment for 11Be breakup on 208Pb. Dynamical effects are weak for elastic scattering.

13.
Rev. esp. enferm. metab. óseas (Ed. impr.) ; 14(4): 61-66, jul.-ago. 2005. tab, graf
Article in Es | IBECS | ID: ibc-039379

ABSTRACT

Introducción. La osteoporosis es la enfermedad del metabolismo mineral más frecuente del mundo occidental pero la más subdiagnosticada y subtratada. Objetivo. Detectar la población en riesgo de sufrir osteoporosis y fracturas de cadera en sujetos de edad igual o superior a 50 años. Materiales y métodos. Se efectuaron charlas diarias organizadas por la Sección Osteopatías Médicas y entrega de folletos informativos sobre osteoporosis a los concurrentes de la campaña. Se realizaron densitometrías de radio (Lunar-Pixi Dual, DXA) en las participantes de 65 años en adelante. De acuerdo a la edad, sexo y a la presencia de factores de riesgo (fracturas osteoporóticas, menopausia temprana y/o corticoterapia) los participantes se dividieron en: Grupo 1: mujeres entre 50 y 64 años y hombres de edad igual o superior a 50 años sin factores de riesgo; Grupo 2: igual que grupo 1, pero con factores de riesgo, y Grupo 3: mujeres de 65 años o más con o sin factores de riesgo. Resultados. Participaron 1.305 personas de edad igual o superior a 50 años (1.202 mujeres y 103 hombres). Grupo 1: total 364 (281 mujeres y 83 hombres); Grupo 2: total 315 (295 mujeres y 20 hombres), y Grupo 3: total 626 mujeres (52% del total de mujeres participantes). Ciento ochenta y cuatro participantes presentaron antecedentes de fracturas osteoporóticas. De éstos, sólo el 7% recibían o habían recibido tratamientos antirresortivos asociados a calcio y/o vitamina D, el 14% sólo calcio y el 5% calcio y vitamina D. El 84% de los participantes que realizaron densitometría de radio distal presentaban baja masa ósea (T-score < ­1). Conclusiones. El 74% de las participantes con fracturas osteoporóticas previas no habían realizado o realizaban ningún tratamiento para osteoporosis y sólo el 7% había recibido medicación antirresortiva. Más de la mitad de las participantes mayores de 65 años presentaron baja masa ósea


Background. Osteoporosis is the most prevalent, and yet the most under-diagnosed and under-treated metabolic bone disease. Objective. To detect population at risk of development osteoporosis and hip fractures in subjects >= 50 years. Materials and methods. The campaign included lectures on osteoporosis, and informative brochures. Densitometry of the distal forearm (Lunar-Pixi Dual, DXA) was performed in women aged >= 65 years. Subjects were divided according to age and presence of risk factors (osteoporotic fractures, early menopause and previous corticoid treatment) as follows. Group 1: women aged 50 to 64 years and men >= 50 years presenting no risk factors; Group 2: women aged 50 to 64 years, men >= 50 presenting risk factors, and Group 3: women >= 65 years regardless of the presence of risk factors. Results. Total number of subjects was 1,305 (1,202 women and 103 men) Group 1: 364 subjects (281 women; 83 men); Group 2: 315 subjects (295 women; 20 men), and Group 3: 626 women (52% of total women). One hundred and eighty four subjects had previous osteoporotic fractures, only 7% of these subjects had received antiresoptive treatment plus calcium and/or vitamin D, 14% had received calcium and 5% had received calcium plus vitamin D. Eighty four per cent of participants who underwent densitometry showed low bone mass (T-score = 65 years showed low bone mass


Subject(s)
Male , Female , Aged , Middle Aged , Humans , Osteoporosis/epidemiology , Hip Fractures/epidemiology , Hip Fractures/prevention & control , Osteoporosis/prevention & control , Bone Diseases, Metabolic/epidemiology , Bone Diseases, Metabolic/prevention & control , Risk Factors , Bone Density/physiology
14.
Phys Rev E Stat Nonlin Soft Matter Phys ; 70(5 Pt 2): 056703, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15600792

ABSTRACT

The evolution operator of a quantum system in a time-dependent potential is factorized in unitary exponential operators at order 6. This expression is derived with the time-ordering method. It is compared with lower-order factorizations on several simple one-dimensional examples. Better accuracies are reached at sixth order for a given time step than at lower orders. Due to a significant increase of computation duration per time step, the sixth-order approximation is mainly useful when high accuracies are required.

15.
Oecologia ; 140(4): 543-50, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15232729

ABSTRACT

We investigated how water transport capacity, wood density and wood anatomy were related to leaf photosynthetic traits in two lowland forests in Panama. Leaf-specific hydraulic conductivity ( k(L)) of upper branches was positively correlated with maximum rates of net CO(2) assimilation per unit leaf area ( A(area)) and stomatal conductance ( g(s)) across 20 species of canopy trees. Maximum k(L) showed stronger correlation with A(area) than initial k(L) suggesting that allocation to photosynthetic potential is proportional to maximum water transport capacity. Terminal branch k(L) was negatively correlated with A(area)/ g(s) and positively correlated with photosynthesis per unit N, indicating a trade-off of efficient use of water against efficient use of N in photosynthesis as water transport efficiency varied. Specific hydraulic conductivity calculated from xylem anatomical characteristics ( k(theoretical)) was positively related to A(area) and k(L), consistent with relationships among physiological measurements. Branch wood density was negatively correlated with wood water storage at saturation, k(L), A(area), net CO(2) assimilation per unit leaf mass ( A(mass)), and minimum leaf water potential measured on covered leaves, suggesting that wood density constrains physiological function to specific operating ranges. Kinetic and static indices of branch water transport capacity thus exhibit considerable co-ordination with allocation to potential carbon gain. Our results indicate that understanding tree hydraulic architecture provides added insights to comparisons of leaf level measurements among species, and links photosynthetic allocation patterns with branch hydraulic processes.


Subject(s)
Photosynthesis/physiology , Plant Leaves/physiology , Trees/physiology , Water/physiology , Carbon Dioxide/metabolism , Panama , Plant Leaves/anatomy & histology , Wood
16.
Tree Physiol ; 24(8): 891-9, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15172839

ABSTRACT

Functional convergence in hydraulic architecture and water relations, and potential trade-offs in resource allocation were investigated in six dominant neotropical savanna tree species from central Brazil during the peak of the dry season. Common relationships between wood density and several aspects of plant water relations and hydraulic architecture were observed. All species and individuals shared the same negative exponential relationship between sapwood saturated water content and wood density. Wood density was a good predictor of minimum (midday) leaf water potential and total daily transpiration, both of which decreased linearly with increasing wood density for all individuals and species. With respect to hydraulic architecture, specific and leaf-specific hydraulic conductivity decreased and the leaf:sapwood area ratio increased more than 5-fold as wood density increased from 0.37 to 0.71 g cm(-3) for all individuals and species. Wood density was also a good predictor of the temporal dynamics of water flow in stems, with the time of onset of sap flow in the morning and the maximum sap flow tending to occur progressively earlier in the day as wood density increased. Leaf properties associated with wood density included stomatal conductance, specific leaf area, and osmotic potential at the turgor loss point, which decreased linearly with increasing wood density. Wood density increased linearly with decreasing bulk soil water potential experienced by individual plants during the dry season, suggesting that wood density was greatest in individuals with mostly shallow roots, and therefore limited access to more abundant soil water at greater depths. Despite their taxonomic diversity and large intrapopulation differences in architectural traits, the six co-occurring species and their individuals shared similar functional relationships between all pairs of variables studied. Thus, rather than differing intrinsically in physiological responsiveness, the species and the individuals appeared to have distinct operating ranges along common physiological response curves dictated by plant architectural and structural features. The patterns of water uptake and access to soil water during the dry season appeared to be the main determinant of wood density, which constrained evolutionary options related to plant water economy and hydraulic architecture, leading to functional convergence in the neotropical savanna trees studied.


Subject(s)
Plant Leaves/physiology , Trees/physiology , Brazil , Plant Stems/physiology , Plant Transpiration/physiology , Tropical Climate
17.
Tree Physiol ; 24(8): 919-28, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15172842

ABSTRACT

We used concurrent measurements of soil water content and soil water potential (Psi(soil)) to assess the effects of Psi(soil) on uptake and hydraulic redistribution (HR) of soil water by roots during seasonal drought cycles at six sites characterized by differences in the types and amounts of woody vegetation and in climate. The six sites included a semi-arid old-growth ponderosa pine (Pinus ponderosa Dougl. ex P. Laws & C. Laws) forest, a moist old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forest, a 24-year-old Douglas-fir forest and three Brazilian savanna sites differing in tree density. At all of the sites, HR was confined largely to the upper 60 cm of soil. There was a common threshold relationship between the relative magnitude of HR and Psi(soil) among the six study sites. Below a threshold Psi(soil) of about -0.4 MPa, overnight recharge of soil water storage increased sharply, and reached a maximum value of 80-90% over a range of Psi(soil) from ~ -1.2 to -1.5 MPa. Although amounts of water hydraulically redistributed to the upper 60 cm of soil were relatively small (0 to 0.4 mm day(-1)), they greatly reduced the rates of seasonal decline in Psi(soil). The effectiveness of HR in delaying soil drying diminished with increasing sapwood area per ground area. The relationship between soil water utilization and Psi(soil) in the 20-60-cm layer was nearly identical for all six sites. Soil water utilization varied with a surrogate measure of rhizosphere conductance in a similar manner at all six sites. The similarities in relationships between Psi(soil) and HR, soil water utilization and relative rhizosphere conductance among the six sites, suggests that, despite probable differences in maximum rooting depth and density, there was a convergence in biophysical controls on soil water utilization and redistribution in the upper soil layers where the density of finer roots is greatest.


Subject(s)
Trees/physiology , Climate , Pinus/physiology , Plant Roots/physiology , Plant Transpiration/physiology , Pseudotsuga/physiology , Seasons , Soil , Water/physiology
18.
Haemophilia ; 8(3): 461-5, 2002 May.
Article in English | MEDLINE | ID: mdl-12010452

ABSTRACT

Haemophilia is a chronic disease, affecting patients and their families. The impact of such a disease upon each family is dependent upon family type and characteristics and adjustment to it varies with time, in concordance with the family's lifecycle. In the National Hemophilia Center in Israel we lead a special support system and conduct group therapy from the very early stage of haemophilia diagnosis throughout the lifetime of patients. The general definitions of a family's lifecycle, the effect of the disease and the required adjustment to it are described in this paper. We refer to special difficulties associated with haemophilia as a chronic, genetic disease and describe ways to cope, discussing the support systems that have been established in our centre.


Subject(s)
Family/psychology , Hemophilia A/psychology , Chronic Disease , Hemophilia A/therapy , Humans , Life Change Events , Self-Help Groups
19.
Tree Physiol ; 21(18): 1327-34, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11731343

ABSTRACT

Photosynthetic gas exchange, nitrogen- and water-use efficiency, leaf water potential and seasonal patterns of leaf production were studied in seven, dominant dry-forest species from the island of Lana'i, Hawaii, including the rapidly colonizing, non-native Schinus terebinthifolius (Raddi). We evaluated whether unique physiological characteristics of the invasive species explain its capacity to rapidly invade dry forests throughout the Hawaiian Islands. Apparent anomalies in stable carbon isotope data (delta13C) relative to other results led us to study effects of environmental conditions and physiological performance during leaf expansion on delta13C. Species that expanded all their foliage at the beginning of the wet season had more negative leaf delta13C values during the dry season than species with continuous leaf expansion. Among species, S. terebinthifolius had a strong seasonal pattern of leaf production and the most negative delta13C (-29 per thousand). With respect to almost every trait measured, S. terebinthifolius fell at an end of the range of values for the native species. Rapid growth of S. terebinthifolius in this ecosystem may be partially explained by its high maximum CO2 assimilation rates (15 micromol m-2 s-1), low leaf mass per area, high photosynthetic nitrogen-use efficiency per unit leaf mass or area and large decrease in stomatal conductance during the dry season. Relative to the native species, the invasive species exhibited striking phenotypic plasticity, including high rates of stem growth and water and CO2 uptake during the wet season, and maintenance of leaves and high leaf water potentials, as a result of reduced water loss, during the dry season, enabling it to utilize available resources effectively.


Subject(s)
Trees/growth & development , Anacardiaceae/growth & development , Anacardiaceae/physiology , Carbon Dioxide/physiology , Hawaii , Nitrogen/physiology , Photosynthesis/physiology , Plant Leaves/physiology , Seasons , Trees/physiology
20.
Dermatol Surg ; 27(11): 975-8, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11737136

ABSTRACT

BACKGROUND: Over the course of the last three decades Americans have grown more and more fond of "alternative" or homeopathic medical therapies. The explosion of the Internet has made these nontraditional remedies more accessible to the general public. OBJECTIVE: To describe two cases of auto-Mohs through patient self-application of products containing zinc chloride paste. The case of a basal cell carcinoma and the case of a squamous cell carcinoma are described. METHODS: Each of our patients applied a homeopathic paste containing zinc chloride to sites of biopsy-proven skin cancer. RESULTS: At the conclusion of the self-directed therapy in both cases, histopathologic analysis of the site determined no further skin cancer to be present. CONCLUSION: We present and describe two cases of auto-Mohs.


Subject(s)
Carcinoma, Basal Cell/drug therapy , Carcinoma, Squamous Cell/drug therapy , Chlorides/therapeutic use , Materia Medica , Self Medication , Skin Neoplasms/drug therapy , Zinc Compounds/therapeutic use , Administration, Topical , Adult , Chlorides/administration & dosage , Female , Humans , Internet , Male , Middle Aged , Ointments , Zinc Compounds/administration & dosage
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