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1.
Support Care Cancer ; 29(7): 3585-3592, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33159221

RESUMEN

PURPOSE: Misconceptions regarding activity and toxicity of therapeutic interventions are common among cancer patients. There is little knowledge about the factors that contribute to a more realistic perception by patients. METHODS: This pilot study was designed as a prospective questionnaire survey and included 101 therapy-naïve patients treated at the Division of Oncology, Medical University of Vienna. After obtaining written informed consent, patients' expectations about treatment aims, side effects and the satisfaction with their oncologic consultation were interrogated before the first treatment cycle by questionnaires. RESULTS: Of 101 patients, 53 (53%) were female and 67/101 (66%) were treated with curative attempt in an adjuvant or neo-adjuvant setting. The most common diagnoses were lung cancer (31%) and breast cancer (30%). Although 92% of patients were satisfied with the information given by their oncologist, palliative patients were more likely to declare that not everything was explained in an intelligible manner (p = 0.01). Patients with a first language other than German stated more often that their physician did not listen carefully enough (p = 0.02). Of 30 patients, 26 (87%) receiving chemotherapy with palliative intent believed that their disease was curable. Concerning adverse events, female patients anticipated more frequently hair loss (p = 0.003) and changes in taste (p = 0.001) compared to men. Patients under curative treatment were more likely to expect weight loss (p = 0.02) and lack of appetite (p = 0.01) compared to patients with palliative treatment intent. CONCLUSION: In conclusion, cancer patients were satisfied with the patient-doctor communication. This prospective study aggregated patients' concerns on side effects and the perception of therapeutic goals in therapy-naïve patients. Of note, the majority of patients treated in the palliative setting expected their treatment to cure the disease.


Asunto(s)
Neoplasias/terapia , Femenino , Objetivos , Humanos , Masculino , Persona de Mediana Edad , Percepción , Estudios Prospectivos
2.
PLoS One ; 18(4): e0283370, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37036870

RESUMEN

Rain-fed pastoral systems are tightly connected to meteorological conditions. It is, therefore, likely that climate change, including changing atmospheric CO2 concentration, temperature, precipitation and patterns of climate extremes, will greatly affect pastoral systems. However, exact impacts on the productivity and carbon dynamics of these systems are still poorly understood, particularly over longtime scales. The present study assesses the potential effects of future climatic conditions on productivity and soil organic carbon (SOC) stocks of mowed and rotationally grazed grasslands in France. We used the CenW ecosystem model to simulate carbon, water, and nitrogen cycles in response to changes in environmental drivers and management practices. We first evaluated model responses to individual changes in each key meteorological variable to get better insights into the role and importance of each individual variable. Then, we used 3 sets of meteorological variables corresponding to 3 Representative Concentration Pathways (RCP 2.6, RCP 4.5 and RCP 8.5) for long-term model runs from 1975 to 2100. Finally, we used the same three RCPs to analyze the responses of modelled grasslands to extreme climate events. We found that increasing temperature slightly increased grasslands productivities but strongly reduced SOC stocks. A reduction in precipitation led to reductions of biomass and milk production but increased SOC. Conversely, doubling CO2 concentration strongly increased biomass and milk production and marginally reduced SOC. These SOC trends were unexpected. They arose because both increasing precipitation and CO2 increased photosynthetic carbon gain, but they had an even greater effect on the proportion of biomass that could be grazed. The amount of carbon remaining on site and able to contribute to SOC formation was actually reduced under both higher precipitation and CO2. The simulations under the three RCPs indicated that grassland productivity was increased, but that required higher N fertilizer application rates and also led to substantial SOC losses. We thus conclude that, while milk productivity may continue at current rates under climate change, or even increase slightly, there could be some soil C losses over the 21st century. In addition, under the highest-emission scenario, the increasing importance of extreme climate conditions (heat waves and droughts) might render conditions at our site in some years as unsuitable for milk production. It highlights the importance of tailoring farming practices to achieve the dual goals of maintaining agricultural production while safeguarding soil C stocks.


Asunto(s)
Carbono , Suelo , Ecosistema , Pradera , Cambio Climático , Dióxido de Carbono
3.
Bone Marrow Transplant ; 40(9): 843-50, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17724447

RESUMEN

We retrospectively evaluated the outcome of reduced-intensity conditioning (RIC) followed by allogeneic hematopoietic stem cell transplantation (HCT) in 43 patients with myelodysplastic syndrome (MDS) or AML arising from MDS. All patients received fludarabine plus melphalan followed by an allogeneic HCT from an HLA-identical sibling (SIB: n=19) or unrelated donor (MUD: n=24). Median age was 58 years (range: 30-71). Diagnoses at transplantation were RA (n=8), RARS (n=1), RAEB (n=13), RAEB-T (n=6), or AML arising from MDS (n=15). Of 28 patients with MDS, two patients had low, 10 had intermediate-1, nine had intermediate-2 and seven had high-risk MDS by IPSS criteria. All patients initially engrafted with the median neutrophil recovery of 15 days (range: 9-27). The 2-year overall survival, disease-free survival, relapse and transplant-related mortality were 53.5% (CI 45.2-61.1), 51.2% (CI 43.3-58.5), 16.3% (CI 7.9-30.7) and 35.2% (26.4-45.7), respectively. Grade II-IV acute graft-versus-host disease occurred in 27 (63%) patients. There was no significant survival difference between SIB and MUD-HCT, but the relapse rate was higher among SIB donor recipients when compared to MUD (38.5 versus 7%, P=0.02). RIC with fludarabine plus melphalan was associated with durable disease control and acceptable toxicity in this high-risk cohort.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Melfalán/uso terapéutico , Síndromes Mielodisplásicos/terapia , Acondicionamiento Pretrasplante/métodos , Vidarabina/análogos & derivados , Adulto , Anciano , Supervivencia de Injerto , Enfermedad Injerto contra Huésped , Enfermedades Hematológicas/terapia , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/mortalidad , Humanos , Melfalán/toxicidad , Persona de Mediana Edad , Síndromes Mielodisplásicos/complicaciones , Síndromes Mielodisplásicos/mortalidad , Síndromes Mielodisplásicos/prevención & control , Estudios Retrospectivos , Análisis de Supervivencia , Trasplante Homólogo , Resultado del Tratamiento , Vidarabina/uso terapéutico , Vidarabina/toxicidad
4.
Adv Cancer Res ; 77: 25-79, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10549355

RESUMEN

Carcinoma, cancer of epithelial cells, is a major cause of morbidity and mortality in Western societies. Clonal fixation and propagation of oncogenic genetic changes, sporadically accumulating in epithelial cells, depend on growth factors and their surface receptors. One of the large families of receptors is that of the ErbB tyrosine kinases, which bind multiple neuregulins and other epidermal growth factor-like molecules. Certain ErbB members and their ligands are involved in human cancers of various origins. However, most of the clinical data relate to ErbB-2, a protein whose overexpression in subsets of carcinomas can predict poor prognosis. Although no ligand has so far been assigned to ErbB-2, recent biochemical evidence implies that this oncoprotein operates as a shared receptor subunit of other ErbBs. Several biochemical attributes enable ErbB-2 to act as an epithelial cell amplifier of stroma-derived growth factor signals: It delays ligand dissociation, enhances coupling to the mitogen-activated protein kinase pathway, and impedes the rate of receptor downregulation. The realization that ErbB-2 is a master regulator of a signaling network that drives epithelial cell proliferation identifies this protein as a target for cancer therapy. Indeed, various ErbB-2-directed therapeutic approaches, including immunological and genetic therapies, demonstrate promising clinical potential.


Asunto(s)
Neoplasias/genética , Neoplasias/terapia , Receptor ErbB-2/fisiología , Receptores de Factores de Crecimiento/fisiología , Transducción de Señal , Evolución Biológica , Genes erbB-2 , Terapia Genética , Humanos , Inmunoterapia , Receptor ErbB-2/genética
5.
Plant Biol (Stuttg) ; 7(1): 58-66, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15666215

RESUMEN

Previous work has shown that the apparent quantum yield of CO2 fixation can be reduced for up to several minutes after prior exposure to darkness. In the work reported here, we investigated this phenomenon more fully and have deduced information about the underlying processes. This was done mainly by concurrent measurements of O2 and CO2 exchange in an oxygen-free atmosphere. Measurements of O2 evolution indicated that photochemical efficiency was not lost through dark adaptation, and that O2 evolution could proceed immediately at high rates provided that there were reducible pools of photosynthetic intermediates. Part of the delay in reaching the full quantum yield of CO2 fixation could be attributed to the need to build up pools of photosynthetic intermediates to high enough levels to support steady rates of CO2 fixation. There was no evidence that Rubisco inactivation contributed towards delayed CO2 uptake (under measurement conditions of low light). However, we obtained evidence that an enzyme in the reaction path between triose phosphates and RuBP must become completely inactivated in the dark. As a consequence, in dark-adapted leaves, a large amount of triose phosphates were exported from the chloroplast over the first minute of light rather than being converted to RuBP for CO2 fixation. That pattern was not observed if the pre-incubation light level was increased to just 3-5 micromol quanta m(-2) s(-1). The findings from this work underscore that there are fundamental differences in enzyme activation between complete darkness and even a very low light level of only 3-5 micromol quanta m(-2) s(-1) which predispose leaves to different gas exchange patterns once leaves are transferred to higher light levels.


Asunto(s)
Dióxido de Carbono/fisiología , Oscuridad , Helianthus/fisiología , Fotosíntesis/fisiología , Helianthus/efectos de la radiación , Hojas de la Planta/fisiología , Hojas de la Planta/efectos de la radiación , Ribulosa-Bifosfato Carboxilasa/fisiología , Factores de Tiempo
6.
J Clin Endocrinol Metab ; 84(8): 2755-8, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10443674

RESUMEN

The objective of the present study was to examine the impact of preeclampsia on the relation of leptin and neuropeptide Y (NPY) gene expression in human placenta. A second goal was to monitor the change of leptin messenger RNA (mRNA) with increasing gestational age. Placental tissue was obtained from 17 premature deliveries, 18 term deliveries, and 10 mothers with preeclampsia. Gene expression of leptin, NPY, and two housekeeping genes (beta-actin and glyceraldehyde-3-phosphate dehydrogenase was quantified using real-time PCR. The leptin/beta-actin mRNA ratio was significantly higher in specimens of patients with preeclampsia than in those of gestational age-matched controls (0.63+/-0.23 vs. 0.09+/-0.04 relative U (RU); P = 0.03). NPY/beta-actin mRNA was significantly reduced in the preeclampsia group (0.003+/-0.001 vs. 0.026+/-0.008 RU in controls; P = 0.01). The NPY/leptin ratio was 0.11+/-0.09 for preeclamptic placenta samples and 1.7+/-0.6 RU for the controls (P = 0.02). The leptin/beta-actin ratio was significantly lower in placenta from premature deliveries than in term deliveries (0.02+/-0.004 vs. 0.12+/-0.05 RU; P = 0.01). Similar results were obtained for normalization to glyceraldehyde-3-phosphate dehydrogenase mRNA. Our data suggest an increase of placental leptin production with gestational age. In patients with preeclampsia, elevated leptin expression goes along with suppressed NPY expression. This resembles hypothalamic regulation.


Asunto(s)
Hipotálamo/fisiología , Neuropéptido Y/genética , Placenta/metabolismo , Proteínas/genética , ARN Mensajero/análisis , Adulto , Femenino , Edad Gestacional , Humanos , Leptina , Preeclampsia/metabolismo , Embarazo
7.
J Clin Endocrinol Metab ; 86(3): 1313-7, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11238526

RESUMEN

Cortisol reduces the activity of the PG-inactivating enzyme 15-hydroxyprostaglandin dehydrogenase (PGDH) in human placental cells. The objective was to investigate a possible relation between 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), converting cortisol to cortisone, and PGDH gene expression in the placenta of patients with preeclampsia. In placental tissue taken from 20 healthy women with normal pregnancy, 20 premature babies born after labor before term, and 18 neonates after preeclamptic pregnancy, 11beta-HSD2 and PGDH messenger RNA (mRNA) expression was determined using quantitative TaqMan real-time PCR and quantitative competitive PCR. When comparing matched pairs, there were 3-fold lower 11beta-HSD2/glyceraldehyde-3-phosphate dehydrogenase (11beta-HSD2/GAPDH) mRNA levels in placentas of patients with preeclampsia than in controls [0.18 +/- 0.04 relative units (RU) and 0.61 +/- 0.10 RU, P = 0.0003]. We also found a 2-fold reduction in placental PGDH/GAPDH mRNA concentrations (0.28 +/- 0.15 RU and 0.50 +/- 0.18 RU, P = 0.0003). PGDH and 11beta-HSD2 mRNA levels correlated significantly (r = 0.66, P < 0.0001). In term placenta, 11beta-HSD2/GAPDH, but not PGDH, showed a significant correlation to birth weight (r = 0.43, P = 0.01) and to placental weight (r = 0.47, P = 0.01). Results could be confirmed by competitive PCR. We conclude that, in preeclampsia, 11beta-HSD2 mRNA expression is reduced, leading to the known decrease of 11beta-HSD2 activity. By means of an autocrine or paracrine mechanism, the diminished conversion of placental cortisol may lead to reduced PGDH mRNA expression as found in the present study.


Asunto(s)
Expresión Génica , Hidroxiprostaglandina Deshidrogenasas/genética , Hidroxiesteroide Deshidrogenasas/genética , Placenta/enzimología , Preeclampsia/enzimología , 11-beta-Hidroxiesteroide Deshidrogenasas , Adolescente , Adulto , Peso al Nacer , Cortisona/metabolismo , Femenino , Edad Gestacional , Humanos , Hidrocortisona/metabolismo , Recién Nacido , Recien Nacido Prematuro , Reacción en Cadena de la Polimerasa , Embarazo , Proteinuria , ARN Mensajero/análisis
8.
Eur J Endocrinol ; 145(2): 187-92, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11454515

RESUMEN

BACKGROUND: During human pregnancy, 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) plays an important role in protecting the fetus from high maternal glucocorticoid concentrations by converting cortisol to inactive cortisone. Furthermore, 11beta-HSD2 is indirectly involved in the regulation of the prostaglandin inactivating enzyme 15-hydroxyprostaglandin dehydrogenase (PGDH), because cortisol reduces the gene expression and enzyme activity of PGDH in human placental cells. OBJECTIVE: To examine developmental changes in placental 11beta-HSD2 and PGDH gene expression during the 2nd and 3rd trimesters of human pregnancies. METHODS: In placental tissue taken from 20 healthy women with normal pregnancy and 20 placentas of 17 mothers giving birth to premature babies, 11beta-HSD2 and PGDH mRNA expression was determined using quantitative real-time PCR. RESULTS: Placental mRNA expression of 11beta-HSD2 and PGDH increased significantly with gestational age (r=0.55, P=0.0002 and r=0.42, P=0.007). In addition, there was a significant correlation between the two enzymes (r=0.58, P<0.0001). CONCLUSIONS: In the course of pregnancy there is an increase in 11beta-HSD2 and PGDH mRNA expression in human placental tissue. This adaptation of 11beta-HSD2 prevents increasing maternal cortisol concentrations from transplacental passage and is exerted at the gene level. 11beta-HSD2 up-regulation may also lead to an increase in PGDH mRNA concentrations that, until term, possibly delays myometrial contractions induced by prostaglandins.


Asunto(s)
Hidroxiprostaglandina Deshidrogenasas/genética , Hidroxiesteroide Deshidrogenasas/genética , Placenta/enzimología , Embarazo/metabolismo , ARN Mensajero/genética , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 2 , Adolescente , Adulto , Peso al Nacer , Femenino , Regulación Enzimológica de la Expresión Génica/genética , Humanos , Hidroxiprostaglandina Deshidrogenasas/biosíntesis , Hidroxiesteroide Deshidrogenasas/biosíntesis , Recién Nacido , Trabajo de Parto Prematuro/enzimología , Placenta/fisiología , Segundo Trimestre del Embarazo/genética , Tercer Trimestre del Embarazo/genética , ARN Mensajero/biosíntesis , Análisis de Regresión , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
9.
J Thorac Cardiovasc Surg ; 82(5): 752-7, 1981 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7300407

RESUMEN

To evaluate right ventricular function following mitral valve replacement, we studied 84 patients with isolated mitral valve disease with the use of first-pass radionuclide angiography before, 1 week after, and up to 1 year after operation. The right ventricular ejection fraction for the entire group improved from 29% +/- 11% to 43% +/- 10% (p less than 0.001) at 1 week. This increase was maintained at 3 months (41% +/- 10%) and up to year after operation (40% +/- 12%). The improvement was found not to be influenced by either the type of valvular lesion or the presence and/or level of pulmonary hypertension. When the patients were grouped according to the type of prosthetic valve placed at operation, the right ventricular ejection fraction increased in all patients within 1 week of operation, with sustained improvement at 3 months postoperatively. Thereafter, it began to decline in patients receiving a Carpentier bioprosthesis while being maintained in those patients who received disc valves. Further analysis revealed that those patients who receiving the larger Carpentier bioprostheses had a greater deterioration of right ventricular function than those receiving the smaller Carpentier valves. Left ventricular function in the entire group was normal preoperatively (62% +/- 16%) and was unchanged at 1 week (60% +/- 16%) and a 1 year (59% +/- 16%) after operation.


Asunto(s)
Bioprótesis , Gasto Cardíaco , Prótesis Valvulares Cardíacas , Válvula Mitral/cirugía , Volumen Sistólico , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/fisiopatología , Insuficiencia de la Válvula Mitral/cirugía , Estenosis de la Válvula Mitral/fisiopatología , Estenosis de la Válvula Mitral/cirugía
10.
Bone Marrow Transplant ; 22(12): 1179-83, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9894721

RESUMEN

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic bone marrow transplantation. Immunosuppressive treatment regimens carry the potential of causing severe morbidity and mortality, so that additional modes of therapy with fewer side-effects are clearly needed. Five cGVHD patients (sclerodermoid cGVHD in two patients, lichenoid cGVHD in one patient and intraoral cGVHD in two patients), who had not responded to standard immunosuppressive drugs, were treated with adjuvant UVB phototherapy. The patient with lichenoid cGVHD experienced complete clearing of cutaneous lesions, whereas both patients with sclerodermoid cGVHD experienced significant relief of pruritus, but showed no change of the sclerodermoid skin lesions. Intraoral lesions cleared in one patient. The effects of UVB phototherapy were furthermore documented by measurement of skin viscoelasticity and mouth opening. No side-effects were encountered. This preliminary study suggests that UVB phototherapy is useful as an adjuvant therapeutic modality in intraoral and cutaneous lichenoid cGVHD.


Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Enfermedad Injerto contra Huésped/radioterapia , Terapia Ultravioleta , Adolescente , Adulto , Niño , Enfermedad Crónica , Femenino , Enfermedad Injerto contra Huésped/etiología , Humanos , Masculino , Trasplante Homólogo , Resultado del Tratamiento
11.
Arch Pediatr Adolesc Med ; 155(12): 1323-7, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11732950

RESUMEN

CONTEXT: Bronchiolitis is the most common lower respiratory tract infection in infancy. A recent Centers for Disease Control and Prevention report confirmed that hospitalization rates for bronchiolitis have increased 2.4-fold from 1980 to 1996. Controversies exist about optimal treatment plans. Milliman and Robertson recommend ambulatory care management; in case of hospitalization, the recommended length of stay is 1 day. OBJECTIVES: To relate actual practice variation for infants admitted with uncomplicated bronchiolitis to Milliman and Robertson's recommendations. DESIGN: Prospective observational study. SETTING: General care wards of 8 pediatric hospitals of the Child Health Accountability Initiative during the winter of 1998-1999. PATIENTS: First-time admissions for uncomplicated bronchiolitis in patients not previously diagnosed as having asthma and who were younger than 1 year. MAIN OUTCOME MEASURES: Respiratory rate, monitored interventions, attainment of discharge criteria goals, and length of stay. RESULTS: Eight hundred forty-six patients were included in the final analysis: 85.7% were younger than 6 months, 48.5% were nonwhite, and 64.1% were Medicaid recipients or self-pay. On admission to the hospital, 18.3% of the infants had respiratory rates higher than higher than 80 breaths per minute, 53.8% received supplemental oxygen therapy, and 52.6% received intravenous fluids. These proportions decreased to 1.9%, 33.8%, and 20.3%, respectively, 1 day after admission, and to 0.7%, 20.1%, and 8.6%, respectively, 2 days after admission. The average length of stay was 2.8 days (SD, 2.3 days). CONCLUSIONS: Milliman and Robertson's recommendations do not correspond to practice patterns observed at the hospitals participating in this study; no hospital met the Milliman and Robertson recommended 1-day goal length of stay. Administration of monitored intervention persisted past the second day of hospitalization.


Asunto(s)
Atención Ambulatoria , Bronquiolitis/terapia , Hospitalización , Guías de Práctica Clínica como Asunto , Fluidoterapia , Hospitales Pediátricos , Humanos , Lactante , Recién Nacido , Tiempo de Internación , Evaluación de Procesos y Resultados en Atención de Salud , Terapia por Inhalación de Oxígeno , Pautas de la Práctica en Medicina , Estudios Prospectivos
12.
Leuk Lymphoma ; 34(1-2): 185-90, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10350348

RESUMEN

Allogeneic peripheral blood stem cell transplantation (allo PBSCT) is a recognized treatment modality for hematological malignancies resistant to conventional chemoradiotherapy. The post-transplant immune-mediated graft-versus-leukemia effect has major curative potential. In this case presentation, the allogeneic approach to resistant recurrent primary central nervous system (CNS) lymphoma using peripheral blood stem cells from an HLA identical sibling after immuno-suppressive non-myeloablative conditioning, was examined clinically. The patient in question had relapsing refractory primary CNS lymphoma and is the first to be treated with this modality. She developed early skin and liver-localized grade II graft-versus-host disease after allo PBSCT, which then responded to short-term treatment. Chimeric studies at the time showed 100% donor cells and repeated magnetic resonance imaging of the brain revealed gradual shrinkage of the tumor. Three months after transplant the cerebral mass was no longer evident and currently, 30 months after transplantation, the patient continues to be disease free. The absence of any signs of malignancy suggests the development of a durable graft-versus-lymphoma effect in this brain tumor and indicates that this effect may be achieved even after non-myeloablative conditioning.


Asunto(s)
Neoplasias Encefálicas/terapia , Efecto Injerto vs Tumor , Trasplante de Células Madre Hematopoyéticas , Linfoma de Células B/terapia , Adulto , Neoplasias Encefálicas/inmunología , Femenino , Humanos , Linfoma de Células B/inmunología , Recurrencia Local de Neoplasia/inmunología , Recurrencia Local de Neoplasia/terapia , Trasplante Homólogo
13.
Oecologia ; 70(2): 273-282, 1986 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28311669

RESUMEN

The rate of CO2 assimilation at light saturation and an intercellular CO2 concentration of 350 µl l-1 (photosynthetic capacity), measured in leaves of Eucalyptus pauciflora, E. behriana, E. delegatensis and Acacia melanoxylon, declined over the course of cloudless days under naturally varying environmental conditions as well as under constant optimal conditions for high CO2 uptake. Since the capacity did not recover during the light period, it was different from the "midday depression" of gas exchange. The change appeared to be caused neither by the diurnal variation of total leaf water potential, by photoinhibition of redox-reaction centres in photosystems nor by changes in the intrinsic properties of Ribulose-bisphosphate carboxylase-oxygenase. The decline was more pronounced in winter than in summer. It was related to the duration of illumination or the cumulative carbon gain. It was reversible in the following dark phase, and it did not occur on changeable days with short peaks of high light.Despite the decline in photosynthetic capacity, the initial slope of the CO2 response of net photosynthesis, as obtained at low intercellular CO2 concentrations, remained constant during the day, but declined at night when photosynthetic capacity recovered. In all cases stomatal conductance varied in parallel with photosynthetic capacity. The relevance of changes in photosynthetic capacity for the intercellular CO2 concentration is discussed.

14.
Plant Biol (Stuttg) ; 6(3): 242-53, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15143433

RESUMEN

Climate change affects plants in many different ways. Increasing CO(2) concentration can increase photosynthetic rates. This is especially pronounced for C(3) plants, at high temperatures and under water-limited conditions. Increasing temperature also affects photosynthesis, but plants have a considerable ability to adapt to their growth conditions and can function even at extremely high temperatures, provided adequate water is available. Temperature optima differ between species and growth conditions, and are higher in elevated atmospheric CO(2). With increasing temperature, vapour pressure deficits of the air may increase, with a concomitant increase in the transpiration rate from plant canopies. However, if stomata close in response to increasing CO(2) concentration, or if there is a reduction in the diurnal temperature range, then transpiration rates may even decrease. Soil organic matter decomposition rates are likely to be stimulated by higher temperatures, so that nutrients can be more readily mineralised and made available to plants. This is likely to increase photosynthetic carbon gain in nutrient-limited systems. All the factors listed above interact strongly so that, for different combinations of increases in temperature and CO(2) concentration, and for systems in different climatic regions and primarily affected by water or nutrient limitations, photosynthesis must be expected to respond differently to the same climatic changes.


Asunto(s)
Efecto Invernadero , Fotosíntesis/fisiología , Transpiración de Plantas/fisiología , Dióxido de Carbono/farmacología , Clima , Modelos Biológicos , Fotosíntesis/efectos de los fármacos , Temperatura , Agua/fisiología
15.
Eur J Obstet Gynecol Reprod Biol ; 76(2): 189-91, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9481573

RESUMEN

Leiomyomatosis peritonealis disseminata (LPD) is a rare disease characterised by the presence of multiple smooth muscle tumour nodules throughout the peritoneal cavity. Approximately 50 cases of LPD have been reported to date in the world literature. There is a very high association with excess exogenous and endogenous female gonadal steroids, specifically oestrogen and progesterone. LPD has been described almost only in premenopausal women and is mostly asymptomatic. Four cases of malignant transformation of this disease have been reported. We report a case of a patient with prolonged exposure to oral contraceptives, operated because of hypermenorrhea and 'myoma in statu nascendi'. A metastasing myomatous tumour was suspected during the operation. LPD was diagnosed by intraoperative histological examination. Abdominal hysterectomy was performed. Five months later a second laparotomy had to be done because of an ovarian endometriosis tumour of about 10 cm size. A bilateral salpingo-oophorectomy and omentectomy were performed.


Asunto(s)
Endometriosis/complicaciones , Leiomiomatosis/diagnóstico , Neoplasias Peritoneales/diagnóstico , Adulto , Anticonceptivos Orales/efectos adversos , Endometriosis/patología , Trompas Uterinas/cirugía , Femenino , Humanos , Histerectomía , Intestinos/patología , Leiomiomatosis/complicaciones , Leiomiomatosis/cirugía , Músculo Liso/patología , Epiplón/patología , Ovariectomía , Neoplasias Peritoneales/complicaciones , Neoplasias Peritoneales/cirugía
16.
Eur J Obstet Gynecol Reprod Biol ; 97(2): 163-7, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11451542

RESUMEN

OBJECTIVE: To investigate the maturation of the paracrine system's endothelial nitric oxide synthase (eNOS), inducible NOS (iNOS), endothelin-1 (ET-1) and adrenomedullin (AM) in human placenta during the 2nd and 3rd trimester of pregnancy. STUDY DESIGN: Placental tissue from 14 healthy women with normal pregnancy and from 13 patients giving birth to premature infants following premature labor was obtained. Messenger RNA expression was determined using quantitative TaqMan real-time PCR. RESULTS: Placental eNOS/GAPDH and ET-1/GAPDH mRNA expression significantly increased as a function of gestational age (r=0.63, P<0.001 and r=0.53, P=0.007, respectively). There was no change in gene expression of neither iNOS nor AM mRNA/GAPDH during gestation (r=0.02, P=0.75 and r=0.001, P=0.99, respectively). CONCLUSION: There is a maturation of eNOS and ET-1 in human placenta with gestation reflecting developmental changes of important paracrine endothelial and trophoblastic regulators. AM and iNOS show no maturation during pregnancy.


Asunto(s)
Endotelina-1/genética , Expresión Génica , Óxido Nítrico Sintasa/genética , Placenta/metabolismo , ARN Mensajero/análisis , Adrenomedulina , Adulto , Femenino , Edad Gestacional , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Humanos , Óxido Nítrico Sintasa de Tipo II , Óxido Nítrico Sintasa de Tipo III , Péptidos/genética , Placenta/química , Placenta/enzimología , Embarazo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
17.
Am J Crit Care ; 2(3): 246-52, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8364676

RESUMEN

PURPOSE: This study was designed to examine the relationships between maternal perceptions of an acutely ill child, nurse caregivers and contextual factors in a pediatric critical care unit. METHODS: Subjects were mothers of 20 children who had had their first bone marrow transplant and the primary nurse of each child. The study was conducted on a bone marrow transplant unit. Variables included the acuity of the child, maternal satisfaction with nursing care, maternal vigilance as measured by the time spent at the child's bedside, nurses' attitudes toward family involvement with care, nursing experience and bone marrow transplant unit variables (census, unit acuity and staffing deficit). RESULTS: Positive associations were observed between the child's acuity and maternal satisfaction with nursing care, and between maternal vigilance and staffing deficit. There was an inverse relationship between maternal vigilance and length of nursing experience of the primary nurse and between positive attitudes of nurses toward family participation and years of nursing experience. CONCLUSION: These results show the complex nature of parental perceptions and involvement in the hospitalized child's care. They suggest that maternal attitudes about caregiving are associated with the child's acuity and that maternal vigilance is related to nursing and environmental factors, principally critical care experience of the primary nurse.


Asunto(s)
Actitud del Personal de Salud , Actitud Frente a la Salud , Trasplante de Médula Ósea/enfermería , Unidades de Cuidado Intensivo Pediátrico/normas , Madres/psicología , Personal de Enfermería en Hospital/psicología , Satisfacción del Paciente , Calidad de la Atención de Salud , Enfermedad Aguda , Adolescente , Adulto , Trasplante de Médula Ósea/psicología , Niño , Cuidado del Niño , Niño Hospitalizado , Preescolar , Femenino , Ambiente de Instituciones de Salud , Humanos , Lactante , Unidades de Cuidado Intensivo Pediátrico/organización & administración , Persona de Mediana Edad , Atención de Enfermería/psicología , Atención de Enfermería/normas , Participación del Paciente , Relaciones Profesional-Familia , Índice de Severidad de la Enfermedad , Factores de Tiempo
18.
Am J Crit Care ; 5(2): 140-6, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8653165

RESUMEN

BACKGROUND: Psychological management of parents during a child's critical illness is a challenge to intensive care nurses because of the uncertainty that accompanies hospitalization. OBJECTIVE: To explore the relationship among illness severity, family resources, and maternal uncertainty during the initial stage of a child's hospitalization in a pediatric intensive care unit for a life-threatening illness. METHODS: A convenience sample of 40 mothers rated perceptions of uncertainty (using Mishel's Uncertainty of Illness Scale: Parent Child Form), family cohesion (using Olson's Family Adaptability and Cohesion Evaluation Scale), and social support (using Norbeck's Social Support Questionnaire). Illness severity was estimated with the Pediatric Risk of Mortality Scale. RESULTS: ¿ Results showed a positive association between illness severity and maternal uncertainty and a negative association between family cohesion and maternal uncertainty. Severity of illness contributed less to maternal uncertainty than did family cohesion. CONCLUSIONS: Family relationship are important factors to consider when clinicians estimated the effect on parents of their child's critical illness, particularly when uncertainty over their child's outcome may lead to parental stress that can interfere with coping and child management. (American Journal of Critical Care.)


Asunto(s)
Niño Hospitalizado/psicología , Cuidados Críticos , Familia/psicología , Madres/psicología , Adolescente , Adulto , Niño , Preescolar , Economía , Femenino , Humanos , Lactante , Masculino , Análisis de Regresión , Índice de Severidad de la Enfermedad , Apoyo Social
19.
ScientificWorldJournal ; 1: 271-80, 2001 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-12806084

RESUMEN

There is the concern among some countries that compliance costs with commitments under the Kyoto Protocol may be unacceptably high. There is also the concern that technical difficulties with the inclusion of land use, land-use change, and forestry activities in non-Annex I countries might lead to an effective exclusion of such activities from consideration under the Protocol. This paper is proposing a mechanism that addresses both these concerns. In essence, it is suggested that parties should be able to purchase fixed-price offset certificates if they feel they cannot achieve compliance through other means alone, such as by improved energy efficiency, increased use of renewable energy, or use of the flexible mechanisms in the Kyoto Protocol. These offset certificates would act as a price cap for the cost of compliance for any party to the Protocol. Revenues from purchase of the offset certificates would be directed to forest-based activities in non-Annex I countries such as forest protection that may carry multiple benefits including enhancing net carbon sequestration.


Asunto(s)
Fuentes Generadoras de Energía/economía , Agricultura Forestal/economía , Efecto Invernadero , Adhesión a Directriz , Cooperación Internacional
20.
ANS Adv Nurs Sci ; 19(1): 51-71, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8866000

RESUMEN

This investigation answered the question, What meaning do parents give to the decision to authorize or to withdraw or forgo authorization of life-sustaining treatment for a child? Using an exploratory design, the author interviewed 20 families who had faced this decision in the prior 6 to 12 months. From content analysis, parents' essential meaning was experienced through their sense of self, their being, and an ethic of responsibility. Parents' decisions reflected values regarding the eight key themes of life, pain and suffering, quality of life, not self, respect for person or best interest, family, faith and nature, and technology.


Asunto(s)
Toma de Decisiones , Ética , Cuidados para Prolongación de la Vida , Padres , Valores Sociales , Adolescente , Adulto , Actitud Frente a la Muerte , Actitud Frente a la Salud , Niño , Preescolar , Familia , Femenino , Humanos , Lactante , Masculino , Ciencia del Laboratorio Clínico , Dolor , Padres/psicología , Calidad de Vida , Religión
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