Distribution of crassulacean acid metabolism in orchids of Panama: evidence of selection for weak and strong modes.

Crassulacean acid metabolism (CAM) is one of three metabolic pathways found in vascular plants for the assimilation of carbon dioxide. In this study, we investigate the occurrence of CAM photosynthesis in 200 native orchid species from Panama and 14 non-native species by carbon isotopic composition (δC) and compare these values with nocturnal acid accumulation measured by titration in 173 species. Foliar δC showed a bimodal distribution with the majority of species exhibiting values of approximately -28‰ (typically associated with the C pathway), or -15‰ (strong CAM).

Fatty Acid ethyl esters: quantitative biomarkers for maternal alcohol consumption.

Objective: To develop a laboratory marker to identify newborns exposed to alcohol.

Study Design: Meconium was collected from 30 infants from Jordan who were unexposed and from 248 Cleveland study infants of varying exposure status. Retrospective maternal alcohol histories were obtained.

Use of ultrasonography to identify infants for whom urinary catheterization will be unsuccessful because of insufficient urine volume: validation of the urinary bladder index.

Study Objective: Frequently, attempts to obtain catheter urine samples from infants are unsuccessful because of an empty bladder, with urinary catheterization failure rates reported up to 16%. We seek to validate a sonographic urinary bladder index that will identify patients for whom catheterization will be unsuccessful.

Methods: We conducted a prospective, blinded, observational study enrolling a convenience sample of children younger than 2 years and undergoing urinary catheterization in an urban pediatric emergency department.

Synergy between imatinib and mycophenolic acid in inducing apoptosis in cell lines expressing Bcr-Abl.

Bcr-Abl tyrosine kinase activity initiates a number of intracellular signaling cascades that result in leukemogenesis. Imatinib mesylate, a specific Bcr-Abl tyrosine kinase inhibitor, has been highly successful in the treatment of chronic myelogenous leukemia (CML). However, the emergence of imatinib resistance and the incomplete molecular response of a significant number of patients receiving this therapy have led to a search for combinations of drugs that will enhance the efficacy of imatinib.

HLA-DQB1 *03 in allergic fungal sinusitis and other chronic hypertrophic rhinosinusitis disorders.

Background: Many common chronic inflammatory disorders have strong HLA gene associations, particularly with MHC class II. Allergic fungal rhinosinusitis (AFS) and hypertrophic sinus disease (HSD) are chronic sinonasal mucosal inflammatory disorders. Allergic bronchopulmonary aspergillosis, a disorder analogous to AFS, was recently reported to have HLA-MHC class II associations.

Retention of provisional crowns cemented with eight temporary cements: comparative study.

Many temporary cements are commercially available; therefore, it is necessary to indicate them for each clinical requirement with regard to the tensile strength of prosthetic retainers. Thus, the purpose of this study was to compare the retention of provisional crowns cemented with eight temporary cements, over full crown preparations with standardized mechanical principles as height, taper, and length. For that purpose, eighty human first premolars received full crown preparation with standardized height and taper.

Involvement of the chemokine RANTES (CCL5) in resistance to experimental infection with Leishmania major.

The expression and putative role of chemokines during infection with Leishmania major in mice were investigated. CCL5 expression correlates with resistance, and blockade of CCL5 rendered mice more susceptible to infection. CCL5 is part of the cascade of events leading to efficient parasite control in L.

Leaf photosynthetic traits scale with hydraulic conductivity and wood density in Panamanian forest canopy trees.

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.

Effect of knee osteoarthritis on the perception of quality of life in Venezuelan patients.

Objective: To measure the perception of quality of life in Venezuelan patients with knee osteoarthritis and to identify those variables that may influence it.

Methods: A multicenter, cross-sectional study of 126 mestizo patients with knee osteoarthritis recruited from 8 rheumatology centers in Venezuela. We used a Spanish-translated version of the Arthritis Impact Measurement Scales (AIMS), as adapted in Venezuela.

Coordinated changes in photosynthesis, water relations and leaf nutritional traits of canopy trees along a precipitation gradient in lowland tropical forest.

We investigated leaf physiological traits of dominant canopy trees in four lowland Panamanian forests with contrasting mean annual precipitation (1,800, 2,300, 3,100 and 3,500 mm). There was near complete turn-over of dominant canopy tree species among sites, resulting in greater dominance of evergreen species with long-lived leaves as precipitation increased. Mean structural and physiological traits changed along this gradient as predicted by cost-benefit theories of leaf life span.

Greater adherence to highly active antiretroviral therapy (HAART) between pregnant versus non-pregnant women living with HIV.

One of the most remarkable advances in the control of the HIV/AIDS pandemic has been the introduction of highly active antiretroviral therapy (HAART). The use of HAART has been associated to reductions in AIDS-related mortality in most countries where HAART is available. Unfortunately, the adherence required to keep good control of viral replication is higher than what is required in other medical conditions.

[Promotion of breastfeeding: the importance of pediatricians with specific training].

Objective: To study the factors involved in the maintenance of exclusive breastfeeding in healthy infants during the first 4 months of life, with emphasis on the role of pediatricians.

Material And Methods: A longitudinal study was carried out with 101 healthy term babies at a pediatrics outpatient clinic in Uberaba, state of Minas Gerais, Brazil. The babies were divided at random into three groups: G1, receiving advice from a multiprofessional breastfeeding team; G2, receiving advice from a pediatrician trained in breastfeeding; and G3, receiving advice from a pediatrician with no breastfeeding training.

Coronary heart disease risk: the results of population screening by the Central Region Branch of the Portuguese Heart Foundation.

Objective: To assess the ten-year risk of coronary heart disease according to the 1998 Task Force Report.

Material And Methods: 1013 adults, aged between 30 and 79 years, were studied by trained paramedics, using a pre-determined routine technique. Prevalences: occasional capillary glycemia > 126 mg/dl in 11.

Development of an assay for ozone-specific antioxidant capacity.

A method of determining the ozone-specific antioxidant capacity (OZAC) of lavage samples from the respiratory system was developed: Gaseous ozone (O(3)) was produced in cuvettes by irradiation with an ultraviolet lamp; aliquots of sample or of a saline control were then added and sufficient time was allowed for ozonation to reach completion; and an aliquot of indigo trisulfonate (ITS) was added to react with excess O(3). Because each molecule of O(3) rapidly bleaches one molecule of the deeply colored ITS, an OZAC value in concentration units was computed from the difference in light absorbance between the sample and the saline control multiplied by the extinction coefficient of ITS. Experiments in 0-40 micro M antioxidant solutions indicated that the OZAC values of uric acid and ascorbic acid were close to their actual concentrations and were independent of O(3) concentration.

Targeted disruption of the inosine 5'-monophosphate dehydrogenase type I gene in mice.

Inosine 5'-monophosphate dehydrogenase (IMPDH) is the critical, rate-limiting enzyme in the de novo biosynthesis pathway for guanine nucleotides. Two separate isoenzymes, designated IMPDH types I and II, contribute to IMPDH activity. An additional pathway salvages guanine through the activity of hypoxanthine-guanine phosphoribosyltransferase (HPRT) to supply the cell with guanine nucleotides.

Transpiration and forest structure in relation to soil waterlogging in a Hawaiian montane cloud forest.

Transpiration, leaf characteristics and forest structure in Metrosideros polymorpha Gaud. stands growing in East Maui, Hawaii were investigated to assess physiological limitations associated with flooding as a mechanism of reduced canopy leaf area in waterlogged sites. Whole-tree sap flow, stomatal conductance, microclimate, soil oxidation-reduction potential, stand basal area and leaf area index (LAI) were measured on moderately sloped, drained sites with closed canopies (90%) and on level, waterlogged sites with open canopies (50-60%).

Induction of apoptosis in IL-3-dependent hematopoietic cell lines by guanine nucleotide depletion.

Inosine 5'-monophosphate dehydrogenase (IMPDH) is a rate-limiting enzyme that catalyzes the conversion of IMP to xanthosine monophosphate (XMP) at the branch point of purine nucleotide biosynthesis, leading to the generation of guanine nucleotides. Inhibition of IMPDH results in the depletion of guanine nucleotides, prevents cell growth by G1 arrest, and induces cell differentiation in a cell-type-specific manner. The molecular and sensing mechanisms underlying these effects are not clear.

Plasma levels of endothelin-1 in retinitis pigmentosa.

Retinitis pigmentosa (RP) is an inherited retinal disorder clinically characterized by a pale, waxy optic nerve head, attenuated retinal blood vessels and bone spicule pigment in the retina. Hemodynamic studies have demonstrated that RP is associated with a reduction in the retinal and choroidal blood flow. Retinal hemodynamic impairment is also present in the early stages of RP and various hypotheses have been advanced as to its cause.

Hypercholesterolemia and associated cardiovascular risk factors in young children and adolescents.

Objective: To determine the prevalence of hypercholesterolemia (HPC) and associated risk factors for cardiovascular disease, in young children and adolescents.

Design: Cross-sectional study, with stratification for age and gender.

Setting: Primary Care study.

Laparoscopic evaluation of indeterminate renal cysts: long-term follow-up.

Purpose: We present our long-term follow-up of patients who have undergone laparoscopic evaluation for their indeterminate renal cysts, specifically reporting those patients who were found to have cystic renal-cell carcinoma (RCC) and assessing the safety and efficacy of the procedure.

Patients And Methods: Fifty-seven patients with indeterminate renal cysts (28 Bosniak category II and 29 Bosniak category III) underwent laparoscopic evaluation between July 1993 and July 2000. A transperitoneal laparoscopic localization and aspiration of the cyst, cytologic analysis, and biopsy of the cyst wall and base were performed.

[Fraction of gemistocytic astrocytes and immunoexpression of p53 protein in astrocytomas grade II and III (WHO)].

Twenty-two patients with astrocytomas, grade II or III WHO, were studied from 1990 to 1998. In all cases, histopathology showed that the astrocytomas had a gemistocytic component. The aims of this study were to establish the fraction of gemistocytic astrocytes, to investigate p53 protein immunoexpression and to evaluate correlations between these two parameters with the tumour outcome.