Immune profiling of plasma and cervical secretions using recycling immunoaffinity chromatography.
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Small volumes of cervical secretions have limited measurements of immunity at the cervix, which may be important to studies of human papillomavirus (HPV). We report the use of recycling immunoaffinity chromatography to efficiently study immune profiles in cervical secretions. Frozen pairs of plasma and cervical secretions (collected on ophthalmic sponges) were selected randomly from women with normal cervical cytology (n = 50) participating in a natural history study of HPV in Guanacaste, Costa Rica. Single 25- micro l aliquots of plasma and (diluted) cervical secretions were assayed for interleukin (IL) -1 beta, -2, -4, -6, -8, -10, -12, -13, -15, IFN-alpha, -beta, -gamma, tumor necrosis factor-alpha, -beta, RANTES (regulated on activation normal T-cell express and secreted), MCP-1 (monocyte chemoattractant protein), -2, -3, macrophage inflammatory protein-1 alpha, -1 beta (regulated on activation normal T-cell express and secreted), macrophage colony-stimulating factor, IgG, IgA, and cyclooxygenase 2. All of the specimens were tested as blind replicates, and refrozen plasma was retested 4 months later. To evaluate the reproducibility of the repeat measurements and to examine the correlation between plasma and cervical secretions, we calculated kappa values with 95% confidence intervals among categorized analyte values and Spearman correlation coefficients (rho) among detectable, continuous analyte values. Measurements of all of the analytes in either plasma or cervical secretions were highly reproducible, with all of the kappa > or = 0.78 (70% above 0.90), and all of the rho > or = 0.88 (96% above 0.90). Only IL-1 beta (kappa = 0.60 and rho = 0.82) and IL-6 (kappa = 0.50 and rho = 0.78) levels were strongly correlated between plasma and cervical secretions. IFN-gamma, tumor necrosis factor-beta, RANTES, MCP-1, MCP -2, macrophage inflammatory protein-1 alpha, and macrophage colony-stimulating factor levels were especially poorly correlated between plasma and cervical secretions (kappa < or = 0.25 and rho < or = 0.25). We conclude that recycling immunoaffinity chromatography is a reproducible method of measuring immune profiles from biological specimens, and immune profiles are not well correlated between plasma and cervical secretions, perhaps necessitating cervical collections to study cervix-specific immunity in HPV natural history studies. (+info)
Pollen feeding in the butterfly Heliconius charitonia: isotopic evidence for essential amino acid transfer from pollen to eggs.
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Heliconius and Laparus butterflies exhibit a unique pollen-collecting behaviour that enhances lifespan and fecundity. The specific nutritional contribution of pollen, however, had not been previously demonstrated. We used stable isotope variation to trace the carbon flow into eggs from corn pollen provided experimentally to ovipositing female Heliconius charitonia, and to evaluate the use of isotopically contrasting nectar sugars in egg amino acids. The delta(13)C of individual amino acids from pollen, larval host plant and the eggs from experimental butterflies was measured with gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS), to evaluate amino acid transfer. The delta(13)C of egg essential amino acids indicated a transfer of essential amino acids from pollen to butterfly eggs. However, the delta(13)C of non-essential amino acids reflected the isotopic composition of the artificial nectar, indicating that H. charitonia synthesizes non-essential amino acids from dietary sugars. This, to our knowledge, is the first direct demonstration of amino acid transfer from pollen to butterfly eggs, and suggests that essential amino acids in particular are a key resource for extending lifespan and fecundity in Heliconius butterflies. (+info)
Seroreactivity to human papillomavirus (HPV) types 16, 18, or 31 and risk of subsequent HPV infection: results from a population-based study in Costa Rica.
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Whether antibodies to human papillomavirus (HPV) capsids, elicited by natural infection, are protective is unknown. This question was addressed in a population-based cohort of 7046 women in Costa Rica by examining the association between baseline seroreactivity to HPV-16, HPV-18, or HPV-31 virus-like particles and the risk of subsequent HPV infection at a follow-up visit 5-7 years after enrollment. Seropositivity to HPV-16, HPV-18, or HPV-31 was not associated with a statistically significant decreased risk of infection with the homologous HPV type [relative risk (RR) and [95% confidence interval (CI)], 0.74 (0.45-1.2), 1.5 (0.83-2.7), and 0.94 (0.48-1.8), respectively]. Seropositivity to HPV-16 or HPV-31 was not associated with a decreased risk of infection with HPV-16 or its genetically related types [RR (95% CI), 0.82 (0.61-1.1) and 0.93 (0.68-1.2), respectively]. Seropositivity to HPV-18 was not associated with a decreased risk of infection with HPV-18 or its genetically related types (RR 1.3; 95% CI 1.0-1.8). Thus, we did not observe immunity, although a protective effect from natural infection cannot be excluded because of the limits of available assays and study designs. (+info)
Histoplasmosis associated with exploring a bat-inhabited cave in Costa Rica, 1998-1999.
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Between October 1998 and April 1999, 51 persons belonging to two separate groups developed acute pulmonary histoplasmosis after visiting a cave in Costa Rica. The first group consisted of 61 children and 14 adults from San Jose, Costa Rica; 44 (72%) were diagnosed with acute histoplasmosis. The second group comprised 14 tourists from the United States and Canada; 9 (64%) were diagnosed with histoplasmosis. After a median incubation time of 14 days, the most common symptoms were headache, fever, cough, and myalgias. Risk factors for developing histoplasmosis included crawling (odds ratio [OR] = 17.5, 95% confidence interval [CI] = 2.3-802) and visiting one specific room (OR = 3.4, 95% CI = 1.0-12.3) in the cave. Washing hands (OR = 0.1, 95% CI = 0.01-0.6) after exiting the cave was associated with a decreased risk of developing histoplasmosis. Histoplasma capsulatum was isolated from bat guano collected from inside the cave. Persons who explore caves, whether for recreation or science, should be aware of the risk bat-inhabited caves pose for developing histoplasmosis, especially if they are immunocompromised in any way. (+info)
Antagonistic pleiotropy for life-history traits at the gene expression level.
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Life-history trade-offs prevent different components of fitness from being maximized simultaneously. Although the existence of trade-offs has been clearly demonstrated, the 'classical' mechanism of adaptive resource allocation that should underlie them has recently received criticism. In this study, we explore the molecular mechanisms of life-history trade-offs by applying a quantitative genomic approach. Analysis of global gene expression in Drosophila melanogaster revealed 34 genes whose expression coincided with the genetic trade-off between larval survival and adult size. The joint expression of these candidate 'trade-off' genes explained 86.3% of the trade-off. Fourteen of these genes have known functions which suggest that the larval survival-adult size trade-off could be the result of resource allocation at the organismal level, but at the level of cellular metabolism the trade-off would reduce to a shift between energy metabolism versus protein biosynthesis, regulated by the RAS signalling pathway. (+info)
Determination of human cytomegalovirus genetic diversity in different patient populations in Costa Rica.
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Seroprevalence of HCMV in Costa Rica is greater than 95% in adults; primary infections occur early in life and is the most frequent congenital infection in newborns. The objectives of this study were to determine the genetic variability and genotypes of HCMV gB gene in Costa Rica. Samples were collected from alcoholics, pregnant women, blood donors, AIDS patients, hematology-oncology (HO) children and HCMV isolates from neonates with cytomegalic inclusion disease. A semi-nested PCR system was used to obtain a product of 293-296 bp of the gB gene to be analyzed by Single Stranded Conformational Polymorphism (SSCP) and sequencing to determine the genetic polymorphic pattern and genotypes, respectively. AIDS patients showed the highest polymorphic diversity with 14 different patterns while fifty-six percent of HO children samples showed the same polymorphic pattern, suggesting in this group a possible nosocomial infection. In neonates three genotypes (gB1, gB2 and gB3), were determined while AIDS patients and blood donors only showed one (gB2). Of all samples analyzed only genotypes gB1, 2 and 3 were determined, genotype gB2 was the most frequent (73%) and mixed infections were not detected. The results of the study indicate that SSCP could be an important tool to detect HCMV intra-hospital infections and suggests a need to include additional study populations to better determine the genotype diversity and prevalence. (+info)
Previous-year reproduction reduces photosynthetic capacity and slows lifetime growth in females of a neotropical tree.
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Females of dioecious plant species typically invest more in reproduction than males because they produce seeds, fruits, and associated structures in addition to flowers. If females are unable to compensate by up-regulating rates of photosynthesis or by reproducing less frequently than males, their greater reproductive investment may result in reduced growth or higher mortality. Here we provide evidence of the cost of reproduction in Ocotea tenera (Lauraceae), a dioecious neotropical tree common in lower montane forests of Monteverde, Costa Rica. Over periods of 12-21 years, females grew more slowly than males in a natural population and in two experimental plots where we were able to control for genotype, age, habitat, and reproductive history. Simultaneous measurements of 10 matched pairs of sibling trees of the opposite sex but same age demonstrated that the photosynthetic capacities of females were 13% lower than those of males. Among females, photosynthetic capacity was negatively correlated with fruit production during the most recent reproductive season but not with lifetime fruit production. Sexual size dimorphism in adult O. tenera trees appears to be a nonadaptive consequence of trading off recent reproduction against maintenance of the photosynthetic apparatus, with long-term negative effects on growth. (+info)
Effect of polymorphic colour vision for fruit detection in the spider monkey Ateles geoffroyi, and its implications for the maintenance of polymorphic colour vision in platyrrhine monkeys.
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Most platyrrhine monkeys have an X-linked tri-allelic polymorphism for medium and long wavelength (M/L) sensitive cone photopigments. These pigments' sensitivity maxima (lambdamax) range from 535 to 562 nm. All animals also have an autosomally coded short-wavelength-sensitive (S) cone pigment. In populations with three M/L alleles there are six different colour vision phenotypes. Heterozygous females have trichromatic colour vision, while males and homozygous females are dichromats. The selective basis for this polymorphism is not understood, but is probably affected by the costs and benefits of trichromatic compared to dichromatic colour vision. For example, it has been suggested that trichromats are better equipped than dichromats to detect fruit against a leaf background. To investigate this possibility, we modeled fruit detection by various colour vision phenotypes present in the frugivorous spider monkey, Ateles geoffroyi. Our study population is thought to have three M/L alleles with cone pigment lambdamax values close to 535, 550 and 562 nm. The model predicted that all trichromat phenotypes had an advantage over dichromats, and the 535/562 nm phenotype was best; however, the model predicted that dichromats could detect all of the fruit species consumed by spider monkeys. We conclude that the heterozygote advantage experienced by females may be the most plausible explanation for the maintenance of this polymorphism in A. geoffroyi. Nevertheless, more studies need to evaluate social foraging behaviour and the performance of different phenotypes of other New World monkeys to determine if this is a global explanation for this phenomena or more specific to A. geofforyi. (+info)