Pollinators of Richardia grandiflora (Rubiaceae): an Important Ruderal Species for Bees.

Ruderal species may provide pollen and nectar to maintain the pollinators of crops in periods of floral resource shortage. The knowledge about the floral biology of these plant species and their interaction with insects is important for management strategies of agricultural systems. The study was carried out at an experimental research station in two different periods (August 2010-April 2011 and August 2012-January 2013). Floral biology was studied, and the reproductive system and reproductive efficacy (RE) were analyzed using controlled pollination experiments. Furthermore, floral visitors and pollination were identified and quantified. Reproductive success obtained in the open pollination and cross-pollination experiments was higher than those obtained in spontaneous self, hand self, and wind pollination. Richardia grandiflora bloomed throughout the experimental period, and flowers were visited by Coleoptera, Diptera, Hymenoptera, and Lepidoptera, which were observed foraging for pollen and/or nectar. Among the floral visitors, bees were the richest and most frequent group and often contacted anthers and stigmas during visits. Africanized honeybees touched the floral reproductive structures in all visits, and their frequency may be related to changes in the reproductive efficacy between the study periods. Pollinator species of crops cultivated at the experimental research station were frequent bee visitors of R. grandiflora. We demonstrated that R. grandiflora requires cross-pollination and biotic pollen vectors. Among floral visitors, bees are the main pollinators, especially the Africanized honeybees. R. grandiflora can be considered an important ruderal species for maintaining bee pollinator populations at the study site, providing resources during the period that crops are not blooming.

Induction of protection in murine experimental models against Trichinella spiralis: an up-to-date review.

The parasitic nematode Trichinella spiralis, an aetiological agent of the disease known as trichinellosis, infects wild and domestic animals through contaminated pig meat, which is the major source for Trichinella transmission. Prevention of this disease by interrupting parasite transmission includes vaccine development for livestock; however, major challenges to this strategy are the complexity of the T. spiralis life cycle, diversity of stage-specific antigens, immune-evasion strategies and the modulatory effect of host responses. Different approaches have been taken to induce protective immune responses by T. spiralis immunogens. These include the use of whole extracts or excretory-secretory antigens, as well as recombinant proteins or synthesized epitopes, using murine experimental models for trichinellosis. Here these schemes are reviewed and discussed, and new proposals envisioned to block the zoonotic transmission of this parasite.

MR (Mre11-Rad50) complex in Giardia duodenalis: In vitro characterization and its response upon DNA damage.

Giardia duodenalis is a well-known protozoan parasite of humans and other mammals. The repair of DNA double strand breaks (DSBs) is crucial for genomic stability and homologous recombination is one of the primary mechanisms used by cells to repair DNA. The Mre11 complex is comprised by Mre11, an endonuclease and 3'-5' exonuclease known to resect ends during homologous recombination, and Rad50, a member of the structural maintenance of chromosomes (SMC) family of ATPases. In this work we cloned, expressed and characterized the catalytic activities of the giardial Mre11 (GdMre11) and Rad50 (GdRad50) proteins. Our results show that while purified recombinant GdMre11 and GdRad50 proteins bind DNA, GdMre11 contains a 3'-5' exonuclease and purified recombinant GdRad50 has ATPase activity. The predicted structure for GdMre11 revealed a conserved Mn(2+) dependent binding pocket. We also explored the expression of giardial mre11 and rad50 genes after ionizing radiation, and our results indicate that both specific transcripts were increased after 1-2 h while their protein levels were found to be significantly increased 4 h after gamma radiation treatment. These proteins were localized in the nuclei before and after irradiation. The implication of these observations is discussed.

Complex temporal decay: a complete analysis.

Relaxation dynamics is universal in science and engineering; its study serves to parameterize a system's response and to help identify a microscopic model of the processes involved. When measured data for a phenomenon cannot be fitted using one exponential, the choice of an alternative function to describe the decay becomes nontrivial. Here, we contrast two different, but fundamentally related approaches to fitting nontrivial decay curves; exponential decomposition and the gamma probability density function.

Micronucleated lymphocytes in parents of Down syndrome children

Down syndrome (DS) is the most common disease due to an autosomal aneuploidy in live born children and also the major known genetic cause of mental retardation. The risk of a DS pregnancy increases substantially with increasing maternal age. However, several women aged less than 35 years at conception have a child with DS. The micronucleus (MN) assay can identify chromosome breakage or chromosome malsegregation and is an ideal biomarker to investigate genomic instability. The aim of the present study was to determine the frequency of peripheral lymphocytes with MN in the parents of DS individuals. The subjects were 17 couples, 1 father and 9 mothers, and 24 couples who had at least one healthy child formed the control group. For each individual we evaluated the frequency of binucleated micronucleated lymphocytes (BNMN%) as number of binucleated lymphocytes containing one or more MN per 1000 binucleated cells. The mean age of DS parents and controls was 32.6 and 29.8 years, respectively. The frequency of MN in DS parents was significantly higher compared to controls. The higher frequency of MN in DS parents suggests a higher predisposition of DS parents to aneuploidy events in this sample.

Micronucleated lymphocytes in parents of Down syndrome children.

Down syndrome (DS) is the most common disease due to an autosomal aneuploidy in live born children and also the major known genetic cause of mental retardation. The risk of a DS pregnancy increases substantially with increasing maternal age. However, several women aged less than 35 years at conception have a child with DS. The micronucleus (MN) assay can identify chromosome breakage or chromosome malsegregation and is an ideal biomarker to investigate genomic instability. The aim of the present study was to determine the frequency of peripheral lymphocytes with MN in the parents of DS individuals. The subjects were 17 couples, 1 father and 9 mothers, and 24 couples who had at least one healthy child formed the control group. For each individual we evaluated the frequency of binucleated micronucleated lymphocytes (BNMN%) as number of binucleated lymphocytes containing one or more MN per 1000 binucleated cells. The mean age of DS parents and controls was 32.6 and 29.8 years, respectively. The frequency of MN in DS parents was significantly higher compared to controls. The higher frequency of MN in DS parents suggests a higher predisposition of DS parents to aneuploidy events in this sample.

PCBs stimulate laccase production and activity in Pleurotus ostreatus thus promoting their removal.

Pleurotus ostreatus degrades polychlorinated biphenyls (PCBs) with an increase of laccase activity. Laccases are well known for their detoxifying activity. We show, using reverse transcription polymerase chain reaction and a biochemical assay, that reduction in PCBs (di, tri, tetra, and penta) levels are correlated with an increase in laccase activity. P. ostreatus cultures were obtained from 0 to 30 days in the presence or absence of 7,100 mg/L PCBs (from transformer oil) and a surfactant. After each selected time cultures were withdrawn and remaining PCBs were determined, a maximal removal percentage of PCBs was obtained at 20 (63.5 ± 2.0) and 30 days (63.8 ± 4.6) post-induction. Also, the activity of the enzyme was analyzed and it was found to increase at 10 (6.9-fold) and 20 (6.77-fold) days post-induction in the presence of PCBs, as determined by its activity. Taken together, these data suggest that PCBs induce laccase expression and that laccase catalyzes PCBs removal.

Exclusion of Class III malocclusion candidate loci in Brazilian families.

The role played by genetic components in the etiology of the Class III phenotype, a class of dental malocclusion, is not yet understood. Regions that may be related to the development of Class III malocclusion have been suggested previously. The aim of this study was to search for genetic linkage with 6 microsatellite markers (D1S234, D4S3038, D6S1689, D7S503, D10S1483, and D19S566), near previously proposed candidate regions for Class III. We performed a two-point parametric linkage analysis for 42 affected individuals from 10 Brazilian families with a positive Class III malocclusion segregation. Analysis of our data indicated that there was no evidence for linkage of any of the 6 microsatellite markers to a Class III locus at = zero, with data supporting exclusion for 5 of the 6 markers evaluated. The present work reinforces that Class III is likely to demonstrate locus heterogeneity, and there is a dependency of the genetic background of the population in linkage studies.

Genotyping of Mexican Cryptococcus neoformans and C. gattii isolates by PCR-fingerprinting.

Cryptococcosis in México is caused by both species of the Cryptococcus species complex i.e., Cryptococcus neoformans and C. gattii. The current study was aimed to determine genetic variability of 72 Mexican clinical isolates using PCR-fingerprinting with the primer M13. PCR fingerprinting revealed 55 VNI, five VNII, three VNIII, one VNIV, two VGI, two VGII, two VGIII and two VGIV isolates among those studied. The results show that most cryptococcosis cases in México are AIDS related and are caused by C. neoformans var. grubii, genotypes VNI and VNII. In addition this study revealed for the first time the presence of genotypes VNIV and VGII among Mexican clinical isolates. The present data show that all genotypes that have been described for the Cryptococcus species complex are found in México, indicating a much wider geographic distribution of genotypes than previously reported. The molecular analysis of Mexican cryptococcal isolates generated PCR-fingerprinting patterns which will provide references for future typing studies to allow the integration of Mexican cryptococcal genotypes into the ongoing global genotyping study of the Cryptococcus species complex.

Axial interface optical phonon modes in a double-nanoshell system.

Within the framework of the dielectric continuum (DC) model, we analyze the axial interface optical phonon modes in a double system of nanoshells. This system is constituted by two identical equidistant nanoshells which are embedded in an insulating medium. To illustrate our results, typical II-VI semiconductors are used as constitutive polar materials of the nanoshells. Resolution of Laplace's equation in bispherical coordinates for the potentials derived from the interface vibration modes is made. By imposing the usual electrostatic boundary conditions at the surfaces of the two-nanoshell system, recursion relations for the coefficients appearing in the potentials are obtained, which entails infinite matrices. The problem of deriving the interface frequencies is reduced to the eigenvalue problem on infinite matrices. A truncating method for these matrices is used to obtain the interface phonon branches. Dependences of the interface frequencies on the ratio of inter-nanoshell separation to core size are obtained for different systems with several values of nanoshell interdistance. Effects due to the change of shell and embedding materials are also investigated in interface phonon modes.

Human papillomavirus infection and cervical ectopy.

OBJECTIVES: To investigate the prevalence of human papillomavirus (HPV), and HPV type 16 (HPV16) infection in cervical ectopy, and the presence of anti-HPV16 secretory IgA (sIgA) antibodies. METHODS: DNA from patients with cervical ectopy (n=218), HPV-associated lesions (n=111), and controls without evidence of cervical ectopy or HPV infection (n=93) were analyzed by PCR for the presence of HPV and HPV16. The presence of mucosal sIgA antibodies against HPV16 capsid antigens (VLP) was assayed in cervical mucus by ELISA. RESULTS: Prevalence of HPV DNA was higher in cervical ectopy than in controls (P=0.04; OR=2.06; 95% CI 0.99-4.33). HPV16 was 6.3 times more prevalent in cervical ectopy than in controls. Anti-HPV16 sIgA were detected more frequently in cervical ectopy patients than in controls (P=0.0004). CONCLUSIONS: Cervical ectopy correlates with HPV infection. HPV16 is highly prevalent in cervical ectopy. sIgA antibodies against HPV16 capsids are generated in patients with cervical ectopy.

Thyroglossal duct carcinoma: a large case series.

Thyroglossal duct cysts (TDCs) are common congenital abnormalities of thyroid development. Carcinoma occurs rarely in patients with TDCs. In a large case series drawn from medical records at a health maintenance organization from 1971 through 1995, 14 cases of carcinoma in a TDC were found. This represents the largest known reported case series to date. Demographics, diagnosis, and treatment methods are reviewed. We recommend the Sistrunk operation and evaluation of the thyroid gland and neck for potential abnormality that would necessitate thyroidectomy and lymph node dissection. Long-term follow-up incorporating clinical examination is mandatory.

Nus A is involved in transcriptional termination on lambda tI.

The transcriptional terminator tI generates the 3'end of the integrase (int) gene transcript that is read from the lambda PI promoter in lambda phage. We have studied the factors that affect transcription termination in vitro and in vivo at the lambda tI terminator. In vitro transcriptional studies showed that tI is about 80% efficient in the presence of purified NusA protein, whereas it is only about 50% efficient in its absence. In vivo studies, where the readthrough transcript of lambda tI was measured by quantitative dot blot analysis, gave about 80% efficiency in wild-type strains, but only 60% in the nusA1 mutant strain at non-permissive temperatures. These results support the idea that termination at lambda tI in vivo involves interaction with the NusA factor.

Efficacy of a eutectic mixture of local anesthetics as a topical anesthetic in minor otologic procedures.

A eutectic mixture of local anesthetics (EMLA), prepared as a cream, is an oil-in-water emulsion of 2 anesthetic agents lidocaine and prilocaine. Several clinical applications of EMLA cream, its effectiveness as a topical anesthetic, and its safety profile have been previously reported. We report our experience with EMLA cream in 17 adult and 24 pediatric patients. We find EMLA to be the preferred anesthetic for performing minor outpatient otologic procedures in adults. We also find EMLA to be a safe, well-tolerated alternative to general anesthesia in some pediatric patients. Potential cost savings of EMLA cream during pediatric myringotomies in the clinic are also discussed.

Sinonasal mucosa-associated lymphoid tissue lymphoma.

Mucosa-associated lymphoid tissue (MALT) is a specialized form of lymphoid tissue that may be acquired at sites in response to chronic inflammation. Most low-grade, B-cell, non-Hodgkin lymphomas that occur at extranodal sites derive from acquired MALT. Confusing and overlapping terms have been used to describe these lymphomas, but immunohistochemical advances now allow more precise subtyping. Our review of the literature yielded only 2 previous reports of sinonasal MALT-derived lymphoma, and we report an additional case in a patient with a history of chronic sinusitis. Current developmental theories of MALT-derived lymphomas are discussed. In addition, we review the clinical, histologic, and immunophenotypic features of MALT-derived lymphomas.

Pediatric adenotonsillectomy for obstructive sleep apnea.

Forty-four children who underwent adenotonsillectomy for obstructive sleep apnea (OSA) were studied. The diagnosis was confirmed polysomnographically. Patients with other medical problems or complications of OSA were excluded. The overall complication rate was 32%. Significant airway complications occurred in 16%. Factors associated with development of statistically significant airway complications were acute airway compromise, age < 3 years, thin body habitus, and both oxygen (O2) desaturation and carbon dioxide (CO2) retention seen polysomnographically. Although many OSA patients can safely have outpatient adenotonsillectomy, perioperative monitoring of patients with these risk factors is needed.

Relation between age and head and neck cancer recurrence after surgery: a multivariate analysis.

Recent reports have described an increase in squamous cell carcinoma of the upper aerodigestive tract in young adults. As the preponderance of epidemiologic data exists for the population between 50 and 70 years of age, controversy has developed regarding the clinical course of head and neck cancer in youth. Some authors advocate more aggressive management, calling attention to the lack of "classic" predisposing factors and suggesting genetic disorders or immunodeficiency. Basic science researchers have reported greater DNA fragility, sensitivity to carcinogens, and altered immune responses in young patients with carcinoma. To further elucidate the clinical aspects of this controversy, we performed a retrospective review using multivariate analysis to determine factors that affect recurrence. After screening 820 charts, 155 patients were found who met strict entrance criteria to the study. The patients were separated into five age groups, and 16 clinical variables were collected on each patient. Cox proportional hazards modeling revealed no significantly higher likelihood of recurrence in the 15- to 39-year-old age group. The model did find that metastatic adenopathy was predictive of recurrence (p = 0.034). The overall model further suggested a trend toward higher relative risk of recurrence in the middle-aged groups (p = 0.0541). In our review of the English biomedical literature, this is the first study to directly compare the outcome of young head and neck cancer patients with that of old patients using multivariate analysis. Future research is indicated in developing precise outcome predictions according to TNM staging, aneuploidy status, and DNA fragility in young patients. Efforts at limiting carcinogen exposure should continue.

Ventricular dysphonia: a profile of 40 cases.

Ventricular dysphonia is a poorly understood disorder involving ventricular fold participation during phonation. A population of ventricular dysphonia patients was evaluated using phonatory function studies such as laryngovideostroboscopy, advanced acoustic analysis, and electroglottography to identify shared epidemiologic characteristics and to discuss possible neuromuscular mechanisms and causes. Forty patients with ventricular dysphonia were studied and epidemiologic, acoustic, and histologic data were analyzed. In almost all cases, the authors found abnormalities affecting the glottis caused by a related medical condition. The abnormalities included true vocal cord (TVC) aperiodicity in 100% of the patients, TVC asymmetry in 65%, a laryngeal mass or foreign body (usually Teflon) in 35%, TVC erythema or edema in 32.5%, and TVC bowing in 22.5%. Ventricular dysphonia seems to be primarily a compensatory mechanism for glottic dysfunction. Therapy is based on identifying and correcting the underlying abnormalities. Laryngovideostroboscopy is a particularly important tool in examining chronic dysphonia.