Effects of size, sex and teneral resources on the resistance to hydric stress in the tephritid fruit fly Anastrepha ludens

Water availability is recognized as one of the most important factors in the distribution and activity of terrestrial organisms. In the case of insects, hydric stress imposes a major challenge for survival because of the small surface-area-to-volume ratio they exhibit. In general, stress resistance is expected to co-vary positively with size; however, this pattern can become obscured in insects that exhibit sexual size dimorphism, as sexes differ in size and/or shape and have dissimilar resource allocations. In the present study, we use an allometric-based approach to (i) assess the desiccation and starvation stress resistance of teneral Anastrepha ludens flies, (ii) disentangle the relationships between resistance, size and sex and (iii) examine the adult fly body differences in water and lipid contents before and after exposure to stress. After controlling for sexual size dimorphism, an allometric increase of resistance with overall size was observed for all stress-based treatments. The scaling exponents that define the proportion of increase resistance varied with size traits and with type and degree of hydric stress. In this allometric relationship, and also in the relationships between mass and wing length and between size and teneral resources, the sexes maintained similar scaling exponents but differed in the intercepts. Males were more resistant to stress than females; this competitive advantage is probably linked to greater amounts of teneral lipids and more water use during stress.

Evaluation of the Host Status of Mature Green Papayas 'Maradol' for the Mexican Fruit Fly (Diptera: Tephritidae)

The suitability of mature green 'Maradol' papaya as a host of Anastrepha ludens (Loew) was studied under field and laboratory conditions. Field tests were conducted on commercial-ripened and spot-ripened fruit in two orchards and during two seasons in the state of Chiapas. Fruits at exportation ripeness are in "commercial ripeness", while fruits that are harvested immediately preceding exportation ripeness are in "spot ripeness." The field tests consisted of forced infestation experiments that evaluated papayas at two ripeness stages: the commercial- or exportation-ripened fruit (green fruits with one or two yellow stripes) and fruit before exportation ripeness called "spot ripeness." These tests were conducted in two orchards and during two seasons in the state of Chiapas, Mexico. Laboratory trials were performed with commercial-ripened fruit only. Fruit from four different postharvest periods (3, 24, 48, and 72 h) were exposed to groups of gravid flies. No larvae emerged from the fruit that was collected in the field experiments. However, some larvae and several fertile flies were obtained from the commercial-ripened fruit 72 h postharvest but not 3, 24, and 48 h postharvest in the laboratory. The results of this study indicate that the commercially ripe fruits of papaya Maradol were resistant to or free from infestation of A. ludens flies under field conditions, though these fruits must be considered nonnatural, conditional host because they became infested in the laboratory.

Impact of perineural and lymphovascular invasion on oncological outcomes in rectal cancer treated with neoadjuvant chemoradiotherapy and surgery

BACKGROUND

The prognostic significance of perineural and/or lymphovascular invasion (PLVI) and its relationship with tumor regression grade (TRG) in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT) and surgery.

METHODS

A total of 324 patients with LARC were treated with CRT and operated on between January 1992 and June 2007. Tumors were graded using a quantitative 5-grade TRG classification and the presence of PLVI was histologically studied.

RESULTS

At a median follow-up of 79.0 months (range 3-250 months), a total of 80 patients (24.7%) relapsed. The observed 5- and 10-year overall survival (OS) was 83.2 and 74.9 %, respectively. The 5- and 10-year disease-free survival (DFS) was 75.1 and 71.4%, respectively. A significant correlation was found between the TRG and survival (log rank, p < 0.001). The 10-year OS was 32.7% for grade 1, 63.8% for grade 2, 75.0% for grade 3, 90.4% for grade 3+, and 96.0%,for grade 4. The 10-year DFS was 31.8% for grade 1, 58.6% for grade 2, 70.4% for grade 3, 88.4% for grade 3+, and 97.1% for grade 4. In patients with PLVI, the TRG had no impact on survival. When excluding patients with PLVI, the TRG was an independent prognostic factor for OS and DFS.

CONCLUSIONS

The presence of PLVI is a more powerful prognostic factor than TRG in LARC patients treated with neoadjuvant CRT followed by surgery. PLVI denotes an aggressive phenotype, suggesting that these patients may benefit from adjuvant systemic therapy.

Effect of multiple endogenous biological factors on the response of the tephritids Anastrepha ludens and Anastrepha obliqua (Diptera: Tephritidae) to multilure traps baited with BioLure or NuLure in mango orchards

The physiological state of an insect is likely the most important endogenous factor influencing resource-oriented behavior, and it varies considerably among individuals. Trials were conducted in mango orchards to study the effect of multiple endogenous biological factors on the response of two fly species, Anastrepha ludens (Loew) and Anastrepha obliqua Maquart (Diptera: Tephritidae), to BioLure and NuLure baits. The biological factors of the two fly species that were tested were the following: 1) fertility status-sterile (irradiated) and fertile flies; 2) two types of diets (only sugar and a 3:1 mixture of sugar and hydrolyzed yeast protein; 3) sex, and 4) two sexual maturity conditions (2-4- and 15-18-d-old flies, representing immature and sexually mature flies, respectively, and 2-4-d-old flies treated with methoprene as an artificially induced sexually state male condition). The laboratory-treated flies were released into three different mango orchards. The trials were conducted in four blocks per orchard using eight traps in each block (50:50 BioLure: NuLure). The traps were replaced every 2 d during the 12-d period and the flies per trap per day values were calculated. More protein-fed, fertile, female, immature, and A. obliqua flies were caught compared with the other flies tested. In addition, the traps baited with NuLure attracted more flies than those baited with BioLure. Interaction analyses indicated that the type of bait and the sexual maturity status were the most important factors affecting the responses of the flies. Our study demonstrated that lures attract only a small segment of the fly population, those that have a specific hunger for amino acids-immature flies-and those that were protein-starved. The implications for improved trapping system designs are discussed.

Susceptibility of 15 mango (Sapindales: Anacardiaceae) cultivars to the attack by Anastrepha ludens and Anastrepha obliqua (Diptera: Tephritidae) and the role of underdeveloped fruit as pest reservoirs: management implications

We evaluated the susceptibility of 15 mango cultivars to the attack of Anastrepha ludens (Loew) and Anastrepha obliqua (Macquart) (Diptera: Tephritidae), the main tephritid pests of this crop in Mexico. In a field experiment, bagged fruit-bearing branches were exposed to gravid females of both fly species. Infestation rates, developmental time, adult eclosion, and F1 adult longevity, fecundity, and fertility were recorded, ranking cultivars in terms of susceptibility to fly attack and development. We also compared the volatile profile in selected resistant and susceptible cultivars in search of possible correlations. In a second experiment, clutch size for A. ludens was determined in each cultivar. Infestation rates, developmental time, and F1 demographic parameters varied sharply among cultivars and between fly species for bagged fruit. Cultivars 'Vishi,' '74-82,' and 'Brooks' were most susceptible to A. ludens infestation while "Tommy,' 'Sensation,' and 'Ataulfo "niño"' (parthenocarpic fruit) were most susceptible to A. obliqua infestation. 'Edward,' 'Kent,' 'Brooks late,' 'Palmer, and 'Ataulfo' exhibited tolerance to attack of both fly species. Fruit of susceptible and resistant cultivars exhibited unique volatile profiles. Fly development and F1 adult demographic parameters varied significantly among cultivars. A. ludens females laid larger clutches in larger and harder fruit. We highlight the important role of Ataulfo "niño" as pest reservoir if fruit is left unharvested on trees. We discuss the possible use of highly resistant cultivars as trap crops or egg sinks.

[DIEP flap reconstruction after palliative curettage mastectomy in locally advanced breast cancer]

BACKGROUND

Curettage mastectomy is indicated as a palliative treatment in locally advanced breast cancer. We present our experience with the use of a DIEP flap reconstruction following extensive mastectomy.

METHODS

We report the case of a patient with very advanced local breast cancer that was subsidiary to aggressive palliative surgery after chemotherapy.

RESULTS

It was considered that the closure that could be performed with the latissimus dorsi muscle was unsuitable, therefore a DIEP flap was performed. The patient was discharged uneventfully.

CONCLUSION

The DIEP reconstruction offers great cutaneous extension. It can be a resource in highly selected cases of locally advanced breast cancer in which surgery becomes the main treatment.

Preliminary outcome of a treatment strategy based on perioperative chemotherapy and surgery in patients with locally advanced colon cancer

AIM

Preoperative chemotherapy followed by radical surgery is an attractive treatment for locally advanced colon cancer (LACC) given the promising results of this approach in other locally advanced tumours. The study evaluates the outcome and treatment-related complications of perioperative oxaliplatin- and capecitabine-based chemotherapy and surgery for clinical Stage III colon cancer.

METHOD

Twenty-two consecutive patients with a CT-staged LACC were included. All were staged at baseline and before surgery. Surgery-related complications and oncological outcome were determined.

RESULTS

Toxicity was manageable, with 19/22 patients completing the planned chemotherapy protocol. The median time from initial diagnosis to surgery was 65.5 days. The median time from the end of chemotherapy to surgery was 22 days. After neoadjuvant treatment, tumour reduction of 69.5% was observed by CT scan and a 59.9% decrease of SUVmax (standard uptake value) was achieved on positron emission tomography/CT. No progressive disease was reported during preoperative chemotherapy and surgery was performed in all 22 patients. Four patients developed postoperative complications. After a median postoperative follow-up of 14.4 months, the actuarial overall and disease-free survival rates were 100 and 90%.

CONCLUSION

Neoadjuvant chemotherapy followed by surgery and chemotherapy for LACC is safe without apparent increase of early and medium-term complications.

Exome sequencing detection of two untranslated GFPT1 mutations in a family with limb-girdle myasthenia

The term 'limb-girdle myasthenia' (LGM) was first used to describe three siblings with proximal limb weakness without oculobulbar involvement, but with EMG decrement and responsiveness to anticholinesterase medication. We report here that exome sequencing in the proband of this family revealed several sequence variations in genes linked to proximal limb weakness. However, the only mutations that cosegregated with disease were an intronic IVS7-8A>G mutation and the previously reported 3'-UTR c.*22C>A mutation in GFPT1, a gene linked to LGM. A minigene assay showed that IVS7-8A>G activates an alternative splice acceptor that results in retention of the last seven nucleotides of intron 7 and a frameshift leading to a termination codon 13 nucleotides downstream from the new splice site. An anconeus muscle biopsy revealed mild reduction of the axon terminal size and postsynaptic fold simplification. The amplitudes of miniature endplate potentials and quantal release were also diminished. The DNA of the mildly affected father of the proband showed only the intronic mutation along with sequence variations in other genes potentially relevant to LGM. Thus, this study performed in the family originally described with LGM showed two GFPT1 untranslated mutations, which may cause disease by reducing GFPT1 expression and ultimately impairing protein glycosylation.

Light conditions affect sexual performance in a lekking tephritid fruit fly

Sensory systems are very susceptible to early environment experience. Mating success depends on the transmission of information from the signaller to the receiver, which means that sensory biases caused by developmental environment are likely to affect sexual selection. We investigated the impact of the developmental visual environment (light spectrum) on male copulation behaviour and female preference in the lekking tephritid Anastrepha ludens. We reared flies in four different light spectrum conditions - red light, blue light, shaded light and darkness - during their first 16 days after emerging from pupae. We found that the light environment experienced during early adulthood affected mating frequency and, in some cases, the latency to copulate, but not copulation duration. Males exposed to any of the three light treatments (red, blue or shaded light) were more frequently chosen as mating partners than dark-reared males. Flies reared under dark conditions exhibited the lowest mating performance out of any of the rearing environments. Under field cage conditions, a slight assortative mating between blue- and red-light-reared flies was detected. Additionally, females reared in blue light and darkness mated less compared with females reared in red and shaded light. Our data demonstrate that male mating behaviour is flexible in response to light environment. The findings suggest that light spectrum only weakly affects the direction of sexual selection by female choice; however, dark rearing environments deeply affect mating success.

Congenital myasthenic syndrome associated with epidermolysis bullosa caused by homozygous mutations in PLEC1 and CHRNE

Mutations in the plectin gene (PLEC1) cause epidermolysis bullosa simplex (EBS), which may associate with muscular dystrophy (EBS-MD) or pyloric atresia (EBS-PA). The association of EBS with congenital myasthenic syndrome (CMS) is also suspected to result from PLEC1 mutations. We report here a consanguineous patient with EBS and CMS for whom mutational analysis of PLEC1 revealed a homozygous 36 nucleotide insertion (1506_1507ins36) that results in a reduced expression of PLEC1 mRNA and plectin in the patient muscle. In addition, mutational analysis of CHRNE revealed a homozygous 1293insG, which is a well-known low-expressor receptor mutation. A skin biopsy revealed signs of EBS, and an anconeus muscle biopsy showed signs of a mild myopathy. Endplate studies showed fragmentation of endplates, postsynaptic simplification, and large collections of thread-like mitochondria. Amplitudes of miniature endplate potentials were diminished, but the endplate quantal content was actually increased. The complex phenotype presented here results from mutations in two separate genes. While the skin manifestations are because of the PLEC1 mutation, footprints of mutations in PLEC1 and CHRNE are present at the neuromuscular junction of the patient indicating that abnormalities in both genes contribute to the CMS phenotype.

Effect of cold storage on larval and adult Anastrepha ludens (Diptera: Tephritidae) viability in commercially ripe, artificially infested Persea americana 'Hass'

Commercially ripe 'Hass' avocados, Persea americana Mill, artificially exposed to wild Anastrepha ludens (Loew) (Diptera: Tephritidae) females 24 h after harvest were placed in a cold storage facility to determine the effect of low temperature on larval survival and adult viability. Fruit were left for 3, 6, 9, and 12 d in a cold room at 5 degrees C followed by a 20-25-d period at ambient temperature to allow for larval development and pupation. Hass avocados and grapefruit, Citrus paradisi Macfadyen, maintained at ambient temperature served as controls. Overall, only 0.23% of the Hass avocados and 19.30% of the grapefruit were infested. The number of infested fruit increased with decreasing exposure time to cold. Puparia from cold-treated Hass avocados were significantly smaller than those stemming from cold-treated grapefruit. Hass avocados exposed for 12 d to 5 degrees C yielded no puparia, and those exposed for 6 and 9 d yielded 22 and two puparia, respectively, but no adults. Although Hass avocados exposed to cold temperature for 3 d yielded adults that reached sexual maturity (N = 16), females laid inviable eggs. Grapefruit exposed to cold for 12 d yielded normal-sized puparia (but no adults), whereas those exposed over 9 d yielded females able to lay viable eggs. We conclude that exposing fruit to cold storage after packing and during transport represents an effective risk-mitigating procedure in the highly improbable event that a gravid A. ludens female might lay eggs in a commercially ripe Hass avocado that had been left unprotected in a packinghouse.

Peutz-Jeghers syndrome and duodeno-jejunal adenocarcinoma--therapeutic implications

The Peutz-Jeghers syndrome (PJS) is an autosomal dominant hamartomatous poliposis describred in 1921. Hemminki in 1997 described the presence of LKB-1 mutation tumor-suppressor gen.The patients with PJS develop a higher cumulative incidence of gastrointestinal, pancreas and extraintestinal tumors, being occasion of a renew interest on hamartomatous polyposis syndromes regarding the clinical care, cancer surveillance treatment and long term follow-up.We report the case of a 38 years old male, diagnosed of PJS who developed a multiple adenocarcinoma in duodenum and yeyunum. Surgically treated and with a long-term free disease survival of 11 years represents the sixth case reported in the spanish literature of PJS associated with a gastrointestinal tumor.A critical review, molecular alterations and the established criteria of tumor screening and surveillance are reviewed.

Mutations in LAMB2 causing a severe form of synaptic congenital myasthenic syndrome

Background:

We describe a severe form of congenital myasthenic syndrome (CMS) associated with congenital nephrosis and ocular malformations caused by two truncating mutations in the gene encoding the laminin β2 subunit (LAMB2).

Methods and results:

Mutational analysis in the affected patient, who has a history of a serious untoward reaction to treatment with acetylcholinesterase inhibition, revealed two frame-shifting heteroallelic mutations, a maternally inherited 1478delG and a paternally inherited 4804delC. An anconeus muscle biopsy demonstrated a profound distortion of the architecture and function of the neuromuscular junction, which was strikingly similar to that seen in mice lacking laminin β2 subunit. The findings included: pronounced reduction of the axon terminal size with encasement of the nerve endings by Schwann cells, severe widening of the primary synaptic cleft and invasion of the synaptic space by the processes of Schwann cells, and moderate simplification of postsynaptic folds and intact expression of the endplate acetylcholinesterase. The endplate potential quantal content was notably reduced, while the frequencies and amplitudes of miniature endplate potentials were only moderately diminished and the decay phases of miniature endplate potentials were normal. Western blot analysis of muscle and kidney tissue and immunohistochemistry of kidney tissue showed no laminin β2 expression.

Conclusion:

This case, which represents a new type of synaptic CMS, exemplifies the wide variability of phenotypes associated with LAMB2 mutations and underscores the fundamental role that laminin β2 plays in the development of the human neuromuscular junction.

Structure and function of the nicotinic arm of acetylcholine regulatory axis in human leukemic T cells

Although acetylcholine (ACh) is widely known as a neurotransmitter, it also functions as a local humoral factor translating environmental stimuli into alterations in T cell development and function. The cholinergic components present in neurons are expressed in T cells where they constitute an independent cholinergic system. Both non-immunologic and immunologic stimulations can alter expression and function of cholinergic elements in T cells. Recent studies have convincingly demonstrated regulation of immune system by auto/paracrine ACh, which provides a basis for development of new immunomodulatory therapies with nicotinic agonists. The purpose of our research is to integrate information about the structure and activity of the ACh regulatory axis with the phenotypic and functional alterations of T cells during their development and commitment. In this study, we used the Ach producing human leukemic T cell line CCRF-CEM (CEM) to investigate auto/paracrine mechanisms of T cell regulation through the nicotinic class of ACh receptors (nAChRs). The intact CEM expressed alpha3, alpha5, alpha6, alpha7, alpha 9, beta2 and beta4 nAChR subunits. Stimulation of CEM with 10 microg/ml of phytohemagglutinin (PHA) for 16 h upregulated expression of the alpha3, alpha5, alpha7, alpha9 and beta2 and downregulated that of alpha6 and beta4 subunits, indicating that TCR activation leads to overexpression of high Ca2+-permeable ACh-gated ion channels. Activation of alpha7- and alpha3 AChRs predominantly abrogated PHA-dependent upregulation of the pro-inflammatory cytokine TNF-alpha and IFN-gamma receptors, respectively, at the mRNA and protein levels. Signaling through alpha7 and alpha3 nAChRs also significantly (p<0.05) altered expression of the cell state regulators p21 and Bcl-2, respectively, suggesting that downregulation of inflammation via nAChRs includes effects on the T cell cycle progression and apoptosis. These findings indicate that constant stimulation of alpha7 and alpha3 nAChRs by endogenously released ACh controls T cell activation and that signaling downstream of distinct nAChR subtypes targets specific inflammatory and cell cycle genes. Learning the cholinergic pharmacology of inflammation should allow to regulate specific types of immune reactions by selectively activating or blocking the types of nAChRs expressed by the immune cells mediating specific immune reactions.

There is no magic fruit fly trap: multiple biological factors influence the response of adult Anastrepha ludens and Anastrepha obliqua (Diptera: Tephritidae) individuals to MultiLure traps baited with BioLure or NuLure

Field-cage experiments were performed to determine the effectiveness of MultiLure traps (Better World MFG Inc., Fresno, CA) baited with NuLure (Miller Chemical and Fertilizer Corp., Hanover, PA) or BioLure (Suterra LLC, Inc., Bend, OR) in capturing individually marked Mexican fruit fly, Anastrepha ludens (Loew), and West Indian fruit fly, Anastrepha obliqua (Macquart) (Diptera: Tephritidae), of both sexes. Experimental treatments involved wild and laboratory-reared flies of varying ages (2-4 and 15-18 d) and dietary histories (sugar only, open fruit, open fruit plus chicken feces, and hydrolyzed protein mixed with sugar). Data were divided into two parts: total captures over a 24-h period and trap visits/landings, entrances into interior of trap ,and effective captures (i.e., drowning in liquid bait or water) over a 5-h detailed observation period (0600-1100 hours). The response to the two baits varied by fly species, gender, physiological state, age, and strain. Importantly, there were several highly significant interactions among these factors, underlining the complex nature of the response. The two baits differed in attractiveness for A. obliqua but not A. ludens. The effect of strain (wild versus laboratory flies) was significant for A. ludens but not A. obliqua. For effect of dietary history, adults of both species, irrespective of sex, were significantly less responsive to both baits when fed on a mixture of protein and sugar when compared with adults fed the other diets. Finally, we confirmed previous observations indicating that McPhail-type traps are quite inefficient. Considering the total 24-h fly tenure in the cage, and independent of bait treatment and fly type (i.e., strain, adult diet, gender and age), of a total of 2,880 A. obliqua and 2,880 A. ludens adults released into the field cages over the entire study (15 replicates), only 564 (19.6%) and 174 (6%) individuals, respectively, were effectively caught. When only considering the 5-h detailed observation period and independent of bait treatment and fly type, of a total of 785 marked flies that landed on traps (519 females and 266 males, respectively), only 10.3% (144 females and 59 males) and 20.8% (25 females and 18 males) A. obliqua and A. ludens individuals, respectively, ended up being effectively captured. We discuss the practical implications of these findings with respect to developing new baits and designing new traps and to the interpretation of capture results in the field.

[Medical students' knowledge of cardiovascular risk factors]

OBJECTIVES

To evaluate cardiovascular risk factor awareness among medical students at the University of Navarra.

MATERIAL AND METHODS

A descriptive cross-sectional study including 334 students of the 1st, 4th and 6th year. They answered an anonymous structured questionnaire, and the results were analyzed using SPSS 11.0.

RESULTS

Most 4th and 6th year students correctly identified the cardiovascular risk factors (CVRF). The 4th year students obtained better results on lipid values while the 6th year students performed better on body mass index and arterial hypertension. 97.8% of the sample considered the Mediterranean diet to be a protective factor.

CONCLUSION

University of Navarra's medical students are well informed about CVRF and their knowledge increases along the degree course.