Methoprene-tolerant and Krüppel homolog 1 are actors of juvenile hormone-signaling controlling the development of male sexual behavior in the moth Agrotis ipsilon

In insects, juvenile hormone (JH) is critical for the orchestration of male reproductive maturation. For instance, in the male moth, Agrotis ipsilon, the behavioral response and the neuronal sensitivity within the primary olfactory centers, the antennal lobes (ALs), to the female-emitted sex pheromone increase with fertility during adulthood and the coordination between these events is governed by JH. However, the molecular basis of JH action in the development of sexual behavior remains largely unknown. Here, we show that the expression of the paralogous JH receptors, Methoprene-tolerant 1 and 2 (Met1, Met2) and of the JH-inducible transcription factor, Krüppel homolog 1 (Kr-h1) within ALs raised from the third day of adult life and this dynamic is correlated with increased behavioral responsiveness to sex pheromone. Met1-, Met2- and Kr-h1-depleted sexually mature males exhibited altered sex pheromone-guided orientation flight. Moreover, injection of JH-II into young males enhanced the behavioral response to sex pheromone with increased AL Met1, Met2 and Kr-h1 mRNA levels. By contrast, JH deficiency suppressed the behavioral response to sex pheromone coupled with reduced AL Met1, Met2 and Kr-h1 mRNA levels in allatectomized old males and these inhibitions were compensated by an injection of JH-II in operated males. Our results demonstrated that JH acts through Met-Kr-h1 signaling pathway operating in ALs, to promote the pheromone information processing and consequently the display of sexual behavior in synchronization with fertility to optimize male reproductive fitness. Thus, this study provides insights into the molecular mechanisms underlying the hormonal regulation of reproductive behavior in insects.

Neuroligin 1 expression is linked to plasticity of behavioral and neuronal responses to sex pheromone in the male moth Agrotis ipsilon

In the moth Agrotis ipsilon, the behavioral response of males to the female-emitted sex pheromone increases throughout adult life and following a prior exposure to sex pheromone, whereas it is temporally inhibited after the onset of mating. This behavioral flexibility is paralleled with changes in neuronal sensitivity to pheromone signal within the primary olfactory centers, the antennal lobes. In the present study, we tested the hypothesis that neuroligins, post-synaptic transmembrane proteins known to act as mediators of neuronal remodeling, are involved in the olfactory modulation in A. ipsilon males. We cloned a full-length cDNA encoding neuroligin 1, which is expressed predominantly in brain and especially in antennal lobes. The level of neuroligin 1 expression in antennal lobes gradually raised from day-2 until day-4 of adult life, as well as at 24 h, 48 h and 72 h following pre-exposure to sex pheromone, and the temporal dynamic of these changes correlated with increased sex pheromone responsiveness. By contrast, there was no significant variation in antennal lobe neuroligin 1 expression during the post-mating refractory period. Taken together, these results highlight that age- and odor experience-related increase in sex pheromone responsiveness is linked to the overexpression of neuroligin 1 in antennal lobes, thus suggesting a potential role played by this post-synaptic cell-adhesion molecule in mediating the plasticity of the central olfactory system in A. ipsilon.

Involvement of Methoprene-tolerant and Krüppel homolog 1 in juvenile hormone-signaling regulating the maturation of male accessory glands in the moth Agrotis ipsilon

Male accessory glands (MAGs) produce seminal fluid proteins that are essential for the fertility and also influence the reproductive physiology and behavior of mated females. In many insect species, and especially in the moth Agrotis ipsilon, juvenile hormone (JH) promotes the maturation of the MAGs but the underlying molecular mechanisms in this hormonal regulation are not yet well identified. Here, we examined the role of the JH receptor, Methoprene-tolerant (Met) and the JH-inducible transcription factor, Krüppel homolog 1 (Kr-h1) in transmitting the JH signal that upregulates the growth and synthetic activity of the MAGs in A. ipsilon. We cloned two full length cDNAs encoding Met1 and Met2 which are co-expressed with Kr-h1 in the MAGs where their expression levels increase with age in parallel with the length and protein content of the MAGs. RNAi-mediated knockdown of either Met1, Met2, or Kr-h1 resulted in reduced MAG length and protein amount. Moreover, injection of JH-II into newly emerged adult males induced the transcription of Met1, Met2 and Kr-h1 associated to an increase in the length and protein content of the MAGs. By contrast, JH deficiency decreased Met1, Met2 and Kr-h1 mRNA levels as well as the length and protein reserves of the MAGs of allatectomized old males and these declines were partly compensated by a combined injection of JH-II in operated males. Taken together, our results highlighted an involvement of the JH-Met-Kr-h1 signaling pathway in the development and secretory activity of the MAGs in A. ipsilon.

A critical role for Dop1-mediated dopaminergic signaling in the plasticity of behavioral and neuronal responses to sex pheromone in a moth

Most animal species, including insects, are able to modulate their responses to sexual chemosignals and this flexibility originates from the remodeling of olfactory areas under the influence of dopaminergic system. In the moth Agrotis ipsilon, the behavioral response of males to the female-emitted sex pheromone increases throughout adult life and after a prior exposure to pheromone signal and this change is accompanied by an increase in neuronal sensitivity within the primary olfactory centers, the antennal lobes (ALs). To identify the underlying neuromodulatory mechanisms, we examined whether this age- and experience-dependent olfactory plasticity is mediated by dopamine (DA) through the Dop1 receptor, an ortholog of the vertebrate D1-type dopamine receptors, which is positively coupled to adenylyl cyclase. We cloned A. ipsilon Dop1 (AiDop1) which is expressed predominantly in brain and especially in ALs and its knockdown induced decreased AL cAMP amounts and altered sex pheromone-orientated flight. The levels of DA, AiDop1 expression and cAMP in ALs increased from the third day of adult life and at 24h and 48h following pre-exposure to sex pheromone and the dynamic of these changes correlated with the increased responsiveness to sex pheromone. These results demonstrate that Dop1 is required for the display of male sexual behavior and that age- and experience-related neuronal and behavioral changes are sustained by DA-Dop1 signaling that operates within ALs probably through cAMP-dependent mechanisms in A. ipsilon. Thus, this study expands our understanding of the neuromodulatory mechanisms underlying olfactory plasticity, mechanisms that appear to be highly conserved between insects and mammals.

[The thin ALT perforator flap for oropharyngeal robotic-assisted reconstruction]

Since a few years, the transoral robotic surgery reduced the morbidity of oropharyngeal tumors excision. Large posterior tumors can now be removed without any scar visible on the face. In this context and to respect the thinness required for reconstructions at the junction of the upper aerodigestive tract, the free radial forearm flap still remains the solution of choice. However, if the transoral robotic surgery respects the anatomy and the aesthetics of patients at the visible and social area that represents the face, the forearm flap provides visible scars on the other region of social interaction that represents the upper limb. The aim of our work was to prove the feasibility and the benefits in terms of reducing sequelae when using a thin anterolateral perforator flap harvested above the plane of the superficial fascia. We present this new original method in detail and the advantages it offers to patients after surgery.

Paclitaxel plus carboplatin (PC) in patients with metastatic melanoma (MM): Experience in a single institution

e20019

Background: The number of agents active in patients with metastatic melanoma is limited and cure is not an objective for treatment at this stage, so that clinical benefit in these patients is the most important. The aim of the study was to evaluate the efficacy and safety of combination regimen consisting of paclitaxel and carboplatin as second-line chemotherapy, in patients with MM. Based on reports of responses to PC, 17 patients with MM was treated at the National Cancer Institute of Mexico. Methods: We evaluated retrospectively the combination of PC in patients with MM. Data regarding patient characteristics and outcomes were abstracted from medical records of NCI of Mexico from 01/05 to 12/08. The regimen was weekly paclitaxel (at a dose of 80 mg/m2) received on days 1, 8, and 15 of a 21-day cycle and carboplatin (AUC 5) on day 1. Response evaluation was using RECIST and toxicity was according to National Cancer Institute Common Toxicity Criteria. This study was approved by the hospital ethics committee. Results: Seventeen patients with MM were treated with PC. All patients were previously treated (and failed) with dacarbazine (DTIC). Sixteen were assessable for response with three cycles of chemotherapy and seventeen for toxicity. One patient was deemed to be ineligible because they presented severe hypersensitivity reaction to paclitaxel at beginning. Objective partial response were obtained in 4 patients (25%); 8 stable disease (50%) at least four months. No patient had a complete response to therapy. Progression disease was in 4 patients (25%). In 12 (75%) we noted clinical benefit. The median time to disease progression for the entire group was 4.2 months (range, 1–11 mos), with a median overall survival of 8.1 months (range, 5.6–10.5 mos). The toxicity grade 3 reported was thrombocytopenic in 2 patients (11%) and anemia in one patient (6%). Additional patients had reversible toxicities grade 3 including alopecia, nausea and fatigue; 2 of them presented moderate hypersensitivity reactions to paclitaxel. No toxic death was noted. Conclusions: The PC combination appears to be safety and well tolerated in second line chemotherapy in MM, however we need more patients to demonstrate a true clinical benefit, we outcomes are according with other clinical reports.

No significant financial relationships to disclose.

Heightened bronchial hyperresponsiveness in the absence of heightened atopy in children with current wheezing and low income status

BACKGROUND

Although global studies such as the International Study of Asthma and Allergies in Childhood (ISAAC) have provided valuable data on the prevalence of asthma in children in Latin America, there is little information on the relationship between asthma symptoms, pulmonary function, bronchial hyperresponsiveness (BHR) and atopy in the region.

METHODS

This study examined the relationship between self-reported wheezing in the past 12 months, pulmonary function, airway responsiveness and atopy in children from a low income population in a neighbourhood of Santiago, Chile. Two random samples (100 each) of children aged 13-14 years who participated in ISAAC phase I were selected according to whether or not they reported wheezing in the past 12 months. Spirometry, the methacholine bronchial challenge test and the prick test were performed in all individuals.

RESULTS

Children who reported current wheezing had significantly higher BHR to methacholine compared with those without wheezing (71.6% vs 52.6%; p = 0.007) and no significant difference was found in forced expiratory volume in 1 s (116.7 (12.3)% vs 120.3 (14.5%); p = 0.11). The prevalence of atopy was not significantly different between those children who reported wheezing compared with those who did not (44.2% vs 42.3%; p = 0.89). Multiple regression analysis showed that only BHR to methacholine (OR 2.72, 95% CI 1.25 to 4.13; p = 0.01) and maternal asthma (OR 3.1, 95% CI 1.2 to 8.3, p = 0.03) were significant risk factors for current wheezing.

CONCLUSIONS

Our results support previous findings suggesting that in adolescents from underprivileged populations, self-reported current wheezing is related to BHR but not to atopy.

Disinfection of sludge with high pathogenic content using silver and other compounds

A physicochemical sludge with high microbial content (10(2)-10(4) FPU/g TS bacteriophages, 10(6)-10(7) MPN/g TS faecal coliforms, 10(4) MPN/g TS Salmonella spp., 10(4) MPN/g TS Shigella spp., 10(3) MPN/g TS Pseudomonas aeruginosa, 10(2) MPN/g TS Vibrio cholerae, 10(2)-10(3) cysts/g TS Giardia sp., 10(2)-10(4) oocyts/g TS Cryptosporidium sp., 168-215 viable helminth ova/g TS) was disinfected using silver, silver-copper, and silver-copper plus a synergistic agent (SA). Twenty milligrams Ag/g TS inactivated 4.8 log of faecal coliforms in 1 h; however, 40 mg Ag/g TS are needed to reduce helminth ova viability from 84 to 38.4% in the same period of time. Combinations of Ag-Cu (60:600 mg Ag-Cu/g TS) and Ag-SA (60:24 mg Ag-SA/g TS) inactivated 7.8 log of faecal coliforms and around 90% of helminth ova in 60 min. To produce USEPA class A biosolids, 10:100:8 and 5:50:13.3 mg Ag-Cu-SA/gTS are needed. Bacterial regrowth was not observed for all conditions producing <1000 MPN/gTS faecal coliforms, suggesting a residual disinfection effect. Recommended doses to produce class A biosolids inactivated 2-4 log of bacteriophages, 4 log of Salmonella spp., 4 log of Shigella spp., 3 log of Pseudomonas aeruginosa, 2 log of Vibrio cholerae, 87-99.9% of Giardia sp., and 75-99.9% of Cryptosporidium sp.

Most humoral non-responders to hepatitis B vaccines develop HBV-specific cellular immune responses

About 10% of health care professionals vaccinated against hepatitis B virus (HBV) fail to develop protective antibodies. We tested the capacity of peripheral blood lymphocytes from 121 health care professionals, including 76 non-responders, to proliferate to four HBV vaccines, examined the proliferating cells' subset, production of IFN-gamma, IL-4 and IL-10, and for 22 subjects, the cytokine production genotype. Specific proliferative responses to at least one HBV antigen were noted in 75% humoral non-responders. These cells differed from the CD4+ strongly proliferating cells of responders. Non-responders frequently displayed a genotype of high TGF-beta and intermediate IL-10 secretion. Most humoral non-responders to HBV thus develop specific cellular immune responses, eventually liable to protect them against viral infection.

[Idiopathic membranous nephropathy associated with anti-calcineurin toxicity. Prognosis and other immunosuppressive treatments]

A 32-year-old male patient was admitted at our department presenting microhematuria and full nephrotic syndrome in April 1995. A percutaneous kidney biopsy showed a stage I-lI membranous nephropathy and an eight-week course with oral prednisone was initiated without response. Then, oral cyclosporine A (3.5 mg/kg/day) was given and after 5 weeks of treatment, remission of the nephrotic syndrome was observed but creatinine raised to 1.6 mg/dl, normalizing after reducing the dose of cyclosporine A. We discuss the settings, prognostic and therapeutic alternatives for idiopathic membranous nephropathy.

Glutamate activates PP125(FAK) through AMPA/kainate receptors in Bergmann glia

Glial glutamate receptors are likely to play a role in plasticity, learning, and memory and in a number of neuropathologies. An enhanced glutamate-dependent tyrosine phosphorylation has been detected in such processes. Using primary cultures of chick Bergmann glia cells and chick cerebellar slices, we addressed whether glial glutamate receptors can activate the nonreceptor tyrosine kinase pp125 focal adhesion kinase (pp125(FAK)). A dose- and time-dependent tyrosine phosphorylation of pp125(FAK) was found in both preparations upon glutamate treatment. This effect was mediated through alpha-amino-3-hydroxy-5-methyl-4-isoaxazolepropionate (AMPA)/kainate (KA) receptors, as shown by its inhibition by the specific antagonists 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7- sulfonamide (NBQX) and 6,7-dinitroquinoxaline-2,3-dione (DNQX) and the lack of effect of metabotropic agonists. FAK tyrosine phosphorylation was dependent on phosphatidylinositol 3-kinase activity. As expected, an increase in pp125(FAK) catalytic activity was found upon glutamate treatment. Immunprecipitation experiments demonstrated that FAK associates with ionotropic glutamate receptors. Taken together, these results suggest a role for glial glutamate receptors in cytoskeletal rearrengments and focal adhesion contact formation and provide new insight into the signaling transactions elicited by this neurotransmitter in glial cells.

Development of reverse transcription-PCR assays specific for detection of equine encephalitis viruses

Specific and sensitive reverse transcription-PCR (RT-PCR) assays were developed for the detection of eastern, western, and Venezuelan equine encephalitis viruses (EEE, WEE, and VEE, respectively). Tests for specificity included all known alphavirus species. The EEE-specific RT-PCR amplified a 464-bp region of the E2 gene exclusively from 10 different EEE strains from South and North America with a sensitivity of about 3,000 RNA molecules. In a subsequent nested PCR, the specificity was confirmed by the amplification of a 262-bp fragment, increasing the sensitivity of this assay to approximately 30 RNA molecules. The RT-PCR for WEE amplified a fragment of 354 bp from as few as 2,000 RNA molecules. Babanki virus, as well as Mucambo and Pixuna viruses (VEE subtypes IIIA and IV), were also amplified. However, the latter viruses showed slightly smaller fragments of about 290 and 310 bp, respectively. A subsequent seminested PCR amplified a 195-bp fragment only from the 10 tested strains of WEE from North and South America, rendering this assay virus specific and increasing its sensitivity to approximately 20 RNA molecules. Because the 12 VEE subtypes showed too much divergence in their 26S RNA nucleotide sequences to detect all of them by the use of nondegenerate primers, this assay was confined to the medically important and closely related VEE subtypes IAB, IC, ID, IE, and II. The RT-PCR-seminested PCR combination specifically amplified 342- and 194-bp fragments of the region covering the 6K gene in VEE. The sensitivity was 20 RNA molecules for subtype IAB virus and 70 RNA molecules for subtype IE virus. In addition to the subtypes mentioned above, three of the enzootic VEE (subtypes IIIB, IIIC, and IV) showed the specific amplicon in the seminested PCR. The practicability of the latter assay was tested with human sera gathered as part of the febrile illness surveillance in the Amazon River Basin of Peru near the city of Iquitos. All of the nine tested VEE-positive sera showed the expected 194-bp amplicon of the VEE-specific RT-PCR-seminested PCR.

A membrane form of brain L-glutamate decarboxylase: identification, isolation, and its relation to insulin-dependent mellitus

A membrane form of L-glutamate decarboxylase (GAD) was identified and purified to apparent homogeneity from hog brain. The purified GAD was established as an integral membrane protein by phase-partitioning assay, charge-shift electrophoresis, and chromatography on a hydrophobic interaction column. This membrane GAD has a native molecular mass of 96 +/- 5 kDa and is a homodimer of 48 +/- 3-kDa subunits. Immunoprecipitation and immunoblotting tests revealed the presence of antibodies against this membrane GAD in sera from patients with insulin-dependent diabetes mellitus. Since this form of GAD appears to be an integral membrane protein and is presumed to have extracellular domains exposed, it seems reasonable to suggest that membrane GAD is more likely than soluble GAD to be involved in the pathogenesis of insulin-dependent diabetes and related autoimmune disorders such as stiff-man syndrome.

Is sodium necessary for stimulus-secretion coupling in toad (Caudiverbera caudiverbera) adrenal chromaffin cells?

1. Chromaffin cells of the toad were used to investigate the effects of total replacement of extracellular Na+ by monovalent cations or sucrose on secretion of catecholamine (CA). 2. K+, Rb+ or Cs+ in place of Na+ produced an immediate secretory response, which are dependent on extracellular Ca2+ and it was blocked by Co2+. Li+ or choline+ did not affect basal secretion. 3. Isosmotic replacement of Na+ by sucrose caused CA secretion even in the absence of external Ca2+ or in the presence of Ca-channel blockers. 4. Tetraethylammonium decreased the extent of CA release produced by either K+ or Rb+. 5. The secretagogue effect of Na+/K+, Na+/Rb+ or Na+/Cs+ replacement could be explained by a depolarization of the cell membrane, which ultimately will cause Ca2+ influx through voltage-dependent Ca-channels. However, the present results indicate that Na+ may be sufficient but not necessary for CA secretion.

[Must acute carotid thrombosis be surgically treated? 1962-1973: long-term results]

A study of long-term results (mean follow-up: 10.6 years) in 22 patients operated on for acute carotid thrombosis between 1962 and 1973 is reported. In most instances, surgery was performed at the acute phase of a massive cerebrovascular occlusion, usually more than 8 hours after onset (10 cases). Five of these patients (22%) died in the postoperative period. Eight (35%) recovered without residual disease. In six, the condition improved, while it remained unchanged or worsened in three (14%). There were ten delayed deaths, including two from a recurrent cerebrovascular episode and four from cardiac disease. The actuarial survival curve does not differ from that of patients treated conservatively, with rates being 60% at five years, 36% at ten years and 28% at thirteen years. The quality of certain postoperative results suggests that surgical indications at the acute stage of carotid occlusion be reviewed. The study of thirty series from the literature (1 046 cases) shows a 17% mortality rate, while 50% of patients recover or improve. This mortality is significantly lower in recent statistics, under 10%: this improvement may be ascribable to more rigid surgical indications (delay under 6 hours, operation in variable neurologic deficiencies, early diagnosis by the Doppler procedure, better postoperative management). The authors conclude that surgical management of acute carotid thrombosis should no longer be systematically dismissed.