Effects of Juvenoids and Retinoic Acid on Development of Larvae and Nymphs in the Tick Ixodes ricinus L. (Acari,Ixodidae) and Regeneration of Haller's Organ during Metamorphosis

Larvae and nymphs of the tick Ixodes ricinus L. display similar reactions to analogs of the insect juvenile hormones (methoprene and pyriproxyfen), which induce at both stages juvenalization of the Haller's sense organ regenerates. Similar effects were also described for retinoic acid. Unlike juvenoids, retinoic acid can affect not only regeneration, but also normal development of the Haller's organ and cause changes corresponding to so-called regenerative induction. Amputation of the leg and treatment with retinoic acid do not affect the duration of larval or nymphal development, while juvenoids somewhat accelerate their development.     

A Comparison of Bone Mineral Density and Its Predictors in HIV-Infected and HIV-Uninfected Older Men

ObjectiveBone health in older individuals with HIV infection has not been well studied. This study aimed to compare bone mineral density (BMD), trabecular bone score (TBS), and bone markers between HIV-infected men and age- and body mass index (BMI)-matched HIV-uninfected men aged ≥60 years. We investigated the associations of risk factors related to fracture with BMD, TBS, and bone markers in HIV-infected men.MethodsThis cross-sectional study included 45 HIV-infected men receiving antiretroviral therapy and 42 HIV-uninfected men. Medical history, BMD and TBS measurements, and laboratory tests related to bone health were assessed in all the participants. HIV-related factors known to be associated with bone loss were assessed in the HIV-infected men.ResultsThe mean BMD, TBS, and osteopenia or osteoporosis prevalence were similar among the cases and controls. The HIV-infected men had significantly higher mean N-terminal propeptide of type 1 procollagen and C-terminal cross-linking telopeptide of type I collagen levels. Stepwise multiple linear regression analysis demonstrated that low BMI (lumbar spine, P = .015; femoral neck, P = .018; and total hip, P = .005), high C-terminal cross-linking telopeptide of type I collagen concentration (total hip, P = .042; and TBS, P = .010), and low vitamin D supplementation (TBS, P = .035) were independently associated with low BMD and TBS.ConclusionIn older HIV-infected men with a low fracture risk, the mean BMD and TBS were similar to those of the age- and BMI-matched controls. The mean bone marker levels were higher in the HIV group. Traditional risk factors for fracture, including low BMI, high C-terminal cross-linking telopeptide of type I collagen level, and low vitamin D supplementation, were significant predictors of low BMD and TBS.     

Hepatic DNAJB9 Drives Anabolic Biasing to Reduce Steatosis and Obesity

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Partial purification and characterization of locust allatotropin I

Methanol extracts of locust brains, corpora cardiaca (CC), and suboesophageal ganglia (SOG) were separated by gradient and/or isocratic reverse-phase high-performance liquid chromatography (HPLC) and allatotropic activity monitored in the eluted fractions. A major peak of activity, separated by isocratic separation with 12% 2-propanol, designated allatotropin I, exhibited identical retention times in the three tissue extracts. Doseresponse curves of allatotropin I indicate similar content in brain and CC-equivalents, whereas optic lobes, similarly separated by isocratic HPLC, contain only one-tenth of this amount of allatotropin. Allatotropin I is resistant to boiling and is susceptible to tryptic and chymotryptic digestion. Methanol extracts of thoracic muscle, Malpighian tubules, fat body or ovaries, similarly prepared and boiled, did not exhibit allatotropic activity at high doses of tissue equivalents.     

Effects of a juvenile hormone analogue on the eggs, post-embryonic development, metamorphosis and diapause induction of the Colorado potato beetle, Leptinotarsa decemlineata

The effect of a juvenile hormone analogue, S-71639, was tested on the eggs, four larval instars and adults of the Colorado potato beetle, Leptinotarsa decemlineata Say, by topical application or after treatment of the foodplant. The last larval instar is very sensitive to S-71639. Treatment of this instar delayed the onset of pupation and prevented adult emergence. Treated animals showed severe abnormalities, but they were not immediately killed at the doses used in this study. Treatment of larvae also interfered with the photoperiodic induction of diapause. Adults, kept under diapausing conditions, started to lay eggs after treatment with S-71639. The ovicidal effect of the compound was rather weak. The implications for practical use of S-71639 in control of the Colorado potato beetle are being discussed.

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Résumé L'effet d'un analogue de l'hormone juvénile, S-71639, a été testé sur les oeufs, les quatre stades larvaires et les adultes du doryphore, Leptinotarsa decemlineata Say, par application topique ou après traitement de la plante-hôte. Le dernier stade larvaire est très sensible au S-71639. Le traitement de ce stade retarde le début de la métamorphose et empêche l'émergence adulte. Les animaux traités montrent de graves anomalies, mais ne sont pas immédiatement tués par les doses utilisées dans cette étude. Le traitement des larves perturbe aussi l'induction photopériodique de la diapause. Les adultes placés dans des conditions de diapause, commencent à pondre après traitement au S-71639. L'effet ovicide de la substance est plutôt faible. Les implications pour l'utilisation pratique du S-71639 dans la lutte contre le doryphore sont discutées.

     

躯体和内脏传入冲动在大鼠束旁核内的会聚

在麻痹的大鼠上,分别刺激迷走神经、内脏大神经、坐骨神经、腓肠神经、睾丸和副睾,在对侧丘脑束旁核记录到了45个细胞的单位放电。根据诱发反应的潜伏期、时程和放电频谱分布的不同,可将他们分为五种类型,并且认为这些类型和刺激引起的感觉性质有关。在观察到的45单位中,29个的反应具有痛放电的特性,而且对躯体及内脏的传入冲动呈聚合性反应。其中2个单位只对内脏传入冲动产生反应。这项研究的结果表明,束旁核不仅是接受内脏传入的丘脑结构,而且也是一个整合内脏与躯体传入信息的中枢。