Occurrence of biopterin in the wings ofMorpho butterflies

A blue fluorescent compound was isolated fromMorpho butterfly wings. Based on thin layer chromatographic, UV and CD-spectrophotometric and HPLC analyses, the blue fluorescent compound was identified as L-erythro biopterin. Biopterin is a major component of blue fluorescent pteridines in bothM. sulkowskyi andM. adonis. Pterin and isoxanthopterin can also be detected as minor components in these species. This paper is the first to report the presence of biopterin in butterfly wings.     

基于STM32的太阳能跟踪系统设计

基于先进Codex—M3内核的微处理器STM32,结合双电机驱动器与高精度光敏传感器,研究并设计了一套高精度太阳能跟踪系统。该系统以实时时间为基准精确追踪太阳位置,以光敏传感器进行误差修正,利用STM32优越的PWM方式控制电机,实现太阳能接受效率的最大化。实验结果表明,系统工作稳定可靠,基本实现了对太阳的实时跟踪。     

Influence of castration and testosterone replacement on hypothalamic tyrosine hydroxylase activity in the rat.

Hypothalamic tyrosine hydroxylase (TH) activity of castrate rats is modulated by testosterone propionate (TP) in vivo. Kinetic studies revealed that both Vmax and Km were virtually unaltered for substrate tyrosine in the presence of an excess of DMPH4 cofactor. TP replacement to castrate rats increased the Km for added DMPH4 cofactor, while Vmax decreased. These results suggest that TP decreases TH activity of castrate rats by inhibiting the enzyme-reduced pteridine cofactor complex.     

Isolation in east Senegal of a yellow fever virus strain from a pool of Aedes belonging to the subgenus Diceromyia]

During an epidemiological survey of yellow fever in Eastern Senegal, one strain of yellow fever virus was isolated in December 1976 from wild Mosquitoes. This first isolate obtained in nature from Aedes subgenus Diceromyia shows the primordial part these vectors may have in the area studied. It corroborates the existence of a selvatic focus of yellow fever in this region. It also gives information on the transmission cycle in a dry area.     

Neurosensitive contacts and new kind of synapses in wall lizard (Lacerta muralis, Laurenti) pineal body]

The neurosensitive synapses between photoreceptor cells and nerve ganglion cells are numerous enough to constitute an additional argument for a photosensitive function of the pineal gland. A new type of synapse, observed between the secretory rudimentary photoreceptor cells and nerve ganglion cells presents a direct relation from cells showing an active secretory function to the central nervous system.     

A strain of amaril virus isolated from Aedes africanus in the Ivory Coast]

The yellow fever virus has been isolated from a pool of Aedes africanus caught on men in a region situated between forest and savannah near Touba, in the Ivory Coast. This isolation, occurring at an interepidemic period, proves for the first time in West Africa, the part played by this mosquito in the transmission of the yellow fever virus.     

Influence of castration and testosterone replacement on hypothalamic tyrosine hydroxylase activity in the rat

Summary Hypothalamic tyrosine hydroxylase (TH) activity of castrate rats is modulated by testosterone propionate (TP) in vivo. Kinetic studies revealed that bothV _max andK _m were virtually unaltered for substrate tyrosine in the presence of an excess of DMPH₄ cofactor. TP replacement to castrate rats increased theK _m for added DMPH₄ cofactor, whileV _max decreased. These results suggest that TP decreases TH activity of castrate rats by inhibiting the enzymereduced pteridine cofactor complex.     

A lens-like specialization for photic input in the pineal window of an Indian catfish,Heteropneustes fossilis

Summary An unusual lens-like structure is reported in the pineal window of the Indian nocturnal catfishHeteropneustes fossilis. This is the first report of its kind for the pineal window of fishes. This structure, coupled with a pineal fossa and a pineal window, forms a specialization that apparently serves to concentrate the photic input to the intracranially situated pineal organ. This structure may play a significant role in the photoneuroendocrine function of the photosensitive pineal under conditions of low light intensity, controlling the fish's circadian rhythmic activities.The work was financially supported by CSIR, New Delhi (sanction No. 38(693)/88/EMR-II dated May, 1988) which is thankfully acknowledged.     

Lesions in folic acid metabolism induced by primidone

Résumé Les auteurs ont étudié le mécanisme de la toxicité de la primidone (Mysoline) chez certains microorganismes. Ces recherches montrent que le métabolisme de l'acide folique est inhibé par le primidone et cela en trois étapes: (a) la réduction de l'acide folique en acide dihydrofolique, (b) le métabolisme des ptéridines nonconjugées et (c) la phosphorylation de la thymidine.

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This work was aided by grants from the National Vitamin Foundation, National Association for Mental Health, American Cancer Society, and U.S. Public Health Service. We thank Dr.Th. Robitcher, Ayerst Laboratories, New York, for aid and gifts of primidone and Dr.E. Patterson of the American Cyanamid Co., Pearl River, New York, for the gifts of unconjugated pteridine.     

The effect of photodynamic therapy on tumor angiogenesis

Photodynamic therapy (PDT), the activation of a photosensitive drug in tumor tissue with light of specific wavelength, has been used effectively to treat certain solid tumors. Though therapeutic responses are encouraging, PDT-mediated oxidative stress can act as an angiogenic switch that ultimately leads to neovascularization and tumor recurrence. This article explores the effect of PDT on angiogenesis in different tumor models. Overexpression of proangiogenic vascular endothelial growth factor, cyclooxygenase-2 and matrix metalloproteases has often been reported post-illumination. Recent clinical studies have demonstrated that inhibiting angiogenesis after chemotherapy and radiotherapy is an attractive and valuable approach to cancer treatment. In this review, we report the effective therapeutic strategy of combining angiogenesis inhibitors with PDT to control and treat tumors.     

Variations de salinité chez les anguilles. Modifications duQO2 et des teneurs en cations des tissues hépatiques et rénaux

Summary Respiratory and ionic contents (Na, K, Ca) measurements were performed on hepatic and renal tissues extracted from yellow eels or silver eels.The increase of hepatic O₂ uptake observed on yellow eels when kept in salt water may be the result of water balance disequilibrium.     

Role of a novel photopigment,melanopsin, in behavioral adaptation to light

Adaptation to changes in the ambient light is of critical importance to life. In mammals, three principal photoadaptation mechanisms depend on ocular photoreception and exhibit spectral sensitivity suggestive of the opsin class of photopigment(s). These include rapid adaptation of the visual system to the ambient light by pupil constriction, direct modulation of neuroendocrine function and entrainment of the circadian clock to the day:night cycle. Surprisingly, these processes can largely function independent of classical rod/cone photoreceptors, suggesting a novel opsin-based signaling mechanism. They appear to involve a recently discovered network of intrinsically photosensitive retinal ganglion cells that make direct or indirect axonal connections to brain centers regulating photoadaptive behaviors. The discovery of a novel opsin, melanopsin, in these cells has offered an exciting entry point to explore, at the molecular level, how mammals adapt to their light environment. There is now genetic proof of a principal role for melanopsin in all three major photoadaptation processes.     

Photoelectric properties of the ‘yellow strips’ of social wasps

Summary The yellow strips on the cuticle of social wasp workers become photoconductive following irradiation with light, the effect being perfectly reversible.     

Effect of light on variations in blood testosterone in the ram: demonstration of a photosensitive phase in diurnal rhythm]

6 groups each of 5 adult rams were subjected in light controlled pens to a pretreatment of normal variations in daylength during May and June. Then one group followed the normal daylength and the other five different "skeleton photoperiods" of 8 hrs of light per day consisting of: 7 hrs continuous light (7 L) + 1 hr light (1 L) situated at different times of the dark period (D) according to groups. Blood samples were taken once each week and hourly during one 24 hr period in June, July and September. Peripheral plasma testosterone measured by radio-immunoassay was used as an index of testicular activity. There was increase in the level of testosterone resuting from a rise in the number of peak release during the 24 hrs. In the different light treatments tested, only the treatment (7L+9D+1L)+7D) stimulated testosterone secretion with the pattern of testosterone of this group being similar to that of the control group. This indicates that there exists a photosensitive phase at 16 to 17 hrs after the beginning of the principal light (the subjective dawn).     

A simple method for observation of capillary nets in rat brain cortex.

By the authors' technic, the profiles of capillaries in rat brain cortex were clearly demonstrated. The capillaries formed complicated nets by sprouting of their finer branches and anastomosing with each other. Further, a kind of perivascular cells with yellow autofluorescent granules was distributed close to capillaries, arterioles or venules. The seemed to be a special form of macrophage in the brain cortex.     

A simple method for observation of capillary nets in rat brain cortex

Summary By the authors' technic, the profiles of capillaries in rat brain cortex were clearly demonstrated. The capillaries formed complicated nets by sprouting of their finer branches and anastomosing with each other. Further, a kind of perivascular cells with yellow autofluorescent granules was distributed close to capillaries, arterioles or venules. They seemed to be a special form of macrophage in the brain cortex.     

The effect of methyl jasmonate on lycopene and β-carotene accumulation in ripening red tomatoes

Cellular and Molecular Life Sciences - Methyl jasmonate at a concentration of 0.5% in lanolin paste was applied to detached mature green tomatoes cv. Venture. It caused the formation of a yellow...     

Isolation of the yellow fever virus from an egg-cluster and the larvae of the tick Amblyomma variegatum]

The yellow fever virus is isolated in natura from eggs of a Tick Amblyomma variegatum. It is then isolated from larvae issued from the same egg-cluster and also from blood of a monkey bitten by larvae of the same origin. It is reported that the same virus has been previously obtained from adults of the same species of Tick. An acarine appears for the first time as a sylvatic vector and reservoir (at least temporary) of yellow fever.     

Diurnal variation of hue discriminatory capability under artificial constant illumination

Diurnal variation of hue discriminatory capability under artificial constant illumination of 4000 lux was studied with 10 young female adults using the 100-hue test. There were conspicuous diurnal variations in the yellow-blue and red-green systems, with marked reductions of error score in the evening. However, observations of the blue, yellow, green and red systems separately disclosed that there existed clear diurnal rhythms in the blue and green systems, but not in the yellow and red systems. This suggests the existence of diurnal variation in function of the S and M cones responsible for the blue and green hue.