Tuberous sclerosis complex without tubers and subependymal nodules: a phenotype-genotype study.

Tuberous sclerosis complex (TSC) is caused by a mutation in the TSC1 or TSC2 genes. However, 15% of patients have no mutation identified. Tubers and subependymal nodules (SENs) are the typical brain lesions in TSC and are present in 90-95% of patients. The objective of this study is to characterize the specific genotype-phenotype of patients without these lesions. We analyzed the features of 11 patients without typical TSC neuroanatomic features. Ten had TSC1/TSC2 mutational analysis, which was negative. Clinically they had lesions thought to be of neural crest (NC) origin, such as hypomelanotic macules, facial angiofibromas, cardiac rhabdomyomas, angiomyolipomas, and lymphangioleiomyomatosis. We hypothesize that patients without tubers and SENs reflect mosaicism caused by a mutation in TSC1 or TSC2 in a NC cell during embryonic development. This may explain the negative results in TSC1 and TSC2 testing in DNA from peripheral leukocytes.

Biological activity of two juvenoids and two ecdysteroids against three stored product insects.

The insecticidal activity of juvenile hormone agonists methoprene and pyriproxyfen, and the ecdysone agonists RH-5849 and tebufenozide was evaluated against susceptible and actellic-resistant strains of Tribolium castaneum and susceptible strains of Rhyzopertha dominica and Sitophilus oryzae. Concentrations ranging from 0.1 to 20 ppm of the analogues were mixed in the food medium to which the tested insects were exposed. The results showed that all these compounds could affect the development of the tested species to differing extents but had no effect on the mortality of parental adults. The two JH analogues did not prolong the life span of R. dominica and S. oryzae, but very greatly extended that of T. castaneum. The extension led to the production of giant larvae and failure to pupate. Actellic-resistant strain of T. castaneum showed some cross-resistance to methoprene and pyriproxyfen, but not to RH-5849 and tebufenozide. Pyriproxyfen was the most effective compound among the four IGRs; a concentration of 0.1 ppm could completely inhibit the F(1) adult occurrence of both S- and R-strains of T. castaneum and its LC(90)s for controlling R. dominica and S. oryzae were 0.1 and 1.2 ppm, respectively. Methoprene was highly effective against R. dominica, but less active on S. oryzae. RH-5849 could achieve almost complete control of F(1) adults of T. castaneum and R. dominica at 10 ppm, but was less potent on S. oryzae. Tebufenozide appeared to be much less active on these three species compared with the other three compounds. The percentage reductions of F(1) adults for S- and R-strains of T. castaneum at a concentration of 20 ppm were 80 and 99%, respectively.

Juvenile hormone and juvenile hormone mimics inhibit proliferation in a lepidopteran imaginal disc cell line.

The action of juvenile hormone (JH) and JH mimics have been examined in vitro by utilizing the imaginal disc-derived cell line, IAL-PID2. We have discovered that the cell line was responsive to JH and a variety of JH mimics. The most consistent response obtained in our studies was inhibition of cell proliferation, in the absence of 20-hydroxyecdysone (20E), which characteristically reduces cell proliferation in its own right in this cell line. JH-I, JH-III, methoprene, fenoxycarb, and farnesol significantly inhibited cell proliferation after 3 days of exposure of the cells in vitro to each of the compounds. Linoleic acid controls had no effect on proliferation in the cultures. The cell proliferation assay demonstrates the JH responsiveness of this cell line, but the concentrations of JH required were high compared to the concentrations of 20E needed for inhibition of proliferation in these cells.

Fumigant toxicity of essential oils against four major stored-product insects.

The fumigant toxicity of 28 essential oils extracted from various spice and herb plants and some of their major constituents were assessed for adult coleopteransRhyzopertha dominica, Oryzaephilus surinamensis, Tribolium castaneum, andSitophilus oryzae. Three groups of active materials were distinguished: (1) The compounds terpinen 4-ol, 1,8-cineole, and the essential oils of three-lobed sage, sage, bay laurel, rosemary, and lavender were most active againstR. dominica; (2) The compounds linalool,α-terpineol, and carvacrol and the essential oils of oregano, basil, Syrian marjoram, and thyme were most active againstO. surinamensis; and (3) the compound 1,8-cineole and the essential oils anise and peppermint were active againstT. castaneum.

Synthesis of giant HnRNA in the epidermal cells of Calliphora and the role of the ring gland.

The appearance of giant HnRNA in the epidermal cells of Calliphora in the transition period from larva to pupa is ecdysone-dependent. In this specific stage of development, the initial increase of this RNA species occurs shortly after the appearance of a small peak of ecdysone. Another main peak of the hormone is a prerequisite for pupation. The removal of the ring gland, the source of ecdysone, prior to the appearance of the second peak of the hormone, was found to have no pronounced effect on HnRNA synthesis for at least 48 h after the operation. It is concluded that the larval pupal differentiation is a two-step process. Initially a gen activation occurs dependent on a low ecdysone titer. This is followed by a second final step of pupal cuticle synthesis and pupation, dependent on the presence of a high concentration of the hormone.

Giant RNA in insects. I. Differential changes during Calliphora development and the role of ecdysone.

The pattern of newly synthesized RNA in the epidermis cells of Calliphora during the larval life to the early pupal stage was analysed by electrophoretic separation of RNA extracts on polyacrylamide gels. During larval life, mainly rRNA was synthesized. The elevation of ecdysone concentration during the synthesis of the new larval cuticle resulted primarily in the stimulation of rRNA synthesis. In the transition period from larva to pupa, the principal RNA synthesized was rapidly labelled giant DNA-like RNA, with an average life span of 30 min. Prior to the change in RNA metabolism at this development stage, the synthesis of all classes of RNA was depressed. The initial increase in hnRNA synthesis occurs at the onset of the wandering stage, shortly after the appearance of a small peak of ecdysone and about two days prior to the main peak of hormone secretion and pupariation. During induced pupariation by ecdysterone, 1 h after hormone treatment, more label was observed in giant hnRNA followed by elevation of rRNA synthesis. Processing and maturation of rRNA also seemed to be stimulated.