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Microcephaly: general considerations and aids to nosology 总被引:2,自引:0,他引:2
Microcephaly is defined as an occipito-frontal head circumference (OFC) 2 or more standard deviations below the mean for age and sex using the new Roche et al. [Pediatrics 1987;79:706-712] charts, and corrected for parental OFC by the method of Weaver and Christian [J Pediatr 1980;96:990-994]. "Relative" microcephaly, i.e., a small head on a small child, may be associated with a much better intellectual prognosis than absolute microcephaly, although the average IQ of children with absolute microcephaly ascertained in a normal school system is normal when compared with that of appropriate control children. "Primary" microcephaly means an abnormal OFC at birth (corrected for gestational age and length), and "secondary" microcephaly a normal birth OFC with later, acquired microcephaly due to deceleration of brain growth reflecting infection, trauma, intoxication, metabolic disease, the Rett syndrome, or a true CNS degenerative disease. Some cases of syndromal microcephaly may be associated with normal intelligence including some "primordial dwarfs," children with Dubowitz syndrome, FAS, mild SC-Roberts syndrome, and an occasional Brachmann-de Lange individual. The nosology of (syndromal) microcephaly is extraordinarily complex and requires the assistance of special library resources and information retrieval expertise. At a minimum, it requires McKusick's Catalog of Mendelian Inheritance in Man (MIM); however, we find that our work is greatly enhanced by recently developed electronic databases such as MIM-online (OMIM), POSSUM, SYNDROME, and MEDLINE, as well. Three groups of syndromal and non-syndromal microcephaly are discussed selectively in order to illustrate the marvels of pleiotropy in human development and its abnormalities and the difficulties encountered in splitting and lumping entities with overlapping manifestations. 相似文献
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Biological pest control by means of beneficial organisms is for long part of agriculture and Integrated Pest Management (IPM). A new and efficient strategy to control the most common timber pest species in churches and museums, the furniture beetle Anobium punctatum (De Geer) (Coleoptera: Anobiidae), is based on the parasitoid wasp species Spathius exarator (Linnaeus) (Hymenoptera: Braconidae). Once this braconid wasp detects its host species beneath the surface, it pierces the wood with its ovipositor to lay one single egg onto the beetle larva. After hatching, the wasp larva feeds on the beetle larva thereby killing it. Afterwards, it pupates and emerges through a self-gnawed hole as an adult wasp. The tiny, 0.5-mm-wide exit hole can easily be distinguished from the 1- to 2-mm-wide exit hole of A. punctatum. Laboratory tests revealed that female wasps have an average life span of 85 days and produce a total of 24 offspring, when nutrition is provided. Between 2012 and 2019, braconid wasps were introduced into 54 different A. punctatum infested buildings. Treatment success was monitored by examining exit holes of new beetles and wasps thereby calculating corresponding parasitism rates. After the first year of treatment, parasitism rates were significantly higher with a mean value of 0.15 when compared to untreated objects with a natural parasitism and a mean value of 0.08 (n = 54). Following treatment of three objects over a period of eight years, parasitism rates continuously increased from 0.02 up to 0.31. In a church organ, which was treated during this period, the monitoring revealed a complete suppression of pest activity. These data prove that this biological method of pest control is an efficient, sustainable and non-toxic option to manage the common furniture beetle. 相似文献
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Owing to its lipophilic property, carbon tetrachloride (CCl4) is rapidly absorbed by both the liver and brain. We investigated the protective effects of crocin against brain damage caused by CCl4. Fifty rats were divided into five groups of ten: control, corn oil, crocin, CCl4 and CCl4 + crocin. CCl4 administration decreased glutathione (GSH) and total antioxidant status (TAS) levels, and catalase (CAT) activity, while significant increases were observed in malondialdehyde (MDA) and total oxidant status (TOS) levels and superoxide dismutase (SOD) activity. The cerebral cortex nuclear lamina developed a spongy appearance, neuronal degeneration was observed in the hippocampus, and heterochromatic and pyknotic neurons with increased cytoplasmic eosinophilia were observed in the hippocampus after CCl4 treatment. Because crocin exhibits strong antioxidant properties, crocin treatment increased GSH and TAS levels and CAT activities, and decreased MDA and TOS levels and SOD activity; significant improvements also were observed in histologic architecture. We found that crocin administration nearly eliminated CCl4 induced brain damage by preventing oxidative stress. 相似文献
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Terpstra AH Brandt CW Opitz R van Tol A von Duvillard SP Vosmeer H Beynen AC 《Laboratory animals》1999,33(1):68-70
We describe a procedure to secure a jugular vein catheter system at the dorsal nape of the neck in the hamster. An 8-cm piece of silicone tubing is connected with a 2.6 cm L-shaped metal tubing which is embedded in prosthetic material. The prosthetic material is placed underneath the neck skin of the hamster and keeps the metal end of the catheter system in a sturdy, upright position. 相似文献
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The high specificity in the recognition and specific binding of potassium ion by the depsipeptide valinomycin (VM) is exploited for its recognition and quantitation using both circular dichroism (CD) and optical rotation dispersion (ORD). The specific rotation of VM is comparably small (2.34 deg ml g(-1) cm(-1)), so that an 8 microM (= 8.89 mg ml(-1)) solution of VM in 95% ethanol rotates polarized light of Lambda = 426 nm passing a 2 cm cuvette by 0.076 degrees only. It is shown, however, that VM undergoes large changes in both ORD and CD on binding to potassium ion. VM, potassium ion and the anionic dye merocyanine 540 form a ternary complex (VM/K/MC) which displays an induced CD with a positive maximum at 488 nm and a negative maximum at 470 nm. The ternary complex also displays fluorescence that is weaker by about 30% when compared to that of the dye alone. The induced CD of the ternary complex is interpreted in terms of the large conformational change which VM is known to undergo on binding potassium ion, thereby forming the prerequisite for a van der Waals interaction between its outwardly directed lipophilic domains and the lipophilic domains of the anionic dye. The method is likely to be applicable to the fluorescent detection of all kinds of ions for which chiral receptors are known, e.g. in studies on the role of ions in biological systems including ion channels. 相似文献
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13C NMR analysis demonstrated incorporation of two 13C labelled phenylalanine units into phenylphenalenones and phenylbenzoisochromenones co-occurring in Wachendorfia thyrsiflora. These results suggest oxidative formation of phenylbenzoisochromenones following a late branching from a common phenylphenalenone biosynthetic pathway. A dioxygenase-type mechanism, followed by decarboxylation, is suggested for the key steps of this conversion. 相似文献
10.
Digilio MC Marino B Giannotti A Dallapiccola B Opitz JM 《Birth defects research. Part A, Clinical and molecular teratology》2003,67(3):149-153