We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Among the offspring of humans and other animals are occasional individuals that are malformed in whole or in part. The most grossly abnormal of these have been referred to from ancient times as monsters, because their birth was thought to foretell doom; the less severely affected are usually known as anomalies. This volume digs deeply into the cellular and molecular processes of embryonic development that go awry in such exceptional situations. It focuses on the physical mechanisms of how genes instruct cells to build anatomy, as well as the underlying forces of evolution that shaped these mechanisms over eons of geologic time. The narrative is framed in a historical perspective that should help students trying to make sense of these complex subjects. Each chapter is written in the style of a Sherlock Holmes story, starting with the clues and ending with a solution to the mystery.
The small volcanic island of Ascension is situated in the middle of the South Atlantic Ocean, more than 1500 km from the coast of Africa, its nearest continental area. To date, eight ‘opisthobranch’ species were reported from the island. As a result of a recent survey, 10 species were found. Seven species are new records from Ascension: Platydoris angustipes (Mörch, 1863), Diaulula sp., Dolabrifera dolabrifera (Rang, 1828), Aplysia parvula Guilding in Mörch, 1863 and Caliphylla mediterranea A. Costa, 1867, and two new species: Phidiana mimica sp. nov.; and Felimida atlantica sp. nov. Half of the species found have a wide geographical distribution, being not restricted to the Atlantic Ocean. However, traditional taxonomy based on few characters is probably masking complexes of species.
Waste from agricultural products represents a disposal liability, which needs to be addressed. Palm oil is the most widely traded edible oil globally, and its production generates 85 million tons of aqueous by-products annually. This aqueous stream is rich in phenolic antioxidants, which were investigated for their composition and potential in vitro biological activity. We have identified three isomers of caffeoylshikimic acid as major components of oil palm phenolics (OPP). The 2,2-diphenyl-1-picrylhydrazyl assay confirmed potent free radical scavenging activity. To test for possible cardioprotective effects of OPP, we carried out in vitro LDL oxidation studies as well as ex vivo aortic ring and mesenteric vascular bed relaxation measurements. We found that OPP inhibited the Cu-mediated oxidation of human LDL. OPP also promoted vascular relaxation in both isolated aortic rings and perfused mesenteric vascular beds pre-contracted with noradrenaline. To rule out developmental toxicity, we performed teratological studies on rats up to the third generation and did not find any congenital anomalies. Thus, these initial studies suggest that OPP is safe and may have a protective role against free radical damage, LDL oxidation and its attendant negative effects, as well as vascular constriction in mitigating atherosclerosis. Oil palm vegetation liquor thus represents a new source of phenolic bioactives.
An objective in current research on children with fetal alcohol spectrum disorders (FASD) is to determine neurobehavioral profiles to identify affected individuals. Deficits observed when children with FASD are compared to typically developing controls may be confounded by lower IQ scores in the subjects with FASD. To determine if prenatal alcohol exposure is associated with neurobehavioral deficits after controlling for IQ differences, multivariate analyses were conducted to compare alcohol-exposed (ALC) subjects to a comparison group closely matched on IQ (IQC). The initial analysis included a broad neuropsychological battery with measures of language, executive function, visual–motor integration, motor ability, and academic achievement. Additional, in depth comparisons focused on visual sustained attention, verbal learning and memory and parent/guardian-reported behavior problems. Group differences (ALC < IQC) were found on verbal learning and parent-rated behavior problems. Group differences were marginally significant (measures within the broad neuropsychological comparison) or not significant (visual attention, retention of verbal material) on the remaining comparisons. Therefore, some deficits (e.g., verbal learning and behavior problems) in children with heavy prenatal alcohol exposure cannot be explained by the lower FSIQ observed in the population. These areas of relative weakness could be useful in distinguishing children with FASD from other children with lowered IQ. (JINS, 2011, 17, 463–473)
Confocal microscopy allows for optical sectioning of tissues, thus
obviating the need for physical sectioning and subsequent registration
to obtain a three-dimensional representation of tissue architecture.
However, practicalities such as tissue opacity, light penetration, and
detector sensitivity have usually limited the available depth of
imaging to 200 μm. With the emergence of newer, more powerful
systems, we attempted to push these limits to those dictated by the
working distance of the objective. We used whole-mount
immunohistochemical staining followed by clearing with benzyl
alcohol-benzyl benzoate (BABB) to visualize three-dimensional
myocardial architecture. Confocal imaging of entire chick embryonic
hearts up to a depth of 1.5 mm with voxel dimensions of 3 μm was
achieved with a 10× dry objective. For the purpose of screening
for congenital heart defects, we used endocardial painting with
fluorescently labeled poly-L-lysine and imaged BABB-cleared hearts with
a 5× objective up to a depth of 2 mm. Two-photon imaging of
whole-mount specimens stained with Hoechst nuclear dye produced clear
images all the way through stage 29 hearts without significant signal
attenuation. Thus, currently available systems allow confocal imaging
of fixed samples to previously unattainable depths, the current
limiting factors being objective working distance, antibody
penetration, specimen autofluorescence, and incomplete clearing.
Retinoic acid, when administered to pregnant mice on d 11·0 of gestation, causes limb skeletal abnormalities consisting of reduced digital number, shortening of the long bones and delayed ossification. We show here that these effects are correlated with a decrease in cell proliferation within 5 h of retinoic acid administration, specifically in the posterior half of the distal limb bud mesenchyme, from which the distal skeletal elements are generated. There is a specific downregulation of Fgf4, a gene known to be involved in limb bud outgrowth and expressed only in the posterior part of the apical ectodermal ridge; Fgf8, which is expressed throughout the apical ectodermal ridge, is unaffected. The reduction in Fgf4 expression is not accompanied by downregulation of Shh, nor of its receptor and downstream target gene Ptc, suggesting that the skeletal reduction defects induced by retinoic acid are mediated specifically by FGF4-induced skeletogenic mesenchymal cell proliferation.
Ce travail donne une série de caractères morphométriques de cinq espèces de lumbriculides très communes dans les rivières du Nord de la Péninsule Ibérique. On y décrit une nouvelle variation du système reproducteur de Lumbriculus variegatus, des phénomènes tératologiques chez Stylodrilus heringianus et S. lemani, ainsi que la nouvelle sous-espèce Trichodrilus strandi campoyi.
There is abundant evidence of injury, teratology and pathological conditions in trilobites although it is commonly difficult to distinguish between their morphological results. Many injuries were probably sustained during moulting, with spines, bilamellar fringes and narrow gaps between dorsal exoskeleton and doublure being most vulnerable. Some injuries were the result of predaceous attack and provide important clues to the trophic structure of Palaeozoic communities. Many injuries show evidence of repair. Some supposedly teratological conditions, most notably the number of paradoxidid thoracic segments, are so common that they must be considered part of normal variation. Others represent genetic mutation or ontogenetic malfunction, the latter possibly externally induced. Undoubted pathological conditions are restricted to swellings and borings presumably caused by parasitic infestation.
Abnormalities affecting lateral areas are more common than those involving the rachis and glabella and this probably reflects both greater mortality when the axial region is involved, and greater vulnerability of peripheral regions to predaceous and moulting damage. The first explanation also accounts for the rarity of cephalic abnormalities compared to those of the pygidium.
Purified suspensions of macerated cuticular lesions from the insectary-reared tsetse Glossina morsitans morsitans were applied on laboratory-reared newly emerged teneral tsetse by three pathways: topical application on the ventral abdominal integument, oral microfeeding, or microinjection into the haemocoel. A second group of flies were subjected to teratological wounding pin-stabs, forcep-pinch and shallow blade-slits, all in attempt to induce cuticular lesions. Samples of tsetse were examined every week for 11 weeks. Application of cuticular lesion suspensions did not result in lesion formation, but three types of lesions were formed due to physical damage induced artificially on the integument.
Total haemocyte counts (THCs) and differential haemocyte counts (DHCs) were also determined for tsetse with, and without, lesions. THCs were significantly higher (P < 0.01) in tsetse with cuticular lesions than in those without lesions. DHCs showed a high number of large spindle-shaped cells and thrombocytoids in the flies with lesions (P < 0.05).
Recommend this
Email your librarian or administrator to recommend adding this to your organisation's collection.