37405816
Cytoarchitecture of sensorimotor areas in the cat cerebral cortex.
The organization of multiple motor areas in the cerebral cortex has been investigated frequently in primates but rarely in nonprimate species. To compare sensorimotor areas in cats and primates, the cytoarchitecture of frontal and parietal areas of the cat cerebral cortex was described and mapped from coronal sections stained with cresyl violet or thionine. Multiple subdivisions of areas 4 and 6 were recognized; of these, the cytoarchitecture of area 4 gamma is similar to that of area 4 described in other carnivores and in primates and is characterized by giant pyramidal cells in multiple rows or clusters in lamina V. In other subdivisions of area 4 (4 delta, 4sfu, and 4fu), giant pyramidal cells are few or absent in lamina V, and these subdivisions resemble area 6 of primates. Area 6 of the cat cortex is heterogeneous, and differences in laminar appearance and size of pyramidal cells in lamina V distinguish its four subdivisions (6a alpha, 6a beta, 6a gamma, and 6iffu). The adjoining prefrontal areas are distinguishable from area 6 by the presence of a thin internal granular lamina (lamina IV) and the reduced size of pyramidal cells in lamina V. Laminae are poorly differentiated in the cingulate areas, where a rostral and caudal subdivision can be distinguished on the basis of the absence or presence of lamina IV. Area 3a is characterized by a thin lamina IV and is located between frontal agranular and parietal granular (well-defined lamina IV) fields (3b, 1, 2, 2pri, 5, and 7). Insular cortex can be subdivided into granular and agranular fields.
27083545
Ipsilateral cortical connections of area 6 in the cat cerebral cortex.
Many motor areas have been identified within cytoarchitectonic area 6 of the cerebral cortex in primates. To provide a better understanding of the motor functions of area 6 in the cat, the ipsilateral cortical connections of the different cytoarchitectonic subdivisions of area 6 (areas 6a alpha, 6a beta, 6a gamma, and 6iffu) were studied by the use of fluorescent retrograde tracers. Tracer injections, made in the forelimb and face regions of areas 6a alpha and 6a gamma, were guided by data from intracortical microstimulation (ICMS). ICMS did not evoke movements from areas 6a beta and 6iffu. Retrogradely labeled neurons were enumerated in cytoarchitectonically identified areas in the frontal and parietal lobes to show that the subdivisions of area 6 are strongly interconnected except for areas 6a gamma and 6a beta. There are considerable differences in the pattern of connections of the area 6 subdivisions with area 4 and with prefrontal, cingulate, and parietal cortices. Area 4 gamma projects strongly to area 6a gamma but not to the other subdivisions. Areas 4 delta, 4fu, and 4sfu project strongly to 6a alpha and 6iffu but relatively weakly to area 6a beta. Prefrontal areas project strongly to area 6a beta and 6iffu, moderately to 6a alpha, but weakly to area 6a gamma. Cingulate areas project strongly to area 6iffu and moderately to areas 6a alpha and 6a beta but do not project to area 6a gamma. Parietal projections from primary and second somatosensory cortex were directed to area 6a gamma, whereas areas 5, 7, and insula were found to project to all the subdivisions of area 6. These findings support earlier suggestions that secondary motor areas may be located in areas 6a alpha and 6a gamma (Ghosh [1997] J. Comp. Neurol. 380:191-214). Features of the pattern of cortical connections of area 6 common to the cat and primates suggest that their motor areas in the frontal lobe are organized in a similar manner.
22910060
Regenerative capability of upper and lower jaws in the newt.
The regenerating amphibian jaw represents an important model for studying pattern formation and the mechanisms underlying regeneration of facial structures. We have studied regeneration of upper and lower jaws in the urodele amphibian, Notophthalmus viridescens, using whole mount preparations stained for bone and cartilage, scanning electron microscopy and immunocytochemistry to further characterize these regenerating systems. In addition, we have investigated whether lower jaws of adults and larvae display similar regenerative ability. Although in adult animals the original shape of both the lower and upper jaws is rather faithfully reproduced following amputation, and the teeth and oral mucosa with its specialized sensory organs fully regenerate, significant differences in the regenerative ability of the various skeletal elements are observed. In fact, only tooth-bearing skeletal elements ossify, while the other elements of the regenerated skeleton remain cartilaginous for as long as 5 months after amputation. In contrast, a regenerated lower jaw in the larva is indistinguishable from an unamputated one at the same stage of development. Interestingly, regenerating adult jaws form directly bicuspid teeth, which are the type of teeth normally found in the adult, rather than the monocuspid teeth characteristic of larval jaws, indicating that jaw regeneration is not a recapitulation of development, in that an adult jaw blastema directly regenerates an adult jaw. Finally, we have studied the expression of tissue specific markers in normal and regenerating upper and lower jaws to establish whether the blastemal cells, which will form the missing part of the jaw, express any of these markers of the differentiated state, or are undifferentiated as suggested by their morphological appearance. Under our experimental conditions, no expression of markers of the differentiated state, such as those for muscle, cartilage and glands is detectable in early regenerates. On the contrary, the mesenchymal marker 22/31, whose expression in normal jaws is restricted to dermal fibroblasts and the dental pulp, is expressed in at least a half of the blastemal cells. The significance of these observations in relation to the origin of blastemal cells in the jaw will be discussed.
46313714
Interaction of trypsin with sodium dodecyl sulfate in aqueous medium: a conformational view.
The conformational behavior of a globular protein, trypsin has been studied in presence of an anionic surfactant, sodium dodecyl sulfate (SDS) in aqueous medium by different techniques, such as, viscometry, circular dichroism, fluorimetry, Fourier transform infra-red, UV-vis absorption, dynamic light scattering and nuclear magnetic resonance. The results indicate that the viscosity of the mixture increases above the critical micelle concentration of SDS micelle supporting an expansion of a protein coil in the cluster. The spectroscopic techniques show the change of the conformation, i.e., the change of the values of alpha-helicity, beta-sheet, and random-coil of trypsin in the presence of SDS, and ultimately unfolding of trypsin occurs due to strong electrostatic repulsion of micellar clusters of the protein-surfactant complexes.
31255336
Abnormal radiological features in a multiple myeloma patient: a case report and radiological review of myelomas.
Multiple myeloma is the prototype of malignant monoclonal gammopathies. The most common skeletal sites are pelvis, skull, spine, ribs and femoral and humeral shafts. The classic radiographic presentation of multiple myeloma is lytic skeletal lesions. Other types of presentation include sclerotic and porotic changes. Primary sclerotic manifestations are rare and occur in only 3% of cases. Although exceptional, multiple myeloma must be borne in mind in the presence of bone sclerosis. This report presents a patient with multiple myeloma with a sunburst/hair-on-end pattern on the radiograph and sclerotic skeletal lesions.
13237503
Linkage mapping of beta 2 EEG waves via non-parametric regression.
Parametric linkage methods for analyzing quantitative trait loci are sensitive to violations in trait distributional assumptions. Non-parametric methods are relatively more robust. In this article, we modify the non-parametric regression procedure proposed by Ghosh and Majumder [2000: Am J Hum Genet 66:1046-1061] to map Beta 2 EEG waves using genome-wide data generated in the COGA project. Significant linkage findings are obtained on chromosomes 1, 4, 5, and 15 with findings at multiple regions on chromosomes 4 and 15. We analyze the data both with and without incorporating alcoholism as a covariate. We also test for epistatic interactions between regions of the genome exhibiting significant linkage with the EEG phenotypes and find evidence of epistatic interactions between a region each on chromosome 1 and chromosome 4 with one region on chromosome 15. While regressing out the effect of alcoholism does not affect the linkage findings, the epistatic interactions become statistically insignificant.
35121171
Bioactive natural compounds for the treatment of gastrointestinal disorders.
Many healthy subjects and patients are taking natural bioactive products for the prevention and treatment of multiple conditions, including gastrointestinal disorders. Based on current evidence, the scientific validity of the use of many of these commercial compounds by the general public is severely limited, with quality control and regulatory issues continuing to be a concern. Nevertheless, there is sufficient preliminary data to warrant further research of these products in order to identify novel compounds for potential clinical use in addition to performing formal randomized controlled clinical trials of the commercial preparations.