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At least 1,279 records · Page 71Linked to original sources
PubMed1981

Effects of ovarian steroids on serotonin metabolism within grossly dissected and microdissected brain regions of the ovariectomized rat.

Brain serotonin (5-HT) levels and accumulation rate within the dorsal raphe nucleus (DR) were elevated in ovariectomized (OVX) rats after ovarian steroid treatment, which consisted of estradiol benzoate (EB) followed by progesterone (P) 48 hr later. Some animals were also given the monoamine oxidase (MAO) inhibitor pargyline at designated times 10-40 min prior to sacrifice. Decapitation occurred 5 hr following the second steroid injection and 4-6 hr into the dark phase of a 14:10 light/dark cycle. Basal 5-HT levels and the rate of 5-HT accumulation (5-HTr) following MAO inhibition were estimated by radioenzymatic assay of brain tissue punched from frozen sections or dissected freehand. Within the DR, 5-HT levels and 5-HTr rates were respectively 13.8% (p less than 0.001) and 23.2% (p less than 0.025) higher in EB+P treated females compared with oil controls. Differences in basal 5-HT were found within the median raphe nucleus, but these were inconsistent from experiment to experiment. No differences were found in tissue immediately adjacent to these nuclear regions or within other brain regions including the ventral medial nucleus and suprachiasmatic nucleus of the hypothalamus. Increased levels of 5-HT were also found in grossly dissected tissue containing the mesencephalic raphe nuclei.

Amygdala↗
PubMed1998

Recurrent chromosomal imbalances detected in biopsy material from oral premalignant and malignant lesions by combined tissue microdissection, universal DNA amplification, and comparative genomic hybridization.

Biopsies routinely performed for the histopathological diagnosis of oral epithelial lesions before treatment were screened for chromosomal imbalances by comparative genomic hybridization. Comparative genomic hybridization was performed on 12 oral premalignant lesions (OPLs; dysplasias and carcinomas in situ) and 14 oral squamous cell carcinomas (OSCCs). Eight biopsies displayed areas of different histopathological appearance, so that OPLs and OSCCs from the same patient were analyzed. To avoid contamination with nonneoplastic cells, defined cell populations were isolated by micromanipulation with a glass needle. Before comparative genomic hybridization analysis, universal DNA amplification was performed using the DOP-polymerase chain reaction protocol. In the 14 OSCCs examined, the average number of chromosomal imbalances was significantly higher than in the 12 OPLs (mean +/- SEM: 11.9 +/- 1.9 versus 3.2 +/- 1.2; P = 0.003). The DNA copy number changes identified in more than one OPL were gains on 8q (3 of 12) and 16p (2 of 12), as well as losses on 3p (5 of 12); 5q (4 of 12); 13q (3 of 12); and 4q, 8p, and 9p (2 of 12 each). In more than 30% of OSCCs, gains of chromosomal material were identified on 20q (8 of 14); 8q, 11q, 22q (7 of 14 each); 3q, 15q, and 17p (6 of 14 each); and 14q, 17q, and 20p (5 of 14 each), and losses were identified on 3p and 4q (9 of 14 each), 5q (7 of 14), 13q (6 of 14), and 2q and 9p (5 of 14 each). These results were validated by positive and negative control comparative genomic hybridization experiments and microsatellite analysis for the detection of allelic loss. The vast majority of genomic alterations found in OPLs were again identified in OSCCs from the same biopsy, supporting the hypothesis that multiple lesions in the same patient are clonally related. In summary, we show that comprehensive information on the genomic alterations in oral epithelial lesions can be obtained from small biopsies. Such data may identify prognostic indicators that could eventually assist in designing therapeutic strategies.

Adult↗
PubMed1985

Superior resolution of gamma-crystallins from microdissected eye lens by cation-exchange high-performance liquid chromatography.

A novel procedure is presented for the rapid quantitative analysis of eye lens gamma-crystallins and beta s-crystallin by ion-exchange high-performance liquid chromatography on Synchropak CM300. At least six different gamma-crystallin gene products can be resolved from the soluble fraction of calf lens extract. This method is applicable to the analysis of microsections from individual lenses, and can be used to rapidly characterize spatial variations in gamma-crystallin composition which occur with aging and cataractogenesis.

Animals↗
PubMed2001

Modulation by acute stress of chloride permeation across microdissected vestibular neurons membranes: different results in two rabbit strains and CRF involvement.

Free hand isolation of adult rabbit vestibular Deiters' neurons and dissection of their single membranes allows the study of their ionic permeability characteristics in a microchambers device. In the case of hare-like rabbits, the dissection of such membranes presents evidence of a high basal permeation of labelled chloride, possibly related to mechanical disturbance of the plasma membrane-related cytoskeleton and activation of chloride channels. This did not apply to the laboratory strain of white New Zealand rabbits. However, membranes from hare-like rabbits which were stressed by being rotated on a platform before the experiment, behaved like those from the New Zealand strain. Vice versa, habituation to handling day after day of New Zealand rabbits resulted in a chloride permeation equal to that of unstressed hare-like rabbits. We propose that the stressful conditions result in the release of neurochemical messages to the vestibular Deiters' cells which influence their electrophysiological behavior. The corticotropin releasing factor (CRF), a stress-related peptide present in the climbing fibers, actually blocks the basal chloride permeation across the Deiters' membranes and this effect is partially reversed by its receptor antagonist, alpha-helical CRF [9-41].

Acute Disease↗
PubMed1984

Microdissection and radiographic studies of the arterial vasculature of the human testes.

Conflicting and sparsely detailed reports concerning the arterial vasculature of the testes prompted us to study 51 human cadaveric testicles radiographically in order to document any interarterial communications. Twelve specimens were harvested from the pediatric age group and 39 from adult cadavers. Vascular communication was demonstrated between the testicular, cremasteric, and vasal arteries in all specimens studied. Large-caliber anastomotic channels were demonstrated between the testicular and vasal arteries in 87% of specimens. No discernible differences in these vascular communications were documented among adult, pediatric, and undescended testes.

Adult↗
PubMed1998

Allelic deletion at chromosome 9p21(p16) and 17p13(p53) in microdissected sporadic dysplastic nevus.

A critical area of chromosomal loss at region p16(9p21-22) and p53(17p13) has been implicated in the genesis of malignant melanoma. It is still unclear whether the genetic alterations can be detected in dysplastic nevus, a premalignant lesion of malignant melanoma. We have searched the frequency of p16 and p53 deletion in nine dysplastic nevi and 13 benign intradermal nevi with five microsatellite markers. Hemizygous deletion was detected in seven of nine (78%) dysplastic nevi at one or more loci for p16 and three of seven (43%) for p53, respectively. No loss of heterozygosity (LOH) was detected in any of the benign intradermal nevi. All three dysplastic nevi with LOH for p53 also showed LOH at p16. However, not all dysplastic nevi showing p16 deletion showed p53 gene deletion. Therefore, these data suggest that deletion of p16 may play an important role in the development of dysplastic nevus as an early event and that the changes may represent an early event in the development of malignant melanoma.

Adolescent↗
PubMed2005

Microdissection of the sequence and structure of intermediate filament chains.

A large number of intermediate filament (IF) chains have now been sequenced. From these data, it has been possible to deduce the main elements of the secondary structure, especially those lying within the central rod domain of the molecule. These conclusions, allied to results obtained from crosslinking studies, have shown that at least four unique but related structures are adopted by the class of structures known generically as intermediate filaments: (1) epidermal and reduced trichocyte keratin; (2) oxidized trichocyte keratin; (3) desmin, vimentin, neurofilaments, and related Type III and IV proteins; and (4) lamin molecules. It would be expected that local differences in sequences of the proteins in these four groups would occur, and that this would ultimately relate to assembly. Site-directed mutagenesis and theoretical methods have now made it possible to investigate these ideas further. In particular, new data have been obtained that allow the role played by some individual amino acids or a short stretch of sequence to be determined. Among the observations catalogued here are the key residues involved in intra- and interchain ionic interactions, as well as those involved in stabilizing some modes of molecular aggregation; the structure and role of subdomains in the head and tail domains; the repeat sequences occurring along the length of the chain and their structural significance; trigger motifs in coiled-coil segments; and helix initiation and termination motifs that terminate the rod domain. Much more remains to be done, not least of which is gaining an increased understanding of the many subtle differences that exist between different IF chains at the sequence level.

Amino Acid Sequence↗