Rehydration before wet fixation in conventional body fluid cytology - An 18-year experience.

PURPOSE: In conventional cytology, preparation of a specimen by wet fixation for Papanicolaou stain is potentially subject to dry effect or cell loss which may make cytologic interpretation difficult or even impossible. We have been routinely making an additional smear for rehydration with normal saline (rehydration method) before wet fixation to overcome the above shortcomings. METHODS: We reviewed malignant pleural effusion and ascites 15 cases each in our cytology laboratory over the past 1 year. Four slides of each specimen were made. Two were air-dried for Liu's stain (a Romanowsky stain) and the other two were wet-fixed for Papanicolaou stain. The air-dried smears were also served as retained cellularity control. One of the two wet-fixed smears was processed as a control of preservation of nuclear detail whereas the other one stayed air-dried for 10 minutes and then covered with normal saline (rehydration method) for 80 seconds before wet fixation. RESULTS: There was minor cell loss (P = .032). The cells appeared larger with good preservation of nuclear detail (P < .0001 by two-sided Wilcoxon rank sum test) but no red blood cells retained on the slide after rehydration. CONCLUSION: The rehydration method can effectively minimise cell loss, enlarge and preserve the cytological features of malignant cells with haemolysis. This method is simple, practical and good for cytological screening for tumour cells and interpretation especially in a bloody smear. We recommend that the rehydration method be part of traditional cytopreparatory work of wet fixation for Papanicolaou stain in conventional body fluid cytology.

Lysophosphatidic acid stimulates calcium transients in enteric glia.

The enteric nervous system plays an integral role in the gastrointestinal tract. Within this intricate network, enteric glia are crucial in the maintenance of normal bowel function, yet their signaling mechanisms are poorly understood. Enteric glia, and not enteric neurons, selectively responded to lysophosphatidic acid (LPA), a product of phosphatidylcholine metabolism, with dose-dependent calcium (Ca(2+)) signaling over a range from 100 pM to 10 microM. The elicited calcium transients involved both the mobilization of intracellular Ca(2+) stores and the influx of extracellular Ca(2+) as LPA signals were obliterated following the depletion of intracellular Ca(2+) and attenuated by the removal of Ca(2+) from the perfusion buffer. Pretreatment with pertussis toxin (100 ng/ml) reduced the magnitude of LPA Ca(2+) transients (95+/-20 nM vs 168+/-17 nM for controls). Repetitive exposure yielded diminished responsiveness, with a 25% reduction in [Ca(2+)](i) between first and second exposures. Inhibition of the inositol 1,4,5-trisphosphate (IP(3)) receptor with 200 microM 2-aminoethoxydiphenylborate (2APB) abolished LPA signals. RT-PCR analysis demonstrated the presence of two LPA-coupled endothelial differentiation gene (EDG) receptor mRNAs (EDG-2 and EDG-7) in myenteric plexus primary cultures. EDG-2 expression in glial cells of the ENS was confirmed immunocytochemically.

Retinal degeneration but not obesity is observed in null mutants of the tubby-like protein 1 gene.

The tub gene is a member of a small, well conserved neuronal gene family of unknown function. Mutations within this gene lead to early-onset blindness and deafness, as well as late-onset obesity and insulin resistance. To test the hypothesis that mutations within other members of this gene family would lead to similar phenotypes as observed in tubby mice, and hence have similar functional properties, we have generated null mutants of the tubby-like protein ( Tulp ) 1 gene by homologous recombination. Similarly to tubby mice, Tulp1 (-/-)mice exhibit an early-onset retinal degeneration with a progressive, rapid loss of photoreceptors, further supporting the notion that previously identified mutations within the human TULP1 gene are indeed causative of retinitis pigmentosa. However, in contrast to tubby mice, Tulp1 (-/-)mice exhibited normal hearing ability and, surprisingly, normal body weight despite the fact that both TUB and TULP1 are expressed in the same neurons within the hypothalamus in areas known to be involved in feeding behavior and energy homeo stasis. However, TUB and TULP1 show a distinctly different staining pattern in the nucleus of these neurons, perhaps explaining the difference in body weight between the Tulp1 (-/-)and tubby mutant mice.

Differential distribution of intercellular adhesion molecules (ICAM-1, ICAM-2, and ICAM-3) and the MS-1 antigen in normal and diseased human synovia. Their possible pathogenetic and clinical significance in rheumatoid arthritis.

OBJECTIVE: Cellular adhesion and differentiation molecules (CAMs) may play a role in the recruitment and retention of inflammatory cells into rheumatoid arthritis synovial tissue (RA ST). In order to determine if certain CAMs are up-regulated in RA ST compared with normal ST, we studied the distribution of intercellular adhesion molecules (ICAMs) 1, 2, and 3 in ST. We also studied the MS-1 antigen since it is preferentially expressed on discontinuous endothelia, such as those found in RA ST; MS-1 is also expressed differentially upon cytokine activation of cells in vitro or in pathologic conditions in situ. Thus, we postulated a possible similarity between MS-1 and ICAM-1 expression in inflamed ST. METHODS: Immunohistochemical analysis was used to determine the distribution of ICAMs and MS-1 in ST from 10 patients with RA, 10 with osteoarthritis (OA), and 4 normal individuals. RESULTS: ICAM-1 expression was found on significantly more RA ST endothelial cells compared with normal cells, as well as on RA ST macrophages and lining cells. ICAM-2, also found on endothelial cells, showed no differential staining pattern. ICAM-3 was present on RA ST macrophages and lining cells as well as on some RA and OA endothelial cells. The MS-1 antigen was present on most RA and OA ST endothelia, lining cells, and macrophages. ICAM-1 expression and MS-1 expression in the lining layer were positively correlated in both RA and OA. CONCLUSION: ICAM-1, while found mainly on endothelial cells, is up-regulated on RA ST macrophages and lining cells, suggesting a role for these cells in the infiltration and tissue damage seen in the RA ST: ICAM-3, which is present mainly on normal resting leukocytes but not on normal endothelium, is expressed by some diseased ST leukocytes and endothelial cells. MS-1 is also found on the RA ST specialized, fenestrated endothelium, on macrophages, and in the lining layer. These results suggest that the differential expression of ICAMs and MS-1 in RA ST compared with normal ST might play a special role in the pathogenesis of RA.