Stable histone deacetylase complexes distinguished by the presence of SANT domain proteins CoREST/kiaa0071 and Mta-L1

Human histone deacetylases I (HDAC1) and II (HDAC2) are homologous proteins (84% identity) that catalyze release of acetyl groups from modified N-terminal lysines of core histones. Histone deacetylation is correlated with both transient and persistent states of transcriptional inactivity (i.e. silencing) in many eukaryotes. In this study, we analyzed complexes containing HDAC1 and HDAC2 to identify the proteins most stably associated with these deacetylases. Complex cI (9.5 S) contained transcriptional corepressor CoREST/kiaa0071 and a protein homologous to FAD-dependent oxidoreductases, kiaa0601. Complex cII (15 S) contained >/=15 proteins, including CHD3/4 (Mi-2), Mta-L1, RbAp48/46, and MBD3, characteristic of vertebrate nucleosome-remodeling complexes. Under native conditions, cI and cII may contain HDAC1, HDAC2 or both; these can be dissociated to cI and cII core complexes containing only HDAC1 or HDAC2. The (m)CpG-binding protein MBD2 was associated only with the HDAC1 cII core complex. A model is proposed in which HDAC1 core complexes can be targeted to methylated DNA via MBD2 with recruitment of HDAC2 occurring through formation of HDAC1/2 cII dimers. We note that the cI component CoREST/kiaa0071 and the cII component Mta-L1 share a region of homology that includes a SANT domain; this domain may play a role in complex assembly.

Low-grade pulmonary myxoid sarcoma of uncertain histogenesis

The present report describes an unusual case of low-grade pulmonary sarcoma with extensive myxoid change in a 60-year-old man. During 30 months, the tumor enlarged gradually and thereafter rapidly to 9 cm. Preoperative biopsy and cytology gave negative results. The resected mass, located at the periphery of the right upper lobe, was well circumscribed and showed gelatinous without necrosis or hemorrhage. Histologically, the tumor was composed of slightly atypical, spindle-shaped or stellate cells, which were loosely distributed within a prominent myxoid stroma. Epithelial differentiation was not seen. Lacunar structures were occasionally evident, but no cartilaginous matrix was seen. Mitotic figures were infrequent. Immunohistochemistry failed to clarify the nature of the neoplastic cells except vimentin positivity. Histochemically, the myxoid ground substance was composed of hyaluronic acid and acid mucopolysaccharide. Electron microscopy revealed no specific differentiation other than aggregates of filaments, which were seen in a number of neoplastic cells. Flow cytometric analysis of the neoplastic cells revealed a diploid pattern. These findings indicated that the neoplasm was a low-grade myxoid sarcoma; however, a definite diagnosis could not be made. The tumor might have been a variant of extraskeletal myxoid chondrosarcoma, especially considering the histochemical results.

Chromophobe renal cell carcinoma with sarcomatoid change. A case report

Chromophobe renal cell carcinoma (RCC) is a newly established entity of renal neoplasm with histological and molecular biological features different from those of common RCCs. Chromophobe RCC shows characteristically cloudy and reticular cytoplasm and cellular features resembling distal nephron. Its prognosis has been reported to be more favorable than that of common RCCs. Recently, however, several cases have been reported which showed sarcomatoid change to present poor prognosis. Here we present a case of chromophobe RCC with sarcomatoid change which was once resected surgically. The surgically resected tumor was histologically composed of chromophobe epithelial cell sheets and sarcomatoid elements. The former showed positivity for colloid iron staining, and was immunohistochemically positive for E-cadherin and epithelial membrane antigen (EMA), whereas the latter was positive for vimentin instead of colloid iron and E-cadherin. EMA was focally positive in the sarcomatoid element. The patient died with systemic metastases 14 months after the operation. Histologically, the metastatic tumors were composed only of sarcomatoid element lacking epithelial element. Based on these findings and previous reports, this case supports the existence of a tumor progression pathway from chromophobe to sarcomatoid RCC. It is necessary to perform careful postoperative investigation of chromophobe RCC due to its possible histological progression to the sarcomatoid subtype.

PTEN/MMAC1/TEP1 mutations in human primary renal-cell carcinomas and renal carcinoma cell lines

Extensive allelotyping studies have implicated several tumor-suppressor loci on chromosomes 3p, 5q, 6q, 8p, 9pq, 10q, 11q, 14q, 17p, 18q and 19p in human kidney tumorigenesis. The PTEN (also called MMAC1 and TEP1) gene, a candidate tumor suppressor located at chromosome 10q23.3, is mutated in a variety of sporadic malignancies as well as in patients with Cowden disease. To investigate the potential role of the PTEN gene in renal tumorigenesis, we searched for abnormalities of the gene in 68 primary renal-cell carcinomas (RCCs) as well as in 17 renal carcinoma-derived cell lines, using DNA-SSCP, sequencing and microsatellite analysis. Five of 68 (7.5%) primary RCCs exhibited intragenic mutations (3 missense, 1 deletion and 1 splice-site), and 1 of 17 (5.9%) cell lines had an insertion mutation. Loss of heterozygosity of the PTEN gene occurred in 25% of primary RCCs, including the 3 cases with intragenic mutation and the 1 PTEN-mutated cell line. Clinical and histopathological examinations revealed that 4 of the 5 primary tumors with PTEN mutation were high-grade, advanced clear-cell RCCs with distant metastases or renal vein tumor invasions, resulting in poor prognostic courses. The other was a low-stage papillary/chromophilic RCC. Our data suggest that PTEN mutation is observed in a subset of RCCs and that, especially in clear-cell RCCs, it occurs as a late-stage event and may contribute to the invasive and/or metastatic tumor phenotype.

Endotoxin clearance and its relation to hepatic and renal disturbances in rats with liver cirrhosis

BACKGROUND/AIMS

Little is known about endotoxin clearance and secretion of cytokines from macrophages in liver cirrhosis. The aims of this study were to investigate the relationship of endotoxin clearance and release of tumor necrosis factor alpha by various macrophages to hepatic and renal disturbances in liver cirrhosis.

METHODS

Male Sprague-Dawley rats were given 0.04% thioacetamide orally for 6 or 12 months. The organ distribution of infused [3H]-endotoxin (10 microg/kg b.w.) was analyzed at 30 min or at 24 h. Uptake of [3H]-endotoxin and secretion of tumor necrosis factor alpha by Kupffer cells, splenic macrophages and peripheral blood monocytes (1 x 10(4) cells/ml) from cirrhotic and control rats were determined.

RESULTS

In cirrhotic rats, more endotoxin was left in the body and more endotoxin accumulated in the spleen and kidney, and thus was related to elevation of serum total bilirubin, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine and tumor necrosis factor alpha. Endotoxin uptake and tumor necrosis factor alpha release by the Kupffer cells were decreased and those by the splenic macrophages and peripheral blood monocytes were increased in cirrhotic rats.

CONCLUSIONS

In liver cirrhosis, impaired clearance of endotoxin together with increased secretion of tumor necrosis factor alpha by extrahepatic macrophages may play an important role in the progression of hepatic and renal disturbances.

Histone acetylases--versatile players

Genomic DNA in eukaryotes is tightly packed in the form of a highly ordered chromatin structure. In view of this tight packing, one of the most important questions in biology is how the transcriptional machinery regulates target genes in chromatin. Reversible modification of histones by acetylation is involved in transcriptional activation as well as repression in chromatin contexts. Recent studies with highly purified histone acetylases have provided insights into the mechanisms whereby acetylases contribute to transcriptional control. Furthermore, they suggest the possibility that histone acetylases could play roles in various forms of DNA metabolism as well as in transcription in chromatin contexts.

PTEN/MMAC1/TEP1 mutations in human primary renal-cell carcinomas and renal carcinoma cell lines

Extensive allelotyping studies have implicated several tumor-suppressor loci on chromosomes 3p, 5q, 6q, 8p, 9pq, 10q, 11q, 14q, 17p, 18q and 19p in human kidney tumorigenesis. The PTEN (also called MMAC1 and TEP1) gene, a candidate tumor suppressor located at chromosome 10q23.3, is mutated in a variety of sporadic malignancies as well as in patients with Cowden disease. To investigate the potential role of the PTEN gene in renal tumorigenesis, we searched for abnormalities of the gene in 68 primary renal-cell carcinomas (RCCs) as well as in 17 renal carcinoma-derived cell lines, using DNA-SSCP, sequencing and microsatellite analysis. Five of 68 (7.5%) primary RCCs exhibited intragenic mutations (3 missense, 1 deletion and 1 splice-site), and 1 of 17 (5.9%) cell lines had an insertion mutation. Loss of heterozygosity of the PTEN gene occurred in 25% of primary RCCs, including the 3 cases with intragenic mutation and the 1 PTEN-mutated cell line. Clinical and histopathological examinations revealed that 4 of the 5 primary tumors with PTEN mutation were high-grade, advanced clear-cell RCCs with distant metastases or renal vein tumor invasions, resulting in poor prognostic courses. The other was a low-stage papillary/chromophilic RCC. Our data suggest that PTEN mutation is observed in a subset of RCCs and that, especially in clear-cell RCCs, it occurs as a late-stage event and may contribute to the invasive and/or metastatic tumor phenotype.

Prognostic impact of plasma brain natriuretic peptide for cardiac events in elderly patients with congestive heart failure

BACKGROUND

Plasma brain natriuretic peptide (BNP) has been reported to be useful in determining the prognosis of patients with ischemic heart disease and cardiomyopathy. However, aging increases the level of plasma BNP; therefore, the prognostic impact of plasma BNP in elderly patients with congestive heart failure has not been fully established.

OBJECTIVE

We sought to determine whether plasma BNP could predict recurrent cardiac events in elderly patients with congestive heart failure.

METHODS

Forty-eight consecutive elderly patients (>65 years old) were enrolled in the present study. All patients were admitted with their first episode of congestive heart failure. Clinical characteristics, plasma BNP, left ventricular ejection fraction, and left ventricular mass index were compared between patients with and those without recurrent cardiac events.

RESULTS

During the follow-up period, twelve cardiac events were observed. The New York Heart Association functional class was signi- ficantly higher in patients with cardiac events than in those without (p < 0.05). The plasma BNP level in pa- tients with cardiac events was significantly higher than in those without (521.0 +/- 156.0 vs. 126.8 +/- 20.1 pg/ml, p<0.001), despite more frequent treatment with angiotensin-converting enzyme inhibitors (75 vs. 28%, p<0.05). The left ventricular ejection fraction was significantly lower and the left ventricular mass index higher in patients with cardiac events as compared with those without (38.1 +/- 5.0 vs. 49.2 +/- 2.4%, p < 0.05; 193.8 +/- 14.3 vs. 132.6 +/- 7.8 g/m(2), p < 0.001, respectively). The plasma BNP was selected as an independent factor associated with cardiac events besides New York Heart Association functional class, left ventricular ejection fraction, and left ventricular mass index using multivariate Cox proportional-hazards regression analysis (hazard ratio = 2.656, p<0.05). The cardiac event rate was significantly higher in patients with a plasma BNP concentration >132 pg/ml using Kaplan-Meier analysis (p < 0.001). Moreover, the plasma BNP level correlated inversely with the length of time from hospital discharge to a cardiac event (r = -0.575, p<0.05).

CONCLUSION

Measuring the plasma BNP level before hospital discharge in elderly patients with congestive heart failure was more useful than other conventional examinations for predicting the recurrence of cardiac events.

Augmented hepatocellular carcinoma progression and depressed Kupffer cell activity in rat cirrhotic livers

To examine the property of hepatocellular carcinoma (HCC), rat HCC cells were implanted into normal and cirrhotic rat livers. Implanted HCC grew much more progressively in cirrhotic livers than in normal livers. Kupffer cells were decreased profoundly in cirrhotic livers, resulting in markedly impaired phagocytic activity. Furthermore, production of Kupffer cell-related cytokines, such as interleukin-1 beta and tumor necrosis factor-alpha, was decreased profoundly in cirrhotic livers. Our results indicate that liver cirrhosis is a prominent promoting factor in HCC progression, and that markedly depressed Kupffer cell activity may play a role in augmented HCC progression in cirrhotic livers.

Hepatic adenomas treated with percutaneous ethanol injection in a patient with glycogen storage disease type Ia

We report a 20-year-old man with glycogen storage disease type Ia (GSD Ia) who presented multiple hepatocellular adenomas (HCAs) in 1993 and in whom percutaneous ethanol injection (PEI) was conducted as treatment for some enlarging tumors beneath the liver surface. In a 6-year follow-up period, we observed gradual enlargement of some of the HCAs, and the rapid growth of a newly developed tumor. In August 1996, one slow-growth HCA was 52 mm in diameter and was located beneath the surface of the liver. We conducted PEI therapy to prevent its spontaneous rupture. During the following year, another tumor developed beneath the liver surface, but showed extremely rapid growth, reaching 51 mm in diameter, from being undetectable, within 12 months. PEI therapy was again conducted for this newly developed tumor. Although additional PEI therapy was required for each tumor, because of suspected recurrence, no findings of discrete recurrence have been detected by computed tomography and magnetic resonance imaging for more than 2 years, up to the time of this study. We consider PEI to be a useful and effective therapeutic modality for individual HCAs in patients with GSD Ia.

[Factors leading to home care of patients in the terminal stage of malignant diseases--a study of 10 cases]

In order to clarify the factors that lead patients in the terminal stage of malignant diseases to home care, we interviewed ten families of such patients. Among factors involving patients, a strong desire to stay at home and to spend time at home with the family were initially required. Adequate understanding of the patients and their diseases was also needed by families. Other factors include guaranteed medical services in emergencies and/or 24 hours/day 7 days/week care. Patients requested referrals to family physicians, visiting nurses or community health services to cover outpatient clinic functions. It is concluded that a strong desire to stay at home, adequate understanding by the family and guaranteed medical services in emergencies were three significant factors leading to home care of patients in the terminal stage of malignant diseases.

Reminiscence therapy using odor in alcohol-dependent patients--psychophysiological evaluation and psychological evaluation; power spectral analysis of heart rate variability

OBJECTIVE

This research was based on the hypothesis that when alcohol-dependent patients describe themselves, awakening of emotion by affirmative odor stimulation may facilitate memory reframing focusing on more affirmative emotion and memories. To prove the hypothesis, physiological changes accompanied by emotional awakening were evaluated by measuring the autonomic activity. In addition, subjective evaluation by a self-report manner was examined to investigate the effectiveness of Reminiscence Therapy (RT) using odor in alcohol-dependent patients.

SUBJECTS

Thirty-four patients who met the DSM-IV criteria of alcohol-related disorders and were hospitalized in a ward specialized to alcohol dependence therapy.

METHODS

Each patient underwent a one-to-one interview twice. For counterbalance, one interview was performed with odor stimulation using an odor with a relaxing effect that recall pleasant emotion, and the other was without odor stimulation. As the evaluation indices of physiological changes accompanied by emotional awakening, index of autonomic function (HRV; Heart rate variability) for objective evaluation and psychological indices (STAI; State-Trait Anxiety Inventory VAS; Visual Analog Scale) for subjective evaluation were measured.

RESULTS

1) Objective evaluation: Regarding the evaluation index of the autonomic function, the sympathetic nervous system activity (LF/HF; low frequency component/high frequency component ratio) was significantly inhibited by odor stimulation (p < 0.05). 2) Subjective evaluation: Compared to the state prior to interview, state anxiety judged by STAI was significantly decreased after interview (p < 0.01). The VAS score was significantly decreased after interview regardless of the presence or absence of odor stimulation (p < 0.0001).

CONCLUSIONS

A reduction in state anxiety was observed. The effect of odor was not significant on the subjective evaluation, but the objective evaluation suggested that the odor inhibited the sympathetic nervous system. Thus, it was suggested that odor can be used in RT, that is, emotional changes due to stimulation of odor may be applicable in RT.

Cellular components that functionally interact with signaling phospholipase A(2)s

Accumulating evidence has suggested that cytosolic phospholipase A(2) (cPLA(2)) and several secretory PLA(2) (sPLA(2)) isozymes are signaling PLA(2)s that are functionally coupled with downstream cyclooxygenase (COX) isozymes for prostaglandin (PG) biosynthesis. Arachidonic acid (AA) released by cPLA(2) and sPLA(2)s is supplied to both COX-1 and COX-2 in the immediate, and predominantly to COX-2 in the delayed, PG-biosynthetic responses. Vimentin, an intermediate filament component, acts as a functional perinuclear adapter for cPLA(2), in which the C2 domain of cPLA(2) associates with the head domain of vimentin in a Ca(2+)-sensitive manner. The heparin-binding signaling sPLA(2)-IIA, IID and V bind the glycosylphosphatidylinositol-anchored heparan sulfate proteoglycan glypican, which plays a role in sorting of these isozymes into caveolae and perinuclear compartments. Phospholipid scramblase, which facilitates transbilayer movement of anionic phospholipids, renders the cellular membranes more susceptible to signaling sPLA(2)s. There is functional cooperation between cPLA(2) and signaling sPLA(2)s in that prior activation of cPLA(2) is required for the signaling sPLA(2)s to act properly. cPLA(2)-derived AA is oxidized by 12/15-lipoxygenase, the products of which not only augment the induction of sPLA(2) expression, but also cause membrane perturbation, leading to increased cellular susceptibility to the signaling sPLA(2)s. sPLA(2)-X, a heparin-non-binding sPLA(2) isozyme, is capable of releasing AA from intact cells in the absence of cofactors. This property is attributed to its ability to avidly hydrolyze zwitterionic phosphatidylcholine, a major phospholipid in the outer plasma membrane. sPLA(2)-V can also utilize this route in several cell types. Taken together, the AA-releasing function of sPLA(2)s depends on the presence of regulatory cofactors and interfacial binding to membrane phospholipids, which differ according to cell type, stimuli, secretory processes, and subcellular distributions.

Reduced expression of p27/Kip1 is associated with the development of pulmonary adenocarcinoma

p27/Kip1 (p27), a negative regulator of cell proliferation, is a powerful prognostic marker in non-small cell lung carcinoma. To clarify the significance of p27 aberrations in the tumourigenesis of lung adenocarcinoma, p27 expression was investigated by immunohistochemistry in lung adenocarcinoma and its precursor lesion, atypical adenomatous hyperplasia (AAH), and correlated with the expression of Ki-67, cyclin D1, and cyclin E. The p27 labelling index decreased in parallel with tumour progression (24.0% to 4.5%) and was found to be lower in neoplastic lesions than in normal bronchiolar epithelial cells (48.8%). There was a negative correlation between p27 and Ki-67 expression (rho=-0.384, p<0.001). Cyclin E-positive lesions (with labelling index >/=5%) were found only in overt adenocarcinomas. The Ki-67 labelling index of cyclin E-positive, high (>/=10%) p27 expressers was lower than that of cyclin E-positive, low (<10%) p27 expressers (16.8% vs. 42.6%; p=0. 046) and was similar to that of cyclin E-negative adenocarcinomas (15.0%). These results indicate that reduced p27 expression is associated with and may play a role in progression during the development of pulmonary adenocarcinoma.

QT dispersion is increased in diabetic patients with foot ulcer

QT dispersion, a measure of inhomogenous ventricular repolarization, was measured in diabetic patients with foot ulcer. We recruited 75 patients with non insulin-dependent diabetes mellitus: patients with neuropathic ulcer (n=15, NU group), with ischemic ulcer (n=20, IU group), with previous myocardial infarction (n=20, MI group) and without any diabetic microangiopathies (n=20, DC group). We also studied normal control subjects (n=15, NC group). The interlead variability of rate corrected QT interval (QTc dispersion) was calculated. QTc interval in the MI group was significantly higher than that in the NC or DC but showed no difference in the NU and IU groups. QTc dispersion in the IU (54+/-15 msec) as well as MI (60+/-21 msec) group were significantly higher than the NC (36+/-18 msec) or DC group (39+/-14 msec). This may be due to complicated coronary artery disease in the IU group. Furthermore, QTc dispersion was also increased (49+/-14 msec) in the NU group in which cardiac autonomic nervous dysfunction was suggested. Patients with both types of diabetic ulcer demonstrated increased QT dispersion due to atherosclerosis or neurological disorder.

Molecular identification of cytosolic prostaglandin E2 synthase that is functionally coupled with cyclooxygenase-1 in immediate prostaglandin E2 biosynthesis

Here we report the molecular identification of cytosolic glutathione (GSH)-dependent prostaglandin (PG) E(2) synthase (cPGES), a terminal enzyme of the cyclooxygenase (COX)-1-mediated PGE(2) biosynthetic pathway. GSH-dependent PGES activity in the cytosol of rat brains, but not of other tissues, increased 3-fold after lipopolysaccharide (LPS) challenge. Peptide microsequencing of purified enzyme revealed that it was identical to p23, which is reportedly the weakly bound component of the steroid hormone receptor/hsp90 complex. Recombinant p23 expressed in Escherichia coli and 293 cells exhibited all the features of PGES activity detected in rat brain cytosol. A tyrosine residue near the N terminus (Tyr(9)), which is known to be critical for the activity of cytosolic GSH S-transferases, was essential for PGES activity. The expression of cPGES/p23 was constitutive and was unaltered by proinflammatory stimuli in various cells and tissues, except that it was increased significantly in rat brain after LPS treatment. cPGES/p23 was functionally linked with COX-1 in marked preference to COX-2 to produce PGE(2) from exogenous and endogenous arachidonic acid, the latter being supplied by cytosolic phospholipase A(2) in the immediate response. Thus, functional coupling between COX-1 and cPGES/p23 may contribute to production of the PGE(2) that plays a role in maintenance of tissue homeostasis.

Regulation of prostaglandin E2 biosynthesis by inducible membrane-associated prostaglandin E2 synthase that acts in concert with cyclooxygenase-2

Here we report the molecular identification of membrane-bound glutathione (GSH)-dependent prostaglandin (PG) E(2) synthase (mPGES), a terminal enzyme of the cyclooxygenase (COX)-2-mediated PGE(2) biosynthetic pathway. The activity of mPGES was increased markedly in macrophages and osteoblasts following proinflammatory stimuli. cDNA for mouse and rat mPGESs encoded functional proteins that showed high homology with the human ortholog (microsomal glutathione S-transferase-like 1). mPGES expression was markedly induced by proinflammatory stimuli in various tissues and cells and was down-regulated by dexamethasone, accompanied by changes in COX-2 expression and delayed PGE(2) generation. Arg(110), a residue well conserved in the microsomal GSH S-transferase family, was essential for catalytic function. mPGES was functionally coupled with COX-2 in marked preference to COX-1, particularly when the supply of arachidonic acid was limited. Increased supply of arachidonic acid by explosive activation of cytosolic phospholipase A(2) allowed mPGES to be coupled with COX-1. mPGES colocalized with both COX isozymes in the perinuclear envelope. Moreover, cells stably cotransfected with COX-2 and mPGES grew faster, were highly aggregated, and exhibited aberrant morphology. Thus, COX-2 and mPGES are essential components for delayed PGE(2) biosynthesis, which may be linked to inflammation, fever, osteogenesis, and even cancer.

Distinct but overlapping roles of histone acetylase PCAF and of the closely related PCAF-B/GCN5 in mouse embryogenesis

PCAF plays a role in transcriptional activation, cell-cycle arrest, and cell differentiation in cultured cells. PCAF contributes to transcriptional activation by acetylating chromatin and transcription factors through its intrinsic histone acetylase activity. In this report, we present evidence for the in vivo function of PCAF and the closely related PCAF-B/GCN5. Mice lacking PCAF are developmentally normal without a distinct phenotype. In PCAF null-zygous mice, protein levels of PCAF-B/GCN5 are drastically elevated in lung and liver, where PCAF is abundantly expressed in wild-type mice, suggesting that PCAF-B/GCN5 functionally compensates for PCAF. In contrast, animals lacking PCAF-B/GCN5 die between days 9.5 and 11.5 of gestation. Normally, PCAF-B/GCN5 mRNA is expressed at high levels already by day 8, whereas PCAF mRNA is first detected on day 12.5, which may explain, in part, the distinct knockout phenotypes. These results provide evidence that PCAF and PCAF-B/GCN5 play distinct but functionally overlapping roles in embryogenesis.

Studies on a mechanism by which cytosolic phospholipase A2 regulates the expression and function of type IIA secretory phospholipase A2

Although it has been proposed that arachidonate release by several secretory phospholipase A2 (sPLA2) isozymes is modulated by cytosolic PLA2 (cPLA2), the cellular component(s) that intermediates between these two signaling PLA2s remains unknown. Here we provide evidence that 12- or 15-lipoxygenase (12/15-LOX), which lies downstream of cPLA2, plays a pivotal role in cytokine-induced gene expression and function of sPLA2-IIA. The sPLA2-IIA expression and associated PGE2 generation induced by cytokines in rat fibroblastic 3Y1 cells were markedly attenuated by antioxidants that possess 12/15-LOX inhibitory activity. 3Y1 cells expressed 12/15-LOX endogenously, and forcible overexpression of 12/15-LOX in these cells greatly enhanced cytokine-induced expression of sPLA2-IIA, with a concomitant increase in delayed PG generation. Moreover, studies using 293 cells stably transfected with sPLA2-IIA revealed that stimulus-dependent hydrolysis of membrane phospholipids by sPLA2-IIA was enhanced by overexpression of 12/15-LOX. These results indicate that the product(s) generated by the cPLA2-12/15-LOX pathway following cell activation may play two roles: enhancement of sPLA2-IIA gene expression and membrane sensitization that leads to accelerated sPLA2-IIA-mediated hydrolysis.

Giant vesicles from 72-membered macrocyclic archaeal phospholipid analogues: initiation of vesicle formation by molecular recognition between membrane components

Stereochemically pure archeal acyclic bola-amphiphilic diphosphates 4 and 5, with the basic structure of the phospholipids found in Sulfolobus, have been synthesized for the first time. The self-assembly properties have been compared with those of the nearly identical 72-membered macrocyclic tetraether phosphates 3a and 3b, analogues of the major phospholipid components of Sulfolobus, Thermoplasma, and methanogenic Archea, which were also synthesized. Phase contrast and fluorescence microscopies have shown that the dipolar lipids 1 and 2 spontaneously formed vesicles. Whereas the macrocyclic dipolar phosphates 3 spontaneously formed vesicles (phase contrast and fluorescence microscopies), the bolaform phosphate 4 gave only a lamellar structure (synchrotron diffraction pattern: repeat distance of about 4.25 nm but with only a few layers). However, upon addition of the unphosphorylated precursors phytanol, phytol, or geranylgeraniol to the acyclic lipids 4 and 5, giant vesicles were rapidly formed. Addition of n-hexadecanol or cholesterol did not lead to vesicle formation. Therefore it was concluded that this vesicle formation occurs only when the added molecule is closely compatible with the constituents of the lipid layer and can be inserted into the double layer. A slight mismatch (cholesterol or n-hexadecanol/polyprenyl chains) is therefore enough to block the insertion process presumably required for vesicle formation.

Interstitial pneumonia in Hermansky-Pudlak syndrome: significance of florid foamy swelling/degeneration (giant lamellar body degeneration) of type-2 pneumocytes

Although usual interstitial pneumonia (UIP)-like IP has been known as the most serious complication of Hermansky-Pudlak syndrome (HPS), its pathologic features and pathogenesis are poorly understood. We investigated biopsied and autopsied lung tissues from five patients who died of UIP-like IP associated with HPS (HPSIP). The salient histopathologic features of HPSIP observed were: (1) alveolar septa displaying florid proliferation of type-2 pneumocytes (2PCs) with characteristic foamy swelling/degeneration; (2) patchy fibrosis with lymphocytic and histiocytic infiltration centered around respiratory bronchioles, occasionally showing constrictive bronchiolitis; and (3) honeycomb change without predilection for the lower lobes or subpleural area. Those peculiar 2PCs were histochemically characterized by the over accumulation of phospholipid, immunohistochemically by a weak positivity for surfactant protein, and ultrastructurally by the presence of numerous giant lamellar bodies that compressed the nucleus with occasional cytoplasmic disruption, together suggesting a form of cellular degeneration with an over accumulation of surfactant (giant lamellar body degeneration). The present study strongly indicates that there is a basic defect in the formation/secretion process of surfactant by the 2PCs in HPS, which may well be the triggering factor for the HPSIP development. Other factors, such as macrophage dysfunction, may be working synergistically for further acceleration of the inflammatory process.

Reduced expression of p27/Kip1 is associated with the development of pulmonary adenocarcinoma

p27/Kip1 (p27), a negative regulator of cell proliferation, is a powerful prognostic marker in non-small cell lung carcinoma. To clarify the significance of p27 aberrations in the tumourigenesis of lung adenocarcinoma, p27 expression was investigated by immunohistochemistry in lung adenocarcinoma and its precursor lesion, atypical adenomatous hyperplasia (AAH), and correlated with the expression of Ki-67, cyclin D1, and cyclin E. The p27 labelling index decreased in parallel with tumour progression (24.0% to 4.5%) and was found to be lower in neoplastic lesions than in normal bronchiolar epithelial cells (48.8%). There was a negative correlation between p27 and Ki-67 expression (rho=-0.384, p<0.001). Cyclin E-positive lesions (with labelling index >/=5%) were found only in overt adenocarcinomas. The Ki-67 labelling index of cyclin E-positive, high (>/=10%) p27 expressers was lower than that of cyclin E-positive, low (<10%) p27 expressers (16.8% vs. 42.6%; p=0. 046) and was similar to that of cyclin E-negative adenocarcinomas (15.0%). These results indicate that reduced p27 expression is associated with and may play a role in progression during the development of pulmonary adenocarcinoma.

HMB-45/melan-A and smooth muscle actin-positive clear-cell epithelioid tumor arising in the ligamentum teres hepatis: additional example of clear cell 'sugar' tumors

HMB-45-positive clear-cell epithelioid tumor arising in the ligamentum teres hepatis of a 13-year-old Japanese girl is described. The well-defined tumor was completely removed and measured 9 x 7 x 6 cm. Cut sections showed a tan-white, homogeneous appearances with no hemorrhage or necrosis. The tumor was composed of nests or sheets of polygonal or oval-shaped cells rich in clear or finely granular cytoplasm. Capillary network was well developed, and sinusoid vessels were often seen with occasional perivascular hyalinization. There was moderate nuclear atypia but mitotic figures were absent. Periodic acid-Schiff stain showed a large amount of glycogen digested by diastase. Immunohistochemical stains for smooth muscle actin, Melan-A, and HMB-45 were positive in most of the tumor cells. Stains for vimentin, muscle actin, and HAM56 were focally positive, whereas stains for desmin, cytokeratin, epithelial membrane antigen, S-100, CD34, CD68, CD99, neurofilament proteins, and estrogen/progesterone receptors were negative. Ultrastructurally, the cytoplasm contained a considerable number of mitochondria, monoparticipate or membrane-bound glycogen, and longitudinally oriented thin filaments with focal condensations and subplasmalemmal densities. The histopathology of the present case, originally interpreted as epithelioid leiomyoma, was consistent with clear cell "sugar" tumors. The present case may indicate ubiquitous distribution of clear cell "sugar tumors" of which histogenesis remains unknown but is presumed to be of perivascular epithelioid cell origin.

[Dissociative disorders: from Janet to DSM-IV]

I reviewed the literature on dissociation and dissociative disorders from Pierre Janet to DSM-IV, and examined the current trends in research. Janet's theory on hysteria is multifaceted, and is based on three psychological models. Based on a hierarchical model, Janet related hysteric symptoms to the activities within the lower strata of mental hierarchy (automatisms psychologiques), which were demonstrably shown in somnambulism. A second model was based on the concept of a psychological system, which was hypothetically composed of ideas, images, feelings, sensations, and movements. According to this model, dissociation of psychological functions was fundamental to the mechanism of hysteria: loss of integration was thought to engender fixed ideas (ideas fixes) and to lead to the development of a system totally isolated from the whole personality system. Janet also attempted to explain various mental disorders using an economic model. He referred to a loss of equilibration between psychological force and psychological tension. Thus, an unexpected emotional experience was conceived to cause a consumption of reserved psychological force, which was in turn followed by exhaustion associated with hysteric symptoms. Whereas most current researchers regard Janet as the first to study psychological trauma as a principal cause of dissociation, I feel it is important to note that he also emphasized the role of stigmata, i.e., permanent traits of hysteric patients, which were represented as a suggestibility and a tendency toward a narrowing of the consciousness field. Discussion about dissociation and its relation to trauma all but disappeared after Janet. However, during the Second World War and post-war period, some psychiatrists began to pay attention to two emerging phenomena: a high incidence of dissociative symptoms such as fugue and amnesia among combatants, and traumatic neurosis frequently observed among ex-inmates of concentration camps. In the 1970s, interest in dissociation and trauma was revived in different areas: the feminism movement was linked with concerns about child sexual abuse, public curiosity about multiple personalities was heightened by novels and movies, and recognition of posttraumatic stress disorder (PTSD) among Vietnam War veterans. In 1980, dissociative disorders were finally adopted as a diagnostic category in the official nomenclature of DSM-III. Although current research on dissociation is being carried out in various fields, two basic assumptions, reflected in the definition of DSM-IV, can be made. One is the "trauma-genic hypothesis," and the other is the great importance attached to multiple personality disorder (MPD). According to the predominantly held view, dissociation represents a reaction to early traumatic experience, especially sexual and physical abuse in childhood. In contrast, some authors argue that the causality of childhood traumatic experience has not been empirically confirmed, and other factors such as the influence of the environment and the predisposition of patients should be taken into consideration. MPD, which was originally described as an unusual phenomenon in classical literature, is currently thought to be a common type of dissociation. However, the reported rapid increase in the number of MPD patients in North America may be partially due to over-diagnosis and inclusion of iatrogenic cases. Significance is also given to MPD in respect to classification of dissociative phenomena. According to the widely held scheme of a "dissociative continuum," which ranges from normal experiences such as daydreams to pathological states, MPD is placed at the extreme end of the continuum. Furthermore, most researchers tend to classify MPD as the severest dissociative disorder due to chronic trauma. On this point, there seems to be confusion about "extremity" and "severity" of MPD. I conclude that the trauma-genic hypothesis of dissociation and the overemphasis placed on MPD should be reexamin

Involvement of the TIP60 histone acetylase complex in DNA repair and apoptosis

It is well known that histone acetylases are important chromatin modifiers and that they play a central role in chromatin transcription. Here, we present evidence for novel roles of histone acetylases. The TIP60 histone acetylase purifies as a multimeric protein complex. Besides histone acetylase activity on chromatin, the TIP60 complex possesses ATPase, DNA helicase, and structural DNA binding activities. Ectopic expression of mutated TIP60 lacking histone acetylase activity results in cells with defective double-strand DNA break repair. Importantly, the resulting cells lose their apoptotic competence, suggesting a defect in the cells' ability to signal the existence of DNA damage to the apoptotic machinery. These results indicate that the histone acetylase TIP60-containing complex plays a role in DNA repair and apoptosis.

p300/CBP-associated factor histone acetyltransferase processing of a peptide substrate. Kinetic analysis of the catalytic mechanism

p300/CBP-associated factor (PCAF) is a histone acetyltransferase that plays an important role in the remodeling of chromatin and the regulation of gene expression. It has been shown to catalyze preferentially acetylation of the epsilon-amino group of lysine 14 in histone H3. In this study, the kinetic mechanism of PCAF was evaluated with a 20-amino acid peptide substrate derived from the amino terminus of histone H3 (H3-20) and recombinant bacterially expressed PCAF catalytic domain (PCAF(cat)). The enzymologic behavior of full-length PCAF and PCAF(cat) were shown to be similar. PCAF-catalyzed acetylation of the substrate H3-20 was shown to be specific for Lys-14, analogous to its behavior with the full-length histone H3 protein. Two-substrate kinetic analysis displayed an intersecting line pattern, consistent with a ternary complex mechanism for PCAF. The dead-end inhibitor analog desulfo-CoA was competitive versus acetyl-CoA and noncompetitive versus H3-20. The dead-end analog inhibitor H3-20 K14A was competitive versus H3-20 and uncompetitive versus acetyl-CoA. The potent bisubstrate analog inhibitor H3-CoA-20 was competitive versus acetyl-CoA and noncompetitive versus H3-20. Taken together, these inhibition patterns support an ordered BiBi kinetic mechanism for PCAF in which acetyl-CoA binding precedes H3-20 binding. Viscosity experiments suggest that diffusional release of product is not rate-determining for PCAF catalysis. These results provide a mechanistic framework for understanding the detailed catalytic behavior of an important subset of the histone acetyltransferases and have significant implications for molecular regulation of and inhibitor design for these enzymes.

Plasma endotoxin and serum cytokine levels in patients with alcoholic hepatitis: relation to severity of liver disturbance

BACKGROUND

Endotoxin plays an important role in the initiation and aggravation of alcoholic liver disease. In this study, we evaluated plasma endotoxin levels and serum concentrations of cytokines and lipopolysaccharide binding protein (LBP) during the acute and recovery phase of patients with alcoholic hepatitis; we also explored the prognostic factors associated with a fatal outcome.

METHODS

Fourteen patients, consisting of eight patients with alcoholic hepatitis (AH), five cirrhotics with superimposed AH (LC+AH), and one patient with severe alcoholic hepatitis (SAH), were studied. Among these, two with LC+AH died of hepatic failure.

RESULTS

Plasma endotoxin levels in the acute phase were higher in patients with AH (184.4 +/- 159.4 pg/ml) and LC+AH (206.9 +/- 174.9 pg/ml) than in healthy subjects (10.4 +/- 5.5 pg/ml, p < 0.001). In particular, in one patient with SAH and one of two nonsurvivors, plasma endotoxin levels were markedly high relative to the other cases. In most survivors, plasma endotoxin levels decreased in the recovery phase, whereas they further increased at the terminal stage in one of two nonsurvivors. Serum interleukin (IL)-6 and IL-8 levels in the acute phase were significantly higher in patients with AH and LC+AH as compared with healthy subjects. These levels were especially high in nonsurvivors and in one patient with SAH. IL-10 increased in two nonsurvivors, one patient with SAH, and one with LC+AH. In the recovery phase, these cytokine levels in survivors tended to decrease, but in nonsurvivors, IL-6 remained high, and IL-8 and IL-10 further increased. Tumor necrosis factor-alpha levels were below the detection limit throughout the course in all patients. Serum lipopolysaccharide binding protein (LBP) generally was elevated in the acute phase and decreased in the recovery phase in all survivors, but in one of the nonsurvivors, LBP was elevated markedly at the terminal stage. In the acute phase, plasma endotoxin levels were correlated positively with white blood cell counts, neutrophil counts, and serum IL-8. IL-8 was correlated positively with neutrophil counts and negatively with serum cholinesterase, hepaplastin test, and serum albumin levels. IL-6 was correlated positively with white blood cell and neutrophil counts, C-reactive protein, and serum total bilirubin and negatively with hepaplastin test and serum total protein levels. Serum LBP was correlated positively with white blood cell and neutrophil counts.

CONCLUSIONS

Endotoxemia and related elevation of IL-8 may play an important role in the activation and migration of neutrophils in patients with alcoholic hepatitis. Marked elevation of inflammatory cytokines, IL-6 and IL-8, are related to severity and poor prognosis of alcoholic hepatitis. Serum LBP may serve as an index of inflammatory reaction in alcoholics.

A role of transcriptional activators as antirepressors for the autoinhibitory activity of TATA box binding of transcription factor IID

The TATA box-binding activity of transcription factor IID (TFIID) is autoinhibited by the N-terminal domain of the Drosophila TATA box-binding protein- (TBP) associated factor 230/yeast TBP-associated factor 145 subunit, which binds to the TATA box-binding domain of TBP by mimicking the TATA box structure. Here, we propose a mechanism of transcriptional activation that involves antirepression of this autoinhibitory activity by transcriptional activators. Like the autoinhibitory domain of TFIID, various acidic activators interact with the TATA box-binding domain of TBP. Moreover, the autoinhibitory domain of TFIID, which is known to interact with only the TATA box-binding domain of TBP, acts as an activation domain when fused to the GAL4 DNA-binding domain, indicating that interaction with the TATA-binding domain of TBP is crucial for activation of transcription. In a reciprocal fashion, the acidic activation domains can function as the autoinhibitory domain when the latter is replaced by the former within TFIID. These results indicate that activation domains and the autoinhibitory domain of TFIID are interchangeable, supporting a role for transcriptional activators as antirepressors of the autoinhibitory activity of the TATA box binding of TFIID.

ATF-2 has intrinsic histone acetyltransferase activity which is modulated by phosphorylation

Transcription factors carry functional domains, which are often physically distinct, for sequence-specific DNA binding, transcriptional activation and regulatory functions. The transcription factor ATF-2 is a DNA-binding protein that binds to cyclic AMP-response elements (CREs), forms a homodimer or heterodimer with c-Jun, and stimulates CRE-dependent transcription. Here we report that ATF-2 is a histone acetyltransferase (HAT), which specifically acetylates histones H2B and H4 in vitro. Motif A, which is located in the HAT domain, is responsible for the stimulation of CRE-dependent transcription; moreover, in response to ultraviolet irradiation, phosphorylation of ATF-2 is accompanied by enhanced HAT activity of ATF-2 and CRE-dependent transcription. These results indicate that phosphorylation of ATF-2 controls its intrinsic HAT activity and its action on CRE-dependent transcription. ATF-2 may represent a new class of sequence-specific factors, which are able to activate transcription by direct effects on chromatin components.

p300 and p300/cAMP-responsive element-binding protein associated factor interact with human T-cell lymphotropic virus type-1 Tax in a multi-histone acetyltransferase/activator-enhancer complex

The human T-cell lymphotropic virus, type (HTLV)-1 trans-activator, Tax, coordinates with cAMP-responsive element-binding protein (CREB) and the transcriptional co-activators p300/CBP on three 21-base pair repeat elements in the proviral long terminal repeat (LTR) to promote viral mRNA transcription. Recruitment of p300/CBP to the activator-enhancer complex, however, is insufficient to support Tax-dependent LTR trans-activation. Here, we report that the p300/CBP-associated factor (P/CAF) is a critical and integral component of the functional HTLV-1 activator-enhancer complex. The HTLV-1 Tax protein directly binds P/CAF in vitro and co-immunoprecipitates with this co-activator in vivo. The Tax mutants (K88A and V89A) defective for p300/CBP-binding and LTR trans-activation, retained their abilities to interact with P/CAF. The M47 mutant (L319R, L320S) protein, which has previously been shown to interact with p300/CBP, by contrast, failed to form complexes with P/CAF and is impaired in LTR trans-activation. Furthermore, LTR trans-activation by Tax is competitively inhibited by the adenoviral E1A 12S gene product, which displaces P/CAF from p300/CBP and inhibits the histone acetyltransferase activities of both P/CAF and p300/CBP. This inhibition is partially reversed by exogenously added P/CAF. These results imply that simultaneous recruitment of two distinct co-activators (p300/CBP and P/CAF) by Tax is essential for the assembly of a trans-activation competent, nucleoprotein complex.

Acetylation of novel sites in the nucleosomal binding domain of chromosomal protein HMG-14 by p300 alters its interaction with nucleosomes

The reversible acetylation of histones is associated with structural alterations in the chromatin fiber that affect various DNA-related activities. Here we show that the histone acetyltransferase p300 specifically acetylates HMG-14, a nonhistone structural protein that binds to nucleosomes and reduces the compactness of the chromatin fiber. We identify 7 major acetylation sites, 6 of which are novel and have not been known to be acetylated in either HMG-14 or the closely related HMG-17 protein. All the acetylation sites involve evolutionarily conserved residues: 3 within the HMG-14/-17 nucleosomal binding domain and 4 in or near the bipartite nuclear localization domains of the proteins. In tissue culture cells the acetylation pattern is indicative of a selective process in which a subfraction of HMG-14 is preferentially acetylated. We find that the nucleosomal binding domain is a major target for acetylation in vivo and that the specific acetylation of HMG-14 by p300 weakens its interaction with nucleosome cores. Our results suggest that p300 modulates the interaction of HMG-14 with nucleosomes. Thus, p300 may affect chromatin-related activities not only by modifying histones or transcription factors but also by targeting structural nonhistone proteins.

Tumor necrosis factor-alpha augments contraction and cytosolic Ca(2+) sensitivity through phospholipase A(2) in bovine tracheal smooth muscle

To elucidate the effects of tumor necrosis factor-alpha (TNF-alpha) on tracheal smooth muscle contraction, we simultaneously measured isometric tension and intracellular Ca(2+) ([Ca(2+)](i)) in fura 2-loaded muscle strips. Smooth muscle force generation was evaluated in a high potassium (K(+); 20.0-80.0 mM) solution and with acetylcholine (3 nM-10 microM ). TNF-alpha (1-100 ng/ml) did not directly contract muscle strips. The contractile response to acetylcholine was enhanced after application of 10 ng/ml of TNF-alpha for 30 min but not the response of [Ca(2+)](i). The contractile response and the response of [Ca(2+)](i) to a high K(+) solution were not altered after application of TNF-alpha. The [Ca(2+)](i)-tension curve indicated that TNF-alpha enhanced the responsiveness of tracheal smooth muscle through the acetylcholine-mediated Ca(2+) sensitivity of intracellular contractile elements. The augmentation of the acetylcholine concentration-response curves for muscle tension in the presence of TNF-alpha (10 ng/ml) was inhibited in part after application of manoalide, a phospholipase A(2) inhibitor. We conclude that a low concentration of TNF-alpha enhances smooth muscle responsiveness to acetylcholine by agonist-mediated Ca(2+) sensitivity facilitated by phospholipase A(2).

Detection of pulmonary metastasis of low-grade endometrial stromal sarcoma 25 years after hysterectomy

Endometrial stromal sarcoma (ESS) is a rare uterine sarcoma. Low-grade ESS occasionally recurs or metastasizes after long disease-free periods, a fact that may complicate the diagnosis. Here we report a case of multiple lung metastases in a 68-year-old woman who had been disease-free for 25 years after hysterectomy for a uterine tumor. Biopsy revealed that the tumor was composed of oval cells with slight nuclear atypism but without mitotic figures, suggesting a low-grade neoplasm. Immunostaining for intermediate filaments revealed strong positivity for vimentin and weak positivity for alpha-smooth muscle actin. In addition, immunostaining for estrogen and progesterone receptors, performed under suspicion of low-grade ESS, was positive. The uterine tumor resected many years before had shown a similar morphology. Thus, it was demonstrated that the lung neoplasm was a metastatic low-grade ESS that had appeared after many disease-free years. A review of the literature revealed that this case had the longest recorded interval between the occurrence of the initial ESS and the development of distant metastases. When low-grade sarcoma appears in the lungs of female patients, it is important to consider the possibility of low-grade ESS. Detailed information on the past clinical history, together with immunostaining for estrogen and progesterone receptors, are important diagnostic keys.

Fatal aspiration of sardine fry in a patient with lung cancer

We report a fatal case of death due to unusual aspiration of sardine fry in an elderly Japanese man with lung cancer. The cause of death was sudden respiratory arrest while eating. Autopsy revealed peculiar materials with cell nests and pigmented particles, together with striated muscle and skin, in the ectatic bronchioles of the left lower lobe. Serial histologic sections suggested that the structures observed were the eyeballs of small animals that appeared to have been inhaled. The patient had habitually eaten sardine fry and rice gruel, which were also detected in the gastric contents. Therefore, the eyes were considered to be those of the fry, which is a popular food item in Japan. This was confirmed by histologic examination of fry that were obtained commercially.

HATs off: selective synthetic inhibitors of the histone acetyltransferases p300 and PCAF

Histone acetyltransferases (HATs) play important roles in the regulation of gene expression. In this report, we describe the design, synthesis, and application of peptide CoA conjugates as selective HAT inhibitors for the transcriptional coactivators p300 and PCAF. Two inhibitors (Lys-CoA for p300 and H3-CoA-20 for PCAF) were found to be potent (IC(50) approximately = 0.5 microM) and selective (approximately 200-fold) in blocking p300 and PCAF HAT activities. These inhibitors were used to probe enzymatic and transcriptional features of HAT function in several assay systems. These compounds should be broadly useful as biological tools for evaluating the roles of HATs in transcriptional studies and may serve as lead agents for the development of novel antineoplastic therapeutics.

TFIIA-TAF regulatory interplay: NMR evidence for overlapping binding sites on TBP

TATA box binding protein (TBP)-promoter interaction nucleates assembly of the RNA polymerase II transcription initiation complex. Transcription factor IIA (TFIIA) stabilizes the TBP-promoter complex whereas the N-terminal domain of the largest TAF(II) inhibits TBP-promoter interaction. We have mapped the interaction sites on TBP of Drosophila TAF(II)230 and yeast TFIIA (comprising two subunits, TOA1 and TOA2), using nuclear magnetic resonance (NMR), and also report structural evidence that subdomain II of the TAF(II)230 N-terminal inhibitory domain and TFIIA have overlapping binding sites on the convex surface of TBP. Together with previous mutational and biochemical data, our NMR results indicate that subdomain II augments subdomain I-mediated inhibition of TBP function by blocking TBP-TFIIA interaction.

Cytologic differential diagnosis among reactive mesothelial cells, malignant mesothelioma, and adenocarcinoma: utility of combined E-cadherin and calretinin immunostaining

BACKGROUND

The differential diagnosis between reactive mesothelial cells (RMs), malignant mesotheliomas (MMs), and adenocarcinomas (ACs) is often difficult in cytologic specimens, and the utility of various immunohistochemical markers have been explored. Because recent immunohistologic studies have suggested that E-cadherin (E-cad) and calretinin (Cal) may be useful markers for epithelial and mesothelial differentiations, respectively, the authors investigated their utility in cytologic diagnosis.

METHODS

In this retrospective study, immunostaining was performed on smears retrieved from Papanicolaou-stained slides of effusions using the labeled streptavidin-biotin method. Sixteen cases of RM, 9 cases of MM, and 52 cases of AC from various sites, including 13 pulmonary primaries, were examined with primary antibodies against E-cad and Cal.

RESULTS

The positive rates for E-cad and Cal, respectively, were as follows: RM, 0/16 (0%) and 16/16 (100%); MM, 9/9 (100%) and 8/8 (100%); and AC, 45/52 (86.5%) and 0/51 (0%). The E-cad expression by neoplastic cells was strongest in the intercellular junctions, and poorly differentiated neoplastic cells in the single cell form showed the weakest expression.

CONCLUSIONS

In contrast to the results of previous immunohistochemical studies, the current study indicates that MMs constantly express E-cad, whereas RMs lack its expression in cytologic specimens, which would be useful in the differential diagnosis between the two. On the other hand, E-cad expression is not reliable for distinguishing AC from MM. The Cal expression can be a very useful marker for the distinction between AC and the mesothelial lineage. The combined immunostaining for E-cad and Cal has utility in differential diagnosis among RM, MM, and AC.

Membrane properties of archaeal macrocyclic diether phospholipids

Several biophysical properties of four synthetic archaeal phospholipids [one polyprenyl macrocyclic lipid A and three polyprenyl double-chain lipids (B, C, D) bearing zero, one or four double bonds in each chain] were studied using differential scanning calorimetry, electron and optical microscopies, stopped-flow/light scattering and solid-state 2H-NMR techniques. These phospholipids gave a variety of self-organized structures in water, in particular vesicles and tubules. These assemblies change in response to simple thermal convection. Some specific membrane properties of these archaeal phospholipids were observed: They are in a liquid-crystalline state over a wide temperature range; the dynamics of their polyprenyl chains is higher than that of n-acyl chains; the water permeability of the membranes is lower than that of n-acyl phospholipid membranes. It was also found that macrocyclization remarkably improves the barrier properties to water and the membrane stability. This may be related to the adaptation of Methanococcus jannaschii to the extreme conditions of the deep-sea hydrothermal vents.

Identification of a cellular protein that functionally interacts with the C2 domain of cytosolic phospholipase A(2)alpha

Cytosolic phospholipase A(2) (cPLA(2)) alpha plays critical roles in lipid mediator synthesis. We performed far-Western analysis and identified a 60-kDa protein (P60) that interacted with cPLA(2)alpha in a Ca(2+)-dependent manner. Peptide microsequencing revealed that purified P60 was identical to vimentin, a major component of the intermediate filament. The interaction occurred between the C2 domain of cPLA(2)alpha and the head domain of vimentin. Immunofluorescence microscopic analysis demonstrated that cPLA(2)alpha and vimentin colocalized around the perinuclear area in cPLA(2)alpha-overexpressing human embryonic kidney 293 cells following A23187 stimulation. Forcible expression of vimentin in vimentin-deficient SW13 cells augmented A23187-induced arachidonate release. Moreover, overexpression of the vimentin head domain in rat fibroblastic 3Y1 cells exerted a dominant inhibitory effect on arachidonate metabolism, significantly reducing A23187-induced arachidonate release and attendant prostanoid generation. These results suggest that vimentin is an adaptor for cPLA(2)alpha to function properly during the eicosanoid-biosynthetic process.