Basophilic crisis of chronic myeloid leukemia with a novel chromosomal aberration.
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Recent work has drawn attention to endothelin as a likely contributor to renal pathogenesis. To elucidate the mechanism of progressive renal disease, we investigated the mRNA expression of endothelin and endothelin receptors, and the effect of endothelin ET(A), and/or ET(B) receptor antagonists on disease progression in the remnant kidney model. Proteinuria progressively increased in rats subjected to 5/6 nephrectomy (Nx) after 8 weeks (from 25+/-3 to 221+/-28 microg min(-1) kg(-1)). Creatinine clearance (Ccr) after renal ablation gradually decreased by 8 weeks (from 5.04+/-0.42 to 2. 68+/-0.26 ml min(-1) kg(-1)). Together with maximal proteinuria and decreased renal function, there was an increase in cortical mRNA expression of prepro endothelin-1 and endothelin ET(A) receptor expression, but a decrease in endothelin ET(B) receptor expression and in urinary excretion of endothelin-1. Administration (1-3 mg/day) of S-0139, (+)-disodium 27-[(E)-3-[2-[(E)-3-carboxylatoacryloylamino]-5-hydroxyphenyl]a crylay loxy]-3-oxoolean-12-en-28-oate, an endothelin ET(A) receptor-specific antagonist, had a beneficial effect on the evolution of the disease, preventing the appearance of intense proteinuria (113+/-11) and decreased Ccr (3.97+/-0.33). High blood pressure was observed in rats with 5/6 Nx and was decreased by S-0139 administration. To examine whether treatment modalities that decrease endothelin ET(B) receptor signaling have a deleterious effect on the kidney remnant, the effect of 97-618, an endothelin ET(B) receptor-specific antagonist, 4-tert-butyl-N-[5-(2-methoxyphenoxy)-6-(4-oxobutoxy)pyromidine+ ++-4-yl]b enzenesulfonamide, was also examined on the action of S-0139. Concomitant administration of S-0139 and 97-618 reversed the beneficial effect of S-0139 alone in the remnant kidney on proteinuria and renal functional impairment. These findings indicate that endothelin participates in the pathogenesis of proteinuria and glomerular injury and that an endothelin ET(A) receptor-specific antagonist could be useful in the treatment of some forms of human nephritis. The loss of endothelin ET(B) receptor seems to be important in the progression of renal disease.
We describe three cases of florid endocervical glandular hyperplasia with intestinal and pyloric gland metaplasia, which can be a benign mimic of adenoma malignum. In two cases, adenoma malignum was seriously considered preoperatively because of watery vaginal discharge and the results of imaging studies. The three cases shared common histopathological features, i.e., (i) proliferating endocervical glands surrounded by clusters of smaller glands, resembling the pyloric glands of the stomach; (ii) occasional intestinal metaplasia; (iii) bland nuclear features; and (iv) predominantly PAS-positive neutral mucin in the glandular epithelium. In two cases, glands were densely and irregularly arranged in some areas. Immunohistochemistry disclosed that the intracytoplasmic mucin of the metaplastic epithelium was positive for M-GGMC-1 (HIK1083), which reacts with mucin of pyloric glands. Monoclonal CEA was negative in all cases. This pseudoneoplastic benign condition should be recognized by both gynecologists and pathologists, although it might be difficult to establish a definite diagnosis preoperatively even with deep cone biopsy.
Two cases of NPM-ALK-positive anaplastic large cell lymphoma (ALCL) with bone marrow involvement are reported. These cases were recognized within a group of NPM-ALK-positive ALCLs (n = 6) by using immunohistochemistry with the ALK1 monoclonal antibody. In case 1, the bone marrow showed diffuse infiltration of round to spindle-shaped lymphoma cells with moderate fibrosis. In case 2, lymphoma cells intermingling with hematopoietic cells could only be identified by immunohistochemical staining. In contrast to the four NPM-ALK-positive ALCL cases, which showed a cohesive growth pattern in the lymph nodes, the two cases reported here displayed lymphoma cells of smaller size, and they were classified as lymphohistiocytic variants histologically. ALK1 stained small-sized components more clearly than did CD30 (HRS-4). These results suggest that bone marrow involvement of NPM-ALK-positive ALCL may be frequently associated with a histological variant showing a small-sized cell component, and that ALK1 immunostaining is a useful tool to investigate lymphomas for bone marrow involvement.
Pneumonia is a major direct cause of death in the elderly. Although aspiration based on a reduced cough reflex is one of the causes of pneumonia in the elderly, there are few studies of angiotensin-I converting enzyme inhibitors (ACE inhibitors), which are antihypertensive drugs that induce cough, as a factor influencing the incidence of pneumonia in institutionalized elderly subjects. To assess the effect of ACE inhibitors and dihydropiridine calcium-channel blockers on the incidence of pneumonia, we conducted a hospital-based case-control study. Cases were 55 pneumonia patients aged > or = 65 years during a 1-year period. The controls were elderly subjects, frequency matched to the cases by age and gender (n = 220). Data were collected on known risk factors and on medication for hypertension, consisting of ACE inhibitors, calcium-channel blockers, and nonantihypertensive medication. The significance of differences in risk factors was analyzed using univariate and multivariate comparisons of cases and controls. After adjustment for potential confounding factors, the relative risk estimates for pneumonia were 0.38 (95% confidence interval [CI], 0.15-0.97) and 1.84 (95% CI, 0.89-3.78) for ACE inhibitors and calcium-channel blockers, respectively, relative to nonantihypertensive medication. The preventive effect of ACE inhibitors on pneumonia was apparent in long-acting ACE inhibitor users (0.24; 95% CI, 0.07-0.88). We conclude that ACE inhibitor use is an independent factor reducing risk of pneumonia among elderly inpatients.
In order to determine the ability of herpes simplex virus type 2 (HSV-2) to suppress apoptosis, we examined the effect of HSV-2 infection on apoptosis induced in HEp-2 cells by treatment with 1 M sorbitol. Although a wild-type strain of HSV-2 induced apoptosis in a significant fraction of the infected cells, HSV-2 could suppress sorbitol-induced apoptosis in a manner similar to that of herpes simplex virus type 1 (HSV-1), indicating that HSV-2, like HSV-1, has an antiapoptosis gene. Characterization of the cells infected with a US3-deletion mutant of HSV-2 revealed the necessity of a US3 gene in the antiapoptotic activity of this virus.
cDNA clones encoding mitochondrial phosphate transporters were isolated from four herbaceous plants. The cDNAs for the soybean, maize and rice transporters contained entire coding regions, whereas the Arabidopsis cDNA lacked the 5' portion. The hydropathy profiles of the deduced amino acid sequences predicted the existence of six membrane-spanning domains which are highly conserved in the mitochondrial transporter family. In soybeans, the mRNA level for the transporter was high in tissues containing dividing cells. It was suggested that there are multiple copies of transporter genes in both dicots and monocots. The soybean transporter was expressed as inclusion bodies in Escherichia coli, solubilized with detergents, and then reconstituted into liposomes. The resulting proteoliposomes exhibited high phosphate transport activity. The activity was inhibited by N-ethylmaleimide, like those of mammalian phosphate transporters.
We isolated a full-length cDNA that encodes ATP-dependent phosphoenolpyruvate carboxykinase (EC 4.1.1.49, PCK) from leaves of maize, an NADP-malic enzyme type C4 plant. The mRNA was specifically and rather abundantly expressed in bundle sheath cells in accordance with the recent finding of cell-type-specific localization of PCK protein in maize, which has been detected with antibodies against cucumber PCK protein. The predicted protein had an N-terminal extension, which is characteristic of plant PCKs. The transcript level was much higher in the daytime than at night in 14-day old seedlings. However, in 42-day old plants the extent of diurnal change decreased. The maize PCK was expressed in Escherichia coli with the pET32 plasmid and purified to homogeneity. Through digestion with enterokinase, two types of enzyme were prepared; one with an intact N-terminus and the other lacking its N-terminal 77 amino acid residues due to over-digestion. The truncated protein had about 2-fold higher specific activity than the intact one, and was inhibited by 3-phosphoglycerate (3-PGA) with an I0.5 of 17.5 mM. In contrast, the intact protein was almost insensitive to 3-PGA. These results strongly suggest that the intact N-terminal extension may be involved in the regulation of PCK activity in vivo through some modification such as reversible phosphorylation.
Concerns over cancer development from exposure to environmental sources of densely ionizing, high linear energy transfer (LET) radiation, such as alpha-particles from radon, is a current public health issue. The study of tumors attributable to high LET irradiation would greatly augment our insights into the biological mechanisms of carcinogenesis. Chronic low-dose-rate internal exposure to alpha-radiation from thorium dioxide deposits following intravascular administration of the radiographic contrast agent Thorotrast is known to markedly increase the risk of cancer development, especially that of hepatic angiosarcomas and cholangiocarcinomas. Although the mechanism is hypothesized to be via cellular damage, DNA being a major target, wrought by the high LET alpha-particles, the specific genes and the actual sequence of events involved in the process of transforming a normal cell into a malignant one are largely unknown. To shed some light on the molecular mechanisms of cancer development during a lifetime exposure to alpha-radiation, we analyzed the most commonly affected tumor suppressor gene in humans, p53, in 20 Thorotrast recipients who developed cancer, mostly of hepatic bile duct and blood vessel origin. Of the 20 cases, 19 were found to harbor p53 point mutations. Moreover, the accompanying non-tumor tissues from these patients also had p53 mutations, albeit at lower frequency. The distribution pattern of the point mutations was significantly different between the non-tumor and tumor tissues, with most mutations in malignant tissues located in the highly conserved domains of the p53 gene. Our results support the idea that p53 mutations are important in the genesis of Thorotrast-induced tumors but that these point mutations are a secondary outcome of genomic instability induced by the irradiation. Additionally, non-tumor cells harboring p53 mutations may gain some survival advantage in situ but mutations in the domains responsible for the formation of structural elements critical in binding DNA may be necessary for a cell to reach full malignancy.
Stromal hyalinization in ovarian clear cell carcinomas has been suggested to be caused by deposition of basement membrane (BM) material, but the biological and diagnostic significance of this finding remains unknown. The distribution of BM material in 17 primary ovarian clear cell carcinomas was examined semiquantitatively using hematoxylin and eosin-stained sections and immunohistochemistry with antibodies to laminin and type IV collagen. For comparison, other surface epithelial tumors, including 8 serous tumors of low malignant potential, 10 serous adenocarcinomas, 6 mucinous tumors of low malignant potential, 5 mucinous adenocarcinomas, 6 endometrioid carcinomas, 4 Brenner tumors, 1 transitional cell carcinoma, and 3 undifferentiated carcinomas, were examined. Stromal hyalinization was found in all 17 clear cell carcinomas and was immunoreactive for type IV collagen and laminin. Other types of surface epithelial tumor lacked these findings. In clear cell carcinoma, areas showing a papillary pattern tended to show abundant deposition regardless of nuclear grade, whereas in solid, tubular, or cystic areas, the deposition was more prominent in areas showing high-nuclear-grade features (grade 2 and 3) than in areas with low-nuclear-grade features (grade 1). Dense deposition of BM material recognized as stromal hyalinization on hematoxylin and eosin-stained sections in primary ovarian clear cell carcinoma is a characteristic feature that is not seen in other ovarian surface epithelial tumors. This matrix production correlates with high-nuclear-grade features and papillary growth pattern.
The La autoantigen (also known as SS-B), a cellular RNA binding protein, may shuttle between the nucleus and cytoplasm, but it is mainly located in the nucleus. La protein is redistributed to the cytoplasm after poliovirus infection. An in vitro translation study demonstrated that La protein stimulated the internal initiation of poliovirus translation. In the present study, a part of the La protein was shown to be cleaved in poliovirus-infected HeLa cells, and this cleavage appeared to be mediated by poliovirus-specific protease 3C (3Cpro). Truncated La protein (dl-La) was produced in vitro from recombinant La protein by cleavage with purified 3Cpro at only one Gln358-Gly359 peptide bond in the 408-amino-acid (aa) sequence of La protein. The dl-La expressed in L cells was detected in the cytoplasm. However, green fluorescence protein linked to the C-terminal 50-aa sequence of La protein was localized in the nucleus, suggesting that this C-terminal region contributes to the steady-state nuclear localization of the intact La protein in uninfected cells. The dl-La retained the enhancing activity of translation initiation driven by poliovirus RNA in rabbit reticulocyte lysates. These results suggest that La protein is cleaved by 3Cpro in the course of poliovirus infection and that the dl-La is redistributed to the cytoplasm. dl-La, as well as La protein, may play a role in stimulating the internal initiation of poliovirus translation in the cytoplasm.
Although alpha(1)-antitrypsin (AAT) deficiency is one of the most common hereditary diseases and a recognized cause of emphysema in Caucasians, variants of this deficiency are extremely rare among Orientals. We present here a Japanese emphysema patient with the AAT deficiency variant originally identified as S(iiyama). After an 8-year follow-up period, the patient suffered from repeated pulmonary Pseudomonas aeruginosa infection for 4 years. He died suddenly of massive pulmonary hemorrhage. The pathologic examination revealed a necrotic hematoma in the right S10 lobe, which exhibited pneumonia due to cytomegalovirus (CMV) infection. Pulmonary hemorrhage due to CMV can occur and be fatal in patients with emphysema and AAT deficiency.
The relationship between potentiation of serotonin (5-hydroxytryptamine, 5-HT)-induced contraction by endothelin-1 (ET-1) and the activity of protein kinase C (PKC) was examined in the porcine coronary artery. Low concentrations (30-100 pM) of ET-1 selectively potentiated the 5-HT-induced contraction 1.5 to 2 times over the control without any additional increase in myosin light-chain phosphorylation. The potentiation was attenuated by PKC down-regulation caused by phorbol 12-myristate 13-acetate. By Western blot analysis with isoform-specific antibodies to PKC, at least four isoforms (PKCalpha, PKCbeta1, PKCdelta and PKCzeta) were identified in the porcine coronary artery. PKCalpha and PKCdelta were mostly in the cytosol fraction, whereas PKCbeta1 and PKCzeta were almost equally distributed in the cytosol and membrane fractions in the resting and contractile states. Of the four isoforms, only PKCdelta was translocated from the cytosol to the membrane fraction during the contractile potentiation by ET-1. These results suggest that the activity of PKCdelta, a Ca2+-independent PKC isoform, is involved in the potentiation of 5-HT-induced contraction by ET-1 in the porcine coronary artery.
We evaluated the clinical significance of p16 and Ki-67 expressions in esophageal squamous cell carcinomas. Operative specimens obtained from 64 patients with esophageal squamous cell carcinomas were investigated by staining with antibodies against p16 and Ki-67. The possible correlations among p16 and Ki-67 expression, clinicopathologic factors and prognosis were studied. The expression of p16 was observed in 68.9%, and it related to histologic classification, lymphatic invasion and clinicopathological stage. Survival rate was significantly better in the patients with p16 positive tumors than in those with p16 negative tumors. Ki-67 positive index (Ki-67-PI) related to only histologic classification. It is suggested that immunohistochemical assessment on the p16 expressions would be useful to select more suitable treatment of squamous cell carcinoma of the esophagus.
The metabolism of 6-N-formylamino-12,13-dihydro-1, 11-dihydroxy-13-(beta-D-glucopyranosil)5H-indolo [2,3-a]pyrrolo [3, 4-c]carbazole-5,7(6H)-dione (NB-506), a potent inhibitor of DNA topoisomerase I, was characterized in mice, rats, dogs, and humans in vitro. NB-506 was deformylated to ED-501 in mouse and rat plasma with enzyme activity of 140 and 116 pmol/min/mg protein, respectively. The enzyme activity in dog and human plasma was found to be less than 1.7 pmol/min/mg protein. In liver S9 and small intestine S9 samples from mice and rats, activity of the enzyme was very low. Also, there was no activity in the liver or small intestine of dogs and humans. The enzyme involved in the conversion of NB-506 to ED-501 in rat plasma is a rodent-specific serine enzyme with a molecular mass of 138KDa. The Vmax and Km values were 6.3 nmol/min/ml plasma and 54 microM at an optimum pH of 7.4, respectively. Although NB-506 was converted to ED-551 in dog and human plasma in vitro, no conversion was observed in mouse and rat plasma. In human plasma this conversion was not affected by heat treatment (100 degreesC for 1 min), but was inhibited completely by 50 mM EDTA, indicating that the reaction is a chemical reaction catalyzed by metal ions. Although NB-506 was not metabolized by cytochrome P-450 isozymes in liver, this drug was glucuronized in mice, rats, and humans, but not in dogs. These results suggest that a species difference in the metabolism of NB-506 occurred in the liver as well as in plasma. There appeared to be species differences in the metabolism of NB-506 in vitro, correlating well with the species-dependent pharmacokinetics of this drug in vivo.
Mutations in the human immunodeficiency virus type 1 (HIV-1) vpr gene only slightly reduce the replication rate of the virus. To study the role of HIV-1 Vpr in biological effects on cells, HEp-2 cells, which express HIV-1 Vpr constitutively but at a low level, were established. While control HEp-2 cells underwent apoptosis when incubated with sorbitol, the morphological and biochemical apoptotic changes were inefficiently induced in the HIV-1 Vpr-expressing cells by the same treatment. These results clearly indicate that HIV-1 Vpr has anti-apoptotic activity, and raise the possibility that Vpr acts as a weak activator of virus replication through anti-apoptosis.
Hydrogen peroxide (H2O2), an oxidant generated by inflammatory cells, is an important mediator of injury of endothelial cells (ECs). Here we show that H2O2 induces up-regulation of the expression of Fas, a death signal, in human ECs in culture. Flow cytometric analysis with a mAb against human Fas showed that incubation for 24 h with H2O2 induced a dose-dependent increase in the level of Fas in ECs. Coincubation with catalase, which rapidly degrades H2O2, inhibited H2O2-induced up-regulation of Fas. H2O2 also induced a dose-dependent increase in Fas mRNA level. A significant increase in Fas mRNA levels was observed from 6 h after stimulation with H2O2. Vanadate, a protein phosphatase inhibitor, significantly enhanced Fas mRNA and protein levels in H2O2-treated ECs. On the other hand, genistein, a tyrosine kinase inhibitor, inhibited H2O2-induced Fas mRNA expression. Furthermore, a flow cytometric method with propidium iodide staining and electron microscopic analysis showed that incubation with an agonistic Ab against Fas (anti-Fas IgM) induced apoptosis in H2O2-treated cells. These findings suggest that H2O2 induces up-regulation of Fas in ECs and that activation of protein tyrosine kinase may be involved in the mechanism of H2O2-induced Fas expression. Therefore, Fas-mediated apoptosis may have a pathologic role in H2O2-induced EC injury and thereby provide a new therapeutic target.
BACKGROUND: 99mTc-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) has been applied clinically in scintigraphy to estimate functioning liver mass, but it is not so sensitive in differentiating mild liver injury from normal liver. 99mTc-GSA is thought to bind to the asialoglycoprotein receptor (ASGP-R) and is then internalized and degraded in the hepatocytes. The aim of this study is to know whether D-galactose inhibits GSA binding or internalization to hepatocyes because ASGP-R recognizes galactose residues of ligands. METHODS: Isolated rat hepatocytes were obtained by collagenase perfusion, pre-cultured for 2 h after plating, and then cultured for 16 to 18 h until use. The effect of galactose on GSA binding and internalization into cells was investigated by using cultured hepatocytes. RESULTS: Galactose non-competitively inhibited GSA binding to cultured hepatocytes, but its Ki value was quite high (505 +/- 38 mM). Galactose significantly inhibited GSA internalization into hepatocytes at 27 mM. CONCLUSION: It was clarified that D-galactose inhibited GSA internalization rather than binding at a low concentration. Further in vivo studies in rats are needed to know whether an administration of galactose prior to performing 99mTc-GSA scintigraphy can brake it possible to estimate the functioning mass in mild liver injury.