Cloning of a cDNA encoding the small subunit of cytochrome b558 (cybS) of mitochondrial fumarate reductase (complex II) from adult Ascaris suum

Complex II in the mitochondria of the adult parasitic nematode, Ascaris suum, exhibits high fumarate reductase activity in addition to succinate dehydrogenase activity and plays a key role in the anaerobic energy metabolism of the worm. In this study, the amino acid sequence of the small subunit of cytochrome b558 (cybS) in adult complex II was deduced from the cDNA isolated by immunoscreening an A. suum muscle cDNA library. Histidine residues, which are possible heme axial ligands in cytochrome b558, were found in the second transmembrane segment of the subunit. This is the first report of the primary structure of the small subunit in the two-subunit cytochrome b in mitochondrial complex II from a multicellular eukaryote.

Somatostatin-14 and somatostatin-28 in chicken pancreatic islet D-cells

Somatostatin (SST)-14 and mammalian (m) SST-28[1-14] immunoreactivities of chicken pancreatic islets were investigated by using light microscopic immunohistochemistry. Chicken D-cells in both A- and B-islets showed immunoreactivity to SST-14, but not to mSST-28[1-14]. The acid-extract from both splenic and ventral lobes of pancreas was fractionated by reverse-phase high-performance liquid chromatography, and the SST-like immunoreactivity was measured in the radioimmunoassay using anti-SST-14 serum. In both lobes, the SST-like immunoreactivity was detected in the fraction which corresponded to that of SST-14 standard, but was not found in that of mSST-28 standard. Immunohistochemically, pancreatic endocrine D-cells of 1 amphibian, 4 reptiles and 12 birds showed the same immunostaining property as chicken D-cells. By contrast, both SST-14- and mSST-28[1-14]-immunoreactive D-cells were observed in the pancreatic islets of 16 mammals. From these results, we concluded that chicken islet D-cells contain only SST-14-like peptide, but not SST-28-like peptide, and that this phenomenon may be common to the avian species.

Frequent expression of P-glycoprotein/MDR1 by nasal T-cell lymphoma cells

BACKGROUND

Lethal midline granuloma is now considered to be a malignant lymphoma derived from peripheral T cells or from natural killer cells. The therapeutic outcome of nasal T-cell lymphoma (NL) treated by conventional chemotherapy for non-Hodgkin's lymphoma is poor, although some patients have a good response to radiotherapy. To clarify the mechanisms of drug resistance, the expression of P-glycoprotein (P-gp)/MDR1, which is the product of the multidrug resistance (MDR) 1 gene, and MDR3 mRNA in NL cells, were examined.

METHODS

Ten Japanese patients with NL were studied. Nine of these patients were examined before therapy. P-glycoprotein expression and phenotypes of lymphoma cells were examined by immunohistochemical staining using UIC2 as an anti-P-gp monoclonal antibody. In one case, the Rhodamine-123 efflux test was performed. MDR1 and MDR3 mRNA were detected by reverse transcription polymerase chain reaction.

RESULTS

Nine of the 10 patients were P-gp positive. In one of nine, functional P-gp expression was observed. MDR1 mRNA was detected in all seven examined patients with P-gp positive NLs, whereas MDR3 mRNA was negative. Retrospectively, patients who received chemotherapy alone had poorer outcome than those treated by combination chemotherapy after irradiation.

CONCLUSION

The poor prognosis for patients with NL treated with chemotherapy may be explained by P-gp expression of the NL cells.

Cloning of the aldehyde reductase gene from a red yeast, Sporobolomyces salmonicolor, and characterization of the gene and its product

An NADPH-dependent aldehyde reductase (ALR) isolated from a red yeast, Sporobolomyces salmonicolor, catalyzes the reduction of a variety of carbonyl compounds. To investigate its primary structure, we cloned and sequenced the cDNA coding for ALR. The aldehyde reductase gene (ALR) comprises 969 bp and encodes a polypeptide of 35,232 Da. The deduced amino acid sequence showed a high degree of similarity to other members of the aldo-keto reductase superfamily. Analysis of the genomic DNA sequence indicated that the ALR gene was interrupted by six introns (two in the 5' noncoding region and four in the coding region). Southern hybridization analysis of the genomic DNA from S. salmonicolor indicated that there was one copy of the gene. The ALR gene was expressed in Escherichia coli under the control of the tac promoter. The enzyme expressed in E. coli was purified to homogeneity and showed the same catalytic properties as did the enzyme from S. salmonicolor.

Relationship of protein synthesis to mRNA levels in the muscle of chicks under various nutritional conditions

The relationship between the rate of protein synthesis and the level of messenger RNA (mRNA) in the breast muscle (pectoralis major) was studied to examine the mechanisms regulating muscle protein synthesis in chicks under various nutritional conditions. The fractional synthesis rate (FSR) of protein was measured by a large-dose injection of L-[4-3H]phenylalanine. Poly(U)-Sepharose 4B affinity chromatography was used to extract Poly(A)+ RNA as mRNA. The first study examined the effect of dietary protein levels (0-60%) on protein synthesis rate and the contents of mRNA and total RNA. The fractional synthesis rate increased with increasing dietary protein levels from 0 to 20%. When chicks were fed high protein diets (40 and 60% of dietary protein), both the FSR and absolute synthesis rate (ASR) of protein were reduced compared with the 20% protein group. Multiple regression analysis indicated that for graded dietary protein levels below the dietary protein requirement, the response of muscle protein synthesis is largely regulated by variation in the ASR per unit RNA (the efficiency of RNA in synthesizing protein). At dietary protein levels above 20%, synthesis rates are also related to changes in the RNA:mRNA ratio (ribosome number relative to mRNA), the mRNA:DNA ratio (mRNA availability) and the DNA:protein ratio (DNA concentration). When chicks were food deprived for 2 d, FSR was reduced to about half that of well-fed controls. Upon refeeding of these chicks with the control diet, the FSR returned to the normal level within 0.5 h. When food-deprived chicks were refed with protein, carbohydrate or fat alone, the FSR returned to the control level within 0.5 h after consumption of each nutrient. The increase in muscle protein synthesis of unfed chicks following refeeding of various nutrients was explained by an increased ASR per unit RNA. Our results suggest that nutrient intake can change muscle protein synthesis rates in chicks largely by altering the ASR per unit RNA, in some cases associated also with changes in the levels of RNA, mRNA and DNA.

Relationship of protein synthesis to mRNA levels in the liver of chicks under various nutritional conditions

The rate of liver protein synthesis in vivo and hepatic messenger ribonucleic acid (mRNA) levels were measured to examine the mechanisms regulating liver protein synthesis in chicks under various nutritional conditions. Fractional synthesis rate (FSR) of liver protein was measured by using a large dose injection of L-[4-3H]phenylalanine. Poly(A)+RNA was extracted as mRNA from total RNA using poly(U)-Sepharose 4B affinity chromatography. The influence of varying dietary protein levels (0-60%) on protein synthesis and mRNA concentration in the liver of chicks was examined. Both FSR (%/d) and absolute synthesis rate (ASR, mg/d) of liver protein increased with increasing dietary protein levels from 0 to 20% (the dietary protein requirement), whereas when dietary protein increased from 20 to 40%, both rates decreased significantly. This change was accounted for by changes in RNA concentration (RNA:protein ratio) and hepatic mRNA content. Second, the time course of changes in liver protein synthesis and hepatic mRNA content were measured in force-fed chicks that had been deprived of food for 2 d. Liver protein synthesis (FSR) was significantly greater 30 min after refeeding compared with that of unfed chicks. Liver protein synthesis (FSR) correlated with the activity of RNA to synthesize protein (r = 0.61, P < 0.001), and ASR was correlated with hepatic mRNA content (r = 0.37, P = 0.030). Third, experimental diets containing individual nutrients were force-fed to chicks after 2 d of food deprivation. When chicks were refed carbohydrate and protein diets, liver protein synthesis (FSR) tended to be greater by 24% (P = 0.063) and 22% (P - 0.075) at 30 min after refeeding compared with that of unfed chicks, respectively. These findings indicate that changes in the rate of liver protein synthesis in vivo due to the alteration in nutritional conditions are, at least partially, accounted for by not only RNA concentration and the activity of RNA synthesizing protein but also hepatic mRNA levels.

Myeloid antigen, CD13, CD14, and/or CD33 expression is restricted to certain lymphoid neoplasms

The authors examined the expression of myeloid antigens (MyAg): CD11b, CD13, CD14, CD15, and CD33 in 249 adults with lymphoid neoplasms using flow cytometric analysis. In this study, acute leukemia that was myeloperoxidase negative by light microscopy and had at least one lymphoid antigen was defined as acute lymphoblastic leukemia (ALL). The patients were classified as follows: 6 with unclassified ALL, 35 early B precursor ALL, 32 T-ALL, 25 B-cell chronic lymphocytic leukemia (B-CLL) and its variants, 24 B-cell non-Hodgkin's lymphoma (B-NHL), 7 plasma cell disorders, 8 T-CLL, 2 adult T-cell leukemia, and 10 T-NHL. CD11b and CD15 were present in a wide range of lymphoid disorders irrespective of B/T lineage and maturity. Unclassified ALL and phenotypically immature ALL frequently expressed CD13 and CD33, and occasionally expressed CD14. Among early B precursor ALL, CD13, and/or CD33 were significantly associated with the presence of stem cell marker CD34 and the chromosomal abnormality t(9;22). In addition, ALL with deletion of chromosome 7 commonly expressed CD13 and CD33. Taken together, CD13 and/or CD33 positive ALL may originate from a multipotential stem cell. Among mature neoplasms, CD14 was frequently, and CD13 and CD33 were occasionally expressed in B-cell, but not T-cell tumors. These results suggest that CD13, CD14, and CD33 are preferentially expressed in two types of lymphoid neoplasms, namely undifferentiated ALL and mature B-cell lymphoproliferative disorders.

Spontaneous and agonist-induced contractions and endothelium-dependent relaxation in aortae from SHRSP and WKY rats under various levels of passive force

1. The influence of the passive force on the contraction and endothelium-dependent relaxation in aortae of normotensive Wistar Kyoto (WKY) rats and stroke-prone spontaneously hypertensive rats (SHRSP) were compared. 2. Force changes of endothelium-intact and -removed preparations were measured isometrically by a force-displacement transducer. Endothelium-dependent relaxation was observed by applying acetylcholine to the preparation precontracted in the presence of 5 x 10(-7) mol/L noradrenaline. 3. The preparations showed spontaneously developed tension (tone) that increased with the increase in the passive force. The effect of passive force was greater in preparations from SHRSP. Contraction initiated by noradrenaline was also increased by passive force up to 30 mN, then showed a tendency to decrease. 4. Endothelium-dependent relaxation was depressed as the passive force was increased. Preparations from SHRSP showed impaired endothelium-dependent relaxation and were influenced by passive force to a lesser degree when compared with preparations from WKY rats. 5. Relaxation by sodium nitroprusside was influenced by passive force to a much lesser extent than that by acetylcholine. 6. Indomethacin potentiated endothelium-dependent relaxation and blocked the effect of passive force in both preparations. 7. The difference in relaxation and the effect of passive force is primarily caused by the difference in the release of endothelium-derived contracting factor, which is thought to be a product of the cyclo-oxygenase pathway of the arachidonic acid cascade.

Late-onset hereditary ataxia with global thermoanalgesia and absence of fungiform papillae on the tongue in a Japanese family

Two Japanese male siblings, aged 68 and 59 years, affected by late-onset progressive ataxia distinguished by extensive sensory and mild autonomic disturbances are described. They had global thermoanalgesia, positive Romberg signs, sensorineural deafness, canal paresis and ageusia. Their autonomic disturbances consisted of absence of overflow tears with usual stimuli, dysphagia, blood pressure and vasomotor instability, diarrhoea/constipation, and urinary frequency. Sensory nerve action potentials were completely absent, whereas motor conduction velocity was slightly reduced only in the lower extremities. Sural nerve biopsy on the younger brother demonstrated a marked loss of myelinated fibres and a reduction in the number of unmyelinated axons. Tongue histology revealed absence of fungiform papillae and taste buds. Autonomic function tests showed widespread but mild sympathetic and parasympathetic failures. Neuro-imaging studies revealed atrophy of the spinal cord, cerebellum, brainstem and corpus callosum, and enlargement of the lateral, third and fourth ventricles. These siblings represent a previously unrecognized variant of late-onset hereditary spinocerebellar degeneration with global thermoanalgesia and absence of fungiform papillae on the tongue.

[Shunt patency after creation of a transjugular intrahepatic portosystemic shunt: evaluation with Doppler ultrasound]

TIPS (transjugular intrahepatic portosystemic shunt) is a new interventional radiologic procedure that is useful in the treatment of variceal bleeding and ascites due to portal hypertension. It is most important that the shunt remains patent for a long time after placement. The potential role of ultrasound in evaluating the patency of the shunt after TIPS has been studied. Duplex and color doppler sonography were performed in 20 patients with portal hypertension after TIPS. Imaging was done in 38 case. The findings were compared with those of follow-up angiography. Shunt patency was evaluated with Doppler US in 28 case. In 27 of them, the equivalent patent shunt was confirmed by angiography; the exception was one case of occlusion in follow-up angiography. Doppler signals in the shunt could not be detected in 10 cases. Follow-up angiography showed occlusion in 7 cases and patency in the other 3. Doppler US sensitivity was 90%, and its specificity was 88%. These results indicate that Doppler US is one of the most useful methods for evaluating shunt patency after TIPS.

Treatment of primary erythromelalgia with cyproheptadine

Erythromelalgia is a rare disorder characterized by burning pain of the extremities associated with red discoloration and increased temperature of the skin. We observed the effects of several drugs on two patients with primary erythromelalgia. Anti-inflammatory drugs such as aspirin had no effects for their symptoms. The alpha-adrenergic agonist midodrine slightly reduced skin temperature and redness of the extremities, and minimally reduced the pain in one patient. The partial alpha-adrenergic agonist and 5-hydroxytryptamine (5-HT) agonist/antagonist dihydroergotamine transiently reduced skin temperature and pain to some degree in one patient. The 5-HT and histamine antagonist cyproheptadine effectively relieved the burning pain and increased skin temperature.

Promoter region of the rat phosphoribosylpyrophosphate synthetase-associated protein 39

The 5' region of the 39-kDa rat phosphoribosylpyrophosphate synthetase-associated protein (PAP39) gene was isolated and sequenced. The promoter region of the rat PAP39 is GC-rich and contains potential binding sites for regulatory factors. Its promoter activity was demonstrated by transfection of the promoter region in fusion with the chloramphenicol acetyltransferase gene into rat pheochromocytoma PC12 cell.

Cloning and sequencing of human complementary DNA for the phosphoribosylpyrophosphate synthetase-associated protein 39

A human cDNA encoding a human homologue of the rat phosphoribosylpyrophosphate synthetase-associated protein of 39 kDa was isolated. The deduced protein contains 356 amino acids and has calculated molecular mass of 38561. The amino acid sequence is 98% identical to that of the rat. The corresponding mRNA is present in all human tissues examined.

Purification and molecular characterization of a novel b5-type cytochrome of the parasitic nematode, Ascaris suum

A b5-type cytochrome was extracted from Ascaris suum muscle at pH 4.5 with 0.3% aluminum sulfate and purified by ammonium sulfate fractionation, ion-exchange chromatography on CM-500 Cellulofine, and gel filtration on Sephadex G-75. The hemoprotein displayed a typical absorption spectrum of cytochrome b with a midpoint redox potential of 78 mV. The N-terminal amino acid sequence was determined and revealed the N-terminus to be highly homologous to the heme-binding domain of vertebrate cytochrome b5. Using an oligonucleotide probe synthesized based on the amino acid sequence of the purified protein, the cDNA clone encoding A. suum cytochrome b5 was isolated from the lambda ZAP II cDNA library. The entire nucleotide sequence of 563 bases comprised an open reading frame of 339 bases encoding a precursor protein of 112 amino acid residues. The purified cytochrome B5 was predicted to contain 82 amino acids with a molecular mass of 9141 Da, matching the 9140 Da obtained from electrospray ionization mass spectometry, and to lack of membrane-anchor domain at the C-terminus. In contrast, an N-terminal extension of 30 amino acids, characteristic of signal peptides, was apparent. Immunoblots revealed the presence of an A. suum cytochrome b5 of 82 amino acids, but no protein with an N-terminal extension. These results demonstrate a novel cytochrome b5 possessing a presequence.

Influence of nutrition on hepatic IGF-I mRNA levels and plasma concentrations of IGF-I and IGF-II in meat-type chickens

We have examined the influence of nutrition on plasma IGF-I, IGF-II and IGF-binding protein (IGFBP) levels and on hepatic IGF-I gene expression in young meat-type chickens. Plasma IGF concentrations were measured by using RIA with recombinant chicken IGFs as standards. In chickens fed the control diet containing 200 g/kg dietary protein ad libitum for 7 days, plasma IGF-I concentrations increased significantly from those found in the initial control group. Food restriction for either 4 or 7 days decreased plasma IGF-I by 30% from the initial control. When chickens were refed ad libitum for 3 days after 4 days of restricted feeding, plasma IGF-I levels recovered to those of the control birds fed ad libitum. In chickens eating a low protein diet (100 g/kg protein), the plasma IGF-I tended to be lowered but the decrease was not significant. Although the intensity of IGF-I and beta-actin mRNA bands protected in the RNase protection assay was changed by nutrition, no statistical effect of nutrition on the ratio of IGF-I to beta-actin was observed. The nutritional treatments had no effect on plasma IGF-II concentrations. Western ligand blot and chromatographic analyses were used to investigate the influence of nutrition on IGFBP profiles. Both IGF-I and IGF-II ligands in the Western ligand blot revealed the most intense binding at 30 kDa for plasma obtained from chickens with restricted food intake. The 30 kDa band also appeared at a lower intensity in the group fed a low protein diet but not in any other groups. These observations were confirmed by neutral gel chromatography. The chicken IGF-II ligand revealed an intensely labelled band corresponding to 75 kDa and this was not affected by nutrition. IGF-I and IGFBP concentrations in the plasma of young broiler chickens were influenced by nutritional state but IGF-II concentrations were not. The lack of a response in circulating IGF-II levels may have been due to the presence of high concentrations of a 75 kDa specific binding protein which did not respond to nutrition in this experiment.

Biological characteristics of CD7(+) acute leukemia

Eighty six of 430 acute myeloblastic leukemia (AML) patients (20.0%) and forty of 173 acute lymphoblastic leukemia (ALL) patients (23.1%) had CD7 on their leukemia cells. CD7(+) AML occurred at a younger age than CD7(-) AML, and is more frequent in males. Hepatomegaly and central nervous system involvement were also more frequent in CD7(+) AML than in CD7(-) AML. The age of onset of CD7(+) ALL is also younger than that of CD7(-) ALL. Phenotypically, CD(+) AML expressed CD34, HLA-DR, and TdT more frequently than CD7(-) AML while CD7(+) ALL expressed CD13/33 more often than CD7(-) ALL cells responded most significantly to interleukin 3 (IL-3), whereas most CD7(-) AML cells responded more significantly to granulocyte macrophage-colony stimulating factor (GM-CSF) and/or granulocyte (G)-CSF than to IL-3. CD7(+)sCD3(-)CD4(-)CD8(-) ALL expressed G-CSF receptor and c-kit mRNA more frequently, which is not usual in other types of ALL. P-glycoprotein (P-gp)/multi-drug resistance gene (MDR1), thought to be expressed in hematopoietic stem cells, is expressed in CD7(+) AML and CD7(+)sCD3(-) CD4(-)CD8(-) ALL significantly more often than in CD7(-) acute leukemias and the CR rate and overall survival of CD7(+)AML was worse than CD7(-) AML. These data, collectively, suggest the close association of CD7(+) AML and CD7(+)sCD3(-)CD4(-)CD8(-) ALL, not only the common expression of CD7 itself but also because their phenotypical immaturity, cytokine receptor expression, P-gp/MDR1 expression and clinical manifestations including the frequent occurrence in males and the poor prognosis. We propose that CD7(+) acute leukemia is an hematopoietic stem cell leukemia which may be separate entity.

MR imaging of liver cirrhosis

PURPOSE

The objective of this study was to identify the factors affecting the visualization of regenerating nodules in cirrhotic liver by MR imaging.

MATERIAL AND METHODS

MR images from patients with liver cirrhosis and normal subjects were studied, and signal intensity within the liver was measured and correlated with histologic findings. A reference phantom was also used as a standard.

RESULTS

The signal intensity of the liver on T2-weighted (T2WI) spin-echo (SE) images was significantly increased in patients with liver cirrhosis. Multiple ring-like or reticular high-intensity areas (RHAs) were demonstrated on T2WI SE images in 44 of 125 cirrhotic livers. Histologic examination in 44 cases revealed various degrees of inflammatory changes in fibrous septa surrounding regenerative nodules in all specimens, vascular dilation in fibrous septa in 4 specimens, and no hemosiderin deposition in some specimens. The results of linear discriminant analysis showed that inflammatory changes in fibrous septa were significantly more pronounced in cases with RHAs on MR.

CONCLUSION

RHAs seen on T2WI SE images may correspond to fibrous septa with inflammation. The signal intensity of fibrous septa surrounding regenerative nodules on T2WI SE images may be increased in liver cirrhosis due to inflammation or vascular dilation, contributing to the visualization of regenerating nodules as relatively low-intensity regions on MR.

Establishment of an undifferentiated leukemia cell line (Kasumi-3) with t(3;7)(q27;q22) and activation of the EVI1 gene

A novel human leukemia cell line (Kasumi-3) was established from the blast cells of a 57-year-old man suffering from myeloperoxidase-negative acute leukemia. The cell line had five distinctive features, as follows. 1) Flow cytometric analyses showed cell surface expression of CD7, CD4, CD13, CD33, CD34, HLA-DR and c-Kit. This phenotype is compatible with that of acute myelocytic leukemia cells with the M0 subtype in the French-American-British classification. 2) Kasumi-3 cells carried chromosomal abnormalities of t(3;7)(q27:q22), del(5)(q15), del(9)(q32), and add(12)(p11). The breakpoint of 3q27 was located near the EVI1 gene, and a high level of expression of the EVI1 gene was observed. 4) Kasumi-3 cells treated with TPA showed maturation to monocytic lineage. 5) Treatment with either interleukin (IL)-2, IL-3, IL-4, granulocyte-macrophage colony-stimulating or stem cell factor induced the proliferation of Kasumi-3 cells. Thus, the Kasumi-3 cell line shows the characteristic features of undifferentiated leukemia. It should, therefore, be useful both for studying the biological characteristics of acute myelogenous leukemia M0 subtype and for investigating the role of the EVI1 gene in leukemogenesis.

PRAD1/Cyclin D1 gene overexpression in mantle cell lymphoma

The t(11;14) (q13;q32) translocation and its molecular counterpart Bcl-1 rearrangement are consistent features of mantle cell lymphoma (MCL). This translocation activates the PRAD1/cyclin D1 gene that is considered to be the Bcl-1 oncogene. PRAD1/cyclin D1 gene overexpression is closely associated with MCL. The PRAD1/cyclin D1 protein is localized to the nucleus, and the strong correlation between PRAD1/cyclin D1 and MCL is also found in the protein level. This finding indicates that PRAD1/cyclin D1 expression is a highly specific and sensitive molecular marker for MCL. This gene may function as an oncogene in the malignant transformation of cells.