Growth hormone-dependent tyrosine phosphorylation of a GH receptor-associated high molecular WEIGHT protein immunologically related to JAK2

A critical step in growth hormone (GH) signalling is the GH-induced activation of the GH receptor (GHR)-associated tyrosine kinase, JAK2. JAK2 is a 120 kD member of the Janus family of tyrosine kinases, whose other mammalian members include JAK1, JAK3, and TYK2. Using 3T3-F442A murine preadipocytes, we now report detection of a Mr approximately 170 kD protein, referred to as HMW ("high molecular weight") JAK2, that is specifically reactive in immunoprecipitation and immunoblotting experiments with three independently-derived anti-JAK2 antibodies--two directed at carboxyl-terminal regions of the molecule and one directed at the amino-terminus. Like JAK2, HMW JAK2 is tyrosine phosphorylated in response to GH treatment of cells and is coimmunoprecipitated with anti-GHR serum. Thus, HMW JAK2 is a protein not heretofore described that is immunologically related to JAK2 and is physically and functionally associated with the GHR.

Insulin-regulated protein kinases during postnatal development of rat heart

The control of glucose uptake and glycogen metabolism by insulin in target organs is in part mediated through the regulation of protein-serine/threonine kinases. In this study, the expression and phosphotransferase activity levels of some of these kinases in rat heart ventricle were measured to investigate whether they might mediate the shift in the energy dependency of the developing heart from glycogen to fatty acids. Following tail-vein injection of overnight fasted adult rats with 2 U of insulin per kg body weight, protein kinase B (PKB), the 70-kDa ribosomal S6 kinase (S6K), and casein kinase 2 (CK2) were activated (30-600%), whereas the MAP/extracellular regulated kinases (ERK)1 and ERK2 were not stimulated under these conditions. When the expression levels of the insulin-activated kinases were probed with specific antibodies in ventricular extracts from 1-, 10-, 20-, 50-, and 365-day-old rats, phosphatidylinositol 3-kinase (PI3K), PKB, S6K, and CK2 were downregulated (40-60%) with age. By contrast, ventricular glycogen synthase kinase-3beta (GSK3beta) protein levels were maintained during postnatal development. Similar findings were obtained when the expression of these kinases was investigated in freshly isolated ventricular myocytes, where they were detected predominantly in the cytosolic fraction of the myocytes. Compared to other adult rat tissues such as brain and liver, the levels of PI3K, PKB, S6K, and GSK3beta were relatively low in the heart. Even though CK2 protein and activity levels were reduced by approximately 60% in 365 day as compared to 1-day-old rats, expression of CK2 in the adult heart was as high as detected in any of the other rat tissues. The high basal activities of CK2 in early neonatal heart may be associated with the proliferating state of myocytes.

Gas chromatographic-mass spectrometric determination of urinary oxoacids using O-(2,3,4,5,6-pentafluorobenzyl)oxime-trimethylsilyl ester derivatization and cation-exchange chromatography

We introduced a new combined method to isolate, purify and quantify oxoacids in human urine. Preparation of O-(2,3,4,5,6-pentafluorobenzyl) oximes of oxoacids at pH 2 to 3 was followed by cation-exchange column chromatography for removing the biological interferences. The effluent with water was extracted with ethyl acetate and the oxoacids were quantitatively converted into their trimethylsilyl derivatives for detection by gas chromatography-mass spectrometry. Good quality control data were obtained through precision and accuracy tests. Analytical recoveries (53.5-99.8%) were quantitative for a wide variety of oxoacids. This method was used for the measurement of 18 oxoacids in the urine of healthy volunteers.

Estrogens and polyamines in breast cancer: their profiles and values in disease staging

The urinary concentrations of 16 estrogens and 11 polyamines were quantitatively determined by gas chromatography-mass spectrometry and gas chromatography with nitrogen-phosphorus detection. Samples from patients with stages I-IV of breast cancer (35 cases, aged 27-65 years) as well as from age-matched normal female subjects (25 cases, aged 22-61 years) were tested. Also, the ratios of precursor to product metabolite including 16alpha-OH E1 to 2-OH E1, which are linked to estrogen and polyamine biosynthetic pathways, were determined to explore enzyme involvement in breast cancer and to evaluate the potential usefulness of these ratios and concentrations as disease staging markers. It was confirmed that major estrogens and 16a-OH E1 were positively associated with breast cancer and catechol estrogens including 2-OH E1 were inversely associated with breast cancer. The ratios of N1-acSp/Spd and 16alpha-OH E1/2-OH E1 might be a useful dual marker for staging of breast cancer. From the variation of the relative ratios of polyamines, it is suggested that alteration in polyamine oxidase (PAO) activity may play an important role in the development of breast cancer.

Expression of mitogen-activated protein kinase pathways during postnatal development of rat heart

The loss of ability to proliferate (terminal differentiation) and reduction in capability to resist ischemia are key phenomena observed during postnatal development of the heart. Mitogen-activated protein kinases (MAPKs) mediate signaling pathways for cell proliferation/differentiation and stress responses such as ischemia. In this study, the expression of these kinases and their associated kinases were investigated in rat heart ventricle. Extracts of 1-, 10-, 20-, 50-, and 365-day-old rat heart ventricles were probed with specific antibodies and their immunoreactivities were quantified by densitometry. Most of the mitogenic protein kinases including Raf1, RafB, Mek1, Erk2, and Rsk1 were significantly down-regulated, whereas the stress signaling kinases, such as Mlk3, Mekkl, Sekl, Mkk3, and Mapkapk2 were up-regulated in expression during postnatal development. Most MAP kinases including Erk1, JNKs, p38 Hog, as well as Rsk2, however, did not exhibit postnatal changes in expression. The proto-oncogene-encoded kinases Mos and Cot/Tpl 2 were up-regulated up to two- and four-fold, respectively, during development. Pakl, which may be involved in the regulation of cytoskeleton as well as in stress signaling, was downregulated with age, but the Pak2 isoform increased only after 50 days. All of these proteins, except RafB, were also detected in the isolated adult ventricular myocytes at comparable levels to those found in adult ventricle. Tissue distribution studies revealed that most of the protein kinases that were up-regulated during heart development tended to be preferentially expressed in heart, whereas the downregulated protein kinases were generally expressed in heart at relatively lesser amounts than in most of other tissues.

Thiopental attenuates relaxation and cyclic GMP production in vascular smooth muscle of endotoxin-treated rat aorta, independent of nitric oxide production

As thiopental (thiopentone) suppresses cyclic GMP (cGMP) formation produced by nitric oxide donor drugs, we have tested if it suppresses cGMP formation and increases vascular tone after induction of calcium-calmodulin-independent nitric oxide synthase (iNOS). Rat aortic rings were treated with Escherichia coli lipopolysaccharide (LPS) 1 microgram ml-1 for 4 h, and the effects of thiopental on tension, cGMP concentrations and nitrite accumulation were determined. Thiopental 0.3 mmol litre-1 reduced the tension of phenylephrine-precontracted aortic rings before LPS treatment, but caused no significant effects on tension in the presence of L-arginine 10 mumol litre-1 after LPS treatment. L-Arginine 1 mumol litre-1 to 1 mmol litre-1 increased concentrations of cGMP in LPS-treated aorta in a concentration-dependent manner. This was reduced by thiopental 0.3-1 mmol litre-1. Treatment with L-arginine 1 mmol litre-1 increased concentrations of nitrite, the end product of nitric oxide; this was not affected by thiopental 1 mmol litre-1. We conclude that thiopental suppressed cGMP formation in iNOS-induced vascular smooth muscle without affecting nitric oxide production.

Expression of second messenger- and cyclin-dependent protein kinases during postnatal development of rat heart

During early postnatal development, cardiomyocytes, which comprise about 80% of ventricular mass and volume, become phenotypically developed to facilitate their contractile functions and terminally differentiated to grow only in size but not in cell number. These changes are due to the expression of contractile proteins as well as the regulation of intracellular signal transduction proteins. In this study, the expression patterns of several protein kinases involved in various cardiac functions and cell-cycle control were analyzed by Western blotting of ventricular extracts from 1-, 10-, 20-, 50-, and 365-day-old rats. The expression level of cAMP-dependent protein kinase was slightly decreased (20%) over the first year, whereas no change was detected in cGMP-dependent protein kinase I. Calmodulin-dependent protein kinase II, which is involved in Ca2+ uptake into the sarcoplasmic reticulum, was increased as much as ten-fold. To the contrary, the expressions of protein kinase C-alpha and iota declined 77% with age. Cyclin-dependent protein kinases (CDKs) such as CDK1, CDK2, CDK4, and CDK5, which are required for cell-cycle progression, abruptly declined to almost undetectable levels after 10-20 days of age. In contrast, other CDK-related kinases, such as CDK8 or Kkialre, did not change significantly or increased up to 50% with age, respectively. Protein kinases implicated in CDK regulation such as CDK7 and Wee1 were either slightly increased in expression or did not change significantly. All of the proteins that were detected in ventricular extracts were also identified in isolated cardiac myocytes in equivalent amounts and analyzed for their relative expression in ten other adult rat tissues.

Electron donation to the flavoprotein NifL, a redox-sensing transcriptional regulator

Transcriptional control of the nitrogen fixation (nif) genes in response to oxygen in Azotobacter vinelandii is mediated by nitrogen fixation regulatory protein L (NifL), a regulatory flavoprotein that modulates the activity of the transcriptional activator nitrogen fixation regulatory protein A (NifA). CD spectra of purified NifL indicate that FAD is bound to NifL in an asymmetric environment and the protein is predominantly alpha-helical. The redox potential of NifL is -226 mV at pH 8 as determined by the enzymic reduction of NifL by xanthine oxidase/xanthine in the presence of appropriate mediators. The reduction of NifL by xanthine oxidase prevented NifL from acting as an inhibitor of NifA. In the absence of electron mediators NifL could also be reduced by Escherichia coli flavohaemoprotein (Hmp) with NADH as reductant. Hmp contains a globin-like domain with haem B as prosthetic group and an FAD-containing oxidoreductase module. The carboxyferrohaem form of Hmp was competent to reduce NifL, suggesting that electron donation to NifL originates from the flavin in Hmp rather than by direct electron transfer from the haem. Spinach ferredoxin:NAD(P) oxidoreductase, which adopts a folding similar to the FAD- and NAD-binding domains of Hmp, also reduced NifL with NADH as reductant. Re-oxidation of NifL occurs rapidly in the presence of air, raising the possibility that NifL might sense intracellular oxygen. We propose a physiological redox cycle in which the oxidation of NifL by oxygen and hence the activation of its inhibitory properties occurs rapidly, in contrast with the switch from the active to the reduced form of NifL, which occurs more slowly.

Nucleotide sequence of nucleocapsid protein (N) of Hantaan virus isolated from a Korean hemorrhagic fever patient

The nucleotide sequence of the nucleocapsid protein (N) coding region of a Hantaan virus strain (CFC94-2) isolated from a Korean Hemorrhagic Fever (KHF) patient was determined by sequencing a series of deletion mutants. Comparison of the N coding sequence of CFC94-2 to the sequence of the prototype of Hantaan virus, strain 76-118 reveals a 4.97% difference in the nucleotide sequence and a 1.6% difference in the deduced amino acid sequence. The rate of amino acid sequence variation in N protein of different Hantaan viruses (1.6%) is quite similar to that in G1 and G2 envelope proteins (1.7%). These results suggest that N protein may be under a similar selection pressure to G1 and G2 envelope proteins against host immune system.

Norms for Behavior and Conditions in Two National Park Campgrounds in Korea

/ This study was conducted to examine norm prevalence, norm agreement, and norm stability in an international setting. Data were collected at two campgrounds in Chiri-Mountain National Park, Korea, in 1993 and 1994. Results showed that a high proportion of users could specify norms for various types of campground impacts. Users who rated high importance on impacts tended to show a higher level of norm prevalence. Generally there were differences in social norms and norm agreement across locations. Among those impacts that showed differences, social norms in a less developed area were more restrictive and norm agreement was higher. The results of this study are consistent with normative studies conducted in North America, suggesting that a normative approach can be applied in a variety of settings. Social norms for selected impact indicators were also stable over a one-year time period. Implications are discussed.KEY WORDS: Norms; Norm prevalence; Norm agreement; Norm stability

Involvement of the Src homology 2-containing tyrosine phosphatase SHP-2 in growth hormone signaling

Growth hormone (GH) signaling requires activation of the GH receptor (GHR)-associated tyrosine kinase, JAK2. JAK2 activation by GH is believed to facilitate initiation of various pathways including the Ras, mitogen-activated protein kinase, STAT, insulin receptor substrate (IRS), and phosphatidylinositol 3-kinase systems. In the present study, we explore the biochemical and functional involvement of the Src homology 2 (SH2)-containing protein-tyrosine phosphatase, SHP-2, in GH signaling. GH stimulation of murine NIH 3T3-F442A fibroblasts, cells that homologously express GHRs, resulted in tyrosine phosphorylation of SHP-2. As assessed specifically by anti-SHP-2 coimmunoprecipitation and by affinity precipitation with a glutathione S-transferase fusion protein incorporating the SH2 domains of SHP-2, GH induced formation of a complex of tyrosine phosphoproteins including SHP-2, GHR, JAK2, and a glycoprotein with properties consistent with being a SIRP-alpha-like molecule. A reciprocal binding assay using IM-9 cells as a source of SHP-1 and SHP-2 revealed specific association of SHP-2 (but not SHP-1) with a glutathione S-transferase fusion incorporating GHR cytoplasmic domain residues 485-620, but only if the fusion was first rendered tyrosine-phosphorylated. GH-dependent tyrosine phosphorylation of SHP-2 was also observed in murine 32D cells (which lack IRS-1 and -2) stably transfected with the GHR. Further, GH-dependent anti-SHP-2 coimmunoprecipitation of the Grb2 adapter protein was detected in both 3T3-F442A and 32D-rGHR cells, indicating that biochemical involvement of SHP-2 in GH signaling may not require IRS-1 or -2. Finally, GH-induced transactivation of a c-Fos enhancer-driven luciferase reporter in GHR- and JAK2-transfected COS-7 cells was significantly reduced when a catalytically inactive SHP-2 mutant (but not wild-type SHP-2) was coexpressed; in contrast, expression of a catalytically inactive SHP-1 mutant allowed modestly enhanced GH-induced transactivation of the reporter in comparison with that found with expression of wild-type SHP-1. Collectively, these biochemical and functional data imply a positive role for SHP-2 in GH signaling.

Polyamine profiles in the urine of patients with leukemia

Eleven urinary polyamine levels were determined in controls (32 cases) and 43 patients with varying stages of leukemia including initial, relapse and complete remission, using gas chromatography nitrogen-phosphorus detection. Also, to indirectly evaluate the possible involvement of enzymes, precursor to product concentration ratios were compared between controls and patients with each stage of leukemia. As a result, it is confirmed that the ratio of N1-acSpd/N8-acSpd could be used as a diagnostic marker and the level of N1,N12-diacetylspermine could be used for determining disease stage and as a malignancy marker for leukemia. An altered metabolic pathway related to leukemia is also proposed in which N1,N12-diacetylspermine can be produced directly from spermine and N1,N12-diacetylspermine is a major source of N1-acetylspermidine.

Paraquat regulation of hmp (flavohemoglobin) gene expression in Escherichia coli K-12 is SoxRS independent but modulated by sigma S

We report the first example of a gene, hmp, encoding a soluble flavohemoglobin in Escherichia coli K-12, which is up-regulated by paraquat in a SoxRS-independent manner. Unlike what is found for other paraquat-inducible genes, high concentrations of paraquat (200 microM) were required to increase the level of hmp expression, and maximal induction was observed only after 20 min of exposure to paraquat. Neither a mutation in soxS nor one in soxR prevented the paraquat-dependent increase in phi(hmp-lacZ) expression, but either mutant allele delayed full expression of phi(hmp-lacZ) activity after paraquat addition. Induction of hmp by paraquat was demonstrated in aerobically grown cultures during exponential growth and the stationary phase, thus revealing two Sox-independent regulatory mechanisms. Induction of hmp by paraquat in the stationary phase was dependent on the global regulator of stationary-phase gene expression, RpoS (sigma S). However, a mutation in rpoS did not prevent an increase in hmp expression by paraquat in exponentially growing cells. Induction of sigma S in the exponential phase by heat shock also induced phi(hmp-lacZ) expression in the presence of paraquat, supporting the role of sigma S in one of the regulatory mechanisms. Mutations in oxyR or rob, known regulators of several stress promoters in E. coli, had no effect on the induction of hmp by paraquat. Other known superoxide-generating agents (plumbagin, menadione, and phenazine methosulfate) were not effective in inducing hmp expression.

Growth hormone receptor cytoplasmic domain differentially promotes tyrosine phosphorylation of signal transducers and activators of transcription 5b and 3 by activated JAK2 kinase

GH-induced activation of JAK2, a GH receptor (GHR)-associated tyrosine kinase, leads to tyrosine phosphorylation and activation of STATs (signal transducers and activators of transcription) 1, 3, and 5. The present study investigates the importance of the GHR cytoplasmic domain in the activation of STAT3 and STAT5b. As the perimembranous Box1 region of the GHR cytoplasmic domain is necessary for activation of wild-type (WT) JAK2 by GH, we examined this question using GHR/JAK2 chimeras that have an activatable JAK2 kinase domain replacing the GHR cytoplasmic domain. STAT5b and STAT3, when each was coexpressed in COS-7 cells with WT GHR and WT JAK2, were both strongly tyrosine phosphorylated in response to GH. Coexpression of STAT3 with GHR/ JAK2 chimeras resulted in a strong GH-independent tyrosine phosphorylation of STAT3 that was 40% as active as that seen with WT GHR plus WT JAK2, whereas STAT5b was more minimally phosphorylated (13% of WT GHR plus WT JAK2) when coexpressed with chimeras devoid of the GHR cytoplasmic domain. Transient coexpression of each STAT together with WT JAK2 and GHR COOH-terminal truncation mutants indicated that a GH-induced STAT3-DNA binding complex, but not a STAT5b-DNA binding complex, was detectable when a GHR devoid of 85% of the cytoplasmic domain COOH-terminus (but eliciting significant JAK2 tyrosine phosphorylation) was expressed. In vitro binding experiments using GST/GHR cytoplasmic domain fusions demonstrated that both STATs could interact at a low basal level with GHR regions distal to residue 317. Phosphorylation of tyrosine residues in those distal regions greatly enhanced the receptor's interaction with STAT5b, but not STAT3. We conclude that GH induces activation of STAT3 and STAT5b by two different pathways: one primarily dependent on activation of JAK2 (STAT3) and another that is additionally reliant on the presence of an intact and tyrosine-phosphorylated GHR cytoplasmic domain (STAT5b).

Regulation of plasminogen receptor expression on monocytoid cells by beta1-integrin-dependent cellular adherence to extracellular matrix proteins

Plasminogen binding sites function to arm cell surfaces with the proteolytic activity of plasmin, critical for degradation of extracellular matrices. We have assessed the effects of adhesion of the representative monocytoid cell lines, THP-1 and U937, to purified extracellular matrix proteins on their expression of plasminogen receptors. After adhesion to immobilized fibronectin, adherent and nonadherent subpopulations of cells were separated. Plasminogen binding to the nonadherent population of cells increased 3-fold, whereas binding to the adherent population decreased by 60%. These changes were due to differences in the plasminogen binding capacities of the cells, while the affinities of the cells for plasminogen were unchanged. The up-regulation of receptor expression in the nonadherent cell population was: 1) induced rapidly and reversibly, 2) independent of new protein synthesis, 3) required an interaction between adherent and nonadherent cell populations, and 4) associated with an enhanced ability of the cells to promote plasminogen activation and to degrade fibronectin. Other immobilized adhesive proteins, laminin and vitronectin, also supported up-regulation of plasminogen receptors in the nonadherent cells. Carboxypeptidase B treatment eliminated the increment in the plasminogen binding capacity of the nonadherent cells, suggesting that the increase in binding was due to exposure of new carboxyl-terminal lysyl residues on the cell surfaces. Furthermore, both the adherence of the cells and up-regulation of plasminogen binding sites was abolished by beta1-integrin monoclonal antibodies. These results suggest that proteins found in extracellular matrices have the capacity to modulate the expression of plasminogen binding sites, thus regulating local proteolysis and cell migration.

Nitric oxide, nitrite, and Fnr regulation of hmp (flavohemoglobin) gene expression in Escherichia coli K-12

Escherichia coli possesses a soluble flavohemoglobin, with an unknown function, encoded by the hmp gene. A monolysogen containing an hmp-lacZ operon fusion was constructed to determine how the hmp promoter is regulated in response to heme ligands (O2, NO) or the presence of anaerobically utilized electron acceptors (nitrate, nitrite). Expression of the phi (hmp-lacZ)1 fusion was similar during aerobic growth in minimal medium containing glucose, glycerol, maltose, or sorbitol as a carbon source. Mutations in cya (encoding adenylate cyclase) or changes in medium pH between 5 and 9 were without effect on aerobic expression. Levels of aerobic and anaerobic expression in glucose-containing minimal media were similar; both were unaffected by an arcA mutation. Anaerobic, but not aerobic, expression of phi (hmp-lacZ)1 was stimulated three- to four-fold by an fnr mutation; an apparent Fnr-binding site is present in the hmp promoter. Iron depletion of rich broth medium by the chelator 2'2'-dipyridyl (0.1 mM) enhanced hmp expression 40-fold under anaerobic conditions, tentatively attributed to effects on Fnr. At a higher chelator concentration (0.4 mM), hmp expression was also stimulated aerobically. Anaerobic expression was stimulated 6-fold by the presence of nitrate and 25-fold by the presence of nitrite. Induction by nitrate or nitrite was unaffected by narL and/or narP mutations, demonstrating regulation of hmp by these ions via mechanisms alternative to those implicated in the regulation of other respiratory genes. Nitric oxide (10 to 20 microM) stimulated aerobic phi (hmp-lacZ)1 activity by up to 19-fold; soxS and soxR mutations only slightly reduced the NO effect. We conclude that hmp expression is negatively regulated by Fnr under anaerobic conditions and that additional regulatory mechanisms are involved in the responses to oxygen, nitrogen compounds, and iron availability. Hmp is implicated in reactions with small nitrogen compounds.

Increased expression of the insulin-like growth factor I (IGF-I) receptor gene in hepatocellular carcinoma cell lines: implications of IGF-I receptor gene activation by hepatitis B virus X gene product

Hepatitis B virus infection is associated with acute and chronic liver disease and the development of hepatocellular carcinoma (hcc). Several lines of evidence have suggested that hepatitis B virus X protein (HBx), which is a transcriptional trans-activator, plays a role in the process of liver carcinogenesis. We have investigated the expression of insulin-like growth factor I (IGF-I) receptor in human hepatocellular carcinoma cell lines using SNU368 cells containing HBx and SNU387 cells, which lack HBx gene transcript (J-G. Park et al., Int. J. Cancer, 62: 276-282, 1995), in an attempt to understand its possible relationship to the HBx-induced hcc. The binding of 125I-labeled IGF-I to the SNU368 cells was 5-fold higher than that of SNU387 cells. The Scatchard analysis of the binding data revealed a single class binding site for IGF-I with Kd of 7.6 and 8.8 nM and maximum binding capacities of 169 and 33 fmol/10(5) cells, respectively. Therefore, the difference observed in 125I-labeled IGF-I binding between SNU368 and SNU387 cells was due to an increase in the number of IGF-I binding sites with no change in affinity for the IGF-I receptor. An enhanced level of IGF-I receptors in SNU368 cells was also observed by fluorescence-activated cell sorting analysis using a monoclonal antibody against human IGF-I receptor, alpha IR3. The level of IGF-I receptor RNA and the basal IGF-I receptor gene promoter activity in SNU368 cells were 5 and 10 times higher than those observed in SNU387 cells, respectively. To substantiate further that HBx could transactivate the expression of the endogenous IGF-I receptor gene, Hep G2 cells were transiently transfected with a HBx expression vector. The transfection of Hep G2 cells with an HBx expression vector resulted in increased levels of IGF-I receptor RNA, promoter activity, and 125I-labeled IGF-I binding by 2.6-, 2.8-, and 2-fold, respectively. As a result of higher levels of IGF-I receptor, the mitogenic effect of IGFs (IGF-I and IGF-II) on SNU368 cells was 6 times higher than that of SNU387 cells. These results suggest that HBx may play a role in the process of hcc by activating IGF-I receptor gene expression.

Double-stranded RNAs in Korean isolates of Rhizoctonia solani AG4

Eighty-one isolates of Rhizoctonia solani AG4 were obtained from soil samples with diverse geographic origins in Korea. Forty-five out of 81 isolates (56%) contained at least one dsRNA molecule with their sizes ranging from 2.3 to > 23.1 kb. Nine different sizes of dsRNA molecules were found and extensive variation in banding patterns was observed among isolates. By comparing the sizes and combinations of dsRNAs, 21 distinct banding patterns were observed. Cytoplasmic fractions from 3 isolates showed the same dsRNA band patterns as those from the total cell extracts. The dsRNAs were stable through 10 successive hyphal tip cultures and serial transfers onto the potato dextrose agar supplemented with cycloheximide or emetine. The presence or absence of dsRNAs was not apparently correlated with disease severity, phenol oxidase activity, and geographic origin.

High-level expression and simple purification of recombinant human insulin-like growth factor I

Human insulin-like growth factor I (IGF-I) was expressed in Escherichia coli as a truncated beta-galactosidase-IGF-I fusion protein. The Lac Z" gene was truncated by removal of a 490 bp fragment which encoded 163 N-terminal residues of beta-galactosidase and was connected to the IGF-I cDNA by a linker encoding hydroxylamine cleavage recognition sequence. By truncating Lac Z" gene, the overall yield and purification procedures of IGF-I from fusion protein have been improved. The fusion protein was produced in the form of insoluble inclusion bodies with isopropyl-1-thio-beta-D-galactoside (IPTG) induction. After cleavage of the fusion protein with hydroxylamine, the released IGF-I was purified to homogeneity by a cation exchange chromatography, refolding and reverse-phase high performance liquid chromatography (rp-HPLC). The purified IGF-I was found to be indistinguishable from the native IGF-I by N-terminal amino acid sequence, SDS-polyacrylamide gel electrophoresis, and rp-HPLC and by biological activities such as thymidine uptake, protein synthesis and receptor binding. These results suggest that the expression and simple purification of recombinant human IGF-I described in this paper may be useful for large scale production of IGF-I.

Sequence of ornithine decarboxylase from Lactobacillus sp. strain 30a

A gene encoding biodegradative ornithine decarboxylase from Lactobacillus sp. strain 30a was isolated from a genomic DNA library and sequenced. Primer extension analysis revealed two transcription initiation sites. The deduced amino acid sequence is compared with the amino acid sequences of five previously reported bacterial decarboxylases, and conserved pyridoxal phosphate motif residues are identified.

Hypersensitivity pneumonitis induced by Penicillium expansum in a home environment

An episode of fever, cough, shortness of breath and leucocytosis developed in a 31-year-old atopic housewife from mould exposure in her home environment is evaluated. A chest radiograph revealed diffuse tiny nodular infiltrations in both whole lung fields. Spirometry revealed a severe restrictive type of ventilation impairment. Bronchoalveolar lavage (BAL) showed an increased lymphocyte count with reversed CD4+/CD8+ ratio and transbronchial lung biopsy showed markedly increased lymphocytic infiltration in alveolar septa. Fungal cultures in the air of her home were positive for Penicillium expansum and other fungi. Double immunodiffusion test with the patient's serum showed two precipitin bands to P. expansum antigens. Her symptoms, abnormal findings of radiograph, and spirometric abnormalities disappeared after 2 months' avoidance. The serum precipitin disappeared after 1 month's avoidance. This study indicates that the patient had hypersensitivity pneumonitis (HP) on exposure to P. expansum in her home environment.

Effect of subinhibitory concentrations of Ciprofloxacin and gentamicin on the adherence of Pseudomonas aeruginosa to Vero cells and voided uroepithelial cells

The effect of subinhibitory concentrations (1/8 x, 1/16 x, 1/32 x MIC) of ciprofloxacin or gentamicin on the adherence of Pseudomonas aeruginosa to Vero cells and voided uroepithelial cells was studied using two different assay methods. Strains studied included both reference strains and clinical strains, including mucoid and nonmucoid isolates. Sub-MICs of ciprofloxacin decreased adherence to Vero cells and voided uroepithelial cells in 3 of 4 ciprofloxacin-susceptible nonmucoid isolates but not in ciprofloxacin-resistant or mucoid isolates. Sub-MICs of gentamicin significantly reduced adherence in 5 of 7 nonmucoid strains but not in mucoid strains. Gentamicin effect on adherence did not correlate with susceptibility to ciprofloxacin. We conclude that ciprofloxacin susceptibility determines the effect of sub-MICs of ciprofloxacin on P. aeruginosa adherence to Vero cells and voided uroepithelial cells. In addition, both the Vero cell assay and voided uroepithelial cell assay demonstrated similar results.

Purification of the human blood platelet thromboxane A2/prostaglandin H2 receptor protein

The human platelet thromboxane A2/prostaglandin H2 receptor has been purified 6100-fold to apparent homogeneity by a three-step chromatographic procedure with an overall yield of 6%. A 6-fold purification of the receptor was first achieved by chromatography of 3-[(3-cholamidopropyl)dimethyl-ammonio]-1-propanesulfonate (CHAPS)-solubilized membrane proteins from human platelets on a diethylaminoethyl (DEAE)-Sepharose column. The DEAE eluate fractions containing receptor activity were then applied to a newly developed affinity column using the cyclohexyl derivative of SQ30,741 (SQ31,491) as the immobilized ligand. Elution of the receptor from the affinity column with BM13.177 yielded a further purification of 1700-fold. An additional 4-fold receptor purification from the affinity column eluate was achieved by HPLC using GPC 500 and GPC 100 columns connected in tandem. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining of the HPLC eluate containing purified receptor revealed a single, distinct band with a molecular weight of 55,000. The receptor binding activity was detected with [3H]SQ29,548 using a newly developed binding assay which involved immobilization of the receptor on polyethyleneimine-treated glass fiber filters. The binding of [3H]SQ29,548 to the purified receptor was time dependent, saturable, reversible and highly specific. Unlabeled SQ29,548, BM13.505, and U46619 (but not thromboxane B2 or 6-keto prostaglandin F1 alpha) competed for [3H]SQ29,548 binding to the purified receptor in a concentration-dependent manner. Scatchard analysis of [3H]SQ29,548 binding to the purified receptor revealed the presence of a single class of high-affinity binding sites, with a Kd of 4 nM and a Bmax of 17 nmol/mg protein.

Polymorphism in V kappa 10 genes encoding L chains of antibodies bearing the Ars-A and A48 cross-reactive idiotypes

p-azophenylarsonate-specific antibodies of A/J mice which bear the Ars-A crossreactive idiotype utilize the V kappa-Ars-A gene segment, a member of the V kappa 10 family. Southern hybridization of genomic DNA from several inbred strains using a probe from the 5' flanking region of the V kappa-Ars-A gene demonstrated three patterns of restriction fragment length polymorphisms (RFLP). Six genes corresponding to hybridizing bands were obtained from DNA libraries of C.AKR, PERU and A/J mice, and nucleotide sequence comparisons revealed two allelic groups: AKR1 (Igk-V10.1a), AJ1 (Igk-V10.1b) and PERU1 (Igk-V10.1c); AKR2 (Igk-V10.2a), AJ2 (Igk-V10.2b), and PERU2 (Igk-V10.2c). The Igk-V10.1b gene of the A/J strain is the V kappa-Ars-A gene used in Ars-A idiotype-positive antibodies. The product of the C.AKR allele (Igk-V10.1a) contained four amino acid substitutions in CDR3 as compared with Igk-V10.1b. These substitutions probably explain the failure of AKR mice and other strains with the same V kappa 10 RFLP pattern to provide in genetic crosses a L chain which, together with the A/J VH-ArsA gene product, form Ars-A idiotype-positive antibodies. Also, the nucleotide sequence identity between the Igk-V10.1c and Igk-V10.1b alleles and the Igk-V10.2c and Igk-V10.2b alleles is significantly greater than that seen in comparisons with the Igk-V10.1a and Igk-V10.2a alleles, respectively, suggesting an evolutionary pathway similar to that of the linked Igk-J locus. BALB/c antibodies bearing the A48 regulatory idiotype contain L chains encoded by the BALB/c Igk-V10.1b and Igk-V10.2b alleles. Strongly A48 idiotype-positive antibodies utilize the Igk-V10.1b chain, and weakly A48-positive antibodies use the Igk-V10.2b L chain. The possible effects of amino acid substitutions specified by the Igk-V10.1a, Igk-V10.1c, Igk-V10.2a, and Igk-V10.2c alleles on their ability to provide L chains used in A48 idiotype-positive antibodies are discussed.

Type III hypersensitivity reaction in mushroom growers

Some respiratory symptoms in mushroom growers such as mushroom worker's lung develop by inhalation of certain agents arising from the environment of mushroom cultivation. Recently we observed mushroom workers who had respiratory symptoms which might be type III hypersensitivity reaction to the antigen of Pleurotus floridae. We gave questionnaires to all the mushroom growers at one of the biggest cultivation areas of mushrooms, Pleurotus floridae in Pocheon, Kyunggi Province. Those with respiratory symptoms were subjects for the study. CBC, chest X-ray, pulmonary function test, skin test with Pleurotus floridae extract, and precipitin antibody test to Pleurotus floridae were performed in the study subjects. Out of a total 308 mushroom workers, 23 workers (14 males, 9 females) had respiratory symptoms. Their mean age was 45 years, and their mean duration of engagement was 3.4 years. Their main symptoms were cough (100%), sputum (82.6%), dyspnea (43.5%), and fever with chills (13.0%). Two cases showed increased interstitial lung markings on chest X-ray films. Sixteen cases (73.9%) showed precipitin antibodies against P. floridae extract by counterimmunoelectrophoresis. Antibodies against Micropolyspora faeni and Thermoactinomyces vulgaris were not detected in any subject.

Influence of photoperiod and 6-methoxybenzoxazolinone on the reproductive axis of inbred LSH/Ss Lak male hamsters

Adult male Syrian hamsters of the inbred LSH/Ss Lak strain were maintained under a 14L:10D light cycle until 13 weeks of age. At this point, they were implanted s.c. with elastomer capsules that were either empty or packed with 30-40 mg of 6-methoxybenzoxazolinone (6-MBOA), a compound found naturally in some monocotyledonous plants; half of the animals from each treatment group were then kept in long days (14L:10D) or transferred to short days (9L:15D). Testicular size was measured and blood samples collected from each hamster immediately before capsule implantation and again 2, 4, 6 and 8 weeks later. Within just 2 weeks of exposure to short days the mean plasma levels of LH and FSH had significantly declined, in both the control and 6-MBOA-treated animals, and were basal within 4 weeks. Testicular size closely followed these gonadotrophin changes; within 4-6 weeks the testes from all of the short-day hamsters had completely regressed to a prepubertal size. At the end of the experiment, at Week 8, the animals were killed and various components of the hypothalamo-pituitary-testicular axis were compared between the treatment groups. The pituitary content of FSH and LH, testicular weight, mean serum level of testosterone, but not hypothalamic LHRH content or pituitary gland weight, were considerably lower in the short-day than in the long-day hamsters, regardless of whether or not they had been chronically treated with 6-MBOA.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of indomethacin by a controlled, cross-over technique in 30 patients with ankylosing spondylitis

A clinical evaluation of indomethacin employing a controlled, cross-over technique with an inert placebo was undertaken in 30 patients with ankylosing spondylitis. Patients were studied for the frequency and dose relationship of side effects and for the subjective response of morning stiffness, chronic spinal pain, acute exacerbations of pain and peripheral arthralgia. Objective evaluation assessed measured change in movements of the cervical and lumbar spines, in chest expansion and in the range of movement of involved peripheral joints.Evaluation of the results indicated that a significant number of patients experienced side effects in the form of headache and dizziness while receiving indomethacin in doses above 150 mg. per day. Many other side effects reported by the patients were not found to occur at a statistically significant level. The significance of pulmonary infections encountered in three patients was reviewed. Relief of chronic spinal pain and peripheral arthralgia occurred in 14 and 16 patients, respectively (p < 0.05). Relief of morning stiffness and acute exacerbations of pain, and increase in the range of movement of any of the segments of the spine or the involved peripheral joints were not significant (p > 0.05). Based on the results of this study, it is suggested that the role of indomethacin in the management of ankylosing spondylitis be re-evaluated and that the daily therapeutic dose of this drug which has been heretofore recommended be decreased.