First results on 236U levels in global fallout

The global fallout (236)U level in soil was deduced from measurements of (236)U, (239+240)Pu and (137)Cs in surface soils which are solely influenced by global fallout. A total of 12 soil cores from the depths of 0-10, 0-20 and 0-30 cm were collected at a flat forest area in Japan. Concentrations of (239+240)Pu and (238)U were determined by alpha-particle spectrometry, while the (236)U/(238)U ratio was measured with accelerator mass spectrometry (AMS). Consistent (236)U/(239)Pu ratios between 0.212 and 0.253 were found. Using this ratio, the total global fallout of (236)U on the earth is estimated to be as much as ca. 900 kg. This knowledge will contribute to the promotion of research on U isotopes, including (236)U, for the fields of geo-resources, waste management and geochemistry.

Nicotianamine synthase specifically expressed in root nodules of Lotus japonicus

In dicotyledonous plants, nicotianamine synthase (NAS) is thought to play a role in the intercellular transport of iron (Fe). Fe is an essential metal for nitrogen-fixing root nodules of legumes, prompting us to characterize the role of the NAS gene in detail. We previously compared gene-expression profiles in ineffective nodules formed on a Lotus japonicus Fix(-) mutant, sen1, with those in wild-type-effective nodules, and showed that expression of an expressed sequence tag (EST) clone encoding an NAS (EC 2.5.1.43) homologue was repressed in the ineffective nodules. In the present study, two EST clones encoding NAS homologues were found in the EST database. We named them LjNAS1 and LjNAS2. Both were detected as single-copy genes in the L. japonicus genome, and conferred NAS activities in transformed Saccharomyces cerevisiae. LjNAS2 was expressed only in nodules, but LjNAS1 was expressed mainly in leaves, stems, and cotyledons. The level of LjNAS2 transcripts was highest in the nodules 24 days after inoculation with Mesorhizobium loti, and was localized in vascular bundles within the nodules. Expression of LjNAS2 was suppressed in ineffective nodules formed on Fix(-) mutants other than sen1. By contrast, nitrogenase activities of nodules were not influenced in LjNAS2-suppressed plants. We discuss the role of LjNAS2 from the aspect of Fe translocation in nodules.

Determination of 240Pu/239Pu isotopic ratios in human tissues collected from areas around the Semipalatinsk Nuclear Test Site by sector-field high resolution ICP-MS

Information on the 240Pu/239Pu isotope ratios in human tissues for people living around the Semipalatinsk Nuclear Test Site (SNTS) was deduced from 9 sets of soft tissues and bones, and 23 other bone samples obtained by autopsy. Plutonium was radiochemically separated and purified, and plutonium isotopes (239Pu and 240Pu) were determined by sector-field high resolution inductively coupled plasma-mass spectrometry. For most of the tissue samples from the former nine subjects, low 240Pu/239Pu isotope ratios were determined: bone, 0.125 +/- 0.018 (0.113-0.145, n = 4); lungs, 0.063 +/- 0.010 (0.051-0.078, n = 5); and liver, 0.148 +/- 0.026 (0.104-0.189, n = 9). Only 239Pu was detected in the kidney samples; the amount of 240Pu was too small to be measured, probably due to the small size of samples analyzed. The mean 240Pu/239Pu isotope ratio for bone samples from the latter 23 subjects was 0.152 +/- 0.034, ranging from 0.088 to 0.207. A significant difference (a two-tailed Student's t test; 95% significant level, alpha = 0.05) between mean 240Pu/239Pu isotope ratios for the tissue samples and for the global fallout value (0.178 +/- 0.014) indicated that weapons-grade plutonium from the atomic bombs has been incorporated into the human tissues, especially lungs, in the residents living around the SNTS. The present 239,240Pu concentrations in bone, lung, and liver samples were, however, not much different from ranges found for human tissues from other countries that were due solely to global fallout during the 1970's-1980's.

Spatial distribution of soil contamination by 137Cs and 239,240Pu in the village of Dolon near the Semipalatinsk nuclear test site: new information on traces of the radioactive plume from the 29 August 1949 nuclear test

The village of Dolon located about 60 km northeast from the border of the Semipalatinsk Nuclear Test Site in Kazakhstan is one of the most affected inhabited settlements as a result of nuclear tests by the former USSR. Radioactive contamination in Dolon was mainly caused by the first USSR nuclear test on 29 August 1949. As part of the efforts to reconstruct the radiation dose in Dolon, Cs and Pu in soil samples collected from 26 locations in the vicinity of and within the village were measured to determine the width and position of the center-axis of the radioactive plume that passed over the village from the 29 August 1949 nuclear test. Measured soil inventories of Cs and Pu were plotted as a function of the distance from the supposed center-axis of the plume. A clear shape similar to a Gaussian function was observed in their spatial distributions with each maximum around a center-axis. It was suggested that the plume width that contaminated Dolon was at most 10 km and the real center-axis of the radioactive plume passed 0.7-0.9 km north of the supposed centerline. A peak-like shape with the maximum near the center-axis was also observed in the spatial distribution of the Pu/Cs activity ratio, which may reflect the fractionation effect between Pu and Cs during the deposition process. These results support the recently reported results. The data obtained here will provide useful information on the efforts to estimate radiation dose in Dolon as reliably as possible. Health Phys. 94(4):328-337; 2008.

Association of serum undercarboxylated osteocalcin with serum estradiol in pre-, peri- and early post-menopausal women

OBJECTIVE

We investigated changes in serum concentration of undercarboxylated osteocalcin (ucOC), which is a sensitive marker of vitamin K status, and association of ucOC concentration with estradiol concentration in pre-, peri- and early post-menopausal women.

METHODS

The study population consisted of 193 pre-, peri- and post-menopausal Japanese women aged 39-66 yr. Serum ucOC concentration was measured to assess vitamin K status; serum concentrations of intact osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) were measured as bone formation markers; and urine concentration of N-telopeptide was measured as a bone resorption marker. Serum estradiol and estrone concentrations were measured by a highly sensitive radioimmunoassay. Bone mineral density (BMD) was measured at the lumbar spine.

RESULTS

Serum concentration of ucOC in peri-menopausal women was significantly (p=0.0005) higher than that in pre-menopausal women, while serum OC concentration in post-menopausal women for whom 1 yr had passed since menopause was significantly (p=0.0003, p=0.024, respectively) higher than the concentrations in pre-menopausal and peri-menopausal women. Serum ucOC concentration showed a significant negative correlation with estradiol concentration (r=-0.372, p<0.0001) and a significant positive correlation with serum FSH concentration (r=0.324, p<0.0001). Serum OC concentration was positively correlated with serum FSH concentration (r=0.317, p<0.001).

CONCLUSIONS

The results showed that the change in ucOC concentration during the menopausal transition is different from that in OC concentration. In addition, serum ucOC concentration is closely associated not only with FSH concentration but also estradiol concentration.

The use of enzyme-linked immunosorbent assays (ELISA) for the determination of pollutants in environmental and industrial wastes

Twelve enzyme-linked immunosorbent assays (ELISA), for the determination of surfactants [linear alkylbenzene sulfonates (LAS), alkyl ethoxylates (AE), and alkylphenol ethoxylates (APE)], endocrine disruptors [alkylphenol (AP), AP + APE, and bisphenol A (BPA)], estrogens [17beta-estradiol (E2), estrone (El), estrogen (ES: El + E2 + estriol (E3)), 1 7alfa-ethynylestradiol (EE2)], dioxins and polychlorinated biphenyls (PCBs), were validated on environmental water and industrial wastes. The lowest quantification limits of these ELISAs were 0.05 microg/L (BPA, E2, El, ES and EE2), 2 microg/L (AE), 3 microg/L (dioxins and PCBs), 5 microg/L (AP, AP + APE) and 20 microg/L (LAS and APE). To apply these ELISAs to environmental or industrial waste samples, simple and appropriate pre-treatment methods were also developed for each ELISA. With optimized pre-treatments, the values of ELISAs were well co-related, in all cases, to those of instrumental analytical methods such as liquid chromatography (HPLC), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and high-resolution gas chromatography mass spectrometry (HR-GC-MS), etc.

Quantitative structure-activity studies of octopaminergic agonists and antagonists against nervous system of Locusta migratoria

The quantitative structure activity relationship (QSAR) of octopaminergic agonists and antagonists against the thoracic nerve cord of the migratory locust, Locusta migratoria L., was analyzed using physicochemical parameters and regression analysis. The hydrophobic effect, dipole moment, and shape index were important in terms of Ki: the more hydrophobic, the greater dipole moment, and the smaller shape index of the molecules, the greater the activity. A receptor surface model (RSM) was generated using some subset of the most active structures. Three-dimensional energetics descriptors were calculated from RSM/ligand interaction and these three-dimensional descriptors were used in QSAR analysis. This data set was studied further using molecular shape analysis.

Quantitative structure-activity studies of octopaminergic 2-(arylimino)thiazolidines and oxazolidines against the nervous system of Periplaneta americana L

The quantitative structure-activity relationship (QSAR) of octopaminergic 2-(arylimino)thiazolidines (AITs) and 2-(arylimino)oxazolidines (AIOs) against the thoracic nerve cord of the American cockroach, Periplaneta americana L., was analysed using reported physicochemical parameters and regression analysis. The more electron-donating, the less bulky at m-position, and the more hydrophobic the substituent, the greater the activity. The plots of observed log Vmax values against calculated log Vmax values having substituents on the m-position deviated downwards from those of compounds having substituents at the 0- and/or p-positions. The more hydrophobic and the more electron-withdrawing the substituent, the greater the activity. AIO with a 2, 3, 4-trichlorophenyl group (58) was more active than its thiazolidine derivative, 2-(2,3,4-trichlorophenylimino)thiazolidine (38) in terms of Vmax:Vmax of 58 was 30% relative to octopamine (OA), whereas that of 38 has been 9% relative to OA, respectively. Superimposition of energy-minimized OA and 58 revealed structural and conformational similarities that might account for the high activity of 58.

Interaction between hypertension and other cardiovascular risk factors in survival of hemodialyzed patients

The interaction of hypertension with other cardiovascular risk factors, namely hypercholesterolemia, smoking, and past history of cardiovascular complications, was examined. One hundred and ninety-five hemodialysis patients were followed up for 54.2 +/- 2.3 months, among whom 66 died. In patients with cardiovascular complications, such as ischemic heart disease, cerebrovascular accident, or atherosclerotic obliteration of peripheral arteries, and in patients older than 70 years, blood pressure had no significant effect on the already poor survival. On the other hand, in patients with hypercholesterolemia (> or = 220 mg/dL) and in smokers, elevated systolic blood pressure made the survival significantly worse. These results suggest an interaction between hypertension and other cardiovascular risk factors in hemodialysis patients.

Role of systolic blood pressure in determining prognosis of hemodialyzed patients

The role of blood pressure in determining the prognosis of hemodialyzed patients was examined in 195 patients who were introduced to hemodialysis. The relationship between blood pressure and survival or death was analyzed. In 46 patients who died within 3 years after the introduction of hemodialysis (nonsurvivors), the age was higher (61 +/- 2 years v 50 +/- 1 years), the occurrence of diabetic nephropathy was higher, and the systolic pressure was higher in both the introduction (178 +/- 4 mm Hg v 167 +/- 2 mm Hg) and maintenance (165 +/- 4 mm Hg v 147 +/- 2 mm Hg) phases than in 132 patients who survived more than 3 years (survivors). On the other hand, there were no significant differences in diastolic pressure during either phase between the two groups of patients. When diabetic nephropathy was excluded, only systolic pressure during the maintenance phase was higher in the nonsurvivors than in the survivors. Therefore, based on systolic pressure during the maintenance phase, patients were divided into two groups, the HT group (> or = 160 mm Hg) and the NT group (< 160 mm Hg), and cumulative survival rates were compared. Whether all patients, only those patients with diabetic nephropathy, or only those patients without diabetic nephropathy were examined, the survival rate was higher in the NT group than in the HT group.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of an angiotensin II receptor antagonist, CV-11974, on angiotensin II-induced increases in cytosolic free calcium concentration, hyperplasia, and hypertrophy of cultured vascular smooth muscle cells

The effects of CV-11974, a potent nonpeptide antagonist of the angiotensin II (AII) type-1 receptor (AT1), on cytosolic free calcium concentration ([Ca2+]i), hyperplasia, and hypertrophy of cultured vascular smooth muscle cells (VSMC) from rat aorta were studied. [Ca2+]i was measured by fura 2, and hyperplasia and hypertrophy were determined by incorporation of [3H]thymidine and [3H]leucine, respectively. CV-11974 had no effect on [Ca2+]i itself, but suppressed 10(-7) M AII-induced increase in [Ca2+]i dose dependently at concentrations from 10(-10) M and completely at 10(-7) M. CV-11974 suppressed both Ca2+ release from intracellular Ca2+ stores and Ca2+ influx from the extracellular space. However, CV-11974 had no effect on the increases in [Ca2+]i induced by prostaglandin F2 alpha (PGF2 alpha), a potent vasoconstrictor, or ionomycin, a Ca2+ ionophore. These results indicate that the suppressive effects of CV-11974 act on the binding of AII and its specific receptors. AII 10(-7) M increased the synthesis of DNA and protein to 1.5 and 1.7 times the control values, respectively. CV-11974 had no effect on synthesis of DNA or protein, but suppressed the AII-stimulated synthesis of DNA and protein dose dependently at concentrations > or = 10(-8) and 10(-10) M, respectively and completely at 10(-6) M. These results indicate that AII increases [Ca2+]i and synthesis of DNA and protein in VSMC through activation of AT1. CV-11974 showed no partial agonistic effects on AII. Thus, CV-11974 may act not only as an antihypertensive agent, but also as an inhibitor of vascular injury stimulated by AII.

Strumal carcinoid of the ovary

A strumal carcinoid arising in a benign cystic teratoma of the left ovary was reported in a 41 year-old woman. The solid tumor was histologically a trabecular carcinoid tumor associated intimately with thyroid follicle-like structures. By Grimelius staining, argyrophil granules were found in the cytoplasm of the tumor cells. The final diagnosis of strumal carcinoid, however, was established by the confirmation of thyroid tissue.

Detection of protein kinase homologues and viral RNA-binding domains utilizing polyclonal antiserum prepared against a baculovirus-expressed ds RNA-activated 68,000-Da protein kinase

The P68 protein kinase (referred to as P68 based on its M(r) of 68,000 in human cells) is a serine/threonine kinase induced by interferon treatment and activated by dsRNAs. The kinase is under tight controls in virus-infected cells since once activated, it phosphorylates its natural substrate eukaryotic initiation factor 2 (elF-2), leading to potential limitations in functional elF-2 and decreases in protein synthesis initiation. To further delineate the molecular mechanisms underlying kinase regulation, we attempted to express the P68 protein kinase in insect cells using a baculovirus vector. Repeated efforts to isolate recombinant baculoviruses containing a wild-type kinase failed, whereas recombinants expressing a nonfunctional kinase with a catalytic domain II mutation were readily isolated. When used to infect Spodoptera frugiperda cells, the recombinant virus expressed the exogenous mutant protein at almost 5-10% of the total proteins synthesized. We then purified the kinase by immunoaffinity chromatography to raise monospecific antiserum which recognized not only the human native wild-type P68, but also kinase homologues in murine, bovine, and monkey cells as determined by immunoblot and immunoprecipitation analysis. Fortunately, kinase function also could be assayed using this antibody since the human and nonhuman kinase homologues, present in immunoprecipitates, were autophosphorylated and phosphorylated the natural substrate, elF-2 alpha. Further, this antiserum recognized epitopes throughout the molecule including the amino and carboxyl termini in contrast to the available monoclonal antibody. In vitro assays using the polyclonal antibody revealed the importance of the amino terminus, especially amino acids 1-97, in the binding of the kinase to viral RNA activators and inhibitors. Finally, we determined that the P68 amino terminus was both necessary and sufficient for binding dsRNA as we were able to transfer dsRNA-binding properties to a reporter gene product previously unable to bind RNA.

Characterization and regulation of the 58,000-dalton cellular inhibitor of the interferon-induced, dsRNA-activated protein kinase

The P68 protein kinase is a serine/threonine kinase induced by interferon treatment and activated by double-stranded RNAs (dsRNAs). Once activated, the kinase phosphorylates its natural substrate, the alpha subunit of eukaryotic initiation factor 2 (eIF-2) leading to potential limitations in functional eIF-2 and decreases in protein synthesis initiation. We have recently purified from influenza virus-infected cells a P68 kinase inhibitor, found to be a 58-kDa cellular protein. We have now investigated the mechanisms by which the 58-kDa inhibitor regulates P68 kinase activity and how the inhibitor itself is controlled. The 58-kDa inhibitor did not function by degrading or sequestering the dsRNA activator of P68 but could repress phosphorylation of eIF-2 alpha by an already activated protein kinase. Utilizing antibody prepared against a 58-kDa-specific peptide, we showed that the 58-kDa proteins from infected and uninfected cells were present in equivalent amounts. Although kinase inhibitory activity could not be detected in crude uninfected cell extracts, ammonium sulfate treatment unmasked this activity and allowed purification of the cellular inhibitor with identical chromatographic properties as that from influenza virus-infected cells. Finally, we have identified and partially purified a specific inhibitor of the 58-kDa protein which we refer to as an "anti-inhibitor." Based on these data, we present a model depicting the complex regulation of the interferon-induced protein kinase in eukaryotic cells.

[Clinical characteristics and liver dysfunction in lymphocyte stimulation test-positive elderly]

In order to clarify the characteristics of the side effects of drugs in the elderly, we evaluated clinical features and liver function in 40 lymphocyte stimulation test (LST)-positive elderly. Their ages ranged from 64 to 90 years, with a mean age of 75 years. The major causative agents were antituberculosis agents, antibiotics and antiinflammatory agents, comprising 28%, 22% and 12% of whole drugs, respectively. Liver dysfunction, skin eruptions and fever were the major causes for carrying out LST. The mean latent period was 15 days, and in 80% of the cases, the side effect developed within four weeks after administration of the causative agent. Major clinical symptoms noted during the course were detected in more than the half of the cases. As for liver dysfunction, elevation of GOT, ALP and total bilirubin levels were noted in 76, 63 and 34% of the cases, respectively. These results showed that the hypersensitive side effects of the drugs could appear at any age even in the elderly, and clinical symptoms were often nonspecific and obscure. It was suggested that the presence of mild liver dysfunction and eosinophilia could be helpful markers for the early detection of drug-induced organ dysfunctions as well as careful observation. The possibility of the occurrence of the side effects must be considered on every drug administration. Presence of mild liver dysfunction and eosinophilia may be helpful markers for the early detection of drug-induced organ dysfunction.

Evaluation of hepatic transport function by hepatobiliary scintigraphy

The transport kinetics of [99mTc]-pyridoxyl-5-methyltryptophan were studied by three-compartment model analysis for hepatobiliary scintigraphy in 45 patients with chronic viral liver diseases. Three-compartment model analysis was studied using the time-activity curves of the regions of the heart, liver, and biliary tract and intestine (excretory compartment). The k12 (hepatic uptake rate constant), k21 (hepatic efflux rate constant), and ke1 (hepatic excretion rate constant) were calculated by the nonlinear least-squares method. Among the three parameters obtained by model analysis, k12 values more prominently differed among diseases and correlated well with blood tests such as total bilirubin, total bile acids, or 15 min retention of ICG. In conclusion, three-compartment model analysis of the hepatic handling of [99mTc]-pyridoxyl-5-methyltryptophan is useful in evaluating hepatic transport function. k12 is the most sensitive parameter for this.

Functional expression and characterization of the interferon-induced double-stranded RNA activated P68 protein kinase from Escherichia coli

The P68 protein (referred to as P68 on the basis of its molecular weight of 68,000 in human cells) is a serine/threonine kinase induced by interferon treatment and activated by double-stranded (ds) RNAs. Although extensively studied, little is currently known about the regulation of kinase function at the molecular level. What is known is that activation of this enzyme triggers a series of events which lead to an inhibition of protein synthesis initiation and may, in turn, play an integral role in the antiviral response to interferon. To begin to understand P68 and its biological functions in the eukaryotic cell, we have expressed the protein kinase in Escherichia coli under control of the bacteriophage T7 promoter. In rifampicin-treated cells, metabolically labeled with [35S]methionine and induced by IPTG, the P68 kinase was the predominant labeled product. Further, P68 was recovered from extracts as a fully functional enzyme, shown by its ability to become activated and phosphorylate its natural substrate, the alpha subunit of eukaryotic protein synthesis initiation factor 2 (eIF-2). Moreover, P68 was phosphorylated in vivo in E. coli, providing conclusive evidence that the kinase has the capacity to phosphorylate and activate itself in the absence of other eukaryotic proteins. In contrast, a mutant P68 protein, containing a single amino acid substitution in the invariant lysine in catalytic domain II, was completely inactive. Interestingly, both the mutant and wild-type protein kinases efficiently bound activator dsRNAs despite the fact that only the latter was activated by these RNAs. Finally, the expressed kinase could be isolated from contaminating E. coli proteins in an active form by immunoaffinity chromatography with a monoclonal antibody specific for P68.

[A rare case of adult-onset Becker muscular dystrophy diagnosed by dystrophin staining]

Different diagnosis of Becker muscular dystrophy (MD) from limb-girdle MD mainly depends on the differences of heredity form and age at onset. However, sporadic cases with either type of MD often occur, and occasionally Becker MD can occur in adult age when limb-girdle MD commonly occurs. We reported the male sporadic case of Becker MD with the onset at 30 year old who was diagnosed by dystrophin staining. At the age of 30, he noticed mild difficulty to stand up and instability when hurrying up stairs. His weakness of lower limb-girdle gradually progressed, but he is able to walk without any support at the present age of 54, and he never showed weakness in upper limbs. Neurological and laboratory examination revealed that severe atrophy of lower limb-girdle, mild calf hypertrophy and moderate elevate of serum CK level. These history and symptoms hardly distinguish between Becker and limb-girdle MD. Immunostaining of biopsy muscle from the patient using the antiserum against synthetic peptide fragment of dystrophin revealed faint and patchy pattern, and immunoblot revealed 380 kd of abnormal size dystrophin. These dystrophin testing confirmed that this case was a rare case of Becker MD with adult-onset and mild clinical course.

Elevated plasma platelet-derived growth factor B-chain levels in cancer patients

Platelet-derived growth factor (PDGF) is produced by a variety of normal and tumor cells in vitro. We have developed an enzyme-linked immunosorbent assay for the detection of the B-chain of PDGF. This assay can reliably detect 0.1 ng/ml of homodimeric recombinant PDGF B-chain and does not cross-react with recombinant PDGF-AA, epidermal growth factor, basic fibroblast growth factor, or transforming growth factor-beta. Citrated plasma from 72 control individuals had a PDGF B-chain (PDGF-B) level of 0.32 +/- 0.14 ng/ml (mean +/- SD) with a range of 0.10-0.69 ng/ml. The plasma platelet factor 4 (PF4) level was 97 +/- 70 ng/ml, with a range of 34-363 ng/ml. Citrated plasma was obtained from 131 cancer patients, and plasma PDGF-B was elevated in 19 (15%) of the patients. Both PDGF-B and PF4 were elevated in 14 (11%) of these patients, consistent with a platelet source of PDGF-B. In 5 patients (4%), however, PDGF-B was elevated and PF4 was not elevated compared to the control group. This last group of patients may have a tumor-derived source of PDGF-B which could be important in autocrine or paracrine growth stimulation of the tumor cells.

Cytotoxic effect and uptake mechanism by isolated rat hepatocytes of lithocholate and its glucuronide and sulfate

The hepatotoxicity and uptake mechanism of lithocholate and its glucuronide and sulfate were studied using isolated rat hepatocytes. Cytotoxicity was in the order of lithocholate greater than lithocholate-glucuronide greater than lithocholate-sulfate; their 50% cytotoxic concentrations on hepatocytes were 50, 150 and 700 microM, respectively. Thus, glucuronidation as well as sulfation acted to detoxify lithocholate, not relating to the previously reported higher cholestatic effect of lithocholate-glucuronide than lithocholate. Lithocholate uptake was linear up to 50 microM, whereas the uptakes of lithocholate-glucuronide and sulfate were saturable with an apparent Km and Vmax of 32 microM and 6.4 nmol/min per 10(6) cells for lithocholate-glucuronide and 26 microM and 11.8 nmol/min per 10(6) cells for lithocholate-sulfate. Na+ replacement by choline+ had no effect on the uptake of lithocholate and lithocholate-glucuronide, whereas it slightly inhibited lithocholate-sulfate uptake. Lithocholate-glucuronide uptake was inhibited by lithocholate-sulfate and sulfobromophthalein, whereas lithocholate-glucuronide and sulfobromophthalein had no effect on lithocholate-sulfate uptake. These data indicate that hepatic lithocholate uptake is mediated by simple diffusion, and that hepatic uptake of lithocholate-glucuronide and sulfate is mainly mediated by a Na(+)-independent carrier.

Purification and partial characterization of a cellular inhibitor of the interferon-induced protein kinase of Mr 68,000 from influenza virus-infected cells

A number of eukaryotic viruses have evolved mechanisms to downregulate activity of the interferon-induced, double-stranded RNA-activated protein kinase (referred to as P68 based on its Mr of 68,000 in human cells). This control is essential because once activated, the P68 kinase phosphorylates its natural substrate, the alpha subunit of the eukaryotic protein synthesis initiation factor 2 (eIF-2), limiting functional eukaryotic protein synthesis initiation factor 2 available for protein synthesis initiation. We have previously shown that influenza virus encoded a specific mechanism to repress the autophosphorylation and activity of P68. Using in vitro assays for P68 inhibition, we now have purified, to near homogeneity, the P68 repressor from influenza virus-infected cells. The purified product inhibited both the autophosphorylation of P68 as well as phosphorylation of the alpha subunit of eukaryotic protein synthesis initiation factor 2 by the kinase. We tested for both protease and phosphatase activity but found neither activity associated with the purified inhibitor. Surprisingly we found the purified repressor, which had an apparent Mr of approximately 58,000, was a cellular and not a viral-encoded protein. Possible mechanisms by which influenza virus activates this cellular regulator of the protein kinase, thereby minimizing potential antiviral effects of interferon, are discussed.

Influenza virus regulates protein synthesis during infection by repressing autophosphorylation and activity of the cellular 68,000-Mr protein kinase

We investigated the mechanisms by which influenza virus prevents shutoff of protein synthesis by a cellular protein kinase normally activated during infection. Earlier work has shown that influenza virus superinfection of cells previously infected by the adenovirus VAI RNA-negative mutant dl331 resulted in selective translation of influenza virus mRNAs and suppression of the elevated protein kinase levels normally found in cells infected by the mutant alone (M. G. Katze, B. M. Detjen, B. Safer, and R. M. Krug, Mol. Cell. Biol. 6:1741-1750, 1986). We elucidated the mechanisms of this kinase repression and can now report that influenza virus encodes a gene product which functions to directly block the autophosphorylation and activity of the interferon-induced, double-stranded-RNA-activated protein kinase, P68. Suppressed P68 activity was found not only in doubly infected cells but also in cells infected by influenza virus alone. Moreover, the decrease in P68 activity correlated with a decrease in the endogenous levels of phosphorylation of the alpha subunit of the eucaryotic initiation factor eIF-2, the natural substrate of the protein kinase. Suppression of P68 activity occurred as early as 2 h after influenza virus infection and required viral gene expression beyond the level of primary mRNA transcription to take place. We confirmed our in vivo observations with in vitro mixing experiments which showed that the influenza virus inhibitor can act in trans to block P68 activity. Combined repression of P68 function and eIF-2 alpha phosphorylation during influenza virus infection is essential for continued catalytic recycling of eIF-2 and efficient mRNA translation.

Ultrastructural localization of acid phosphatase activity in plasma cells containing Russell's bodies in periodontitis

Acid phosphatase activity was examined ultracytochemically in gingival specimens to elucidate the response of plasma cells to Russell's bodies. The acid phosphatase activity was discernible in lysosomes of various morphology, some of which contained Russell's bodies. The acid phosphatase activity was stronger in the peripheries of such lysosomes, but weak activity was also found inside Russell's bodies. These findings indicated that at least some of Russell's bodies formed within the plasma cells were degraded in autophagolysosomes.

Cell surface alterations on colon adenocarcinoma cells

By the use of five independent techniques, cell surface alterations distinctive of malignant as compared to normal colon cells were detected on in vivo surgical specimens and on cultured cell lines established in our laboratory. The findings, which were distinctive of the malignant as compared to the normal cell included: (a) polymorphism of surface microvilli on scan electron microscopy; (b) decreased susceptibility to infection with vaccinia and reovirus, but not to herpes, adeno- or echovirus: (c) production of large quantities of carcinoembryonic antigen; (d) presence of specific membrane proteins on sodium dodecyl sulfate-polyacrylamide gel analysis of plasma membranes purified from cell homogenates by ultracentrifugation in polyethylene glycol-dextran partitions; and (e) reaction with specific, cytotoxic, rabbit heteroantisera. Solubilized extracts of the malignant cells formed precipitin lines with the heteroantisera, suggesting that the distinctive antigens could be released from the cell surface. These results suggest that human colon carcinomas bear tumor-distinctive proteins and offer the prospect of specific immunodiagnostic reagents and immunotherapeutic tools.