Changes in alpha 2- and beta-adrenoceptors in hepatocytes from rats during treatment with 3'-methyl-4-dimethylaminoazobenzene. A 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB) containing diet was given to 6 weeks old female Donryu rats, and the number of adrenoceptors and the response of adenylate cyclase in the hepatocytes were measured. The treatment with 3'-MeDAB led to rapid increases in [125I]iodocyanopindolol ([125I]ICYP)- and [3H]clonidine-binding sites to hepatic membranes without significant changes in the Kd values. The number or beta-adrenoceptors defined by [125I]ICYP binding sites was increased with a biphagic mode. The [3H]clonidine binding reached a peak 2 weeks after the start of the carcinogen diet and then began a slow descent. The alpha 2-adrenoceptor was defined by [3H]clonidine binding being selectively inhibited by an alpha 2-antagonist, yohimbine, but not by an alpha 1-antagonist, prazosin, or a beta-antagonist propranolol. Catecholamine responsiveness to adenylate cyclase in hepatocytes also increased during treatment with 3'-MeDAB. However, the efficacy of norepinephrine (NE) in activating cyclase was lower than that of isoproterenol (IPN) during 4 to 8 weeks of the carcinogen diet. The difference between the efficacies of IPN and NE resulted from inhibiting adenylate cyclase through alpha 2-adrenoceptors by NE. Therefore, we noticed that the increasing pattern of the number of beta-adrenoceptors did not always parallel IPN-stimulated adenylate cyclase activity and that the increase in the number of alpha 2-adrenoceptors preceded the difference between the efficacies of IPN and NE in activating adenylate cyclase.(ABSTRACT TRUNCATED AT 250 WORDS)


Central opioid modulation of breathing dynamics in the fetal lamb: effects of [D-Pen2,D-Pen5]-enkephalin and partial antagonism by naltrindole. The effects of opiates on fetal breathing movements (FBM) have been shown to be complicated, with stimulation at low doses and suppression at higher doses. Recent studies have shown that morphine-induced stimulation of FBM can be blocked by naloxonazine (NALZ), suggesting action at the mu 1 opioid receptor. To examine the role of delta receptors in modulating FBM, the effects of [D-Pen2,D-Pen5]-enkephalin (DPDPE) on breathing dynamics were studied in fetal lambs with chronically implanted diaphragmatic electromyographic electrodes. DPDPE given i.c.v. (4.6-465 nmol/hr) caused significant time and dose-related increases in the number of breaths/hr and the incidence of fetal breathing movements, without significant changes in blood pH, PCO2 or PO2. Higher doses resulted in an attenuation of the responses, with a significant decrease in breaths/hr at 465 nmol/hr. DPDPE also induced a much more continuous and regular breathing pattern. All DPDPE effects were completely abolished by pretreatment with i.v. naloxone, but were unaffected by naloxonazine pretreatment. Naltrindole did not alter the effects of DPDPE on breath number or incidence of FBM, but blocked the effects on continuity and regularity of the breathing pattern. These results demonstrate that DPDPE stimulates breathing activity as well as alters breathing dynamics in the fetal lamb. The differential sensitivity of these two actions to naltrindole suggest that they may be mediated by different delta receptor subtypes, and that the mu 1 receptor is not involved.


Epileptogenesis reduces the sensitivity of presynaptic gamma-aminobutyric acidB receptors on glutamatergic afferents in the amygdala. Intracellular recordings were obtained from the basolateral amygdala in in vitro rat brain slice preparations to examine whether gamma-aminobutyric acid (GABA)B receptors are altered after in vivo kindling-induced epileptogenesis. Stimulating the stria terminalis evoked excitatory (EPSPs) and inhibitory (IPSPs) postsynaptic potentials in control neurons, and epileptiform bursting or enhanced EPSPs, but no IPSPs, in neurons from animals, 4 to 8 weeks after the last kindled seizure. Baclofen (0.1 nM-100 microM) depressed EPSPs in control and kindled basolateral amygdala neurons, but the EC50 appeared to be shifted 100-fold from 5 nM in control to 500 nM in kindled neurons. Further analysis suggested a high-affinity component may be affected in kind led neurons. The absence of IPSPs in kindled neurons could not account for this shift, because effects of baclofen on EPSP amplitude were reduced in kindled animals even when GABAA receptors were blocked with bicuculline methiodide (30 microM) and postsynpatic GABAB receptors with intracellular guanosine 5'-O-3-thiotriphosphate (10 mM); 6-cyano-2,3-dihydroxy-7-nitroquinoxaline (10 microM) was also present to block bicuculline methiodide-induced bursting. Membrane responses to exogenously applied N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid were not affected by baclofen. Baclofen also hyperpolarized basolateral amygdala neurons and reduced membrane input resistance with an EC50 of 1 microM in control and kindled neurons. Post- but not presynaptic effects of baclofen were blocked by 2-hydroxy-saclofen (100 microM) and pertussis toxin pretreatment. In conclusion, kindling-induced epileptogenesis reduces the sensitivity of presynaptic GABAB receptors, an effect which may contribute to the enhancement of excitatory transmission in kindled animals. Furthermore, different pharmacological properties of pre- and postsynaptic receptors in the amygdala suggest two distinct populations of GABAB receptors whose long-lasting responses to kindling-induced seizures are different.


Nalbuphine, a mixed kappa 1 and kappa 3 analgesic in mice. Nalbuphine is a mixed opioid agonist/antagonist analgesic. It labels mu receptors most potently where it acts as an antagonist. Nalbuphine is analgesic in the tail-flick assay after systemic (ED50, 41.8 mg/kg s.c.), i.c.v. (ED50, 21.3 micrograms) or intrathecal administration (ED50, 11.2 micrograms). Analgesia elicited by systemic nalbuphine was reversed by nor-binaltorphimine, but not by beta-funaltrexamine or naltrindole despite their ability to antagonize morphine and [D-Pen2,D-Pen5]enkephalin analgesia, respectively. This insensitivity toward beta-funaltrexamine and naltrindole argued strongly against either a mu or delta component of analgesia. Nor-binaltorphimine antagonized systemic nalbuphine analgesia over 10-fold more potently after intrathecal injection of the antagonist than after i.c.v. administration, implying a role for kappa 1 receptors at the spinal level. The presence of analgesic cross-tolerance between nalbuphine and both naloxone benzoylhydrazone and nalorphine indicated an analgesic role for kappa 3 receptors, which act supraspinally. Additional studies revealed synergistic interactions between spinal kappa 1 and supraspinal kappa 3 receptors when nalbuphine was given both intrathecally and i.c.v. In conclusion, these studies suggest that nalbuphine elicits analgesia through a complex interaction of supraspinal kappa 3 and spinal kappa 1 mechanisms.


Clocinnamox: a novel, systemically-active, irreversible opioid antagonist. The warm water (55 degrees C) tail-withdrawal procedure was used to assess the analgesic effects of the prototypic mu opioid agonists, morphine and fentanyl, in mice. Both drugs produced full analgesic effects under these conditions, which were dose-dependently antagonized by naltrexone. The pA2 values for naltrexone with morphine and with fentanyl were not significantly different. Low doses (e.g., 0.32 mg/kg) of clocinnamox [C-CAM.14 beta-(p- chlorocinnamoylamino)-7,8-dihydro-N-cyclopropylmethylnormorphin one mesylate] produced rightward shifts in the dose-effect curves for each drug, whereas high doses (e.g., 32 mg/kg) depressed the maximal analgesic response. In addition, it was observed that higher doses of C-CAM were required to produce a shift down in the fentanyl dose-effect curve than were required to produce a shift down in the morphine dose-effect curve, which suggests that fentanyl is more efficacious than morphine. The highest dose of C-CAM (32 mg/kg) antagonized the analgesic effect of morphine for up to 8 days. In contrast, the antagonist activity of naltrexone (100 mg/kg) against morphine lasted for only 2 days. Finally, when naloxone was administered simultaneously with 32 mg/kg C-CAM 2 days before determination of the morphine dose-effect function, the antagonist effect of C-CAM was prevented in a dose-dependent manner. Taken together, these results suggest that C-CAM may be producing its antagonist action at opioid receptors through a nonequilibrium mechanism.


Guinea pig gall bladder contains a single peptide leukotriene receptor which resembles that present in human conducting airway smooth muscle. The peptide leukotrienes (LTs), LTC4, LTD4 and LTE4, produced concentration-related contraction of isolated strips of guinea pig gall bladder (GPGB) with pD2 values of 8.48 +/- 0.11, 8.26 +/- 0.22 and 7.28 +/- 0.08, respectively. In the presence of propranolol and indomethacin in epithelium-denuded GPGB, pKB values for the LT antagonist ICI198,615 vs. LTC4, LTD4 and LTE4 were, respectively: 8.61 +/- 0.12, 8.89 +/- 0.13 and 8.70 +/- 0.17. Similarly, pKB values for the LT antagonist SKF104,353 were 7.28 +/- 0.19, 7.88 +/- 0.17 and 7.45 +/- 0.17. Previous studies have shown that inhibition of LTC4 metabolism can alter the apparent affinity of the LT, especially LTC4; consequently, metabolism of [3H]LTC4 in chopped GPGB was investigated. [3H]LTC4 was converted rapidly by gamma-glutamyl transpeptidase to [3H]LTD4 with little accumulation of [3H]LTE4. The combination of acivicin (ACI) and reduced glutathione (GSH) provided complete inhibition of gamma-glutamyl transpeptidase. pD2 values for LTC4 in the presence of ACI/GSH were 8.54 +/- 0.16. pKB values for ICI198,615 and SKF104353 in the presence of ACI/GSH were, i.e., 8.42 +/- 0.14 and 7.53 +/- 0.12, respectively, vs. LTC4 and identical to those obtained in the absence of inhibitors. The mechanism(s) underlying LT-induced contraction was evaluated using the calcium channel blockers diltiazem, nifedipine and verapamil. Noncompetitive antagonism was observed against all LTs indicating the involvement of voltage-sensitive calcium channels in the contractile response. Similarly, all LTs increased polyphosphoinositide hydrolysis. These data indicate: 1) GPGB contains a single type of LT receptor similar to that in human airways and 2) LT-induced contraction appears to involve both polyphosphoinositol formation and voltage-dependent Ca++ channels.


Dietary choline supplementation increases the density of nicotine binding sites in rat brain. The objective of these studies was to determine whether the chronic administration of choline, like the chronic administration of nicotine, increased the density of nicotine binding sites in brain. To accomplish this, rats were maintained on a choline-deficient (0% choline chloride), basal choline (0.2% choline chloride) or choline-supplemented (2.0% choline chloride) diet for 30 days or were fed a standard rodent chow and received injections of saline or nicotine (3.6 mumol/kg s.c.) twice daily for 10 days. Membranes from striatum, hippocampus and frontal cortex were isolated, and the binding of L-(-)-[N-methyl-3H]nicotine (0.5-60 nM) was studied. A single binding site for nicotine was evident for all brain regions from all animals studied with a dissociation constant (Kd) of approximately 2 to 5 nM. Chronic supplementation with choline, which increased circulating choline levels by 92%, did not alter binding affinity, but increased significantly the maximal number (Bmax) of nicotine binding sites in cortical and hippocampal membranes by 20 and 73%, respectively, compared to animals fed the basal choline diet; the Bmax in striatal membranes was unaltered. Nicotine binding parameters for membranes from animals maintained on the choline-deficient diet were not different from those maintained on the basal diet. The chronic administration of nicotine did not alter binding affinity, but increased significantly the maximal density of nicotine binding sites in striatal and cortical preparations by 47 and 18%, respectively; the Bmax in hippocampal membranes was unaltered.(ABSTRACT TRUNCATED AT 250 WORDS)


Characterization of the antagonist activity of the PAF antagonists RP 59227 and WEB 2086 on elicited guinea pig peritoneal macrophages. Evidence for variable affinities and kinetics. The pharmacological selectivity and affinity of the two PAF antagonists RP 59227 and WEB 2086 for macrophage platelet activating factor (PAF) receptors have been investigated. PAF produced a dose-related increase in superoxide generation from elicited guinea pig peritoneal macrophages (IC50 41 +/- 16 nM, n = 9). After a 5 min preincubation time RP 59227 (0.1, 1.0 and 10 microM) produced a dose-related rightward displacement of the PAF dose-response curve, the Schild plot gave a pA2 of 7.39 +/- 0.07 (n = 5) with a slope of 1.17 +/- 0.11, indicating competitive antagonism. WEB 2086 over the same concentration range was without effect at the lower two concentrations, but at 10 microM, the displacement of the PAF dose-response curve was similar to that obtained with 10 microM RP 59227. Increasing the preincubation time to 30 min increased the affinity of RP 59227 (apparent pA2 8.76 +/- 0.28, n = 5). This was associated with a reduction in the slope of the Schild plot to 0.67 +/- 0.11, suggesting noncompetitive kinetics. The affinity of WEB 2086 could not be determined, but the antagonism appeared noncompetitive in nature. The results indicate that PAF antagonists can show variable affinities for macrophage PAF receptors depending on the experimental conditions, as well as competitive or noncompetitive kinetics depending on the contact time.


Concentration- and time-dependence of phosphoinositide hydrolysis induced by endothelin-1 in relation to the positive inotropic effect in the rabbit ventricular myocardium. The effects of endothelin-1 on phosphoinositide hydrolysis in relation to the positive inotropic effect of the compound were studied in the rabbit ventricular myocardium. Endothelin-1 elicited a concentration- and time-dependent accumulation of [3H]inositol monophosphate (IP1) in ventricular muscle slices prelabeled with myo-[3H]inositol in concentrations similar to those that caused a positive inotropic effect. The EC50 value of endothelin-1, both for the induction of [3H]IP1 accumulation and for the positive inotropic effect was 6 x 10(-9) M. The endothelin-induced positive inotropic effect was linearly related to [3H]IP1 accumulation. Endothelin-1 induced a small transient negative inotropic effect before the onset of a gradually developing and sustained positive inotropic effect which reached a steady level at 30 min. After administration of endothelin-1, [3H]IP3 accumulated rapidly and transiently before the development of the positive inotropic effect. [3H]IP2 accumulated slowly and peaked at 20 min. [3H]IP1 accumulation occurred more slowly and of the inositol phosphates its time course coincided best with that of the positive inotropic effect. Phorbol 12,13-dibutyrate inhibited both the [3H] IP1 accumulation and positive inotropic effect induced by endothelin-1. The present results indicate that an acceleration of phosphoinositide hydrolysis induced by activation of endothelin-1 receptors may be responsible for induction of the positive inotropic effect of endothelin-1 on rabbit ventricular myocardium.


Kinetic disposition of temafloxacin and ciprofloxacin in a murine model of pneumococcal pneumonia. Relevance for drug efficacy. The authors studied whether pharmacokinetic parameters could explain differences in the in vivo antipneumococcal activity of temafloxacin and ciprofloxacin in a mouse model of pneumonia. The effects of infection on the disposition and clearance mechanisms of the two drugs were evaluated after a single administration (100 mg/kg s.c.) relative to noninfected controls. Effective drug concentrations and possible drug inactivation at sites of infection were assessed using both microbiological (active drug levels) and high-performance liquid chromatography (total drug levels) procedures and by recording bacterial clearance in blood and lung homogenates. Pulmonary bacterial clearance was correlated more closely to concentrations in serum than to those in lung homogenates, probably because they better reflect interstitial fluid concentrations. Neither the serum and lung concentrations nor the clearance of ciprofloxacin were modified greatly by infection. Ciprofloxacin was not inactivated at sites of infection. Temafloxacin exhibited higher serum concentrations and tissue penetration than ciprofloxacin. The differences between the two drugs in noninfected controls were accentuated, with apparent retention of temafloxacin in infected mice resulting in more persistent activity in lung and serum. The renal failure observed in infected mice did not apparently account for the reduction in the total clearance of temafloxacin, suggesting its probable trapping at sites of infection. The observation that serum (and tissue) concentrations of temafloxacin exceeded the minimal inhibitory concentration of the test organism over the whole dosing interval (12 hr), could account for its efficacy in severe pneumococcal disease.


Inhibition by amiloride of ouabain-evoked catecholamine secretion from cultured adrenal chromaffin cells: evidence for its blocking action on interaction between ouabain and Na+/K(+)-pump. The effect of amiloride on ouabain-evoked catecholamine secretion was investigated in primary cultures of bovine adrenal chromaffin cells. Catecholamine secretion evoked by ouabain was inhibited markedly by amiloride, but the secretion evoked by Na+ removal was not affected by the drug. In contrast, adriamycin, a putative inhibitor of the Na(+)-Ca++ exchange, inhibited the secretion evoked by Na+ removal as well as that evoked by ouabain. The inhibitory action of amiloride on the ouabain-evoked secretion was therefore considered to be due to its action on other mechanism(s) than the Na(+)-Ca++ exchange process. Further studies showed that the uptake of 86Rb+ into the cells was slightly but significantly reduced by amiloride, and the inhibitory action of ouabain on 86Rb+ uptake was considerably blocked by this drug under the experimental conditions in which the inhibition of ouabain-evoked secretion was observed. The binding of [3H] ouabain to the intact cells was also inhibited by amiloride under the same conditions. These results suggest that amiloride may inhibit ouabain-evoked catecholamine secretion as a consequence of blocking the inhibitory action of ouabain on the plasma membrane Na+/K(+)-pump in adrenal chromaffin cells.


Characterization and localization of leukotriene C4 receptors in bullfrog lung. Specific binding sites for [3H]leukotriene C4, ([3H]LTC4) were characterized in lung membrane preparations and localized to the septa of lung tissue from the American bullfrog (Rana catesbeiana). Binding assays were carried out at 23 degrees C for 30 min in the presence of serine (5 mM)-borate (10 mM) to prevent metabolism of LTC4 to LTD4. Specific binding reached steady state within 10 min and was completely reversible with the addition of 1000-fold excess unlabeled LTC4. Scatchard analysis predicted a single class of binding sites with a Kd of 55.7 nM and a Bmax of 61.9 pmol/mg protein. The Hill coefficient was 0.958. LTC4 was the most potent inhibitor of [3H]LTC4 binding, with a Ki of 33 nM. LTD4 and LTE4 are less potent inhibitors, with Ki values of 3350 and 5979 nM, respectively. Mammalian LTD4 antagonists LY171883, L-649,923 and ICI 198,615 only displaced [3H]LTC4 specific binding at concentrations in excess of 1 x 10(-4) M. Guanosine 5' triphosphate and its analog guanyl-5'-yl-imidodiphosphate did not affect specific binding of [3H]LTC4, suggesting that a Gi protein is not involved in the LTC4 transduction mechanism. Glutathione, S-decyl-glutathione and hematin had Ki values of 35,000, 280 and 29,000 nM, respectively, suggesting the binding site is not the enzyme LTC4-synthase. LTC4 contracted lung strips, with S-decyl-glutathione a partial agonist. Computer-enhanced autoradiographs localized the binding sites to the smooth muscle regions of the septa in lung tissue. These data suggest that LTC4 binds to distinct receptors in bullfrog lung.


Nonadrenergic, noncholinergic contractile responses of the guinea pig hilar bronchus involve the preferential activation of tachykinin neurokinin2 receptors. Experiments were designed to characterize receptor(s) that mediate nonadrenergic, noncholinergic contractions of the guinea pig hilar bronchus using selective neurokinin (NK)1 (CP 96,345) and NK2 (R396 and MEN 10,376) tachykinin receptor antagonists. Left and right hilar bronchi were studied as pairs in the presence of atropine, propranolol, phentolamine; indomethacin and thiorphan. (2S, 3S)-cis-2-(diphenylmethyl)-N-(2-methoxyphe nyl)-1-azabicyclo[2,2,2]octan-3-amine (CP 96,345) selectively antagonized contractions of the bronchus to the NK1 agonist Ac-[Arg6,Sar9,Met(O2)11]-SP(6-11) with a -log molar KB value of about 8.0. Similarly, Ac-Leu-Asp-Gln-Trp-Phe-Gly-NH2 (R396) and [Tyr5, D-Trp6,8,9, Lys10]-NKA(4-10) (MEN 10,376) selectively antagonized contractions to the NK2 agonist [beta Ala8]-NKA(4-10) with -log molar KB values of about 5.5 and 6.7, respectively. CP 96,345 (3 x 10(-7) M) had no effect on contractions evoked by transmural electrical stimulation (TES). However, both R396 (1 x 10(-5) to 1 x 10(-4) M) and MEN 10,376 (1 x 10(-6) to 1 x 10(-5) M) caused blockade of responses to TES. CP 96,345 (3 x 10(-7) M) antagonized TES-induced contractions only when studied after substantial blockade by R396 or MEN 10,376. Contractions to TES were not abolished by R396, MEN 10,376 or a combination of these antagonists with CP 96,345. R396 (1 x 10(-6) M) increased the maximum contraction to TES and potentiated the frequency-response curve in bronchi treated with MEN 10,376 (1 x 10(-6) M).(ABSTRACT TRUNCATED AT 250 WORDS)


2-Aryl-3-indoleacetamides (FGIN-1): a new class of potent and specific ligands for the mitochondrial DBI receptor (MDR). The 2 aryl-3-indoleacetamides (FGIN-1) are a new class of compounds that potently (nM) and selectively bind to glial mitochondrial diazepam binding inhibitor (DBI) receptors (MDR), previously called peripheral benzodiazepine receptors, and increase mitochondrial steroidogenesis. The high-affinity binding of FGIN-1 to MDR derivatives depends on the following chemical characteristics: 1) the dialkylation of the amide; 2) the chain length of this alkyl substitution; and 3) the halogenation of aryl groups appended to the indole nucleus. FGIN-1 derivatives do not bind to gamma-aminobutyric acid (GABAA), GABAB, glycine, glutamate, dopamine, serotonin, opiate, cholecystokinin, beta adrenergic, cannabinoid or sigma receptors. FGIN-1-27 [N, N-di-n-hexyl 2-(4-fluorophenyl)indole-3-acetamide] enters the brain, and for this reason, this FGIN-1 compound is potent and efficacious behaviorally. Like the neurosteroid 3 alpha-5 alpha tetrahydrodeoxycorticosterone (THDOC), FGIN-1-27 delays the onset of isoniazid-induced convulsions, but fails to delay the onset of bicuculline-induced convulsions. However, differently from THDOC, the FGIN-1-27 anticonvulsant action is blocked by the isoquinoline carboxamide PK 11195. In the elevated plus maze test, FGIN-1-27 inhibits neophobia manner that is antagonized by PK 11195 but not by flumazenil. Because FGIN-1-27 binds to MDR and does not bind to the GABAA receptors, it is inferred that FGIN-1-27 may act on GABAA receptors indirectly, presumably via a stimulation of neurosteroid synthesis and release from glial cells.


Evidence that endogenous opioids mediate the antinociceptive effects of intrathecally administered calcium in mice. Mice injected with calcium in the intrathecal (i.t.) space display dose-dependent antinociception in the tail-flick test. The aims of this study were to evaluate whether endogenous opioids mediate the antinociceptive effects of calcium (i.t.) and to determine if antinociception resulted from calcium acting directly in segmental spinal sites. Mice spinalized at T6 to T8 were more sensitive to the antinociceptive effects of calcium (150-600 nmol i.t.) than sham-lesioned mice. In intact mice, naloxone (138-275 pmol i.t.) and naltrindole (2.8-22 nmol i.t.) dose-dependently blocked the antinociceptive effects of calcium (600 nmol i.t.), with inhibitory dose-50 (ID50) values of 235 picomol and 11.4 nanomol, respectively. nor-Binaltorphimine (nor-BNI) (14-54 nmol i.t.) did not antagonize the antinociceptive effects of calcium (i.t.). Furthermore, the calcium (i.t.) dose-response curve was shifted right-ward by naloxone (206 pmol i.t.) and naltrindole (5.5 nmol i.t.). nor-BNI (54 nmol i.t.) was ineffective in shifting the dose-response curve. In spinalized mice, naloxone (206-687 pmol i.t.) and naltrindole (11-44 nmol i.t.) blocked the antinociceptive effects of calcium (i.t.), with ID50 values of 342 and 19.2 nmol, respectively. nor-BNI did not antagonize antinociception. In addition, the calcium (i.t.) dose-response curve was shifted right-ward by naloxone (275 pmol i.t.) and naltrindole (11 nmol i.t.). The dose-response curve was not shifted by nor-BNI (54 nmol i.t.). A 4-hr pretreatment with the irreversible mu receptor antagonist beta-funaltrexamine (0.01-0.4 nmol i.t.) blocked [D-Ala2, N-Me-Phe4, Gly5-ol]enkephalin but not [D-Pen2,5]enkephalin or calcium (i.t.)-mediated antinociception.(ABSTRACT TRUNCATED AT 250 WORDS)


Synthesis and antiviral properties of (+/-)-5'-noraristeromycin and related purine carbocyclic nucleosides. A new lead for anti-human cytomegalovirus agent design. (+/-)-5'-Noraristeromycin (3) has been prepared in three steps beginning with the 2,3-O-isopropylidene derivative of (+/-)-(1 alpha, 2 beta, 3 beta, 4 alpha)-4-amino-1,2,3-cyclopentanetriol (7). Also prepared from the same starting material were the related hypoxanthine (4), guanine (5), and 2,6-diaminopurine (6) analogues. Compounds 3-6 were evaluated for antiviral activity against a large number of viruses with marked activity being observed for 3 towards vaccinia virus, human cytomegalovirus, vesicular stomatitis virus, parainfluenza (type 3) virus, measles virus, respiratory syncytial virus, reovirus (type 1), and the arenaviruses Junin and Tacaribe. None of the compounds showed cytotoxicity to the host cell monolayers used in the antiviral studies. Both 3 and 6 have been found to be inhibitors of S-adenosyl-L-homocysteine hydrolase (AdoHcy hydrolase), which likely accounts for their antiviral activity. Inhibition of AdoHcy hydrolase represents a new approach to human cytomegalovirus drug design that should be pursued. Also, the activity of 3 should be further scrutinized for the treatment of pox-, rhabdo-, paramyxo-, reo-, and arenavirus infections.


Reversible inhibitors of the gastric (H+/K+)-ATPase. 3. 3-substituted-4-(phenylamino)quinolines. Previously, gastric (H+/K+)-ATPase inhibitors such as 2 have been prepared as analogues of 1a on the presumption that the 3-carbethoxy substituent plays a key role in establishing the orientation of the 4-arylamino group. In this paper we explore further the contribution made to activity by the quinoline 3-substituent. We show that, for compounds bearing such a substituent, only a particular combination of properties provides high activity, both in vitro and as inhibitors of gastric acid secretion in vivo. The ability of the substituent to affect activity by restricting rotation about the Cquin-N bond through a combination of both a pi-electron withdrawal and hydrogen bonding is supported by the current study. However, high activity is only achieved if the effect of this group on the quinoline pK(a) is kept to a minimum. 3-Acyl substituents provide an optimum combination of electronic properties. From this series, compound 17c (SK&F 96067) was shown to be a potent inhibitor of histamine-stimulated gastric acid secretion after oral dosing in the Heidenhain pouch dog and was selected for further development and evaluation in man.


Function and evolution in the NGF family and its receptors. The gene family of neurotrophins includes nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4). Recently, neurotrophin-5 (NT-5), a possible mammalian homologue to NT-4 described in the frog Xenopus, has been cloned in man and rat. The neurotrophins stimulate survival and differentiation of a range of target neurons by binding to cell surface receptors. The structure of NGF has recently been clarified from crystallographic data. The similarities between the different neurotrophins are substantial with the variable regions, giving specificity to each of the family members, being localized to some exposed loop regions. Low-affinity binding (Kd of 10(-9) M) of all tested neurotrophins is mediated via a 75 K glycoprotein (LNGFR) that has been cloned and characterized. A 140 K tyrosine protein kinase encoded by the proto-oncogene trk has been found to bind NGF with high affinity (Kd of 10(-11) M) and to evoke the cellular neurotrophic responses. In addition, a protein encoded by the trk-related gene trkB has been shown to bind BDNF. Recently, a third member of the trk family, trkC, has been cloned and demonstrated to function as a high-affinity receptor for NT-3. The expression of trk and LNGFR mRNA are co-localized in the rat brain to the medial septal nucleus and the nucleus of Broca's diagonal band containing the NGF-responsive magnocellular cholinergic neurons projecting to hippocampus and cerebral cortex. In sharp contrast, the pattern of expression of trkB is widely spread in many areas of the cortex as well as lateral septum. The trkB protein might serve general functions in large areas of the cortex. Site-directed mutagenesis and expression of recombinant chimaeric neurotrophin proteins have made it possible to localize a likely region for the interaction between NGF and the LNGFR. This region could be altered, resulting in the total loss of LNGFR binding by the mutant NGF protein without affecting the binding to the trk receptor which was sufficient for the full biological activity. Cladistic analysis of likely phylogenies within the neurotrophins shows BDNF and NT-4 to be most closely related whereas NGF may be the sister group to NT-3, BDNF, and NT-4. Neurotrophins offer obvious clinical possibilities for treatment of neurodegenerative diseases.


Phylogenetic analysis of 48 papillomavirus types and 28 subtypes and variants: a showcase for the molecular evolution of DNA viruses. Papillomaviruses are attractive models for studying the molecular evolution of DNA viruses because of the large number of isolates that exhibit genomic diversity and host species and tissue specificity. To examine their relationship, we selected two amino acid sequences, one of 52 residues within the early gene E1 and the other of 44 residues within the late gene L1, which allowed insertion- and deletion-free alignment of all accessible papillomavirus sequences. We constructed phylogenetic trees from the amino acid and corresponding nucleotide sequences from 28 published and 20 newly determined animal and human papillomavirus (HPV) genomic sequences by using distance matrix, maximum-likelihood, and parsimony methods. The trees agreed in all important topological aspects. One major branch with two clearly separated clusters contained 11 HPV types associated with epidermodysplasia verruciformis. A second major branch had all the papillomaviruses involved in genital neoplasia and, in distant relationship, the cutaneous papillomaviruses HPV type 2a (HPV-2a), HPV-3, and HPV-10 as well as the "butcher's" papillomavirus HPV-7 and two simian papillomaviruses. Four artiodactyl (even-toed hoofed mammal) papillomaviruses, the cottontail rabbit papillomavirus, and avian (chaffinch) papillomavirus type 1 formed a third major branch. Last, four papillomaviruses exhibited little affinity to any of these three branches; these were the cutaneous types HPV-1a, HPV-4, and HPV-41 and B-group bovine papillomavirus type 4. The phylogeny suggests that some branches of papillomavirus evolution are restricted to particular target tissues and that a general process of long-term papillomavirus-host coevolution has occurred. This latter hypothesis is still conjectural because of bias in the current data base for human types and the paucity of animal papillomavirus sequences. The comparison of evolutionary distances for the most closely related types with those of 28 subtypes and variants of HPV-2, HPV-5, HPV-6, HPV-16, and HPV-18 supports the type as a natural taxonomic unit, with subtypes and variants being expressions of minor intratype genomic diversity similar to that found in the natural populations of all biological species. An exception to this seems to be HPV-2c, which has an evolutionary distance from HPV-2a of the intertype magnitude and may eventually have to be regarded as a distinct type. We describe an experimental approach that estimates the taxonomic and phylogenetic positions of newly identified papillomaviruses without viral isolation and complete genomic sequencing.(ABSTRACT TRUNCATED AT 400 WORDS)


JC virus DNA is present in many human brain samples from patients without progressive multifocal leukoencephalopathy. Sections of normal and diseased brain and kidney tissues were screened for the presence of JC virus (JCV) DNA by using the polymerase chain reaction. As expected, all samples obtained from patients with progressive multifocal leukoencephalopathy (PML) tested positive when multiple JCV-specific primer and probe combinations were used. Unexpectedly, more than 50% of non-PML-affected brains were also found to harbor low levels of JCV DNA. To confirm that the positive signals seen in the tissue sections were not the result of contamination, amplified DNA was cloned and sequenced and in some cases was shown to represent strains of JCV not identified previously. Two predominant regulatory region configurations of JCV have been detected in the human host: archetype JCV, which is excreted in the urine of normal and immunocompromised individuals, and "PML-type" JCV found in diseased brains. This latter group of variants appears to derive from archetype JCV by the deletion and duplication of sequences within the promoter-enhancer region. In the present study, the archetype strain of JCV was identified only in normal kidney samples; JCV DNA found in non-PML-affected brain specimens and in kidney tissue from patients with PML resembled that of strains isolated from PML-affected brain tissue. Our findings indicate that JCV reaches the brain more frequently than previously thought and may persist at this site without causing demyelinating disease. A subsequent episode of prolonged immunodeficiency or a direct interaction with an immunocompromising agent (e.g., human immunodeficiency virus type 1) might activate the latent JCV infection and lead to the development of PML.


Monoclonal anti-idiotype induces antibodies against bovine Q17 rotavirus. This study describes, for the first time, the production and use of an "internal-image" anti-idiotypic monoclonal antibody (MAb) to elicit a rotavirus-specific antibody response. An immunoglobulin G2a MAb, designated RQ31 (MAb1), specific for the outer capsid protein VP4 of bovine Q17 rotavirus and capable of neutralizing viral infection in vitro was used to generate an anti-idiotypic MAb (MAb2). This MAb2, designated RQA2, was selected by enzyme-linked immunosorbent assay (ELISA) using F(ab')2 fragments of RQ31. RQA2 (MAb2) inhibited the binding of RQ31 (MAb1) to the virus but had no effect on the binding of other rotavirus-specific MAbs. The MAb2 also inhibited virus neutralization mediated by MAb1 in a dose-dependent fashion. Naive guinea pigs immunized with the MAb2 produced anti-anti-idiotypic antibodies (Ab3) that reacted with bovine Q17 rotavirus in an ELISA and neutralized rotavirus infection in vitro. The Ab3 response was characterized as MAb1-like because the Ab3 recognizes only the Q17 and neonatal calf diarrhea virus rotavirus strains in ELISA, as did RQ31 (MAb1). The Ab3 response also possessed two other characteristics of RQ31: the abilities to bind the 1.36 (double-capsid) but not the 1.38 (single-capsid) purified rotavirus fraction in ELISA and to immunoprecipitate the VP4 rotavirus protein.


Polyomavirus middle T-antigen NPTY mutants. A polyomavirus middle T-antigen (MTAg) mutant containing a substitution of Leu for Pro at amino acid 248 has previously been described as completely transformation defective (B. J. Druker, L. Ling, B. Cohen, T. M. Roberts, and B. S. Schaffhausen, J. Virol. 64:4454-4461, 1990). This mutant had no alterations in associated proteins or associated kinase activities compared with wild-type MTAg. Pro-248 lies in a tetrameric sequence, NPTY, which is reminiscent of the so-called NPXY sequence in the low-density-lipoprotein receptor. In the low-density-lipoprotein receptor, mutations in the NPXY motif but not in the surrounding amino acids abolish receptor function, apparently by decreasing receptor internalization (W. Chen, J. L. Goldstein, and M. S. Brown, J. Biol. Chem. 265:3116-3123, 1990). To determine whether this sequence represents a functional motif in MTAg as well, a series of single amino acid substitutions was constructed in this region of MTAg. All of the mutations of N, P, T, or Y, including the relatively conservative substitution of Ser for Thr at amino acid 249, resulted in a transformation-defective MTAg, whereas mutations outside of this sequence allowed mutants to retain near-wild-type transformation capabilities. Transformation-defective mutants with mutations in the NPTY region behaved similarly to the mutant with the original Pro-248-to-Leu-248 mutation when assayed for associated proteins and activities in vitro; that is, they retained a full complement of wild-type activities and associated proteins. Further, insertion of the tetrameric sequence NPTY downstream of the mutated motif restored transforming abilities to these mutants. Thus, the tetrameric sequence NPTY in MTAg appears to represent a well-defined functional motif of MTAg.


Poliovirus infection results in structural alteration of a microtubule-associated protein. Poliovirus infection results in profound changes in cellular metabolism and architecture. To identify alterations in cellular proteins following poliovirus infection which might account for these changes, monoclonal antibodies were prepared by screening for differences in antigen pattern in infected and uninfected cell lysates. Further characterization of the antigen of one such antibody (25 C C1) is described in this report. The 25 C C1 antigen is a cytoskeleton-associated protein which decreases in size 4 to 5 h postinfection. It copurifies with some of the protein synthesis initiation factors but not with eucaryotic initiation factor (eIF)-4F, the p220 subunit of which is cleaved following infection (D. Etchison, S. C. Milburn, I. Edery, N. Sonenberg, and J. W. B. Hershey, J. Biol. Chem. 257:14806-14810, 1982). Unlike alteration of p220, alteration of the 25 C C1 antigen is not due to a protease which can be detected by cell lysate mixing experiments. Alteration of the antigen occurs during purification, suggesting progressive proteolysis, but the alteration is more extensive in preparations from infected cells than in those from uninfected cells. A recombinant phage expressing the antigenic determinant was isolated from a human fibroblast cDNA library, and the sequence of the cDNA insert was found to be entirely contained within the established sequence of microtubule-associated protein (MAP) 4 (R. R. West, K. M. Tenbarge, and J. B. Olmsted, J. Biol. Chem. 266:21886-21896, 1991). The antigen distribution, as detected by indirect immunofluorescence, was similar to, but more diffuse than, the distribution of tubulin. The antibody recognized the largest abundant HeLa cell MAP, which copurified with tubulin after three cycles of polymerization-depolymerization, thus confirming the identity of the antigen as MAP 4. These results indicate that poliovirus infection of HeLa cells affects the structural integrity of a cytoskeletal protein, MAP 4.


Expression of the major capsid protein VP6 of group C rotavirus and synthesis of chimeric single-shelled particles by using recombinant baculoviruses. VP6 of group C (Cowden strain) rotavirus was expressed in the baculovirus system. The recombinant protein, expressed to a high level in insect cells, was purified by ion-exchange chromatography. The purified protein was proven to be trimeric. The effect of pH on the trimer's stability was investigated. Coexpression of VP6 from group A (bovine strain RF) and VP6 from group C in the baculovirus system did not result in the formation of chimeric trimers. Coexpression of VP2 from group A rotavirus (bovine strain RF) and VP6 from group C in the baculovirus system led to the formation of chimeric, empty, single-shelled particles. These results demonstrate conservation in the domains necessary for binding to VP2 in different serogroups of VP6. The locations of the domains involved in trimerization and in the interaction with VP2 are discussed.


Phosphorylation of specific serine residues within the acidic domain of the phosphoprotein of vesicular stomatitis virus regulates transcription in vitro. The phosphorylated state of the vesicular stomatitis virus phosphoprotein (P), an essential component of the virion-associated RNA polymerase complex, has been shown to be important for the transcriptional activity of the complex. Recent studies indicate that phosphorylation within the acidic domain of the P protein by cellular casein kinase II is necessary for its activity. In an attempt to identify the exact location of the cell kinase-mediated phosphorylation, we altered specific serine and threonine residues within the acidic domain of the New Jersey serotype of P protein by site-directed mutagenesis. The altered P proteins were then tested to determine what effect these mutations had on the phosphorylated state of the protein in vivo as well as its transcriptional activity in vitro. We report that serine residues 59 and 61 within the acidic domain of the P protein must be phosphorylated for it to be functionally active in a reconstituted transcription assay. These results demonstrate the importance of site-specific phosphorylation in the transcriptional activity of a negative-strand RNA viral phosphoprotein and the crucial role played by a cell protein kinase in this process.


Induction of AP-1 DNA-binding activity and c-fos mRNA by the adenovirus 243R E1A protein and cyclic AMP requires domains necessary for transformation. The 243R E1A protein can act in synergy with cyclic AMP to induce AP-1 DNA-binding activity and c-fos mRNA in mouse S49 cells. A series of deletion mutants was used to identify two domains of the 243R protein that were required for these effects. Interestingly, these domains correlated precisely with regions known to be necessary for E1A-mediated transformation. One domain was located at the N terminus of E1A. The other domain spanned residues 36 to 81, corresponding to conserved region 1 of E1A. S49 cellular proteins that associate with E1A were coimmunoprecipitated with anti-E1A antibody. These included the previously identified proteins p300, p130, p107, p105Rb, and cyclin A. In addition, proteins of 90 kDa and a series of proteins in the 120- to 170-kDa range were identified. Binding of p300, p90, and the 120- to 170-kDa proteins was abolished in cells expressing mutants of E1A that were unable to induce AP-1 DNA-binding activity and c-fos mRNA. These data strongly suggest that specific cellular E1A-binding proteins are involved in the induction of AP-1 DNA-binding activity and c-fos mRNA by the synergistic action of the 243R E1A protein and cyclic AMP and that these transcriptional events are related to the transformation process.


Persistence of Marek's disease virus in a subpopulation of B cells that is transformed by avian leukosis virus, but not in normal bursal B cells. Previous studies have described an augmentation of avian leukosis virus (ALV)-induced lymphoid leukosis in chickens that were coinfected with a serotype 2 Marek's disease virus (MDV) strain, SB-1. As a first step toward understanding the mechanism of this augmentation, we have analyzed the tropism of the MDV for the ALV-transformed B cell. After hatching, chickens were coinfected with ALV and a nonpathogenic strain of MDV, SB-1. Seventy primary and metastatic ALV-induced lymphomas that developed in chickens between 14 and 20 weeks of age were found, with only one exception, to carry SB-1 DNA. The MDV genome was maintained in cell lines derived from the tumors. However, MDV DNA could not be detected in nontransformed bursal B cells from chickens carrying ALV lymphomas. Moreover, during and after the lytic phase of MDV infection, SB-1 DNA was near or below the level of detection in bursal cells, suggesting that MDV most likely infects only a small subpopulation of bursal cells. By contrast, ALV-transformed B cells from MDV-free chickens could be persistently infected with MDV in vitro. These findings indicate that ALV lymphoma cells, unlike nontransformed bursal B cells, are susceptible to persistent MDV infection and can serve as a reservoir of MDV that can potentially influence the physiology of the transformed cell.


Adenovirus E4orf4 protein reduces phosphorylation of c-Fos and E1A proteins while simultaneously reducing the level of AP-1. Adenovirus E1A protein and cyclic AMP cooperate to induce transcription factor AP-1 and viral gene expression in mouse S49 cells. We report that a protein encoded within the viral E4 gene region acts to counterbalance the induction of AP-1 DNA-binding activity by E1A and cyclic AMP. Studies with mutant adenoviruses demonstrated that in the absence of E4orf4 protein, AP-1 DNA-binding activity is induced to substantially higher levels than in wild-type virus-infected cells. The induction is the result of increased production of JunB and c-Fos proteins. Hyperphosphorylated forms of c-Fos and E1A proteins accumulate in the absence of functional E4orf4 protein. We propose that the E4orf4 protein acts to inhibit the activity of a cellular kinase that phosphorylates both the E1A and c-Fos proteins. Phosphorylation-dependent alterations in the activity of c-Fos, E1A, or some unidentified protein might, then, lead to decreased synthesis of AP-1 components. This E4 function likely plays an important role in natural infections, since a mutant virus unable to express the E4orf4 protein is considerably more cytotoxic than the wild-type virus.


Mapping of homologous, amino-terminal neutralizing regions of human T-cell lymphotropic virus type I and II gp46 envelope glycoproteins. Twelve synthetic peptides containing hydrophilic amino acid sequences of human T-cell lymphotropic virus type I (HTLV-I) envelope glycoprotein were coupled to tetanus toxoid and used to raise epitope-specific antisera in goats and rabbits. Low neutralizing antibody titers (1:10 to 1:20) raised in rabbits to peptides SP-2 (envelope amino acids [aa] 86 to 107), SP-3 (aa 176 to 189), and SP-4A (aa 190 to 209) as well as to combined peptide SP-3/4A (aa 176 to 209) were detected in the vesicular stomatitis virus-HTLV-I pseudotype assay. Higher-titered neutralizing antibody responses to HTLV-I (1:10 to 1:640) were detected with pseudotype and syncytium inhibition assays in four goats immunized with a combined inoculum containing peptides SP-2, SP-3, and SP-4A linked to tetanus toxoid. These neutralizing anti-HTLV-I antibodies were type specific in that they did not inhibit HTLV-II syncytium formation. Neutralizing antibodies in sera from three goats could be absorbed with peptide SP-2 (aa 86 to 107) as well as truncated peptides containing envelope aa 90 to 98, but not with equimolar amounts of peptides lacking envelope aa 90 to 98. To map critical amino acids that contributed to HTLV-I neutralization within aa 88 to 98, peptides in which each amino acid was sequentially replaced by alanine were synthesized. The resulting 11 synthetic peptides with single alanine substitutions were then used to absorb three neutralizing goat antipeptide antisera. Both asparagines at positions 93 and 95 were required for adsorption of neutralizing anti-HTLV-I antibodies from all three sera. Peptide DP-90, containing the homologous region of HTLV-II envelope glycoprotein (aa 82 to 97), elicited antipeptide neutralizing antibodies to HTLV-II in goats that were type specific. In further adsorption experiments, it was determined that amino acid differences between homologous HTLV-I and HTLV-II envelope sequences at HTLV-I aa 95 (N to Q) and 97 (G to L) determined the type specificity of these neutralizing sites. Thus, the amino-terminal regions of HTLV-I and -II gp46 contain homologous, linear, neutralizing determinants that are type specific.


The fitness of defective interfering murine coronavirus DI-a and its derivatives is decreased by nonsense and frameshift mutations. The genome of the defective interfering (DI) mouse hepatitis virus DI-a carries a large open reading frame (ORF) consisting of ORF1a, ORF1b, and nucleocapsid sequences. To test whether this fusion ORF is important for DI virus replication, we constructed derivatives of the DI-a genome in which the reading frame was truncated by a nonsense codon or a frameshift mutation. In vitro-transcribed DI RNAs were transfected into mouse hepatitis virus-infected cells followed by undiluted passage of the resulting virus-DI virus stocks. The following observations were made. (i) Truncation of the fusion ORF was not lethal but led to reduced accumulation of DI RNA. (ii) When pairs of nearly identical in-frame and out-of-frame DI RNAs were directly compared by cotransfection, DI viruses containing in-frame genomic RNAs prevailed within three successive passage even when the out-of-frame RNAs were transfected in 10-fold molar excess. (iii) When DI viruses containing out-of-frame genomic RNAs were passaged, mutants emerged and were selected for that had restored the reading frame. We conclude that translation of the fusion ORF is indeed required for efficient propagation of DI-a and its derivatives.


Transient replication of human papillomavirus DNAs. Information on papillomavirus DNA replication has primarily derived from studies with bovine papillomavirus type 1 (BPV-1). Our knowledge of DNA replication of the human papillomaviruses (HPVs) is quite limited, in part because of the lack of a cell culture system capable of supporting the stable replication of HPV DNA. This study demonstrates that the full-length genomic DNAs of HPV types 11 and 18 (HPV-11 and HPV-18), but not HPV-16, are able to replicate transiently after transfection into several different human squamous cell carcinoma cell lines. This system was used to identify the viral cis and trans elements required for DNA replication. The viral origins of replication were localized to a region of the viral long control region. Like BPV-1, E1 and E2 were the only viral factors required in trans for the replication of plasmids containing the origin. Cotransfection of a plasmid expressing the E1 open reading frame (ORF) from HPV-11 with a plasmid that expresses the E2 ORF from HPV-6, HPV-11, HPV-16, or HPV-18 supported the replication of plasmid DNAs containing the origin regions of HPV-11, HPV-16, or HPV-18, indicating that there are functions shared among the corresponding E1 and E2 proteins and origins of these viruses. Although HPV-16 genomic DNA did not replicate by itself under experimental conditions that supported the replication of HPV-11 and HPV-18 genomic DNAs, expression of the HPV-16 early region functions from a strong heterologous promoter supported the replication of a cotransfected plasmid containing the HPV-16 origin of replication. This finding suggests that the inability of the HPV-16 genomic DNA to replicate transiently in the cell lines tested was most likely due to insufficient expression of the viral E1 and/or E2 genes required for DNA replication.


Fv-1 restriction and its effects on murine leukemia virus integration in vivo and in vitro. We have investigated the mechanisms by which alleles at the mouse Fv-1 locus restrict replication of murine leukemia viruses. Inhibition of productive infection is closely paralleled by reduced accumulation of integrated proviral DNA as well as by reduced levels of linear viral DNA in a cytoplasmic fraction. Nevertheless, viral DNA is present at nearly normal levels in a nuclear fraction, and total amounts of viral DNA are only mildly affected in restrictive infections, suggesting a block in integration to account for reduced levels of proviral DNA. However, integrase (IN)-dependent trimming of 3' ends of viral DNA occurs normally in vivo during restrictive infections, demonstrating that not all IN-mediated events are prevented in vivo. Furthermore, viral integration complexes present in nuclear extracts of infected restrictive cells are fully competent to integrate their DNA into a heterologous target in vitro. Thus, the Fv-1-dependent activity that restricts integration in vivo may be lost in vitro; alternatively, Fv-1 restriction may prevent a step required for integration in vivo that is bypassed in vitro.


Two cellular single-strand-specific DNA-binding proteins interact with two regions of the bovine papillomavirus type 1 genome, including the origin of DNA replication. We have identified and purified to near homogeneity two specific single-stranded DNA-binding factors (SPSF I and II) with molecular masses of 42 and 39 kDa, respectively, from calf thymus. Gel retention analysis and competition experiments demonstrate that the ubiquitous proteins SPSF I and II specifically interact with single-stranded DNA derived from the minimal in vitro origin of replication of bovine papillomavirus type 1 and a region of the viral genome proposed to be involved in plasmid maintenance. Bovine papillomavirus type 1 proteins do not interfere with DNA binding of SPSF I and II. The exact location of the binding domains of SPSF I and II on the DNA has been determined by methylation interference and T4 DNA polymerase footprinting. A potential cellular binding site for SPSF I and II is the major promoter (P2) of the human c-myc gene.


cis-acting lesions targeted to the hydrophobic domain of a poliovirus membrane protein involved in RNA replication. The structural requirements of the hydrophobic domain contained in poliovirus polypeptide 3AB were studied by using a molecular genetic approach in combination with an in vitro biochemical analysis. We report here the generation and analysis of deletion, insertion, and amino acid replacement mutations aimed at decreasing the hydrophobic character of the domain. Our results indicated that the hydrophobicity of this region of 3AB is necessary to maintain normal viral RNA synthesis. However, in vitro membrane association assays of the mutated proteins did not establish a direct correlation between 3AB membrane association and viral RNA synthesis. Some of the lethal mutations we engineered produced polyproteins with abnormal P2- and P3-processing capabilities due to an alteration in the normal cleavage order of the polyprotein. A detailed analysis of these mutants suggests that P2 is not the major precursor for polypeptides 2A and 2BC and that P2 protein products are derived from P2-P3-containing precursors (most likely P2-P3 or P2-3AB). Such precursors are likely to result from primary polyprotein cleavage events that initiate a proteolytic cascade not previously documented. Our results also indicated that the function provided by the hydrophobic domain of 3AB cannot be provided in trans. We discuss the implications of these results on the formation of limited-diffusion replication complexes as a means of sequestering P2- and P3-region polypeptides required for RNA synthesis and protein processing.


Mutational analysis of the proposed FG loop of poliovirus proteinase 3C identifies amino acids that are necessary for 3CD cleavage and might be determinants of a function distinct from proteolytic activity. Mutations were introduced into a cDNA clone of poliovirus resulting in single-amino-acid substitutions within the region of the proposed FG loop of proteinase 3C. RNAs were made by in vitro transcription with T7 RNA polymerase and used to transfect HeLa cells. Virus viability was assessed as indicated by cell lysis. In parallel, RNAs were translated in vitro by using a HeLa cell lysate, and the patterns of the processed poly-proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Replacement of Lys-78, Arg-79, and Glu-81 had apparently no effect on virus viability and on proteolytic processing. In contrast, virus viability was abolished by mutation of Phe-83, Arg-84, Asp-85, Ile-86, and Arg-87. With respect to substitution of Phe-83, Asp-85, and Arg-87, these effects correlated with impaired processing of the 3CD cleavage site, separating 3C and 3D, and, to a lesser extent, of the P1 precursor. Replacement of Arg-84 and Ile-86, on the other hand, did not alter the processing pattern. Thus, the lethal effects in these mutant genomes may not have been caused by impaired processing. A special case was the mutant of Lys-82-Gln. Virus recovered from cells transfected with RNA carrying this mutation always contained an A-to-G transition which resulted in the replacement of glutamine for arginine. Our data suggest that residues in the proposed FG loop of proteinase 3C influence 3CD cleavage and that they are determinants of a function unrelated to proteolytic processing.


Mutational analysis of the adeno-associated virus rep gene. The replication (rep) gene of the human parvovirus adeno-associated virus (AAV) is a pleiotropic effector of numerous viral functions and experts profound effects on cellular transformation. Of the four Rep proteins, the primarily nuclear Rep78 and Rep68 direct AAV DNA replication, trans activation of the capsid (cap) gene promoter, and inhibition of cellular proliferation mediated by various oncogenes. In an initial attempt to define functional domains in Rep78, we have constructed a comprehensive set of XhoI linker insertion and deletion mutations in the rep gene. Each of the mutant genes has been expressed in cell culture and assayed for the following functions: (i) nuclear localization, (ii) AAV DNA replication, (iii) trans activation of the AAV capsid gene transcription promoter, and (iv) suppression of cellular transformation mediated by the adenovirus E1a and an activated ras oncogene pair. Modest disruptions in the normal conformation of Rep78 inactivated its AAV DNA replication function and trans activation of the cap gene promoter. Linker insertion mutations in the amino-terminal one-third of the protein inactivated Rep78's ability to suppress oncogene-mediated cellular transformation. The transformation suppression domains are not limited to the amino-terminal regions, however, since deletions throughout the protein altered its suppression capabilities. A putative nuclear localization signal that is essential for each of the above functions was found in the Rep proteins. These results provide a preliminary screening of the functional domains in the AAV Rep proteins and pave the way for more subtle mutational analysis.


Differentiation-induced and constitutive transcription of human papillomavirus type 31b in cell lines containing viral episomes. The expression of viral genes during the productive life cycle of human papillomaviruses (HPV) is tightly coupled to the differentiation program of epithelial cells. We have examined transcription of HPV as a function of differentiation in an in vitro organotypic raft culture system which allows for epithelial stratification at the air-liquid interface. When CIN612 cells, which contain episomal copies of HPV type 31b (HPV31b), were allowed to stratify in raft cultures, they differentiated in a manner which was histologically similar to that seen in a cervical intraepithelial neoplasia I biopsy lesion. In monolayer cultures of CIN612 cells, two major polycistronic HPV31b transcripts of 1.7 kb which encode (i) E6, E7, E1-E4, and E5 and (ii) E6*, E7, E1-E4, and E5 were identified. These RNAs initiated at a promoter, P97, in the upstream regulatory region of the virus. Following differentiation in raft cultures, the relative abundance of RNAs initiated at P97 was unchanged. In contrast, the expression of a 1.3-kb RNA encoding an E1-E4 fusion protein and E5 was found to increase substantially following differentiation. This transcript was initiated at a novel promoter within the E7 gene (P742). These studies have therefore identified a constitutive viral promoter which is active throughout stratified epithelium as well as a novel promoter which is induced upon epithelial cell differentiation.


Transposition of a Ty3 GAG3-POL3 fusion mutant is limited by availability of capsid protein. Ty3 encodes structural proteins in its upstream open reading frame (GAG3) and catalytic proteins in an overlapping open reading frame (POL3). As is the case for retroviruses, high levels of structural protein versus catalytic proteins are synthesized and we show here that catalytic proteins are derived from a GAG3-POL3 fusion polyprotein. To evaluate the relative contributions of structural and catalytic components of the Ty3 particle, we perturbed the balance of these proteins by fusing the GAG3 and POL3 frames. This fusion Ty3 was capable of complementing low levels of transposition of a donor Ty3 which contained only cis-acting sequences required for transposition. Examination of extracts of cells expressing the GAG3-POL3 fusion mutant showed that particle formation differed qualitatively and quantitatively from viruslike particle formation by wild-type Ty3. Suprisingly, expression of 238 codons of GAG3, encoding only capsid protein, complemented transposition and particle formation defects of the fusion mutant, showing that the limiting deficiency was in capsid, and not in nucleocapsid, function. In addition, protein containing the capsid domain expressed alone accumulated in the same particulate fraction as viruslike particles, showing that it was sufficient for particle formation. The activity of the Ty3 fusion mutant contrasts with the inviability of mutant retroviruses in which gag and pol frames were fused and argues that retrotransposons tolerate considerable variation in the nucleoprotein complexes that permit replication and integration.


Adenovirus E1A proteins stimulate inositol phospholipid metabolism in PC12 cells. To study the influence of nuclear oncogenes on inositol phospholipid metabolism, we examined the various parameters of inositol phospholipid metabolism in PC12 cells expressing adenovirus type 12 or adenovirus type 5 E1A. Although the inositol 1,4,5-trisphosphate content was increased only slightly, the diacylglycerol content was 2.4-fold higher in E1A-expressing PC12 cells. Furthermore, we found that the activity of phospholipase C, one of the key enzymes in inositol phospholipid metabolism, was increased at least five- to eightfold. Diacylglycerol kinase activity in the membrane fraction was 10 to 15% of that in parental PC12 cells. Overall protein kinase C activities in E1A-expressing PC12 cells were decreased, but the activity of membrane-bound protein kinase C was significantly increased. These observations clearly indicate that inositol phospholipid metabolism is stimulated in cells producing E1A and suggest that nuclear oncogene E1A has the ability to stimulate inositol phospholipid metabolism.


Localization of cis-acting sequences in the latency-related promoter of bovine herpesvirus 1 which are regulated by neuronal cell type factors and immediate-early genes. Bovine herpesvirus 1 (BHV-1) establishes a latent infection in sensory ganglionic neurons of cattle. During a latent infection, a single latency-related (LR) transcript is expressed. This observation suggested that DNA sequences in the LR promoter are positively regulated by neural cell type factors. The regulation of the LR gene was examined in neural cells as well as nonneural cells in transient assays. A 258-bp XbaI-SphI fragment from the LR promoter cis activated the herpes simplex virus type 1 thymidine kinase promoter in rat pheochromocytoma (PC-12) cells and differentiated human (HCN1A) neurons. In contrast, cis activation was not observed with rat (Rat-2) fibroblasts, undifferentiated HCN1A cells, or bovine turbinate cells. Treatment of PC-12 cells with nerve growth factor increased transcriptional activity of the XbaI-SphI fragment. Exonuclease III footprinting experiments suggested that nuclear factors bind to the XbaI-SphI fragment. The immediate-early genes of BHV-1 trans activated the LR promoter, and DNA sequences 5' to the XbaI-SphI fragment were necessary for maximal stimulation. These results imply that neural-cell-type-specific factors and BHV-1 immediate-early genes positively regulate LR gene expression.


Phenotypes of murine leukemia virus-induced tumors: influence of 3' viral coding sequences. Murine leukemia viruses (MuLVs) induce leukemias and lymphomas in mice. We have used fluorescence-activated cell sorter analysis to determine the hematopoietic phenotypes of tumor cells induced by a number of MuLVs. Tumor cells induced by ecotropic Moloney, amphotropic 4070A, and 10A1 MuLVs and by two chimeric MuLVs, Mo(4070A) and Mo(10A1), were examined with antibodies to 13 lineage-specific cell surface markers found on myeloid cell, T-cell, and B-cell lineages. The chimeric Mo(4070A) and Mo(10A1) MuLVs, consisting of Moloney MuLV with the carboxy half of the Pol region and nearly all of the Env region of 4070A and 10A1, respectively, were constructed to examine the possible influence of these sequences on Moloney MuLV-induced tumor cell phenotypes. In some instances, these phenotypic analyses were supplemented by Southern blot analysis for lymphoid cell-specific genomic DNA rearrangements at the immunoglobulin heavy-chain, the T-cell receptor gamma, and the T-cell receptor beta loci. The results of our analysis showed that Moloney MuLV, 4070A, Mo(4070A), and Mo(10A1) induced mostly T-cell tumors. Moloney MuLV and Mo(4070A) induced a wide variety of T-cell phenotypes, ranging from immature to mature phenotypes, while 4070A induced mostly prothymocyte and double-negative (CD4- CD8-) T-cell tumors. The tumor phenotypes obtained with 10A1 and Mo(10A1) were each less variable than those obtained with the other MuLVs tested. 10A1 uniformly induced a tumor consisting of lineage marker-negative cells that lack lymphoid cell-specific DNA rearrangements and histologically appear to be early undifferentiated erythroid cell-like precursors. The Mo(10A1) chimera consistently induced an intermediate T-cell tumor. The chimeric constructions demonstrated that while 4070A 3' pol and env sequences apparently did not influence the observed tumor cell phenotypes, the 10A1 half of pol and env had a strong effect on the phenotypes induced by Mo(10A1) that resulted in a phenotypic consistency not seen with other viruses. This result implicates 10A1 env in an active role in the tumorigenic process.


RNA recombination in a coronavirus: recombination between viral genomic RNA and transfected RNA fragments. Mouse hepatitis virus (MHV), a coronavirus, has been shown to undergo a high frequency of RNA recombination both in tissue culture and in animal infection. So far, RNA recombination has been demonstrated only between genomic RNAs of two coinfecting viruses. To understand the mechanism of RNA recombination and to further explore the potential of RNA recombination, we studied whether recombination could occur between a replicating MHV RNA and transfected RNA fragments. We first used RNA fragments which represented the 5' end of genomic-sense sequences of MHV RNA for transfection. By using polymerase chain reaction amplification with two specific primers, we were able to detect recombinant RNAs which incorporated the transfected fragment into the 5' end of the viral RNA in the infected cells. Surprisingly, even the anti-genomic-sense RNA fragments complementary to the 5' end of MHV genomic RNA could also recombine with the MHV genomic RNAs. This observation suggests that RNA recombination can occur during both positive- and negative-strand RNA synthesis. Furthermore, the recombinant RNAs could be detected in the virion released from the infected cells even after several passages of virus in tissue culture cells, indicating that these recombinant RNAs represented functional virion RNAs. The crossover sites of these recombinants were detected throughout the transfected RNA fragments. However, when an RNA fragment with a nine-nucleotide (CUUUAUAAA) deletion immediately downstream of a pentanucleotide (UCUAA) repeat sequence in the leader RNA was transfected into MHV-infected cells, most of the recombinants between this RNA and the MHV genome contained crossover sites near this pentanucleotide repeat sequence. In contrast, when exogenous RNAs with the intact nine-nucleotide sequence were used in similar experiments, the crossover sites of recombinants in viral genomic RNA could be detected at more-downstream sites. This study demonstrated that recombination can occur between replicating MHV RNAs and RNA fragments which do not replicate, suggesting the potential of RNA recombination for genetic engineering.


Oncogenicity of AKR mink cell focus-inducing murine leukemia virus correlates with induction of chronic phosphatidylinositol signal transduction. Naturally occurring recombinant murine leukemia viruses (MuLVs), termed mink cell focus-inducing (MCF) viruses, are the proximal leukemogens in spontaneous thymic lymphomas of AKR mice. The mechanism by which these viruses transform lymphocytes is not clear. Previous studies have implicated either integrational activation of proto-oncogenes, chronic autocrine immune stimulation, and/or autocrine stimulation of growth factor receptors (e.g., interleukin 2 receptors) via binding of the viral env glycoprotein (gp70) to these receptors. Any one of these events could also involve activation of second messenger signaling pathways in the cell. We examined whether infection with oncogenic AKR-247 MCF MuLV induced transmembrane signaling cascades in thymocytes of AKR mice. Cyclic AMP levels were not changed, but there was enhanced turnover of phosphatidylinositol phosphates, with concomitant increases in diacyglycerol and inositol 1,4,5-triphosphate. Thus, phospholipase C activity was increased. Protein kinase C activity was also elevated in comparison to that in uninfected thymocytes. The above events occurred in parallel with MCF expression in the thymus and were chronically maintained thereafter. No changes in phospholipid turnover occurred in an organ which did not replicate the MCF virus (spleen) or in thymocytes of AKR mice infected with a thymotropic, nononcogenic MCF virus (AKV-1-C36). Therefore, only the oncogenic MCF virus induced phosphatidylinositol signal transduction. Flow cytometric comparison of cell surface gp70 revealed that AKR-247 MCF virus-infected thymocytes expressed more MCF virus gp70 than did thymocytes from AKV-1-C36 MCF virus-infected mice, suggesting that certain threshold quantities of MCF virus env glycoproteins may be involved in this signaling. This type of signal transduction is not induced by stimulation of the interleukin 2 receptor but is involved in certain oncogene systems (e.g., ras and fms). Its chronic induction by oncogenic MCF MuLV may thus initiate thymocyte transformation.


Molecular cloning of osteoma-inducing replication-competent murine leukemia viruses from the RFB osteoma virus stock. We report the molecular cloning of two replication-competent osteoma-inducing murine leukemia viruses from the RFB osteoma virus stock (M. P. Finkel, C. A. Reilly, Jr., B. O. Biskis, and I. L. Greco, p. 353-366, in C. H. G. Price and F. G. M. Ross, ed., Bone--Certain Aspects of Neoplasia, 1973). Like the original RFB osteoma virus stock, viruses derived from the molecular RFB clones induced multiple osteomas in mice of the CBA/Ca strain. The cloned RFB viruses were indistinguishable by restriction enzyme analysis and by nucleotide sequence analysis of their long-terminal-repeat regions and showed close relatedness to the Akv murine leukemia virus.


Mouse hepatitis virus utilizes two carcinoembryonic antigens as alternative receptors. The cellular receptor for the murine coronavirus mouse hepatitis virus (MHV) has been identified as a member of the murine carcinoembryonic antigen (CEA) family (R. K. Williams, G. S. Jiang, and K. V. Holmes, Proc. Natl. Acad. Sci. USA 88:5533-5536, 1991). However, the receptor protein was not detected in some of the susceptible mouse tissues. We therefore examined whether other types of MHV receptor might exist. By polymerase chain reaction with the conserved sequences of murine CEA gene family members (mmCGM) as primers, we detected two CEA-encoding RNAs in the mouse liver. One of them (1.3 kb) encodes mmCGM1, which has previously been identified as the receptor for MHV, and the other one (0.8 kb) was shown to encode another member of mouse CGM, mmCGM2. The sequence analysis showed that mmCGM2 lacks 564 nucleotides in the middle of the gene compared with mmCGM1. These two CEA transcripts are probably derived from the same gene by an alternative splicing mechanism. Expression of either of these cDNA clones in COS-7 cells rendered these cells susceptible to MHV infection, suggesting that not only mmCGM1 but also mmCGM2 serves as a receptor for MHV. The mmCGM2 was the major CEA species in the mouse brain, which is a main target organ for the neurotropic strains of MHV. Very little mmCGM1 was detected in the mouse brain or in cells of the susceptible mouse astrocytoma cell line DBT. This result indicates that MHV may utilize different CEA molecules as the major receptor in the mouse brain and in the liver. This is a first identification of multiple receptors for a single virus. The presence of different receptors in different tissues may explain the target cell specificity of certain MHVs.


The putative E5 open reading frame of cottontail rabbit papillomavirus is dispensable for papilloma formation in domestic rabbits. In the cottontail rabbit papillomavirus (CRPV)-rabbit system, recombinant CRPV DNA can induce papillomas. This investigation was undertaken to evaluate whether the E5 open reading frame (ORF) of CRPV is required for papilloma formation. The CRPV genome we utilized, CRPV-WA, was sequenced in the E5 region and was found to contain one deletion, two insertions, and one transition mutation compared with CRPV-KS, the CRPV genome that has been fully sequenced. Despite these differences, an intact E5 ORF is preserved, supporting the notion that this gene may serve a biological function. One frameshift and two in-frame mutations were constructed in the small region of the 5' end of the E5 ORF that follows the E2 stop codon and precedes the L2 ORF. Several hundred rabbit skin sites were inoculated with each DNA preparation with a jet injector to test the ability of three CRPV E5 mutant DNAs to induce papillomas. In vivo results showed that each of the mutants induced papillomas, and biochemical analysis demonstrated that the E5 mutations present in DNA inocula were retained in the papillomas. The frequency of papilloma formation, however, was generally lower with each of the CRPV E5 mutants than with wild-type CRPV DNA, particularly so for the E5 frameshift mutant, suggesting that although the recognized E5 ORF is not required in domestic rabbits for the induction of papillomas by CRPV DNA, it may facilitate their formation.


Protein P4 of the bacteriophage phi 6 procapsid has a nucleoside triphosphate-binding site with associated nucleoside triphosphate phosphohydrolase activity. Bacteriophage phi 6 contains three segments of double-stranded RNA. The procapsid consists of proteins P1, P2, P4, and P7, which are encoded by the viral L segment. cDNA copies of this segment have been cloned into plasmids that direct the production of these proteins, which assemble into polyhedral procapsids. These procapsids are capable of packaging plus-sense phi 6 RNA in the presence of nucleoside triphosphate and synthesizing the complementary minus strand to form double-stranded RNA. In this article, we report the presence of a nucleotide-binding site in protein P4. The viral procapsid and nucleocapsid exhibit a nucleoside triphosphate phosphohydrolase activity that converts nucleoside triphosphates into nucleoside diphosphates.


Bovine leukemia virus gene expression in vivo. The in vivo transcriptional status of bovine leukemia virus was assessed at three stages of infection during the progression of the disease: aleukemic stage, persistent lymphocytosis, and leukemia/lymphosarcoma. Bovine leukemia virus transcripts could be amplified from total or cytoplasmic enriched lymphocyte RNA by reverse transcription polymerase chain reaction in cells from all but a few aleukemic animals. With primer pairs diagnostic for differentially spliced transcripts (full length-genomic, envelope, tax/rex, and alternatively spliced), a trend toward exclusion of both full-length and envelope RNAs, with retention of the tax/rex message, appears as leukemia/lymphosarcoma develops.


Analysis of the gB promoter of herpes simplex virus type 1: high-level expression requires both an 89-base-pair promoter fragment and a nontranslated leader sequence. To investigate the cis-acting sequences involved in regulation of a herpes simplex virus gamma 1 gene, deletion analyses of the glycoprotein B (gB) gene promoter were performed. In transfection assays with gB-chloramphenicol acetyltransferase plasmids, high-level constitutive expression from the gB promoter was found with an 89-bp sequence (-69 to +20). Additional sequences in the 5'-transcribed noncoding leader region (+20 to +136) were required for full stimulation by herpes simplex virus infection. Plasmids with progressive deletions of the gB leader sequence demonstrated that chloramphenicol acetyltransferase expression in infected cells was proportional to the length of the leader region retained. In recombinant viruses containing a gB-gC gene fusion, a similar 83-bp (-60 to +23) region of the gB gene was found to promote accurately initiated gC mRNA from the viral genome with the same kinetics as the wild-type gB gene. Although the kinetics of expression remained the same, RNA abundance was greater with a 298-bp (-260 to +38) promoter than with the 83-bp promoter.


Differential splicing of Epstein-Barr virus immediate-early RNA. A variant form of splicing of RNA crossing the Epstein-Barr virus (EBV) BZLF1 gene was observed in the late productive cycle of EBV. This splice omits the middle exon of BZLF1 and joins the outer two exons of BZLF1 in frame, but the shortened form of BZLF1 protein (Z delta) could not be detected in natural EBV infections.


Human papillomavirus type 16 E6 increases the degradation rate of p53 in human keratinocytes. The E6 proteins of the high-risk human papillomaviruses (HPVs) have been shown to form a complex with and induce the degradation of human p53 in vitro. To determine whether p53 is degraded more rapidly in cells expressing E6 in vivo, the half-life of p53 was determined by pulse-chase analysis in early-passage normal human keratinocytes and fibroblasts, human keratinocytes immortalized with HPV type 16 (HPV16) E6 plus E7, and nonimmortal keratinocytes transfected with E6. The results of these experiments indicate that (i) the half-life of newly synthesized p53 is relatively long (4 h) in early-passage human keratinocytes and fibroblasts but short in keratinocytes expressing E6 (15 to 30 min), (ii) a similar increased rate of p53 degradation was measured in lines immortalized with HPV16 E6 plus E7 and senescent cells expressing E6, indicating that this increase is not simply the result of selection in the immortalized lines, and (iii) very low levels of expression of E6 result in a greatly decreased half-life of p53, suggesting that E6 acts in a catalytic manner.


Loss of transformed phenotype upon senescence of Rous sarcoma virus-infected chicken neuroretinal cells. Success in obtaining permanent Rous sarcoma virus-infected chicken cell lines has been limited because of a senescence phenomenon. We show that a diminished, transformed phenotype, followed by dramatic morphological changes, precedes senescence. These changes are associated with continued expression of pp60v-src, as well as specific alterations in expression of two possible phosphorylated substrates of pp60v-src.


Prevalence and correlates of herpes simplex infections. The population-based AIDS in Multiethnic Neighborhoods Study. To examine the extent and correlates of infection with herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in an inner-city community, we studied the prevalence of antibodies to these viruses and their association with risk behaviors in a representative sample of unmarried white, black, and Hispanic adults living in San Francisco, Calif. Cross-sectional, community-based, random household survey. In 1988 and 1989, we surveyed 1770 unmarried men and women aged 20 to 44 years from three San Francisco neighborhoods of varying geographic and cultural characteristics. HSV-1 and HSV-2 antibodies based on an immunodot assay using type-specific glycoproteins gG-1 and gG-2. Of blood samples from 1212 participants available for testing, 750 (62%) had HSV-1 antibodies and 400 (33%) had HSV-2 antibodies. After controlling for other variables, HSV-1 antibody was significantly correlated (P less than .05) with older age (in heterosexual men, women, and homosexually active men), less education (in heterosexual men and women), and Hispanic (especially those not born in the United States) or black race. HSV-2 antibody was significantly correlated (P less than .05) with female gender, number of lifetime sexual partners and older age (in heterosexual men and women), and low levels of education and black or Hispanic race (in women). Among those with antibody to HSV-2, only 28 (19%) of 149 men and 32 (13%) of 251 women reported a history of genital herpes. However, most men (62%) and women (84%) who reported a history of genital herpes had HSV-2 antibodies. We observed a similar pattern (low sensitivity and moderate specificity) for a history of facial herpes and the presence of HSV-1 antibodies. After controlling for other variables, HSV-2 antibodies were associated with a lower frequency of HSV-1 antibodies among homosexual men infected with the human immunodeficiency virus. HSV-1 antibodies were found in nearly two thirds of single urban adults and were most common among Hispanics not born in the United States. HSV-2 antibodies were found in one third of this population and were associated with risk behaviors for sexually transmitted diseases. For both facial and genital herpes infections, self-reporting of infection was very insensitive and moderately specific.


[Effect of antihypertensive therapy with captopril on gluco- and mineralocorticoid receptors of peripheral blood lymphocytes in hypertensive patients of various age]. Binding of 3H-dexamethasone and 3H-aldosterone by peripheral lymphocyte receptors was investigated in healthy persons and hypertensive patients before and after 2-week captopril treatment. The number of glucocorticoid and mineralocorticoid binding sites was increased in hypertensives vs normotensives. The treatment with the ACE inhibitor captopril led to activation of hormone-receptor interactions. There was a more marked rise of the number of receptors in middle-aged (44-55 years) hypertensives vs elderly (61-80 years) subjects after captopril treatment.


[Regulation of the adenylate cyclase system of lymphocytes in patients with therapy-resistant arterial hypertension and during PGE2 administration]. The effects of prostaglandin E2 (PGE2) infusions on lymphocyte beta 2-adrenoceptor-dependent adenylate cyclase (beta 2ARAC) system were studied in 26 patients with resistant hypertension (RH). The density of beta 2-adrenoceptors and their affinity for 1-isoproterenol were measured with 125ICYP and adenylate cyclase activity was determined by alpha-[32P]AMP generation in mononuclear lymphocytes of RH patients before and 1, 7, and 14 days after the last PGE2 infusion. Plasma epinephrine and norepinephrine concentrations were analyzed by using HPLC. The resistance to the four-component drug therapy was overcome with PGE2 infusions in patients, leading to a decrease in lymphocyte beta 2-adrenoceptor density and an increase in beta 2-receptor affinity for catecholamines and in adenylate cyclase activation by stimulating agents. PGE2 infusions unchanged the sensitivity to antihypertensive drugs in patients resulting in an increase in lymphocyte beta 2-adrenoceptor density, a decrease in beta 2-receptor affinity for catecholamines and in adenylate cyclase activation.


Thiamine transport by erythrocytes and ghosts in thiamine-responsive megaloblastic anaemia. A 9-year study of thiamine metabolism and cellular transport was performed in two patients with thiamine-responsive megaloblastic anaemia associated with diabetes mellitus and sensorineural deafness, in their relatives, and in age-matched controls from the same area. The ratios between the content of thiamine and that of its phosphoesters in erythrocytes were within the normal range, whereas the absolute values of thiamine and thiamine compounds were reduced by about 40% as compared to controls. Thiamine pyrophosphokinase activity was about 30% lower than in controls. Thiamine treatment restored the levels of thiamine and thiamine compounds to normal values, whereas kinase was unaffected. Both the saturable (specific, predominant at low, less than 2 mumol/L, physiological concentrations of thiamine) and the non-saturable component of thiamine transport were investigated. Erythrocytes and ghosts from patients exhibited no saturable component, this abnormality being specific for the patients and not shared by their parents. It is concluded that the cells from thiamine-responsive megaloblastic anaemia patients contain low levels of thiamine compounds, probably due to their inability to take up and retain physiological concentrations of thiamine, as a result of the lack of the saturable, specific component of transport and reduced thiamine pyrophosphokinase.


Intracellular cyclic AMP levels in endothelial cells subjected to cyclic strain in vitro. Human saphenous vein endothelial cells (EC) were grown to confluence in fibronectin-coated culture plates with flexible membrane bottoms and maintained in M-199 supplemented with substrates. One hour prior to experimentation 5 mM IBMX, a phosphodiesterase inhibitor, was added. Vacuum was used to deform the membrane bottoms to 24% strain at 60 cycles/min (0.5 sec elongation alternating with 0.5 sec relaxation). After 10-60 min of cyclic strain, or upon exposure of EC to 100 microM forskolin or 0.1 microM galanin, intracellular cyclic AMP (cAMP) was measured by radioimmunoassay. In parallel experiments, tissue plasminogen activator (tPA) secretion was determined after 24 hr of cyclic strain in the absence or presence of forskolin or galanin. The results demonstrate that exposure of EC to cyclic strain led to no change in cAMP levels and confirmed our previous observation that tPA secretion was enhanced with cyclic strain. Addition of forskolin, which led to an almost 10-fold increase in cAMP levels, or galanin, which led to a 34% decrease in cAMP levels, did not significantly alter the rise in tPA induced by cyclic strain.


Endotoxin after gut ischemia/reperfusion causes irreversible lung injury. We have recently reported that 45 min of gut ischemia causes moderate 125I-albumin lung leak at 6 hr of reperfusion which was reversed at 18 hr. Our purpose was to determine the effect of a second insult, low dose endotoxin (LPS, 2.5 mg/kg), given 6 hr after gut ischemia/reperfusion (I/R) on this lung injury as assessed by 125I-albumin leak, neutrophil influx (myeloperoxidase assay, MPO), histopathology, and mortality. Rats were randomized to either sham laparotomy (LAP) or 45 min of superior mesenteric artery occlusion and 6 hr later were treated with LPS or saline. At 18 hr reperfusion the lungs were harvested, assayed for 125I-albumin leak and MPO, and microscopically examined by an unbiased observer after routine H&E staining. We observed that LPS increased lung neutrophil levels both with or without gut I/R. However, only the combined insult (I/R + LPS) increased 125I-albumin leak at 18 hr of reperfusion. Lung histology confirmed that the sequential combination of I/R + LPS caused marked interstitial edema and neutrophil sequestration accompanied by alveolar edema, hemorrhage, and fibrinous exudate, while I/R or LAP + LPS did not. The mortality rate of I/R + LPS was 39% which was significantly higher than LAP alone (0%), gut I/R alone (0%), or LAP + LPS (4%). In conclusion, a delayed exposure to low dose endotoxin converts moderate gut I/R-induced lung dysfunction into advanced organ failure.


Modulation of postsurgical macrophage function by early postsurgical polymorphonuclear leukocytes. Surgical trauma to the peritoneum, in the absence of infection, elicits a rapid and transient influx of polymorphonuclear leukocytes (PMNs) into the peritoneal cavity prior to the accumulation of macrophages. The aim of this study was to characterize the effects of these PMNs on macrophage function in the early postsurgical period. Rabbits underwent intestinal reanastomosis and peritoneal exudate cells were collected at various times after surgery. Macrophage-enriched preparations were incubated with spent media from cultures of PMNs obtained at the corresponding times after surgery. Superoxide anion (O2-) release by macrophages in response to phorbol myristate acetate was determined by cytochrome c reduction. Fibrinolytic and protease inhibitory activities in macrophage-spent media were also evaluated. The release of O2- had already increased at 2 hr, reached peak levels at 6 hr, and decreased by 24 hr after surgery. Spent media from PMNs harvested 6 hr after surgery suppressed, whereas spent media from postsurgical 12- or 24-hr PMNs increased O2- release from macrophages harvested at 6 and 12 hr after surgery. PMN-spent media had no effect on the secretion of plasminogen activator (PA) from macrophages harvested within 12 hr after surgery. In contrast, PA activity in the spent media from macrophages harvested 24 hr after surgery was elevated after exposure to PMN-spent media. PA inhibitory activity was reduced in macrophage-spent media at 2 hr after surgery and increased by 24 hr, while PMN-spent media had no effect on the level of PA inhibitory activity. Thus, soluble factors secreted into the culture medium by PMNs modulate macrophage function as soon as 6-12 hr after surgery.


Ibuprofen intervention in canine septic shock: reduction of pathophysiology without decreased cytokines. This study was undertaken to evaluate the effect of a cyclooxygenase inhibitor, ibuprofen, at various time intervals in a live Escherichia coli model of canine septic shock. Group I (control) animals (n = 5) received a LD100 dose of 10(9) live E. coli per kilogram were given no further treatment. Group II animals (n = 5) received a 10 mg/kg bolus of ibuprofen 10 min prior to bacterial infusion. Group III animals (n = 5) received ibuprofen 15 min after the bacterial infusion. Statistical analysis revealed the following: Group II animals had significantly higher MABP and significantly lower levels of serum fluorescent products (superoxide radical activity), plasma thromboxane B2, prostaglandin E2, and endotoxin levels compared to Group I animals (P less than 0.05). Plasma levels of tumor necrosis factor (TNF) and interleukin-6 (IL-6) were significantly elevated (P less than 0.05) from baseline in all animals (Groups I, II, and III), but ibuprofen treatment failed to either increase or decrease these levels. This study demonstrates that ibuprofen treatment can significantly reverse the deleterious hemodynamic and metabolic effects commonly seen in live E. coli septic shock without depressing the endogenous production of TNF or IL-6. These data support the hypothesis that sepsis initiates a cascade of mediators with the cytokines TNF and IL-6 being proximal events which in turn stimulate the next level, with ibuprofen probably exerting its inhibitory effect distal to this point in the cascade.


TNF alpha therapy activates human B-lymphoma cells in vivo and may protect myelopoiesis. In vitro TNF alpha induces proliferation and expression of predominantly type A TNF-receptors on B-lymphoma cells. In a pilot study we treated 2 patients with refractory B lymphomas with two courses of TNF alpha and consecutive aggressive chemotherapy (high dose Ara-C and mitoxantrone). TNF alpha was applied on days 1-4, chemotherapy on days 2-4 (TNF-AraM). The TNF-AraM therapy was repeated on day 43. Both patients responded to therapy. TNF alpha therapy induced expression of the 75 kD TNF receptor and the interleukin 2 receptor (CD25) and weakly the 55 kD TNF receptor on leukemic B lymphocytes. Interleukin 3, interleukin 6 and GM-CSF were induced and measured in the serum of patients. The mean time of severe granulocytopenia (less than 0.5/nl) was 9 days (range 8-10 days), the mean time of thrombocytopenia (less than 20/nl) was 5 days (range 2-6 days). In 7 patients, who were treated with high dose Ara-C and mitoxantrone (AraM) mean time of granulocytopenia (less than 0.5/nl) was 23 days (range 18-34 days), and of thrombocytopenia (less than 20/nl) was 13.3 (range 3-27 days). We conclude that TNF alpha can activate tumor B cells in vivo and may exhibit also myeloprotective effects when applied before aggressive chemotherapy.


Influence of antibodies against IGF-I, insulin or their receptors on proliferation of human acute lymphoblastic leukemia cell lines. To evaluate the potential role of IGF-I and insulin as growth-promoting factors in malignant lymphocyte development, we examined established T-acute lymphoblastic leukemic (ALL) cell lines with increasing stage of differentiation, HSB2, HUT78, CEM, MOLT3, Jurkat, JM-P, JM-886, and four established preB- and B-ALL cell lines REH, SKW6 CESS, BJAB for production of IGF-I and growth in the presence of antibodies, directed against IGF-I or insulin or their receptors. Basal DNA synthesis of the early differentiated T-cell lines HSB2 and HUT78, as well as the B-cell line REH, could be inhibited in a dose-dependent manner by both monoclonal antibodies against IGF-I (ASC41) and antibodies against the IGF-I receptor (alpha-IR3), suggesting that IGF-I acts as an auto- or paracrine growth factor for these cells via the IGF-I receptor. From these cells HUT78 and REH secreted IGF-I into cell culture medium. DNA synthesis of the further differentiated T-cell lines CEM and MOLT3 was inhibited by alpha-IR3 and antibodies directed against the insulin receptor (RPN.538) and against insulin (RPN.1661). These results suggest that insulin via the IGF-I receptor or insulin receptor can function as an autocrine or paracrine growth factor in these T-ALLs. Proliferation of the most differentiated T-ALL Jurkat and JMP was inhibited only by alpha-IR3 and 2C2, an antibody directed against the IGF-II receptor, suggesting that IGF-I or IGF-II acting via the IGF-I receptor or IGF-II receptor may be involved in proliferation of these cell lines. Inhibition of the DNA synthesis by RPN.538 and RPN.1661 indicate a more important role for insulin in growth of leukemias of the B-ALL cell lines SKW6 and CESS.


Treatment of mycoplasma-contaminated continuous cell lines with mycoplasma removal agent (MRA). Thirty-nine continuous adherent or suspension cell lines were treated with a quinolone antibiotic, Mycoplasma Removal Agent (MRA), for the elimination of chronic mycoplasma contamination. In preliminary experiments MRA did not show any cytostatic or cytotoxic effects on mycoplasma-free cell cultures in concentrations up to ten-fold the concentration used for mycoplasma eradication. Twenty-eight cell lines (72%) were effectively cleansed of the mycoplasma contaminants by MRA treatment. The persistent removal of the mycoplasma infection was monitored by three mycoplasma detection assays. In seven cell lines (18%) the mycoplasmas were resistant to treatment with MRA. The resistant species was mainly M. arginini followed by M. orale and A. laidlawii; however, other cell lines harboring these species were cured. Four cell lines (10%) which prior to treatment presented with decreased viability and poor or no cell growth were lost during or shortly after the exposure to the antibiotic. If an antibiotic elimination is attempted it is imperative to closely examine the effectiveness of treatment and possible eukaryotic cytotoxicity. The treated mycoplasma-free cells may also no longer express the original features as a result of treatment or the absence of mycoplasma.


Purification of opioid receptor in the presence of sodium ions. Opioid receptor was solubilized from rat brain membranes with a mixture of the detergents CHAPS and digitonin in the presence of protease inhibitors and 1 M NaCl. The solubilized receptor bound mu-opioid agonists and antagonists with affinities similar to those of native membrane receptor. The affinity of solubilized receptor for the agonist PL017 was greatly reduced by GTP gamma S, suggesting the receptor is still associated with G-protein. The solubilized material was passed through an opioid antagonist (10cd) affinity column and a wheat germ agglutinin column, set up in series, to obtain a partially purified receptor preparation. This partially purified material bound mu-agonist with low affinity and the binding affinity was no longer affected by GTP gamma S. The partially purified receptor was further purified by repeating the affinity and lectin chromatography with smaller size column. Binding of opioid antagonist [3H]diprenorphine to the partially or purified receptors was dependent upon the presence of sodium ions. The purified receptor showed saturable and stereospecific binding for opioid ligands, was predominantly of the mu-type, and exhibited as a diffuse band with a medium molecular mass of 62 kD upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The average specific binding activity of the purified receptor was 18.8 +/- 2.3 pmol/micrograms protein, a value close to the theoretical estimation.