bluuebunny/crossref_metadata_2025 huggingface dataset:
Using pseudo amino acid composition to predict protein structural class: Approached by incorporating 400 dipeptide components
Authors: Lin Hao , Li Qian‐Zhong
Published: March 2007

The proteins structure can be mainly classified into four classes: all‐α, all‐β, α/β, and α + β protein according to their chain fold topologies. For the purpose of predicting the protein structural class, a new predicting algorithm, in which the increment of diversity combines with Quadratic Discriminant analysis, is presented to study and predict protein structural class. On the basis of the concept of the pseudo amino acid composition (Chou, Proteins: Struct Funct Genet 2001, 43, 246; Erratum: Proteins Struct Funct Genet 2001, 44, 60), 400 dipeptide components and 20 amino acid composition are, respectively, selected as parameters of diversity source. Total of 204 nonhomologous proteins constructed by Chou (Chou, Biochem Biophys Res Commun 1999, 264, 216) are used for training and testing the predictive model. The predicted results by using the pseudo amino acids approach as proposed in this paper can remarkably improve the success rates, and hence the current method may play a complementary role to other existing methods for predicting protein structural classification. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Atoms in molecules interpretation of the anomeric effect in the OCO unit
Authors: Vila Antonio , Mosquera Ricardo A.
Published: March 2007

The conformational preferences of two model compounds for the OCH2O anomeric unit: methanediol and dimethoxymethane analyzed within the framework of the QTAIM theory provide a new interpretation of the anomeric effect. The characteristic stabilization of the gauche conformers of these compounds is accompanied by a progressive reduction of the electron population of the hydrogens of the central methylene as the number of their gauche interactions to lone pairs rises. The electron population removed from these atoms during the conformational change is gained in the gauche conformers by atoms of larger atomic number, which results in a more negative molecular energy. Also, the variations displayed by atomic populations and the QTAIM delocalization indexes are not keeping in line with the hyperconjugative model of the anomeric effect. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Pseudopericyclic design drives antara‐antara [1,5] methylene sigmatropic shifts from a stepwise to a concerted mechanism
Authors: López Carlos Silva , Faza Olalla Nieto , Souto José A. , Álvarez Rosana , De Lera Ángel R.
Published: March 2007

Antara‐antara [1,5]‐methylene sigmatropic shifts of propenylidene cyclopropane and its heteroanalogues are shown to proceed through concerted or stepwise mechanisms depending on a delicate balance that is directly related to the presence or absence of heteroatoms at the termini atoms of the rearrangement. Lowering of activation energies upon heteroatom replacement are more significant for the oxacyclopropane analogues 1D, 1E, and 1F but double heterosubstitution is still needed to achieve a pseudopericyclic reaction. In fact only after reaching a pseudopericyclic process the energy balance favors the concerted pathway. Negligible NICS values and a clear disconnection in the ACID plot as well as some structural and energetical parameters reveal the pseudopericyclic nature of this concerted antara‐antara [1,5] sigmatropic shift. Although the product of the pseudopericyclic process is unprecedented, similar cycloisomerizations after allene activation should be considered within this hitherto undescribed reactions. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Accuracy of the three‐body fragment molecular orbital method applied to Møller–Plesset perturbation theory
Authors: Fedorov Dmitri G. , Ishimura Kazuya , Ishida Toyokazu , Kitaura Kazuo , Pulay Peter , Nagase Shigeru
Published: March 2007

The three‐body energy expansion in the fragment molecular orbital method (FMO) was applied to the 2nd order Møller–Plesset theory (MP2). The accuracy of both the two and three‐body expansions was determined for water clusters, alanine n‐mers (α‐helices and β‐strands) and one synthetic protein, using the 6‐31G* and 6‐311G* basis sets. At the best level of theory (three‐body, two molecules/residues per fragment), the absolute errors in energy relative to ab initio MP2 were at most 1.2 and 5.0 mhartree, for the 6‐31G* and 6‐311G* basis sets, respectively. The relative accuracy was at worst 99.996% and 99.96%, for 6‐31G* and 6‐311G*, respectively. A three‐body approximation was introduced and the optimum threshold value was determined. The protein calculation (6‐31G*) at the production level (FMO2/2) took 3 h on 36 3.2‐GHz Pentium 4 nodes and had the absolute error in the MP2 correlation energy of only 2 kcal/mol. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Electronic properties of tricoordinated phosphorus in hexagonal phosphininium compounds and molecular aromaticity
Authors: Li Wei‐Qi , Tian Wei‐Quan , Feng Ji‐Kang , Liu Zi‐Zhong , Ren Ai‐Min , Sun Chia‐Chung , Aoki Yuriko
Published: March 2007

Calculations with B3LYP within quantum chemical density functional theory have been carried out for 1‐H‐phosphininium cation and a series of 1‐R‐phosphininium molecules (R = cyclopentadiene, α and β pyrroles, α and β phosphole, C5BH5 and CH2). The negative nuclear‐independent chemical shift values and the positive aromatic stabilization energies confirm that they are aromatic compounds. In particular, the 1‐H‐phosphininium cation even exhibits stronger aromatic character than the well‐known aromatic phosphinine. The aromatic substituents have strong capability to attract electrons. It is the conjugation and aromaticity that keeps the stability and conformations of the molecules investigated. Owing to the perturbation of the aromatic substituted groups, the predicted large T values and the enlarged HOMO‐LUMO gap of the phosphininium cation indicate that these compounds are expected in experiment. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Vibrational corrections to geometries of transition metal complexes from density functional theory
Authors: Waller Mark P. , Bühl Michael
Published: March 2007

Zero‐point vibrational corrections are computed at the BP86/AE1 level for the set of 50 transition‐metal/ligand bonds that have recently been proposed as testing ground for DFT methods, because of the availability of precise experimental gas‐phase geometries (Bühl and Kabrede, J Chem Theory Comput 2006, 2, 1282). These corrections are indicated to be transferable to a large extent between various density‐functional/basis‐set combinations, so that they can be used to estimate zero‐point averaged r distances from re values optimized at other theoretical levels. Applying this approach to a number of popular DFT levels does not, in general, improve their overall accuracy in terms of mean and standard deviations from experiment. The hybrid variant of the meta‐functional TPSS is confirmed as promising choice for computing structures of transition‐metal complexes. © 2007 Wiley Periodicals, Inc. J Comput Chem 28: 1531–1537, 2007
Vibrational anharmonic calculations in solution: Performance of various DFT approaches
Authors: Begue Didier , Pouchan Claude
Published: March 2007

We report anharmonic spectra calculated for formaldehyde in acetonitrile solution using the quartic force field obtained for various DFT/solvent coupled models. A statistical study has been carried out for each mode by using several classes of DFT functionals and comparing them to the reference ab‐initio CCSD(T)/cc‐pVQZ calculations. Results lead to the recommended use of hybrid functionals associated with the 6‐31+G** basis set and the Polarized Continuum model (PCM) to predict the expected shifts relative to the gas phase. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Serological relatedness of monkeypox, variola, and vaccinia viruses
Authors: Esposito Joseph J. , Obijeski John F. , Nakano James H.
Published: March 2007

Closely related human and monkey orthopoxviruses were differentiated by serologic techniques. Antiviral sera were tested by immunodiffusion for reactivity against six different viral antigens prepared from either infected cell cultures or infected chorioallantoic membranes (CAMs) of embryonated eggs. Portions of each antiserum were separately absorbed with heterologous antigens from infected CAMs to remove common reactivity. The absorbed sera formed immunodiffusion precipitates with both types of antigen preparation and revealed specific‐character differences that made it possible to classify the viruses as variola, vaccinia, or monkeypox. Cross‐complement fixation tests were also used to examine the immunologic reactivities of antisera to detergent‐treated, purified preparations of three orthopoxviruses. Only common reactivities were detected by this method, however, and differentiating reactivities were not observed.
Pharmacologic effects of polyinosinic• polycytidylic acid in man
Authors: Freeman Arnold I. , Al‐Bussam Nazar , O'Malley Judith A. , Stutzman Leon , Bjornsson Sigurdur , Carter William A.
Published: March 2007

Twenty‐four patients with cancer and concomitant infections with either herpes virus hominis or varicella zoster virus were treated with polyinosinic·polycytidylic acid (rIn·rCn) to determine: (1) the reliability of rIn·rCn to induce interferon production, and (2) the toxicity of the drug. Seven additional patients with herpes zoster were observed as controls. Two lots of rIn·rCn were used; Lot 1 was consistently effective in stimulating serum interferon at doses of 9 and 12 mg/kg, whereas Lot 2 was effective at doses of 3–12 mg/kg. There was no correlation between rIn·rCn doses within these ranges and the resultant interferon levels. Generally, peak serum interferon occurred within the first day.

Toxicity to rIn·rCn consisted of fever in 21/24 patients, mild elevation of liver enzymes in 8/24 patients, and laboratory abnormalities of coagulation in 9 patients. The coagulation abnormalities appeared linearly related to the dose of rIn·rCn used. All these abnormalities were reversible, and none were considered severe or lifethreatening.

Sincer rIn·rCn was effective in stimulating interferon and since toxicity was considered acceptable, a randomized double‐blind study was initiated to determine whether rIn·rCn is effective in the treatment of herpes zoster.
Antibody‐modification of measles “in vitro” infection
Authors: Gould Janine J. , Almeida June D.
Published: March 2007

While the involvement of measles‐like virus with subacute sclerosing panencephalitis (SSPE) has been shown in many laboratories, the possible mechanisms by which a normal measles infection may lead to the chronic condition are unclear. The work reported here demonstrates that the growth and maintenance of Vero cells infected with the MV 30 strain of measles, in the presence of multivalent antibody, results in a redistribution of the viral antigens within the cells and an alteration in the properties of this attenuated virus which persists even after removal of the antiserum from the culture medium. It is suggested that these in vitro findings could be parallel to the situation that occurs in vivo with measles encephalitis in hamsters and human SSPE.
Cyclic excretion of hepatitis A virus in experimentally infected chimpanzees: Biophysical characterization of the associated HAV particles
Authors: Bradley D. W. , Gravelle C. R. , Cook E. H. , Fields R. M. , Maynard J. E.
Published: March 2007

Experimental infection of two chimpanzees with the Phoenix Antigen strain of HAV resulted in the cyclic excretion of virus particles on days 9–11, 14–15, and 20–21 postinoculation. Isopycnic banding in CsCl of stool suspensions prepared from 9–11; 14–15;and 17, 19, 21 dav stool pools revealed multiple buoyant densities for the associated HAV particles. Hollow HAV particles found in the 9–11 day pool banded primarily at a buoyant density of 1.30 g/cm3. HAV in the 14–15 day stool banded bimodally in a CsCl gradient, with antigen peaks at buoyant densities of 1.29 and 1.33 g/cm3. HAV in the days 17, 19, 21 stool pool also banded bimodally in a CsCl gradient; however, the antigen peaks occurred at buoyant densities of 1.33 and 1.40 g/cm3.
Incidence and distribution of herpes simplex virus types 1 and 2 from genital lesions in college women
Authors: Kalinyak Judith E. , Fleagle Genevra , Docherty John J.
Published: March 2007

During a 9‐month period, 9,772 women were treated at the student health center's gynecology clinic. Herpes simplex virus was isolated from 30 of 57 patients clinically diagnosed as suffering from a herpetic or herpetic‐like genital infection for a virological incidence rate of 0.31%. Using virus plaque diameter in chick embryo cells and heat stability of viral thymidine kinase, 37% of the isolates were classified as herpes simplex virus type 1 and 63% were classified as herpes simplex virus type 2.
Interaction of coxsackievirus B‐3 and peritoneal exudate cells of adult mice treated with cyclophosphamide
Authors: Kabiri M. , Hadaegh M. D.
Published: March 2007

Interaction of coxsackievirus B‐3 with peritoneal exudate cells (p.e.c.) of adult mice treated with cyclophosphamide (CP) and of normal untreated mice were examined. The measurement of virus concentration in the supernates and the infective center assay of the virus‐treated p.e.c. showed no significant differences in viral uptake between the p.e.c. of mice treated with CP for 1 and 24 hours, and the cells of normal untreated mice. However, a significant decrease in viral uptake was found in p.e.c. of mice collected 72 hours after treatment with CP. This relationship in viral uptake between the CP‐treated and normal p.e.c. was reversed when the cells were exposed to antimacrophage serum (AMS). The p.e.c. from normal mice exposed to AMS inactivated significantly less virus than similar cells treated with normal rabbit serum. The peritoneal cell‐free fluid of mice treated with CP and coxsackievirus B‐3 for 24 hours, contained less virus than the fluid from mice injected with virus alone. It is therefore concluded that the reduction in viral uptake by the p.e.c. derived from mice 72 hours after CP‐treatment may contribute to the severity of infection in CP‐treated mice.
Multiple buoyant densities of hepatitis A virus in cesium chloride gradients
Authors: Bradley Daniel W. , McCaustland Karen A. , Schreeder Marshall T. , Cook E. H. , Gravelle Clifton R. , Maynard James E.
Published: March 2007

Hepatitis A virus (HAV) recovered from stools of human cases of hepatitis A and from stools of chimpanzees experimentally infected with HAV was shown to possess multiple buoyant densities in CsCl gradients. The greatest proportion of HAV was most frequently found at a buoyant density of 1.32–1.34 g/cm3, however, large proportions of HAV were also frequently found at higher densities, including 1.36–1.37, 1.40–1.42, and 1.45–1.48 g/cm3. These findings are consistent with the notion that HAV may be a parvovirus.
The isolation of a Bwamba virus variant from man in Western Kenya
Authors: Johnson B. K. , Chanas A. C. , Squires E. J. , Shockley Pauline , Simpson D. I. H. , Smith D. H.
Published: March 2007

A Bwamba group virus was isolated from the blood of a febrile child on the Kano Plain, Kenya. The isolate (NY‐45), closely resembling Bwamba, established infection in both Anopheles gambiae and Mansonia uniformis. Neither the Bwamba nor the Pongola prototype strains grew in both species. In gel‐diffusion tests NY‐45 virus passaged through mosquitoes exhibited a line of identity with Pongola antiserum. In contrast no cross‐reaction was observed with NY–45 virus which had not previously been passaged through mosquitoes.
A nonlytic transforming mutant of herpes simplex virus type 2
Authors: Howett Mary K. , Rapp Fred
Published: March 2007

A small‐plaque mutant (No. 69) of herpes simplex virus type 2 (HSV‐2) strain 333 has been previously isolated and characterized in this laboratory. This mutant was shown to produce a high ratio of noninfectious to infectious particles when grown at the nonpermissive temperature in hamster embryo fibroblasts [Westmoreland D. and Rapp F. (1976). Journal of Virology 18:92–102]. In this study, we have demonstrated that it is possible to obtain noninfectious stocks of this virus which retain transforming ability in a biochemical transformation assay specific for detection of the HSV gene for thymidine kinase. This mutant contains a DNA genome that has a density identical to the DNA of wildtype virus. Virus and cell DNA synthesis after infection with the mutant at both the permissive and nonpermissive temperature are similar to that observed in cultures infected with the parental virus. Clones of mouse cells biochemically transformed by this virus contain HSV antigens and are presently being examined for oncogenicity.
Prevalence of hepatitis B e antigen and its antibody as detected by radioimmunoassays
Authors: Mushahwar Isa K. , Overby Lacy R. , Frosner G. , Deinhardt Friedrich , Ling Chung‐M.
Published: March 2007

A solid‐phase radioimmunoassay (RIA) for the detection of hepatitis B e antigen (HBeAg) and antibody (anti‐HBe) was developed. The RIA was approximately 1,000‐fold more sensitive than rheophoresis for HBeAg, and approximately 6,000‐fold more sensitive than rheophoresis for anti‐HBe. Generally, less than one‐fifth of hepatitis B antigen (HBsAg)‐positive sera from blood donors were positive for either HBeAg or anti‐HBe by rheophoresis; in contrast, more than 90% of the samples were positive by the RIA method. The ratio of HBeAg to anti‐HBe among HBsAg carriers varied in different geographic localities. Also, the presence of HBeAg correlated directly with the titer of HBsAg and the presence of Dane core particles. Anti‐HBe was associated with lower titers of serum HBsAg.
Evaluation of a simplified sucrose gradient method for the detection of rubella‐specific IgM in routine diagnostic practice
Authors: Caul E. O. , Hobbs S. J. , Roberts P. C. , Clarke S. K. R.
Published: March 2007

Rubella‐specific IgM was measured in a single fraction of serum from a sucrose density gradient. Haemagglutination inhibition (HAI) tests were performed on paired aliquots of the fraction untreated and after treatment with 2‐mercaptoethanol, dilutions of the aliquots being incubated over night with rubella antigen before the addition of red cells. Of 822 sera tested, specific IgM was found in 249, but not in 492. When first tested, the remaining 81 sera gave unsatisfactory results because of contamination of the IgM fraction with IgG (6.0%), probable aggregation of IgG (3.5%), or the persistence of chick red cell agglutinins (0.4%). Tests were performed on 134 patients with rubella confirmed by a rise of HAI antibodies. Rubella‐specific IgM was found at a litre‐of more than eight in the sera taken from 62 of 64 patients between 10 and 29 days after the onset of the rash but in only one of the sera taken between 80 and 119 days, and in none taken later. However, specific IgM was still to be found at lower titre in the sera of 13 patients collected between 80 and 162 days after the onset of the illness. In routine diagnostic tests over three years on the serum from 479 patients with suspected acquired rubella, specific IgM was found at a titre of more than eight in 51 patients and in only 10 instances (2.1%) did a lower level pose a problem in interpretation.
Biochemical and biophysical characterization of light and heavy density hepatitis A virus particles: Evidence HAV is an RNA virus
Authors: Bradley Daniel W. , Fields Howard A. , McCaustland Karen A. , Cook E. H. , Gravelle Clifton R. , Maynard James E.
Published: March 2007

Heavy density HAV was also shown to be sensitive to low concentrations of RNase. The results of these biophysical and biochemical studies strongly support the notion HAV is an enterovirus.
Effects of phosphonoacetic acid on subacute myeloopticoneuropathy virus in vitro and in vivo
Authors: Nishibe Y. , Inoue Y. K.
Published: March 2007

The effect of phosphonoacetic acid (PAA) in vitro and in vivo on subacute myeloopticoneuropathy (SMON) virus isolated from the spinal fluid of SMON patients was studied. PAA inhibited multiplication of SMON virus in cultures, but it did not show a direct effect on the virus. The drug did not influence the disease when the medication was started from 10 days after infection of suckling mice. However, the drug did elicit a delay in the incubation period.
Influenza virus infection in newborn rats: A possible marker of attenuation for man
Authors: Michaels R. H. , Mahmud M. I. A. , Coup A. J. , Jennings R. , Potter C. W.
Published: March 2007

The growth of parent influenza viruses A/England/939/69 and A/PR/8/34, and clones 6, 7, and 64C, derived by recombination, was studied in newborn rats. Using an inoculum of 104.0 EID50, influenza virus A/England/939/69 produced the highest titres of virus in rat turbinates at 48 hours after inoculation; clones 6 and 7 and A/PR/8/34 grew to lower titres; and clone 64C grew to the lowest titre. These differences were less apparent when 102.0 EID50 of virus was used as an inoculum, and rats were not infected by smaller inoculum of any of the virus strains. Infection with 104.0 EID50 of all viruses produced lung infection; at 48 hours after infection, the highest titres were recovered from rats infected with A/PR/8/34 and A/England/939/69 virus. Prior infection with A/England/939/69 or A/PR/8/34 increased the incidence of bacteraemia and meningitis following intranasal inoculation of Haemophilus influenzae type b; infection with clone 64C did not enhance bacterial meningitis, while infection with clone 6 gave an intermediate result. Volunteer studies with these viruses have shown that influenza virus A/England/939/69 was virulent, clones 6 and 7 were attenuated, clone 64C was overattenuated, and A/PR/8/34 virus was noninfective for man. The relative titres of virus recovered from turbinates taken 48 hours after infection with 104.0 EID50 of virus and the ability of virus infection to enhance bacterial infection correlated with the property of virus attenuation for man for four of the five strains tested; however, no correlation was seen for A/PR/8/34 virus, which is a result also found in other laboratory tests designed to measure virulence for man.
Human rotavirus infection in infants and young children with intussusception
Authors: Konno Tasuke , Suzuki Hiroshi , Kutsuzawa Toyoko , Imai Aki , Katsushima Noriko , Sakamoto Michiyo , Kitaoka Setsuko , Tsuboi Reiko , Adachi Michiko
Published: March 2007

Human rotavirus was detected by electron microscopy in 11 of 30 infants and young children with intussusception (37% of subjects under study). Serologic complement fixation tests revealed evidence of infection with the rotavirus in 70% of the patients examined who eliminated the rotavirus in their stools. These results indicate that human rotavirus, in addition to adenovirus, may be an infectious agent causing intussusception in infants and young children.
Infection of human amnion cells with cytomegalovirus
Authors: Figueroa Manuel E. , Geder Laszlo , Rapp Fred
Published: March 2007

Human cytomegalovirus (CMV), known to replicate in vitro in human fibroblastic cells, was found to replicate in epithelial human amnion (HA) cells. Large syncytia formed in these cells after infection with CMV; inclusion bodies were observed in the nuclei, and CMV antigens were demonstrated in both the cytoplasm and the nucleus by indirect immunofluorescence techniques. The synthesis of virus DNA was also detected, and the production of infectious virus was followed. The titers were lower (from 104 to 6 × 105 using different isolates of CMV) than those obtained in human embryo fibroblast (HEF) cells, and the replication cycle was slower in HA than in HEF cells.
Rapid detection of hepatitis B surface antigen by double antibody radioimmunoassay
Authors: Burrell C. J. , Leadbetter G. , Black S. H. , Hunter W. M.
Published: March 2007

HBsAg and anti‐HBs can be detected by double‐antibody radioimmunoassay in a reliable routine overnight assay of sensitivity approaching that of solidphase immunoradiometric assay. The test requires careful standardisation and regular preparation of I125‐HBsAg of appropriate quality, but otherwise uses only small quantities of commercially available reagents. In this paper, the reaction kinetics of the first incubation (test sample + limiting amount of rabbit anti‐HBs), second incubation (reaction mixture + I125‐HBsAg) and precipitation reaction (reaction mixture + antirabbit globulin) were examined, to determine the minimum time required for the assay compatible with adequate sensitivity and user convenience; in addition, in order to reduce the time of radioactive counting, the maximum amount of I125‐HBsAg per test compatible with a satisfactory assay was examined. It was concluded that, by terminating each reaction before equilibrium was reached, results could be obtained in 2–3 hours with a detection limit similar to the standard overnight procedure. To allow routine examination of large numbers of samples, the possibilities of complete automation of this liquid‐phase type of assay were discussed.
Experiences with radioimmunoassay in the detection of HBsAg in the presence of anti‐HBs
Authors: Siebke Jens‐Christian
Published: March 2007

Interference from anti‐HBs present during hepatitis B antigenemia caused the appearance of several false negative reactions in a competition radioimmuno‐precipitation procedure. The results indicate that such interference is considerably less in the solid‐phase radioimmunoassay (Ausria II) and probably causes few false negative tests. The use of pepsin treatment as a means to destroy interfering antibodies is discussed.
Detection of HBeAg and anti‐HBe in acute hepatitis B by a sensitive radioimmunoassay
Authors: Frösner Gert G. , Brodersen Manfred , Papaevangelou George , Sugg Udo , Haas Hans , Mushahwar Isa K. , Ling Chung‐Mei , Overby Lacy R. , Deinhardt Friedrich
Published: March 2007

A solid‐phase radioimmunoassay using anti‐HBe‐coated polysterene beads and iodine‐125‐labeled anti‐HBe of human origin was developed for the detection of HBeAg. Anti‐HBe could be determined by a blocking test. Both assays were about 500‐fold more sensitive than immunodiffusion. Few nonspecific positive results for HBeAg could be recognized in the anti‐HBe test by increase in cpm over that of the negative control.

HBeAg was not found in acute hepatitis A and non A‐non B heptatis or in a control group of accident patients. On admission to the hospital 12 of 48 (25%) acute hepatitis B patients from Greece and 17 of 20 (85%) acute hepatitis B patients from Germany were HBeAg‐positive. All 39 initially HBeAg negative sera were already anti‐HBe positive. Tests of the acute stage and follow‐up sera of the 20 German patients indicated that HBeAg is regularly present in the incubation period and early acute phase of hepatitis B. After onset of disease the antigen is cleared from the serum very rapidly in uncomplicated cases and is usually followed by the appearance of anti‐HBe. Like anti‐HBe, anti‐HBe. can serve as a tool for the diagnosis of hepatitis B after the disappearance of HBsAg.
Diagnosis of hepatitis B by dane particle associated DNA polymerase assay
Authors: Cappel R. , De Cuyper F. , Van Beers D.
Published: March 2007

We have studied prospectively 478 subjects exposed to hepatitis B virus and 20 pregnant women who developed HBs antigen during the last trimester of pregnancy. The results suggest that the DNA polymerase assay might be useful for the diagnosis of hepatitis B infection and that in confirmed cases of hepatitis, the enzyme might be detected in the absence of HBs antigen. HBe antigen appeared in 19% of those subjects who developed HBs and a positive correlation between HBe antigen and DNA polymerase was found in 40% of the cases positive for this antigen. The data presented also suggest that HBe antigenemia in pregnant women is not consistently associated with HBs infection in the babies born to them. However the children born to HBe positive mothers are at higher risk than those born to HBe negative mothers.
Evaluation of five temperature‐sensitive mutants of respiratory syncytial virus in primates: I. Viral shedding, immunologic response, and associated illness
Authors: Richardson Linda S. , Belshe Robert B. , London William T. , Sly D. Lewis , Prevar David A. , Camargo Ena , Chanock Robert M.
Published: March 2007

Approximately 104 plaque‐forming units (pfu) of five temperature‐sensitive (ts) mutants of respiratory syncytial (RS) virus were administered intranasally to seronegative chimpanzees to evaluate their level of attenuation. When the ts‐1 mutant was given to two chimpanzees, the pattern of viral growth and illness (rhinorrhea) was similar to that seen during wild‐type RS virus infection. Two further defective subclones of ts‐1, ts‐1 NG‐1 and ts‐1 NG‐16, appeared more attenuated than ts‐1 with respect to severity of rhinorrhea. The ts‐7 mutant infected the one animal tested; illness was similar to that induced by ts‐1 or wild‐type virus. 104 pfu of the ts‐2 mutant failed to infect two chimpanzees; virus was not isolated, a serum antibody response was not detected, and unlike chimpanzees given the other ts mutants, these animals were not resistant to challenge with wild‐type virus. A 40‐fold larger inoculum of ts‐2, 105, 6pfu, infected each of four chimpanzees, but the peak quantity of virus shed was approximately 500‐fold lower than during wild‐type virus infection. Significantly, the ts‐2 infected chimpanzees did not become ill, but infection did stimulate the development of RS virus serum neutralizing antibodies. The one chimpanzee given 107, 6 pfu of the ts‐2 mutant shed as much virus as the chimpanzees infected with wild‐type virus; however, there were no signs of upper respiratory tract illness. Owl monkeys resembled chimpanzees in shedding s large amount of virus and developing rhinorrhea following administration of wild‐type virus or the ts‐1 mutant. Significantly, 105, 3 pfu of ts‐2 infected only one of two owl monkeys tested, but a small quantity of virus (>10 pfu/ml) was shed. These observations suggested that the ts‐2 mutant was the most attenuated vaccine cadidate strain tested, and that extent of infection with rs‐2 appeared to be related to the quantity of virus administered.
Evaluation of five temperature‐sensitive mutants of respiratory syncytial virus in primates: II. Genetic analysis of virus recovered during infection
Authors: Belshe Robert B. , Richardson Linda S. , London William T. , Sly D. Lewis , Camargo Ena , Prevar David A. , Chanock Robert M.
Published: March 2007

Five temperature‐sensitive (ts) mutants of respiratory syncytial (RS) virus (ts‐1, ts‐1, NG‐1, ts‐1, NG‐16, ts‐2, and ts‐7), previously evaluated for infectivity and virulence in chimpanzees and owl monkeys, were also assayed for in vivo genetic stability. None of the five mutants tested was completely stable genetically. Thus, virus which had lost some or all of the ts property was recovered from each infected chimpanzee. Significantly, each ts‐1 NG‐1 isolate retained some degree of temperature sensitivity and hence was not true wild‐type virus. Clonal analysis of viruses shed by ts‐1, ts‐1, NG‐1, ts‐1, NG‐16, or ts‐7 infected chimpanzees indicated that in most instances only a minority of the virus shed was altered genetically. Of five chimpanzees infected with the ts‐2 mutant, three shed only ts virus, and the remaining two chimpanzees shed only ts+ virus. Such ts+ virus proved to be avirulent when evaluated in chimpanzees or owl monkeys, indicating that loss of the ts property did not restore virulence. Based upon these findings, the ts‐2 mutant appears to be a suitable candidate for clinical trials in man.
Rat tracheal organ culture supports replication of parainfluenza 1 (6/94) virus and promotes 6/94 virus rescue from latently infected human brain cells
Authors: Wroblewska Zofia , Wellish Mary , Rorke Lucy B. , Gilden Donald H.
Published: March 2007

Rat tracheal organ culture (TOC) supported replication of parainfluenza 1 (6/94) virus. Cell‐associated and cell‐free viruses were found after primary infection of TOC. In contrast to other mammalian systems, rat TOC was capable of maintaining 6/94 virus infectivity after primary infection. Rat TOC may be considered a potential indicator system that could be used to detect virus latent in human tissue.
The role of the hepatitis B virus infection in patients with chronic hepatitis in argentina
Authors: Tanno Hugo , Fay Oscar , Findor Jorge , Igartua Estela Bruch , Gerety Robert J. , Roncoroni Mario , Vyas Girish N.
Published: March 2007

Over a seven‐year period, we monitored 221 patients with chronic hepatitis from two medical centers. By using the counterelectrophoresis (CEP) test to detect the presence of HBsAg and anti‐HBc, or both, we established that 87.7% of them had hepatitis B infection. Serum specimens originally found negative for HBsAg by CEP were further tested by reversed passive hemagglutination (RPH), and those originally found negative for anti‐HBc by CEP were further tested by radioimmunoassay (RIA). Five patients were anti‐HBc‐positive and HBsAg‐negative. No sex predominance was observed, but HBsAg incidence increased with increasing age. The HBeAg antigen was detected in 46.8% of the 161 cases tested for it; the most frequent subtype found was adw (63.7%). The present findings indicate that HBV infection largely contributes to the development of chronic hepatitis in Argentinian patients.
Biological activity of hepatitis B antigens in cell culture
Authors: Brumpt Ivan , Mann George F. , Zuckerman Arie J.
Published: March 2007

Direct interference by purified hepatitis B surface antigen or virus particles was not demonstrated in tissue culture. Significant levels of interferon were not induced. The surface antigen did not block the adsorption of other viruses.
Attenuated influenza produced by experimental intranasal inoculation
Authors: Little John W. , Gordon R. Douglas , Hall William J. , Roth Frieda K.
Published: March 2007

To assess the relative effect of natural versus experimental influenza illness on pulmonary function, we compared 43 normal adults with documented nonpneumonic influenza A infection during three outbreaks, 1974 (A/Port Chalmers/74), 1975 (A/Port Chalmers/74), and 1976 (A/Victoria/75) to 24 normal volunteers following nasal inoculation with wild‐type influenza A/England/42/72, A/Scotland/74 or A/Victoria/75. In naturally acquired illness, abnormalities in small airway function and transiently increased airway reactivity were observed. In contrast, no such dysfunction was observed in experimentally induced illness. This group manifested milder illness and significantly shorter duration of cough.
The absence of differences in cellular immunity in elderly individuals with and without delayed local cutaneous reactions to influenza vaccine
Authors: Roberts Norbert J. , Baum John , Douglas Jr. R. Gordon
Published: March 2007

Two groups of elderly subjects who received bivalent influenza virus vaccine were identified. Those in Group I manifested marked local reactions, suggestive of delayed hypersensitivity reactions, whereas those in Group II, matched with Group I for vaccine preparation, had no cutaneous reactions. In vitro assays of immune function were performed on pairs of subjects from the two groups and included serum immunoglobulin and complement levels, antibody response to vaccine, lymphocyte transformation to mitogens (phytohemagglutinin, pokeweed mitogen and concanavalin A) and antigens (streptokinase‐strepto‐dornase, influenza virus vaccine antigens and multiple mixed lymphocytes), and polymorphonuclear leukocyte chemotactic responsiveness. There was no demonstrable correlation between delayed local cutaneous reaction and preservation of in vitro cell‐mediated immune function in these elderly individuals.
The stability of herpes simplex virus on vaginal tampons
Authors: Myers Martin G. , Ekwo Edem E. , Pitts Anita K.
Published: March 2007

Herpes simplex virus can be quantitatively recovered from vaginal tampons suspended in tissue culture medium and stored over a wide range of temperatures. Because herpes simplex virus is stable for several days with refrigeration or after freezing, this method of culture of cervicovaginal virus lends itself to epidemiologic studies.
Properties of coxsackievirus B3 variants which are amyocarditic or myocarditic for mice
Authors: Gauntt C. J. , Trousdale M. D. , Labadie D. R. L. , Paque R. E. , Nealon T.
Published: March 2007

Inoculation of adolescent CD‐1 mice with one variant of coxsackievirus B3 (CVB3m) results in induction of readily observable myocardial lesions, whereas inoculation of siblings with a second variant (CVB3o) results in little or no myocarditis. These variants could not be distinguished from each other on the basis of replication properties in HeLa cells or cardiac tissues in vivo, sensitivity to human interferon in HeLa cells, induction of interferon in the mouse, generation of detectable levels of defective‐interfering particles in HeLa cells or in cardiac tissue in vivo, stimulation of serum‐neutralizing antibody titers, nor in their rate of clearance by the spleen. Infectivity of CVB3o was slightly more heat labile at 34oC than CVB3m. Little if any replication of either CVB3o or CVB3m occurred in either adherent or nonadherent populations of normal murine lymphoid cells. Cardiac tissues from mice inoculated with CVB3m but not CVB3o contain new antigens that can inhibit migration of sensitized lymphocytes from CVB3m ‐immunized mice in an in vitro cell‐migrationinhibition assay. However, the CVB3o variant was shown to have the genetic capability of inducing myocarditis if the mice were treated with cyclophosphamide prior to virus inoculation. These results suggest, in agreement with our previously published work, that induction of myocarditis by CVB3 requires destruction of myocytes by virus and subsequent stimulation of cell‐mediated responses to new antigens produced in the myocardium during virus replication.
Fusion of cytomegalovirus infected fibroblasts to form multinucleate giant cells
Authors: Garnett Helen M.
Published: March 2007

Multinucleate giant cells have been observed to arise by cell fusion in cultures of human embryonic fibroblasts infected with human cytomegalovirus (CMV), strain AD 169. The infected cells developed intranuclear and intracytoplasmic inclusions and began to fuse three to four days postinfection when the majority of the cells were showing signs of a cytopathic effect.
Identification of an enteric adenovirus by immunoelectroosmophoresis (IEOP) technique
Authors: Jacobsson P. Åke , Johansson Mats E. , Wadell Göran
Published: March 2007

Infantile gastroenteritis can be caused by several of the established adenovirus types. There are also adenoviruses that defy in vitro cultivation but have been recognized by electron microscopy. One isolate of these viruses, which have been designated enteric adenoviruses, has been characterized.

Several of the established adenovirus types are shed in stools over long periods. The conditions for direct identification of enteric adenoviruses by immunoelectroosmophoresis (IEOP) have therefore been evaluated. Application of this technique requires highly specific reagents. However, a high prevalence of antibodies in rabbits reacting with human rotavirus was noted. For these reasons, immunoadsorbent purified antibodies were prepared. Because of the difficulty in purifying immunogens from stools, an immunization procedure characterized by immunization with adenovirus subunits bound to affinity chromatography beads was elaborated.

An identification procedure for adenoviruses causing infantile gastroenteritis based a) on IEOP using group‐specific and monospecific antibodies and b) on the determination of the in vitro cultivatability is suggested.
Decreased cell‐mediated cytotoxicity against virus‐infected cells in systemic lupus erythematosus
Authors: Pons Vincent G. , Reinertsen James L. , Steinberg Alfred D. , Dolin Raphael
Published: March 2007

Cell‐mediated cytotoxicity, directed against virus‐infected tissue culture cells, was studied with peripheral blood mononuclear cells from 11 patients with systemic lupus erythematosus (SLE) and 12 matched, normal subjects in a 51Cr release assay. Baseline (preimmunization) levels of cytotoxicity against target cells infected with influenza A/Victoria, influenza B/Hong Kong, Newcastle disease virus, and herpes simplex virus were significantly decreased in patients with SLE compared to normal subjects (P < 0.001), although serum antibody levels to the respective viruses were similar in both groups. After intramuscular administration of inactivated influenza A/Victoria vaccine, SLE patients failed to generate elevated levels of cytotoxicity against A/Victoria infected cells, in contrast to normal subjects. SLE patients responded with levels of serum hemagglutination‐inhibition antibody which were similar to those of normal subjects.

Thus, SLE patients manifest decreased cell‐mediated cytotoxicity against virus‐infected target cells, although humoral antibody responses appeared to be intact. Studies of SLE patients with influenza may help to define the role of cell‐mediated immunity in the pathogenesis of certain viral infections.
Normal lymphocyte interferon production in adult HBsAg‐positive chronic active liver disease
Authors: Ponzetto Antonio , Zucca Mario , Marcucci Fabrizio , Rizzetto Mario , Actis Giovanni C. , Bonino Ferruccio , Gioannini Paolo
Published: March 2007

To challenge the hypothesis that interferon (IF) production in chronic hepatitis‐B virus liver disease is defective, lymphocytes from 14 patients with chronic active liver disease (CALD); from nine patients with chronic inactive liver disease (CILD), and from six healthy chronic carriers (HCC) were stimulated by Newcastle Disease virus. The patients with CILD showed a weak IF response by comparison with the controls (P < 0.0005), whereas IF production by CALD patients and the HCC did not statistically differ from IF production in the healthy hepatitis‐B surface antigen negative subjects who served as controls. These results indicate that IF treatment of CALD does not rely on a completely proved background.
Serologic response in human hepatitis A: Detection of antibody by radioimmunoassay and immune adherence hemagglutination
Authors: Drucker Jacques , Smallwood Linda , Lorenz Douglas , Tabor Edward , Coursaget Pierre , Maupas Philippe , Barker Lewellys F. , Gerety Robert J.
Published: March 2007

An indirect solid‐phase radioimmunoassay (RIA) for detection of antibody to the hepatitis A antigen (anti‐HAV) was developed using polystyrene pearls as the solid phase and hepatitis A antigen (HAAg) extracted from marmoset livers. This RIA was compared to an immune adherence hemagglutination assay (IAHA) which employed HAAg derived from the stools of chimpanzees collected during acute hepatitis A. Anti‐HAV was detected in the sera of 15 humans with naturally acquired hepatitis A infection. Sensitivity and specificity were greater using the RIA, permitting the detection of anti‐HAV as early as the time of onset of jaundice. Either seroconversion or a significant increase in the titer of anti‐HAV was demonstrated following hepatitis A exposure in paired sera from six patients by both techniques. No significant difference in anti‐HAV responses was noted between patients with icteric compared to anicteric hepatitis A or between children and adults with hepatitis A.
Isolation and characterisation of a defective measles virus from a subacute sclerosing panencephalitis patient
Authors: Wild T. F. , Giraudon P. , Bernard A. , Huppert J.
Published: March 2007

A cytopathic measles virus was isolated from a brain biopsy of a subacute sclerosing panencephalitis (SSPE) patient. The agent could be transferred to Vero cells by cocultivation, but the infectivity always remained cell‐associated — ie, a defective virus infection. The cell‐associated nature of the virus was retained through 25 passages in Vero cells. Intracerebral inoculation of hamsters (2—6 days old) with the cocultured Vero cells gave rise to 100% mortality in 5—7 days. The virus retained its cell‐associated nature after passage in hamsters. Electron microscopy of the brain and Vero cocultures showed the presence of virus‐like ribonucleoparticles mainly in the nucleus. The presence of viral antigens in the nucleus, cytoplasm, and on the plasma membranes was confirmed by immunofluorescence. Using a combination of immunological and biochemical technqiues, it was shown that all the viral proteins were synthesized with the exception of the haemagglutinin.

Inclusion of the fusion inhibitor SV4814 (CBZ‐D phenylalanine‐L‐phenylalanine‐L‐arginine‐NO2) in the culture medium led to the elimination of the SSPE infection.
Cell‐mediated immunity to cytomegalovirus in patients receiving immunosuppressive therapy
Authors: Agatsuma Yoshitaka , Fitzpatrick Paul , Baliah Tadla , Kaul Aditya , Kim Pyung‐Kil , Ogra Pearay L.
Published: March 2007

Employing the techniques of complement‐fixation (CF), immunofluorescence (IF), and in vitro lymphocyte transformation (LTF), the humoral antibody response and cell‐mediated immune (CMI) response to cytomegalovirus (CMV) were studied in the serum and peripheral blood lymphocytes in 19 normal children (controls) and 23 patients with renal disease who were receiving immunosuppressive therapy or undergoing hemodialysis. The LTF activity was determined by the whole blood microassay using two strains of CMV (AD‐169 and Davis) and phytohemagglutinin (PHA). The antibody level responses to CMV in different groups of subjects were generally similar. The LTF response to PHA as evidenced by δ cpm activity was moderately depressed in immunosuppressed and hemodialyzed subjects compared to the response observed in the controls. The mean δ cpm activities in response to AD—169 and Davis strains of CMV in seropositive immunosuppressed patients were about one‐fifth and one‐third lower respectively than those of seropositive normal controls. These observations suggest that an impairment of CMV specific cellular immunity may be an important mechanism underlying the increased susceptibility to CMV infections in patients with chronic renal disease who receive immunosuppressive therapy.
Cryptic association of e antigen with different morphologic forms of hepatitis B surface antigen
Authors: Vnek J. , Prince A. M. , Trepo C. , Williams A. E. , Mushahwar I. K. , Ling C. M. , Overby L. R.
Published: March 2007

When highly purified HBsAg particles, separated by rate zonal centrifugation into populations differing in predominant size, were tested for HBeAg, the e1 specificity was detected preferentially in association with particle fractions containing large filaments and Dane particles. These results were obtained both by agar gel diffusion and by radioimmunoassay for e antigen. The e antigen activity present in these fractions was potentiated by prior treatment of particles with Tween 80, suggesting cryptic localization of e1 specificity within or under the outer membrane. The HBeAg released by detergent treatment from a purified preparation composed predominantly of small‐particle forms of HBsAg was separated by electrofocusing into a peak of nonparticulate e antigen in the pH range of 5.7–6.0. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis showed three major polypeptides in this preparation with approximate molecular weights of 25,000, 55,000, and 70,000. Furthermore, two additional peaks of e antigen activity were detected which migrated in association with HBsAg particles at isoelectric points of 4.4 and 5.5–5.6. The major portion of e antigen remained in association with particles after further purification by rate zonal centrifugation.