The clinico-epidemiological characteristics of the course of a mixed epidemic of influenza and respiratory syncytial infection in Novoshakhtinsk in the summer of 1986

In the summer of 1986 the epidemic, whose etiological agents were influenza viruses A (H1N1) and respiratory syncytial virus, was registered among the population of Novoshakhtinsk. In a number of mines 15.3-16.7% of the employees were affected. Influenza viruses A (H1N1) proved to be closely related in their antigenic and biological properties to viruses isolated in the USSR in March-June 1986, as well as to viruses A (H1N1), the etiological agents of the epidemic which developed in the USSR in October-December 1986.     

Seroepidemiological study of coronavirus infection in children and adults in St. Petersburg

As the result of prolonged (17 years) observations of patients with acute respiratory infections hospitalized in basic departments of clinics of the Research Institute of Influenza, coronavirus infection was found to be the cause of respiratory diseases, on the average, in 12% of cases (in some years in 6.8% to 28.6% of cases). The analysis of extensive morbidity rates among different age groups of the population showed that children were affected by coronavirus infection 5-7 times more often than adults. Three year cycles of this infection were established. The periods of coronaviruses activation were accompanied by their detection in patient material by electron-microscopy, a sharp increase of immune response of patients as well as in the number of nosocomial infections and the proportion of the monoinfection of the coronavirus nature. Coronaviruses played the leading role among other viruses in the etiology of hospital respiratory infections. Mucosal antibodies to coronaviruses in the secretions of the nasal cavity proved to be more important than serum antibodies not only in protection from infection, but also in the pattern of clinical manifestations of the disease.     

Replication slippage may cause parallel evolution in the secondary structures of mitochondrial transfer RNAs

Presence of the dihydrouridine (D) stem in the mitochondrial cysteine tRNA is unusually variable among lepidosaurian reptiles. Phylogenetic and comparative analyses of cysteine tRNA gene sequences identify eight parallel losses of the D-stem, resulting in D-arm replacement loops. Sampling within the monophyletic Acrodonta provides no evidence for reversal. Slipped-strand mispairing of noncontiguous repeated sequences during replication or direct replication slippage can explain repeats observed within cysteine tRNAs that contain a D-arm replacement loop. These two mechanisms involving replication slippage can account for the loss of the cysteine tRNA D-stem in several lepidosaurian lineages, and may represent general mechanisms by which the secondary structures of mitochondrial tRNAs are altered.      

cDNA cloning of a developmentally regulated hemocyanin subunit in the crustacean Cancer magister and phylogenetic analysis of the hemocyanin gene family

The complete cDNA sequence and protein reading frame of a developmentally regulated hemocyanin subunit in the Dungeness crab (Cancer magister) is presented. The protein sequence is aligned with 18 potentially homologous hemocyanin-type proteins displaying apparent sequence similarities. Functional domains are identified, and a comparison of predicted hydrophilicities, surface probabilities, and regional backbone flexibilities provides evidence for a remarkable degree of structural conservation among the proteins surveyed. Parsimony analysis of the protein sequence alignment identifies four monophyletic groups on the arthropodan branch of the hemocyanin gene tree: crustacean hemocyanins, insect hexamerins, chelicerate hemocyanins, and arthropodan prophenoloxidases. They form a monophyletic group relative to molluscan hemocyanins and nonarthropodan tyrosinases. Arthropodan prophenoloxidases, although functionally similar to tyrosinases, appear to belong to the arthropodan hexamer- type hemolymph proteins as opposed to molluscan hemocyanins and tyrosinases.      

Microsatellite allele frequencies in humans and chimpanzees, with implications for constraints on allele size

The distributions of allele sizes at eight simple-sequence repeat (SSR) or microsatellite loci in chimpanzees are found and compared with the distributions previously obtained from several human populations. At several loci, the differences in average allele size between chimpanzees and humans are sufficiently small that there might be a constraint on the evolution of average allele size. Furthermore, a model that allows for a bias in the mutation process shows that for some loci a weak bias can account for the observations. Several alleles at one of the loci (Mfd 59) were sequenced. Differences between alleles of different lengths were found to be more complex than previously assumed. An 8-base-pair deletion was present in the nonvariable region of the chimpanzee locus. This locus contains a previously unrecognized repeated region, which is imperfect in humans and perfect in chimpanzees. The apparently greater opportunity for mutation conferred by the two perfect repeat regions in chimpanzees is reflected in the higher variance in repeat number at Mfd 59 in chimpanzees than in humans. These data indicate that interspecific differences in allele length are not always attributable to simple changes in the number of repeats.      

Monoclonal antibodies against chicken type V collagen: production, specificity, and use for immunocytochemical localization in embryonic cornea and other organs

Two monoclonal antibodies have been produced against chick type V collagen and shown to be highly specific for separate, conformational dependent determinants within this molecule. When used for immunocytochemical tissue localization, these antibodies show that a major site for the in situ deposition of type V is within the extracellular matrices of many dense connective tissues. In these, however, it is largely in a form unavailable to the antibodies, thus requiring a specific “unmasking” treatment to obtain successful immunocytochemical staining. The specificity of these two IgG antibodies was determined by inhibition ELISA, in which only type V and no other known collagen shows inhibition. In ELISA, mixtures of the two antibodies give an additive binding reaction to the collagen, suggesting that each is against a different antigenic determinant. That both antigenic determinants are conformational dependent, being either in, or closely associated with, the collagen helix is demonstrated by the loss of antibody binding to molecules that have been thermally denatured. The temperature at which this occurs, as assayed by inhibition ELISA, is very similar to that at which the collagen helix melts, as determined by optical rotation. This gives strong additional evidence that the antibodies are directed against the collagen. The antibodies were used for indirect immunofluorescence analyses of cryostat sections of corneas and other organs from 17 to 18-day-old chick embryos. Of all tissues examined only Bowman’s membrane gave a strong staining reaction with cryostat sections of unfixed material. Staining in other areas of the cornea and in other tissues was very light or nonexistent. When, however, sections were pretreated with pepsin dissolved in dilute HAc or, surprisingly, with the dilute HAc itself dramatic new staining by the antibodies was observed in most tissues examined. The staining, which was specific for the anti-type V collagen antibodies, was largely confined to extracellular matrices of dense connective tissues. Experiments using protease inhibitors suggested that the “unmasking” did not involve proteolysis. We do not yet know the mechanism of this unmasking; however, one possibility is that the dilute acid causes swelling or conformational changes in a type-V collagen-containing supramolecular structure. Further studies should allow us to determine whether this is the case.     

Coronavirus infection in immunodeficient patients with hemoblastosis and deficient hemopoesis

Coronavirus infection (CVI) was studied in 227 patients hospitalized in the clinic of the Research Institute of Hematology and Transfusiology in 1993-2003 with diagnosed acute and chronic leucosis, multiple myelogenic disease and aplastic anemia. Their blood sera and secretions of the nasal cavity were examined in the indirect hemagglutination (IHA) test with dried standard erythrocyte diagnostic preparations. CVI was shown to be activated in three year cycles in immunodeficient patients, which occurred, respectively, in 66.1, 56.9, 47.8 and 51.6% of cases in the above mentioned groups of patients. In 87% of cases CVI was associated with other respiratory pathogens, the following being prevailed: respiratory syncytial virus (37.9%), parainfluenza virus (32.2%) and Mycoplasma pneumoniae (36.8%). CVI was provoked by such factors as the course of the main disease and specific treatment, previous respiratory infections of other etiology with M. pneumoniae infection playing the leading role (60%). The most severe course of CVI was observed in patients with acute leucosis (in 75% of cases accompanied by lesions of lower respiratory tracts). The use of the highly sensitive IHA test made it possible to determine the potential for both serum and local antibodies production in the patients under observation.     

Effectiveness of remantadine in outpatients during a period of epidemic outbreaks of influenza A and B

Extensive clinical data demonstrate that the use of remantadine for the treatment of ambulant influenza patients during the epidemic of influenza, types A and B, proved to be effective, which was manifested by an essential increase in the number of complications, mainly in the respiratory organs, and by a reduced length of the disease. The positive result of the curative action of remantadine is believed to be connected with the simultaneous wide circulation of type A (H1N1) and (H3N2) influenza viruses.     

A novel deconvolution method for modeling UDP-N-acetyl-D-glucosamine biosynthetic pathways based on 13C mass isotopologue profiles under non-steady-state conditions

This article is a response to Wang and Luo. See correspondence article http://www.biomedcentral.com/1741-7007/10/30/ [WEBCITE] and the original research article http://www.biomedcentral.com/1741-7007/9/24 [WEBCITE].     

Etiology of acute bronchitis in young children

In the microbiological examination of 132 children aged 0-3 years with acute bronchitis, Streptococcus pneumoniae and Haemophilus influenzae at a concentration of greater than or equal to 10(4) cells/ml, as well as different species of opportunistic bacteria, were isolated from tracheobronchial washings obtained from 100 of these children. S. pneumoniae and H. influenzae were found to play the leading role in the etiology of the acute bacterial inflammatory process in acute bronchitis in children.