- Volume 140, Issue 8, 1994
Volume 140, Issue 8, 1994
- Genetics And Molecular Biology
-
-
-
Cloning and DNA sequence analysis of the region containing attP of the temperate phage ΦAR29 of Prevotella ruminicola AR29
More LessPhage ΦAR29 was shown to exist as a prophage integrated into the chromosome of Prevotella ruminicola AR29. By DNA hybridization studies, the point of integrative recombination on the phage genome (attP) was located on a 4.5 kb EcoRV fragment. After preliminary mapping with restriction endonucleases, a 2.8 kb EcoRV/Hindlll fragment was isolated, cloned in Escherichia coli and sequenced. DNA hybridization localized the attP site to the vicinity of an internal Dral site. Sequence analysis showed the presence of several direct and inverted repeats around the attP site, with consensus core sequences similar to the integrase binding sites of phage λ. Two open reading frames are present adjacent to attP (ORF1 and ORF2). The predicted polypeptide product of ORF1 has a region of structural similarity to known integrases. Although the predicted product of ORF2 shows at best weak homology with known excisionases, no other ORFs occur in the sequence upstream from ORF1, leaving ORF2 as the most likely candidate for this role. However, if ORF2 does represent an xis gene, then this putative integration module would possess a notable difference from that of other temperate phages in the inversion of the positions of int and xis relative to attP. The proposed ΦAR29 integration module is being used to develop phage-based integrative vector systems for the genetic manipulation of rumen bacteria.
-
-
-
-
Nuclear replacement during mating in Armillaria ostoyae (Basidiomycotina)
More LessIn Armillaria ostoyae diploid mycelium may mate with haploid mycelium in a process analogous to dikaryon-monokaryon matings in other basidiomycete fungi. Cultural characteristics and molecular markers were used to study inheritance of nuclear and mitochondrial DNA in four diploid-haploid matings of A. ostoyae. When haploids are mated with diploids, morphological changes from fluffy to flat in the haploid thallus can be used to follow mating progress. Progeny originating from the haploid thallus had mitochondrial haplotypes identical to the haploid parent. Progeny with fluffy colony morphology (putatively haploid) all had nuclear haplotypes identical to the haploid parent. Flat progeny (putatively diploid) had nuclear haplotypes either the same as the diploid parent or a combination of all of the diploid and haploid parent nuclear markers. Diploid-diploid pairings between the parents and flat progeny resulted in somatic incompatibility between genetically unlike diploids and demonstrated that somatic incompatibility is a reliable indicator of nuclear, but not mitochondrial, condition. The data suggest that nuclei of the diploid parent, but not mitochondria, migrate into the haploid thallus and eventually displace the haploid nuclei. In some instances, stable 2N + N dikaryons were maintained.
-
-
-
Mechanism of catabolite repression of tryptophanase synthesis in Escherichia coli
More LessRepression of tryptophanase (tryptophan indole-lyase) by glucose and its non-metabolizable analogue methyl α-glucoside has been studied employing a series of isogenic strains of Escherichia coli lacking cyclic AMP phosphodiesterase and altered for two of the proteins of the phosphoenolpyruvate:sugar phosphotransferase system (PTS), Enzyme I and Enzyme IIAGIc. Basal activity of tryptophanase was depressed mildly by inclusion of glucose in the growth medium, but inducible tryptophanase synthesis was subject to strong glucose repression in the parental strain, which exhibited normal PTS enzyme activities. Methyl α-glucoside was without effect in this strain. Loss of Enzyme I decreased sensitivity to repression by glucose but enhanced sensitivity to repression by methyl α-glucoside. Loss of Enzyme IIAGIc activity largely abolished repression by methyl α-glucoside but had a less severe effect on glucose repression. The repressive effects of both sugars were fully reversed by inclusion of cyclic AMP in the growth medium. Tryptophan uptake under the same conditions was inhibited weakly by glucose and more strongly by methyl α-glucoside in the parental strain. Inhibition by both sugars was alleviated by partial loss of Enzyme I. Inhibition by methyl α-glucoside appeared to be largely due to energy competition and was not responsible for repression of tryptophanase synthesis. Measurement of net production of cyclic AMP as well as intracellular concentrations of cyclic AMP revealed a good correlation with intensity of repression. The results suggest that while basal tryptophanase synthesis is relatively insensitive to catabolite repression, inducible synthesis is subject to strong repression by two distinct mechanisms, one dependent on enzyme IIAGIc of the PTS and the other independent of this protein. Both mechanisms are attributable to depressed rates of cyclic AMP synthesis. No evidence for a cyclic-AMP-independent mechanism of catabolite repression was obtained.
-
-
-
Molecular cloning of a gene encoding the immunogenic 21 kDa protein of Cowdria ruminantium
More LessMajor immunogenic polypeptides (21, 32, 40, 46, 58, 85 and 160 kDa) of Cowdria ruminantium were identified by immunoprecipitation and immunoblotting. A pUC13 library of C. ruminantium genomic DNA was screened with hyperimmune sheep serum to identify Escherichia coli colonies which expressed genes encoding these immunogenic proteins. A recombinant E. coli colony, F5.2, was identified containing plasmid insert DNA of 2773 bp. The cloned DNA insert contained two long open reading frames (ORFs) of 627 bp (complete) and 831 bp (incomplete), both potentially encoding proteins containing an N-terminal signal peptide. Deletion experiments suggested that the hyperimmune sheep serum recognized a protein that was encoded by the 627 bp ORF. The 627 bp ORF was amplified by polymerase chain reaction (PCR), subcloned and expressed to a high level in E. coli. A sheep antiserum made to the expressed recombinant fusion protein recognized a 21 kDa protein of all strains of C. ruminantium tested, confirming that the 627 bp ORF encodes a native 21 kDa protein in C. ruminantium. Similarly, the recombinant protein was recognized by all sera tested from heartwater-infected animals. The antigenic conservation of the 21 kDa protein and its immunogenic nature are reasons for further testing of this recombinant protein in subunit diagnostic tests.
-
-
-
Nucleotide sequence and characterization of the Rhodobacter sphaeroides glnB and glnA genes
More LessThe glnA gene of Rhodobacter sphaeroides encoding glutamine synthetase (GS) has been cloned and sequenced. Molecular analysis revealed that there is a glnB gene upstream of glnA, in a single glnBA operon. A putative glnAp1-type promoter sequence, a consensus ntrC gene product binding site and a consensus upstream activator sequence were detected upstream of the glnB gene. The deduced amino acid sequences of the GS and GlnB proteins of R. sphaeroides showed strong homology with the same proteins from other Gram-negative bacteria. The sequence of the glnA gene isolated from glutamine auxotroph Gln83 was also determined. The glnA83 mutation was shown to result in premature termination of GS synthesis and formation of a 17 kDa C-truncated GS which could be complemented by a 5′-truncated glnA gene which encodes a 30 kDa N-truncated GS. This phenomenon is characteristic for interallelic complementation.
-
- Pathogenicity And Medical Microbiology
-
-
-
Identification and characterization of a putative serine protease expressed in vivo by Mycobacterium avium subsp. paratuberculosis
More LessA putative serine protease expressed in vivo by Mycobacterium avium subsp. paratuberculosis was isolated from a lambda gt11 genomic expression library by screening with serum from a naturally infected sheep. The gene was contained in two overlapping clones, which were shown by antibody elution to encode a protein of 34 kDa in M. a. paratuberculosis. The clones were sequenced and database searches detected a motif identical to the active serine site in trypsin, and 30% homology to the putative serine proteases (HtrA proteins) of Escherichia coli, Salmonella typhimurium, Brucella abortus and Rochalimaea henselae.
-
-
-
-
Mycobacterium leprae isolates from different sources have identical sequences of the spacer region between the 16S and 23S ribosomal RNA genes
More LessTo test for genotypic variations between different isolates of Mycobacterium leprae, the causative agent of leprosy, the 282 bp spacer region between the 16S and 23S rRNA genes was amplified using PCR, and submitted to single-strand conformation polymorphism (SSCP) analysis. The procedure was optimized using four modified spacer fragments, containing mutations at one, three, four and six positions, respectively. Seventy-five M. leprae isolates from different sources, including isolates from leprosy patients, healthy individuals, armadillos and mouse footpads were identical in the SSCP analysis. DNA sequencing and restriction enzyme analysis performed on four and 40 samples, respectively, confirmed the results obtained with SSCP analysis.
-
-
-
Cytokine gene expression in the lungs of BALB/c mice during primary and secondary intranasal infection with Mycoplasma pneumoniae
More LessCytokine gene expression was determined in vivo in the lungs and spleens of Mycoplasma pneumoniae-infected BALB/c mice by means of qualitative and semiquantitative PCR-mediated mRNA amplification. During the acute phase of both primary and secondary infections, cytokines commonly associated with innate resistance, TNFα, IFNγ, IL-1β and IL-6, were expressed. In contrast, early expression of the genes for IL-2 and IL-2 receptor was detected only during reinfection. Expression was greater in the lungs than in the spleen, attesting to the rapid accumulation of lymphocytes at the infected site. Interestingly, IL-2 mRNA expression declined rapidly and was no longer detectable after 24 h, whereas IL-10 mRNA levels rose sharply during the same period. During reinfection, mRNAs for TNFα and IL-6 were 10-fold and for IFNγ about 50-fold higher than during primary challenge. The results suggest that the pathogenesis of M. pneumoniae diseases may be associated with elevated expression of proinflammatory cytokines.
-
- Physiology And Growth
-
-
-
Activity of the plasma membrane H+-ATPase is a key physiological determinant of thermotolerance in Saccharomyces cerevisiae
The role of membrane integrity and the membrane ATPase in the mechanism of thermotolerance in Saccharomyces cerevisiae was investigated. The resistance to lethal heat of a mutant strain with reduced expression of the membrane ATPase was significantly less than that of the wild-type parent. However, prior exposure to sub-lethal temperatures resulted in the induction of similar levels of thermotolerance in the mutant compared to the parent strain, suggesting that the mechanism of sub-lethal heat-induced thermotolerance is independent of ATPase activity. Supporting this, exposure to sub-lethal heat stress did not result in increased levels of glucose-induced acid efflux at lethal temperatures and there was little correlation between levels of acid efflux and levels of heat resistance. ATPase activity in crude membrane preparations from sub-lethally heat-stressed cells was similar to that in preparations from unstressed cells. Study of net acid flux during heating revealed that pre-stressed cells were able to protect the proton gradient for longer. This may confer an ‘advantage’ to these cells that results in increased thermotolerance. This was supported by the observation that prior exposure to sub-lethal heat resulted in a transient protection against the large increase in membrane permeability that occurs at lethal temperatures. However, no protection against the large drop in intracellular pH was detected. Sub-lethal heat-induced protection of membrane integrity also occurred to the same extent in the reduced-expression membrane ATPase mutant, further implying that the mechanism of induced thermotolerance is independent of ATPase activity. To conclude, although the membrane ATPase is essential for basal heat resistance, thermotolerance induced by prior exposure to stress is largely conferred by a mechanism that is independent of the enzyme.
-
-
-
-
Decrease in glycolytic flux in Saccharomyces cerevisiae cdc35-1 cells at restrictive temperature correlates with a decrease in glucose transport
More LessThe glycolytic flux was investigated in the thermosensitive Saccharomyces cerevisiae adenylate cyclase mutant cdc35-1. Directly after a shift to restrictive temperature, the specific CO2 production rate increased from about 250 nmol min−1 (mg protein)−1 to more than 400 nmol min−1 (mg protein)−1, but then the CO2 production gradually fell to about 70 nmol min−1 (mg protein)−1 after 5 h. O2 consumption at restrictive temperature continued at more or less the same rate as at permissive temperature. The temperature shift in the mutant resulted in an increase in the estimated intracellular cAMP concentration from about 1.1 μM to 1.8 μM. This indicates that high cAMP levels are not sufficient for cell cycle progression and high glycolytic activity. The decrease in glycolytic activity at restrictive temperature was not paralleled by a similar decrease in the specific activity of any of the glycolytic enzymes, but correlated with a decrease in hexose transport. A drop in intracellular concentrations of the early metabolites of glycolysis further indicated a defect in transport at restrictive temperature. Our data suggest that glucose transport has a high control on glycolytic flux.
-
-
-
Volume regulation in Spiroplasma floricola: Evidence that Na+ is extruded by a Na+/H+ antiporter
More LessMarked cell swelling followed by lysis was observed when Spiroplasma floricola cells were incubated in iso-osmotic solutions of NaCl, KCI, choline chloride or sorbitol in the absence of an energy source. In the presence of an energy source the cells did not swell suggesting that S. floricola relies on an energy-dependent mechanism(s) for cell volume regulation. An ammonium chloride dilution procedure was utilized to generate a pH gradient (inside acid) across the cell membrane of S. floricola cells. The addition of NaCl resulted in an intracellular alkalization suggesting the presence of a Na+/H+ exchange activity. In 22Na+-loaded cells, glucose-dependent 22Na+ extrusion was observed at acidic pH in both the presence and absence of Na+ ions. The extrusion was completely inhibited by carbonyl cyanide m-chlorophenylhydrazone (CCCP, 10 μM) and partially inhibited by dicyclohexylcarbodiimide (DCCD, 100 μM) indicating that in S. floricola, Na+ movement is driven by the electrochemical gradient of H+ via a Na+/H+ antiporter. The specific ATPase activity of S. floricola membranes was at least twofold higher than that described in other mollicutes. Activity was Mg2+-dependent over the pH range (6.5-8.5) tested, but was very little affected by Na+ (up to 100 mM). DCCD (25 μM) markedly inhibited both membrane-bound and solubilized ATPase activity, whereas orthovanadate (50 μM) had only a small inhibitory effect. The properties of the enzyme are consistent with a F0F1-ATPase. It is suggested that the enzyme operates in the direction of hydrolysing ATP formed by glycolysis leading to the generation of a δpH, which is the major driving force for the Na+/H+ antiport activity.
-
-
-
Response of Rhizobium fredii P220 to osmotic shock: Interrelationships between K+, Mg2+, glutamate and homospermidine
More LessThe response of Rhizobium fredii P220, a salt-tolerant strain of soybean rhizobia, to osmotic shock was investigated by using non-growing washed cells. Rapid changes in K+, Mg2+, glutamate and homospermidine were observed in strain P220 cells subjected to sudden changes in the osmolarity of incubation buffer. Osmotic upshock resulted in elevation of cellular K+ and glutamate, and reduction in cellular homospermidine and Mg2+. When the cells were transferred to upshock buffer lacking K+, the reduction in Mg2+ was totally blocked, but the elevation of glutamate and the reduction in homospermidine were only partially repressed. Osmotic downshock resulted in the opposite phenomenon: There was an elevation of homospermidine and Mg2+, and a rapid fall of K+ and glutamate. When the cells were transferred to downshock buffer lacking Mg2+, the elevation of homospermidine was partially repressed, but the decrease in K+ and glutamate was not repressed at all. Lowering of the cellular K+ by treatment with ionophores nigericin and monensin resulted in a slight decrease in glutamate and a slight increase in homospermidine and Mg2+, possibly due to a pH effect caused by the K+-H+ exchange. Raising the cellular Mg2+ content by treatment with ionophore A23187 brought about an increase in homospermidine. The homospermidine content of Mg2+-deficient cells grown with low-Mg2+ medium reduced to 35% of those grown with the basal medium. These results indicate that in R. fredii, K+ strictly controls Mg2+ flux during osmotic shock whereas the reverse is not true, and that glutamate and homospermidine essentially escape direct control by K+. We also suggest that Mg2+, which has no effect on the pool size of glutamate, is one of the factors which regulate homospermidine content in rhizobial cells.
-
-
-
Autoregulation of nitrogenase expression in Klebsiella pneumoniae
More LessAn investigation into the influence of N2 on the expression of Klebsiella pneumoniae nitrogenase has led to a reassessment of the role of the nitrogenase MoFe protein in autoregulation. Anaerobic derepression of nitrogenase (C2H2-reducing) activity, of NifD and K polypeptides, and of nifH-lac expression, following the removal of excess NH+ 4, were greater under N2 than Ar. This enhancement occurred in Nif+ but not in Nif− strains, and in Nif+ strains was prevented by C2H2, an inhibitor of N2 fixation. Thus N2 fixation is important for maintaining derepression. Derepression of nifH-lac under Ar in various Nif+ and Nif− strains (including NifH−, NifD−, NifB− and NifL− mutants) and of wild-type lac under N2 or Ar in a Nif+ strain were measured to investigate the regulation. The mechanism regulating the enhancement under N2 neither involved the MoFe protein of nitrogenase, as proposed by Dixon et al. (1980, Nature 286, 128-132), nor the nifL product, but was probably due to a general upgrading of the N status. Moreover, during batch growth limited by a non-repressing fixed N source, the levels of nifH-lac expression in the Nif+ and Nif− strains suggested that the nifH gene product (or Fe protein) may have a positive autoregulatory function.
-
-
-
Growth and regulation of enzyme synthesis in the nitrilotriacetic acid (NTA)-degrading bacterium Chelatobacter heintzii ATCC 29600
More LessIn the aerobic bacterium Chelatobacter heintzii, growth and regulation of enzymes involved in nitrilotriacetic acid (NTA) degradation have been investigated in chemostat culture during cultivation with glucose, NTA or mixtures thereof. In batch culture μmax with NTA was 0.18 h−1 and with glucose 0.22 h−1. Growth yields for both substrates were reduced at low dilution rates. During growth with NTA specific activity of the NTA monooxygenase (NTA-MO) exhibited a maximum at D = 0.03 h−1 and gradually decreased with increasing dilution rates. In glucose-grown cells the specific activity as well as immunologically detectable NTA-MO protein was always close to the detection limit. During cultivation with different mixtures of NTA and glucose at a dilution rate of 0.06 h−1, both substrates were utilized simultaneously, irrespective of the NTA/glucose ratio and the presence of excess ammonia. Synthesis of both NTA-MO and iminodiacetic acid dehydrogenase became induced when NTA contributed to more than approximately 1-3% of the total carbon in the substrate mixture supplied. However, NTA was also degraded when the proportion of NTA in the mixture was lower than 1%, which is consistent with the low constitutive level of expression for NTA-MO observed. Results are discussed with respect to NTA biodegradation during sewage treatment and in ecosystems.
-
-
-
Inhibition of lipid biosynthesis induces the expression of the pspA gene
More LessTreatment of Escherichia coli with diazaborine strongly induces the synthesis of a 28 kDa protein which is associated with the cytoplasmic membrane. The partial amino acid sequence proved that this protein is identical to the phage shock protein PspA. The kinetics of the expression of the pspA gene were determined in an E. coli strain which carried a pspA-lacZ fusion in the chromosome. PspA synthesis is independent of the growth phase. It is, however, strongly induced when fatty acid biosynthesis is inhibited by diazaborine or cerulenin. Treatment with either compound also causes dose-dependent inhibition of phospholipid biosynthesis whose degree correlates with the induction of PspA. Another cause of induction of PspA synthesis is treatment of E. coli with globomycin, which is an inhibitor of the processing of lipoproteins.
-
-
-
Metabolic and energetic aspects of the growth response of Streptococcus rattus to environmental acidification in anaerobic continuous culture
More LessStreptococcus rattus, a serotype b strain of mutans streptococci, was grown in an anaerobic glucose-limited chemostat. The molar growth yield of glucose [Y glucose, g dry wt (mol glucose)−1] together with the maximum growth yields (Y max) and maintenance coefficients for glucose utilization and calculated ATP generation were estimated as a function of pH. When the pH was lowered from 7.0 to 5.0, Y glucose decreased, with a concomitant gradual change in the composition of the end product from a mixture of formate, acetate and ethanol to one mostly of lactate. Whereas the Y max for glucose decreased without any change in the Y max for ATP on acidification, both of the maintenance coefficients markedly increased. Kinetic and immunochemical examinations indicated the presence of an F1F0-type proton-translocating ATPase in the membrane fraction prepared from bacterial cells grown under acidic conditions; no detectable level of the enzyme was found in cells grown at neutral pH. However, when incubated with glucose under non-growing conditions, these acid-adapted and unadapted cells showed an insignificant difference in the ability to maintain the intracellular pH alkaline relative to the acidic environments. These results suggest that the organism responds and adapts to environmental acidification by sacrificing some energy cost in terms of both the efficiency of glucose utilization to generate ATP and the extra maintenance required to continue biomass production as efficiently as under neutral pH.
-
-
-
Isolation and characterization of a strain of Rhodobacter sulfidophilus: A bacterium which grows autotrophically with dimethylsulphide as electron donor
More LessA marine photosynthetic bacterium (strain SH1) was isolated after enrichment under phototrophic conditions in media containing dimethylsulphide (DMS) and bicarbonate (HCO− 3) as potential carbon sources. Analysis of culture medium using nuclear magnetic resonance spectrometry showed that during phototrophic and chemotrophic growth of strain SH1 on DMS/HCO− 3 dimethylsulphoxide (DMSO) was produced from DMS. These results indicate that strain SH1 grew autotrophically with DMS serving as an electron donor in photosynthesis and respiration, but not as a carbon source. Biochemical characterization and 16S rRNA analysis indicated that the isolate was a strain of Rhodobacter sulfidophilus. An assay for the enzyme catalysing the oxidation of DMS (DMS:acceptor oxidoreductase) was developed by measuring electron transfer from DMS to 2,6-dichlorophenolindophenol (DCPIP). This reaction was dependent on phenazine ethosulphate to mediate electron transfer from DMS:acceptor oxidoreductase to DCPIP. DMS:acceptor oxidoreductase was found to have a periplasmic location in strain SH1 as was a reduced methylviologen: DMSO oxidoreductase activity. Zymogram staining patterns of periplasmic fractions indicated that DMS: acceptor oxidoreductase and DMSO reductase were distinct enzymes. This was confirmed by resolution of the two activities by gel filtration.
-
-
-
Cis/trans isomerization of fatty acids as a defence mechanism of Pseudomonas putida strains to toxic concentrations of toluene
More LessDefence mechanisms of three Pseudomonas putida strains growing in the presence of toluene up to 50%
-
-
-
Biochemical diversity within the ‘Mycoplasma mycoides cluster‘
More LessThe metabolism of 51 strains within the ‘Mycoplasma mycoides cluster’ was investigated by measuring oxygen uptake following the addition of organic substrates to washed cell suspensions. There were extensive differences between strains in the range of substrates utilized, the relative rates of oxidation and the observed saturation constants for substrates, which ranged from a few μM to several mM. M. mycoides subsp. capri and M. mycoides subsp. mycoides LC (large colony) strains were diverse and could not be distinguished by substrate utilization patterns. However, there were consistent differences in the patterns of substrate utilization between other groups of the M. mycoides cluster, suggesting that these patterns may be useful in identification. In particular, SC (small colony) strains of M. mycoides subsp. mycoides were distinguished by their inability to oxidize maltose, trehalose and (at low concentrations) mannose and glucosamine. Surprisingly, the type strain, M. F38, of Mycoplasma capricolum subsp. capripneumoniae and two further isolates differed from all other strains in that they did not oxidize glucose or other sugars. They did, however, oxidize pyruvate, lactate and 2-oxobutyrate at high rates. The marked metabolic differences between these strains and M. capricolum subsp. capricolum strains is in contrast to the genetic evidence that was used to support the designation of the M. F38 group as a subspecies of M. capricolum.
-
-
-
Kinetic characterization of sporulation in Streptomyces albidoflavus SMF301 during submerged culture
More LessWe report the first quantitative analysis of the relationship between environmental changes and sporulation of a streptomycete, Streptomyces albidoflavus SMF301, in submerged culture. A chemically defined medium was constructed for sporulation, over 109 spores ml−1 being formed in the submerged batch culture. Kinetic parameters calculated from batch and chemostat cultures showed that specific submerged spore formation rate (qspo) was inversely related to the specific mycelial growth rate (μ). The optimum growth rate for submerged spore formation was 0.05 h−1, when the maximum value of qspo was 1.0 × 106 spores g−1 h−1. The turnover rate of biomass at maximum growth yield was 0.029 h−1 when 5.6 × 106 spores were formed from 1 g mycelium. The present quantitative analysis of submerged spore formation using a controlled system opens the way for biochemical and molecular biological studies related to the morphological differentiation of Streptomyces spp.
-
Volumes and issues
-
Volume 170 (2024)
-
Volume 169 (2023)
-
Volume 168 (2022)
-
Volume 167 (2021)
-
Volume 166 (2020)
-
Volume 165 (2019)
-
Volume 164 (2018)
-
Volume 163 (2017)
-
Volume 162 (2016)
-
Volume 161 (2015)
-
Volume 160 (2014)
-
Volume 159 (2013)
-
Volume 158 (2012)
-
Volume 157 (2011)
-
Volume 156 (2010)
-
Volume 155 (2009)
-
Volume 154 (2008)
-
Volume 153 (2007)
-
Volume 152 (2006)
-
Volume 151 (2005)
-
Volume 150 (2004)
-
Volume 149 (2003)
-
Volume 148 (2002)
-
Volume 147 (2001)
-
Volume 146 (2000)
-
Volume 145 (1999)
-
Volume 144 (1998)
-
Volume 143 (1997)
-
Volume 142 (1996)
-
Volume 141 (1995)
-
Volume 140 (1994)
-
Volume 139 (1993)
-
Volume 138 (1992)
-
Volume 137 (1991)
-
Volume 136 (1990)
-
Volume 135 (1989)
-
Volume 134 (1988)
-
Volume 133 (1987)
-
Volume 132 (1986)
-
Volume 131 (1985)
-
Volume 130 (1984)
-
Volume 129 (1983)
-
Volume 128 (1982)
-
Volume 127 (1981)
-
Volume 126 (1981)
-
Volume 125 (1981)
-
Volume 124 (1981)
-
Volume 123 (1981)
-
Volume 122 (1981)
-
Volume 121 (1980)
-
Volume 120 (1980)
-
Volume 119 (1980)
-
Volume 118 (1980)
-
Volume 117 (1980)
-
Volume 116 (1980)
-
Volume 115 (1979)
-
Volume 114 (1979)
-
Volume 113 (1979)
-
Volume 112 (1979)
-
Volume 111 (1979)
-
Volume 110 (1979)
-
Volume 109 (1978)
-
Volume 108 (1978)
-
Volume 107 (1978)
-
Volume 106 (1978)
-
Volume 105 (1978)
-
Volume 104 (1978)
-
Volume 103 (1977)
-
Volume 102 (1977)
-
Volume 101 (1977)
-
Volume 100 (1977)
-
Volume 99 (1977)
-
Volume 98 (1977)
-
Volume 97 (1976)
-
Volume 96 (1976)
-
Volume 95 (1976)
-
Volume 94 (1976)
-
Volume 93 (1976)
-
Volume 92 (1976)
-
Volume 91 (1975)
-
Volume 90 (1975)
-
Volume 89 (1975)
-
Volume 88 (1975)
-
Volume 87 (1975)
-
Volume 86 (1975)
-
Volume 85 (1974)
-
Volume 84 (1974)
-
Volume 83 (1974)
-
Volume 82 (1974)
-
Volume 81 (1974)
-
Volume 80 (1974)
-
Volume 79 (1973)
-
Volume 78 (1973)
-
Volume 77 (1973)
-
Volume 76 (1973)
-
Volume 75 (1973)
-
Volume 74 (1973)
-
Volume 73 (1972)
-
Volume 72 (1972)
-
Volume 71 (1972)
-
Volume 70 (1972)
-
Volume 69 (1971)
-
Volume 68 (1971)
-
Volume 67 (1971)
-
Volume 66 (1971)
-
Volume 65 (1971)
-
Volume 64 (1970)
-
Volume 63 (1970)
-
Volume 62 (1970)
-
Volume 61 (1970)
-
Volume 60 (1970)
-
Volume 59 (1969)
-
Volume 58 (1969)
-
Volume 57 (1969)
-
Volume 56 (1969)
-
Volume 55 (1969)
-
Volume 54 (1968)
-
Volume 53 (1968)
-
Volume 52 (1968)
-
Volume 51 (1968)
-
Volume 50 (1968)
-
Volume 49 (1967)
-
Volume 48 (1967)
-
Volume 47 (1967)
-
Volume 46 (1967)
-
Volume 45 (1966)
-
Volume 44 (1966)
-
Volume 43 (1966)
-
Volume 42 (1966)
-
Volume 41 (1965)
-
Volume 40 (1965)
-
Volume 39 (1965)
-
Volume 38 (1965)
-
Volume 37 (1964)
-
Volume 36 (1964)
-
Volume 35 (1964)
-
Volume 34 (1964)
-
Volume 33 (1963)
-
Volume 32 (1963)
-
Volume 31 (1963)
-
Volume 30 (1963)
-
Volume 29 (1962)
-
Volume 28 (1962)
-
Volume 27 (1962)
-
Volume 26 (1961)
-
Volume 25 (1961)
-
Volume 24 (1961)
-
Volume 23 (1960)
-
Volume 22 (1960)
-
Volume 21 (1959)
-
Volume 20 (1959)
-
Volume 19 (1958)
-
Volume 18 (1958)
-
Volume 17 (1957)
-
Volume 16 (1957)
-
Volume 15 (1956)
-
Volume 14 (1956)
-
Volume 13 (1955)
-
Volume 12 (1955)
-
Volume 11 (1954)
-
Volume 10 (1954)
-
Volume 9 (1953)
-
Volume 8 (1953)
-
Volume 7 (1952)
-
Volume 6 (1952)
-
Volume 5 (1951)
-
Volume 4 (1950)
-
Volume 3 (1949)
-
Volume 2 (1948)
-
Volume 1 (1947)