Characterization of centromere arrangements and test for random distribution in G0, G1, S,G2, G1, and early S′ phase in human lymphocytes

Summary The arrangement of centromeres, cluster formation and association with the nucleolus and the nuclear membrane were characterized in human lymphocytes during the course of interphase in a cell-phase-dependent manner. We evaluated 3 893 cell nuclei categorized by five parameters. The centromeres were visualized by means of indirect immunofluorescent labeling with anti-centromere antibodies (ACA) contained in serum of patients with CREST syndrome. The cell nuclei were classified as G₀, G₁, S, G₂, Gl₁ and early S phase by comparing microscopically identified groups of cell nuclei with flow cytometric determination of cell cycle stage of synchronized and unsynchronized lymphocyte cell cultures. Based on a discrimination analysis, a program was devised that calculated the probability for any cell nucleus belonging to the G₀, G₁, S, G₂, G₁ and early S phase using only two microscopic parameters. Various characteristics were determined in the G₀, S, and G₂ stages. A transition stage to S phase within G₁ was detected. This stage shows centromere arrangements not repeated in later cell cycles and which develop from the dissolution of centromere clusters in the periphery of the nucleus during G₀ and G₁. S phase exhibits various non-random centromere arrangements and associations of centromeres with the nucleolus. G₁ and early S phase of the second cell cycle display no characteristic centromere arrangement. The duplication of centromeres in G₂ is asynchronous in two phases. For all cell phases a test for random distribution of the centromeres in the cell nucleus was performed. There is a distinct tendency for centromeres to be in a peripheral position during Go and G₁; this tendency becomes weaker in S phase. Although the visual impression is a seemingly random distribution of centromeres in G₂ and G₁ statistical analysis still demonstrates a significant deviation from random distribution in favor of a peripheral location. Only the early S phase of the second cell cycle shows no significant deviation from a random distribution.     

Evaluation of IgG, IgM, and IgA antibodies to mycoplasma penetrans detected by ELISA and immunoblot in HIV-1-infected and STD patients, in São Paulo, Prazil

The aim of the present study was to determine the frequency of IgG, IgA, and IgM antibodies to Mycoplasma penetrans in HIV-1-infected patients and in patients with sexually transmitted diseases. We tested serum samples from 106 HIV-1-positive patients and 110 individuals with clinical symptoms of urethritis. ELISA and the immunoblot test were performed using M. penetrans lipid associated membrane proteins as antigen. By ELISA, we found a higher frequency (P < 0.05) of IgG against M. penetrans in HIV-1-infected and STD patients (25.5 and 17.3%) than in controls (1.2%), as well as a higher frequency of IgA (P < 0.05) (15.1 and 17.3% compared to 1.2%). For IgM, no differences were observed (P >/= 0.05) (3.8, 9.1, and 5. 8%, respectively). When the frequencies of IgG, IgM, and IgA antibodies of the HIV-1-infected patients were compared taking into account the CD4/CD8 cell ratios < 0.3 and >/= 0.3, no significant differences were observed between the two groups (13.3, 10, and 20%, compared to 20, 0, and 5%, respectively) (P > 0.05), possibly due to the low number of samples on which we could perform T-cell counts (53/106). The M. penetrans peptide of 38 kDa, considered immunodominant, was recognized in immunoblot by 51.8% of positive sera by ELISA for IgG, 50.0% for IgM, and 75% for IgA in the AIDS patients group, and by 47.4, 60.0, and 75.0%, respectively, in the sexually transmitted disease group. Cross-reactions in immunoblot for IgG were observed in sera from individuals infected with Mycoplasma pneumoniae and Mycoplasma hominis, and cross-reactions in immunoblot for IgA were observed in sera from individuals infected with M. hominis; all of them were ELISA negative to M. penetrans.     

Diverse and atypical genotypes identified in Toxoplasma gondii from dogs in São Paulo, Brazil

The prevalence of Toxoplasma gondii in 118 unwanted dogs from S?o Paulo City, S?o Paulo State, Brazil, was determined. Antibodies to T. gondii were assayed by the modified agglutination test and found in 42 (35.8%) dogs, with titers of 1:20 in 10, 1:40 in 6, 1:80 in 5, 1:160 in 5, 1:320 in 6, 1:640 in 7, and 1:1,280 or higher in 3. Hearts and brains of 36 seropositive dogs were bioassayed in mice, or cats, or both. Tissues from 20 seropositive dogs were fed to 20 T. gondii-free cats. Feces of cats were examined for oocysts. Toxoplasma gondii was isolated from 15 dogs by a bioassay in mice, from the brain alone of 1, from the heart alone of 4, and from both brains and hearts of 10. All infected mice from 5 of 15 isolates died of toxoplasmosis during primary infection. Four additional isolates were obtained by bioassay in cats. Genotyping of these 19 T. gondii isolates using polymorphisms at 10 nuclear markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and a new SAG2 (an apicoplast marker Apico) revealed 12 genotypes. One isolate had Type III alleles at all 11 loci, and the remaining 18 isolates contained a combination of different alleles and were divided into 11 genotypes. The absence of Type II in Brazil was confirmed. The result supports previous findings that T. gondii population genetics is highly diverse in Brazil.     

Antimicrobial susceptibility, phage types, and pulse types of Salmonella Typhimurium, in São Paulo, Brazil

A total of 283 Salmonella Typhimurium strains isolated from cases of human infections and non human sources, were examined for antimicrobial susceptibility and the incidence of resistance was 38% and multiple resistance (to three or more antimicrobials) was 15%. All 43 multidrug-resistant strains (MDR) and 13 susceptible ones were characterized by phage typing and pulsed- field gel electrophoresis (PFGE). The strains encompassed 14 definitive phage types (DT), three were untypable (UT), and 18 atypicals or reaction does not conform (RDNC), which belonged to 21 PFGE patterns, A1-A21. The predominant phage types were DT49, DT193, and RDNC and two strains belonging to DT 104 and 104b were also identified. The most common PFGE patterns were A1 and A8. Analysis by PFGE and phage typing demonstrated that the most of the MDR were multiclonal and association among multiresistance, phage typing, and PFGE patterns was not so significant.     

Comparative catches and food habits of dolly varden and arctic charrs,Salvelinus malma and S. alpinus,at Karluk,Alaska, in 1939–1941

Synopsis For many years the seriousness of the predations of dolly varden (Salvelinus malma) upon the eggs, alevins and juveniles of Pacific salmons (Oncorhynchus) has been a controversial subject. Over $ 300,000 was spent in Western Alaska from 1920 to 1941 for bounties on dolly varden in the belief that they were serious salmon predators. The writter undertook this study because of an intense desire to evaluate the need and justification for such a bounty system. The incidental examination of stomach contents of charrs which were captured for tagging or for tag recovery purposes from Karluk Lake and Karluk River on Kodiak Island, Alaska, and from Shelikof Strait and Uyak Bay during the summer months of 1939, 1940 and 1941 presented an excellent opportunity to pursue such a project. Stomachs were collected and contents analyzed from 1,992 arctic charr (Salvelinus alpinus) and 2,565 dolly varden charr (Salvelinus malma), taken by beach seine, gill net, fyke net, hook and line and by weir trap from Karluk Lake; from 956 dolly varden taken by seine and weir trap from the Karluk River; and from 462 dolly varden taken by beach seine and commercial salmon traps in Uyak Bay. Among the more than 5,000 charr stomachs examined, only 42 were found to contain salmon smolts, parr or alevin. Examination of 500 stomachs taken from dolly varden charr captured in the lower Karluk River at the height of the red salmon (Oncorhynchus nerka) smolt migration in May of 1939 revealed very little evidence of predation on the smolts in fresh water. There was some evidence that this relationship may have changed after the migrating charr had become adjusted to salt water, although the examination of 460 stomachs of dolly varden captured in salt water revealed nothing particularly incriminating in its role as a salmon predator. The fact that the downstream migration of the dolly varden reached its peak before that of the red salmon smolts was considered significant. Examination of the 4,500 charr stomachs at Karluk Lake in the months from April through September led to the discovery that two distinct species of charrs were present, one, the dolly varden, primarily stream-inhabiting and anadromous, and the other, the arctic charr, primarily lake-inhabiting and nonanadromous. Although red salmon eggs constituted 32% of the total volume of food ingested by both species of charr at Karluk Lake, there was considerable evidence that they were consumed in salvage or scavenger feeding, and there was practically no evidence that they were consumed as a result of predatory feeding. Only five, or one-tenth of one percent, of the thousands of charr stomachs examined at Karluk Lake contained red salmon parr or alevin.A summary of the contrasts in the feeding and migratory habits and physical characteristics of Salvelinus malma and Salvelinus alpinus led to the conclusion that alpinus was a more serious potential salmon predator than malma at Karluk Lake. In view of the fact that alpinus was seldom reached by the predator-control program whereas malma was being systematically destroyed only because it was more easily captured due to its migratory tendencies, it was recommended that the predator control program be terminated in Karluk waters.Published post mortem in shortened and slightly edited version. Reprint requests to the Editor.     

A review of antimalarial plants used in traditional medicine in communities in Portuguese-speaking countries: Brazil, Mozambique, Cape Verde, Guinea-Bissau, São Tomé and Príncipe and Angola

The isolation of bioactive compounds from medicinal plants, based on traditional use or ethnomedical data, is a highly promising potential approach for identifying new and effective antimalarial drug candidates. The purpose of this review was to create a compilation of the phytochemical studies on medicinal plants used to treat malaria in traditional medicine from the Community of Portuguese-Speaking Countries (CPSC): Angola, Brazil, Cape Verde, Guinea-Bissau, Mozambique and S?o Tomé and Príncipe. In addition, this review aimed to show that there are several medicinal plants popularly used in these countries for which few scientific studies are available. The primary approach compared the antimalarial activity of native species used in each country with its extracts, fractions and isolated substances. In this context, data shown here could be a tool to help researchers from these regions establish a scientific and technical network on the subject for the CPSC where malaria is a public health problem.     

Prevalence, behavioural and social factors associated with Schistosoma intercalatum and geohelminth infections in São Tomé and Principe

A pilot study was conducted in schoolchildren from three main districts of S?o Tome to assess the relationship between the prevalence of infections caused by Schistosoma intercalatum or intestinal helminths and individual behaviour and social conditions. Coprological examination revealed an increase of schistosome infections and a persisting high endemicity for ascariasis and trichuriasis. Infection rates were 36.2% for S. intercalatum and 70.8%, 68.5% and 4.6% for Ascaris lumbricoides, Trichuris trichiura and Ancylostomidae, respectively. Out of the 47 children positive for S. intercalatum, 35 (74.5%) were co-infected with one or more geohelminths. Logistic regression analysis of data collected through questionnaire demonstrate that behaviour and/or social conditions in the house were positively associated with S. intercalatum or T. trichiura. Neither sex nor age groups were associated with infections, suggesting that low personal hygiene and sanitation practices were similar for all groups of children. These data are in accordance to those of other studies and highlight the importance of assessing multivariate factors that may contribute to the transmission of these diseases, in order to design integrated control approaches for schistosomiasis and geohelminthiasis which could have more rapid effects on reduction of infections as well as greater cost-effectiveness.     

Mycotoxins and fungi in wheat harvested during 1990 in test plots in the state of São Paulo,Brazil

Wheat from two cultivars with contrasting characteristics were harvested in ten experimental plots located in wheat producing areas of the State of São Paulo, Brazil. The samples (10 of each cultivar) were analyzed by a gaschromatographic method for deoxynivalenol (DON), nivalenol (NIV), diacetoxyscirpenol (DAS), toxins T-2 (T-2) and HT-2, T-2 tetraol, T-2 triol, and by a thin-layer chromatographic method for zearalenone (ZEN), aflatoxins B₁, B₂, G₁, G₂, ochratoxin A and sterigmatocystin. No mycotoxins were detected in 13 samples. DON was found in four samples (0.47–0.59 µg/g), NIV in three samples (0.16–0.40 µg/g), T-2 in two samples (0.40, 0.80 µg/g), DAS in one sample (0.60 µg/g), and ZEN in three samples (0.04–0.21 µg/g). The wheat samples were also examined for the incidence of fungi.Alternaria, Drechslera, Epicoccum andCladosporium were the prevailing genera. Among theFusarium spp.,F. semitectum was present in 19 samples andF. moniliforme in 18 samples. NoF. graminearum was isolated in the samples.Abbreviations DAS diacetoxyscirpenol - DON deoxynivalenol - NIV nivalenol - T-2 T-2 toxin - ZEN zearalenone     

Use of the STR loci D18S53, D18S59, and D18S488 in the diagnosis of Edwards’ syndrome

The aim of this study was to investigate the feasibility of using short tandem repeats (STRs) to diagnose Edwards’ syndrome (ES). Quantitative fluorescence polymerase chain reaction (QF-PCR) was performed to amplify STR loci on chromosome 18, specifically D18S53, D18S59, and D18S488. The amplified products were subjected to a fluorescence signal analysis and their application to ES diagnosis was examined. Among the 807 cases that showed normal results in the karyotype analysis, 793 showed one or two fluorescence bands with a fluorescence intensity ratio of 1:1, and 14 cases showed 3 bands, which were false-positive results. ES was diagnosed in 9 samples. The sensitivities of D18S53, D18S59, and D18S488 for the diagnosis of ES were 77.78, 44.44, and 55.56 % and the specificities were 96.16, 96.03, and 96.28 %, respectively. The combined sensitivity of the three loci for diagnosing DS was 100 % (9/9), with a specificity of 98.27 % (793/807). QF-PCR amplification of STR loci had high sensitivity, strong specificity, and was simple and rapid. Thus, it might have wide clinical applications, and could be an ideal tool for large-scale genetic and prenatal diagnosis of ES.     

Absorption and Translocation of O-Ethyl S,S-Diphenyl Phosphorodithiolate (Hinosan®) in Rice Plants

Absorption and translocation of (O-ethyl S,S-diphenyl phosphorodithiolate (Hinosan) in rice plants were studied by means of techniques of gas-liquid chromatography, radioautograph and ³²P-radioactivity determination. ³²P-labeled Hinosan was used in the present study. Hinosan on the surface of a leaf and on a glass plate was dissipated in a much slower rate than the other phosphorus pesticides tested. Hinosan was chemically transformed to a small extent after taken up into the plant tissues and largely remained in the local region. Up- and downward translocation of Hinosan occurred slightly in the ride seedlings. Translocation and accumulation of Hinosan were also studied concerning with growth stage of rice plants, such as the seedling, the milk-ripening, and the ripening stage. Accumulation in grains was in most cases found to be less than the limit of determination. Translocation of Hinosan was discussed in relation to physiological conditions of rice plants.     

Karyotype and chromosomal characteristics of Ag–NOR sites and 5S rDNA in European smelt, Osmerus eperlanus

Karyotype and cytogenetic characteristics of European smelt Osmerus eperlanus were investigated using different staining techniques (sequential Ag-, CMA3 and DAPI banding) and PRINS to detect 5S rDNA and telomeric sites. The diploid chromosome number was invariably 2n = 56 and karyotype composed of 5 pairs of metacentrics, 9 pairs of subtelocentrics and 14 pairs of subtelo- to acrocentrics. The DAPI-positive heterochromatic regions were found in centromeric positions on bi-armed chromosomes and few acrocentrics. Additionally, some interstitial DAPI-positive bands were identified on three pairs of submetacentric chromosomes. The nucleolar organizer regions (NORs) were detected in the short (p) arms of the largest metacentric pair of chromosomes No. 1. Sequential banding (Giemsa-, AgNO₃ and CMA₃ stainings) revealed NOR sites corresponding to achromatic regions but not associated with CMA₃-positive blocks of heterochromatin located on either side of NORs. Individuals from the analyzed population had this conspicuous pair of chromosomes always in heterozygous combination. A complex inversion system was hypothesized to be involved in the origin of the observed variation but analysis with telomeric PRINS and PNA-FISH did not reveal any Interstitial Telomeric Sites (ITS). Hybridization signals were confined exclusively to terminal chromosomal regions. The 5S ribosomal sites as revealed by PRINS were found to be invariably located in the short (p) arms of four pairs of subtelocentric chromosomes. Cytotaxonomic comparisons of the present results with the voluminous available cytogenetic data-set from salmoniform and esociformes fishes appear to support the recent view, based on robust molecular-based phylogeny, that salmoniform and osmeriform fishes are not as closely related as previously assumed.     

CO2 and O2 dynamics in human-impacted watersheds in the state of São Paulo, Brazil

We studied the spatial and temporal variation in O₂ and dissolved inorganic carbon (DIC) forms concentrations in ten subtropical watersheds located in the state of São Paulo, Brazil, with different degrees of impact by urbanization and land-use changes. Additionally, we used stable carbon isotopic composition of DIC to explain observed patterns. We found that land-cover changes and watershed geology are the main drivers of DIC distribution. Land-cover/use changes influence the riverine DIC in two ways: by replacing the original Cerrado 3 (C3)-type forest vegetation by C4-type vegetation composed of grasses (pasture), and by sugarcane. Most domestic sewage is dumped untreated into rivers in the state of São Paulo. Consequently, in the most densely populated watersheds, sewage is an important source of labile carbon and consequently of DIC to rivers. In terms of geology, although silicate weathering that produces kaolinite is the main type of weathering in the watersheds, the weathering of carbonate cements present in the geological formations of the western portion of the state of São Paulo are also an important source of DIC to rivers.     

Sex, Death, and Evolution in Proto- and Metazoa, 1876–1913

In the period 1875–1920, a debate about the generality and applicability of evolutionary theory to all organisms was motivated by work on unicellular ciliates like Paramecium because of their peculiar nuclear dualism and life cycles. The French cytologist Emile Maupas and the German zoologist August Weismann argued in the 1880s about the evolutionary origins and functions of sex (which in the ciliates is not linked to reproduction), and death (which appeared to be the inevitable fate of lineages denied sexual conjugation), an argument rooted in the question of whether the ciliates and their processes where homologous to other cellular organisms. In the beginning of the twentieth century, this question of homology came to be less important as the ciliates were used by the British protozoologist Clifford Dobell and the American zoologist Herbert Spencer Jennings to study evolutionary processes in general rather than problems of development and cytology. For them, homology mattered less than analogy. This story illustrates two partially distinct problems in evolutionary biology: first, the question of whether all living things have common features and origins; and second, whether their history and current nature can be described by identical mechanisms. Where Maupas (contra Weismann) made the ciliates qualitatively the same as all other organisms in order to create a cohesive evolutionary theory for biology, Jennings and Dobell made them qualitatively different in order to achieve the same end. This revised version was published online in July 2006 with corrections to the Cover Date.     

Science,philosophy, and politics in the work of J. B. S. Haldane, 1922–1937

This paper analyzes the interaction between science, philosophy and politics (including ideology) in the early work of J. B. S. Haldane (from 1922 to 1937). This period is particularly important, not only because it is the period of Haldane's most significant biological work (both in biochemistry and genetics), but also because it is during this period that his philosophical and political views underwent their most significant transformation. His philosophical stance first changed from a radical organicism to a position far more compatible with mechanical materialism. The primary intellectual influence that was responsible for this shift was that of F. G. Hopkins. Later, Haldane came to accept Marxism and its official metaphysics, dialectical materialism, a move that let him accept the materialist conception of the world while still maintaining a resolute distance from mechanism. Throughout all these changes, what is most obvious is the influence of science on Haldane's philosophical views. An influence in the opposite direction is far less apparent.Parts of this paper are extracted from a longer work which concerns the interactions between philosophy and science throughout Haldane's scientific career (Sarkar forthcoming). The general conclusions reached here, from a consideration of Haldane's work only from 1922 to 1937 (see Section 6), remain the same for the rest of his life, as is detailed in the longer work. Thanks are due to R. S. Cohen, J. F. Crow, A. R. Fersht, J. Maynard Smith, R. C. Olby, D. Paul, M. Ruse, J. Stachel and S. Sturdy for helpful discussions and comments and criticism of the positions outlined in this paper. This is Contribution No. BTBG-92-4 from the Theoretical Biology Group, Boston University.     

Morphological and phytochemical variation, genetic structure and phenology in an introgressive hybrid swarm of Senecio hercynicus and S. ovatus (Compositae, Senecioneae)

Introgressive hybridisation between Senecio hercynicus and Senecio ovatus (Compositae, Senecioneae) was studied in a mixed stand of the two species on the S- and SW-facing slopes of the German part of the Bohemian Forest (SE Germany). Morphological variation based on multivariate analysis of 14 diagnostic characters, along with genetic data from an amplified fragment length polymorphism (AFLP) fingerprinting analysis, indicates that the surveyed stand forms an intensively introgressed hybrid swarm. The majority of individuals were found to be intermediate between the two parental taxa, and strong statistical correlation between phenetic and genetic distances was observed. In contrast to that, flowering time of individuals (expressed as the time when 50% of the capitula of a plant were in flower) was found to follow a bimodal distribution in the hybrid swarm and lacked any correlation with the genetic and morphological relationships among plants. The same was true for the spectra of pyrrolizidine alkaloids (PA) revealed by a gas-chromatographic survey: most of the 142 individuals surveyed fell into one of two main chemotypes, only a few plants exhibited an intermediate and additive PA spectrum, and no correlation with the genetic and morphological relationships among plants was observed. Assuming that most of the AFLP markers are neutral, we conclude that the correlation of morphology with the genetic pattern may argue for the neutrality of morphological features analysed. Consequently, we interpret the lack of correlation between phenological and phytochemical data with the neutral genetic markers as evidence that both phenology and phytochemistry may be either under selection or that these features are genetically or biosynthetically constrained.