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PubMed1975

Hemoglobin switching in sheep and goats. V. Effect of erythropoietin concentration on in vitro erythroid colony growth and globin synthesis.

Erythroid colonies were generated in response to erythropoietin in plasma clot cultures of sheep and goat bone marrow cells. At low concentration erythropoietin only hemoglobin A (betaA globin) was synthesized in goat cultures, but at high concentrations 50% of the hemoglobin synthesized was hemoglobin C (betaC globin). This effect of erythropoietin on the expression of a specific beta globin gene was manifested only after 72 h in vitro and followed the development of erythroid colonies. Sheep colonies behaved differently from those of goat in that little or no betaC globin synthesis occurred even at high erythropoietin concentration. To investigate this difference, sheep marrow cells were fractionated by unit gravity sedimentation. The erythroid colony-forming cells sedimented more rapidly (3.5-6mm/h) than the hemoglobinized eththroid precursors (1-3.5 mm/h), suggesting that the colonies were formed from an early erythroid precursor, However, the colonies formed from the sheep marrow fractions synthesized only betaA globin even at concentrations of erythropoietin sufficient to stimulate betaC globin synthesis in goat colonies. Morphologically, the goat colonies were larger and more mature than those of the sheep. By 96 h in vitro three-fourths of the goat colonies contained enucleated red cells compared to only 3% of the sheep colonies. Thus, erythropoietin had an equivalent effect in stimulating erythroid colony growth from the marrow of both species although there were both biochemical and morphological differences between the colonies. Hemoglobin switching appeared to require exposure of an early precursor to high erythropoietin concentration, but the results with sheep marrow suggested that the rate of colony growth and cellular maturation might also be important.

Animals↗
PubMed2005

Colony social organization and population genetic structure of an introduced population of formosan subterranean termite from New Orleans, Louisiana.

The Formosan subterranean termite, Coptotermes formosanus Shiraki, is an invasive species in many parts of the world, including the U.S. mainland. The reasons for its invasive success may have to do with the flexible social and spatial organization of colonies. We investigated the population and breeding structure of 14 C. formosanus colonies in Louis Armstrong Park, New Orleans, LA. This population has been the focus of extensive study for many years, providing the opportunity to relate aspects of colony breeding structure to previous findings on colony characteristics such as body weight and number of workers, wood consumption, and intercolony aggression. Eight colonies were headed by a single pair of outbred reproductives (simple families), whereas six colonies were headed by low numbers of multiple kings and/or queens that were likely the neotenic descendants of the original colony (extended families). Within the foraging area of one large extended family colony, we found genetic differentiation among different collection sites, suggesting the presence of separate reproductive centers. No significant difference between simple family colonies and extended family colonies was found in worker body weight, soldier body weight, foraging area, population size, or wood consumption. However, level of inbreeding within colonies was negatively correlated with worker body weight and positively correlated with wood consumption. Also, genetic distance between colonies was positively correlated with aggression levels, suggesting a genetic basis to nestmate discrimination cues in this termite population. No obvious trait associated with colony reproductive structure was found that could account for the invasion success of this species.

Animals↗
PubMed2003

Proximate and ultimate control of sex ratios in Myrmica brevispinosa colonies.

The literature on sex ratio evolution in ant colonies is dominated by inclusive fitness arguments. In general, genetic theory makes good predictions about sexual investment in ant populations, but understanding colony-level variance in sex investment ratios has proven more difficult. Recently, however, more studies have addressed ecological factors that influence colony-level sex investment ratios. Food availability, in particular, has been manipulated because larval nutrition influences female caste determination, thus implying that resource availability should be of critical importance for colony sex investment ratios. However, results from food supplementation experiments are equivocal, and it is clear that ant colony response to food supplementation is dependent on the ecological background of the population. We presented field colonies of the ant Myrmica brevispinosa with two food types (proteins and carbohydrates), and assessed their relative impact on colony-level sex investment ratios. We show that colonies receiving carbohydrate enhancement invested in more female sexuals and produced more female-biased sex allocation ratios than protein-fed or control colonies. Thus, our study is the first, to our knowledge, to demonstrate that sex ratios in social insect colonies might be sensitive to resource quality. Male investment was not influenced by food treatment, but was positively correlated with colony size. Therefore, the shift in sex ratios in our study must have been mediated through nutritional influences on female caste determination rather than male brood elimination. We also used our data to evaluate evidence for sex ratio compensation by queenright colonies in response to male production by workers from orphaned colonies.

Animals↗
PubMed2004

Variable queen number in ant colonies: no impact on queen turnover, inbreeding, and population genetic differentiation in the ant Formica selysi.

Variation in queen number alters the genetic structure of social insect colonies, which in turn affects patterns of kin-selected conflict and cooperation. Theory suggests that shifts from single- to multiple-queen colonies are often associated with other changes in the breeding system, such as higher queen turnover, more local mating, and restricted dispersal. These changes may restrict gene flow between the two types of colonies and it has been suggested that this might ultimately lead to sympatric speciation. We performed a detailed microsatellite analysis of a large population of the ant Formica selysi, which revealed extensive variation in social structure, with 71 colonies headed by a single queen and 41 by multiple queens. This polymorphism in social structure appeared stable over time, since little change in the number of queens per colony was detected over a five-year period. Apart from queen number, single- and multiple-queen colonies had very similar breeding systems. Queen turnover was absent or very low in both types of colonies. Single- and multiple-queen colonies exhibited very small but significant levels of inbreeding, which indicates a slight deviation from random mating at a local scale and suggests that a small proportion of queens mate with related males. For both types of colonies, there was very little genetic structuring above the level of the nest, with no sign of isolation by distance. These similarities in the breeding systems were associated with a complete lack of genetic differentiation between single- and multiple-queen colonies, which provides no support for the hypothesis that change in queen number leads to restricted gene flow between social forms. Overall, this study suggests that the higher rates of queen turnover, local mating, and population structuring that are often associated with multiple-queen colonies do not appear when single- and multiple-queen colonies still coexist within the same population, but build up over time in populations consisting mostly of multiple-queen colonies.

Animals↗
PubMed2004

Molecular insight into patterns of colony composition and paternity in the common mole-rat Cryptomys hottentotus hottentotus.

We report the discovery of intraspecific variation in both colony composition and patterns of paternity in two populations of the social common mole-rat Cryptomys hottentotus hottentotus. These two populations represent the mesic and arid habitat extremes of the species' broad ecological range in South Africa. Until recently colonies of the common mole-rat were thought to consist of familial groups whereby all colony members were the offspring of a monogamous reproductive pair. The remaining colony members were thought to forego reproduction until both social and ecological conditions favoured dispersal and opportunities for independent outbreeding. Results from genetic assignment tests using microsatellite markers indicate that while colony composition is dominated by familial groups, colonies within both populations included both adult and subadult foreign conspecifics. Analysis of parentage reveals that the social organization of C. h. hottentotus is not that of strict monogamy; paternity of offspring was not assigned consistently to the largest, most dominant male within the colony. Moreover, a number of significantly smaller males were found to sire offspring, suggesting a sneak-mating strategy by subordinate within-colony males. Extra-colony extra-pair paternity (ECP) was also found to characterize C. h. hottentotus colonies, occurring with similar frequencies in both habitats. Both dominant established breeding males and subordinate males were identified as siring young in nonsource colonies. Furthermore, established breeding males were found to sire extra-colony young in the same season as siring young within their source colonies. We discuss the significance of these results within the context of the divergent ecological regimes characterizing the two sites and observe that our results revisit the accuracy of using behavioural and morphological characters, which have structured the basis of our understanding of the behavioural ecology of this species, as indicators of breeding status in mark-recapture studies.

Animals↗
PubMed1994

Scanning electron microscopy of Eikenella corrodens colony morphology variants.

Eikenella corrodens is a gram-negative, human pathogen which exhibits colony morphology variation. Scanning electron microscopy (SEM) was used to examine large (non-corroding) and small (corroding) colony variants from the type strain (ATCC 23834) and two clinical isolates (strains VA1 and CM1). Large colonies were large, flatter, and appeared relatively featureless compared to small colonies and had even, smooth colony margins. Small colonies were more raised from the medium surface, and often had a central raised region surrounded by flatter border. Cells on the surface of large colonies were more regularly arranged at the colony edge, and end-to-end rows of cells around the colony were seen in some strains. Cells in the center of the upper surface of small colonies were usually randomly arranged. Within cross sections of small colonies, cells were arranged randomly or perpendicular to the medium; in large colonies, cells were random or arranged horizontally. Amorphous, "slime" material was often seen covering groups of cells in large and small variants. An unusual variant, possibly a mutant, which combined features of both colony types was isolated.

Eikenella corrodens↗
PubMed1997

Ultrastructure of colony-like communities of bacteria.

Colony-like communities are poorly studied forms of bacterial growth on agar. These communities are formed after the growth of large amounts of bacteria simultaneously plated onto a limited area of agar, while "classical" colonies are formed as a result of single bacterial cell multiplication. Colony-like communities of Gram-negative and Gram-positive bacteria differ from "classical" microbial colonies in their ultrastructural organization. Almost every cell in colony-like communities has an individual capsule-like envelope (glycocalyx). The cells in these communities are characterized by accelerated ageing. In the course of their development both bacterial colony-like communities and "classical" colonies produce a film, the basic part of which is represented by an elementary membrane. In contrast to "classical" colonies, the thickness of the amorphous layers of this film in colony-like communities did not significantly increase after 24 h of cultivation. The formation of a three-dimensional network of cells in colony-like communities is similar to this process in "classical" colonies. The intercellular matrix of colony-like communities contains numerous membrane vesicles, and has a more amorphous structure and higher electron density than that of "classical" bacterial colonies.

Bacteria↗
PubMed1966

Colonial morphology of Escherichia coli on Tergitol-7 medium.

Escherichia coli cultures grown on Tergitol-7 medium, with 2,3,5-triphenyltetrazolium chloride added, produced three main types of colonies: rough, intermediate, and mucoid. These colonies were yellow to amber in color and produced slight yellow zones in the medium. Rough colonies were flat, dry, and spreading, with a cut-glass appearance. Intermediate-type colonies varied considerably, but could be divided into two general subtypes. Intermediate-rough colonies had the cut-glass appearance characteristic of rough colonies, but were much more compact and raised, with irregular edges. Intermediate-smooth colonies had a slight cut-glass appearance, but were smooth and entire. Mucoid-type colonies also appeared in two subtypes. Mucoid A colonies were mucoid hemispheres. Mucoid B colonies, after incubation at 37 C for 24 hr, appeared as small, intermediate colonies. However, during a 24-hr holding period at room temperature, mucuslike material proliferated around the colonies. A fourth type of colony was red with blue surrounding medium. Only mucoid-type cultures could not be serologically O-grouped.

Antigens↗
PubMed1987

Differential effects of growth hormone and insulin-like growth factor I on colony formation of epiphyseal chondrocytes in suspension culture in rats of different ages.

The effect of human GH (hGH) and insulin-like growth factor I (IGF-I) on the colony formation of rat epiphyseal chondrocytes was studied in suspension culture. Chondrocytes from epiphyseal growth plates of the proximal tibia of 7-, 20-, and 28-day-old normal male rats were enzymatically isolated and cultured in the presence of 10% newborn calf serum in suspension stabilized with 0.5% agarose. The cloning efficiency (number of formed colonies per 1000 seeded cells) was 13.7 +/- 1.9, 3.2 +/- 0.6, and 3.5 +/- 0.4 for chondrocytes isolated from 7-, 20- and 28-day-old rats and cultured for 14 days, respectively. The colonies were classified according to size (colony diameter), and the number of colonies was estimated as a function of colony size (distribution of cloning efficiency). IGF-I (25-200 ng/ml) increased the total colony number among chondrocytes isolated from the three different age groups and particularly increased the number of small colonies. However, IGF-I did not significantly change the distribution of cloning efficiency as compared to the control group. hGH potentiated colony formation at concentrations of 10-80 ng/ml, but no stimulatory effect of hGH was apparent at a concentration of 160 ng/ml. GH caused an assymetric distribution of cloning efficiency that was significantly different from the control group due to an increased number of large colonies (diameter exceeding 80 microns). The differential effects of GH and IGF-I were apparent after an extended period of culture (28 days) at various concentrations of the peptides. These results show that GH as well as IGF-I induced colony formation among epiphyseal chondrocytes in suspension culture, although the effects of GH and IGF-I are different in terms of distribution of cloning efficiency. The observation that GH particularly potentiated the formation of large size colonies suggests that GH promotes the differentiation of prechondrocytes, or young chondrocytes as suggested earlier. The finding that IGF-I stimulation resulted in a higher proportion of small size chondrocyte colonies, compared to the control group, suggests that IGF-I stimulates epiphyseal chondrocytes at a later stage of differentiation.

Aging↗
PubMed2001

Redox state, reactive oxygen species and adaptive growth in colonial hydroids.

Colonial metazoans often encrust surfaces over which the food supply varies in time or space. In such an environment, adaptive colony development entails adjusting the timing and spacing of feeding structures and gastrovascular connections to correspond to this variable food supply. To investigate the possibility of such adaptive growth, within-colony differential feeding experiments were carried out using the hydroid Podocoryna carnea. Indeed, such colonies strongly exhibited adaptive growth, developing dense arrays of polyps (feeding structures) and gastrovascular connections in areas that were fed relative to areas that were starved, and this effect became more consistent over time. To investigate mechanisms of signaling between the food supply and colony development, measurements were taken of metabolic parameters that have been implicated in signal transduction in other systems, particularly redox state and levels of reactive oxygen species. Utilizing fluorescence microscopy of P. carnea cells in vivo, simultaneous measurements of redox state [using NAD(P)H] and hydrogen peroxide (using 2',7'-dichlorofluorescin diacetate) were taken. Both measures focused on polyp epitheliomuscular cells, since these exhibit the greatest metabolic activity. Colonies 3-5h after feeding were relatively oxidized, with low levels of peroxide, while colonies 24h after feeding were relatively reduced, with high levels of peroxide. The functional role of polyps in feeding and generating gastrovascular flow probably produced this dichotomy. Polyps 3-5h after feeding contract maximally, and this metabolic demand probably shifts the redox state in the direction of oxidation and diminishes levels of reactive oxygen species. In contrast, 24h after feeding, polyps are quiescent, and this lack of metabolic demand probably shifts the redox state in the direction of reduction and increases levels of reactive oxygen species. Within-colony differential feeding experiments were carried out on colonies 24h after the usual, colony-wide feeding. At this time, a single polyp was fed, and this polyp was compared with an otherwise similar polyp from the same colony. A pattern similar to the whole-colony experiments was obtained: the just-fed polyp, as it begins contracting shortly after feeding, appears to be relatively oxidized, with low levels of peroxide compared with the polyp that was not fed. These data are consistent with the hypothesis that adaptive colony development in response to a variable food supply is mediated by redox state or reactive oxygen species or both, although alternative hypotheses are also discussed.

Adaptation, Physiological↗
PubMed1995

Short-term and long-term-effects of phorbol 12-myristate 13-acetate and different inhibitors on the ability of bone marrow cells to form colonies in vitro.

The process of signal transduction responsible for the phorbol 12-myristate 13-acetate mediated increase in the colony-forming potential of murine (CBA) bone marrow cells was studied using known modulators of the mitogenic signal. Pretreatment of cells for 60 minutes with staurosporine (1 mumol/l), an inhibitor of protein kinase C, completely prevented colony formation in the control group of cells and significantly reduced the number of colonies formed in the phorbol ester-treated group. Brief exposure (60 min) of cells to the phospholipase A2 inhibitors, mepacrine (500 mumol/l) and heparin (1 g/l), reduced the number of colonies formed in the control group and completely abolished the increase in the number of colonies formed after treatment of the cells with phorbol ester. When inhibitors of protein kinase C or phospholipase A2 were present during the entire period of the colony forming assay (7 days), no colonies could be scored in either the control or phorbol ester-treated groups of bone marrow cells. Long-term treatment or temporary exposure (60 min) of cells to indomethacin (50 mumol/l), an inhibitor of cyclooxygenase, or nordihydroguaiaretic acid (50 mumol/l), an inhibitor of lipoxygenase, had no effect on colony formation in both groups. Pretreatment of cells for 45 min with calcium ionophore A23187 (10 mumol/l) failed to increase the number of colonies, compared with the control group. Moreover, simultaneous treatment of cells for 45 min with phorbol ester (500 nmol/l) and A23187 (10 mumol) did not produce any further increase in the number of colonies, compared with the phorbol ester-treated group, suggesting that elevation of intracellular calcium is unimportant in the phorbol ester-mediated response. Dibutyryl cyclic adenosine monophosphate (50 mumol/l) in the presence or absence of phorbol ester, failed to stimulate colony formation, indicating that cyclic AMP-dependent protein kinases are not involved in the signalling process. Temporary exposure (75 min) of bone marrow cells to okadaic acid (1 mumol/l), a potent inhibitor of serine/threonine phosphatases, or to tyrphostine AG-115 (20 mumol/l), a tyrosine kinase inhibitor, did not effect colony growth in the control or phorbol ester-treated group. The results indicate that phospholipase A2 activation is involved in the phorbol ester-mediated increase in colony formation, since, of the different agents applied, only staurosporine, an inhibitor of protein kinase C, and mepacrine and heparin, putative inhibitors of phospholipase A2, were capable of abolishing phorbol ester-mediated effects.

Animals↗
PubMed2002

Impact of Thelohania solenopsae (Microsporidia: Thelohaniidae) on polygyne colonies of red imported fire ants (Hymenoptera: Formicidae).

Three studies were conducted to assess the effects of the entomopathogen Thelohania solenopsae on polygynous, red imported fire ant, Solenopsis invicta Buren, colonies. A total of 57 of 122 queens (46.7%) from nine, field-collected, polygyne, S. invicta colonies, was infected with T. solenopsae. Infection rate of queens for each colony ranged from 25 to 75%. Laboratory colonies of polygyne S. invicta, with three to 12 queens, were inoculated and infected with T. solenopsae. Brood levels in all infected colonies declined to 0 after 26-52 wk. Brood did not reappear in any of the colonies after 3-11 wk, even though in two of the eight infected colonies, five fertile queens that were uninfected were recovered. Thus, polygyne, S. invicta colonies infected with T solenopsae, which were confined and isolated under laboratory conditions, did not recover. Field plots that contained polygynous S. invicta colonies, which were infected with T solenopsae, were monitored over a 2-yr period. Infection rates increased during the study and reached a maximum of 9.3%. Fire ant nest density and colony sizes fluctuated over time, with maximum reduction of 63% per plot. In general, fire ant reductions were attributed to smaller colony sizes. T. solenopsae infections in polygynous S. invicta can result in a slow colony decline and death. Under field conditions, the prolonged colony death may mask the impact of T. solenopsae by allowing for concurrent reinfestations.

Animals↗
PubMed1975

Receptors for C3 and IgG on macrophage, neutrophil and eosinophil colony cells grown in vitro.

Macrophage, neutrophil, and eosinophil colony cells from bone marrow culture in semisolid agar medium were studied for membrane C3 and IgG receptors. The capacity of these cells to bind either erythrocytes-19S antibody-complement (EAC) or erythrocyte-7S antibody (EA7S) complexes was measured using the rosette method. Whereas macrophage and neutrophil colony cells showed receptors for both C3 and IgG, eosinophil colony cells appear to bear only IgG receptors. Studies correlating colony age and the presence of receptors showed that 60 to 70% of the cells from 3-day-old macrophage colonies were reactive for EAC and EA7S contrasting with 80 to 90% of the cells from 6- to 12-day-old colonies. Neutrophils behaved somewhat differently: EAC and EA7S reactive cells were seen in colonies after 4 or 5 days in culture and comprised only 50 to 60% of the colony population. Eosinophilic colonies showed 50 to 60% EA7S reactive cells after 6 to 7 days in culture, but no EAC reactive cells were found among these colonies at any time. The characteristics and properties of the receptors detected on colony cells were similar to those on macrophages and neutrophils from normal peritoneal fluid or bone marrow. Most macrophage colony cells were actively phagocytic whereas neutrophils and eosinophilic colony cells failed to show phagocytosis under the same conditions.

Animals↗
PubMed1992

Interactions between recombinant human erythropoietin and serum factor(s) on murine megakaryocyte colony formation.

We investigated the interactions between human erythropoietin (hEpo) and serum factor(s) on murine megakaryocyte (MK) colony formation. Serum-free cultures supported the growth of a large number of murine MK colonies in the presence of murine interleukin-3 (mIL-3). The addition of fetal calf serum (FCS) to mIL-3-containing cultures resulted in only a minimal increase in the number of murine MK colonies. In contrast, hEpo alone had no murine MK colony-stimulating activities in serum-free cultures. hEpo required the presence of FCS, murine serum, or human serum in cultures to promote murine MK colony growth and synergized with these sera to stimulate murine MK colony formation. Furthermore, sera from patients with aplastic anemia showed higher synergistic activities with hEpo than sera from hematologically normal persons (normal human serum). When normal human serum was fractionated by gel-filtration chromatography, two peaks with the synergistic activity were observed in the eluent. However, serum did not show any synergistic effects with hEpo on the growth of murine GM colonies or murine colony-forming unit-erythroid-derived colonies. Although human serum synergized with hEpo to stimulate murine MK colony formation, human cytokines such as IL-3, IL-4, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte-CSF (G-CSF) failed to induce murine MK colony formation in Epo-containing cultures. In cultures containing human IL-1 alpha + human IL-6 + hEpo as well as in cultures containing hEpo, human IL-3 and human GM-CSF failed to show stimulatory effects on murine MK colony formation. Moreover, the synergistic activity of human serum with hEpo could not be neutralized by antibodies such as antihuman IL-1 alpha, antihuman IL-3, antihuman IL-4, antihuman IL-6, antihuman G-CSF, and antihuman GM-CSF. Our data show that serum contains a growth factor(s) that synergizes with Epo to stimulate the proliferation and differentiation of MK precursors, and strongly suggest that this factor(s) is an unique growth factor(s) that is distinct from IL-1 alpha, IL-3, IL-4, IL-6, G-CSF, and GM-CSF.

Anemia, Aplastic↗
PubMed1989

[Studies on human basophil and eosinophil colonies in human blood mononuclear cell culture: presence of common basophil-eosinophil progenitors].

Human peripheral blood mononuclear cells (PBMC) obtained from healthy volunteers gave rise to three types of colonies that could be distinguished by their unique morphological characteristics; 5.1 +/- 0.9 (mean +/- SE) loose colonies of small cells, 2.1 +/- 0.9 packed colonies of larger cells, and 1.6 +/- 0.7 mixed colonies, were formed when PBMC (2 x 10(5) cells/dish) from 10 healthy volunteers were cultured in the medium containing methylcellulose. Cytochemical analysis with Astra blue-eosin dual staining revealed that all types of colonies consisted of various proportions of basophils, eosinophils, and hybrid (eosinophilic and basophilic) granulocytes which contained both of granules. These hybrid granulocytes were also identified by the ultrastructural features of two kinds of the granules. Relationships between cell numbers added to culture and formed colony numbers indicated colony of the cells to form the colonies. The colonies formed from untreated patients with chronic myelogenous leukemia (CML) during chronic phase were sevenfold of those from healthy volunteers. The colonies formed from treated patients with CML were normal in number. The number was 40 times greater in culture from a patient with basophilic crisis and a patient with myeloid crisis than normal, whereas that from a patient with lymphoid crisis were within normal limit. The number of the colonies from PBMC of patients with eosinophilia were in normal range, whereas those from bone marrow were six times or more than those from PBMC. These findings suggest that PBMC contains common basophil-eosinophil progenitors, and the culture used in this study in considered to be useful in the examination of basophil and eosinophil production from PBMC. Further studies using more purified cell population and other sources of colony stimulating factors such as interleukin-3 (IL-3), IL-4, IL-5, and granulocyte-macrophage colony stimulating factor should be carried out in order to clarify the significance of hybrid granulocytes in basophil and eosinophil proliferation and differentiation.

Adult↗
PubMed1989

[Interrelationship among colonial morphology, susceptibility to antituberculosis drugs, growth rate, and viability in Dubos liquid medium in Mycobacterium avium complex strains].

Interrelationship among colonial morphology, susceptibility to antituberculosis drugs, growth rate, and viability in Dubos liquid medium were studied in Mycobacterium avium complex strains, which were not exposed to any antituberculosis drugs. All five strains that were relatively susceptible to the majority of antituberculosis drugs formed smooth, opaque, domed colonies (SmD) on 7H10 agar medium, and all five strains that were naturally resistant to those drugs formed smooth, transparent, flat colonies (SmT). The SmD colony-forming strains showed small, domed, smooth colonies (DS-type) on Ogawa egg medium, and the SmT colony-forming strains usually large, flat, wrinkled colonies (FW-type) on Ogawa egg medium. However, there was one exceptional strain (11004) that formed DS-type colonies on Ogawa egg medium and SmT-type on 7H10 agar medium. Accordingly, the SmD morphology correlated with drug susceptibility and the SmT colonial morphology with drug resistance. All six DS-colony-forming strains had slow growth rates on Ogawa egg medium, whereas all four FW-colony-forming strains had rapid growth rates on Ogawa egg medium. However, such correlation was not observed in Dubos liquid medium. When the viability was defined as a ratio of the number of colony-forming units contained in 1 mg wet weight of bacteria, the five drug-susceptible strains usually showed low viability and the five drug-resistant strains showed high viability in the Dubos liquid medium. The above four characteristics, colonial morphology, drug susceptibility, growth rate on Ogawa egg medium, and viability in Dubos liquid medium, usually correlated with each other.(ABSTRACT TRUNCATED AT 250 WORDS)

Antitubercular Agents↗
PubMed1983

Induction of human T-lymphocyte colonies by phorbol myristate acetate.

Colony growth of human lymphocytes by phorbol myristate acetate (PMA) was studied. PMA was able to induce lymphocyte colony growth in methylcellulose semi-solid cultures in the absence of lectin mitogens, phytohaemagglutinin or concanavalin A. PMA-induced colonies were found in cultures of mononuclear cells, monocyte-depleted mononuclear cells and the T-enriched cell fraction, whereas no colonies were obtained from the non-T cell fraction. At least one million mononuclear cells were required to form colonies by PMA. The colony cells were mainly T cells as judged from sheep red blood cell rosette formation. Surface immunoglobulin positive cells and peroxidase positive cells were not detected in colony cells. Non-specific esterase positive cells were only found to be less than 1% of colony cells. T cells formed more colonies than did mononuclear cells, presumably because of a concentration of colony forming cells and/or co-operating cells. Colony formation by PMA was induced from monocyte-depleted mononuclear cells and monocyte-depleted T cells, suggesting independence of monocytes. When mononuclear cells were precultured at 37 degrees for 5 min or 30 min with PMA and then cultured in the semi-solid medium without PMA, only a small number of colonies grew. Further studies of PMA-induced T-cell colonies will provide information the identification and characterization of immunological states in various immunological diseases.

Cells, Cultured↗
PubMed1982

Clonal origin of human erythro-eosinophilic colonies in culture.

We have observed the presence of erythropoietic bursts containing eosinophils and their precursors in methylcellulose culture of human peripheral blood and marrow nucleated cells in the presence of erythropoietin and medium conditioned by phytohemagglutinin-stimulated leukocytes (PHA-LCM). It was possible to identify these bursts (colonies) in situ in methylcellulose culture on the basis of their unique red and black colors. Transmission electron microscopy revealed that the constituent erythroid and eosinophilic cells lay intermixed with each other, and through close intercellular connections formed compact colonies and bursts consisting of several sub-colonies. Differential counts of individual erythro-eosinophil colonies (EEo colonies) revealed only a small percentage of blast cells in most of the colonies. Replating experiments of single EEo colonies yielded only eosinophilic colonies and clusters and erythroid colonies. The clonal nature of the EEo colonies was documented by analysis of Y-chromatin-positive cells in individual EEo colonies derived from cocultures of male and female peripheral blood mononuclear cells. Comparison of conditioned media indicated that PHA-LCM is the best stimulator for EEo colonies. These studies suggest that the differentiation capabilities of the progenitors for EEo colonies are restricted to erythroid and eosinophilic differentiation.

Adult↗