The effect of rifampicin on the developmental phases of germinating spores of Clostridum sp., MSp+

1977 ◽  
Vol 23 (12) ◽  
pp. 1706-1713 ◽  
Author(s):  
R. Z. Hawirko ◽  
P. K. Bhatnagar ◽  
K. L. Chung ◽  
C. T. Chow
Keyword(s):  
Clostridium Botulinum ◽  
Normal Cell ◽  
Daughter Cell ◽  
Total Protein Content ◽  
Chemical Analyses ◽  
Ultrastructural Studies ◽  
Rna And Protein Synthesis ◽  
Time Periods ◽  
Developmental Phases ◽  
Sublethal Concentrations

The effect of rifampicin on the developmental phases of germinating spores of Clostridium botulinum, MSp+, has been studied. At sublethal concentrations of rifampicin (0.05 ng/ml) the time periods required for outgrowth and vegetative growth was significantly prolonged because of the inhibition of RNA and protein synthesis. However, rifampicin had essentially no effect on DN A synthesis or on subsequent spore formation. Chemical analyses showed that the amount of protein present in vegetative cells of the rifampicin-treated cultures was twice as great as in the untreated cultures but the total protein content of endospores was the same in both cases. It was revealed in ultrastructural studies of rifampicin (0.1 ng/ml) treated cultures, examined after 22 h, that septum formation and normal cell division of the emerging cell was blocked and a few cells showed constriction which produced one normal and one protoplast-like daughter cell.

scholarly journals Effect of Selenate on Viability and Selenomethionine Accumulation ofChlorella sorokinianaGrown in Batch Culture

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Živan Gojkovic ◽  
Carlos Vílchez ◽  
Rafael Torronteras ◽  
Javier Vigara ◽  
Veronica Gómez-Jacinto ◽  
...  
Keyword(s):  
Large Subunit ◽  
Cell Activity ◽  
Protein Band ◽  
Chlorella Sorokiniana ◽  
Chloroplast Gene ◽  
Batch Cultures ◽  
Ultrastructural Studies ◽  
Sds Page ◽  
Sublethal Concentrations ◽  
Page Electrophoresis

The aim of this work was to study the effect of Se(+VI) on viability, cell morphology, and selenomethionine accumulation of the green algaChlorella sorokinianagrown in batch cultures. Culture exposed to sublethal Se concentrations of 40 mg·L−1(212 μM) decreased growth rates for about 25% compared to control. A selenate EC50value of 45 mg·L−1(238.2 μM) was determined. Results showed that chlorophyll and carotenoids contents were not affected by Se exposure, while oxygen evolution decreased by half. Ultrastructural studies revealed granular stroma, fingerprint-like appearance of thylakoids which did not compromise cell activity. Unlike control cultures, SDS PAGE electrophoresis of crude extracts from selenate-exposed cell cultures revealed appearance of a protein band identified as 53 kDa Rubisco large subunit ofChlorella sorokiniana, suggesting that selenate affects expression of the corresponding chloroplast gene as this subunit is encoded in the chloroplast DNA. Results revealed that the microalga was able to accumulate up to 140 mg·kg−1of SeMet in 120 h of cultivation. This paper shows thatChlorella sorokinianabiomass can be enriched in the high value aminoacid SeMet in batch cultures, while keeping photochemical viability and carbon dioxide fixation activity intact, if exposed to suitable sublethal concentrations of Se.

scholarly journals Seasonal effects of heavy metals on the date mussel Lithophaga lithophaga (Mollusca:Bivalvia) at Eastern harbor, Alexandria, Egypt

2020 ◽  
Vol 1 (1) ◽  
pp. 62-77
Author(s):  
Shahenaz M. Abd-Ellah ◽  
◽  
Soheir El-Sherif ◽  
Rehab El-Morshedy ◽  
◽  
...  
Keyword(s):  
Heavy Metals ◽  
Protein Content ◽  
Digestive Gland ◽  
Total Protein ◽  
Soft Tissues ◽  
Food Sources ◽  
Total Protein Content ◽  
Ultrastructural Studies ◽  
Different Tissues ◽  
Lithophaga Lithophaga

The edible mussel Lithophaga lithophaga is considered as one of the most important human food sources in Alexandria, Mediterranean Sea. The present study is designed to determine the seasonal bioaccumulation levels of Cd, Co and Pb in the whole soft tissues as well as different tissues of Lithophaga lithophaga. Results revealed that the seasonal bioaccumulation levels of Cd, Co and Pb in date mussel were below the permissible limits or other reported values from other regions of the Mediterranean. On the other hand, the order of metals accumulation level in different tissues was as follows: digestive gland>remaining soft tissues>gonads. The present study confirmed the role of digestive gland as a concentration center for heavy metals. Moreover, total protein content and stress protein responses of the whole soft tissues were evaluated. The total protein content was arranged in the following order: summer>autumn>spring>winter. Five novel stress proteins appeared in summer. The histological and ultrastructural studies of the digestive gland of Lithophaga lithophaga collected in summer and spring showed marked histopathological alternations.

Response of the rat erythrocyte to ozone exposure

1978 ◽  
Vol 45 (6) ◽  
pp. 893-898 ◽  
Author(s):  
E. C. Larkin ◽  
S. L. Kimzey ◽  
K. Siler
Keyword(s):  
Superoxide Dismutase ◽  
Glutathione Peroxidase ◽  
Ozone Exposure ◽  
Sprague Dawley ◽  
Ultrastructural Studies ◽  
Sprague Dawley Rats ◽  
Rubidium Influx ◽  
Potassium Influx ◽  
Time Periods ◽  
Differential Counts

Sprague-Dawley rats were exposed to high (6--8 ppm) and moderate (1.5 ppm) amounts of ozone (O3) for various time periods. Response of the rat erythrocyte to ozone was monitored with red blood cell potassium (rubidium) influx studies, with storage stress combined with ultrastructural studies and with levels of erythrocyte glutathione peroxidase and superoxide dismutase. Erythrocytes of rats exposed to O3 showed no significant changes either in their potassium influx or in their glutathione peroxidase and superoxide dismutase activities compared to controls. Erythrocyte differential counts on O3-exposed animals showed significant changes initially as well as following storage stress compared to controls. Rats exposed to 8 ppm O3 for 4 h showed a marked increase in echinocytes. These consistent transformations from discocytes to echinocytes following O3 exposure suggest latent erythrocyte damage has occurred.

Estimation of protein, chemical fat and energy content in pigs

1962 ◽  
Vol 4 (3) ◽  
pp. 391-398 ◽  
Author(s):  
Zofia Osińska
Keyword(s):  
Body Weight ◽  
Total Protein ◽  
Energy Content ◽  
Live Weight ◽  
Total Protein Content ◽  
Carcass Quality ◽  
Chemical Analyses ◽  
Large White ◽  
Body Components ◽  
Edible Parts

Complete chemical analyses of all body components of 20 Large White pigs were carried out. At the average live-weight of 90·3 kg. (empty body weight 86·5 kg.) the total protein content was found to be 12·7 kg. and that of the chemical fat 25·4 kg. The edible parts of the carcass (i.e. lean and separable fat) contained only 58·5% (range 55·2–61·3) of the total protein but as much as 85% of the total chemical fat. Simple and multiple correlations were computed between various carcass characters and protein, chemical fat and energy content. The results indicate that it may be possible to obtain fairly accurate estimates of the chemical composition and energy content of the edible parts of the carcass, of the whole carcass, and of the empty body by methods based on various systems of assessing the carcass quality.

Influence of a Minimal Change in pH on Germination of Clostridium botulinum 52A in Media Containing Sodium Acid Pyrophosphate and Potassium Sorbate

1985 ◽  
Vol 48 (8) ◽  
pp. 693-696 ◽  
Author(s):  
M. K. WAGNER ◽  
F. F. BUSTA
Keyword(s):  
Clostridium Botulinum ◽  
Normal Cell ◽  
Phase Contrast ◽  
Minimal Change ◽  
Potassium Sorbate ◽  
Phase Contrast Microscopy ◽  
Contrast Microscopy ◽  
Sodium Acid Pyrophosphate ◽  
Scanning Electron ◽  
Treatment Culture

The influence of 0.4% sodium acid pyrophosphate (SAPP) or 0.26% potassium sorbate (PS) on Clostridium botulinum 52A growth and toxicity from spores was studied at two pH levels 5.55 and 5.85. Absorbancy measurements at 630 nm were used in combination with microscopic evaluations and toxin analysis to compare effects of additives on normal cell development. Treatment cultures containing 0.4% SAPP and 0.26% PS at a higher pH of 5.85 showed no increase in absorbancy and no sign of toxicity, but elongated vegetative cells (≥9 μm) were observed using phase contrast microscopy rather than scanning electron microscopy. The SAPP–PS treatment culture at a lower pH of 5.55 displayed no signs of growth spectrophometrically or microscopically, as well as no toxicity. These data suggest that a SAPP–PS combination in a laboratory medium at pH 5.85 does not halt germination and outgrowth, yet may prevent cell division; whereas, the same treatment at pH 5.55 inhibits normal spore germination.

Effect of chemical element deficiencies in nutrient solutions on the reproduction of Aceria sheldoni (Ewing)(Acarina, Eriophyidae)

1975 ◽  
Vol 65 (3) ◽  
pp. 433-442 ◽  
Author(s):  
M. Sternlicht ◽  
S. Regev ◽  
S. Goldenberg
Keyword(s):  
Nitrogen Content ◽  
Chemical Element ◽  
Free Solution ◽  
Chemical Analyses ◽  
High Nitrogen ◽  
Mite Reproduction ◽  
Standard Solution ◽  
Time Periods ◽  
The Relationship ◽  
Nutrient Solutions

AbstractPomello and lemon seedlings kept for different time periods in various nutrient solutions were examined for their degree of infestation with Aceria sheldoni (Ewing), the citrus bud mite. Chemical analyses indicated that seedling leaves and buds had a higher nitrogen content in a potassium-free solution, and a lower nitrogen content in a nitrogen-free solution, when compared with their respective contents in a standard solution; in buds these differences were also shown by certain amino acids. Infested seedlings kept in a potassium-free solution had significantly more mites than those kept in a nitrogen-free solution, and the latter had significantly fewer mites than those kept in a standard solution. No increase in mite populations was noted on seedlings kept in high-nitrogen solutions. The relationship between the levels of potassium, nitrogen, magnesium and manganese and the mite population is discussed. No effect on mite reproduction was noted when sodium or calcium was used as a substitute for potassium.

scholarly journals Osteogenic differentiation of hypertrophic chondrocytes involves asymmetric cell divisions and apoptosis.

1995 ◽  
Vol 131 (2) ◽  
pp. 483-494 ◽  
Author(s):  
H I Roach ◽  
J Erenpreisa ◽  
T Aigner
Keyword(s):  
Osteogenic Differentiation ◽  
Daughter Cell ◽  
Type I Collagen ◽  
Asymmetric Cell Division ◽  
The Other ◽  
Hypertrophic Chondrocytes ◽  
Lineage Commitment ◽  
Type I ◽  
Dna Breaks ◽  
Ultrastructural Studies

We have investigated the early cellular events that take place during the change in lineage commitment from hypertrophic chondrocytes to osteoblast-like cells. We have induced this osteogenic differentiation by cutting through the hypertrophic cartilage of embryonic chick femurs and culturing the explants. Immunocytochemical characterization, [3H]thymidine pulse-chase labeling, in situ nick translation or end labeling of DNA breaks were combined with ultrastructural studies to characterize the changing pattern of differentiation. The first responses to the cutting, seen after 2 d, were upregulation of alkaline phosphatase activity, synthesis of type I collagen and single-stranded DNA breaks, probably indicating a metastable state. Associated with the change from chondrogenic to osteogenic commitment was an asymmetric cell division with diverging fates of the two daughter cells, where one daughter cell remained viable and the other one died. The available evidence suggests that the viable daughter cell then divided and generated osteogenic cells, while the other daughter cell died by apoptosis. The results suggest a new concept of how changes in lineage commitment of differentiated cells may occur. The concepts also reconcile previously opposing views of the fate of the hypertrophic chondrocyte.

scholarly journals Remodeling of the rat distal colon in diabetes: function and ultrastructure

2016 ◽  
Vol 310 (2) ◽  
pp. C151-C160 ◽  
Author(s):  
Marion J. Siegman ◽  
Masumi Eto ◽  
Thomas M. Butler
Keyword(s):  
Collagen Type ◽  
Force Production ◽  
Distal Colon ◽  
Total Protein Content ◽  
Active Force ◽  
Cross Sectional ◽  
Active Length ◽  
Ultrastructural Studies ◽  
Collagen Type 1

This study seeks to define and explain remodeling of the distal colon in the streptozotocin (STZ)-treated rat model of diabetes through analysis of resting and active length dependence of force production, chemical composition, and ultrastructure. Compared with untreated controls, the passive stiffness on extension of the diabetic muscle is high, and active force produced at short muscle lengths is amplified but is limited by an internal resistance to shortening. The latter are accounted for by a significant increase in collagen type 1, with no changes in types 3 and 4. In the diabetic colon, ultrastructural studies show unique, conspicuous pockets of collagen among muscle cells, in addition to a thickened basement membrane and an extracellular space filled with collagen fibers and various fibrils. Measurements of DNA and total protein content revealed that the diabetic colon underwent hypertrophy, along with a proportional increase in actin and myosin contents, with no change in the actin-to-myosin ratio. Active force production per cross-sectional area was not different in the diabetic and normal muscles, consistent with the proportionality of changes in contractile proteins. The stiffness and the limit to shortening of the diabetic colon were significantly reduced by treatment with the glycation breaker alagebrium chloride (ALT-711), with no change in collagen contents. Functionally, this study shows that, in diabetes, the production of collagen type 1 and glycation increase stiffness, which limits distensibility on filling and limits shortening and expulsion of contents, both of which can be alleviated by treatment with ALT-711.

Ultrastructure of Cercarial Tails

1974 ◽  
Vol 32 ◽  
pp. 180-181
Author(s):  
Richard S. Demaree ◽  
Donald M. Wootton
Keyword(s):  
Schistosoma Japonicum ◽  
Intermediate Hosts ◽  
Suitable Host ◽  
Ultrastructural Studies ◽  
Tail Structure

Cercariae (juvenile trematodes with tails) emerge from mollusk intermediate hosts and swim toward definitive hosts or encystment objects. The locomotor power is furnished by the tail. Upon reaching a suitable host or encystment object, the tail is cast off and the cercariae penetrate and/or encyst. Ultrastructural studies of cercariae are sparse. There is even lessUltrastructural studies of cercariae are sparse. There is even less information about the tail structure; and body-to-tail morphology has been documented only for Acanthatrium oregonense and Schistosoma japonicum.

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