Effect of 4,6-Dinitro-o-sec-butylphenol on Phosphorus Accumulation and Incorporation in Tomato Leaf Disks

The accumulation and incorporation of externally applied P³² into ATP and the effect of 4,6-dinitro-o-sec-butylphenol (DNBP) on these processes was studied, using tomato (Lycopersicon esculentum Mill.) leaf disks.

P³² was, in most part, actively accumulated into leaf disks with time and was incorporated into ATP and other organic phosphates. DNBP inhibited both P³² accumulation and ATP generation. The amount of inhibition increased with time of incubation.

It is concluded that P³² accumulation is related to ATP generation. Even though DNBP greatly inhibits phosphorus accumulation, there is little or no effect on its retention.

DNBP has the ability to uncouple oxidative phosphorylation. Therefore, it is assumed that its inhibitory effect on phosphate accumulation and generation of high-energy phosphorus esters is related to its inhibition of oxidative phosphorylation.

A method is described which appears to be satisfactory to determine the relative amounts of ATP and ADP in leaf disks labeled with P³².

     

Forward and backward masking in motor systems

Masking in motor systems was defined as the omission of one act in a sequence due to an earlier or later act in the sequence. A study of phoneme omission in natural speech showed that:

1. 1.

   Masked phonemes were usually preceded or followed by an identical phoneme (referred to as the masking phoneme).

2. 2.

   Backward masking, where the masked phoneme preceded the masking phoneme was as frequent as forward masking.

3. 3.

   The phonemes immediately adjacent to the masked and masking phonemes were usually similar in distinctive features, but rarely identical.

4. 4.

   The masking phoneme usually occurred in a stressed syllable and the masked phoneme in an unstressed one, suggesting that motor intensity may be a factor in masking.

5. 5.

   The components for an adequate model of motor masking were shown to be similar to those in models of other types of errors in speech.

     

Absorption and translocation of sodium in beans and cotton

At the end of a 4 hour absorption period approximately 95% of the sodium absorbed by bean plants was retained in the secondary roots. The sodium translocated to the shoot was retained in the stem.

2,4-Dinitrophenol decreased the amount retained in the secondary roots of bean plants and increased the amount translocated to the shoot. The stem retained most of the translocated sodium.

Bean plants without roots absorbed considerably more sodium than plants with roots and translocated a greater proportion of the sodium to the petioles and blades. 2,4-Dinitrophenol reduced the amount of sodium in the stem and petioles and increased the amount in the blades.

2,4-Dinitrophenol reduced the amount of sodium retained by the secondary roots of cotton plants but did not appreciably affect the amounts translocated to the shoot.

     

Translocation of C in the sugarcane plant during the day and night

The time-course of translocation of ¹⁴C from the blades of the sugarcane plant was investigated by analysis and radioactive counting of successive samples punched from a single blade. In 1 experiment, the time-course was studied by determining the specific activity of the carbon dioxide respired by the roots.

The rate of translocation, expressed as percentage, was highest immediately after the application of the radioactive carbon dioxide. Morning-made photosynthate translocated a higher percentage during the morning than during the afternoon in 90-minute periods in the light. Afternoon-made photosynthate translocated as well or better than morning-made photosynthate for the first hour in the light.

The leaf-disk data and the specific activity of the carbon dioxide respired by the roots corresponded by showing lower rates of translocation by night than by day for several successive days. Also, the translocation of ¹²C sucrose was slower at night.

The ¹⁴C sucrose translocated by day was made primarily by photosynthesis; the sucrose translocated by night was made primarily by the conversion of other labeled compounds, e.g. organic acids, organic phosphates, and insoluble residue.

The radioactive constituent of the residue, which was converted to sucrose, was tentatively identified as a glucose-xylose-glucuronic acid hemicellulose, with most or all of the ¹⁴C in the glucose moiety.

Translocation of sucrose may be triggered by different mechanisms during the night than the day. The conversion of insoluble residue to sucrose by increasing the osmotic potential at the source would favor a pressure-flow mechanism for nocturnal translocation; whereas translocation by day is thought to be a process of phototranslocation, a photoactivation of the translocation mechanism.

     

Effects of high-temperature stress on various biomembranes of leaf cells in situ and in vitro

The sensitivity of photosynthetic and respiratory functions to supraoptimal temperature stress was compared after heating of leaves, protoplasts and membrane systems of spinach (Spinacia oleracea L. cv. Monatol) and lettuce (Valerianella locusta [L.] Betcke) in situ and in vitro.

After heating of whole leaves or protoplasts, endogenous respiration was not or only slightly affected at temperatures which caused a marked decrease of photosynthesis. This was manifested when mitochondria and thylakoids were isolated from heat-treated leaves. In the presence of exogenous substrates, mitochondrial electron transport and phosphorylation were even somewhat stimulated compared to the controls.

Inactivation of net CO₂ uptake of whole leaves following heat stress and of the photochemical activities of chloroplast membranes isolated from heat-treated leaves of the same origin occurred nearly simultaneously. In protoplasts, photosynthesis was inactivated at temperatures far below those which caused drastic changes in the integrity of the tonoplast and the plasmalemma. This indicates that damage occurring within the chloroplasts rather than alterations in the compartmentation of the cell is responsible for the high sensitivity of photosynthesis to supraoptimal temperature stress.

Mitochondria and thykaloids isolated from the same preparation of intact leaves under comparable conditions and subjected to heat treatment in vitro, however, were inactivated nearly in the same temperature range. Thus, mitochondria are much more stable within their cytoplasmic environment.

     

Effect of Moisture Supply upon Translocation and Storage of C in Sugarcane

Low moisture supply, controlled by 3 methods (adding NaCl to a complete nutrient solution, allowing a cut stalk to wilt, or withholding irrigation in the field), decreased the velocity and percentage rate of translocation of ¹⁴C-photosynthate. The surplus sucrose not used in growth moved more slowly in the phloem and was stored in the stalk.

Low moisture supply depressed translocation of ¹⁴C-photosynthate more severely than it curtailed formation of ¹⁴C-photosynthate in the same leaf: therefore, the effect of moisture supply upon translocation was primary.

Low moisture supply retarded profile development in the stem, and a loss in moisture gradient was associated with a steepened slope of the profile. These results indicate a flow mechanism of translocation rather than diffusion.

Results reported now and previously point to the operation of a slow pressure-flow mechanism particularly during the night but also during the day; superimposed upon this general mass transport is the more rapid process of phototranslocation which is independent of sugar gradients and which can cause the accumulation of sucrose at the storage-sink.

During ripening, storage of sucrose in the stalk may be increased by withholding water because less sucrose is hydrolyzed in transit, less is used in growth, and the slowly moving sucrose has more time for transfer from the phloem to the storage parenchyma.

     

Effect of oxygen on photosynthesis, photorespiration and respiration in detached leaves. I. Soybean

The effect of O₂ on the CO₂ exchange of detached soybean leaves was measured with a Clark oxygen electrode and infrared carbon dioxide analysers in both open and closed systems.

The rate of apparent photosynthesis was inhibited by O₂ while the steady rate of respiration after a few minutes in the dark was not affected. Part of the inhibition of apparent photosynthesis was shown to be a result of increased photorespiration. This stimulation of photorespiration by O₂ was manifested by an increase in the CO₂ compensation point.

The differential effects of O₂ on dark respiration (no effect) and photorespiration (stimulation) indicated that these were 2 different processes.

Moreover the extrapolation of the CO₂ compensation point to zero at zero O₂ indicated that dark respiration was suppressed in the light at least at zero O₂ concentration.

     

Prognostic values of VEGF and IL-8 in malignant pleural effusion in patients with lung cancer

Abstract

Objective: The aim of this study was to evaluate the prognostic value of VEGF and IL-8 in pleural effusion in patients with lung cancer.

Materials and method: Commercially available ELISA was used to determine VEGF and IL-8 levels.

Results: The level of VEGF showed significant correlations with lymph node metastasis and distant metastasis. But, IL-8 was only correlated with lymph node metastasis. Univariate and multivariate analysis revealed elevated VEGF level was an independent predictor of shorter OS and DFS.

Conclusion: VEGF could be an important component that contributes to pleural effusion formation, and an important prognostic factor for lung cancer.     

Molecular Identification and Antifungal Susceptibility of Clinical Isolates of Sporothrix schenckii Complex in Medellin,Colombia

Background

Sporotrichosis is a subcutaneous mycosis that affects humans and other animals. Infection prevails in tropical and subtropical countries. Until a few years ago, it was considered that two varieties of Sporothrix schenckii caused this mycosis, but by applying molecular taxonomic markers, it has been demonstrated that there are several cryptic species within S. schenckii complex which varies in susceptibility, virulence, and geographic distribution.

Objective

This study aimed to identify the clinical isolates of Sporothrix spp. from patients with sporotrichosis in Medellin, Colombia, using two markers and to evaluate the in vitro susceptibility to itraconazole.

Methods

Thirty-four clinical isolates of Sporothrix spp. from Colombia, three from Mexico, and one from Guatemala were identified through sequencing of the noncoding region ITS-1?+?5.8SDNAr?+?ITS-2 and of the fragment containing exons 3 and 4 of the β-tubulin gene. Clinical isolate sequences were compared with GenBank reference sequences using the BLASTN tool, and then, phylogenetic analysis was performed. Besides, the in vitro susceptibility to itraconazole was evaluated by determining the minimum inhibitory concentrations according to the CLSI M38-A2 method.

Results

Clinical isolates were identified by morphology as Sporothrix spp. Using the molecular markers, ITS and β-tubulin, isolates were identified as S. schenckii sensu stricto (25) and Sporothrix globosa (13). Susceptibility to itraconazole was variable among clinical isolates.

Conclusion

This is the first scientific publication that identifies species that cause sporotrichosis in Colombia, along with the antifungal susceptibility to itraconazole.

     

Biosynthesis of dolichyl phosphate: characterization and site of synthesis in algae

This is the first report not only on the presence of polyprenyl phosphates and their site of synthesis in algae, but also on the formation of their sugar derivatives in this system.

A glucose acceptor lipid was isolated from the nonphotosynthetic alga Prototheca zopfii. The lipid was acidic and resistant to mild acid and alkaline treatments. The glucosylated lipid was labile to mild acid hydrolysis and resistant to phenol treatment and catalytic hydrogenation, as dolichyl phosphate glucose is. These results are consistent with the properties of an α-saturated polyprenyl phosphate.

The polyprenylic nature of the lipid was confirmed by biosynthesis from radioactive mevalonate. The [¹⁴C]lipid had the same chromatographic properties as dolichyl phosphate in DEAE-cellulose and Sephadex LH-20. Strong alkaline treatment and enzymic hydrolysis liberated free alcohols with chain lengths ranging from C₉₀ to C₁₀₅, C₉₅ and C₁₀₀ being the most abundant molecular forms. The glucose acceptor activity of the biosynthesized polyprenyl phosphate was confirmed.

The ability of different subcellular fractions to synthesize dolichyl phosphate was studied. Mitochondria and the Golgi apparatus were the sites of dolichyl phosphate synthesis from mevalonate.

     

Ameliorating effects of troxerutin on nickel-induced oxidative stress in rats

Abstract

Objective

This study investigates the effects of troxerutin on nickel (Ni)-induced oxidative stress in rats.

Methods

Nickel as nickel sulfate (20 mg/kg body weight (b.w.)) was administered intraperitoneally for 20 days to induce toxicity in the subject rats. The levels of stress markers AST, ALT, ALP, LDH, and GGT in the hepatic tissue were significantly increased while a decrease in the levels of enzymic and non-enzymic antioxidants was observed in Ni intoxicated rats.

Results

Oral administration of troxerutin along with Ni for 20 days in a dose-dependent manner significantly reverted the stress markers in the liver tissue to near normal level. Troxerutin exhibited significant protection at 100 mg/kg b.w. Histopathological studies also supported the above findings.

Conclusions

Thus, we conclude that troxerutin preserved the histo-architecture and ameliorated stress markers in the liver tissue of Ni-intoxicated rats.     

Fermented soybean meal extract improves oxidative stress factors in the lung of inflammation/infection animal model

Context

Fermented soybean products have been used in various ways, and more research is being conducted on them to reveal their benefit.

Objective

The objective of this study was to evaluate the antioxidative activity of fermented soybean meal extract by Lactobacillus plantarum in vitro and in vivo tests.

Materials and methods

A Lactobacillus plantarum strain RM10 was selected through plate and fermentation experiment, which increased the degree of protein hydrolysis (1.015 μg/mL) and antioxidant activity in soybean meal fermented by selected bacteria (FSBM). In vivo study was done on septic rats as an inflammation/infection model, and then the trial groups were treated with different concentrations of fermented soybean meal extracts (FSBM, 5, 10, and 20%).

Results

DPPH radical-scavenging and ferrozine ion-chelating activity enhanced (P < 0.05) after fermentation of soybean meal compared to control group. Reduced (P < 0.05) expression of inflammatory genes and enzymes was detected in the lungs of rats treated with fermented soybean meal extract.

Discussion and conclusions

These results demonstrated that a diet containing fermented soybean meal extract improved extreme inflammatory response in an infectious disease like sepsis by reducing inflammatory factors.

     

Glycaemic and insulinemic response to dietary carbohydrates in horses

Background

Dietary sugar and starch affect plasma glucose and insulin concentrations. Little information is available about the effect of dietary fibre on plasma glucose and insulin concentration. It is hypothesized that different dietary fibre compositions will alter post-prandial glycaemic- and insulinemic index of test meals. The objective was to measure postprandial glucose and insulin concentrations in horses fed meals of different fibre compositions.

Methods

Blood was drawn via jugular vein puncture and the glycaemic and insulinemic index were calculated.

Results

The meal effect on glycaemic and insulinemic response followed the expected pattern, where plasma concentrations increased after feeding and declined after peak concentration. Glycaemic index was 100 (H), 102 (OB), 102 (BB) and 106 (M) and did not differ significantly between meals. Insulinemic index was 100 (H), 140 (OB), 121 (BB) and 125 (M) and did not differ significantly between meals.

Conclusions

In conclusion, meals containing different fibre compositions did not affect the glycaemic- and insulinemic index in horses.

     

Seasonal Changes in the Distribution of Photo-assimilated C in Young Pine Plants

Pinus strobus L. plants in their third year of growth were permitted to photoassimilate ¹⁴CO₂ for about 1 hour at monthly intervals between April and October, and the subsequent distribution of ¹⁴C in these plants was determined 8 hours, 1 month, 2 months or 4 months after photo-assimilation. In this way, the fate of ¹⁴CO₂ photo-assimilated during different months of the growing season was observed.

In the spring, old needles played a significant role in photo-assimilating ¹⁴CO₂ and exporting current photosynthate to the developing new shoots and roots. By July, the new shoot had replaced the old shoot both as the primary photo-assimilating part of the plant and as an exporter, particularly to the root.

The root received current photosynthate from the shoot throughout the entire growing season, although plant analysis only 8 hours after photo-assimilation did not always reveal this. Translocation of recent photosynthate from shoot to root was particularly high in August, September, and October.

The amounts of photo-assimilated ¹⁴C lost from the plants over a 4 month interval, principally through respiration and photorespiration, were about one-half of that absorbed during photo-assimilation, with the greatest loss occurring within the first month.

     

Translocation in colored light

The translocation of ¹⁴C-photosynthate in detached blades of sugarcane was studied under illumination from red, green, blue, and cool-white fluorescent lamps; under far-red illumination from the sun, and from incandescent lamps; and in total darkness.

The percentage of basipetal translocation and the accumulation against the concentration gradient were stimulated by light from the red or blue lamps more than by green or cool-white fluorescent illumination.

Basipetal translocation took place equally well in red light lacking blue irradiation and in blue light. Since the action spectrum for light-induced change in viscosity is a typical blue-type spectrum, the effect of light upon translocation is not due merely to changes in the physicochemical properties of protoplasm.

Basipetal translocation took place in red light lacking blue irradiation better than in cool-white fluorescent light, which may suggest a red stimulation of translocation.

Illumination in the far-red region of the spectrum did not support basipetal translocation but acted like total darkness.

Because of the wide emission characteristics of the fluorescent lamps employed, it is impossible to decide whether a chlorophyll-like system or some other pigment is involved in the light stimulation of phototranslocation.

Whatever the activating wavelength and whatever the pigment system involved, these results show that the phototranslocation of sucrose in the phloem is influenced by the quality of illumination.

     

Transient production of receptor-binding domain of SARS-CoV-2 in Nicotiana benthamiana plants induces specific antibodies in immunized mice

Background

The COVID-19 pandemic caused by the SARS-CoV-2 coronavirus has currently affected millions of people around the world. To combat the rapid spread of COVID-19 there is an urgent need to implement technological platforms for the production of vaccines, drugs and diagnostic systems by the scientific community and pharmaceutical companies. The SARS-CoV-2 virus enters the cells by the interaction between the receptor-binding domain (RBD) present in the viral surface spike protein and its human receptor ACE2. The RBD protein is therefore considered as the target for potential subunit-based vaccines.

Methods and results

We evaluate the use of Nicotiana benthamiana plants as the host to transiently-producing recombinant RBD (RBDr) protein. The identity of the plant-produced RBDr was confirmed by immune assays and mass spectrometry. Immunogenicity was confirmed through the specific antibodies generated in all of the immunized mice compared to the PBS treated group.

Conclusions

In conclusions, the immunogenicity of the RBDr produced in N. benthamiana was confirmed. These findings support the use of plants as an antigen expression system for the rapid development of vaccine candidates.

     

Biomass and nutritive value of Spirulina (Arthrospira fusiformis) cultivated in a cost-effective medium

Introduction

Cultivation of spirulina at commercial-scales relies on analytical grade–based media, which are expensive and so are the product.

Purpose

This study assessed the biomass, proximate composition, and other useful compounds in Spirulina (Arthrospira fusiformis) produced with a cost-effective culture medium (LCMA), and the results were compared with those from a standard Zarrouk medium–grown spirulina.

Methods

The LCMA medium was formulated by using a commercial NPK10-20-20 fertilizer as a source of the three major nutrients for spirulina growth, and other three ingredients from Zarrouk medium. The experiment was conducted for 28 days in the glass aquaria under indoor conditions. Standard analytical methods were applied for the determination of proximate composition, chlorophyll, minerals, and vitamins in the spirulina biomass.

Result

The LCMA medium showed the best growth conditions by accumulating higher chlorophyll content (0.99 ± 0.02%) and dry weight (0.75 ± 0.01 g/100 ml) as well as attaining higher optical density (2.06 at day 15) earlier than the Zarrouk medium. The results of the proximate analysis for spirulina cultured in the LCMA medium were of good quality, with the protein contributing more than 50% of its dry matter. It was further noticed that the LCMA was an ideal medium for optimization of vitamins and some minerals since it recorded a significant amount of most of the analyzed vitamins together with the minerals sodium and potassium compared with the Zarrouk medium.

Conclusion

It is suggested that LCMA medium could be used as the alternative and cheap medium for maximization of biomass and production of useful biochemical compounds in spirulina species.