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At least 19 recordsLinked to original sources
PubMed1977

Total body water and the exchangeable hydrogen. II. A review of comparative data from animals based on isotope dilution and desiccation, with a report of new data from the rat.

Total body water (TBW) determination by tritium space could be factitiously elevated by exchangeable H+ contained within water-soluble chemical configurations. Should this nonaqueous (molecular) exchangeable H+ turn out to be a large fraction of total exchangeable H+, TBW measurement by tritiated water (THO) dilution would display a systematic upward and non-random error. TBW was measured by THO dilution and subsequently by total body desiccation in 21 rats (weight 227+/-83 g, mean+/-SD). TBW was 71.38+/-2.4% by THO dilution and 70.20+/-1.5% by body desiccation. Analysis of variance of TBW vs. body weight showed a highly significant correlation both with desiccation (P less than 0.0005, r=-0.78) and dilution (P less than 0.03, r= -0.50). Convariance analysis of both methods showed no difference in slope (P greater than 0.9). There was a difference in variance (P less than 0.001) and means (P less than 0.03). Tritium space is 1.2% of body weight larger than TBW measured by desiccation. TBW measured by THO dilution gives a 1.71% overestimation of TBW as measured by desiccation. TBW measurement by THO dilution is accurate within less than 2% error. These findings have particular significance in the light of our theoretical model of the total nonaqueous exchangeable H+ in fat, protein, and carbodhydrate in the living vertebrate.

Animals↗
PubMed1978

Free proline content and sensitivity to desiccation and heat during yeast sporulation and spore germination.

Ascospores of a strain of Saccharomyces cerevisiae Hansen were less sensitive to desiccation and heat than vegetative cells. Desiccation resistance was acquired earlier during sporulation and lost later during spore germination than heat resistance. As spores matured, resistance to both stresses increased. With the exception of the first few hours in sporulation medium, when proline appeared to be utilized, the intracellular free proline content increased during sporulation and decreased during spore germination. Not all the proline lost could be detected in the germination medium, indicating that some was metabolically utilized by the germinating spores. Since exogenous proline supplied to vegetative or sporulating cells before desiccation increased their survival, it is suggested that the high level of free proline in mature spores may protect against desiccation stress.

Amino Acids↗
PubMed1977

Triiodothyronine and thyroxine content of desiccated thyroid tablets.

Triiodothyronine (T3) and thyroxine (T4) were measured by radioimmunoassay in Pronase hydrolysates of four lots each of 1- and 2-grain tablets of desiccated thyroid (Thyroid, Armour) and thyroglobulin (Proloid, Warner-Chilcott). The methodology used was verified by studies of tablets containing known quantities of T4 and T3. One grain of desiccated thyroid contained 12 +/- 1 and 64 +/- 3 microgram (mean +/- SD) of T3 and T4 per tablet, respectively (T4/T3 molar ratio, 4.3). A 1-grain tablet of thyroglobulin contained 16 +/- 2 and 55 +/- 5 microgram of T3 and T4, respectively with a T4/T3 ratio of 2.9. Two-grain tablets generally contained twice the quantity of T3 and T4 in the 1-grain preparations. The variation in T3 and T4 content between the four lots of each tablet strength for each product was 10% or less. These estimates of T3 and T4 content are 1.5- to 2-fold greater than those previously published. This difference probably results from the more sophisticated methodology now available which does not require chromatographic separation of T3 and T4 or iodometry. Using calculations based on published estimates of T4 and T3 absorption and of the T3/T4 potency ratio, it would appear that the T3 content of desiccated thyroid and thyroglobulin provide approximately 39% and 51%, respectively, of the thyromimetic activity of these two medications.

Chemistry, Pharmaceutical↗
PubMed2025

Phosphoproteomics analysis provides novel insight into the mechanisms of extreme desiccation tolerance of the desert moss Syntrichia caninervis.

Syntrichia caninervis is a model species for research on desiccation tolerance (DT) because it is capable of rapidly responding to drastic changes in water conditions. Phosphorylation, a key post-translational modification process that is rapid and reversible, enables the rapid regulation of protein functions, aiding plants to quickly adapt to changing environments. Modifications to phosphorylation may play a crucial role in the DT of S. caninervis, although no studies have been published. Here, we report a 4D label-free high-resolution dynamic proteomic and phosphoproteomic analysis of S. caninervis during dehydration and rehydration, allowing for the quantification of 2854 proteins and 1177 phosphoproteins, including 1447 differentially expressed proteins (DEPs) and 699 differentially phosphorylated proteins (DPPs). Among the phosphoproteins, 36.5% displayed changes in protein abundance. The proteomic and phosphoproteomic changes involved proteins (DEPs and DPPs) that were mainly involved in photosynthesis, glutathione metabolism, the citrate cycle, and the biosynthesis of secondary metabolism pathways during dehydration. During rehydration, DEPs and DPPs were mainly associated with processes related to ribosome and energy metabolism. In summary, during dehydration, phosphorylation mainly regulates signal transduction and metabolic processes, allowing plants to adapt to a loss of water. During rehydration, phosphorylation controls repair and recovery mechanisms, restoring metabolic activity and reestablishing cellular functions. ScDHAR1, a protein involved in glutathione metabolism, was differentially phosphorylated at two serine sites (S29 and S218) in response to desiccation. Further analysis revealed that phosphorylation of S29/S218 in ScDHAR1 significantly increased its enzymatic activity, thereby enhancing the DT of S. caninervis in situ. This work establishes a phosphoprotein database for a DT moss. These findings not only broaden our understanding of S. caninervis DT but also fill knowledge gaps in the field of phosphoproteomics in DT mosses, while providing valuable data resources for future related research.

Phosphoproteins↗
PubMed2026

Radiation-resistant and desiccation-tolerant bacteria from the Chavara-Neendakara high background radiation area, india: phenotypic characterisation and genomic insights.

Radiation-resistant microorganisms that survive high doses of ionising radiation serve as valuable models for understanding stress adaptation; however, the genomic determinants underlying extreme radiation tolerance in bacteria from natural environments with high background radiation remain insufficiently characterised. Bacterial isolates from the Chavara-Neendakara HBRA (Kerala, India) were evaluated for desiccation tolerance, and the desiccation-resistant isolates were subsequently exposed to gamma irradiation (1-10 kGy) using a 60Co source. Isolates were identified through 16S rRNA sequencing, morphologically characterised by FE-SEM, and screened for antibiotic susceptibility. The highly radiation-resistant strain underwent whole-genome sequencing via Oxford Nanopore Technology, with De novo assembly, polishing, and genome annotation. Four bacterial isolates (Micrococcaceae and Paenibacillaceae) exhibited D10 values of 1-7 kGy, including one multidrug-resistant strain; no endospores were observed in the Paenibacillus isolate under the tested conditions. Paenibacillus sp. HBRA004 survived 10 kGy gamma radiation, exceeding all previously reported HBRA isolates by over fourfold. Its 5.0 Mbp genome (GC = 48.27%, ≥ 99% completeness) encodes five mechanistically independent DNA repair pathways; homologous recombination (recA, recN, radA), base excision repair (mutM, mutY, mutT), mismatch repair (mutL, mutS), nucleotide excision repair (uvrA, uvrB, uvrD), and non-homologous end joining (ku, ligD), alongside a redundant antioxidant network comprising triple-copy Fe/Mn-family superoxide dismutases and ahpC peroxiredoxin. A thioredoxin system (trxA, trxB, msrA) and manganese uptake via mntH may contribute to further layers of ROS defence. Their specific contribution to the HBRA004 phenotype remains to be experimentally and comparatively validated. These findings represent the first genomically characterised 10 kGy-resistant bacterial isolate from the Chavara-Neendakara HBRA, establishing a new benchmark for radiation tolerance within this ecologically significant environment. Pathway depth, gene copy amplification, and Mn/Fe homeostasis appear to be candidate mechanisms contributing to high-level radiation tolerance, consistent with patterns in other radiation-resistant taxa, though their contribution requires functional validation.

India↗
PubMedDate not supplied

Ecology of Zygnema stellinum Vauch. during desiccation of a shallow body of water.

the effect of desiccation on the green alga Zygnema, a typical aquatic form of the order Conjugatae, family Zygnemaceae, is investigated. The vegetative reproduction of Zygnema occurs with the separation of the filaments in two different ways. It is shown that changes take place in cell morphology during desiccation. After division most of the cells acquire the shape of a square. These are usually half as large as the vegetative cells prior to division. Also, the form and color of the chromatophores change; they become green-brown, i.e., Zygnema falls into a state of rest, since no cell division is observed. During this state of rest the filaments suffer the unfavorable conditions of summer drought. In the fall, at the end of August, with the shortening of the day and reduction of temperature, the alga develops parthenospores for overwintering.

Chlorophyta↗
PubMed2026

Dual Roles of RAD23b and RAD4 on the Desiccation Tolerance of Germinated Seeds.

Desiccation tolerance (DT) is a survival trait enabling orthodox seeds to withstand extremely low water content. While some protective factors are characterised, it remains mechanistically obscure. Here, based on PEG-induced DT re-establishment in germinated Brassica napus L. seeds, we investigated the dual functions of nucleotide excision repair (NER) components RAD23b and RAD4 in DNA repair and transcriptional regulation of root development. PEG pre-treatment alleviated dehydration-induced DNA damage and activated NER genes, suggesting the involvement of NER in seed DT. Unexpectedly, Arabidopsis atrad23b mutant and BnRAD23b/BnRAD4 over-expressing seeds all exhibited significantly decreased DT after dry back, which evoked a hypothesis that BnRAD23b-BnRAD4 functions beyond NER. Normally, BnRAD4 interacted with BnRAD23b and repressed the expression of root development genes NAC103, EMB1444, RRA1 by directly binding to STRE elements within their promoters. Dehydration stress alleviated this repression, drove transcriptional reprogramming and might redirect the complex to execute DNA repair. Genetic analyses revealed that germinated seeds of atnac103, atemb1444, and atrra1 single mutants all exhibited reduced DT, and double mutants under atrad23b background almost abolished DT. This study suggests that RAD23b and RAD4 may regulate DT re-establishment of germinated seeds through balancing genome integrity and radicle development, with implications for DT study broadly.

Brassica napus L.↗
PubMed1978

Modified culture technique for Corynebacterium diphtheriae isolation from desiccated swabs.

Corynebacterium diphtheriae was isolated from pyoderma and ulcerative skin lesions with a modified delayed culture procedure as late as 9 weeks after field collection of silica gel-desiccated swabs. Biotypes gravis and mitis were identified. Most isolates were nontoxigenic. Todd-Hewitt broth enrichment enhanced recovery of C. diphtheriae by 70%.

Bacteriological Techniques↗
PubMed1977

Immune reactions following desiccation surgery of the canine prostate. An initial report.

Desiccation surgery of the canine prostate induces a chronic inflammatory cell infiltrate that persists at the site for more than 1 year. Specific autoantibody was demonstrated by direct immunofluorescence with prostatic tissue only. The mononuclear cell infiltrate occurring in large focal aggregates within 2 months after surgery was similar to the lesions seen in certain chronic inflammatory diseases. Precipitating antibody was not demonstrable by agar double diffusion techniques. The possible therapeutic effect of the induction of such a lesion in cancerous prostatic tissue is discussed.

Animals↗
PubMed1978

Why does anyone still use desiccated thyroid USP?

The effect on thyroid status of changing from thyroid USP to sodium L-thyroxine was evaluated in 40 patients. With thyroid, abnormally high triiodothyronine (T3) levels were seen in 36 of 38 patients receiving doses of 90 to 240 mg; compared to sodium L-thyroxine, 0.15 to 0.2 mg, the serum T3 was higher (289 +/- 15 ng/dl versus 176 +/- 9 ng/dl, p less than 0.0005) and the thyroxine (T4) lower (7.4 +/- 0.3 microgram/dl versus 11.6 +/- 0.5 microgram/dl, P less than 0.01). Thyrotoxic symptoms occurred in six patients and diminished or disappeared after the change to sodium L-thyroxine, suggesting that the raised T3 level with thyroid may have undesirable effects in some patients. The T4 level, because it is low whether symptoms are present or not, may inadvertently suggest the need for higher dosage of desiccated thyroid in patients who have already received adequate replacement. The dose of sodium L-thyroxine was adequately assessed by measurement of both T4 and T3 levels. Thyroid USP should be discontinued as thyroid medication since it produces thyroid hormone levels that are misleading estimates of thyroid function and can cause thyrotoxic symptoms.

Humans↗
PubMed1976

Selective resistance to desiccation of nuclear ribonucleic acid synthesis in isolated nuclei of Artemia salina embryos during pre-emergence development.

The developing gastrula embryos of Artemia salina are resistant to a complete redesiccation during a period of pre-emergence development. Isolated nuclei from these dehydrated embryos could retain a transcriptional activity in vitro comparable with that of non-desiccated controls. On the other hand, redesiccation of both prenauplii and nauplii completely destroys their viability as well as the nuclear transcriptional activity. However, those gastrula embryos that did not develop in a first incubation period could remain viable and develop with a considerable time-lag after a subsequent second incubation.

Animals↗
PubMedDate not supplied

[Isolated water in desiccated microorganisms].

The presence of isolated mobile water in dehydrated eukaryotic microorganisms established earlier by NMR has been confirmed by direct chemical registration of this water in the yeast Cryptococcus albidus. This water constitutes several per cent of the dry biomass weight. Apparently, its preservation should be attributed to changes in the permeability of intracellular membranes upon dehydration. The water is released by the cells when they are heated to 150--200 degrees C and the cellular structures containing water are destroyed.

Adsorption↗