Studies of temperature stress in cultured pear cells

1984 Summer.Covers not scanned.Includes bibliographical references.Studies were undertaken to examine the heat stress and freezing stress responses of cultured plant cells. Suspension- cultured pear (Pyrus communis cv. Bartlett} cells were used as the experimental materials. The response of pear cells to heat stress was studied using three viability tests: regrowth (culture growth during 10 days after stress); triphenyltetrazolium chloride reduction; and electrolyte leakage. Critical temperatures (those causing 50% injury} for a 20 minute exposure were 42°, 52°, and 56°C , respectively, for these viability tests. The measurements of direct response, i. e., TTC reduction and electrolyte leakage, were not adequate substitutes for regrowth tests in assessing heat injury to cultured plant cells. The pipetting of pear suspension cultures was followed by a substantial but transient decrease in heat sensitivity. During a culture cycle, pear cells were most sensitive to heat at around day three. The influence of these normal culture variables (handling and age) are potentially serious artefacts and must be well characterized in order to minimize systematic errors in measuring heat tolerance. Beyond this, they may provide clues concerning physiological factors governing the responses of cells to heat. Both elevated growth temperature and brief heat shock increased the heat tolerance of pear cells. Several features of heat acclimation induced by these two methods were compared. Based on these comparisons, it was concluded that heat acclimation in response to growth at 30°C and to heat shock occurred via different mechanisms. The effect of low temperature on heat tolerance and high temperature on freezing tolerance of pear cells was also examined. The heat acclimation induced by elevated growth temperature increased freezing tolerance, but cold acclimation did not increase heat tolerance. It seems likely that some component(s) of cold and heat acclimation may be the same. This indicates that studies of response to different stimuli may help in clarifying mechanisms of temperature acclimation. The only potential mechanism examined in this study was the role of extracellular polysaccharides in cell response to freezing stress. Extracellular macromolecules from non-acclimated cultures aggregated irreversibly during freezing, while those from acclimated cultures did not. The aggregation of polysaccharides may be related to the observation that macromolecules from a non-acclimated medium increased the freezing injury of pear cells. Analyses of polysaccharides from acclimated and non-acclimated cultures indicated that the polysaccharides were changed during cold acclimation

Cold hardiness and cryopreservation of small fruits

1981 Fall.Covers not scanned.Includes bibliographical references.This study examined cold hardiness and the occurrence of deep supercooling in stem with an attached bud of 4 cv. of grape and 4 of raspberry. Cryoprotectants were also tested for their influence on cold hardiness of raspberry vegetative bud and stem. Differential thermal analysis (DTA) of 4 cv. of grapes, Vi tis species hybrids, 'Concord', 'Beta', ' Valient', and 'Rougeon' showed that the stem and bud pieces of all cv. deep supercool in winter. They all showed a bud exotherm at approximately -25 to -30°C, and a stem tissue exotherm at approximately -40°C. The temperature at which the bud exotherm occurs may be the killing point of the bud which in turn could lead to the death of the above-ground canes. Evidence of this was the observation of the death of 'Rougeon' buds, bud exotherm observed at approximately -20°C, during the winter of 1980-1981 when the lowest temperature was -2S.6°C. DTA profiles of stem with attached bud samples of the 4 raspberry cv., 'Heritage', Ruhus idaeus L., 'Black Hawk', R. occidentalis L., ' Amethyst', R. neglectus Peck, and 'Darrow', R. allegheniensis Porter, suggest that these do not deep supercool during winter. The mechanism of freezing resistance of these may be tolerance of extracellular freezing. Survival, indicated by sprouting, on January 30, 1981 showed that the LT50 (lethal temperature for at least 50% bud sprouting) was -55°C -50°C, and -45°C for 'Black Hawk', 'Amethyst', and 'Heritage', respectively. This supports the idea that at least these 3 cv. resist freezing by tolerance of extracellular freezing. Therefore minimum temperature may not be the major limiting factor in their northernly distribution. In descending order the observed degree of hardiness was 'Black Hawk', 'Amethyst', and 'Heritage'. Survival tests of 'Heritage' samples treated with cryoprotectants showed no benefit of cryoprotectants for enhancing the resistance of acclimated buds and stem to cold injury. However, there were some implications that cryoprotectants may enhance the resistance of nonacclimated samples to lower temperatures

Acute-on-chronic kidney injury at hospital discharge is associated with long-term dialysis and mortality

Existing chronic kidney disease (CKD) is among the most potent predictors of postoperative acute kidney injury (AKI). Here we quantified this risk in a multicenter, observational study of 9425 patients who survived to hospital discharge after major surgery. CKD was defined as a baseline estimated glomerular filtration rate <45ml/min per 1.73m2. AKI was stratified according to the maximum simplified RIFLE classification at hospitalization and unresolved AKI defined as a persistent increase in serum creatinine of more than half above the baseline or the need for dialysis at discharge. A Cox proportional hazard model showed that patients with AKI-on-CKD during hospitalization had significantly worse long-term survival over a median follow-up of 4.8 years (hazard ratio, 3.3) than patients with AKI but without CKD. The incidence of long-term dialysis was 22.4 and 0.17 per 100 person-years among patients with and without existing CKD, respectively. The adjusted hazard ratio for long-term dialysis in patients with AKI-on-CKD was 19.8 compared to patients who developed AKI without existing CKD. Furthermore, AKI-on-CKD but without kidney recovery at discharge had a worse outcome (hazard ratios of 4.6 and 213, respectively) for mortality and long-term dialysis as compared to patients without CKD or AKI. Thus, in a large cohort of postoperative patients who developed AKI, those with existing CKD were at higher risk for long-term mortality and dialysis after hospital discharge than those without. These outcomes were significantly worse in those with unresolved AKI at discharge

Anti–SARS-CoV Immunoglobulin G in Healthcare Workers, Guangzhou, China

Low level of immunity for SARS-CoV among well healthcare workers reinforces the need for infection control measures in hospitals to prevent epidemics

Fosmid library end sequencing reveals a rarely known genome structure of marine shrimp Penaeus monodon

<p>Abstract</p> <p>Background</p> <p>The black tiger shrimp (<it>Penaeus monodon</it>) is one of the most important aquaculture species in the world, representing the crustacean lineage which possesses the greatest species diversity among marine invertebrates. Yet, we barely know anything about their genomic structure. To understand the organization and evolution of the <it>P. monodon </it>genome, a fosmid library consisting of 288,000 colonies and was constructed, equivalent to 5.3-fold coverage of the 2.17 Gb genome. Approximately 11.1 Mb of fosmid end sequences (FESs) from 20,926 non-redundant reads representing 0.45% of the <it>P. monodon </it>genome were obtained for repetitive and protein-coding sequence analyses.</p> <p>Results</p> <p>We found that microsatellite sequences were highly abundant in the <it>P. monodon </it>genome, comprising 8.3% of the total length. The density and the average length of microsatellites were evidently higher in comparison to those of other taxa. AT-rich microsatellite motifs, especially poly (AT) and poly (AAT), were the most abundant. High abundance of microsatellite sequences were also found in the transcribed regions. Furthermore, <it>via </it>self-BlastN analysis we identified 103 novel repetitive element families which were categorized into four groups, <it>i.e</it>., 33 WSSV-like repeats, 14 retrotransposons, 5 gene-like repeats, and 51 unannotated repeats. Overall, various types of repeats comprise 51.18% of the <it>P. monodon </it>genome in length. Approximately 7.4% of the FESs contained protein-coding sequences, and the Inhibitor of Apoptosis Protein (IAP) gene and the Innexin 3 gene homologues appear to be present in high abundance in the <it>P. monodon </it>genome.</p> <p>Conclusions</p> <p>The redundancy of various repeat types in the <it>P. monodon </it>genome illustrates its highly repetitive nature. In particular, long and dense microsatellite sequences as well as abundant WSSV-like sequences highlight the uniqueness of genome organization of penaeid shrimp from those of other taxa. These results provide substantial improvement to our current knowledge not only for shrimp but also for marine crustaceans of large genome size.</p

Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan

AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities