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1.
Chronic vitamin C deficiency was induced in guinea pigs by restricting their vitamin C intake to 0.5 mg daily. This was just sufficient to prevent rapidly fatal scurvy and 55 per cent of the animals survived. In 16 weeks their serum ascorbic acid (SAA) fell to 0.16 +/- 0.06 mg/dl as compared to 0.73 +/- 0.11 in control animals receiving 5 mg vitamin C daily. There was a marked increase in serum cholesterol, LDL-cholesterol, VLDL-cholesterol, triglycerides and total lipids. HDL-cholesterol was, however, decreased resulting in a shift of the LDL/HDL ratio from 1.13 +/- 0.16 in the control to 5.91 +/- 1.70 in the low vitamin C group. Cholesterol feeding (100 mg/day) by itself lowered the SAA significantly, besides producing hyperlipidemia. When the vitamin C intake was reduced to only 0.5 mg/day, the effects of cholesterol feeding were exaggerated; the magnitude of hyperlipidemia was now significantly greater than with simple cholesterol feeding. The LDL/HDL ratio rose to 19.02 +/- 3.32 from 1.13 +/- 0.16 in the normal guinea pigs. Chronic vitamin C deficiency seems to affect the blood lipid profile unfavourably which could promote atherogenesis. 相似文献
2.
Isolation of Bacillus licheniformis mutants for stable production profiles of alkaline protease 总被引:1,自引:0,他引:1
Summary A phenotypic requirement for cysteine was introduced inBacillus licheniformis producing alkaline protease to facilitate its isolation from poor or nonproducerBacillus species. This facilitated purification of the strain in cases of cross-contamination, preparation of good inocula for commercial production and stabilization of alkaline protease harvest values, alleviating economic losses incurred through cross-contamination. 相似文献
3.
In vitro clonal propagation of Capparis decidua was achieved using nodal explants from mature trees, and cotyledonary node, cotyledon and hypocotyl explants taken from the seedlings. Explants cultured on MS medium supplemented with BAP showed differentiation of multiple shoots and shoot buds in 4–5 weeks in the primary cultures. The medium with BAP (5 mg/l) was the best for shoot bud proliferation from the nodal as well as seedling explant. Shoot multiplication was best on cotyledonary node. In the nodal explants shoot multiplication was best on medium supplemented with 5 mg/l BAP and after second subculturing further multiplication of shoot buds was highest on the medium containing 3 mg/l BAP. Shoots were separated from mother cultures in each subculturing for rooting. Rooting was best achieved using 1 mg/l IBA in the medium. Rooted plantlets were transferred td earthen pots with garden soil and peat moss mixture. 相似文献
4.
Embryogenic and non-embryogenic calluses were induced from 3,4,5 and 7d old coleoptile segments of indica rice (Oryza sativa L. cv. CH 1039). Compact, globular, yellow and creamy embryogenic and white friable non-embryogenic callus arose from the cut end and entire length of the coleoptile segments. Murashige and Skoog's (MS) medium supplemented with 2.5mg/1 2,4-D was used as callus induction medium. Plant regeneration from coleoptile segments occurred with the transfer of embryogenic callus to MS basal medium supplemented with 2.0mg/1 BAP and 0.5mg/1 NAA in combination. Average number of regenerated plants from one coleoptile ranged from9.1 to 14.0.Four day old coleoptiles showed the highest frequency of plant regeneration.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- BAP
6-benzylaminopurine
- MS
Murashige and Skoog (1962)
- NAA
1-naphthalene acetic acid 相似文献
5.
V. Ramamurthy S. P. Thacker R. M. Kothari 《Journal of industrial microbiology & biotechnology》1992,9(2):121-125
Summary A 25-l scale protocol is devised for the optimal secretion and recovery of fungal cellulase. Using a selected higher yieldingTrichoderma viride SMC strain, a protocol consisted of: a) an optimized production medium rich in microcrystalline cellulose (MCC), fortified with 1% (w/v) ammonium sulphate, 0.5% (w/v) soybean flour, 0.1% (v/v) Tween-80 and other trace nutrients; b) optimized physical parameters of production, such as an inoculum containing a homogeneous suspension of 6×107 conidia per 1,28±1°C, pH 4.0±0.5, 300±20 rpm, 11000±1000 l/h aeration, and 170–220 h duration; c) optimal recovery through a filter press (450 l/h rate of filtration) followed by precipitation with 2.5–3.0 volumes of acetone (15°C and basket centrifugation (27°C, 1700 rpm)); and d) vacuum drying (35°C, 4–6 h). This afforded 70% recovery of cellulase in the form of white fluffy powder containing 20000±2000 carboxy methyl cellulase and 1000±50 units filter paperase per g activities, with raw material cost of US$ 8–10 per million carboxy methyl cellulase units. During storage for 18 months at 4°C, ambient temperature and 37°C, the cellulase preparation was found to retain 100, 75 and 60% of its initial activity, respectively. 相似文献
6.
In a study to identify and define a central group of long-stay psychiatric patients who are resistant to discharge 422 were found who had been in hospital for eight to 23 years. These "problem" patients represented 40% of all long-stay patients. The total number of years that they had spent in hospital was nearly double that of the remaining patients. They were mostly unvisited, unoccupied, and single, and most were suffering from schizophrenia or organic psychosis. Half were in a good or reasonably good state of mental health, and three-quarters were in a good or reasonably good state of physical health. The findings have implications for the rehabilitation and treatment of these patients and also for the provision of community aftercare facilities. 相似文献
7.
John D. Loike Anna Plitt Komal Kothari Jona Zumeris Sadna Budhu Kaitlyn Kavalus Yonatan Ray Harold Jacob 《PloS one》2013,8(8)
Biofilms are structured communities of bacteria that play a major role in the pathogenicity of bacteria and are the leading cause of antibiotic resistant bacterial infections on indwelling catheters and medical prosthetic devices. Failure to resolve these biofilm infections may necessitate the surgical removal of the prosthetic device which can be debilitating and costly. Recent studies have shown that application of surface acoustic waves to catheter surfaces can reduce the incidence of infections by a mechanism that has not yet been clarified. We report here the effects of surface acoustic waves (SAW) on the capacity of human neutrophils to eradicate S. epidermidis bacteria in a planktonic state and within biofilms. Utilizing a novel fibrin gel system that mimics a tissue-like environment, we show that SAW, at an intensity of 0.3 mW/cm2, significantly enhances human neutrophil killing of S. epidermidis in a planktonic state and within biofilms by enhancing human neutrophil chemotaxis in response to chemoattractants. In addition, we show that the integrin CD18 plays a significant role in the killing enhancement observed in applying SAW. We propose from out data that this integrin may serve as mechanoreceptor for surface acoustic waves enhancing neutrophil chemotaxis and killing of bacteria. 相似文献
8.
9.
C García-Vielma MI Dávila-Rodríguez F Hernández-Garza RM Cerda-Flores 《Biotechnic & histochemistry》2016,91(2):102-107
We performed a hospital-based, unmatched case-control study to investigate the association between progressive stages of cervical neoplasia and digital analysis of cell proliferation by silver stained nucleolus organizer region associated proteins (AgNORs). We measured cell proliferation levels in the cervical epithelial cells of 10 women with low grade squamous intraepithelial lesions (LG-SIL), eight with high grade squamous intraepithelial lesions (HG-SIL), 11 with cervical cancer (CC) and eight with no cervical lesions (controls) using the AgNORs technique. Cell proliferation was measured by digital image analysis (DIA). DIA revealed increased total areas of AgNORs in HG-SIL and CC compared to LG-SIL and control patients. AgNORs with a kidney or cluster shape exhibited greater areas than those with a spherical or long shape. We propose a cut-off of 118 pixels to differentiate benign (control and LG-SIL) from malignant (HG-SIL and CC) lesions. DIA of AgNORs is a simple and inexpensive method for studying proliferation. The increased total area of AgNORs in malignant lesions provides information regarding cell behavior and may be related to cervical carcinogenesis; however, further validation studies are required to establish its usefulness in cytological analysis. 相似文献
10.
Extract from root, stem and leaf of L. camara proved inhibitory for germination of the spores of A. angusta. Leaf extract was found to exhibit maximum allelopathic potentiality followed by stem and root extract and may be interpreted to be the result of phytotoxic substances which are possibly synthesized in the leaf and translocated to other organs. 相似文献