Interactions of Cd with Zn, Cu, Mn and Fe for lettuce (Lactuca sativa L.) in hydroponic culture

Abstract. The effect and accumulation of cadmium (Cd) in lettuce grown by means of the hydroponic technique was investigated by multivariate analysis, and was found to be affected by the concentration of other trace elements. Particularly iron acted in a strongly antagonistic way against Cd. Consequently, no absolute toxicity limits for Cd can be drawn without considering other trace elements.     

Preparation of Chloroplast DNA from Barley and Lettuce and Comparison of Restriction Fragments

Chloroplast DNA from three barley cultivars and from one lettuce cultivar was prepared from chloroplasts isolated by Conventional differential centrifugation. Barley chloroplast DNA size was sensibly lower (130 kpb) than lettuce chloroplast DNA (150 kpb). Chloroplast DNAs from the three barley cultivars showed similar restriction fragment patterns after digestion with: BamHI, EcoRI or HindIII. The lettuce chloroplast DNA restriction pattern was very different from the barley chloroplast DNA restriction pattern.     

The salivary and crop apyrase activity of Rhodnius prolixus

A calcium dependent apyrase activity (ATP→AMP + 2Pi) has been characterized in the salivary secretion of Rhodnius prolixus. High levels of this activity were found in the crop of all stages of larvae and the adults after a single blood or saline meal. The activity persisted for several days but was totally absent in the crop insects from which the salivary glands had been removed. The use of this activity as a saliva marker shows that the insect salivates during the whole meal and most of the saliva is ingested with the food. The physiological role of this activity is discussed. A simple method for saliva collection and a technique for the surgical ablation of the salivary glands in adult insects are described.     

Polymorphism of Ps (parotid size variant) and detection of a protein (PmS) related to the Pm (parotid middle band) system with genetic linkage of Ps and Pm to Gl,Db, and Pr genetic determinants

Genetic polymorphism of the Ps (parotid size variant) proteins found in saliva is determined by autosomal inheritance of two expressed and one unexpressed allele. This hypothesis is supported by studies in 43 families including 153 children. Gene frequencies determined for 150 randomly collected salivas from whites and 101 randomly collected salivas from blacks are as follows: for whites, Ps ¹=0.598, Ps ²=0.101, Ps ⁰=0.301; for blacks, Ps ¹=0.185, Ps ²=0.126, and Ps ⁰=0.689. The electrophoretic polymorphism is manifested by apparent differences in molecular weights between Ps proteins. The Ps proteins are glycosylated and have an approximate isoelectric point of pI 8.1 as determined by isoelectric focusing in gels. We have also found in saliva the presence of a protein (PmS) which shows strong positive correlations with the presence of the smaller sized Pm (PmF) salivary protein described by Ikemoto et al. (1977). This suggested that PmS is probably part of the Pm protein polymorphic system. For randomly collected salivas from whites, the gene frequencies are PmF+=0.15 (N=140) and PmS+=0.12 (N=150). For randomly collected salivas from blacks, the gene frequency is PmS+=0.24 (N=101). The gene frequency of PmF+ was not determined. Family studies support autosomal inheritance of PmF and PmS proteins. There is strong evidence for linkage of Pm to the proline-rich protein (PPP) region (11 families, lod score at =0.01 is 7.64) and of Ps to the PPP region (13 families, lod score at =0.01 is 11.50). Protein products of six linked loci (Pr, Pa, Db, Ps, Pm, and Gl), when tested against rabbit anti-Gl antiserum, show immunological reactions of partial or complete identity with each other by double diffusion analysis.This study was supported by a grant from the National Institutes of Dental Research (DEO 3658-14). Paper No. 2340 of the Laboratory of Genetics, University of Wisconsin, Madison, Wisconsin 53706.     

Comparison of wheat albumin inhibitors of α-amylase and trypsin

Wheat albumins were extracted from whole wheat flour with 150 mM sodium chloride solution and precipitated between 0·4 and 1·8 M ammonium sulphate. The albumin precipitate was separated by gel filtration on Sephadex G100 into five peaks. Three peaks (II, III, and IV), whose MWs were 60 000, 24 000 and 12 500 daltons respectively, were active toward several insect α-amylases, whereas only peak III inhibited human saliva and pancreatic α-amylases. Peaks III and IV also inhibited trypsin. In each active peak, we found several α-amylase inhibitors slightly different in their electrophoretic mobilities in a Tris—glycine buffer system (pH 8·5), whereas only one major trypsin inhibitor was present in peaks III and IV. In contrast to α-amylase inhibitors that were all anodic, trypsin inhibitors migrated to the cathode under our experimental conditions. From a quantitative standpoint, wheat albumins that inhibit trypsin are negligible, whereas about 2/3 of the total albumin inhibits amylases from different origins. All inhibitor components of peak III were active toward both insect and mammalian α-amylases. Moreover, they reversibly dissociated in the presence of 6 M guanidine hydrochloride giving two similar subunits.     

ABO blood groups and ABH saliva secretion in Reddis and Kammas of Southern Andhra Pradesh

ABO blood groups and ABH saliva secretion were investigated in two caste populations, Reddis and Kammas of Southern Andhra Pradesh, and compared with the data of other populations. In ABO gene frequencies, the present series of Reddis and Kammas approach the values from other Andhra caste data. Moderate gene frequency of non-secretor gene in both Reddis and Kammas are noted.     

Quantifying blood leakage into the oral mucosa and its effects on the measurement of cortisol, dehydroepiandrosterone, and testosterone in saliva

The impact of blood leakage due to microinjury to the oral cavity on the measurement of salivary hormones was examined. Saliva samples were collected before, immediately after, and then every 15 min for 1 h following vigorous tooth brushing. Blood in saliva was quantified by visual inspection of discoloration, Hemastix reagent strips to detect hemoglobin, and an immunoassay for transferrin. The presence of blood in saliva immediately after microinjury was confirmed by all methods. Hemoglobin and transferrin levels remained elevated over baseline for at least 30 min. Levels of salivary testosterone increased over baseline and remained elevated for 30 min in response to microinjury. Microinjury induced change in salivary testosterone was more closely associated with the change in transferrin than hemoglobin levels or discoloration ratings. On average, levels of salivary dehydroepiandrosterone (DHEA) did not increase in response to microinjury. However, individual differences in microinjury induced change in DHEA were associated with discoloration ratings. Salivary cortisol levels, on average, were neither responsive to microinjury, nor were individual differences in cortisol change associated with blood contamination measures. Neither diurnal nor gender-related differences in baseline hormone levels predicted the impact of blood leakage on quantitative salivary measurements. The findings suggest ecologically valid minor-to-moderate level microinjuries to the oral cavity have negligible effects on the measurement of salivary cortisol, but may be important to quantify and control when assessing other hormones especially testosterone.     

Acute high-intensity exercise test in soccer athletes affects salivary biochemical markers

Saliva has been reported as a potential biological fluid for biochemical monitoring. This study investigated salivary markers of exercise intensity, oral mucosal immunity, and redox homeostasis in soccer athletes subjected to an acute high-intensity interval exercise (HIIE) protocol characterised by a repeated sprint ability test. Thirty-two professional soccer athletes were recruited and saliva aliquots were collected at rest and immediately after HIIE protocol. When compared with pre-test values we observed that HIIE protocol induced moderate changes for total protein (p?=?.015; effect size (ES)?=?0.51; smallest worthwhile change (SWC)_factor?=?5.7) and for cortisol levels (p?factor?=?3.9). Lactate levels showed very large changes (p?factor?=?10.8), while Ig-A alterations were considered unclear. Besides, transferrin changes were trivial and maintained its levels at rest and after HIIE below the proposed threshold of 0.5?mg/dL. Regarding redox homeostasis we observed unclear effects for TBARs, MDA, GSH, GSSG, CAT, and SOD while uric acid showed large decreases (p?=?.005; ES?=?0.80; SWC_factor?=??5.4). HIIE protocol as a physical test conducted in soccer athletes increased salivary concentration of exercise intensity markers, such as lactate, total protein, and cortisol, but did not affect Ig-A levels. Redox homeostasis in saliva seems to be more related with uric acid levels as a possible key factor TBARs homeostasis.     

Tick saliva: recent advances and implications for vector competence

Abstract . Secretions of the tick salivary glands are essential to the successful completion of the prolonged feeding of these ectoparasites as well as the conduit by which most tick-borne pathogens are transmitted to the host. In ixodid ticks the salivary glands are the organs of osmoregulation, and excess water from the bloodmeal is returned via saliva into the host. Host blood must continue to flow into the feeding lesion as well as remain fluid in the tick mouthparts and gut. The host's haemostatic mechanisms are thwarted by various anti-platelet aggregatory, anticoagulatory and anti-vasoconstrictory factors in tick saliva. Saliva components suppress the immune and inflammatory response of the host permitting the ticks to remain on the host for an extended period of time and, adventitiously, enhancing the transmission and establishment of tick-borne pathogens. Over the years much work has been done on the numerous enzyme and pharmacological activities found in the tick saliva. The present article reviews the most recent work on salivary gland secretionith special emphasis on how they favour pathogen transmission.     

苜蓿抗甲硫氨酸变异体的筛选

紫花苜蓿(Medicago sativa L.)下胚轴愈伤组织用NaN_3溶液诱变处理后,在含有全致死浓度甲硫氨酸的MS培养基上进行了6个月的连续筛选培养,获得了能抗100mmol/L甲硫氨酸的变异细胞系,并分化成再生植株。所获变异细胞系在脱离选择压力6个月后,对甲硫氨酸的抗性仍比对照高7.2倍,并表现出对乙硫氨酸的交叉抗性(为对照抗性的3.3倍)。抗性细胞系及其再生植株的甲硫氨酸、赖氨酸、苏氨酸和异亮氨酸含量均比对照有大幅度增加。抗性系的SDS-PAGE电泳图谱及过氧化物酶同工酶谱带均与对照有显著不同,并出现了新带,表明变异系已经产生变化了的基因产物。