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1.
We investigated the uptake of inorganic elements (Be, Na, Mg, K, Ca, Sc, Mn, Co, Zn, Se, Rb, Sr, Y, Zr, Ce, Pm, Gd, and Hf) and the effect of Ca on their uptake in carrots (Daucus carota cv. U.S. harumakigosun) by the radioactive multitracer technique. The experimental results suggested that Na, Mg, K, and Rb competed for the functional groups outside the cells in roots with Ca but not for the transporter-binding sites on the plasma membrrane of the root cortex cells. In contrast, Y, Ce, Pm, and Gd competed with Ca for the transporters on the plasma membrane. The selectivity, which was defined as the value obtained by dividing the concentration ratio of an elemental pair, K/Na, Rb/Na, Be/Sr, and Mg/Sr, in the presence of 0.2 and 2 ppm Ca by that of the corresponding elemental pair in the absence of Ca in the solution was estimated. The selectivity of K and Rb in roots was increased in the presence of Ca. The selectivity of Be in roots was not affected, whereas the selectivity of Mg was increased by Ca. These observations suggest that the presence of Ca in the uptake solution enhances the selectivity in the uptake of metabolically important elements against unwanted elements.  相似文献   

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3.
The effect of incubation temperature and pH on the hatch rate of eggs of Necator americanus, and the desiccation tolerance of the resulting infective stage-3 larvae were investigated in the laboratory under controlled conditions. Hatching did not occur below 15 C and above 35 C. A 21% hatch rate was obtained at 15 C while a 10.6% hatch rate was obtained at 35 C. The highest hatch rate (93.7%) was obtained at 30 C. The optimum pH for hatching was 6.0, but the larvae did not reach the infective stage. Incubation temperature of the eggs affected the longevity and desiccation tolerance of resultant infective larvae. Larvae hatched at 30 C and maintained at 26 C under bright fluorescent light had a 50% survival time (S50) of 4 days. In the dark or shade, the S50 for larvae raised at 30 C was 5 weeks, while that of larvae hatched at 20 C was 7 weeks. Incubation temperature also affected the desiccation tolerance of larvae. Larvae developed at 20 C were more resistant to desiccation at various relative humidity values than larvae hatched at 30 C.  相似文献   

4.
An increased understanding of lake sturgeon (Acipenser fulvescens) population dynamics is a key requirement for successful management efforts. Little is known regarding the Grasse River population of lake sturgeon except that it is one of a few populations in New York State where spawning has been documented. Thus our purpose was to assess the current status of lake sturgeon in the Grasse River system, including age, growth, mortality, and abundance. Age was determined for 196 of 211 lake sturgeon by examination of sectioned pectoral fin rays. Ages ranged from 0 to 32 years and the annual mortality rate for fish between ages 7 and 14 was 16.8%. The weight (W, g) to total length (TL, mm) relationship was W = 1.281 × 10?6TL3.202. The von Bertalanffy growth equation was TL = 1913(1?e?0.0294(t+9.5691)). While the range of observed ages was similar to that of nearby St. Lawrence River populations, mean weight at age for an individual at 1000 mm TL was lower than that observed for lake sturgeon within Lake St. Francis of the St. Lawrence River. Predicted growth based on von Bertalanffy parameters was similar to that observed for the nearby Lake St. Francis. An open population estimator using the POPAN sub‐module in the Program MARK produced an abundance estimate of 793 lake sturgeon (95% CI = 337–1249).  相似文献   

5.
Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine.  相似文献   

6.
In order to compare the endocrine response of placental minces to luteinizing hormone releasing hormone (LHRH) and dibutyryl cAMP (dbcAMP) and to screen for effects of potential stimulatory and inhibitory substances, the simultaneous outputs of PGF2 alpha, 13, 14-dihydro-15-keto-prostaglandin F2 alpha (PGFM), progesterone, 17 beta-estradiol, and hCG were evaluated during a 4 hour incubation in 5 placentas. The output of hCG was highest for 12-week placentas, intermediate for a 16 week placenta, and lowest for term placentas. The output of 17 beta-estradiol by 12 and 16 week placentas in the presence of 30 microM dehydroepian-drosterone sulfate (DHEAS) was greater than that by term placentas. Progesterone output was apparently independent of gestational age although some variation between 12-week placentas was demonstrated. Output of PGF2 alpha was lower in 12 and 16-week placentas than in term placentas and that of PGFM was lower in 12-week placentas than in term placentas. LHRH (100 nM) produced stimulation of PGF2 alpha output (P less than .005) and a trend toward inhibition of progesterone output (which failed to achieve statistical significance) but no stimulation of hCG under these conditions. Stimulation of the outputs of hCG (P less than .005) and PGF2 alpha (P less than .001) and inhibition of that of progesterone (P less than .005) was produced by 20 mM dbcAMP. DHEAS inhibited output of progesterone (P less than .01) and PGF2 alpha (P less than .01). There were no effects of potassium, estrogens, progesterone, or prostaglandins on output of any measured substance.  相似文献   

7.
For six strains of Bifidobacterium bifidum (Lactobacillus bifidus), fermentation balances of glucose, lactose, galactose, mannitol, and xylose were determined. Products formed were acetate, l(+)-lactate, ethyl alcohol, and formate. l(+)-Lactate dehydrogenase of all strains studied was found to have an absolute requirement for fructose-1,6-diphosphate. The phosphoroclastic enzyme could not be demonstrated in cell-free extracts. Cell suspensions fermented pyruvate to equimolar amounts of acetate and formate. Alcohol dehydrogenase was shown in cell-free extracts. Possible explanations have been suggested for the differences in fermentation balances found for different strains and carbon sources. By enzyme determinations, it was shown that bifidobacteria convert mannitol to fructose-6-phosphate by an inducible polyol dehydrogenase and fructokinase. For one strain of B. bifidum, molar growth yields of glucose, lactose, galactose, and mannitol were determined. The mean value of Y (ATP), calculated from molar growth yields and fermentation balances, was 11.3.  相似文献   

8.
Age, growth, and reproductive characteristics of blacktail snapper, Lutjanus fulvus, which is a commercial fish species, were investigated using 322 specimens (40–332 mm in fork length) caught around the Yaeyama Islands, Okinawa, Japan. Spawning season was estimated to be from April to October, and spawning was confirmed around the full moon and the last quarter moon. Age determination using sectioned otoliths revealed that ages ranged from 0 to 34 years and the majority was ≥ 3 years. Parameters of the von Bertalanffy growth function were estimated to be L  = 270 mm, k = 0.40, and t 0  = ?0.48 years for females, and 257 mm, 0.44, and ?0.42 years for males. Initial growth was rapid during the first 3 years, attaining over 200 mm for both sexes, and then females grew larger than males. Sizes (ages) at the first sexual maturity were 225 mm (4 years) for females and 207 mm (3 years) for males. The wide range of age composition in catch with majority of ≥3 years old implied that the current fishing effort to harvest was not sufficiently large enough to collapse the stock immediately.  相似文献   

9.
The common excision skin pattern is either a fusiform ellipse or another pattern with dissimilar length and width. The purpose of this study was to define the most advantageous skin pattern regarding skin waste, vertex angle, and scar length. Five skin excision patterns used traditionally for closure of round lesions were analyzed: fusiform ellipse, fusiform circle, rhomboid, mosque, and S-shaped. In the analysis, the pattern characteristics were formulated by geometric principles, from which the results were compared. The smallest skin waste was found in rhomboid and mosque patterns, whereas the largest skin waste was found in the fusiform circle and ellipse. The vertex angle was found to decrease monotonously with the excision length-to-width ratio for all patterns except the mosque shape, which is zero per definition. The paradigm stating that a vertex angle of 30 degrees or less is maintained for length-to-width ratios below 4 in the surgical ellipse was found incorrect. It holds only for rhomboid and S-shaped excisions. The scar length was found almost independent of the pattern, with a variance of 3 percent. The authors conclude that the most advantageous surgical skin patterns are the rhomboid and mosque excisions.  相似文献   

10.
The 528 murine monoclonal antibody (MAb) to the human epidermal growth factor receptor (EGFR) was sequentially cationized with hexamethylenediamine and conjugated with diethylenetriaminepentaacetic acid (DTPA) as a potential antibody radiopharmaceutical for imaging EGFR-expressing cancer. The cationized 528 MAb was characterized with isoelectric focusing and electrophoresis, and an immunoradiometric assay, which showed the affinity of the 528 MAb for the human EGFR was retained following cationization. The native or cationized 528 MAb, labeled with (111)In, was injected intravenously in scid mice bearing human U87 flank tumors, which express the EGFR, and tumor imaging was performed with both external detection in live animals and with whole body autoradiography. However, the tumor signal was not increased with the cationized MAb, relative to the native MAb, and this was due to a serum inhibition phenomenon that was confirmed by a pharmacokinetics analysis in control mice. In an attempt to block the serum inhibition, the cationized 528 MAb was pegylated with 2000 Da poly(ethylene glycol), and the cationized/pegylated MAb was conjugated with DTPA and labeled with (111)In. However, a pharmacokinetics analysis showed the pegylation did not reverse the serum inhibition of the cationic charge on the MAb. These studies describe methods for reformulating monoclonal antibodies to develop improved radiopharmaceuticals, but show that radiolabeling a cationized MAb with DTPA produces a serum neutralization of the initial cationization modification.  相似文献   

11.
12.
The concentrations of the trace elements Cd, Hg, Pb, and Se during the perinatal period in human placenta and in the blood of the mother and the newborn (cord blood) were determined. Breast milk (colostrum and mature milk) was also included to permit correlations between the different compartments. For Cd, a placental barrier exists, in accord with previous observations. For Pb, a strong correlation between the concentrations in the blood of the mother and of the newborn was found. The concentration of Hg was in most cases below low the detection limit. Its concentration in colostrum was higher than in the mature milk. The results for Se reflect the knowledge about an essential trace element. Strong positive correlations were noted between maternal blood and cord blood and maternal milk. Anodic stripping voltammetry (DPASV) was used for the determination of Cd and Pb, cold vapor AAS (CVAAS) for the determination of Hg, and instrumental neutron activation analysis (INAA) for the determination of Se.  相似文献   

13.
The efficacy of a chelating agent in binding a given metal in a biological system depends on the binding constants of the chelator for the particular metals in the system, the concentration of the metals, and the presence and concentrations of other ligands competing for the metals in question. In this study, we make a comparison of the in vitro binding constants for the chelator, ethylenediaminetetraacetic acid, with the quantitative urinary excretion of the metals measured before and after EDTA infusion in 16 patients. There were significant increases in lead, zinc, cadmium, and calcium, and these increases roughly corresponded to the expected relative increases predicted by the EDTA-metal-binding constants as measured in vitro. There were no significant increases in urinary cobalt, chromium, or copper as a result of EDTA infusion. The actual increase in cobalt could be entirely attributed to the cobalt content of the cyanocobalamin that was added to the infusion. Although copper did increase in the post-EDTA specimens, the increase was not statistically significant. In the case of magnesium, there was a net retention of approximately 85% following chelation. These data demonstrate that EDTA chelation therapy results in significantly increased urinary losses of lead, zinc, cadmium, and calcium following EDTA chelation therapy. There were no significant changes in cobalt, chromium, or copper and a retention of magnesium. These effects are likely to have significant effects on nutrient concentrations and interactions and partially explain the clinical improvements seen in patients undergoing EDTA chelation therapy.  相似文献   

14.
The trehalose-phosphate phosphatase (TPP) was purified from the cytosol of Mycobacterium smegmatis to near homogeneity using a variety of conventional steps to achieve a purification of about 1600-fold with a yield of active enzyme of about 1%. Based on gel filtration, the active enzyme had a molecular weight of about 27,000, and the most purified fraction also gave a major band on SDS-PAGE corresponding to a molecular weight of about 27,000. A number of peptides from the 27-kDa protein were sequenced and these sequences showed considerable homology to the trehalose-P phosphatase (otsB) of Escherichia coli. Based on these peptides, the M. smegmatis gene for TPP was cloned and expressed in E. coli. The recombinant protein was synthesized with a (His)(6) tag at the amino terminus. Most of the TPP activity in the crude E. coli sonicate was initially found in the membrane fraction, but it became solubilized in the presence of 0.2% Sarkosyl. The solubilized protein was purified to apparent homogeneity on a metal ion column and this fraction had high phosphatase activity that was completely specific for trehalose-P. The purified enzyme, either isolated from M. smegmatis, or expressed in E. coli, rapidly dephosphorylated trehalose-6-P, but had essentially no activity on any other sugar phosphates, or on p-nitrophenyl phosphate. The K(m) for trehalose-6-P was about 1.6 mm, and the pH optimum was about 7.5. The native enzyme showed an almost absolute requirement for Mg(2+) and was not very active with Mn(2+), whereas both of these cations were equally effective with the recombinant TPP. The enzyme activity was inhibited by the antibiotics, diumycin and moenomycin, but not by a number of other antibiotics or trehalose analogs. TPP activity was strongly inhibited by the detergents, Sarkosyl and deoxycholate, even at 0.025%, but it was not inhibited by Nonidet P-40, Triton X-100, or octyl glucoside, even at concentrations up to 0.3%. The purified enzyme was stable to heating at 60 degrees C for up to 6 min, but was slowly inactivated at 70 degrees C. Circular dichroism studies on recombinant TPP indicate that the secondary structure of this protein has considerable beta-pleated sheet and is very compact. TPP may play a key role in the biosynthesis of trehalose compounds, such as trehalose mycolates, and therefore may represent an excellent target site for chemotherapy against tuberculosis and other mycobacterial diseases.  相似文献   

15.
Lymphocyte subpopulation levels are used for prognosis and monitoring of a variety of human diseases, especially those with an infectious etiology. As a primary step to defining the major gene variation underlying these phenotypes, we conducted the first whole-genome screen for quantitative variation in lymphocyte count, CD4 T cell, CD8 T cell, B cell, and natural killer cell numbers, as well as CD4:CD8 ratio. The screen was performed in 15 of the CEPH families that form the main human genome genetic project mapping resource. Quantitative-trait loci (QTLs) that account for significant proportions of the phenotypic variance of lymphocyte subpopulations were detected on chromosomes 1, 2, 3, 4, 8, 9, 11, 12, and 18. The most significant QTL found was for CD4 levels on chromosome 8 (empirical P=.00005). Two regions of chromosome 4 showed significant linkage to CD4:CD8 ratio (empirical P=.00007 and P=.003). A QTL for the highly correlated measures of CD4 and CD19 levels colocalized at 18q21 (both P=.003). Similarly, a shared region of chromosome 1 was linked to CD8 and CD19 levels (P=.0001 and P=.002, respectively). Several of the identified chromosome regions are likely to harbor polymorphic candidate genes responsible for these important human phenotypes. Their discovery has important implications for understanding the generation of the immune repertoire and understanding immune-system homeostasis. More generally, these data show the power of an integrated human gene-mapping approach for heritable molecular phenotypes, using large pedigrees that have been extensively genotyped.  相似文献   

16.
Avian paramyxoviruses (APMV) serotypes 1–9 are frequently isolated from domestic and wild birds worldwide. APMV-1 (also called Newcastle disease virus, NDV) is attenuated in non-human primates and is being developed as a candidate human vaccine vector. The vector potential of the other serotypes was unknown. In the present study, we evaluated nine different biologically- or recombinantly-derived APMV strains for the ability to replicate and cause disease in rhesus macaque model. Five of the viruses were: biologically-derived wild type (wt) APMV-2, -3, -5, -7 and -9. Another virus was a recombinant (r) version of wt APMV-4. The remaining three viruses were versions of wt rAPMV-2, -4 and -7 in which the F cleavage site had been modified to be multi-basic. Rhesus macaques were inoculated intranasally and intratracheally and monitored for clinical disease, virus shedding from the upper and lower respiratory tract, and seroconversion. Virus shedding was not detected for wt APMV-5. Very limited shedding was detected for wt rAPMV-4 and modified rAPMV-4, and only in a subset of animals. Shedding by the other viruses was detected in every infected animal, and usually from both the upper and lower respiratory tract. In particular, shedding over a number of days in every animal was observed for modified rAPMV-2, wt APMV-7, and modified rAPMV-7. Modification of the F protein cleavage site appeared to increase shedding by wt rAPMV-2 and marginally by wt rAPMV-4. All APMVs except wt APMV-5 induced a virus-specific serum antibody response in all infected animals. None of the animals exhibited any clinical disease signs. These results indicate that APMVs 2, 3, 4, 7, and 9 are competent to infect non-human primates, but are moderately-to-highly restricted, depending on the serotype. This suggests that they are not likely to significantly infect primates in nature, and represent promising attenuated candidates for vector development.  相似文献   

17.
The purposes of this study were (1) to document outcome after primary fronto-orbital advancement for the four major eponymous craniosynostotic syndromes (Apert, Crouzon, Pfeiffer, and Saethre-Chotzen) and (2) to identify factors that might influence need for primary and secondary fronto-orbital advancement or foreheadplasty. Also tested was the hypothesis that coincident sagittal synostosis could modulate brachycephaly and affect whether a primary or secondary frontal operation was necessary. Data were collected on age and indications for initial operation, type of primary and secondary frontal procedures, and concomitant sagittal synostosis. Patients initially managed by subcranial Le Fort III were included in the study group but excluded from analysis of fronto-orbital advancement. Patients treated by monobloc advancement or Le Fort III osteotomies with frontal grafting or Anderl modification were assessed as having had primary fronto-orbital advancement. Minimum time to follow-up was 5 years. A total of 126 patients met inclusion criteria. Lateral photographs were examined to assess preoperative and postoperative sagittal position of supraorbital rims-to-globes. Frontal re-advancement was indicated if the corneal apex was anterior to the supraorbital rim. Foreheadplasty was indicated for unacceptable frontal contour and normal supraorbital rim-to-globe relationship. Primary correction for frontal retrusion was not required in 4 percent of Apert (1 of 25), 16 percent of Crouzon (7 of 44), 6 percent of Pfeiffer (2 of 31), and 19 percent of Saethre-Chotzen (5 of 26) patients. Of those infants who had a primary fronto-orbital advancement, reoperation for either supraorbital retrusion or frontal deformity was necessary in all 16 Apert patients and in 5 of 19 Crouzon (26 percent), 10 of 26 Pfeiffer (38 percent), and 13 of 20 Saethre-Chotzen (65 percent) patients (p < 0.001). Age at initial fronto-orbital advancement did not influence reoperative rate. No correlation was found between concomitant sagittal synostosis and necessity for primary or secondary frontal correction (p = 0.22). In summary, phenotypic diagnosis was determinant for outcome as defined by need for secondary fronto-orbital advancement, foreheadplasty, or both. Apert patients had the highest incidence of reoperation for frontal retrusion or forehead contour. Crouzon and Saethre-Chotzen patients were most likely to express a minor phenotype and not require fronto-orbital correction. Coincident sagittal synostosis did not influence frontal projection, as reflected in need for either primary or secondary frontal advancement.  相似文献   

18.
Peroxyacetyl nitrate was reactive with small molecular-weight sulfur-containing compounds The order of susceptibility was cysteine > reduced lipoic acid = reduced lipoamide > oxidized lipoic acid > oxidized lipoamide > methionine ? cystine. From thiols the predominant product was disulfide. In the early stages of oxidation methionine yielded methionine sulfoxide. Products of oxidation of oxidized lipoic acid and lipoamide were the respective sulfoxides. Cystine was resistant to oxidation, yielding cysteic acid when oxidation took place.Papain was readily inactivated by peroxyacetyl nitrate while lysozyme was resistant. The small amount of inactivation of lysozyme was correlated with methionine oxidation. Papain inactivation was correlated with thiol oxidation and could be reversed by thiol compounds. The oxidation product was judged to be a dimer by methods for determining molecular weight.  相似文献   

19.
To establish whether several amino acids were equally able to enter the phloem of oat (Avena sativa L.) plants and be transported, several (14)C-labeled amino acids were applied individually to an abraded spot on a fully expanded source leaf. The base of an immature sink leaf was monitored with a GM tube for time and rate of arrival of radioactivity. Transport of (14)C-sucrose and (14)CO(2) assimilates was measured for a comparison. The applied l-serine, l-lysine, and l-leucine, as well as sucrose, entered the phloem and were transported to the sink leaf at rates between 1.16 and 1.83 cm/min. Transport velocity for CO(2) assimilates was 1.57 cm/min. A heat girdle near the top of the source leaf sheath blocked most transport, which indicated that transport was primarily through the phloem. Mass transfer rates for amino acids were only 3% as great as that for sucrose, suggesting different mechanisms of entry for sucrose than for amino acids into the phloem. The higher percentage of CO(2) assimilates mobilized to the sink leaf was attributed to the greater surface area of minor veins accessible to loading, as compared to those compounds supplied via an abraded spot. Serine was extensively metabolized in the source leaf, and radioactive products in the sink leaf mirrored those in the source leaf. Most radioactivity of lysine and leucine remained within these compounds in the source, path, and sink tissues. We concluded that there was no barrier to entry of amino acids into the phloem and transport therein. Data do not suggest a specific mechanism for entry of amino acids into the phloem.  相似文献   

20.
Reproduction, feeding and population structure were investigated in the mountain mullet, Agonostomus monticola, in eastern Jamaica between 1982 and 1986. Female fishes just outnumbered males 1.2 : 1. Minimum size at maturity for females was 123 mm fork length (FL) and 96 mm FL for males. Mean size at maturity for females was 165.8 mm FL (S.D.=1.61) and for males was 148.4 mm FL (S.D.=2.97). Fecundity was 340 000 eggs for a 25 g ovary. Fecundity (F) was related to size by the equation F=153.8 FL1.36. Mean lengths of males and females captured by all methods were 129.4 mm (S.D.=5.56) and 160.4 mm FL (S.D.=0.70), respectively. A. monticola was found to be chiefly an insectivorous feeder. The major food items found in stomach contents in ranked sequence were insects, freshwater prawns, plant detritus and algae.  相似文献   

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