Promoter strength and tissue specificity effects on growth of tomato plants transformed with maize sucrose-phosphate synthase

When sucrose-phosphate synthase (SPS; EC 2.4.1.14) is expressed in tomato (Lycopersicon esculentum Mill.) from a ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) small subunit (rbcS) promoter, yields are often unchanged but when SPS is expressed from a Cauliflower Mosaic Virus 35S promoter, yield is enhanced up to 80%. Two explanations for this phenomenon are (i) that expression of SPS in tissues other than leaves accounts for the increased yield or (ii) that the lower level of expression directed by the 35S promoter is more beneficial than the high level of expression directed by the rbcS promoter. To test the first hypothesis, we conducted a reciprocal graft experiment, which showed that root SPS activity did not substantially affect growth. To test the second hypothesis, we conducted a field trial using a backcrossed, segregating, population of SPS-transformed plants derived from 35S and rbcS lines. The optimal dose of SPS activity for growth was approximately twice that of the wild type regardless of which promoter was used. The effect of SPS on growth was the result of a shift in partitioning of carbon among starch, sucrose, and ionic compounds (primarily amino acids), rather than of an increase in net photosynthesis. Excessive SPS activity resulted in a decreased rate of amino acid synthesis, which could explain the non-linear response of plant growth to the level of SPS expression. Received: 23 May 2000 / Accepted: 24 July 2000     

Adsorption of bacteria to roots as related to host specificity in the Rhizobium-clover symbiosis.

Quantitative microscope techniques were utilized to examine the adsorption of rhizobial cells to clover root hairs. Adsorption of cells of noninfective strains of Rhizobium trifolii or infective R. meliloti strains to clover root hairs was four to five times less than that of the infective R. trifolii strains. Attachment of the rod-shaped bacteria to clover root cells occurred in a polar, end-on fashion. Viable or heat-killed R. trifolii cells precoated with a clover lectin having 2-deoxyglucose specificity had increased adsorption to clover roots. Adsorption of bacteria to roots was not increased if the clover lectin was inactivated by heat or 2-deoxyglucose treatment prior to incubation with R. trifolii. Adsorption of R. trifolii to clover root hairs was inhibited by 2-deoxyglucose (30 mM) but not by 2-deoxygalactose or alpha-D-glucose. Adsorption of R. meliloti cells to alfalfa root hairs was not affected by 2-deoxyglucose at that concentration. These results suggest that expression of host specificity in the Rhizobium-clover symbiosis involves a preferential adsorption of infective cells to clover root hairs through a 2-deoxyglucose-sensitive receptor site.     

Cellular immunity to Hodgkin's splenic tissue measured by leucocyte migration inhibition.

Patients with lymphoreticular malignancy were shown by a leucocyte migration inhibition technique to have cellular immunity to Hodgkin''s splenic tissue. Migration was significantly inhibited in 31 out of 55 patients with Hodgkin''s lymphoma and 19 out of 39 patients with other types of lymphoma. Inhibition was also shown in only three out of 29 patients with other malignancy, one out of 23 normal volunteers, and one out of 25 patients with non-malignant disease. The splenic factor that inhibits leucocyte migration, which has yet to be isolated and identified, may be a helpful diagnostic tool in patients with suspected lymphoma.     

Fetal growth as measured by ultrasound

Until the last decade, investigation of fetal growth has been based on data from premature births and abortuses. Advances in ultrasound scanning have expanded the precision and uses of this technology in studies of fetal growth. Most ultrasound studies of fetal growth are based on clinical populations and are reported in clinical journals. The present paper reviews features of ultrasound technology relating to fetal measurement. The most commonly measured dimensions and their associated measurement errors, distributions and uses are detailed. Ultrasound studies of intrauterine growth retardation and in utero fetal weight estimation are critically reviewed. Finally, a comparison between the fetal growth curve based on ultrasound measurement and on data from preterm or aborted fetuses is compared. Critical comments on sample design and statistical treatment of the data from ultrasound studies is included in each of the areas discussed.     

Towards a unifying approach to diversity measures: bridging the gap between the Shannon entropy and Rao's quadratic index

The diversity of a species assemblage has been studied extensively for many decades in relation to its possible connection with ecosystem functioning and organization. In this view most diversity measures, such as Shannon's entropy, rely upon information theory as a basis for the quantification of diversity. Also, traditional diversity measures are computed using species relative abundances and cannot account for the ecological differences between species. Rao first proposed a diversity index, termed quadratic diversity (Q) that incorporates both species relative abundances and pairwise distances between species. Quadratic diversity is traditionally defined as the expected distance between two randomly selected individuals. In this paper, we show that quadratic diversity can be interpreted as the expected conflict among the species of a given assemblage. From this unusual interpretation, it naturally follows that Rao's Q can be related to the Shannon entropy through a generalized version of the Tsallis parametric entropy.     

Relationships between body fat measured by DXA and subcutaneous adipose tissue thickness measured by Lipometer in adults

The aim of this study was to examine the relationships between body fat measured by DXA and subcutaneous adipose tissue layers (SAT-layers) measured by LIPOMETER in adult males (n=28) and females (n=53). Body height and mass were measured and BMI was calculated (kg/m2). Measurements of the thicknesses of SAT-layers by LIPOMETER were performed at 15 original body sites. Body composition was measured using DXA. Total body fat % measured by DXA was highly dependent on the SAT-layers in the upper back and inner thigh in males (87.1%, R(2)x100) and the lateral chest, biceps, and calf in females (78.5%, R(2)x100). There were gender differences in trunk fat mass and right hand and leg fat mass calculation using specific SAT-layers. In conclusion, our results indicate that there are close relationships between SAT-layers and body fat measured by DXA. However, there are big differences between genders.     

Glucocorticoid response to exercise as measured by serum and salivary cortisol

Serum and salivary cortisol concentrations were studied in 78 elite athletes engaged in different sports, by subjecting them to high-intensity laboratory exercise. The mean difference in the pre-exercise cortisol concentrations in the seven groups studied were more marked in serum (from 311 to 768 nmol.l-1) than in saliva (from 17.9 to 22.7 nmol.l-1, only one group reaching 40 nmol.l-1). Judging from the correlation coefficients based on total variances, the post-/pre-exercise differences in cortisol concentrations in serum depended chiefly on pre-exercise values, while those in saliva tended to depend more on the postexercise concentrations. The coefficients of correlation between that difference and either the pre- or postexercise values were -0.71 and 0.47, respectively, for serum, and -0.51 and 0.58, respectively, for saliva. This would suggest that salivary cortisol concentration might be a more suitable variable for assessing glucocorticoid activity in exercise than serum cortisol concentration, probably being less sensitive to pre-exercise emotional state.     

Cryoprotection in hearts as measured by CPK

Rat hearts were treated with a cryoprotectant solution composed of glycerol and DMSO in concentrations ranging from 10–25% $\text{v}\text{v}$, and then frozen in liquid nitrogen. Creatine phosphokinase activity was then measured spectrophotometrically and activities were compared with activities of frozen-untreated hearts, unfrozen-treated hearts, and unfrozen-untreated hearts. Independently freezing or treating increased enzyme activity, but when hearts were treated and then frozen, activity diminished below that of the unfrozen-untreated group. Evidence suggests (1) DMSO-glycerol solution either has a toxic effect that increases with concentration and freezing additionally aggravates this effect, or the concentrations of cryoprotectants used do not adequately protect the tissue during freezing which causes damage to the contractile mechanism; and (2) the anoxic state of the tissue causes depletion of ATP and creatine phosphate such that creatine phosphokinase is inactive or not able to function.     

Forces applied by cilia measured on explants from mucociliary tissue

Forces applied by intact mucus-propelling cilia were measured for the first time that we know of using a combined atomic force microscopy (AFM) and electrooptic system. The AFM probe was dipped into a field of beating cilia and its time-dependent deflection was recorded as it was struck by the cilia while the electrooptic system simultaneously and colocally measured the frequency to ensure that no perturbation was induced by the AFM probe. Using cilia from frog esophagus, we measured forces of ~0.21 nN per cilium during the effective stroke. This value, together with the known internal structure of these cilia, leads to the conclusion that most dynein arms along the length of the axoneme contribute to the effective stroke of these cilia.     

The biochemical profile of rat testicular tissue as measured by magic angle spinning 1H NMR spectroscopy

The testis is the principal organ of male fertility, responsible for the production of spermatozoa and their maturation into sperm. However, the underlying biochemistry of the testis is relatively understudied. The fluidic and homogeneous nature of the testis makes it an ideal organ for high resolution magic angle spinning (MAS) 1H NMR spectroscopy. In this study we have catalogued the low molecular weight metabolites. The testis contains large amounts of creatine, of which a substantial proportion was shown to be extracellular using bipolar gradients to measure apparent diffusion coefficients. The tissue also contained relatively high amounts of uridine.     

Oxygen consumption rate of tissue measured by a micropolarographic method

A new method for measuring the oxygen consumption rate of a sheet of homogeneous tissue is described. The method measures, by a Clark-type oxygen electrode without a membrane, the time for the tissue to consume all its dissolved oxygen. The electrode is applied to one surface of the tissue sheet and the other surface is sealed from the atmosphere by a cover slip. The consumption is calculated from an estimate of the oxygen dissolved in the tissue at the moment it is covered and the time for the oxygen tension at one surface to fall to zero. The data also yield the oxygen diffusion coefficient in the oxygen-consuming tissue.     

The biomechanical effects of deep tissue support as related to brow and facelift procedures

The adverse effects of increased tension across a healing wound are well known. However, the effect of closing a wound in layers in order to decrease tension on the epidermis has been a source of controversy. It is hypothesized that deep tissue support decreases skin tension upon wound closure. In order to clarify this issue, a two-part study was designed to address the immediate effects of deep tissue support in vitro using fresh-frozen cadavers and in vivo on patients undergoing scheduled surgery. Closing skin tension was measured at standard reference points in coronal brow lift and rhytidectomy procedures performed with and without galeal closure and superficial musculoaponeurotic system (SMAS) procedures, respectively. Deep tissue support was found to significantly (p less than 0.05) decrease skin tension at the time of skin closure at standard reference points in coronal brow lift and rhytidectomy procedures performed on fresh-frozen cadavers. Similar significant (p less than 0.05) decreases in closing skin tension also were found in vivo in patients undergoing similar surgical procedures. Stress relaxation was not found to play a significant role in contributing to this immediate decrease in closing skin tension. It would appear, therefore, that deep tissue support, in the form of galeal closure and an SMAS procedure in coronal brow lift and rhytidectomy procedures, respectively, provides increased viscoelastic support, producing immediate significant decreases in closing skin tension in these procedures. The beneficial effects on wound healing, scar formation, tension-related trophic skin changes, and possible improved long-term results are discussed.     

Addiction to MTH1 protein results in intense expression in human breast cancer tissue as measured by liquid chromatography-isotope-dilution tandem mass spectrometry

MTH1 protein sanitizes the nucleotide pool so that oxidized 2′-deoxynucleoside triphosphates (dNTPs) cannot be used in DNA replication. Cancer cells require MTH1 to avoid incorporation of oxidized dNTPs into DNA that results in mutations and cell death. Inhibition of MTH1 eradicates cancer, validating MTH1 as an anticancer target. By overexpressing MTH1, cancer cells may mediate cancer growth and resist therapy. To date, there is unreliable evidence suggesting that MTH1 is increased in cancer cells, and available methods to measure MTH1 levels are indirect and semi-quantitative. Accurate measurement of MTH1 in disease-free tissues and malignant tumors of patients may be essential for determining if the protein is truly upregulated in cancers, and for the development and use of MTH1 inhibitors in cancer therapy. Here, we present a novel approach involving liquid chromatography–isotope-dilution tandem mass spectrometry to positively identify and accurately quantify MTH1 in human tissues. We produced full length ¹⁵N-labeled MTH1 and used it as an internal standard for the measurements. Following trypsin digestion, seven tryptic peptides of both MTH1 and ¹⁵N-MTH1 were identified by their full scan and product ion spectra. These peptides provided a statistically significant protein score that would unequivocally identify MTH1. Next, we identified and quantified MTH1 in human disease-free breast tissues and malignant breast tumors, and in four human cultured cell lines, three of which were cancer cells. Extreme expression of MTH1 in malignant breast tumors was observed, suggesting that cancer cells are addicted to MTH1 for their survival. The approach described is expected to be applicable to the measurement of MTH1 levels in malignant tumors vs. surrounding disease-free tissues in cancer patients. This attribute may help develop novel treatment strategies and MTH1 inhibitors as potential drugs, and guide therapies.