Automated imaging MS: Toward high throughput imaging mass spectrometry

The term molecular histology has been used to convey the potential of imaging mass spectrometry to describe tissue by its constituent peptides and proteins, and to link this with established histological features. The low throughput of imaging mass spectrometry has been one of the factors inhibiting a full investigation of the clinical potential of molecular histology. Here we report the development of an automated set-up, consisting of a controlled environment sample storage chamber, a sample loading robot, and a MALDI-TOF/TOF mass spectrometer, all controlled by a single user interface. The automated set-up is demonstrated to have the positional stability and experimental reproducibility necessary for its clinical application.     

Long‐term Successful Weight Loss Improves Vascular Endothelial Function in Severely Obese Individuals

Obesity is associated with increased cardiovascular risk. Although short‐term weight loss improves vascular endothelial function, longer term outcomes have not been widely investigated. We examined brachial artery endothelium‐dependent vasodilation and metabolic parameters in 29 severely obese subjects who lost ≥10% body weight (age 45 ± 13 years; BMI 48 ± 9 kg/m²) at baseline and after 12 months of dietary and/or surgical intervention. We compared these parameters to 14 obese individuals (age 49 ± 11 years; BMI 39 ± 7 kg/m²) who failed to lose weight. For the entire group, mean brachial artery flow‐mediated dilation (FMD) was impaired at 6.7 ± 4.1%. Following sustained weight loss, FMD increased significantly from 6.8 ± 4.2 to 10.0 ± 4.7%, but remained blunted in patients without weight decline from 6.5 ± 4.0 to 5.7 ± 4.1%, P = 0.013 by ANOVA. Endothelium‐independent, nitroglycerin‐mediated dilation (NMD) was unaltered. BMI fell by 13 ± 7 kg/m² following successful weight intervention and was associated with reduced total and low‐density lipoprotein cholesterol, glucose, hemoglobin A_1c, and high‐sensitivity C‐reactive protein (CRP). Vascular improvement correlated most strongly with glucose levels (r = ?0.51, P = 0.002) and was independent of weight change. In this cohort of severely obese subjects, sustained weight loss at 1 year improved vascular function and metabolic parameters. The findings suggest that reversal of endothelial dysfunction and restoration of arterial homeostasis could potentially reduce cardiovascular risk. The results also demonstrate that metabolic changes in association with weight loss are stronger determinants of vascular phenotype than degree of weight reduction.     

Synthesis and in vitro evaluation of a novel iodinated resiniferatoxin derivative that is an agonist at the human vanilloid VR1 receptor

Using a 'directed' iodination procedure, novel iodo-resiniferatoxin congeners were synthesized from 4-acetoxy-3-methoxyphenylacetic acid and resiniferinol- 9,13,14-ortho-phenylacetate (ROPA). The 2-iodo-4-hydroxy-5-methoxyphenylacetic acid ester of resiniferinol 5 displayed high affinity binding (K(i)=0.71 nM) for the human vanilloid VR1 receptor and functioned as a partial agonist.     

Response of Peach Seedlings to Infection by the Root Lesion Nematode Pratylenchus penetrans under Controlled Conditions

Twenty-one open pollinated populations of peach rootstock seedlings were evaluated for their response to infection by the root lesion nematode, Pratylenchus penetrans, over a period of 98 days. Nematode-infected peach seedling populations were shorter in plant height and had less shoot weight but more dry root weight than nematode-free controls. Rootstock differences were demonstrated for nematode increase over the 98-day period, and average total numbers of nematodes in soil and roots. Rootstocks were classified into three groups differing in total nematode population levels, ratio of nematode increase, and the number of nematodes per root. The heritable nature of rootstock response to nematodes was evident. Rootstocks showing the lowest response to nematode infection included Tzim Pee Tao, Rutgers Red Leaf, and two progenies of a cross of these two rootstocks.     

Oxygen and nitrate reduction kinetics of a nonflocculating strain of Zoogloea ramigera

The oxygen and nitrate reduction kinetics of a nonflocculating strain of Zoogloea ramigera were determined. Axenic, nitrate-reducing bacterial suspensions were acclimated to various oxygen levels in a chemostat while measuring nitrate reduction in the presence of high ammonium nitrogen concentrations. Significant nitrate reduction was observed at oxygen concentrations up to 8 mg L^–1. Oxygen consumption was inhibited by oxygen concentrations in excess of 2 mg L^–1.     

Micrometastases in bone marrow in patients with primary breast cancer: evaluation as an early predictor of bone metastases.

The bone marrow of 307 patients with primary breast cancer was examined for tumour cells by immunocytochemistry using an antiserum to epithelial membrane antigen. Micrometastases were found in 81 cases (26.4%) and their presence was related to various poor prognostic factors: spread to lymph nodes, vascular invasion, T stage, and pathological size. The median duration of follow up was 28 months. Seventy five patients relapsed, 60 at distant sites. Of these 60 patients, 26 had micrometastases detected at presentation and 34 were free of micrometastases initially. The relapse free interval was significantly shorter for patients with micrometastases, and these patients had a shorter survival. Analysis of the sites of relapse showed that the test predicted bone metastases only. Thus 10 out of 19 patients (53%) who developed bone metastases at first relapse had micrometastases at presentation compared with only 41 out of 288 patients (14%) who remained free of bone metastases or relapsed in non-skeletal sites. The presence of micrometastases detected at the time of initial surgery in a patient with primary breast cancer is a useful predictor of early relapse in bone and may help in selecting patients for subsequent systemic treatment.     

Some mechanisms of salt tolerance in crop plants

Summary In the first part of this review the main features of salt tolerance in higher plants are discussed. The hypothesis of intracellular compartmentation of solutes is used as a basis for models of tolerance mechanisms operating in roots and in leaves. Consideration is given to the implications of the various mechanisms for the yield potential of salt-tolerant crop plants.Some work on the more salt-tolerant members of the Triticeae is then described. The perennial speciesElytrigia juncea andLeymus sabulosus survive prolonged exposure to 250 mol m^–3 NaCl, whereas the annual Triticum species are severely affected at only 100 mol m^–3 NaCl. In the perennial species the tissue ion levels are controlled within narrow limits. In contrast, the more susceptible wheats accumulate far more sodium and chloride than is needed for osmotic adjustment, and the effects of salt stress increase with time of exposure.Two different types of salt tolerance are exhibited in plants capable of growing at high salinities. In succulent Chenopodiaceae, for example, osmotic adjustment is achieved mainly by accumulation of high levels of sodium and chloride in the shoots, accompanied by synthesis of substantial amounts of the compatible solute glycinebetaine. This combination of mechanisms allows high growth rates, in terms of both fresh and dry weight. At the opposite end of the spectrum of salt tolerance responses are the halophytic grasses, which strictly limit the influx of salts into the shoots, but suffer from very much reduced growth rates under saline conditions. Another variation is shown in those species that possess salt glands. The development and exploitation of crop plants for use on saline soils is discussed in relation to the implications of these various mechanisms.     

Protein-polynucleotide scattering centers as a protein structure probe.

When certain basic globular proteins are mixed with nucleic acids near a critical concentration ratio, large, low density scattering centers of about 10(9) particle weight are created. Scattering from these complexes is altered when thermally inactivated proteins are substituted for enzymes in their native, globular conformation. Scattering data from heat-treated ribonuclease and lysozyme mixed with four different synthetic homopolyribonucleotides are reported. The concentration of nucleic acid necessary to produce maximum scattering from a heat-treated protein sample is shown to be a direct indication of the amount of enzyme that remains biologically active after being heated.