Innate mucosal-associated invariant T (MAIT) cells are activated in inflammatory bowel diseases.

Inflammatory bowel diseases are characterized by a deregulated immune response targeting the gut bacterial flora. Mucosal-associated invariant T (MAIT) cells are major histocompatibility complex (MHC) class Ib-restricted innate-like lymphocytes with anti-bacterial functions. They display an effector/memory phenotype and are found in large numbers in the blood, mucosae and liver. They have also been implicated in inflammatory diseases such as multiple sclerosis. Therefore, we aimed to analyse the possible involvement of MAIT cells in Crohn's disease (CD) and ulcerative colitis (UC). To this end, a phenotypical and functional analysis of MAIT cells isolated from the blood of healthy subjects, CD and UC patients was undertaken. MAIT cells were also quantified in ileal biopsies of CD patients. The frequency of blood MAIT cells was specifically reduced in IBD patients compared with healthy donors, whereas it was dramatically greater in the inflamed versus healthy tissue. MAIT cells were activated as they expressed significantly more the Ki67 antigen, and this was accompanied by phenotypical changes such as increased expression of natural killer (NK)G2D and B and T lymphocyte attenuator (BTLA). Finally, in-vitro-activated MAIT cells from CD and UC patients secreted significantly more interleukin (IL)-17, together with a decreased interferon (IFN)-γ in CD but an increased IL-22 in UC. These data show that MAIT cells are activated in IBD, which results in an increased recruitment towards the inflamed tissues, an altered phenotype and a switch in the pattern of cytokine secretion. This is the first demonstration that MAIT cells are immune players in IBD, whose precise functions in this context need to be addressed.

Kinetics of conformational changes of fibronectin adsorbed onto model surfaces.

Fibronectin (FN), a large glycoprotein found in body fluids and in the extracellular matrix, plays a key role in numerous cellular behaviours. We investigate FN adsorption onto hydrophilic bare silica and hydrophobic polystyrene (PS) surfaces using Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) in aqueous medium. Adsorption kinetics using different bulk concentrations of FN were followed for 2h and the surface density of adsorbed FN and its time-dependent conformational changes were determined. When adsorption occurs onto the hydrophilic surface, FN molecules keep their native conformation independent of the adsorption conditions, but the amount of adsorbed FN increases with time and the bulk concentration. Although the protein surface density is the same on the hydrophobic PS surface, this has a strong impact on the average conformation of the adsorbed FN layer. Indeed, interfacial hydration changes induced by adsorption onto the hydrophobic surface lead to a decrease in unhydrated beta-sheet content and cause an increase in hydrated beta-strand and hydrated random domain content of adsorbed FN. This conformational change is mainly dependent on the bulk concentration. Indeed, at low bulk concentrations, the secondary structures of adsorbed FN molecules undergo strong unfolding, allowing an extended and hydrated conformation of the protein. At high bulk concentrations, the molecular packing reduces the unfolding of the stereoregular structures of the FN molecules, preventing stronger spreading of the protein.

L-carnitine supplementation does not promote weight loss in ovariectomized rats despite endurance exercise.

In this five-week study, we tested the hypotheses that free access to a maintenance diet supplemented with L-carnitine (L-C) would reduce body fat in adult, sedentary, ovariectomized (OVX) rats, and that there would be an additive effect of L-C on weight reduction in swim-trained animals. As expected, serum carnitine was higher in rats fed the L-C diet, and the OVX-induced weight gain and abdominal fat were counteracted by swimming. L-C supplementation did not reduce the weight gain or abdominal fat in these adult female rats, Moreover, though not reaching statistical significance, rats that were fed L-C demonstrated a tendency for greater weight gain than their basal-fed counterparts despite no difference in energy intake. If the results of this study on ovariectomized rats can be translated to postmenopausal women, moderate intensity exercise may be recommended, but L-C supplementation, with no energy restriction, may be contraindicated as a weight loss method in this cohort.

Cotton boll age influences feeding preference by brown stink bug (Heteroptera: Pentatomidae).

Cotton plants were infested with brown stink bug, Euschistus servus (Say), to define cotton boll age classes (based on heat unit accumulation beyond anthesis) that are most frequently injured during each of the initial 5 wk of flowering. Bolls from each week were grouped into discrete age classes and evaluated for the presence of stink bug injury. Brown stink bug injured significantly more bolls of age class B (approximately 165-336 heat units), age class C (approximately 330-504 heat units), and age class D (approximately 495-672 heat units) during the initial 3 wk in both years and in week 5 in 2002 compared with other boll ages. Generally, the frequency of injured bolls was lowest in age class A (< or = 168 heat units) during these periods. The preference by brown stink bug for boll age classes B, C, and D within a week was similar when ages were combined across all 5 wk. Based on these data, bolls that have accumulated 165.2 through 672 heat units beyond anthesis (approximately 7-27-d-old) are more frequently injured by brown stink bug when a range of boll ages are available. The boll ages in our studies corresponded to a boll diameter of 1.161-3.586 cm with a mid-range of 2.375 cm. A general protocol for initiating treatments against stink bugs is to sample bolls for evidence of injury as an indicator of presence of infestations in cotton. Sampling bolls within a defined range, which is most likely to be injured, should improve the precision of this method in detecting economic stink bug infestations in cotton.

Boll injury and yield losses in cotton associated with brown stink bug (Heteroptera: Pentatomidae) during flowering.

Brown stink bug, Euschistus servus (Say), was infested on cotton, Gossypium hirsutum L., plants during reproductive stages to determine the effects on boll injury and seedcotton yield. During each week in 2002 and 2003, significantly more bolls with > or = 1 injured locule, bolls with > or = 2 injured locules, and bolls with discolored lint were recorded on stink bug-infested plants compared with that on noninfested plants. Significantly fewer bolls displayed external injury on the boll exocarp compared with bolls with only internal locule injury. Boll injury was significantly underestimated by the presence of external symptomology. The boll population increased 6.6- and 5.1-fold from weeks 1-5 in 2002 and 2003, respectively. There was a corresponding 6.2- and 4.6-fold increase in 2002 and 2003, respectively, for total bolls injured from weeks 1-5. Percentage of boll injury ranged from 10.7 (week 4) to 27.4 (week 2) in 2002 and from 9.2 (week 3) to 16.0 (week 2) in 2003. Percentage of injury was greatest during weeks 1 and 2 in both years and also in week 5 in 2002. Brown stink bug significantly reduced seedcotton yield of bolls present on cotton plants during weeks 1, 2, and 5 in 2002 and in weeks 4 and 5 in 2003. However, total seedcotton yield, as a function of bolls exposed to brown stink bug and subsequent bolls produced on plant in the absence of stink bugs, was not significantly different for plots infested during weeks 1-4 in 2002 and weeks 1-3 in 2003. Flowering period and boll population influence the severity of stink bug injury on seedcotton yield. Infestation timing and number of bolls should be considered, in addition to insect densities, when initiating treatments against brown stink bug.

Compensatory responses in mice carrying a null mutation for Ins1 or Ins2.

Intrauterine growth retardation and postnatal acute diabetes result from insulin deficiency in double homozygous null mutants for Ins1 and Ins2 (Duvillié B, et al., Proc. Natl. Acad. Sci. USA 94:5137-5140, 1997). The characterization of single homozygous null mutants for Ins1 or Ins2 is described here. Neither kind of mutant mice was diabetic. Immunocytochemical analysis of the islets showed normal distribution of the endocrine cells producing insulin, glucagon, somatostatin, or pancreatic polypeptide. Analysis of the expression of the functional insulin gene in Ins1-/- or Ins2-/- mice revealed a dramatic increase of Ins1 transcripts in Ins2-/- mutants. This compensatory response was quantitatively reflected by total pancreatic insulin content similar for both types of mutants and wild-type mice. Moreover, both mutants had normal plasma insulin levels and normal glucose tolerance tests. The determination of beta-cell mass by morphometry indicated beta-cell hyperplasia in the mutant mice. The beta-cell mass in Ins2-/- mice was increased almost threefold, which accounts for the increase of Ins1 transcripts in Ins2-/-mutants. This study thus contributes to evaluate the potential of increasing the beta-cell mass to compensate for low insulin production.

Stressors and rearing diseases of Trichoplusia ni: evidence of vertical transmission of NPV and CPV.

Inability to consistently rear healthy Trichoplusia ni led to a study of its rearing diseases. Four diseases were designated after preliminary research which included electron microscopy: cytoplasmic polyhedrosis (due to cytoplasmic polyhedrosis virus, or CPV), nuclear polyhedrosis (due to nucleopolyhedrovirus, or NPV), "neonate death" syndrome (mortality in first or second instars), and "late-instar" syndrome (death in late instars accompanied by bacterial decomposition). Infectious agents were not detected by electron microscopy in insects with the latter two diseases. Prevalence of CPV and NPV, but not the neonate-death or late-instar diseases, in progeny was significantly associated with pairs of mating adults. In conjunction with egg-surface decontamination, this indicated that both viruses may be transmitted transovarially. Pupae killed by CPV had virions in the cytoplasm of infected cells, but polyhedra were empty, not occluding virions. None of the diseases had a consistent pattern of prevalence associated with the date on which eggs were laid after oviposition began. Prevalence rates of cytoplasmic polyhedrosis, nuclear polyhedrosis, and the late-instar disease were significantly greater at 95-100% relative humidity (RH) than at RH levels of 75% or below. These same three diseases killed significantly more insects in crowded rearing conditions (four or five larvae per cup with 10.2-cm(2) diet surface) than in uncrowded conditions (one to three larvae per cup). As a result of these experiments, healthy T. ni have been reared for 10 generations by use of a modified Pasteur method and rearing cups containing no more than two larvae.

A simplified closed artificial ecosystem--recycling of organic matter into wheat plants.

A simplified closed system consisting of a plant growth chamber coupled to a decomposition chamber was used to study carbon exchange dynamics. The CO2 produced via the decomposition of wheat straw was used for photosynthetic carbon uptake by wheat plants. The atmosphere of the two chambers was connected through a circuit of known flow rate. Thus, monitoring the CO2 concentrations in both compartments allowed measurement of the carbon exchange between the chambers, and estimation of the rate of respiration processes in the decomposition chamber and photosynthetic rate in the producer chamber. The objective for CELSS research was to simulate a system where a compartment producing food via photosynthesis, would be supplied by CO2 produced from respiration processes. The decomposition of biomass by the decomposer simulated both the metabolism of a crew and the result of a recycling system for inedible biomass. Concerning terrestrial ecosystems, the objective was to study organic matter decomposition in soil and other processes related to permanent grasslands.

Genetic engineering in mice: impact on insulin signalling and action.

The expression of a number of genes encoding key players in insulin signalling and action, including insulin, insulin receptor (IR), downstream signalling molecules such as insulin receptor substrate-1 (IRS-1) and IRS-2, glucose transporters (GLUT4, GLUT2) and important metabolic enzymes such as glucokinase, has now been altered in transgenic or knockout mice. Such mice presented with phenotypes ranging from mild defects, revealing complementarity between key molecules or pathways, to severe diabetes with ketoacidosis and early postnatal death. Insulin action could also be improved by overproduction of proteins acting at regulatory steps. The development of diabetes by combining mutations, which alone do not lead to major metabolic alterations, validated the 'diabetogenes' concept of non-insulin-dependent diabetes mellitus. Genes encoding insulin-like growth factors (IGF-I and IGF-II) and their type I receptor (IGF-IR) have also been disrupted. It appears that although IR and IGF-IR are both capable of metabolic and mitogenic signalling, they are not fully redundant. However, IR could replace IGF-IR if efficiently activated by IGF-II. Studies with cell lines lacking IR or IGF-IR lend support to such conclusions. Concerning the issues of specificity and redundancy, studies with cell lines derived from IRS-1-deficient mice showed that IRS-1 and IRS-2 are also not completely interchangeable.

Laboratory reliability of the Papanicolaou smear.

Variation in clinical cytology diagnoses was examined at the microscope and in the cytology laboratory as a unit. Results provide preliminary information about the comparability of cytologic diagnosis under specified conditions. In onsite proficiency testing using "normed" smears with a wide range of findings, 814 individual cytotechnologists and cytopathologists from 306 laboratories in 44 states made the target diagnosis in 63.8% of 8929 cases. False negative diagnoses were made in 7.5% of 4520 smears with moderate dysplasia through frank malignancy, and false positive diagnoses were recorded in 8.9% of 3808 smears with no more than benign atypia. Evaluation of a sample of actual work output from two laboratories showed 3.2 to 3.4% false positive and 4.8 to 11.2% false negative diagnoses on the cases rescreened.

The issue of quality of personnel.

Sophisticated laboratory tests must be performed by competent personnel. But how is that competence to be judged? This paper argues that determination of personnel competence be left up to individual laboratory directors and supervisors. Likewise, accountability for having competent employees on staff should reside with the laboratory director. This paper suggests that professional organizations create reasonable standards of knowledge and competence that individual laboratory supervisors can apply to their own employees.

Comparison of laboratory performance with blind and mail-distributed proficiency testing samples.

Simulated addict urine samples containing drugs were sent to collaborating hospital administrators and officials of methadone centers, who then forwarded the samples to their supporting laboratories as though they were ordinary specimens from patients. The laboratories, which were already participating in the proficiency testing program of the Center for Disease Control, received the identical test samples in the mail as part of a regular Center for Disease Control proficiency testing program. Most of the laboratories performed acceptably with the mail-distributed samples, but many performed poorly when the identical samples were sent to them as if they were specimens from patients. Because of the limitations of proficiency testing involving mail-distribution samples and the impracticality of extensive testing with blind samples on a national level, the Center for Disease Control proposes to compliment its regular proficiency testing program with a monitored, onsite program of performance evaluation.

The impact of laboratory improvement programs on laboratory performance: the CLIA 67 experience.

The experience acquired by the Center for Diseases Control during the past 7 years in the administration of the Clinical Laboratories Improvement Act of 1967 suggests that the key indicators of reliability have been identified and that sensitive measurement of those indicators is now possible and practical. The costs of assuring high quality are inconsequential compared to the costs to the patient and taxpaying public of inaccurate test results. This objective system for evaluating clinical laboratories has been applied to licensed interstate laboratories and has been shown to be effective. This proven system has been offered to the Bureau of Health Insurance of the Social Security Administration for application to Medicare laboratories.

Human chorionic somatomammotropin in normal adolescent primiparous pregnancy. I. Effect of smoking.

PIP: Human chorionic somatomammotropin (HCS) levels were studied in normal smoking and nonsmoking primiparous adolescent pregnancies. 136 teenagers, aged 12-18 years, were divided into groups: nonsmokers, deep, and shallow inhalers, long, and short puffers, high, and low tar, and high, and low nicotin. Shallow inhaling and low nicotine exposure patients were found to have a later age of menarche than did nonsmokers (13.2 vs. 12.3 years, p=.03). The mean body weight of the mothers who smoked was slightly less (61 gm) than that of nonsmoking mothers. Except for long puffers, overall, smokers had significantly lower HCS values throughout pregnancy than noosmokers (p = .48 high tar-p = .002 low tar). However, in the third trimester those with the lowest smoking exposures had the lowest HCS values and the heavier smokers had slightly higher mean values than nonsmokers. These data suggest that HCS production may be more sensitive to low tar and nicotine exposure with possible tolerance or even stimulation occurring in larger doses.^ieng

Pectin esterase in relation to leaf abscission in coleus and phaseolus.

Pectin esterase (PE) activities in abscission zones, other portions of leaves, and adjacent stem tissues were compared in attached leaves and abscissing petioles (previously debladed) of Coleus blumei Benth. and Phaseolus vulgaris L., cv. Canadian Wonder. Earlier findings of Osborne in bean were confirmed and changes in PE activity in coleus were shown to resemble those in bean in some respects. In both plants PE was lower in the distal portion of abscission zones of abscissing petioles than in that portion of attached leaves but this difference was not as large or as consistently clear-cut in coleus as in bean. The general level of PE activity was an order of magnitude lower and changes associated with abscission were smaller in coleus than in bean. Auxin treatment of debladed petioles of coleus prevented abscission and resulted in small increases in PE activity in abscission zones and most of the other regions sampled. The largest increase was observed in the stem tissue adjacent to the attached leaf opposite the debladed, auxin treated one.The activity of coleus PE was highest in the pH range from 7.3 to 7.6. The pH of distal tissue from abscission zones of abscissing petioles was 5.8. This was 0.7 pH units lower than that of proximal tissue from the same zones.PE from both coleus and bean appears to be denatured by freezing and/or thawing.