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PubMed2005

Extracellular sensors and extracellular alarmones, which permit cross-talk between organisms, determine the levels of alkali tolerance and trigger alkaliinduced acid sensitivity in Escherichia coli.

For several stress responses in Escherichia coli, switching on involves conversion by the stress of an extracellular stress sensor (an extracellular sensing component, ESC) to an extracellular induction component (EIC), the latter functioning as an alarmone and inducing the response. The aim of this study was to establish whether alkali tolerance induction at pH 9.0, alkali sensitisation induced at pH 5.5 and the acid sensitisation induced at pH 9.0 involve sensing of pH changes by ESCs. The techniques involved made use of studies with cell-free culture filtrates. With respect to the inducible responses under test, these filtrates were prepared either from induced or uninduced cultures and filtrates from uninduced cultures were also activated in vitro, by the pH stress, in the absence of bacteria. Tests were then made to examine whether EICs (known to be needed for all these systems) are formed by activation, at the appropriate pH values, of filtrates from pH 7.0-grown cultures (i.e. uninduced culture filtrates); appearance of an EIC on activation would indicate the presence in the uninduced culture filtrate of an ESC. The studies showed that all three systems use ESCs to detect pH changes. Tests involving attempted enzymic and physical inactivation of the ESCs, and attempted removal of the ESCs by dialysis, showed that the ESC involved in alkali sensitisation is a small very heat-resistant protein. Strikingly, protease only partially inactivated the ESCs needed for alkali tolerance induction and for acid sensitisation; each system may be complex, involving both protein and non-protein (RNA?) ESCs, although other explanations are possible. It was also established that appropriate killed cultures can induce all three responses when incubated with pH 7.0-grown living cultures. The occurrence of ESC/EIC pairs for these three responses has led to the evolution of early warning systems for each, the diffusibility of the EICs, and their interaction with non-producers, allowing them to act pheromonally, inducing sensitive organisms to stress tolerance, prior to exposure to stressor.

Acids↗

PubMed2005

[Confirmation of non-permitted dyes detected in Akasu (red vinegar) by LC/MS].

Suitable liquid chromatography/mass spetrometry (LC/MS) conditions were examined for Amaranth, Red 2G (R2G), Azo Rubine (Azo), Fast Red E (FRE) and Brilliant Blue FCF, which were detected in Akasu, a red vinegar made in Hong Kong from sake lees, on both thin layer chromatography (TLC) and photodiode array high-performance liquid chromatography (PDA-HPLC). Molecular-related ions for each dye were detected with excellent sensitivity by LC/MS using electro-spray ionization with negative ion mode, capillary voltage 3.00 kV, cone voltage 50 V and desolvation temperature 400 degrees C. LC/MS analysis of refined Akasu under these conditions enabled us to obtain clear mass spectra of R2G, Azo and FRE, which were present at trace levels in the Akasu. The results were consistent with those from TLC and PDA-HPLC. These experiments suggested that LC/MS analysis is applicable for confirmation of dyes in food.

Acetic Acid↗

PubMed2005

The use of pancreas biopsy scoring provides reliable porcine islet yields while encapsulation permits the determination of microbiological safety.

For clinical xenogenic islet transplantation to be successful, several requirements must be met. Among them is a sizeable and reliable source of fully functional and microbiologically safe islets. The inherent variability among porcine pancreases, with respect to islet yield, prompted us to develop a Biopsy Score technique to determine the suitability of each pancreas for islet isolation processing. The Biopsy Score consists of an assessment of five variables: warm ischemia time, pancreas color, fat content, islet size, and islet demarcation, each of which is assigned a value of -1 or +1, depending on whether or not the established criteria is met. For determination of islet size and demarcation, fresh biopsies of porcine pancreases are stained with dithizone (DTZ) solution and examined under a dissecting microscope. Based on the scoring of such biopsies in pancreases from 26-56-month-old sows, we report here that the presence of large (>100 microm diameter), well-demarcated islets in the pancreas biopsy is a reliable predictor of isolation success. Encapsulation of the isolated porcine islets within the inner layer of a 1.5% agarose and an outer layer of 5.0% agarose macrobead, containing 500 equivalent islet number (EIN), provides for extended in vitro functional viability (>6 months of insulin production in response to glucose), as well as for comprehensive microbiological testing and at least partial isolation of the xenogeneic islets from the host immune system. All microbiological testing to date has been negative, except for the presence of porcine endogenous retrovirus (PERV). Taken together, we believe that the Biopsy Score enhancement of our islet isolation technique and our agarose-agarose macroencapsulation methodology bring us significantly closer to realizing clinical porcine islet xenotransplantation for the treatment of insulin-dependent diabetic patients.

Animals↗

PubMed1992

Planar motion permits perception of metric structure in stereopsis.

A fundamental problem in the study of spatial perception concerns whether and how vision might acquire information about the metric structure of surfaces in three-dimensional space from motion and from stereopsis. Theoretical analyses have indicated that stereoscopic perceptions of metric relations in depth require additional information about egocentric viewing distance; and recent experiments by James Todd and his colleagues have indicated that vision acquires only affine but not metric structure from motion--that is, spatial relations ambiguous with regard to scale in depth. The purpose of the present study was to determine whether the metric shape of planar stereoscopic forms might be perceived from congruence under planar rotation. In Experiment 1, observers discriminated between similar planar shapes (ellipses) rotating in a plane with varying slant from the frontal-parallel plane. Experimental conditions varied the presence versus absence of binocular disparities, magnification of the disparity scale, and moving versus stationary patterns. Shape discriminations were accurate in all conditions with moving patterns and were near chance in conditions with stationary patterns; neither the presence nor the magnification of binocular disparities had any reliable effect. In Experiment 2, accuracy decreased as the range of rotation decreased from 80 degrees to 10 degrees. In Experiment 3, small deviations from planarity of the motion produced large decrements in accuracy. In contrast with the critical role of motion in shape discrimination, motion hindered discriminations of the binocular disparity scale in Experiment 4. In general, planar motion provides an intrinsic metric scale that is independent of slant in depth and of the scale of binocular disparities. Vision is sensitive to this intrinsic optical metric.

Adult↗

PubMed2001

Of mice and men: virtual Hebb-Williams mazes permit comparison of spatial learning across species.

We developed a computer-generated virtual environment to test humans, for the first time, on the Hebb-Williams mazes. The goal was to provide a standardized test that could be used to directly compare human performance with that of C57BL/6J mice performing in real versions of the mazes. Such a comparison seems crucial if conclusions regarding genetic manipulations of rodents are to be mapped onto human cognitive disorders. The learning curves across species were strikingly similar, lending support to the rodent model of human spatial memory. Humans learned faster than rodents in both the acquisition and the test portions of the protocol, and females of both species were less efficient in solving these problems than males. These results represent the first modern comparison of human and rodent learning that uses the same test of spatial problem solving.

Adult↗

PubMed2005

Potential for radiation therapy technology innovations to permit dose escalation for non-small-cell lung cancer.

BACKGROUND: Innovations in radiation therapy (RT) technology could have the potential to allow for radiation dose escalation by evaluating tumor motion, minimizing and compensating for motion, and evaluating delivery technologies such as 3-dimensional (3D) conformal radiation therapy (CRT) and intensity-modulated RT (IMRT) using tomotherapy. MATERIALS AND METHODS: Ninety different RT plans were generated using 3 different treatment techniques for 10 patients. These were evaluated using dosimetric tools such as dose-volume histogram (DVH) analysis, tumor equivalent uniform dose (EUD), and dosimetric parameters predictive for lung toxicity, such as the volume of lung receiving > 20 Gy of radiation (V20) and the normalized mean total radiation dose to the lung (NTDmean). The 3 techniques studied included free breathing using 3D CRT, 3D CRT with maximum-inspiration breath-hold (MIBH) to minimize tumor motion, and IMRT delivery with MIBH; the combination of 3 separate planning treatment-volume sets resulted in the generation of 90 different treatment plans. To plan these, patients underwent treatment-planning computed tomography in MIBH and free breathing followed by simulation with measurement of tumor motion and generation/evaluation of DVHs, EUDs, V20, and NTDmean. RESULTS: Average tumor motion was 1.54 cm in the cephalocaudad directions, 1.26 cm in the anteroposterior directions, and 0.56 cm in the lateral directions between maximum inspiration and expiration. Maximum-inspiration breath-hold produced superior lung sparing evidenced by lower V20 and NTDmean values, and these parameters predicted lower modeled pneumonitis rates. Tomotherapy-based IMRT provided further lung sparing. CONCLUSION: Treatment in MIBH results in lower V20 and NTDmean values and lower modeled pneumonitis rates. This effect is enhanced by the use of IMRT. The use of MIBH with IMRT may therefore aid in escalating the dose in RT.

Adenocarcinoma↗

PubMed2006

Pecking orders, social permits, & reverse discrimination. Interview by Shirley A Smoyak.

The first step in moving toward changing the current system is recognizing how these unspoken beliefs and "word compartments" create incredible pain and cause unnecessary delay in providing help. Anne also had eloquent things to say about the failure of parity, as far as people with mental illnesses are concerned. Using an e-mail list, Anne collected reflections of some Vermonters involved in the mental health field. Here are two of my favorites about the term "behavioral health": From a consumer: "To me, it implies if I would just change my behaviors, I wouldn't have a mental illness." From a nurse: "Call it what it is. We have cardiac care units, not happy heart units." If you have your own reflections or experiences with the descriptions in this editorial, do send them to us at jpn@slackinc.com.

Adaptation, Psychological↗

PubMed2000

Expression of a human coxsackie/adenovirus receptor transgene permits adenovirus infection of primary lymphocytes.

Replication-defective adenoviruses are effective vehicles for gene transfer, both for the repair of defective genes and for studies of gene function in primary cells. Many cell types, including lymphocytes, are refractory to adenovirus infection because they lack the Coxsackie/adenovirus receptor (CAR) needed for virus attachment. To extend the advantages of adenovirus-mediated gene transfer to primary lymphoid populations and other cell types lacking endogenous CAR, we produced a mouse that expresses human (h) CAR as a transgene under control of a murine MHC class I promoter. hCAR protein is expressed on T and B lymphocytes from a variety of organs (spleen, lymph node, bone marrow, thymus, and peritoneum). These lymphocytes are susceptible to adenovirus infection, as demonstrated by reporter green fluorescent protein gene expression, with the fraction of expressing cells as high as 70%. Some lymphocyte subpopulations required stimulation subsequent to adenovirus infection for reporter expression. This activation requirement is a restriction imposed by the promoter used in the adenovirus construct. In subpopulations requiring activation, the elongation factor 1 promoter was far superior to a hCMV promoter for directing green fluorescent protein production. We also find that hCAR mRNA is produced in nonlymphoid tissues from all founder lines, including tissues that do not express endogenous murine CAR, suggesting the opportunity for effecting gene delivery to and testing gene function in a wide variety of primary cell types previously resistant to gene transfer.

Adenoviridae↗

PubMed2001

Combinatorial peptide libraries and biometric score matrices permit the quantitative analysis of specific and degenerate interactions between clonotypic TCR and MHC peptide ligands.

The interaction of TCRs with MHC peptide ligands can be highly flexible, so that many different peptides are recognized by the same TCR in the context of a single restriction element. We provide a quantitative description of such interactions, which allows the identification of T cell epitopes and molecular mimics. The response of T cell clones to positional scanning synthetic combinatorial libraries is analyzed with a mathematical approach that is based on a model of independent contribution of individual amino acids to peptide Ag recognition. This biometric analysis compares the information derived from these libraries composed of trillions of decapeptides with all the millions of decapeptides contained in a protein database to rank and predict the most stimulatory peptides for a given T cell clone. We demonstrate the predictive power of the novel strategy and show that, together with gene expression profiling by cDNA microarrays, it leads to the identification of novel candidate autoantigens in the inflammatory autoimmune disease, multiple sclerosis.

Amino Acid Motifs↗

PubMed2006

Dectin-1 and TLRs permit macrophages to distinguish between different Aspergillus fumigatus cellular states.

Aspergillus fumigatus is a common cause of invasive and allergic pulmonary disease. Resting conidia of the filamentous fungus are constantly inhaled, but cause infection only after initiating hyphal growth. In this study, we have explored whether macrophages can distinguish between resting spores and the maturing, potentially invasive form of the fungus. Although macrophages bind and ingest A. fumigatus resting conidia efficiently, there is little inflammatory response; NF-kappabeta is not activated, inflammatory cytokines are not induced, and reactive oxygen species are not produced. However, maturing A. fumigatus conidia and germ tubes stimulate NF-kappabeta, secretion of proinflammatory cytokines and production of reactive oxygen by human monocyte-derived macrophages and murine macrophages from multiple anatomical sites. These responses are in part mediated by dectin-1, which binds cell wall beta-glucan that is not present on the surface of dormant conidia, but is present after cellular swelling and loss of the hydrophobic proteinaceous cell wall. Dectin-1 binding to germ tubes augments, but is not required for, TLR2-mediated inflammatory cytokine secretion. Dectin-1 recognition of germ tubes also stimulates TNF-alpha production in the absence of both TLR2 and MyD88 signaling. These data demonstrate one mechanism by which the pulmonary inflammatory response is tailored toward metabolically active cells, thereby avoiding unnecessary tissue damage with frequent inhalation of ubiquitous spores.

Animals↗

PubMed2006

Reversal of p53 epigenetic silencing in multiple myeloma permits apoptosis by a p53 activator.

Inactivation of the p53 pathway is a common feature of neoplasia. Dysregulation of the p53 pathway has been shown to involve mutations of p53, increased expression of the p53 inhibitor HDM-2, or epigenetic silencing of the p53 promoter. In multiple myeloma, a neoplasia of terminally differentiated B cells, p53 mutations and deletions are relatively rare and occur in late stage disease. Here, we show that the p53 promoter is hypermethylated in several multiple myeloma cell lines in comparison to normal plasma cells. Two cell lines containing mutant p53, Lp-1 and OPM-2, show a methylation pattern that suggests that they contain one methylated and one unmethylated mutant allele. Two other cell lines, KMS-11 and OPM-2, show hypermethylation of p53 with a lack of expression. In all cell lines tested, treatment with a demethylating agents results in higher expression of p53. Furthermore, following increased expression of p53, treatment of the myeloma cell lines with a p53 activating peptide induces apoptosis. Therefore, combinatorial treatment with demethylating agents followed by delivery of a p53 activating peptide may be an effective therapeutic strategy against multiple myeloma.

Amino Acid Sequence↗

PubMed2001

Expanding access through public coverage: permitting families to use tax credits to buy into Medicaid or SCHIP.

A new tax credit to help low-income families and individuals purchase health insurance can address the problem of affordability, but will not overcome other barriers these populations face in obtaining coverage. This paper proposes that families have the option of using a new tax credit to buy into a state-administered system such as Medicaid or the State Children's Health Insurance Program. This option has three advantages. First, it allows families to remain with a single health program and health plan as their income fluctuates. Second, it provides an alternative to the complex and confusing individual insurance market. This alternative is community rated, does not use underwriting, and allows health plan behavior to be monitored closely by the state. Third, it allows the state to act as a financial buffer-helping overcome the barrier to participation that cash-flow problems and year-end reconciliation concerns are likely to create among a low-income population. Many people would want to use their tax credit in the private market, but the buy-in option increases the likelihood that the tax credit approach would succeed.

Adult↗

PubMedDate not supplied

Xmas (brand substitution not permitted).

OBJECTIVE: To study drug prescribing by brand name versus generic name in an Australian teaching hospital. RESULTS: Overall, 53% of drugs were prescribed by brand name. Brand names were preferred when they were shorter and easier to remember and spell, when there was only one brand on the market, and when the brand name ended in an x. CONCLUSION: Doctors might be encouraged to prescribe generically if generic names were devised using the same principles marketers use for devising brand names.

Australian Capital Territory↗

PubMed2000