Menin and GIP are inversely regulated by food intake and diet via PI3/AKT signaling in the proximal duodenum.

BACKGROUND AND AIMS: Ingestion of food stimulates the secretion of incretin peptides glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 to ensure the proper absorption and storage of nutrients. Menin is the 67 kDa protein product of the MEN1 gene recently reported to have a role in metabolism. In this study, we will determine the regulation of menin in the proximal duodenum by food intake and diet in correlation with GIP levels in the proximal duodenum of mice after an 18 h fast followed by 4 and 7 h refeeding and 3 months of high-fat diet. METHODS: A dual luciferase assay was used to determine GIP promoter activity and ELISA was used to measure the levels of GIP after inhibition of menin through small interfering RNA (siRNA) and exposure to MAPK and AKT inhibitors. Colocalization of menin and GIP were determined by immunofluorescence. RESULTS: Menin and GIP expression are regulated by fasting, refeeding and diet in the proximal duodenum. Overexpression of menin in STC-1 cells significantly inhibited GIP mRNA and promoter activity, whereas menin siRNA upregulated GIP levels. Inhibition of GIP expression by the PI3/AKT inhibitor, LY294002, was abrogated in STC-1 cells with reduced menin levels, whereas the MAPK inhibitor, UO126, inhibited the expression of GIP independent of menin. Exposure of STC-1 cells to GIP reduced menin expression in a dose-dependent manner via PI3K-AKT signaling. CONCLUSION: Feeding and diet regulates the expression of menin, which inversely correlates with GIP levels in the proximal duodenum. In vitro assays indicate that menin is a negative regulator of GIP via inhibition of PI3K-AKT signaling. We show menin colocalizing with GIP in K cells of the proximal gut and hypothesize that downregulation of menin may serve as a mechanism by which GIP is regulated in response to food intake and diet.

The genome sequence of Desulfatibacillum alkenivorans AK-01: a blueprint for anaerobic alkane oxidation.

Desulfatibacillum alkenivorans AK-01 serves as a model organism for anaerobic alkane biodegradation because of its distinctive biochemistry and metabolic versatility. The D. alkenivorans genome provides a blueprint for understanding the genetic systems involved in alkane metabolism including substrate activation, CoA ligation, carbon-skeleton rearrangement and decarboxylation. Genomic analysis suggested a route to regenerate the fumarate needed for alkane activation via methylmalonyl-CoA and predicted the capability for syntrophic alkane metabolism, which was experimentally verified. Pathways involved in the oxidation of alkanes, alcohols, organic acids and n-saturated fatty acids coupled to sulfate reduction and the ability to grow chemolithoautotrophically were predicted. A complement of genes for motility and oxygen detoxification suggests that D. alkenivorans may be physiologically adapted to a wide range of environmental conditions. The D. alkenivorans genome serves as a platform for further study of anaerobic, hydrocarbon-oxidizing microorganisms and their roles in bioremediation, energy recovery and global carbon cycling.

Decreased osteoclastogenesis and high bone mass in mice with impaired insulin clearance due to liver-specific inactivation to CEACAM1.

Type 2 diabetes is associated with normal-to-higher bone mineral density (BMD) and increased rate of fracture. Hyperinsulinemia and hyperglycemia may affect bone mass and quality in the diabetic skeleton. In order to dissect the effect of hyperinsulinemia from the hyperglycemic impact on bone homeostasis, we have analyzed L-SACC1 mice, a murine model of impaired insulin clearance in liver causing hyperinsulinemia and insulin resistance without fasting hyperglycemia. Adult L-SACC1 mice exhibit significantly higher trabecular and cortical bone mass, attenuated bone formation as measured by dynamic histomorphometry, and reduced number of osteoclasts. Serum levels of bone formation (BALP) and bone resorption markers (TRAP5b and CTX) are decreased by approximately 50%. The L-SACC1 mutation in the liver affects myeloid cell lineage allocation in the bone marrow: the (CD3(-)CD11b(-)CD45R(-)) population of osteoclast progenitors is decreased by 40% and the number of (CD3(-)CD11b(-)CD45R(+)) B-cell progenitors is increased by 60%. L-SACC1 osteoclasts express lower levels of c-fos and RANK and their differentiation is impaired. In vitro analysis corroborated a negative effect of insulin on osteoclast recruitment, maturation and the expression levels of c-fos and RANK transcripts. Although bone formation is decreased in L-SACC1 mice, the differentiation potential and expression of the osteoblast-specific gene markers in L-SACC1-derived mesenchymal stem cells (MSC) remain unchanged as compared to the WT. Interestingly, however, MSC from L-SACC1 mice exhibit increased PPARgamma2 and decreased IGF-1 transcript levels. These data suggest that high bone mass in L-SACC1 animals results, at least in part, from a negative regulatory effect of insulin on bone resorption and formation, which leads to decreased bone turnover. Because low bone turnover contributes to decreased bone quality and an increased incidence of fractures, studies on L-SACC1 mice may advance our understanding of altered bone homeostasis in type 2 diabetes.

Dysfunctional innate immune responsiveness to Porphyromonas gingivalis lipopolysaccharide in diabetes.

INTRODUCTION: Type 1 diabetes is a major risk factor for the development of severe periodontal disease. As diabetes increases in severity, so does the susceptibility to and severity of periodontitis. People with diabetes who have periodontal disease have a harder time maintaining healthy blood glucose levels. Macrophages play an important role in both diabetes and periodontitis. Previous research comparing bone-marrow-derived macrophages (BM-Mvarphi) from diabetic non-obese diabetic (NOD) mice and control mice illustrates that a dysregulation in cytokine, Toll-like receptor (TLR) expression, and cell signaling occurs in the diabetic state. METHODS: This study examines the effect of chronic hyperglycemia on BM-Mvarphi TLR expression and activation, cell signaling, cytokine production, and phagocytic function in the diabetic state, when challenged with the periodontal stimulus Porphyromonas gingivalis lipopolysaccharide (LPS) to further understand how diabetes and associated hyperglycemia may contribute to the increased susceptibility of people with diabetes to periodontitis. RESULTS: When BM-Mvarphi, obtained from diabetic NOD mice, are stimulated with P. gingivalis LPS under hyperglycemic conditions the following changes occur: reduced messenger RNA expression and cell surface expression of TLR2, reduced messenger RNA expression and protein production of tumor necrosis factor-alpha, reduced signal transduction, and a reduction in phagocytic function. All the activity of BM-Mvarphi from diabetic NOD mice was restored when differentiation and stimulation occurred under normoglycemic conditions. DISCUSSION: Diabetic patients in a hyperglycemic state may be generating macrophages that are inherently immunocompromised, contributing to an environment allowing periodontal infections to flourish. As a consequence, people with diabetes who maintain proper control of blood sugar levels may experience an increased immunological benefit when challenged with a periodontal infection.

In situ biosurfactant production by Bacillus strains injected into a limestone petroleum reservoir.

Biosurfactant-mediated oil recovery may be an economic approach for recovery of significant amounts of oil entrapped in reservoirs, but evidence that biosurfactants can be produced in situ at concentrations needed to mobilize oil is lacking. We tested whether two Bacillus strains that produce lipopeptide biosurfactants can metabolize and produce their biosurfactants in an oil reservoir. Five wells that produce from the same Viola limestone formation were used. Two wells received an inoculum (a mixture of Bacillus strain RS-1 and Bacillus subtilis subsp. spizizenii NRRL B-23049) and nutrients (glucose, sodium nitrate, and trace metals), two wells received just nutrients, and one well received only formation water. Results showed in situ metabolism and biosurfactant production. The average concentration of lipopeptide biosurfactant in the produced fluids of the inoculated wells was about 90 mg/liter. This concentration is approximately nine times the minimum concentration required to mobilize entrapped oil from sandstone cores. Carbon dioxide, acetate, lactate, ethanol, and 2,3-butanediol were detected in the produced fluids of the inoculated wells. Only CO(2) and ethanol were detected in the produced fluids of the nutrient-only-treated wells. Microbiological and molecular data showed that the microorganisms injected into the formation were retrieved in the produced fluids of the inoculated wells. We provide essential data for modeling microbial oil recovery processes in situ, including growth rates (0.06 +/- 0.01 h(-1)), carbon balances (107% +/- 34%), biosurfactant production rates (0.02 +/- 0.001 h(-1)), and biosurfactant yields (0.015 +/- 0.001 mol biosurfactant/mol glucose). The data demonstrate the technical feasibility of microbial processes for oil recovery.

Benzoate fermentation by the anaerobic bacterium Syntrophus aciditrophicus in the absence of hydrogen-using microorganisms.

The anaerobic bacterium Syntrophus aciditrophicus metabolized benzoate in pure culture in the absence of hydrogen-utilizing partners or terminal electron acceptors. The pure culture of S. aciditrophicus produced approximately 0.5 mol of cyclohexane carboxylate and 1.5 mol of acetate per mol of benzoate, while a coculture of S. aciditrophicus with the hydrogen-using methanogen Methanospirillum hungatei produced 3 mol of acetate and 0.75 mol of methane per mol of benzoate. The growth yield of the S. aciditrophicus pure culture was 6.9 g (dry weight) per mol of benzoate metabolized, whereas the growth yield of the S. aciditrophicus-M. hungatei coculture was 11.8 g (dry weight) per mol of benzoate. Cyclohexane carboxylate was metabolized by S. aciditrophicus only in a coculture with a hydrogen user and was not metabolized by S. aciditrophicus pure cultures. Cyclohex-1-ene carboxylate was incompletely degraded by S. aciditrophicus pure cultures until a free energy change (DeltaG') of -9.2 kJ/mol was reached (-4.7 kJ/mol for the hydrogen-producing reaction). Cyclohex-1-ene carboxylate, pimelate, and glutarate transiently accumulated at micromolar levels during growth of an S. aciditrophicus pure culture with benzoate. High hydrogen (10.1 kPa) and acetate (60 mM) levels inhibited benzoate metabolism by S. aciditrophicus pure cultures. These results suggest that benzoate fermentation by S. aciditrophicus in the absence of hydrogen users proceeds via a dismutation reaction in which the reducing equivalents produced during oxidation of one benzoate molecule to acetate and carbon dioxide are used to reduce another benzoate molecule to cyclohexane carboxylate, which is not metabolized further. Benzoate fermentation to acetate, CO(2), and cyclohexane carboxylate is thermodynamically favorable and can proceed at free energy values more positive than -20 kJ/mol, the postulated minimum free energy value for substrate metabolism.

Foot care practices, services and perceptions of risk among medicare beneficiaries with diabetes at high and low risk for future foot complications.

A cohort of Medicare beneficiaries with diabetes was identified from inpatient and outpatient claims data and their risk for foot complications was estimated based on claims reflecting services for recent foot problems. A telephone survey of a random sample from this cohort was conducted to assess their foot care practices, barriers, and perceptions of risk. Eight percent of respondents reported a history of foot ulcers and 7% a history of lower extremity amputation. Based on claims data, 30% of respondents were at high risk for future foot complications. Compared to those at low risk, those at high risk were more likely to report having an annual foot exam, using protective footwear, and perceiving themselves to be high risk for future foot complications. However, 50% of those with claims indicating a high risk perceived themselves to be at low risk for future foot complications. Overall, 20% of respondents seldom checked their feet daily for sores or irritations. Among this group, 60% felt that it was unimportant and 9% reported they were limited by poor vision or physical problems. Our findings suggest that strategies are needed to improve the delivery of preventive foot care services to older persons with diabetes. Additionally, emphasis is needed to help individuals understand their risk and seek and perform appropriate preventive foot care.

MHC class I-restricted determinants on the glutamic acid decarboxylase 65 molecule induce spontaneous CTL activity.

CD4(+) T cell responses to glutamic acid decarboxylase (GAD65) spontaneously arise in nonobese diabetic (NOD) mice before the onset of insulin-dependent diabetes mellitus (IDDM) and may be critical to the pathogenic process. However, since both CD4(+) and CD8(+) T cells are involved in autoimmune diabetes, we sought to determine whether GAD65-specific CD8(+) T cells were also present in prediabetic NOD mice and contribute to IDDM. To refine the analysis, putative K(d)-binding determinants that were proximal to previously described dominant Th determinants (206-220 and 524-543) were examined for their ability to elicit cytolytic activity in young NOD mice. Naive NOD spleen cells stimulated with GAD65 peptides 206-214 (p206) and 546-554 (p546) produced IFN-gamma and showed Ag-specific CTL responses against targets pulsed with homologous peptide. Conversely, several GAD peptides distal to the Th determinants, and control K(d)-binding peptides did not induce similar responses. Spontaneous CTL responses to p206 and p546 were mediated by CD8(+) T cells that are capable of lysing GAD65-expressing target cells, and p546-specific T cells transferred insulitis to NOD.scid mice. Young NOD mice pretreated with p206 and p546 showed reduced CTL responses to homologous peptides and a delay in the onset of IDDM. Thus, MHC class I-restricted responses to GAD65 may provide an inflammatory focus for the generation of islet-specific pathogenesis and beta cell destruction. This report reveals a potential therapeutic role for MHC class I-restricted peptides in treating autoimmune disease and revisits the notion that the CD4- and CD8-inducing determinants on some molecules may benefit from a proximal relationship.

Signature metabolites attesting to the in situ attenuation of alkylbenzenes in anaerobic environments.

Accurate assessment of the fate of hydrocarbons spilt in aquifers is essential for gauging associated health and ecological risks. Regulatory pressure to actively remediate such contaminated ecosystems can be substantially diminished if solid evidence for in situ microbial destruction of pollutants is obtained. In laboratory incubations, sediment-associated microorganisms from a gas condensate-contaminated aquifer anaerobically biodegraded toluene, ethylbenzene, xylene, and toluic acid isomers with stoichiometric amounts of sulfate consumed or methane produced. The activation of the alkylated aromatic contaminants involved conversion to their corresponding benzylsuccinic acid derivatives, a reaction known to occur for toluene and m-xylene decay, but one previously unrecognized for ethylbenzene, o- and p-xylene, and m-toluate metabolism. Benzylsuccinates were further biodegraded to toluates, phthalates, and benzoate. In laboratory incubations, these metabolites were transiently produced. Several of the metabolites were also detected in groundwater samples from an aquifer where alkylbenzene concentrations decreased over time, suggesting that anaerobic microbial metabolism of these contaminants also occurs in situ. Our studies confirm the utility of the aforementioned compounds as signature metabolites attesting to the natural attenuation of aromatic hydrocarbons in anaerobic environments.

Relationship of hydrogen bioavailability to chromate reduction in aquifer sediments.

Biological Cr(VI) reduction was studied in anaerobic sediments from an aquifer in Norman, Okla. Microcosms containing sediment and mineral medium were amended with various electron donors to determine those most important for biological Cr(VI) reduction. Cr(VI) (about 340 microM) was reduced with endogenous substrates (no donor), or acetate was added. The addition of formate, hydrogen, and glucose stimulated Cr(VI) reduction compared with reduction in unamended controls. From these sediments, an anaerobic Cr(VI)-utilizing enrichment was obtained that was dependent upon hydrogen for both growth and Cr(VI) reduction. No methane was produced by the enrichment, which reduced about 750 microM Cr(VI) in less than six days. The dissolved hydrogen concentration was used as an indicator of the terminal electron accepting process occurring in the sediments. Microcosms with sediments, groundwater, and chromate metabolized hydrogen to a concentration below the detection limits of the mercury vapor gas chromatograph. In microcosms without chromate, the hydrogen concentration was about 8 nM, a concentration comparable to that under methanogenic conditions. When these microcosms were amended with 500 microM Cr(VI), the dissolved hydrogen concentration quickly fell below the detection limits. These results showed that the hydrogen concentration under chromate-reducing conditions became very low, as low as that reported under nitrate- and manganese-reducing conditions, a result consistent with the free energy changes for these reactions. The utilization of formate, lactate, hydrogen, and glucose as electron donors for Cr(VI) reduction indicates that increasing the availability of hydrogen results in a greater capacity for Cr(VI) reduction. This conclusion is supported by the existence of an enrichment dependent upon hydrogen for growth and Cr(VI) reduction.

Metabolism of benzoate, cyclohex-1-ene carboxylate, and cyclohexane carboxylate by "Syntrophus aciditrophicus" strain SB in syntrophic association with H(2)-using microorganisms.

The metabolism of benzoate, cyclohex-1-ene carboxylate, and cyclohexane carboxylate by "Syntrophus aciditrophicus" in cocultures with hydrogen-using microorganisms was studied. Cyclohexane carboxylate, cyclohex-1-ene carboxylate, pimelate, and glutarate (or their coenzyme A [CoA] derivatives) transiently accumulated during growth with benzoate. Identification was based on comparison of retention times and mass spectra of trimethylsilyl derivatives to the retention times and mass spectra of authentic chemical standards. (13)C nuclear magnetic resonance spectroscopy confirmed that cyclohexane carboxylate and cyclohex-1-ene carboxylate were produced from [ring-(13)C(6)]benzoate. None of the metabolites mentioned above was detected in non-substrate-amended or heat-killed controls. Cyclohexane carboxylic acid accumulated to a concentration of 260 microM, accounting for about 18% of the initial benzoate added. This compound was not detected in culture extracts of Rhodopseudomonas palustris grown phototrophically or Thauera aromatica grown under nitrate-reducing conditions. Cocultures of "S. aciditrophicus" and Methanospirillum hungatei readily metabolized cyclohexane carboxylate and cyclohex-1-ene carboxylate at a rate slightly faster than the rate of benzoate metabolism. In addition to cyclohexane carboxylate, pimelate, and glutarate, 2-hydroxycyclohexane carboxylate was detected in trace amounts in cocultures grown with cyclohex-1-ene carboxylate. Cyclohex-1-ene carboxylate, pimelate, and glutarate were detected in cocultures grown with cyclohexane carboxylate at levels similar to those found in benzoate-grown cocultures. Cell extracts of "S. aciditrophicus" grown in a coculture with Desulfovibrio sp. strain G11 with benzoate or in a pure culture with crotonate contained the following enzyme activities: an ATP-dependent benzoyl-CoA ligase, cyclohex-1-ene carboxyl-CoA hydratase, and 2-hydroxycyclohexane carboxyl-CoA dehydrogenase, as well as pimelyl-CoA dehydrogenase, glutaryl-CoA dehydrogenase, and the enzymes required for conversion of crotonyl-CoA to acetate. 2-Ketocyclohexane carboxyl-CoA hydrolase activity was detected in cell extracts of "S. aciditrophicus"-Desulfovibrio sp. strain G11 benzoate-grown cocultures but not in crotonate-grown pure cultures of "S. aciditrophicus". These results are consistent with the hypothesis that ring reduction during syntrophic benzoate metabolism involves a four- or six-electron reduction step and that once cyclohex-1-ene carboxyl-CoA is made, it is metabolized in a manner similar to that in R. palustris.

Is interspecies hydrogen transfer needed for toluene degradation under sulfate-reducing conditions?

Sediments from a hydrocarbon-contaminated aquifer, where periodic shifts between sulfate reduction and methanogenesis occurred, were examined to determine whether the degradation of toluene under sulfate-reducing conditions depended on interspecies hydrogen transfer. Toluene degradation under sulfate-reducing conditions was inhibited by the addition of 5 mM sodium molybdate, but the activity was not restored upon the addition of an actively growing, hydrogen-using methanogen. Toluene degradation was not inhibited in microcosms where hydrogen levels were maintained at a level theoretically sufficient to inhibit toluene degradation if the process proceeded via interspecies hydrogen transfer. Finally, the addition of carbon monoxide, a potent inhibitor of hydrogenase activity, inhibited hydrogen but not toluene consumption in sulfate-reducing microcosms. These results suggest that toluene is degraded directly by sulfate-reducing bacteria without the involvement of interspecies hydrogen transfer. The sequence of experiments used to reach this conclusion could be applied to determine the role of interspecies hydrogen transfer in the degradation of a variety of compounds in different environments or under different terminal electron-accepting conditions.

Direct mail intervention to increase retinal examination rates in Medicare beneficiaries with diabetes.

The objective of this study was to identify the baseline frequency of eye examinations for Medicare beneficiaries with diabetes in Montana and to determine whether a direct mail reminder increased eye examinations. Using Medicare Part A and Medicare Part B claims data, a cohort of Medicare beneficiaries with diabetes was defined. Eye examination claims were identified using billing codes specific for retinal examinations, as well as visits to ophthalmologists and optometrists during which retinal exams were likely to have been performed. A random sample of the identified beneficiaries with diabetes received a letter encouraging regular annual retinal examinations. In the first 3-month period after the mailing, the billed eye examination rate for those to whom letters were sent was 2.2 percentage points greater than the rate for those to whom letters were not sent (19.4% vs 17.2%; relative risk, 1.13; 95% confidence interval, 1.01-1.26). However, 6 months after the letters were sent, there was no longer a significant difference in the rates for these 2 groups (32.9% vs 32.4%; relative risk, 1.02; 95% confidence interval, 0.94-1.10). In this study, direct mail outreach initially influenced the proportion of Medicare beneficiaries receiving an eye examination, but this pattern was not sustained over the 6-month follow-up period.

Improving the pneumococcal immunization rate for patients with diabetes in a managed care population: a simple intervention with a rapid effect.

BACKGROUND: Pneumococcal disease kills more people in the United States than any other vaccine-preventable bacterial disease, and a national health objective for the year 2000 is that at least 60% of eligible persons be immunized with pneumococcal vaccine. METHODS: An electronic care monitoring system was used to track immunization of patients with diabetes in a managed care plan who were receiving their care through a staff-model primary care clinic in Guam. In November 1998 a letter was sent to all patients not known to be immunized. The letter invited these patients to attend immunization clinics and waived usual copayment. Standing orders were also created for the clinic nurses to administer pneumococcal vaccines. In addition, a diabetes care status report was placed on each patient's medical record. RESULTS: The immunization rate for the 1,278 actively enrolled patients with diagnosed diabetes increased from 42% in October 1998 to 62% in January 1999. Compared to November 1995, 1996, and 1997, the number of pneumococcal immunizations increased more than 15-fold in November 1998. DISCUSSION: The combined use of patient outreach letters, special immunization clinics, standing orders, and practitioner reminders on medical records resulted in a rapid, marked increase in the pneumococcal immunization rate for patients with diabetes. The electronic care monitoring system is being used to target get interventions for improvement opportunities for an array of diabetes care measures, including regular foot care and eye exams.

High density insulin receptor-positive diabetogenic T lymphocytes in nonobese diabetic mice are memory cells.

Our previous work examining the importance of insulin receptor (IR) expression on T cells has demonstrated that when T cells from nonobese diabetic mice were sorted into populations expressing a high (IR(High)) and a low (IR(Low)) density of IR, IR(High) T cells rapidly transferred insulitis and diabetes. We have further characterized IR(High) T cells. Both CD4+ and CD8+ cells were detected in the IR(High) T cell population, but IR(High) expression was detected predominantly on CD4+ cells. IRHigh T cells were polyclonal for TCR Vbeta-chain expression. By 3 color flow cytometric analysis, virtually all IR(High) T cells expressed low or negligible levels of CD62L (CD62L(Low)/-) and high levels of CD44 (CD44(High)). The lack of IL-2 receptor and transferrin receptor expression as seen previously, together with the CD62L(Low)/- CD44(High) phenotype suggests that IR(High) T cells are memory cells. However, since only about one quarter of all of the CD62L(Low)/- or CD44(High) T cells were also IR(High), the IR(High) phenotype defines a subpopulation of memory T cells that are aggressively diabetogenic.

Thiosulfate disproportionation by Desulfotomaculum thermobenzoicum.

Desulfotomaculum thermobenzoicum, but not Desulfotomaculum nigrificans, Desulfotomaculum ruminis, or Desulfosporosinus orientis, grew by disproportionation of thiosulfate, forming stoichiometric amounts of sulfate and sulfide; sulfite was not disproportionated. The addition of acetate enhanced growth and thiosulfate disproportionation by D. thermobenzoicum compared to those observed with thiosulfate alone.

An islet-specific CD8+ T cell hybridoma generated from non-obese diabetic mice recognizes insulin as an autoantigen.

Although CD8+ T cells play a major role in beta cell destruction in insulin-dependent diabetes in the non-obese diabetic mouse, the T cell autoantigen(s) recognized by such cells remains to be identified. Therefore, an islet-reactive, CD8+ T cell line was generated from islet-infiltrating cells and hybridized by fusion with a CD8+ alphabeta TCR- BW5147 thymoma. In the presence of islets, none of the 12 CD3+ CD8+ T cell hybridomas isolated secreted IL-2/IL-4 or IFNgamma but three were islet specific, as shown by activation induced cell death. Subclone 4A7.7.15 recognized only islets expressing H-2Kd, demonstrated islet-specific inhibition of proliferation and concomitant partial arrest in the G2/M phase of the cell cycle. Further analysis using a panel of cell lines, expressing H-2Kd, and transfected with the cDNA for various putative autoantigens in type 1 diabetes showed that 4A7.7.15 recognizes insulin as an antigen.

Haloanaerobium kushneri sp. nov., an obligately halophilic, anaerobic bacterium from an oil brine.

Three strains, designated VS-751T, VS-511 and VS-732, of a strictly anaerobic, moderately halophilic, Gram-negative, rod-shaped bacterium were isolated from a highly saline (15-20%) brine from an oil reservoir in central Oklahoma, USA. The optimal concentration of NaCl for growth of these three strains was 2 M (12%), and the strains also grew in the presence of an additional 1 M MgCl2. The strains were mesophilic and grew at a pH range of 6-8. Carbohydrates used by all three strains included glucose, fructose, arabinose, galactose, maltose, mannose, cellobiose, sucrose and inulin. Glucose fermentation products included ethanol, acetate, H2 and CO2, with formate produced by two of the three strains. Differences were noted among strains in the optimal temperature and pH for growth, the maximum and minimum NaCl concentration that supported growth, substrate utilization and cellular fatty acid composition. Despite the phenotypic differences among the three strains, analysis of the 16S rRNA gene sequences and DNA-DNA hybridizations showed that these three strains were members of the same genospecies which belonged to the genus Haloanaerobium. The phenotypic and genotypic characteristics of strains VS-751T, VS-511 and VS-732 are different from those of previously described species of Haloanaerobium. It is proposed that strain VS-751T (ATCC 700103T) be established as the type strain of a new species, Haloanaerobium kushneri.

Syntrophus aciditrophicus sp. nov., a new anaerobic bacterium that degrades fatty acids and benzoate in syntrophic association with hydrogen-using microorganisms.

Strain SBT is a new, strictly anaerobic, gram-negative, nonmotile, non-sporeforming, rod-shaped bacterium that degrades benzoate and certain fatty acids in syntrophic association with hydrogen/formate-using microorganisms. Strain SBT produced approximately 3 mol of acetate and 0.6 mol of methane per mol of benzoate in coculture with Methanospirillum hungatei strain JF1. Saturated fatty acids, some unsaturated fatty acids, and methyl esters of butyrate and hexanoate also supported growth of strain SBT in coculture with Desulfovibrio strain G11. Strain SBT grew in pure culture with crotonate, producing acetate, butyrate, caproate, and hydrogen. The molar growth yield was 17 +/- 1 g cell dry mass per mol of crotonate. Strain SBT did not grow with fumarate, iron(III), polysulfide, or oxyanions of sulfur or nitrogen as electron acceptors with benzoate as the electron donor. The DNA base composition of strain SBT was 43.1 mol% G+C. Analysis of the 16 S rRNA gene sequence placed strain SBT in the delta-subdivision of the Proteobacteria, with sulfate-reducing bacteria. Strain SBT was most closely related to members of the genus Syntrophus. The clear phenotypic and genotypic differences between strain SBT and the two described species in the genus Syntrophus justify the formation of a new species, Syntrophus aciditrophicus.

An investigation of the placebo effect and age-related factors in the report of needle pain from venipuncture in children.

To examine the potential role for a placebo cream in reducing reported needle pain severity in children, and the impact of age-related factors on pain self-report, a convenience sample of 117 children scheduled for venipuncture were randomly assigned to one of three treatments: (a) placebo cream with the suggestion that it might help reduce needle pain, (b) placebo cream with no indication as to the cream's purpose, and (c) no cream (control group). In allocation to treatment, children were stratified by age group, (3-7, 8-11, 12-17 years). They rated their needle pain severity (both predicted and reported) using the Faces Pain Scale, and rated their anxiety about the procedure using the Children's Anxiety and Pain Scale. Children in the cream groups were also asked whether they thought the cream had helped. Using video-tapes, an independent observer, blind to the placebo manipulation, rated each child's reaction to the needle. For the two groups receiving cream, 83% of those children told it might help stated that they believed it did, as compared with only 33% of children who received the cream but were told nothing of its purpose. These beliefs, however, were not reflected in self-report ratings of pain which showed no statistically significant treatment effect. Similarly, children who gave higher preprocedural anxiety ratings were no more likely to report less pain as a result of receiving the cream. There was, however, a treatment effect on the observer's ratings: children receiving cream plus suggestion were assigned significantly lower ratings of pain-related behaviour than those children who received the cream alone. While venipuncture was associated with only mild levels of pain, younger children, irrespective of treatment group, did report more pain than older children. Hierarchical regression analysis indicated that 60% of the variance in self-reported pain severity scores could be accounted for by how much the child thought the needle would hurt, how anxious the child was about receiving the needle, gender (higher pain ratings associated with girls), and estimated body surface area (higher pain ratings associated with smaller bodies). We conclude that the efficacy of placebo treatments for needle pain in children may depend on the suggestion of a possible benefit rather than upon treatment application per se.