Home screening of taste and oral trigeminal function: a feasibility study.

PURPOSE: gustatory ability is a marker of health not routinely tested in the medical practice. The current study wants to assess whether taste strips can be useful to monitor taste function from home. METHODS: we performed simple sensory tests in lab setting vs. unassisted testing at home, and compared the results with self-reports ability to taste and smell. Using paper strips impregnated with sweet, bitter, salty, or sour tastants, and with two trigeminal stimuli (capsaicin, tannins) in high and low concentrations, we assessed gustatory and trigeminal function in 74 participants (47 women) in the lab, where paper strips were administered by an experimenter, and in 77 participants (59 women) at home, where they self-administered the test. RESULTS: we found that high (but not low) concentration taste strips are correctly identified by vast majority of participants. On average, taste identification, intensity and pleasantness scores did not differ for the 8 taste strips, while identification of capsaicin was significantly better in the lab. Taste identification scores correlated with intensity ratings in both settings (r = 0.56, in the lab, r = 0.48, at home, p < 0.005). Self-rated taste ability correlated with self-rated smell ability (r = 0.68, and r = 0.39, p ≤ 0.005), but not with scores in the strips test. CONCLUSION: home testing with impregnated taste strips is feasible, and can be used for telemedical purposes.

Single-institution clinical experience using robust intensity modulated proton therapy in chordoma and chondrosarcoma of the mobile spine and sacrum: Feasibility and need for plan adaptation.

BACKGROUND: Due to its specific physical characteristics, proton irradiation is especially suited for irradiation of chordomas and chondrosarcoma in the axial skeleton. Robust plan optimization renders the proton beam therapy more predictable upon individual setup errors. Reported experience with the planning and delivery of robustly optimized plans in chordoma and chondrosarcoma of the mobile spine and sacrum, is limited. In this study, we report on the clinical use of robustly optimized, intensity modulated proton beam therapy in these patients. METHODS: We retrospectively reviewed patient, treatment and acute toxicity data of all patients with chordoma and chondrosarcoma of the mobile spine and sacrum, treated between 1 April 2019 and 1 April 2020 at our institute. Anatomy changes during treatment were evaluated by weekly cone-beam CTs (CBCT), supplemented by scheduled control-CTs or ad-hoc control-CTs. Acute toxicity was scored weekly during treatment and at 3 months after therapy according to CTCAE 4.0. RESULTS: 17 chordoma and 3 chondrosarcoma patients were included. Coverage of the high dose clinical target volume was 99.8% (range 56.1-100%) in the nominal and 80.9% (range 14.3-99.6%) in the voxel-wise minimum dose distribution. Treatment plan adaptation was needed in 5 out of 22 (22.7%) plans. Reasons for plan adaptation were either reduced tumor coverage or increased dose to the OAR. CONCLUSIONS: Robustly optimized intensity modulated proton beam therapy for chordoma and chondrosarcoma of the mobile spine is feasible. Plan adaptations due to anatomical changes were required in approximately 23 percent of treatment courses.

A Simple Taste Test for Clinical Assessment of Taste and Oral Somatosensory Function-The "Seven-iTT".

Taste dysfunctions may occur, for example, after viral infection, surgery, medications, or with age. In clinical practice, it is important to assess patients' taste function with rapidity and reliability. This study aimed to develop a test that assesses human gustatory sensitivity together with somatosensory functions of astringency and spiciness. A total of 154 healthy subjects and 51 patients with chemosensory dysfunction rated their gustatory sensitivity. They underwent a whole-mouth identification test of 12 filter-paper strips impregnated with low and high concentrations of sweet, sour, salty, bitter (sucrose, citric acid, NaCl, quinine), astringency (tannin), and spiciness (capsaicin). The percentage of correct identifications for high-concentrated sweet and sour, and for low-concentrated salty, bitter and spicy was lower in patients as compared with healthy participants. Interestingly, a lower identification in patients for both astringent concentrations was found. Based on the results, we proposed the Seven-iTT to assess chemo/somatosensory function, with a cut-off of 6 out of 7. The test score discriminated patients from healthy controls and showed gender differences among healthy controls. This quantitative test seems to be suitable for routine clinical assessment of gustatory and trigeminal function. It also provides new evidence on the mutual interaction between the two sensory systems.

Mitochondrial reactive oxygen species enable proinflammatory signaling through disulfide linkage of NEMO.

A major function of macrophages during infection is initiation of the proinflammatory response, leading to the secretion of cytokines that help to orchestrate the immune response. Here, we identify reactive oxygen species (ROS) as crucial mediators of proinflammatory signaling leading to cytokine secretion in Listeria monocytogenes-infected macrophages. ROS produced by NADPH oxidases (Noxes), such as Nox2, are key components of the macrophage response to invading pathogens; however, our data show that the ROS that mediated proinflammatory signaling were produced by mitochondria (mtROS). We identified the inhibitor of κB (IκB) kinase (IKK) complex regulatory subunit NEMO [nuclear factor κB (NF-κB) essential modulator] as a target for mtROS. Specifically, mtROS induced intermolecular covalent linkage of NEMO through disulfide bonds formed by Cys54 and Cys347, which was essential for activation of the IKK complex and subsequent signaling through the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and NF-κB pathways that eventually led to the secretion of proinflammatory cytokines. We thus identify mtROS-dependent disulfide linkage of NEMO as an essential regulatory step of the proinflammatory response of macrophages to bacterial infection.

Co-inhibition of PGF and VEGF blocks their expression in mononuclear phagocytes and limits neovascularization and leakage in the murine retina.

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of visual impairment in the elderly. The neovascular (wet) form of AMD can be treated with intravitreal injections of different anti-vascular endothelial growth factor (VEGF) agents. Placental growth factor (PGF) is another member of the VEGF family of cytokines with pro-angiogenic and pro-inflammatory effects. Here, we aimed to compare single and combined inhibition of VEGF-A and PGF in the laser-induced mouse model of choroidal neovascularization (CNV) with a focus on the effects on retinal mononuclear phagocytes. METHODS: CNV was induced in C57BL/6J mice using a YAG-Laser. Immediately after laser damage antibodies against VEGF-A (aVEGF), anti-PGF (aPGF), aVEGF combined with aPGF, aflibercept, or IgG control were injected intravitreally in both eyes. Three and 7 days after laser damage, the vascular leakage was determined by fluorescence angiography. Lectin staining of retinal and RPE/choroidal flat mounts was used to monitor CNV. In situ mRNA co-expression of Iba1, VEGF and PGF were quantified using in situ hybridization. Retinal and RPE/choroidal protein levels of VEGF and PGF as well as the pro-inflammatory cytokines IL-6, IL1-beta, and TNF were determined by ELISA. RESULTS: Early (day 3) and intermediate (day 7) vascular leakage and CNV were significantly inhibited by PGF and VEGF-A co-inhibition, most effectively with the trap molecule aflibercept. While VEGF-A blockage alone had no effects, trapping PGF especially with aflibercept prevented the accumulation of reactive microglia and macrophages in laser lesions. The lesion-related mRNA expression and secretion of VEGF-A and PGF by mononuclear phagocytes were potently suppressed by PGF and partially by VEGF-A inhibition. Protein levels of IL-6 and IL1-beta were strongly reduced in all treatment groups. CONCLUSIONS: Retinal inhibition of PGF in combination with VEGF-A prevents vascular leakage and CNV possibly via modulating their own expression in mononuclear phagocytes. PGF-related, optimized strategies to target inflammation-mediated angiogenesis may help to increase efficacy and reduce non-responders in the treatment of wet AMD patients.

α-Hederin inhibits G protein-coupled receptor kinase 2-mediated phosphorylation of ß2-adrenergic receptors.

BACKGROUND: Recently is has been shown that α- and ß-hederin increase the ß2-adrenergic responsiveness of alveolar type II cells (A549) and human airway smooth muscle cells (HASM), respectively, by inhibiting the internalization of ß2-adrenergic receptors (ß2AR) under stimulating conditions. Internalization of ß2AR is initiated by phosphorylations of certain serines and threonines by cAMP dependent protein kinase A (PKA) and G protein-coupled receptor kinases (GRK). PURPOSE: To evaluate the effect of α-hederin on PKA and GRK2 mediated phosphorylation of GFP-tagged ß2AR. STUDY DESIGN: To study this process we performed In-Cell Western using isoprenaline stimulated HEK293 cells overexpressing ß2AR as GFP fusion protein and specific antibodies against PKA (Ser345/346) and GRK2 (Ser355/356) phosphorylation sites. RESULTS: There was no effect found on the PKA mediated phosphorylation (n = 14) but we could show that α-hederin (1 µM, 12 h) significantly inhibits GRK2 mediated phosphorylation at Ser355/356 by 11 ± 5% (n ≥ 29, p ≤ 0.01) under stimulating conditions compared to the positive control. In Förster resonance energy transfer (FRET) experiments using the isolated kinases in solution α-hederin did not show any influence neither to GRK2 nor to PKA. CONCLUSION: Taken together, these results indicate that α-hederin acts as an indirect GRK2 inhibitor leading to a reduced homologous desensitization of ß2AR-GFP in HEK293 cells.

Dynamic collimator angle adjustments during volumetric modulated arc therapy to account for prostate rotations.

PURPOSE: Rotations of the prostate gland induce considerable geometric uncertainties in prostate cancer radiation therapy. Collimator and gantry angle adjustments can correct these rotations in intensity modulated radiation therapy. Modern volumetric modulated arc therapy (VMAT) treatments, however, include a wide range of beam orientations that differ in modulation, and corrections require dynamic collimator rotations. The aim of this study was to implement a rotation correction strategy for VMAT dose delivery and validate it for left-right prostate rotations. METHODS AND MATERIALS: Clinical VMAT treatment plans of 5 prostate cancer patients were used. Simulated left-right prostate rotations between +15° and -15° were corrected by collimator rotations. We compared corrected and uncorrected plans by dose volume histograms, minimum dose (Dmin) to the prostate, bladder surface receiving ≥78 Gy (S78) and rectum equivalent uniform dose (EUD; n=0.13). Each corrected plan was delivered to a phantom, and its deliverability was evaluated by γ-evaluation between planned and delivered dose, which was reconstructed from portal images acquired during delivery. RESULTS: On average, clinical target volume minimum dose (Dmin) decreased up to 10% without corrections. Negative left-right rotations were corrected almost perfectly, whereas Dmin remained within 4% for positive rotations. Bladder S78 and rectum EUD of the corrected plans matched those of the original plans. The average pass rate for the corrected plans delivered to the phantom was 98.9% at 3% per 3 mm gamma criteria. The measured dose in the planning target volume approximated the original dose, rotated around the simulated left-right angle, well. CONCLUSIONS: It is feasible to dynamically adjust the collimator angle during VMAT treatment delivery to correct for prostate rotations. This technique can safely correct for left-right prostate rotations up to 15°.

Ca2+ clearance mechanisms in cancer cell lines and stromal cells of the prostate.

BACKGROUND: Three prostatic cell lines, PC3, LNCaP, and DU 145, are used as established models to study cell signaling in prostate cancer. Recently, stromal cell lines of the prostate, such as P21, were also introduced. Here we investigate a basic and important mechanism of living cells: Ca(2+) homeostasis in PC3, DU 145, and P21. METHODS: We examined Ca(2+) clearance mechanisms by monitoring the kinetics of recovery from histamine stimulation under conditions which inhibit prospect mechanisms for storing or extrusion of Ca(2+) from the cytosol by photometry. RESULTS: Despite the fact that in all three cell lines the Ca(2+) ATPase of the plasma membrane and the SERCA are most important for Ca(2+) homeostasis, inhibition of PMCA in epithelial cells has a greater effect than in stromal cells. Furthermore, the proportion of PMCA and SERCA differs in PC3 and DU145 cells. PMCA is most effective at reaching resting [Ca(2+) ]i in the final recovery stage. In contrast to DU 145 and P21 cells, PC3 are the only cells substantially affected by the inhibition of the mitochondrial uniporter. In all cell lines the role of the sodium calcium exchanger is marginal. CONCLUSION: These results demonstrate that not only cancer and stromal cell lines show significant differences in the modes and extent of their use of Ca(2+) clearance mechanisms, but also the cancer cell lines themselves.

FDG-PET and diffusion-weighted MRI in head-and-neck cancer patients: implications for dose painting.

PURPOSE: The purpose of this study was to investigate if FDG-PET and DWI identify the same or different targets for dose escalation in the GTV of HN cancer patients. Additionally, the dose coverage of DWI-targets in an FDG-PET-based dose painting plan was analyzed. MATERIALS AND METHODS: Eighteen HN cancer patients underwent FDG-PET and DWI exams, which were converted to standardized uptake value (SUV)- and apparent diffusion coefficient (ADC)-maps. The correspondence between the two imaging modalities was determined on a voxel-level using Spearman's correlation coefficient (ρ). Dose painting plans were optimized based on the 50% isocontour of the maximum SUV ( SUV(50%max)). Dose coverage was analyzed in three different SUV- and three different ADC-targets using the mean dose and the near-minimum and near-maximum doses. RESULTS: The average maximum SUV was 13.9 and the mean ADC was 1.17 · 10(-3) mm(2)/s. The average ρ between SUV and ADC was -0.2 (range: -0.6 to 0.4). The ADC-targets were only partly overlapping the SUV(50%max)-target and the dose parameters were significantly smaller in the ADC-targets compared to the SUV(50%max)-target. CONCLUSIONS: FDG-PET and DWI contain different information, resulting in different targets. Further information about failure patterns and dose relations can be obtained by adding DWI to currently ongoing dose painting trials.

Obesity prevention: recommended strategies and challenges.

Lifelong healthy weight maintenance is an important goal for all Americans to avoid the health problems associated with excessive body weight. In those who are overweight, even modest weight loss can reduce the risk of developing diseases associated with obesity. Federal health agencies, including the Centers for Disease Control and Prevention and the US Department of Agriculture, have recognized the critical nature of the obesity epidemic and the importance of lifelong weight management. As a result, these agencies have published evidence-based dietary and exercise recommendations, as well as analyses of population-based efforts to achieve weight loss that specifically address strategies to maintain a healthy weight. Despite the availability of recommendations and increased public education efforts, however, obesity rates continue to climb. The rising prevalence of obesity in the United States suggests that current efforts to control weight have been inadequate. Large-scale prevention programs that involve interventions targeting individuals as well as the larger community, including initiatives spearheaded through workplaces and schools, are needed to control weight and reduce the risk of long-term health consequences.

Alpha-hederin, but not hederacoside C and hederagenin from Hedera helix, affects the binding behavior, dynamics, and regulation of beta 2-adrenergic receptors.

Hederacoside C, alpha-hederin, and hederagenin are saponins of dry extracts obtained from the leaves of ivy (Hedera helix L.). Internalization of beta(2)-adrenergic receptor-GFP fusion proteins after stimulation with 1 microM terbutaline was inhibited by preincubation of stably transfected HEK293 cells with 1 microM alpha-hederin for 24 h, whereas neither hederacoside C nor hederagenin (1 microM each) influenced this receptor regulation. After incubation of A549 cells with 5 nM Alexa532-NA, two different diffusion time constants were found for beta(2)AR-Alexa532-NA complexes by fluorescence correlation spectroscopy. Evaluation of the autocorrelation curve revealed diffusion time constants: tau(bound1) = 1.4 +/- 1.1 ms (n = 6) found for receptor-ligand complexes with unrestricted lateral mobility, and tau(bound2) = 34.7 +/- 14.1 ms (n = 6) for receptor-ligand complexes with hindered mobility. The distribution of diffusion time constants was 24.3 +/- 2.5% for tau(bound1) and 8.7 +/- 4.3% for tau(bound2) (n = 6). A549 cells pretreated with 1 microM alpha-hederin for 24 h showed dose-dependent alterations in this distribution with 37.1 +/- 5.5% for tau(bound1) and 4.1 +/- 1.1% for tau(bound2). Simultaneously, the level of Alexa532-NA binding was significantly increased from 33.0 +/- 6.8 to 41.2 +/- 4.6%. In saturation experiments, alpha-hederin did not influence the beta(2)-adrenergic receptor density (B(max)), whereas the K(D) value for Alexa532-NA binding decreased from 36.1 +/- 9.2 to 24.3 +/- 11.1 nM. Pretreatment of HASM cells with alpha-hederin (1 microM, 24 h) revealed an increased intracellular cAMP level of 13.5 +/- 7.0% under stimulating conditions. Remarkably, structure-related saponins like hederacoside C and hederagenin did not influence either the binding behavior of beta(2)AR or the intracellular cAMP level.

Cost-effectiveness of diabetes education.

Diabetes cost the United States an estimated $132 billion in 2002 as a result of medical costs and lost productivity. Because of these overwhelming numbers, the cost-efficacy of preventing and treating diabetes, and the cost-effectiveness of diabetes self-management training and medical nutrition therapy to treat diabetes are receiving increased attention. This article reviews the published research concerning the cost-effectiveness of diabetes education.

Hepatic venous pressure gradient supplements liver biopsy in the diagnosis of cirrhosis.

BACKGROUND: Liver biopsy is the gold standard for establishing cirrhosis, but may provide inadequate tissue for interpretation in some patients. GOALS: The aim of this study was to determine whether the hepatic venous pressure gradient predicts the presence of cirrhosis. STUDY: Patients with liver disease who had undergone hepatic venous pressure gradient measurements were identified. Clinical, laboratory, and hepatic venous pressure gradient data were collected and biopsies were staged for fibrosis. Univariable logistic regression was used to identify potential predictors of cirrhosis. Multivariable logistic regression was applied to determine adjusted odds ratios. RESULTS: Thirty-two patients were included. The hepatic venous pressure gradient was an independent predictor of cirrhosis. On multivariable analysis, the hepatic venous pressure gradient predicted cirrhosis, with an odds ratio of 1.46 (95% confidence interval 1.05-2.02, P=0.023). Using a cutoff of >or=6.5 mm Hg, the hepatic venous pressure gradient was 86% sensitive and 80% specific for diagnosing cirrhosis. CONCLUSIONS: The hepatic venous pressure gradient measurement predicts the presence of cirrhosis in patients with liver disease. Therefore, when the diagnosis of cirrhosis is in question, an elevated hepatic venous pressure gradient can support the diagnosis.

Effects of lifestyle intervention on health care costs: Improving Control with Activity and Nutrition (ICAN).

OBJECTIVE: To evaluate program and health care costs of a lifestyle intervention in a high-risk obese population. DESIGN: Twelve-month randomized controlled trial comparing lifestyle case management to usual care. SUBJECTS/SETTING: Health plan members (n=147) with obesity (body mass index >/=27) and type 2 diabetes. INTERVENTION: Lifestyle case management entailed individual and group education, support, and referrals by registered dietitians. Those in the usual-care group received educational material. MAIN OUTCOME MEASURES: Medical and pharmaceutical health care costs reimbursed by the participant's primary insurance company. STATISTICAL ANALYSIS: Total costs were modeled using the four-equation model using previous year cost as a predictor. RESULTS: Net cost of the intervention was $328 per person per year. After incorporating program costs, mean health plan costs were $3,586 (95% confidence interval [CI]: -$8,036, -$25, P<0.05) lower in case management compared to usual care. The difference was driven by group differences in medical (-$3,316, 95% CI: -$7,829 to -$320, P<0.05) but not pharmaceutical costs (-$239, 95% CI: -$870 to $280, not statistically significant), with fewer inpatient admissions and costs among case management compared with usual care (admission prevalence: 2.8% vs 22.5% respectively, P<0.001). CONCLUSION: Addition of a modest-cost, registered dietitian-led lifestyle case-management intervention to usual medical care did not increase health care costs and suggested modest cost savings among obese patients with type 2 diabetes. Larger trials are needed to determine whether these results can be replicated in a broader population. The findings can be judiciously applied to support that the addition of a registered dietitian-led lifestyle case-management program to medical care does not increase health care costs.

Impact of anticoagulation on rebleeding following endoscopic therapy for nonvariceal upper gastrointestinal hemorrhage.

OBJECTIVE: Endoscopic therapy for nonvariceal upper gastrointestinal hemorrhage achieves hemostasis in greater than 90% of patients, but up to 20% rebleed. The aim of this study was to determine the impact of anticoagulation on rebleeding in patients undergoing endoscopic therapy for nonvariceal upper gastrointestinal hemorrhage. METHODS: Patients who underwent successful endoscopic therapy for nonvariceal upper gastrointestinal hemorrhage between July 1, 1999, and June 30, 2004, at a large, tertiary care teaching hospital were identified. The primary outcome was rebleeding within 30 days. Secondary outcomes were transfusion requirement, length of stay, surgery, and mortality. Baseline data were analyzed using t-tests and chi(2) tests. Multivariable logistic and linear regression analyses were carried out to calculate the adjusted odds ratios for the international normalized ratio (INR) predicting the primary and secondary outcomes. The multivariable analyses controlled for: age, Charlson comorbidity index, antiplatelet agent use, postprocedure heparin use, postprocedure proton pump inhibitor use, hypotension, ulcer as the bleeding source, and active bleeding at endoscopy. RESULTS: The study included 233 patients. Forty-four percent of the patients had an INR >or=1.3. Ninety-five percent of the anticoagulated patients had an INR between 1.3 and 2.7. The rebleeding rate was 23% in the anticoagulated patients and 21% in the patients with INRs <1.3. On multivariable analyses, INR was not a predictor of rebleeding, transfusion requirement, surgery, length of stay, or mortality. CONCLUSIONS: Mild to moderate anticoagulation does not increase the risk of rebleeding following endoscopic therapy for nonvariceal upper gastrointestinal hemorrhage, suggesting that endoscopic therapy is appropriate in these patients.

Densonucleosis virus purification by ion exchange membranes.

Preparative chromatography is widely used in the downstream purification of biopharmaceutical products. Replacement of resins by membranes as chromatographic supports, overcomes many of the limitations associated with resin-based chromatography such as high-pressure drops, slow processing rates due to pore diffusion and channeling of the feed through the bed. In particular, adsorptive membranes may be ideally suited for virus capture. Virus capture is critical in a number of applications. In gene therapy and vaccine production, large-scale purification of virus vectors is often essential. In the manufacture of biopharmaceuticals, validation of virus clearance is critical. Here results for purification of Aedes aegypti densonucleosis virus (AeDNV) using anion and cation exchange membranes are presented. AeDNV is a non-enveloped, single-stranded mosquito-specific parvovirus. Virus particles are around 20 nm in size. AeDNV could find potential applications in integrated vector-borne disease control programs. In addition, capture of parvovirus for validation of virus clearance in the manufacture of biopharmaceuticals is of commercial importance. By adjusting the pH of the feed stream, AeDNV particles may be adsorbed by both anion and cation exchange membranes. However, strongly basic anion exchange membranes were the most effective in adsorbing AeDNV particles. Adsorption and subsequent elution of AeDNV by anion exchange membranes leads to significant virus concentration. Dynamic and static capacities for anion exchange membranes were similar. Further, a sharp elution curve was obtained suggesting that pore diffusional resistances are insignificant. The adsorption of AeDNV particles by anion exchange membranes may be described by a linear isotherm.

Translating lifestyle intervention to practice in obese patients with type 2 diabetes: Improving Control with Activity and Nutrition (ICAN) study.

OBJECTIVE: To assess the efficacy of a lifestyle intervention program that can be readily translated into clinical practice for obese patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: The study consisted of a 12-month randomized controlled trial of 147 health plan members with type 2 diabetes and obesity (BMI >or=27 kg/m(2)). Participants were randomized to lifestyle case management or usual care. Case management entailed individual and group education, support, and referral by registered dietitians; intervention cost was US dollars 350 per person. Individuals treated with usual care received educational material. Both groups received ongoing primary care. Outcomes were difference between groups for change in weight (kilograms), waist circumference (centimeters), HbA(1c), fasting lipid levels, use of prescription medications, and health-related quality of life. RESULTS: Case management resulted in greater weight loss (P < 0.001), reduced waist circumference (P < 0.001), reduced HbA(1c) level (P = 0.02), less use of prescription medications (P = 0.03), and improved health-related quality of life (P < 0.001) compared with usual care. The 12-month group difference in weight loss and waist circumference was 3.0 kg (95% CI -5.4 to -0.6) and -4.2 cm (-6.8 to -1.6). HbA(1c) differences were greatest at 4 months (-0.59%, P = 0.006) but not significant by 12 months (-0.19%, P = 0.45). Participants in the case management group lowered their use of medications, primarily diabetes medications, by 0.8 medications per day more than participants treated with usual care (P = 0.03). In seven of nine quality-of-life domains, the case management group improved compared with usual care (P < 0.05). CONCLUSIONS: Moderate-cost dietitian-led lifestyle case management may improve diverse health indicators among obese patients with type 2 diabetes.

Gangliosides that associate with lipid rafts mediate transport of cholera and related toxins from the plasma membrane to endoplasmic reticulm.

Cholera toxin (CT) travels from the plasma membrane of intestinal cells to the endoplasmic reticulum (ER) where a portion of the A-subunit, the A1 chain, crosses the membrane into the cytosol to cause disease. A related toxin, LTIIb, binds to intestinal cells but does not cause toxicity. Here, we show that the B-subunit of CT serves as a carrier for the A-subunit to the ER where disassembly occurs. The B-subunit binds to gangliosides in lipid rafts and travels with the ganglioside to the ER. In many cells, LTIIb follows a similar pathway, but in human intestinal cells it binds to a ganglioside that fails to associate with lipid rafts and it is sorted away from the retrograde pathway to the ER. Our results explain why LTIIb does not cause disease in humans and suggest that gangliosides with high affinity for lipid rafts may provide a general vehicle for the transport of toxins to the ER.