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Metal oxide pseudocapacitors are limited by low electrical and ionic conductivities. The present work integrates defect engineering and architectural design to exhibit, for the first time, intercalation pseudocapacitance in CeO2-x. An engineered chronoamperometric electrochemical deposition is used to synthesize 2D CeO2-x nanoflakes as thin as â¼12 nm. Through simultaneous regulation of intrinsic and extrinsic defect concentrations, charge transfer and charge-discharge kinetics with redox and intercalation capacitances together are optimized, where reduction increases the gravimetric capacitance by 77% to 583 F g-1, exceeding the theoretical capacitance (562 F g-1). Mo ion implantation and reduction processes increase the specific capacitance by 133%, while the capacitance retention increases from 89 to 95%. The role of ion-implanted Mo6+ is critical through its interstitial solid solubility, which is not to alter the energy band diagram but to facilitate the generation of electrons and to establish the midgap states for color centers, which facilitate electron transfer across the band gap, thus enhancing n-type semiconductivity. Critically, density functional theory simulations reveal, for the first time, that the reduction causes the formation of ordered oxygen vacancies that provide an atomic channel for ion intercalation. These channels enable intercalation pseudocapacitance but also increase electrical and ionic conductivities. In addition, the associated increased active site density enhances the redox such that the 10% of the Ce3+ available for redox (surface only) increases to 35% by oxygen vacancy channels. These findings are critical for any oxide system used for energy storage systems, as they offer both architectural design and structural engineering of materials to maximize the capacitance performance by achieving accumulative surface redox and intercalation-based redox reactions during the charge/discharge process.
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Assembled structures tend to exhibit nonlinear dynamic behaviour at high excitation levels due to the presence of contact interfaces. The possibility of building predictive models relies on the ability of the modelling strategy to capture the complex nonlinear phenomena occurring at the interface. One of these phenomena, normally neglected, is the fretting wear occurring at the frictional interface. In this paper, a computationally efficient modelling approach which enables considerations of the effect of fretting wear on the nonlinear dynamics is presented. A multi-scale strategy is proposed, in which two different time scales and space scales are used for the contact analysis and dynamic analysis. Thanks to the de-coupling of the contact and dynamic analysis, a more realistic representation of the contact interface, which includes surface roughness, is possible. The proposed approach is applied to a single bolted joint resonator with a simulated rough contact interface. A tendency towards an increase of real contact area and contact stiffness at the interface is clearly observed. The dynamic response of the system is shown to evolve over time, with a slight decrease of damping and an increase of resonance frequency, highlighting the impact of fretting wear on the system dynamics.
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Characterisation of atmospheric aerosols is of major importance for: climate, the hydrological cycle, human health and policymaking, biogeochemical and palaeo-climatological studies. In this study, the chemical composition and source apportionment of PM2.5 (particulate matter with aerodynamic diameters less than 2.5µm) at Yarrangobilly, in the Snowy Mountains, SE Australia are examined and quantified. A new aerosol monitoring network was deployed in June 2013 and aerosol samples collected during the period July 2013 to July 2017 were analysed for 22 trace elements and black carbon by ion beam analysis techniques. Positive matrix factorisation and back trajectory analysis and trajectory clustering methods were employed for source apportionment and to isolate source areas and air mass travel pathways, respectively. This study identified the mean atmospheric PM2.5 mass concentration for the study period was (3.3±2.5)µgm-3. It is shown that automobile (44.9±0.8)%, secondary sulfate (21.4±0.9)%, smoke (12.3±0.6)%, soil (11.3±0.5)% and aged sea salt (10.1±0.4)% were the five PM2.5 source types, each with its own distinctive trends. The automobile and smoke sources were ascribed to a significant local influence from the road network and bushfire and hazard reduction burns, respectively. Long-range transport are the dominant sources for secondary sulfate from coal-fired power stations, windblown soil from the inland saline regions of the Lake Eyre and Murray-Darling Basins, and aged sea salt from the Southern Ocean to the remote alpine study site. The impact of recent climate change was recognised, as elevated smoke and windblown soil events correlated with drought and El Niño periods. Finally, the overall implications including potential aerosol derived proxies for interpreting palaeo-archives are discussed. To our knowledge, this is the first long-term detailed temporal and spatial characterisation of PM2.5 aerosols for the region and provides a crucial dataset for a range of multidisciplinary research.
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Cancer immunotherapy is coming of age; it has prompted a paradigm shift in oncology, in which therapeutic agents are used to target immune cells rather than cancer cells. The first generation of new immunotherapies corresponds to antagonistic antibodies that block specific immune checkpoint molecules cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death protein (PD-1) and its ligand PD-L1. Targeting these checkpoints in patients living with cancer had led to long-lasting tumour responses. By unbalancing the immune system, these new immunotherapies also generate dysimmune toxicities, called immune-related adverse events (IRAEs) that mainly involve the gut, skin, endocrine glands, liver, and lung but can potentially affect any tissue. In view of their undisputed clinical efficacy, anti-CTLA-4 and anti-PD-1 antibodies are entering in the routine oncological practice, and the number of patients exposed to these drugs will increase dramatically in the near future. Although steroids can be used to treat these IRAEs, the associated immunosuppression may compromise the antitumour response. Oncologists must be ready to detect and manage these new types of adverse events. This review focuses on the mechanisms of IRAE generation, putative relationship between dysimmune toxicity and antitumour efficacy, as a basis for management guidelines.
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Anticuerpos/efectos adversos , Antineoplásicos/efectos adversos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/inmunología , Inmunoterapia/efectos adversos , Neoplasias/tratamiento farmacológico , Abatacept/efectos adversos , Animales , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/inmunología , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/antagonistas & inhibidores , Antígeno CTLA-4/inmunología , Antígeno CTLA-4/metabolismo , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/diagnóstico , Humanos , Inmunoterapia/métodos , Terapia Molecular Dirigida , Neoplasias/inmunología , Neoplasias/metabolismo , Neoplasias/patología , Factores de Riesgo , Transducción de Señal/efectos de los fármacos , Resultado del TratamientoAsunto(s)
Herpes Simple/complicaciones , Herpes Simple/diagnóstico , Pleuresia/virología , Esclerodermia Sistémica/complicaciones , Aciclovir/uso terapéutico , Anciano , Antivirales/uso terapéutico , Femenino , Herpes Simple/tratamiento farmacológico , Herpes Simple/inmunología , Humanos , Huésped Inmunocomprometido , Pleuresia/tratamiento farmacológico , Pleuresia/inmunologíaRESUMEN
Photocatalytic activity of oxide semiconductors is commonly considered in terms of the effect of the band gap on the light-induced performance. The present work considers a combined effect of several key performance-related properties (KPPs) on photocatalytic activity of TiO2 (rutile), including the chemical potential of electrons (Fermi level), the concentration of surface active sites, and charge transport, in addition to the band gap. The KPPs have been modified using defect engineering. This approach led to imposition of different defect disorders and the associated KPPs, which are defect-related. This work shows, for the first time, a competitive influence of different KPPs on photocatalytic activity that was tested using oxidation of methylene blue (MB). It is shown that the increase of oxygen activity in the TiO2 lattice from 10(-12) Pa to 10(5) Pa results in (i) increase in the band gap from 2.42 to 2.91 eV (direct transitions) or 2.88 to 3 eV (indirect transitions), (ii) increase in the population of surface active sites, (iii) decrease of the Fermi level, and (iv) decrease of the charge transport. It is shown that the observed changes in the photocatalytic activity are determined by two dominant KPPs: the concentration of active surface sites and the Fermi level, while the band gap and charge transport have a minor effect on the photocatalytic performance. The effect of the defect-related properties on photoreactivity of TiO2 with water is considered in terms of a theoretical model offering molecular-level insight into the process.
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This work reports the effect of indium segregation on the surface versus bulk composition of indium (In)-doped TiO(2). The studies are performed using proton-induced X-ray emission (PIXE), secondary-ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), and Rutherford backscattering spectroscopy (RBS). The results of XPS analysis indicate that annealing of In-doped TiO(2) containing 0.3 atom % In at 1273 K in the gas phase of controlled oxygen activity [p(O(2)) = 75 kPa and 10 Pa] results in a surface enrichment of 2.95 and 2.61 atom % In, respectively. The obtained segregation data are considered in terms of the transport of indium ions from its titanium sites in the bulk phase to the surface where these ions are incorporated into interstitial sites. The effect of oxygen activity on the segregation-induced surface enrichment is considered in terms of the formation of a low-dimensional surface structure and a sublayer, which are charged negatively. The latter is formed as a result of strong interactions between titanium vacancies and interstitial indium ions, leading to the formation of defect complexes. The data obtained in this work may be used for engineering of TiO(2)-based semiconductors with enhanced performance in solar energy conversion.
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BACKGROUND: ES-285 (spisulosine) is a novel compound derived from the marine mollusk Spisula polynoma with evidence of preclinical antitumor activity. This phase I clinical trial was designed to identify the maximum tolerated dose (MTD) and the recommended dose for phase II trials (RD), as well as to evaluate the safety profile, pharmacokinetics and preliminary efficacy data of ES-285 in patients with advanced solid tumors. PATIENTS AND METHODS: Sixty-one patients at two medical institutions were treated with a 3-h ES-285 intravenous infusion every 3 weeks. Nine dose levels were evaluated. RESULTS: No dose-limiting toxicities (DLTs) were observed during dose escalation from 4 to 128 mg/m(2). Six patients had seven DLTs at the three highest dose levels tested: 256 mg/m(2) (n = 2), 200 mg/m(2) (n = 3) and 160 mg/m(2) (n = 1). Grade 3/4 transaminase increases (n = 3), grade 3/4 central nervous system disorders [confusion (n = 2) and ataxia (n = 1)], and grade 3 pyrexia (n = 1) were the dose-limiting toxicities found with this ES-285 administration schedule. Pharmacokinetic analysis showed ES-285 dose linearity, wide distribution and a long half-life. One non-confirmed partial response was observed in a patient with metastatic melanoma treated with ES-285 128 mg/m(2), and 18 patients showed stable disease at different dose levels, lasting longer than 3 months in six patients. CONCLUSION: Dose level VIII (200 mg/m(2)) was considered the MTD, and dose level IX (160 mg/m(2)) was defined as the RD. Limited antitumor activity was observed.
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Antineoplásicos/administración & dosificación , Lípidos/administración & dosificación , Adulto , Anciano , Antineoplásicos/sangre , Antineoplásicos/farmacocinética , Esquema de Medicación , Femenino , Humanos , Infusiones Intravenosas , Lípidos/sangre , Lípidos/farmacocinética , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismoRESUMEN
PURPOSE: We studied the safety, tolerability, and recommended dose of BMS-599626, an orally bioavailable inhibitor of the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases. PATIENTS AND METHODS: Patients with advanced solid tumors that expressed epidermal growth factor receptor (EGFR) and/or HER-2 were recruited and enrolled in a phase I, open-label, dose escalation trial of oral BMS-599626 starting at 100 mg/day given once daily for at least 28 days. RESULTS: Forty-five patients received BMS-599626 (100-660 mg/day). Dose-limiting toxic effects were reported at 660 mg/day (grade 3 elevation of hepatic transaminases [two patients] and QTc interval prolongation [one patient]), therefore the recommended maximum tolerated dose was 600 mg/day. The most frequent drug-related toxic effects were diarrhea (30% of patients), anorexia (13%), asthenia (30%), and cutaneous toxic effects, including skin rash (30%). Pharmacokinetic analysis demonstrated C(max) and exposure to BMS-599626 in patients increased with dose. Eleven patients had stable disease and received BMS-599626 for ≥ 4 months. Serial skin and tumor biopsies taken before and after treatment revealed expected changes in pharmacodynamic biomarkers, indicating that the EGFR and HER-2 pathways were affected. Positron emission tomography imaging showed a metabolic response in 2 of 10 patients evaluated. CONCLUSION: BMS-599626 was generally well tolerated, with disease stabilization across a range of tumor types and doses.
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Antineoplásicos/farmacocinética , Carbamatos/farmacocinética , Receptores ErbB/antagonistas & inhibidores , Neoplasias/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacocinética , Triazinas/farmacocinética , Administración Oral , Adulto , Anciano , Femenino , Humanos , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Receptor ErbB-2/antagonistas & inhibidoresRESUMEN
BACKGROUND: Sequential tumour biopsies are of potential interest for the rational development of molecular targeted therapies. PATIENTS AND METHODS: From June 2004 to July 2009, 186 patients participated in 14 phase I clinical trials in which sequential tumour biopsies (13 trials) and/or sequential normal skin biopsies (6 trials) were optional. All patients had to sign an independent informed consent for the biopsies. RESULTS: Tumour biopsies were proposed to 155 patients and 130 (84%) signed the consent while normal skin biopsies were proposed to 70 patients and 57 (81%) signed the consent. Tumour biopsies could not be carried out in 41 (31%) of the 130 consenting patients. Tumour biopsies were collected at baseline in 33 patients, at baseline and under treatment in 56 patients. Tumour biopsies were obtained using an 18-gauge needle, under ultrasound or computed tomography guidance. Only nine minor complications were recorded. Most tumour biopsy samples collected were intended for ancillary molecular studies including protein or gene expression analysis, comparative genomic hybridization array or DNA sequencing. According to the results available, 70% of the biopsy samples met the quality criteria of each study and were suitable for ancillary studies. CONCLUSIONS: In our experience, the majority of the patients accepted skin biopsies as well as tumour biopsies. Sequential tumour and skin biopsies are feasible and safe during early-phase clinical trials, even when patients are exposed to anti-angiogenic agents. The real scientific value of such biopsies for dose selection in phase I trials has yet to be established.
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Investigación Biomédica/métodos , Ensayos Clínicos Fase I como Asunto/efectos adversos , Ensayos Clínicos Fase I como Asunto/métodos , Neoplasias/patología , Aceptación de la Atención de Salud , Piel/patología , Adolescente , Adulto , Anciano , Algoritmos , Biopsia/efectos adversos , Biopsia/métodos , Biopsia/psicología , Biopsia/estadística & datos numéricos , Ensayos Clínicos Fase I como Asunto/psicología , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud/psicología , Seguridad del Paciente/estadística & datos numéricos , Adulto JovenRESUMEN
BACKGROUND: Sunitinib is a multitargeted, oral tyrosine kinase inhibitor with antitumour and antiangiogenic activity. We investigated the safety and pharmacokinetics of sunitinib in combination with irinotecan in patients with advanced, refractory solid tumours. METHODS: Sunitinib was initially administered once daily at 37.5 mg per day on days 1-14 of a 21-day cycle, in which irinotecan 250 mg m(-2) was given on day 1. In a second cohort, the sunitinib dose was reduced to 25 mg per day. Blood samples were collected for pharmacokinetic studies. RESULTS: In the sunitinib 37.5 mg per day cohort, 3 out of 10 evaluable patients had objective responses, but dose-limiting toxicities (DLTs) of neutropenia, pneumococcal sepsis, and fatigue were observed. There were no DLTs in the sunitinib 25 mg per day cohort. Paired observations of pharmacokinetic parameter values of sunitinib and irinotecan alone vs the combination did not reveal significant drug-drug interactions. The maximum tolerated dose was defined as sunitinib 25 mg per day (days 1-14) with irinotecan 250 mg m(-2) (day 1), but no activity was observed at this dose. CONCLUSION: Although a higher sunitinib dose of 37.5 mg per day (days 1-14) with irinotecan showed preliminary evidence of antitumour activity, this dose was poorly tolerated. Therefore, this particular combination will not be pursued for further studies.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Camptotecina/análogos & derivados , Indoles/administración & dosificación , Neoplasias/tratamiento farmacológico , Pirroles/administración & dosificación , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Camptotecina/administración & dosificación , Esquema de Medicación , Femenino , Humanos , Indoles/efectos adversos , Indoles/farmacocinética , Irinotecán , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Neoplasias/patología , Pirroles/efectos adversos , Pirroles/farmacocinética , Sunitinib , Resultado del TratamientoRESUMEN
BACKGROUND: Masitinib is a tyrosine kinase inhibitor with a pre-clinical profile suggesting greater affinity and selectivity in vitro for the wild-type c-Kit receptor and its juxtamembrane mutation than imatinib. METHODS: This dose-escalation study was conducted in patients with advanced and/or metastatic cancer to determine the maximum tolerated dose (MTD) for orally administered masitinib over a 12-week period. Secondary objectives were a clinical assessment of masitinib's activity in cancer patients and establishment of a pharmacokinetic profile. RESULTS: Forty patients with various solid tumours (predominantly GIST, 19 patients) were treated with masitinib at doses ranging between 0.7 and 17.2mg/kg/day. Although the MTD was not formally reached, an acceptable dose for chronic use was identified at 12 mg/kg/day. Treatment-related AEs were frequent (38/40 patients), however, the majority were grade 1 or 2 and demonstrated dose dependency at higher concentrations. Pharmacokinetic results showed a linear, dose-dependent increase of C(max) and AUC. One of two GIST patients with imatinib intolerance had a partial response at 11.1mg/kg/day. About 29% of the imatinib-resistant GIST population and 38% of the overall population had stable disease. CONCLUSIONS: The safety profile of masitinib at 12 mg/kg/day b.i.d. for the treatment of solid cancers appears favourable and compatible with a long-term regimen. Tumour control rate in imatinib-resistant patients was encouraging, hence, the activity of masitinib in c-Kit expressing tumours, such as GIST, warrants further exploration as first-line anticancer therapy as well as for imatinib-resistant patients.
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Antineoplásicos/administración & dosificación , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Administración Oral , Adulto , Anciano , Antineoplásicos/efectos adversos , Antineoplásicos/farmacocinética , Benzamidas , Relación Dosis-Respuesta a Droga , Femenino , Tumores del Estroma Gastrointestinal/metabolismo , Humanos , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Piperidinas , Piridinas , Tiazoles/administración & dosificación , Tiazoles/efectos adversos , Tiazoles/farmacocinética , Resultado del TratamientoRESUMEN
BACKGROUND: The oncology community usually perceives phase I oncology trials as associated with poor or limited benefits and substantial risks. There is scarce data concerning outcome and survival of patients enrolled in current phase I oncology trials. PATIENTS AND METHODS: We reviewed all phase I oncology trials conducted by investigators from the Adult Phase I Unit at Institut Gustave Roussy from 2003 to 2006. We report data concerning patient demographics, treatment outcome, toxicity, survival and type of care after trial exit. RESULTS: We analyzed 10 trials involving 180 participants. The overall response rate was 7.2%. Disease control (objective response plus stable disease) was achieved in 48.2% of patients. The rate of toxic death was 0.5%. In all, 38% of patients had at least one episode of grade 3 or 4 toxic events. The median progression-free survival and the median overall survival (OS) were 2.3 and 8.7 months, respectively. On multivariate analysis, a time between diagnosis of disease and inclusion in the phase I trial > or =24 months and evidence of disease control were statistically significant predictors of improved OS. CONCLUSION: Current phase I oncology trials are safe and are associated with clinical benefit in a substantial proportion of patients.
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Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Neoplasias/mortalidad , Neoplasias/terapia , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/efectos adversos , Antineoplásicos/farmacocinética , Antineoplásicos Hormonales/uso terapéutico , Ensayos Clínicos Fase I como Asunto , Supervivencia sin Enfermedad , Femenino , Francia/epidemiología , Humanos , Inmunoterapia , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Análisis Multivariante , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Neoplasias/radioterapia , Resultado del TratamientoRESUMEN
Currently, only epidemiological injury data have been reported for the new extreme sport of aggressive inline skating, or trick skating. No studies have examined the biomechanics of this sport, which involves repetitive jumping and landing from railings, ramps, and ledges, often over 1 m in height. We present results of a pilot study that examined the effect of skater experience and lower extremity biomechanics on energy absorption ability, and observed balance strategies used during two basic tricks. In these tricks, the skater jumps onto an elevated rail and maintains balance while standing in a single position (stall) or sliding along the rail (grind). Lower extremity joint kinematics, impact force characteristics, and general movement behaviours were examined during landing and balance phases. Ten male skaters performed ten stalls and ten frontside grinds on an instrumented grind rail, capable of measuring vertical force. Vertical impact force was found to decrease with increasing skater experience in stalls (r = -0.84, P = 0.002) and grinds (r = -0.84, P = 0.009). This might imply that less-experienced skaters are (subconsciously) more concerned about maintaining balance than refining technique to minimize impact force. Similar to drop landing experiments, peak impact force decreased with increasing knee flexion during stalls (r = -0.65, P = 0.04). During stalls, skaters demonstrated classic balance maintenance strategies (ankle, hip, or multi-joint) depending on trick length. During grinds, skater centre of mass never passed over the rail base of support, suggesting the use of momentum produced from obliquely approaching the rail.
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Fenómenos Biomecánicos , Extremidad Inferior/fisiología , Movimiento/fisiología , Equilibrio Postural/fisiología , Postura/fisiología , Patinación/fisiología , Adolescente , Adulto , Humanos , Masculino , Persona de Mediana Edad , Proyectos PilotoRESUMEN
A 35-year-old man presented with traumatic iritis, angle-recession glaucoma, and a retinal dialysis secondary to blunt trauma from a Taser gun in the right eye and a unique electrical cataract in the left eye. Taser guns, which can also function as stun guns, can lead to electrical cataract formation. Given the increasing use of Taser guns by law enforcement and citizens, blunt mechanical and electrical sequelae of Taser gun injuries should be recognized.
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Catarata/etiología , Traumatismos por Electricidad/complicaciones , Lesiones Oculares/etiología , Cristalino/lesiones , Heridas no Penetrantes/etiología , Adulto , Glaucoma de Ángulo Cerrado/etiología , Humanos , Iritis/etiología , Masculino , Perforaciones de la Retina/etiologíaRESUMEN
The present work reports the tracer diffusion coefficient for (93)Nb in rutile TiO(2) single crystals using secondary ion mass spectrometry (SIMS). The determined tracer diffusion coefficient exhibited the following temperature dependence in air ( p(O2) = 21 kPa) over the range 1073-1573 K: D93(Nb) = (4.7 m2 s(-1))x10(-7+/-0.4) exp ((-244 +/- 9 kJ mol-1)/RT) Through comparison to the self-diffusion of (44)Ti in rutile TiO(2), (93)Nb is interpreted to diffuse via the interstitialcy mechanism. The obtained tracer diffusion data are useful for ensuring compositional control during the processing of Nb-doped TiO(2)-based semiconductors using solid-state reactions between Nb(2)O(5) and TiO(2).
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Failure to express the Gimap5 protein is associated with lymphopenia (lyp) and linked to spontaneous diabetes in the diabetes-prone BioBreeding (BBDP) rat. Gimap5 is a member of seven related genes located within 150 Kb on rat chromosome 4. Congenic DR.(lyp/lyp) rats, where BBDP lyp was introgressed onto the diabetes-resistant BBDR background (BBDR.BBDP.(lyp/lyp)), all develop diabetes between 46 and 81 days of age (mean +/- SE, 61 +/- 1), whereas DR.(lyp/+) and DR.(+/+) rats are nonlymphopenic and diabetes resistant. In an intercross between F1(BBDP x F344) rats, we identified a rat with a recombination event on chromosome 4, allowing us to fix 33 Mb of F344 between D4Rat253 and D4Rhw6 in the congenic DR.lyp rat line. Gimap1 and Gimap5 were the only members of the Gimap family remaining homozygous for the BBDP allele. Offspring homozygous for the F344 allele (f/f) between D4Rat253 and D4Rhw6 were lymphopenic (85 of 85, 100%) but did not develop diabetes (0 of 85). During rescue of the recombination, 102 of 163 (63%) rats heterozygous (b/f) for the recombination developed diabetes between 52 and 222 days of age (88 +/- 3). Our data demonstrate that introgression of a 33-Mb region of the F344 genome, proximal to the mutated Gimap5 gene, renders the rat diabetes resistant despite being lymphopenic. Spontaneous diabetes in the BB rat may therefore be controlled, in part, by a diabetogenic factor(s), perhaps unrelated to the Gimap5 mutation on rat chromosome 4.