Real-World Evaluation of the Effectiveness and Safety of Dupilumab in Bullous Pemphigoid: An Ambispective Multicenter Case Series.

BACKGROUND: Bullous pemphigoid affects elderly individuals with multiple comorbidities, making conventional treatments unsuitable. OBJECTIVE: Evaluate the effectiveness and safety of dupilumab in the treatment of bullous pemphigoid. METHODS: A multicenter ambispective cohort study was conducted in 34 hospitals. Patients with bullous pemphigoid treated with Dupilumab were included. Most of patients (97.1%) received an initial 600 mg dose followed by 300 mg every two weeks. OUTCOMES AND MEASURES: The primary outcome was the proportion of patients achieving complete remission within 4 weeks, defined as Investigator Global Assessment score of 0 or 1. Complete remission at weeks 16, 24, and 52, adverse events, reductions in peak pruritus numerical rating scale, and systemic glucocorticoid use were also assessed. RESULTS: The study included 103 patients with a median age of 77.3 years, 58.0% male. Complete remission was achieved by 53.4% within 4 weeks and 95.7% by week 52. Peak pruritus scale reduced by 70.0% by week 4 and was completely controlled by week 24. Thirteen patients presented adverse events, most of which were mild. Systemic glucocorticoid use reduced by 82.1% by week 52. Shorter disease duration and exclusive cutaneous involvement predicted better response at 16 weeks. No differences in response rates to dupilumab were observed between drug-associated bullous pemphigoid and idiopathic cases. No significant difference in response rates was observed between patients treated with dupilumab in monotherapy and those receiving dupilumab with concomitant treatments. CONCLUSIONS: Dupilumab is effective, rapid, and safe in managing bullous pemphigoid, reducing the need for corticosteroids and other treatments. Early initiation and exclusive skin involvement predict better outcomes.

Which roads lead to access? A global landscape of six COVID-19 vaccine innovation models.

BACKGROUND: Unequal and inequitable access to Covid-19 vaccines in low- and middle-income countries (L&MICs) was a major political, ethical and public health failure in the pandemic. However, vaccine developers' practices were not monolithic, but rather, took diverse approaches to supplying different countries, with important implications for global access. RESULTS: Using data on R&D investments, regulatory approvals, manufacturing and purchase agreements, and vaccine deliveries, we identified six distinct innovation models that apply across the 14 COVID-19 vaccines with more international presence from 2020-2022. "Western Early Arrivers" Pfizer/BioNTech and Moderna supplied the largest volumes quickly and prioritized high-income countries (HICs) from registration to vaccine delivery. "Western Latecomers" Janssen and Novavax supplied intermediate volumes later, also prioritizing HICs but with a greater proportion to L&MICs. "Major Chinese Developers" Sinopharm and Sinovac supplied intermediate volumes early, primarily to middle-income countries (MICs). "Russian Developer" Gamaleya completed development early but ultimately supplied small volumes, primarily to middle-income countries (MICs). "Cosmopolitan Developer" Oxford/AstraZeneca supplied large volumes early to HICs and MICs at the lowest prices. Finally, "Small MIC Developers" CanSino, Bharat Biotech, Medigen, Finlay Institute and the Center for Genetic Engineering and Biotechnology (CGEB), exported relatively small volumes to a few MICs. Low-income countries (LICs) were not targeted by any developer, and received far fewer doses, later, than any other income group. Almost all developers received public funding and other forms of support, but we found little evidence that such support was leveraged to expand global access. CONCLUSIONS: Each of the six innovation models has different implications for which countries get access to which vaccines, how quickly, and at which prices. Each offers different strengths and weaknesses for achieving equitable access. Our findings also suggest that Western firms had the greatest capacity to develop and deliver vaccines quickly during the pandemic, but such capacity is rapidly becoming more globally distributed with MICs playing a significant role, especially in supplying other MICs. Given the critical role of public support in enabling pandemic vaccine development and supply, governments have both the capacity and responsibility to craft international rules that will make responses to future pandemics more equitable and effective.

ß-Turn Induction by a Diastereopure Azepane-Derived Quaternary Amino Acid.

ß-Turns are one of the most common secondary structures found in proteins. In the interest of developing novel ß-turn inducers, a diastereopure azepane-derived quaternary amino acid has been incorporated into a library of simplified tetrapeptide models in order to assess the effect of the azepane position and peptide sequence on the stabilization of ß-turns. The conformational analysis of these peptides by molecular modeling, NMR spectroscopy, and X-ray crystallography showed that this azepane amino acid is an effective ß-turn inducer when incorporated at the i + 1 position. Moreover, the analysis of the supramolecular self-assembly of one of the ß-turn-containing peptide models in the solid state reveals that it forms a supramolecular helical arrangement while maintaining the ß-turn structure. The results here presented provide the basis for the use of this azepane quaternary amino acid as a strong ß-turn inducer in the search for novel peptide-based bioactive molecules, catalysts, and biomaterials.

Inhibiting ERK dimerization ameliorates BRAF-driven anaplastic thyroid cancer.

BACKGROUND: RAS-to-ERK signaling is crucial for the onset and progression of advanced thyroid carcinoma, and blocking ERK dimerization provides a therapeutic benefit in several human carcinomas. Here we analyzed the effects of DEL-22379, a relatively specific ERK dimerization inhibitor, on the activation of the RAS-to-ERK signaling cascade and on tumor-related processes in vitro and in vivo. METHODS: We used a panel of four human anaplastic thyroid carcinoma (ATC) cell lines harboring BRAF or RAS mutations to analyze ERK dynamics and tumor-specific characteristics. We also assessed the impact of DEL-22379 on the transcriptional landscape of ATC cell lines using RNA-sequencing and evaluated its therapeutic efficacy in an orthotopic mouse model of ATC. RESULTS: DEL-22379 impaired upstream ERK activation in BRAF- but not RAS-mutant cells. Cell viability and metastasis-related processes were attenuated by DEL-22379 treatment, but mostly in BRAF-mutant cells, whereas in vivo tumor growth and dissemination were strongly reduced for BRAF-mutant cells and mildly reduced for RAS-mutant cells. Transcriptomics analyses indicated that DEL-22379 modulated the transcriptional landscape of BRAF- and RAS-mutant cells in opposite directions. CONCLUSIONS: Our findings establish that BRAF- and RAS-mutant thyroid cells respond differentially to DEL-22379, which cannot be explained by the previously described mechanism of action of the inhibitor. Nonetheless, DEL-22379 demonstrated significant anti-tumor effects against BRAF-mutant cells in vivo with an apparent lack of toxicity, making it an interesting candidate for the development of combinatorial treatments. Our data underscore the differences elicited by the specific driver mutation for thyroid cancer onset and progression, which should be considered for experimental and clinical approaches.

Yap governs a lineage-specific neuregulin1 pathway-driven adaptive resistance to RAF kinase inhibitors.

BACKGROUND: Inactivation of the Hippo pathway promotes Yap nuclear translocation, enabling execution of a transcriptional program that induces tissue growth. Genetic lesions of Hippo intermediates only identify a minority of cancers with illegitimate YAP activation. Yap has been implicated in resistance to targeted therapies, but the mechanisms by which YAP may impact adaptive resistance to MAPK inhibitors are unknown. METHODS: We screened 52 thyroid cancer cell lines for illegitimate nuclear YAP localization by immunofluorescence and fractionation of cell lysates. We engineered a doxycycline (dox)-inducible thyroid-specific mouse model expressing constitutively nuclear YAPS127A, alone or in combination with endogenous expression of either HrasG12V or BrafV600E. We also generated cell lines expressing dox-inducible sh-miR-E-YAP and/or YAPS127A. We used cell viability, invasion assays, immunofluorescence, Western blotting, qRT-PCRs, flow cytometry and cell sorting, high-throughput bulk RNA sequencing and in vivo tumorigenesis to investigate YAP dependency and response of BRAF-mutant cells to vemurafenib. RESULTS: We found that 27/52 thyroid cancer cell lines had constitutively aberrant YAP nuclear localization when cultured at high density (NU-YAP), which rendered them dependent on YAP for viability, invasiveness and sensitivity to the YAP-TEAD complex inhibitor verteporfin, whereas cells with confluency-driven nuclear exclusion of YAP (CYT-YAP) were not. Treatment of BRAF-mutant thyroid cancer cells with RAF kinase inhibitors resulted in YAP nuclear translocation and activation of its transcriptional output. Resistance to vemurafenib in BRAF-mutant thyroid cells was driven by YAP-dependent NRG1, HER2 and HER3 activation across all isogenic human and mouse thyroid cell lines tested, which was abrogated by silencing YAP and relieved by pan-HER kinase inhibitors. YAP activation induced analogous changes in BRAF melanoma, but not colorectal cells. CONCLUSIONS: YAP activation in thyroid cancer generates a dependency on this transcription factor. YAP governs adaptive resistance to RAF kinase inhibitors and induces a gene expression program in BRAFV600E-mutant cells encompassing effectors in the NRG1 signaling pathway, which play a central role in the insensitivity to MAPK inhibitors in a lineage-dependent manner. HIPPO pathway inactivation serves as a lineage-dependent rheostat controlling the magnitude of the adaptive relief of feedback responses to MAPK inhibitors in BRAF-V600E cancers.

Sociodemographic and Clinical Characteristics of 1350 Patients With Young Onset Dementia: A Comparison With Older Patients.

OBJECTIVE: To determine the sociodemographic and clinical characteristics of a large cohort of patients with young onset dementia (YOD) (aged below 65), and whether they differ from older (age 65+) adults with dementia. METHODS: Retrospective cross-sectional study. Participants were New Zealanders who were assessed with International Residential Assessment Instrument (interRAI) assessments (including community-dwelling adults and those in long-term care) from 2016 to 2019 and had a diagnosis of dementia. Outcomes were sociodemographic and clinical characteristics captured in the interRAI assessment. RESULTS: People with YOD were more likely to be male, of non-European ethnicity, and live in a dwelling other than a private home or be homeless. They were more likely to exhibit problematic behaviors and neuropsychiatric symptoms but were less frail and less dependent for activities of daily living. Financial strain and loneliness were more common in people with YOD. Carers of people with YOD were more likely to feel distress, anger, or depression, and families of people with YOD were more likely to feel overwhelmed. CONCLUSIONS: YOD patients have different needs than older adults with dementia. These differences must be considered by clinicians and organizations that provide care and support to people living with dementia.

Caregiving burnout of community-dwelling people with dementia in Hong Kong and New Zealand: a cross-sectional study.

BACKGROUND: Informal caregiving for people with dementia can negatively impact caregivers' health. In Asia-Pacific regions, growing dementia incidence has made caregiver burnout a pressing public health issue. A cross-sectional study with a representative sample helps to understand how caregivers experience burnout throughout this region. We explored the prevalence and contributing factors of burnout of caregivers of community-dwelling older people with dementia in Hong Kong (HK), China, and New Zealand (NZ) in this study. METHODS: Analysis of interRAI Home Care Assessment data for care-recipients (aged ≥65 with Alzheimer's disease/other dementia) who had applied for government-funded community services and their caregivers was conducted. The sample comprised 9976 predominately Chinese in HK and 16,725 predominantly European in NZ from 2013 to 2016. Caregiver burnout rates for HK and NZ were calculated. Logistic regression was used to determine the adjusted odds ratio (AOR) of the significant factors associated with caregiver burnout in both regions. RESULTS: Caregiver burnout was present in 15.5 and 13.9% of the sample in HK and NZ respectively. Cross-regional differences in contributing factors to burnout were found. Care-recipients' ADL dependency, fall history, and cohabitation with primary caregiver were significant contributing factors in NZ, while primary caregiver being child was found to be significant in HK. Some common contributing factors were observed in both regions, including care-recipients having behavioural problem, primary caregiver being spouse, providing activities-of-daily-living (ADL) care, and delivering more than 21 h of care every week. In HK, allied-health services (physiotherapy, occupational therapy and speech therapy) protected caregiver from burnout. Interaction analysis showed that allied-health service attenuates the risk of burnout contributed by care-recipient's older age (85+), cohabitation with child, ADL dependency, mood problem, and ADL care provision by caregivers. CONCLUSIONS: This study highlights differences in service delivery models, family structures and cultural values that may explain the cross-regional differences in dementia caregiving experience in NZ and HK. Characteristics of caregiving dyads and their allied-health service utilization are important contributing factors to caregiver burnout. A standardized needs assessment for caregivers could help policymakers and healthcare practitioners to identify caregiving dyads who are at risk of burnout and provide early intervention.

Prognostic value of diagnostic scales in community-acquired sepsis mortality at an emergency service. Prognosis in community-adquired sepsis.

OBJECTIVES: To asses the prognostic value of diagnostic scales in mortality of community-adquired sepsis and added value of additional parameters. METHODS: Prospective observational study of patients with community-adquired sepsis in the Emergency Room of University Hospital. The study population were patients presented in the Emergency Room with confirmed infection and practicians sepsis diagnosis. Demographics, triage vital signs, inhaled oxygen fraction, inflammatory markers, biochemistry, all-cause mortality during hospitalization and three months after were recorded. Prognostic value of qSOFA, NEWS, SOFA, SIRS, and amplified scales were calculated by using logistic regression and ROC curves. RESULTS: 201 patients, 54% male, average age 77±11,2 years were included. Sixty-three (31.5%) died during hospitalization and 24 (12%) three months after discharge. At the time of admission vital signs related with in-hospital mortality were Glasgow Coma Scale <13, respiratory rate ≥22 bpm, temperature, oxygen desaturation, high flow oxygen therapy and heart rate. Patients dead in-hospital had lower PaCO2, higher lactate, glucose and creatinine. Greater predictive capacity of the scales, from higher to lower, was: qSOFA, NEWS2, SOFA and SIRS. Amplified scales with lactate >2mg/dl, glucose, blood level >190mg/dl and PaCO2 <35mmHg improved predictive value. CONCLUSION: Amplified-qSOFA and amplified-NEWS2 scales at Emergency Department may offer a better prognostic of septic patients mortality.

Impact of COVID-19 on the health and psychosocial status of vulnerable older adults: study protocol for an observational study.

BACKGROUND: Many countries around the world have adopted social distancing as one of the public health measures to reduce COVID-19 transmissions in the community. Such measures could have negative effects on the mental health of the population. The aims of this study are to (1) track the impact of COVID-19 on self-reported mood, self-rated health, other health and psychosocial indicators, and health services utilization of people who have an interRAI assessment during the first year of COVID-19; (2) compare these indicators with the same indicators in people who had an interRAI assessment in the year before COVID-19; and (3) report these indicators publicly as soon as data analysis is completed every 3 months. METHODS: interRAI COVID-19 Study (iCoS) is an observational study on routinely collected national data using the interRAI Home Care and Contact Assessment, which are standardized geriatric assessment tools mandated for all people assessed for publicly funded home support services and aged residential care in New Zealand. Based on the 2018/19 figures, we estimated there are 36,000 interRAI assessments per annum. We will compare the four post-lockdown quarters (from 25th March 2020) with the respective pre-lockdown quarters. The primary outcomes are self-reported mood (feeling sad, depressed or hopeless: 0 = no, 1 = yes) and self-rated health (0 = excellent, 1 = good, 2 = fair, 3 = poor). We will also analyze sociodemographics, other secondary health and psychosocial indicators, and health services utilization. Descriptive statistics will be conducted for primary outcomes and other indicators for each of the eight quarters. We will compare the quarters using regression models adjusted for demographic characteristics using weights or additional variables. Key health and psychosocial indicators will be reported publicly as soon as data analysis is completed for each quarter in the 12-month post-lockdown period by using a data visualization tool. DISCUSSION: This rapid translation of routinely collected national interRAI data will provide a means to monitor the health and psychosocial well-being of vulnerable older New Zealanders. Insights from this study can be shared with other countries that use interRAI and prepare health and social services for similar epidemics/pandemics in the future.

Immune-unreactive urinary albumin as a predictor of cardiovascular events: the Hortega Study.

BACKGROUND: We aimed to determine if immune-unreactive albumin excretion (IURAE) is associated with cardiovascular (CV) events in a representative sample of a general population from Spain. METHODS: We included 1297 subjects (mean age ± standard error 48.0 ± 0.2 years, 48% females), who participated in the Hortega Follow-Up Study. The primary endpoint was incidence of fatal and non-fatal CV events. Urinary albumin excretion (UAE) was measured in spot voided urine, frozen at -80°C, by immunonephelometry [immune-reactive albumin excretion (IRAE)] and by high-performance liquid chromatography (HPLC) [total albumin excretion (AE)]. IURAE was calculated as the difference between HPLC measurements and IRAE. We estimated fully adjusted hazard ratios (HRs) of CV incidence by Cox regression for IRAE, IURAE and total AE. RESULTS: After an average at-risk follow-up of 13 years, we observed 172 CV events. urinary albumin to creatinine ratio (UACR) of ≥30 mg/g assessed by IRAE, IURAE or total AE concentrations was observed in 74, 273 and 417 participants, respectively. Among discordant pairs, there were 49 events in those classified as micro- and macroalbuminuric by IURAE, but normoalbuminuric by IRAE. Only the IRAE was a significant independent factor for the incidence of CV events [HR (95% confidence interval) 1.15 (1.04-1.27)]. The association of UAE with CV events was mainly driven by heart failure (HF) [HR 1.33 (1.15-1.55) for IRAE; HR 1.38 (1.06-1.79) for IURAE; HR 1.62 (1.22-2.13) for total AE]. Those subjects who were micro- and macroalbuminuric by both IRAE and IURAE had a significant increase in risk for any CV event, and especially for HF. CONCLUSIONS: IRAE, IURAE and AE were associated with an increased risk for CV events, but IRAE offered better prognostic assessment.

International Perspectives on Old Age Psychiatry Training.

Psychiatry of old age is a psychiatric subspecialty that has been developed in many countries since the 1950s as an attempt to improve the care of older adults with mental health disorders. Psychiatry of old age specialist training programs were subsequently established to develop a medical workforce that has the required competencies to work in this subspecialty. This article describes the psychiatry of old age specialist training programs in Australia, New Zealand, the United Kingdom, and Mexico. These training programs have varying durations, ranging from 1 to 3 years. Although it may not be a mandatory requirement to complete a psychiatry of old age clinical rotation, psychiatry of old age experience and competencies are expected during general psychiatry training. There is generally a lack of opportunity to learn about other clinical specialties relevant to older adults, such as geriatric medicine and neurology. Finally, much work is needed to better coordinate psychiatry of old age specialist training positions, workforce development, and service delivery to ensure there is a sufficient supply of psychiatry of old age specialists to meet the mental health needs of older adults in different countries in the coming years.

Narrative Review of Decision-Making Processes in Critical Care.

Several theories describing the decision-making process in the intensive care unit (ICU) have been formulated. However, none of them appreciate the complexities of the process in an eclectic way by unifying several miscellaneous variables in 1 comprehensive theory. The purpose of this review is to highlight the key intricacies associated with the decision-making process in the ICU, to describe the theoretical frameworks with a special emphasis on gaps of knowledge, and to offer some avenues for improvement. The application of theoretical framework helps us to understand and to modify the structure of the process. Expected utility theory, regret theory, prospect theory, fuzzy-trace theory, construal level theory, and quantum probability theory were formulated over the years to appreciate an increased complexity of the decision-making process in the ICU. However the decision makers engage, these models may affect patient care because each of these frameworks has several benefits and downsides. There are gaps of knowledge in understanding how physicians match the different theoretical frameworks of the decision-making process with the potentially high ICU variability and load, especially when the "best outcome" is often nondiscrete and multidimensional. Furthermore, it is unclear when the preferential application of reflexive, habitual, variable, and biased-prone processes results in patient and staff detriment. We suggest better matching of theoretical frameworks with strengths of the human decision-making process and balanced application computer aids, artificial intelligence, and organizational modifications. The key component of this integration is work to increase the self-awareness of decision-making processes among residents, fellows, and attending physicians.

Ryanodine-sensitive intracellular Ca2+ channels are involved in the output from the SCN circadian clock.

The suprachiasmatic nuclei (SCN) contain the major circadian clock responsible for generation of circadian rhythms in mammals. The time measured by the molecular circadian clock must eventually be translated into a neuronal firing rate pattern to transmit a meaningful signal to other tissues and organs in the animal. Previous observations suggest that circadian modulation of ryanodine receptors (RyR) is a key element of the output pathway from the molecular circadian clock. To directly test this hypothesis, we studied the effects of RyR activation and inhibition on real time expression of PERIOD2::LUCIFERASE, intracellular calcium levels and spontaneous firing frequency in mouse SCN neurons. Furthermore, we determined whether the RyR-2 mRNA is expressed with a daily variation in SCN neurons. We provide evidence that pharmacological manipulation of RyR in mice SCN neurons alters the free [Ca2+ ]i in the cytoplasm and the spontaneous firing without affecting the molecular clock mechanism. Our data also show a daily variation in RyR-2 mRNA from single mouse SCN neurons with highest levels during the day. Together, these results confirm the hypothesis that RyR-2 is a key element of the circadian clock output from SCN neurons.

Evaluation of MALDI Biotyper Mycobacteria Library v3.0 for Identification of Nontuberculous Mycobacteria.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has demonstrated its ability to promptly identify nontuberculous mycobacteria using the Mycobacteria Library v2.0. However, some species are particularly difficult to identify reliably using this database, providing a low log(score). In this study, the identification power of an updated Mycobacteria Library (v3.0) has been evaluated. Overall, 109 NTM isolates were analyzed with both databases. The v3.0 database allowed a high-level confidence in the identification [log(score) value, ≥1.8] of 91.7% of the isolates versus 83.5% with the v2.0 version (P< 0.01).

When to eat? The influence of circadian rhythms on metabolic health: are animal studies providing the evidence?

As obesity and metabolic diseases rise, there is need to investigate physiological and behavioural aspects associated with their development. Circadian rhythms have a profound influence on metabolic processes, as they prepare the body to optimise energy use and storage. Moreover, food-related signals confer temporal order to organs involved in metabolic regulation. Therefore food intake should be synchronised with the suprachiasmatic nucleus (SCN) to elaborate efficient responses to environmental challenges. Human studies suggest that a loss of synchrony between mealtime and the SCN promotes obesity and metabolic disturbances. Animal research using different paradigms has been performed to characterise the effects of timing of food intake on metabolic profiles. Therefore the purpose of the present review is to critically examine the evidence of animal studies, to provide a state of the art on metabolic findings and to assess whether the paradigms used in rodent models give the evidence to support a 'best time' for food intake. First we analyse and compare the current findings of studies where mealtime has been shifted out of phase from the light-dark cycle. Then, we analyse studies restricting meal times to different moments within the active period. So far animal studies correlate well with human studies, demonstrating that restricting food intake to the active phase limits metabolic disturbances produced by high-energy diets and that eating during the inactive/sleep phase leads to a worse metabolic outcome. Based on the latter we discuss the missing elements and possible mechanisms leading to the metabolic consequences, as these are still lacking.

Evaluation of MALDI-TOF MS (Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry) for routine identification of anaerobic bacteria.

Information regarding the use of MALDI-TOF MS as an alternative to conventional laboratory methods for the rapid and reliable identification of bacterial isolates is still limited. In this study, MALDI-TOF MS was evaluated on 295 anaerobic isolates previously identified by 16S rRNA gene sequencing and with biochemical tests (Rapid ID 32A system, BioMérieux). In total, 85.8% of the isolates were identified by MALDI-TOF MS at the species level vs 49.8% using the Rapid ID 32A system (p < 0.0001). None of the isolates was discordantly identified at the genus level using MALDI-TOF MS and only 9 of them could not be identified using the method. Thus, our results show that MALDI-TOF MS is a robust and reliable tool for the identification of anaerobic isolates in the microbiology laboratory. Its implementation will reduce the turnaround time for a final identification and the number of isolates that require 16S rRNA sequencing.

Hypothalamic expression of anorexigenic and orexigenic hormone receptors in obese females Neotomodon alstoni: effect of fasting.

Obesity is a world problem that requires a better understanding of its physiological and genetic basis, as well as the mechanisms by which the hypothalamus controls feeding behavior. The volcano mouse Neotomodon alstoni develops obesity in captivity when fed with regular chow diet, providing a novel model for the study of obesity. Females develop obesity more often than males; therefore, in this study, we analysed in females, in proestrous lean and obese, the differences in hypothalamus expression of receptors for leptin, ghrelin (growth hormone secretagogue receptor GHS-R), and VPAC, and correlates for plasma levels of total ghrelin. The main comparisons are between mice fed ad libitum and mice after 24 hours of fasting. Mice above 65 g body weight were considered obese, based on behavioral and physiological parameters such as food intake, plasma free fatty acids, and glucose tolerance. Hypothalamic tissue from obese and lean mice was analysed by western blot. Our results indicate that after ad libitum food access, obese mice show no significant differences in hypothalamic leptin receptors, but a significant increase of 60% in the GHS-R, and a nearly 62% decrease in VPAC2 was noted. After a 24-hour fast, plasma ghrelin increased nearly two fold in both lean and obese mice; increases of hypothalamic leptin receptors and GHS-R were also noted, while VPAC2 did not change significantly; levels of plasma free fatty acids were 50% less after fasting in obese than in lean animals. Our results indicate that in obese N. alstoni mice, the levels of orexigenic receptors in the hypothalamus correlate with overfeeding, and the fact that lean and obese females respond in different ways to a metabolic demand such as a 24-hour fast.