Rationnel La majorité des organismes vivants possèdent des oscillateurs circadiens. Ces horloges sont présentes dans la majorité des cellules du corps. Les oscillateurs circadiens sont fonctionnels ...dans les cellules en culture primaire ou immortalisées. Une évidence croissante, apportée par des études récentes, établit l’existence d’une connexion entre le nombre de syndromes métaboliques, comme l’obésité et le diabète, et l’horloge circadienne. Notre but principal était d’apporter de nouveaux éléments pour mieux comprendre comment le système circadien agit sur la fonction du pancréas endocrine chez l’Homme. Dans cette étude, nous cherchons à explorer l’impact de l’oscillateur pancréatique sur la fonction des cellules de l’îlot. Matériels et méthodes Nous avons établi un modèle de visualisation de l’oscillation circadienne de l’îlot humain en enregistrant la bioluminescence in vivo, à long terme, dans des îlots pancréatiques entiers ou dans les cellules primaires de l’îlot. Résultats Les îlots humains intacts ainsi que les cellules d’îlots dispersés synchronisés in vitro exhibent des oscillations circadiennes du reporteur Bmal1-luciferase avec une longueur de période de respectivement 23.6 et 23.9 heures. Les transcrits endogènes de BMAL1 and CRY1 ont le profile circadien pendant 48 heures, qui sont en antiphase aux seines de REV-ERBα, PER1, PER2, PER3 et DBP. HNF1A et PDX1 exhibent des oscillations circadiennes faibles avec une phase correspondant à celle du REV-ERBα. Les cellules d’îlots dispersés montrent également des oscillations fortes au niveau de la population ainsi qu’au niveau des cellules isolées. Les horloges des cellules beta et non-beta fonctionnent de manière synchronisée. Conclusion Nous avons démontré et caractérisé, pour la première fois, la présence des oscillateurs circadiens autonomes dans les îlots pancréatiques humains. La dissection de la fonction de l’oscillateur pancréatique physiologique ou diabétique pourrait avancer la compréhension du mécanisme liant le système circadien pancréatique, les désordres d’origines métaboliques et le diabète de type 2.
Aim
To determine the impact of a functional human islet clock on insulin secretion and gene transcription.
Methods
Efficient circadian clock disruption was achieved in human pancreatic islet cells by ...small interfering RNA‐mediated knockdown of CLOCK. Human islet secretory function was assessed in the presence or absence of a functional circadian clock by stimulated insulin secretion assays, and by continuous around‐the‐clock monitoring of basal insulin secretion. Large‐scale transcription analysis was accomplished by RNA sequencing, followed by quantitative RT‐PCR analysis of selected targets.
Results
Circadian clock disruption resulted in a significant decrease in both acute and chronic glucose‐stimulated insulin secretion. Moreover, basal insulin secretion by human islet cells synchronized in vitro exhibited a circadian pattern, which was perturbed upon clock disruption. RNA sequencing analysis suggested alterations in 352 transcript levels upon circadian clock disruption. Among them, key regulators of the insulin secretion pathway (GNAQ, ATP1A1, ATP5G2, KCNJ11) and transcripts required for granule maturation and release (VAMP3, STX6, SLC30A8) were affected.
Conclusions
Using our newly developed experimental approach for efficient clock disruption in human pancreatic islet cells, we show for the first time that a functional β‐cell clock is required for proper basal and stimulated insulin secretion. Moreover, clock disruption has a profound impact on the human islet transcriptome, in particular, on the genes involved in insulin secretion.
Aims/hypothesis
Following on from the emerging importance of the pancreas circadian clock on islet function and the development of type 2 diabetes in rodent models, we aimed to examine circadian gene ...expression in human islets. The oscillator properties were assessed in intact islets as well as in beta cells.
Methods
We established a system for long-term bioluminescence recording in cultured human islets, employing lentivector gene delivery of the core clock gene
Bmal1
(also known as
Arntl
)-luciferase reporter. Beta cells were stably labelled using a rat insulin2 promoter fluorescent construct. Single-islet/cell oscillation profiles were measured by combined bioluminescence–fluorescence time-lapse microscopy.
Results
Human islets synchronised in vitro exhibited self-sustained circadian oscillations of
Bmal1-luciferase
expression at both the population and single-islet levels, with period lengths of 23.6 and 23.9 h, respectively. Endogenous
BMAL1
and
CRY1
transcript expression was circadian in synchronised islets over 48 h, and antiphasic to
REV-ERB
α (also known as
NR1D1
),
PER1
,
PER2
,
PER3
and
DBP
transcript circadian profiles.
HNF1A
and
PDX1
exhibited weak circadian oscillations, in phase with the
REV-ERB
α transcript. Dispersed islet cells were strongly oscillating as well, at population and single-cell levels. Importantly, beta and non-beta cells revealed oscillatory profiles that were well synchronised with each other.
Conclusions/interpretation
We provide for the first time compelling evidence for high-amplitude cell-autonomous circadian oscillators displayed in human pancreatic islets and in dispersed human islet cells. Moreover, these clocks are synchronised between beta and non-beta cells in primary human islet cell cultures.
Soft-tissue sarcomas are a group of malignancies of mesenchymal origin, which typically have a dismal prognosis if they reach the metastatic stage. The observation of rare spontaneous remissions in ...patients suffering from concomitant bacterial infections had triggered the clinical investigation of the use of heat-killed bacteria as therapeutic agents (Coley's toxin), which induced complete responses in patients in the pre-chemotherapy era and is now known to mediate substantial elevations in serum TNF levels.
We designed and developed a novel immunocytokine based on murine TNF sequentially fused to the antibody fragment F8 (specific to extra-domain A of fibronectin). The antitumor activity was studied in two syngeneic murine sarcoma models.
The L19 antibody (specific to extra-domain B of fibronectin) has shown by SPECT imaging procedures to selectively localise on sarcoma in a patient with a peripheral nerve sheath tumour, and immunohistochemical analysis of human soft-tissue sarcoma samples showed comparable antigen expression of EDA and EDB. The antibody-based pharmacodelivery of TNF by the fusion protein 'F8-TNF' to oncofetal fibronectin in sarcoma-bearing mice leads to complete and long-lasting tumour eradications when administered in combination with doxorubicin, the first-line drug for the treatment of sarcomas in humans. Doxorubicin alone did not display any therapeutic effect in both tested models of this study. The cured mice had acquired protective immunity against the tumour, as they rejected subsequent challenges with sarcoma cells.
The findings of this study provide a rationale for the clinical study of the fully human immunocytokine L19-TNF in combination with doxorubicin in patients with soft-tissue sarcoma.
Purpose
L19-TNF is an armed antibody that selectively targets human TNF to extra domain B-fibronectin on tumour blood vessels. We performed a phase I/II first-in-man trial with L19-TNF monotherapy in ...metastatic solid cancer patients to study safety and signs of clinical activity.
Methods
Six cohorts of patients were treated with increasing (1.3–13 μg/kg) doses of intravenous L19-TNF on day 1, 3, and 5 of repeated 3-weekly cycles, and 12 colorectal cancer patients were treated at 13 μg/kg. PK, antibody formation, changes in lymphocyte subsets, 5-HIAA plasma levels as well as safety and clinical activity were analysed.
Results
Thirty-four patients received at least one L19-TNF dose. The serum half-life of L19-TNF at 13 μg/kg was 33.6 min, and maximum peak serum concentration was 73.14 μg/L. Mild chills, nausea and vomiting but no haemato- or unexpected toxicity were observed. Grade 3 lumbar pain in bone metastasis was the only dose-limiting toxicity found in one patient. Objective tumour responses were not detected. Transient stable disease occurred in 19 of 31 evaluable patients.
Conclusions
Intravenous L19-TNF on day 1, 3, and 5 of a 3-weekly schedule was safe up to 13 μg/kg, but did not result in objective tumour responses. The maximally tolerated dose (MTD) was not reached, allowing for further dose escalation of L19-TNF possibly in combination with chemotherapy.
The effect of the COVID-19 infection on nutritional status is not well established. Worldwide epidemiological studies have begun to investigate the incidence of malnutrition during hospitalization ...for COVID-19. The prevalence of malnutrition during follow-up after COVID-19 infection has not been investigated yet. The primary objective of the present study was to estimate the prevalence of the risk of malnutrition in hospitalized adult patients with COVID-19, re-evaluating their nutritional status during follow-up after discharge. The secondary objective was to identify factors that may contribute to the onset of malnutrition during hospitalization and after discharge.
We enrolled 142 COVID-19 patients admitted to Careggi University Hospital. Nutritional parameters were measured at three different timepoints for each patient: upon admission to hospital, at discharge from hospital and 3 months after discharge during follow-up. The prevalence of both the nutritional risk and malnutrition was assessed. During the follow-up, the presence of nutritional impact symptoms (NIS) was also investigated. An analysis of the association between demographic and clinical features and nutritional status was conducted.
The mean unintended weight loss during hospitalization was 7.6% (p < 0.001). A positive correlation between age and weight loss during hospitalization was observed (r = 0.146, p = 0.08). Moreover, for elderly patients (>61 years old), a statistically significant correlation between age and weight loss was found (r = 0.288 p = 0.05). Patients admitted to an Intensive Care Unit (ICU) or Intermediate Care Unit (IMCU) had a greater unintended weight loss than patients who stayed in a standard care ward (5.46% vs 1.19%; p < 0.001). At discharge 12 patients were malnourished (8.4%) according to the ESPEN definition. On average, patients gained 4.36 kg (p < 0.001) three months after discharge. Overall, we observed a weight reduction of 2.2% (p < 0.001) from the habitual weight measured upon admission. Patients admitted to an ICU/IMCU showed a higher MUST score three months after discharge (Cramer's V 0.218, p = 0.035). With regard to the NIS score, only 7 patients (4.9%) reported one or more nutritional problems during follow-up.
The identification of groups of patients at a higher nutritional risk could be useful with a view to adopting measures to prevent worsening of nutritional status during hospitalization. Admission to an ICU/IMCU, age and length of the hospital stay seem to have a major impact on nutritional status. Nutritional follow-up should be guaranteed for patients who lose more than 10% of their habitual weight during their stay in hospital, especially after admission to an ICU/IMCU.
Objectives
To comparatively assess periodontal status in patients who chew different products and patients who do not have this habit and to assess how this practice interacts with predisposing ...factors and risk indicators of disease.
Methods
Patients included in the dental care carried out in a rural community in India were considered for a cross‐sectional study. The simplified oral hygiene index and the community periodontal index (CPI) were assessed. Furthermore, a validated survey with items concerning chewing habits was administered. Statistical analysis of the effects of age range, gender, chewing products and hygiene status on CPI was performed.
Results
In total, 1,023 patients met the inclusion criteria. The chewer patients (430) exhibited a significantly higher CPI than the non‐chewers (593). The chewing habit increased the likelihood of a higher CPI by 6.76‐fold, while excellent‐good oral hygiene status decreased the probability of a higher CPI by approximately 45%. CPI did not differ significantly among chewers of different products.
Conclusion
In the population studied, a chewing habit was associated with a worse periodontal status, and this association was not modified by gender and age as predisposing factors. Oral hygiene could decrease the effect of chewing habit on periodontal health.
Since the starting of Space Age astronaut's health has been a subject of the utmost importance. To date, numerous studies describe the effect of microgravity on the body health of the astronauts. ...Some of these studies analyzed dental diseases and were conducted in conditions of microgravity and simulated microgravity, during short or long periods. Taking into account the increase of long space missions, it is necessary to systematically review the oral health events related with short and long periods spent in space missions with all the available evidence.
To identify all relevant oral diseases attributed to the effects of microgravity, we performed a rigorous systematic review regarding the published articles regarding microgravity and dental diseases from 1969 to 2018. Databases such as Pubmed, Cochrane, Scielo, Google Scholar and the NASA were consulted. Additional studies from the reference lists of the selected articles were included in order to get a greater complete overview. Ten scientific documents (containing 12 studies) with a direct relation with oral/dental health and microgravity were assessed.
Five studies about short period missions (≤30 days) were included. The studies showed increases of cortisol as well as salivary immunoglobulin A (IgA) and salivary IgG. Seven studies about long period missions (>30–220 days) were included, and the more important fact retrieved was the increase of anaerobic bacteriae.
Future long-term missions to Mars or to space stations will require 18–24 months of exposure to microgravity, that, added to other conditions, could have potentially deleterious effects on human physiology, including oral health. Preventive measures, adequate material and training of the crew have to be applied to avoid an oral health event to jeopardize the mission.
•Astronaut's health is of the utmost importance for future space missions.•Long-term microgravity exposition could have deleterious effects on oral physiology.•Radiation, isolation, stress also affect oral and systemic health in space.•The added effect on health of all long term space conditions should be studied.•Prevention, adequate material and training are essential for mission's success.
The extracellular matrix protein ED-B fibronectin (ED-B) is upregulated in inflammatory atherosclerotic lesions. However, functional in vivo imaging of ED-B-containing plaques has not been explored. ...This study evaluated whether (99m)Tc-conjugated AP39 ((99m)Tc-AP39), a single-chain antibody specific to ED-B, can be used for in vivo detection of atherosclerotic plaques in Western diet (WD)-fed, apolipoprotein E-deficient (apoE-/-) mice as compared to wildtype (WT) control mice.
Using SPECT, 12-month-old WD-fed apoE-/- and WT mice were studied 4 hours after injecting (99m)Tc-AP39 (148 MBq). Subsequently, mice were sacrificed, thoracic aortas measured in a g-counter, and plaques analyzed using histology, immuno-histochemistry, autoradiography, and morphometry.
In vivo (99m)Tc-AP39-SPECT imaging of apoE-/- mice demonstrated a significant signal activity in the plaque-ridden thoracic aorta (52.236 ± 40.646 cpm/cm³) that co-localized with the aortic arch and the supra-aortic arteries in MRI scans. Low signal activity (9.468 ± 4.976 cpm/cm³) was observed in WT mice. In apoE-/- mice, the strongest signals were detected in the aortic root, aortic arch and along the abdominal aorta. Autoradiography analysis of aortas from apoE-/- mice confirmed the in vivo observation by demonstrating signal localization in atherosclerotic plaques. The size of autoradiography-positive plaque areas correlated significantly with the size of ED-B-positive (r=0.645, P=0.044) or macrophage-infiltrated (r=0.84, P<0.002) plaques. A significant correlation was found between the sizes of ED-B-positive and macrophage-infiltrated plaque areas (r=0.93, P<0.01).
(99m)Tc-AP39-SPECT in vivo imaging detects inflammatory plaque lesions in WD-fed apoE-/- mice.
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