An advanced biphasic porous and injectable scaffold displays a fine balance between mechanical strength and remodeling capabilities essential for cartilage regeneration.

An important challenge in tissue engineering is the regeneration of functional articular cartilage (AC). In the field, biomimetic hydrogels are being extensively studied as scaffolds that recapitulate microenvironmental features or as mechanical supports for transplanted cells. New advanced hydrogel formulations based on salmon methacrylate gelatin (sGelMA), a cold-adapted biomaterial, are presented in this work. The psychrophilic nature of this biomaterial provides rheological advantages allowing the fabrication of scaffolds with high concentrations of the biopolymer and high mechanical strength, suitable for formulating injectable hydrogels with high mechanical strength for cartilage regeneration. However, highly intricate cell-laden scaffolds derived from highly concentrated sGelMA solutions could be deleterious for cells and scaffold remodeling. On this account, the current study proposes the use of sGelMA supplemented with a mesophilic sacrificial porogenic component. The cytocompatibility of different sGelMA-based formulations is tested through the encapsulation of osteoarthritic chondrocytes (OACs) and stimulated to synthesize extracellular matrix (ECM) components in vitro and in vivo. The sGelMA-derived scaffolds reach high levels of stiffness, and the inclusion of porogens impacts positively the scaffold degradability and molecular diffusion, improved fitness of OACs, increased the expression of cartilage-related genes, increased glycosaminoglycan (GAG) synthesis, and improved remodeling toward cartilage-like tissues. Altogether, these data support the use of sGelMA solutions in combination with mammalian solid gelatin beads for highly injectable formulations for cartilage regeneration, strengthening the importance of the balance between mechanical properties and remodeling capabilities.

A novel porous hydrogel based on hybrid gelation for injectable and tough scaffold implantation and tissue engineering applications.

Although there have been many advances in injectable hydrogels as scaffolds for tissue engineering or as payload-containing vehicles, the lack of adequate microporosity for the desired cell behavior, tissue integration, and successful tissue generation remains an important drawback. Herein, we describe an effective porous injectable system that allowsin vivoformation of pores through conventional syringe injection at room temperature. This system is based on the differential melting profiles of photocrosslinkable salmon gelatin and physically crosslinked porogens of porcine gelatin (PG), in which PG porogens are solid beads, while salmon methacrylamide gelatin remains liquid during the injection procedure. After injection and photocrosslinking, the porogens were degraded in response to the physiological temperature, enabling the generation of a homogeneous porous structure within the hydrogel. The resultant porogen-containing formulations exhibited controlled gelation kinetics within a broad temperature window (18.5 ± 0.5-28.8 ± 0.8 °C), low viscosity (133 ± 1.4-188 ± 16 cP), low force requirements for injectability (17 ± 0.3-39 ± 1 N), robust mechanical properties after photo-crosslinking (100.9 ± 3.4-332 ± 13.2 kPa), and favorable cytocompatibility (>70% cell viability). Remarkably,in vivosubcutaneous injection demonstrated the suitability of the system with appropriate viscosity and swift crosslinking to generate porous hydrogels. The resulting injected porous constructs showed favorable biocompatibility and facilitated cell infiltration for desirable potential tissue remodeling. Finally, the porogen-containing formulations exhibited favorable handling, easy deposition, and good shape fidelity when used as bioinks in 3D bioprinting technology. This injectable porous system serves as a platform for various biomedical applications, thereby inspiring future advances in cell therapy and tissue engineering.

Type 1 Corticotropin-Releasing Factor Receptor Differentially Modulates Neurotransmitter Levels in the Nucleus Accumbens of Juvenile versus Adult Rats.

Adversity is particularly pernicious in early life, increasing the likelihood of developing psychiatric disorders in adulthood. Juvenile and adult rats exposed to social isolation show differences in anxiety-like behaviors and significant changes in dopamine (DA) neurotransmission in the nucleus accumbens (NAc). Brain response to stress is partly mediated by the corticotropin-releasing factor (CRF) system, composed of CRF and its two main receptors, CRF-R1 and CRF-R2. In the NAc shell of adult rats, CRF induces anxiety-like behavior and changes local DA balance. However, the role of CRF receptors in the control of neurotransmission in the NAc is not fully understood, nor is it known whether there are differences between life stages. Our previous data showed that infusion of a CRF-R1 antagonist into the NAc of juvenile rats increased DA levels in response to a depolarizing stimulus and decreased basal glutamate levels. To extend this analysis, we now evaluated the effect of a CRF-R1 antagonist infusion in the NAc of adult rats. Here, we describe that the opposite occurred in the NAc of adult compared to juvenile rats. Infusion of a CRF-R1 antagonist decreased DA and increased glutamate levels in response to a depolarizing stimulus. Furthermore, basal levels of DA, glutamate, and γ-Aminobutyric acid (GABA) were similar in juvenile animals compared to adults. CRF-R1 protein levels and localization were not different in juvenile compared to adult rats. Interestingly, we observed differences in the signaling pathways of CRF-R1 in the NAc of juveniles compared to adult rats. We propose that the function of CRF-R1 receptors is differentially modulated in the NAc according to life stage.

Reactive oxygen species modulate locomotor activity and dopamine extracellular levels induced by amphetamine in rats.

The increase of dopamine (DA) in the reward system is related to the reinforcing effects of drugs of abuse and hyper locomotion induced by psychostimulants. The increase of DA induced by drugs of abuse generates high amounts of ROS by monoamines metabolization. It has been showed that ROS could modulate psychomotor response and reinforcing effects induced by drugs of abuse as cocaine and methamphetamine (METH). The aim of this study is to evaluate the relation of ROS and amphetamine (AMPH). Here, we show that pretreatment of the ROS scavenger 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) attenuates the induction of locomotion and oxidative stress generated in nucleus accumbens (Nac) by acute AMPH administration. Interestingly, TEMPOL also attenuates the increase of DA induced by AMPH in Nac. Finally, TEMPOL reduces DAT phosphorylation when AMPH is co-infused in Nac synaptosomes. Taking together, our results suggest that ROS modulate AMPH effects in rats.

Microgenetic Analysis of Thought Trajectories: A Mixed Design.

This article reports the results of an investigation that used a mixed methodology with microgenetic orientation, to observe the genetic development of small acts of thought and their bodily manifestations. A qualitative design was carried out through a videographic record with 10 participants to explore thought trajectories and their genetic unfolding in gestures. In a second moment, a quantitative sequential analysis was conducted with 50 participants, who were invited to the laboratory to participate in a tachistoscopic presentation. The procedure was videotaped and coded, identifying categories of thought and their respective gestural expressions. An analysis of different trajectories was carried out to observe the transitions that thought takes and its gestural movements. The results show trajectories in the forms of thought that are investigated through a qualitative microgenetic analysis, which shows the anticipation of verbal meaning through gestures and the transitions backwards to then advance into more integrated forms of thought. On the other hand, trajectories between voluntary and involuntary forms of thought, as well as transitions in verbal and imaginative forms of thought are detected in a quantitative sequence analysis. Finally, the results are integrated and the utility of mixed designs to study the microgenesis of the consciousness phenomenon is discussed.

Social isolation of adolescent male rats increases anxiety and K+ -induced dopamine release in the nucleus accumbens: Role of CRF-R1.

Early life adversity can disrupt development leading to emotional and cognitive disorders. This study investigated the effects of social isolation after weaning on anxiety, body weight and locomotion, and on extracellular dopamine (DA) and glutamate (GLU) in the nucleus accumbens (NAc) and their modulation by corticotropin releasing factor receptor 1. On the day of weaning, male rats were housed singly or in groups for 10 consecutive days. Anxiety-like behaviors were assessed by an elevated plus maze (EPM) and an open field test (OF). Neurotransmitter levels were measured by in vivo microdialysis. Single-housed rats spent less time, and entered more, into the closed arms of an EPM than group-housed rats. They also spent less time in the center of an OF, weighed more and showed greater locomotion. In the NAc, no differences in CRF, or in basal extracellular DA or GLU between groups, were observed. A depolarizing stimulus increased DA release in both groups but to higher levels in isolated rats, whereas GLU increased only in single-housed rats. Blocking CRF-R1 receptors with CP-154,526 decreased DA release in single-housed but not in group-housed rats. The corticotropin releasing factor receptor type 1 receptor antagonist also decreased GLU in group-housed animals. These results show that isolating adolescent rats increases anxiety, body weight and ambulation, as well as the sensitivity of dopaminergic neurons to a depolarizing stimulus. This study provides further evidence of the detrimental effects of social isolation during early development and indicates that dysregulation of the CRF system in the NAc may contribute to the pathologies observed.

Fertility is reduced in women and in men with type 1 diabetes: results from the Type 1 Diabetes Genetics Consortium (T1DGC).

AIMS/HYPOTHESIS: A recent Finnish study described reduced fertility in patients with childhood-onset type 1 diabetes. The Type 1 Diabetes Genetics Consortium (T1DGC) is an international programme studying the genetics and pathogenesis of type 1 diabetes that includes families with the disease. Our aim was to assess fertility, defined as number of offspring, in the affected and unaffected siblings included in the T1DGC. METHODS: Clinical information from participants aged ≥18 years at the time of examination was included in the present analysis. The number of offspring of affected and unaffected siblings was compared (in families including both) and the influence of birth year, disease duration and age of onset was assessed, the last in affected siblings only, using Poisson regression models. RESULTS: A total of 3010 affected and 801 unaffected adult siblings that belonged to 1761 families were assessed. The mean number of offspring was higher in the unaffected than in the affected individuals, and the difference between the two groups was more pronounced in women than men. Poisson regression analysis showed that both sex and birth cohort significantly affected the differences between groups. In the affected siblings, adult onset (≥18 years), female sex and older birth cohort were associated with higher fertility. CONCLUSIONS/INTERPRETATION: Patients with type 1 diabetes have fewer children than their unaffected siblings. This effect is more evident in women and in older birth cohorts. Onset of type 1 diabetes as an adult rather than a child is associated with a higher number of offspring, even after accounting for birth cohort and disease duration.

Clinical and immunogenetic factors associated with pneumonia in patients with systemic lupus erythematosus: a case-control study.

OBJECTIVE: To determine the incidence of pneumonia and associated factors in a single-center systemic lupus erythematosus (SLE) cohort. METHODS: We included all our SLE patients [1997 American College of Rheumatology (ACR) criteria] with ≥ 1 pneumonia event, and 196 age and sex-matched SLE controls with no pneumonia events. Cumulative clinical data, weighted Systemic Lupus International Collaborating Clinics/ACR damage index (wSLICC/ACR-DI), comorbidities, and risk factors for pneumonia were retrospectively collected. The standardized incidence ratio (SIR) of pneumonia was estimated. Polymorphisms at genes coding for mannose binding lectin (MBL), MBL-associated serine protease 2, Fc-gamma receptors, and surfactant proteins A1, A2, and D were determined, and their potential association with pneumonia was analyzed. Patients with and without pneumonia were compared using a multivariate logistic regression model for adjustment of pneumonia-associated factors. RESULTS: Thirty-six of 232 patients with SLE had experienced ≥ 1 pneumonia event. SIR for pneumonia was 5.1 (95% CI 3.5-7.4; p < 0.0001). Excluding patients receiving immunosuppressive therapy at the time of pneumonia (13%), associations were found for Katz Severity Index (KSI) (p = 0.016), wSLICC/ACR-DI (p = 0.044), number of SLE criteria (p = 0.005), hospital admissions (p < 0.001), FCGR2A HH genotype (p = 0.03), previous use of immunosuppressive therapy (p = 0.049), cutaneous ulcers (p < 0.001), and vasculitis (p = 0.008) in bivariate analyses. In the multivariate analysis adjusted to previous immunosuppressive treatment, only KSI and FCGR2A HH genotype remained statistically significant (p = 0.05 and p = 0.03, respectively). CONCLUSION: The incidence of pneumonia in patients with SLE is higher than that in the general population, and particularly high in severe SLE, regardless of immunosuppressive therapy. The HH genetic variant of FCGR2A appears to predispose patients with SLE to pneumonia.

Predictors of associated autoimmune diseases in families with type 1 diabetes: results from the Type 1 Diabetes Genetics Consortium.

BACKGROUND: Type 1 diabetes (T1D) is a clinically heterogeneous disease. The presence of associated autoimmune diseases (AAIDs) may represent a distinct form of autoimmune diabetes, with involvement of specific mechanisms. The aim of this study was to find predictors of AAIDs in the Type 1 Diabetes Genetics Consortium data set. METHODS: Three thousand two hundred and sixty-three families with at least two siblings with T1D were included. Clinical information was obtained using questionnaires, anti-GAD (glutamic acid decarboxylase) and anti-protein tyrosine phosphatase (IA-2) were measured and human leukocyte antigen (HLA) genotyping was performed. Siblings with T1D with and without AAIDs were compared and a multivariate regression analysis was performed to find predictors of AAIDs. T1D-associated HLA haplotypes were defined as the four most susceptible and protective, respectively. RESULTS: One or more AAIDs were present in 14.4% of the T1D affected siblings. Age of diabetes onset, current age and time since diagnosis were higher, there was a female predominance and more family history of AAIDs in the group with AAIDs, as well as more frequent anti-GAD and less frequent anti-IA-2 antibodies. Risk and protective HLA haplotype distributions were similar, though DRB1*0301-DQA1*0501-DQB1*0201 was more frequent in the group with AAIDs. In the multivariate analysis, female gender, age of onset, family history of AAID, time since diagnosis and anti-GAD positivity were significantly associated with AAIDs. CONCLUSIONS: In patients with T1D, the presence of AAIDs is associated with female predominance, more frequent family history of AAIDs, later onset of T1D and more anti-GAD antibodies, despite longer duration of the disease. The predominance of certain HLA haplotypes suggests that specific mechanisms of disease may be involved.

Detection of ketonemia and its relationship with hyperglycemia in type 1 diabetic patients.

The aims of this study were to assess the prevalence of ketosis in type 1 diabetic patients with casual hyperglycemia (>250 mg/dl), to establish the relationship between glycemia and ketonemia during daily life, and to determine the utility of ketonemia. Capillary glycemia levels from 562 type 1 diabetic patients were recorded. Prevalence of casual hyperglycemia was 27.58%, and prevalence of asymptomatic ketonemia was 8.39%. Regarding blood ketone levels, 110 out of 155 patients (70.96%) had blood ketone levels of between 0 and 0.1 mmol/l and 32 out of 155 patients (20.63%) had blood ketone levels of between 0.2 and 0.4 mmol/l. Surprisingly, the mean glycemia levels in these subgroups did not differ and was consistently high (around 300 mg/dl), leading to the observation that even ketone levels considered as non-pathologic should probably be taken into account for a proper diabetes control. Some discrepancies between quantitative determination of ketonuria and qualitative determination of ketonemia were observed. That is in 20 patients with positive ketonuria, ketonemia was not detected, probably because ketosis was already resolved. Asymptomatic ketosis was observed in the hyperglycemic type 1 diabetic population, and metabolic control of these patients with a point of care device is recommended, together with a subsequent revision of insulin treatment. Furthermore, this study supports the opinion that the presence of ketosis, detected by beta-OHB levels, even below levels considered as pathologic, together with hyperglycemia, must be taken into account for proper monitoring and therapeutic control of diabetic patients.