Development and validation of a real-time PCR assay protocol for the specific detection and quantification of pelagiphages in seawater samples.

Earth is inhabited by numerous adaptations of cellular forms shaped by the persistent scrutiny of natural selection. Thus, as natural selection has fixed beneficial adaptations of functional traits, cellular life has conquered almost all environmental niches on our planet. However, cellular life succumbs in number and genetic diversity to viruses. Among all viruses, phages are highly prevalent in diverse environments, and due to their vast genetic diversity and abundance, their relevant role as significant players in several ecological processes is now fully recognized. Pelagiphages, bacteriophages infecting bacteria of the SAR11 clade, are the most abundant viruses in the oceans. However, the ecological contribution of pelagiphages on populations of Pelagibacterales remains largely underestimated. An essential aspect of estimating the impact of bacteriophages is their absolute and precise quantification, which provides relevant information about the host-virus interactions and the structure of viral assemblages. Consequently, due to its abundance and claimed influence in the biogeochemical cycling of elements, the accurate quantification of pelagiphages results in an essential task. This study describes the development and validation of a sensitive, specific, accurate and reproducible qPCR platform targeting pelagiphages. Moreover, this method allowed the detection and quantification of pelagiphages in the Gulf of California for the first time.

ß-hydroxybutyrate is a metabolic regulator of proteostasis in the aged and Alzheimer disease brain.

Loss of proteostasis is a hallmark of aging and Alzheimer disease (AD). Here, we identify ß-hydroxybutyrate (ßHB), a ketone body, as a regulator of protein solubility in the aging brain. ßHB is a small molecule metabolite which primarily provides an oxidative substrate for ATP during hypoglycemic conditions, and also regulates other cellular processes through covalent and noncovalent protein interactions. We demonstrate ßHB-induced protein insolubility across in vitro, ex vivo, and in vivo mouse systems. This activity is shared by select structurally similar metabolites, is not dependent on covalent protein modification, pH, or solute load, and is observable in mouse brain in vivo after delivery of a ketone ester. Furthermore, this phenotype is selective for pathological proteins such as amyloid-ß, and exogenous ßHB ameliorates pathology in nematode models of amyloid-ß aggregation toxicity. We have generated a comprehensive atlas of the ßHB-induced protein insolublome ex vivo and in vivo using mass spectrometry proteomics, and have identified common protein domains within ßHB target sequences. Finally, we show enrichment of neurodegeneration-related proteins among ßHB targets and the clearance of these targets from mouse brain, likely via ßHB-induced autophagy. Overall, these data indicate a new metabolically regulated mechanism of proteostasis relevant to aging and AD.

Arena surface vertical impact forces vary with surface compaction.

Mechanical properties of arena surfaces are extrinsic factors for musculoskeletal injury. Vertical impact forces of harrowed and compacted cushion were measured at five locations on 12 arena surfaces (five dirt, seven synthetic [dirt and fiber]). Eight variables related to impact force, displacement, and acceleration were calculated. Surface temperature, cushion depth and moisture content were also measured. The effects of surface material type (dirt/synthetic) and cushion compaction (harrowed/compacted) on vertical impact properties were assessed using an analysis of variance. Relationships of manageable surface properties with vertical impact forces were examined through correlations. Compacted cushion exhibited markedly higher vertical impact force and deceleration with lower vertical displacement than harrowed cushion (P < 0.001), and the effect was greater on dirt than synthetic surfaces (P = 0.039). Vertical displacement (P = 0.021) and soil rebound (P = 0.005) were the only variables affected by surface type. Surface compaction (harrowed, compacted) had a significantly greater effect on vertical impact forces than surface type (dirt, synthetic). By reducing surface compaction through harrowing, extrinsic factors related to musculoskeletal injury risk are reduced. These benefits were more pronounced on dirt than synthetic surfaces. These results indicate that arena owners should regularly harrow surfaces, particularly dirt surfaces.

Shear ground reaction force variation among equine arena surfaces.

Shear forces at the surface-hoof interface affect hoof slide, surface grip, forces transferred to the limb, and injury risk. However, the variation in shear forces among surfaces with different compositions have not been quantified. Shear ground reaction forces were measured on five dirt and seven synthetic arena surfaces. Cohesion/adhesion and angle of internal friction/coefficient of friction were calculated. Surface composition, surface temperature, cushion depth, and moisture content were also measured. The effects of surface material (dirt/synthetic) on shear properties were assessed using analysis of variance (ANOVA; P < 0.05). The relationships between surface composition or management properties and shear properties were analyzed using linear correlation. Shear properties were not different between dirt and synthetic surface categories; however, surface fiber content was correlated with adhesion and coefficient of friction. These correlations predict that more fiber will decrease soil adhesion (r = -0.75; P < 0.01) and increase the coefficient of friction (r = 0.81; P < 0.01). Furthermore, maximum shear force was significantly correlated with cushion depth (r = 0.61; P < 0.01) and moisture content (r = 0.57; P < 0.01), where shear force was greater on surfaces with thicker cushion layers or higher moisture content. The findings suggest that shear mechanical behavior is more dependent on surface composition than surface material categories (dirt/synthetic) and also indicate that arena owners can influence shear forces by adjusting either surface composition or management.

Impact of BK Polyomavirus Plasma Viral Load in Kidney Transplant Outcomes.

BACKGROUND: BK polyomavirus infection (BKVi) is an important cause of kidney transplant (KT) loss, but there is scarce evidence on the impact of BK plasma viral load on graft function and long-term KT survival. METHODS: A retrospective cohort study including all KT recipients with BKVi (BK viremia identified in ≥3 consecutive samples by polymerase chain reaction) in our center from January 2010 to December 2020 was performed. A case-control study (1:2) was performed. We grouped the cases according to their highest peak viral load: low-level viremia (<10,000 copies/mL) and high-level viremia (≥10,000 copies/mL). To identify risk factors for BKVi, a logistic regression analysis was achieved, and a multivariable Cox regression was used to describe risk factors for graft loss. RESULTS: A total of 849 KTs were performed, and 67 presented BKVi (low-level viremia, n = 35 and high-level viremia, n = 26). In logistic regression analysis male sex (odds ratio [OR], 4.226; 95% CI, 1.660-10.758, P = .002), age (OR, 1.047; 95% CI, 1.008-1.088; P = .018), and retransplant (OR, 4.162; 95% CI, 1.018-17.015; P = .047) were predictors of BKVi. Acute rejection was more frequent in the BKVi group (18% vs 4.9%, P = .004), and graft survival was lower in patients with BKVi and high-level viremia (P = .027). In Cox regression analysis, BKVi (hazard ratio, 3.657; 95% CI, 1.146-11.670; P = .029) and specific BKV (BK polyomavirus) high-level viremia (hazard ratio, 1.988; 95% CI, 1.012-3.907; P = .046) were predictors of shorter graft survival. CONCLUSIONS: BKV high-level viremia was associated with BKV nephropathy and poorer graft survival. Additionally, acute rejection is more frequent after BKVi. It is necessary to develop strategies safe and effective for these patients.

Regulation of cardiac ion channels by transcription factors: Looking for new opportunities of druggable targets for the treatment of arrhythmias.

Cardiac electrical activity is governed by different ion channels that generate action potentials. Acquired or inherited abnormalities in the expression and/or function of ion channels usually result in electrophysiological changes that can cause cardiac arrhythmias. Transcription factors (TFs) control gene transcription by binding to specific DNA sequences adjacent to target genes. Linkage analysis, candidate-gene screening within families, and genome-wide association studies have linked rare and common genetic variants in the genes encoding TFs with genetically-determined cardiac arrhythmias. Besides its critical role in cardiac development, recent data demonstrated that they control cardiac electrical activity through the direct regulation of the expression and function of cardiac ion channels in adult hearts. This narrative review summarizes some studies showing functional data on regulation of the main human atrial and ventricular Na+, Ca2+, and K+ channels by cardiac TFs such as Pitx2c, Tbx20, Tbx5, Zfhx3, among others. The results have improved our understanding of the mechanisms regulating cardiac electrical activity and may open new avenues for therapeutic interventions in cardiac acquired or inherited arrhythmias through the identification of TFs as potential drug targets. Even though TFs have for a long time been considered as 'undruggable' targets, advances in structural biology have led to the identification of unique pockets in TFs amenable to be targeted with small-molecule drugs or peptides that are emerging as novel therapeutic drugs.

Acute Kidney Injury and Urinary and Histopathological Disorders in Kidney Transplant Patients with SARS-CoV-2 Infection.

BACKGROUND: Acute kidney injury (AKI) is a manifestation of SARS-CoV-2 infection. The evidence in kidney transplant (KT) is limited, as there are scarce data about the histologic features in graft biopsies of these patients. MATERIAL AND METHODS: A retrospective cohort study of KTs with SARS-CoV-2 infection from August 28, 2020, to April 23, 2021. We collected the incidence of AKI and the presence of urinary and histopathological disorders. Both groups were compared (AKI vs no AKI). Immunohistochemical and reverse transcription-polymerase chain reaction studies were performed on the anatomopathological samples. RESULTS: In our study, 72 KTs had SARS-CoV-2 infection and, among them, 27 patients (35.1%) developed AKI related to increased severity and a worse evolution of the infection, defined by a greater presence of pneumonia (P < .001), hospitalization (P < .001), admission to the intensive care unit (P < .001), the need for ventilation support (P < .001), and continuous renal replacement therapy (P < .001). In the multivariable analysis, pneumonia behaved as an independent predictor for AKI development (P = .046). No differences were observed between proteinuria a month before and after infection (P = .224). In addition, 5 patients showed microhematuria and 2 patients presented transient glycosuria without hyperglycemia. Of the 5 kidney biopsies performed, 1 biopsy (20%) showed positive reverse transcription polymerase chain reaction for SARS-CoV-2. CONCLUSIONS: AKI is a frequent and potentially serious complication in KT patients. Occasionally it could be accompanied by abnormalities in the urinary sediment. Of 5 biopsied patients, 1 patient had positive reverse transcription polymerase chain reaction in renal tissue, which suggests the systemic spread of the virus and the tropism for the renal graft.

Mismatch repair system in colorectal cancer. Frequency, cancer phenotype, and follow-up.

INTRODUCTION AND AIMS: A frequent task in the study of colorectal carcinomas (CRC) is to identify tumors harboring deficient DNA mismatch repair systems (dMMR), which are associated with microsatellite instability. Given that there is scant information on those tumors in Mexican patients, our aim was to describe their frequency, clinical and pathologic characteristics, and results, which are necessary for future trials. MATERIALS AND METHODS: A consecutive series of CRC patients, treated and followed at a tertiary care center was performed. The clinical and pathologic variables and the risk of hereditary or familial cancer syndrome were retrieved. The original slides and hMLH1, hPMS2, hMSH2, hMSH6 immunohistochemistry were evaluated. Tumors with an absence of at least one protein were considered dMMR. Differences were contrasted, utilizing non-parametric tests. RESULTS: One hundred and forty-four patients were included, with a median age of 65 years. A total of 134/93% patients presented with sporadic CRC, 8/5.6% had a family history of CRC, and 2/1.4% met the diagnostic criteria for hereditary non-polyposis colon cancer, according to the Amsterdam and Bethesda criteria. dMMR tumors were found in 39 patients, distributed among the three groups. They were locally advanced (p<0.001), right-sided, had the mucinous phenotype, and harbored a Crohn's-like lymphoid reaction (all three features, p<0.04). Adjuvant or palliative chemotherapy was administered to 57 (39.6%), concomitant chemoradiotherapy to 24 (16.7%), but 63 (43.8%) patients received no additional treatment to surgery. Five-year follow-up was completed in 131 of the patients and the outcomes alive-with-disease or died-of-disease were more frequently observed in the proficient (pMMR) lesions. CONCLUSIONS: In the present pre-FOLFOX case series, outcomes were better in dMMR CRC than in proficient lesions.

Evaluation of Expanded Criteria Donors Using the Kidney Donor Profile Index and the Preimplantation Renal Biopsy.

The increasing comorbidity of kidney transplant (KT) donors make it necessary to develop scores to correctly assess the quality of kidney grafts. This study analyzes the usefulness of the preimplantation biopsy and the Kidney Donor Profile Index (KDPI) as indicators of KT survival from expanded criteria donors (ECD). Retrospective study of KT in our center between January 2010 to June 2019 who received a kidney from an ECD and underwent a preimplantation biopsy. 266 KT were included. Graft survival was categorized by KDPI quartiles: Q1 = 86%, Q2 = 95%, Q3 = 99% and Q4 = 100%. KT from KDPI Q1 presented better survival (p = 0.003) and Q4 donors had worse renal function (p = 0.018) and poorer glomerular filtration rate (3rd month; p = 0.017, 1st year; p = 0.010). KT survival was analyzed according to KDPI quartile and preimplantation biopsy score simultaneously: Q1 donors with biopsy score ≤3 had the best survival, especially comparing against Q3 with a biopsy score >3 and Q4 donors (p = 0.014). In multivariable analysis, hyaline arteriopathy, glomerulosclerosis, and KDPI Q4 were predictors for graft survival. High KDPI and a greater histological injury in the preimplantation biopsy, especially glomerular and vascular lesions, were related to a higher rate of KT loss from ECD.

Endothelial Nitric Oxide Synthase (eNOS) and the Cardiovascular System: in Physiology and in Disease States.

Endothelial nitric oxide synthase (eNOS) plays a critical role in regulating and maintaining a healthy cardiovascular system. The importance of eNOS can be emphasized from the genetic polymorphisms of the eNOS gene, uncoupling of eNOS dimerization, and its numerous signaling regulations. The activity of eNOS on the cardiac myocytes, vasculature, and the central nervous system are discussed. The effects of eNOS on the sympathetic autonomic nervous system (SANS) and the parasympathetic autonomic nervous system (PANS), both of which profoundly influence the cardiovascular system, will be elaborated. The relationship between the eNOS protein with cardiovascular autonomic reflexes such as the baroreflex and the Exercise Pressor Reflex will be discussed. For example, the effects of endogenous nitric oxide (NO) are shown to be mediated by the eNOS protein and that eNOS-derived endothelial NO is most effective in regulating blood pressure oscillations via modulating the baroreflex mechanisms. The protective action of eNOS on the CVS is emphasized here because dysfunction of the eNOS enzyme is intricately correlated with the pathogenesis of several cardiovascular diseases such as hypertension, arteriosclerosis, myocardial infarction, and stroke. Overall, our current understanding of the eNOS protein with a focus on its role in the modulation, regulation, and control of the cardiovascular system in a normal physiological state and in cardiovascular diseases are discussed.

Surgical Wound Dehiscence in Kidney Transplantation: Risk Factors and Impact on Graft Survival.

BACKGROUND: Surgical wound dehiscence (SWD) is a frequent complication after kidney transplantation (KT) but there is not enough evidence of its impact on graft survival. METHODS: A retrospective cohort study including all KT patients with SWD in our center from January 2015 to July 2020 was performed. A case-control study was performed and for each case of SWD, 2 controls were selected (2:1). To identify risk factors for SWD, a logistic regression analysis was carried out and a multivariable Cox regression was used to describe risk factors for graft survival. RESULTS: In our center, 503 KT were performed, and 39 patients presented SWD. They were older (62.1 vs 57.1 years; P = .030), most had diabetes mellitus (59% vs 28.6%; P = .002) and their body mass index was higher (31 vs 26.9 kg/m2; P < .001). In multivariable logistic regression analysis, diabetes mellitus (P = .024) and a body mass index ≥30 kg/m2 at time of transplantation (P = .018) were predictors of SWD. A higher rate of delayed graft function was described in SWD (P = .013) and it was associated with a longer hospital stay (20.9 vs 15 days; P = .004). Graft survival was lower in patients with SWD (P = .036). In multivariable Cox regression analysis, time in renal replacement therapy (P = .020) and SWD (P = .028) were predictors of shorter graft survival. CONCLUSION: SWD is a risk factor for graft survival. The presence of diabetes mellitus and a higher body mass index are predictors for the appearance of this complication.

Intravitreal triamcinolone injections in non-arteritic anterior ischemic optic neuropathy - A retrospective report.

BACKGROUND: Non-arteritic anterior ischemic optic neuropathy (NAION) is a common cause of vision loss but no treatment has demonstrated its efficiency. A preliminary study showed an improvement on the visual acuity (VA) in a group of patients who received intravitreal administration of triamcinolone acetonide (IVTA) versus a non-treated group. In the present series, the visual outcome of IVTA in NAION was evaluated on a larger group of patients. METHODS: This retrospective, unmasked and non-randomized study took place at Reims University Hospital between 2009 and 2017. The data of consecutive patients presenting with isolated optic disc edema characteristic of recent NAION (<1month of visual acuity loss) were included. After informed consent, a single intravitreal injection of filtrated 4mg/0.1mL triamcinolone acetonide were administered. Twenty-seven control patients chose not to be injected and therefore served as controls. LogMar visual acuity (VA), VA rating (VAR) (1 line=0.1LogMAR=5 VAR letters), retinal nerve fiber layer thickness assessed by OCT and static visual field were evaluated at presentation, after 7days, after 3months and after 6months. RESULTS: Sixty-eight patients with NAION were evaluated. Forty-one received IVTA, 29 were injected within 15days after the onset of symptoms and 12 after 15days. There was a higher proportion of patients improving VA of 2 lines or more (10 or more VAR letters) in the injected group (49%) compared with the non-injected group (11%, P=0.019). Among the patients injected before 15days, the proportion improving for 2 lines or more (55% vs. 11%, respectively, P=0.013) and for 3 lines or more (45% vs. 11%, respectively, P=0.035) were significantly higher than in the non-injected group. Also, comparing the VA at presentation with the VA after 6months in the injected eyes, it improved significantly (P=0.003) and also in the subgroup injected within 15days (P=0.0007) but not in the injected group after 15days (P=0.801). Visual field improvement was only observed in the subgroup of patients injected within 15days with a significant improvement of the mean deviation (dB) within 6months (P=0.015). CONCLUSIONS: This follow-up study confirms the results of the previous series displaying an apparent benefit of intravitreal steroids injected in the acute phase of NAION. Only patients receiving IVTA within 15days from onset of NAION have a significant improvement of VA and visual field during the follow-up period of 6months.

Causes of hypercalcemia in renal transplant recipients: persistent hyperparathyroidism and others.

Hypercalcemia is common in patients after kidney transplantation (KTx) and is associated with persistent hyperparathyroidism in the majority of cases. This retrospective, single-center study evaluated the prevalence of hypercalcemia after KTx. KTx recipients were evaluated for 7 years after receiving kidneys from living or deceased donors. A total of 301 patients were evaluated; 67 patients had hypercalcemia at some point during the follow-up period. The median follow-up time for all 67 patients was 62 months (44; 80). Overall, 45 cases of hypercalcemia were classified as related to persistent post-transplant hyperparathyroidism (group A), 16 were classified as "transient post-transplant hypercalcemia" (group B), and 3 had causes secondary to other diseases (1 related to tuberculosis, 1 related to histoplasmosis, and 1 related to lymphoma). The other 3 patients had hypercalcemia of unknown etiology, which is still under investigation. In group A, the onset of hypercalcemia after KTx was not significantly different from that of the other groups, but the median duration of hypercalcemia in group A was 25 months (12.5; 53), longer than in group B, where the median duration of hypercalcemia was only 12 months (10; 15) (P<0.002). The median parathyroid hormone blood levels around 12 months after KTx were 210 pg/mL (141; 352) in group A and 72.5 pg/mL (54; 95) in group B (P<0.0001). Hypercalcemia post-KTx is not infrequent and its prevalence in this center was 22.2%. Persistent hyperparathyroidism was the most frequent cause, but other important etiologies must not be forgotten, especially granulomatous diseases and malignancies.

Causes of hypercalcemia in renal transplant recipients: persistent hyperparathyroidism and others

Hypercalcemia is common in patients after kidney transplantation (KTx) and is associated with persistent hyperparathyroidism in the majority of cases. This retrospective, single-center study evaluated the prevalence of hypercalcemia after KTx. KTx recipients were evaluated for 7 years after receiving kidneys from living or deceased donors. A total of 301 patients were evaluated; 67 patients had hypercalcemia at some point during the follow-up period. The median follow-up time for all 67 patients was 62 months (44; 80). Overall, 45 cases of hypercalcemia were classified as related to persistent post-transplant hyperparathyroidism (group A), 16 were classified as "transient post-transplant hypercalcemia" (group B), and 3 had causes secondary to other diseases (1 related to tuberculosis, 1 related to histoplasmosis, and 1 related to lymphoma). The other 3 patients had hypercalcemia of unknown etiology, which is still under investigation. In group A, the onset of hypercalcemia after KTx was not significantly different from that of the other groups, but the median duration of hypercalcemia in group A was 25 months (12.5; 53), longer than in group B, where the median duration of hypercalcemia was only 12 months (10; 15) (P<0.002). The median parathyroid hormone blood levels around 12 months after KTx were 210 pg/mL (141; 352) in group A and 72.5 pg/mL (54; 95) in group B (P<0.0001). Hypercalcemia post-KTx is not infrequent and its prevalence in this center was 22.2%. Persistent hyperparathyroidism was the most frequent cause, but other important etiologies must not be forgotten, especially granulomatous diseases and malignancies.

Oral squamous cell carcinoma: epidemiological study and risk factor assessment based on a 39-year series.

Oral squamous cell carcinoma (OSCC) remains a challenge for head and neck surgeons, with low 5-year survival rates despite improvements in diagnostic techniques and therapies. This retrospective observational study was performed to evaluate the epidemiology and risk factors in a cohort of 666 patients with invasive OSCC over a 39-year period. Risk factors assessed were age, sex, toxic habits, premalignant lesions, tumour location and size, and neck involvement, and pathological factors such as surgical margins, tumour thickness, perineural invasion, and bone invasion. These factors were analysed over time, and their influence on recurrence and survival rates examined. Results were compared with those of current epidemiological studies in the literature. This series showed a tendency to diagnosis at older ages (P<0.001) and decreased differences in sex distribution (P<0.001) over time. Regarding risk factors, tobacco and alcohol drinking increased significantly in females, but remained stable in males. Forty percent of the patients developed recurrences during follow-up; the relapse rate did not improve over time (45.6% in the 1980s to 36.1% in 2010-2017). The 5-year survival rate also remained stable over time, ranging from 62.7% (1980s) to 71.7% (2010-2017). This epidemiological study analysed trends across four decades in a stable cohort, with results that may be extrapolated to the populations of European countries. The results confirmed that recurrence rates and survival rates have not improved over time, despite better surgical treatments and new therapies. Further studies are needed to improve knowledge about genetics and tumour behaviour in oral cancer.

Intra- and Extra-articular Features of Temporomandibular Joint Ankylosis in the Cat (Felis catus).

Temporomandibular joint (TMJ) ankylosis is an uncommon clinical entity in human and veterinary medicine. However, the condition is severely debilitating and is life-limiting if not treated. This study sought to characterize the intra- and extra-articular features of naturally occurring TMJ ankylosis in cats. TMJs from client-owned cats (n = 5) that underwent bilateral TMJ gap arthroplasty were examined and compared with TMJs from healthy, age-matched feline cadavers (n = 2) by cone-beam computed tomography (CBCT), micro-computed tomography (µCT) and histologically. Features of bilateral intra- and extra-articular ankylosis compounded by degenerative joint lesions were identified radiographically and histologically in all affected cats. Features of TMJ 'true' ankylosis included variable intracapsular fibro-osseous bridging, degeneration of the disc and the articular surfaces, narrowing of the joint space and flattening of the condylar process of the mandible. Extra-articular features of TMJ ankylosis included periarticular bone formation and fibro-osseous bridging between the mandible, zygomatic arch and coronoid process. In addition, subchondral bone loss or sclerosis, irregular and altered joint contours and irregularly increased density of the medullary bone characterized the degenerative changes of the osseous components of the TMJ. Complex radiological and histological features of both ankylosis and pseudoankylosis were identified that clinically manifested in complete inability to open the mouth.

Synthesis of La-Sr-Mn-O and La-Sr-Ca-Mn-O Perovskites Through Solution Combustion Using Urea at Fuel Deficient Conditions.

La0.7 Sr0.3 MnO3 (LSMO) nanoparticles have been obtained via solution combustion synthesis (SCS) using urea and glycine as fuels. Also, La0.7 Sr0.27 Ca0.03 MnO3 (LSCMO) nanoparticles have been synthesized through solution combustion using urea as fuel. In this paper, the combustion process was carried out with a fuel to oxidant ratio giving fuel deficient conditions ( ). The thermal analysis (TGA) indicate that the organic residues from the urea-nitrates gel mixture are eliminated above 600 °C and the post-synthesis heat treatment yields the formation of the desired phase without impurities. The obtained phases were analyzed using X-ray diffraction. The infrared analysis confirms the purity of the samples obtained using urea. However, the sample obtained using glycine confirms the formation of SrCO3. The morphology was analyzed using a FE-SEM microscope, and it was found that the particles present a spherical shape with a mean size of around 45 nm in the selected samples. The samples' energy dispersive X-ray spectra show that the desired elements (La, Sr, Ca, Mn and O) are present in the nanoparticles. The measured zero field cooled (ZFC) and field cooled (FC) magnetizations were recorded from 4.5 to 380 K at 105 A/m to obtain their blocking and Curie temperatures. Moreover, the hysteresis loops measured at room temperature confirm the superparamagnetic behavior of the elaborated samples. According to the results obtained, these nanoparticles have interesting properties that make them candidates to explore not only for their potential in biomedical applications but also in refrigeration and magnetic storage devices.