[Streptococcus suis meningitis]. / Meningitis por Streptococcus suis.

Streptococcus suis (S. suis) is a globally prevalent swine pathogen, capable of generating infections in humans who were in contact with the animal or its raw meat. Clinical manifestations range from asymptomatic cases to systemic involvement, with low mortality, but with the possibility of leaving definitive sequelae such as ataxia and hearing loss. There are few case reports, due to lack of knowledge of the disease and its atypical presentation. The objective of this article is to report the case of a man with an occupational history of contact with pigs, who was admitted for meningitis and in whom the isolation of S. suis was obtained in cerebrospinal fluid and paired blood cultures; He completed antibiotic treatment adjusted to bacterial sensitivity, and was left with mild hearing loss as a consequence.

Streptococcus suis (S. suis) es un patógeno porcino prevalente a nivel mundial, capaz de generar infecciones en humanos que estuvieron en contacto con el animal o la carne cruda del mismo. Las manifestaciones clínicas comprenden desde casos asintomáticos hasta compromiso sistémico, con una baja mortalidad, pero con la posibilidad de dejar secuelas definitivas como la ataxia e hipoacusia. Son pocos los reportes de casos, debido al desconocimiento de la enfermedad y a su forma atípica de presentación. El objetivo de este artículo es relatar el caso de un varón con antecedentes ocupacionales de contacto con porcinos, que ingresó por meningitis y en el cual se obtuvo el aislamiento de S. suis en líquido cefalorraquídeo y hemocultivos pareados; completó tratamiento antibiótico ajustado a la sensibilidad bacteriana, quedó con hipoacusia leve como secuela.

Partial volume correction in longitudinal tau PET studies: is it really needed?

BACKGROUND: [18F]flortaucipir (FTP) tau PET quantification is known to be affected by non-specific binding in off-target regions. Although partial volume correction (PVC) techniques partially account for this effect, their inclusion may also introduce noise and variability into the quantification process. While the impact of these effects has been studied in cross-sectional designs, the benefits and drawbacks of PVC on longitudinal FTP studies is still under scrutiny. The aim of this work was to study the performance of the most common PVC techniques for longitudinal FTP imaging. METHODS: A cohort of 247 individuals from the Alzheimer's Disease Neuroimaging Initiative with concurrent baseline FTP-PET, amyloid-beta (Aß) PET and structural MRI, as well as with follow-up FTP-PET and MRI were included in the study. FTP-PET scans were corrected for partial volume effects using Meltzer's, a simple and popular analytical PVC, and both the region-based voxel-wise (RBV) and the iterative Yang (iY) corrections. FTP SUVR values and their longitudinal rates of change were calculated for regions of interest (ROI) corresponding to Braak Areas I-VI, for a temporal meta-ROI and for regions typically displaying off-target FTP binding (caudate, putamen, pallidum, thalamus, choroid plexus, hemispheric white matter, cerebellar white matter, and cerebrospinal fluid). The longitudinal correlation between binding in off-target and target ROIs was analysed for the different PVCs. Additionally, group differences in longitudinal FTP SUVR rates of change between Aß-negative (A-) and Aß-positive (A+), and between cognitively unimpaired (CU) and cognitively impaired (CI) individuals, were studied. Finally, we compared the ability of different partial-volume-corrected baseline FTP SUVRs to predict longitudinal brain atrophy and cognitive decline. RESULTS: Among off-target ROIs, hemispheric white matter showed the highest correlation with longitudinal FTP SUVR rates from cortical target ROIs (R2=0.28-0.82), with CSF coming in second (R2=0.28-0.42). Application of voxel-wise PVC techniques minimized this correlation, with RBV performing best (R2=0.00-0.07 for hemispheric white matter). PVC also increased group differences between CU and CI individuals in FTP SUVR rates of change across all target regions, with RBV again performing best (No PVC: Cohen's d = 0.26-0.66; RBV: Cohen's d = 0.43-0.74). These improvements were not observed for differentiating A- from A+ groups. Additionally, voxel-wise PVC techniques strengthened the correlation between baseline FTP SUVR and longitudinal grey matter atrophy and cognitive decline. CONCLUSION: Quantification of longitudinal FTP SUVR rates of change is affected by signal from off-target regions, especially the hemispheric white matter and the CSF. Voxel-wise PVC techniques significantly reduce this effect. PVC provided a significant but modest benefit for tasks involving the measurement of group-level longitudinal differences. These findings are particularly relevant for the estimations of sample sizes and analysis methodologies of longitudinal group studies.

Biodistribution and pharmacokinetics of [89Zr]-anti-VEGF mAbs using PET in glioblastoma rat models.

INTRODUCTION: Glioblastomas present intensive angiogenesis, thus anti-Vascular Endothelial Growth Factor (VEGF) antibodies (mAbs) have been proposed as promising therapies. However, the results of clinical trials reported moderate toxicity and limited effectiveness. This study evaluates the in vivo pharmacokinetics and biodistribution of these mAbs in a growing model of glioblastoma in rats using Positron Emission Tomography (PET). MATERIAL: &Methods: mAbs were radiolabeled with zirconium-89. Four days after the model induction, animals were injected with 2.33 ± 1.3 MBq of [89Zr]-DFO-bevacizumab (n = 8) or 2.35 ± 0.26 MBq of [89Zr]-DFO-aflibercept (n = 6). PETs were performed at 0H, 48H, 168H, 240H, and 336H post-injection. Tumor induction was confirmed using [18F]-Fluorodeoxyglucose-PET and immunohistochemistry. Radiotracer uptake was estimated in all pre-defined Volumes-of-Interest. RESULTS: Anti-VEGF mAbs showed 100 % Radiochemical-Purity. [89Zr]-DFO-bevacizumab showed a significantly higher bioavailability in whole-blood. A significant increase in the tumor uptake was detectable at 168H PET with [89Zr]-DFO-bevacizumab meanwhile with [89Zr]-DFO-aflibercept it was only detectable at 336H. [89Zr]-DFO-bevacizumab tumor uptake was significantly higher than that of [89Zr]-DFO-aflibercept in all the scans. Tumor induction was confirmed in all animal models. CONCLUSION: MAbs detect VEGF-expression in glioblastoma models. Tumors were earlier targeted by Bevacizumab. The lower blood availability of aflibercept resulted in a lower tumor uptake than bevacizumab in all the scans.

Abscesos renales bilaterales multifocales por Candida albicans / Bilateral multifocal kidney abscess due to Candida al bicans

Resumen Los abscesos renales son una complicación poco frecuente de las infecciones del tracto urinario y suelen asociarse con un aumento de la morbi-mortalidad. La mayoría de los casos ocurre en pacientes con factores predisponentes como la inmunosupresión. El diagnóstico requiere de una elevada sospecha clínica y el trata miento consiste en el uso de antibióticos y antifúngicos parenterales asociados o no a intervenciones quirúrgicas como nefrostomía y nefrectomía. Son pocos los casos publicados en la literatura médi ca de abscesos renales bilaterales multifocales y menos aún por Candida albicans. Se presenta el caso de una mujer de 20 años de edad con diabetes mellitus tipo 1 diagnosticada a los 8 años, múltiples internaciones por cetoacidosis diabética y reciente internación por can didemia (Candida albicans) completando tratamiento con fluconazol por 23 días. A los 18 días de su externación, consulta por dolor en flancos de tipo sordo y síntomas ge nerales; se realizó tomografía de abdomen con contraste que mostró abscesos multifocales bilaterales. Aislándose Candida albicans en una de las muestras obtenidas de las lesiones; recibió tratamiento con fluconazol 400 mg por 6 semanas endovenoso y 2 semanas vía enteral, evolu cionando favorablemente con mejoría clínica e image nológica continuando seguimiento clínico ambulatorio. Este reporte resalta la importancia del diagnóstico y tratamiento de esta complicación infrecuente en enfer medades complejas como la diabetes.

Abstract Renal abscesses are a rare complication of urinary tract infections and may be associated with increased morbidity and mortality. Most cases occur in patients with predisposing factors such as immunosuppression. Diagnosis requires high clinical suspicion and its treat ment consists in the use of parenteral antibiotics and antifungals associated or not with surgical interventions such as nephrostomy and nephrectomy. Few cases have been published in the medical literature of multifocal bilateral renal abscesses and even fewer due to Candida albicans. We present the case of a 20-year-old woman with type 1 diabetes mellitus, diagnosed at age 8, multiple hospitalizations for diabetic ketoacidosis, and recent hospitalization for candidemia (Candida albicans) treated with fluconazole for 23 days. Eighteen days after her discharge, she consulted for dull flank pain and gen eral symptoms. Contrast enhanced abdominal tomography showed bilateral multifocal abscesses and Candida albicans was isolated in one of the samples obtained from lesions. She received fluconazole 400 mg, 6 weeks i.v. and 2 weeks via enteral route, evolving favorably with clinical and imag ing improvement, continuing outpatient clinical monitoring. This report highlights the importance of diagnosis and treatment of this rare complication in complex diseases such as diabetes mellitus.

Vasculitis crioglobulinémica de rápida evolución / Rapidly evolving cryoglobulinemic vasculitis

Las vasculitis se manifiestan por la inflamación de los vasos sanguíneos, afectando desde los capilares hasta los vasos de mayor tamaño. El compromiso dermatológico por vasculitis comprende desde casos leves, que generan compromiso superficial, hasta úlceras y necrosis de diferentes tejidos. La crioglobulinemia se caracteriza por la presencia de crioglobulinas séricas, que precipitan a temperaturas menores a 37 ºC. Se pueden asociar a enfermedades infecciosas (destacándose la infección por virus de hepatitis C, VHC), inmunomediadas y linfoproliferativas. La vasculitis en contexto de crioglobulinemia se produce por depósitos de inmunocomplejos en capilares, arteriolas, y arterias de pequeño y mediano calibre. El tratamiento consiste en tratar la causa subyacente y modular la respuesta inflamatoria. Se presenta el caso clínico de un varón de 50 años, con historia de hepatitis B crónica, que manifestó isquemia aguda y crítica de ambas extremidades, documentándose vasculitis crioglobulinémica con mala evolución.

Vasculitis is manifested by inflammation of the blood vessels, affecting from the capillaries to the largest vessels. Dermatological compromise due to vasculitis ranges from mild cases that generate superficial involvement to ulcers and necrosis of different tissues. Cryoglobulinemia is characterized by the presence of serum cryoglobulins, which precipitate at temperatures below 37 degrees Celsius. It is associated with infectious, immune-mediated, and lymphoproliferative diseases, especially infection by the hepatitis C virus. Vasculitis in the context of cryoglobulins is produced by immune complex deposits in capillaries, arterioles, and small and medium-sized arteries. Treatment is based on treating the underlying cause and modulating the inflammatory response. We present the case of a 50-year-old man, with a history of chronic hepatitis B, who presented acute and critical ischemia of both extremities, documenting cryoglobulinemic vasculitis with poor evolution.

[Bilateral multifocal kidney abscess due to Candida albicans]. / Abscesos renales bilaterales multifocales por Candida albicans.

Renal abscesses are a rare complication of urinary tract infections and may be associated with increased morbidity and mortality. Most cases occur in patients with predisposing factors such as immunosuppression. Diagnosis requires high clinical suspicion and its treatment consists in the use of parenteral antibiotics and antifungals associated or not with surgical interventions such as nephrostomy and nephrectomy. Few cases have been published in the medical literature of multifocal bilateral renal abscesses and even fewer due to Candida albicans. We present the case of a 20-year-old woman with type 1 diabetes mellitus, diagnosed at age 8, multiple hospitalizations for diabetic ketoacidosis, and recent hospitalization for candidemia (Candida albicans) treated with fluconazole for 23 days. Eighteen days after her discharge, she consulted for dull flank pain and general symptoms. Contrast enhanced abdominal tomography showed bilateral multifocal abscesses and Candida albicans was isolated in one of the samples obtained from lesions. She received fluconazole 400 mg, 6 weeks i.v. and 2 weeks via enteral route, evolving favorably with clinical and imaging improvement, continuing outpatient clinical monitoring. This report highlights the importance of diagnosis and treatment of this rare complication in complex diseases such as diabetes mellitus.

Los abscesos renales son una complicación poco frecuente de las infecciones del tracto urinario y suelen asociarse con un aumento de la morbi-mortalidad. La mayoría de los casos ocurre en pacientes con factores predisponentes como la inmunosupresión. El diagnóstico requiere de una elevada sospecha clínica y el tratamiento consiste en el uso de antibióticos y antifúngicos parenterales asociados o no a intervenciones quirúrgicas como nefrostomía y nefrectomía. Son pocos los casos publicados en la literatura médica de abscesos renales bilaterales multifocales y menos aún por Candida albicans. Se presenta el caso de una mujer de 20 años de edad con diabetes mellitus tipo 1 diagnosticada a los 8 años, múltiples internaciones por cetoacidosis diabética y reciente internación por candidemia (Candida albicans) completando tratamiento con fluconazol por 23 días. A los 18 días de su externación, consulta por dolor en flancos de tipo sordo y síntomas generales; se realizó tomografía de abdomen con contraste que mostró abscesos multifocales bilaterales. Aislándose Candida albicans en una de las muestras obtenidas de las lesiones; recibió tratamiento con fluconazol 400 mg por 6 semanas endovenoso y 2 semanas vía enteral, evolucionando favorablemente con mejoría clínica e imagenológica continuando seguimiento clínico ambulatorio. Este reporte resalta la importancia del diagnóstico y tratamiento de esta complicación infrecuente en enfermedades complejas como la diabetes.

A murine model of BSCL2-associated Celia's encephalopathy.

Celia's encephalopathy or progressive encephalopathy with/without lipodystrophy is a neurodegenerative disease with a fatal prognosis in childhood. It is generally caused by the c.985C > T variant in the BSCL2 gene, leading to the skipping of exon 7 and resulting in an aberrant seipin protein (Celia-seipin). To precisely define the temporal evolution and the mechanisms involved in neurodegeneration, lipodystrophy and fatty liver in Celia's encephalopathy, our group has generated the first global knock-in murine model for the aberrant human transcript of BSCL2 (Bscl2Celia/Celia) using a strategy based on the Cre/loxP recombination system. In order to carry out a characterization at the neurological, adipose tissue and hepatic level, behavioral studies, brain PET, metabolic, histological and molecular studies were performed. Around 12% of homozygous and 5.4% of heterozygous knock-in mice showed severe neurological symptoms early in life, and their life expectancy was dramatically reduced. Severe generalized lipodystrophy and mild hepatic steatosis were present in these affected animals, while serum triglycerides and glucose metabolism were normal, with no insulin resistance. Furthermore, the study revealed a reduction in brain glucose uptake, along with patchy loss of Purkinje cells and the presence of intranuclear inclusions in cerebellar cortex cells. Homozygous, non-severely-affected knock-in mice showed a decrease in locomotor activity and greater anxiety compared with their wild type littermates. Bscl2Celia/Celia is the first murine model of Celia's encephalopathy which partially recapitulates the phenotype and severe neurodegenerative picture suffered by these patients. This model will provide a helpful tool to investigate both the progressive encephalopathy with/without lipodystrophy and congenital generalized lipodystrophy.

Increased Medial Temporal Tau Positron Emission Tomography Uptake in the Absence of Amyloid-ß Positivity.

Importance: An increased tau positron emission tomography (PET) signal in the medial temporal lobe (MTL) has been observed in older individuals in the absence of amyloid-ß (Aß) pathology. Little is known about the longitudinal course of this condition, and its association with Alzheimer disease (AD) remains unclear. Objective: To study the pathologic and clinical course of older individuals with PET-evidenced MTL tau deposition (TMTL+) in the absence of Aß pathology (A-), and the association of this condition with the AD continuum. Design, Setting, and Participants: A multicentric, observational, longitudinal cohort study was conducted using pooled data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), Harvard Aging Brain Study (HABS), and the AVID-A05 study, collected between July 2, 2015, and August 23, 2021. Participants in the ADNI, HABS, and AVID-A05 studies (N = 1093) with varying degrees of cognitive performance were deemed eligible if they had available tau PET, Aß PET, and magnetic resonance imaging scans at baseline. Of these, 128 participants did not meet inclusion criteria based on Aß PET and tau PET biomarker profiles (A+ TMTL-). Exposures: Tau and Aß PET, magnetic resonance imaging, cerebrospinal fluid biomarkers, and cognitive assessments. Main Outcomes and Measures: Cross-sectional and longitudinal measures for tau and Aß PET, cortical atrophy, cognitive scores, and core AD cerebrospinal fluid biomarkers (Aß42/40 and tau phosphorylated at threonine 181 p-tau181 available in a subset). Results: Among the 965 individuals included in the study, 503 were women (52.1%) and the mean (SD) age was 73.9 (8.1) years. A total of 51% of A- individuals and 78% of A+ participants had increased tau PET signal in the entorhinal cortex (TMTL+) compared with healthy younger (aged <39 years) controls. Compared with A- TMTL-, A- TMTL+ participants showed statistically significant, albeit moderate, longitudinal (mean [SD], 1.83 [0.84] years) tau PET increases that were largely limited to the temporal lobe, whereas those with A+ TMTL+ showed faster and more cortically widespread tau PET increases. In contrast to participants with A+ TMTL+, those with A- TMTL+ did not show any noticeable Aß accumulation over follow-up (mean [SD], 2.36 [0.76] years). Complementary cerebrospinal fluid analysis confirmed longitudinal p-tau181 increases in A- TMTL+ in the absence of increased Aß accumulation. Participants with A- TMTL+ had accelerated MTL atrophy, whereas those with A+ TMTL+ showed accelerated atrophy in widespread temporoparietal brain regions. Increased MTL tau PET uptake in A- individuals was associated with cognitive decline, but at a significantly slower rate compared with A+ TMTL+. Conclusions and Relevance: In this study, individuals with A- TMTL+ exhibited progressive tau accumulation and neurodegeneration, but these processes were comparably slow, remained largely restricted to the MTL, were associated with only subtle changes in global cognitive performance, and were not accompanied by detectable accumulation of Aß biomarkers. These data suggest that individuals with A- TMTL+ are not on a pathologic trajectory toward AD.

Association of periodontitis with cognitive decline and its progression: Contribution of blood-based biomarkers of Alzheimer's disease to this relationship.

AIM: To assess whether periodontitis is associated with cognitive decline and its progression as well as with certain blood-based markers of Alzheimer's disease. MATERIALS AND METHODS: Data from a 2-year follow-up prospective cohort study (n = 101) was analysed. Participants with a previous history of hypertension and aged ≥60 years were included in the analysis. All of them received a full-mouth periodontal examination and cognitive function assessments (Addenbrooke's Cognitive Examination (ACE) and Mini-Mental State Examination [MMSE]). Plasma levels of amyloid beta (Aß)1-40 , Aß1-42 , phosphorylated and total Tau (p-Tau and t-Tau) were determined at baseline, 12 and 24 months. RESULTS: Periodontitis was associated with poor cognitive performance (MMSE: ß = -1.5 [0.6]) and progression of cognitive impairment (hazard ratio [HR] = 1.8; 95% confidence interval: 1.0-3.1). Subjects with periodontitis showed greater baseline levels of p-Tau (1.6 [0.7] vs. 1.2 [0.2] pg/mL, p < .001) and Aß1-40 (242.1 [77.3] vs. 208.2 [73.8] pg/mL, p = .036) compared with those without periodontitis. Concentrations of the latter protein also increased over time only in the periodontitis group (p = .005). CONCLUSIONS: Periodontitis is associated with cognitive decline and its progression in elderly patients with a previous history of hypertension. Overexpression of p-Tau and Aß1-40 may play a role in this association.

Quantitative PET tracking of intra-articularly administered 89Zr-peptide-decorated nanoemulsions.

Intra-articular (IA) administration of drugs for the treatment of diseases such as rheumatoid arthritis, osteoarthritis and psoriatic arthritis is a common strategy; however, the rapid clearance from the synovial fluid restricts their effectivity due to the limited retention time. Drug Delivery Systems (DDS) are currently being developed to increase their joint retention time. This study compares the biodistribution and retention time of a senolytic peptide (PEP), with potential application in osteoarthritis disease, and this senolytic peptide encapsulated in a DDS based on a lipid nanoemulsion (PEPNE) by using positron emission tomography (PET) imaging. To this aim, the PEP was conjugated with a chelating agent (DFO) and radiolabeled with zirconium-89 (89Zr). Then, [89Zr]-PEP was encapsulated in a novel nanoemulsion formulation, composed by vitamin E, sphingomyelin, and a lipid-PEG. Afterward, healthy rats were administered with either the [89Zr]-PEP or the [89Zr]-PEP-NE via IA injection and underwent PET scans at 0.5-, 24-, 48-, 72-, 168-, 240- and 336 h post-injection. To assess the biodistribution of both radiotracers, several volume-of-interest were manually drawn in different organs of the rat body and the %ID/organ was calculated. The [89Zr]-PEP was successfully encapsulated in the NE and their physicochemical properties were minimally affected by the radiolabeling buffer. Adequate stability of both [89Zr]-PEP and [89Zr]-PEP-NE was found in synovial fluid over 72 h. Quantitative data from PET images revealed a significantly higher [89Zr]-PEP-NE retention in the injected knee than with [89Zr]-PEP in all follow-up PET scans. The [89Zr]-PEP %ID/organ values in the liver and kidney were significantly higher than those from [89Zr]-PEP-NE, which might indicate a faster elimination of the [89Zr]-PEP. Therefore, the study highlights the higher retention time on the target site of the [89Zr]-PEP-NE which may improve the therapeutic effects of the peptide. Thereby, the novel nanoemulsion formulation seems to be a successful DDS for IA injection. In addition, these results represent the first study that evaluates the distribution of a PET-guided DDS after its IA administration.

Pharmacokinetic Evaluation of New Drugs Using a Multi-Labelling Approach and PET Imaging: Application to a Drug Candidate with Potential Application in Neuromuscular Disorders.

BACKGROUND AND OBJECTIVE: The determination of pharmacokinetic properties of new chemical entities is a key step in the process of drug development. Positron emission tomography (PET) is an ideal technique to obtain both biodistribution and pharmacokinetic parameters of new compounds over a wide range of chemical modalities. Here, we use a multi-radionuclide/multi-position labelling approach to investigate distribution, elimination, and metabolism of a triazole-based FKBP12 ligand (AHK2) with potential application in neuromuscular disorders. METHODS: Target engagement and stabilizing capacity of the drug candidate (AHK2) towards FKBP12-RyR was evaluated using competitive ligand binding and proximity ligation assays, respectively. Subsequently, AHK2 was labelled either with the positron emitter carbon-11 (11C) via 11C-methylation to yield both [11C]AHK2.1 and [11C]AHK2.2, or by palladium-catalysed reduction of the corresponding 5-iodotriazole derivative using 3H gas to yield [3H]AHK2. Metabolism was first investigated in vitro using liver microsomes. PET imaging studies in rats after intravenous (IV) administration at different doses (1 µg/Kg and 5 mg/Kg) were combined with determination of arterial blood time-activity curves (TACs) and analysis of plasma samples by high performance liquid chromatography (HPLC) to quantify radioactive metabolites. Arterial TACs were obtained in continuous mode by using an in-house developed system that enables extracorporeal blood circulation and continuous measurement of radioactivity in the blood. Pharmacokinetic parameters were determined by non-compartmental modelling of the TACs. RESULTS: In vitro studies indicate that AHK2 binds to FKBP12 at the rapamycin-binding pocket, presenting activity as a FKBP12/RyR stabilizer. [11C]AHK2.1, [11C]AHK2.2 and [3H]AHK2 could be obtained in overall non-decay corrected radiochemical yields of 14 ± 2%, 15 ± 2% and 0.05%, respectively. Molar activities were 60-110 GBq/µmol, 68-122 GBq/µmol and 0.4-0.5 GBq/µmol, respectively. In vitro results showed that oxidation of the thioether group into sulfoxide, demethylation of the CH3O-Ar residue and demethylation of -N(CH3)2 were the main metabolic pathways. Fast metabolism was observed in vivo. Pharmacokinetic parameters obtained from metabolite-corrected arterial blood TACs showed a short half-life (12.6 ± 3.3 min). Dynamic PET imaging showed elimination via urine when [11C]AHK2.2 was administered, probably reflecting the biodistribution of [11C]methanol as the major metabolite. Contrarily, accumulation in the gastrointestinal track was observed after administration of [11C]AKH2.1. CONCLUSIONS: AHK2 binds to FKBP12 at the rapamycin-binding pocket, presenting activity as a FKBP12/RyR stabilizer. Studies performed with the 3H- and 11C-labelled FKBP12/RyR stabilizer AHK2 confirm fast blood clearance, linear pharmacokinetics and rapid metabolism involving oxidation of the sulfide and amine moieties and oxidative demethylation of the CH3-O-Ar and tertiary amine groups as the main pathways. PET studies suggest that knowledge about metabolic pathways is paramount to interpret images.

Changes in the Treatment Strategy Following Intracoronary Pressure Wire in a Contemporaneous Real-Life Cohort of Patients With Intermediate Coronary Stenosis. Results From a Nationwide Registry.

BACKGROUND: Intracoronary pressure wire is useful to guide revascularization in patients with coronary artery disease. AIMS: To evaluate changes in diagnosis (coronary artery disease extent), treatment strategy and clinical results after intracoronary pressure wire study in real-life patients with intermediate coronary artery stenosis. METHODS: Observational, prospective and multicenter registry of patients in whom pressure wire was performed. The extent of coronary artery disease and the treatment strategy based on clinical and angiographic criteria were recorded before and after intracoronary pressure wire guidance. 12-month incidence of MACE (cardiovascular death, non-fatal myocardial infarction or new revascularization of the target lesion) was assessed. RESULTS: 1414 patients with 1781 lesions were included. Complications related to the procedure were reported in 42 patients (3.0 %). The extent of coronary artery disease changed in 771 patients (54.5 %). There was a change in treatment strategy in 779 patients (55.1 %) (18.0 % if medical treatment; 68.8 % if PCI; 58.9 % if surgery (p < 0.001 for PCI vs medical treatment; p = 0.041 for PCI vs CABG; p < 0.001 for medical treatment vs CABG)). In patients with PCI as the initial strategy, the change in strategy was associated with a lower rate of MACE (4.6 % vs 8.2 %, p = 0.034). CONCLUSIONS: The use of intracoronary pressure wire was safe and led to the reclassification of the extent of coronary disease and change in the treatment strategy in more than half of the cases, especially in patients with PCI as initial treatment.

[COVID-19 pandemic: outcomes and mortality in inpatients related to vaccination]. / Pandemia por COVID-19: evolución de la enfermedad y mortalidad de pacientes internados en relación a la vacunación.

INTRODUCTION: Different COVID-19 vaccines were developed in a short time after the beginning of pandemics, reducing mortality, especially in high risk population. This was demonstrated in several studies, mostly retrospective or based in mathematical models. The objective was to compare mortality in inpatients with COVID-19 related to vaccination. METHODS: Longitudinal, prospective, comparative, observational study. Inpatients with COVID-19 diagnosis were included between 17/12/2021 and 23/02/22, in Hospital Nacional Prof. A Posadas and Hospital Interzonal General de Agudos Eva Perón. RESULTS: Inpatients (245) were analyzed, finding an overall mortality of 25.3%, 16.8% in fully vaccinated patients (two or more doses with less than 150 days since the last dose until the COVID-19 test) and 31.9% in those with incomplete vaccination (unvaccinated, one dose or two or more doses with more than 150 days since the last dose) (p = 0.007), OR 2.31 (IC95; 1.25-4.28) for incomplete vaccination. Mortality was 32.2% in patients who developed pneumonia, 22.2% for fully vaccinated and 38% for incompletely vaccinated (p = 0.048), OR 2.15(IC95; 1.01-4.58). Mortality was associated with older age (70 vs. 59 years; p < 0.001), female sex (54.8% vs. 37.7%; p < 0.02) and oncologic disease (27.4 vs. 14.8%; p = 0.02). PESI score was higher in incompletely vaccinated (102.5 vs. 93, p = 0.05) and SOFA score was lower (2 vs. 3, p = 0.01). The necessary number to treat (NNT) to prevent one death was 7 patients for the overall sample (IC95;4-22) and 6 (IC95;3-106) for pneumonia. DISCUSSION: This study constitutes a starting point for developing other investigations and raising awareness of medical community and people about the beneficial effects of vaccination.

Introducción: Luego del inicio de la pandemia por COVID-19, se desarrollaron diferentes vacunas, disminuyendo la mortalidad según estudios retrospectivos o con modelos de cálculo. El objetivo fue comparar la mortalidad de pacientes internados con diagnóstico de COVID-19 según su vacunación. Métodos: Estudio comparativo observacional longitudinal. Se incluyeron pacientes internados con COVID-19 del 17/12/21 al 23/02/2022 en el Hospital Nacional Prof. A Posadas y en el Hospital Interzonal General de Agudos Eva Perón. Resultados: Se analizaron 245 pacientes hallando una mortalidad total del 25.3%, 16.8% en aquellos con vacunación completa (2 dosis o más y menos de 150 días desde la última) y 31.9% con vacunación incompleta (no vacunados, 1 o 2 dosis y más de 150 días desde la última) (p = 0.007), OR 2.31(IC95; 1.25-4.28). En aquellos con neumonía, la mortalidad fue del 32.2%, 22.2% con vacunación completa y 38% con vacunación incompleta (p = 0.048), OR 2.15(IC95; 1.01-4.58. La mortalidad se asoció a mayor edad (70 vs. 59 años; p < 0.001), sexo femenino (54.8% vs. 37.7%; p < 0.02) y enfermedad oncológica (27.4 vs. 14.8%; p = 0.02). El PESI score fue mayor en aquellos con vacunación incompleta (102.5 vs. 93, p = 0.05) y el SOFA score fue menor (2 vs. 3, p = 0.01). El número necesario a tratar (NNT) para evitar una muerte fue de 7 pacientes para el total de la muestra (IC95; 4-22) y 6 (IC95;3-106) para aquellos con neumonía. Discusión: Este trabajo constituye un punto de partida de nuevas investigaciones, contribuyendo a la concientización acerca de los efectos beneficiosos de la vacunación en profesionales y pacientes.

Pandemia por COVID-19: evolución de la enfermedad y mortalidad de pacientes internados en relación a la vacunación / COVID-19 pandemic: outcomes and mortality in inpatients related to vaccination

Resumen Introducción: Luego del inicio de la pandemia por COVID-19, se desarrollaron diferentes vacunas, disminuyendo la mortalidad según estudios retrospectivos o con modelos de cálculo. El objetivo fue comparar la mortalidad de pacientes internados con diagnóstico de COVID-19 según su vacunación. Métodos: Es tudio comparativo observacional longitudinal. Se incluyeron pacientes internados con COVID-19 del 17/12/21 al 23/02/2022 en el Hospital Nacional Prof. A Posadas y en el Hospital Interzonal General de Agudos Eva Perón. Resultados: Se analizaron 245 pacientes hallando una mortalidad total del 25.3%, 16.8% en aquellos con vacu nación completa (2 dosis o más y menos de 150 días desde la última) y 31.9% con vacunación incompleta (no vacunados, 1 o 2 dosis y más de 150 días desde la última) (p = 0.007), OR 2.31(IC95; 1.25-4.28). En aquellos con neumonía, la mortalidad fue del 32.2%, 22.2% con vacunación completa y 38% con vacunación incompleta (p = 0.048), OR 2.15(IC95; 1.01-4.58. La mortalidad se asoció a mayor edad (70 vs. 59 años; p < 0.001), sexo femenino (54.8% vs. 37.7%; p < 0.02) y enfermedad oncológica (27.4 vs. 14.8%; p = 0.02). El PESI score fue mayor en aquellos con vacunación incompleta (102.5 vs. 93, p = 0.05) y el SOFA score fue menor (2 vs. 3, p = 0.01). El número necesario a tratar (NNT) para evitar una muerte fue de 7 pacientes para el total de la muestra (IC95; 4-22) y 6 (IC95;3-106) para aquellos con neumonía. Discusión: Este trabajo constituye un punto de partida de nuevas investigaciones, contribuyendo a la concientización acerca de los efectos beneficiosos de la vacunación en profesionales y pacientes.

Abstract Introduction: Different COVID-19 vaccines were developed in a short time after the beginning of pandemics, reducing mortality, especially in high risk population. This was demonstrated in several studies, mostly retrospective or based in mathematical models. The objective was to compare mortality in inpatients with COVID-19 related to vaccination. Methods: Longitudinal, prospective, comparative, observational study. Inpatients with COVID-19 diagnosis were included between 17/12/2021 and 23/02/22, in Hospital Nacional Prof. A Posadas and Hospital Interzonal General de Agudos Eva Perón. Results: Inpatients (245) were analyzed, finding an overall mortality of 25.3%, 16.8% in fully vaccinated patients (two or more doses with less than 150 days since the last dose until the COVID-19 test) and 31.9% in those with incomplete vaccination (unvaccinated, one dose or two or more doses with more than 150 days since the last dose) (p = 0.007), OR 2.31 (IC95; 1.25-4.28) for incomplete vaccination. Mortality was 32.2% in patients who developed pneumonia, 22.2% for fully vaccinated and 38% for incompletely vaccinated (p = 0.048), OR 2.15(IC95; 1.01-4.58). Mortality was associated with older age (70 vs. 59 years; p < 0.001), female sex (54.8% vs. 37.7%; p < 0.02) and oncologic disease (27.4 vs. 14.8%; p = 0.02). PESI score was higher in incompletely vaccinated (102.5 vs. 93, p = 0.05) and SOFA score was lower (2 vs. 3, p = 0.01). The necessary number to treat (NNT) to prevent one death was 7 patients for the overall sample (IC95;4-22) and 6 (IC95;3-106) for pneumonia. Discussion: This study constitutes a starting point for develop ing other investigations and raising awareness of medical community and people about the beneficial effects of vaccination.

PET study of intravitreal adalimumab pharmacokinetics in a uveitis rat model.

Adalimumab is an anti-TNFα drug approved for uveitis treatment by subcutaneous injection. This administration route exposes patients to systemic adverse effects and makes difficult to obtain therapeutic drug concentrations in the site of action due to the anatomical and physiological barriers of the eye. These inconveniences could be avoided by intravitreal injection. The aim of this study is to evaluate the pharmacokinetic profile and the biodistribution of the intravitreal administration of 89Zr-adalimumab in a uveitis rat model using PET imaging. Adalimumab was radiolabelled to 89Zr with a maximum specific activity of 10 MBq/mg. Four µL containing ≃1.74 MBq of 89Zr-labelled adalimumab were injected into the vitreous. A microPET acquisition was carried out immediately after the injection and at different time points through a 10-day study and blood samples were obtained through the tail vein. Radiolabelling was successfully performed with a radiochemical purity after ultrafiltration of 99.69 %. The antibody ocular pharmacokinetics followed a one-compartment model, showing an intraocular elimination half-life of 15.57 h for healthy rats and  33.64 h for rats with uveitis, implying that 89Zr-adalimumab remains around two times longer in rats with the disease compared to healthy ones. However, blood concentration half-life had similar values in both groups. In conclusion, this study shows for the first time the ocular and blood pharmacokinetic analysis of adalimumab in a uveitis model in rats.

Cysteamine Eye Drops in Hyaluronic Acid Packaged in Innovative Single-Dose Systems: Stability and Ocular Biopermanence.

Cystinosis is a rare genetic disorder characterized by the accumulation of cystine crystals in different tissues and organs causing, among other symptoms, severe ocular manifestations. Cysteamine eye drops are prepared in hospital pharmacy departments to facilitate access to treatment, for which vehicles that provide adequate biopermanence, as well as adaptable containers that maintain its stability, are required. Difficulties related to cysteamine preparation, as well as its tendency to oxidize to cystamine, show the importance of conducting rigorous galenic characterization studies. This work aims to develop and characterize an ophthalmic compounded formulation of cysteamine prepared with hyaluronic acid and packaged in innovative single-dose systems. For this task, the effect of different storage temperatures and the presence/absence of nitrogen on the physicochemical stability of the formulation and its packaging was studied in a scaled manner, until reaching the optimal storage conditions. The results showed that 0.55% cysteamine, prepared with hyaluronic acid and packaged in single-dose containers, is stable for 30 days when stored at -20 °C. In addition, opening vials every 4 h at room temperature after 30 days of freezing maintains the stability of the cysteamine formulation for up to 16 h. Moreover, ocular biopermanence studies were conducted using molecular imaging, concluding that the biopermanence offered by the vehicle is not affected by the freezing process, where a half-life of 31.11 min for a hyaluronic acid formulation stored for 30 days at -20 °C was obtained, compared with 14.63 min for 0.9% sodium chloride eye drops.

Impact of spill-in counts from off-target regions on [18F]Flortaucipir PET quantification.

BACKGROUND: [18F]Flortaucipir (FTP) PET quantification is usually hindered by spill-in counts from off-target binding (OFF) regions. The present work aims to provide an in-depth analysis of the impact of OFF in FTP PET quantification, as well as to identify optimal partial volume correction (PVC) strategies to minimize this problem. METHODS: 309 amyloid-beta (Aß) negative cognitively normal subjects were included in the study. Additionally, 510 realistic FTP images with different levels of OFF were generated using Monte Carlo simulation (MC). Images were corrected for PVC using both a simple two-compartment and a multi-region method including OFF regions. FTP standardized uptake value ratio (SUVR) was quantified in Braak Areas (BA), the hippocampus (which was not included in Braak I/II) and different OFF regions (caudate, putamen, pallidum, thalamus, choroid plexus (ChPlex), cerebellar white matter (cerebWM), hemispheric white matter (hemisWM) and cerebrospinal fluid (CSF)) using the lower portion of the cerebellum as a reference region. The correlations between OFF and cortical SUVRs were studied both in real and in simulated PET images, with and without PVC. RESULTS: In-vivo, we found correlations between all OFF and target regions, especially strong for the hemisWM (slope>0.63, R2>0.4). All the correlations were attenuated but remained significant after applying PVC, except for the ChPlex. In MC simulations, the hemisWM and CSF were the main contributors to PVE in all BA (slopes 0.15-0.26 and 0.13-0.21 respectively). The hemisWM (slope=0.2), as well as the ChPlex (slope=0.02), influenced SUVRs in the hippocampus. The CerebWM was negatively correlated with all target regions (slope<-0.02, R2>0.8). While no other correlations between OFF and target regions were found, hemisWM was correlated with all OFF regions but the cerebWM (slopes 0.06-0.33). HemisWM correlations attenuated (slopes<0.06) when applying two-compartment PVC, but the hippocampus-ChPlex and the cerebWM correlations required more complex PVC with dedicated compartments for these regions. In-vivo, PVC removed a notably higher fraction of the correlation between OFF regions found to be affected by PVE in the simulation studies and BA (≈50%) than for OFF regions not affected by PVE (16%). CONCLUSION: HemisWM is the main driver of spill-in effects in FTP PET, affecting both target regions and the rest of OFF regions. PVC successfully reduces PVE, even when using a simple two-compartment method. Despite PVC, non-zero correlations were still observed between target and OFF regions in vivo, which suggests the existence of biological or tracer-related contributions to these correlations.

Sialoadenitis esclerosante asociada a enfermedad por IgG4: reporte de un caso / Sclerosing sialadenitis associated with IgG4 disease: case report

Las enfermedades relacionadas con IgG4 (ER-IgG4) son entidades fibroinflamatorias e inmunomediadas, caracterizadas por la afección multiorgánica, con la formación de pseudotumores que provocan lesión tisular y daño orgánico subsecuente. Se describe el caso de un paciente de 43 años que presentó sialoadenitis esclerosante y cumplió todos los criterios diagnósticos de enfermedad relacionada con IgG4.

IgG4-related diseases (IgG4-RD) are fibroinflammatory immune-mediated entities characterized by multiorgan involvement with the development of pseudotumors that cause tissue injury and subsequent organ damage. We describe the case of a 43-year-old man who presented sclerosing sialadenitis and fulfilled the diagnostic criteria for IgG4-related disease.

Dose-response assessment of cerebral P-glycoprotein inhibition in vivo with [18F]MC225 and PET.

The Blood-Brain Barrier P-glycoprotein (P-gp) function can be altered in several neurodegenerative diseases and due to the administration of different drugs which may cause alterations in drug concentrations and consequently lead to a reduced effectiveness or increased side-effects. The novel PET radiotracer [18F]MC225 is a weak P-gp substrate that may show higher sensitivity to detect small changes in P-gp function than previously developed radiotracers. This study explores the sensitivity of [18F]MC225 to measure the dose-dependent effect of P-gp inhibitor tariquidar. Twenty-three rats were intravenously injected with different doses of tariquidar ranging from 0.75 to 12 mg/kg, 30-min before the dynamic [18F]MC225-PET acquisition with arterial sampling. Tissue and blood data were fitted to a 1-Tissue-Compartment-Model to obtain influx constant K1 and distribution volume VT, which allow the estimation of P-gp function. ANOVA and post-hoc analyses of K1 values showed significant differences between controls and groups with tariquidar doses >3 mg/kg; while applying VT the analyses showed significant differences between controls and groups with tariquidar doses >6 mg/kg. Dose-response curves were fitted using different models. The four-parameter logistic sigmoidal curve provided the best fit for K1 and VT data. Half-maximal inhibitory doses (ID50) were 2.23 mg/kg (95%CI: 1.669-2.783) and 2.93 mg/kg (95%CI: 1.135-3.651), calculated with K1 or VT values respectively. According to the dose-response fit, differences in [18F]MC225-K1 values could be detected at tariquidar doses ranging from 1.37 to 3.25 mg/kg. Our findings showed that small changes in the P-gp function, caused by low doses of tariquidar, could be detected by [18F]MC225-K1 values, which confirms the high sensitivity of the radiotracer. The results suggest that [18F]MC225 may allow the quantification of moderate P-gp impairments, which may allow the detection of P-gp dysfunctions at the early stages of a disease and potential transporter-mediated drug-drug interactions.