An artificial intelligence-generated model predicts 90-day survival in alcohol-associated hepatitis: A global cohort study.

BACKGROUND AND AIMS: Alcohol-associated hepatitis (AH) poses significant short-term mortality. Existing prognostic models lack precision for 90-day mortality. Utilizing artificial intelligence in a global cohort, we sought to derive and validate an enhanced prognostic model. APPROACH AND RESULTS: The Global AlcHep initiative, a retrospective study across 23 centers in 12 countries, enrolled patients with AH per National Institute for Alcohol Abuse and Alcoholism criteria. Centers were partitioned into derivation (11 centers, 860 patients) and validation cohorts (12 centers, 859 patients). Focusing on 30 and 90-day postadmission mortality, 3 artificial intelligence algorithms (Random Forest, Gradient Boosting Machines, and eXtreme Gradient Boosting) informed an ensemble model, subsequently refined through Bayesian updating, integrating the derivation cohort's average 90-day mortality with each center's approximate mortality rate to produce posttest probabilities. The ALCoholic Hepatitis Artificial INtelligence Ensemble score integrated age, gender, cirrhosis, and 9 laboratory values, with center-specific mortality rates. Mortality was 18.7% (30 d) and 27.9% (90 d) in the derivation cohort versus 21.7% and 32.5% in the validation cohort. Validation cohort 30 and 90-day AUCs were 0.811 (0.779-0.844) and 0.799 (0.769-0.830), significantly surpassing legacy models like Maddrey's Discriminant Function, Model for End-Stage Liver Disease variations, age-serum bilirubin-international normalized ratio-serum Creatinine score, Glasgow, and modified Glasgow Scores ( p < 0.001). ALCoholic Hepatitis Artificial INtelligence Ensemble score also showcased superior calibration against MELD and its variants. Steroid use improved 30-day survival for those with an ALCoholic Hepatitis Artificial INtelligence Ensemble score > 0.20 in both derivation and validation cohorts. CONCLUSIONS: Harnessing artificial intelligence within a global consortium, we pioneered a scoring system excelling over traditional models for 30 and 90-day AH mortality predictions. Beneficial for clinical trials, steroid therapy, and transplant indications, it's accessible at: https://aihepatology.shinyapps.io/ALCHAIN/ .

Is It Safe to Omit the 1-week Post-operative Examination after Uncomplicated Phacoemulsification?

SIGNIFICANCE: The incidence of cataract surgery is increasing, accounting for a large percentage of eye care expenses. Scientific evidence supporting the medical necessity of the traditional post-operative schedule is lacking. Further studies are needed to optimize post-operative care to reduce the burden on patients and medical providers. PURPOSE: This study aimed to study the rate of complication 1 week after uncomplicated phacoemulsification to determine if the 1-week post-operative examination can be safely omitted. METHODS: A retrospective record review was conducted on all consecutive patients who had uncomplicated phacoemulsification between February 1, 2019, and February 1, 2020, at a clinic in an urban setting with a predominantly Black and African American patient population. Subjects were included if they had no complications during the 1-day post-operative examination. Complications at the 1-week and 1-month post-operative examination were recorded and analyzed. RESULTS: Omitting the 1-week post-operative examination would result in missed complications in 4.48 to 15.97% of patients and failure to make unexpected management changes in 1.78 to 13.84% of patients. CONCLUSIONS: The results of this study do not support omitting the 1-week post-operative examination after uncomplicated phacoemulsification. Further studies are needed to determine whether telemedicine can be safely substituted for post-operative examinations.

Identification of optimal therapeutic window for steroid use in severe alcohol-associated hepatitis: A worldwide study.

BACKGROUND & AIMS: Corticosteroids are the only effective therapy for severe alcohol-associated hepatitis (AH), defined by a model for end-stage liver disease (MELD) score >20. However, there are patients who may be too sick to benefit from therapy. Herein, we aimed to identify the range of MELD scores within which steroids are effective for AH. METHODS: We performed a retrospective, international multicenter cohort study across 4 continents, including 3,380 adults with a clinical and/or histological diagnosis of AH. The main outcome was mortality at 30 days. We used a discrete-time survival analysis model, and MELD cut-offs were established using the transform-the-endpoints method. RESULTS: In our cohort, median age was 49 (40-56) years, 76.5% were male, and 79% had underlying cirrhosis. Median MELD at admission was 24 (19-29). Survival was 88% (87-89) at 30 days, 77% (76-78) at 90 days, and 72% (72-74) at 180 days. A total of 1,225 patients received corticosteroids. In an adjusted-survival-model, corticosteroid use decreased 30-day mortality by 41% (hazard ratio [HR] 0.59; 0.47-0.74; p <0.001). Steroids only improved survival in patients with MELD scores between 21 (HR 0.61; 0.39-0.95; p = 0.027) and 51 (HR 0.72; 0.52-0.99; p = 0.041). The maximum effect of corticosteroid treatment (21-30% survival benefit) was observed with MELD scores between 25 (HR 0.58; 0.42-0.77; p <0.001) and 39 (HR 0.57; 0.41-0.79; p <0.001). No corticosteroid benefit was seen in patients with MELD >51. The type of corticosteroids used (prednisone, prednisolone, or methylprednisolone) was not associated with survival benefit (p = 0.247). CONCLUSION: Corticosteroids improve 30-day survival only among patients with severe AH, especially with MELD scores between 25 and 39. LAY SUMMARY: Alcohol-associated hepatitis is a condition where the liver is severely inflamed as a result of excess alcohol use. It is associated with high mortality and it is not clear whether the most commonly used treatments (corticosteroids) are effective, particularly in patients with very severe liver disease. In this worldwide study, the use of corticosteroids was associated with increased 30-day, but not 90- or 180-day, survival. The maximal benefit was observed in patients with an MELD score (a marker of severity of liver disease; higher scores signify worse disease) between 25-39. However, this benefit was lost in patients with the most severe liver disease (MELD score higher than 51).

Association between AT1 and AT2 angiotensin II receptor expression with cell proliferation and angiogenesis in operable breast cancer.

Angiotensin II (ANGII) has been associated with vascular proliferation in tumor and non-tumor models through its receptors AT1 and AT2. Our objective was to determine AT1 and AT2 receptor expression in operable breast cancer and its association with tumor grade, vascular density, and cellular proliferation. Seventy-seven surgically malignant breast tumors with no distant metastasis were included, and 7 benign lesions were used as controls. AT1 and AT2 receptor expression was determined by RT-PCR and immunohistochemistry (IHC) in 68 out of the 77 malignant lesions and in the 7 benign lesions. AT1 and AT2 receptor expression was detected in 35.3 and 25 % of cases, in both RT-PCR and IHC. Tumors that express AT1 showed an increase in T3 stage (92.3 vs. 7.7 % p < 0.001), mitotic index (4 ± 1 vs 2 ± 1, p = 0.05), vascular density (15 ± 3 vs 8 ± 5, p = 0.05), and cellular proliferation (85 ± 18 vs 55 ± 10, p = 0.01) versus AT1-negative lesions. Non-differences between clinical-pathologic variables and AT2 expression were found. AT1 receptor expression was associated to enhance angiogenesis and cellular proliferation rate, but no relationship with AT2 was found. ANGII and its peptides might play a role in the development and pathophysiology of breast cancer, and this could be valuable in the in the development of targeted therapies.

Concise review: Generation of neurons from somatic cells of healthy individuals and neurological patients through induced pluripotency or direct conversion.

Access to healthy or diseased human neural tissue is a daunting task and represents a barrier for advancing our understanding about the cellular, genetic, and molecular mechanisms underlying neurogenesis and neurodegeneration. Reprogramming of somatic cells to pluripotency by transient expression of transcription factors was achieved a few years ago. Induced pluripotent stem cells (iPSC) from both healthy individuals and patients suffering from debilitating, life-threatening neurological diseases have been differentiated into several specific neuronal subtypes. An alternative emerging approach is the direct conversion of somatic cells (i.e., fibroblasts, blood cells, or glial cells) into neuron-like cells. However, to what extent neuronal direct conversion of diseased somatic cells can be achieved remains an open question. Optimization of current expansion and differentiation approaches is highly demanded to increase the differentiation efficiency of specific phenotypes of functional neurons from iPSCs or through somatic cell direct conversion. The realization of the full potential of iPSCs relies on the ability to precisely modify specific genome sequences. Genome editing technologies including zinc finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeat/CAS9 RNA-guided nucleases have progressed very fast over the last years. The combination of genome-editing strategies and patient-specific iPSC biology will offer a unique platform for in vitro generation of diseased and corrected neural derivatives for personalized therapies, disease modeling and drug screening.

[National guidelines of diagnosis and treatment of the non-Hodgkin lymphoma]. / Guías nacionales de diagnóstico y tratamiento de linfoma no Hodgkin.

Non-Hodgkin lymphoma comprises a heterogeneous group of haematological malignancies, classified according to their clinic, anatomic-pathological features and, lately, to their molecular biomarkers. Despite the therapeutic advances, nearly half of the patients will die because of this disease. The new diagnostic tools have been the cornerstone to design recent therapy targets, which must be included in the current treatment guidelines of this sort of neoplasms by means of clinical trials and evidence-based medicine. In the face of poor diagnoses devices in most of the Mexican hospitals, we recommend the present diagnose stratification, and treatment guidelines for non-Hodgkin lymphoma, based on evidence. They include the latest and most innovative therapeutic approaches, as well as specific recommendations for hospitals with limited framework and therapy resources.

SARS-CoV-2 self-testing in Peru: a cross-sectional survey of values and attitudes of the general population.

OBJECTIVES: To assess the values of and attitudes towards the use of rapid SARS-CoV-2 antigen-detection tests for self-testing in a rural and an urban area in Peru. DESIGN: Cross-sectional, street-based population survey. SETTING: A series of over 400 randomly selected street points in Valle del Mantaro and in Lima. PARTICIPANTS: 438 respondents (203 female) participated. They were all older than 17 years and provided informed consent for participation. INTERVENTION: All respondents answered on the spot, a 35-item questionnaire developed in KoboToolbox. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcomes of interest were: likelihood to use a SARS-CoV-2 self-test; willingness to pay for a SARS-CoV-2 self-test and likelihood to comply with recommended actions following a positive SARS-CoV-2 self-test result. Bivariate analyses and Poisson regression (PR) analyses were performed to identify significant associations between dependent variables and independent variables pertaining to respondents' characteristics, risk perception and previous experiences with conventional COVID-19 testing. RESULTS: Of the 438 respondents, 51.49% had previous experience with conventional COVID-19 testing; 20.37% had COVID-19 disease; 86.96% accepted the idea of SARS-CoV-2 self-testing; and, 78.95% would be likely to use it if needed. Almost all (94.75%) would pay for a self-testing device (mean acceptable payment: US$10.4) if it was not provided free of charge by health authorities. Overall, 93.12%, 86.93% and 85.32% would self-isolate, report the results and warn their contacts, respectively. Being a female (adjusted PR 1.05, 95% CI 1.00 to 1.09, p<0.018), having completed secondary education (adjusted PR 1.18, 95% CI 1.02 to 1.37, p<0.024) and expressing likelihood to use self-testing (adjusted PR 1.08, 95% CI 1.01 to 1.16, p<0.0.24) could be predictors of willingness to pay for a self-test. CONCLUSIONS: Self-testing is perceived as an acceptable approach. Health authorities in Peru should facilitate access to this approach to complement healthcare facilities-led testing efforts for COVID-19. Future research is necessary to understand the impact of self-testing in case detection and pandemic control.

MELD 3.0 adequately predicts mortality and renal replacement therapy requirements in patients with alcohol-associated hepatitis.

Background & Aims: Model for End-Stage Liver Disease (MELD) score better predicts mortality in alcohol-associated hepatitis (AH) but could underestimate severity in women and malnourished patients. Using a global cohort, we assessed the ability of the MELD 3.0 score to predict short-term mortality in AH. Methods: This was a retrospective cohort study of patients admitted to hospital with AH from 2009 to 2019. The main outcome was all-cause 30-day mortality. We compared the AUC using DeLong's method and also performed a time-dependent AUC with competing risks analysis. Results: A total of 2,124 patients were included from 28 centres from 10 countries on three continents (median age 47.2 ± 11.2 years, 29.9% women, 71.3% with underlying cirrhosis). The median MELD 3.0 score at admission was 25 (20-33), with an estimated survival of 73.7% at 30 days. The MELD 3.0 score had a better performance in predicting 30-day mortality (AUC:0.761, 95%CI:0.732-0.791) compared with MELD sodium (MELD-Na; AUC: 0.744, 95% CI: 0.713-0.775; p = 0.042) and Maddrey's discriminant function (mDF) (AUC: 0.724, 95% CI: 0.691-0.757; p = 0.013). However, MELD 3.0 did not perform better than traditional MELD (AUC: 0.753, 95% CI: 0.723-0.783; p = 0.300) and Age-Bilirubin-International Normalised Ratio-Creatinine (ABIC) (AUC:0.757, 95% CI: 0.727-0.788; p = 0.765). These results were consistent in competing-risk analysis, where MELD 3.0 (AUC: 0.757, 95% CI: 0.724-0.790) predicted better 30-day mortality compared with MELD-Na (AUC: 0.739, 95% CI: 0.708-0.770; p = 0.028) and mDF (AUC:0.717, 95% CI: 0.687-0.748; p = 0.042). The MELD 3.0 score was significantly better in predicting renal replacement therapy requirements during admission compared with the other scores (AUC: 0.844, 95% CI: 0.805-0.883). Conclusions: MELD 3.0 demonstrated better performance compared with MELD-Na and mDF in predicting 30-day and 90-day mortality, and was the best predictor of renal replacement therapy requirements during admission for AH. However, further prospective studies are needed to validate its extensive use in AH. Impact and implications: Severe AH has high short-term mortality. The establishment of treatments and liver transplantation depends on mortality prediction. We evaluated the performance of the new MELD 3.0 score to predict short-term mortality in AH in a large global cohort. MELD 3.0 performed better in predicting 30- and 90-day mortality compared with MELD-Na and mDF, but was similar to MELD and ABIC scores. MELD 3.0 was the best predictor of renal replacement therapy requirements. Thus, further prospective studies are needed to support the wide use of MELD 3.0 in AH.

Allopregnanolone potentiates the glutamate-mediated seizures induced by 4-aminopyridine in rat hippocampus in vivo.

Excitatory and inhibitory neurotransmission in the central nervous system can be modulated by neurosteroids. We previously found that in rat hippocampal slices allopregnanolone (3α-hydroxy-5α-pregnan-20-one), a positive GABA(A) receptor modulator, suppresses the epileptic discharges induced by 4-aminopyridine (4-AP), a convulsant K(+) channel blocker that stimulates glutamate release. Here, we tested the action of allopregnanolone on the epileptogenic and excitotoxic effects of the intrahippocampal administration of 4-AP in vivo. Drugs were perfused by a microdialysis cannula-electrode in the dorsal hippocampus and the EEG was recorded. Extracellular levels of aspartate, glutamate and GABA were analyzed by HPLC in the microdialysis fractions, and 24 h after the experiment the hippocampus was studied histologically. 4-AP induced intense epileptic discharges, increased the extracellular levels of aspartate, glutamate, and GABA by 383, 420, and 245%, respectively, and produced a notable neurodegeneration in CA1 and CA3 areas. Allopregnanolone administration alone did not affect the electrical activity, amino acids levels or cellular morphology, but when co-infused with 4-AP incremented 55-77% the duration of the epileptic discharges, and potentiated 32-49% the release of glutamate in comparison with 4-AP alone. The 4-AP-induced neurodegeneration was not modified by allopregnanolone. The NMDA receptor antagonist MK-801 protected against the epilepsy and neurodegeneration produced by 4-AP, and allopregnanolone did not affect this protection. We conclude that, differently from the observations in vitro, allopregnanolone potentiated the stimulatory effect of 4-AP on glutamate release and that this may explain the potentiation of the epileptogenic effect of 4-AP in vivo.

Ruxolitinib as a treatment strategy for SARS-CoV-2 pneumonia: clinical experience in a real-world setting.

INTRODUCTION: Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) infection is characterised by a viral phase and a severe pro-inflammatory phase. The inhibition of the JAK/STAT pathway limits the pro-inflammatory state in moderate to severe COVID-19. METHODOLOGY: We analysed the data obtained by an observational cohort of patients with SARS-CoV-2 pneumonia treated with ruxolitinib in 22 hospitals of Mexico. The applied dose was determined based on physician's criteria. The benefit of ruxolitinib was evaluated using the 8-points ordinal scale developed by the NIH in the ACTT1 trial. Duration of hospital stay, changes in pro-inflammatory laboratory values, mortality, and toxicity were also measured. RESULTS: A total of 287 patients were reported at 22 sites in Mexico from March to June 2020; 80.8% received ruxolitinib 5 mg BID and 19.16% received ruxolitinib 10 mg BID plus standard of care. At beginning of treatment, 223 patients were on oxygen support and 59 on invasive ventilation. The percentage of patients on invasive ventilation was 53% in the 10 mg and 13% in the 5 mg cohort. A statistically significant improvement measured as a reduction by 2 points on the 8-point ordinal scale was described (baseline 5.39 ± 0.93, final 3.67± 2.98, p = 0.0001). There were 74 deaths. Serious adverse events were presented in 6.9% of the patients. CONCLUSIONS: Ruxolitinib appears to be safe in COVID-19 patients, with clinical benefits observed in terms of decrease in the 8-point ordinal scale and pro-inflammatory state. Further studies must be done to ensure efficacy against mortality.

Feasibility of Noninvasive Positive Pressure Ventilation in the Treatment of Oxygen-Dependent COVID-19 Patients in Peru.

Intensive care is expensive, and availability is limited. Low- and middle-income countries in particular have struggled to cope with the large influx of critically ill patients during the COVID-19 pandemic. Noninvasive respiratory support devices delivering continuous positive airways pressure (CPAP) require less resource and staff expertise compared with invasive mechanical ventilators and can be routinely used outside of intensive care units. This study assessed the use of the UCL-Ventura Wayrachi CPAP device in hospitalized patients with COVID-19 in Peru. A secondary analysis of data collected for a feasibility study commissioned by the Peruvian Ministry of Health was conducted. Data were collected from three hospitals, including patient demographics, clinical data, and outcomes. Forty-five patients were enrolled from July 16 to September 1, 2020. Eight patients (18%) were intolerant of the CPAP mask. Of the remainder, 18 (48.7%) improved and were discharged from hospital after 6 days. Eight (21.6%) died while on CPAP and 11 (29.7%) were eventually intubated, of whom two died. In total, 27 (60%) survived to hospital discharge. Participating physicians noted the device was easy to use and provided patient benefit, though voiced concerns about the strain on hospital oxygen supplies. In conclusion, the UCL Ventura Wayrachi CPAP device proved feasible in COVID-19 patients in Peru, and offered a bridging therapy for patients who required a ventilator when none were available.

Current and future suitable habitat areas for Nasuella olivacea (Gray, 1865) in Colombia and Ecuador and analysis of its distribution across different land uses.

Nasuella olivacea is an endemic mammal from the Andes of Ecuador and Colombia. Due to its rarity, aspects about its natural history, ecology and distribution patterns are not well known, therefore, research is needed to generate knowledge about this carnivore and a first step is studying suitable habitat areas. We performed Ecological Niche Models and applied future climate change scenarios (2.6 and 8.5 RCP) to determine the potential distribution of this mammal in Colombia and Ecuador, with current and future climate change conditions; furthermore, we analysed its distribution along several land covers. We found that N. olivacea is likely to be found in areas where no records have been reported previously; likewise, climate change conditions would increase suitable distribution areas. Concerning land cover, 73.4% of N. olivacea potential distribution was located outside Protected Areas (PA), 46.1% in Forests and 40.3% in Agricultural Lands. These findings highlight the need to further research understudied species, furthering our understanding about distribution trends and responses to changing climatic conditions, as well as informig future PA designing. These are essential tools for supporting wildlife conservation plans, being applicable for rare species whose biology and ecology remain unknown.

GABA effects during neuronal differentiation of stem cells.

Gamma-amino butyrate (GABA) is the most prevalent inhibitory neurotransmitter in the adult brain. In this review, we summarize the pharmacology and regulation of GABAergic transmission components (biosynthetic enzymes, receptors and transporters) in adult non-neurogenic brain regions. The effects of targeted mutations in genes relevant for GABAergic functions and how they influence specific neuronal circuits and pathological states are presented. We then review GABA actions on neuronal differentiation. During brain development, GABA has depolarizing activity in cerebrocortical neural precursors, controlling cell division and contributing to neuronal migration and maturation. In the adult forebrain there are two neurogenic regions exposed to synaptic and non-synaptic GABA release. Neural stem cells and neuronal progenitors express GABA receptors in subventricular and subgranular zones. GABA effects in these cells are very similar to those found in embryonic cortical precursor cells, and therefore it is possible that this amino acid has important roles during adult brain plasticity.

GABA promotes gastrin-releasing peptide secretion in NE/NE-like cells: Contribution to prostate cancer progression.

In prostate cancer (PCa), neuroendocrine cells (NE) have been associated with the progression of the disease due to the secretion of neuropeptides that are capable of diffusing and influence surrounding cells. The GABAergic system is enriched in NE-like cells, and contributes to PCa progression. Additionally, γ-aminobutyric acid (GABA) stimulates the secretion of gastrin-releasing peptide (GRP) in peripheral organs. For the first time, in this study we show the role of GABA and GABAB receptor 1 (GABBR1) expression in GRP secretion in NE-like prostate cancer cells. We demonstrated an increase in GRP levels in NE-like cell medium treated with GABAB receptor agonist. Moreover, the blocking of this receptor inhibited GABA-induced GRP secretion. The invasive potential of PC3 cells was enhanced by either GRP or conditioned medium of NE-like cells treated with GABA. Additionally, we confirmed a positive correlation between GABA and GRP levels in the serum of PCa patients with NE markers. Finally, using public available data sets, we found a negative correlation between GABBR1 and androgen receptor (AR) expression, as well as a strong positive correlation between GABBR1 and enolase 2. These results suggest that GABA via GABBR1 induces GRP secretion in NE like cells involved in PCa progression.

Changes in the content of estrogen alpha and progesterone receptors during differentiation of mouse embryonic stem cells to dopamine neurons.

Embryonic stem cells (ESC) can differentiate to derivatives of the three embryonic germ layers. Dopamine neurons have been produced from mouse and human ESC. This in vitro induction mimics the developmental program followed by dopaminergic cells in vivo. Production of dopamine neurons might have clinical applications for Parkinson's disease, which has a higher incidence in men than in women, suggesting a protective role for sex hormones, particularly progesterone and estradiol. These hormones exert many of their effects through the interaction with their nuclear receptors. In this study, we used a described 5-stage protocol for dopamine neuron differentiation of ESC, allowing neuronal commitment as evidenced by specific markers and by behavioural recovery of hemiparkinsonian rats after grafting. We studied the expression of steroid hormone receptors by immunoblot during this procedure and found an increase in the content of both A and B isoforms of progesterone receptor (PR) and a decrease in estrogen receptor alpha (ER-alpha) when cells were at the neural/neuronal stages, when compared with the amount found in initial pluripotent conditions. We also found the same pattern of PR and ER-alpha expression by immunocytochemistry. Ninety-two percent of dopamine neurons expressed progesterone receptors and only 19% of these neurons co-expressed tyrosine hydroxylase and ER-alpha. These results show a differential expression pattern of ER-alpha and PR isoforms during neuronal differentiation of ESC.

[IgG4-related disease: a case report]. / Enfermedad asociada a IgG4: reporte de un caso.

IgG4-related disease is an inflammatory condition characterized by high levels of IgG4. It affects salivary and lacrimal glands, pancreas, lymph nodes, lungs or kidney. The diagnosis is based on identifying a histological pattern with a dense lymphocyte and plasmacyte infiltration, focal fibrosis or phlebitis, finding more than 10 IgG4 positive cells per high power field and/or IgG4/IgG ratio in plasma higher than 40%. We present a patient with Mikulicz's disease who meets histological findings required for the diagnosis of IgG4 related disease.

La enfermedad relacionada con IgG4 es una condición fibroinflamatoria en la que existe elevación de IgG4, afección a nivel de glándulas salivares, lacrimales, páncreas, ganglios linfáticos y pulmón. Para su diagnóstico se requiere la identificación de un patrón histológico sugestivo que muestre infiltrado linfoplasmocitario denso, fibrosis focal o flebitis a nivel de una glándula, más de 10 células positivas para IgG4 por campo de gran aumento y relación de IgG4/IgG arriba de 40% en plasma. Describimos el caso de una paciente que presentó enfermedad de Mikulicz y cumplió con los datos histológicos para diagnóstico de enfermedad relacionada con IgG4.

A two-step synthetic strategy to obtain a water-soluble derivative of curcumin with improved antioxidant capacity and in vitro cytotoxicity in C6 glioma cells.

A novel water-soluble derivative of curcumin (Cur-[G-2]-OH) was designed and synthesized from accessible raw materials in only two steps with an overall yield of 80%. The modification of curcumin phenol groups with second-generation polyester dendrons (dendronization) as a strategy to achieve an optimal hydrophilic/hydrophobic balance allows the complete water solubilization of the new curcumin derivative (5mg/ml) at room temperature. The therapeutic potential of Cur-[G-2]-OH was investigated in terms of antioxidant capacity, intracellular uptake and cytotoxicity in both rat glioblastoma cells and normal human dermal fibroblasts. Although the phenolic groups of curcumin were locked by dendronization, Cur-[G-2]-OH exhibited antioxidant capacity in water that was even higher than curcumin in dimethylsulfoxide (DMSO). This compound showed a steady cellular uptake contrasted with curcumin, which has a saturation capture at high concentrations. Combined with improved stability, this property seems to allow the intracellular accumulation of Cur-[G-2]-OH. Furthermore, the new compound exhibited increased cytotoxicity in rat C6 glioma cells in a time- and concentration-dependent manner, whereas in normal human fibroblasts, its IC50 value was >600µM versus the IC50 of curcumin found between 100 and 200µM. Surprisingly, Cur-[G-2]-OH drives cell death of C6 cells by a different mechanism of apoptosis triggered by curcumin. Together, these results suggest that curcumin dendronization could promote molecular and cellular mechanisms that are different from those induced by curcumin, presumably due to structural factors and not only for improved water solubility.

Termination of epileptiform activity by cooling in rat hippocampal slice epilepsy models.

Cooling has been shown to terminate experimentally induced epileptiform activity in models of epilepsy without causing injury to the cooled brain, suggesting that cooling could represent an approach to seizure control in intractable focal epilepsies. Here we sought to determine the most effective way to apply cooling to abort spontaneous epileptiform discharges in in vitro brain slice models. We induced spontaneous epileptiform activity in rat brain slices by exposure to 4-aminopyridine (4-AP), 4-AP plus bicuculline, and Mg(2+)-free artificial CSF (aCSF) at 28-34 degrees C. Extracellular field recordings were made at hippocampal or neocortical sites. Slice temperature was reduced by perfusion with cold aCSF. Rapid cooling at rates of 2-5 degrees C/s was compared to cooling at slower rates of 0.1-1 degrees C/s. Cooling at both rates reversibly aborted epileptiform discharges in all three models and at all recording sites. With rapid cooling, small temperature drops were highly effective in terminating discharges, an effect that was sustained for as long as the reduced temperature level was maintained. In contrast, slow cooling required much larger temperature drops to inhibit discharges. With slow cooling, absolute temperature drops to 21-22 degrees C caused a 90% reduction in event frequency, but cooling to 14-15 degrees C was required to terminate discharges. We conclude that rapid cooling as effectively aborts discharges in in vitro epilepsy models as does slow cooling, but the magnitude of the temperature change required is less. Practical devices to inhibit seizure activity may only need to induce small temperature drops, if the cooling can be applied sufficiently rapidly.

Semaphorin 3C Released from a Biocompatible Hydrogel Guides and Promotes Axonal Growth of Rodent and Human Dopaminergic Neurons.

Cell therapy in experimental models of Parkinson's disease replaces the lost dopamine neurons (DAN), but we still need improved methods to guide dopaminergic axons (DAx) of grafted neurons to make proper connections. The protein Semaphorin 3C (Sema3C) attracts DAN axons and enhances their growth. In this work, we show that the hydrogel PuraMatrix, a self-assembling peptide-based matrix, incorporates Sema3C and releases it steadily during 4 weeks. We also tested if hydrogel-delivered Sema3C attracts DAx using a system of rat midbrain explants embedded in collagen gels. We show that Sema3C released by this hydrogel attracts DAx, in a similar way to pretectum, which is known to attract growing DAN axons. We assessed the effect of Sema3C on the growth of DAx using microfluidic devices. DAN from rat midbrain or those differentiated from human embryonic stem cells showed enhanced axonal extension when exposed to hydrogel-released Sema3C, similar to soluble Sema3C. Notably, DAN of human origin express the cognate Sema3C receptors, Neuropilin1 and Neuropilin2. These results show that PuraMatrix is able to incorporate and release Sema3C, and such delivery guides and promotes the axonal growth of DAN. This biocompatible hydrogel might be useful as a Sema3C carrier for in vivo studies in parkinsonian animal models.

Epilepsy and hippocampal neurodegeneration induced by glutamate decarboxylase inhibitors in awake rats.

Glutamic acid decarboxylase (GAD), the enzyme responsible for GABA synthesis, requires pyridoxal phosphate (PLP) as a cofactor. Thiosemicarbazide (TSC) and γ-glutamyl-hydrazone (PLPGH) inhibit the free PLP-dependent isoform (GAD65) activity after systemic administration, leading to epilepsy in mice and in young, but not in adult rats. However, the competitive GAD inhibitor 3-mercaptopropionic acid (MPA) induces convulsions in both immature and adult rats. In the present study we tested comparatively the epileptogenic and neurotoxic effects of PLPGH, TSC and MPA, administered by microdialysis in the hippocampus of adult awake rats. Cortical EEG and motor behavior were analyzed during the next 2h, and aspartate, glutamate and GABA were measured by HPLC in the microdialysis-collected fractions. Twenty-four hours after drug administration rats were fixed for histological analysis of the hippocampus. PLPGH or TSC did not affect the motor behavior, EEG or cellular morphology, although the extracellular concentration of GABA was decreased. In contrast, MPA produced intense wet-dog shakes, EEG epileptiform discharges, a >75% reduction of extracellular GABA levels and remarkable neurodegeneration of the CA1 region, with >80% neuronal loss. The systemic administration of the NMDA glutamate receptor antagonist MK-801 30 min before MPA did not prevent the MPA-induced epilepsy but significantly protected against its neurotoxic effect, reducing neuronal loss to <30%. We conclude that in adult awake rats, drugs acting on PLP availability have only a weak effect on GABA neurotransmission, whereas direct GAD inhibition produced by MPA induces hyperexcitation leading to epilepsy and hippocampal neurodegeneration. Because this degeneration was prevented by the blockade of NMDA receptors, we conclude that it is due to glutamate-mediated excitotoxicity consequent to disinhibition of the hippocampal excitatory circuits.