Cellular automata model for human articular chondrocytes migration, proliferation and cell death: An in vitro validation.

Articular cartilage is characterized by low cell density of only one cell type, chondrocytes, and has limited self-healing properties. When articular cartilage is affected by traumatic injuries, a therapeutic strategy such as autologous chondrocyte implantation is usually proposed for its treatment. This approach requires in vitro chondrocyte expansion to yield high cell number for cell transplantation. To improve the efficiency of this procedure, it is necessary to assess cell dynamics such as migration, proliferation and cell death during culture. Computational models such as cellular automata can be used to simulate cell dynamics in order to enhance the result of cell culture procedures. This methodology has been implemented for several cell types; however, an experimental validation is required for each one. For this reason, in this research a cellular automata model, based on random-walk theory, was devised in order to predict articular chondrocyte behavior in monolayer culture during cell expansion. Results demonstrated that the cellular automata model corresponded to cell dynamics and computed-accurate quantitative results. Moreover, it was possible to observe that cell dynamics depend on weighted probabilities derived from experimental data and cell behavior varies according to the cell culture period. Thus, depending on whether cells were just seeded or proliferated exponentially, culture time probabilities differed in percentages in the CA model. Furthermore, in the experimental assessment a decreased chondrocyte proliferation was observed along with increased passage number. This approach is expected to having other uses as in enhancing articular cartilage therapies based on tissue engineering and regenerative medicine.

Advancing ocular safety research: A comprehensive examination of benzocaine acute exposure without animal testing.

Benzocaine is a widely employed local anaesthetic; however, there is a notable dearth of preclinical and clinical evidence regarding its safety in ophthalmological products. To address this, a comprehensive strategy incorporating in silico and in vitro methodologies was proposed for assessing benzocaine's ocular toxicity without animal testing. To collect the in silico evidence, the QSAR Toolbox (v4.5) was used. A single exposure to two benzocaine concentrations (2% and 20%) was evaluated by in vitro methods. Hen's Egg Chorioallantoic Membrane Test (HET-CAM) was performed to evaluate the effects on the conjunctiva. To study corneal integrity, Short Time Exposure test (STE) and Bovine Corneal Opacity and Permeability (BCOP) assay, followed by histopathological analysis, were carried out. Results from both in silico and in vitro methodologies categorize benzocaine as non-irritating. The histopathological analysis further affirms the safety of using benzocaine in eye drops, as no alterations were observed in evaluated corneal strata. This research proposes a useful combined strategy to provide evidence on the safety of local anaesthetics and particularly show that 2% and 20% benzocaine solutions do not induce eye irritation or corneal damage, supporting the potential use of benzocaine in the development of ophthalmic anesthetic products.

Longitudinal outcomes of obeticholic acid therapy in ursodiol-nonresponsive primary biliary cholangitis: Stratifying the impact of add-on fibrates in real-world practice.

BACKGROUND: Suboptimal response to ursodeoxycholic acid occurs in 40% of primary biliary cholangitis (PBC) patients, affecting survival. Achieving a deep response (normalisation of alkaline phosphatase [ALP] and bilirubin ≤0.6 upper limit of normal) improves survival. Yet, the long-term effectiveness of second-line treatments remains uncertain. AIMS: To evaluate the long-term effectiveness of obeticholic acid (OCA) ± fibrates. Focusing on biochemical response (ALP ≤1.67 times the upper limit of normal, with a decrease of at least 15% from baseline and normal bilirubin levels), normalisation of ALP, deep response and biochemical remission (deep response plus aminotransferase normalisation). METHODS: We conducted a longitudinal, observational, multicentre study involving ursodeoxyccholic acid non-responsive PBC patients (Paris-II criteria) from Spain and Portugal who received OCA ± fibrates. RESULTS: Of 255 patients, median follow-up was 35.1 months (IQR: 20.2-53). The biochemical response in the whole cohort was 47.2%, 61.4% and 68.6% at 12, 24 and 36 months. GLOBE-PBC and 5-year UK-PBC scores improved (p < 0.001). Triple therapy (ursodeoxycholic acid plus OCA plus fibrates) had significantly higher response rates than dual therapy (p = 0.001), including ALP normalisation, deep response and biochemical remission (p < 0.001). In multivariate analysis, triple therapy remained independently associated with biochemical response (p = 0.024), alkaline phosphatase normalisation, deep response and biochemical remission (p < 0.001). Adverse effects occurred in 41.2% of cases, leading to 18.8% discontinuing OCA. Out of 55 patients with cirrhosis, 12 developed decompensation. All with baseline portal hypertension. CONCLUSION: Triple therapy was superior in achieving therapeutic goals in UDCA-nonresponsive PBC. Decompensation was linked to pre-existing portal hypertension.

Unique genetic profile of sporadic colorectal cancer liver metastasis versus primary tumors as defined by high-density single-nucleotide polymorphism arrays.

Most genetic studies in colorectal carcinomas have focused on those abnormalities that are acquired by primary tumors, particularly in the transition from adenoma to carcinoma, whereas few studies have compared the genetic abnormalities of primary versus paired metastatic samples. In this study, we used high-density 500K single-nucleotide polymorphism arrays to map the overall genetic changes present in liver metastases (n=20) from untreated colorectal carcinoma patients studied at diagnosis versus their paired primary tumors (n=20). MLH1, MSH2 and MSH6 gene expression was measured in parallel by immunohistochemistry. Overall, metastatic tumors systematically contained those genetic abnormalities observed in the primary tumor sample from the same subject. However, liver metastases from many cases (up to 8 out of 20) showed acquisition of genetic aberrations that were not found in their paired primary tumors. These new metastatic aberrations mainly consisted of (1) an increased frequency of genetic lesions of chromosomes that have been associated with metastatic colorectal carcinoma (1p, 7p, 8q, 13q, 17p, 18q, 20q) and, more interestingly, (2) acquisition of new chromosomal abnormalities (eg, losses of chromosomes 4 and 10q and gains of chromosomes 5p and 6p). These genetic changes acquired by metastatic tumors may be associated with either the metastatic process and/or adaption of metastatic cells to the liver microenvironment. Further studies in larger series of patients are necessary to dissect the specific role of each of the altered genes and chromosomal regions in the metastatic spread of colorectal tumors.

Detection of breastmilk antibodies targeting SARS-CoV-2 nucleocapsid, spike and receptor-binding-domain antigens.

A 40-year-old female was found to have strongly neutralizing SARS-CoV-2 breastmilk IgA and IgG antibodies reactive against multiple SARS-CoV-2 antigens at 2.5 months after documented infection with SARS-CoV-2. At 6.5 months following the infection, she remained positive for breastmilk and serum SARS-CoV-2 neutralizing antibodies. Holder breast milk pasteurization did not diminish SARS-CoV-2 antibody titres but it reduced its neutralizing capacity, while serum heat inactivation had no negative effect on SARS-CoV-2 serum antibody levels and neutralizing capacity. Current data on SARS-CoV-2 and breastmilk are reviewed.

Urticaria caused by antihistamines: report of 5 cases.

Antihistamines are widely used drugs. Hypersensitivity reactions with these drugs are rare and a challenge for the physician. We describe 5 outpatients who experienced urticaria after taking antihistamines. All 5 were treated at our outpatient clinic over a period of 15 years. The allergy workup included a clinical history, skin prick testing, patch testing with antihistamines, and single-blind placebo-controlled oral challenge tests. Biopsy samples were taken and serum tryptase levels were determined in 1 patient. The results of the skin prick tests and patch tests were negative in all patients but 1, in whom the prick test result was positive to some antihistamines. We confirmed all diagnoses using a single-blind challenge test. The biopsy obtained from 1 patient strongly supported urticaria. We present 5 cases of antihistamine-induced urticaria where the immunologic mechanism remains unclear. Hypersensitivity reactions should be taken into account in patients receiving antihistamines, especially in those who experience urticaria.

[Effect of pentoxifylline on survival, cardiac function and both portal and systemic hemodynamics in advanced alcoholic cirrhosis--a randomized double-blind placebo-controlled trial]. / Effecto de la pentoxifilina en la supervivencia, la función cardiaca y en la hemodinámica portal y sistémica de la cirrosis alcohólica avanzada.

OBJECTIVE: To assess the effect of pentoxiphylline (a potent inhibitor of tumor necrosis factor alpha) on survival, on systemic and portal hemodynamics, and on cardiac function in patients with alcoholic cirrhosis. DESIGN: A randomized double-blind placebo-controlled trial. SETTING: A single center using parallel groups of patients to compare pentoxiphylline with placebo. PATIENTS: We recruited 24 patients with alcoholic cirrhosis (8 Child-Pugh B and 16 Child-Pugh C). INTERVENTIONS: Patients were randomly assigned to receive pentoxiphylline (400 mg tid; n = 12) or placebo (n = 12) over a 4-week period. OUTCOME MEASURES: The primary outcome was to extend short-term and long-term survival. Secondary outcomes included hemodynamic benefits (improvement in cardiac function and/or systemic vascular resistance index, or decrease in portal pressure). RESULTS: Portal pressure and cardiac function remained unchanged and there were no significant differences in short-term or long-term survival between treatment and placebo groups. The group on pentoxiphylline increased systemic vascular resistance and decreased cardiac indices (from 1,721 +/- 567 to 2,082 +/- 622 dyn.sec(-1) cm(-5) m(-2) and from 4.17 +/- 1.4 to 3.4 +/- 0.9 l.m(-2), p = 0.05). CONCLUSIONS: Although pentoxiphylline seems to provide some short-term hemodynamic benefits in patients with advanced alcoholic cirrhosis, this drug has no effect on survival or portal pressure in these patients.

[Anaphylaxis after carrying out prick tests]. / Anafilaxia tras realización de pruebas cutáneas en prick.

The skin prick test (SPT) is a simple and fast method used routinely in allergology practice. Systemic reactions have been described with this technique on few occasions. We are presenting a case of anaphylaxis with hemodynamic consequences after carrying out skin prick test with a cat dander extract. A 23 years old female who suffered rhinoconjunctivitis and asthma following contact with cats. We performed skin prick test with a battery of the usual inhalants. Twenty minutes after carrying out the prick test the patient showed intense ocular irritation and reddening followed by dysphonia and a feeling of pharyngeal occupation. Although skin prick test is a safe diagnostic approach, it should be performed only in places equipped to treat anaphylaxis and for trained specialists .

Long-term reversal of hypocholesterolaemia in patients with chronic hepatitis C is related to sustained viral response and viral genotype.

BACKGROUND: Genotype-3 of hepatitis C virus (HCV) has been associated with serum lipid changes (reversible with sustained viral response) and liver steatosis. AIM: To characterize the relationships among hepatic steatosis, cholesterol and sustained viral response in these patients. METHODS: Patients (n = 215) with chronic hepatitis C (157 with genotype-1 of HCV) had age, body mass index, gender, alcohol intake, glycaemia, serum lipids, transaminases, grade and stage (METAVIR and Scheuer), degree of liver steatosis, sustained viral response, insulinaemia, leptinaemia, beta-hydroxybutyrate and glycerol measured, and were compared with 32 hepatitis B virus (HBV)-infected subjects. RESULTS: Genotype-3 of HCV patients had age-adjusted hypocholesterolaemia and more frequent hepatic steatosis (P < 0.001). Steatosis was inversely correlated with serum cholesterol (P < 0.01) and directly with viral load (P < 0.03). In patients with genotype-3 of HCV and sustained viral response, serum cholesterol increased from 138 (95% CI: 120-151) to 180 mg/dL (95% CI: 171-199) 12 months after treatment conclusion (P < 0.0001). By contrast, cholesterol values were unchanged in genotype-3 of HCV non-responders and in patients with genotype-1 of HCV regardless of response. Rising cholesterol in sustained viral response did not parallel the changes in beta-hydroxybutyrate. CONCLUSIONS: Besides causing hepatic steatosis, genotype-3 specifically decreases serum cholesterol. This interference with the metabolic lipid pathway is related to viral load, is reversed with sustained viral response, and seems unrelated to mitochondrial dysfunction.

[Induction of tolerance in hypersensitivity to mesalazine (5-ASA)]. / Inducción de tolerancia en la hipersensibilidad a mesalazina (5-ASA).

Mesalazine is a derivative of 5-aminosalicylic acid (5-ASA), which is useful in the treatment of intestinal inflammatory disease. Sulfasalazine is formed by two parts, sulfapyridine and 5-ASA, the latter being the active part of the molecule. The new preparatives derived from 5-ASA were developed in an attempt to avoid the traditionally associated side effects to sulfapyridine, although they are still observed and new effects appear. We present two cases. The first is a man diagnosed of inflammatory intestinal disease, with background of two previous reactions of urticaria and angioedema after acetyl salicylic acid, who presented urticaria after taking mesalazine. The second one had generalized urticaria after three months of initiating treatment with mesalazine. Given the need for treatment in both cases, a desensitization protocol to mesalazine was made. It was developed in 17 days in our service. Tolerance to that drug to therapeutic doses is reached. When faced with patients with hypersensitivity to different drugs, that are necessary to treat their disease, "desensitization" regimes, that assure good tolerance, can be made.

Tolerance to the sedative and anxiolytic effects of diazepam is associated with different alterations of GABAA receptors in rat cerebral cortex.

The clinical use of benzodiazepines is limited by the development of tolerance to their pharmacological effects. Tolerance to each of the pharmacological actions of benzodiazepines develops at different rates. The aim of this work was to investigate the mechanism of tolerance by performing behavioral tests in combination with biochemical studies. To this end, we administered prolonged treatments of diazepam to rats for 7 or 14 days. Tolerance to the sedative effects of diazepam was detected by means of the open field test after the 7- and 14-day treatments, whereas tolerance to the anxiolytic actions of benzodiazepine manifested following only the 14-day treatment in the elevated plus maze. The cerebral cortical concentrations of diazepam did not decline after the diazepam treatments, indicating that tolerance was not due to alterations in pharmacokinetic factors. The uncoupling of GABA/benzodiazepine site interactions and an increase in the degree of phosphorylation of the GABAA receptor γ2 subunit at serine 327 in the cerebral cortex were produced by day 7 of diazepam treatment and persisted after 14 days of exposure to benzodiazepine. Thus, these alterations could be part of the mechanism of tolerance to the sedative effects of diazepam. An increase in the percentage of α1-containing GABAA receptors in the cerebral cortex was observed following the 14-day treatment with diazepam but not the 7-day treatment, suggesting that tolerance to the anxiolytic effects is associated with a change in receptor subunit composition. The understanding of the molecular bases of tolerance could be important for the development of new drugs that maintain their efficacies over long-term treatments.

Growth plate stress distribution implications during bone development: a simple framework computational approach.

Mechanical stimuli play a significant role in the process of long bone development as evidenced by clinical observations and in vivo studies. Up to now approaches to understand stimuli characteristics have been limited to the first stages of epiphyseal development. Furthermore, growth plate mechanical behavior has not been widely studied. In order to better understand mechanical influences on bone growth, we used Carter and Wong biomechanical approximation to analyze growth plate mechanical behavior, and explore stress patterns for different morphological stages of the growth plate. To the best of our knowledge this work is the first attempt to study stress distribution on growth plate during different possible stages of bone development, from gestation to adolescence. Stress distribution analysis on the epiphysis and growth plate was performed using axisymmetric (3D) finite element analysis in a simplified generic epiphyseal geometry using a linear elastic model as the first approximation. We took into account different growth plate locations, morphologies and widths, as well as different epiphyseal developmental stages. We found stress distribution during bone development established osteogenic index patterns that seem to influence locally epiphyseal structures growth and coincide with growth plate histological arrangement.

Black/white differences in prenatal care utilization: an assessment of predisposing and enabling factors.

OBJECTIVE: This article reports on analysis of the predisposing and enabling factors that affect black/white differences in utilization of prenatal care services. DATA SOURCES: We use a secondary data source from a survey conducted by the Michigan Department of Public Health. STUDY DESIGN: The study uses multivariate analysis methods to examine black/white differences in (1) total number of prenatal care visits, (2) timing of start of prenatal care, and (3) adequacy of care received. We use the model advanced by Aday, Andersen, and Fleming (1980) to examine the effect of enabling and predisposing factors on black/white differences in prenatal care utilization. DATA COLLECTION: A questionnaire was administered to all women who delivered in Michigan hospitals with an obstetrical unit. PRINCIPAL FINDINGS: Enabling factors fully accounted for black/white differences in timing of start of prenatal care; however, the model could not fully account for black/white differences in the total number or the adequacy of prenatal care received. CONCLUSION: Although there are no black/white differences in the initiation of prenatal care, black women are still less likely to receive adequate care as measured by the Kessner index, or to have as many total prenatal care contacts as white women. It is possible that barriers within the health care system that could not be assessed in this study may account for the differences we observed. Future research should consider the characteristics of the health care system that may account for the unwillingness or inability of black women to continue to receive care once they initiate prenatal care.