Infection after Anterior Cruciate Ligament Reconstruction: A Narrative Review of the Literature.

Infection is an uncommon side effect of arthroscopic surgery, and this percentage is higher in anterior cruciate ligament reconstruction (ACLR) surgery, where graft and fixation devices are used. Infections can not only lead to high re-admission rates and poor functional recovery of the knee but can also have a significant negative impact on the patient's psychological and economic health, especially in athletes, as it can affect their sports career. It is important to be aware of the many risk factors, especially the manifestation of symptoms. These may sometimes be non-specific to the infectious pathology and common to other situations, such as the presence of a significant intra-articular hematoma. Septic arthritis after ACLR can occur at any time after surgery but typically presents acutely, while late manifestation is relatively rare. Diagnosis of infection is based on patient history, physical examination, laboratory parameters, and analysis of synovial fluid after joint aspiration, which is the gold standard for diagnosing post-operative infection. Once symptoms appear and the diagnosis seems certain, it is necessary to intervene quickly with arthroscopic debridement and long-term antibiotic treatment to try to save the graft and resolve the infectious situation to avoid graft failure and arthrofibrotic sequelae. The aim of this paper is to provide an overview of the epidemiology, pathogenesis, risk factors, clinical presentation, diagnostic evaluation, and current treatment guidelines of septic arthritis after ACLR surgery by analyzing recent literature, in particular meta-analyses and systematic reviews.

Bari Shoulder Telemedicine Examination Protocol (B-STEP): A Standard Protocol for Personalized Remote Shoulder Examination.

The COVID-19 pandemic drastically changed many aspects of the traditional functioning of health systems all around the world. In Italy, as reported by the CIO, compared to the previous year, there was a significant reduction in 2020 in overall outpatient activities by up to 75%. These data support the need for telemedicine, which represents a current challenge and can no longer be postponed in the future. This study aims to elaborate on a possible model for remote shoulder examination based on traditional tests to improve the quality of telemedicine in orthopedic and rehabilitation. Between May 2020 and November 2020, ten orthopedic surgeons individually examined six patients with a known shoulder disorder, both in hospital and via webcam according to the previously shared protocol (B-STEP). According to the 10 observers, completing 100% of the ASES score and at least 87.5% of the Constant score is possible. Shoulder ROM and many specific tests are also reproducible via webcam, but with less sensitivity, according to the subjective opinion of observers. The B-STEP is a useful protocol for the standardization of the objective examination of the shoulder via webcam. Further studies are necessary to determine if the B-STEP protocol is useful for diagnosing pathology in unknown patients and evaluating its sensitivity and specificity for each pathology.

Anterior Cruciate Ligament Reconstruction with Quadrupled Semitendinosus Graft or Synthetic Ligament: Knee Stability and Clinical Outcomes at Three Years Follow-Up.

The incidence of anterior cruciate ligament reconstruction (ACLR) surgeries is increasing and graft choice is important for a rapid return to activity, especially in patients older than 30 years. The aim of this study is to compare in term of quality of life and knee stability of patients who undergone ACLR using quadrupled semitendinosus (ST4) graft against patients who undergone ACLR with synthetic ligaments. Thirty-nine patients undergoing ACLR were enrolled in the study and were divided into two groups: ACLR with synthetic ligaments-LARS (group A) and ACLR with quadrupled semitendinosus graft ST4 (group B). They underwent surgery at Policlinico di Bari Orthopedic Unit between January 2017 and January 2020. Group A was composed by nineteen patients (36.16 ± 4.41 mean age-years, 22.47 ± 2.63 mean BMI-kg/m2, 39.37 ± 10.05 mean time evaluation after surgery-months) and group B was composed by twenty patients (34.95 ± 3.59 mean age-years, 21.1 ± 2.88 mean BMI-kg/m2, 36.75 ± 8.69 mean time evaluation after surgery-months). For each patient, the following data were recorded: age; side of injury, BMI, date of surgery, anterior knee laxity with the arthrometer, and Lysholm knee scoring scale. Mean value of anterior tibial translation (ATT) in group A was 3.09 mm ± 0.65 and in group B was 2.66 mm ± 1.61 (pvalue of 0.1139). Mann--Whitney U test used to compare the Lysholm means values between groups showed a pvalue of 0.9307. LARS has comparable clinical and functional outcomes compared with hamstring autografts at short-term of 3 years follow-up. Level of Evidence: IV.

The Efficacy of Temperature-Controlled High-Energy Polymodal Laser Therapy in Tendinopathy of the Shoulder.

BACKGROUND: Rotator cuff tendinopathy is a common diagnosis among patients with shoulder pain and dysfunction. Laser therapy is recommended for the treatment of this tendon disease due to the possibility of increasing tissue biostimulation. The aim of this study was to investigate the effects of HELT (high-energy laser therapy) in relation to the wavelengths of 650 nm, 810 nm, 980 nm, and 1064 nm administered. METHODS: The study design was prospective and observational. Thirty patients with shoulder tendinopathy were recruited and treated in one of two high-energy laser therapy groups (5 Watt/cm2, 450 Joule, super-pulsed mode). Group A received a high-energy laser therapy protocol with a single wavelength (1064 nm); group B received a high-energy laser therapy program with four wavelengths (650 nm, 810 nm, 980 nm, and 1064 nm). Pain (VAS), function (ASES), and disability (DASH) were monitored at the time of recruitment (T0), 1 month later (T1), and 6 months later (T2). Roles and Maudsley scores were also evaluated at T1 and T2. RESULTS: Both protocols resulted in improvement of pain and in functional and disability recovery at the two times of assessment, without statistically significant differences. In group B, treated with the four wavelengths, a trend emerged, bordering on statistical significance, for a greater reduction in pain. CONCLUSIONS: The high-energy laser proved to be an effective therapy for the treatment of rotator cuff tendinopathy. The possibility of modulating the choice of wavelengths could allow the customization of the protocol in relation to the patient's clinical condition.

Surgical strategies in pediatric supracondylar humeral fractures: our experience.

BACKGROUND AND AIM: Supracondylar humeral fractures are the most common skeletal injury of childhood elbow. Treatment option for Gartland type II-III-IV fractures is based on closed reduction and percutaneous pinning (CRPP) fixation using Kirshner wires. Seldom open reduction is needed. Literature described different method of CRPP. The aim of the study is to report our experience in the surgical management of supracondylar humeral fractures comparing it with the literature, in order to identify useful information for a correct and better approach to reduce complications and improve clinical outcomes. METHODS: 148 patients with a mean age of 5.72 ± 2.52 years and with Gartland type II-III-IV humeral supracondylar fractures were treated with CRPP at our Orthopedic Pediatric Unit. They were divided into three groups according to surgical technique. Group A was represented by patients treated with cross pinning (1 medial and 1 lateral pin), Group B represented by 2 lateral pins while Group C represented by 2 lateral and one medial pin. Evaluation criteria are based on Mayo Elbow Performance Index (MEPI); Bauman's and Carrying Angle and Flynn's criteria. Data were recorded at the following times: T0 (before surgical procedure); T1 (one-month post-surgery); T2 (six months post-surgery). RESULTS: The three surgical techniques showed comparable results according to MEPI, Bauman's angle, Carrying's angle and Flynn's criteria from T0 to T1. There is an improvement for all Groups. Group C reported the best MEPI outcome at T2. However, 2 patients in this group did not show excellent results according to Flynn's criteria. CONCLUSIONS: There is no single and superior treatment for displaced humeral supracondylar fractures and that each fracture has its own personality.

Graft Intra-Articular Remodeling and Bone Incorporation in ACL Reconstruction: The State of the Art and Clinical Implications.

The knee is one of the most frequently affected joints in sports trauma, and anterior cruciate ligament (ACL) injury and meniscal tears are the most common lesions. ACL reconstruction (ACLR) remains the treatment of choice for patients willing to return to their previous activity. There are different surgical techniques and different possible usable grafts. The graft used for ACLR surgery undergoes a bone incorporation process and an intra-articular remodelling named ligamentization until it reaches characteristics similar to the native ligament. After the first incorporation stage, the remodelling process is divided into an early stage that could last 4 weeks, a proliferative stage that lasts 4 to 12 weeks, and a final stage of ligamentization that could last over 1 year. The period of return to sport (RTS) after ACLR, which is becoming shorter and shorter, can be a high-risk period for athletes due to the risk of graft failure. This systematic review aims to define the phases of the ligamentization process considering graft type and fixation techniques, as well as the graft's anatomopathological and biomechanical characteristics, to evaluate a criterion-based rehab progression and maximize patient outcomes for an RTS respecting graft biology. The rehabilitative program has to promote and optimize the graft remodelling and incorporation processes; moreover, it has to accommodate physiological graft healing and avoid overloading. An early RTS and noncompliance with the biological characteristics of the graft in the various phases are associated with a high incidence of re-injury.

Platelet Rich Plasma Injections for Knee Osteoarthritis Treatment: A Prospective Clinical Study.

Background: The aim of this prospective study was to evaluate the efficacy and safety of Platelet Rich Plasma (PRP) injections in patients affected by knee osteoarthritis (KOA). An autologous blood product containing a high percentage of various growth factors (GFs), cytokines and modulating factors as PRP has shown promising results in achieving this goal. Methods: One hundred and fifty-three patients (72 males, mean age 59.06 ± 8.78, range 40−81 years old) from January 2018 to January 2020 received three consecutive PRP injections and completed the follow ups. Western Ontario and McMaster University Osteoarthritis index (WOMAC), Knee society score (KSS) and Visual Analogic Scale (VAS) were evaluated before PRP injection (T0), one month (T1), three months (T2) and six months (T3) after the treatment. All patients underwent baseline and at 6 months MRI and X-ray evaluation. Results: A statistically significant VAS, KSS and WOMAC reduction emerged in the comparison between evaluations (p < 0.05), MRI demonstrated non-statistically significant improvement in cartilage thickness for both tibial plate and femoral plate (p = 0.46 and p = 0.33 respectively), and no radiographic changes could be seen in any patients. Conclusions: PRP injection represents a valid conservative treatment to reduce pain, improve quality of life and functional scores even at midterm of 6 months follow-up.

Thermal versus cooled radiofrequency in patients with sacroiliac joint pain: a systematic review of the literature and pooled analysis of clinical outcomes.

INTRODUCTION: Chronic low back pain (LBP) can be caused by sacroiliac joint (SIJ) disease. Many conditions could cause SIJ dysfunction. The lateral branches of the L4-S3 dorsal rami are responsible for the primary innervation of the posterior SI joint. Radiofrequency (RF) denervation represent an emerging promising treatment for refractory sacroiliac joint pain. There are different types of RF denervation such as thermal or cooled. Use of irrigation cooled electrodes allows targeted tissues to reach the neuroablative temperatures slowly, preventing collateral damage of adjacent tissue. EVIDENCE ACQUISITION: We conducted electronic database (PubMed, Medline, Cochrane and Google Scholar) research (time frame: January 1st, 2010 to May 31st, 2021) for clinical studies that had tested conventional radiofrequency (RFT) and cooled radiofrequency (RFC) to treat sacroiliac joint pain. These studies were evaluated according to Level of Evidence. Quantitative assessment of qualifying studies was done using the random effects model. We calculated the pooled size effect using standardized mean difference (SMD) as the main effect measure. EVIDENCE SYNTHESIS: We identified nine studies, with a total of 276 patients affected by sacroiliac joint pain and treated with radiofrequency. The analysis revealed a small and non-significant difference in pain reduction and an improvement in quality of life in RFT subgroup (Pain measured in Visual Analogic Scale: RFT subgroups SMD=-3.643 (95% CI -4.478, -2.807), RFC subgroup SMD=-3.285 (95% CI -4.428, -2.141), P=0.587; Quality of Life measured in Oswestry Disability Index: RFT subgroup SMD=-35.969 (95% CI -53.993%, -17.945%), RFC subgroup SMD=-20.589% (95% CI -33.424%. -7.754%), P=0.123). Publication bias was found in quality-of-life assessment due to the low number and high heterogeneity of studies. Two techniques showed no major complications. CONCLUSIONS: Current evidence indicates no statistical difference between two techniques examined. The literature is currently lacking, and well-constructed randomized clinical trials are necessary to evaluate this deficient aspect.

Biophysical Stimulation in Athletes' Joint Degeneration: A Narrative Review.

Osteoarthritis (OA) is the most prevalent degenerative joint disease and the main cause of pain and disability in elderly people. OA currently represents a significant social health problem, since it affects 250 million individuals worldwide, mainly adults aged over 65. Although OA is a multifactorial disease, depending on both genetic and environmental factors, it is reported that joint degeneration has a higher prevalence in former athletes. Repetitive impact and loading, joint overuse and recurrent injuries followed by a rapid return to the sport might explain athletes' predisposition to joint articular degeneration. In recent years, however, big efforts have been made to improve the prevention and management of sports injuries and to speed up the athletes' return-to-sport. Biophysics is the study of biological processes and systems using physics-based methods or based on physical principles. Clinical biophysics has recently evolved as a medical branch that investigates the relationship between the human body and non-ionizing physical energy. A physical stimulus triggers a biological response by regulating specific intracellular pathways, thus acting as a drug. Preclinical and clinical trials have shown positive effects of biophysical stimulation on articular cartilage, subchondral bone and synovia. This review aims to assess the role of pulsed electromagnetic fields (PEMFs) and extracorporeal shockwave therapy (ESWT) in the prevention and treatment of joint degeneration in athletes.

Quality of Life and Clinical Evaluation of Calcaneoplasty with a Balloon System for Calcaneal Fracture at 5 Years of Follow-Up.

Calcaneal fractures are a challenging clinical problem. Management of this type of injury remains controversial, especially in the context of intra-articular fractures. Surgical treatment with open reduction and internal synthesis (ORIF) is considered the standard treatment for CF, but it is associated with many complications. Several minimally invasive techniques such as balloon-assisted reduction, pin fixation, and tricalcium phosphate augmentation have been proposed to avoid the frequent and recurrent postoperative problems related to these fractures. We retrospectively examined 20 patients (mean age was 54.5), all undergoing minimally invasive calcaneoplasty surgery at our Department of Orthopaedics and Traumatology between 2012 and 2016. X-ray and CT scan were performed preoperatively and at 5 years of follow-up (57.9 ± 6 months). The American Orthopaedic Foot and Ankle Society (AOFAS) score was used for clinical examination, and the Short-Form (36) Health Survey (SF-36) score and Visual Analogue Scale (VAS) were used to assess the Health-Related Quality of Life (HRQoL). All 20 patients were available at the final follow-up. The mean AOFAS score was 82.25/100. The VAS results attest an overall average of 2.7/10 (0-9). The average of the parameters "Physical Health" and "Mental Health" was, respectively, 81.25 and 83.55. In terms of postoperative complications, we observed no cases of superficial or deep infections. Clinical response after balloon-assisted reduction, pin fixation, and tricalcium phosphate augmentation has shown a comparable or better outcome according to the AOFAS and VAS score. Quality-of-life scores, obtained according to the SF-36 questionnaire, are considered high. From both a clinical and quality-of-life point of view, our study highlights that there is not gender distinction. Further comparative studies with a higher number of patients are needed which assess the quality of life in the various techniques used to treat calcaneal fractures.

Volar locking plate versus external fixation in distal radius fractures: A meta-analysis.

The purpose of this meta-analysis is to evaluate the efficacy of plate or external fixator treatments in distal radius fractures, based not only on clinical and radiographic parameters but on Health Related Quality of Life (HRQOL) parameters. The Preferred Reporting Items for Systematic Reviews and Metanalyses (PRISMA) guidelines were followed when conducting this systematic review. The Revised Assessment of Multiple Systematic Reviews (RAMSTAR) checklist was additionally consulted in order to ensure a high-quality methodological process, encompassing such elements as an 'a priori' design, independent reviews and comprehensive search. The literature search was carried out on PubMed, MEDLINE and Scopus. The search terms used were "Radius fracture AND osteosynthesis", "Wrist fracture AND external fixator" and "Wrist fracture AND plate". Two reviewers independently screened titles, abstracts and full texts. To determine inter-reviewer agreement, a k score was calculated after each screening state. Of the 5753 studies collected through the initial databases search, two studies were included in the final meta-analysis (125 treated with external fixator vs 132 with volar plate). There was a substantial inter-reviewer agreement as to the title (0.73; 95% confidence interval, 0.67-0.79) abstract (0.65; 95% CI, 0.46-0.83) and fulltext screening stages (0.89; 95%CI, 0.67-1). The meta-analysis reported a mean difference equal to 0.00 (95%CI= -0.05 - 0.05), in accordance with I2= 0% and p test for the heterogeneity value=0.089. This meta analysis confirms and quantifies that the two techniques are superimposable as regards the quality of life reported by patients at least one year of follow-up.

High-affinity sigma-1 (σ1) receptor ligands based on the σ1 antagonist PB212.

Aim: The σ1 receptor is a druggable target involved in many physiological processes and diseases. To clarify its physiology and derive therapeutic benefit, nine analogs based on the σ1 antagonist PB212 were synthesized replacing the 4-methylpiperidine with basic moieties of varying size and degree of conformational freedom. Results & methodology: 3-Phenylpyrrolidine, 4-phenylpiperidine or granatane derivatives displayed the highest affinity (Ki.#x00A0;= 0.12, 0.31 or 1.03 nM). Calcium flux assays in MCF7σ1 cells indicated that the highest σ1 receptor affinity are σ1 antagonists. Molecular models provided a structural basis for understanding the σ1 affinity and functional activity of the analogs and incorporated Glennon's σ1 pharmacophore model. Conclusion: Herein, we identify new compounds exploitable as therapeutic drug leads or as tools to study σ1 receptor physiology.

The σ1 receptor agonist (+)-pentazocine increases store-operated Ca2+ entry in MCF7σ1 and SK-N-SH cell lines.

BACKGROUND: The intracellular [Ca2+] is modulated by σ receptors. An important component of the cellular machinery governing the intracellular [Ca2+] is Store-Operated Calcium Entry (SOCE). Here we want to investigate whether ligands of σ receptors affect SOCE. METHODS: The intracellular [Ca2+] was monitored, with the fluorescent Ca2+-sensitive probe Fura-2, in four cell lines with a different expression of σ receptors, namely MCF7 (expressing σ1 receptors with a low density and overexpressing σ2 receptors), MCF7σ1 (overexpressing σ1 receptors), SK-N-SH, and HT-29. RESULTS: When thapsigargin was used to deplete intracellular Ca2+ stores, in a Ca2+-free incubation medium, the Ca2+ influx (following Ca2+ re-addition) was significantly increased by 1µM (+)-pentazocine (σ1 receptor agonist) in MCF7σ1 (by 22.5%) and SK-N-SH (by 45.6%), but not in HT-29 and MCF7 cells. We have used, as a second approach, the "Mn2+ quenching" protocol. In MCF7σ1 cells, after thapsigargin treatment, the fluorescence quenching induced by Mn2+ influx (evidence of Ca2+ influx) was significantly increased (by 25.8%) by 1µM (+)-pentazocine, significantly decreased (by 18.0%) by BD1063 (σ1 receptor antagonist), and not affected by the presence of both ligands. These effects were not observed in MCF7 cells. Finally, in MCF7 cells, 1µM PB28 (σ2 receptor agonist), did not affect both the Ca2+ response after Ca2+ re-addition and the fluorescence quenching induced by Mn2+ influx. CONCLUSIONS: We propose that the σ1 receptor agonist (+)-pentazocine increases SOCE in MCF7σ1 and SK-N-SH cell lines. The σ2 receptor agonist PB28 does not affect SOCE in MCF7 cells.

The effects of new sigma (σ) receptor ligands, PB190 and PB212, in the models predictive of antidepressant activity.

BACKGROUND: A number of σ receptor ligands have been demonstrated to possess antidepressant-like effect in some experimental paradigms (e.g. forced swim test, tail suspension test, olfactory bulbectomy model, conditioned fear stress). The objective of the present study was to find out whether PB190 and PB212, new σ1 receptor ligands, show the effects in some models predictive of antidepressant activity. METHODS: The impact of PB190 and PB212 on the immobility time in the forced swim test (FST) and tail suspension test (TST) was assessed in C57BL/6J male mice. Extracellular bradykinin triggers a transient increase in intracellular calcium concentration by activating the phospholipase C/IP3 pathway. The intracellular calcium concentration was estimated with the dual wavelength ratiometric probe Fura-2. RESULTS: In the FST model, PB190 showed a moderate antidepressant-like effect (only in the dose of 3mg/kg) which was enhanced by joint treatment with amantadine (AMA), 10mg/kg (inactive per se). The decrease in the immobility time induced by the combined treatment with PB190 and AMA was counteracted by PB212 and by BD1047, a σ1-receptor antagonist. The in vitro studies indicated that Ca(2+)-response was increased by 1µM PB190, like by the σ1-agonist (+)-pentazocine, while 1 µM PB212 behaved line σ1-antagonist, BD1063. On the other hand, 100 µM PB190 negatively affected the Ca(2+)-response after bradykinin. CONCLUSIONS: The obtained results: 1/indicated that in the in vivo conditions PB190 behaved as a σ1-receptor agonist while PB212 counteracted its effect, confirming the in vitro data; 2/gave support to the hypothesis that σ1-receptors might be one of possible mechanisms by which drugs induce antidepressant-like activity; 3/revealed that this effect may be potentiated by NMDA receptor antagonists, e.g. AMA.

Investigation of σ receptors agonist/antagonist activity through N-(6-methoxytetralin-1-yl)- and N-(6-methoxynaphthalen-1-yl)alkyl derivatives of polymethylpiperidines.

A series of polymethyl-substituted piperidines linked to either a 6-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl or a 6-methoxynaphthalen-1-yl moiety was generated with the aim of verifying a previously generated hypothesis: tetralin and naphthalene nuclei confer opposite activity at the σ1 receptor. Compounds 6, 9 and 10 displayed appreciable affinity at both σ subtypes, but none of the novel compounds displayed significant antiproliferative activity in MCF7wt and MCF7σ1 cell lines. The effect on bradikynin-triggered Ca(2+) mobilization was studied as a methodology to suggest σ receptors mediated activity.

Naphthalenyl derivatives for hitting P-gp/MRP1/BCRP transporters.

Substituted naphthalenyl derivatives bearing oxazole, or thiazole or furyl heteronuclei have been carried out as bioisosters of aryl-oxazoles and -thiazoles derivatives previously reported in order to investigate the role of the hindrance on the activity towards P-gp/BCRP/and MRP1 transporters. In addition, the role of naphthalenyl group to modulate P-gp intrinsic activity of these compounds was ascertained. The results demonstrated that all naphthalenyl derivatives displayed comparable P-gp activity with respect to lead compounds previously characterized in our SAR studies but were less active towards BCRP and MRP1 pumps. In terms of intrinsic activity, the replacement of aryl with naphthalenyl moiety led to P-gp inhibitors, unambiguous or ambiguous substrates on the base of the heteronucleus and the substituent on the naphthalenyl fragment. Indeed, oxazole derivatives were: inhibitors (R=H, F, OH), unambiguous substrates (R=OCH(3)), or ambiguous substrate (R=Br); thiazole derivatives were: unambiguous substrates (R=OCH(3), Br), or ambiguous substrates (R=H, F). Finally furyl derivatives were ambiguous substrates.

The sigma-1 receptor antagonist PB212 reduces the Ca²âº-release through the inositol (1, 4, 5)-trisphosphate receptor in SK-N-SH cells.

Sigma-1 receptors are specifically located at the endoplasmic reticulum-mitochondrion interface, but upon stimulation by ligands or under prolonged cellular stress, they translocate to other areas of the cell. Sigma-1 receptors are involved in the regulation of intracellular [Ca(2+)] by affecting the Ca(2+)-influx or the release from intracellular stores. In SK-N-SH cells, we measured the affinity of 4-methyl-1-[4-(6-methoxynaphthalen-1-yl)butyl]piperidine (PB212) at sigma-1 receptor by using a competition binding assay with specific radioligand; we obtained a K(i) value=316 ± 19 nM. PB212 also showed an antiproliferative effect in SK-N-SH cells (EC(50)=32 ± 4 µM) but had no effect in MCF7 cells, which only express sigma-2 receptor; these findings suggest that PB212 behaves as a sigma-1 receptor antagonist. We have studied the effect of PB212 on Ca(2+) homeostasis of the SK-N-SH cell line with the fluorescent probe Fura-2. 100 µM PB212 induced a Ca(2+)-efflux from the endoplasmic reticulum through the inositol (1, 4, 5)-trisphosphate (IP(3)) receptor. Moreover, [PB212] ranging from 1 to 100µM reduced the Ca(2+)-response, triggered by carbachol or bradykinin that engage the phospholipase C/IP(3) pathway; such a response is generally increased by sigma-1 receptor agonists. On the other hand, PB212 did not reduce the Ca(2+)-response mediated by IP(3) in LoVo cells, which do not express neither sigma-1 nor sigma-2 receptors, and in MCF7 cells. The fact that the activity of the sigma-1 receptor can be experimentally modulated by agonists and antagonists supports the intriguing hypothesis that some endogenous molecules, unknown at the moment, modulate the sigma-1 receptor and its cellular targets.

MC70 potentiates doxorubicin efficacy in colon and breast cancer in vitro treatment.

A major limitation of cancer treatment is the ability of cancer cells to develop resistance to chemotherapeutic drugs, by the establishment of multidrug resistance. Here, we characterize MC70 as ABC transporters inhibitor and anticancer agent, alone or with chemotherapy. MC70 was analyzed for its interaction with ABCB1, ABCG2 and ABCC1 by specific transport assays. In breast and colon cancer cell lines, cell growth and apoptosis were measured by MTT assay and DNA laddering Elisa kit, respectively. Cell cycle perturbation and cellular targets modulation were analyzed by Flow-cytometry and Western blotting, respectively. MC70 interacted with ABC transporters. In breast cancer cells, MC70 slightly inhibited cell proliferation strongly enhancing doxorubicin effectiveness. By contrast, MC70 was found to inhibit cell growth in colon cancer cells without affecting doxorubicin efficacy and in combination with topoisomerase I inhibitors it could be a promising therapeutic approach. What is more, it was also observed that MC70 induced apoptosis, canceled in favor of necrosis when given in combination with high doses of doxorubicin. MC70 inhibited cell migration probably through its interaction with sigma-1 receptor. Modulations of i) cell cycle, ii) pAkt and the phosphorylation of the three MAPKs were highlighted, while any activity was excluded at transcription level, thus accounting for the phenotypic effects observed. MC70 might be considered as a new potential anticancer agent capable to i) enhance chemotherapy effectiveness and ii) to play a contributory role in the treatment of chemotherapy resistant tumors.

Why amphibians are more sensitive than mammals to xenobiotics.

Dramatic declines in amphibian populations have been described all over the world since the 1980s. The evidence that the sensitivity to environmental threats is greater in amphibians than in mammals has been generally linked to the observation that amphibians are characterized by a rather permeable skin. Nevertheless, a numerical comparison of data of percutaneous (through the skin) passage between amphibians and mammals is lacking. Therefore, in this investigation we have measured the percutaneous passage of two test molecules (mannitol and antipyrine) and three heavily used herbicides (atrazine, paraquat and glyphosate) in the skin of the frog Rana esculenta (amphibians) and of the pig ear (mammals), by using the same experimental protocol and a simple apparatus which minimizes the edge effect, occurring when the tissue is clamped in the usually used experimental device.The percutaneous passage (P) of each substance is much greater in frog than in pig. LogP is linearly related to logKow (logarithm of the octanol-water partition coefficient). The measured P value of atrazine was about 134 times larger than that of glyphosate in frog skin, but only 12 times in pig ear skin. The FoD value (Pfrog/Ppig) was 302 for atrazine, 120 for antipyrine, 66 for mannitol, 29 for paraquat, and 26 for glyphosate.The differences in structure and composition of the skin between amphibians and mammals are discussed.

F281, synthetic agonist of the sigma-2 receptor, induces Ca2+ efflux from the endoplasmic reticulum and mitochondria in SK-N-SH cells.

We demonstrate that F281, a synthetic agonist of the sigma-2 receptor (s2R), induces a non transient increase in intracellular [Ca(2+)] ([Ca(2+)](i)) and cell death in SK-N-SH cells. Sigma receptors are classified into two subtypes, with different molecular weight and tissue distribution. While the sigma-1 receptor has been cloned, the s2r is less characterized and its physiological ligand and role need further investigation. In tumour cell lines, synthetic agonists of the s2R trigger apoptosis and modulate [Ca(2+)](i). In particular, CB-64D induces a Ca(2+) response while PB28 supresses Ca(2+) signalling. We have recently synthesized F281, by replacing the 5-methoxytetraline moiety of PB28 with a carbazole nucleus. Although this bioisosteric substitution should not affect the ligand affinity at the receptor, F281 (after 24h incubation) was more cytotoxic than PB28 (EC(50) values 65.4nM and 8.13 microM, respectively) in SK-N-SH cells. We used the fluorescent probes fura-2, rhod-2 and JC-1. F281 mobilizes Ca(2+) from mitochondria and from the endoplasmic reticulum, by opening its inositol 1,4,5-trisphosphate receptor; Ca(2+)-entry through the channels activated by store depletion was also observed. After the increase in [Ca(2+)](i) and within 10 min, we observed a sudden drop in metabolic activity and intracellular [ATP] leading to cell death.