Mason type III fractures of the radial head: ORIF, resection or prosthetic replacement?

PURPOSE: This study focused on a comparison of mid-term clinical, functional and radiographic outcomes of adults treated by open reduction and internal fixation (ORIF), radial head prosthesis (RHP) and resection (RHR). METHODS: The retrospective evaluation concerned 47 surgically treated patients after a mean follow-up of 53 months. All patients were grouped according to the surgical procedure performed: 15 in the RHP group, 16 in the ORIF group and 16 in the RHR group. At the follow-up, outcome assessment was based on radiographs, range of motion (ROM) and functional rating scores. RESULTS: Patients treated by RHR had significantly higher mean age and shorter operation time than other two groups. Compared to ROM, flexion, extension and pronation were significantly worse in patients treated by ORIF than those in the RHP group and the RHR group. Supination was significantly better in the RHP group. However, no statistical differences were observed in functional rating scores among the three groups. Regarding complications, instability was the only cause of revision surgery in the RHP group and the RHR group. On the other hand, the ORIF group revision rate was 50% and secondary displacement was the most frequent cause of failure. CONCLUSION: The ORIF group did not show good results with greater elbow stiffness and higher revision rate than the other two techniques. RHR may be suitable for elderly patients with lower functional demands as it reported good clinical results and reduced operation time.

Arthroscopic surgery or exercise therapy for degenerative meniscal lesions: a systematic review of systematic reviews.

BACKGROUND: Arthroscopic partial meniscectomy (APM) is widely applied for the treatment of degenerative meniscal lesions in middle-aged patients; however, such injury is often associated with mild or moderate osteoarthritis and has been reported by MRI in asymptomatic knees. Previous studies suggested, in most patients, a lack of benefit of surgical approach over conservative treatment, yet many controversies remain in clinical practice. Our aims were to assess the functional and pain scores between exercise therapy and arthroscopic surgery for degenerative meniscal lesions and to evaluate the methodological quality of the most recent systematic reviews (SRs). METHODS: Two authors independently searched PubMed and Google Scholar for SRs comparing the outcome (in knee pain and functionality) of arthroscopic treatment and exercise therapy or placebo for degenerative meniscal lesions. The timeframe set was from 2009 to 2019 included. RESULTS: A total of 13 SRs were selected. Two reviewers independently assessed the methodological quality of each paper using the AMSTAR 2 tool: seven scored as "moderate," four obtained a "low" grade while the remaining two were evaluated as "critically low." SRs agreed that in middle-aged patients with degenerative meniscal lesions arthroscopic surgery appears to grant no long-term improvement in pain and function over exercise therapy or placebo. CONCLUSIONS: Conservative treatment based on physical therapy should be the first-line management. However, most SRs revealed subgroups of patients that fail to improve after conservative treatment and find relief when undergoing surgery. In the future, randomized controlled trials, evidence should be looked for that APM can be successful in case of the unsatisfactory results after physical therapy.

Retrospective evaluation of WALANT in emergency hand surgery in the Bordeaux university hospital.

The Wide-Awake Local Anesthesia No Tourniquet (WALANT) technique uses local anesthesia based on lidocaine and adrenaline, enabling surgery without the tourniquet normally used in hand surgery. Only a few studies have been conducted on the use of WALANT for emergency hand surgery in teaching hospitals. We therefore set up the WALANT procedure in our emergency department in the university hospital of Bordeaux, France, to evaluate its feasibility and the satisfaction of patients and operators. Between April and June 2020, we included 58 patients undergoing surgery for acute trauma of the hand/wrist. WALANT was performed following a specific protocol. A tourniquet was systematically available on standby. After the procedure, patients and operators were asked to complete a questionnaire. Patients rated pain on a 0-10 numerical analog scale. Surgeons reported their feelings about bleeding and patient cooperation. All patients underwent a nearly painless operation, with a mean pain score of 0.36/10. The mean pain score during injection was 2.57, and postoperatively 5.2. Bleeding complications were reported to be absent or slight by 43% of operators, moderate but acceptable by 47%, and significant by 10%. Bipolar forceps were used in 76% of cases. No digital necrosis or prolonged ischemia requiring the use of phentolamine was reported. WALANT offers a simple, safe, and effective alternative to traditional anesthesia techniques in an emergency setting. Patients and surgeons reported overall satisfaction, with no increase in the complications rate.

Angular stable plate versus reverse shoulder arthroplasty for proximal humeral fractures in elderly patient.

BACKGROUND: Treatment of complex proximal humeral fractures in the elderly is a challenge and reverse shoulder arthroplasty (RTSA) is now an important alternative to open reduction internal fixation (ORIF) with angular stable plate. The purpose of this study is to compare clinical and radiological outcomes of RTSA and ORIF in the elderly. METHODS: We retrospectively analyzed patients treated for three- or four-part displaced fractures of the proximal humerus. Range of motion, disabilities of the arm, shoulder and hand (DASH) and Constant scores were recorded. X-ray exam in three projections completed the clinical observation at follow-up. RESULTS: Forty-eight patients were enrolled after a mean follow-up of 37 months: 22 RTSA and 26 ORIF. Mean age at trauma was 74 years. Compared with RTSA patients, ORIF patients had significantly higher mean external rotation (28° vs. 14°) and better results in modal internal rotation (hand at D7 vs. hand at L5-S1). No significant differences were seen in DASH and Constant scores. Avascular necrosis and loss of reduction with varus dislocation of the humeral head were the most frequent causes of revision surgery in ORIF (34.6%) while the revision rate of the RTSA was 9.1%. CONCLUSION: In this study, both treatments showed good clinical outcomes, but RTSA resulted in lower revision rate than ORIF. Even if external and internal rotation in RTSA patients were worse than ORIF, they did not affect the patient's quality of life. So, the reverse arthroplasty seems to be a more reliable treatment.

Surgical management of 2- or 3-part proximal humeral fractures: comparison of plate, nail and K-wires.

BACKGROUND: Proximal humeral fractures (PHFs) are fairly common injuries, and their treatment is a challenge. The aim of this study is to compare clinical and functional outcomes of different osteosynthesis techniques. MATERIALS AND METHODS: We retrospectively reviewed patients' files and the hospital's digital database between March 2002 and April 2018. We treated surgically 148 patients with 2- and 3-part PHFs: 64 with plate and screws, 53 with intramedullary nailing and 31 with retrograde K-wires. We constituted three groups according to the type of treatment and two subgroups for each according to the number of fragments (Neer II or Neer III). Disabilities of the Arm, Shoulder and Hand (DASH) and Short Form-12 (SF-12) scores were recorded. RESULTS: Mean DASH and SF-12 scores both from the group treated with plate (Group I) and the one subjected to intramedullary nailing (Group II) were statistically superior to results from the patients treated by retrograde K-wires (Group III), while nails showed better functional results than the locking plates. In the first two groups, no difference was found between Neer II and III subgroups, while in Group III the DASH scores were significantly better in Neer II subgroup than those in Neer III subgroup. Avascular necrosis was the most frequent cause of revision surgery in Group I (4 cases) where we had 8 cases of reintervention (12.5%). In Group II, the subacromial impingement was the only cause for revision surgery with 3 cases (5.6%). CONCLUSIONS: Intramedullary nails showed better functional results and a lower complication rate than the locking plates. Both techniques showed superior results compared to those available with retrograde K-wires. So the nail seems to be a more reliable and adequate method for treating 2- and 3-part proximal humeral fractures.

A unique neuroendocrine cell model derived from the human foetal neural crest.

PURPOSE: Nowadays, no human neuroendocrine cell models derived from the neural crest are available. In this study, we present non-transformed long-term primary Neural Crest Cells (NCCs) isolated from the trunk region of the neural crest at VIII-XII gestational weeks of human foetuses obtained from voluntary legal abortion. METHODS AND RESULTS: In NCC, quantitative real-time RT PCR demonstrated the expression of neural crest specifier genes, such as Snail1, Snail2/SLUG, Sox10, FoxD3, c-Myc, and p75NTR. Moreover, these cell populations expressed stemness markers (such as Nanog and nestin), as well as markers of motility and invasion (TAGLN, MMP9, CXCR4, and CXCR7), and of neuronal/glial differentiation (MAP2, GFAP, SYP, and TAU). Functional analysis demonstrated that these cells not only possessed high migration properties, but most importantly, they expressed markers of sympatho-adrenal lineage, such as ASCL1 and tyrosine hydroxylase (TH). Moreover, the expression of TH increased after the induction with two different protocols of differentiation towards neuronal and sympatho-adrenal phenotypes. Finally, exposure to conditioned culture media from NCC induced a mature phenotype in a neuronal cell model (namely SH-SY5Y), suggesting that NCC may also act like Schwann precursors. CONCLUSION: This unique human cell model provides a solid tool for future studies addressing the bases of human neural crest-derived neuroendocrine tumours.

Synovial and serum levels of NGF in osteoarthritis and rheumatic diseases: a systematic review.

NGF has raised interest as a target molecule in the treatment of OA, after the clinical evidences that antagonization of NGF axis provides symptoms relief in OA. Thus, we conducted a systematic review of the literature to investigate the evidence of NGF being overexpressed during OA. We conducted a database search on Medline using keywords including NGF, serum, synovial fluid, AND osteoarthritis or arthritis. We included study conducted on human, with serum or synovial specimens and an OA cohort. Nine studies met the inclusion criteria. Serum levels ranged from non-detectable to 153.5±28.6 pg/ml. Synovial fluid levels ranged from non-detectable to nearly 210±82 pg/ml. One study supported the evidence of an increased level of NGF in SF and serum of OA patients. The concentration of NGF reported in these studies is controversial and evidence of overexpression of NGF is low.

The metabolic effects of quinolones and steroids on human ligament cells: an in vitro study.

The toxic effects of fluoroquinolones and steroid on tendon cells have been well established, but their role on human ligamentocytes remain unclear. We have investigated the effects of ciprofloxacin and methylprednisolone on human anterior cruciate ligamentocytes after 7 and 14 days of culture. We evaluated cell viability, Annexin V-FITC/PI assay, senescence-associated ß-galactosidase staining, and collagen type I detection. Regarding quinolones administration, we observed that ligament cells treated with ciprofloxacin have characterized by a significantly decrease of cell viability and collagen type I expression and an increase of apoptotic cells. In cells treated with high dose of steroid we observed a significantly decrease of cell viability and collagen type I expression and the presence of senescent cells. Therefore, ciprofloxacin and methylprednisolone might have cytotoxic effects on ligamentocytes by two distinct mechanisms. Quinolones seem to induce cell apoptosis, while steroids might be able to induce cellular senescence. Hence their use should be avoided in athletes and in orthopedic surgery.

Neuronal distress induced by low extracellular sodium in vitro is partially reverted by the return to normal sodium.

BACKGROUND: Hyponatremia is associated with negative clinical outcomes even when chronic and mild. It is also known that hyponatremia treatment should be appropriately performed, to avoid dramatic consequences possibly leading to death. We have previously demonstrated that chronically low extracellular [Na(+)], independently of reduced osmolality, is associated with signs of neuronal cell distress, possibly involving oxidative stress. AIM: The aim of the present study was to assess whether the return to normal extracellular [Na(+)] is able to revert neuronal cell damage. METHODS: After exposing SH-SY5Y and SK-N-AS cells to low [Na(+)] and returning to normal [Na(+)], we analyzed cell viability by MTS assay, ROS accumulation by FASCan and expression of anti-apoptotic genes. RESULTS: We found that the viability of cells was restored upon return to normal [Na(+)]. However, when more subtle signs of cell distress were assessed, such as the expression level of the anti-apoptotic genes Bcl-2 and DHCR24 or of the heme oxygenase 1 gene, a complete return to basal values was not observed, in particular in SK-N-AS, even when [Na(+)] was gradually increased. We also demonstrated that the amount of ROS significantly increased in low [Na(+)], thus confirming that oxidative stress appears to contribute to the effects of low [Na(+)] on cell homeostasis. CONCLUSIONS: Overall, this study provided the first demonstration that the correction of chronically low extracellular [Na(+)] may not be able to revert all the cell alterations associated with reduced [Na(+)]. These results suggest that prompt hyponatremia treatment might prevent possible residual abnormalities.

Low extracellular sodium promotes adipogenic commitment of human mesenchymal stromal cells: a novel mechanism for chronic hyponatremia-induced bone loss.

Hyponatremia represents an independent risk factor for osteoporosis and fractures, affecting both bone density and quality. A direct stimulation of bone resorption in the presence of reduced extracellular sodium concentrations ([Na(+)]) has been shown, but the effects of low [Na(+)] on osteoblasts have not been elucidated. We investigated the effects of a chronic reduction of extracellular [Na(+)], independently of osmotic stress, on human mesenchymal stromal cells (hMSC) from bone marrow, the common progenitor for osteoblasts and adipocytes. hMSC adhesion and viability were significantly inhibited by reduced [Na(+)], but their surface antigen profile and immuno-modulatory properties were not altered. In low [Na(+)], hMSC were able to commit toward both the osteogenic and the adipogenic phenotypes, as demonstrated by differentiation markers analysis. However, the dose-dependent increase in the number of adipocytes as a function of reduced [Na(+)] suggested a preferential commitment toward the adipogenic phenotype at the expense of osteogenesis. The amplified inhibitory effect on the expression of osteoblastic markers exerted by adipocytes-derived conditioned media in low [Na(+)] further supported this observation. The analysis of cytoskeleton showed that low [Na(+)] were associated with disruption of tubulin organization in hMSC-derived osteoblasts, thus suggesting a negative effect on bone quality. Finally, hMSC-derived osteoblasts increased their expression of factors stimulating osteoclast recruitment and activity. These findings confirm that hyponatremia should be carefully taken into account because of its negative effects on bone, in addition to the known neurological effects, and indicate for the first time that impaired osteogenesis may be involved.

Family directed umbilical cord blood banking for acute leukemia: usage rate in hematopoietic stem cell transplantation.

Family-directed umbilical cord blood (UCB) collection and banking is indicated in women delivering healthy babies who already have a member of their own family with a disease potentially treatable with an allogeneic hematopoietic stem cell (HSCs) transplantation (HSCT). The rapid availability of UCB is an important issue in HSCs procurement particularly for recipients with acute leukemia who urgently need HSCT. The aims of this study were to assess the usage rate of family UCB collections directed to patients with acute leukemia and to investigate the factors influencing the usage rate. A total of 113 families were enrolled, 118 UCB units were successfully collected and one collection failed due to emergency occurred during delivery. Among these, 7 collections were required for children who were in urgent need of a transplant: three HLA-matched units were successfully transplanted, respectively after 2, 5 and 6 months from collection; three collections resulted HLA-mismatched, while HLA-typing is pending for one unit. The remaining collections were mostly required for potential future use, among these units only one was transplanted in a HLA compatible sibling after 3 years and 4 months from collection. After a median time of storage of 8.5 years (range 0.1-20 years) a total of 4/118 (3.4 %) collection has been transplanted. During this time interval, considering only patients who have had the need of a transplant, the main factor influencing low utilization rate of UCB collections was due to HLA disparity, indeed among typed UCB unit mostly (77 %) resulted HLA mismatched with the intended recipient.

Assessment of sleep apnea syndrome in treated acromegalic patients and correlation of its severity with clinical and laboratory parameters.

BACKGROUND: Sleep apnea syndrome (SAS) is a frequent disorder in acromegalic patients and its frequency ranges from 45 to 87.5% of patients. Obstructive SAS is the prevailing form in acromegaly and its pathogenesis is based on craniofacial deformations and thickening of soft tissues and mucosas of upper airways and bronchi. Central and mixed types are less frequent. Respiratory complications, and SAS in particular, may contribute to the increased mortality observed in acromegaly. AIM: Aim of the present study is to assess the presence of SAS in acromegalic patients, its features and to correlate the severity of SAS with factors such as disease duration, body mass index (BMI), smoking, GH/IGF-I serum levels, associated comorbidities. SUBJECTS AND METHODS: Polygraphy (SOMNOcheck Effort Weinmann V2.05) was performed in 25 consecutive acromegalic patients (9 men and 16 women). Statistical analysis was performed with Mann-Whitney's test and Spearman coefficient. RESULTS: Fourteen out of 25 patients (56%) were affected by SAS. The prevailing form was obstructive SAS (12/14 patients). Smoking, female gender, and presence of lung disease appear to lead to a more severe form. We also found that the prevalence of hypertension was significantly higher in the group of patients with SAS, whereas no correlation was proved among SAS and disease duration, GH/IGF-I serum levels, somatostatin analogs treatment, BMI, and associated comorbidities. CONCLUSIONS: SAS is a frequent complication of acromegaly. Severe forms seem to be correlated with smoking and lung disease. Therefore, all acromegalic patients should be subjected to a polygraphic study for an early diagnosis and treatment and smoking should be discouraged.

Relationship between the neuroprotective effects of insulin-like growth factor-1 and 17ß-oestradiol in human neuroblasts.

Insulin-like growth factor-1 (IGF-1) and oestrogens interact with each other as neuroprotective factors. We have previously demonstrated that 17ß-oestradiol protects against ß-amyloid and oxidative stress toxicity and increases the amount of cell cholesterol in human foetal neuroblasts (FNC). The present study aimed: (i) to assess the protective effects of IGF-1 in FNC cells; (ii) to investigate the relationship between IGF-1 and 17ß-oestradiol; and (iii) to determine whether cholesterol was a major mediator of the effects of IGF-1, similarly to 17ß-oestradiol. We found that IGF-1 effectively exerts neuroprotective effects in FNC cells. We also demonstrated that the IGF-1 receptor (IGF-1R) pathway is needed to maintain oestrogen-mediated neuroprotection. Finally, we found that, opposite to 17ß-oestradiol, IGF-1 did not cause a significant increase in cell cholesterol. These findings indicate that a cross-talk between IGF-1 and 17ß-oestradiol occurs in FNC cells. In particular, the activation of the IGF-1R cascade appears to be fundamental to warrant 17ß-oestradiol-mediated neuroprotection, even though cell cholesterol does not play a major role as an effector of this pathway.

Androgens and estrogens prevent rosiglitazone-induced adipogenesis in human mesenchymal stem cells.

Thiazolidinediones (TZD), a class of anti-diabetic drugs, determine bone loss and increase fractures particularly in post-menopausal women, thus suggesting a protective role of sex steroids. We have previously demonstrated that the TZD rosiglitazone (RGZ) negatively affects bone mass by inhibiting osteoblastogenesis, yet inducing adipogenesis, in bone marrow-derived human mesenchymal stem cells (hMSC). The aim of this study was to determine whether estrogens and androgens are able to revert the effects of RGZ on bone. hMSC express estrogen receptor α and ß and the androgen receptor. We found that 17ß-estradiol (10 nM), the phytoestrogen genistein (10 nM), testosterone (10 nM) and the non-aromatizable androgens dihydrotestosterone (10 nM) and methyltrienolone (10 nM) effectively counteracted the adipogenic effect of RGZ (1 µM) in hMSC induced to differentiate into adipocytes, as determined by evaluating the expression of the adipogenic marker peroxisome proliferator-activated receptor γ and the percentage of fat cells. Furthermore, when hMSC were induced to differentiate into osteoblasts, all the above-mentioned molecules and also quercetin, another phytoestrogen, significantly reverted the inhibitory effect of RGZ on the expression of the osteogenic marker osteocalcin and decreased the number of fat cells observed after RGZ exposure. Our study represents, to our knowledge, the first demonstration in hMSC that androgens, independently of their aromatization, and estrogens are able to counteract the negative effects of RGZ on bone. Our data, yet preliminary, suggest the possibility to try to prevent the negative effects of TZD on bone, using steroid receptor modulators, such as plant-derived phytoestrogens, which lack evident adverse effects.

Membrane cholesterol as a mediator of the neuroprotective effects of estrogens.

Alzheimer's disease (AD), the most common neurodegenerative disease associated with aging, is still an incurable condition. Although in vitro evidence strongly indicates that estrogens exert neurotrophic and neuroprotective effects, the role of this class of hormones in the treatment of AD is still a debated issue. In 2000 a new gene, named seladin-1 (for SELective Alzheimer's Disease INdicator-1), was identified and found to be down regulated in vulnerable brain regions in AD. Seladin-1 was considered a novel neuroprotective factor, because of its anti-apoptotic activity. Subsequently, it was demonstrated that seladin-1 has also enzymatic activity [3-ß-hydroxysterol delta-24-reductase, (DHCR24)], which catalyzes the synthesis of cholesterol from desmosterol. The amount of membrane cholesterol may play an important role both in protecting neuronal cells against toxic insults and in inhibiting the production of ß-amyloid. We demonstrated that seladin-1 overexpression increases the amount of membrane cholesterol and induces resistance against ß-amyloid aggregates in neuroblastoma cells, whereas a specific inhibitor of DHCR24 increased cell vulnerability. We also hypothesized that seladin-1 might be a mediator of the neuroprotective effects of estrogens. We first demonstrated that, in human fetal neuroepithelial cells (FNC), 17ß-estradiol, raloxifene, and tamoxifen exert protective effects against ß-amyloid toxicity and oxidative stress. In addition, these molecules significantly increased the expression of seladin-1 and the amount of cell cholesterol. Then, we showed that, upon seladin-1 silencing, the protective effects of estrogens were abolished, thus indicating this factor as a fundamental mediator of estrogen-mediated neuroprotection, at least in FNC cells. Furthermore, we detected the presence of functionally active half-palindromic estrogen responsive elements upstream the coding region of the seladin-1 gene. Overall, our results indicate that seladin-1 may be viewed as a multi-faceted protein, which conjugates both the neuroprotective properties of estrogens and the important functions of cholesterol in maintaining brain homeostasis. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain.

In vivo effects of rosiglitazone in a human neuroblastoma xenograft.

BACKGROUND: Neuroblastoma (NB) is the most common extra-cranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. There is in vitro evidence that the peroxisome proliferator-activated receptor gamma (PPARgamma) might be a target for pharmacological intervention in NB. We have previously demonstrated that the PPARgamma agonist rosiglitazone (RGZ) exerts strong anti-tumoural effects in the human NB cell line, SK-N-AS. The aim of this study was to evaluate whether RGZ maintains its anti-tumoural effects against SK-N-AS NB cells in vivo. METHODS AND RESULTS: For this purpose, tumour cells were subcutaneously implanted in nude mice, and RGZ (150 mg kg(-1)) was administered by gavage daily for 4 weeks. At the end of treatment, a significant tumour weight inhibition (70%) was observed in RGZ-treated mice compared with control mice. The inhibition of tumour growth was supported by a strong anti-angiogenic activity, as assessed by CD-31 immunostaining in tumour samples. The number of apoptotic cells, as determined by cleaved caspase-3 immunostaining, seemed lower in RGZ-treated animals at the end of the treatment period than in control mice, likely because of the large tumour size observed in the latter group. CONCLUSIONS: To our knowledge, this is the first demonstration that RGZ effectively inhibits tumour growth in a human NB xenograft and our results suggest that PPARgamma agonists may have a role in anti-tumoural strategies against NB.

Sphingosine 1-phosphate induces differentiation of adipose tissue-derived mesenchymal stem cells towards smooth muscle cells.

Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid which regulates multiple biological parameters in a number of cell types, including stem cells. Here we report, for the first time, that S1P dose-dependently stimulates differentiation of adipose tissue-derived mesenchymal stem cells (ASMC) towards smooth muscle cells. Indeed, S1P not only induced the expression of smooth muscle cell-specific proteins such as alpha-smooth muscle actin (alpha SMA) and transgelin, but also profoundly affected ASMC morphology by enhancing cytoskeletal F-actin assembly, which incorporated alpha SMA. More importantly, S1P challenge was responsible for the functional appearance of Ca(2+) currents, characteristic of differentiated excitable cells such as smooth muscle cells. By employing various agonists and antagonists to inhibit S1P receptor subtypes, S1P(2) turned out to be critical for the pro-differentiating effect of S1P, while S1P(3) appeared to play a secondary role. This study individuates an important role of S1P in AMSC which can be exploited to favour vascular regeneration.

Gemini surfactant based carriers in gene and drug delivery.

Lipid-based drug carriers, such as liposomes or drug/lipid complexes, have been extensively investigated in a large number of therapeutic protocols such as gene therapy, drug delivery, drug targeting and antibacterial treatments, in preclinical and clinical trials. Many formulations composed of natural and/or synthetic amphiphiles have been studied. Many synthetic lipids and surfactants have been designed and tested in order to improve liposomes and lipid complexes performances, such as fusion with cellular membrane, cellular uptake, target selectivity, transfection efficiency, low toxicity. Among these, gemini surfactants have been shown to be highly effective in delivering genetic material to cells, and also have been shown promising as synthetic additives in liposome formulations for drug delivery. The encouraging results obtained in gene therapy have given impulse to chemist creativity: an extensive selection of pH sensitive, sugar-, aminoacid- , and peptide-based gemini surfactants have been developed, many of which have shown good biological features. This review focuses on recent progress in gemini surfactant based formulations and their applications in different therapeutic protocols.

Intermittent high glucose concentrations reduce neuronal precursor survival by altering the IGF system: the involvement of the neuroprotective factor DHCR24 (Seladin-1).

The exposure of neurons to high glucose concentrations is considered a determinant of diabetic neuropathy, whereas members of the IGF system are neurotropic factors. Here, we investigated the effects of constant and intermittent high glucose concentrations on IGF1 and IGF-binding proteins (IGFBPs) in human neuroblast long-term cell cultures fetal neuroepithelial cells (FNC). These cells express the IGF1 receptor, and express and release in the culture medium IGFBP2, IGFBP4, and IGF1. The release of IGF1 was significantly increased by 17beta-estradiol (10 nM). IGF1 (100 nM) treatment determined a significant increase of IGFBP2 and a decrease of IGFBP4 release. In addition, IGF1 (1-100 nM) stimulated FNC cell proliferation in a dose-dependent manner. We hypothesized that this effect may be, at least partially, due to IGF1-induced up-regulation of the expression of the Alzheimer's disease related gene SELADIN-1 (now known as DHCR24 ), which acts as a pro-survival factor for neuronal cells. Conversely, the exposure to intermittent (20/10 mM), but not stable (20 mM), high glucose concentrations decreased the release of IGF1 and IGFBP2 in the culture medium and inhibited FNC growth by inducing apoptosis. The latter was prevented by the addition of IGF1 to the culture medium. Furthermore, high glucose concentrations reduced the expression of DHCR24. In conclusion, our results indicate for the first time that intermittent high glucose concentrations, similar to those observed in poorly controlled diabetic patients, may contribute to the development of diabetic neuropathy by interfering with the tropic effects exerted by the IGF system, and suggest the involvement of the neuroprotective factor DHCR24.