From orphan to oncogene: The role of GPR35 in cancer and immune modulation.

G protein-coupled receptors (GPCRs) are well-studied and the most traceable cell surface receptors for drug discovery. One of the intriguing members of this family is G protein-coupled receptors 35 (GPR35), which belongs to the class A rhodopsin-like family of GPCRs identified over two decades ago. GPR35 presents interesting features such as ubiquitous expression and distinct isoforms. Moreover, functional and genome-wide association studies on its widespread expression have linked GPR35 with pathophysiological disease progression. Various pieces of evidence have been accumulated regarding the independent or endogenous ligand-dependent role of GPR35 in cancer progression and metastasis. In the current scenario, the relationship of this versatile receptor and its putative endogenous ligands for the activation of oncogenic signal transduction pathways at the cellular level is an active area of research. These intriguing features offered by GPR35 make it an oncological target, justifying its uniqueness at the physiological and pathophysiological levels concerning other GPCRs. For pharmacologically targeting receptor-induced signaling, few potential competitive antagonists have been discovered that offer high selectivity at a human level. In addition to its fascinating features, targeting GPR35 at rodent and human orthologue levels is distinct, thus contributing to the sub-species selectivity. Strategies to modulate these issues will help us understand and truly target GPR35 at the therapeutic level. In this article, we have provided prospects on each topic mentioned above and suggestions to overcome the challenges. This review discusses the molecular mechanism and signal transduction pathways activated by endogenous ligands or spontaneous auto-activation of GPR35 that contributes towards disease progression. Furthermore, we have highlighted the GPR35 structure, ubiquitous expression, its role in immunomodulation, and at the pathophysiological level, especially in cancer, indicating its status as a versatile receptor. Subsequently, we discussed the various proposed ligands and their mechanism of interaction with GPR35. Additionally, we have summarized the GPR35 antagonist that provides insights into the opportunities for therapeutically targeting this receptor.

Copper metabolism and cuproptosis in human malignancies: Unraveling the complex interplay for therapeutic insights.

Copper, a vital trace element, orchestrates diverse cellular processes ranging from energy production to antioxidant defense and angiogenesis. Copper metabolism and cuproptosis are closely linked in the context of human diseases, with a particular focus on cancer. Cuproptosis refers to a specific type of copper-mediated cell death or copper toxicity triggered by disruptions in copper metabolism within the cells. This phenomenon encompasses a spectrum of mechanisms, such as oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, and perturbations in metal ion equilibrium. Mechanistically, cuproptosis is driven by copper binding to the lipoylated enzymes within the tricarboxylic acid (TCA) cycle. This interaction participates in protein aggregation and proteotoxic stress, ultimately culminating in cell death. Targeting copper metabolism and its associated pathways in cancer cells hold therapeutic potential by selectively targeting and eliminating cancerous cells. Strategies to modulate copper levels, enhance copper excretion, or interfere with cuproptotic pathways are being explored to identify novel therapeutic targets for cancer therapy and improve patient outcomes. Understanding the relationship between cuproptosis and copper metabolism in human malignancies remains an active area of research. This review provides a comprehensive overview of the association among copper metabolism, copper homeostasis, and carcinogenesis, explicitly emphasizing the cuproptosis mechanism and its implications for cancer pathogenesis. Additionally, we emphasize the therapeutic aspects of targeting copper and cuproptosis for cancer treatment.

Hydroxychloroquine interaction with phosphoinositide 3-kinase modulates prostate cancer growth in bone microenvironment: In vitro and molecular dynamics based approach.

Patients with advanced prostate cancer (PCa) are more likely to develop bone metastases. Tumor cells thrive in the bone microenvironment, interacting with osteoblasts and osteoclasts. Given the PI3K/AKT pathway's metastatic potential and signal integration's ability to modulate cell fates in PCa development, drugs targeting this system have great therapeutic promise. Hydroxychloroquine (HCQ) is an anti-malarial medication commonly used to treat clinical conditions such as rheumatology and infectious disorders. We explored the anti-neoplastic effect of HCQ on PC3 and C4-2B cell lines in the bone microenvironment. Interestingly, HCQ treatment substantially decreases the viability, proliferation, and migration potential of PCa cells in the bone microenvironment. HCQ induces apoptosis and cell cycle arrest, even in the presence of osteoblast-secreted factors. Mechanistically, HCQ inhibited the activity of the PI3K/AKT signaling pathway, which ultimately regulates the proliferation and migration of PCa cells in the bone. The binding energy for docking HCQ with PI3K was -6.7 kcal/mol, and the complex was stabilized by hydrogen bonds, hydrophobic forces, and van der Waals forces. Molecular simulations further validated the structural integrity of the HCQ-PI3K complex without altering PI3K's secondary structure. Our findings underscore the efficacy of HCQ as a potential therapeutic agent in treating PCa.

α-lipoic acid modulates prostate cancer cell growth and bone cell differentiation.

Prostate cancer (PCa) progression leads to bone modulation in approximately 70% of affected men. A nutraceutical, namely, α-lipoic acid (α-LA), is known for its potent anti-cancer properties towards various cancers and has been implicated in treating and promoting bone health. Our study aimed to explore the molecular mechanism behind the role of α-LA as therapeutics in preventing PCa and its associated bone modulation. Notably, α-LA treatment significantly reduced the cell viability, migration, and invasion of PCa cell lines in a dose-dependent manner. In addition, α-LA supplementation dramatically increased reactive oxygen species (ROS) levels and HIF-1α expression, which started the downstream molecular cascade and activated JNK/caspase-3 signaling pathway. Flow cytometry data revealed the arrest of the cell cycle in the S-phase, which has led to apoptosis of PCa cells. Furthermore, the results of ALP (Alkaline phosphatase) and TRAP (tartrate-resistant acid phosphatase) staining signifies that α-LA supplementation diminished the PCa-mediated differentiation of osteoblasts and osteoclasts, respectively, in the MC3T3-E1 and bone marrow macrophages (BMMs) cells. In summary, α-LA supplementation enhanced cellular apoptosis via increased ROS levels, HIF-1α expression, and JNK/caspase-3 signaling pathway in advanced human PCa cell lines. Also, the treatment of α-LA improved bone health by reducing PCa-mediated bone cell modulation.

Implication of Caffeic Acid for the Prevention and Treatment of Alzheimer's Disease: Understanding the Binding with Human Transferrin Using In Silico and In Vitro Approaches.

In present times, a switch from chemical molecules towards natural products is taking place, and the latter is being increasingly explored in the management of diseases due to their broad range of therapeutic potential. Consumption of coffee is thought to reduce Alzheimer's disease (AD); however, the mechanism is still unexplored. Primarily, it is thought that components of coffee are the key players in making it a neuroprotectant. Caffeic acid (CA) is found in high quantities in coffee; thus, it is being increasingly explored to decipher its neuroprotection by various mechanisms. Iron is a toxic element in a free form capable of causing oxidative damage and ultimately contributing to the pathogenesis of AD. Thus, maintaining the proper iron levels is vital and human transferrin (Htf), a glycoprotein, is a key player in this aspect. In this work, we explored the binding mechanism of CA with Htf at the atomistic level, employing molecular docking and extensive molecular dynamics simulation (MD) approaches coupled with spectroscopic techniques in a bid to decipher the mode of interaction of CA with Htf. Molecular docking results demonstrated a strong binding affinity between CA and Htf. Furthermore, MD study highlighted the Htf-CA complex's stability and the ligand's minimal impact on Htf's overall structure. In silico approaches were further backed up by experimental approaches. Strong binding of CA with Htf was ascertained by UV-visible and fluorescence spectroscopy observations. Together, the study provides a comprehensive understanding of the Htf-CA interaction, adding to the knowledge of the use of CA in the treatment of AD, thereby adding another feather to its already known neuroprotective role.

Linagliptin and Empagliflozin Inhibit Microtubule Affinity Regulatory Kinase 4: Repurposing Anti-Diabetic Drugs in Neurodegenerative Disorders Using In Silico and In Vitro Approaches.

Type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) are significant public health burdens. Many studies have revealed the possibility of common pathophysiology between T2DM and AD. Thus, in recent years, studies deciphering the action mechanism of anti-diabetic drugs with their future use in AD and related pathologies are on high demand. Drug repurposing is a safe and effective approach owing to its low cost and time-saving attributes. Microtubule affinity regulating kinase 4 (MARK4) is a druggable target for various diseases and is found to be linked with AD and diabetes mellitus. MARK4 plays a vital role in energy metabolism and regulation and thus serves as an irrefutable target to treat T2DM. The present study was intended to identify the potent MARK4 inhibitors among FDA-approved anti-diabetic drugs. We performed structure-based virtual screening of FDA-approved drugs to identify the top hits against MARK4. We identified five FDA-approved drugs having an appreciable affinity and specificity toward the binding pocket of MARK4. Among these identified hits, two drugs, linagliptin, and empagliflozin, favorably bind to the MARK4 binding pocket, interacting with its critical residues and thus subjected to detailed analysis. All-atom detailed molecular dynamics (MD) simulations revealed the dynamics of binding of linagliptin and empagliflozin with MARK4. Kinase assay showed significant inhibition of MARK4 kinase activity in the presence of these drugs, implying them as potent MARK4 inhibitors. In conclusion, linagliptin and empagliflozin may be promising MARK4 inhibitors, which can further be exploited as potential lead molecules against MARK4-directed neurodegenerative diseases.

Block-based spectral image reconstruction for compressive spectral imaging using smoothness on graphs.

A novel reconstruction method for compressive spectral imaging is designed by assuming that the spectral image of interest is sufficiently smooth on a collection of graphs. Since the graphs are not known in advance, we propose to infer them from a panchromatic image using a state-of-the-art graph learning method. Our approach leads to solutions with closed-form that can be found efficiently by solving multiple sparse systems of linear equations in parallel. Extensive simulations and an experimental demonstration show the merits of our method in comparison with traditional methods based on sparsity and total variation and more recent methods based on low-rank minimization and deep-based plug-and-play priors. Our approach may be instrumental in designing efficient methods based on deep neural networks and covariance estimation.

Insight into the In Vitro Antiglycation and In Vivo Antidiabetic Effects of Thiamine: Implications of Vitamin B1 in Controlling Diabetes.

Hyperglycemia is considered to be a driving factor for advanced glycated end products (AGEs) formation. Inhibition of this process plays a vital role in reducing the problems of diabetes. This study aimed to explore the in vitro antiglycation and in vivo antidiabetic effect of thiamine. Human serum albumin (HSA) was used as a model protein to delineate the antiglycation potential of thiamine. Fructosamine levels were low in the presence of thiamine, implying the inhibition of early stages of glycation by thiamine. Furthermore, HSA-glucose assays depict the inhibition of post-Amadori products by thiamine. CD spectroscopy suggested fewer alterations in the secondary structure in the presence of thiamine. It was found that the administration of thiamine to diabetic rats leads to an increase in hexokinase activity and increased insulin secretion coupled with glycolysis utilization of glucose. Moreover, the activity of glucose-6-phosphatase and fructose- 1-6-phosphatase (increased in the liver and kidney of diabetic rats) is restored to near-normal levels upon thiamine administration. Histopathological studies also advocated that thiamine supplementation decreases the pathological abnormalities associated with diabetes in the liver and kidney. This study provides a rationale that vitamins can be implicated in controlling diabetes.

Mechanistic insight into glycation inhibition of human serum albumin by vitamin B9: Multispectroscopic and molecular docking approach.

Advanced glycation end products (AGEs) formation produces free radicals that play a role in diabetes mellitus; hence inhibition of glycation plays a part in minimizing diabetes-related complications. This study was intended to examine the AGEs formation of HSA upon prolonged incubation of 28 days at 37 °C and further investigate the antiglycation potential of folic acid (FA). FA shows a significant binding affinity to the HSA with a binding constant (K) of 104 M-1. The evaluation of enthalpy change (∆H0) and entropy change (∆So) implied that the HSA-FA complex is stabilized primarily by hydrophobic interaction and hydrogen bonding. Molecular docking analysis depicted that FA binds with HSA in subdomain IIA (Sudlow's site I) with a binding energy of -7.0 kcal mol-1. AGEs were characterized by free lysine and thiol groups, carbonyl content, and AGEs specific fluorescence. The presence of FA significantly decreased glycation from free lysine and carbonyl content estimation and AGEs specific fluorescence. Multispectroscopic observations and molecular docking and examination of various biomarkers demonstrate the antiglycation activity of FA and its capacity to prevent disease progression in diabetes.

Anti-diabetic study of vitamin B6 on hyperglycaemia induced protein carbonylation, DNA damage and ROS production in alloxan induced diabetic rats.

Oxidative stress performs an imperative role in the onset and progression of diabetes. Metabolic enzymes and cellular organelles are detrimental to increased levels of free radicals and the subsequent reduction in anti-oxidant defence. Pyridoxamine (vitamin B6) is an indispensible nutrient for humans and is considered to be an important food additive too. The aim of this research was to examine the effect of vitamin B6 in a diabetic environment. This study reports the effects of pyridoxamine supplementation in alloxan induced diabetic rats. Diabetes was induced by the single intra peritoneal dose of alloxan (120 mg per kg body weight). Diabetic rats were treated with pyridoxamine (10 and 15 mg per kg body weight) and compared with a control set of diabetic rats without supplementation. Pyridoxamine treatment showed dose dependent recovery in all parameters. A notable decline in oxidative stress parameters and ROS production with reductions in fasting blood glucose levels along with normal patterns of the glucose tolerance test has been reported here. Histological studies reveal damage recovery in the liver as well as kidney tissues. A notable amount of recovery was observed in cellular DNA distortion and damage. It is thus advocated that pyridoxamine might help in reducing problems associated with diabetes. A probable mechanism pertaining to the action of pyridoxamine is proposed as well.

Study of pyridoxamine against glycation and reactive oxygen species production in human serum albumin as model protein: An in vitro & ex vivo approach.

Hyperglycaemia is considered to be a driving factor for advanced glycated end products (AGEs). Inhibiting the process of glycation play an important role in reducing the diabetes related complications. We have explored the glucose mediated glycation and antiglycation activity of pyridoxamine using human serum albumin (HSA). Protein was incubated with glucose for 28 days at physiological temperature to achieve glycation. Antiglycation activity was assessed by the estimation of carbonyl content, free lysine and AGE specific fluorescence. Molecular docking was used to study the interaction of pyridoxamine with HSA and to get a detailed understanding of binding sites and binding energy. Glycation was reduced by pyridoxamine to commendable levels which was evident by the quantification of free lysine and carbonyl content. Pyridoxamine treatment also prevented the loss in secondary structure induced by glycation. It has also emerged as the quencher of reactive oxygen species which lead to the protection of DNA from oxidative damage. Pyridoxamine was found to be located at subdomain IIA of HSA with binding energy of -5.6 kcal/mol. These results are high points in the antiglycation activity of pyridoxamine. Its antioxidant nature and antiglycation activity are proof of its potential in preventing disease progression in diabetes.

Therapeutic effect of vitamin B3 on hyperglycemia, oxidative stress and DNA damage in alloxan induced diabetic rat model.

Evidences in the form of experimental analysis and scientific investigations suggest that oxidative stress embody an imperative role in the onset and progression of type-2 diabetes mellitus (T2DM). Aberrant elevation in levels of free radicals, as observed upon disease onset, and the subsequent reduction in anti-oxidant defenses is pernicious to metabolic enzymes and cellular organelles. Niacin (Vitamin B3) is an essential nutrient for humans and is considered to be an important food additive for animals too. This research was conducted to examine the effect of nutraceutical antioxidant on diabetic environment. This important member of Vitamin B complex is a forerunner of nicotinamide adenine dinucleotide (NAD) and also nicotinamide adenine dinucleotide phosphate (NADP), both of them serving as coenzymes for several metabolic enzymes. This study reports the effects of niacin supplementation in alloxan induced diabetic rats divided into five groups. Diabetes induced rats were further treated with niacin at two doses (10 and 15 mg /kg body weight) and compared with a control set of diabetes without treatment. Niacin treatment showed recovery in almost all parameters in a dose reliant pattern. A notable decline in oxidative stress parameters with reductions in fasting blood glucose levels was observed. Histological studies reveal damage recovery in the liver as well as kidney tissues. A notable amount of recovery was observed in cellular DNA damage. As a deduction, it is advocated that dietary niacin supplementation might help in reducing problems associated with diabetes. A probable mechanism pertaining to the action of niacin is proposed as well.

Inhibitory effect of vitamin B3 against glycation and reactive oxygen species production in HSA: An in vitro approach.

Hyperglycaemia is a key factor for the formation of advanced glycated endproducts (AGEs). Inhibition of glycation may play key role in minimizing the diabetes related complications. We have tried to explore the glucose and methyl glyoxal mediated glycation and antiglycation activity of niacin using human serum albumin as model protein. Protein was incubated with glucose for 28 days at physiological temperature to achieve glycation. Antiglycation activity was evaluated by assessing free lysine, carbonyl content, AGE specific fluorescence. Molecular docking and isothermal titration calorimetry was deployed to study the interaction of niacin with HSA and get a detailed insight of binding site and thermodynamics of interaction. Niacin reduced the glycation significantly which was evident from the estimation of free lysine and carbonyl content. Niacin binds with HSA in a spontaneous manner with the binding constant in the range of 104 M-1. Niacin also prevented the loss in secondary structure induced by glycation. Reactive oxygen species were also effectively quenched by niacin leading to protection from DNA damage. Niacin was found to be located at Sudlow's site I with binding energy of 5.3 kcal/mol. These results clearly highlight the antiglycation activity of niacin and its potential in preventing disease progression in diabetes.

Interaction of capsaicin with calf thymus DNA: A multi-spectroscopic and molecular modelling study.

Studying the mode of interaction between small molecules and DNA has received much attention in recent years, as many drugs have been reported to directly interact with DNA thereby regulating the expression of many genes. Capsaicin is a capsaiciniods family phytocompound having many therapeutic applications including diabetic neuropathy, rheumatoid arthritis, prevention of DNA strand breaks and chromosomal aberrations. In this study, we have investigated the interaction of capsaicin with calf thymus DNA using a number of biophysical techniques to get an insight and better understanding of the interaction mechanism. Analysis of UV-vis absorbance spectra and fluorescence spectra indicates the formation of complex between capsaicin and Ct-DNA. Thermodynamic parameters ΔG, ΔH, and ΔS measurements were taken at different temperatures indicated that hydrogen bonding and van der Waal's forces played major role in the binding process. Additional experiments such as iodide quenching, CD spectroscopy suggested that capsaicin possibly binds to the minor groove of the Ct-DNA. These observations were further confirmed by DNA melting studies, viscosity measurements. Molecular docking provided detailed computational interaction of capsaicin with Ct-DNA which proved that capsaicin binds to Ct-DNA at minor groove. Computational molecular docking also revealed the exact sites and groups to which capsaicin interacted.

The 'best fit' endotracheal tube in children --comparison of four formulae.

BACKGROUND: Uncuffed endotracheal tubes are still being recommended by most pediatric of anesthetists at our Institutes. Different algorithms and formulae have been proposed to choose the best-fitting size of the tracheal tube. The most widely accepted is related to the age of the child [inner diameter [ID] in mm = (age in yr/4) + 4; the second is a body, length-related formula (ID in mm = 2 + height in cm/30); the third, a multivariate formula (ID in mm = 2.44 + age in yr x 0.1 + height in cm x 0.02 + weight in kg x 0.016]5; the fourth, the width of the 5th fingernail is used for ID prediction of the ETT (ID in mm = maximum width of the 5th fingernail). The primary endpoint of this prospective study was to compare the size of the 'best fit' tracheal tube with the size predicted using each of the above mentioned formulae. PATIENTS AND METHODS: With Institutional Ethics Committee approval and parental consent, 27 boys, 23 girls, ASA I-III, 2-10 years, scheduled for different surgical procedures requiring general anesthesia and endotracheal intubation, were enrolled in the study. The size of 'best fit' endotracheal tubes in those children were compared. The internal diameter considered the 'best fit' by the attending pediatric anesthesiologist was compared to age-based, length-based, multivariate-based and 5th fingernail width-based formulae. For all tests, P < 0.05 was considered to be statistically significant. RESULTS: The mean (SD) IDs for the 'best fit', age-based, length-based, multivariate and 5th fingernail techniques were 5.31 (0.691), 5.54 (0.622), 5.82 (0.572), 5.71 (0.67) and 5.43 (0.821) mm, respectively. CONCLUSIONS: The age-based and 5th fingernail width-based predictions of ETT size are more accurate than length-based and multivariate-based formulae in terms of mean value and case matching.

Antioxidant capacity of 3D human skin EpiDerm model: effects of skin moisturizers.

The objective of this study was to determine the effects of skin moisturizers on total antioxidant capacity (TAC) of human skin using EpiDerm model. Three different skin moisturizers containing antioxidant ingredients (samples 1-3) or aloe vera extract were topically applied to EpiDerm units and incubated for 2 and 24 h to determine acute and longer-term effects of applied samples on TAC and glutathione peroxidase activity in medium and/or homogenized skin tissues. Total antioxidant capacity in medium and skin homogenates was enhanced (P < 0.0001) by gel containing antioxidant ingredients (sample 2) after 2 and 24 h of incubation. Total antioxidant capacity in medium was also enhanced (P < 0.001) by cream containing antioxidant ingredients (sample 3) after 24 h of incubation. Overall, TAC in medium was greater (P < 0.02) after 24 h than 2 h of incubation. Skin moisturizer cream with high antioxidant levels determined by using oxygen radical absorbance capacity testing (sample 1) and aloe vera extract did not affect TAC. Glutathione peroxidase activity was enhanced (P < 0.0001) in medium and skin homogenates by sample 2 but not by any other sample. These data demonstrate high potential of gel and cream (samples 2 and 3) containing antioxidant ingredients in enhancing antioxidant capacity of EpiDerm which will likely contribute to overall skin health. Results of this experiment will help to better understand mechanisms of effects of skin moisturizers containing antioxidant ingredients on skin function at the tissue level and to establish effective strategies for skin protection and clinical treatments of skin disorders and possibly healing wounds.

Melatonin premedication and the induction dose of propofol.

BACKGROUND AND OBJECTIVES: Melatonin (N-acetyl-5-methoxytryptamine) is the main indolamine secreted by the pineal gland. Many studies showed that premedication with melatonin is associated with preoperative anxiolysis and sedation without impairment of cognitive and psychomotor skills and without prolonging recovery. We hypothesized that melatonin decreases the amount of propofol required to produce an adequate depth of hypnosis at induction time. METHODS: After approval from the research committee of the anaesthesia department, informed written consent was taken from 45 adult patients undergoing different surgical procedures. They were allocated randomly into three groups according to the premedication. At 100 min preoperatively, premedication was given in the form of oral melatonin 3 mg (M3 group), oral melatonin 5 mg (M5 group) or no premedication (P group). After preoxygenation an anaesthesiologist who was blinded to the premedication injected propofol 10 mg over 5 s every 15 s until the bispectral index (BIS) score fell to 45. The total dose of propofol required to achieve a BIS score of 45 was recorded. Response to verbal commands and eyelash reflex was evaluated and correlated to the BIS score and propofol dosage. When a BIS score of 45 was reached, tracheal intubation was accomplished after administration of a narcotic and muscle relaxant. RESULTS: The mean (standard devitation (SD)) induction dose of propofol producing a BIS score of 45 was 134 (25) mg in the placebo group vs. 115 (19.5) and 114 (20.9) mg in the M3 and M5 groups, respectively (P < 0.05). The propofol dose required to achieve loss of eyelash reflex and loss of response to verbal commands was more in the placebo group. Anxiety score as assessed by visual analogue scale (VAS) scored more in the placebo group than both melatonin groups. Time spent in the recovery room did not differ between the three groups. CONCLUSION: Melatonin premedication, in an oral dose of either 3 or 5 mg, reduced the required dose of propofol to achieve a BIS score of 45, reflecting a sufficient level of hypnosis for tracheal intubation without prolongation of postoperative recovery room stay.

Effect of topical tranexamic acid in open heart surgery.

BACKGROUND AND OBJECTIVE: Cardiopulmonary bypass is known to induce postoperative coagulopathy including fibrinolysis. We have evaluated the effect of the topical use of tranexamic acid in the pericardial cavity on postoperative bleeding following open heart surgery. METHODS: One hundred patients, scheduled for elective open heart surgery, were included in this double-blind, prospective, randomized, controlled study. They were allocated to a treatment group (Group I), or placebo group (Group II). Patients with coagulopathies, renal failure, re-do surgery, or recent anti-platelet treatment were excluded. In Group I, tranexamic acid (2 g in 100 mL of saline solution) was poured into the pericardial cavity before sternal closure. Placebo patients received 100 mL of saline. Postoperative blood loss, need for transfusion of blood products and the rate of re-sternotomy for bleeding were documented. RESULTS: During the first postoperative 24 h, cumulative blood loss was significantly higher in Group II compared to Group I (1208 +/- 121 mL vs. 733 +/- 93 mL, respectively) (P < 0.001). More blood transfusions were administered to Group II patients (4.54 +/- 1.4 units) as compared to Group I patients (2.64 +/- 1.5 units) (P < 0.01). CONCLUSION: Topical application of tranexamic acid in patients undergoing primary open heart surgery led to a significant reduction of both postoperative mediastinal bleeding, and rate of re-exploration for haemostasis.

Effects of basic fibroblast growth factor (FGF-2) on proliferation of human skin fibroblasts in type II diabetes mellitus.

Skin fibroblasts from patients with diabetes mellitus display abnormalities in cell proliferation. The use of exogenous growth factors on diabetic wounds has been found to stimulate fibroblast proliferation and facilitate wound healing. However, the results of application of FGF-2 alone to diabetic wounds in clinical trials have been disappointing. The objective of this experiment was to study the effects of FGF-2 and media supplements on in vitro proliferation of skin fibroblasts from patients with type II diabetes and nondiabetic controls, and to evaluate the association between fibroblast proliferation and cAMP production. Fibroblast cell lines (n = 5 from diabetic and n = 5 from control individuals) were cultured in DMEM + 20% FBS for 7 days. Cells were then counted, plated into 24-well plates at a concentration of 2 x 10(4) cells/well and incubated for 24 h in DMEM with serum. The next day, medium was changed to serum-free DMEM alone or DMEM with supplements (albumin, transferrin, insulin and hydrocortisone). Cells were cultured in the presence or absence of varying doses of FGF-2 (0, 0.3, 1, 3, 10 and 30 ng/ml) for 72 hrs then counted and medium was collected for cAMP radioimmunoassay. The doubling time for cell number tended to be greater (p < 0.2) for diabetic fibroblasts than for control fibroblasts. The addition of supplements to the medium reduced (p < 0.05) the doubling time for both fibroblast types. FGF-2 stimulated (p < 0.05) proliferation of diabetic fibroblasts only in medium containing supplements. In contrast, FGF-2 stimulated proliferation of control fibroblasts in medium with or without supplements. The maximal effects of FGF-2 on fibroblast proliferation were greater (p < 0.02) in medium with supplements than in medium without supplements. The K(D) of FGF-2 for fibroblast proliferation was greater (p < 0.06) for diabetic than for control fibroblasts, and lower (p < 0.02) for medium with supplements than for medium without supplements. Fibroblasts from patients with diabetes mellitus produced more (p < 0.05) cAMP than control fibroblasts. These results demonstrate that FGF-2 requires the presence of supplements to enhance proliferation of fibroblasts from patients with type II diabetes mellitus. In addition, fibroblasts from diabetic patients showed a greater K(D) for FGF-2 in terms of cell proliferation. These data suggest a defective FGF receptor or down-regulation of the FGF receptor-mediated cascade that leads to cell proliferation. Identifying methods of reducing the K(D) of FGF-2 in stimulating the proliferation of diabetic fibroblasts may improve the clinical response of diabetic wounds to FGF-2.

Cell-to-cell communication and expression of gap junctional proteins in human diabetic and nondiabetic skin fibroblasts: effects of basic fibroblast growth factor.

Wound healing involves the interactions of many cell types, and is controlled in part by growth factors. Intercellular communication mediated by gap junctions is considered to play an important role in the coordination of cellular metabolism duringthe growth and development of tissues and organs. Basic fibroblast growth factor (bFGF), known to be important in wound healing, has been found to increase Cx43 expression and intercellular communication in endothelial cells and cardiac fibroblasts. It has been proposed that an increased coupling is necessary for the coordination of these cells in wound healing and angiogenesis, and that one of the actions of bFGF is to modulate intercellular communication. The aim of our study was to evaluate the effects of bFGF on gap junctional intercellular communication (GJIC) in vitro, and the presence of gap junctional proteins connexin (Cx) 26, Cx32, and Cx43 in fibroblasts of diabetic and nondiabetic individuals. Fibroblast cell lines (n = 10) were cultured for 3 d in serum-free media with or without bFGF (3 ng/mL). Cells were evaluated for the rate of GJIC by using laser cytometry, and for the presence of Cx26, Cx32, and Cx43 by immunohistochemical and Western analyses. All cell types communicated via contact-dependent mechanisms. The rate of GJIC was greater (p < 0.01) for diabetic than for nondiabetic fibroblasts (4.1 +/- 0.01 vs 3.3 +/- 0.01%/min). bFGF increased (p < 0.01) the rate of GJIC for diabetic (4.9 +/- 0.01 vs 4.1 +/- 0.01%) and nondiabetic (4.1 +/- 0.01 vs 3.3 +/- 0.01%) fibroblasts. Immunohistochemistry identified Cx26 in the cytoplasm, Cx32 was not detected, and Cx43 was present on the cellular borders in all cultures. Image analysis of immunofluorescent staining demonstrated that bFGF increased (p < 0.05) Cx43 expression in diabetic and nondiabetic fibroblasts. Western immunoblot analysis revealed bands at 43-46 kD that were similar in volume for diabetic and nondiabetic fibroblasts. Thus, gap junctions involving Cx43 and GJIC among fibroblasts appear to be targets for bFGF. Fibroblasts of diabetic individuals appear to have an increased rate of cell-cell coupling, correlating with a decreased rate of proliferation.