Prevention of postsurgical adhesions with an autocrosslinked hyaluronan derivative gel

BACKGROUND: ACP gel is a new crosslinked derivative of hyaluronic acid (HA) that displays the biocompatibility properties of its original polymer but has a higher viscosity. It has been demonstrated in an animal model that the gel reduces adhesions after gynecological surgery. The aim of the present study was therefore to investigate the efficacy of ACP gel in increasing viscosity for the prevention of adhesions after abdominal surgery. METHODS: The antiadhesive effect of ACP gel was tested in a controlled randomized study using a standardized animal model of abdominal surgery involving the creation of defects in the parietal peritoneum and muscular fascia and cecal abrasion. The animals (100 female New Zealand white rabbits) were randomly allocated into five treatment groups to receive: ACP gel (1, 2, 4, and 6%) on the injured area or no ACP gel (control). The incidence of adhesions and their grade (score 0-11) were blindly evaluated 10 weeks after surgery. RESULTS: The percentages of adhesion-free animals were 60, 84, 90, and 84% in the 1, 2, 4, and 6% ACP gel concentration groups, respectively, versus 15% in the control group (P = 0.001). The mean adhesion scores were 3.00 +/- 0.91, 1.37 +/- 0.75, 0.65 +/- 0.45, and 1.16 +/- 0.64 in the 1, 2, 4, and 6% ACP gel groups, respectively, versus 7.70 +/- 0.83 in the control group (P < 0.001). CONCLUSION: ACP gel prevents postsurgical abdominal adhesions even at a 1% concentration. This finding may be of clinical importance in situations in which large volumes of antiadhesive solution are required.     

Adhesion reduction after knee surgery in a rabbit model by Hyaloglide, a hyaluronan derivative gel

A randomized controlled experimental trial was performed in a rabbit model of surgical adhesions to investigate the anti-adhesive effects of Hyaloglide, a highly viscous hyaluronan derivative absorbable gel after knee surgery. Twenty New Zealand white rabbits were prepared and randomly divided into two groups of 10 animals each. An intra-articular fibro-adhesive scar was created in the right knee joint of the hind paw of each rabbit using a standardized surgical procedure, and Hyaloglide was administered into the joint cavity of the knee at the end of intervention in the animals belonging to the treatment group. No anti-adhesive treatment was applied in the control group. Additionally, immobilization using a Kirschner wire was applied in order to increase the risk of adhesions. Six weeks after surgery the animals were euthanized and after removal of the immobilization system, adhesions were evaluated both macroscopically and histologically. Results of gross observations using a specific adhesion scoring system showed a significant reduction (p<0.01) of both incidence and severity of adhesions in the hyaluronan-treated group compared to the control group. Histologically, adhesions in the treated group were thinner with less collagenic fibers. In conclusion, Hyaloglide may be considered as a promising absorbable barrier for prevention of post-operative fibrotic adhesions after knee surgery.     

棚式黄韧带加玻璃酸钠预防硬膜外瘢痕粘连的实验研究

目的 观察带血运的黄韧带后路搭棚式屏蔽加玻璃酸钠隔离保护对椎板间开窗、椎间盘纤维环损伤后硬膜周围粘连的预防作用.方法 64只成年新西兰大白兔L3-4、L5-6水平左侧椎板开窗1.0×0.5 cm,椎间隙处用限制性环刀和磨钻制造约2×2×0.2 mm纤维环损伤,分为空白对照组(A组)、玻璃酸钠组(B组)、棚式黄韧带组(C组)及棚式黄韧带加玻璃酸钠组(D组)4组.术后2、4、8、12周对硬膜外瘢痕形成及粘连做大体及组织学观察,并用免疫组化法检测相应脊髓中P物质的含量.结果 与空白对照组相比,玻璃酸钠早期可减轻硬膜外瘢痕粘连,但后期瘢痕粘连有所加重,P物质的含量也有相应改变;棚式黄韧带及其合用玻璃酸钠组术后硬膜外瘢痕粘连明显减轻,P物质的含量明显减少,两者之间差异也存在显著意义.结论 棚式黄韧带可减轻硬膜外的瘢痕形成及相应脊髓中的P物质的含量,有助于减少术后腰腿痛;玻璃酸钠术后早期有一定的预防硬膜周围粘连的作用.     

The role of the gastrointestinal microflora in postsurgical adhesion formation--a study in germfree rats.

The elucidation of the pathogenesis of postsurgical adhesion formation is still lacking. In this study experimental adhesion formation was studied in germfree (i.e. void of bacteria) and conventional rats (intestinal flora comprising over 400 species) using a caecal crush model. The germfree rats responded significantly weaker to the same stimuli, forming adhesions in only 20% of the cases as compared to the conventional rats 87.5% (p = 0.0076). The findings indicate that the bowel flora is of importance but not essential for postsurgical adhesion formation in rats.     

聚乳酸凝胶对兔术后腹腔粘连的疗效

目的 探讨聚乳酸凝胶预防腹腔粘连的疗效.方法 将大白兔随机分为实验组和对照组,在全麻下于兔回盲部结肠人工形成创面并切除对应的壁层腹膜建立肠粘连动物模型.实验组创面均匀涂布聚乳酸凝胶,对照组创面不予处理,分别于术后2周和12个月行大体、光镜和电镜观察.结果术后2周实验组粘连分级比对照组低(P＜0.05);术后12个月实验...     

Novel formulation of fibroblast growth factor-2 in a hyaluronan gel accelerates fracture healing in nonhuman primates.

Recent advances in understanding the biology of fracture healing and the availability of specific macromolecules has resulted in the development of novel treatments for injuries to bone. Fibroblast growth factor-2 or basic fibroblast growth factor (4 mg/ml), a potent mitogen, and hyaluronan (20 mg/ml), an extracellular matrix component, were combined into a viscous gel formulation intended for direct, percutaneous injection into fresh fractures. In an experimental primate fracture model, a bilateral 1-mm-gap osteotomy was surgically created in the fibulae of baboons. A single direct administration of this hyaluronan/fibroblast growth factor-2 formulation to the defect site significantly promoted local fracture healing as evidenced by increased callus formation and mechanical strength. Radiographic analysis showed that the callus area was statistically significantly larger at the treated sites than at the untreated sites. Specimens treated with 0.1, 0.25, and 0.75 ml hyaluronan/fibroblast growth factor-2 demonstrated a 48, 50, and 34% greater average load at failure and an 82, 104, and 66% greater energy to failure than the untreated controls, respectively. By histologic analysis, the callus size, periosteal reaction, vascularity, and cellularity were consistently more pronounced in the treated osteotomies than in the untreated controls. These results suggest that hyaluronan/fibroblast growth factor-2 may provide a significant advance in the treatment of fractures.     

Efficacy of adhesion prevention and impact on wound healing of intraperitoneal phospholipids

BACKGROUND: Postoperative peritoneal adhesions are a major complication of abdominal surgery. Adjuvant therapy is needed to prevent adhesion formation and subsequent sequelae. Previously published data proved the efficacy of phospholipids (PL) for this indication; however, additional information on drug safety was still outstanding. The underlying study was designed to investigate the influence of phospholipids on three different types of healing tissue. MATERIALS AND METHODS: A total of 48 Chinchilla rabbits underwent median laparotomy, standardized abrasion of the visceral and parietal peritoneum, jejunal anastomosis, and an electrocautery incision of the liver. The operation was completed by intraperitoneal administration of 10 ml/kg of either normal saline (NaCl) or phospholipids (12%). RESULTS: After 5 (NaCl 691 mm(2) vs PL 192 mm(2)) and 10 days (NaCl 625 mm(2) vs PL 88 mm(2)) the control group presented with significantly larger adhesion areas (P < 0.05). The bursting pressure of the anastomosis on the 5th (NaCl 16.1 kPa vs PL 18.2 kPa) and 10th (NaCl 19.7 kPa vs PL 18.6 kPa) postoperative days showed no statistically significant difference. The tensile strength of the laparotomy wound measured after intervals of 5 (NaCl 8.5 N cm(-1) vs PL 6.8 N cm(-1)) and 10 days (NaCl 23.0 N cm(-1) vs PL 20.2 N cm(-1)) was not statistically different either. The collagen protein ratio of anastomoses, laparotomy wounds, and liver incisions as well as the inflammatory-reparative response of the different tissues was not affected by PL. CONCLUSIONS: These results confirm the efficacy of phospholipids in adhesion prevention. The findings of uncompromised healing of anastomoses, laparotomy wounds, and liver incisions demonstrate the safety of this agent. Further data may qualify phospholipids for a clinical trial.     

New adhesion prevention concept in gynecological surgery.

Postsurgical adhesion formation is a common but significant problem. This is the first clinical evaluation of a new barrier material designed to reduce or eliminate postsurgical adhesions. SprayGel can be delivered laparoscopically or via laparotomy to form a strongly adherent hydrogel film. In this multicenter study, we evaluated the safety and effectiveness of SprayGel absorbable adhesion barrier system in patients undergoing open or laparoscopic myomectomy procedures. Here, we discuss the results of our evaluation conducted at the University of Kiel and Polyclinic of Bordeaux, and assess some of the features of this novel adjunct to prevent formation of postsurgical adhesions.     

The presence of an antibacterial glycoprotein in a spectrum of transitional gel carcinomas.

The mucin lining of the bladder is thought to serve as a primary defense mechanism against bacterial colonization, and has recently been implicated in the urothelial resistance to carcinogenic insult. We have isolated a unique glycoprotein fraction (GP1) of this lining from the normal rabbit bladder which may have a function in preventing bacterial adherence and colonization in the urinary tract. This glycoprotein has been shown to bind to a wide range of uropathic bacteria. The present study examines changes in the bladder's antibacterial defense mechanisms as measured by GP1 expression in the neoplastic state. Using an anti-GP1 serum, immunohistochemical staining was performed on 20 paraffinized and fresh frozen transitional cell carcinomas ranging from low grade, superficial tumors to high grade, invasive tumors. The presence of GP1 was seen throughout the mucosal layer in normal specimens with increased amounts noted towards the mucosal surface. Progressively decreased expression was noted with increasing grades of all transitional carcinoma specimens. Mucosal field changes in GP1 expression were not noted in any of the patients. Intestinal mucosal controls failed to detect the presence of GP1. These studies suggest that the expression of GP1 decreases with tumor dedifferentiation and that bladder tumorogenesis may serve a role in handicapping the bladder's primary antibacterial defense mechanism.     

透明质酸衍生物Seprafilm防粘连薄膜防止肌腱粘连的实验研究

目的观察透明质酸衍生物Seprafilm防粘连薄膜在急性肌腱损伤后防止肌腱粘连的有效性。方法 4月龄中国白兔18只,雌雄各半,体重2.0～2.5kg。于双侧后足第2、3足趾制作屈肌腱损伤模型。根据处理方法不同随机分为4组(n=18),右侧第2趾应用Seprafilm防粘连薄膜包裹肌腱(A组),右侧第3趾应用聚乳酸可吸收防粘连膜包裹损伤段后缝线缝合固定(B组),左侧第2趾将透明质酸钠凝胶涂布于损伤肌腱段的腱周(C组),左侧第3趾不作任何处理作为对照(D组)。术后观察实验动物一般情况,于1、2、4周取材测量远趾间关节活动度,并行大体及组织学观察,对粘连程度分级。结果所有实验动物均存活至实验完成。各时间点A组远趾间关节活动度与B组比较,差异均无统计学意义(P>0.05);除术后1周外均优于C、D组(P<0.05)。大体观察及组织学观察粘连分级一致,术后1周时各组间比较差异均无统计学意义(P>0.05);2、4周时,A组与B组比较差异无统计学意义(P>0.05),但粘连程度较C、D组轻,比较差异均有统计学意义(P<0.05)。结论透明质酸衍生物Seprafilm防粘连薄膜可防止兔急性肌腱损伤后的肌腱粘连,并能改善关节功能。     

Adipocyte-derived serum amyloid A3 and hyaluronan play a role in monocyte recruitment and adhesion

Obesity is characterized by adipocyte hypertrophy and macrophage accumulation in adipose tissue. Monocyte chemoattractant protein-1 (MCP-1) plays a role in macrophage recruitment into adipose tissue. However, other adipocyte-derived factors, e.g., hyaluronan and serum amyloid A (SAA), can facilitate monocyte adhesion and chemotaxis, respectively. The objective was to test the potential involvement of these factors in macrophage recruitment. Differentiated 3T3-L1 adipocytes made hypertrophic by growth in high glucose conditions were used to study SAA and hyaluronan regulation in vitro. Two mouse models of obesity were used to study their expression in vivo. Nuclear factor-kappaB was upregulated and peroxisome proliferator-activated receptor (PPAR)gamma was downregulated in hypertrophic 3T3-L1 cells, with increased expression of SAA3 and increased hyaluronan production. Rosiglitazone, a PPARgamma agonist, reversed these changes. Hypertrophic adipocytes demonstrated overexpression of SAA3 and hyaluronan synthase 2 in vitro and in vivo in diet-induced and genetic obesity. SAA and hyaluronan existed as part of a complex matrix that increased the adhesion and retention of monocytes. This complex, purified by binding to a biotinylated hyaluronan binding protein affinity column, also showed monocyte chemotactic activity, which was dependent on the presence of SAA3 and hyaluronan but independent of MCP-1. We hypothesize that adipocyte hypertrophy leads to increased production of SAA and hyaluronan, which act in concert to recruit and retain monocytes, thereby leading to local inflammation in adipose tissue.     

Urinary hyaluronan as a marker for the presence of residual transitional cell carcinoma of the urinary bladder

OBJECTIVE: The purpose of this report is to evaluate the value of urinary hyaluronan (HA) as a maker of residual transitional cell carcinoma (TCC). PATIENTS AND METHODS: Urine samples were collected from 83 patients hospitalized for transurethral resection (TUR). Patient ages ranged from 36 to 86 years. Samples were taken both before and after surgery. HA analysis was performed using an "ELISA-like" fluorometric assay. RESULTS: Patients were divided into two groups: a control group whose previous diagnosis was negative for tumors (n=22) and another with positive diagnosis for tumors (n=61) which was further sub-divided into with and without residual tumor. After the second procedure 47 individuals did not display residual tumor, whereas 14 (23%) did. The average HA in the control group was 8.3 microg/L pre- and 7.1 post-operatively, hence, no change occurred (p=0.471). In the group with TCC patients, the HA dropped from 885.5 microg/L to 215.3 microg/L with residual tumors and from 234.3 microg/L to 11.2 microg/L for those without residual tumor. Using a cut-off value of 20 microg/L, the sensitivity to detect residual tumor is 92.9% and specificity is 83%. CONCLUSION: HA in addition to being one of the best markers for the initial evaluation of bladder carcinoma can be used to determine the presence of a residual tumor. This is associated with poor prognosis.     

三七凝胶预防椎板切除术后粘连的实验研究

目的:从大体、组织形态学观察分析三七凝胶预防椎板切除术后粘连的有效性和可行性。方法:84只Sprague-Daw ley大鼠(SD大鼠)按单纯随机方法分为4组:三七凝胶组(NG)、单纯三七组(N)、空白对照组(C)、纤维蛋白胶组(FG),每组21只。切除L1-L2右侧椎板,分别在硬膜囊周围涂抹三七凝胶、三七浓缩液、生理盐水、纤维蛋白胶。每组大鼠分别在术后2、4、8周处死。各组在每个时间段各处死7只,其中1个标本作大体观察瘢痕的量、范围、致密程度以及解剖过程中硬膜囊的完整性,其余6个标本作组织切片(HE染色)观察术后硬膜外瘢痕粘连的程度、计算椎管内粘连百分率。结果:术后各个时间段三七凝胶组椎管内预防粘连百分率明显优于单纯三七组、纤维蛋白胶组、空白组(P<0.05或P<0.01)。结论:三七凝胶可以作为一种良好的材料用于预防椎板切除术后硬膜外瘢痕粘连。     

Pathophysiology of intra-abdominal adhesion and abscess formation,and the effect of hyaluronan

BACKGROUND: Intra-abdominal adhesions and abscesses cause significant morbidity and mortality. The formation of fibrin in the abdominal cavity is a common pathophysiological pathway for both. The aim of this review was to investigate the pathophysiology of intra-abdominal adhesions and abscesses, and to explore the possible sites of action of hyaluronan. METHODS: Data were reviewed from the literature using the Medline database. RESULTS: Both surgery and peritonitis disturb the equilibrium between coagulation and fibrinolysis in the abdominal cavity in favour of the coagulation system. Hyaluronan-based agents reduce adhesion formation after surgery. Moreover, hyaluronan solution reduces abscess formation in experimental peritonitis. Possible mechanisms of action include mechanical separation of wound surfaces, improvement of peritoneal healing, modulation of the inflammatory response and enhanced fibrinolysis. CONCLUSION: Diminished fibrin degradation is a common pathway for the formation of adhesions and abscesses. The potential of hyaluronan-based agents to reduce intra-abdominal adhesions and abscesses in abdominal surgery and sepsis is a promising new concept. Elucidating the mechanisms involved and the clinical application of hyaluronan in peritonitis are challenges for future research.     

Evaluation of a respiratory rate monitor in postsurgical patients.

STUDY OBJECTIVE: To evaluate the clinical use of a cardiorespiratory rate monitor in patients receiving epidural opioids following major surgery. DESIGN: For 6 hours during the night following surgery, patients were continuously monitored with a cardiorespiratory rate monitor and a pulse oximeter, as well as by an in-room observer. SETTING: Postoperative surgical ward at a university hospital. PATIENTS: Eight ASA physical status I and II patients ages 30 to 76 years. INTERVENTIONS: Any bradypneic, hypoxemic, bradycardic, or tachycardic event was confirmed by the observer and recorded. MEASUREMENTS AND MAIN RESULTS: The cardiorespiratory rate monitor accurately identified true bradypneic episodes in five of the eight patients. There were no false-positive alarms. The respiratory rate monitor and the pulse oximeter identified one episode of hypoxemia. There were no episodes of bradycardia or tachycardia. CONCLUSIONS: The cardiorespiratory rate monitor is useful in patients at risk for bradypnea following surgery.     

Effects of intra-abdominal drainages on adhesion formation and prevention by phospholipids in a rat model. Drainages and adhesion formation

BACKGROUND AND AIMS: The study was designed to asses the adhesiogenic capacity of silicone drainages and the protective effect of phospholipids (PL). MATERIALS AND METHODS: A total of 75 Wistar rats were randomly assigned to the different groups. In a preliminary trial (pt; n = 15), all rats underwent midline laparotomy. The control group (C(pt); n = 5) received no further treatment. In the other animals, either an 'easy flow' drainage (EF(pt); n = 5) or an 'Aachen' drainage (AC(pt); n = 5) was placed into the abdominal cavity. In the final study (fs; n = 60), rats underwent laparotomy and colonic anastomosis. The control groups (C(fs)) received no drainages. In the other groups either one of the two types of drainages (EF(fs), AC(fs)) were introduced. In 50% of the rats, 75 mg/kg of PL were administered intraperitoneally (C(fs)+PL, EF(fs)+PL, AC(fs)+PL). The other rats received no additional treatment (C(fs)?PL, EF(fs)?PL, AC(fs)?PL). All animals were sacrificed 10 days after surgery. Areas of adhesions and anastomotic bursting pressures were measured (mean +/- SD). RESULTS: In the preliminary trial, analysis of variance (ANOVA) revealed no differences between the groups after application of drainages (values are given in mean +/- SD): C(pt) mean 23.3 +/- 29.4 mm(2), EF(pt) 829.7 +/- 679.3 mm(2), AC(pt) 609.9 +/- 219.4 mm(2). In the final study, 2-factorial ANOVA showed a significant effect (p < 0.001) for the use of drainages but not for the application of PL (C(fs)?PL 140.6 +/- 124.2 mm(2), C(fs)+PL 67.7 +/- 60.4 mm(2), EF(fs)?PL 1,217.0 +/- 458.3 mm(2), EF(fs)+PL 1,266.8 +/- 368.3 mm(2), AC(fs)?PL 861.7 +/- 274.8 mm(2), AC(fs)+PL 544.2 +/- 193.8 mm(2)). Post hoc test for pairwise comparisons adjusted to Bonferroni showed significant differences (p < 0.001) between all of the three pairs (C(fs) 104.1 +/- 92.3 mm(2) vs. EF(fs) 1,241.9 mm(2) +/- 413.3 mm(2); C(fs) vs. AC(fs) 702.9 mm +/- 234.3 mm(2); EF(fs) vs. AC(fs)). DISCUSSION: The final study demonstrates the adhesiogenic capacity of silicone drainage tubes in combination with anastomoses. Any protective effect of PL alone or in combination with drainages could not be shown. CONCLUSIONS: Indication for the use of drainages in standard surgical procedures should be reconsidered within the scope of their potential to cause adhesions and subsequent complications.     

Efficacy of ephedrine in the prevention of postoperative nausea and vomiting.

Although reported in the aerospace literature and anecdotally by anesthesiologists, the putative antiemetic effect of ephedrine remains unquantitated. We therefore prospectively studied ephedrine as an antiemetic agent in the perioperative setting in 97 patients undergoing general anesthesia for outpatient gynecologic laparoscopy. Patients were assigned in a double-blind randomized fashion to receive a standardized general anesthetic followed by an intramuscular dose of either ephedrine (0.5 mg/kg), droperidol (0.04 mg/kg), or saline before the conclusion of surgery. Nausea, retching, or vomiting, as well as the degree of sedation and discharge times, were assessed in the recovery room and for 24 h postoperatively. Ephedrine was found to have a significantly antiemetic effect (P less than 0.05) when compared with placebo and an antiemetic effect similar to that of droperidol. Sedation scores were also significantly less in the ephedrine group than in both placebo and droperidol groups. Finally, variations in mean arterial blood pressure among the three groups were not statistically significant. We conclude that ephedrine is an effective antiemetic agent with minimal sedative side effects in patients undergoing outpatient laparoscopy.     

预防肌腱粘连方法的研究进展

肌腱粘连是指肌腱损伤修复过程中周围组织的增生和侵入。虽然显微外科技术、缝合方法及肌腱移植手段获得了一定进步 ,肌腱粘连仍然是制约手外科发展的障碍。如何防止周围组织侵入愈合过程中的腱组织 ,以免发生粘连 ,是目前肌腱外科领域的重要研究课题。笔者对预防肌腱粘连研究的有关文献作一综述。1　肌腱缝合技术目前肌腱缝合的方法较多 ,如Bun nell缝合法、“8”字缝合法、Kessler缝合法、Kleinert缝合法、津下方法及编织法等 ,但不管采取哪一种方法 ,对肌腱缝合的要求是 :①肌腱缝合后 ,结合部要有一定的抗张能力。②肌腱缝合部要光滑 …     

Postoperative pericardial adhesion prevention using Carbylan-SX in a rabbit model

INTRODUCTION: The presence of dense adhesions within the pericardial space complicates reoperative cardiac surgery. Prior attempts to reduce adhesion formation after primary cardiac surgery using medications or biomaterials have had variable success. Carbylan-SX (Carbylan Biosurgery Inc., Palo Alto, CA) is a hyaluronan-based biomaterial, which has been shown to be effective at reducing adhesions in a nonthoracic rat model. This study evaluates whether Carbylan-SX can effectively reduce postoperative adhesions within the pericardial cavity. METHODS: Thirty-eight New Zealand white rabbits underwent a left lateral thoracotomy. A pericardiotomy was made and epicardial adhesions were induced on the anterior surface of the heart using a Dremel device (Racine, WI). The rabbits were divided into four groups: controls with abrasions only receiving no treatment (n=10), Carbylan-SX films (n=10), Carbylan-SX aerosolized hydrogel (n=10), and Seprafilm (n=8). The pericardial sac and chest were subsequently closed. Rabbits were sacrificed at a mean of 15 days. For histological analysis, each heart was divided into 12 separate 1 mm sections. Computer imaging software was used to measure the adhesion thickness and the mean of 12 random measurements for each animal was recorded and statistical analysis performed. RESULTS: Histological analysis revealed all treatment groups to be significantly better than the control (2159 mum thickness, P<0.0001) at preventing adhesions. The Carbylan-SX film and Carbylan-SX aerosolized hydrogel both proved to be better at preventing adhesions than Seprafilm (Genzyme Corp., Cambridge, MA) with an average adhesion thickness of 454 and 577 microm, respectively, compared with 1319 microm for Seprafilm (P<0.0001 and P<0.0005, respectively). The Carbylan-SX film and Carbylan-SX aerosolized hydrogel were equally effective at preventing adhesion formation. CONCLUSION: Carbylan-SX film and Carbylan-SX aerosolized crosslinkable hydrogel are equally effective methods of reducing postoperative pericardial adhesions within the pericardial cavity. Both the Carbylan-SX film and aerosolized hydrogel showed a significantly greater reduction in adhesions than Seprafilm. Clinical application of Carbylan-SX could have significant therapeutic implications in the future.