Assessment of ideal ratio of mesh area to number of fixation tacks in laparoscopic ventral and incisional IPOM Plus hernia repair.

BACKGROUND: To clarify the optimum mesh-tack ratio MTR (mesh area in cm2 divided by the number of fixation tacks) in laparoscopic ventral and incisional hernia repair, we compared IPOM Plus procedures with more intensive mesh fixation to those with standard mesh fixation. METHODS: In a retrospective cohort study, 84 patients (mean hernia width 6.6 ± 4.4 cm) intraoperatively received an intensive mesh fixation I-IPOM Plus with MTR ≤ 4:1 (e.g. ,150 cm2 mesh fixed by 50 tacks) and 74 patients (mean hernia width 6.7 ± 3.4 cm) received a standard mesh fixation S-IPOM Plus with MTR > 4:1 (e.g., 150 cm2 mesh fixed by 30 tacks) at a community hospital between 2014 and 2017. Outcomes in recurrence rates, immediate and chronic postoperative pain, as well as long-term functionality of the abdominal wall were then evaluated. RESULTS: After a mean follow-up time of 34 months, a 2.3% recurrence rate in I-IPOM Plus patients and a 13.5% recurrence rate in S-IPOM Plus patients were recorded (p = 0.018). The recurrence was associated with large hernia > 10 cm (OR 3.7, 95% CI 1.3-5.4) and MTR > 5 (OR 2.4, 95% CI 1.1-3.8) in the multivariate analysis. There was a positive correlation between immediate postoperative pain intensity measured on day 7 and number of fixation tacks placed (I-IPOM Plus: mean 4.5 ± 2.5 VAS versus S-IPOM Plus: mean 2.7 ± 2.0 VAS, p = 0.001). However, there were no outcome differences in terms of length of immediate postoperative pain experience, sick leave duration, chronic pain rate and long-term abdominal wall functionality between these two groups. CONCLUSION: For ventral and incisional hernia patients with multiple recurrence risk factors, a mesh-tack ratio MTR ≤ 4:1 should be applied in laparoscopic IPOM Plus procedures.

Comparison of mesh fixation devices for laparoscopic ventral hernia repair: an experimental study on human anatomic specimens.

BACKGROUND: As there is a lack of clarity in terms of the tensile strength of mesh fixation for laparoscopic ventral hernia repair (LVHR), our aim was to investigate the immediate tensile strength of currently available mesh fixation devices on human anatomic specimens. METHODS: Sixteen recently deceased body donators (mean body mass index of 24.4 kg/m2) were used to test the immediate tensile strength (Newton) of 11 different LVHR mesh fixation devices. RESULTS: Each of the 11 different laparoscopic fixation devices was tested 44 times. Non-articulating tackers provided higher fixation resistance to tensile stress in comparison to articulating tackers (5.1-mm ReliaTack™: 16.9 ± 8.7 N vs. 12.2 ± 5.6 N, p = 0.013; 7-mm ReliaTack™: 19.8 ± 9.4 N vs. 15.0 ± 7.0 N, p = 0.007). Absorbable tacks with a greater length, i.e. ≥6 mm (7-mm ReliaTack™, 6-mm SorbaFix™ and 7.2-mm SecureStrap™) had significantly higher fixation tensile strength than tacks with a shorter length, i.e. < 6 mm (5.1-mm ReliaTack™ and 5.1-mm AbsorbaTack™) (p < 0.001). Furthermore, transfascial sutures (PDS 2-0 sutures 26.3 ± 5.6 N) provided superior fixation tensile strength than 5.1-mm AbsorbaTack™ (13.6 ± 7.3 N) and cyanoacrylate glues such as LiquiBand FIX8™ (3.5 ± 2.4 N) (p < 0.001, respectively). There was a significant deterioration in fixation capacity in obese body donators with a body mass index > 30 kg/m2 (13.8 ± 8.0 vs. 17.9 ± 9.7 N, p = 0.044). CONCLUSIONS: Although articulating laparoscopic tackers improve accessibility and facilitate the utilization of tacks within the fixation weak spot adjacent to the trocar placement, an articulating shaft that is not ergonomic to use may limit mechanisms of force transmission. For mesh fixation in LVHR, transfascial sutures and tacks with a longer length provide better immediate fixation tensile strength results.

An immunoinformatic approach to assessing the immunogenic capacity of alpha-neurotoxins in elapid snake venoms.

Introduction: Most elapid snakes produce venoms that contain alpha-neurotoxins (α-NTXs), which are proteins that cause post-synaptic blockade and paralysis in snakebite envenoming. However, existing elapid antivenoms are known for their low potency in neutralizing the neurotoxic activity of α-NTXs, while the immunological basis has not been elucidated. Methods: In this study, a structure-based major histocompatibility complex II (MHCII) epitope predictor of horse (Equus caballus), complemented with DM-editing determinant screening algorithm was adopted to assess the immunogenicity of α-NTXs in the venoms of major Asiatic elapids (Naja kaouthia, Ophiophagus hannah, Laticauda colubrina, Hydrophis schistosus, Hydrophis curtus). Results: The scoring metric M2R, representing the relative immunogenic performance of respective α-NTXs, showed all α-NTXs have an overall low M2R of <0.3, and most of the predicted binders feature non-optimal P1 anchor residues. The M2R scores correlate strongly (R2 = 0.82) with the potency scores (p-score) generated based on the relative abundances of α-NTXs and the neutralization potency of commercial antivenoms. Discussion: The immunoinformatic analysis indicates that the inferior antigenicity of α-NTXs is not only due to their small molecular size but also the subpar immunogenicity affected by their amino acid composition. Structural modification with conjugation and synthetic epitope as immunogen may potentially enhance the immunogenicity for improved antivenom potency against α-NTXs of elapid snakes.

Decomplexation proteomic analysis and purity assessment of a biologic for snakebite envenoming: Philippine Cobra Antivenom.

BACKGROUND: Philippine Cobra Antivenom (PCAV) is the only snake antivenom manufactured in the Philippines. It is used clinically to treat envenoming caused by the Philippine Spitting Cobra (Naja philippinensis). While PCAV is effective pharmacologically, it is crucial to ensure the safety profile of this biologic that is derived from animal plasma. METHODS: This study examined the composition purity of PCAV through a decomplexation proteomic approach, applying size-exclusion chromatography (SEC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and tandem mass spectrometry liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: SDS-PAGE and SEC showed that the major protein in PCAV (constituting ∼80% of total proteins) is approximately 110 kDa, consistent with the F(ab')2 molecule. This protein is reducible into two subunits suggestive of the light and heavy chains of immunoglobulin G. LC-MS/MS further identified the proteins as equine immunoglobulins, representing the key therapeutic ingredient of this biologic product. However, protein impurities, including fibrinogens, alpha-2-macroglobulins, albumin, transferrin, fibronectin and plasminogen, were detected at ∼20% of the total antivenom proteins, unveiling a concern for hypersensitivity reactions. CONCLUSIONS: Together, the findings show that PCAV contains a favorable content of F(ab')2 for neutralization, while the antibody purification process awaits improvement to minimize the presence of protein impurities.

Preclinical assessment of VPEAV, a new trivalent antivenom for elapid snakebite envenoming in the Philippines: Proteomics, immunoreactivity and toxicity neutralization.

Snakebite envenoming is an important neglected tropical disease. Antivenom supply, however, remains limited in many parts of the world. This study aimed to examine the protein composition, immunoreactivity and neutralization efficacy of a new antivenom product (VINS Philippine Elapid Antivenoms, VPEAV) developed for the treatment of snakebite envenoming caused by the Philippine Cobra (Naja philippinensis), Samar Cobra (Naja samarensis) and King Cobra (Ophiophagus hannah). Size-exclusion chromatography, sodium-dodecyl sulfate-polyacrylamide gel electrophoresis and tandem mass spectrometry showed that VPEAV consisted of F(ab)'2 (∼90% of total antivenom proteins) with minimal protein impurities. Indirect ELISA showed varying immunoreactivity of VPEAV toward the different venoms (EC50 = 4-16 µg/ml), indicating distinct venom antigenicity between the species. In mice, the neutralization potency of VPEAV against the King Cobra venom was moderate (potency, P = 2.6 mg/ml, defined as the amount of venom completely neutralized per unit volume of antivenom). The potency was significantly lower against the N. philippinensis and N. samarensis venoms (P = 0.18-0.30 mg/ml), implying a higher dose may be needed for effective neutralization of the Naja venoms. Together, the findings suggest the potential and limitation of VPEAV in neutralizing the venom toxicity of the three Philippine elapid snakes.

Snake Venom Proteomics of Samar Cobra (Naja samarensis) from the Southern Philippines: Short Alpha-Neurotoxins as the Dominant Lethal Component Weakly Cross-Neutralized by the Philippine Cobra Antivenom.

The Samar Cobra, Naja samarensis, is endemic to the southern Philippines and is a WHO-listed Category 1 venomous snake species of medical importance. Envenomation caused by N. samarensis results in neurotoxicity, while there is no species-specific antivenom available for its treatment. The composition and neutralization of N. samarensis venom remain largely unknown to date. This study thus aimed to investigate the venom proteome of N. samarensis for a comprehensive profiling of the venom composition, and to examine the immunorecognition as well as neutralization of its toxins by a hetero-specific antivenom. Applying C18 reverse-phase high-performance liquid chromatography (RP-HPLC) and tandem mass spectrometry (LC-MS/MS), three-finger toxins (3FTx) were shown to dominate the venom proteome by 90.48% of total venom proteins. Other proteins in the venom comprised snake venom metalloproteinases, phospholipases A2, cysteine-rich secretory proteins, venom nerve growth factors, L-amino acid oxidases and vespryn, which were present at much lower abundances. Among all, short-chain alpha-neurotoxins (SαNTX) were the most highly expressed toxin within 3FTx family, constituting 65.87% of the total venom proteins. The SαNTX is the sole neurotoxic component of the venom and has an intravenous median lethal dose (LD50) of 0.18 µg/g in mice. The high abundance and low LD50 support the potent lethal activity of N. samarensis venom. The hetero-specific antivenom, Philippine Cobra Antivenom (PCAV, raised against Naja philippinensis) were immunoreactive toward the venom and its protein fractions, including the principal SαNTX. In efficacy study, PCAV was able to cross-neutralize the lethality of SαNTX albeit the effect was weak with a low potency of 0.20 mg/ml (defined as the amount of toxin completely neutralized per milliliter of the antivenom). With a volume of 5 ml, each vial of PCAV may cross-neutralize approximately 1 mg of the toxin in vivo. The findings support the potential para-specific use of PCAV in treating envenomation caused by N. samarensis while underscoring the need to improve the potency of its neutralization activity, especially against the highly lethal alpha-neurotoxins.

Anatomical changes after inguinal hernia treatment: a reason for chronic pain and recurrent hernia?

BACKGROUND: Chronic pain and hernia recurrence are the most frequent long-term complications of treating inguinal hernia. One reason may be postsurgical changes in the anatomy of the groin. METHODS: In a retrospective investigation from 1994 to 2008, 1,194 patients undergoing 1,421 laparoscopic transabdominal preperitoneal (TAPP) herniorrhaphies were studied. Anatomical structures in the groin, seen in 1,214 primary and 207 recurrent hernias, were charted by means of video analysis. Hernia orifices, myopectineal orifice (MPO), and Hesselbach's and Hessert's triangles were measured in their respective vertical and horizontal diameters in order to calculate the surface area. Other anatomical changes were also recorded. RESULTS: The mean surface area of hernial orifices was 3.00 +/- 2.01 cm(2) in primary hernias and 3.60 +/- 3.81 cm(2) in recurrent hernias. The mean surface area of Hesselbach's triangle was 4.23 +/- 2.21 cm(2) in the former group and 2.09 +/- 2.10 cm(2) in the latter (p < 0.0001). The mean surface area of Hessert's triangle in primary hernias (9.03 +/- 6.17 cm(2)) was significantly larger than that in recurrent hernias (3.11 +/- 3.67 cm(2); p < 0.0001). Further anatomical changes in suture-treated recurrent hernias included a dislocated spermatic cord, a raised inguinal ligament, and asymmetry in the region. CONCLUSION: The treatment of inguinal hernia by the suture technique is followed by significant anatomical changes such as reduction of the surface area and a subsequent increase of tension in the inguinal region. This could be one of the main reasons for chronic pain and hernia recurrence.

Structure-informed separation of bioactive peptides.

The application of proteomic and peptidomic technologies for food-derived bioactive peptides is an emerging field in food sciences. These technologies include the use of separation tools coupled to a high-resolution spectrometric and bioinformatic tools for prediction, identification, sequencing, and characterization of peptides. To a large extent, one-dimensional separation technologies have been extensively used as a continuous tool under different optimized conditions for the identification and analysis of food peptides. However, most one-dimensional separation technologies are fraught with significant bottlenecks such as insufficient sensitivity and specificity limits for complex samples. To address this limitation, separation systems based on orthogonal, multidimensional principles, which allow for the coupling of more than one analytical separation tool with different operational principles, provide a higher separation power than one-dimensional separation tools. This review describes the structure-informed separation and purification of protein hydrolyzates to obtain peptides with desirable bioactivities. PRACTICAL APPLICATIONS: Application of bioactive peptides in the formulation of functional foods, nutraceuticals, and therapeutic agents have increasingly gained scholarly and industrial attention. The bioactive peptides exist originally in protein sources and are only active after hydrolysis of the parent protein. Currently, several tools can be configured in one-dimensional or multidimensional systems for the separation and purification of protein hydrolyzates. The separations are informed by the structural properties such as the molecular weight, charge, hydrophobicity or hydrophilicity, and the solubility of peptides. This review provides a concise discussion on the commonly used analytical tools, their configurations, advantages and challenges in peptide separation. Emphasis is placed on how the structural properties of peptides assist in the separation and purification processes and the concomitant effect of the separation on peptide bioactivity.

Characterisation of aptamer-anchored poly(EDMA-co-GMA) monolith for high throughput affinity binding.

Immobilisation of aptameric ligands on solid stationary supports for effective binding of target molecules requires understanding of the relationship between aptamer-polymer interactions and the conditions governing the mass transfer of the binding process. Herein, key process parameters affecting the molecular anchoring of a thrombin-binding aptamer (TBA) onto polymethacrylate monolith pore surface, and the binding characteristics of the resulting macroporous aptasensor were investigated. Molecular dynamics (MD) simulations of the TBA-thrombin binding indicated enhanced Guanine 4 (G4) structural stability of TBA upon interaction with thrombin in an ionic environment. Fourier-transform infrared spectroscopy and thermogravimetric analyses were used to characterise the available functional groups and thermo-molecular stability of the immobilised polymer generated with Schiff-base activation and immobilisation scheme. The initial degradation temperature of the polymethacrylate stationary support increased with each step of the Schiff-base process: poly(Ethylene glycol Dimethacrylate-co-Glycidyl methacrylate) or poly(EDMA-co-GMA) [196.0 °C (±1.8)]; poly(EDMA-co-GMA)-Ethylenediamine [235.9 °C (±6.1)]; poly(EDMA-co-GMA)-Ethylenediamine-Glutaraldehyde [255.4 °C (±2.7)]; and aptamer-modified monolith [273.7 °C (±2.5)]. These initial temperature increments reflected in the associated endothermic energies were determined with differential scanning calorimetry. The aptameric ligand density obtained after immobilisation was 480 pmol/µL. Increase in pH and ionic concentration affected the surface charge distribution and the binding characteristics of the aptamer-modified disk-monoliths, resulting in the optimum binding pH and ionic concentration of 8.0 and 5 mM Mg2+, respectively. These results are critical in understanding and setting parametric constraints indispensable to develop and enhance the performance of aptasensors.

Parametric study of immobilized cellulase-polymethacrylate particle for the hydrolysis of carboxymethyl cellulose.

Biocarriers are pivotal in enhancing the reusability of biocatalyst that would otherwise be less economical for industrial application. Ever since the induction of enzymatic technology, varied materials have been assessed for their biocompatibility with enzymes of distinct functionalities. Herein, cellulase was immobilized onto polymethacrylate particles (ICP) as the biocarrier grafted with ethylenediamine (EDA) and glutaraldehyde (GA). Carboxymethyl cellulose (CMC) was used as a model substrate for activity assay. Enzyme immobilization loading was determined by quantifying the dry weight differential of ICP (pre-& post-immobilization). Cellulase was successfully demonstrated to be anchored upon ICP and validated by FTIR spectra analysis. The optimal condition for cellulase immobilization was determined to be pH 6 at 20 °C. The maximum CMCase activity was achieved at pH 5 and 50 °C. Residual activity of ∼50% was retained after three iterations and dipped to ∼18% on following cycle. Also, ICP displayed superior pH adaptability as compared to free cellulase. The specific activity of ICP was 65.14 ±â€¯1.11% relative to similar amount of free cellulase.

Needlescopic Surgery Versus Single-port Laparoscopy for Inguinal Hernia.

BACKGROUND AND OBJECTIVES: In recent years, 2 modifications of laparoscopic transabdominal preperitoneal (TAPP) inguinal hernia repair-needlescopic (nTAPP) surgery and single-port (sTAPP) surgery-have greatly improved patient outcomes over traditional approaches. For a comparison of these 2 modifications, we sought to investigate and compare the extent of surgical trauma and postoperative consequences for the abdominal wall in these two procedures. METHODS: In a retrospective study, 50 nTAPP and 35 sTAPP procedures occurring at a community hospital from November 1, 2009, through July 31, 2012 were reviewed. Intraoperative data, including length of the umbilical skin incision and operative time, were recorded. A follow-up evaluation included investigation of hernia recurrence, postoperative pain, abdominal wall mobility, cosmetic satisfaction, and period of sick leave. RESULTS: The mean umbilical skin incision was 13 ± 4 mm in nTAPP vs 27 ± 3 mm in sTAPP (P < .001). The nTAPP procedure required less operating time than the sTAPP procedure (54.8 ± 16.9 minutes vs 85.9 ± 19.7 minutes; P < .001). The mean immediate postoperative pain score on the visual analog scale was 2.7 ± 2.1 in the nTAPP group and 4.4 ± 1.9 in the sTAPP group (P = .016). In addition, patients who underwent nTAPP had a shorter period of sick leave (11.2 ± 8.4 days vs 24.1 ± 20.1 days; P = .02). At the follow-up evaluation after approximately 30 months, abdominal wall mobility and cosmetic satisfaction were equally positive, with no hernia recurrence. CONCLUSION: In patients with uncomplicated inguinal hernia, the nTAPP procedure, with less surgical trauma and operating time, has distinct advantages in reduction of immediate postoperative pain and sick leave time.

Malignant fibrous histiocytoma of the maxillary sinus presenting as toothache.

Malignant fibrous histiocytoma (MFH) is a high-grade and aggressive sarcoma. It is relatively rare in the head and neck region. Its diagnosis is based on immunohistochemical stains. Wide excision followed by postoperative radiotherapy is believed to be the treatment of choice for MFH. In October 2001, a case of MFH in the maxillary sinus, which presented as a toothache at the beginning, was successfully diagnosed and treated. Using the external approach, the tumor mass was completely removed, and postoperative radiotherapy was subsequently performed. Seventeen months after the surgery, the patient was clinically well without any evidence of local recurrence or distant metastasis.