Zinc deficiency impairs wound healing of colon anastomosis in rats

Impact of an Injectable Trace Mineral Supplement on the Immune Response and Outcome of Mannheimia haemolytica Infection in Feedlot Cattle

The study aimed to assess the impact of injectable trace mineral ("ITM"; Multimin90; Fort Collins, CO) supplementation on bacterial infection in cattle. Angus-crossbred steers (n = 32) were organized into two blocks by initial body weight. Steers were maintained on a ryelage and dry-rolled corn-based growing diet without supplementation of Zn, Cu, Mn, and Se for the duration of the study. The steers were transported 6 h, then randomized into three treatment groups: control received sterile saline ("CON"), ITM administered 1 day after transport (6 days before infection, "ITMPRE"), and ITM administered 2 days post infection (dpi) concurrent with antibiotic treatment ("ITMPOST"). Steers were infected with Mannheimia haemolytica on day 0, and all were treated with tulathromycin at 2 dpi. Plasma levels of Zn, Cu, and Se did not differ among treatments (P ≥ 0.74). Liver Se was higher in ITMPRE at 2 dpi (P < 0.05), and both ITM groups had higher liver Se at 5 dpi (P < 0.05) compared to CON. A time × treatment interaction was detected for liver Cu (P = 0.02). Clinical scores were lower (P < 0.05) in ITMPRE on 1 and 8 dpi and ITMPOST on 8 dpi compared to CON. Thoracic ultrasonography scores were lower in ITMPRE at 2 dpi compared to CON (P < 0.05) and ITMPOST (P < 0.1). No treatment effects (P > 0.10) were observed for bacterial detection from bronchoalveolar lavage (BAL) or nasopharyngeal swabs. At 5 dpi, both ITMPRE and ITMPOST showed higher frequencies of γδ T cells and NK cells in BAL compared to CON (P < 0.05). Before infection, leukocytes from ITMPRE steers produced more IL-6 (P < 0.01) in response to stimulation with the TLR agonist, Pam3CSK4. Use of ITM may be an effective strategy for improving disease resistance in feedlot cattle facing health challenges.

Curcumin-based nanoformulations alleviate wounds and related disorders: A comprehensive review

Despite numerous advantages, curcumin's (CUR) low solubility and low bioavailability limit its employment as a free drug. CUR-incorporated nanoformulation enhances the bioavailability and angiogenesis, collagen deposition, fibroblast proliferation, reepithelization, collagen synthesis, neovascularization, and granulation tissue formation in different wounds. Designing nanoformulations with controlled-release properties ensure the presence of CUR in the defective area during treatment. Different nanoformulations encompassing nanofibers, nanoparticles (NPs), nanospray, nanoemulsion, nanosuspension, nanoliposome, nanovesicle, and nanomicelle were described in the present study comprehensively. Moreover, for some other systems which contain nano-CUR or CUR nanoformulations, including some nanofibers, films, composites, scaffolds, gel, and hydrogels seems the CUR-loaded NPs incorporation has better control of the sustained release, and thereby, the presence of CUR until the final stages of wound healing is more possible. Incorporating CUR-loaded chitosan NPs into nanofiber increased the release time, while 80% of CUR was released during 240 h (10 days). Therefore, this system can guarantee the presence of CUR during the entire healing period. Furthermore, porous structures such as sponges, aerogels, some hydrogels, and scaffolds disclosed promising performance. These architectures with interconnected pores can mimic the native extracellular matrix, thereby facilitating attachment and infiltration of cells at the wound site, besides maintaining a free flow of nutrients and oxygen within the three-dimensional structure essential for rapid and proper wound healing, as well as enhancing mechanical strength.

Regulation of matrix metalloproteinase-9 during monopoiesis and zinc deficiency by chromatin remodeling

INTRODUCTION

Matrix metalloproteinase-9 (MMP-9) cleaves various extracellular matrix proteins, hence significantly contributes to numerous physiological but also pathological processes. Monocytic differentiation is associated with increased MMP-9 gene expression. Interestingly, MMP-9 upregulation during monocytic differentiation is paralleled by a decline in intracellular zinc levels. Hence, an influence of zinc on the regulation of MMP-9 expression may exist. Although, previous studies suggest a vital role of zinc regarding MMP-9 activity, the possible relevance of zinc homeostasis during transcriptional regulation of MMP-9 for example via epigenetic mechanisms is rather unclear.

AIM

This study aims to find a correlation between zinc deficiency and MMP-9 transcriptional regulation, focusing on epigenetics as the possible mechanism behind zinc deficiency-induced changes.

METHODS

The effect of differentiation and zinc deficiency on MMP-9 expression and MMP9 promoter accessibility was investigated using the acute promyelocytic cell line NB4. Intracellular free zinc levels were detected by flow cytometry. MMP-9 gene expression was measured by real-time PCR and ELISA. Analysis of chromatin structures was done using chromatin accessibility by real-time PCR (CHART) assay.

RESULTS

During monocytic differentiation of NB4 cells, the decrease in intracellular zinc levels was paralleled by an increased production of MMP-9. Assessment of chromatin structure revealed increased accessibility of certain regions within the MMP-9 promoter in differentiated cells. Interestingly, upregulated activation-induced MMP-9 gene expression as well as a more accessible MMP-9 promoter were in zinc-deficient NB4 cells whereas zinc resupplementation reversed the effects.

CONCLUSION

These data demonstrate an important role of epigenetic mechanisms in regulating MMP-9 expression under zinc deficiency. This could provide an encouraging step to expand the research on using zinc for the treatment of various pathological conditions such as inflammatory, vascular and autoimmune diseases resulting from MMP-9 deregulation.

Zinc in Prostate Health and Disease: A Mini Review

Introduction-With the high global prevalence of prostate cancer and associated mortalities, it is important to enhance current clinical practices for better prostate cancer outcomes. The current review is towards understanding the value of Zn towards this mission. Method-General information on Zn in biology and multiple aspects of Zn involvement in prostate health and disease were referred to in PubMed. Results-The most influential feature of Zn towards prostate health is its ability to retain sufficient citrate levels for a healthy prostate. Zn deficiencies were recorded in serum, hair, and prostate tissue of men with prostate cancer compared to non-cancer controls. Zn gut absorption, albumin binding, and storage compete with various factors. There are multiple associations of Zn cellular influx and efflux transporters, Zn finger proteins, matrix metalloproteinases, and Zn signaling with prostate cancer outcomes. Such Zn marker variations associated with prostate cancer recorded from biological matrices may improve algorithms for prostate cancer screening, prognosis, and management when coupled with standard clinical practices. Discussion-The influence of Zn in prostatic health and disease is multidimensional, therefore more personalized Zn requirements may be beneficial. Several opportunities exist to utilize and improve understanding of Zn associations with prostate health and disease.

Zinc deficiency as a possible risk factor for increased susceptibility and severe progression of Corona Virus Disease 19

The importance of Zn for human health becomes obvious during Zn deficiency. Even mild insufficiencies of Zn cause alterations in haematopoiesis and immune functions, resulting in a proinflammatory phenotype and a disturbed redox metabolism. Although immune system malfunction has the most obvious effect, the functions of several tissue cell types are disturbed if Zn supply is limiting. Adhesion molecules and tight junction proteins decrease, while cell death increases, generating barrier dysfunction and possibly organ failure. Taken together, Zn deficiency both weakens the resistance of the human body towards pathogens and at the same time increases the danger of an overactive immune response that may cause tissue damage. The case numbers of Corona Virus Disease 19 (COVID-19) are still increasing, which is causing enormous problems for health systems and economies. There is an urgent need to reduce both the number of severe cases and the resulting deaths. While therapeutic options are still under investigation, and first vaccines have been approved, cost-effective ways to reduce the likelihood of or even prevent infection, and the transition from mild symptoms to more serious detrimental disease, are highly desirable. Nutritional supplementation might be an effective option to achieve these aims. In this review, we discuss known Zn deficiency effects in the context of an infection with Severe Acute Respiratory Syndrome-Coronavirus-2 and its currently known pathogenic mechanisms and elaborate on how severe pre-existing Zn deficiency may pre-dispose patients to a severe progression of COVID-19. First published clinical data on the association of Zn homoeostasis with COVID-19 and registered studies in progress are listed.

The effects of zinc treatment on matrix metalloproteinases: A systematic review

BACKGROUND

Zinc (Zn) acts as a cofactor of matrix metalloproteinases (MMPs) and is vital for their activity and controlling their expression. Alteration of Zn in the body could affect the expression, activity, and destructive impacts of MMPs.

OBJECTIVE

This systematic review aimed to summarize existing evidence on the effects of Zn treatment on the expression and activity of MMPs.

METHOD

International sources from Pub Med, Scopus and Google Scholar were searched for the original and English-language studies, published up to the end of May 2018.

RESULTS

During the initial search, 179 records were found, and 135 articles of them remained after the exclusion of duplicate articles. 47 studies met the inclusion criteria, after multiple stages of screening and critical reviews of articles.

CONCLUSION

Approximately 62% of the included studies (29 of 47) showed an inhibitory impact of Zn on MMPs production and activities. The inhibitory or stimulatory effect of Zn on MMPs seems to depend on physiological conditions of the cells or animals used, dose of Zn used, and duration of treatment.

A ZnO-curcumin nanocomposite embedded hybrid collagen scaffold for effective scarless skin regeneration in acute burn injury

Scar formation in severe burn injury is a major health concern. Herein, we developed a hybrid collagen scaffold with an incorporated ZnO-curcumin nanocomposite, which facilitates scarless wound healing. Biocompatibility and hemocompatibility studies unveiled that the hybrid scaffold is apt for in vivo wound healing studies. Histological and immunohistochemical analyses demonstrate that the hybrid scaffold accelerated scarless burn wound healing in albino rats owing to the ZnO-curcumin nanocomposite induced up-regulation of angiogenesis and TGF-β3 expression. The semi-quantitatively measured scar elevation index of the hybrid scaffold-treated animals is on a par with that of the unwounded or normal skin. The studies suggest that the prepared hybrid biomaterial could be a potential candidate for scarless healing in severe burn injuries.

Recurring Anastomotic Leak-A Prospective Clinicopathological Investigation of a Distinct Disease Pattern

BACKGROUND

Intestinal anastomotic insufficiency (AI) is a common problem in visceral surgery associated with overexpression of matrix metalloproteinases (MMPs). In some patients it occurs more than once. The etiology of recurring anastomotic insufficiency (RAI) is not understood yet and should be addressed as an independent disease entity.

MATERIALS AND METHODS

Thirty nine consecutive patients with AI were treated at our university center and were included in this prospective study. Clinical data were evaluated by correlative statistical analysis to identify independent risk factors for RAI. Patients were divided in two groups: 18 patients had a single operative revision until restoration (group SAI), and 21 patients had two or more revisions (group RAI). Anastomotic tissue samples as well as untouched bowel wall were collected during reoperations for analysis of MMPs and tissue inhibitor of metalloproteinases (TIMP2). Clinical data were correlated with pathological observations.

RESULTS

Significant differences of clinical and molecular pathological data were found between the two groups. Transfusion of red blood cells until the first reoperation and alcohol abuse led to RAI and were the only independent risk factors for RAI in multivariate analysis. Overexpression of MMP-8, -9, and -13 in anastomotic tissue correlated with the administration of red blood cells during initial operation. Reduced expression of TIMP2 was frequent in nearly all patients without differences throughout the subgroups.

CONCLUSIONS

RAI seems to have an independent disease pattern. Transfusion of blood products is not only a known risk factor for AI but seems to significantly disturb the anastomotic healing process leading to RAI.

Schiff base complexes of copper and zinc as potential anti-colitic compounds

The design, synthesis and activity of polymodal compounds for the treatment of inflammatory bowel disease are reported. The compounds, being based on a metal-Schiff base motif, are designed to degrade during intestinal transit to release the bioactive components in the gut. The compounds have been developed sequential with the biomodal compounds combining copper or zinc with a salicylaldehyde adduct. These compounds were tested in a formalin induced colonic inflammation model in BK:A mice. From these studies a trimodal compound based on a zinc Schiff base analogue of sulfasalazine was designed. This was tested against a trinitrobenzenesulfonic acid (TNB) induced colitic model in Wistar rats. The use of two models allows us to test our compounds in both an acute and a chronic model. The trimodal compound reported is observed to provide anticolitic properties in the chronic TNB induced colitis model commensurate with that of SASP. However, the design of trimodal compound still has the capacity for further development. This the platform reported may offer a route into compounds which can markedly outperform the anti-colitic properties of SASP.

Can specific nutrients stimulate bowel wound healing?

PURPOSE OF REVIEW

The purpose of review is to provide an overview on specific nutrients which play an important role in bowel wound healing, and to judge the efficacy of supplementation to derive recommendations for clinical practice.

RECENT FINDINGS

Glutamine, arginine, butyrate, ω-3 fatty acids, nucleotides, and several micronutrients are involved in bowel wound healing. However, with regard to clinical trials, the efficacy of supplementation of specific nutrients on bowel wound healing in patients with inflammatory bowel diseases has not been clarified yet. In patients undergoing colon surgery, sufficient evidence exists that the perioperative supply of an enteral immunomodulating formula enriched with arginine, nucleotides, and ω-3 fatty acids may improve intestinal wound healing, considering the lower risk of wound infections, wound dehiscence, and intra-abdominal abscess.

SUMMARY

Even if a range of nutrients are involved in bowel wound healing, only perioperative supply of an enteral immunomodulating formula to cancer patients undergoing colon surgery, can be recommended. Further randomized controlled trials are needed to elucidate the efficacy of individual nutrients on intestinal wound healing.

International consensus statement regarding the use of animal models for research on anastomoses in the lower gastrointestinal tract

PURPOSE

This project aimed to reach consensus on the most appropriate animal models and outcome measures in research on anastomoses in the lower gastrointestinal tract (GIT). The physiology of anastomotic healing remains an important research topic in gastrointestinal surgery. Recent results from experimental studies are limited with regard to comparability and clinical translation.

METHODS

PubMed and EMBASE were searched for experimental studies investigating anastomotic healing in the lower GIT published between January 1, 2000 and December 31, 2014 to assess currently used models. All corresponding authors were invited for a Delphi-based analysis that consisted of two online survey rounds followed by a final online recommendation survey to reach consensus on the discussed topics.

RESULTS

Two hundred seventy-seven original articles were retrieved and 167 articles were included in the systematic review. Mice, rats, rabbits, pigs, and dogs are currently being used as animal models, with a large variety in surgical techniques and outcome measures. Forty-four corresponding authors participated in the Delphi analysis. In the first two rounds, 39/44 and 35/39 participants completed the survey. In the final meeting, 35 experts reached consensus on 76/122 items in six categories. Mouse, rat, and pig are considered appropriate animal models; rabbit and dog should be abandoned in research regarding bowel anastomoses. ARRIVE guidelines should be followed more strictly.

CONCLUSIONS

Consensus was reached on several recommendations for the use of animal models and outcome measurements in research on anastomoses of the lower GIT. Future research should take these suggestions into account to facilitate comparison and clinical translation of results.

Colorectal anastomotic healing: why the biological processes that lead to anastomotic leakage should be revealed prior to conducting intervention studies

BACKGROUND

Anastomotic leakage (AL) remains the most dreaded complication after colorectal surgery and causes high morbidity and mortality. The pathophysiology of AL remains unclear, despite numerous studies that have been conducted on animals and humans, probably due to the undetermined healing process of colorectal anastomoses. Increasing basic knowledge on this healing process may shed more light on causal factors of AL, and additionally reduce the quantity and accelerate the quality of experimental studies. In this debate article, our aim was to provide different perspectives on what is known about the colorectal healing process in relation to wound healing and AL.

DISCUSSION

Since knowledge on anastomotic healing is lacking, it remains difficult to conclude which factors are essential in preventing AL. This is essential information in the framework of humane animal research, where the focus should lie on Replacement, Reduction and Refinement (3Rs). While many researchers compare anastomotic healing with wound healing in the skin, there are substantial recognized differences, e.g. other collagen subtypes and different components involved. Based on our findings in literature as well as discussions with experts, we advocate stop considering anastomotic healing in the gastrointestinal tract and cutaneous healing as a similar process. Furthermore, intervention studies should at least address the anastomotic healing process in terms of histology and certain surrogate markers. Finally, the anastomotic healing process ought to be further elucidated - with modern techniques to achieve 3Rs in animal research--to provide starting points for potential interventions that can prevent AL.

Zinc: physiology, deficiency, and parenteral nutrition

The essential trace element zinc (Zn) has a large number of physiologic roles, in particular being required for growth and functioning of the immune system. Adaptive mechanisms enable the body to maintain normal total body Zn status over a wide range of intakes, but deficiency can occur because of reduced absorption or increased gastrointestinal losses. Deficiency impairs physiologic processes, leading to clinical consequences that include failure to thrive, skin rash, and impaired wound healing. Mild deficiency that is not clinically overt may still cause nonspecific consequences, such as susceptibility to infection and poor growth. The plasma Zn concentration has poor sensitivity and specificity as a test of deficiency. Consequently, diagnosis of deficiency requires a combination of clinical assessment and biochemical tests. Patients receiving parenteral nutrition (PN) are susceptible to Zn deficiency and its consequences. Nutrition support teams should have a strategy for assessing Zn status and optimizing this by appropriate supplementation. Nutrition guidelines recommend generous Zn provision from the start of PN. This review covers the physiology of Zn, the consequences of its deficiency, and the assessment of its status, before discussing its role in PN.

Mucosal healing in inflammatory bowel diseases: is there a place for nutritional supplementation?

Advanced mucosal healing (MH) after intestinal mucosal inflammation coincides with sustained clinical remission and reduced rates of hospitalization and surgical resection, explaining why MH is increasingly considered as a full therapeutic goal and as an endpoint for clinical trials. Intestinal MH is a complex phenomenon viewed as a succession of steps necessary to restore tissue structure and function. These steps include epithelial cell migration and proliferation, cell differentiation, restoration of epithelial barrier functions, and modulation of cell apoptosis. Few clinical studies have evaluated the needs for specific macronutrients and micronutrients and their effects on intestinal MH, most data having been obtained from animal and cell studies. These data suggest that supplementation with specific amino acids including arginine, glutamine, glutamate, threonine, methionine, serine, proline, and the amino acid-derived compounds, polyamines can favorably influence MH. Short-chain fatty acids, which are produced by the microbiota from undigested polysaccharides and protein-derived amino acids, also exert beneficial effects on the process of intestinal MH in experimental models. Regarding supplementation with lipids, although the effects of ω-3 and ω-6 fatty acids remain controversial, endogenous prostaglandin synthesis seems to be necessary for MH. Finally, among micronutrients, several vitamin and mineral deficiencies with different frequencies have been observed in patients with inflammatory bowel diseases and supplementation with some of them (vitamin A, vitamin D3, vitamin C, and zinc) are presumed to favor MH. Future work, including clinical studies, should evaluate the efficiency of supplementation with combination of dietary compounds as adjuvant nutritional intervention for MH of the inflamed intestinal mucosa.

Zinc supplementation modifies tight junctions and alters barrier function of CACO-2 human intestinal epithelial layers

BACKGROUND

Zinc deficiency is known to result in epithelial barrier leak in the GI tract. Precise effects of zinc on epithelial tight junctions (TJs) are only beginning to be described and understood. Along with nutritional regimens like methionine-restriction and compounds such as berberine, quercetin, indole, glutamine and rapamycin, zinc has the potential to function as a TJ modifier and selective enhancer of epithelial barrier function.

AIMS

The purpose of this study was to determine the effects of zinc-supplementation on the TJs of a well-studied in vitro GI model, CACO-2 cells.

METHODS

Barrier function was assessed electrophysiologically by measuring transepithelial electrical resistance (Rt), and radiochemically, by measuring transepithelial (paracellular) diffusion of 14C-D-mannitol and 14C-polyethyleneglycol. TJ composition was studied by Western immunoblot analyses of occludin, tricellulin and claudins-1 to -5 and -7.

RESULTS

Fifty- and 100-μM zinc concentrations (control medium is 2 μM) significantly increase Rt but simultaneously increase paracellular leak to D-mannitol. Claudins 2 and 7 are downregulated in total cell lysates, while occludin, tricellulin and claudins-1, -3, -4 and -5 are unchanged. Claudins-2 and -7 as well as tricellulin exhibit decreased cytosolic content as a result of zinc supplementation.

CONCLUSIONS

Zinc alters CACO-2 TJ composition and modifies TJ barrier function selectively. Zinc is one of a growing number of "nutraceutical" substances capable of enhancing epithelial barrier function, and may find use in countering TJ leakiness induced in various disease states.

Subcellular redistribution and mitotic inheritance of transition metals in proliferating mouse fibroblast cells

Synchrotron X-ray fluorescence microscopy of non-synchronized NIH 3T3 fibroblasts revealed an intriguing redistribution dynamics that defines the inheritance of trace metals during mitosis. At metaphase, the highest density areas of Zn and Cu are localized in two distinct regions adjacent to the metaphase plate. As the sister chromatids are pulled towards the spindle poles during anaphase, Zn and Cu gradually move to the center and partition into the daughter cells to yield a pair of twin pools during cytokinesis. Colocalization analyses demonstrated high spatial correlations between Zn, Cu, and S throughout all mitotic stages, while Fe showed consistently different topographies characterized by high-density spots distributed across the entire cell. Whereas the total amount of Cu remained similar compared to interphase cells, mitotic Zn levels increased almost 3-fold, suggesting a prominent physiological role that lies beyond the requirement of Zn as a cofactor in metalloproteins or messenger in signaling pathways.

Comparison of intestinal microcirculation and wound healing in a rat model

PURPOSE

If a colonic or small bowel lesion is not accessible for endoscopic mucosal resection, enterotomy is a possible although rarely performed surgical technique. It has never been compared to circular anastomosis regarding leakage rate, bowel wall perfusion, and wound healing. Thus, the aim of this basic experimental scientific study was to investigate perianastomotic microcirculation and wound healing.

METHODS

Forty rats were divided into four groups (1 jejunal anastomosis, 2 jejunal enterotomy, 3 colonic anastomosis, and 4 colonic enterotomy). Following anastomosis and enterotomy, the intestinal perfusion was measured using laser fluorescence angiography (IC-View). On postoperative day 7, the surface of the mucosal villi, expression of matrix metalloproteinases (MMP) 2, 8, 9, and 13, and the number of proliferating cells (Ki67) as well as the collagen types I/III ratio were analyzed.

RESULTS

The perianastomotic microperfusion was significantly reduced in all groups compared to the reference region. The perianastomotic perfusion index was significantly reduced in group 1 compared with group 2, whereas the perfusion index in group 3 was slightly but not significantly reduced in comparison to group 4. Ki67 was elevated in both circular anastomosis groups. Surface of the mucosal villi, MMP expression, and collagen type I/III ratio revealed no significant differences.

CONCLUSIONS

Our study affirms the theoretical consideration of a better microperfusion of the bowel wall following an antimesenterial enterotomy and demonstrates that enterotomy is not inferior compared to circular anastomosis. Even though enterotomy is a rarely used surgical technique, it should be regarded as a possible alternative in particular situations.

Hemorrhagic shock and surgical stress alter distribution of labile zinc within high- and low-molecular-weight plasma fractions

Zinc ions (Zn) are essential for tissue repair following injury or stress. We hypothesize that during such stresses Zn is redistributed to labile pools in plasma components. Here we tested this hypothesis using a novel assay to monitor labile Zn in plasma in hemorrhagic shock. Adult rats in the shock group (S group) underwent hemorrhage and resuscitation. Blood samples were drawn at baseline and at 1, 4, and 24 h. The surgical control group (SC group) was anesthetized and instrumented, but not bled. Albumin, total Zn, and labile Zn levels were assayed in plasma. Binding capacity for Zn was assessed in high- and low-molecular-weight pools. Significant decreases in total Zn were observed by 24 h, in both S and SC groups. Albumin levels were significantly reduced in the S group at 1 and 4 h but restored at 24 h; significant changes were not observed in other groups. In whole plasma, labile Zn levels were stable initially in the S and SC groups, but declined at 24 h. In the high-molecular-weight pool, marked and significant impairment of binding was noted throughout all time periods following the shock period in the S group. Such changes were observed in the SC group of less intensity and duration. These experiments suggest that shock alters affinity of plasma proteins for Zn, promoting delivery to peripheral tissues during periods of increased Zn utilization.

Update on micronutrients in bariatric surgery

PURPOSE OF REVIEW

Obesity is a growing worldwide epidemic. Obese patients are often deficient in micronutrients despite macronutrient excess. Bariatric surgery is an increasingly utilized modality in the treatment of obesity and obesity-related conditions. Bariatric surgery itself may cause or exacerbate micronutrient deficiencies with serious sequelae. This review will focus on perioperative strategies to detect, prevent and treat micronutrient deficiencies in patients undergoing bariatric surgery, and will highlight practical and clinical aspects of these nutritional problems.

RECENT FINDINGS

Micronutrient deficiency is common in obese patients undergoing bariatric surgery both preoperatively and postoperatively. Bariatric procedures with a malabsorptive component are more likely to result in postoperative micronutrient deficiency. A system-based approach will facilitate clinical suspicion of specific or combined micronutrient deficiencies, leading to appropriate laboratory tests for confirmation. Supplementation by the oral route is always tried first, reserving parenteral administration for specific situations.

SUMMARY

Clinicians should be aware that micronutrient deficiencies are common in obese patients who may have macronutrient excess. Micronutrient deficiency may exist preoperatively or be caused by bariatric procedures themselves. A systematic and team-based approach will decrease morbidity associated with delays in diagnosis and treatment.

Impact of bevacizumab chemotherapy on craniotomy wound healing

Object

The FDA approval of bevacizumab for recurrent glioblastoma has resulted in its increased use in this patient population. Phase II trials reported 4%–6% impaired wound healing for bevacizumab initiated postoperatively. The effect of preoperative bevacizumab on subsequent craniotomy healing has not been addressed.

Methods

The authors retrospectively reviewed the cases of patients who underwent craniotomy for recurrent glioblastoma between 2005 and 2009, evaluating bevacizumab therapy/duration and healing complications (dehiscence, pseudomeningocele, CSF leak, and wound/bone infection). The Wilcoxon rank-sum test and Kruskal-Wallis test were used to compare continuous variables between groups. The Fisher exact test was used to assess for an association between categorical variables, including the comparison of wound-healing complication rates. Logistic regression models were used to estimate odds ratios of wound-healing complications while adjusting for baseline variables.

Results

Two hundred nine patients underwent a second craniotomy (161 patients) or third craniotomy (48 patients) for recurrent glioblastoma. Twenty-six individuals (12%) developed wound-healing complications. One hundred sixty-eight patients received no bevacizumab, 23 received preoperative bevacizumab, and 18 received postoperative bevacizumab. Significantly more patients receiving preoperative bevacizumab developed healing complications (35%) than non–bevacizumab-treated patients (10.0%, p = 0.004). Postoperative bevacizumab was associated with 6% impaired healing, not significantly different from non–bevacizumab-treated controls (p = 1.0). Preoperative bevacizumab treatment duration (weeks) did not influence healing (OR 0.98, p = 0.55). More healing complications occurred in patients receiving preoperative bevacizumab than in non–bevacizumab-treated controls before the third craniotomy (44% vs 9%, p = 0.03).

Conclusions

Although subject to the limitations of a retrospective study, we demonstrate that preoperative bevacizumab treatment resulted in impaired healing after a second and third craniotomy, compared with minimal effect of postoperative bevacizumab. This effect is more striking for the third craniotomy and for a shorter delay between bevacizumab and surgery. These complications should be acknowledged as increased bevacizumab use results in more post–bevacizumab-treated patients in whom surgery for recurrent glioblastoma is considered. Based on these results, the authors recommend performing repeated craniotomy more than 28 days after last administered dose of bevacizumab whenever possible.

Balancing zinc deficiency leads to an improved healing of colon anastomosis in rats

BACKGROUND

In colorectal surgery, anastomotic leakage is a relevant complication. The aim of this study was to investigate whether intraperitoneally (i.p.) administered zinc improves the healing of colon anastomosis in rats.

MATERIALS AND METHODS

Male Wistar rats (66) received zinc-deficient diet for 21 days. To determine the effective dose of zinc which is necessary to compensate this deficiency, preliminary analysis in 30 rats were performed. In these rats, analysis by atom-absorption spectrophotometry revealed a dose of 1.0 mg zinc aspartate/kg body weight to be the compensatory dosage. In the remaining zinc-deficient rats (n= 36), a transverse colonic anastomosis was performed. Eighteen rats received either a zinc supplementation i.p. or 0.9% NaCl i.p. (n = 18; control group). On postoperative days 3, 5, and 14, the surface of the mucosal villi, expression of MMP 2, MMP 8, MMP 13, TIMP 1, as well as the collagen types I/III ratio were analyzed.

RESULTS

Protein expression of MMP 2 and MMP 8 was significantly higher in the anastomosis of the zinc group on day 3 and on day 5. The collagen types I/III ratio was significantly increased in the zinc group on days 5 and 14.

CONCLUSION

Balancing zinc deficiency benefits wound healing of colonic anastomosis qualitatively due to an increased collagen type I/III ratio. Surprisingly, these zinc supplements, however, increased the expression of MMP 2 and MMP 8 that are supposed to impair wound healing in case of an over-expression. Thus, further investigations are needed to elucidate the influence of zinc supplementation on regulation of MMPs.