Citations

Background Bowel flaps are a good and reliable method to restore the continuity of the aerodigestive tract. Radiated fields, contaminated recipient sites, or depleted recipient vessels may increase the risk for ischemic injury after transfer. During ischemic events, we believe that bowel conduits with serosa have a delayed neovascularization process at its new recipient site.We conducted an ischemia/reperfusion murine model to understand the difference among bowel conduits with and without serosa. Materials and Methods Two groups of rats were compared: control group (jejunal conduit with serosa) and a target group (jejunal conduit without serosa). These conduits were harvested from the peritoneal cavity and transferred into a subcutaneous pocket. After 72 hours of transfer and pedicle ligation, histological changes related to ischemia/reperfusion were assessed. In addition, tissue markers of angiogenesis (CD34), ischemia (lactate dehydrogenase [LDH]), and inflammation (interleukin [IL]-1β and IL-6) were analyzed. Results Two groups (n = 20) of male rats were analyzed. Histology showed intact jejunal mucosa in the target group. The control group showed decreased number of mucin, globet cells, decreased height, and fragmentation of villi with the absence of intestinal glands. Markers of angiogenesis (CD34) were higher in the target group. In addition, markers of ischemia (LDH) (p = 0.0045) and inflammation (IL-1b, p = 0.0008, and IL-6, p = 0.0008) were significantly lower in the target group as compared with the control group. Conclusions In circumstances in which the recipient site does not offer an adequate and healthy bed or a vascular insult occurs, bowel flaps with less amount of serosa may be able to neovascularize faster thereby increasing its chances of survival.

Background: Strict glycemic control is known to be a vital key in the management of diabetes mellitus (DM). However, traditional methods face limitations in their efficacy due to the pain and invasiveness of needle pricking which often discourages DM patients from performing the required number of tests per day. Saliva glucose (SG) sensing has long been considered a noninvasive alternative to blood glucose monitoring for diabetes management, however the sample preparation and sensor detection limit have been deemed as challenges to overcome. Herein, we describe a preliminary clinical validation of a disposable SG sensor without any requirement for sample preparation. Methods: The sensor utilizes glucose dehydrogenase flavine-adenine dinucleotide (GDH-FAD) in conjunction with disposable screen printed electrodes to measure glucose levels in saliva collected directly from 9 healthy subjects. Cyclic voltammetry and amperometric-time (Amp-it) assays were used to develop calibration curves and test subjects. Sensor calibration was performed using simulated saliva at 6.5 pH and 37ºC. Results: The lower limit of detection was determined to be 0.11 mg/dL. A lag time of 15 minutes with a positive correlation between SG and BG levels was found, which agrees with literature results. The detected SG ranges from 2.38 to 3.40 mg/dL over a BG range of 90 to 143 mg/dL. Conclusion: This is the first reported use of measuring SG with GDH-FAD without prior sample preparation. Upon optimization, the sensor has the potential to serve as a supplement to blood glucose monitoring.

Background Patients diagnosed with end-stage renal disease (ESRD) are increasing at around 5% annually. Some of these patients will require free tissue transfers to reconstruct their body after trauma or cancer resection. Comorbidities can increase the level of complexity during reconstruction. Aim Our goal is to describe the outcomes of ESRD patients under dialysis who underwent free tissue transfer for head and neck reconstruction. Methods Two cohorts were analyzed: ESRD group on dialysis and a non-ESRD control group after free tissue transfer for head and neck reconstruction. Postoperative complications and mortality were recorded. For coexisting comorbidities, we determine the presence of diabetes mellitus (DM) and peripheral vascular disease (PVD). Results In this study, 85 cases with ESRD on dialysis and 841 controls were analyzed. Most patients were aged ≤ 65 years (82.5%) and nearly 92.9% of them were men. Types of head and neck cancer were neoplasm of other and unspecified parts of the mouth followed by neoplasm of tongue, the gingiva, hypopharynx, and floor of mouth. Patients with ESRD tended to have higher rates of DM and PVD (p < 0.001) and were significantly associated with an increased risk of stroke and increased risk of 30-day mortality. However, there was no significant difference regarding flap failure among groups. Conclusion Despite greater preoperative risk factors, patients with renal failure on hemodialysis do not appear to have a higher rate of free flap failure following head and neck reconstruction. However, other complications can be minimized by optimizing patient's medical condition to succeed with this reconstructive effort.

Vascularized lymph node (VLN) transfer has been of high interest in the past decade for the treatment of lymphedema, since it has been shown to be effective in reducing limb volumes, decreasing infectious episodes and improving quality of life. Multiple donor sites have been described in the quest for the optimal one. Herein, we describe a novel lymph node flap option based on the ileocolic artery and vein. The ileocecal vascularized lymph node (IC‐VLN) flap was used in the management of a 33‐year‐old male patient with lower extremity lymphedema secondary to left inguinal trauma. The patient had previously underwent a pedicled omentum flap transposition with minimal improvement in limb size and persistent episodes of infection. At 15 month follow‐up, the IC‐VLN flap improved the lymphatic drainage in the affected limb with a mean limb circumference reduction rate of 26.3%. No donor site complications or further episodes of infection were noted. According to our findings, the IC‐VLN flap may be another option for VLN transfer in very selected cases. Nevertheless, larger series with a longer follow‐up are required to analyze the efficacy and long‐term results of this flap.

The large conductance Ca2+-activated K+ (BK) channel β1-subunit (BK-β1) is a key modulator of BK channel electrophysiology and the downregulation of BK-β1 protein expression in vascular smooth muscle cells (SMCs) underlies diabetic vascular dysfunction. In this study, we hypothesized that the nuclear factor erythroid-2–related factor 2 (Nrf2) signaling pathway plays a significant role in the regulation of coronary BK channel function and vasodilation in high-fat diet (HFD)–induced obese/diabetic mice. We found that the protein expressions of BK-β1 and Nrf2 were markedly downregulated, whereas those of the nuclear factor-κB (NF-κB) and the muscle ring finger protein 1 (MuRF1 [a ubiquitin E3 ligase for BK-β1]) were significantly upregulated in HFD mouse arteries. Adenoviral expression of Nrf2 suppressed the protein expressions of NF-κB and MuRF1 but enhanced BK-β1 mRNA and protein expressions in cultured coronary SMCs. Knockdown of Nrf2 resulted in reciprocal changes of these proteins. Patch-clamp studies showed that coronary BK-β1–mediated channel activation was diminished in HFD mice. Importantly, the activation of Nrf2 by dimethyl fumarate significantly reduced the body weight and blood glucose levels of HFD mice, enhanced BK-β1 transcription, and attenuated MuRF1-dependent BK-β1 protein degradation, which in turn restored coronary BK channel function and BK channel–mediated coronary vasodilation in HFD mice. Hence, Nrf2 is a novel regulator of BK channel function with therapeutic implications in diabetic vasculopathy.

BK channels are major ionic determinants of vasodilation. BK channel function is impaired in diabetic vessels due to accelerated proteolysis of its beta-1 (BK-β1) subunits in response to increased oxidative stress. The nuclear factor E2-related factor-2 (Nrf2) signalling pathway has emerged as a master regulator of cellular redox status, and we hypothesized that it plays a central role in regulating BK channel function in diabetic vessels. We found that Nrf2 expression was markedly reduced in db/db diabetic mouse aortas, and this was associated with significant downregulation of BK-β1. In addition, the muscle ring finger protein 1 (MuRF1), a known E-3 ligase targeting BK-β1 ubiquitination and proteasomal degradation, was significantly augmented. These findings were reproduced by knockdown of Nrf2 by siRNA in cultured human coronary artery smooth muscle cells. In contrast, adenoviral transfer of Nrf2 gene in these cells downregulated MuRF1 and upregulated BK-β1 expression. Activation of Nrf2 by dimethyl fumarate preserved BK-β1 expression and protected BK channel and vascular function in db/db coronary arteries. These results indicate that expression of BK-β1 is closely regulated by Nrf2 and vascular BK channel function can be restored by Nrf2 activation. Nrf2 should be considered a novel therapeutic target in the treatment of diabetic vasculopathy.

AbstractBackgroundVascularized lymph node (VLN) transfer for lymphedema treatment has shown promising results. Optimal donor and recipient sites remain a matter of debate. We describe the technique and outcomes of a laparoscopically harvested extended gastroepiploic VLN flap with two levels of inset.Patients and MethodsBetween 2014 and 2015, four‐patients with upper limb breast cancer‐related lymphedema and three‐patients with lower limb pelvic cancer‐related lymphedema who underwent VLN transfers were included. After harvest, the gastroepiploic VLN flap was divided into two halves that were separately inset at the level of elbow and wrist (upper limb) or knee and ankle (lower limb). The mean patient age was 53.1 years (range, 42–65 years).ResultsThe average flap size after division was 6.3 cm in length (range, 5–7 cm) and 3.4 cm in width (range, 3–4 cm). The mean pedicle length was 3.2 cm (range, 2.5–4 cm). All flaps survived completely. No donor or recepient site complication was noted. At a mean follow‐up of 9.7 months (range, 8–11 months), the mean circumference reduction rate was 43.7 ± 2.5% along the entire limb (P < 0.05). No episode of infection was noted postoperatively.ConclusionsDouble gastroepiploic VLN transfers to middle and distal limb are a safe approach with very promising results. This technique may be used to improve clinical outcomes by enhancing the lymphatic drainage of the entire affected limb in a uniform fashion. In addition, the laparoscopic harvest can provide decreased donor site morbidity with a faster recovery.