[Effect of accurately localized mini anterolateral thigh perforator flap in repairing medium-sized skin and soft tissue defects in fingers]

Objective: To explore the effect of accurately localized mini anterolateral thigh perforator flap in repairing medium-sized skin and soft tissue defects in fingers. Methods: The study was a retrospective observational study. From December 2019 to September 2022, 15 patients with medium-sized skin and soft tissue defects who met the inclusion criteria in fingers were admitted to the Second Affiliated Hospital of Wenzhou Medical University, including 12 males and 3 females, aged 23 to 62 years. After debridement, the wounds were all accompanied by exposed tendons, bones, vessels and nerves, with an area from 4.0 cm×3.0 cm to 8.0 cm×3.5 cm. Computed tomography angiography and color Doppler ultrasonography examinations were performed on both lower limbs of the patient before surgery to accurately locate the anterolateral thigh perforators. When the flap with area from 6.0 cm×3.0 cm to 11.0 cm×4.0 cm was harvested, the flap was thinned. The artery and vein perforators of the flap were anastomosed respectively with the digital artery and dorsal metacarpal vein. If there was avulsion injury, infection, or burn in the recipient area, the main arterial and veinous vessels carried by the skin flap was anastomosed with the radial artery and accompanying vein. The lateral thigh cutaneous nerve carried by the flap was anastomosed with the stump of the digital nerve. The types of perforators of the lateral thigh artery were observed during operation and compared with the location of the vessels before operation. After operation, the survival and adverse complication of the flap were closely observed. During follow-up, the skin flap color, texture, and shape were observed; the wound healing in donor area was observed. At the last follow-up, the two-point discriminative distance of the affected finger pulp was measured, and the function of the affected finger was evaluated using the trial standard for the evaluation of functions of upper limbs of Hand Surgery Society of Chinese Medical Association, and the interphalangeal joint movement of the affected finger was observed; the patients' complaints about the adverse effects of flap resection on lower limbs were recorded. Results: During the operation, it was observed that the perforators of the flaps in 11 patients were the descending branch of the lateral circumflex thigh artery, in two patients, the perforators of skin flaps were the oblique branch of the lateral thigh artery, and the perforators in another two patients were the transverse branch of the lateral circumflex thigh artery, which were consistent with the preoperative vascular localization. After operation, all flaps survived without vascular crisis and infection. The patients were followed up for 6-12 months, the flaps had excellent color, texture, and appearance; only linear scars remained on the donor wound. At the last follow-up, the two-point discrimination distance in the finger pulp was 7-11 mm; the affected finger function was rated as excellent in 6 cases, good in 6 cases, and fair in 3 cases; the flexion and extension function of the finger was not affected; two patients complained of numbness in the lateral thigh after excision of the skin flap, and the other 13 patients had no complain of adverse complaints. Conclusions: The perforating branch in lateral thigh region can be accurately located by computed tomography angiography and color Doppler ultrasonography, accurate positioning of perforators before operation can reduce the damage to the donor area during the incision of the flap, the appearance and function of the affected finger can be restored to the maximum extent by thinning the transplanted flap and rebuilding the finger sensation. Therefore, it is an effective and reliable way to repair the medium-sized skin and soft tissue defects of fingers with the mini thigh anterolateral perforator flap.

Exploratory Multisite MR Spectroscopic Imaging Shows White Matter Neuroaxonal Loss Associated with Complications of Type 1 Diabetes in Children

BACKGROUND AND PURPOSE

Type 1 diabetes affects over 200,000 children in the United States and is associated with an increased risk of cognitive dysfunction. Prior single-site, single-voxel MRS case reports and studies have identified associations between reduced NAA/Cr, a marker of neuroaxonal loss, and type 1 diabetes. However, NAA/Cr differences among children with various disease complications or across different brain tissues remain unclear. To better understand this phenomenon and the role of MRS in characterizing it, we conducted a multisite pilot study.

MATERIALS AND METHODS

In 25 children, 6-14 years of age, with type 1 diabetes across 3 sites, we acquired T1WI and axial 2D MRSI along with phantom studies to calibrate scanner effects. We quantified tissue-weighted NAA/Cr in WM and deep GM and modeled them against study covariates.

RESULTS

We found that MRSI differentiated WM and deep GM by NAA/Cr on the individual level. On the population level, we found significant negative associations of WM NAA/Cr with chronic hyperglycemia quantified by hemoglobin A1c (P < .005) and a history of diabetic ketoacidosis at disease onset (P < .05). We found a statistical interaction (P < .05) between A1c and ketoacidosis, suggesting that neuroaxonal loss from ketoacidosis may outweigh that from poor glucose control. These associations were not present in deep GM.

CONCLUSIONS

Our pilot study suggests that MRSI differentiates GM and WM by NAA/Cr in this population, disease complications may lead to neuroaxonal loss in WM in children, and deeper investigation is warranted to further untangle how diabetic ketoacidosis and chronic hyperglycemia affect brain health and cognition in type 1 diabetes.

Erastin Reverses ABCB1-Mediated Docetaxel Resistance in Ovarian Cancer

Overexpression of drug efflux transport ABCB1 is correlated with multidrug resistance (MDR) among cancer cells. Upregulation of ABCB1 accounts for the recurrence of resistance to docetaxel therapy in ovarian cancer with poor survival. Erastin is a novel and specific small molecule that targets SLC7A11 to induce ferroptosis. In the present research, we explored the synergistic effect of erastin and docetaxel in ovarian cancer. We confirmed that the co-delivery of erastin with docetaxel significantly decreased cell viability, promoted cell apoptosis, and induced cell cycle arrest at G2/M in ovarian cancer cells with ABCB1 overexpression. Mechanistically, erastin dominantly elevated the intracellular ABCB1 substrate levels by restricting the drug-efflux activity of ABCB1 without alteration of the expression of ABCB1. Consequently, erastin can reverse ABCB1-mediated docetaxel resistance in ovarian cancer, revealing that the combination of erastin and docetaxel may potentially offer an effective administration for chemo-resistant patients suffering from ovarian cancers.

[Construction and assessment of a three-dimensional finite element model of mandibualr second molar mesialization using customized lingual appliance and mini-implant]

Objective: To construct a three-dimensional (3D) finite element model and analyze the biomechanical characteristics during mandibular second molar mesialization using customized lingual appliances and mini-implant. Methods: One adult student volunteer from The First Affiliated Hospital of Zhengzhou University with lower left first molar extraction was selected. After CT scanning, Mimics, Geomagic, ANSYS were employed to develop a 3D finite element model including customized lingual brackets, stainless steel lingual arch wire, buccal buckles, lower dentition, periodontal ligaments and alveolar bone. Four different loading methods (1. the force of 1.470 N loaded at the lingual side only; 2, 3, 4. the forces of 0.490, 0.735 and 0.980 N loaded at both buccal and lingual sides, respectively.) were included. The initial displacements of the lower second molar and stress distribution in the periodontal ligaments were analyzed. Results: More uniform stress distributions in the periodontal membrane of mandibular left second molar were found when the mesial force were loaded at both buccal and lingual sides than the force loaded at lingual side only. More inclination of the second molar was observed when force loaded at both sides than at lingual side only. With the values of the force increased, the mesial inclination potential of the second molar, the initial movement of the second molar and the stress distribution in the periodontal membrane increased. Under the force of 0.735 N at both buccal and lingual sides, mesially inclined initial displacements of the mandibuar second molar were observed and the stress values of von Mises was in the suitable area. Conclusions: Less second molar rotation was found when the force loaded at both buccal and lingual sides than loaded at lingual side only. However, force loaded at both sides would increase the measial inclination potential of the second molar.

[Application of Metagenomics in Forensic Identification]

With the development of molecular biology and genomics, metagenomics is playing a more important role in forensic science and forensic identification. In recent years, as a branch discipline studying the composition profile and diversity of microbe flora as well as studying the interaction within microbe and with environment, the application of metagenomics has gradually risen and brought new opportunities for forensic identification-related area. In this review, strategy of metagenomics and its application in forensic identification including individual identification, origin determination of biological stain in crime scene and drug abuse detection are summarized. This article aims to elucidate the role and application value of metagenomics in forensic science.

[Effects and related mechanism of bivalirudin on the survival of random skin flap on the back of rat]

Objective: To investigate the effects and related mechanism of bivalirudin on the survival of random skin flap on the back of rat. Methods: Thirty SD rats were divided into bivalirudin group and normal saline group according to the random number table, with 15 rats in each group. The random flap model with size of 9 cm×3 cm was reproduced on the back of rats in two groups. Immediately post injury, rats in bivalirudin group were intraperitoneally injected with 5 mg/mL bivalirudin (0.8 mL/kg), while rats in normal saline group were intraperitoneally injected with normal saline (0.8 mL/kg) once a day. The continuous injection lasted for 7 days. The flap was divided into distal area, middle area and proximal area averagely based on the flap blood supply. On post injury day (PID) 1, 3, and 7, the overall survival of each area of flap was observed with naked eyes. On PID 7, the survival rate of flap was calculated, and then the morphology of skin tissue at the center of the three areas of flap was observed by HE staining, the microvessel density (MVD) of the middle area of flap was calculated, and the expression of vascular endothelial growth factor (VEGF) of the middle area of flap was detected with immunohistochemical staining. Data were processed with t test. Results: (1) On PID 1, flaps of rats in two groups had different degrees of swelling, mainly concentrated in distal area, but there was no obvious necrosis. The middle area and proximal area of flaps in two groups were survived. On PID 3, the necrosis of flaps of rats in two groups was concentrated in the middle area, while the proximal area of flap was still in survival state, and most distal area of flap was necrosis with a little scab. On PID 7, the necrosis of middle area of flaps of rats in two groups was gradually fused, and the survival area of flap of rats in bivalirudin group was larger than that in normal saline group. The distal area of flap was almost necrotic, and the proximal area of flap was almost survived. (2) On PID 7, the survival rate of flap of rats in bivalirudin group was (64±4)%, significantly higher than that in normal saline group [(45±3)%, t=13.49, P<0.01]. (3) On PID 7, the histological morphology of distal area of flap of rats in two groups was similar, the inflammatory cells were infiltrated abundantly, and tissue edema was obvious. A large number of new blood vessels appeared in the middle area of flap of rats in bivalirudin group, with the formation of collateral vessels, and basic dilation of new blood vessels was seen. There were fewer new blood vessels appeared in the middle area of flap of rats in normal saline group, and dilation of new blood vessels was not obvious. There was little inflammatory cells infiltration in the proximal area of flap of rats in two groups. Compared with that in normal saline group, tissue edema extent of proximal area of flap of rats in bivalirudin group was less, and expansion was observed in more blood vessels. (4) The MVD of middle area of flap of rats in bivalirudin group was (26±5)/mm(2,) significantly higher than that in normal saline group [(18±3)/mm(2,) t=5.43, P<0.05]. (5) The expression of VEGF of middle area of flap of rats in bivalirudin group was 6 534±384, significantly higher than that in normal saline group (4 659±448, t=12.31, P<0.05). Conclusions: Bivalirudin can promote the survival of random skin flap in rats, and the mechanisms may include reducing the formation of thrombosis, improving the blood supply of flap, and increasing the expression of VEGF, promoting the formation of new blood vessels.

Preparation and malachite green adsorption behavior of polyurethane/chitosan composite foam

A series of Polyurethane/Chitosan composite foam with different chitosan content of 5–25 wt% was prepared, and their adsorption performance of malachite green (MG) in aqueous solutions was investigated by pH values, contact time, temperatures and chitosan content. It was observed that Polyurethane/Chitosan composite foam exhibited well-developed open cell structures. Malachite green adsorption capacities of the composite foam increased with the increment of chitosan content in composite foam. Polyurethane/Chitosan composite foam with 20% chitosan content exhibited a maximum removal capacity of 16.67 mg/g and 95.60% MG removal efficiency. In addition, MG adsorption capacities of composite foam increased with pH value increase, 30℃ was the optimum temperature, which affects the adsorption process, and the adsorption maximum was attained within 12 hours. The result of SEM showed the prepared composite foam possess well-developed open cell structures. The MG adsorption kinetics and equilibrium isotherm of the composite foam were well described with the pseudo-second order kinetic model and Langmuir isotherm model, respectively. This work provided an attractive adsorbent for removing of the hazardous materials from water.

Dioxins in ascites and serum of women with endometriosis: a pilot study

BACKGROUND

Animal studies and laboratory experiments have demonstrated that exposure to dioxins may be involved in the pathophysiology of endometriosis. However, recent epidemiological investigations have shown conflicting results. Although peritoneal fluid is a specific microenvironment playing a pivotal role in the development of endometriosis, to our knowledge, there is no published study evaluating the concentrations of dioxins in serum and peritoneal fluid simultaneously. The present study explores the possible correlation between the local peritoneal fluid levels of dioxins and concurrent endometriosis.

METHODS

There were 17 infertile women enrolled in the present study. After the diagnostic laparoscopic examination, the women were divided into two groups: endometriosis (n = 10) and controls (n = 7). We measured 29 dioxins simultaneously in serum and peritoneal fluid samples: 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), and 12 polychlorinated biphenyls (dioxin-like PCBs). A dioxin toxic equivalency (TEQ) system was utilized to calculate the dioxin concentration in each sample.

RESULTS

Serum concentrations of itemized components of 29 dioxins were similar in the endometriosis patients compared with the controls. Higher concentrations of PCDFs and dioxin-like PCBs were observed in peritoneal fluid than in serum, whereas the reverse was shown for PCDDs. Statistical analysis showed that higher levels of dioxin TEQ (PCDDs and PCDFs) in peritoneal fluid were significantly associated with an increased risk of endometriosis (OR: 2.5; 95% CI: 1.17-5.34; P = 0.035).

CONCLUSIONS

This is the first report suggesting that higher concentrations of dioxins (PCDDs and PCDFs) in peritoneal fluid are linked to endometriosis. More detail and epidemiological research is warranted to further explore this link.

[Complexity analysis of surface EMG signals]

OBJECTIVE

Since the neurophysiological system is a highly nonlinear dynamic system, nonlinear dynamic information of EMG signals were extracted to describe its characteristics.

METHOD

Two-channel surface EMG signals were extracted and analyzed to reflect the complexity degree of the dynamics of the neurophysiological system.

RESULT

Complexity measures of four kinds of forearm motions were calculated and compared. They showed a good separability.

CONCLUSION

Experimental results proved that this measure, having a simple algorithm, is suitable for short data sets and suitable for real time processing. It provides a new measurable index for both physiological and pathological analysis.

[A surface EMG signal identification method based on short-time Fourier transform]

A surface EMG signal identification method based on short-time fourier transform is presented in this paper. To fully utilize the nonstationary character of the EMG signal, short-time fourier transform is employed to get the signal's time-frequency representation. Singular value decomposition is then used in the spectrogram to extract feature vector for pattern identification. Four types of movement of forearm, hand grasp, hand extension, wrist pronation and wrist supination can be identified from surface EMG signals. Experimental results show that it is a stable and efficient method for extracting features.