Long-term outcome and prognostic factors of syringo-subarachnoid shunt for syringomyelia.

BACKGROUND: Syringo-subarachnoid shunt (SSS) is often considered a rescue procedure or a second-line treatment option for syringomyelia. However, the clinical efficacy of SSS in treating this condition remains controversial. OBJECTIVE: To evaluate the long-term outcome of the SSS and its relationship with the syrinx area, as well as to investigate the factors that influence the prognosis. METHODS: This retrospective study included twenty-seven consecutive patients who underwent SSS between 2014 and 2020. The study evaluated several independent variables such as age, sex, duration of progressive symptoms, morphological characteristics of the syrinx, changes in the syrinx area, and Chiari malformation. The long-term follow-up (>2 years) Japanese Orthopaedic Association (JOA) score was used to assess neurological function and outcome. Statistical analysis was performed using a stepwise logistic regression test. RESULTS: All patients were followed up for an average of 48.6 ± 14.8(26.8 to 78.0) months. Follow-up magnetic resonance imaging showed syrinx collapse to different degrees occurred in 96.3% (26 of 27) patients. The JOA score was improvedinonly6patients (22.2%), remained stable in 5 patients (18.5%),and deteriorated in 16 patients(59.3%).A logistic regression test showed that the tension syrinx (odds ratio 0.111) and early shunting intervention (odds ratio 0.138) were favorable independent prognostic factors. CONCLUSIONS: It is important to note that the shrinkage of the syrinx does not necessarily translate to an improvement in clinical outcomes. Therefore, the decision to perform SSS should be made with caution and considered as a last resort.

Clinical management and prognosis of spinal myxopapillary ependymoma: a single-institution cohort of 72 patients.

PURPOSE: Myxopapillary ependymoma (MPE) was classified as grade 2 tumor in the 2021 World Health Organization central nervous system classification because of its high recurrence probability. This study aimed to investigate predictive factors and management of tumor recurrence. METHODS: Seventy-two patients with spinal MPE underwent initial surgical treatment at our hospital between 2011 and 2021. Kaplan-Meier curves and Cox regression were used to analyze the correlation between clinical variables and progression-free survival (PFS). RESULTS: The median age at diagnosis was 33.5 years (range 8-60 years). Twenty-one patients (29.2%) had preoperative spinal drop metastases. Gross total resection (GTR) was performed in 37 patients (51.4%). The median follow-up was 7.2 years, and the follow-up rate was 88.9% (64 of 72 cases). Twelve of the 64 patients (18.9%) relapsed, and preoperative drop metastasis occurred in 7 patients (58.3%). The estimated 5-year and 10-year PFS rates were 82% and 77%, respectively. Univariate analysis showed that GTR was associated with improved PFS (hazard ratio [HR] 0.149, p = 0.014), while preoperative drop metastasis (HR 3.648, p = 0.027) and tumor involvement sacrococcygeal region (HR 7.563, p = 0.003) were associated with tumor recurrence. Adjuvant radiotherapy (RT) was significantly associated with improved PFS in patients with preoperative drop metastasis (p = 0.039). CONCLUSION: Complete surgical resection under the premise of protecting neurological function is an important factor in reducing spinal MPE recurrence. Adjuvant RT is recommended when the tumor invades the capsule with preoperative drop metastasis or adhesion to the nerve and cannot reach GTR.

Long-term outcomes of foramen magnum decompression with duraplasty for Chiari malformation type I in adults: a series of 297 patients.

OBJECTIVE: Foramen magnum decompression with duraplasty (FMDD) is one of the most frequently utilized surgical treatments for Chiari malformation type I (CMI) in adults. However, its long-term outcomes remain controversial. The object of this study was to evaluate the long-term outcomes of FMDD in adults with CMI. METHODS: In total, 297 adults with CMI who had undergone FMDD at the authors' institution between 2011 and 2020 were included in this retrospective study. Long-term (> 1 year) outcomes were evaluated using the Chicago Chiari Outcome Scale (CCOS), visual analog scale (VAS), and Japanese Orthopaedic Association (JOA) scale. RESULTS: The median patient age was 44 years (range 18-65 years). The mean clinical follow-up period was 67 months (range 14-123 months). Compared with preoperative conditions, the postoperative syringomyelia regression rate was 91.3% (242/265), and the cerebellar tonsil ascended in 18.2% of patients (54/297), was stable in 64.3% (191/297), and continuously descended in 17.5% (52/297). Long-term clinical follow-up data were acquired from 267 patients. According to the CCOS score, the patient's condition improved in 62.5% of cases (167/267), was stable in 31.8% (85/267), and worsened in 5.6% (15/267). According to the VAS score, the patient's condition improved in 59.5% of cases (110/185), remained unchanged in 27.6% (51/185), and worsened in 13.0% (24/185) among the follow-up patients with relevant data. According to the JOA score, the patient's condition improved in 40.1% of cases (107/267), remained unchanged in 50.2% (134/267), and worsened in 9.7% (26/267). Notably, there was no association between clinical outcomes and syringomyelia regression (p = 0.227) or changes in the cerebellar tonsillar position (p = 0.323). CONCLUSIONS: FMDD is a simple, safe, and effective surgical procedure for adult CMI that yields significant and sustained improvement in clinical and radiological outcomes. However, clinical improvement does not always correlate with syringomyelia regression and cerebellar tonsillar shift.

Spinal Cord Diffuse Midline Gliomas With H3 K27m-Mutant: Clinicopathological Features and Prognosis.

BACKGROUND: "Diffuse midline glioma, H3 K27M-mutant" (DMG) mainly arises within the pontine, thalamic, and spinal cord regions. Because of the rarity of spinal cord gliomas, the general knowledge surrounding DMGs is mainly based on pontine and thalamic gliomas, whereas tumor location tends to influence the clinicopathological features and prognosis. OBJECTIVE: To determine the clinicopathological characteristics and molecular profiles of DMGs located in the spinal cord. METHODS: The clinical and molecular pathologic features and prognosis were comprehensively analyzed in a series of 44 patients with spinal cord DMGs. RESULTS: The median age was 36 yr, and 88.7% of patients (39/44) were adults (≥18 yr). Histopathologically, malignant grades included grade II (16 cases), grade III (20 cases), and grade IV (8 cases). Compared with patients with histological grade IV, patients with lower histological grade (grade II/III) were older (37 vs 24 yr, P = .020) and were associated with longer overall survival (24.1 vs 8.6 mo, P = .007). All 30 tested tumors were isocitrate dehydrogenase (IDH) wild type, and 96% of cases (22/23) presented with unmethylated O6-methylguanine-DNA methyltransferase. Univariate and multivariate analyses showed that histological grade and presurgery McCormick Scale scores were independent prognostic factors for overall survival, whereas extensive surgical resection and chemoradiotherapy were not significantly associated with improved survival. The most frequent anatomic locations were the cervical enlargement (C4-T1, n = 16) and conus medullaris (T12-L1, n = 13), which exhibited distinctive clinical characteristics and molecular features. CONCLUSION: The findings provide guidelines for the evidence-based practice of the specialized management of spinal cord DMGs.

A comprehensive model including preoperative peripheral blood inflammatory markers for prediction of the prognosis of diffuse spinal cord astrocytoma following surgery.

PURPOSE: Due to the rarity of diffuse spinal cord astrocytoma, an effective model is still lacking to stratify their prognosis. Here, we aimed to establish a prognostic model through comprehensively evaluating clinicopathological features and preoperative peripheral blood inflammatory markers in 89 cases. METHODS: We performed univariate and multivariate Cox regression to identify prognosis factors. The Kaplan-Meier curves and ROC curves were employed to compare the prognostic value of selected factors. RESULTS: In addition to clinicopathological factors, we revealed the preoperative peripheral blood leukocyte count, neutrophils-to-lymphocytes ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were also significantly correlated with overall survival of spinal cord astrocytoma in univariate Cox regression, and NLR was still significant in multivariate Cox analysis. Further, we demonstrated that NLR ≤ 3.65 and preoperative McCormick score (MMS) ≤ 3 were independently correlated with better survival of WHO grade IV tumors. Meanwhile, Ki-67 < 10% and resection extent ≥ 90% were independent prognostic factors in WHO grade II/III tumors. Finally, we developed a prognostic model that had better predictive efficiencies than WHO grade and histological grade for 1-year (AUC = 76.6), 2- year (AUC = 80.9), and 3-year (AUC = 80.3) survival. This model could classify tumors into 4 classifications with increasingly poor prognosis: 1, WHO grade II/III, with Ki-67 < 10% and resection extent ≥ 90%; 2, WHO grade II/III, Ki-67 ≥ 10% or resection < 90%; 3, WHO grade IV, NLR ≤ 3.65 and MMS ≤ 3; 4, WHO grade IV, with NRL > 3.65 or MMS = 4. CONCLUSION: We successfully constructed a comprehensive prognostic model including preoperative peripheral blood inflammatory markers, which can stratify diffuse spinal cord astrocytoma into 4 subgroups.

Clinicopathological characteristics and survival of spinal cord astrocytomas.

BACKGROUND: Due to their rarity, the clinicopathological characteristics and prognostic factors of spinal cord gliomas are still unclear. Here, we aimed to clarify these issues in a cohort of 108 spinal cord astrocytomas. METHODS: We characterized the clinicopathological characteristics, including 2016 World Health Organization (WHO) grade, age, sex, location, segment length, resection, pre- and postsurgery, Modified McCormick Scale (MMS), radio- and chemotherapy, and Ki-67 and H3 K27M mutations, in 108 spinal cord astrocytomas through heatmaps. The Cox regression analysis and Kaplan-Meier curves were used to study the prognostic value of these clinicopathological features. RESULTS: There are a total 38 H3 K27M-mutant tumors, including 31 cases with histological grade II/III tumors. The age of low-grade astrocytoma patients (WHO grade I/II, n = 54) was significantly younger (27.0 vs 35.5 years, P = .001) than those with high-grade tumors (WHO grade III/IV, n = 54). All patients underwent surgical resection with neurophysiological monitoring, and the surgery did not result in significant changes in MMS. The presurgery MMS was associated with overall survival in the high-grade subgroup (P = .008) but not in the low-grade subgroup (P = .312). While, the high content of resection improved the survival of only patients with low-grade astrocytomas (P = .016) but not those with high-grade astrocytomas (P = .475). Both the low-grade and high-grade astrocytomas had no obvious benefit from neither adjuvant chemotherapy nor radiotherapy (all P > .05). CONCLUSIONS: We characterized the clinicopathological characteristics and their prognostic values in 108 spinal cord astrocytomas, which could help with evidence-based management of spinal cord astrocytomas.

[Mercury Distribution Characteristics and Its Mass Balance in a Multifunctional Urban Wetland].

The distribution characteristics and the source-sink relationship of total mercury (THg) and methyl mercury (MeHg) were studied in a wastewater treatment area and in a lake deep purification area of a multifunctional urban wetland that integrates domestic sewage treatment plant effluent, water purification, and leisure entertainment in Chongqing. The results showed that the THg concentration ranged from 1.98 ng·L-1 to 38.03 ng·L-1[average concentration was (9.10±5.84) ng·L-1] and MeHg concentration ranged from 0.09 ng·L-1 to 0.84 ng·L-1[average concentration was (0.34±0.08) ng·L-1] in an outlet of wastewater treatment area. In the deep purification zone, the THg concentration ranged from 0.37 ng·L-1 to 85.69 ng·L-1[average concentration of (6.76±2.29) ng·L-1] and the MeHg concentration ranged from 0.04 ng·L-1 to 1.47 ng·L-1[average concentration of (0.35±0.17) ng·L-1]. The interference of human activities on mercury concentration is prominent. The vertical distribution of THg in the water is consistent with that of MeHg, the surface layer has lower values than the deep layer. Material balance suggested that THg in the wetland system decreases by 155.50 g per year, and MeHg decreases by 1.65 g per year, which has a protective effect on the downstream water.

[Distribution Characteristics of Mercury in Different Urban Constructed Wetlands].

To explore the spatial and temporal distribution and the methylation characteristics of mercury in different constructed wetlands in cities, and to understand the potential ecological exposure of mercury in urban wetlands, four artificial wetlands in Chongqing were studied from March 2017 to March 2018. The water samples were collected separately in four quarters, and the mass concentration of total mercury (THg) and methyl mercury (MeHg) was researched for one year. The results showed that the THg concentration in the four wetland waters is higher than the background value of the world's lakes and reservoirs for dam construction, but it is far lower than the waters with pollution history. The THg mass concentration of the water inside the wetlands is slightly higher than in the inlet and outlet. In addition, the THg mass concentration in the aquatic plant growing area, the construction area, the cruise ship parking area, and the frequent play area has an increasing trend, indicating that urban wetlands have a trapping and converging effect of the water's THg, so human activities influence total mercury a lot. The mass concentration of MeHg in the four wetland waters was slightly higher than that in other water bodies. With the exception of the Caiyun Lake, where the mass concentration of MeHg at the outlet was higher than that of the water inlet, the other three wetlands showed lower MeHg mass concentration in the outlet than the inlet. The mass concentration of MeHg in the wetland water increased with increasing water depth. The ratio of MeHg concentration to THg mass concentration (MeHg/THg) was higher than in other waters, indicating that urban wetlands have effect on net mercury methylation from waters. The photoreduction of mercury and its absorption by aquatic plants can reduce the mercury load from urban wetlands to downstream watersheds. The THg mass concentration of the four urban wetland water bodies was high in the spring and autumn, with a slight decrease in the summer, and lowest in the winter. The mass concentration of MeHg was the lowest in winter, and in the other three seasons it was basically flat, about three times higher than in winter. This study clarifies the temporal and spatial distribution and methylation of mercury in urban wetlands. It explores the degree of disturbance of human activities on wetlands and the response characteristics, as well as the impact of wetland mercury on downstream watersheds. To avoid potential mercury exposure, measures need to be established for the construction of artificial wetlands.

Tissue electrical properties monitoring for the prevention of pressure sore.

BACKGROUND: Pressure sores are a significant problem in the healthcare sector. Although they may cause considerable morbidity, they are preventable. OBJECTIVES: The objectives of this study are to (1) investigate the electrical properties of a tissue close to and away from the pressure sore site, and (2) establish a new approach for objective, reliable, low-cost and noninvasive screening or detection of pressure sore in its early stage. STUDY DESIGN: Randomised controlled trial. METHODS: Fifteen patients participated in this study. They all had stage I or stage II sacral pressure sores. Tiny surface electrodes in four-electrode configuration were used for all tissue electrical properties measurements recorded over the frequency range of 30-10 MHz. RESULTS: Intraclass correlation coefficient (ICC) showed that all measurements (ICC > 0.90 for all measurements) had good reliability and validity. The real part of impedance (R) and the imaginary part of impedance (X) of a tissue measured close to the pressure sore site was found to be significantly smaller (p < 0.05 in all cases) than that measured away from the pressure sore site at a specific frequency range (R: 30.00-38.55 Hz; X: 43.95-606.40 Hz). It was also found that the extracellular resistance (R(e)) and the ratio of extracellular resistance to intracellular resistance (R(e)/R(i)) of a tissue measured close to the pressure sore site were significantly smaller (p < 0.05 in all cases) than that measured away from the pressure sore site. CONCLUSIONS: Since the electrical properties (R, X, R(e), R(e)/R(i) ) of a tissue close to, and away from, the pressure sore site can be significantly distinguished, a potentially promising method for the screening of pressure sores at an early stage has been proposed.

Non-invasive and transdermal measurement of blood uric acid level in human by electroporation and reverse iontophoresis.

The aim of this study was to find out the optimum combination of electroporation (EP) and reverse iontophoresis (RI) on noninvasive and transdermal determination of blood uric acid level in humans. EP is the use of high-voltage electric pulse to create nano-channels on the stratum corneum, temporarily and reversibly. RI is the use of small current to facilitate both charged and uncharged molecule transportation across the skin. It is believed that the combination of these two techniques has additional benefits on the molecules' extraction across the human skin. In vitro studies using porcine skin and diffusion cell have indicated that the optimum mode for transdermal uric acid extraction is the combination of RI with symmetrical biphasic direct current (current density = 0.3 mA/cm²; phase duration = 180 s) and EP with 10 pulses per second (voltage = 100 V/cm²; pulse width = 1 ms). This optimum mode was applied to six human subjects. Uric acid was successfully extracted through the subjects' skin into the collection solution. A good correlation (r² = 0.88) between the subject's blood uric acid level and uric acid concentrations in collection solutions was observed. The results suggest that it may be possible to noninvasively and transdermally determine blood uric acid levels.

Carbon nanotube composites for glucose biosensor incorporated with reverse iontophoresis function for noninvasive glucose monitoring.

This study aims to develop an amperometric glucose biosensor, based on carbon nanotubes material for reverse iontophoresis, fabricated by immobilizing a mixture of glucose oxidase (GOD) and multiwalled carbon nanotubes (MWCNT) epoxy-composite, on a planar screen-printed carbon electrode. MWCNT was employed to ensure proper incorporation into the epoxy mixture and faster electron transfer between the GOD and the transducer. Results showed this biosensor possesses a low detection potential (+500 mV), good sensitivity (4 microA/mM) and an excellent linear response range (r(2) = 0.999; 0-4 mM) of glucose detection at +500 mV (versus Ag/AgCl). The response time of the biosensor was about 25 s. In addition, the biosensor could be used in conjunction with reverse iontophoresis technique. In an actual evaluation model, an excellent linear relationship (r(2) = 0.986) was found between the glucose concentration of the actual model and the biosensor's current response. Thus, a glucose biosensor based on carbon nanotube composites and incorporated with reverse iontophoresis function was developed.

The use of bioimpedance in the detection/screening of tongue cancer.

Oral cancers are the 11th most common malignancy reported worldwide, accounting for 3% of all newly diagnosed cancer cases, and one with high mortality ratios among all malignancies. The objectives of this study were therefore to study the electrical properties of cancerous tongue tissue and normal tongue tissue, as well as to investigate a new approach for low-cost, noninvasive, and real-time screening of oral cancer. Twelve tongue cancer patients and twelve healthy subjects participated in this study. A disposable probe with four silver electrodes was used to measure the electrical properties of patient's and healthy subject's tongue tissues at six different frequencies, which were 20Hz, 50kHz, 1.3MHz, 2.5MHz, 3.7MHz and 5MHz. The amplitude of the applied voltage was limited to 200mV. Four measurement parameters of impedance, phase angle, real part of impedance, and imaginary part of impedance of tongue were assessed to see if significant difference in values obtained in patient's and healthy subject's tongue tissues existed. Intraclass correlation coefficient showed that all measurements had good reliability and validity (ICC>0.95 for all measurements). Significant differences were found at 20Hz (p<0.05-0.001 for the four measurement parameters) and 50kHz (p<0.001 for the four measurement parameters) between patient's and healthy subject's tongue tissues. In conclusion, bioimpedance at a particular frequency is a potentially promising technique for tongue cancer screening.