The role of electrode direction during axonal bipolar electrical stimulation: a bidomain computational model study

Background  

Direct electrical stimulation of cortical and axonal areas is widely used for brain mapping of functional areas during intraparenchymatous resections. However, there are very few data (be they experimental or computational) regarding the exact volume of activated axons surrounding the bipolar electrodes. The aim of this study was to provide a computational model to estimate the regions in which electrical stimulation will generate an action potential in the axons.     

Primary sensory neurons with dichotomizing axons projecting to the facet joint and the low back muscle in rats

Background

Clinically, the origin of low back pain is unknown. The pain may originate from the lumbar muscles directly, or it may be referred pain from the spine. Dorsal root ganglion (DRG) neurons with dichotomizing axons have been reported in several species and are thought to be related to referred pain. However, these neurons, which have dichotomizing axons to the lumbar facet joints and to the lumbar muscle, have not been fully investigated.

Methods

Two neurotracers — 1,1′-dioctadecyl-3,3,3′,3′- tetramethyl-indocarbocyanine perchlorate (DiI) and fluorogold (FG) — were used in the present double-labeling study. DiI crystals were placed in the right L5/6 facet joint, and FG was applied to right multifidus muscles at the L5 level in 10 rats. Two weeks later, bilateral DRGs from L1 through L6 were harvested, sectioned, and observed under a fluorescence microscope.

Results

DiI-labeled DRG neurons innervating the L5/6 facet joint (5.17% of the total DRG neurons) were distributed from L1 to L6. FG-labeled DRG neurons innervating the lower back muscle (15.9% of the total) were also distributed from L1 to L6. Double-labeled DRG neurons were found from L1 to L6. The ratio of total double-labeled/total DiI-labeled DRG neurons was 17% and that of total double-labeled/total FG-labeled DRG neurons was 7%. Approximately 17% of all DRG neurons innervating the facet joints had other axons that extended to the lower back muscle.

Conclusions

This finding provides a possible neuroanatomical explanation for referred low back muscle pain from the lower facet joints.     

Follow-up investigation of open trigger digit release

Purpose  

The purpose of this retrospective study was to identify the postoperative complications and disorders associated with open trigger finger release. Factors that were investigated by this study included demographic details, the number of digits affected, BMI, level of manual strain, trauma, received systemic medication, hand dominance, pre-treatment with steroid injection, and concomitant diseases.     

An Algorithm Informed by the Parathyroid Hormone Level Reduces Hypocalcemic Complications of Thyroidectomy

Background  

Measurement of the parathyroid hormone (PTH) level following total thyroidectomy (TTx) may allow prediction of postoperative hypocalcemia. We present an algorithmic method of managing hypocalcemia pre-emptively, based on the PTH level 1 h after operation.     

Axon counts of potential nerve transfer donors for peroneal nerve reconstruction

BACKGROUND:

The common peroneal nerve is the most commonly injured nerve in the lower limb. Nerve transfer using expendable donor nerves is emerging in the literature as an alternative surgical procedure to traditional treatments.

OBJECTIVE:

To identify potential donors of motor axons from the tibial nerve that can be transferred to the common peroneal nerve branches.

METHODS:

Using 10 human cadaveric lower extremities, all motor nerve branches of the tibial nerve were identified and biopsied. These were compared with the motor branches to tibialis anterior and extensor hallucis longus (branches of the deep peroneal nerve).

RESULTS:

The most suitable donor nerves with respect to cross-sectional area to tibialis anterior (cross sectional area [mean ± SD] 0.255±0.111 mm) was the motor branch to lateral gastrocnemius (0.256±0.105 mm). When comparing the total number of axons, the branch to the tibialis anterior had a mean of 3363±1997 axons. The branch to the popliteus was most similar, with 3317±1467 axons. The most suitable donor nerves for the motor branch to extensor hallucis longus (cross sectional area 0.197±0.302 mm) with respect to cross-sectional area was the motor branch to flexor hallucis longus (0.234±0.147 mm). When comparing the total number of axons, the branch to the extensor hallucis longus had an average of 2062±2314 axons. The branch to the lateral gastrocnemius was most similar with 2352±1249 axons and was a suitable donor.

CONCLUSION:

Nerve transfers should be included in the armamentarium for lower extremity reinnervation, as it is in the upper limb.     

Enquête nationale sur l’utilisation du rémifentanil comme alternative à l’analgésie péridurale obstétricale dans les maternités de niveau II et III

Objectives

The last French survey on alternatives to neuraxial anaesthesia for labour pain was published in 1997. However, intravenous remifentanil has become increasingly used as an option for labour analgesia. We evaluated the use of remifentanil as an alternative to epidural analgesia in level 2 and 3 French maternities in 2009.

Study design

This was an internet-based French survey performed in 2009 including all level 2 and 3 maternities. Data recorded were maternity unit characteristic, alternatives to neuraxial analgesia used, and remifentanil administration protocols.

Results

Two hundred and forty maternity units received the survey and 103 responses were completed. A written institutional alternative analgesia protocol for labour pain was present in 78%. Alternative labour analgesia included intermittent nitrous oxide inhalation (58%), intravenous nalbuphine (52%), patient-controlled intravenous administration of remifentanil (52%) and sufentanil (46%). Pethidine administration was reported by one maternity unit (1%). The bolus dose of remifentanil scheduled, and background infusion varied widely between maternity units. The analgesic efficacy of remifentanil used for labour pain was evaluated as moderate (55%) or good (43%). Two serious adverse events were reported.

Conclusion

Intravenous administration of remifentanil was largely reported as an alternative to neuraxial anaesthesia for labour pain. Although remifentanil administration was most often based on a local written protocol, bolus dose and background infusion varied widely between maternity units.     

Loss via peritoneal fluid as a factor for low 25(OH)D3 level in peritoneal dialysis patients

Background/aims  

In patients with end-stage renal disease (ESRD), the 25-hydroxyvitamin D3 (25(OH)D3) level is known to be lower compared to that of the normal population. In the present study, we evaluated the influences of dialysis methods on the serum 25(OH)D3 level in patients with ESRD who are treated with hemodialysis and peritoneal dialysis.     

Role of progesterone in melatonin-mediated protection against acute kidney injury

Background

Melatonin is released by pineal gland and maintains circadian rhythm in the body. It has been reported as renoprotective agent because of its antioxidant property. Recently, a cross talk between progesterone and melatonin has been observed in various preclinical studies. The present study investigated the involvement of progesterone receptors in melatonin-mediated protection against ischemia reperfusion induced acute kidney injury (AKI) in rats.

Materials and methods

The rats were subjected to bilateral renal ischemia for 40 min followed by reperfusion for 24 h to induce AKI. The AKI was assessed by measuring creatinine clearance, serum urea, uric acid level, potassium level, fractional excretion of sodium, lactate dehydrogenase activity, and microproteinuria. The oxidative stress in renal tissues was assessed by quantification of myeloperoxidase activity, thiobarbituric acid reactive substances, superoxide anion generation, reduced glutathione level, and catalase activity. The hematoxylin–eosin staining was carried out to observe histopathologic changes in renal tissues. The melatonin (4 and 10 mg/kg, intraperitoneally) and progesterone receptor antagonist mifepristone (5 mg/kg, intraperitoneally) were used in the present study.

Results

The renal ischemia reperfusion induced AKI as indicated by significant change in serum, urinary, and tissue parameters that was ameliorated by prior treatment with melatonin. No significant difference in serum progesterone level was observed between various groups used in the present study. The prior administration of mifepristone abolished melatonin-mediated protection against AKI.

Conclusions

It is concluded that melatonin treatment affords protection against ischemia reperfusion induced AKI. Moreover, progesterone receptors are essentially involved in mediating protective role of melatonin against AKI in rats.     

A Phase I Study of Intraoperative Radiotherapy for Early Breast Cancer in Japan

Background  

The present study was designed to identify the optimal intraoperative radiotherapy (IORT) dose for early breast cancer in Japanese women.     

Concurrent schwannoma and intradural neuroma after resection of a cauda equina schwannoma. A case report and first description

Purpose  

We present the case of a 33-year-old female complaining of recurrent pain and sensory disturbance in both legs, 3 years after the removal of a schwannoma at the level of L2/3.     

Strain distribution in the lumbar vertebrae under different loading configurations

Background context

The stress/strain distribution in the human vertebrae has seldom been measured, and only for a limited number of loading scenarios, at few locations on the bone surface.

Purpose

This in vitro study aimed at measuring how strain varies on the surface of the lumbar vertebral body and how such strain pattern depends on the loading conditions.

Methods

Eight cadaveric specimens were instrumented with eight triaxial strain gauges each to measure the magnitude and direction of principal strains in the vertebral body. Each vertebra was tested in a three adjacent vertebrae segment fashion. The loading configurations included a compressive force aligned with the vertebral body but also tilted (15°) in each direction in the frontal and sagittal planes, a traction force, and torsion (both directions). Each loading configuration was tested six times on each specimen.

Results

The strain magnitude varied significantly between strain measurement locations. The strain distribution varied significantly when different loading conditions were applied (compression vs. torsion vs. traction). The strain distribution when the compressive force was tilted by 15° was also significantly different from the axial compression. Strains were minimal when the compressive force was applied coaxial with the vertebral body, compared with all other loading configurations. Also, strain was significantly more uniform for the axial compression, compared with all other loading configurations. Principal strains were aligned within 19° to the axis of the vertebral body for axial-compression and axial-traction. Conversely, when the applied force was tilted by 15°, the direction of principal strain varied by a much larger angle (15° to 28°).

Conclusions

This is the first time, to our knowledge, that the strain distribution in the vertebral body is measured for such a variety of loading configurations and a large number of strain sensors. The present findings suggest that the structure of the vertebral body is optimized to sustain compressive forces, whereas even a small tilt angle makes the vertebral structure work under suboptimal conditions.     

Clinicopathological Prognostic Factors After Hepatectomy for Patients with Mass-Forming Type Intrahepatic Cholangiocarcinoma: Relevance of the Lymphatic Invasion Index

Background  

The present study was conducted to clarify the pathological factors in patients who underwent surgery for mass-forming type intrahepatic cholangiocarcinoma (IHC).     

MicroRNA expression patterns of tumors in early-onset colorectal cancer patients

Background

The expression of microRNAs (miRNAs) may differ in tumors from patients with different ethnic origins and ages. The aims of the present study were to clarify the appropriate alterations of miRNA expression associated with the early stages of carcinogenesis in early-onset Turkish colorectal cancer (CRC) patients and to define specific biomarkers that could be used as new diagnostic and prognostic markers for this population.

Materials and methods

The expression profiles of 38 different miRNAs associated with CRC were evaluated using miRNA polymerase chain reaction arrays in tumors and surgical margin tissue samples from 40 sporadic early-onset Turkish CRC patients. The relationships between the miRNA expression profiles and the characteristics of the tumors and patients were evaluated.

Results

The expression of miR-106a was found to be upregulated, and miR-143 and miR-125b levels were found to be downregulated in tumor tissues compared with the normal tissues. The high expression level of miR-106a (2.93-fold; P = 0.031) and low expression level of miR-125b (2.42-fold; P = 0.063) were observed in tumors with lymph node metastases compared with the normal colorectal mucosa samples. However, the deregulation of these miRNAs was not significantly associated with survival (log-rank P > 0.05).

Conclusions

The present results implied that miR-106a and the miR-125b were associated with the formation and invasion of colorectal tumors. Thus, these miRNAs might be used as significant prognostic factors and indicators of early-stage CRC. Further studies and validations are required; these miRNAs may provide novel molecular targets for CRC treatment.     

Preoperative localizing studies for initial parathyroidectomy in MEN1 syndrome: is there any benefit?

Background  

The objective of the present study was to evaluate the utility of preoperative localizing studies in patients with MEN1 undergoing initial bilateral neck exploration (BNE) and parathyroidectomy for pHPT.     

Functional liver reserve parameters predictive for posthepatectomy complications

Background

Posthepatectomy complications have markedly decreased with advances in techniques and management; however, surgical risk to patients with injured livers is still not negligible. We evaluated several preoperative parameters of functional liver reserve tests in patients with various liver diseases as predictors of posthepatectomy complications. A comprehensive evaluation of preoperative liver functions is necessary for the prediction of the risk of posthepatectomy complications.

Methods

Over a 10-y period, we examined 442 patients who underwent hepatectomy for liver and biliary diseases. The patients' background liver diseases included chronic viral liver diseases in 211 patients, obstructive jaundice in 29 patients, and normal liver in 202 patients. Hepatectomy-related postoperative complications (i.e., long-term ascites, intra-abdominal infection, and hepatic failure) occurred in 115 (26%) patients. A multivariate logistic analysis was performed to detect the predictive parameters, and a multivariate linear regression analysis was performed to derive a predictive formula for complications.

Results

A univariate analysis identified 15 significant parameters associated with hepatectomy-related complications, and eight parameters (i.e., presence of chronic hepatic injury, clearance index by technetium-99 m galactosyl human serum albumin liver scintigraphy of ≥0.60, total bilirubin level of >1 mg/dL, serum hyaluronic acid level of ≥75 ng/mL, major hepatectomy, blood loss of ≥950 mL, operating time of ≥500 min, and combined resection of another organ or major vessel) were independent predictive factors identified in the multivariate analysis. Clearance index by technetium-99 m galactosyl human serum albumin liver, bilirubin level, hyaluronic acid level, and major hepatectomy were the parameters included in the predictive formula.

Conclusions

In the present study, we present a comprehensive formula based on the predictive parameters for hepatic complications for prospective assessment to avoid posthepatectomy morbidity.     

Initial Parathyroid Surgery in 606 Patients with Renal Hyperparathyroidism

Background  

The aim of the present study was to evaluate the outcome of different surgical procedures for patients on permanent dialysis who underwent initial parathyroidectomy for renal hyperparathyroidism (rHPT).     

Percutaneous endoscopic treatment of foraminal and extraforaminal disc herniation at the L5-S1 level

Background  

Microsurgery of foraminal and extraforaminal disc herniation at the L5-S1 level remains a challenge because of the limited access by a high iliac crest, the sacral ala, large transverse processes of L5 and hidden disc fragments lateral to the zygapophyseal joint. Our aim was to present the outcome of percutaneous endoscopic lumbar discectomy (PELD) of these lateral and far lateral disc herniations at the L5-S1 level using the newly described foraminal retreat technique in a group of patients with similar preoperative diagnostic studies.     

Timing and Risk Factors of Hepatectomy in the Management of Complications Following Laparoscopic Cholecystectomy

Introduction  

Complex bile duct injury (BDI) is a serious condition requiring hepatectomy in some instances. The present study was to analyse the factors that led to hepatectomy for patients with BDI after laparoscopic cholecystectomy (LC).     

Roux-en-Y Reconstruction is Superior to Billroth I Reconstruction in Reducing Reflux Esophagitis After Distal Gastrectomy: Special Relationship with the Angle of His

Background  

The aim of the present study was to evaluate the relationship between the angle of His in Roux-en-Y (RY) or Billroth I (BI) reconstruction and reflux esophagitis after distal gastrectomy for gastric cancer.     

Postoperative impairment of cognitive function in old mice: a possible role for neuroinflammation mediated by HMGB1, S100B,and RAGE

Background

Postoperative cognitive dysfunction, a common complication after surgery in elderly patients, is an increasing and largely underestimated problem without a defined etiology. Neuroinflammation plays an important role in the pathogenesis of postoperative cognitive dysfunction. The present study sought to investigate the role of neuroinflammation mediated by high-mobility group box 1 (HMGB1), S100B, and the receptor for advanced glycation end product (RAGE) in cognitive dysfunction after partial hepatectomy in aged mice.

Materials and methods

Old C57BL/6 mice were randomly divided into three groups: normal control (n = 18), anesthetic (n = 66), and surgery (n = 66). The mice in the surgery or anesthetic group received isoflurane anesthesia for either partial hepatectomy or no surgery, respectively. Cognitive function was subsequently assessed using a Y-maze. HMGB1, S100B, RAGE, interleukin-1β, and nuclear factor-kappaB p65 levels were measured at 12 h and 1, 3, and 7 d after surgery. Immunofluorescence double labeling was performed to study the colocalization between RAGE and its ligands, HMGB1 and S100B.

Results

The mice’s learning and memory abilities were significantly impaired at 1 and 3 d and 2 and 4 d after surgery, respectively. The expression of HMGB1, S100B, RAGE, and nuclear factor-kappaB p65 had increased significantly at 12 h and 1 and 3 d after surgery. The interleukin-1β level was significantly increased at 1 and 3 d after surgery. The interaction of HMGB1 or S100B with RAGE was confirmed at 1 d after surgery.

Conclusions

These data suggest that HMGB1, S100B, and RAGE signaling modulate the hippocampal inflammatory response and might play key roles in surgery-induced cognitive decline.