Evaluation of apocynin in vitro on high glucose-induced oxidative stress on tenocytes.

AIMS: The purpose of this study was to evaluate the in vitro effects of apocynin, an inhibitor of nicotinamide adenine dinucleotide phosphate oxidase (NOX) and a downregulator of intracellular reactive oxygen species (ROS), on high glucose-induced oxidative stress on tenocytes. METHODS: Tenocytes from normal Sprague-Dawley rats were cultured in both control and high-glucose conditions. Apocynin was added at cell seeding, dividing the tenocytes into four groups: the control group; regular glucose with apocynin (RG apo+); high glucose with apocynin (HG apo+); and high glucose without apocynin (HG apo-). Reactive oxygen species production, cell proliferation, apoptosis and messenger RNA (mRNA) expression of NOX1 and 4, and interleukin-6 (IL-6) were determined in vitro. RESULTS: Expression of NOX1, NOX4, and IL-6 mRNA in the HG groups was significantly higher compared with that in the RG groups, and NOX1, NOX4, and IL-6 mRNA expression in the HG apo+ group was significantly lower compared with that in the HG apo- group. Cell proliferation in the RG apo+ group was significantly higher than in the control group and was also significantly higher in the HG apo+ group than in the HG apo- group. Both the ROS accumulation and the amounts of apoptotic cells in the HG groups were greater than those in the RG groups and were significantly less in the HG apo+ group than in the HG apo- group. CONCLUSION: Apocynin reduced ROS production and cell death via NOX inhibition in high-glucose conditions. Apocynin is therefore a potential prodrug in the treatment of diabetic tendinopathy.Cite this article: Bone Joint Res 2020;9(1):23-28.

Postoperative changes in cerebral metabolites associated with cognitive improvement and impairment after carotid endarterectomy: a 3T proton MR spectroscopy study.

BACKGROUND AND PURPOSE: Cognitive function can improve or decline after carotid endarterectomy. Proton MR spectroscopy can be used evaluate cerebral metabolites, such as N-acetylaspartate, choline, and creatine, in vivo. The purpose of the present study was to determine whether postoperative changes in cerebral metabolites measured by using 3T proton MR spectroscopy were associated with changes in cognitive function after CEA. MATERIALS AND METHODS: In 100 patients undergoing CEA for ipsilateral cervical internal carotid artery stenosis (≥70%), brain proton MR spectroscopy was performed before and after surgery. NAA/Cr and Cho/Cr ratios were measured in regions of interest placed in the centrum semiovale of both cerebral hemispheres. Neuropsychological testing was also performed preoperatively and 1 month postoperatively. Multivariate statistical analysis of factors related to postoperatively changed cognition was performed, and odds ratios with 95% confidence intervals were calculated. RESULTS: On the basis of the neuropsychological assessments, 10 (10%), 80 (80%), and 10 (10%) patients were defined as having postoperatively improved, unchanged, and impaired cognition, respectively. A positive and high ΔNAA/Cr ratio (postoperative value-preoperative value) in the cerebral hemisphere ipsilateral to the operative site was significantly associated with postoperatively improved cognition (95% CI, 13.3-21.3; P = .0016). Negative and high absolute values of the ΔNAA/Cr ratio (95% CI, 0.018-0.101; P = .0039) and ΔCho/Cr ratio (95% CI, 0.042-0.135; P = .0046) in the ipsilateral cerebral hemisphere were significantly associated with postoperatively impaired cognition. CONCLUSIONS: Postoperative changes in cerebral metabolites measured by using proton MR spectroscopy were associated with changes in cognitive function after CEA.

Simple assessment of cerebral hemodynamics using single-slab 3D time-of-flight MR angiography in patients with cervical internal carotid artery steno-occlusive diseases: comparison with quantitative perfusion single-photon emission CT.

BACKGROUND AND PURPOSE: Visualization of the peripheral arteries on single-slab 3D time-of-flight (TOF) MR angiography (MRA) can reflect blood flow velocity. The velocity in the middle cerebral artery (MCA) may correlate with cerebrovascular reactivity (CVR) to acetazolamide, which can be used to assess hemodynamic impairment. The goal of this study was to compare the signal intensity of the MCA on MRA versus CVR quantified by perfusion single-photon emission CT (SPECT). MATERIALS AND METHODS: The signal intensity of the MCA on single-slab 3D time-of-flight MRA was graded according to the ability to visualize the MCA in 108 cerebral hemispheres of 87 patients with unilateral or bilateral cervical internal carotid artery (ICA) steno-occlusive diseases. SPECT-CVR was also calculated by measuring cerebral blood flow before and after acetazolamide challenge. Ten healthy subjects were studied to obtain control SPECT-CVR values. All subjects provided written informed consent before the study. RESULTS: CVR was significantly lower in cerebral hemispheres with reduced MCA signal intensity than in those with normal intensity (P < .05). When the reduced signal intensity of the MCA on MRA was defined as abnormal, and when a CVR less than the mean--2 SD of healthy subjects was defined as reduced, MRA grading resulted in a 86.2% sensitivity and 69.6% specificity, with 51.0% positive-predictive and 93.2% negative-predictive values to detect reduced CVR. CONCLUSIONS: This simple MRA method can assess hemodynamic impairment with a high negative-predictive value.

Prediction of cerebral hyperperfusion after carotid endarterectomy using cerebral blood volume measured by perfusion-weighted MR imaging compared with single-photon emission CT.

BACKGROUND AND PURPOSE: Cerebral hyperperfusion syndrome is a rare but serious complication of carotid revascularization, including carotid endarterectomy (CEA) and carotid stent placement, which can occur in patients with preoperative impairments in cerebral hemodynamics. The purpose of this study was to determine whether preoperative cerebral blood volume (CBV) measured by perfusion-weighted MR imaging (PWI) could identify patients at risk for cerebral hyperperfusion after CEA. MATERIALS AND METHODS: CBV was measured by using PWI before CEA in 70 patients with unilateral internal carotid artery (ICA) stenosis (>or=70%) and without contralateral ICA steno-occlusive disease. Cerebral blood flow (CBF) was also measured by using single-photon emission CT before and immediately after CEA and on the 3rd postoperative day. RESULTS: A significant correlation was observed between preoperative CBV and increases in CBF immediately after CEA (r = 0.785, P < .0001). Whereas hyperperfusion immediately after CEA (CBF increase of >or=100% compared with preoperative values) was observed in 7 of 15 patients (47%) with elevated preoperative CBV, no patients with normal preoperative CBV exhibited post-CEA hyperperfusion. Furthermore, elevated preoperative CBV was the only significant independent predictor of post-CEA hyperperfusion. Finally, hyperperfusion syndrome developed on the 5th postoperative day in 2 of the 7 patients who displayed hyperperfusion immediately after CEA. CONCLUSION: Measurements of preoperative CBV by PWI might help to identify patients at risk for cerebral hyperperfusion after CEA in the absence of contralateral ICA steno-occlusive disease.

Gene expression of glucose transporter (GLUT) 1, 3 and 4 in bovine follicle and corpus luteum.

Glucose is the main energy substrate in the bovine ovary, and a sufficient supply of it is necessary to sustain the ovarian activity. Glucose cannot permeate the plasma membrane, and its uptake is mediated by a number of glucose transporters (GLUT). In the present study, we investigated the gene expression of GLUT1, 3 and 4 in the bovine follicle and corpus luteum (CL). Ovaries were obtained from Holstein x Japanese Black F1 heifers. Granulosa cells and theca interna layers were harvested from follicles classified into five categories by their physiologic status: follicular size (>or= 8.5 mm: dominant; < 8.5 mm: subordinate), ratio of estradiol (E(2)) to progesterone in follicular fluid (>or= 1: E(2) active;<1: E(2) inactive), and stage of estrous cycle (luteal phase, follicular phase). CL were also classified by the stage of estrous cycle. Expression levels of GLUT1, 3 and 4 mRNA were quantified by a real-time PCR. The mRNA for GLUT1 and 3 were detected in the bovine follicle and CL at comparable levels to those in classic GLUT-expressing organs such as brain and heart. Much lower but appreciable levels of GLUT4 were also detected in these tissues. The gene expression of these GLUT showed tissue- and stage-specific patterns. Despite considerable differences in physiologic conditions, similar levels of GLUT1, 3 and 4 mRNA were expressed in subordinate follicles as well as dominant E(2)-active follicles in both luteal and follicular phases, whereas a notable increase in the gene expression of these GLUT was observed in dominant E(2)-inactive follicles undergoing the atretic process. In these follicles, highly significant negative correlations were observed between the concentrations of glucose in follicular fluid and the levels of GLUT1 and 3 mRNA in granulosa cells, implying that the local glucose environment affects glucose uptake of follicles. These results indicate that GLUT1 and 3 act as major transporters of glucose while GLUT4 may play a supporting role in the bovine follicle and CL.

Clinical outcomes of multilevel anterior corpectomy and fusion as a revision surgery of the cervical spine: report of seven cases.

STUDY DESIGN: Report of seven cases. OBJECTIVE: There is no general consensus on the best surgical procedures for late-onset complications of cervical operations. We reported seven patients who had been treated effectively by multilevel anterior corpectomy and fusion (ACF) as revision surgery of the cervical spine. SETTING: Gifu University Hospital, Gifu, Japan. METHOD: Multilevel ACF using autogenous fibular strut graft as revision surgery was performed on seven patients: four patients having disorders of adjacent discs after anterior discectomy and fusion and three patients having postlaminoplasty disorders. Japanese Orthopedic Association scores (JOA scores) of the cervical myelopathy and severity of radicular and axial pains were used to evaluate outcomes. RESULTS: Rigid osseous fusion was achieved in all patients. JOA scores of the cervical myelopathy and the radicular pain, which had worsened just before the revision surgery, were improved significantly. CONCLUSION: In the present seven patients who had variety of pathological conditions with various previous surgeries, multilevel ACF using strut graft was effective as a revision procedure in ameliorating their symptoms.

Sudden onset of paraparesis caused by hypertrophy of the thoracic posterior longitudinal ligament.

STUDY DESIGN: Case report of a rare form of hypertrophy of the thoracic posterior longitudinal ligament (HPLL), causing paraparesis. OBJECTIVE: To describe this very rare pathological condition in the thoracic spine and the results of surgical intervention. SETTING: A department of orthopaedic surgery in Japan. METHODS: A 61-year-old man presented with acute paraparesis associated with HPLL in the thoracic region. A radiographic and pathological review of the case was conducted. Anterior decompression was performed, and he was followed for 3 years after the operation. RESULTS: Pathologic examination of the surgical specimen revealed proliferation of fibrocartilage and calcification. The patient's paraparesis ameliorated after the operation. CONCLUSION: For this case of myelopathy due to HPLL in the thoracic spine, urgent decompression gave excellent results. Clinical awareness of HPLL may aid correct diagnosis and prompt therapy.

Metabolic derangements in interstitial brain edema with preserved blood flow: selective vulnerability of the hippocampal CA3 region in rat hydrocephalus.

Hydrocephalus induces interstitial brain edema, which causes neurological deficits, even if the intracranial pressure is maintained within the normal range, and the cerebral blood flow (CBF) does not decline to an ischemic level. The precise mechanisms underlying such edema-induced neuronal dysfunction remain unclear. In the present study, in an attempt to elucidate the metabolic derangements in brain tissue with interstitial edema, we evaluated the changes in CBF and oxidative/glucose metabolism using a rat model of kaolin-induced hydrocephalus. Hydrocephalus was produced in male Wistar rats by intrathecal injection of 0.1 ml aluminum silicate suspension (200 mg/ml) via the cisterna magna. CBF was determined by 14[C]-iodoantipyrine autoradiography. Oxidative metabolism was evaluated by cytochrome oxidase (CYO) histochemistry, and glucose metabolism by hexokinase (HK) histochemistry. CBF declined with the development of hydrocephalus, but did not reach an ischemic level. The CYO activity was diffusely depressed in both the cortex and hippocampus. The HK activity was preserved at the early stage of hydrocephalus. At the advanced stage, the HK activity was reduced in the hippocampal CA3 region first, and diffusely thereafter. In conclusion, interstitial brain edema impairs oxidative metabolism even at the early stage of hydrocephalus, and shifts the metabolism to anaerobic glycolysis despite a preserved CBF. Impairment of glucose metabolism was first observed in the CA3 region, suggesting that the CA3 is metabolically vulnerable, and CA3 dysfunction may contribute to the memory deficits seen in hydrocephalus.

Intramedullary teratoma of the spine: report of two adult cases.

STUDY DESIGN: Two case reports of intramedullary teratoma in the spinal cord of adults, and a review of the literature. OBJECTIVE: To investigate and describe unusual cases of spinal teratoma using MRI to define features that may be used to avoid misdiagnosis. SETTING: A department of orthopedic surgery in Japan. METHODS: One patient, a 37-year-old woman, was referred because of gait disturbance. She was evaluated by myelography, CT scan with myelography, and MRI. T12 through L1 laminoplasty was performed and the tumor was subtotally removed. The other patient, a 56-year-old man, was referred because of muscle weakness and sensory disturbance. MRI revealed multiple spinal tumors. C4 through C6 laminoplasty and T12 through L2 laminoplasty were performed, and the tumors in these regions were subtotally removed. RESULTS: In Case 1, the postoperative course was excellent, and histological examination of the resected specimen revealed a spinal teratoma consisting of ectodermal and mesodermal elements. In Case 2, the symptoms were resolved after surgery, and ectodermal, mesodermal and endodermal elements were revealed. CONCLUSIONS: Although intramedullary teratomas are very rare in adults, they need to be considered in differential diagnosis.

Auditory brainstem response and temporal bone pathology findings in a brain-dead infant.

The criteria for assessing adult brain death have been already established, but those for infant brain death have not been yet established in Japan. We report auditory brainstem response (ABR) and postmortem pathology of the temporal bone and brain of a brain-dead 9-month-old female. During the comatose state, her ABR showed only waves I and II bilaterally. Autopsy revealed the presence of a left cerebellar astrocytoma, herniation and anoxic encephalopathy. The pathological examination of the temporal bone revealed the destruction of the inner ear particularly on the left side. In the auditory pathway of brain-dead patients, degeneration occurs first in the cerebrum, followed by the cochlear nerve. Thus, ABR is one of the useful means to assess brain death even in infants.

Radical hysterectomy: An anatomic evaluation of parametrial dissection.

OBJECTIVES: This study was designed to demonstrate a reduction in the amount of blood loss for vesicouterine ligament dissection and to investigate the intrapelvic autonomic nerve pathway and its preservation by means of anatomic analysis. METHODS: The anchoring mechanism of the pelvic viscera to the pelvic wall was divided into a supporting system facing laterally and a suspensory system facing dorsoventrally. An operative procedure was designed in which both systems were separated and dissected independently. RESULTS: Between the two systems, an artificial space was developed, which required a new dissection method for the parametrium and revealed a new anatomic pathway for the ureter and autonomic nerve. The amount of blood loss (mean +/- SD) during dissection of the vesicouterine ligament was ultimately 260.1 +/- 114.8 ml. Postoperatively, the maximum capacity of the bladder was 393.9 +/- 40.4 ml, maximum detrusor pressure 6.3 +/- 4.1 cm H(2)O, mean compliance >10 ml/cm H(2)O, residual urine 23.8 +/- 9.4 ml, and maximum flow rate 25. +/- 8 2.2 ml/s, respectively. CONCLUSION: A new classification for the parametrium and its dissection method have been established. Development of this new operative procedure has also contributed to a decrease in blood loss and preservation of bladder function.

Experimental metastasis is suppressed in MMP-9-deficient mice.

Matrix metalloproteinases (MMPs) are thought to play a key role in tumor invasion and metastasis. The role of MMP-9 (gelatinase B) in tumor metastasis was examined in MMP-9-deficient mice produced by gene targeting using embryonic stem cells. MMP-9-deficient mice develop normally and are fertile. In these mice, the number of metastatic colonies of B16-BL6 melanoma cells or Lewis lung carcinoma cells that were implanted intravenously fell by 45% for B16-BL6 melanoma and 59% for Lewis lung carcinoma (p = 0.03 and p = 0.0043, respectively). Gelatin zymography showed that both tumor cell lines did not secrete MMP-9 by themselves but the host cells surrounding the tumor cells secrete MMP-9 in vivo. These results indicated that host-derived MMP-9 plays an important role in the process of tumor metastasis.

Immunologic abnormalities exhibited in IL-7 transgenic mice with dermatitis.

Interleukin (IL)-7 transgenic mice, which we established previously, developed severe dermatitis characterized by massive infiltration of gammadelta T cells in the dermal lesion. To fully understand the pathology of this intriguing skin disease, we examined several immunologic features of dermis infiltrating lymphocytes from the lesional skin of IL-7 transgenic mice. We observed a moderate response to mitogens, a poor response to alloantigens, and the absence of cytotoxic activities to several tumor cell lines and skin derived cells regardless of the presence of IL-2 or IL-7. On the other hand, dermis infiltrating lymphocytes could proliferate with exogenous IL-2 and IL-7. Moreover, reverse transcriptase polymerase chain reaction and fluorescence activated cell sorter analysis revealed that dermis infiltrating lymphocytes expressed various cytokines including IL-4 and IL-7, and several activation markers for T cells (CD44, CD69, IL-2R alpha), in addition to IL-7R alpha. In the sera of the affected mice, hyper epsilon-globulinemia was observed. These findings suggested that dermis infiltrating lymphocytes proliferated in an activated state in the skin lesion in an autocrine and/or paracrine manner and produced Th2 type cytokines that might evoke immunologic abnormalities. This study and previous findings suggest that IL-7 transgenic mouse with dermatitis offer the potential of serving as a useful tool for investigating the immunologic role of cutaneous gammadelta T cells, especially their participation in IgE production in vivo.