Differential Expression of Pax6 Following Bilateral Common Carotid Artery Occlusion.

BACKGROUND/AIM: Chronic cerebral hypoperfusion causes neuronal damage involving cognitive impairment and development of dementia. Permanent bilateral common carotid artery occlusion (BCCAO) in rat models is used to study chronic cerebral hypoperfusion. Pax6 is used as an early neurogenesis marker which affects the maturation of neuronal cells. However, the expression of PAX 6 after BCCAO is not well understood. In this study, we investigated the expression of PAX6 in the neurogenic zones after BCCAO to evaluate the effects of Pax6 on chronic hypoperfusion. MATERIALS AND METHODS: Chronic hypoperfusion was induced by BCCAO. Common carotid artery was laid parallel to the vagus nerve and separated from it. Both arteries were occluded using 4-0 silk sutures. Rats who underwent bi-common carotid artery occlusion formed in the BCCAO group, while unoperated rats served as the control group. Brain samples were obtained on days 3 and 14 after BCCAO and subjected to immunohisto-chemistry with NeuN and western blotting for Pax6 and HIF1α. RESULTS: Compared to the control, the expression of Pax6 increased three days after surgery but did not differ on day 14, while that of NeuN showed the opposite trend. The expression of HIF1α increased three days after surgery. CONCLUSION: Bilateral common carotid artery occlusion induced early neurogenesis at three days after BCCAO but this result was not maintained at fourteen days after BCCAO.

Differential Expression of BDNF and BIM in Streptozotocin-induced Diabetic Rat Retina After Fluoxetine Injection.

BACKGROUND: Chronic diabetic retinopathy (DR) is a diabetic complication that causes blindness. Brain-derived neurotrophic factor (BDNF) expression is induced by fluoxetine. We observed the effects of fluoxetine on a streptozotocin (STZ)-induced diabetic rat model in this study. MATERIALS AND METHODS: Rats were divided into three groups: Control, diabetic (65 mg/kg STZ injection), and diabetic with fluoxetine injection (20 mg/kg/week, six times). Western blotting was performed using anti-BDNF and anti-hexaribonucleotide-binding protein-3. Expression of BCL2 apoptosis regulator-like protein 11 (BIM) was analysed using a reverse transcription-polymerase chain reaction. RESULTS: BDNF levels were significantly higher in the diabetic group treated with fluoxetine than in the untreated diabetic group. BIM expression was higher in the diabetic group than in the control group. BIM gene expression was lower in fluoxetine-treated diabetic group than in the untreated diabetic group. CONCLUSION: Fluoxetine had an anti-apoptotic effect with upregulation of BDNF expression in retina of rats with STZ-induced diabetes.

Immunoreactivity of MAPK Signaling in a Rat Model of Intrauterine Growth Retardation Induced by Uterine Artery Ligation.

BACKGROUND/AIM: Intrauterine growth retardation (IUGR) causes very low birth weight and is related to the morbidity and mortality of the newborn. In our previous study, expression of brain-derived neurotrophic factor (BDNF) was found reduced in the cerebral cortex and dentate gyrus of fetuses with IUGR. BDNF protected cortical neurons against hypoxic injury via activation of the extracellular signal-related kinase (ERK) pathway. The aim of the current study was to observe the immunoreactivity of ERK in mature neurons and proliferating cells. MATERIALS AND METHODS: Uterine artery ligation was performed at 17 days of gestation (dg). Rat fetuses were obtained at 21 dg using cesarean section. Fetuses were designated either to the growth retardation (GR) group when removed from the horn with uterine artery ligation, or to the control group when removed from the other horn with the untied artery. Immunohistochemistry was performed with primary antibodies on paraffin-embedded forebrain sections. RESULTS: The density and proportion of cells expressing PCNA, ERK, and phosphate ERK in the subventricular zone (SVZ) was not different between the control and GR group. The density and proportion of NeuN- and phosphate ERK-positive cells in the cerebral parietal cortex was lower in the GR group, compared to the control group. CONCLUSION: Although IUGR had no effect on the proliferation of cells in the SVZ, it reduced neuronal survival in the cerebral parietal cortex, which was associated with the decrease of pERK-positive cell density and proportion in the cerebral cortex.

Differential Expression of Vascular Endothelial Growth Factor in the Cortex and Hippocampus upon Cerebral Hypoperfusion.

BACKGROUND/AIM: Vascular endothelial growth factor (VEGF) provides tolerance against ischemic brain injury, yet, the pattern of VEGF expression in the neurogenic zones following chronic cerebral hypoperfusion has not been studied. Here we evaluated the immunoreactivity of VEGF in a rat model of chronic cerebral hypoperfusion. MATERIALS AND METHODS: Chronic hypoperfusion was induced by bilateral common carotid artery ligation in rats. Immunohistochemistry was performed against hypoxia-inducible factor-1α (HIF-1α) and VEGF on brain sections. RESULTS: The density of HIF1α-positive cells in the hypoxia group was increased in the cerebral cortex and hippocampus. Further, the density of VEGF-positive cells was significantly higher in the hypoxia group compared to the control group in the cerebral cortex whereas it was similar in the subventricular zone, and in the dentate gyrus in the hippocampus between the two groups. CONCLUSION: The pattern of VEGF expression varies in different brain regions following chronic cerebral hypoperfusion.

Anatomical configuration of the inferior alveolar neurovascular bundle: a histomorphometric analysis.

PURPOSE: The inferior alveolar neurovascular bundle (NVB) is important in implant placement and many other surgeries in dentistry because it is a major supplier of sensation and blood to the mandible via the mandibular canal. The purposes of the present study were to determine the areas and diameters of the NVB, the inferior alveolar nerve (IAN), and the inferior alveolar artery (IAA), and to verify the buccolingual location of the mandibular canal. METHODS: The anatomical configuration of the NVB was examined by histomorphometrically analyzing 20 embalmed dentulous hemimandibles. The areas and maximum horizontal and vertical diameters of the NVB, IAN, and IAA were measured according to tooth region. The distances from the internal border of the mandibular canal to the outer surface of the buccal and lingual cortical plates were also measured. RESULTS: The areas of the vertically oval-shaped NVB and IAN appeared to be constant between the molar and premolar regions, which contain the mental branch, and decreased sharply in the lateral incisor after branching off of the mental branch via the mental canal. The mandibular canal was located close to the lingual cortical plate in the posterior tooth region before passing through the mental canal, immediately after which it was situated quite close to the buccal cortical plate, and then closer to the middle toward the anterior tooth region. CONCLUSIONS: The findings of this study provide useful anatomical information that should help to minimize the risk of injury to the NVB during surgical procedures in the mandibular region.

Acute hydrocephalus as a complication of cervical spine fracture and dislocation: a case report.

Hydrocephalus is a well-known complication of head injury, but an uncommon complication of a spinal lesion. Here, we present a rare case of acute obstructive hydrocephalus secondary to a cervical fracture and dislocation. A 60-year-old female patient was transferred to the emergency department with quadriplegia and respiratory difficulty. Imaging studies showed a cervical fracture and dislocation at the C3-4 level. She required intubation and mechanical ventilation. Twenty-four hours after admission, her mental status had deteriorated and both pupils were dilated. Computed tomography of the brain showed acute hydrocephalus; therefore, extraventricular drainage (EVD) was performed. After the EVD, her mental status recovered and she became alert, but she remained quadriplegic and dependent on the ventilator. Two months after injury, she died because of respiratory failure caused by pneumonia.

Topographical relationship of the greater palatine artery and the palatal spine. Significance for periodontal surgery.

AIM: The aims of this study were to (1) identify the branching pattern and course of the greater palatine artery (GPA), (2) carry out a morphological analysis of the palatal bony prominence that divides the medial and lateral grooves and (3) characterize the topographical relationships between these two structures. METHODS: Thirty-six hemimaxillae were studied with the aid of a surgical microscope to elucidate the GPA. A further 25 dry skulls were examined to establish the morphology of the palatal spine. RESULTS: The most common GPA branching pattern was type I (41.7%, 15 sides), which gave off the medial and canine branches after the bony prominence. The distances from the CEJ to the lateral branch of the GPA were 9.04 ± 2.93 mm (canine), 11.12 ± 1.89 mm (first premolar), 13.51 ± 2.08 mm (second premolar), 13.76 ± 2.86 mm (first molar) and 13.91 ± 2.20 mm (second molar). The palatal spine was frequently observed as the bony prominence (66.3%, 57 sides), and was located at 6.49 ± 1.76 mm from the greater palatine foramen, with a length of 10.42 ± 2.45 mm. There was no a correlation between the bony prominence shape and the GPA branching pattern. CONCLUSIONS: These results could provide the reference data regarding the topography of the GPA for periodontal surgery.

Cortical neuronal loss after chronic prenatal hypoxia: a comparative laboratory study.

OBJECTIVE: The purpose of this study was to investigate the prenatal hypoxic effect on the fetal brain development. METHODS: We used the guinea pig chronic placental insufficiency model to investigate the effect of hypoxia on fetal brain development. We ligated unilateral uterine artery at 30-32 days of gestation (dg : with term defined as -67 dg). At 50 dg, 60 dg, fetuses were sacrificed and assigned to either the growth-restricted (GR) or control (no ligation) group. After fixation, dissection, and sectioning of cerebral tissue from these animals, immunohistochemistry was performed with NeuN antibody, which is a mature neuronal marker in the cerebral cortex. RESULTS: The number of NeuN-immunoreactive (IR) cells in the cerebral cortex did not differ between the GR and control groups at 50 dg. However, the number of NeuN-IR cells was lesser in GR fetuses than in controls at 60 dg (p<0.05). CONCLUSION: These findings show that chronic prenatal hypoxia affect the number of neuron in the cerebral cortex of guinea pig fetus at 60 dg. The approach used in this study is helpful for extending our understanding of neurogenesis in the cerebral cortex, and the findings may be useful for elucidating the brain injury caused by prenatal hypoxia.

Iron differentially regulates gene expression and extracellular secretion of Vibrio vulnificus cytolysin-hemolysin.

In a previous study, we showed that Vibrio vulnificus is a ferrophilic bacterium that requires high levels of available iron for growth. In the present study, we show that iron stimulates, in an unusual manner, the production of cytolysin-hemolysin (VvhA), the most potent exotoxin produced by V. vulnificus. The vvhA gene possesses a putative ferric uptake regulator (Fur)-binding box in the regulatory region, andvvhA transcription was repressed by iron and de-repressed by fur mutation. However, extracellular secretion of VvhA was conversely increased by iron. Iron increased transcription of pilD, which encodes PilD, a component of the type II general secretion system responsible for extracellular VvhA secretion. These results indicate that iron increases extracellular VvhA secretion via the type II general secretion system, although it can repress vvhA transcription via Fur.

Novel role of IL-6/SIL-6R signaling in the expression of inducible nitric oxide synthase (iNOS) in murine B16, metastatic melanoma clone F10.9, cells.

Inducible nitric oxide synthase (iNOS) has been shown to be frequently expressed in melanomas; up-regulation of this enzyme is though to be associated with tumor progression. In this study, we investigated whether diverse cytokines such as: IL-6, TNF-alpha, IL-1beta, IFN-gamma and IL6RIL6 (a highly active fusion protein of the soluble form of the IL-6R (sIL-6R) and IL-6) enhance the iNOS gene expression in B16/F10.9 murine metastatic melanoma cells. An increase at iNOS expression and NO production was observed with the co-treatment of IL6RIL6 plus TNF-alpha. Gel shift and reporter gene analyses revealed that IL6RIL6 selectively activated AP-1; while TNF-alpha increased the activities of both NF-kappaB and AP-1. Persistent activation of AP-1 was also seen in cells treated with IL6RIL6 plus TNF-alpha. Stimulation of cells with IL6RIL6/TNF-alpha resulted in the activation of mitogen-activated protein kinases (MAPK) such as c-Jun N-terminal kinase (JNK) and p38, and the abrogation by pretreatment with JNK or p38 MAPK inhibitor. IL6RIL6 or IL6RIL6/TNFalpha-inducible AP-1 binding increase was supershifted by anti-c-Jun or c-Fos antibodies, and the activation of c-Jun and c-Fos was dependent on JNK and p38, respectively. These results suggest that IL-6/sIL-6R/gp130 complex signaling has an unexpected positive effect on iNOS gene expression through JNK/p38 MAPK mediated-AP-1 activation in melanoma cells.

Proteases of a Bacillus subtilis clinical isolate facilitate swarming and siderophore-mediated iron uptake via proteolytic cleavage of transferrin.

We isolated a highly serine protease-producing Bacillus subtilis strain (PRY) from a clinical sample and identified it through biochemical testing and ribosomal DNA sequencing. The PRY strain exhibited a robust swarming behavior and was able to digest human transferrin efficiently, concomitantly with the production of catechol-siderophore in the exponential growth phase. The growth of PRY was in proportion to increased iron availability resulting from transferrin destruction. These results suggest that proteases of the B. subtilis PRY strain may play a significant role in the pathogenesis of human infections by facilitating siderophore-mediated iron uptake from transferrin and swarming motility.

X-gal inhibits the swarming of Vibrio species.

The expressional levels of genes in swarmer cells can be determined by a simple method using X-gal-containing semisolid agars and lacZ-fusion transcription reporter strains of the genes concerned. However, X-gal alone inhibited the swarming of Vibrio, regardless of their ability to digest X-gal. Moreover, X-gal inhibited the growth of V. vulnificus containing functional lacZ. These effects of X-gal itself should be carefully considered when trying to determine the expression levels of genes in swarming cells using X-gal-containing semisolid agar.

Human serum albumin enhances the hemolytic activity of Vibrio vulnificus.

Vibrio vulnificus hemolysin (VvhA) is inactivated in the late growth phase by its oligomerization. Albumin is known to affect the activities of many bacterial toxins. In this study, we investigated the effects of human or bovine serum albumin (HSA or BSA) on the production and activity of VvhA. HSA did not affect V. vulnificus growth and vvhA transcription. However, VvhA hemolytic activity in culture supernatants was significantly higher in the presence of HSA than in the absence of HSA. By Western blot analysis, the oligomerization of VvhA was inhibited and the remaining active VvhA monomer was increased in culture supernatants containing HSA. BSA produced similar results. These findings indicate that both HSA and BSA stabilize VvhA and delay VvhA inactivation by oligomerization, and thus enhance VvhA activity.

Postnatal development of parvalbumin and calbindin D-28k immunoreactivities in the canine anterior cingulate cortex: transient expression in layer V pyramidal cells.

We have examined the ontogeny of parvalbumin (PV) and calbindin D-28k (CB) immunoreactivities in the canine anterior cingulate cortex (ACC) from the day of birth (P0) through P180. At P7, PV immunoreactivity first appeared in layer VI multipolar cells. The PV immunoreactivity in GABAergic nonpyramidal cells appeared to follow an inside-out gradient of radial emergence. Although immunoreaction was limited mainly to the developing nonpyramidal cells, pyramid-like PV immunoreactive cells were transitorily observed in layer V from P14 to P90. The developmental pattern of CB immunoreactivity differed from that of PV immunoreactivity. CB immunoreactivity first developed in layer V pyramidal cells from P0, which continued through P90. CB immunoreactive nonpyramidal cells were located in the infragranular layers and white matter at P0 and matured in both the supragranular and infragranular layers without clear inside-out gradient. This developmental study revealed the comparable belated expression of PV immunoreactivity and the transient expression of both calcium-binding proteins in layer V pyramidal cells. These results suggest that the transient expression of calcium-binding proteins in layer V pyramidal cells might be related to the critical period of early postnatal development.

Endoscopic transnasal approach for the treatment of medial orbital blow-out fracture: a technique for controlling the fractured wall with a balloon catheter and Merocel.

The authors repaired a medial blow-out fracture by using an endoscopic transnasal technique with a balloon catheter and Merocel packing in 17 subjects. The follow-up periods were from 6 weeks to 2 years, and averaged 6 months. The length of the operation was 50 minutes on average. The enophthalmos was corrected in seven of the eight patients. Supporting material for the fractured medial orbital wall was kept in place for 1 to 3 weeks. The mean volume of balloon inflation was 2 cc. The result was satisfactory. No complications resulted from the transnasal endoscopic technique. This endoscopic transnasal approach allows for a better aesthetic result because it eliminates external scarring and permits a direct approach to the medial orbital wall and has a superior visualization. A balloon catheter was used to support the fractured medial orbital fracture, which was adapted, ballooned, and then visualized using a radiopaque dye (Visipaque) in 11 cases. A postoperative computed tomographic scan revealed that this is a very useful method for controlling the status of the reduced orbital wall and eliminates the possibility of complications resulting from infection. A resected uncinate process was used as a bone graft material to repair the large defect in five cases. This method provides several advantages including a mucoperiosteal attached bone graft, working in the same operative field, and cost-effective surgical time. A transnasal endoscopic technique for medial orbital fracture is also very useful for releasing entrapment of the medial rectus muscle, because it directly pushes against the fractured wall and gives good exposure of the medial orbital wall.