Ocular abnormalities have apparent effects on brain activation. However, neuroimaging data about the ocular characteristics of healthy participants are still lacking to be compared with data for patients with ocular pathology. The objective of this multiple participants’ functional magnetic resonance imaging (fMRI) studies was to investigate the brain activation characteristics of healthy participants when they view stimuli of various shapes, pattern and size. During the fMRI scans, the participants view the growing ring, rotating wedge, fl ipping hour glass/bow tie, quadrant arc and full checker board stimuli. All stimuli have elements of black-and-white checkerboard pattern. Statistical parametric mapping (SPM) was used in generating brain activation via fi xed-effects (FFX) and conjunction analyses. The stimuli of various shapes, pattern and size produce different brain activation with more activation concentrated in the left hemisphere. These results are supported by the conjunction analysis which indicated that the left pre-central, post-central, superior temporal and occipital gyrus as well as the left cingulate cortices were involved when the participants viewed each given stimulus. Differential activation analysis showed activation with high specifi city in the occipital region due to the stimuli of various shapes, pattern and size. The activation in the right middle temporal gyrus was found to be signifi cantly higher in response to moving stimuli as compared to stationary stimuli. This confi rms the involvement of the right middle temporal gyrus in the observation of movements. The black-and-white checkerboard stimuli of various shapes, pattern and size, stationary and moving was found to 1) activate visual as well as other cortices in temporal and parietal lobes, 2) cause asymmetry in brain function and 3) exhibit functional integration characteristics in several brain areas.
Photic Stimulation

Background: Reversible focal lesions in the splenium of the corpus callosum (SCC) or reversible splenial lesion syndrome are rare and little is known about their pathophysiology. Case summary: The authors describe a case of a 65-year-old female who presented with fever, abnormal behaviour and mild hypernatremia. She was on neuropsychiatric treatment for bipolar disorder but denied any history of seizure. After an extensive workout to exclude infection, a clinical diagnosis of neuroleptic malignant syndrome (NMS) was made. Initial magnetic resonance imaging (MRI) of the brain showed a lesion in the SCC characterized by high-signal intensity on T2-weighted and FLAIR sequences with reduced signal intensity on T1-weighted sequence. Diffuse weighted imaging (DWI) showed restricted diffusion. There was no enhancement following Gadolinium administration. The follow-up MRI 8 weeks later showed complete resolution of the SCC lesion. Conclusion: While the pathophysiology of reversible SCC lesions is still unclear, this case highlights the need to consider NMS in the differential diagnosis of reversible splenial lesion of the corpus callosum.

INTRODUCTIONGlucocorticoids cause osteoporosis by decreasing bone formation and increasing bone resorption activity. Glucocorticoid action in bones depends on the activity of 11-beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme, which plays an important role in regulating corticosteroids. 11β-HSD1 is expressed by human and rat osteoblasts. We aimed to investigate the relationship between 11β-HSD1 dehydrogenase activity and bone histomorphometric changes in glucocorticoid-induced osteoporotic bone in rats.

METHODSA total of 30 male Sprague-Dawley rats (aged three months, weighing 200-250 g) were divided into three groups of ten each. Group 1 rats were the baseline control, which were sacrificed untreated at the beginning of the study. Group 2 rats underwent sham operation and were administered with vehicle olive oil intramuscularly at 0.05 ml/kg. Group 3 rats were adrenalectomised and administered with an intramuscular injection of dexamethasone 120 μg/kg body weight/day. The treatment was started two weeks after the operation, for a duration of two months. Plasma osteocalcin, plasma pyrodinoline, plasma corticosterone and 11β-HSD1 were measured, and bone histomorphometry analysis was performed.

RESULTSDexamethasone treatment caused an increase in plasma corticosterone level, together with a significant reduction in 11β-HSD1 dehydrogenase activity of the bone, along with a higher plasma level of the bone resorption marker, pyridinoline. Dexamethasone treatment also caused a reduction in trabecular volume, number and thickness, and an increase in trabecular separation.

CONCLUSIONLong-term glucocorticoid treatment reduces the 11β-HSD1 dehydrogenase activity in the bone, which can otherwise lead to bone loss due to the increased level of active glucocorticoids.

11-beta-Hydroxysteroid Dehydrogenase Type 1 ; metabolism ; Adrenal Cortex Hormones ; metabolism ; Amino Acids ; pharmacology ; Animals ; Body Weight ; Bone and Bones ; metabolism ; Corticosterone ; blood ; Dexamethasone ; pharmacology ; Enzyme-Linked Immunosorbent Assay ; methods ; Gene Expression Regulation, Enzymologic ; Glucocorticoids ; metabolism ; Humans ; Male ; Osteoporosis ; metabolism ; Rats ; Rats, Sprague-Dawley

Tooth avulsion is a dental emergency that needs prompt treatment to minimise complications. This study aims to evaluate the knowledge and awareness of avulsed tooth management among dental surgery assistants at the UKM Dental Polyclinic. This survey research design of a 19- item questionnaire was distributed to 59 dental surgery assistants (DSAs). The questionnaire consisted of demographic profile questions and questions regarding awareness and knowledge of tooth avulsion and its immediate management. The results showed that 78% of DSAs at the Institute know about first aid management of avulsed teeth, with the majority being taught during their training course. Moreover, 96.2% of the DSAs know what tooth avulsion is and recognise it as a dental emergency. Although 75% of the DSAs have never previously handled any avulsed tooth case, 50% are confident in advising the public on what to do with an avulsed tooth at the time of injury. As for the specific management questions of an avulsed tooth, the responses from the DSAs varied according to the questions, ranging from 50% to 85%. DSAs at the Institute have varying levels of awareness and knowledge regarding tooth avulsion. Therefore, regular education programmes on dental trauma and its management will help improve the DSAs’ current knowledge and ability to manage avulsion injuries better in emergencies.