Age-Dependent Sensitivity to the Neurotoxic Environmental Metabolite, 1,2-Diacetylbenzene

1,2-Diacetylbenzene (DAB) is a metabolite of 1,2-diethylbenzene, which is commonly used in the manufacture of plastics and gasoline. We examined the neurotoxic effects of DAB in young and old rats, particularly its effects on hippocampus. Previously, we reported DAB impairs hippocampal neurogenesis but that the underlying mechanism remained unclear. In this study, we evaluate the toxicities exhibited by DAB in the hippocampi of 6-month-old (young) and 20-month-old (old) male SD rats by treating animals intraperitoneally with DAB at 3 mg/kg/day for 1 week. Hippocampal areas were dissected from brains and RNA was extracted and subjected to RNA-seq analysis. RNA results showed animals exhibited age-dependent sensitivity to the neurotoxic effects of DAB. We observed that inflammatory pathways were up-regulated in old rats but that metabolism- and detoxification-related pathways were up-regulated in young rats. This result in old rats, especially upregulation of the TREM1 signaling pathway (an inflammatory response involved in Alzheimer’s disease (AD)) was confirmed by RT-PCR. Our study results provide a better understanding of age-dependent responses to DAB and new insight into the association between DAB and AD.

Age-Dependent Sensitivity to the Neurotoxic Environmental Metabolite, 1,2-Diacetylbenzene

1,2-Diacetylbenzene (DAB) is a metabolite of 1,2-diethylbenzene, which is commonly used in the manufacture of plastics and gasoline. We examined the neurotoxic effects of DAB in young and old rats, particularly its effects on hippocampus. Previously, we reported DAB impairs hippocampal neurogenesis but that the underlying mechanism remained unclear. In this study, we evaluate the toxicities exhibited by DAB in the hippocampi of 6-month-old (young) and 20-month-old (old) male SD rats by treating animals intraperitoneally with DAB at 3 mg/kg/day for 1 week. Hippocampal areas were dissected from brains and RNA was extracted and subjected to RNA-seq analysis. RNA results showed animals exhibited age-dependent sensitivity to the neurotoxic effects of DAB. We observed that inflammatory pathways were up-regulated in old rats but that metabolism- and detoxification-related pathways were up-regulated in young rats. This result in old rats, especially upregulation of the TREM1 signaling pathway (an inflammatory response involved in Alzheimer’s disease (AD)) was confirmed by RT-PCR. Our study results provide a better understanding of age-dependent responses to DAB and new insight into the association between DAB and AD.

Development of Laser Ruler in Rigid Laryngoscope

OBJECTIVES: The objective of this study was to develop a new device that provides a simple, noninvasive method of measuring accurate lesion size while using an endoscope. METHODS: We developed a rigid laryngoscope with a built-in laser-ruler using a one-light emitting diode and an acrylic plate. The invention incorporates a built-in laser diode that projects an auto-parallel beam into the optical path of the rigid laryngoscope to form two spots in the field of view. RESULTS: While the interspot distance remains consistent despite changes in focal plane, magnification, or viewing angle of the laryngoscope, projection to an uneven surface introduces certain variations in the shape, and size of the spots, and the distance between the two spots. CONCLUSION: The device enables a laryngologist to easily measure the distance between landmarks, as well as the change in real size, and the progressive change of vocal fold lesions in an outpatient setting.

Detection of point mutation at C-terminal region of phagosomal coat protein (TACO) in patients with leprosy / 나학회지

Mycobacteria, which are highly successful pathogen, resist delivary to lysosomes and instead survive within a specialized vacuole, the mycobacterial phagosome. The bacteria survive intracellularly because they are able to actively recruit and retain TACO ( tryptophane aspartate-containing coat protein ) at the mycobacterial phagosome, where it prevents lysosomal delivary in a cholesterol-dependent manner. In this study, we investigated the difference of TACO expression is whether related to mutant in coro1a gene in patients with leprosy and normal volunteer. First, we screened for detection of a mutant in the leucine zipper motif within the exon 11, and then in the exon 9 to 10, and finally in the coiled-coil region. Interestingly, single base substitutions ( point mutation ) presents at assembly site of U1 snRNP, around of 5' splice site in the intron 9, there are a C to T and G to A transition are at 9 bp and 14 bp downstream of 5' splice site, respectively, and both of it. Among the 3 types of polymorphism, frequency of a G to A transition is markedly increased in patients of lepromatous type, which are new cases or relapsed. Both a C to T and G to A transitions are found in 1 case of tuberculoid type and 2 cases in lepromatoue type, but not found in control group. The silent mutation in leucine zipper motif within the exon 11 is located at codon at 454 ( CTG-->CTA), which is 1st leucine from C-terminal among four leucine zipper. In coiled-coil region, no mutation is found in genomic DNA of patients with leprosy. Further, we will do functional study about the identified point mutation and will screen any possible mutation in the region of promotor and WD repeat.

The association study on infection of Mycobacterium leprae and RIPK2 / 나학회지

Receptor-interacting serine/threonine kinase 2(RIPK2) is an adaptor molecule involved in the signal pathway of TLRs. However, there is no report on association between RIPK2 expression and infectious disease including mycobacterial disease in which TLRs play main role on interaction of infection. We evaluated relationship between Mycobacterium leprae and RIPK 2 by real-time RT-PCR. This study revealed that RIPK2 expression was down-regulated in the footpads and skin but was up-regulated in the liver, lymph node, and spleen of Mycobacterium leprae-infected nu/nu mice compared with those of non-infected nu/nu mice. It was observed that the IL-12p40, IFN-gamma, and IL-18 involved in the susceptibility of Mycobacterium leprae were down-regulated in the skin and footpad but up-regulated in the liver. These results suggest that regulation of RIPK2 expression is tissue-specific and is associated with M. leprae infection.

Both Carotid Endarterectomy in Obstrution of Carotid Arteries and Bypass Graft with Kidney Preservation in Obstrution of Abdominal Aorta: A Report of Case / 대한흉부외과학회지

A 56 years old male patient admitted to our neurology department because of repeated tingling sensation in right 3, 4, 5th. fingers and weakness on grasping, which were progressively developed recently. At this time, he had also suffered from claudication in both lower extremities. Carotid angiogram showed that right internal carotid artery was obstructed completely, and both common, both external and left internal carotid arteries had significant stenosis, Concommitantly, aortogram suggested complete obstruction just below the renal arteries. We planned staged operation for two separated arterial lesions. Both carotid endarterectomy was performed. and we used carotid shunt for left side during operation. Abdominal aortic lesion was operated 2 weeks later. We obligately clamped aorta just below the celiac artery and infused kidney perservation solution to pertect kidney during ischemia. Reversed Y bypass graft and kidney perservation was successful despite of 40 minute ischemia. Postoperative coure was uneventful and patient was discharged without any specific problem.

Bronchial Rupture Following Blunt Chest Trauma: 3 cases reports

The incidence of the bronchial rupture following blunt chest trauma has increased gradually with the increases of traffic accident and mechanization. We have experienced the 3 cases of the bronchial rupture following blunt chest trauma. The first case was a 38 year old man who was compressed into a blank wall by fork-lift. He complained of severe dyspnea with air leak through the chest tube and right pneumothorax with collapsed lung was seen in his chest X-ray film after closed thoracostomy. Emergency bronchoscopy showed disruptions of the right upper lobar bronchus and the membranous portion of the intermediate bronchus. The second was 8 year old boy who was sustained a crushing chest injury by bus. He also complained of severe dyspnea with air leak through the chest tube and right pneumothorax with collapsed lung was seen in his chest X-ray film after closed thoracostomy. We performed the computed tomogram of the chest and found the bronchial rupture at the distal portion of the right main bronchus. The third case was 40 year old male who was sustained a crushing chest injury by in-car accident. He complained of mild dyspnea without air leak through the chest tube and the left lung was well expanded in his chest X-ray film after closed thoracostomy. Bronchoscopy showed disruption of the 6th cartilaginous portion of the left main bronchus. Emergency bronchoplasties were performed with interrupted end-to-end anastomosis in all cases. Postoperative air leak occurred for 7 days in the third case. Others were uneventful.