Investigation of the existence of and a block technique for the inferior lateral genicular nerve: cadaveric study.

Background: Among the four genicular nerves innervating the anterior aspect of the knee, the inferior lateral genicular nerve has been omitted as a target of blocking. Some authors have suggested that the inferior lateral genicular nerve of the knee might pass beneath the lateral collateral ligament of knee. The authors aimed to study the location of the inferior lateral genicular nerve and the spread of injectate during the inferior lateral genicular nerve block. Methods: In ten knees from fresh frozen cadavers, the authors performed on each an ultrasound-guided block of the inferior lateral genicular nerve of the knee just below the lateral collateral ligament. The needle was inserted below the lateral collateral ligament, and 2 mL of blue dye was injected. A week later, the cadavers were dissected, and the existence of the inferior lateral genicular nerve and the spread of dye around it was investigated. Results: The proportion of inferior lateral genicular nerves branching from the common peroneal nerve was found in 8 of 10 (80.0%) cadavers. Of these eight cadavers with inferior lateral genicular nerve, five specimens (62.5%) were stained with blue dye. The common peroneal nerve was not infiltrated with dye in any specimens. Conclusions: When 2 mL of dye was inserted inferiorly to the lateral collateral ligament, the inferior lateral genicular nerve could be blocked in 62.5% of specimens. Because the common peroneal nerve was not involved in any specimen, motor weakness would be avoided with this method.

Quantitative magnetic susceptibility assessed by 7T magnetic resonance imaging in Alzheimer's disease caused by streptozotocin administration.

Streptozotocin treatment has emerged as an alternative model of sporadic Alzheimer's disease (SAD). Streptozotocin-induced alterations in iron and calcium levels reflect magnetic susceptibility changes, while susceptibility distribution in the cerebral regions has not been reported yet. This study aimed to investigate susceptibility distribution in the limbic system after streptozotocin administration to cynomolgus monkeys for exploring informative SAD biomarkers. Quantitative susceptibility mapping (QSM) using 7T magnetic resonance imaging (MRI) was utilized to quantitatively compare the susceptibility distributions in monkeys with sporadic Alzheimer disease and age-matched healthy controls. Compared to healthy controls, overall susceptibility values differed in the SAD models. Notable substantial susceptibility changes were observed in the hypothalamus with a 4.38-time decrease (AD: -47.45±12.19 ppb, healthy controls: 14.02±9.51 ppb) and in the posterior parts of the corpus callosum with a 2.83-times increase (AD: 31.49±15.90 ppb; healthy controls: 11.13±4.02 ppb). These susceptibility alterations may reflect neuronal death, and could serve as key biomarkers in the SAD. These results may be useful for specifying AD pathologies such as cognitive and non-cognitive symptoms.

Genetic Dissection of Alzheimer's Disease Using Drosophila Models.

Alzheimer's disease (AD), a main cause of dementia, is the most common neurodegenerative disease that is related to abnormal accumulation of the amyloid ß (Aß) protein. Despite decades of intensive research, the mechanisms underlying AD remain elusive, and the only available treatment remains symptomatic. Molecular understanding of the pathogenesis and progression of AD is necessary to develop disease-modifying treatment. Drosophila, as the most advanced genetic model, has been used to explore the molecular mechanisms of AD in the last few decades. Here, we introduce Drosophila AD models based on human Aß and summarize the results of their genetic dissection. We also discuss the utility of functional genomics using the Drosophila system in the search for AD-associated molecular mechanisms in the post-genomic era.

Nardostachys jatamansi Ethanol Extract Ameliorates Aß42 Cytotoxicity.

The Nardostachys jatamansi DC (NJ) root has been used as a sedative or analgesic to treat neurological symptoms and pain in traditional Korean medicine. Here, we investigate the potential effects of NJ on Alzheimer's disease (AD) and reveal the molecular mechanism through which NJ exerts its effects. The neuroprotective effect of the NJ root ethanol extract against ß amyloid (Aß) toxicity was examined in vitro using a cell culture system and in vivo using a Drosophila AD model. The NJ extract and chlorogenic acid, a major component of NJ, inhibited Aß-induced cell death in SH-SY5Y cells. Moreover, the NJ extract rescued the neurological phenotypes of the Aß42-expressing flies (decreased survival and pupariation rate and a locomotor defect) and suppressed Aß42-induced cell death in the brain. We also found that NJ extract intake reduced glial cell number, reactive oxygen species level, extracellular-signal-regulated kinase (ERK) phosphorylation, and nitric oxide level in Aß42-expressing flies, without affecting Aß accumulation. These data suggest that the neuroprotective activity of NJ might be associated with its antioxidant and anti-inflammatory properties, as well as its inhibitory action against ERK signaling; thus, NJ is a promising medicinal plant for the development of AD treatment.

Preventative effect of ketamine on post-surgical hyperalgesia induced at a body part remote from the surgical site.

BACKGROUND: It is known that pain hypersensitivity can be induced at a body part remote from a surgical site (tertiary hyperalgesia), leading to patient discomfort. Nevertheless, no reported study to date has investigated methods to attenuate such tertiary hyperalgesia. Ketamine is known to modulate hyperalgesia induced by central sensitization. Thus, we investigated whether intraoperative administration of ketamine could decrease post-surgical tertiary hyperalgesia in patients undergoing a laparoscopic hysterectomy. METHODS: In total 46 patients were studied. Ketamine (1 mg/kg IV and 0.5 mg/kg/h or the same volume of 0.9% saline) was administered during surgery in the ketamine and control groups, respectively. The mechanical pain threshold was measured on the patients' dominant palm before and 24 hours after the surgery to evaluate hyperalgesia. RESULTS: The change in mechanical pain threshold over time (preoperative and postoperative) differed between the groups, with a lower postoperative threshold in the control group (118.6±170.5 vs. 419.2±233; P=0.015). The postoperative visual analogue scale score at rest was lower in the ketamine group (22±16 vs. 13±9; P=0.02). Visual analogue scale scores during deep breathing, consumption of analgesia and antiemetics, and the incidence of dizziness did not differ significantly between the groups (P>0.05). CONCLUSIONS: These results suggest that the intraoperative administration of ketamine may decrease post-surgical hyperalgesia developing at a region remote from the surgical site.

Phenotypic differences between Drosophila Alzheimer's disease models expressing human Aß42 in the developing eye and brain.

Drosophila melanogaster expressing amyloid-ß42 (Aß42) transgenes have been used as models to study Alzheimer's disease. Various Aß42 transgenes with different structures induce different phenotypes, which make it difficult to compare data among studies which use different transgenic lines. In this study, we compared the phenotypes of four frequently used Aß42 transgenic lines, UAS-Aß422X , UAS-Aß42BL33770 , UAS-Aß4211C39 , and UAS-Aß42H29.3 . Among the four transgenic lines, only UAS-Aß422X has two copies of the upstream activation sequence-amyloid-ß42 (UAS-Aß42) transgene, while remaining three have one copy. UAS-Aß42BL33770 has the 3' untranslated region of Drosophila α-tubulin, while the others have that of SV40. UAS-Aß4211C39 and UAS-Aß42H29.3 have the rat pre-proenkephalin signal peptide, while UAS-Aß422X and UAS-Aß42BL33770 have that of the fly argos protein. When the transgenes were expressed ectopically in the developing eyes of the flies, UAS-Aß422X transgene resulted in a strongly reduced and rough eye phenotype, while UAS-Aß42BL33770 only showed a strong rough eye phenotype; UAS-Aß42H29.3 and UAS-Aß4211C39 had mild rough eyes. The levels of cell death and reactive oxygen species (ROS) in the eye imaginal discs were consistently the highest in UAS-Aß422X , followed by UAS-Aß42BL33770 , UAS-Aß4211C39 , and UAS-Aß42H29.3 . Surprisingly, the reduction in survival during the development of these lines did not correlate with cell death or ROS levels. The flies which expressed UAS-Aß4211C39 or UAS-Aß42H29.3 experienced greatly reduced survival rates, although low levels of ROS or cell death were detected. Collectively, our results demonstrated that different Drosophila AD models show different phenotypic severity, and suggested that different transgenes may have different modes of cytotoxicity. Abbreviations: Aß42: amyloid-ß42; AD: Alzheimer's disease; UAS: upstream activation sequence.

Characterization of Fusarium oxysporum Isolated from Paprika in Korea.

In the present study we first report in Korea the identification and characterization of Fusarium oxysporum isolated from rotten stems and roots of paprika (Capsicum annuum var. grossum) at Masan, Kyungsangnamdo in 2006. The fungal species produced white aerial mycelia accompanying with dark violet pigment on PDA. The optimal temperature and pH for the growth of the species was 25℃ and pH 7, respectively. Microscopic observation of one of isolates of the species shows that its conidiophores are unbranched and monophialides, its microconidia have oval-ellipsoidal shape with no septate and are of 3.0~11 × 1.5~3.5 µm sizes, its macroconidia are of 15~20 × 2.0~3.5 µm sizes and have slightly curved or slender shape with 2~3 septate. The results of molecular analysis show that the ITS rDNA of F. oxysporum from paprika shares 100% sequence identity with that of known F. oxysporum isolates. The identified species proved it's pathogenicity by causing rotting symptom when it was inoculated on paprika fruits. The growth of F. oxysporum from paprika was suppressed on PDA by agrochemicals such as benomyl, tebuconazole and azoxystrobin. The identified species has the ability of producing extracelluar enzymes that degrade cellobiose and pectin.

Characterization of Sclerotinia sclerotiorum Isolated from Paprika.

A fungal isolate collected from infected paprika (Capsicum annuum var. grossum) was characterized as Sclerotinia sclerotiorum based on its ability of sclerotium formation, physiological and molecular properties. When the isolate was grown on potato dextrose agar, oatmeal agar, and malt extract agar, it grew most well on PDA. Optimal temperature and pH for its growth were 25℃ and pH 7, respectively. The fungal isolate produced sclerotia on PDA within 10 days, and the color and shape of the sclerotia were similar to those of S. sclerotiorum . The ITS rDNA regions including ITS1 and ITS2 and 5.8S sequences were amplified using ITS1F and ITS4 primers from the genomic DNAs of the paprika isolate and other known pathogenic S. sclerotiorum isolated from different crops in Korea, and their nucleotide sequences were determined. Sequence comparison analysis showed the ITS rDNA of the paprika isolate shares 100% sequence identity with those of S. sclerotiorum isolated from red pepper, lettuce and a S. sclerotiorum isolate registered in GenBank DNA database. Neighbor joining analysis based on the ITS rDNA sequence revealed the paprika isolate has very close phylogenetic relationships with known Sclerotinia sclerotiorum isolates. This is the first report that S. sclerotiorum has been found associated with paprika rot in paprika growing countries.