Regional Reductions of Transketolase in Thiamine-Deficient Rat Brain

Abstract: Thiamine deficiency impairs oxidative metabolism and causes metabolic encephalopathy. An early reduction in transketolase (TK) activity may be an important pathogenic event. To assess the role of TK, we have delineated the regional/cellular distribution of TK protein and mRNA in adult rat brain in pyrithiamine-induced thiamine deficiency. TK activity declined in both vulnerable and spared regions. Immunoblots showed a parallel reduction of TK protein. With a few exceptions, immunocytochemistry indicated an overall decline of TK immunoreactivity and the decrease was not specific to vulnerable areas. In contrast to the pronounced, general decline of TK protein, in situ hybridization revealed a regional decrease of 0–25% of TK mRNA in thiamine deficiency. Northern blots indicated a similar level of TK mRNA in whole brain in thiamine deficiency. These results show that the decline of TK activity results from a proportional decrease of TK protein, and the deficiency may be due to an instability of TK protein or an inhibition of TK mRNA translation. The lack of correlation of the distribution, and the absence of specific alteration, of TK in affected regions suggest that the reduced TK may not be linked directly to selective vulnerability in thiamine deficiency.     

Enlarged Cavum Septum Pellucidum as a Neurodevelopmental Marker in Adolescent-Onset Opiate Dependence

Objective

Adolescent-onset exposure to highly addictive substances such as opiates may induce far-reaching deleterious effects on later mental and physical health. However, little is known about the neurodevelopmental basis for adolescent-onset opiate dependence. Here we examined whether having an abnormally large cavum septum pellucidum (CSP), a putative marker of limbic structural maldevelopment, is associated with opiate dependence particularly beginning in adolescence.

Method

The overall length of the CSP and the prevalence of abnormal enlargement of the CSP were assessed and compared in 65 opiate-dependent subjects (41 adolescent-onset opiate users and 24 adult-onset opiate users) and 67 healthy subjects.

Results

Opiate-dependent subjects showed a greater prevalence of abnormal CSP enlargement relative to healthy subjects (odds ratio [OR]=3.64, p=0.034). The overall CSP length of adolescent-onset opiate-dependent subjects was greater, as compared not only with healthy subjects (F_1,104=11.03, p=0.001) but also with those who began opiate use during adulthood (F_1,61=4.43, p=0.039).

Conclusions

The current findings provide the first evidence that abnormal CSP enlargement, which reflects limbic system dysgenesis of neurodevelopmental origin, may be linked to later development of opiate dependence. In addition, a greater CSP length, which indicates more severe limbic abnormalities, appears to confer higher risk for earlier onset of opiate use.     

Network-Level Structural Abnormalities of Cerebral Cortex in Type 1 Diabetes Mellitus

Type 1 diabetes mellitus (T1DM) usually begins in childhood and adolescence and causes lifelong damage to several major organs including the brain. Despite increasing evidence of T1DM-induced structural deficits in cortical regions implicated in higher cognitive and emotional functions, little is known whether and how the structural connectivity between these regions is altered in the T1DM brain. Using inter-regional covariance of cortical thickness measurements from high-resolution T1-weighted magnetic resonance data, we examined the topological organizations of cortical structural networks in 81 T1DM patients and 38 healthy subjects. We found a relative absence of hierarchically high-level hubs in the prefrontal lobe of T1DM patients, which suggests ineffective top-down control of the prefrontal cortex in T1DM. Furthermore, inter-network connections between the strategic/executive control system and systems subserving other cortical functions including language and mnemonic/emotional processing were also less integrated in T1DM patients than in healthy individuals. The current results provide structural evidence for T1DM-related dysfunctional cortical organization, which specifically underlie the top-down cognitive control of language, memory, and emotion.     

Pong-like elements in Arabidopsis and Brassica rapa: its regulation of F-box protein gene in different ecotypes of Arabidopsis thaliana

Pong elements are active class 2 transposons in rice. We found Pong-like elements in Arabidopsis thaliana and named them as AtPong (Arabidopsis thaliana Pong) elements. The AtPong elements carried 13 bp of TIRs and two ORFs in which NAM DNA binding domain and DDE catalytic domain are encoded. Ping and mPing (miniature Ping) elements are deficient Pong elements and we found AtPong derived deficient AtPing and AtmPing elements. We also found a homologous element of the AtPong element in Brassica rapa. This element was a deficient element by internal deletion, but showed high sequence similarity with the AtmPing so that it was named as BrmPing (Brassica rapa miniature Ping). The AtPong, AtPing, and AtmPing elements were present in intergenic regions except one element, AtPing1, which was present in an exon of a F-box protein gene. Among the different A. thaliana ecotypes, the AtPing1 showed polymorphisms of present and absent in the F-box protein gene. The excision of the AtPing1 restored the expression of the F-box protein gene, indicating that the expression of the F-box protein genes is regulated by the AtPing1.     

Detection and characterization of the Gloeosporium gloeosporioides growth inhibitory compound iturin A from Bacillus subtilis strain KS03

The Bacillus subtilis strain KS03 was isolated, and identified as a biological control agent that inhibits the anthracnose disease fungus Gloeosporium gloeosporioides. The antifungal compound was purified from its culture broth through butanol extraction, diethylaminoethyl (DEAE) Sepharose CL-6B chromatography, and preparative thin layer chromatography. Tandem mass spectrometric analyses (MS/MS), with matrix-assisted laser desorption ionization (MALDI) time-of-fight/time-of-flight (TOF/TOF) mass spectrometry, showed that the antifungal compound was iturin A, a cyclic lipopeptide antibiotic. The major compound, with a molecular mass of 1042 Da, was identified as iturin A(2).     

Identification of canine norovirus in dogs in South Korea

Background

Canine noroviruses (CaNoVs) are classified into genogroups GIV, GVI, and GVII and have been detected in fecal samples from dogs since their first appearance in a dog with enteritis in Italy in 2007. CaNoVs may be a public health concern because pet animals are an integral part of the family and could be a potential reservoir of zoonotic agents. Nonetheless, there was no previous information concerning the epidemiology of CaNoV in South Korea. In the present study, we aimed to detect CaNoV antigens and to investigate serological response against CaNoV in dogs.

Results

In total, 459 fecal samples and 427 sera were collected from small animal clinics and animal shelters housing free-roaming dogs in geographically distinct areas in South Korea. For the detection of CaNoV, RT-PCR was performed using target specific primers, and nucleotide sequences of CaNoV isolates were phylogenetically analyzed. Seroprevalence was performed by ELISA based on P domain protein. CaNoVs were detected in dog fecal samples (14/459, 3.1%) and were phylogenetically classified into the same cluster as previously reported genogroup GIV CaNoVs. Seroprevalence was performed, and 68 (15.9%) of 427 total dog serum samples tested positive for CaNoV IgG antibodies.

Conclusion

This is the first study identifying CaNoV in the South Korean dog population.