Gliovascular changes precede white matter damage and long‐term disorders in juvenile mild closed head injury

Traumatic brain injury (TBI) is a leading cause of hospital visits in pediatric patients and often leads to long‐term disorders even in cases of mild severity. White matter (WM) alterations are commonly observed in patients months or years after the injury assessed by magnetic resonance imaging (MRI), but little is known about WM pathophysiology early after mild pediatric TBI. To evaluate the status of the gliovascular unit in this context, mild TBI was induced in postnatal‐day 17 mice using a closed head injury model with two grades of severity (G1, G2). G2 resulted in significant WM edema (increased T2‐signal) and BBB damage (IgG‐extravasation immunostaining) whereas decreased T2 and the increased levels of astrocytic water‐channel AQP4 were observed in G1 mice 1 day post‐injury. Both severities induced astrogliosis (GFAP immunolabeling). No changes in myelin and neurofilament were detected at this acute time point. One month after injury G2 mice exhibited diffusion tensor imaging MRI alterations (decreased fractional anisotropy) accompanied by decreased neurofilament staining in the WM. Both severities induced behavioral impairments at this time point. In conclusion, long‐term deficits and WM changes similar to those found after clinical TBI are preceded by distinct early gliovascular phenotype alterations after juvenile mild TBI, revealing AQP4 as a potential candidate for severity‐based treatments.     

Impacts and effects of COVID-19 infection in pregnancy

Objectives:To explore the trimester wise significance of the primary outcome in pregnant women during coronavirus disease-19 (COVID-19) pandemic.Methods:Retrospective observational study of pregnant women who were infected with COVID-19 from April 2020 until March 2021 at Bahrain Defense Force Hospital, Riffa, Bahrain. The study focused on the effects in relation to gestational age (GA), association with variables, severity, and treatment. A p-value of ≤0.05 was considered significant.Results:During the study period, 74 COVID-19 cases were identified from the recorded 2944 pregnant women. The mean GA at diagnosis was 33.5±12.2 weeks, and the mean GA at birth was 38.4±1.8 weeks. Analysis of the obstetric complications revealed fetal growth restriction (FGR) had a p-value of <0.001. According to the trimester wise analysis, between the gestational period at diagnosis and the outcome of pregnancy, significant p-value of <0.01 was found in miscarriage. There were no significant associations found in GA at diagnosis and delivery, complications in relation to maternal age and body mass index, and no maternal morbidities or mortalities.Conclusion:In our study, FGR and miscarriage were the identified complications. However, the maternal and neonatal end result of COVID-19 was satisfactory.     

Behavioral misperceptions,attitudinal discrepancies,and adolescent alcohol and marijuana use

Background: Adolescents’ risk of substance use is shaped by perceptions of peers’ use and peers’ approval, and also by attitudes, values, and behaviors of broader, peer-based, school-level climates. Yet misperceiving peer behavior and/or possessing beliefs/values discrepant from peers may also increase substance use.

Methods: Using school-based survey data, we examined (a) associations between individual- and school-level norms and adolescents’ risk of alcohol and marijuana use, (b) accuracy of adolescents’ perception of peer behavior and consistency between individual and peer attitudes, and (c) consequences of behavioral misperceptions and attitudinal discrepancies.

Results: Both individual- and school-level perceptions and attitudes were associated with adolescent substance use, and students aligned behaviors with their perceptions of the broader normative climate.

Conclusions: Peers are key correlates of adolescents’ use, and their influence is nuanced and complex. Substance use prevention and intervention efforts should thus attend to the prevailing norms within certain developmental contexts, and also adolescents’ deviation from such norms.     

Isolation and molecular characterization of Candida africana from Jos, Nigeria

During a survey of the prevalence of Candida spp. in Jos, Plateau State, Nigeria, two atypical C. albicans isolates were recovered. These two yeasts were germ tube positive, chlamydospore-negative and gave a green color on CHROMagar Candida. Molecular analysis performed by amplification of the hwp1 gene showed that these two isolates belonged to C. africana, a newly proposed Candida species closely related to C. albicans. Based on the presence or absence of an intron in DNA sequences encoding rRNA, the two C. africana, including all C. albicans isolates examined, were found to belong to genotype A and no other genotypes or species such as C. dubliniensis were found. To our knowledge, this is the first isolation of C. africana in Nigeria.     

Genotyping and fluconazole susceptibility of Candida albicans strains from patients with vulvovaginal candidiasis in Jos,Nigeria

ObjectiveTo investigate the fluconazole susceptibility of the genotypes of Candida albicans (C. albicans) strains isolated from patients with vulvovaginal candidiasis (VVC) in Jos, Plateau State, Nigeria.MethodsA total of one hundred and seventy seven (177) Candida isolates were examined. The strains were obtained from 320 female patients with VVC and were identified using both phenotypic and molecular methods. Their genotypes were determined, based on the presence or absence of a transposable intron in the 25S rDNA.ResultsEighty four (84) strains were recognized as being C. albicans and all the 84 C. albicans strains resulted to be genotype A. Antifungal susceptibility testing showed that 13 of those isolates (15.48%) were resistant to fluconazole.ConclusionsBased on these data, we concluded that C. albicans genotype A was common among VVC patients in Jos, and resistance to fluconazole is quite high. To our knowledge, this is the first study that reports C. albicans genotypes in Jos and its resistance to fluconazole.     

Comparative Analysis of Multiple GWAS Results Identifies Metabolic Pathways Associated with Resistance to A. flavus Infection and Aflatoxin Accumulation in Maize

Aflatoxins are carcinogenic secondary metabolites produced by several species of Aspergillus, including Aspergillus flavus, an important ear rot pathogen in maize. Most commercial corn hybrids are susceptible to infection by A. flavus, and aflatoxin contaminated grain causes economic damage to farmers. The creation of inbred lines resistant to Aspergillus fungal infection or the accumulation of aflatoxins would be aided by knowing the pertinent alleles and metabolites associated with resistance in corn lines. Multiple Quantitative Trait Loci (QTL) and association mapping studies have uncovered several dozen potential genes, but each with a small effect on resistance. Metabolic pathway analysis, using the Pathway Association Study Tool (PAST), was performed on aflatoxin accumulation resistance using data from four Genome-wide Association Studies (GWAS). The present research compares the outputs of these pathway analyses and seeks common metabolic mechanisms underlying each. Genes, pathways, metabolites, and mechanisms highlighted here can contribute to improving phenotypic selection of resistant lines via measurement of more specific and highly heritable resistance-related traits and genetic gain via marker assisted or genomic selection with multiple SNPs linked to resistance-related pathways.     

Cloning, characterization, and sequence of the yeast DNA topoisomerase I gene.

The structural gene for yeast DNA topoisomerase I (TOP1) has been cloned from two yeast genomic plasmid banks. Integration of a plasmid carrying the gene into the chromosome and subsequent genetic mapping shows that TOP1 is identical to the gene previously called MAK1. Seven top1 (mak1) mutants including gene disruptions are viable, demonstrating that DNA topoisomerase I is not essential for viability in yeast. A 3787-base-pair DNA fragment including the gene has been sequenced. The protein predicted from the DNA sequence has 769 amino acids and a molecular weight of 90,020.     

A method to measure pain associated with hypersensitive dentin

Pain associated with dental hypersensitivity has been difficult to assess. An electronic threshold measure was developed to increase the degree of objectivity in a subject's response to a cold thermal stimulus. The apparatus consisted of a miniature thermistor connected to a medical multichannel recorder with a hand-held event recorder. The thermistor was placed adjacent to the hypersensitive area for an accurate temperature measure of the point at which the subject first reported pain. Room temperature air was gently blown on the hypersensitive area, dropping the surface temperature evenly from intraoral temperature to room temperature. Results indicated that this method of assessment provided consistent and reproducible data. The apparatus can detect changes in sensitivity and offers an objective approach to sensitivity studies.     

Systematic assessment of color removal following vital bleaching of intrinsically stained teeth

Various treatment variables associated with a standard bleaching technique were systematically recorded in 53 individuals exhibiting intrinsic discoloration of permanent teeth. These variables (predictors) included: (1) etiology (fluoride or tetracycline); (2) age of the patient; (3) the presented color of the stain; (4) the intensity of that color; (5) a long versus short bleaching time technique; and (6) the number of bleaching sessions. These were assessed as to their relationship with the results of treatment (dependent variable). The findings of a multiple regression analysis revealed that the contributions of the individual predictors were significantly different between those stains caused by tetracycline ingestion (N = 27) and those stains due to fluoride ingestion (N = 20). The analysis also revealed that those variables contributing to a significant proportion of the variance in results of treatment when tetracycline was the cause were: (1) the color of the stain and (2) the number of bleaching sessions. When fluoride was apparently the causal agent: (1) the bleaching time technique; (2) age of the patient; (3) color of the stain; and (4) the number of bleaching sessions contributed to a significant proportion of the variance in the results of treatment.     

Relapse after rigid fixation of mandibular advancement

In 19 subjects rigid fixation of bilateral sagittal split osteotomies was used for mandibular advancement. Five angles and four linear measurements were determined cephalometrically for two time intervals: before surgery to immediately after surgery (T1-T2), and immediately after surgery to six months to one year after surgery (T2-TL). A multiple regression analysis with a backward stepping procedure was used to determine relationships between relapse, as defined by the position of pogonion at T2-TL (PgT2) and B point during this same time interval (BT2). The only significant predictor of PgT2 was PgT1 (P less than 0.001) (amount of advancement of pogonion during the time interval T1-T2). When BT2 was examined, both the change in position of B point at T1-T2 (P less than 0.001) and the change in anterior facial height at T1-T2 (P less than 0.02) were significant predictors of relapse. There were no other predictors of relapse. Advancements of 6 to 7 mm or greater as measured at B or Pg deserve special attention as they were more predisposed to relapse. Methods for preventing relapse are discussed.