Mast cell activation markers for in vitro study

ABSTRACT

Mast cells (MCs) are well known for their role in allergic conditions. This cell can be activated by various types of secretagogues, ranging from a small chemical to a huge protein. Mast cell activation by secretagogues triggers the increase in intracellular calcium (iCa²⁺) concentration, granule trafficking, and exocytosis. Activated mast cells release their intra-granular pre-stored mediator or the newly synthesized mediator in the exocytosis process, in the form of degranulation or secretion. There are at least three types of exocytosis in mast cells, which are suggested to contribute to the release of different mediators, i.e.,, piecemeal, kiss-and-run, and compound exocytosis. The status of mast cells, i.e., activated or resting, is often determined by measuring the concentration of the released mediator such as histamine or β-hexosaminidase. This review summarizes several mast cell components that have been and are generally used as mast cell activation indicator, from the classical histamine and β-hexosaminidase measurement, to eicosanoid and granule trafficking observation. Basic principle of the component determination is also explained with their specified research application and purpose. The information will help to predict the experiment results with a certain study design.     

Assessing the magnitude of the HIV/AIDS epidemic in Burma

OBJECTIVES: Estimates of the HIV/AIDS burden in Burma (Myanmar) are uncertain. Using data from the 1999 national HIV sentinel surveillance and available population data, we generated estimates of Burma's HIV burden in 1999. METHODOLOGY: The 1999 sentinel surveillance included women attending antenatal clinics, male military recruits, blood donors, injecting drug users, patients of sexually transmitted disease clinics, and sex workers. We used data for women attending antenatal clinics and male recruits aged 20-29 years to estimate HIV prevalence among women and men, respectively. Data points were merged to give five regional estimates of prevalence for men and women. Census figures were used to obtain national population estimates of the numbers of Burmese living with HIV infection, along with confidence intervals (CIs). RESULTS: HIV prevalence varied by region, with the lowest rates in the West, intermediate rates in the central region, and highest rates in the North, East, and South. The highest rates were in the East (Shan State), with female prevalence of 3.0% (95% CI, 1.9-4.5). The total number of infected women nationwide was 218,300 (95% CI, 159,400-277,100), and that of men was 468,700 (95% CI, 343,300-594,200). We estimated HIV prevalence of at least 3.46% (95% CI, 2.72-4.19) among adults aged 15-44 years; 5700 infants were born with HIV infection in 1999. DISCUSSION: Burma has a generalized epidemic of HIV-1 in reproductive age adults. We estimated that there were 687,000 (95% CI, 541,100-832,900) Burmese adults living with HIV infection in 1999, or about one of every 29 adult citizens. This estimate is higher than the UNAIDS estimate for the same year of 530,000 adults and children living with AIDS, or a population prevalence of about one in 50 adults. HIV prevention and care programs are urgently needed in Burma.     

Bone formation using novel interconnected porous calcium hydroxyapatite ceramic hybridized with cultured marrow stromal stem cells derived from Green rat

The clinical use of cultured marrow stromal stem cells (MSCs) has recently attracted attention in the field of tissue engineering. For the clinical use of the MSCs, a prominent scaffold is needed. A scaffold hybridized with MSCs is transformed into a "bioactive bone substitute," and this provides good osteoconduction. In this study, a novel calcium hydroxyapatite ceramic with an interconnected porous structure (IP-CHA) was used as a scaffold. MSCs were harvested from Green rats containing Green Fluorescent Protein (GFP), and then these hybrids were implanted into the tibias of Sprague-Dawley rats. The purposes of this study were to examine the osteogenic ability of these hybrids without coculture, and to evaluate whether the resulting bone formation originated from the grafted MSCs or the recipient's cells. The hybridized group showed excellent bone formation compared with the IP-CHA-only implant group. Observation of the implanted MSCs revealed that they survived 8 weeks after surgery, and differentiated into osteoblast-like cells, thus providing bone formation. This implantation of the MSCs/IP-CHA composite provides excellent osteoconduction, and is expected to have extensive clinical applications.     

Ocular measurements in fetal alcohol spectrum disorders

Fetal alcohol spectrum disorders (FASD) describe a range of physical, behavioral, and neurologic deficits in individuals exposed to alcohol prenatally. Reduced palpebral fissure length is one of the cardinal facial features of FASD. However, other ocular measurements have not been studied extensively in FASD. Using the Fetal Alcohol Syndrome Epidemiologic Research (FASER) database, we investigated how inner canthal distance (ICD), interpupillary distance (IPD), and outer canthal distance (OCD) centiles differed between FASD and non‐FASD individuals. We compared ocular measurement centiles in children with FASD to non‐FASD individuals and observed reductions in all three centiles for ICD, IPD, and OCD. However, when our non‐FASD children who had various forms of growth deficiency (microcephaly, short‐stature, or underweight) were compared to controls, we did not observe a similar reduction in ocular measurements. This suggests that reductions in ocular measurements are a direct effect of alcohol on ocular development independent of its effect on growth parameters, which is consistent with animal models showing a negative effect of alcohol on developing neural crest cells. Interpupillary distance centile appeared to be the most significantly reduced ocular measure we evaluated, suggesting it may be a useful measure to be considered in the diagnosis of FASD.     

Differentiating molecular etiologies of Angelman syndrome through facial phenotyping using deep learning

Angelman syndrome (AS) is caused by several genetic mechanisms that impair the expression of maternally‐inherited UBE3A through deletions, paternal uniparental disomy (UPD), UBE3A pathogenic variants, or imprinting defects. Current methods of differentiating the etiology require molecular testing, which is sometimes difficult to obtain. Recently, computer‐based facial analysis systems have been used to assist in identifying genetic conditions based on facial phenotypes. We sought to understand if the facial‐recognition system DeepGestalt could find differences in phenotype between molecular subtypes of AS. Images and molecular data on 261 individuals with AS ranging from 10 months through 32 years were analyzed by DeepGestalt in a cross‐validation model with receiver operating characteristic (ROC) curves generated. The area under the curve (AUC) of the ROC for each molecular subtype was compared and ranked from least to greatest differentiable phenotype. We determined that DeepGestalt demonstrated a high degree of discrimination between the deletion subtype and UPD or imprinting defects, and a lower degree of discrimination with the UBE3A pathogenic variants subtype. Our findings suggest that DeepGestalt can recognize subclinical differences in phenotype based on etiology and may provide decision support for testing.     

DFNB39, a recessive form of sensorineural hearing impairment, maps to chromosome 7q11.22-q21.12

This article describes the identification of a novel locus (DFNB39) responsible for an autosomal recessive form of hearing loss segregating in a Pakistani consanguineous family. The hearing impaired members of this family present with profound prelingual sensorineural hearing impairment and use sign language for communications. Linkage was established to microsatellite markers located on chromosome 7q with a maximum multipoint lod score of 3.8. The region of homozygosity spans a 19 cM region that is bounded by markers D7S3046 and D7S644.     

Carbonic anhydrase gene expression in CA II-deficient (Car2−/−) and CA IX-deficient (Car9−/−) mice

Using real-time PCR and immunohistochemistry, we have examined the expression of carbonic anhydrase isozymes (CA) I, II, III, IV, IX, XII, XIII and XIV in the brain, kidney, stomach and colon of the wild-type, CA II-deficient ( Car2^−/− ), and CA IX deficient ( Car9^−/− ) mice. The expression of Car4, Car12, Car13 and Car14 mRNAs did not show any significant deviations between the three groups of mice, whereas both groups of CA deficient mice showed decreased expression levels of Car1 in the colon and Car3 in the kidney. The Car2 mRNA level was greatly reduced but not completely abolished in all four tissues from the Car2^−/− mice in which no CA II protein was expressed. Sequencing the Car2 cDNA isolated from C57BL6 Car2^−/− mice revealed two nucleotide differences from the wild-type C57BL6 mice. One is a silent polymorphism found in Car2 mRNA from wild-type DBA mice, which is the strain that provided the original mutagenized chromosome. The second change is a mutation that causes prematurely terminated translation at codon 155 (Gln155X). Car9 mRNA and CA IX protein expression levels were up-regulated about 2.5- and 3.6-fold, respectively, in the stomach of the Car2^−/− mice. These results suggest that the loss of function of cytosolic CA II in the stomach of Car2^−/− mice leads to up-regulation of an extracellular CA, namely CA IX, which is expressed on the cell surface of the gastric epithelium.