Abstract:We studied the effects of early weaning on immunocompetence and parasite resistance in a precocial rodent Acomys cahirinus. We hypothesized that if parasite resistance is energetically expensive and nutritional and immunological support from mothers are necessary for the long-term health of offspring, then early weaned animals would be immunologically weaker and less able to defend themselves against parasites than later weaned animals. We weaned pups at 14, 21 or 28 days after birth and assessed their immunoc… Show more
“…The immune systems gradually deteriorate with age, and these changes include diminished T cells and modifications to the antigenic repertoire that underlies both humoral and cell-mediated immune responses. The key abnormalities have been demonstrated in the T cells which experience functional changes, such as a decrease in precursor frequencies of helper and cytotoxic T-cells, and an increase of T cells which are unresponsive activators [45,46]. These findings agree with a study carried out in the Netherlands which also established no significant association between alloimmunization and age [47].…”
Background : Multiple blood transfusions may result in the production of alloantibodies against one or more red blood cell antigens which might make it more challenging to execute subsequent transfusions. Despite age and gender being risk factors for transfusion and being associated with alloimmunization frequency, they are not routinely taken into account before transfusion. This study assessed red blood cell alloimmunization and its association with risk factors among multi-transfused oncology patients at Moi Teaching and Referral Hospital Cancer Centre, Kenya.
Methodology : The study employed a cross-sectional study design and focused on multi-transfused oncology patients at the Moi Teaching and Referral Hospital Cancer Centre. A sample size of 162 was used in the study based on Fisher's exact test formulae and a consecutive sampling technique was applied. The gel-based antibody screening and identification were performed with "ID-Diacell I-IIIII®" panel cells. The frequency, mean, median, and dispersion of descriptive statistics were shown and the association between alloimmunization with the number of transfusions, age and sex were determined by Spearman's correlation analysis. Statistical significance was established at P< 0.05 and statistical tests were run at a 95% level of significance.
Results : This study established no association between alloimmunization and the number of transfusions (P= 0.753). There was also no association between alloimmunization and age (P= 0.159). However, there was a significant positive association between alloimmunization with gender (P= 0.01). The study had a 6.2% prevalent rate of red blood cell alloimmunization, females had a greater prevalent rate than male patients. Anti-E and anti-K were the most prevalent alloantibodies.
Conclusion and Recommendation : There is a need to improve current blood grouping and cross-match practices in most Kenyan hospitals by performing antibody screening and antibody identification tests. This study suggests routinely assessing alloimmunization in patients getting several transfusions while taking gender into account.
“…The immune systems gradually deteriorate with age, and these changes include diminished T cells and modifications to the antigenic repertoire that underlies both humoral and cell-mediated immune responses. The key abnormalities have been demonstrated in the T cells which experience functional changes, such as a decrease in precursor frequencies of helper and cytotoxic T-cells, and an increase of T cells which are unresponsive activators [45,46]. These findings agree with a study carried out in the Netherlands which also established no significant association between alloimmunization and age [47].…”
Background : Multiple blood transfusions may result in the production of alloantibodies against one or more red blood cell antigens which might make it more challenging to execute subsequent transfusions. Despite age and gender being risk factors for transfusion and being associated with alloimmunization frequency, they are not routinely taken into account before transfusion. This study assessed red blood cell alloimmunization and its association with risk factors among multi-transfused oncology patients at Moi Teaching and Referral Hospital Cancer Centre, Kenya.
Methodology : The study employed a cross-sectional study design and focused on multi-transfused oncology patients at the Moi Teaching and Referral Hospital Cancer Centre. A sample size of 162 was used in the study based on Fisher's exact test formulae and a consecutive sampling technique was applied. The gel-based antibody screening and identification were performed with "ID-Diacell I-IIIII®" panel cells. The frequency, mean, median, and dispersion of descriptive statistics were shown and the association between alloimmunization with the number of transfusions, age and sex were determined by Spearman's correlation analysis. Statistical significance was established at P< 0.05 and statistical tests were run at a 95% level of significance.
Results : This study established no association between alloimmunization and the number of transfusions (P= 0.753). There was also no association between alloimmunization and age (P= 0.159). However, there was a significant positive association between alloimmunization with gender (P= 0.01). The study had a 6.2% prevalent rate of red blood cell alloimmunization, females had a greater prevalent rate than male patients. Anti-E and anti-K were the most prevalent alloantibodies.
Conclusion and Recommendation : There is a need to improve current blood grouping and cross-match practices in most Kenyan hospitals by performing antibody screening and antibody identification tests. This study suggests routinely assessing alloimmunization in patients getting several transfusions while taking gender into account.
“…Pregnancy-induced thymic involution is conserved in all mammalian species examined and certainly represents a major biological challenge. Indeed, failure to regain immunocompetence would jeopardize survival of both females and their progeny (4).…”
During gestation, sex hormones cause a significant thymic involution which enhances fertility. This thymic involution is rapidly corrected following parturition. As thymic epithelial cells (TECs) are responsible for the regulation of thymopoiesis, we analyzed the sequential phenotypic and transcriptomic changes in TECs during the postpartum period in order to identify mechanisms triggering postpartum thymic regeneration. In particular, we performed flow cytometry analyses and deep RNA-sequencing on purified TEC subsets at several time points before and after parturition. We report that pregnancy-induced involution is not caused by loss of TECs since their number does not change during or after pregnancy. However, during pregnancy, we observed a significant depletion of all thymocyte subsets downstream of the double-negative 1 (DN1) differentiation stage. Variations in thymocyte numbers correlated with conspicuous changes in the transcriptome of cortical TECs (cTECs). The transcriptomic changes affected predominantly cTEC expression of Foxn1, its targets and several genes that are essential for thymopoiesis. By contrast, medullary TECs (mTECs) showed very little transcriptomic changes in the early postpartum regenerative phase, but seemed to respond to the expansion of single-positive (SP) thymocytes in the late phase of regeneration. Together, these results show that postpartum thymic regeneration is orchestrated by variations in expression of a well-defined subset of cTEC genes, that occur very early after parturition.
“…Altricial species are buffered from such challenges by attending parents who supply energy, hygiene or other forms of protection [ 1 , 2 ]. In species that lack parental care, however, offspring must be self-sufficient in defending themselves from pathogens [ 3 ]. When the risk of infections or virulence of pathogens is high, we expect strong selection on offspring immune function [ 4 ].…”
Like most ectothermic vertebrates, keelback snakes (Tropidonophis mairii) do not exhibit parental care. Thus, offspring must possess an immune system capable of dealing with challenges such as pathogens, without assistance from an attendant parent. We know very little about immune system characteristics of neonatal reptiles, including the magnitude of heritability and other maternal influences. To identify sources of variation in circulating white blood cell (WBC) concentrations and differentials, we examined blood smears from 246 hatchling snakes and their field-caught mothers. WBC concentrations were lower in hatchlings than in adults, and hatchlings had more basophils and fewer azurophils than adults. A hatchling keelback's WBC differential was also influenced by its sex and body size. Although hatchling WBC measures exhibited negligible heritability, they were strongly influenced by maternal body size and parasite infection (but not by maternal body condition, relative clutch mass or time in captivity). Larger mothers produced offspring with more azurophils and fewer lymphocytes. The mechanisms and consequences of WBC variation are currently unknown, but if these maternal effects enhance offspring fitness, the impact of maternal body size on reproductive success may be greater than expected simply from allometric increases in the numbers and sizes of progeny.
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