Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The immune system was studied in 30 cases of local infection (pneumonia) and 56 cases of generalized infection (sepsis). Predominantly children with immunologic deficiency of the humoral type (77% of the cases) characterized by unscheduled fatty transformation of the thymus, underdevelopment of B-zones of lymphoid organs, low level of IgM production and the lack of IgG and IgA production were found to die with pneumonia, whereas children with physiological immaturity of the immune system and in smaller numbers (41% of the cases) with deficiency of immunity of the cellular and phagocytic type as confirmed by immaturity of the thymic tissue or its dysplasia with hypoplasia of lymphoid organs died with sepsis. Immunological deficiency of the humoral type is accompanied by suppurative destructive lesions of the respiratory organs, immunodeficiency of the cellular and phagocytic type by necrotic changes in the septic focus and mucous membranes of the organs contacting the environment.
 ...
PMID:[The immune system and its relation with infection process in children]. 660 38

Maturation of the immune system starts early in fetal life. Lymphocytes of the B series develop in the liver by 9 weeks' gestation and are present in the blood and spleen by 12 weeks. T lymphocytes start to leave the thymus from about 14 weeks' gestation and subsequently cells with helper and suppressor phenotypes are present in the spleen. The relative lack of development of secondary lymphoid tissues in healthy fetuses most probably reflects the lack of antigen stimulus. Newborn plasma contains adult levels of IgG which is acquired across the placenta from the mother. The small amounts of IgM (less than 20 mg/dL) which are normally present in healthy newborns have been reported to include antibody with specificity for maternal lymphocytes. IgA synthesis normally starts in the secretory immune system, about 2-3 weeks after birth. Poor antibody responses by newborns following immunization, especially with bacterial capsular polysaccharides, suggest that newborn immune responses are immature as compared with adults. The susceptibility of newborns to severe HSV and VZV supports this view. In vitro correlates of this immaturity include 1) deficiency of the response by newborn B cells to polyclonal activators, and 2) a lack of T cells which proliferate in HSV- or VZV-stimulated cultures. These characteristics more likely result from a lack of prior antigen stimulation and resulting clonal expansion than from intrinsic lymphocyte suppression. Antigen handling by newborn monocytes, in contrast, appears to be mature by the time of birth.
 ...
PMID:The human fetus and newborn: development of the immune response. 660 46

Using fluorescein-conjugated peanut agglutinin (PNA) and the fluorescence-activated cell sorter, we have shown that the cytotoxic T cells generated by culturing thymocytes (about 85% PNA+ cells) with Con A and medium conditioned by Con A-stimulated spleen cells were mostly PNA+. Cytotoxic T cells generated in parallel cultured of PNA- thymocytes or normal lymph node cells (in which the T cells are PNA-), however, were also mostly PNA+. The development of PNA+ cells from PNA- mature peripheral T cells was confirmed by using cultures of PNA- T cells separated on a fluorescence-activated cell sorter from lymph node cells. Immunization in vivo also resulted in the appearance of PNA+ T cells in the lymph node. These results indicate that receptors for PNA can no longer be regarded as unambiguous markers of T cell immaturity, or of the origin of a T cell from a PNA+ precursor. The possibility that a variable proportion of the PNA+ cells in the thymus may be generated by intrathymic activation of PNA- medullary thymocytes is discussed.
 ...
PMID:The acquisition of receptors for peanut agglutinin by peanut agglutinin-negative thymocytes and peripheral T cells. 697 77

Lymphoid system was studied morphologically in 61 infants aged under 1 year dying of sepsis, nonseptic inflammatory diseases and non-inflammatory processes. It was established that in sepsis generalization of the immune response and decompensation of the lymphoid system occurred in the development of which previous disorders of immune responsiveness (thymus pathology, immaturity of the lymphoid system of premature babies, respiratory viral infections) are of great importance. Unlike sepsis, local inflammatory processes are characterized predominantly by limited immune reaction and decompensation of lymphoid system has a local character. In babies of the first month of age reactions of the T-lymphocyte system predominate, in older babies those of the B-lymphocyte system.
 ...
PMID:[Immunomorphologic aspects of sepsis in children under 1-year-old]. 708 93

Peanut (Arachis hypogaea) lectin (PNL) has been shown to agglutinate the 90% of cells from murine thymus which are supposed to be immature cortical thymocytes. Further studies on the numbers of thymocytes binding fluorescein isothiocyanate conjugated PNL (FITC-PNL) confirmed the large proportion of PNL binding cells. In other organs such as bone marrow, spleen and peripheral lymph nodes, smaller proportions of PNL positive cells have been recorded. PNL-positive cells outside the thymus have been reported to be either Thy 1-positive or null cells. It has also been suggested that PNL binding may be a marker for immaturity not only in relation to T lymphocytes but also amongst haematopoietic stem cells. Thus PNL binding as an aspect of lymphocyte differentiation is a matter of considerable interest. The current study describes the distribution of horseradish peroxidase-conjugated PNL (HRP-PNL) on frozen sections of mouse lymphoid organs. It seems that PNL binds to cells in germinal centres but not to those in some other areas containing activated lymphocytes. There is good correlation between the presence of PNL-binding germinal centres in frozen sections of lymphoid organs and the number of PNL-binding cells counted in cell suspensions from the same organs.
 ...
PMID:Peanut lectin binding properties of germinal centres of mouse lymphoid tissue. 736 Feb 73

Three hundred (300) cases of perinatal death were autopsied and the thymus was removed for histologic examination. The histologic findings were classified into five groups: a) normal-mature thymus, b) involutional changes--"Starry sky" pattern, c) involutional changes--intense lymphocytic depletion, d) hypoplasia--aplasia, e) agenesis. The perinatal deaths were classified into five groups according to Wigglesworth's classification: 1) normally formed macerated stillborn neonates, 2) congenital malformations, 3) conditions associated with immaturity, 4) asphyxial conditions developing in labor, 5) other specific conditions (e.g. known-beta-hemolytic streptococcal infection or a fatal inborn error of metabolism). The main objective was to identify a possible correlation between sex, gestational age, birth weight, thymus weight, histologic features of the thymus and cause of death. In conclusion, a strong correlation was found between: a) weight of thymus and gestational age, b) weight of thymus and birth weight, c) weight of thymus and its histologic features, d) histologic features of thymus and cause of death, e) weight of thymus and cause of death, f) gestational age and cause of death. No correlation was found between: a) gestational age and histologic features of thymus, b) birth weight and histologic features of thymus, c) weight of thymus and sex, d) histologic features of thymus and sex, e) cause of death and sex.
 ...
PMID:Perinatal death and thymus gland. 785 35

This work investigates how thymic dysfunction contributes to the depression of cell-mediated immunity in protein-energy malnutrition (PEM). In Bolivian children hospitalized for severe PEM, the size of the thymus was measured by echography, and the lymphocyte subpopulations were detected by using monoclonal antibodies. These data were compared with those obtained from healthy control subjects. Regardless of the clinical form of PEM, our results show a high degree of T lymphocyte immaturity in severely malnourished children, which correlates with a severe involution of the thymus. Before in vitro incubation with thymulin, this significant increase in the percentage of circulating immature T lymphocytes was concomitant with a decrease in mature T lymphocytes and a slight increase in cytotoxic T subpopulations. After in vitro incubation with thymulin, immature T lymphocytes decreased and mature T lymphocytes increased.
 ...
PMID:In vitro lymphocyte-differentiating effects of thymulin (Zn-FTS) on lymphocyte subpopulations of severely malnourished children. 803 Jun 7

Morphological and virological studies were carried out in 26 cases of perinatal and neonatal deaths in a group at a high risk of vertical transmission of Coxsackie viruses. Antigens of Coxsackie viruses A and B were identified in 73.1% of autopsy materials, including the thymus. Adenovirus and rubella virus antigens were detected much more rarely: in 26.9 and 30.8% of cases. The incidence of Coxsackie viruses was minimal (50%) in cases when thymic abnormalities were confined to the initial signs of preterm involution and reliably increased if the involution was more expressed in the presence of underdeveloped thymus, reaching 100% in cases with the terminal stage of preterm involution in the presence of marked immaturity. The data confirm the hypothesis about the principal role of Coxsackie virus in the etiology of secondary congenital immunodeficiencies detected in children at a high risk of vertical transmission of these viruses.
 ...
PMID:[Study of vertical transmission of coxsackie group enteroviruses in the etiology of congenital immunodeficiencies]. 930 99

Clonal deletion of autoreactive T cells in the thymus is one of the major mechanisms for establishing tolerance to self-antigens, and self-reactive T cells bearing Vbeta6 T-cell receptors are usually deleted before their maturation in Mls-1a mice. However, these T cells develop transiently in the neonatal thymus, and migrate to the periphery. In order to understand the mechanisms which permit these potentially auto-toxic T cells to generate, we investigated in vivo the physiological or functional properties of the elements involved, such as neonatal T cells, antigens and antigen-presenting cells (APC). Confirming the previous findings that each of these elements per se is already completed in function in neonates, we investigated the possibility of the absence or immaturity of particular APC with Mls antigens of their own products in the neonatal thymus. In the search for the cellular and histological changes occurring in the newborn thymus, we found that the elimination of Vbeta6+ T cells progressed in parallel with the development of thymic B cells. Involvement of B cells in purging the autoreactive T cells from the newborn thymus was shown by prevention of the deletion of Vbeta6+ T cells after the removal of B cells by the treatment of neonates with anti-immunoglobulin M antibodies. The restricted and stable expression of CD5 on the thymic B cells, but not on the splenic cells, suggests that these B cells are not postnatal immigrants from the periphery. Finally, it is concluded that the deficiency in the deletion of self-reactive T cells in the thymus of Mls-1a neonates is due to the delayed development of B cells.
 ...
PMID:Failure to remove autoreactive Vbeta6+ T cells in Mls-1 newborn mice attributed to the delayed development of B cells in the thymus. 1092 68

AML1 (RUNX1) encodes a DNA-binding subunit of the CBF transcription factor family and is required for the establishment of definitive hematopoiesis. AML1 is one of the most frequently mutated genes associated with human acute leukemia, suggesting that genetic alterations of the gene contribute to leukemogenesis. Here, we report the analysis of mice carrying conditional AML1 knockout alleles that were inactivated using the Cre/loxP system. AML1 was deleted in adult mice by inducing Cre activity to replicate AML1 deletions found in human MDS, familial platelet disorder and rare de novo human AML. At a latency of 2 months after induction, the thymus was reduced in size and frequently populated by immature double negative thymocytes, indicating defective T-lymphocyte maturation, resulting in lymphatic diseases with 50% penetrance, including atypical hyperplasia and thymic lymphoma. Metastatic lymphomas to the liver and the meninges were observed. Mice also developed splenomegaly with an expansion of the myeloid compartment. Increased Howell-Jolly body counts indicated splenic hypofunction. Thrombocytopenia occurred due to immaturity of mini-megakaryocytes in the bone marrow. Together with mild lymphocytopenia in the peripheral blood and increased fractions of immature cells in the bone marrow, AML1 deficient mice display features of a myelodysplastic syndrome, suggesting a preleukemic state.
 ...
PMID:AML1 deletion in adult mice causes splenomegaly and lymphomas. 1624 65


<< Previous 1 2 3 4 Next >>