During embryonic development, T-lymphoid precursor cells colonize the thymus. Chemoattraction by the fetal thymus is thought to mediate T-precursor cell colonization. However, the molecules that attract T-precursor cells to the thymus remain unclear. By devising time-lapse visualization in culture, the present results show that alymphoid fetal thymus lobes attract T-precursor cells from fetal l...

A chemical fractionation procedure, previously found applicable to bovine thymus and bovine and ovine palatine tonsils, was used to fractionate rabbit and hog thymus. With respect to the chemical fractionation steps, yields of fractions, and optical and electrophoretic properties, extracts from hog and rabbit thymus were indistinguishable from similar extracts prepared from calf thymus. The stu...

A steady increase in the frequency of invasive fungal infections has been observed in the past 2 decades, particularly in immunosuppressed patients. In recipients of bone marrow transplants, Candida albicans and Aspergillus fumigatus remain the primary pathogens. In many centers, however, Candida species other than C albicans now predominate, and many cases of aspergillosis are due to species o...

Six different mixtures of garlic distilled oils containing diallyl disulfide (DDS) and diallyl trisulfide (DTS), ranging from 1 to 51% and 88 to 38% respectively, have been assayed against a number of yeasts (C. albicans, C. tropicalis and B. capitatus), gram-positive bacteria (S. aureus and B. subtilis) and gram-negative bacteria (P. aeruginosa and E. coli). Results obtained support a specific...

BACKGROUND Absence or severe reduction in the amount of ergosterol in the fungal membrane and its replacement with other sterols have been described as potential antifungal resistance mechanisms in fungi. AIMS AND METHODS The ergosterol content in a collection of 51 clinical yeast isolates, including susceptible and resistant strains to amphotericin B and azoles, was estimated by a simple chr...

In hymenopteran societies, workers are not always sterile, and may produce parthenogenetically either males (arrhenotoky) or females (thelytoky). Thelytoky however is exceptional, and has been recorded in only four ant species. Here we provide evidence for worker thelytoky in an additional species, the harvesting ant Messor capitatus (Latreille) (Hymenoptera Formicidae Myrmicinae). Two orphaned...

Congenitally thymusless nude mice that lacked functional T cells were reconstituted with H-2-compatible or -incompatible thymus grafts taken from either fetal, newborn, or adult mice and transplanted under the kidney capsule or subcutaneously. Transplantation with unirradiated fetal (15--17 d) or newborn thymus grafts reconstituted the nude mice as assessed by their subsequent generation of vir...

Background & Objective: The thymus gland significantly affects fetal immune system maturation. Additionally, there is a linear association between size and its performance. Given the high prevalence of vitamin D deficiency in Iran scarce studies with conflicting results, subjecting maternal concentration effect on thymus, we decided to investigate relation mid-gestation. This study also aimed g...

Maintenance of the peripheral T-cell pool throughout the life requires uninterrupted generation of T cells. The majority of peripheral T cells are generated in the thymus. However, the thymus does not contain hematopoietic progenitors with unlimited self-renewing potential, and continuous production of T cells requires importation of such progenitors from the bone marrow into the thymus. Thymus...

The endodermal epithelial thymus anlage develops in tight association with neural crest (NC)-derived mesenchyme. This epithelial-NC interaction is crucial for thymus development, but it is not known how NC supports thymus development or whether NC cells or their progeny make any significant contribution to the adult thymus. By nude mouse blastocyst complementation and by cell surface phenotype,...