Differentiation of pluripotent stem cells is viewed in parallel with maturation of lymphoid cells. Both processes share many features each occurring within a reticular framework with its component RE cells. RE cells are seen as providing control over stem cell differentiation in marrow thus minimizing stem cell competition by concentrating differentiation stimuli of a particular kind. The differentiation molecules are considered to be histocompatibility and tissue specific antigen components derived from aging or activated mature blood cells. They are probably low molecular weight glycoproteins. Evidence that histocompatibility antigens are of importance in cellular differentiation is presented. The hypothesis presupposes positive feedback mechanisms to bone-marrow with threshold responses being determined by RE cells.

Cell Differentiation↗

PubMedDate not supplied

Epstein-Barr virus (herpesvirus 4) types A, B and herpesvirus-6 variants A and B in patients presenting with recurrent upper respiratory inflammation, persistent paravertebral thoraco-lumbar muscle spasm and fatigue by polymerase chain reaction (PCR).

DNA from Epstein-Barr virus (EBV) Types A, B and Herpesvirus-6 (HHV-6) Variants A and B was detected by the Polymerase chain reaction (PCR) in the saliva of 51 non-immunocompromised donor patients and in the blood of seventy non-immunocompromised donor patients with specific signs and symptoms. The minimum selection criteria for each patient included acute or recurrent upper respiratory infection, unilateral thoracolumbar muscle spasm and fatigue. PCR DNA detection in the saliva of selected donors revealed 80% of the donors had either Type A or B EBV (41 of 51), 34.1% Type B EBV only (14 of 41), 9% Type A only (4 of 41), and 56.1% Type A and B EBV (23 of 41). HHV-6 DNA was detected in 45.0% (23 of 51). PCR for EBV in blood of selected donors revealed 68.5% Type A or B EBV (48 of 70), 0% type B EBV alone, 64.8% Type A EBV only (31 of 48) and 35.4% both Type A and B EBV (17 of 48). HHV-6 was detected in 96.4% (64 of 70). The association of Type B EBV in the pathogenesis of these patients is explored based on the PCR quantitation of B type EBV DNA present in the samples.

Antibodies, Viral↗

PubMedDate not supplied

Unusual manifestations of type 1 autoimmune polyendocrinopathy.

We present a family with five members affected by Type 1 autoimmune polyendocrinopathy. All patients had chronic mucocutaneous candidiasis and dental abnormalities. Four patients had ocular abnormalities, four had hypoparathyroidism, and three had Addison's disease. The family was unusual in that all four affected females had premature ovarian failure. The ocular abnormalities included two patients with subcapsular lens opacities, one patient with asymptomatic corneal opacities, and one patient with severe bilateral iridocyclitis with cataract formation. One patient had pernicious anaemia and one had insulin dependent diabetes mellitus. All patients were negative on repeated occasions for organ specific and non-organ specific autoantibodies. Lymphocyte studies were performed in four patients. A deficiency of T suppressor cells was found in three and low normal levels were present in the fourth suggesting that the syndrome may be due to a defect in suppressor T cells.

Adolescent↗