Stimulation of mouse hematopoietic stem cells by angiogenin and DNA preparations.

Immature hematopoietic progenitors are a constant source for renewal of hemocyte populations and the basic component of the tissue and cell repair apparatus. A unique property of these cells of internalizing extracellular double-stranded DNA has been previously shown. The leukostimulatory effect demonstrated in our pioneering studies was considered to be due to the feature of this cell. In the present research, we have analyzed the effects of DNA genome reconstructor preparation (DNAgr), DNAmix, and human recombinant angiogenin on both hematopoietic stem cells and multipotent progenitors. Treatment with bone marrow cells of experimental mice with these preparations stimulates colony formation by hematopoietic stem cells and proliferation of multipotent descendants. The main lineage responsible for this is the granulocyte-macrophage hematopoietic lineage. Using fluorescent microscopy as well as FACS assay, co-localization of primitive c-Kit- and Sca-1-positive progenitors and the TAMRA-labeled double-stranded DNA has been shown. Human recombinant angiogenin was used as a reference agent. Cells with specific markers were quantified in intact bone marrow and colonies grown in the presence of inducers. Quantitative analysis revealed that a total of 14,000 fragment copies of 500 bp, which is 0.2% of the haploid genome, can be delivered into early progenitors. Extracellular double-stranded DNA fragments stimulated the colony formation in early hematopoietic progenitors from the bone marrow, which assumed their effect on cells in G0. The observed number of Sca1+/c-Kit+ cells in colonies testifies to the possibility of both symmetrical and asymmetrical division of the initial hematopoietic stem cell and its progeny.

Stimulation of mouse hematopoietic stem cells by angiogenin and DNA preparations

Immature hematopoietic progenitors are a constant source for renewal of hemocyte populations and the basic component of the tissue and cell repair apparatus. A unique property of these cells of internalizing extracellular double-stranded DNA has been previously shown. The leukostimulatory effect demonstrated in our pioneering studies was considered to be due to the feature of this cell. In the present research, we have analyzed the effects of DNA genome reconstructor preparation (DNAgr), DNAmix, and human recombinant angiogenin on both hematopoietic stem cells and multipotent progenitors. Treatment with bone marrow cells of experimental mice with these preparations stimulates colony formation by hematopoietic stem cells and proliferation of multipotent descendants. The main lineage responsible for this is the granulocyte-macrophage hematopoietic lineage. Using fluorescent microscopy as well as FACS assay, co-localization of primitive c-Kit- and Sca-1-positive progenitors and the TAMRA-labeled double-stranded DNA has been shown. Human recombinant angiogenin was used as a reference agent. Cells with specific markers were quantified in intact bone marrow and colonies grown in the presence of inducers. Quantitative analysis revealed that a total of 14,000 fragment copies of 500 bp, which is 0.2% of the haploid genome, can be delivered into early progenitors. Extracellular double-stranded DNA fragments stimulated the colony formation in early hematopoietic progenitors from the bone marrow, which assumed their effect on cells in G0. The observed number of Sca1+/c-Kit+ cells in colonies testifies to the possibility of both symmetrical and asymmetrical division of the initial hematopoietic stem cell and its progeny.

Skin infections and immunoglobulin A in serum, sweat, and saliva of patients recovered from poststreptococcal acute glomerulonephritis or acute rheumatic fever and their siblings.

Differences in hygienic habits and base-line secretory immunoglobulin (Ig) A which might have contributed to the prevalence of skin infections and/or absence of increased serum IgA values were sought in patients with poststreptococcal acute glomerulonephritis (nephritis) in contrast to patients with acute rheumatic fever in Trinidad by studying patients and their siblings after the patients had recovered from these diseases. The overall history of skin infections was similar at this time in all groups, although they had been much more common in patients with nephritis and their families at the time of acute illness. The recovered nephritis patients bathed slightly less often than the other individuals, used a cream or lotion after bathing rather than coconut oil, and tended to sweat less than the others, but none of these differences was statistically significant. Neither were significant differences demonstrated in amounts of IgA and IgG in serum and saliva of recovered nephritis patients and their siblings compared to recovered rheumatic fever patients and their siblings, while only small amounts of IgA and IgG were present in any sweat, and probably had been transuded rather than secreted. These studies suggest that the lower serum IgA titers in patients with nephritis compared to patients with rheumatic fever in Trinidad do not reflect basic differences in serum IgA or secretory IgA as measured in saliva, and that IgA is not secreted by the eccrine glands.

Clinical healing two to six years after poststreptococcal glomerulonephritis in Trinidad.

To determine the incidence of chronic nephritis after poststreptococcal acute glomerulonephritis in Trinidad, 760 patients (41 adult) were examined two to six years after recovery from the illness, 344 being studied twice (four and six years). Only 1.8 per cent had persistent urine abnormalities on their last follow-up examination, and another 8.0 per cent had abnormalities that were transient or occurred only after the patient had assumed the lordotic position. In 1.4 per cent hypertension was present, whereas only one had azotemia. Both persistent urine abnormalities and hypertension increased in prevalence with age at onset of prior poststreptococcal glomerulonephritis but did not vary between sexes, races or epidemic versus endemic forms. Half the urine abnormalities present four years after recovery were absent two years later. Thus, poststreptococcal acute glomerulonephritis appears to have a low incidence of chronicity in Trinidad, with continuing resolution for more than four years.

Tropical acute rheumatic fever and associated streptococcal infections compared with concurrent acute glomerulonephritis.

Ninety-three patients with acute rheumatic fever and 195 patients with acute glomerulonephritis were observed in Trinidad during an outbreak of scabies with a high incidence of secondary streptococcal infections. Clinical and laboratory manifestations of ARF were the same as those seen in temperate zones, except that antistreptolysin O titers were less markedly increased. The patients with ARF were similar to those with AGN in respect to sex, race, location of residence, and living conditions, but were older and had markedly fewer skin infections. Currently prevalent nephritogenic streptococcal strains never were isolated from patients with ARF even when M55 streptococci appeared and led to an epidemic of AGN.

The families of patients with acute rheumatic fever or glomerulonephritis in Trinidad.

The families of 21 patients with acute rheumatic fever (ARF) and 44 patients with acute glomerulonephritis (AGN) in Trinidad were examined in their homes. The ARF and AGN families were equally large and crowded and they lived in the same largely rural areas. However, only 22% of the ARF family members had skin infections in contrast to 61% of the AGN family members. Sixty-eight per cent of skin infections in ARF families and 69% of skin infections in Agn families yielded group A streptococci. Throat cultures were positive in 19% of ARF family members and 25% of AGN family members. Thirty-two per cent of 51 group A strains isolated from ARF family members (29 from throat, 22 from skin) were M11 or "M41" strains which were associated with ARF during the study, while only 8% were M1, T4 (MNT or 60) or M55 strains which were associated with AGN. In contrast, 49% of 171 group A strains isolated from Agn family members (64 from throat, 107 from skin) were M1, T4 (MNT or 60) or M55 while only 10% were M11 or "M41." Serum antibody titers were similar in both groups: antistreptolysin-0 titers were not markedly increased in either while anti-hyaluronidase and/or antideoxyribonuclease-B titers were increased in both. Evidence of subclinical AGN was found equally often in both groups: 6% of each had abnormal urine and 4% of each had decreased serum complement while 2% of the ARF and 3% of the AGN family members had both abnormal urine and decreased serum complement.

Changing types of nephritogenic streptococci in Trinidad.

The relation of seven different M types of streptococci to acute glomerulonephritis associated with skin lesions in South Trinidad has been studied by means of type-specific antibody assays as well as by isolation and identification of the strains. The data indicate that, one after another, five of these strains have prevailed among patients with acute glomerulonephritis during the past five years. At least three of the strains (M-types 55, 49, 57, and/or 60) were associated with epidemic increases in nephritis cases. The appearance of five consecutively predominant types of nephritogenic streptococci during a relatively short period of time is in contrast to the continuing prevalence of M-type 12 strains among nephritogenic streptococci primarily associated with respiratory infections in temperate zones. These observations suggest that the skin sores commonly found on children in tropical Trinidad, provide a particularly suitable environment for development of nephritogenic types. It remains to be seen whether these types will recur or whether new types will continue to emerge in Trinidad.