PubMed · 4101801
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G Enăchescu, C David. 1971. [Aging and immunological processes].. https://pubmed.ncbi.nlm.nih.gov/4101801/
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We have previously hypothesized that the osteopenic changes seen in the skeletons of old male BALB/c mice are due to reductions in the availability and/or synthesis of bone TGF-beta which results in fewer, less osteogenic marrow osteoprogenitor cells (CFU-f; OPCs) and lower levels of bone formation. Among other things, this hypothesis would predict that introducing exogenous TGF-beta into old mice (growth factor replacement) should stimulate marrow CFU-f and increase bone formation. In the present study, we have tested this prediction and, indirectly the hypothesis, by injecting human recombinant TGF-beta1, i.p., into both young adult (4 month) and old mice (24 month). The effects of the growth factor on the skeleton were then assessed by measurements of trabecular bone volume, bone formation, fracture healing, and the number, proliferative, apoptotic, and alkaline phosphatase activity of marrow CFU-f/OPCs. Our data show that the introduction of 0.5 or 5.0 ug/day of TGF-beta1 into old mice for 20 days 1) increases trabecular bone volume, bone formation and the mineral apposition rate, 2) augments fracture healing, 3) increases the number and size of CFU-f colonies, and 4) increases proliferation and diminishes apoptosis of CFU-f in primary bone marrow cultures. Importantly, these stimulatory effects of injected growth factor are apparently age-specific, i.e., they are either not seen in young animals or, if seen, are found at much lower levels. While these observations do not exclude other possible mechanisms for the osteopenia of old mice, they provide further support for the hypothesis that, with age, diminished TGF-beta synthesis or availability results in a reduction in the marrow osteoprogenitor pool and bone formation. The findings also demonstrate that the latter changes can be reversed, at least transiently, by introducing exogenous TGF-beta1.
The increase in the incidence of prostate cancer observed over the past 2 decades is suggested to be largely due to increased detection of insignificant tumors. To explore this assumption, we investigated trends in survival of prostate cancer patients in southeastern Netherlands, an area with almost 1 million inhabitants, where the age-adjusted incidence of prostate cancer increased by 53% between 1971 and 1989, i.e., before the introduction of prostate-specific antigen testing. Survival was calculated for all patients registered in the Eindhoven Cancer Registry between 1971 and 1989 (n = 2,562). In spite of earlier diagnosis, survival barely changed during this time period. Five-year relative survival improved slightly from 53% [95% confidence interval (CI) 47%, 59%] in 1975-1979 to 56% (CI 51%, 61%) in 1985-1989. Stratified analyses suggested an improvement since 1980 for patients below 75 years with localized tumors but, despite possible stage migration, decreased survival for those with metastasized and/or poorly differentiated tumors. Patients below 75 years whose tumors were diagnosed unexpectedly during transurethral resection of the prostate (TURP) exhibited a relative survival of 85% 5 years and 68% 10 years after diagnosis. Less extensive application of TURP in The Netherlands might explain why our findings do not agree with those in Sweden and the United States. Inference from country-specific trends in survival appears not to be necessarily generalizable to other countries with a similar increase in the incidence of prostate cancer. We conclude from our results that earlier diagnosis of prostate cancer between 1971 and 1989 may be accompanied by an increased incidence of an aggressive variant.
When we attempted to characterize the immunological state in G-CSF transgenic mice, a large number of not only granulocytes but also lymphoid cells expanded in various immune organs. Such lymphoid cells were present at unusual sites of these organs, e.g., the parenchymal space in the liver. We then determined the phenotype of these lymphoid cells by immunofluorescence tests. It was demonstrated that CD3intIL-2Rbeta+ cells (i.e., extrathymic T cells), including the NK1.1+ subset of CD3int cells (i.e., NKT cells), increased in the liver and all other tested organs. These T cells as well as NK cells mediated NK and NK-like cytotoxicity, especially at youth. However, they were not able to mediate such cytotoxicity in the presence of granulocytes. This result might be associated with deficiency in the hybrid resistance previously ascribed to these mice. In other words, G-CSF transgenic mice had a large number of extrathymic T cells (including NKT cells) and NK cells that mediate hybrid resistance, but their function was suppressed by activated granulocytes. Indeed, these granulocytes showed an elevated level of Ca2+ influx upon stimulation. The present results suggest that, in parallel with overactivation of granulocytes, extrathymic T cells and NK cells are concomitantly activated in number but that their function is suppressed in G-CSF transgenic mice.