Showing papers by "Erhard Haus published in 1997"
TL;DR: The increasing number of subjects reaching the age of 65 or older, thanks to medical progress, makes necessary establishing time-qualified references values in the aged, as this kind of investigation should lead to an improvement of the conditions and quality of life of elderly subjects.
62 citations
TL;DR: Circannual rhythms of 3H-thymidine uptake in the DNA of the thymus, spleen, lymph nodes, and bone marrow are found in mice reared for generations under a LD 12:12 lighting regimen and persist if the animals are kept under a regimen of LD 8:16 or LD 16:8 for 3-4 weeks prior to sacrifice.
Abstract: BDF1 male mice, which had been raised for several generations on a lighting regimen of LD 12:12, were studied. Experiments were conducted over 24h spans during winter, spring, summer, and fall. For 3–4 weeks prior to each study, one-third of the animals were kept on a lighting regimen of 8h of light alternating with 16h of darkness (LD 8:16), one-third was kept on a regimen of LD 12:12, and one-third was kept on a regimen of LD 16:8. Subgroups of mice on all three lighting regimens were killed at 4h intervals over a 24h span. At 20 minutes prior to sacrifice, the animals received 5 μCi of 3H-thymidine/0.2 ml/20 gm body weight intraperitoneally. The thymidine uptake in DNA (DPM[3H]/μg DNA) was studied as an index of cell proliferation in the thymus, inguinal lymph node, spleen, femur, and a segment of the lumbar vertebral column. A circannual variation of 3H-Uiymidine uptake in DNA was found in all organs irrespective of the lighting regimen under which the animals were kept. The timing of the circannual v...
13 citations
01 Jan 1997
TL;DR: A circann annual variation of 3H-thymidine uptake in DNA was found in all organs irrespective of the lighting regimen under which the animals were kept, however, the timing of the circannual variation varied among the organs.
Abstract: BDFl male mice, which had been raised for several generations on a lighting regimen of LD 12: 12, were studied. Experiments were conducted over 24h spans during winter, spring, summer, and fall. For 3-4 weeks prior to each study, one-third of the animals were kept on a lighting regimen of 8h of light alternating with 16h of darkness (LD 8 : 16), one-third was kept on a regimen of LD 12 : 12, and one-third was kept on a regimen of LD 16 : 8. Subgroups of mice on all three lighting regimens were killed at 4h intervals over a 24h span. At 20 minutes prior to sacrifice, the animals received 5 FCi of %-thymidinel0.2 mV20 gm body weight intraperitoneally. The thymidine uptake in DNA (DPM[3H]/pg DNA) was studied as an index of cell proliferation in the thymus, inguinal lymph node, spleen, femur, and a segment of the lumbar vertebral column. A circannual variation of 3H-thymidine uptake in DNA was found in all organs irrespective of the lighting regimen under which the animals were kept. The timing of the circannual variation, however, varied among the organs. In the thymus, the lowest thymidine uptake occurred during summer, with higher thymidine uptake during the other three seasons. In the inguinal lymph node, the peak in thymidine uptake was in the spring, with lower values during the other three seasons, the lowest during summer. In the spleen, the highest thymidine uptake occurred in the mice on all three lighting regimens during fall, with lower uptake during winter, spring, and summer. In the bone marrow of both the femur and the vertebral