Reduced total number of cobblestone area forming cells and in vitro stromal-cell growth in autografts from acute myeloid leukemia patients.

Background: It is well known that ABMT in acute myeloid leukemia (AML) often results in delayed hematopoietic engraftment, but the reason behind this has not been resolved. Previous studies have largely dealt with measurements of committed myeloid progenitors as surrogate markers for hematopoiesis.

Methods: Measurements of Week 5 cobblestone area forming cells (CAFC) and stromal-cell growth in BM autografts from 14 AML patients were compared with those from 10 NHL patients.

Peripheral blood accessory cells modulate committed colony-forming units but not 5-week cobblestone-area-forming cell outgrowth from CD34+ cells.

While cellular modulation in vitro of committed hematopoietic stem cell (HSC) growth has been known for some time, less is known about the effect of accessory cells (AC) on the growth of more immature HSC. We have examined the effect of peripheral blood (PB) AC on hematopoiesis by coculturing enriched PB CD34+ cells (>96% pure) with different quantities of CD34 cells (<1% contamination) harvested from 10 breast cancer patients. As expected colony growth was predominantly present in the CD34+ fractions, in which colony forming units granulocyte-macrophage (CFU-GM) varied between 89-3289/10(5) (median 1422/10(5) seeded cells) and week 5 cobblestone area forming cells (CAFC) between 64-1330/10(5) (median 427/10(5) seeded cells).

Long-term culture of hematopoietic stem cells - validating the stromal component of the CAFC assay.

Background: The stroma-based long-term culture is the assay of choice when a functional detection of primitive hematopoietic cells in vitro is sought. However, different stromal cell lines varying in supporting capacity have been raised and applied in different laboratories, resulting in a wide range in published frequencies of LTCIC alternative CAFC.

Methods: In order to identify the most suitable stromal source in terms of supportive capacity, reproducibility, and ease of handling, we have compared some of the most commonly employed murine cell lines to human bone marrow stroma in secondary long-term culture set-ups.

Histological changes in the penis of the Chacma baboon--a model to study aging penile vascular impotence.

Light and scanning electron microscopy was performed on the penes of Chacma baboons to establish their suitability as animal model for studying vascular impotence. Analogous aging penile vascular changes were found in man, and a fibrous trabeculopathy with intertrabecular senechiae was demonstrated. Considering the corresponding changes, the Chacma baboon could thus be regarded suitable for studying the pathophysiology of aging penile vascular changes.

Abnormal vessels in the urinary tract following analgesic abuse in man.

A brownish discoloration of the bladder mucosa around the ureteric orifices has been observed on cystoscopy in three patients taking excessive quantities of analgesics. Biopsy specimens revealed an unusual degree of hyalinization of the vessels in the submucosa. Similar changes have been noted in the renal medulla, pelvis, and ureter of patients with classical analgesic nephritis.