Progesterone stimulates proliferation of a long-lived epithelial cell population in rat mammary gland.

BACKGROUND: Long-lived somatic cells such as stem/progenitor cells may progressively accumulate oncogenic mutations and cause cancer. Some evidence suggests that pre-menopausal administration of progesterone confers a long-term increased risk of breast cancer. AIM: To clarify the effect of progesterone on long-lived mammary epithelial cells in rats. MATERIALS AND METHODS: Female Sprague- Dawley rats (3 and 7 weeks of age) were implanted sc with 14-day slow-release pellets of 5-bromo-2'-deoxyuridine (BrdU) and were sacrificed every 2 weeks between 0 and 10 weeks after the release period. Some rats at 7 weeks of age were also implanted with progesterone and sacrificed 0 or 10 weeks after the release period. Mammary glands were examined by immunohistochemistry and immunofluorescence for BrdU, proliferative cell nuclear antigen (PCNA) and progesterone receptor (PR). RESULTS: After BrdU labeling of 3- and 7-week-old rats, the BrdU index decreased gradually over 10 weeks and resulted in small fractions (1-3%) of label-retaining epithelial cells (LREC) 10 weeks after BrdU labeling in both mammary lobules and ducts. Treatment with progesterone during labeling significantly increased the fraction of long-lived LREC in lobules and ducts by 9- and 4-fold, respectively. The long-lived LREC population in the ducts was enriched for PCNA- and PR-positive cells, but the percentage of positive cells was not affected by progesterone in either lobules or ducts. CONCLUSIONS: Progesterone stimulates proliferation of a long-lived epithelial cell population in the mammary lobules and ducts of rats. Such cells in the duct are characterized by a high proliferation rate and PR expression.

[Hand-mirror cells acute lymphoblastic leukemia (L3)].

To our knowledge, this report represents the first confirmed case in Japan of a 15-year-old boy with acute lymphoblastic leukemia (ALL).L3 with hand-mirror cells (HMC) in the bone marrow. HMC lymphoid leukemia is an unusual variant of ALL in which the bone marrow lymphoblasts manifest distinctive hand-mirror morphologic features. HMC lymphoblast is characterized by an asymmetric foot-like cytoplasmic process that extends from the portion of the cell, thus giving it the light-microscopic appearance responsible for its name. Besides ALL, HMC has been reported in acute myeloblastic leukemia (AML), blastic crisis of chronic myelogenous leukemia, non-Hodgkin's lymphoma, and infectious mononucleosis. HMC has been reported to be prevalent in ALL.L1 and L2 as compared with L3.

Posterior chamber lens implantation and anterior segment barrier function: a fluorophotometric study.

We used fluorophotometry and pachymetry to examine the early postoperative effects on the anterior segment of the eye after posterior chamber intraocular lens implantation combined with extracapsular cataract extraction as compared to extra-capsular cataract extraction alone. Fluorophotometry was performed by a method of intravenous injection of fluorescein solution (1 mg/kg of body weight) on the 6th postoperative day. We calculated the value of the Fa/Fp ratio, where Fa and Fp were fluorescein concentration in the aqueous and the plasma ultrafiltrate, respectively, and treated it as an index of the blood-aqueous barrier function. Also, we optically measured the corneal thickness and the anterior chamber depth. There were no significant differences between the values of the Fa/Fp ratio and corneal thickness in the two groups. The anterior chamber depth in the pseudophakic eyes (2.89 +/- 0.48 mm, mean +/- SD) differed significantly from that of the eyes undergoing extracapsular cataract extraction alone (3.10 +/- 0.51, P less than 0.001). In the cases of posterior chamber lens implantation, the postoperative value of the Fa/Fp ratio in the intact fellow eyes showed a significant increase compared to the preoperative value in the same eyes (1.2 +/- 0.8 times, P less than 0.05). We conclude that the effects on the anterior segment barrier function of extracapsular lens extraction followed by posterior chamber intraocular lens implantation are not significantly different from those of extracapsular lens extraction alone.

Fluorophotometric study of anterior segment barrier functions after extracapsular cataract extraction and posterior chamber intraocular lens implantation.

We used fluorophotometry and pachymetry to examine the longer-term (more than three months) postoperative effects in the anterior segment of extracapsular lens extraction with and without posterior chamber intraocular lens implantation. Fluorophotometry was performed after oral administration of fluorescein solution (5 mg/kg of body weight under fasting condition). We calculated the corneal endothelial transfer coefficient, fluorescein distribution ratio, aqueous transfer coefficient in reference to chamber volume, and loss coefficient and measured corneal thickness with a modified pachymeter. There were no significant differences between the values for corneal endothelial transfer coefficient and corneal thickness in the two groups of surgically treated eyes combined vs the intact fellow eyes. The aqueous transfer coefficient and loss coefficient values were not significantly different between the two surgically treated groups. Anterior chamber depth did not differ significantly between the two surgical groups, but the value for the two groups combined (3.79 mm) did differ significantly from that of the fellow eyes (2.87 mm) (P less than .005). We concluded that endothelial function recovers three months after extracapsular lens extraction with or without posterior chamber intraocular lens implantation, and that the effects of intraocular lens implantation on anterior segment barrier functions are not significantly different from those of extracapsular lens extraction alone.

Clinical classification of after-cataract following planned extracapsular cataract extraction.

A total of 100 eyes underwent planned extracapsular cataract extraction and were followed more than three months with a mean follow-up period of 12 +/- 8 months. After-cataract was found in 72 eyes. The after-cataract was classified by slit-lamp microscopy into two types, the remnant type and the proliferative type. The former type was due to remains of the lens materials and was present immediately after the surgery: this type was divided into veil-like and Soemmering forms. The proliferative type developed after a period following surgery and was divided into fibrous form and Elschnig form. The fibrous form was thought to be due to fibrous proliferation of the lens epithelial cells, since it was seen at or to originate from the sites of adhesion of the anterior and posterior capsules. The Elschnig form consisted of Elschnig's pearls and was divided into progressive and localized subforms. The former subform was seen more frequently in young patients than the latter subform. The incidences of the above types and forms of the after-cataract were determined. Impairment of the visual acuity due to after-cataract was seen in the proliferative type and was found in 7 eyes. A fluorophotometric study to evaluate the function of the blood-aqueous barrier was carried out in 7 patients with the presence of after-cataract and in 11 patients with no or subtle after-cataract. No difference was found in the barrier function between the two groups.