Epithelial proliferative potential of organ cultured corneoscleral rims; implications for allo-limbal transplantation and eye banking

AIMS

To determine the epithelial proliferative capacity of organ cultured limbal tissue and correlate this with various donor and eye banking factors.

METHODS

24 corneoscleral limbal (CSL) rims left over from penetrating keratoplasty were split in half and set up as in vitro explant cultures. Corneal epithelial proliferative potential (CEPP) was assessed by the number of "cycles" of growth achieved before explants underwent exhaustion and failure to generate an epithelium to subconfluence. The dependence of CEPP on the age of the donor, time of death to enucleation, time of enucleation to organ culture, and time in organ culture in the eye bank was determined.

RESULTS

CSL rims were capable of up to four cycles of culture with a wide variation between tissue samples. Of the various factors examined, death to enucleation time was the only statistically significant factor affecting the CEPP (regression coefficient: -0.062 (cycles/hour), CI -0.119 to -0.004, p = 0.037). Time in organ culture had little effect on CEPP.

CONCLUSIONS

Preselected organ cultured CSL rims from eye banks may offer a viable alternative tissue source for use in allo-limbal transplantation.

[Sodium caseinate induces differentiation of 32D pluripotential hematopoietic cells]

AIM

To determine the role of sodium caseinate (CasNa) in the modulation of hemopoiesis.

MATERIALS AND METHODS

32D cells, a murine hemopoietic multipotential cell line dependent on interleukin-3 (IL-3) for proliferation and survival, were used. These cells were cultured with 0.5 ng/mL of IL-3, together with different concentrations of CasNa. We evaluated: proliferation (direct counting under the microscope and use of thymidine 3H), morphological differentiation (giemsa staining), cytochemistry (specific staining for monocytes and granulocytes), and function (presence of Fc receptors and reduction of nitro-blue tetrazolium). In addition, we determined cell viability through trypan blue exclusion and apoptosis using the TUNEL assay in situ.

RESULTS

We showed that CasNa induced a decrease in cell proliferation, which is dose dependent, and is neither a result of a diminished cell viability, nor due to an increase in cell death through apoptosis. In addition, CasNa induces cell differentiation towards the monocytic lineage.

CONCLUSIONS

CasNa has the capacity to differentiate 32D cells towards the monocytic lineage, and, importantly, has a potent differentiating activity on 32D cells being able to promote differentiation in a shorter time than the well known factors G-CSF and GM-CSF.

The impact of a hospital and clinic-based breastfeeding promotion programme in a middle class urban environment

Hospital interventions in support of breastfeeding have been highly successful in areas where the indigenous population has a well established environment of breastfeeding. However, programmes designed to improve breastfeeding patterns in urban populations have met with mixed success. This paper presents a prospective intervention study with a control group in which a health system-based breastfeeding promotion programme was initiated to support optimal breastfeeding for both child health and child spacing. Following collection of control data, a four-step intervention programme (Breastfeeding Promotion Program) was instituted. This paper reports the process of the development of the intervention programme as well as the comparison of the control and study populations. Major findings include significant increases in duration of full breastfeeding from 31.6 per cent at 6 months in the control group to 66.8 per cent in the intervention group. The duration of lactational amenorrhea was similarly increased: 22 per cent of the control mothers and 56 per cent of the intervention group women were in amenorrhoea at 180 days. The cost-effectiveness of the hospital changes is illustrated.