Homelessness in pregnancy.

OBJECTIVES: To evaluate the association, if any, of homelessness or refuge accommodation on delivery and short term perinatal outcomes in an Irish tertiary maternity hospital. METHODS: A retrospective cohort study of 133 singleton pregnancies in women reporting to be homeless or living in refuge at their booking antenatal appointment between 2013 and 2022. Analysis compared sociodemographic characteristics and perinatal outcomes in this cohort to a reference population of 76,858 women with stable living arrangements. RESULTS: Women in the homeless/refuge population were statistically more likely to be single (75.2 % vs 39.5 %, p < 0.001), have an unplanned pregnancy (73.7 % vs 27.2 %, p < 0.001), report a history of psychiatric illness (42.9 % vs 22.4 %, p < 0.001), domestic violence (18.8 % vs 0.9 %, p < 0.001) alcohol consumption in pregnancy (3.0 % vs 0.8 %, p < 0.001) or smoking in pregnancy (41.3 % vs 9.7 %, p < 0.001). They were significantly more likely to have a preterm birth (adjusted OR 1.71 (1.01-2.87) p = 0.04). They also had a significantly lower median birth weight compared to the reference population (birthweight 3270 g vs 3420 g, p < 0.001). CONCLUSION: Women in the homeless and refuge population are more likely to experience poorer perinatal outcomes compared to women with stable living arrangements.

A non-stationary model for simulating the dynamics of ocular aberrations.

The time-evolution of ocular aberrations has been the subject of many studies, but so far there has been little discussion involving the modelling of the underlying temporal statistics. This paper presents a non-stationary modelling approach based on a coloured-noise generator, which can be applied to ocular aberration dynamics. The model parameters are computed from measured ocular aberration data. A custom-built aberrometer based on a Shack-Hartmann sensor was used for measurement. We present simulations based on our modelling approach, and validate them through comparison to real data. This work could be useful in areas such as the testing of ophthalmic devices and the development of improved algorithms for laser refractive surgery.

Leukemia inhibitory factor (LIF) inhibits basal bone resorption in fetal rat long bone cultures.

Leukemia inhibitory factor (LIF) has a wide variety of biologic actions. In vivo, its net effect on bone is to increase new bone formation. Recently, the sequence of human LIF was found to differ by only a single amino acid from that of human differentiation-inducing factor (D-factor). The effects of LIF on bone appear to be complex since purified murine D-factor and recombinant LIF stimulate bone resorption in cultured newborn mouse calvaria. To examine further the responses of bone to LIF, we studied the effects of recombinant human LIF (glycosylated and nonglycosylated) and recombinant human D-factor (non-glycosylated) on resorption in another in vitro organ culture model, fetal rat long bones. Both LIF preparations and D-factor inhibited basal bone resorption rates by 25% to 44% in these cultures. Resorption rates in maximally inhibited LIF-treated cultures were similar to those in devitalized bones. Inhibitory effects typically occurred at concentrations of greater than or equal to 10 ng/mL (0.5 nM) for the non-glycosylated LIF and D-factor and 1000 U/mL for glycosylated LIF. Neither LIF nor D-factor blocked the resorptive response to interleukin 1 (IL 1) or parathyroid hormone (PTH) nor did they alter total DNA synthesis. Hence, their inhibitory effects appeared to be specific for the mechanisms regulating basal resorptive activity. These results demonstrate that LIF has potent inhibitory actions on basal resorption rates in these cultures. These effects may be important for the anabolic responses that LIF has on bone in vivo. In addition, they may also be involved in the interactions between inflammatory or tumor cells and bone.