Embryo donation in New Zealand: a pilot study

BACKGROUND

In New Zealand, embryo donation to others was approved in late 2005 and follows strict guidelines. To date, few donations have proceeded. Given the novelty of embryo donation and New Zealand's guidelines around donation, this study explores how potential recipients in New Zealand made meaning of embryo donation.

METHODS

Thirteen potential recipients were interviewed regarding decision-making around embryo donation. Data were analysed thematically, identifying the major concerns that shaped their perspectives and decision-making regarding embryo donation.

RESULTS

The concept of genetic lineage emerged as the most important consideration. Participants viewed the embryo as a direct and permanent link between the genetic parents and the child resulting from donation. The genetic link implied ongoing responsibility, interest, care and even ownership. Participants were particularly cognizant of the need for children born from embryo donation to have access to information regarding their heritage. Wider concerns around the quality of the embryo's genetic material were expressed. Neither discarding surplus embryos nor embryo donation was seen as easy options. Participants found embryo donation to be a psychologically and morally complex issue and expressed some caution about pursuing this option.

CONCLUSIONS

The emphasis on genetic lineage as a priority in decision-making needs to be recognized especially within contexts where guidelines emphasize donor registration and cultures are shaped by open-adoption practices and the importance of knowing one's lineage.

Expression of chemokine receptors CXCR4, CXCR5 and CCR7 on B and T lymphocytes from patients with primary antibody deficiency

The interaction of chemokines and their receptors directs lymphocyte migration, and is involved in the distribution and organization of lymphocytes within lymphoid tissues. We reasoned that abnormal chemokine receptor expression might give rise to defects of lymphocyte migration into and within lymphoid tissues, and consequently be associated with defective antibody production in primary antibody deficiencies. In this study, we have investigated the expression of chemokine receptors CXCR4, CXCR5 and CCR7 on lymphocyte subpopulations (naive and memory B cells; CD4(+) and CD8(+) T cells) in a cohort of patients with primary antibody deficiency (n = 23), and compared these with a group of healthy controls (n = 19). We show that there were significant differences in both the proportions of lymphocytes expressing, and the levels of expression of, specific chemokine receptors on individual lymphocyte subpopulations between patients and controls. Furthermore, these changes appeared more pronounced in patients with more severe antibody deficiency. These data support the hypothesis that abnormal lymphocyte trafficking may be involved in the pathogenesis of primary antibody deficiencies.

Acute post-streptococcal glomerulonephritis associated with prolonged hypocomplementaemia

The case of a 6-year-old boy who presented with acute post-streptococcal glomerulonephritis is reported. C3 levels and complement alternative pathway activity remained low for at least 10 months after presentation, before returning to normal. There was no evidence of other renal disease. This case highlights that hypocomplementaemia in acute post-streptococcal glomerulonephritis may persist for several months, and that prolonged hypocomplementaemia does not exclude this diagnosis.

Make or break. Mothers' experiences of returning to paid employment and breastfeeding: a New Zealand study

When mothers return to paid employment, which more and more are doing, they often give up breastfeeding. This qualitative study aims to describe New Zealand mothers' experiences of returning to paid employment and infant feeding. Thirty-four mothers who had given birth between 2003 and 205 were interviewed regarding their experiences and decisions about returning to paid employment following the birth of their child. The presence or absence of the factors of space, time, and support emerged as key factors in the mothers' perception of their ability to continue to breastfeed on their return to paid employment. Employers need to make changes to the workplace environment to encourage and support breastfeeding. But societal attitudes also need to change to become more supportive and positive of breastfeeding workers.

Antiretroviral pre-exposure prophylaxis prevents vaginal transmission of HIV-1 in humanized BLT mice

BACKGROUND

Worldwide, vaginal transmission now accounts for more than half of newly acquired HIV-1 infections. Despite the urgency to develop and implement novel approaches capable of preventing HIV transmission, this process has been hindered by the lack of adequate small animal models for preclinical efficacy and safety testing. Given the importance of this route of transmission, we investigated the susceptibility of humanized mice to intravaginal HIV-1 infection.

METHODS AND FINDINGS

We show that the female reproductive tract of humanized bone marrow-liver-thymus (BLT) mice is reconstituted with human CD4+ T and other relevant human cells, rendering these humanized mice susceptible to intravaginal infection by HIV-1. Effects of HIV-1 infection include CD4+ T cell depletion in gut-associated lymphoid tissue (GALT) that closely mimics what is observed in HIV-1-infected humans. We also show that pre-exposure prophylaxis with antiretroviral drugs is a highly effective method for preventing vaginal HIV-1 transmission. Whereas 88% (7/8) of BLT mice inoculated vaginally with HIV-1 became infected, none of the animals (0/5) given pre-exposure prophylaxis of emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) showed evidence of infection (Chi square = 7.5, df = 1, p = 0.006).

CONCLUSIONS

The fact that humanized BLT mice are susceptible to intravaginal infection makes this system an excellent candidate for preclinical evaluation of both microbicides and pre-exposure prophylactic regimens. The utility of humanized mice to study intravaginal HIV-1 transmission is particularly highlighted by the demonstration that pre-exposure prophylaxis can prevent intravaginal HIV-1 transmission in the BLT mouse model.

Image-guided lung radiotherapy: Bringing technology into routine clinical practice

18093

Background: Cone-beam CT (CBCT), an imaging system integrated into the RT treatment unit, produces 3D images far superior to the conventional 2D portal images used for verification of patient (pt) set-up. This allows direct matching to the RT treatment planning CT images, potentially increasing the precision of RT delivery. We report on the broad implementation of this new RT image-guided paradigm in lung cancer patients at our center. Methods: All lung cancer pts undergoing radical RT were planned using 4DCT and imaged daily for repositioning with CBCT since 04/06. Initially, CBCT datasets were compared with the planning CT to assess the setup error (bone surrogate), using two immobilisation methods: evacuated bags (EB) and chest-board (ChB). Discrepancies >3 mm between the two datasets, in any direction, were corrected before the start of each RT fraction. Data were retrospectively analyzed to assess the initial and residual discrepancies (43 pts; 1,128 CBCTs).Alternative matching strategies were also tested (carina & tumor) using both manual and automatic methods (30 pts). Protocols had REB approval. Results: In total, 657 (58%) RT treatments required adjustment after initial positioning on the treatment couch. The two immobilization methods were equivalent (p=0.18); the mean pt shift required for ChB pts was 55±18mm and for EB pts was 69±32mm. Given that residual uncertainties were <3 mm, margin calculations reveal that large reductions (54–79%) may be possible for tumors not influenced by respiratory motion. The performance of automatic matching was reasonable for carina (correlation [r] 0.8–0.84) and bone (r 0.58–0.81) but discrepancies were seen for tumor (r 0.63–0.69). Conclusions: Daily CBCT provides greatly increased accuracy of set-up, to within 3 mm of the planned bony anatomy, which may improve tumor control by confirming geographic accuracy. The role of image-guided RT in reducing the volume of irradiated normal tissue may play an important role in addressing toxicity concerns associated with combined modality treatment and facilitate safe RT dose escalation. In addition to increasing RT precision, daily CBCT allows routine visualisation of the tumor as well as to bony anatomy, presenting an exciting opportunity to adapt the treatment plan based on an individual response.

[Table: see text]

Photodarkening in Yb-doped aluminosilicate fibers induced by 488 nm irradiation

Photodarkening of Yb-doped aluminosilicate fibers by continuous wave 488 nm irradiation was investigated. The irradiation induced significant excess loss in the UV-visible spectroscopy (VIS) region in Yb-doped aluminosilicate fibers while pure aluminosilicate fibers showed negligible induced loss. Ultraviolet-VIS-near-infrared spectroscopy revealed an absorption peak at 220 nm in unexposed Yb-doped aluminosilicate fiber preforms. The observed peak was attributed to Yb-associated oxygen deficiency centers (ODCs) and proposed as a precursor of the photodarkening. The proposed model was supported by measurements on oxygen-loaded Yb-doped aluminosilicate fibers. In these, the photodarkening could be significantly reduced, which we attribute to a smaller number of ODCs following oxygen loading.