A prospective observational study of developmental outcomes in survivors of neonatal hypoxic ischaemic encephalopathy in South Africa.

BACKGROUND: Neonatal hypoxic ischaemic encephalopathy (NHIE) is an important cause of long-term handicap in survivors. There is limited information on the burden of handicap from NHIE in sub-Saharan Africa. OBJECTIVES: To determine the developmental outcomes in survivors of NHIE in South Africa (SA). METHODS: In this prospective observational study, the developmental outcomes in 84 infants who had survived hypoxic ischaemic encephalopathy (the NHIE group) were compared with those in 64 unaffected infants (the control group). The Bayley Scales of Infant Development version III were used for assessment of developmental outcomes. RESULTS: Significant differences were found between the developmental outcomes of the two groups, with a significantly lower composite language score and higher proportions with language, motor and cognitive developmental delays in the NHIE group than in the control group. Cerebral palsy (CP) was present in 13 of the infants with NHIE (15.5%) and none in the control group (p<0.001). CP was associated with developmental delay, and also with the severity of NHIE. Therapeutic hypothermia (TH) was administered in 58.3% of the study group, but although it was associated with lower rates of CP and developmental delay than in the group without TH, the only significant difference was for delay on the language subscale. CONCLUSIONS: Survivors of NHIE in SA are at risk of poor developmental outcomes.

Adenovirus-mediated hypoxia-targeted gene therapy using HSV thymidine kinase and bacterial nitroreductase prodrug-activating genes in vitro and in vivo.

Hypoxia is an important factor in tumor growth. It is associated with resistance to conventional anticancer treatments. Gene therapy targeting hypoxic tumor cells therefore has the potential to enhance the efficacy of treatment of solid tumors. Transfection of a panel of tumor cell lines with plasmid constructs containing hypoxia-responsive promoter elements from the genes, vascular endothelial growth factor (VEGF) and erythropoietin, linked to the minimal cytomegalovirus (mCMV) or minimal interleukin-2 (mIL-2) promoters showed optimum hypoxia-inducible luciferase reporter gene expression with five repeats of VEGF hypoxic-response element linked to the mCMV promoter. Adenoviral vectors using this hypoxia-inducible promoter to drive therapeutic transgenes produced hypoxia-specific cell kill of HT1080 and HCT116 cells in the presence of prodrug with both herpes simplex virus thymidine kinase/ganciclovir and nitroreductase (NTR)/CB1954 prodrug-activating systems. Significant cytotoxic effects were also observed in patient-derived human ovarian cancer cells. The NTR/CB1954 system provided more readily controllable transgene expression and so was used for in vivo experiments of human HCT116 xenografts in nude mice. Subjects treated intratumorally with Ad-VEGFmCMV-NTR and intraperitoneal injection of CB1954 demonstrated a statistically significant reduction in tumor growth. Immunohistochemistry of treated xenografts showed a good correlation between transgene expression and hypoxic areas. Further investigation of these hypoxia-inducible adenoviral vectors, alone or in combination with existing modalities of cancer therapy, may aid in the future development of successful Gene-Directed Enzyme Prodrug Therapy systems, which are much needed for targeting solid tumors.

Small molecule FGF receptor inhibitors block FGFR-dependent urothelial carcinoma growth in vitro and in vivo.

BACKGROUND: Activating mutations of FGFR3 are frequently identified in superficial urothelial carcinoma (UC) and increased expression of FGFR1 and FGFR3 are common in both superficial and invasive UC. METHODS: The effects of inhibition of receptor activity by three small molecule inhibitors (PD173074, TKI-258 and SU5402) were investigated in a panel of bladder tumour cell lines with known FGFR expression levels and FGFR3 mutation status. RESULTS: All inhibitors prevented activation of FGFR3, and inhibited downstream MAPK pathway signalling. Response was related to FGFR3 and/or FGFR1 expression levels. Cell lines with the highest levels of FGFR expression showed the greatest response and little or no effect was measured in normal human urothelial cells or in UC cell lines with activating RAS gene mutations. In sensitive cell lines, the drugs induced cell cycle arrest and/or apoptosis. IC(50) values for PD173074 and TKI-258 were in the nanomolar concentration range compared with micromolar concentrations for SU5402. PD173074 showed the greatest effects in vitro and in vivo significantly delayed the growth of subcutaneous bladder tumour xenografts. CONCLUSION: These results indicate that inhibition of FGFR1 and wild-type or mutant FGFR3 may represent a useful therapeutic approach in patients with both non-muscle invasive and muscle invasive UC.

Retargeted adenoviral cancer gene therapy for tumour cells overexpressing epidermal growth factor receptor or urokinase-type plasminogen activator receptor.

We have assessed the ability of bispecific fusion proteins to improve adenovirus-mediated transfer of therapeutic and marker transgenes. We constructed an expression vector that can be easily modified to synthesize a variety of fusion proteins for retargeting adenoviral gene therapy vectors to cell surface markers, which are differentially expressed between normal and cancer cells. Adenoviral transduction can be improved in a number of tumour cell lines which overexpress EGFR (epidermal growth factor receptor) or uPAR (urokinase-type plasminogen activator receptor), but which have only low levels of endogenous hCAR (human coxsackie B and adenovirus receptor) expression. Up to 40-fold improvement in beta-galactosidase transgene expression was seen using an EGFR retargeting protein, and up to 16-fold using a second fusion protein targeting uPAR. In vitro, our uPAR retargeting fusion protein improved the sensitivity to adenoviral herpes simplex virus thymidine kinase/ganciclovir by an order of magnitude, whereas in vivo, our EGFR retargeting protein is able to significantly delay tumour growth in rodent animal models in a dose-dependent manner. The 'cassette' design of our fusion protein constructs offers a flexible method for the straightforward synthesis of multiple adenoviral retargeting proteins, directed against a variety of tumour-associated antigens, for use in clinical trials.

Growth of Infants Born To HIV-Positive Mothers Fed a Whey-Adapted Acidified Starter Formula with Prebiotics and Nucleotides

Objectives: The objectives of this study were to evaluate whether infants born to known HIV-positive mothers; but who were not themselves infected with HIV and who were fed a chemically acidified starter formula with prebiotics with or without nucleotides during their first six months; displayed growth rates equal to uninfected infants fed a chemically acidified starter formula without prebiotics or nucleotides. Design: The design was a multi-centre; double-blinded randomised controlled trial. Setting: The study was carried out in four academic hospitals; three in Johannesburg and one in Cape Town; South Africa. Subjects and intervention: The subjects were newborn infants born to consenting HIV-positive women who had previously decided not to breast feed. The infants were randomised to receive one of three milk formulas. The intervention comprised chemically acidified formula without prebiotics or nucleotides; with prebiotics only; or with prebiotics and nucleotides. Outcome measures: The outcome measures were the growth parameters through the first six months of life. Results: Of the 150 randomised infants; 50 did not complete the study and 16 (12.8of those tested) were infected with HIV; leaving 84 infants available for analysis. All three formulas were tolerated well; with no differences in growth parameters seen with the addition of prebiotics and nucleotides. The growth rates of the study infants up to the age of six months were very good; showing an increase in Z-scores from negative values at the time of enrolment in the first week after birth to around zero for length and 0.5 for weight.Conclusions: The three chemically acidified formulas were tolerated well and resulted in good growth over the first six months of life. No benefits were seen with the addition of prebiotics or nucleotides. The growth rates were similar to those found in previous studies of ours on biologically acidified formulas. The chemical acidification of infant formulas appears to be a realistic alternative to biological acidification should an acidified formula be required

Growth of Infants Born To HIV-Positive Mothers Fed a Whey-Adapted Acidified Starter Formula with Prebiotics and Nucleotides

Objectives: The objectives of this study were to evaluate whether infants born to known HIV-positive mothers; but who were not themselves infected with HIV and who were fed a chemically acidified starter formula with prebiotics with or without nucleotides during their first six months; displayed growth rates equal to uninfected infants fed a chemically acidified starter formula without prebiotics or nucleotides. Design: The design was a multi-centre; double-blinded randomised controlled trial. Setting: The study was carried out in four academic hospitals; three in Johannesburg and one in Cape Town; South Africa. Subjects and intervention: The subjects were newborn infants born to consenting HIV-positive women who had previously decided not to breast feed. The infants were randomised to receive one of three milk formulas. The intervention comprised chemically acidified formula without prebiotics or nucleotides; with prebiotics only; or with prebiotics and nucleotides. Outcome measures: The outcome measures were the growth parameters through the first six months of life. Results: Of the 150 randomised infants; 50 did not complete the study and 16 (12.8of those tested) were infected with HIV; leaving 84 infants available for analysis. All three formulas were tolerated well; with no differences in growth parameters seen with the addition of prebiotics and nucleotides. The growth rates of the study infants up to the age of six months were very good; showing an increase in Z-scores from negative values at the time of enrolment in the first week after birth to around zero for length and 0.5 for weight.Conclusions: The three chemically acidified formulas were tolerated well and resulted in good growth over the first six months of life. No benefits were seen with the addition of prebiotics or nucleotides. The growth rates were similar to those found in previous studies of ours on biologically acidified formulas. The chemical acidification of infant formulas appears to be a realistic alternative to biological acidification should an acidified formula be required

Factors affecting sodium hypochlorite extraction of CCA from treated wood.

Significant amounts of chromated copper arsenate (CCA) treated wood products, such as utility poles and residential construction wood, remain in service. There is increasing public concern about environmental contamination from CCA-treated wood when it is removed from service for reuse or recycling, placed in landfills or burned in commercial incinerators. In this paper, we investigated the effects of time, temperature and sodium hypochlorite concentration on chromium oxidation and extraction of chromated copper arsenate from CCA-treated wood (Type C) removed from service. Of the conditions evaluated, reaction of milled wood with sodium hypochlorite for one hour at room temperature followed by heating at 75 degrees C for two hours gave the highest extraction efficiency. An average of 95% Cr, 99% Cu and 96% As could be removed from CCA-treated, milled wood by this process. Most of the extracted chromium was oxidized to the hexavalent state and could therefore be recycled in a CCA treating solution. Sodium hypochlorite extracting solutions could be reused several times to extract CCA components from additional treated wood samples.

Reducing the cost of screening novel agents using the hollow fibre assay.

Although the in vivo hollow fibre assay (HFA) as utilised by the National Cancer Institute is a highly effective screening tool, it has not been adopted en masse in the cancer pharmacology field. However, in laboratories which have adopted it, the effectiveness of HFA has also been confirmed. If immunocompetent mice could be used with the HFA, thereby reducing the cost of the assay, accessibility would increase and reductions in the cost of selecting appropriate agents for early clinical trials would result. It was demonstrated here that there was no difference in terms of cell growth and response to chemotherapy for cancer cells in hollow fibres in immunocompetent compared with immunodeficient mice. The HFA can thus be performed in these less expensive and more easily available mice with the implication of considerable savings to the preclinical cancer pharmacology community.

Effect of carbon dioxide injection on production of wood cement composites from waste medium density fiberboard (MDF).

The possibility of recycling waste medium density fiberboard (MDF) into wood-cement composites was evaluated. Both new fibers and recycled steam exploded MDF fibers had poor compatibility with cement if no treatment was applied, due to interference of the hydration process by the water soluble components of the fiber. However, this issue was resolved when a rapid hardening process with carbon dioxide injection was adopted. It appears that the rapid carbonation allowed the board to develop considerable strength before the adverse effects of the wood extractives could take effect. After 3-5 min of carbon dioxide injection, the composites reached 22-27% of total carbonation and developed 50-70% of their final (28-day) strength. Composites containing recycled MDF fibers had slightly lower splitting tensile strength and lower tensile toughness properties than those containing new fibers especially at a high fiber/cement ratio. Composites containing recycled MDF fibers also showed lower values of water absorption. Unlike composites cured conventionally, composites cured under CO(2) injection developed higher strength and toughness with increased fiber content. Incorporation of recycled MDF fibers into wood cement composites with CO(2) injection during the production stage presents a viable option for recycling of this difficult to manage waste material.

Survival of very-low-birth-weight infants according to birth weight and gestational age in a public hospital.

OBJECTIVES: To determine the survival rates for infants weighing 500 - 1 499 g according to birth weight (BW) and gestational age (GA). DESIGN: This was a retrospective cohort study. Pregnancy and delivery data were collected soon after birth and neonatal data at discharge or at death. SETTING: Chris Hani Baragwanath Hospital (CHBH), a public-sector referral hospital, affiliated to the University of the Witwatersrand. SUBJECTS: Live births weighing between 500 g and 1 499 g delivered at or admitted to CHBH from January 2000 to December 2002. OUTCOME MEASURES: BW and GA-specific survival rates for all live infants born at CHBH and for those admitted for neonatal care. RESULTS: Seventy-two per cent of infants survived until discharge. The survival to discharge rate was 32% for infants weighing < 1 000 g, and 84% for those weighing 1 000 - 1 499 g. Survival rates at 26, 27 and 28 weeks' gestation were 38%, 50% and 65% respectively. Survival rates for infants admitted to the neonatal unit were better than rates for all live births, especially among those weighing < 1 000 g or with a GA < 28 weeks. There was a marked increase in survival between the 900 - 999 g and 1 000 - 1 099 g weight groups. Provision of antenatal care, caesarean section, female gender and an Apgar score more than 5 at 1 or 5 minutes were associated with better survival to hospital discharge. CONCLUSION: Survival among infants weighing less than 1 000 g is poor. In addition to severe prematurity, the poor survival among these infants (< 1 000 g) is most likely related to the fact that they were not offered mechanical ventilation. Mechanical ventilation should be offered to infants weighing < 1 000 g as it may improve their survival even in institutions with limited resources.

Development of a modified hollow fibre assay for studying agents targeting the tumour neovasculature.

BACKGROUND: Previous studies have shown extensive vascularisation surrounding subcutaneously implanted fibres when the duration of the US National Cancer Institute (NCI) hollow fibre assay was prolonged. MATERIALS AND METHODS: The feasibility of adapting the NCI assay for evaluating agents targeting the tumour vasculature was investigated in vitro and in vivo. Finally, in the optimised assay, changes in neovasculature formation around the fibres following treatment with the anti-vascular agent paclitaxel were quantified by immunohistochemistry. RESULTS: Correlations between cell number seeded, time in culture and vascular endothelial growth factor (VEGF) secretion were seen. In vivo studies showed that transplanting single rather than 3 fibres at a site reduced inflammation, reducing the length of the fibre transplanted, as did without any significant loss in cell growth over 21 days. A statistically significant reduction in neovascularisation surrounding the fibres was seen accompanying paclitaxel treatment. CONCLUSION: Modifications made here to the NCI hollow fibre assay demonstrate its potential for analysing anti-tumour vasculature agents.

Evaluation of transgenic approaches for controlling tuber moth in potatoes.

A wide spectrum of strategies to genetically engineer potato plants resistant to potato tuber moth, Phthorimaea operculella (Zeller), have been investigated. The potato cv Iwa was transformed with a range of genes under the transcriptional control of the CaMV 35S promoter using Agrobacterium-mediated gene transfer. The transferred genes encode protease inhibitors (spleen inhibitor and alpha1-antitrypsin inhibitor), biotin-binding proteins (avidin and streptavidin) and Cry proteins (crylAc9, cry1Ba1, crylCa5 and cry9Aa2). Of these three transgenic approaches, cry genes have proved the most useful. In order to control the expression of the cry genes in foliage and not in the tubers a light-inducible Lhca3 promoter from potato was also used. The interaction of different cry genes was investigated using an experimental approach to simulate gene pyramiding in potato. Potato plants transgenic for both the crylAc9 and cryAa2 genes were developed and evaluated to help provide a more durable resistance to potato tuber moth.

Transgenic Pinus radiata from Agrobacterium tumefaciens-mediated transformation of cotyledons.

A method for Agrobacterium tumefaciens-mediated transformation of Pinus radiata cotyledon explants was developed using commercially available open-pollinated seed. Pinus radiata is the most widely planted commercial conifer species in the Southern Hemisphere. Reports on transformation of this species have relied on particle bombardment of embryogenic callus derived from immature embryos. The main drawback to the method is the small number of genotypes that are amenable to transformation and regeneration. Since more than 80% of genotypes of radiata pine can be regenerated using cotyledons from mature seed, cotyledon explants were cocultivated with A. tumefaciens strain AGL1 containing a plasmid coding for the neomycin phosphotransferase II (nptII) gene and the beta-glucuronidase (GUS) gene (uidA). Transformed shoots were selected using either geneticin or kanamycin. Critical factors for successful transformation were survival of the cotyledons after cocultivation and selection parameters. Of the 105 putative transformants that were recovered from selection media, 70% were positive for integration of the nptII gene when analysed by PCR. GUS histochemical assay for uidA expression was unreliable because of reaction inhibition by unidentified compounds in the pine needles. Further, only 4 of the 26 independent transformants characterised by PCR and Southern analysis contained an intact copy of both genes. The remaining 22 transformants appeared to have a truncated or rearranged copy of the T-DNA. It is possible that the truncation/rearrangements are due to the Cauliflower mosaic virus (CaMV) 35S promoter. Analysis of the T-DNA junction sites and sequencing of the introduced DNA will help elucidate the nature of T-DNA insertion so that genetic modification of radiata pine can be targeted effectively.

Influence of Agrobacterium tumefaciens strain on the production of transgenic peas ( Pisum sativum L.).

We compared the efficiency of two Agrobacterium tumefaciens strains, AGL 1 and KYRT1, for producing transgenic pea plants. KYRT1 is a disarmed strain of Chry5 that has been shown to be highly tumourigenic on soybean. The efficacies of the strains were compared using cotyledon explants from three pea genotypes and two plasmids. The peas were sourced from field-grown plants over three Southern Hemisphere summer seasons. Overall, KYRT1 was found to be on average threefold more efficient than AGL 1 for producing transgenic plants. We suggest that KYRT1 is sensitive to cocultivation temperature as the expected increase in efficiency was not achieved at high laboratory temperatures.

Combretastatin A-1 phosphate potentiates the antitumour activity of cisplatin in a murine adenocarcinoma model.

BACKGROUND: The tubulin depolymerizing drug Combretastatin A-1 phosphate (CA1P), a water-soluble derivative of combretastatin A-1, has been recently shown to have a better efficacy in experimental models than the clinically active, close structural analogue, combretastatin A-4 phosphate (CA4P). Previous studies with CA4P in combination with standard anti-cancer agents have demonstrated improved efficacy relative to the standard agents. MATERIALS AND METHODS: In this study the synergistic effects of administering CA1P in combination with cisplatin (CPL) in a well-differentiated transplantable murine colon model (MAC 29) was evaluated. RESULTS: CA1P at 100 mgkg-1 significantly potentiated the anti-tumour effects of CPL. The effect with CPL was similar to that seen for CA1P at its maximum tolerated dose (MTD) alone. CONCLUSION: These data demonstrate that the combination of CA1P and CPL has significant preclinical antitumour activity against a transplantable murine adenocarcinoma model that is related to the antivascular effects of CA1P.

Antitumour 2-(4-aminophenyl)benzothiazoles generate DNA adducts in sensitive tumour cells in vitro and in vivo.

2-(4-Aminophenyl)benzothiazoles represent a potent and highly selective class of antitumour agent. In vitro, sensitive carcinoma cells deplete 2-(4-aminophenyl)benzothiazoles from nutrient media; cytochrome P450 1A1 activity, critical for execution of antitumour activity, and protein expression are powerfully induced. 2-(4-Amino-3-methylphenyl)benzothiazole-derived covalent binding to cytochrome P450 1A1 is reduced by glutathione, suggesting 1A1-dependent production of a reactive electrophilic species. In vitro, 2-(4-aminophenyl)benzothiazole-generated DNA adducts form in sensitive tumour cells only. At concentrations >100 nM, adducts were detected in DNA of MCF-7 cells treated with 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203). 5F 203 (1 microM) led to the formation of one major and a number of minor adducts. However, treatment of cells with 10 microM 5F 203 resulted in the emergence of a new dominant adduct. Adducts accumulated steadily within DNA of MCF-7 cells exposed to 1 microM 5F 203 between 2 and 24 h. Concentrations of the lysylamide prodrug of 5F 203 (Phortress) > or = 100 nM generated adducts in the DNA of sensitive MCF-7 and IGROV-1 ovarian cells. At 1 microM, one major Phortress-derived DNA adduct was detected in these two sensitive phenotypes; 10 microM Phortress led to the emergence of an additional major adduct detected in the DNA of MCF-7 cells. Inherently resistant MDA-MB-435 breast carcinoma cells incurred no DNA damage upon exposure to Phortress (< or = 10 microM, 24 h). In vivo, DNA adducts accumulated within sensitive ovarian IGROV-1 and breast MCF-7 xenografts 24 h after treatment of mice with Phortress (20 mg kg(-1)). Moreover, Phortress-derived DNA adduct generation distinguished sensitive MCF-7 tumours from inherently resistant MDA-MB-435 xenografts implanted in opposite flanks of the same mouse.

Vinflunine potentiates the activity of cisplatin but not 5-fluorouracil in a transplantable murine adenocarcinoma model.

BACKGROUND: Vinflunine is a novel Vinca alkaloid currently undergoing Phase II clinical trials, which have previously demonstrated anti-vascular effects in a transplantable murine colon adenocarcinoma model. Previous studies with compounds showing similar effects in combination with standard anti-cancer agents have demonstrated an improved efficacy relative to the standard agents. MATERIALS AND METHODS: In this study the synergistic effects of administering vinflunine in combination with either Cisplatin (CPL) or 5-fluorouracil (5-FU) were investigated in a well-differentiated transplantable murine colon adenocarcinoma model (MAC 29). RESULTS: Vinflunine significantly potentiated the anti-tumour effects of CPL, but had little effect in combination with 5-FU. Using Hoescht 33342 dye labelling of the functional vasculature, clear evidence of vascular shutdown was seen for treatment groups including vinflunine. CONCLUSION: These data demonstrate that the combination of vinflunine and CPL has significant preclinical anti-tumour activity against a transplantable murine adenocarcinoma model that is related to the anti-vascular effects of vinflunine.

The intrauterine environment is a strong determinant of glucose tolerance during the neonatal period, even in prematurity.

The aim of this study was to determine the contribution of birth weight and gestational age to glucose tolerance in premature neonates. The study group consisted of 100 premature and/or small-for-gestational age infants. Anthropometric measurements were performed both at birth and at the time of a standardized milk feed carried out at 19.6 +/- 12.1 d (range, 1-65 d) after birth. Fasting and postprandial glucose and insulin levels were measured. Birth weight, as a proxy mirror of the intrauterine environment, was found to influence the glucose concentration following a standardized milk feed (beta = -0.46; P = 0.01 for birth weight z-score with 60-min glucose level), whereas gestational age did not. Small-for-gestational age neonates had higher 60-min insulin levels than appropriate-for-gestational age neonates (115.4 +/- 9.5 vs. 68.4 +/- 14.2; P < 0.05) despite similar glucose levels. Neonates born of mothers who were on antihypertensive treatment were smaller and had a higher insulin secretory response than neonates from normotensive mothers. Postnatal growth velocity (kilograms per day) correlated with birth weight (beta = -0.65; P < 0.0001) and insulin resistance (beta = -0.31; P = 0.0004), independently of each other. This study shows that glucose tolerance of the neonate is determined by weight attained at birth irrespective of gestational age and that maternal blood pressure may influence insulin sensitivity of the newborn. Furthermore, catch-up growth in neonates is determined by birth weight and insulin sensitivity.

A comparison of high versus low dose recombinant human erythropoietin versus blood transfusion in the management of anaemia of prematurity in a developing country.

The purpose of this study was to evaluate the effectiveness of early treatment with erythropoietin (EPO) in two different treatment regimes (high vs. low dose) in comparison to the conventional treatment of packed red blood cell (PRBC) transfusions in the management of anaemia of prematurity in a country with limited resources. An open controlled trial was conducted on 93 preterm infants (7 days postnatal age, 900-1500 g birthweight). Patients were randomly assigned either to a low dose (250 IU/kg), a high dose (400 IU/kg), or a control group. EPO was administered subcutaneously three times a week and all infants received 6 mg/kg iron orally from study entry to endpoint of therapy. Haematological parameters were measured and compared. The success was defined as an absence of transfusions and a haematocrit that did not fall below 30 per cent during the time period that the infants were in the study. The three groups were statistically comparable at study entry with respect to gestational age, birthweight, Apgar scores, and haematological values. Over the period that the infants were in the study, 75 per cent of the low dose group and 71 per cent of the high dose group met the criteria for success compared with 40 per cent in the control group (p < 0.001). However, there was no significant difference in the number of transfusions when the low and high EPO dose groups (9.5 per cent) were combined and compared with the control group (26.7 per cent) p = 0.0587. It was concluded that in stable infants, 900-1500 g, where phlebotomy losses are minimized and stringent transfusion guidelines are adhered to, EPO does not significantly decrease the number of transfusions. A conservative approach in the management of anaemia of prematurity, is a viable alternative in areas with limited resources.

Combretastatin A-1 phosphate a novel tubulin-binding agent with in vivo anti vascular effects in experimental tumours.

In view of the clinical potential of a number of natural products, Combretastatin A-1 phosphate was developed as a water-soluble derivative of combretastatin A-1. This study examined the anti-tumour activity of this compound against an experimental colon tumour (MAC29) in mice. A comparison was made with the clinically active combretastatin A-4 phosphate. The new compound was well-tolerated up to a dose of 250 mg/kg and was more effective at producing tumour growth delays than the A-4 analogue. Significant growth delays were seen at a dose of 50 mg/kg whereas the A-4 phosphate produced no measurable growth delay until a dose of 150 mg/kg was administered. Histological examination of treated tumours indicated that combretastatin A-1 phosphate caused very severe haemorrhagic necrosis in the tumour tissue and analysis of the sections indicated that almost 94 percent of the tumour was dead within 24 hours of treatment. The mechanism of action of combretastatin A-1 phosphate appears to be similar to the A-4 phosphate in that tumour vascular shutdown occurs within 4 hours of treatment. In summary combretastatin A-1 phosphate, the water-soluble analogue of combretastatin A-1, is more potent against a well-vascularised murine colon tumour than its predecessor, combretastatin A-4 phosphate. These data suggest this compound may have potential for clinical development.