Achieving the UNAIDS 90-90-90 targets: a comparative analysis of four large community randomised trials delivering universal testing and treatment to reduce HIV transmission in sub-Saharan Africa.

BACKGROUND: Four large community-randomized trials examining universal testing and treatment (UTT) to reduce HIV transmission were conducted between 2012-2018 in Botswana, Kenya, Uganda, Zambia and South Africa. In 2014, the UNAIDS 90-90-90 targets were adopted as a useful metric to monitor coverage. We systematically review the approaches used by the trials to measure intervention delivery, and estimate coverage against the 90-90-90 targets. We aim to provide in-depth understanding of the background contexts and complexities that affect estimation of population-level coverage related to the 90-90-90 targets. METHODS: Estimates were based predominantly on "process" data obtained during delivery of the interventions which included a combination of home-based and community-based services. Cascade coverage data included routine electronic health records, self-reported data, survey data, and active ascertainment of HIV viral load measurements in the field. RESULTS: The estimated total adult populations of trial intervention communities included in this study ranged from 4,290 (TasP) to 142,250 (Zambian PopART Arm-B). The estimated total numbers of PLHIV ranged from 1,283 (TasP) to 20,541 (Zambian PopART Arm-B). By the end of intervention delivery, the first-90 target (knowledge of HIV status among all PLHIV) was met by all the trials (89.2%-94.0%). Three of the four trials also achieved the second- and third-90 targets, and viral suppression in BCPP and SEARCH exceeded the UNAIDS target of 73%, while viral suppression in the Zambian PopART Arm-A and B communities was within a small margin (~ 3%) of the target. CONCLUSIONS: All four UTT trials aimed to implement wide-scale testing and treatment for HIV prevention at population level and showed substantial increases in testing and treatment for HIV in the intervention communities. This study has not uncovered any one estimation approach which is superior, rather that several approaches are available and researchers or policy makers seeking to measure coverage should reflect on background contexts and complexities that affect estimation of population-level coverage in their specific settings. All four trials surpassed UNAIDS targets for universal testing in their intervention communities ahead of the 2020 milestone. All but one of the trials also achieved the 90-90 targets for treatment and viral suppression. UTT is a realistic option to achieve 95-95-95 by 2030 and fast-track the end of the HIV epidemic.

Intimate Partner Violence (IPV) and Associated Factors in HPTN 071 (PopART) Study Communities in Zambia and South Africa-A Comparison by HIV Status.

The HPTN 071(PopART) study was a community-randomised trial in Zambia and South Africa, examining the impact of combination-prevention including universal testing and treatment (UTT), on HIV-incidence. This sub-study evaluated factors associated with IPV (physical and/or sexual) to identify differences by HIV status. During 2015-16, a random subset of adults who participated in the first year of the PopART intervention were recruited and standardised questionnaires were administered. Logistic regression was performed to estimate odds ratios of factors associated with IPV. Among > 700 women studied (300 HIV-negative;400 HIV-positive), ~ 20% reported experiencing physical and/or sexual violence in the last 12-months. Sexual violence was similar by HIV status, but physical violence and reporting both physical/sexual violence was more common among HIV-positive women. Spending nights away from the community in the last 12-months was associated with higher odds of IPV among both HIV-negative (aOR 3.17, 95% CI 1.02-9.81) and HIV-positive women (aOR 1.79, 95% CI 0.99-3.24). Among HIV-positive women, financial autonomy was associated with reduced IPV (aOR:0.41,95%CI:0.23-0.75) while pregnancy in the last 12-months (aOR 2.25, 95% CI 1.07-4.74), risk of alcohol dependence (aOR 2.75, 95% CI 1.51-5.00) and risk of mental distress (aOR 2.62, 95% CI 1.33-5.16) were associated with increased IPV. Among HIV-negative women reporting sex in the last 12-months, transactional sex (aOR 3.97, 95% CI 1.02-15.37) and not knowing partner's HIV status (aOR 3.01, 95% CI 1.24-7.29) were associated with IPV. IPV was commonly reported in the study population and factors associated with IPV differed by HIV status. The association of mobility with IPV warrants further research. The high prevalence of harmful alcohol use and mental distress, and their association with IPV among HIV-positive women require urgent attention.

RESUMEN: El estudio HPTN 071 (PopART) fue un ensayo aleatorio-comunitario realizado en Zambia y Sudáfrica, que examinó el impacto de la prevención combinada, incluyendo las pruebas y tratamiento universal (UTT), en la incidencia del VIH. Este subestudio evaluó los factores asociados con la IPV (físicos y / o sexuales) para identificar diferencias en el estado del VIH. Durante 2015-16, un subconjunto aleatorio de adultos fueron reclutados para participar en el primer año de intervención de PopART, donde se administraron cuestionarios estandarizados. Se realizó una regresión logística para estimar las ratios de probabilidad de los factores asociados con la VPI. Entre las > 700 mujeres estudiadas (300 VIH negativas; 400 VIH positivas), ~ 20% informó haber experimentado violencia física y / o sexual en los últimos 12 meses. La violencia sexual fue similar en cuanto al estado del VIH. La denuncia de violencia física y sexual fue más común entre las mujeres VIH positivas. Pasar noches fuera de la comunidad en los últimos 12 meses, se asoció con mayores probabilidades de VPI entre las mujeres VIH negativas (ORa 3,17, 95% IC 1,02­9,81) y las mujeres VIH positivas (ORa 1,79, 95% IC 0,99­3,24). Entre las mujeres VIH positivas, la autonomía financiera se asoció con una reducción de la VPI (ORa 0,41; IC del 95% 0,23-0,75) mientras que en el embarazo en los últimos 12 meses (ORa 2,25; IC del 95% 1,07­4,74), riesgo a la dependencia del alcohol (ORa 2,75% IC 1,51­5,00) y el riesgo de angustia mental (ORa 2,62% IC del 95% 1,33­5,16) se asociaron con un aumento de la VPI. Entre las mujeres VIH negativas que informaron haber tenido relaciones sexuales en los últimos 12 meses, el sexo transaccional (ORa 3.97, 95% CI 1.02­15.37) y el desconocimiento del estado de VIH de la pareja (ORa 3.01, 95% CI 1.24­7.29) se asociaron con IPV. La IPV fue notificada mayoritariamente en la población de estudio y los factores asociados con la IPV diferían según el estado del VIH. La asociación de la movilidad con la IPV justifica una mayor investigación. La alta prevalencia de l consumo nocivo de alcohol y la angustia mental, y su asociación con la VPI entre las mujeres seropositivas, requieren atención urgente.

Community-based health workers implementing universal access to HIV testing and treatment: lessons from South Africa and Zambia-HPTN 071 (PopART).

The global expansion of HIV testing, prevention and treatment services is necessary to achieve HIV epidemic control and promote individual and population health benefits for people living with HIV (PLHIV) in sub-Saharan Africa. Community-based health workers (CHWs) could play a key role in supporting implementation at scale. In the HPTN 071 (PopART) trial in Zambia and South Africa, a cadre of 737 study-specific CHWs, working closely with government-employed CHW, were deployed to deliver a 'universal' door-to-door HIV prevention package, including an annual offer of HIV testing and referral services for all households in 14 study communities. We conducted a process evaluation using qualitative and quantitative data collected during the trial (2013-2018) to document the implementation of the CHW intervention in practice. We focused on the recruitment, retention, training and support of CHWs, as they delivered study-specific services. We then used these descriptions to: (i) analyse the fidelity to design of the delivery of the intervention package, and (ii) suggest key insights for the transferability of the intervention to other settings. The data included baseline quantitative data collected with the study-specific CHWs (2014-2018); and qualitative data from key informant interviews with study management (n = 91), observations of CHW training events (n = 12) and annual observations of and group discussions (GD) with intervention staff (n = 68). We show that it was feasible for newly recruited CHWs to implement the PopART intervention with good fidelity, supporting the interpretation of the trial outcome findings. This was despite some challenges in managing service quality and CHW retention in the early years of the programme. We suggest that by prioritizing the adoption of key elements of the in-home HIV services delivery intervention model-including training, emotional support to workers, monitoring and appropriate remuneration for CHWs-these services could be successfully transferred to new settings.

Quantum circuits with many photons on a programmable nanophotonic chip.

Growing interest in quantum computing for practical applications has led to a surge in the availability of programmable machines for executing quantum algorithms1,2. Present-day photonic quantum computers3-7 have been limited either to non-deterministic operation, low photon numbers and rates, or fixed random gate sequences. Here we introduce a full-stack hardware-software system for executing many-photon quantum circuit operations using integrated nanophotonics: a programmable chip, operating at room temperature and interfaced with a fully automated control system. The system enables remote users to execute quantum algorithms that require up to eight modes of strongly squeezed vacuum initialized as two-mode squeezed states in single temporal modes, a fully general and programmable four-mode interferometer, and photon number-resolving readout on all outputs. Detection of multi-photon events with photon numbers and rates exceeding any previous programmable quantum optical demonstration is made possible by strong squeezing and high sampling rates. We verify the non-classicality of the device output, and use the platform to carry out proof-of-principle demonstrations of three quantum algorithms: Gaussian boson sampling, molecular vibronic spectra and graph similarity8. These demonstrations validate the platform as a launchpad for scaling photonic technologies for quantum information processing.

Is home-based HIV testing universally acceptable? Findings from a case-control study nested within the HPTN 071 (PopART) trial.

OBJECTIVE: The HPTN 071 (PopART) trial is examining the impact of a package including universal testing and treatment on community-level HIV incidence in Zambia and South Africa. We conducted a nested case-control study to examine factors associated with acceptance of home-based HIV testing and counselling (HB-HTC) delivered by community HIV-care providers (CHiPs) in PopART intervention communities. METHODS: Of 295 447 individuals who were offered testing, random samples of individuals who declined HB-HTC (cases) and accepted HB-HTC (controls), stratified by gender and community, were selected. Odds ratios comparing cases and controls were estimated using multivariable logistic regression. RESULTS: Data from 642 participants (313 cases, 329 controls) were analysed. There were no differences between cases and controls by demographic or behavioural characteristics including age, marital or socio-economic position. Participants who felt they could be open with CHiPs (AOR: 0.46, 95% CI: 0.30-0.71, P < 0.001); self-reported as not previously tested (AOR: 0.64; 95% CI: 0.43-0.95, P = 0.03); considered HTC at home to be convenient (AOR: 0.38, 95% CI: 0.27-0.54, P = 0.001); knowing others who had accepted HB-HTC from the CHiPs (AOR: 0.49, 95% CI: 0.31-0.77, P = 0.002); or were motivated to get treatment without delay (AOR: 0.60, 95% CI: 0.43-0.85, P = 0.004) were less likely to decline the offer of HB-HCT. Those who self-reported high-risk sexual behaviour were also less likely to decline HB-HCT (AOR: 0.61, 95% CI: 0.39-0.93, P = 0.02). Having stigmatising attitudes about HB-HTC was not an important barrier to HB-HCT uptake. Men who reported fear of HIV were more likely to decline HB-HCT (AOR: 2.68, 95% CI: 1.33-5.38, P = 0.005). CONCLUSION: Acceptance of HB-HTC was associated with lack of previous HIV testing, positive attitudes about HIV services/treatment and perception of high sexual risk. Uptake of HB-HCT among those offered it was similar across a range of demographic and behavioural subgroups suggesting it was 'universally' acceptable.

Hospital-based routine HIV testing in high-income countries: a systematic literature review.

OBJECTIVES: To produce a summary of the published evidence of the barriers and facilitators for hospital-based routine HIV testing in high-income countries. METHODS: Electronic databases were searched for studies, which described the offer of HIV testing to adults attending emergency departments (EDs) and acute medical units (AMUs) in the UK and US, published between 2006 and 2015. Other high-income countries were not included, as their guidelines do not recommend routine testing for HIV. The main outcomes of interest were HIV testing uptake, HIV testing coverage, factors facilitating HIV screening and barriers to HIV testing. Fourteen studies met the pre-defined inclusion criteria and critically appraised using mixed methods appraisal tool (MMAT). RESULTS: HIV testing coverage ranged from 9.7% to 38.3% and 18.7% to 26% while uptake levels were high (70.1-84% and 53-75.4%) in the UK and US, respectively. Operational barriers such as lack of time, the need for training and concerns about giving results and follow-up of HIV positive results, were reported. Patient-specific factors including female sex, old age and low risk perception correlated with refusal of HIV testing. Factors that facilitated the offer of HIV testing were venous sampling (vs. point-of-care tests), commitment of medical staff to HIV testing policy and support from local HIV specialist providers. CONCLUSIONS: There are several barriers to routine HIV testing in EDs and AMUs. Many of these stem from staff fears about offering HIV testing due to the perceived lack of knowledge about HIV. Our systematic review highlights areas which can be targeted to increase coverage of routine HIV testing.

Suppression of acetylpolyamine oxidase by selected AP-1 members regulates DNp73 abundance: mechanistic insights for overcoming DNp73-mediated resistance to chemotherapeutic drugs.

Enhanced resistance to chemotherapy has been correlated with high levels of Delta-Np73 (DNp73), an anti-apoptotic protein of the p53 tumor-suppressor family which inhibits the pro-apoptotic members such as p53 and TAp73. Although genotoxic drugs have been shown to induce DNp73 degradation, lack of mechanistic understanding of this process precludes strategies to enhance the targeting of DNp73 and improve treatment outcomes. Antizyme (Az) is a mediator of ubiquitin-independent protein degradation regulated by the polyamine biosynthesis pathway. We show here that acetylpolyamine oxidase (PAOX), a catabolic enzyme of this pathway, upregulates DNp73 levels by suppressing its degradation via the Az pathway. Conversely, downregulation of PAOX activity by siRNA-mediated knockdown or chemical inhibition leads to DNp73 degradation in an Az-dependent manner. PAOX expression is suppressed by several genotoxic drugs, via selected members of the activator protein-1 (AP-1) transcription factors, namely c-Jun, JunB and FosB, which are required for stress-mediated DNp73 degradation. Finally, chemical- and siRNA-mediated inhibition of PAOX significantly reversed the resistant phenotype of DNp73-overexpressing cancer cells to genotoxic drugs. Together, these data define a critical mechanism for the regulation of DNp73 abundance, and reveal that inhibition of PAOX could widen the therapeutic index of cytotoxic drugs and overcome DNp73-mediated chemoresistance in tumors.

p53 promotes cellular survival in a context-dependent manner by directly inducing the expression of haeme-oxygenase-1.

A variety of cellular insults activate the tumour suppressor p53, leading generally to cell-cycle arrest or apoptosis. However, it is not inconceivable that cellular protective mechanisms may be required to keep cells alive while cell-fate decisions are made. In this respect, p53 has been suggested to perform functions that allow cells to survive, by halting of the cell-cycle, and thus preventing immediate cell death. Nonetheless, the existence of direct pro-survival p53 target genes regulating cellular survival is lacking. We show here evidence for p53-dependent cellular survival in a context-dependent manner. Both mouse and human cells lacking p53 are hypersensitive to hydrogen peroxide (H(2)O(2))-induced cell death compared with their isogenic wild-type counterparts. By contrast, p53(-/-) cells are expectedly resistant to cell death upon exposure to DNA-damaging agents such as cisplatin (CDDP) and etoposide. Although p53 and its classical targets such as p21 and Mdm2 are activated by both H(2)O(2) and CDDP, we found that the expression of haeme-oxygenase-1 (HO-1)-an antioxidant and antiapoptotic protein-was directly induced only upon H(2)O(2) treatment in a p53-dependent manner. Consistently, p53, but not its homologue p73, activated HO-1 expression and was bound to the HO-1 promoter specifically only upon H(2)O(2) treatment. Moreover, silencing HO-1 expression enhanced cell death upon H(2)O(2) treatment only in p53-proficient cells. Finally, H(2)O(2)-mediated cell death was rescued significantly in p53-deficient cells by antioxidant treatment, as well as by bilirubin, a by-product of HO-1 metabolism. Taken together, these data demonstrate a direct role for p53 in promoting cellular survival in a context-specific manner through the activation of a direct transcriptional target, HO-1.

Serine 312 phosphorylation is dispensable for wild-type p53 functions in vivo.

Cellular stimulation results in phosphorylation of the tumor suppressor p53 on multiple residues, though the functional relevance is not always clear. It is noteworthy that the serine (S) 315 residue is unique, as it has been suggested to be phosphorylated not only by genotoxic signals, but also during cell-cycle progression and by endoplasmic-reticulum stress. However, in vitro data have been conflicting as phosphorylation at this site was shown to both positively and negatively regulate p53 functions. We have thus generated knock-in mice expressing an unphosphorylable S312 (equivalent to human S315), by substitution with an alanine (A) residue, to clarify the conflicting observations and to evaluate its functional relevance in vivo. Born at Mendelian ratios, the p53(S312A/S312A) mice show no anomalies during development and adulthood. p53 activation, stability, localization and ability to induce apoptosis, cell-cycle arrest and prevent centrosome amplification are not compromised in p53(S312A/S312A) cells. p53(S312A/S312A) mice are unable to rescue mdm2(-/-) lethality, and tumorigenesis--both spontaneous and irradiation/oncogene-induced--is not accentuated. Taken together, the results show that the S312 phosphorylation site is not in itself necessary for efficient p53 function, and advocates the possibility that it is neither relevant in the mouse context nor important for p53 functions in vivo.

Antiretroviral therapy for HIV prevention: many concerns and challenges, but are there ways forward in sub-Saharan Africa?

Scientists from the WHO have presented a theoretical mathematical model of the potential impact of universal voluntary HIV testing and counselling followed by immediate antiretroviral therapy (ART). The results of the model suggests that, in a generalised epidemic as severe as that in sub-Saharan Africa (SSA), HIV incidence may be reduced by 95% in 10 years and that this approach may be cost effective in the medium term. This offers a 'ray of hope' to those who have thus far only dreamed of curbing the HIV/AIDS epidemic in SSA, as until now the glaring truth has been pessimistic. When it comes to ART, approximately 7 of 10 people who clinically need ART still do not receive it. From an epidemic point of view, for every person placed on ART an estimated four to six others acquire HIV. The likelihood of achieving the targets of the Millennium Development Goals for 2015 and universal ART access by 2010 are thus extremely low. A new window of opportunity may have now opened, but there are many unanswered feasibility and acceptability issues. In this paper, we highlight four key operational challenges linked to acceptability and feasibility and discuss possible ways forward to address them.

An essential role for p73 in regulating mitotic cell death.

The molecular mechanisms regulating cell death during mitosis are poorly understood. We show here a critical role for p73, but not p53, in regulating mitotic cell death induced by various means. Prolonged mitotic arrest and the activation of spindle checkpoint are required for mitotic death, which occurs before mitotic exit and which can be ameliorated by accelerated mitotic exit. Absence or silencing of p73 expression abrogated mitotic death without accelerating mitotic exit, and was independent of BubR1 and Mad2, the loss of which promotes mitotic exit. However, the absence of p73 reduced mitotic death by compromising the expression of the proapoptotic BH3-only protein Bim and thereby affecting cytochrome c release and caspase activation. p73 was found to induce bim expression through direct binding to regulatory elements in intron 1. Congruently, mitotic cell death was rescued to similar extents by silencing either bim or p73 expression. Taken together, the data show an important role for the p73-Bim axis in regulating cell death during mitosis that is independent of p53.

The prolyl cis/trans isomerase cyclophilin 18 interacts with the tumor suppressor p53 and modifies its functions in cell cycle regulation and apoptosis.

The functional diversity of the tumor suppressor protein p53 is mainly regulated by protein interactions. In this study, we describe a new interaction with the peptidyl-prolyl cis/trans isomerase cyclophilin 18 (Cyp18). The interaction reduced the sequence-specific DNA binding of p53 in vitro, whereas the inhibition of the interaction increased p53-reporter gene activity in vivo. The active site of the folding helper enzyme Cyp18 was directly involved in binding. The proline-rich region (amino acids 64-91) of p53 was most likely responsible for the observed binding because a synthetic peptide comprising amino acids 68-81 of p53 inhibited this interaction, and a p53 variant containing a proline residue at position 72 (p53(P72)) interacted with Cyp18 more effectively than the corresponding p53(R72) variant. Impairment of the Cyp18-p53 interaction induced an accumulation of cells in the G2/M phase of the cell cycle, which was more pronounced when p53(P72) was expressed compared with p53(R72) in an otherwise isogenic cellular background. Moreover, p53-dependent apoptosis was elevated in Cyp18 knockout cells, suggesting an antiapoptotic potential of Cyp18-p53 complexes. Functional in vivo data hint to a possible clinical relevance of the p53-Cyp18 interaction observed.

Defective MHC class I antigen surface expression promotes cellular survival through elevated ER stress and modulation of p53 function.

Defects in Major Histocompatibility class I cell surface expression is thought to allow escape of tumor cells from immune surveillance. Hitherto, it is unclear whether this deficiency confers immune-independent survival advantage. We show here that class I cell surface expression deficiency due to defects in beta2 microglobulin or the transporter-associated with antigen processing (TAP) results in resistance to apoptosis in response to various cytotoxic signals. Reduced apoptosis correlated with altered p53 activation, which was due to compromised nuclear translocation of p53. Binding of p53 to glycogen synthase kinase-3beta (GSK3beta), which is known to phosphorylate and lead to cytoplasmic sequestration of p53, was enhanced in these cells. Consistently, endoplasmic reticulum (ER) stress, which promotes binding of p53 to GSK3beta was constitutively elevated in the absence of class I cell surface expression. Taken together, the results suggest a non-immunological causal role for defective class I cell surface expression in regulating cellular survival in a p53-dependent manner, through the upregulation of ER stress, which could be another mechanism leading to carcinogenesis.

c-Jun promotes cellular survival by suppression of PTEN.

Activation of c-Jun, a component of the AP-1 family of transcription factors, leads to either promotion or prevention of apoptosis. However, the molecular determinants of c-Jun-mediated cell survival are still unclear. We show here that inducible expression of c-Jun promotes cellular survival by negatively regulating the expression of the tumor-suppressor PTEN, resulting in the concomitant activation of the Akt survival pathway. Consistently, c-jun-/- fibroblasts, which are sensitive to nutrient deprivation, and human cell lines in which c-Jun expression is silenced, express elevated levels of PTEN. siRNA-mediated silencing of PTEN resulted in the reduction of cell-death owing to c-Jun deficiency. c-Jun was found to suppress PTEN expression by binding to a variant AP-1 site found in the 5' upstream sequences of PTEN promoter. Finally, an inverse correlation between c-Jun and PTEN levels was apparent in a panel of human tumor cell lines, independent of their p53 status. Together, the data demonstrate that c-Jun contributes to the promotion of cellular survival by regulating the expression of PTEN.

The codon 72 polymorphism-specific effects of human p53 are absent in mouse cells: implications on generation of mouse models.

Human p53, unlike mouse p53, contains a polymorphic site at codon 72 in exon 4 encoding either an arginine amino acid (72R) or a proline residue (72P). The 72R form was shown to induce apoptosis better than the 72P form, partly owing to its ability to efficiently bind to the nuclear-export protein CRM1 and localize to the mitochondria. This polymorphism has also been associated with cancer predisposition and chemo-sensitivity. Further understanding of the in vivo significance of this polymorphism in carcinogenesis requires the generation of mouse models. We have thus evaluated if the polymorphism-specific effects of human p53 are retained in mouse cells. Though being transcriptionally active, both the human polymorphs were found to have lost their ability to differentially suppress growth and bind to CRM1 or MDM2 in mouse cells. Moreover, chimaeric proteins containing mouse exons 2-3 and human exons 4-11 have also lost the polymorphism-specific effects in human cells, suggesting that human exons 2-3 are important in regulating the polymorphism-specific effects. Furthermore, human p53 and the various chimaeric proteins were generally less effective in inhibiting growth of mouse cells compared to mouse p53, suggesting that mouse p53 is more potent than human p53 in suppressing growth, partly due to enhanced binding of MDM2 to human p53. The data together suggest that mouse cells may not provide an appropriate environment for the manifestation of the polymorphism-specific functional differences of human p53, and hence, cautions against the expression of full-length or chimaeric p53 proteins in mice to study the effects of the polymorphism.

Trp53-dependent DNA-repair is affected by the codon 72 polymorphism.

Trp53 is arguably the most critical tumour suppressor gene product that inhibits malignant transformation. Besides mutations that inactivate Trp53 functions, genetic polymorphisms have been suggested to be risk factors for cancer. A polymorphic site at codon 72 in exon 4 encodes either an arginine amino acid (Trp53(72R)) or a proline residue (Trp53(72P)). Previous studies have shown that the Trp53(72R) form is more efficient in apoptosis induction, whereas the Trp53(72P) form was suggested to induce G1 arrest better. Here we report that Trp53(72P) is more efficient than Trp53(72R) in specifically activating several Trp53-dependent DNA-repair target genes in several cellular systems. Moreover, using isogenic cell lines and several DNA-repair assays, we show that Trp53(72P) cells have a significantly higher DNA-repair capacity than the Trp53(72R) cells. Furthermore, Trp53(72P)-expressing cells exhibit reduced micronuclei formation compared to Trp53(72R)-expressing cells, suggesting that genomic instability is reduced in these cells. Together, the data highlight the functional differences between the Trp53 polymorphic variants, and suggest that their expression status may influence cancer risk.

Role of splenectomy in chronic idiopathic thrombocytopenic purpura.

AIM OF THE STUDY: To evaluate the usefulness of splenectomy and factors which predict long term remission in chronic idiopathic thrombocytopenic purpura (ITP). METHODS: We reviewed the data of 364 patients diagnosed as chronic ITP between January 1983 to December 1996 of whom 71 patients underwent splenectomy. The patients were followed up for an average period of 58 months and the short and long term response to splenectomy were analyzed at the end of one month and 60 months, respectively. RESULTS: At the end of one month after splenectomy, 82% had complete response, 7% partial response and 11% had no response. At the end of 60 months, 42% maintained complete response, 7% partial response, 34% had no response and 17% were lost to follow up. The results were statistically evaluated by using non-parametric test (Chi-square test) to age, sex, platelet count prior to treatment, initial response to steroids, time interval between diagnosis and splenectomy and post-operative platelet count. Of these factors only preoperative response to steroids (p value = 0.018303) and postoperative platelet count (p value = 0.013536) were found to be significant, statistically to predict long term remission. Age, sex, initial platelet count and time interval between diagnosis and splenectomy didn't seem to be statistically significant. CONCLUSION: This study suggests, that patients with an initial complete response to steroids and a post-operative platelet count > 300 x 10(9)/L at the time of discharge were associated with a long term remission. Splenectomy in ITP is a safe procedure with minimal morbidity and mortality and gives a good long term remission in steroid- failure patients with chronic ITP.