A qualitative exploration of health-related quality of life and health behaviours in children with sickle cell disease and healthy siblings

OBJECTIVES

This study explored the health-related quality of life (HRQL) and health behaviours of children with sickle cell disease (SCD) and healthy siblings, drawing on Gap theory, which suggests HRQL is the discrepancy between current and ideal selves.

DESIGN

Thirty-two interviews, facilitated by children's drawings of their current and ideal selves were thematically analysed.

RESULTS

Two themes were identified. First, limitations of SCD and adjusted expectations. Children with SCD report some discrepancy in HRQL as they would like to participate in more physical activity, but overall, they appear to have normalised their condition and adjusted their expectations in the context of the limits of their condition. Healthy siblings worry about their sibling and have greater expectations about engaging in adventurous activities and for their future. Second, coping with SCD. Children have limited social support, although children with SCD seek support from their mothers. They also modify health behaviours, like reducing exercise to help prevent and cope with sickle-related pain.

CONCLUSION

Children have some discrepancies in their HRQL but adjusted expectations among children with SCD may reduce discrepancy. Adapting health behaviours may help to cope with SCD but it is important that reductions in physical activity do not impair HRQL.

Breast cancer trends in women in Cyprus: a population-based study between 2004-2017

Background

In Cyprus, breast cancer (BC) is the first in incidence and second in mortality cancer in women. A national screening programme (NSP), targeting women 50-69 years, was introduced in 2007. The aim of this study is to provide a better understanding of cancer trends.

Methods

Data from the national population-based Cyprus Cancer Registry on adult women diagnosed with BC between 2004-2017 with follow-up until 2019 were analysed as follows: Joinpoint regression for age-adjusted (overall and by tumor stage at diagnosis - TSD) and age-specific rates (<50, 50-59, 60-69, 70-79, ≥ 80) incidence and mortality rates; 5-year age-adjusted Net Survival (NS) rates, overall and by TSD. TSD was categorised as localised, regional, and distant.

Results

Age-adjusted incidence rate increased from 135.3 (2004) to 153.2 (2017) per 100,000, with an annual percentage change (APC) of 1.1% (95%CI: 0.4-1.9). The greatest increase was in the age groups ≥70 years. A positive time trend was found for localized cancers between 2006-2017, while for all other stages nonsignificant trends were detected. Age-adjusted mortality rate increased from 37.0 (2004) to 50.0 (2019) per 100,000 (APC: 2.7%; 95%CI: 1.9-9.4). Significant increases in mortality rates were detected in the age groups ≥70 years. By TSD, increased rates were found at localised and regional stages, however smaller increases were detected since 2007. NS rates for the most recent period (2014-2017) was 93% for localized, 81% for regional, and 32% for distant and did not significantly improve compared to the previous years.

Conclusions

Trends in BC incidence continues to increase, especially in the older age groups and for early-stage cancers. As expected, since the introduction of the NSP, the incidence of localised cancers increased whilst the incidence of advanced stage cancer decreased, albeit non-significantly. Survival trends did not change but mortality rates for localised and regional cancers increased at a slower pace.

Key messages

• The introduction of the national screening programme may have played an important role in the increasing BC incidence trends.

• Despite survival rates not improving since the introduction of the national screening programme, mortality rates for early-stage cancers show a less steep increase.

Potential life years lost to COVID-19 in 17 countries during the pandemic period, up to August 2020

Background

COVID-19 pandemic is affecting populations and regions in different ways. In this study, we assess the Potential Years of Life Lost (PYLL) to COVID-19 across different regions.

Methods

We used age-group and sex-specific weekly COVID-19 deaths (from January to August 2020) from national primary sources of 17 countries from the C-MOR consortium (Australia, Brazil, Cape Verde, Colombia, Cyprus, France, Georgia, Israel, Kazakhstan, Peru, Norway, England & Wales, Scotland, Slovenia, Sweden, Ukraine, and the United States). PYLL were calculated by summing up the numbers of deaths in each age group multiplied by the remaining years of life up to age 80. Age-standardized PYLL rates (per 100,000 population), using the World (WHO 2000-2025) Standard population as the reference population, were estimated to facilitate comparison across countries.

Results

Countries in South America displayed the highest PYLL rates (567-1,377 PYLL/100,000). Countries in Asia & Middle East (besides Kazakhstan), Australia, and some European countries (Georgia, Norway, and Slovenia) observed <50 PYLL/100,000. Furthermore, the male to female PYLL rate ratio was above one in all countries [1.3 (Ukraine) - 14.4 (Cyprus)], besides Georgia (ratio = 0.5).

Conclusions

South America, and males were found to be the most affected by COVID-19. Ongoing monitoring of the COVID-19 mortality impact is essential in order to assess health system performances, control measures, and identify vulnerable populations. Differences in mortality burden among populations will help public health officials in their efforts to minimize the COVID-19 mortality burden on a local, and on a global level.

Key messages

Up to August 2020, COVID-19 was a cause of premature mortality in all the participating countries, with South America and males to be more affected.

The timing of the pandemic, seasonal trends, the control measures enforced, and underlying social conditions are probable explanations for the differences observed among countries.

Excess all-cause mortality from January to August 2020: a temporal analysis in 20 countries

 

Analysis of all-cause mortality is an important tool to investigate the impact of the COVID-19 pandemic. This study aims to investigate the magnitude and potential determinants of excess all-cause mortality, from January until August 2020, using national mortality databases from 20 countries part of the C-MOR consortium. Excess weekly mortality for 2020 was calculated by comparing observed against expected weekly number of deaths for 2020. Expected 2020 weekly mortality was estimated using 2015-19 data based on a time series model adjusting for time trend and seasonality. The excess mortality was visualized against a stringency index (SI), based on nine government response indicators, downloaded from the Oxford COVID-19 Government Response Tracker. Brazil, Cyprus, France, Ireland, Italy, countries of the UK, Spain and the USA showed a substantial increase in the observed mortality during 2020, which lasted from 1 (Cyprus) to 7 (England and Wales, Scotland) weeks. Australia, Denmark and Georgia observed fewer than expected deaths, whereas in Austria, Estonia, Israel, Norway, Slovenia and Ukraine 2020 mortality was as expected. Italy, Spain, UK and Brazil enforced high SI measures at least after 3 weeks from the first COVID-19 death. Sweden and the USA did not apply high SI measures for the duration of this study. In Austria, Estonia, Israel, Norway, Cyprus, Georgia, Slovenia and Ukraine, measures of high SI were implemented within 2 weeks of the first COVID-19 death. The decreased mortality in Australia is probably attributed to different seasonality patterns coupled with strict control measures. Several but not all countries showed excess all-cause mortality. Excess mortality was shown to be influenced by the seasonality patterns of each country, as well as the promptness of governments to apply high SI control measures. As the pandemic continues, the lessons learned from the first months of the pandemic can prove useful to minimize increases in all-cause mortality.

Key messages

Some countries showed excess all-cause mortality between January and August 2020, whereas others displayed either negligible excess mortality or even a decrease in all-cause mortality.

Excess mortality may be partly attributed to delayed application of strict control measures whereas lack of excess mortality may be due to seasonality and/or strict control measures.

Feeding olive cake silage up to 20% of DM intake in sheep improves lipid quality and health-related indices of milk and ovine halloumi cheese

This study aimed to evaluate the use of a by-product, olive cake silage (OCS), as a forage replacement in sheep diets for the improvement of fatty acid (FA) content of milk and thus, the lipids of the ovine halloumi cheese produced. Sixty second-parity purebred Chios ewes in mid-lactation were assigned to three diet treatments (2 lots of 10 animals per treatment) receiving 0%, 10%, and 20% of OCS on dry matter basis for 3 weeks (treatments S0, S10, and S20, respectively). Halloumi cheese was manufactured from fresh raw milk of ewes fed the three different diets. Inclusion of OCS in the diets increased linearly the concentration in milk of unsaturated FA up to 20%, monounsaturated FA up to 23%, polyunsaturated FA up to 11%, rumenic acid (CLA cis-9, trans-11) up to 61%, and consequently reduced the atherogenicity and thrombogenicity milk indices by 31% and 27%, for the S10 and S20 treatments, respectively, compared with the control treatment. Moreover, these differences were carried over to the lipid profile of ovine halloumi cheese showing, on average, more than 25% increase of unsaturated, polyunsaturated, and monounsaturated FA, with particularly enhanced oleic and rumenic acid content. These changes resulted in reduced atherogenicity by 29% and 45% and thrombogenicity by 23% and 24% of ovine halloumi cheese made from milk of S10 and S20 diets, respectively. Milk yield, milk fat, or protein content was not affected by S10 or S20 feeding treatments compared to control. Overall, the applied ensiling method of olive cake produces a by-product that can be included as a forage replacement up to 20% of DM intake in Chios sheep without adversely affecting the lactating performance. Furthermore, the present study showed that such substitution improves the lipid quality of milk and related halloumi cheese enriching these ovine dairy products with beneficial to human health fatty acids.

Geographical inequalities in breast cancer incidence, mortality and late stage at diagnosis in Cyprus

Background

A national breast cancer (BC) screening programme, targeting women 50-69 years old, was introduced in Cyprus in 2007. This study aims to assess rural/urban differences in BC incidence, tumour stage at diagnosis (TSD) and mortality, since 2004 and since the introduction of the screening programme.

Methods

Data were obtained for 6589 new cases of BC (diagnosis 2004-2016) from a national population-based cancer registry (1998-today) in Cyprus. TSD was recorded according to the Surveillance, Epidemiology, and End Results categories. We defined late TSD as regional or distant stage. Unknown stages were excluded. We linked cases to the population census data and place of residence (rural/urban) and calculated incidence and mortality rate ratios (RR) by place of residence. We conducted logistic regression to measure the association between place of residence and TSD or mortality, adjusting for sex, age, ethnicity, smoking and marital status. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) are reported.

Results

Since 2004, 54.7% of BC cases were diagnosed at localised stage, 40.6% at regional stage and 4.7% at distant stage. Incidence, but not mortality, rate for all BC was higher in urban than in rural areas (RRincidece=1.22;95%CI=1.51-1.28 and RRmortality=1.10;95%CI=0.97-1.24). Rural place of residence was associated with higher odds of late TSD (aOR=1.34; 95%CI=1.15-1.58) and death (aOR=1.36; 95%CI=1.11-1.68). After the introduction of the screening programme, for the targeted age group, rural place of residence was still associated with higher odds of late TSD (aOR=1.31; 95%C= 1.03-1.67), but not with death (p &gt; 0.05).

Conclusions

Even though BC incidence is higher in urban than in rural areas, women residing in rural areas had higher odds of late TSD and death. The introduction of the national BC screening programme only slightly reduced geographical inequalities in TSD. Further studies are needed to understand and reduce the role of inequalities in TSD.

Key messages

Rural/Urban inequalities in TSD are evident among BC cases in Cyprus, diagnosed between 2004 and 2016. The introduction of the national BC screening programme reduced but did not overcome geographical inequalities in TSD.

The use of ensiled olive cake in the diets of Friesian cows increases beneficial fatty acids in milk and Halloumi cheese and alters the expression of SREBF1 in adipose tissue

This study aimed to evaluate the effect of dietary inclusion of ensiled olive cake, a by-product of olive oil production, on milk yield and composition and on fatty acid (FA) profile of milk and Halloumi cheese from cows. Furthermore, the effect of olive cake on the expression of selected genes involved in mammary and adipose lipid metabolism was assessed in a subset of animals. A total of 24 dairy cows in mid lactation were allocated into 2 isonitrogenous and isoenergetic feeding treatments, named the control (CON) diet and the olive cake (OC) diet, in which part of the forages (alfalfa, barley hay, and barley straw) were replaced with ensiled OC as 10% of dry matter according to a 2 × 2 crossover design with two 28-d experimental periods. At the end of the second experimental period, mammary and perirenal adipose tissue samples were collected from 3 animals per group for gene expression analysis by quantitative reverse-transcription PCR. The expression of 11 genes, involved in FA synthesis (ACACA, FASN, G6PDH), FA uptake or translocation (VLDLR, LPL, SLC2A1, CD36, FABP3), FA saturation (SCD1), and transcriptional regulation (SREBF1, PPARG), was evaluated. No significant differences were observed between groups concerning milk yield, fat percentage, protein percentage, and protein yield (kg/d), whereas milk fat yield (kg/d) increased in the OC group. Dietary supplementation with ensiled OC modified the FA profile of milk and Halloumi cheese produced. There was a significant decrease in the concentration of de novo synthesized FA, saturated FA, and the atherogenic index, whereas long-chain and monounsaturated FA concentration was increased in both milk and cheese. Among individual saturated FA, only stearic acid was elevated, whereas among individual monounsaturated FA, increments of oleic acid (C18:1 cis-9) and the sum of C18:1 trans-10 and trans-11 acids were demonstrated in milk and Halloumi cheese produced. Although no diet effect was reported on total polyunsaturated FA, the concentration of CLA cis-9,trans-11 was increased in both milk and Halloumi cheese fat of the OC group. The expression of the genes tested was unaffected apart from an observed upregulation of SREBF1 mRNA expression in perirenal fat from cows fed the OC diet. Milk FA differences observed were not associated with alterations in mammary expression of genes involved in FA synthesis, uptake, translocation, and regulation of lipogenesis. Overall, the inclusion of ensiled OC in cow diets for a 4-wk period improved, beneficially for human health, the lipid profile of bovine milk and Halloumi cheese produced without adversely affecting milk yield and composition or the expression of genes involved in lipid metabolism of mammary and adipose tissues in cows.

Variants in the 3' untranslated region of the ovine acetyl-coenzyme A acyltransferase 2 gene are associated with dairy traits and exhibit differential allelic expression

The acetyl-CoA acyltransferase 2 (ACAA2) gene encodes an enzyme of the thiolase family that is involved in mitochondrial fatty acid elongation and degradation by catalyzing the last step of the respective β-oxidation pathway. The increased energy needs for gluconeogenesis and triglyceride synthesis during lactation are met primarily by increased fatty acid oxidation. Therefore, the ACAA2 enzyme plays an important role in the supply of energy and carbon substrates for lactation and may thus affect milk production traits. This study investigated the association of the ACAA2 gene with important sheep traits and the putative functional involvement of this gene in dairy traits. A single nucleotide substitution, a T to C transition located in the 3' untranslated region of the ACAA2 gene, was used in mixed model association analysis with milk yield, milk protein yield and percentage, milk fat yield and percentage, and litter size at birth. The single nucleotide polymorphism was significantly associated with total lactation production and milk protein percentage, with respective additive effects of 6.81 ± 2.95 kg and -0.05 ± 0.02%. Additionally, a significant dominance effect of 0.46 ± 0.21 kg was detected for milk fat yield. Homozygous TT and heterozygous CT animals exhibited higher milk yield compared with homozygous CC animals, whereas the latter exhibited increased milk protein percentage. Expression analysis from age-, lactation-, and parity-matched female sheep showed that mRNA expression of the ACAA2 gene from TT animals was 2.8- and 11.8-fold higher in liver and mammary gland, respectively. In addition, by developing an allelic expression imbalance assay, it was estimated that the T allele was expressed at an average of 18% more compared with the C allele in the udder of randomly selected ewes. We demonstrated for the first time that the variants in the 3' untranslated region of the ovine ACAA2 gene are differentially expressed in homozygous ewes of each allele and exhibit allelic expression imbalance within heterozygotes in a tissue-specific manner, supporting the existence of cis-regulatory DNA variation in the ovine ACAA2 gene. This is the first study reporting differential allelic imbalance expression of a candidate gene associated with milk production traits in dairy sheep.

Pharmacological assessment of ibuprofen arginate on platelet aggregation and colon cancer cell killing

Nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen, are amongst the most commonly used medications and produce their anti-inflammatory and analgesic benefits by blocking cyclooxygenase (COX)-2. These drugs also have the potential to prevent and treat cancer and some members of the class including ibuprofen can produce anti-platelet effects. Despite their utility, all NSAIDs are associated with increased risk of cardiovascular side effects which our recent work suggests could be mediated by increased levels of the endogenous NO synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) leading to reduced endothelial NOS activity and associated endothelial cell dysfunction. ADMA is a cardiotoxic hormone and biomarker of cardiovascular risk whose effects can be prevented by l-arginine. The ibuprofen salt, ibuprofen arginate (Spididol^®) was created to increase drug solubility but we have previously established that it not only effectively blocks COX-2 but also provides an arginine source able to reverse the effects of ADMA in vitro and in vivo. Here we have gone on to explore whether the formulation of ibuprofen with arginine influences the potency and efficacy of the parent molecule using a range of simple in vitro assays designed to test the effects of NSAIDs on (i) platelet aggregation and (iii) colon cancer cell killing. Our findings demonstrate that ibuprofen arginate retains these key functional effects of NSAIDs with similar or increased potency compared to ibuprofen sodium, further illustrating the potential of ibuprofen arginate as an efficacious drug with the possibility of improved cardiovascular safety.

Induction of DNA damage and caspase-independent programmed cell death by vitamin E

Vitamin E comprises 8 functionally unique isoforms and may be a suitable candidate for the adjuvant treatment of prostate cancer. In this study, we examined the ability of 2 vitamin E isoforms [α-tocotrienol (γ-TT) and δ-tocotrienol (δ-TT)] and 4 synthetic derivatives [γ- and δ-tocotrienol succinate (γ-TS, δ-TS), α-tocopheryl polyethylene glycol succinate (TPGS), and α-tocopheryl polyethylene glycol ether (TPGS-e)] of vitamin E to induce cell death in AR- (DU145 and PC-3) and AR+ (LNCaP) prostate cancer cell lines. Our results show that δ-TT and TPGS-e are the most effective isoform and synthetic derivative, respectively, of all compounds examined. Overall, the results of our study suggest that isoforms and synthetic derivatives of vitamin E have the potency to trigger both caspase-dependent and -independent DNA damage and dominant caspase-independent programmed cell death. The capacity of vitamin E to trigger caspase-independent programmed cell death suggests that it may be useful in the chemotherapy of prostate cancer since it may prevent the tumor resistance commonly associated with the use of classical chemotherapeutic agents that trigger caspase-dependent programmed cell death.

Caspase-independent pathways of programmed cell death: the unraveling of new targets of cancer therapy?

In the past few years, accumulating evidence in the literature supports the existence of pathways of caspase-independent programmed cell death (CI-PCD). These pathways are likely to be acting as 'death backup systems' that ensure effective removal of defective cells from the organism. Similar to classical apoptosis i.e. caspase-dependent programmed cell death (CD-PCD), the mitochondrion is the main organelle orchestrating the series of events which are required for the induction of CI-PCD. In addition, the pro-apoptotic proteins Bax and Bid are also key participants in CI-PCD. However, contrary to CD-PCD, CI-PCD involves executioners other than the caspases which include the cathepsins, the calpains and serine proteases. The protein AIF may also play an important role in the induction of CI-PCD. In this review we report current knowledge on CI-PCD and provide evidence for its regulation by chemotherapeutic agents currently used in the clinic and under investigation in clinical trials. Lastly, we discuss how the study of natural and synthetic agents triggering CI-PCD may help in the pharmacological design of a new generation of more effective chemotherapeutic drugs. The use of such drugs activating both CD-PCD and CI-PCD pathways should achieve a more successful eradication of carcinogenic cells and the attainment of lower levels of tumor resistance.

Effects of protein phosphorylation on ubiquitination and stability of the translational inhibitor protein 4E-BP1

The availability of the eukaryotic polypeptide chain initiation factor 4E (eIF4E) for protein synthesis is regulated by the 4E-binding proteins (4E-BPs), which act as inhibitors of cap-dependent mRNA translation. The ability of the 4E-BPs to sequester eIF4E is regulated by reversible phosphorylation at multiple sites. We show here that, in addition, 4E-BP1 is a substrate for polyubiquitination and that some forms of 4E-BP1 are simultaneously polyubiquitinated and phosphorylated. In Jurkat cells inhibition of proteasomal activity by MG132 enhances the level of hypophosphorylated, unmodified 4E-BP1 but only modestly increases the accumulation of high-molecular-weight, phosphorylated forms of 4E-BP1. In contrast, inhibition of protein phosphatase activity with calyculin A reduces the level of unmodified 4E-BP1 but strongly enhances the amount of phosphorylated, high-molecular-weight 4E-BP1. Turnover measurements in the presence of cycloheximide show that, whereas 4E-BP1 is normally a very stable protein, calyculin A decreases the apparent half-life of the normal-sized protein. Affinity chromatography on m(7)GTP-Sepharose indicates that the larger forms of 4E-BP1 bind very poorly to eIF4E. We suggest that the phosphorylation of 4E-BP1 may play a dual role in the regulation of protein synthesis, both reducing the affinity of 4E-BP1 for eIF4E and promoting the conversion of 4E-BP1 to alternative, polyubiquitinated forms.

Changes in levator ani anatomical configuration following physiotherapy in women with stress urinary incontinence

PURPOSE

We quantified the effect of pelvic floor muscle training on the anatomical configuration of the levator ani using magnetic resonance imaging.

MATERIALS AND METHODS

Five female participants with stress urinary incontinence underwent magnetic resonance imaging before and after participating in a pelvic floor muscle physiotherapy program. Axial T1-weighted images of the levator ani were taken with the participant in a supine position. Source images were then manually segmented and surface modeling was applied to build a 3-dimensional model of the levator ani. Models were then measured to determine the levator ani surface area as well as the encircled volume at rest and during voluntary contraction. The percentage of levator ani retraction and symphysis pubis movement during voluntary contraction before and after physiotherapy were also measured.

RESULTS

After physiotherapy the levator ani surface area at rest was significantly smaller than before physiotherapy, decreasing from 677.11 +/- 45.00 to 620.48 +/- 36.14 mm(2) (p = 0.04). The relative reduction in volume encircled by the levator ani during contraction increased significantly from -11.66 +/- 7.42 to -26.02 +/- 13.52 mm(3) (p = 0.04). Levator ani surface retraction during a voluntary contraction increased significantly from 65.61% +/- 17.07% to 81.70% +/- 16.30% (p = 0.02). Symphysis pubis movement during pelvic floor muscle contraction decreased from 1.45 +/- 1.32 to 0.44 +/- 0.61 mm (p = 0.05).

CONCLUSIONS

Findings from this preliminary study indicate that pelvic floor muscle training results in anatomical changes in the levator ani and reduction of pubic movement. These results provide insight into the possible anatomical mechanisms through which physiotherapy enables the pelvic floor muscle to minimize urine leakage.

Phase II trial of carboplatin, weekly paclitaxel, and biweekly bevacizumab in patients with unresectable stage IV melanoma

8560

Background: In patients with metastatic melanoma, the combination of chemotherapy with an agent that specifically targets vascular endothelial growth factor (VEGF) might be able to control tumor growth and progression much more effectively than chemotherapy alone. Methods: A two-stage phase II clinical trial was conducted in patients with unresectable stage IV melanoma to assess the anti-tumor activity and toxicity profile of the combination of paclitaxel (80 mg/m2 IV on days 1, 8 and 15 of a 28-day cycle), carboplatin (AUC = 6 IV on day 1) and bevacizumab (10 mg/kg IV on days 1 and 15). The primary end point of the study was the 8-week progression-free survival rate (PFS). Enrollment to the second stage of the study was opened if 8 or more of the first 20 patients enrolled remained progression-free at 8 weeks. Eligible patients had measurable disease by RECIST criteria, a performance status (PS) of 0–2 and acceptable pre-registration organ function. Exclusion criteria included: brain metastases, significant recent bleeding, uncontrolled hypertension and ongoing anticoagulation. The study opened in February 2006 and completed full study accrual in August 2006. Data from the 20 patients enrolled in the first stage are presented here. Results: Patients (60% male) had a median age of 63 and had a good performance status (85% had PS of 0). M1c disease was present in 45% of patients and 35% had undergone previous chemotherapy for stage IV melanoma (50% prior immunotherapy). Only 6 patients did not complete more than 2 cycles of chemotherapy due to refusal (3), desire for alternative treatment (1) or progression (2). Median follow-up among the 15 patients still alive was 5.5 months (range: 6 weeks - 9 months). The 8-week PFS rate was 70% (14/20). The median time to progression was 163 days. One partial response was observed. There were 3 disease-related deaths at 65, 120 and 190 days post-registration. The most common toxicities were neutropenia (95%; 45% = grade 3), anemia (95%; 15% = grade 3), fatigue (90%; 5% = grade 3), leukopenia (85%; 25% = grade 3), and thrombocytopenia (75%; 5% = grade 3). Conclusions: The combination of paclitaxel, carboplatin and bevacizumab appears to be well tolerated and clinically active in patients with stage IV melanoma.

No significant financial relationships to disclose.

Regulation of translation factors eIF4GI and 4E-BP1 during recovery of protein synthesis from inhibition by p53

Activation of the tumour suppressor protein p53 rapidly inhibits protein synthesis. This is associated with dephosphorylation and cleavage of initiation factor eIF4GI and the eIF4E-binding protein 4E-BP1. When the activation of p53 is reversed within 16 h 4E-BP1 becomes rephosphorylated, the level of intact eIF4GI slowly increases and protein synthesis gradually recovers. The recovery of protein synthesis is partially blocked by rapamycin and wortmannin but not by the protein kinase inhibitors PD98059 and CGP74514A. Both rapamycin and wortmannin, but not PD98059 or CGP74514A, delay the reappearance of eIF4GI. In contrast, full-length 4E-BP1 rapidly becomes rephosphorylated and this process is partially inhibited by rapamycin, PD98059 and CGP74514A. Thus, activation of p53 results in the inhibition of distinct rapamycin- and wortmannin-sensitive pathways that target eIF4GI, and rapamycin-sensitive and -insensitive pathways that target 4E-BP1. Following inactivation of p53 the gradual recovery is determined largely by the kinetics of restoration of eIF4GI rather than by the rephosphorylation of full-length 4E-BP1. These findings suggest that the ability of cells to rephosphorylate 4E-BP1, resynthesise eIF4GI and restore the rate of protein synthesis after inactivation of p53 is an important aspect of recovery following the relief of physiological stress.

A comparison of outbreak- and nonoutbreak-related multidrug-resistant tuberculosis among human immunodeficiency virus-infected patients in a South African hospital

Nosocomial multidrug-resistant tuberculosis (MDR-TB) in human immunodeficiency virus (HIV)-infected people is recognized in Europe and America. We report the first such outbreak in South Africa. Six hospitalized women, identified by DNA fingerprinting, were infected with an outbreak strain of MDR-TB while receiving treatment for drug-susceptible tuberculosis. The putative source case was identified as an HIV-positive woman who underwent prolonged hospitalization for chronic cavitary tuberculosis. Compared with other HIV-positive patients in the hospital, outbreak patients were more immunocompromised, had fewer cavitary lung changes, and were less likely to have been treated before. They had high fevers, infiltrative patterns on chest radiographs, and a mean survival of 43 days. When individual isolation is not possible, separating highly immunocompromised patients with first-time tuberculosis from previously treated patients with cavitary lesions and from those with established drug resistance may reduce nosocomial transmission.

A mobile computed tomographic scanner with intraoperative and intensive care unit applications

INTRODUCTION

A mobile computed tomographic scanner has been developed in which the scan plane is selected by means of gantry translation, rather than by translation of the patient table. This permits computed tomographic scanning in situ of any patient who is positioned on a radiolucent surface that fits within the inner diameter of the gantry. We report the design of and initial experience with this scanner as used with adapters for intraoperative and bedside computed tomography (CT).

METHODS

The scanner is equipped with wheels, draws power from wall outlets (120 V, 20 A) in combination with batteries, and has a translating gantry. Preclinical studies of image quality were performed with phantoms. An operating table adapter was built for use with a radiolucent cranial fixation device. A bedside adapter was built that holds the head and shoulders of a patient in the intensive care unit.

RESULTS

The preclinical phantom studies showed satisfactory image spatial resolution (0.8 mm) and low-contrast resolution signal-to-noise relative standard deviation (0.37%). Experience to date with 12 patients has confirmed the feasibility of intraoperative CT on demand. Experience to date with 26 patients has confirmed the feasibility of routine bedside CT in the intensive care unit.

CONCLUSION

With these adaptations, mobile CT may increase the efficiency of intraoperative scanning by making it available to multiple operating rooms without committing it to any room for an entire operation and may increase the efficiency and safety of CT of critically ill patients who currently need to leave the intensive care unit to travel to a fixed CT installation and back.

The treatment of relapsed or refractory intermediate grade non-Hodgkin's lymphoma with autologous bone marrow transplantation followed by cyclosporine and interferon

In an effort to decrease the relapse rate following autologous bone marrow transplantation for non-Hodgkin's lymphoma, patients were given cyclosporine and interferon following autologous marrow transplantation. Forty patients with intermediate grade non-Hodgkin's lymphoma that was relapsed or refractory to standard chemotherapy underwent autologous marrow transplantation. The preparative regimen consisted of cyclophosphamide 6.8 g/m2, etoposide 1600 mg/m2, and carmustine 400 mg/m2 over 4 days followed by reinfusion of bone marrow. Intravenous cyclosporine was started on day -1 as a 16 mg/kg loading dose followed by 3.6 mg/kg/day for 28 days after transplant. Patients were begun on alpha-interferon (starting dose, 0.5 million units s.c. every other day) following platelet engraftment (median day 24 post-transplant) and continued on 1.5 million units s.c. daily for 2 years. Regimen-related toxicities resulted in four (10%) deaths. Twenty-one (53%) patients developed marked erythema of the palms, soles, and arms. Biopsies of the erythema were consistent with grade I GVHD. Patients who did not develop rashes were not biopsied. The erythema persisted for a median of 10 days and resolved in all cases without treatment. Visceral GVHD was not apparent. All patients have been followed for a median of 24 months (range 12-54 months). To date, only five patients (13%) have relapsed after bone marrow transplant. Multivariant analysis could not identify risk factors for relapse post-transplant. Disease-free survival of all patients is 77% (95% confidence interval, 67-93%). The results of this pilot study suggest that the administration of cyclosporine and interferon may decrease the relapse rate of relapsed/refractory non-Hodgkin's lymphoma following autologous bone marrow transplantation.

Evaluation of water-equivalent plastics as phantom material for electron-beam dosimetry

This investigation evaluated samples of three phantom materials designed as substitutes for water for electron beam calibration and depth ionization measurements. Two of the materials are commercially available (photon-electron Solid Water and Plastic Water), while the third (Homat) is not. Applying the values for water for all factors used in the calibration protocol of the American Association of Physicists in Medicine [Task Group 21, Med. Phys. 10, 741-771 (1983)] results in a discrepancy in calculated peak dose rates. Eliminating this discrepancy requires the additional inclusion of a multiplicative correction factor of approximately 1.015 for beam energies below 10 MeV, 1.01 for beam energies between 10 and 12 MeV, and 1.005 for beam energies above 12 MeV. Measurements for R50 and extrapolated range may be made in these materials with no corrections. Some improvement can be made in the performance of the phantom material by optimizing the match to water specifically for electron beams without regard for photon beam response. As with all radiation oncology apparatus, calibration phantoms need acceptance testing before routine use.

An electron density calibration phantom for CT-based treatment planning computers

In order to correct for tissue heterogeneities on a voxel-by-voxel basis during CT-based treatment planning, the relationship between the correction factor (CF) and the CT number in Hounsfield units (HU) for the scanner in use must be established. Since the relationship between CF and electron density (rho e) of various materials is well documented, the rho e vs HU is required for direct computation of the correction factors by treatment planning computers. A CT phantom with 18 different tissue substitutes has been used to establish the rho e vs HU relationship. A description of the phantom and its contents is given and the calibration of the CT function of the planning computer is discussed.

Voiding cystourethrography in children: value of digital fluoroscopy in reducing radiation dose

Voiding cystourethrography is a commonly used fluoroscopic procedure in children that can directly irradiate the gonads. As a consequence, much attention has been given to reducing the dose of radiation received during the procedure. A digital fluoroscope, especially adapted for use in children, was evaluated for potential reduction of the dose of radiation during the procedure. Entrance and midplane doses were calculated on child-sized phantoms by using the digital fluoroscope, digital spot films, and 105-mm spot films. Subsequently, data were collected on 47 children, grouped by ages (neonate to 1 year, 1-5 years, and 5-7 years), in whom voiding cystourethrography was performed by using the same exposure factors as those for the phantoms. On the basis of the exposure doses for the phantoms and recorded clinical peak kilovoltages, milliamperes, milliseconds, and fluoroscopic time, average skin and ovarian doses were calculated for each group of children. These doses were compared with previously reported doses for fluoroscopic and radionuclide voiding cystourethrography. Results of line-pair resolution studies for the digital spot films and 105-mm spot films were similar. Images from the digital device and 105-mm images obtained on a conventional fluoroscope were considered equally adequate for clinical decision making. The average midplane and skin doses with digital spot films for children less than 5 years old were equal to or less than 0.66 and 2.37 mGy, respectively, as opposed to 1.37 and 5.32 mGy with the 105-mm spot films. Previously reported ovarian doses range from 2.52 to 10.0 mGy for fluoroscopic voiding cystourethrography and from 0.04 to 0.05 mGy for radionuclide voiding cystourethrography. The use of digital spot films reduced dose approximately 50% compared with 105-mm spot films; the ovarian dose was 0.62 mGy greater than that for radionuclide voiding cystourethrography.

Value of dual-energy CT in differentiating focal fatty infiltration of the liver from low-density masses

Focal (irregular, partial) fatty infiltration of the liver may simulate neoplastic or other hypodense masses on CT. On the basis of previous observations of the phenomenon that differences in X-ray attenuation diminish with increasing energy of X-rays used, we performed a preliminary study to determine if dual-energy CT could be used to discriminate between fatty infiltration and hypodense liver masses. Dual-energy CT at 140 and 80 kVp was performed in 14 patients undergoing liver biopsy and in seven control subjects with presumedly normal liver. Attenuation measurements were taken, and the changes in attenuation between 140 and 80 kVp were calculated. The mean changes in attenuation were 3.5 H for normal liver (n = 7), 2.5 H for hypodense liver masses (n = 6), 13 H for fatty liver (n = 5), 0.3 H for fatty liver combined with hemochromatosis or hemosiderosis (n = 3), and 2 H for the spleen (n = 18). The change in attenuation increased as the fat content in the liver increased. Analysis of variance showed a statistically significant difference (p less than .001) between fatty liver and the other groups. A difference greater than 10 H was unique to fatty infiltration. These results suggest that dual-energy CT may help to differentiate focal fatty infiltration of the liver from low-density neoplastic or other lesions, but only if the iron content of the liver is not increased.

Repellents for Escherichia coli operate neither by changing membrane fluidity nor by being sensed by periplasmic receptors during chemotaxis

A long-standing question in bacterial chemotaxis is whether repellents are sensed by receptors or whether they change a general membrane property such as the membrane fluidity and this change, in turn, is sensed by the chemotaxis system. This study addressed this question. The effects of common repellents on the membrane fluidity of Escherichia coli were measured by the fluorescence polarization of the probe 1,6-diphenyl-1,3,5-hexatriene in liposomes made of lipids extracted from the bacteria and in membrane vesicles. Glycerol, indole, and L-leucine had no significant effect on the membrane fluidity. NiSO4 decreased the membrane fluidity but only at concentrations much higher than those which elicit a repellent response in intact bacteria. This indicated that these repellents are not sensed by modulating the membrane fluidity. Aliphatic alcohols, on the other hand, fluidized the membrane, but the concentrations that elicited a repellent response were not equally effective in fluidizing the membrane. The response of intact bacteria to alcohols was monitored in various chemotaxis mutants and found to be missing in mutants lacking all the four methyl-accepting chemotaxis proteins (MCPs) or the cytoplasmic che gene products. The presence of any single MCP was sufficient for the expression of a repellent response. It is concluded (i) that the repellent response to aliphatic alcohols can be mediated by any MCP and (ii) that although an increase in membrane fluidity may take part in a repellent response, it is not the only mechanism by which aliphatic alcohols, or at least some of them, are effective as repellents. To determine whether any of the E. coli repellents are sensed by periplasmic receptors, the effects of repellents from various classes on periplasm-void cells were examined. The responses to all the repellents tested (sodium benzoate, indole, L-leucine, and NiSO4) were retained in these cells. In a control experiment, the response of the attractant maltose, whose receptor is periplasmic, was lost. This indicates that these repellents are not sensed by periplasmic receptors. In view of this finding and the involvement of the MCPs in repellent sensing, it is proposed that the MCPs themselves are low-affinity receptors for the repellents.

AIDS-related beliefs and behaviours of Australian university students

Parallel questionnaires that enquired into the beliefs and behaviours which related to the acquired immunodeficiency syndrome (AIDS) were administered by postal survey during August and September 1987 to two separate samples of students. Each sample comprised 300 students who were selected at random, were aged up to 30 years, and at the time were enrolled at The University of Sydney; the response rate was 70%. Results showed a high level of "correctness" of belief about AIDS and safer sexual practices. More than half the population had experienced sexual intercourse during 1987, 25% of whom had experienced sexual intercourse on a casual basis. A marked discrepancy was found between the knowledge of and the performance of safer sexual behaviours, as measured by two sets of key questions, which covered condom use in casual vaginal encounters and enquiry into a casual partner's history with regard to sexual experience, abuse of intravenous drugs and history of blood transfusions. A log-linear regression analysis showed no correlation between scores on the two sets of key questions on knowledge of safer sexual practices and the demographic variables of age, sex, sexual experience or religious commitment. It is suggested that an educational campaign that is directed at the problem of behavioural change will fail to be productive if it is focused narrowly on the knowledge of safer sexual techniques; in addition, it should take into account other attitudinal components, such as the perception of social pressures from peer-groups. Within this particular student population, the most-effective immediate stratagem may be to restructure the perceived personal and peer-group risks.

Tissue compensators made of solid water or lead for megavoltage X-ray radiotherapy

Curvature of the body within the treatment field of a patient undergoing radiotherapy can result in a non-uniformity of the dose distribution within the tumor volume which, for a 20 cm X 20 cm field and 6 MV X-rays, could exceed 30% of the prescribed tumor dose. The use of bolus is usually not satisfactory as skin sparing is lost. The use of a compensator at the position of the block holder assembly attenuates the primary beam while not significantly effecting the scattered radiation in the patient's body. Consequently, the necessary compensator thickness depends on the type of material used, the field size, beam energy, and depth of the point of interest. Using a compensator with thickness equal to that of the missing tissue would result in significant underdosing of the tumor. In this paper, measurements of the necessary thickness of solid water and lead required to reduce the non-uniformity of dose on the central axis to within 3% of the prescribed dose are presented for 6 MV and 10 MV X-rays.

Development of radiographic chest phantoms

Diagnostic imaging studies, particularly in chest radiography, require adequate phantoms. Two such phantoms have been made and used; one is a semianthropomorphic phantom and the other is a geometric phantom with embedded test objects. These phantoms, constructed of epoxy resin-based solid water, are described in detail and compared to a common commercial phantom.

Reduction of the "horns" observed on the beam profiles of a 6-MV linear accelerator

The presence of large "horns" was found while plotting beam profiles during acceptance testing of a 6-MV linear accelerator. The in-phantom off-axis ratio (OAR), measured at 22 cm off the central axis along the diagonal of a 40 X 40 cm field at dmax was found to be 1.19, while beam uniformity was within specifications at 10-cm depth. A change in the gun injection voltage and the replacement of the magnet surrounding the magnetron with one of greater strength resulted in a reduction of the OAR to 1.085. The beam uniformity at depth was maintained within specifications. An alternative solution of adding a modifying filter in the primary beam was considered undesirable because of the 20%-25% reduction in dose rate caused by such filters. The relationship between the energy, the intensity distribution of the beam, and the magnitude of the horns is discussed, and the beam profiles, isodoses, and central axis depth doses before and after the changes are compared.

A solid water phantom material for radiotherapy x-ray and gamma-ray beam calibrations

The formulation, manufacture and testing of an epoxy resin-based solid substitute for water is presented. This "solid water" has radiation characteristics very close volumetrically to those of water. When it is used as a dosimetry phantom for x- and gamma-ray beams in the radiotherapy range, phantom-to-water corrections and density corrections are eliminated. Relative transmission measurements have shown that the transmission through 10 cm of solid water is within 0.2% of that through an equal thickness of water for x and gamma rays. The use of this material for calibration phantoms can help achieve the goal of radiotherapy beam calibrations within +/- 1.0% of the true dose rate, easier to achieve.

Physical measurements with a high-energy proton beam using liquid and solid tissue substitutes

The measurement of the physical parameters of a high-energy proton beam, using a range of liquid and solid tissue substitutes, is described. The system, the detectors used and the experimental verification of the tissue equivalence of the new tissue substitutes is presented. The measurements with the scattered but uncollimated proton beam in muscle- and brain-equivalent liquids and in water are compared to similar data obtained from the scattered but collimated beam. The effect of lung, fat and bone on the dose distributions in composite phantoms is also investigated and the necessary corrections established. A simulated patient treatment indicated that the Bragg peak can be positioned with an error not exceeding +/- 0.5 mm.

Statistical analysis and graphical representation the temporal and distributive properties of urodynamic data

A collection of programs are described to analyze and display urodynamic data on a digital plotter. Utilizing a small programmable calculator, routines have been written to characterize the temporal and distributive properties of experimentally observed ureteral peristalses and associated urine output. The encoding pricipals used are designed to optimally use limited calculator memory.