Risk factors for neurocognitive impairment, emotional distress, and poor quality of life in survivors of pediatric rhabdomyosarcoma: A report from the Childhood Cancer Survivor Study

BACKGROUND

Prevalence and risk of poor psychological outcomes following rhabdomyosarcoma (RMS) are not well-established.

METHODS

Participants in this cross-sectional, case-control study (n = 713 survivors, 42.5% female; mean [SD] age, 30.5 [6.6] years; n = 706 siblings, 57.2% female; mean age, 32.8,[7.9] years) completed measures of neurocognition, emotional distress, and health-related quality of life (HRQOL). Multivariable logistic regression models identified treatments, health behaviors, and chronic conditions associated with impairment.

RESULTS

Relative to siblings, more survivors reported neurocognitive impairment (task efficiency: 21.1% vs. 13.7%, emotional regulation: 16.7% vs. 11.0%, memory: 19.3% vs. 15.1%), elevated emotional distress (somatic distress: 12.9% vs. 4.7%, anxiety: 11.7% vs. 5.9%, depression: 22.8% vs. 16.9%) and poorer HRQOL (physical functioning: 11.1% vs. 2.8%, role functioning due to physical problems: 16.8% vs. 8.2%, pain: 17.5% vs. 10.0%, vitality: 22.3% vs. 13.8%, social functioning: 14.4% vs. 6.8%, emotional functioning: 17.1% vs. 10.6%). Cranial radiation increased risk for impaired task efficiency (odds ratio [OR], 2.30; 95% confidence interval [CI], 1.14-4.63), whereas chest and pelvic radiation predicted increased risk of physical functioning (OR, 2.68; 95% CI, 1.16-6.21 and OR, 3.44; 95% CI, 1.70-6.95, respectively). Smoking was associated with impaired task efficiency (OR, 2.06; 95% CI, 1.14-3.70), memory (OR, 2.23; 95% CI, 1.26-3.95), anxiety (OR, 2.71; 95% CI, 1.36-5.41) and depression (OR, 1.77; 95% CI, 1.01-3.11). Neurologic conditions increased risk of anxiety (OR, 2.30; 95% CI, 1.04-5.10), and hearing conditions increased risk of depression (OR, 1.79; 95% CI, 1.05-3.03). Neurologic and hearing conditions, respectively, were associated with impaired memory (OR, 2.44; 95% CI, 1.20-4.95 and OR, 1.87; 95% CI, 1.05-3.35) and poor health perception (OR, 2.62; 95% CI, 1.62-1.28 and OR, 2.33; 95% CI, 1.34-4.06).

CONCLUSIONS

RMS survivors are at significant risk for poor psychological outcomes. Advancing therapies for local control, smoking cessation, and managing chronic medical conditions may mitigate poor outcomes following RMS.

Validation of satisfaction questionnaire for services provided in the labour rooms of government health facilities

INTRODUCTION AND OBJECTIVES

Using the assessment of satisfaction of patients of labour room services, the caregiver or policymakers can identify the gaps in the implemented programmes and health policies. This study was aimed to design a valid and reliable satisfaction questionnaire that will help in identifying the aspects of gaps that need improvement.

METHODS

A facility and community-based observational cross-sectional study was conducted in the district of western Uttar Pradesh (India) between January 2019 and August 2020. Validation of the structured questionnaire with 34 dichotomous questions categorized under five subscales was performed by evaluating its validity and reliability. A total of 380 beneficiaries were selected from 48 government health facilities.

RESULTS

The calculated Content validity index was calculated to be 9.5 which was adequate as per the guidelines. The reliability analysis of the questionnaire showed that the internal consistency was high with an overall Cronbach's alpha of 0.710. The variation in Cronbach's alpha on the elimination of any question from the questionnaire ranged from 0.676 to 0.767. The mean patient satisfaction score in the total surveyed population was 24.39±4.684 (total score=34) and there was a greater variation in the satisfaction score of infrastructure when compared with other subscales.

CONCLUSION

The findings from this study support the reliability and validity of the patient satisfaction questionnaire as it is capable of evaluating the satisfaction in terms of delivery services provided in labour rooms as a whole.

Health-related quality of life of multidrug-resistant tuberculosis patients: A study of eastern Uttar Pradesh, India

INTRODUCTION

Much attention has been given to the microbiological aspect, drug treatment, and clinical indicators of MDR-TB, but patients' QOL has remained a neglected area. In this study, we aimed to find the quality of MDRTB on various quality of life domains during the initiation of the MDR Treatment regimen.

MATERIALS & METHODS

A cross-sectional study was conducted over a period of 6 months at the Drug-Resistance Tuberculosis Management Centre (DR-TB Centre), of a tertiary care centre in the eastern Uttar pradesh, India. Patients with age >18 years diagnosed with MDR-TB (Multidrug resistance TB) were included in the study. The WHO QOL-BREF scale was used to assess the health-related quality of life of patients. Data were analyzed using SPSS version 21. The institutional ethical review committee approved the study, and consent was taken before the participation of patients.

RESULTS

A total of 157 patients were included in the study & 45.85% were dissatisfied with their condition. Social domain of WHO QOL-BREF is having the lowest mean score (28.51 ± 15.4) while psychological has high mean values (39.92 ± 6.91). There was a significant difference in the physical health domain with respect to age (p-value 0.001). Similar differences have been seen in the psychological domain regarding patient sex (p-value 0.001), smoking and alcohol within the social domain, and loss of income in the environmental domain.

CONCLUSION

The mean value of different domains of WHO QOL-BREF is low in MDR-TB patients, with social relation domain being the most affected.

First report of Fusarium equiseti (Corda) Sacc. causing wilt of Cajanus scarabaeoides, a wild relative of pigeonpea in India

Wild species or crop wild relatives (CWRs) provide a unique opportunity to introduce novel traits and expand the genetic base of the cultivated pigeonpea (Bohra et al. 2010, 2020). Among the wild relatives of pigeonpea, Cajanus scarabaeoides is cross-compatible with cultivated pigeonpea (C. cajan). To identify the resistant sources for use in the pigeonpea breeding, the present study was conducted using 79 wild pigeonpea accessions at ICAR-Indian Institute of Pulses Research, Kanpur, India during 2016-17 and 2017-18 (Figures 1 a and b). The pigeonpea accessions belonged to three different genera Cajanus, Rhynchosia and Flemingia. During field scouting, seedlings were observed with foliar chlorosis and wilting (Fig. 2a). Infected stem tissue exhibited brown to black discoloration, followed by gradual plant drying, and ultimately plant death (Fig. 2b). Infected plants were collected from the field and pathological examination was performed in the laboratory conditions. Wilted plant parts were surface-disinfected with 1% sodium hypochlorite for two minutes and 5.0 mm size pieces of stem tissue were transferred to petri-dishes containing 90ml of Fusarium Specific Medium (FSM) (Nash and Snyder 1962) and incubated at 27oC. After 48 hrs of incubation, white to orange aerial mycelial growth was observed (Fig. 2c). The fungus was transferred to fresh FSM and purified by the single-spore technique (Choi et al. 1999). Macroconidia had four to six septa, slightly curved at the apex ranged from 20.0 to 25.0 × 3.0 to 5.5 μm (Fig. 2d). Microconidia were absent. The isolated fungus was putatively identified as belonging to the F. equiseti species complex based on colony morphology and macroconidia characteristics and size (Booth, 1977; Leslie and Summerell 2004). The pathogenicity test was conducted on 15-day old healthy seedlings of wild pigeonpea using 'root dip inoculation' and 'soil inoculation' technique (Haware and Nene 1994). Plant roots were immersed in a conidial suspension (6×106 conidia/ml water as determined by a hemocytometer) for 3-4 minutes (Marley and Hillocks 1996), while the roots of control plant were immersed in sterilized distilled water. A single spore culture of F. equiseti was grown on PDA-containing perti-dishes. Two actively grown mycelia discs (5 mm dia) from the periphery of 7-day old pure culture of F. equiseti were separately inoculated in 500 ml conical flasks containing 100g pigeonpea meal medium. The flasks were incubated at 28±2°C for 10 days. A fungus-soil mixture was prepared by mixing 200 g of inoculums with 2kg of autoclaved sand: soil mixture (3:7). Earthen pots having 15-cm diameter were sterilized by formalin (0.1%). These pots were then filled with fungus-soil mixture. Seeds sterilized with mercuric chloride (1%) were sown in each pot. Seeds sown in uninoculated pots served as control. Five seeds were sown in each pot with three replications. Disease symptoms developed 10 days after inoculation of wild pigeonpea plants in greenhouse. Symptoms were identical to those observed in the field. No symptoms were observed in control. Re-isolating the F. equiseti pathogen from the inoculated wild pigeonpea seedlings corroborated Koch's postulates. Reference cultures of three isolates of F. equiseti were deposited in Indian Type of Culture Collection (ITCC), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute (IARI), New Delhi with the accession numbers ITCC8413, ITCC8414 and ITCC8415. Fungal genomic DNA was extracted through modified CTAB method (Murray and Thompson 1980). The ITS regions 1 and 2, including 5.8S ribosomal DNA (rDNA) region, and part of translation elongation factor 1-α (TEF) were amplified by using the ITS6F (GAAGGTGAAGTCGTAACAGG) and ITS4R (TCCTCCGCTTATTGATATGC) and tef (F: ATGGGTAAGGAAGACAAGAC; R: GGAAGTACCAGTGAATCATGTT) primers. BLASTn analysis of the sequences generated showed a 98.78% homology with F. equiseti. The sequences were deposited at GenBank (Accession numbers of ITS region: MF351849, MF351850, MF351851, and Tef region: MK259963, MK264345, MK264346). Phylogenetic analysis of the ITS and Tef region sequences revealed that all Fusarium isolates belong to the F. equiseti species complex and other available sequences of Fusarium spp. (Fig. 3). Occurrence of F. equiseti on various plant species is reported worldwide by several researchers (Liang et al. 2011; Ramachandra and Bhatt 2012; Prasad et al. 2017). To the best of our knowledge and based on the literature, this is the first report of wilt disease on wild pigeonpea in India, caused by F. equiseti (Corda) Sacc.

Maximum likelihood estimation for the proportional odds model with mixed interval-censored failure time data

This article discusses regression analysis of mixed interval-censored failure time data. Such data frequently occur across a variety of settings, including clinical trials, epidemiologic investigations, and many other biomedical studies with a follow-up component. For example, mixed failure times are commonly found in the two largest studies of long-term survivorship after childhood cancer, the datasets that motivated this work. However, most existing methods for failure time data consider only right-censored or only interval-censored failure times, not the more general case where times may be mixed. Additionally, among regression models developed for mixed interval-censored failure times, the proportional hazards formulation is generally assumed. It is well-known that the proportional hazards model may be inappropriate in certain situations, and alternatives are needed to analyze mixed failure time data in such cases. To fill this need, we develop a maximum likelihood estimation procedure for the proportional odds regression model with mixed interval-censored data. We show that the resulting estimators are consistent and asymptotically Gaussian. An extensive simulation study is performed to assess the finite-sample properties of the method, and this investigation indicates that the proposed method works well for many practical situations. We then apply our approach to examine the impact of age at cranial radiation therapy on risk of growth hormone deficiency in long-term survivors of childhood cancer.

Neighborhood effect and obesity in adult survivors of pediatric cancer: A report from the St. Jude lifetime cohort study

Survivors of childhood cancer are at risk for obesity, a condition potentially modifiable if dietary intake and physical activity are optimized. These health behaviors are likely influenced by neighborhood of residence, a determinant of access to healthy, affordable food and safe and easy exercise opportunities. We examined associations between neighborhood level factors and obesity among survivors in the St. Jude Lifetime cohort and community comparison group members. Persons with residential addresses available for geocoding were eligible for analysis (n = 2,265, mean age 32.5 [SD 9.1] years, 46% female, 85% white). Survivors completed questionnaires regarding individual behaviors; percent body fat was assessed via dual X-ray absorptiometry (obesity: ≥25% males; ≥35% females); neighborhood effect was characterized using census tract of residence (e.g., neighborhood socioeconomic status [SES], rurality). Structural equation modeling was used to determine associations between neighborhood effect, physical activity, diet, smoking, treatment exposures and obesity. Obese survivors (n = 1,420, 62.7%) were more likely to live in neighborhoods with lower SES (RR: 1.23, 95% CI: 1.10-1.38) and rural areas (RR: 1.22, 95% CI: 1.07-1.39) compared to survivors with normal percent body fat. Resource-poor neighborhoods (standardized effect: 0.06, p < 0.001) and cranial radiation (0.16, p < 0.001) had direct effects on percent body fat. Associations between neighborhood of residence and percent body fat were increased (0.01, p = 0.04) among individuals with a poor diet. Neighborhoods where survivors reside as an adult is associated with obesity. Interventions targeting survivors should incorporate strategies that address environmental influences on obesity.

Impact of ovarian transposition before pelvic irradiation on ovarian function among long-term survivors of childhood Hodgkin lymphoma: A report from the St. Jude Lifetime Cohort Study

BACKGROUND

We reviewed the effect of ovarian transposition (OT) on ovarian function among long-term survivors of childhood Hodgkin lymphoma (HL) treated with pelvic radiotherapy.

PROCEDURE

Female participants (age 18+ years) with HL in the St. Jude Lifetime Cohort Study (SJLIFE) were clinically evaluated for premature ovarian insufficiency (POI) 10 or more years after pelvic radiotherapy. Reproductive history including age at menopause and pregnancy/live births was available on all patients.

RESULTS

Of 127 eligible females with HL, 90 (80%) participated in SJLIFE, including 49 who underwent OT before pelvic radiotherapy. Median age at STLIFE evaluation was 38 years (range 25-60). In a multiple regression adjusted for age at diagnosis, pelvic radiotherapy doses > 1,500 cGy (hazard ratio [HR] = 25.2, 95% confidence interval [CI] = 3.1-207.3; P = 0.0027) and cumulative cyclophosphamide equivalent doses of alkylating agents > 12,000 mg/m² (HR = 11.2, 95% CI = 3.4-36.8; P < 0.0001) were significantly associated with POI. There was no significant association between OT and occurrence of POI (HR = 0.6, 95% CI = 0.2-1.9; P = 0.41).

CONCLUSIONS

OT did not appear to modify risk of POI in this historic cohort of long-term survivors of HL treated with gonadotoxic therapy. Modern fertility preservation modalities, such as mature oocyte cryopreservation, should be offered to at-risk patients whenever feasible.

Real-time monitoring of conformational transitions of single-molecule histone deacetylase 8 with nanocircuits

Using single-molecule approaches, we directly observed the dynamic interaction between HDAC8 and various ligands as well as conformational interconversions during the catalytic reaction. Statistical analysis identified key kinetic parameters, demonstrating that the enzymatic activity is highly sensitive to both minor variations in the ligand structures and small synthetic molecules.

Epidemiological profile of multidrug-resistant tuberculosis patients in Gorakhpur Division, Uttar Pradesh, India

Introduction:

Multidrug-resistant tuberculosis (MDR-TB) poses a major threat to control of TB worldwide. Adequate information on socioepidemiological factors and their interaction is required for its control. The aim was to study the social and epidemiological profile of MDR-TB patient in Gorakhpur division.

Methodology:

A cross-sectional study of 157 MDR-TB patients from Gorakhpur division admitted at DR-TB Center of a tertiary care center were interviewed during initiation of MDR-TB treatment using structured questionnaire and collected data were described using descriptive statistics.

Results:

More than 2/3^rd of patients were male and the mean age was 32.15 ± 13.19 years. Overcrowding was present in 82.8% of households and ventilation of living room was inadequate in 72.7% of households. About 21.7% had history of contact with TB cases. Two-third of the patients practice unhygienic sputum disposal practices at home and at public places it was more than 90%. More than 60% of patients have the history of irregular treatment in intensive phase and 80% in continuation phase. Nearly 68.8% of patients were resistance to isoniazid (H) and rifampicin (R) and 18.5% were resistance to H, R, and S (streptomycin) followed by H, R and E (Ethambutol). Nearly 3.8% of patients were HIV positive and 7% had history of diabetes. 64.3% were under severe thinness category according to the WHO classification.

Conclusion:

Study point out need of nutritional counseling and support throughout the treatment. Use of incentives, enhancing contact tracing and increasing awareness regarding sputum disposal practices are recommended for effective control.

The cumulative burden of surviving childhood cancer: an initial report from the St Jude Lifetime Cohort Study (SJLIFE)

BACKGROUND

Survivors of childhood cancer develop early and severe chronic health conditions (CHCs). A quantitative landscape of morbidity of survivors, however, has not been described. We aimed to describe the cumulative burden of curative cancer therapy in a clinically assessed ageing population of long-term survivors of childhood cancer.

METHODS

The St Jude Lifetime Cohort Study (SJLIFE) retrospectively collected data on CHCs in all patients treated for childhood cancer at the St Jude Children's Research Hospital who survived 10 years or longer from initial diagnosis and were 18 years or older as of June 30, 2015. Age-matched and sex-frequency-matched community controls were used for comparison. 21 treatment exposure variables were included in the analysis, with data abstracted from medical records. 168 CHCs for all participants were graded for severity using a modified Common Terminology Criteria of Adverse Events. Multiple imputation with predictive mean matching was used for missing occurrences and grades of CHCs in the survivors who were not clinically evaluable. Mean cumulative count was used for descriptive cumulative burden analysis and marked-point-process regression was used for inferential cumulative burden analysis.

FINDINGS

Of 5522 patients treated for childhood cancer at St Jude Children's Research Hospital who had complete records, survived 10 years or longer, and were 18 years or older at time of study, 3010 (54·5%) were alive, had enrolled, and had had prospective clinical assessment. 2512 (45·5%) of the 5522 patients were not clinically evaluable. The cumulative incidence of CHCs at age 50 years was 99·9% (95% CI 99·9-99·9) for grade 1-5 CHCs and 96·0% (95% CI 95·3-96·8%) for grade 3-5 CHCs. By age 50 years, a survivor had experienced, on average, 17·1 (95% CI 16·2-18·1) CHCs of any grade, of which 4·7 (4·6-4·9) were CHCs of grade 3-5. The cumulative burden in matched community controls of grade 1-5 CHCs was 9·2 (95% CI 7·9-10·6; p<0·0001 vs total study population) and of grade 3-5 CHCs was 2·3 (1·9-2·7, p<0·0001 vs total study population). Second neoplasms, spinal disorders, and pulmonary disease were major contributors to the excess total cumulative burden. Notable heterogeneity in the distribution of CHC burden in survivors with differing primary cancer diagnoses was observed. The cumulative burden of grade 1-5 CHCs at age 50 years was highest in survivors of CNS malignancies (24·2 [95% CI 20·9-27·5]) and lowest in survivors of germ cell tumours (14·0 [11·5-16·6]). Multivariable analyses showed that older age at diagnosis, treatment era, and higher doses of brain and chest radiation are significantly associated with a greater cumulative burden and severity of CHCs.

INTERPRETATION

The burden of CHCs in survivors of childhood cancer is substantial and highly variable. Our assessment of total cumulative burden in survivors of paediatric cancer, with detailed characterisation of long-term CHCs, provide data to better inform future clinical guidelines, research investigations, and health services planning for this vulnerable, medically complex population.

FUNDING

The US National Cancer Institute, St Baldrick's Foundation, and the American Lebanese Syrian Associated Charities.

Effect of Low-Magnitude, High-Frequency Mechanical Stimulation on BMD Among Young Childhood Cancer Survivors: A Randomized Clinical Trial

IMPORTANCE

Bone accrual during youth is critical to establish sufficient strength for lifelong skeletal health. Children with cancer may develop low bone mineral density (BMD) any time before or after diagnosis.

OBJECTIVE

To evaluate the ability of low-magnitude, high-frequency mechanical stimulation to enhance BMD among childhood cancer survivors.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind randomized clinical trial conducted at St Jude Children's Research Hospital from June 1, 2010, to January 22, 2013, using cancer survivors, ages 7 to 17 years, who were previously treated at St Jude Children's Research Hospital, were in remission, and at least 5 years from diagnosis, with whole-body or lumbar spine BMD z scores of -1.0 or lower. Participants were randomized (stratified by sex and Tanner stage) to either a placebo device or low-magnitude, high-frequency mechanical stimulation device, which was used at home.

INTERVENTIONS

Placebo or low-magnitude, high-frequency mechanical stimulation (0.3 g; 32-37 Hz) for 2 sessions lasting 10 minutes each, 7 days per week for 1 year. All participants were prescribed daily cholecalciferol (vitamin D) and calcium.

MAIN OUTCOMES AND MEASURES

Changes in areal and volumetric BMD and bone biomarkers were compared by analysis of variance, adjusted for strata.

RESULTS

Of the 65 participants, 32 were randomized to the intervention group (mean [SD] age was 13.6 [3.7] years, 18 [56.2%] were male, and 27 [84.4%] were white), and 33 were randomized to the placebo group (mean [SD] age was 13.6 [2.9] years, 17 [51.5%] were male, and 26 [78.8%] were white). Forty-eight participants completed the trial, 22 in the intervention group and 26 in the placebo group with median adherence of 70.1% for intervention and 63.7% for placebo groups. With intention-to-treat analysis, mean (SD) whole-body BMD z score by dual x-ray absorptiometry improved by 0.25 (0.78) in the intervention (n = 22), but decreased by -0.19 (0.79) in the placebo group (n = 26, P = .05). Circulating osteocalcin at 12 months correlated with change in total body BMD (r = 0.35, P = .02). Tibial trabecular bone among participants completing 70% or more of the prescribed sessions increased by a mean of 11.2% (95% CI, 5.2 to 17.2%) compared with those completing less than 70% who decreased by a mean of -1.3% (95% CI, -7.3 to 4.7%; P = .02). Change in circulating receptor activator of nuclear factor κ-B ligand was higher in the intervention than in the placebo group (0.06 [0.16] vs -0.04 [0.17] pmol/L) (P = .04).

CONCLUSIONS AND RELEVANCE

Pediatric cancer survivors with low BMD may benefit from low-magnitude, high-frequency mechanical stimulation as a novel and safe intervention to optimize peak bone mass during youth, alone or in conjunction with other therapies.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01010230.

Nuclear Localizing Peptide-Conjugated, Redox-Sensitive Polymersomes for Delivering Curcumin and Doxorubicin to Pancreatic Cancer Microtumors

Improving the therapeutic index of anticancer agents is an enormous challenge. Targeting decreases the side effects of the therapeutic agents by delivering the drugs to the intended destination. Nanocarriers containing the nuclear localizing peptide sequences (NLS) translocate to the cell nuclei. However, the nuclear localization peptides are nonselective and cannot distinguish the malignant cells from the healthy counterparts. In this study, we designed a "masked" NLS peptide which is activated only in the presence of overexpressed matrix metalloproteinase-7 (MMP-7) enzyme in the pancreatic cancer microenvironment. This peptide is conjugated to the surface of redox responsive polymersomes to deliver doxorubicin and curcumin to the pancreatic cancer cell nucleus. We have tested the formulation in both two- and three-dimensional cultures of pancreatic cancer and normal cells. Our studies revealed that the drug-encapsulated polymeric vesicles are significantly more toxic toward the cancer cells (shrinking the spheroids up to 49%) compared to the normal cells (shrinking the spheroids up to 24%). This study can lead to the development of other organelle targeted drug delivery systems for various human malignancies.

Long-term functional outcomes and quality of life in adult survivors of childhood extremity sarcomas: a report from the St. Jude Lifetime Cohort Study

PURPOSE

This study compared measured physical performance, health-related quality of life (HRQOL), and social role attainment between extremity sarcoma survivors and controls, and evaluated associations between disease and treatment exposures, health conditions, and performance measures.

METHODS

Survivors of extremity sarcoma from the St. Jude Lifetime cohort and controls frequency matched by age-, sex-, and race completed physical performance testing and questionnaires. Survivors with Z-scores on outcome measures ≤ -2.0 SD (compared to controls) were categorized with severe impairment/limitation.

RESULTS

Among 206 survivors (52.4 % male median age 36 years (range 19-65)), 37 % had low relative lean mass, 9.7 % had an ejection fraction <50 %, 51.5 % had diffusion capacity for carbon monoxide <75 %, 27.7 % had sensory and 25.2 % motor neuropathy, and 78.2 % had musculoskeletal complications. Severe impairments/limitations were present among ≥25 % of survivors on fitness, balance, and physical HRQOL measures, and among ≥15 % on strength and activity of daily living measures. Lower extremity tumor location (OR 8.23, 95 % CI 2.54-26.67, P value 0.0004) and amputation (OR 8.07, 95 % CI 3.06-21.27, P value <0.0001) were associated with poor fitness. Poor fitness was associated with increased odds of scoring <40 on the SF-36 physical component summary (OR 4.83, 95 % CI 1.95-11.99, P value 0.001) and role-physical subscale (OR 3.34, 95 % CI 1.33-8.43, P value 0.01). Survivors and controls had similar rates of marriage, independent living, employment, and college attendance.

CONCLUSIONS

Extremity sarcoma survivors experience high rates of physical impairment and report lower than expected physical HRQOL. However, they are as likely as peers to be married, live independently, be employed, and attend college.

IMPLICATIONS FOR CANCER SURVIVORS

Follow-up for extremity sarcoma survivors should include assessment of need for further orthopedic care and rehabilitation to address cardiopulmonary and musculoskeletal health.

Cumulative burden of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma: an analysis from the St Jude Lifetime Cohort Study

BACKGROUND

The magnitude of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma is not known. Using medically ascertained data, we applied the cumulative burden metric to compare chronic cardiovascular health conditions in survivors of Hodgkin's lymphoma and general population controls.

METHODS

For this study, participant data were obtained from two ongoing cohort studies at St Jude Children's Research Hospital: the St Jude Lifetime Cohort Study (SJLIFE) and the St Jude Long-term Follow-up Study (SJLTFU). SJLIFE is a cohort study initiated on April 27, 2007, to enable longitudinal clinical evaluation of health outcomes of survivors of childhood cancer treated or followed at St Jude Children's Research Hospital, and SJLTFU is an administrative system-based study initiated in 2000 to collect outcome and late toxicity data for all patients treated at the hospital for childhood cancer. The patient cohort for our study was defined as patients treated at St Jude Children's Research Hospital who reached 18 years of age and were at least 10 years post-diagnosis of pathologically confirmed primary Hodgkin's lymphoma. Outcomes in the Hodgkin's lymphoma survivors were compared with a sample of SJLIFE community control participants, aged 18 years or older at the time of assessment, frequency-matched based on strata defined by 5-year age blocks within each sex, who were selected irrespective of previous medical history. All SJLIFE participants underwent assessment for 22 chronic cardiovascular health conditions. Direct assessments, combined with retrospective clinical reviews, were used to assign severity to conditions using a modified Common Terminology Criteria of Adverse Events (CTCAE) version 4.03 grading schema. Occurrences and CTCAE grades of the conditions for eligible non-SJLIFE participants were accounted for by multiple imputation. The mean cumulative count (treating death as a competing risk) was used to estimate cumulative burden.

FINDINGS

Of 670 survivors treated at St Jude Children's Research Hospital, who survived 10 years or longer and reached age 18 years, 348 were clinically assessed in the St Jude Lifetime Cohort Study (SJLIFE); 322 eligible participants did not participate in SJLIFE. Age and sex frequency-matched SJLIFE community controls (n=272) were used for comparison. At age 50 years, the cumulative incidence of survivors experiencing at least one grade 3-5 cardiovascular condition was 45·5% (95% CI 36·6-54·3), compared with 15·7% (7·0-24·4) in community controls. The survivor cohort at age 50 experienced a cumulative burden of 430·6 (95% CI 380·7-480·6) grade 1-5 and 100·8 (77·3-124·3) grade 3-5 cardiovascular conditions per 100 survivors; these numbers were appreciably higher than those in the control cohort (227·4 [192·7-267·5] grade 1-5 conditions and 17·0 [8·4-27·5] grade 3-5 conditions per 100 individuals). Myocardial infarction and structural heart defects were the major contributors to the excess grade 3-5 cumulative burden in survivors. High cardiac radiation dose (≥35 Gy) was associated with an increased proportion of grade 3-5 cardiovascular burden, whereas increased anthracyline dose was not.

INTERPRETATION

The true effect of cardiovascular morbidity in paediatric, adolescent, and young adult survivors of Hodgkin's lymphoma is reflected in the cumulative burden. Survivors aged 50 years will experience more than two times the number of chronic cardiovascular health conditions and nearly five times the number of more severe (grade 3-5) cardiovascular conditions compared with community controls and, on average, have one severe, life-threatening, or fatal cardiovascular condition. The cumulative burden metric provides a more comprehensive approach for assessing overall morbidity compared with currently used cumulative incidence based analytic methodologies, and will assist clinical researchers when designing future trials and refining general practice screening guidelines.

FUNDING

US National Cancer Institute, St Baldrick's Foundation, and American Lebanese Syrian Associated Charities.

Mechanism of N-Acylthiourea-mediated activation of human histone deacetylase 8 (HDAC8) at molecular and cellular levels

We reported previously that an N-acylthiourea derivative (TM-2-51) serves as a potent and isozyme-selective activator for human histone deacetylase 8 (HDAC8). To probe the molecular mechanism of the enzyme activation, we performed a detailed account of the steady-state kinetics, thermodynamics, molecular modeling, and cell biology studies. The steady-state kinetic data revealed that TM-2-51 binds to HDAC8 at two sites in a positive cooperative manner. Isothermal titration calorimetric and molecular modeling data conformed to the two-site binding model of the enzyme-activator complex. We evaluated the efficacy of TM-2-51 on SH-SY5Y and BE(2)-C neuroblastoma cells, wherein the HDAC8 expression has been correlated with cellular malignancy. Whereas TM-2-51 selectively induced cell growth inhibition and apoptosis in SH-SY5Y cells, it showed no such effects in BE(2)-C cells, and this discriminatory feature appears to be encoded in the p53 genotype of the above cells. Our mechanistic and cellular studies on HDAC8 activation have the potential to provide insight into the development of novel anticancer drugs.

Thermodynamics of binding of structurally similar ligands to histone deacetylase 8 sheds light on challenges in the rational design of potent and isozyme-selective inhibitors of the enzyme

Among the different histone deacetylase (HDAC) isozymes, HDAC8 is the most highly malleable enzyme, and it exhibits the potential to accommodate structurally diverse ligands (albeit with moderate binding affinities) in its active site pocket. To probe the molecular basis of this feature, we performed detailed thermodynamic studies of the binding of structurally similar ligands, which differed with respect to the “cap”, “linker”, and “metal-binding” regions of the suberoylanilide hydroxamic acid (SAHA) pharmacophore, to HDAC8. The experimental data revealed that although the enthalpic (ΔH°) and entropic (ΔS°) changes for the binding of individual SAHA analogues to HDAC8 were substantially different, their binding free energies (ΔG°) were markedly similar, conforming to a strong enthalpy–entropy compensation effect. This effect was further observed in the temperature-dependent thermodynamics of binding of all SAHA analogues to the enzyme. Notably, in contrast to other metalloenzymes, our isothermal titration calorimetry experiments (performed in different buffers of varying ionization enthalpies) suggest that depending on the ligand, its zinc-binding group may or may not be deprotonated upon the binding to HDAC8. Furthermore, the heat capacity changes (ΔC_p°) associated with the ligand binding to HDAC8 markedly differed from one SAHA analogue to the other, and such features could primarily be rationalized in light of the dynamic flexibility in the enzyme structure in conjunction with the reorganization of the active site resident water molecules. Arguments are presented that although the binding thermodynamic features described above would facilitate identification of weak to moderately tight-binding HDAC8 inhibitors (by a high-throughput and/or virtual screening of libraries of small molecules), they would pose major challenges for the structure-based rational design of highly potent and isozyme-selective inhibitors of human HDAC8.

Bridging of a substrate between cyclodextrin and an enzyme's active site pocket triggers a unique mode of inhibition

BACKGROUND

Methionyl-7-amino-4-methylcoumarin (MetAMC) serves as a substrate for the Escherichia coli methionine aminopeptidase (MetAP) catalyzed reaction, and is routinely used for screening compounds to identify potential antibiotic agents. In pursuit of screening the enzyme's inhibitors, we observed that 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), utilized to solubilize hydrophobic inhibitors, inhibited the catalytic activity of the enzyme, and such inhibition was not solely due to sequestration of the substrate by HP-β-CD.

METHODS

The mechanistic path for the HP-β-CD mediated inhibition of MetAP was probed by performing a detailed account of steady-state kinetics, ligand binding, X-ray crystallographic, and molecular modeling studies.

RESULTS

X-ray crystallographic data of the β-cyclodextrin-substrate (β-CD-MetAMC) complex reveal that while the AMC moiety of the substrate is confined within the CD cavity, the methionine moiety protrudes outward. The steady-state kinetic data for inhibition of MetAP by HP-β-CD-MetAMC conform to a model mechanism in which the substrate is "bridged" between HP-β-CD and the enzyme's active-site pocket, forming HP-β-CD-MetAMC-MetAP as the catalytically inactive ternary complex. Molecular modeling shows that the scissile bond of HP-β-CD-bound MetAMC substrate does not reach within the proximity of the enzyme's catalytic metal center, and thus the substrate fails to undergo cleavage.

CONCLUSIONS

The data presented herein suggests that the bridging of the substrate between the enzyme and HP-β-CD cavities is facilitated by interaction of their surfaces, and the resulting complex inhibits the enzyme activity.

GENERAL SIGNIFICANCE

Due to its potential interaction with physiological proteins via sequestered substrates, caution must be exercised in HP-β-CD mediated delivery of drugs under pathophysiological conditions.

pH-triggered echogenicity and contents release from liposomes

Liposomes are representative lipid nanoparticles widely used for delivering anticancer drugs, DNA fragments, or siRNA to cancer cells. Upon targeting, various internal and external triggers have been used to increase the rate for contents release from the liposomes. Among the internal triggers, decreased pH within the cellular lysosomes has been successfully used to enhance the rate for releasing contents. However, imparting pH sensitivity to liposomes requires the synthesis of specialized lipids with structures that are substantially modified at a reduced pH. Herein, we report an alternative strategy to render liposomes pH sensitive by encapsulating a precursor which generates gas bubbles in situ in response to acidic pH. The disturbance created by the escaping gas bubbles leads to the rapid release of the encapsulated contents from the liposomes. Atomic force microscopic studies indicate that the liposomal structure is destroyed at a reduced pH. The gas bubbles also render the liposomes echogenic, allowing ultrasound imaging. To demonstrate the applicability of this strategy, we have successfully targeted doxorubicin-encapsulated liposomes to the pancreatic ductal carcinoma cells that overexpress the folate receptor on the surface. In response to the decreased pH in the lysosomes, the encapsulated anticancer drug is efficiently released. Contents released from these liposomes are further enhanced by the application of continuous wave ultrasound (1 MHz), resulting in substantially reduced viability for the pancreatic cancer cells (14%).

Bone mineral density among long-term survivors of childhood acute lymphoblastic leukemia: results from the St. Jude Lifetime Cohort Study

BACKGROUND

The prevalence of low bone mineral density (BMD) in adult survivors of childhood acute lymphoblastic leukemia (ALL), and the degree of recovery or decline, are not well elucidated.

PROCEDURE

Study subjects (age ≥ 18 years and ≥10 years post-diagnosis) participated in an institutional follow-up protocol and risk-based clinical evaluation based on Children's Oncology Group guidelines. Trabecular volumetric BMD was ascertained using quantitative computed tomography, reported as age- and sex-specific Z-scores.

RESULTS

At median age 31 years, 5.7% of 845 subjects had a BMD Z-score of ≤-2 and 23.8% had a Z-score of -1 to -2. Cranial radiation dose of ≥24 Gy, but not cumulative methotrexate or prednisone equivalence doses, was associated with a twofold elevated risk of a BMD Z-score of ≤-1. The cranial radiation effect was stronger in females than in males. In a subset of 400 subjects, 67% of those who previously had a BMD Z-score of ≤-2 improved by one or more categories a median of 8.5 years later.

CONCLUSIONS

Very low BMD was relatively uncommon in this sample of adult survivors of childhood ALL, and BMD Z-scores tended to improve from adolescence to young adulthood. High-dose cranial or craniospinal radiation exposure was the primary predictor of suboptimal BMD in our study. Given that cranial radiation treatment for childhood ALL is used far more sparingly now than in earlier treatment eras, concerns about persistently low BMD among most current childhood ALL patients may be unwarranted.

Early infections after autologous hematopoietic stem cell transplantation in children and adolescents: the St. Jude experience

INTRODUCTION

Advances in autologous hematopoietic stem cell transplantation (HSCT) over the past 20 years may have had an impact on the morbidity and mortality associated with infections post transplant.

PATIENTS AND METHODS

We sought to retrospectively analyze the epidemiology of the first episode of bacterial, fungal, viral, or parasitic infections 0-30 days post transplant in a cohort of 320 children and adolescents who underwent autologous HSCT in a single institution, between 1990 and 2009 for solid tumors or lymphoma, and in 65 children transplanted for acute leukemia during the same period.

RESULTS

Infections occurred in 66 (21%) patients with solid tumors or lymphoma. Bacterial infections occurred in 33 (10%) including bacteremia in 23 (7%), and viral infections in 34 (11%) patients. Gram-positive bacterial infections were more prevalent than gram-negative bacterial infections (P = 0.03). Infections caused by fungal or parasitic pathogens were uncommon. The decade when transplant was performed (1990-1999 vs. 2000-2009) had no impact on the incidence of bacterial (P = 0.41) or viral (P = 0.47) infection. Between 1990 and 1999, a total of 60 (92%) children were transplanted for leukemia, and 5 (8%) in the 2000-2009 period (P < 0.0001). Infections occurred in 32 (49%) patients. Bacterial (P = 0.004), candidal (P = 0.003), and herpes simplex viral (P = 0.03) infections were more common in patients transplanted for leukemia. In patients transplanted for leukemia, 3 deaths occurred attributed to infection, all before 2000.

CONCLUSION

Changes in epidemiology of infection are likely a result of decline in autologous transplantation for childhood leukemia in the recent era. Autologous transplantation for solid tumors or lymphoma was not associated with mortality from early infections at our institution.

Kinetic and thermodynamic rationale for suberoylanilide hydroxamic acid being a preferential human histone deacetylase 8 inhibitor as compared to the structurally similar ligand, trichostatin a

Of the different hydroxamate-based histone deacetylase (HDAC) inhibitors, suberoylanilide hydroxamic acid (SAHA) has been approved by the Food and Drug Administration for the treatment of T-cell lymphoma. Interestingly, a structurally similar inhibitor, trichostatin A (TSA), which has a higher in vitro inhibitory potency against HDAC8, reportedly shows poor efficacy in clinical settings. To gain molecular insight into this discriminatory feature, we performed transient kinetic and isothermal titration calorimetric studies for the interaction of SAHA and TSA with the recombinant form of human HDAC8. The transient kinetic data revealed that the binding of both inhibitors to the enzyme showed biphasic profiles, which represented an initial encounter of the enzyme with the inhibitor followed by the isomerization of the transient enzyme-inhibitor complexes. The temperature-dependent transient kinetic studies with these inhibitors revealed that the bimolecular process is primarily dominated by favorable enthalpic changes, as opposed to the isomerization step, which is solely contributed by entropic changes. The standard binding enthalpy (ΔH°) of SAHA, deduced from the transient kinetic as well as the isothermal titration calorimetric experiments, was 2-3 kcal/mol higher than that of TSA. The experimental data presented herein suggest that SAHA serves as a preferential (target-specific and -selective) HDAC8 inhibitor as compared to TSA. Arguments that the detailed kinetic and thermodynamic studies may guide the rational design of HDAC inhibitors as therapeutic agents are presented.

A disintegrin and metalloproteinase-12 (ADAM12): function, roles in disease progression, and clinical implications

BACKGROUND

A disintegrin and metalloproteinase-12 (ADAM12) is a member of the greater ADAM family of enzymes: these are multifunctional, generally membrane-bound, zinc proteases for which there are forty genes known (21 of these appearing in humans). ADAM12 has been implicated in the pathogenesis of various cancers, liver fibrogenesis, hypertension, and asthma, and its elevation or decrease in human serum has been linked to these and other physiological/pathological conditions.

SCOPE

In this review, we begin with a brief overview of the ADAM family of enzymes and protein structure. We then discuss the role of ADAM12 in the progression and/or diagnosis of various disease conditions, and we will conclude with an exploration of currently known natural and synthetic inhibitors.

MAJOR CONCLUSION

ADAM12 has potential to emerge as a successful drug target, although targeting the metalloproteinase domain with any specificity will be difficult to achieve due to structural similarity between the members of the ADAM and MMP family of enzymes. Overall, more research is required to establish ADAM12 being as a highly desirable biomarker and drug target of different diseases, and their selective inhibitors as potential therapeutic agents.

GENERAL SIGNIFICANCE

Given the appearance of elevated levels of ADAM12 in various diseases, particularly breast cancer, our understanding of this enzyme both as a biomarker and a potential drug target could help make significant inroads into both early diagnosis and treatment of disease.

Melanoma as a subsequent neoplasm in adult survivors of childhood cancer: a report from the childhood cancer survivor study

BACKGROUND

Childhood cancer survivors have a sixfold increased risk of developing subsequent neoplasms when compared to the general population. We sought to describe the occurrence of melanoma as a subsequent neoplasm among adult survivors of childhood cancer.

PATIENTS AND METHODS

Among 14,358 5-year survivors of childhood cancer diagnosed between 1970 and 1986, we calculated the cumulative incidence, standardized incidence ratio (SIR), and absolute excess risk (AER) of subsequent melanoma. Potential risk factors were assessed using a cause-specific hazards model.

RESULTS

Fifty-seven melanomas (46 invasive, 2 ocular, and 9 in situ) occurred in 51 survivors. The median time to the development of melanoma was 21.0 years (range: 5.6-35.4 years) and the median age at melanoma was 32.3 years (range: 10.9-49.0 years). Initial cancer diagnoses included soft tissue and bone sarcoma (n = 15), leukemia (13), lymphoma (14), central nervous system malignancy (5), Wilms tumor (3), and neuroblastoma (1). The cumulative incidence of first subsequent melanoma at 35 years from initial cancer diagnosis was 0.55% [95% confidence interval (CI): 0.37-0.73]. The SIR of subsequent invasive malignant melanoma of the skin was 2.42 (95% CI: 1.77-3.23), and the AER was 0.10 (95% CI: 0.05-0.15) per 1,000 person-years. No statistically significant associations were found between melanoma risk and family history of cancer, demographic, or treatment-related factors.

CONCLUSION

Survivors of childhood cancer have an approximate 2.5-fold increased risk of melanoma. Early screening and prevention strategies are warranted.

Polymer-coated echogenic lipid nanoparticles with dual release triggers

Although lipid nanoparticles are promising drug delivery vehicles, passive release of encapsulated contents at the target site is often slow. Herein, we report contents release from targeted, polymer-coated, echogenic lipid nanoparticles in the cell cytoplasm by redox trigger and simultaneously enhanced by diagnostic frequency ultrasound. The lipid nanoparticles were polymerized on the external leaflet using a disulfide cross-linker. In the presence of cytosolic concentrations of glutathione, the lipid nanoparticles released 76% of encapsulated contents. Plasma concentrations of glutathione failed to release the encapsulated contents. Application of 3 MHz ultrasound for 2 min simultaneously with the reducing agent enhanced the release to 96%. Folic acid conjugated, doxorubicin-loaded nanoparticles showed enhanced uptake and higher cytotoxicity in cancer cells overexpressing the folate receptor (compared to the control). With further developments, these lipid nanoparticles have the potential to be used as multimodal nanocarriers for simultaneous targeted drug delivery and ultrasound imaging.

Detection of respiratory viruses in asymptomatic children undergoing allogeneic hematopoietic cell transplantation

Detection of respiratory viruses by molecular methods, in children without respiratory symptoms undergoing hematopoietic cell transplantation (HCT), has not been well described. A prospective study of 33 asymptomatic children detected respiratory viruses in 8 of 33 (24%) patients before HCT. Human rhinovirus (HRV) was detected in five patients, and human adenovirus (hADV) in three patients. Two additional patients shed HRV, and one shed human coronavirus (hCoV), post-HCT. Two patients had co-infections. Of the 11 asymptomatic patients where respiratory virus was detected, 3 (27%) later developed an upper respiratory tract infection, from the same virus.

Ultrasound enhanced matrix metalloproteinase-9 triggered release of contents from echogenic liposomes

The extracellular enzyme matrix metalloproteinase-9 (MMP-9) is overexpressed in atherosclerotic plaques and in metastatic cancers. The enzyme is responsible for rupture of the plaques and for the invasion and metastasis of a large number of cancers. The ability of ultrasonic excitation to induce thermal and mechanical effects has been used to release drugs from different carriers. However, the majority of these studies were performed with low frequency ultrasound (LFUS) at kilohertz frequencies. Clinical usage of LFUS excitations will be limited due to harmful biological effects. Herein, we report our results on the release of encapsulated contents from substrate lipopeptide incorporated echogenic liposomes triggered by recombinant human MMP-9. The contents release was further enhanced by the application of diagnostic frequency (3 MHz) ultrasound. The echogenic liposomes were successfully imaged employing a medical ultrasound transducer (4-15 MHz). The conditioned cell culture media from cancer cells (secreting MMP-9) released the encapsulated dye from the liposomes (30-50%), and this release is also increased (50-80%) by applying diagnostic frequency ultrasound (3 MHz) for 3 min. With further developments, these liposomes have the potential to serve as multimodal carriers for triggered release and simultaneous ultrasound imaging.

Phase I study of the tolerability and pharmacokinetics of palifermin in children undergoing allogeneic hematopoietic stem cell transplantation

The maximum tolerated dose of palifermin, a keratinocyte growth factor, in children is not known, and its pharmacokinetics in this population has not been well studied. This is a phase I study of palifermin was designed to evaluate its tolerability at doses of 40, 60, and 90 μg/kg/day in children age 2-18 years of age, receiving a myeloablative preparative regimen for allogeneic hematopoietic stem cell transplantation (HSCT). In each cohort, palifermin was given for 3 consecutive days before the preparative regimen and for 3 days after the stem cell infusion. Twelve patients were enrolled. Palifermin 90 μg/kg/day was tolerated in 6 patients without dose-limiting toxicity. All patients had at least 1 adverse event, mostly National Cancer Institute grade 1 or 2 severity. Skin rash, grade 2 or lower, was the most common adverse event, seen in 67% of patients. Only 3 patients (25%) had mucositis. The area under the concentration-time curve increased proportionally to the dose, and approximately 97% of palifermin exposure occurred in the first 24 hours after administration. Palifermin clearance increased linearly with body weight, supporting dosing by body weight. The mean clearance was 1893 mL/hour/kg, and it did not change significantly between administration of the first and last doses (P = .80). The mean elimination half-life was 4.6 hours. Our data show that palifermin was tolerated at a dose of 90 μg/kg/day, and exhibits linear pharmacokinetics in children undergoing allogeneic HSCT.

A phase I/II study of CY and topotecan in patients with high-risk malignancies undergoing autologous hematopoietic cell transplantation: the St Jude long-term follow-up

Fifty-eight consecutive children with high-risk malignancies were treated with CY, and targeted topotecan followed by autologous hematopoietic cell transplantation (AHCT) in a phase I/II Institutional Review Board-approved study. Twelve participants enrolled in phase I; 5 received dose level 1 of topotecan 3 mg/m(2) per day, with subsequent doses targeted to total systemic exposure of 100±20 ng h/mL and CY 750 mg/m(2) per day. Seven participants received dose level 2. CY dose escalation to 1 g/m(2) per day was considered excessively toxic; one died from irreversible veno-occlusive disease and two experienced reversible hepatotoxicity. These adverse events halted further dose escalation. A total of 46 participants were enrolled in phase II; results are on the 51 participants who received therapy at dose level 1, the maximum tolerated dose. Diagnoses included neuroblastoma (26), sarcoma (9), lymphoma (8), brain tumors (5), Wilms (2) and retinoblastoma (1). Twenty participants (39.3%) were in CR1 at enrollment; median age was 5.1 years. Most common non-hematological grade III-IV toxicity was gastrointestinal (n=37). Neutrophil and platelet engraftment occurred at a median of 15 and 24 days, respectively. Twenty-six (51%) participants remain alive at a median of 6.4 years after AHCT. CY 3.75 g/m(2), and targeted topotecan followed by AHCT are feasible and produce acceptable toxicity in children with high-risk malignancies.

Histone deacetylase activators: N-acetylthioureas serve as highly potent and isozyme selective activators for human histone deacetylase-8 on a fluorescent substrate

We report, for the first time, that certain N-acetylthiourea derivatives serve as highly potent and isozyme selective activators for the recombinant form of human histone deacetylase-8 in the assay system containing Fluor-de-Lys as a fluorescent substrate. The experimental data reveals that such activating feature is manifested via decrease in the K(m) value of the enzyme's substrate and increase in the catalytic turnover rate of the enzyme.

Fluorescent water soluble polymers for isozyme-selective interactions with matrix metalloproteinase-9

Matrix metalloproteinases (MMPs) are overexpressed in various pathological conditions, including cancers. Although these isozymes have similar active sites, the patterns of exposed amino acids on their surfaces are different. Herein, we report the synthesis and molecular interactions of two water soluble, fluorescent polymers which demonstrate selective interactions with MMP-9 compared to MMP-7 and -10.

Increasing prevalence of nasal and rectal colonization with methicillin-resistant Staphylococcus aureus in children with cancer

BACKGROUND

Infections with methicillin-resistant Staphylococcus aureus (MRSA), in community-settings, especially with strains carrying the Panton-Valentine Leukocidin (PVL) genes, have increased markedly in recent years. Colonization with S. aureus is a risk factor for infection. However, there are few studies that examine colonization and infection with PVL-positive strains of MRSA in cancer patients.

PROCEDURE

The epidemiology of colonization and infection with MRSA was studied in children with cancer during two time periods: 2000/2001 and 2006/2007. PVL genes were screened and spa typing performed on the isolates.

RESULTS

The prevalence of colonization with MRSA increased from 0.6% in 2000/2001 to 2.9% in 2006/2007 (P = 0.0003). MRSA colonization at admission was associated with infection (P < 0.0001; RR 38.32; 95% CI: 23.36-62.84). The prevalence of infection increased from 0.99% in 2000/2001 to 3.78% in 2006-2007 (P = 0.0002). Of the 32 colonized patients, 18 (56%) had infection. None of the 14 colonized but non-infected patients had dual colonization of nares and rectum, while 8 of the 18 infected patients had colonization of both of these sites (P = 0.004). Ten patients (31%) were colonized with PVL-positive strains. Patients colonized with PVL-positive strains were more likely to be colonized both in the nares and rectum (P = 0.005), and more likely to have infection (P = 0.001). Recurrent MRSA infections were seen in 22% of patients.

CONCLUSION

An increasing prevalence of colonization with MRSA was observed in children with cancer at our institution. Colonization with MRSA especially with PVL-positive strains was associated with infection.

Coumarin-suberoylanilide hydroxamic acid as a fluorescent probe for determining binding affinities and off-rates of histone deacetylase inhibitors

Histone deacetylases (HDACs) are intimately involved in epigenetic regulation and, thus, are one of the key therapeutic targets for cancer, and two HDAC inhibitors, namely suberoylanilide hydroxamic acid (SAHA) and romidepsin, have been recently approved for cancer treatment. Because the screening and detailed characterization of HDAC inhibitors has been time-consuming, we synthesized coumarin-SAHA (c-SAHA) as a fluorescent probe for determining the binding affinities (K(d)) and the dissociation off-rates (k(off)) of the enzyme-inhibitor complexes. The determination of the above parameters relies on the changes in the fluorescence emission intensity (λ(ex)=325 nm, λ(em)=400 nm) of c-SAHA due to its competitive binding against other HDAC inhibitors, and such determination neither requires employment of polarization accessories nor is dependent on the fluorescence energy transfer from the enzyme's tryptophan residues to the probe. Our highly sensitive and robust analytical protocol presented here is applicable to most of the HDAC isozymes, and it can be easily adopted in a high-throughput mode for screening the HDAC inhibitors as well as for quantitatively determining their K(d) and k(off) values.

Liposome-mediated amplified detection of cell-secreted matrix metalloproteinase-9

A liposome-based amplified detection system is presented for the cancer cell secreted pathogenic enzyme matrix metalloproteinase-9 which does not require the use of biological antibodies.

Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus infections in children with cancer

BACKGROUND

New strains of methicillin-resistant Staphylococcus aureus (MRSA) which frequently carry the Panton-Valentine leukocidin (PVL) genes have been recognized to cause invasive infections in otherwise healthy children and adults. However, the epidemiology of PVL-positive MRSA infections has not been described in children or adults with cancer.

PROCEDURE

The epidemiology of MRSA infections in patients with cancer was retrospectively studied from 2000 to 2007. Molecular typing was performed by polymerase chain reaction (PCR) for the detection of the PVL genes. Staphylococcus cassette chromosome (SCC) mec and spa typing was performed on all PVL-positive isolates.

RESULTS

A total of 88 MRSA isolates from clinically distinct infectious episodes were collected from 88 patients with cancer during the 8-year study period. Infections were predominant in the skin and soft tissues (SSTI; P = 0.0003). PVL-positive isolates, bearing the type IV SCCmec element, encoding the gene for methicillin resistance, increased significantly during this period (P = 0.043) and comprised 35 of 88 (40%) MRSA isolates. Of these 35 isolates, 32 belonged to spa type 8 and were USA300 genotype. Patients infected with PVL-positive strains did not have more SSTI (P = 0.166) or bacteremia (P = 0.510) as compared to patients with PVL-negative strains. A greater percentage of PVL-positive isolates were susceptible to ciprofloxacin (P = 0.006).

CONCLUSIONS

PVL-positive MRSA infections are not associated with a higher morbidity as compared to PVL-negative MRSA infections in children with cancer.

Short communication: methicillin-resistant Staphylococcus aureus infections in children and young adults infected with HIV

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) infections, in particular with Panton-Valentine leukocidin (PVL)-positive strains, has not been well characterized in children and young adults with HIV infection. It is not known if PVL-positive strains of MRSA cause an increased morbidity in this population compared to PVL-negative strains. The purpose of this study was to retrospectively analyze the epidemiology of PVL-positive and PVL-negative MRSA infections in children and young adults with HIV from 2000 to 2007. Molecular typing was performed by polymerase chain reaction (PCR) for detection of the PVL genes. Staphylococcus Cassette Chromosome (SCC) mec and spa typing were performed on all PVL-positive isolates. The number of HIV patients with MRSA infection increased significantly between 2000 and 2007 ( p=0.0015). Twenty seven (87%) of the 31 MRSA isolates were from skin and soft tissue infections (SSTI). Clindamycin resistance was observed in 19% of the MRSA isolates. PVL-positive isolates bearing the type IV SCC mec element comprised 16 of 31 (52%) MRSA isolates. All the PVL-positive isolates belonged to the USA300 pulsed-field type. There was no difference in the mean CD4 count and HIV viral load between patients with PVL-positive and PVL-negative MRSA infections. PVL-positive MRSA infections were associated with more SSTI ( p=0.043) but not with increased morbidity or a higher risk of complications compared to PVL-negative MRSA infections in children and young adults with HIV.

Solvent-assisted slow conversion of a dithiazole derivative produces a competitive inhibitor of peptide deformylase

Due to its potential as an antibiotic target, E. coli peptide deformylase (PDF(Ec)) serves as a model enzyme system for inhibitor design. While investigating the structural-functional and inhibitory features of this enzyme, we unexpectedly discovered that 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) served as a slow-binding inhibitor of PDF(Ec) when the above compound was dissolved only in dimethylformamide (DMF), but not in any other solvent, and allowed to age. The time dependent inhibitory potency of the DMF-dissolved AMT was correlated with the broadening of the inhibitor's 295 nm spectral band toward the visible region, concomitant with the increase in the mass of the parent compound by about 2-fold. These data led to the suggestion that DMF facilitated the slow dimerization of AMT (via the formation of a disulfide bond), and that the dimeric form of AMT served as an inhibitor for PDF(Ec). The latter is not caused by the simple oxidation of sulfhydryl groups by oxidizing agents such as H(2)O(2). Newly synthesized dimeric/dithiolated form of AMT ("bis-AMT") exhibited similar spectral and inhibitory features as given by the parent compound when incubated with DMF. The computer graphic modeling data revealed that bis-AMT could be reliably accommodated within the active site pocket of PDF(Ec), and the above enzyme-ligand interaction involves coordination with the enzyme resident Ni(2+) cofactor. The mechanism of the DMF-assisted activation of AMT (generating bis-AMT), the overall microscopic pathway for the slow-binding inhibition of PDF(Ec) by bis-AMT, and the potential of bis-AMT to serve as a new class of antibiotic agent are presented.

Release of liposomal contents by cell-secreted matrix metalloproteinase-9

Liposomes have been widely used as a drug delivery vehicle, and currently, more than 10 liposomal formulations are approved by the Food and Drug Administration for clinical use. However, upon targeting, the release of the liposome-encapsulated contents is usually slow. We have recently demonstrated that contents from appropriately formulated liposomes can be rapidly released by the cancer-associated enzyme matrix metalloproteinase-9 (MMP-9). Herein, we report our detailed studies to optimize the liposomal formulations. By properly selecting the lipopeptide, the major lipid component, and their relative amounts, we demonstrate that the contents are rapidly released in the presence of cancer-associated levels of recombinant human MMP-9. We observed that the degree of lipid mismatch between the lipopepides and the major lipid component profoundly affects the release profiles from the liposomes. By utilizing the optimized liposomal formulations, we also demonstrate that cancer cells (HT-29) which secrete low levels of MMP-9 failed to release a significant amount of the liposomal contents. Metastatic cancer cells (MCF7) secreting high levels of the enzyme rapidly release the encapsulated contents from the liposomes.

A study of interface of ASHA with the community and the service providers in Eastern Uttar Pradesh

OBJECTIVE

To study the functioning of ASHA in the community with special focus on interface with community and service providers in Eastern Uttar Pradesh.

METHODS

This was a descriptive cross-sectional study conducted in two blocks each in Gorakhpur and Maharajganj districts of Eastern Uttar Pradesh during October-December 2008. A multi stage sampling design was used. The study subjects included 120 mothers, 60 ASHAs, 20 AWWs, 20 ANMs, 4 Medical Officers in charge, 2 Chief Medical Officers (CMOs) and PRI members. Data was collected through pre-designed and pre-tested structured interview schedules and through checklists for FGDs.

RESULTS

Most (95%) of the ASHAs were 8th Pass or above. The residential status and marital status was as per guidelines. Induction training was received by all. Major motivating factor for ASHAs were either money (81.66%) or getting a government job (66.66%). Most of the ASHAs (86.66%) got the support from their supervisors in solving their problem and majority of them (95%) were satisfied with their supervisors. All the ASHAs have been accepted very well in the community and are acting a good link between community and health providers. The faith and confidence of community on ASHAs are reflected by the demand of additional jobs like help in getting widow pension and ration card etc.

CONCLUSION

Though accepted by the community, ASHAs need regular training, support and cooperation from other functionaries.

A novel approach for quantification of KIR expression in healthy donors and pediatric recipients of hematopoietic SCTs

The killer cell Ig-like receptor (KIR) expression repertoire may offer valuable information for hematopoietic SCT (HSCT). We designed a quantitative KIR RNAtype assay and used it to determine KIR gene expression in healthy donors and patients before HSCT. The specificity of the assay was ensured by specific primers and by electrophoretic distinction of PCR products of unique length. In 87 healthy donors, the KIR repertoire was broadly distributed (32 categories of profiles). There was an overall trend toward inverse correlation of KIR expression level and donor age. Age affected mainly the activating KIR families. Leukemia patients showed lower KIR expression before transplantation than healthy donors. Stem cell mobilization caused a transient increase of KIR expression. We conclude that KIR expression differs quantitatively with age and primary disease and is transiently altered by stem cell recruitment and selection.

Delineation of alternative conformational states in Escherichia coli peptide deformylase via thermodynamic studies for the binding of actinonin

We investigated the binding of a naturally occurring antibiotic, actinonin, to the Ni(2+)-reconstituted recombinant form of Escherichia coli peptide deformylase (PDF(Ec)) via isothermal titration microcalorimetry. The binding data conformed to both exothermic and endothermic phases with magnitudes of DeltaG degrees , DeltaH degrees , and TDeltaS degrees being equal to -12, -2.7, and 9.3 kcal/mol and -8.7, 3.9, and 12.6 kcal/mol, respectively. Evidently, although both phases are dominated by favorable entropic changes, the exothermic phase has about 6.7 kcal/mol enthalpic advantage over the endothermic phase. We observed that the removal of bound Ni(2+) from PDF(Ec) abolished the exothermic phase without affecting the endothermic phase, but it was regained upon addition of Zn(2+). In conjunction with metal analysis data, we propose that the recombinant form of PDF(Ec) is expressed in two stable conformational states that yield markedly distinct ITC profiles (i.e., exothermic versus endothermic) upon interaction with actinonin. The existence of two conformational states of PDF(Ec) is further supported by the observation of two distinct and independent transitions during the thermal unfolding of the enzyme. In addition, the thermodynamic data reveal that the formation of the PDF(Ec)-actinonin complex results in the transfer of one H(+) from the enzyme phase to the bulk solvent at pH 6.3. Both exothermic and endothermic phases produce highly negative DeltaC(p) degrees values, but there is no apparent enthalpy-entropy compensation effect upon formation of the PDF(Ec)-actinonin complex. In view of the known structural features of the enzyme, arguments are presented that the alternative conformational states of PDF(Ec) are modulated by the metal ligation at the enzyme site.

Influence of "Flexible" versus "Rigid" Nanoparticles on the Stability of Matrix Metalloproteinase-7

Matrix Metalloproteinase-7 (MMP-7) is invariably expressed in a variety of cancer cells, and exhibits the potentials to interact with differently charged macromolecular surfaces 1. To ascertain whether the nature of the charge carrying surfaces influences the stability as well as catalytic properties of the enzyme, we compared the effects of differently charged lipid (representative of "flexible") and gold ("rigid") nanoparticles. The experimental data revealed that the catalytic activity of MMP-7 is impaired only by the positively charged lipid nanoparticles, and it remains unaffected by their negatively charged or neutral counterparts. On the other hand, both positively and negatively charged gold nanoparticles impair the enzyme activity with nearly equal potency; no significant influence of neutral gold nanoparticles was noted on the enzyme activity. Unlike lipid nanoparticles, the charged gold nanoparticles mediated effects were found to be manifested partially via the inactivation of the enzyme. Arguments are presented that both the "rigidity" as well as the surface curvature of the lipid ("flexible") vis a vis the gold ("rigid") nanoparticles are responsible for eliciting differential influence on the catalytic activity as well as the stability of MMP-7.

Alternative Modes of Binding of Recombinant Human Histone Deacetylase 8 to Colloidal Gold Nanoparticles

Histone deacetylases are intimately involved in the transcriptional regulation of genes, and they are high priority drug targets for cancer therapy. Due to prevalence of several sulfhydryl groups on the surface of histone deacetylase 8, we explored the possibility of its binding to colloidal gold nanoparticles by determining its potentials to inhibit the flocculation as well as retaining the enzyme activity. It was observed that although both these processes conformed to the binding affinity of the gold-histone deacetylase 8 conjugate as being equal to 15-20 nM, only 30% of the nanoparticle-bound enzyme exhibited the enzymatic activity. In the light of the structural features of histone deacetylase 8, we propose that the enzyme interacts with the gold nanoparticles via the surface exposed thiol groups, and such interaction occurs in two alternative modes. Whereas the enzyme bound via mode-1 is catalytically inactive (presumably due to the orientation of the enzyme's active site toward the gold nanoparticle surface), and it prevents the flocculation of the nanoparticles, the enzyme bound via mode-2 shows the full catalytic activity (as its active site is believed to be oriented away from the nanoparticle surface). Although the histone deacetylase 8 bound to AuNP via mode-2 exhibits the same inhibitory potency against Trichostatin A as the free enzyme, the former is more susceptible to thermal denaturation. The potential of potent interaction between gold nanoparticles and histone deacetylase 8 via alternative modes may find diagnostic and/or therapeutic applications for different forms of cancers.

Energetic rationale for an unexpected and abrupt reversal of guanidinium chloride-induced unfolding of peptide deformylase

Peptide deformylase (PDF) catalyzes the removal of formyl group from the N-terminal methionine residues of nascent proteins in prokaryotes, and this enzyme is a high priority target for antibiotic design. In pursuit of delineating the structural-functional features of Escherichia coli PDF (EcPDF), we investigated the mechanistic pathway for the guanidinium chloride (GdmCl)-induced unfolding of the enzyme by monitoring the secondary structural changes via CD spectroscopy. The experimental data revealed that EcPDF is a highly stable enzyme, and it undergoes slow denaturation in the presence of varying concentrations of GdmCl. The most interesting aspect of these studies has been the abrupt reversal of the unfolding pathway at low to moderate concentrations of the denaturant, but not at high concentration. An energetic rationale for such an unprecedented feature in protein chemistry is offered.

Intrinsic selectivity in binding of matrix metalloproteinase-7 to differently charged lipid membranes

We provide evidence that matrix metalloproteinase-7 (MMP-7) interacts with anionic, cationic and neutral lipid membranes, although it interacts strongest with anionic membranes. While the catalytic activity of the enzyme remains unaffected upon binding to neutral and negatively charged membranes, it is drastically impaired upon binding to the positively charged membranes. The structural data reveal that the origin of these features lies in the "bipolar" distribution of the electrostatic surface potentials on the crystallographic structure of MMP-7.

A strategy for designing "multi-prong" enzyme inhibitors by incorporating selective ligands to the liposomal surface

We offer a novel strategy for designing "multi-prong" inhibitors of enzymes by incorporating selective ligands on the liposomal surface.

New fluorescent probes for carbonic anhydrases

We report the synthesis and fluorescence properties of naphthalenesulfonamide derivatives as active site probes for carbonic anhydrases.