Incidence Rate Of Leukemia Research Articles

Study on Transportation of Arsenic Trioxide Nanoparticles Across Blood-Brain Barrier in ICR Mice

Abstract 4292With the progress of leukemia therapy and the improvement of supportive treatment, all-trans-retinoic acid (ATRA) and arsenic trioxide (As2O3) are extensively used in clinical. In recent years, remission rate of acute promyelocytic leukemia (APL) is obviously improved, and the survival is gradually extended. However, the incidence rate of central nervous system leukemia (CNSL) is increasing, and the therapeutic effect and prognosis are poor. This will severely influence the survival of the patients, and it is also one of the important reasons of leukemia relapse.The method for prevention of CNSL is intrathecal injection. However, it will cause discomfort to the patients, and also has some adverse reaction and certain risk. With the increase of the incidence of CNSL, new methods are urgently needed. We developed new Arsenic trioxide Nanoparticles (ASN), which are easier to penetrate blood-brain barrier (BBB).Previous studies showed that ASN had a stronger anti-tumor activity compared with traditional Arsenic trioxide. The underlying reason may be associated with physical and chemical properties of the nanoparticles. When material processed into nanometer scale (0.1 ~ 100 nm), it will present a new physical and chemical characteristics, which may gift the drug new biological characteristics and functions. In the present study, we found that ASN could pass through blood brain barrier more easily than traditional arsenic trioxide. In this study, we evaluate the penetrability of ASN across BBB with ICR mice.Arsenic trioxide nanopaticles (ASN) were prepared with sol-gel method, about 40nm in diameter. And the Electronic differential system (EDS) showed that these nanopaticles were arsenic trioxide. Healthy ICR mice were chosen, and then they were divided into ASN group and arsenic acids group. The mice were gavaged with ASN or arsenic acids at the dose of 1 mg/kg body weight. After treated with different drugs, the mice were sacrificed in different time. The brain tissue was removed for analysis. Ultimately, atomic fluorescence spectrometry was utilized to determine the concentration of As in cerebral tissues. All the experiments were performed in accordance with the Regulations of Experimental Animal Administration issued by the State Committee of Science and Technology of People's Republic of China.Compare with arsenic acids group, the concentration of As was evidently higher in cerebral tissues of ASN group in 1□‘4 hour (P<0.01) after treatment. In ASN group, the concentration of As in brains reached the peak about 171.2061 ± 43.1 ng/g at two hours after administration, and then declined. In contrast, the peak concentration of As in brain tissue was only 69.6563 ± 14.9 ng/g (vs. ASN group P=0.028) at two hour after treatment in arsenic acids group. There was no significant difference of the As concentration in CSF at 8□‘24 hour. Hence, the nanoparticles were easier to pass through the BBB.The penetrability of nanoparticle across of BBB was increased and the drug could quickly reach therapeutic concentration. The metabolism characteristics of ASN suggested that ASN may have less unfavorable effect. DisclosuresThe authors have declared that there is no conflict of interest. Disclosures:No relevant conflicts of interest to declare.

Survival and Disease Progression in Essential Thrombocythemia Are Significantly Influenced by Accurate Morphologic Diagnosis: An International Study

The WHO diagnostic criteria underscore the role of bone marrow (BM) morphology in distinguishing essential thrombocythemia (ET) from early/prefibrotic primary myelofibrosis (PMF). This study examined the clinical relevance of such a distinction. Representatives from seven international centers of excellence for myeloproliferative neoplasms convened to create a clinicopathologic database of patients previously diagnosed as having ET (N = 1,104). Study eligibility criteria included availability of treatment-naive BM specimens obtained within 1 year of diagnosis. All bone marrows subsequently underwent a central re-review. Diagnosis was confirmed as ET in 891 patients (81%) and was revised to early/prefibrotic PMF in 180 (16%); 33 patients were not evaluable. In early/prefibrotic PMF compared with ET, the 10-year survival rates (76% and 89%, respectively) and 15-year survival rates (59% and 80%, respectively), leukemic transformation rates at 10 years (5.8% and 0.7%, respectively) and 15 years (11.7% and 2.1%, respectively), and rates of progression to overt myelofibrosis at 10 years (12.3% and 0.8%, respectively) and 15 years (16.9% and 9.3%) were significantly worse. The respective death, leukemia, and overt myelofibrosis incidence rates per 100 patient-years for early/prefibrotic PMF compared with ET were 2.7% and 1.3% (relative risk [RR], 2.1; P < .001), 0.6% and 0.1% (RR, 5.2; P = .001), and 1% and 0.5% (RR, 2.0; P = .04). Multivariable analysis confirmed these findings and also identified age older than 60 years (hazard ratio [HR], 6.7), leukocyte count greater than 11 × 10(9)/L (HR, 2.01), anemia (HR, 2.95), and thrombosis history (HR, 2.81) as additional risk factors for survival. Thrombosis and JAK2V617F incidence rates were similar between the two groups. Survival in ET was similar to the sex- and age-standardized European population. This study validates the clinical relevance of strict adherence to WHO criteria in the diagnosis of ET and provides important information on survival, disease complication rates, and prognostic factors in strictly WHO-defined ET and early/prefibrotic PMF.

Incidence of childhood leukemia in Yogyakarta, Indonesia, 1998–2009

In most developing countries, incidence data for childhood cancers are less reliable, because very few population-based registries exist. The aim of this study was to present the epidemiology of childhood leukemia in the Dr. Sardjito Hospital (DSH) region, which catchment area extends beyond the boundaries of the Yogyakarta Special Province (YSP). Health records of children, 0-14 years of age, who were diagnosed with leukemia between January 1998 and December 2009, were reviewed. Diagnosis of leukemia was confirmed by morphological and histochemical examination of marrow samples. The estimated average annual incidence rate (AAIR) of childhood acute leukemia in DSH was 46.2 per million per year. Interestingly, the annual incidence rate (AIR) of childhood acute leukemia from the catchment area of DSH significantly increased from 35 in 1999 to 70 in 2009 (ANOVA, P = 0.003). The YSP population data, analyzed separately, showed an increase in AIR from 15.7 to 32.9 (ANOVA, P = 0.325) and an AAIR of 28.8. Remarkably, a relatively high frequency (25.5% in DSH and 27.7% in YSP) of children with AML was found in the group of acute leukemias. The DSH incidence calculations may be overestimated due to an underestimation of the population number. Since the population count for YSP is more precise, the data of YSP were used for comparison with developed countries. AAIR of ALL (20.8) is relatively low compared to Western countries (22.4-37.9). The AAIR of AML (8.0) is similar to Western countries (5.0-8.0) resulting a relatively high percentage of AML versus ALL (27.7%) in YSP.

Ultraviolet B and Incidence Rates of Leukemia Worldwide

Recent research has suggested a relationship between vitamin D deficiency and risk of leukemia. Using data from the UN cancer database, GLOBOCAN, this study will determine whether a relationship exists for latitude and ultraviolet B (UVB) irradiance with incidence rates of leukemia in 175 countries. Multiple regression was used to analyze the independent association between UVB and age-adjusted incidence rates of leukemia in 139 countries in 2002. This study controlled for dietary data on intake of energy from animal sources and per capita healthcare expenditures. The analyses were performed in 2009. People residing in the highest-latitude countries had the highest rates of leukemia in both men (R(2)=0.34, p<0.0001) and women (R(2)=0.24, p<0.0001). In men, UVB was independently inversely associated with leukemia incidence rates (p≤0.001), whereas animal energy consumption (p=0.02) and per capita healthcare expenditures (p≤0.0001) were independently positively associated (R(2) for model=0.61, p≤0.0001). In women, UVB adjusted for cloud cover was independently inversely associated with leukemia incidence rates (p≤0.01), whereas animal energy consumption (p≤0.05) and per capita healthcare expenditures (p=0.0002) were independently positively associated (R(2) for model=0.51, p<0.0001). Countries with low UVB had higher age-adjusted incidence rates of leukemia. This suggests the possibility that low serum 25-hydroxyvitamin D status, because of lower levels of UVB, somehow might predict the development of leukemia.

A retrospective study of leukemia epidemiology in Northern Tunisia

A hospital-based epidemiological study of leukemia was carried out in the northern part of Tunisia during a 5-year period, from 1999 to 2003. Of 402 Tunisians diagnosed with leukemia, 344 (85·6%) had acute leukemia and 58 (14·4%) had chronic leukemia. Age-specific incidence rates for acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), chronic lymphoid leukemia (CLL) and chronic myeloid leukemia (CML) are described. The distribution of leukemia in the governorate of Nabeul was established. These results are useful for the organization and follow-up of medical care.

CREB and Leukemogenesis

Acute myeloid leukemia (AML) is one of the most common leukemias with a 20% 5-year event-free survival in adults and 50% overall survival in children, despite aggressive chemotherapy treatment and bone marrow transplantation. The incidence and mortality rates for acute leukemia have only slightly decreased over the last 20 years, and therefore greater understanding of the molecular mechanisms associated with leukemic progression is needed. To this end, a number of transcription factors that appear to play a central role in leukemogenesis are being investigated; among them is the cAMP response element binding protein (CREB). CREB is a transcription factor that can regulate downstream targets involving in various cellular functions including cell proliferation, survival, and differentiation. In several studies, the majority of bone marrow samples from patients with acute lymphoid and myeloid leukemia demonstrate CREB overexpression. Moreover, CREB overexpression is associated with a poor outcome in AML patients. This review summarizes the role of CREB in leukemogenesis.

Childhood leukemia incidence in Brazil according to different geographical regions

Resource-rich countries tend to have a higher incidence of childhood acute lymphoblastic leukemia (ALL), whereas lower rates are seen in more deprived countries. This study describes the incidence of childhood acute leukemia in Brazil, an upper middle-income country, based on data from 16 population-based cancer registries (PBCRs). Data were examined from 16 PBCRs in Brazilian cities located in five geographical regions during the period from 1997 to 2004. Incidence rates were analyzed according to gender, age, and type of leukemia. The Wilcoxon test was performed to evaluate for gender-age based difference between by leukemia type. The median age-adjusted incidence rate (AAIR) of leukemia in children aged 0-14 years old was 53.3 per million. A different AAIR was found regarding ALL and myeloproliferative disorders (MPD) that ranged from 24.8 to 76.84 per 1,000,000 children. Manaus, although located in a poor area of Brazil, exhibited the highest AAIR (56.6 per million) of ALL. Goiania had the highest AAIR (24.5 per million) of MPD. The median age-specific incidence rate (ASIR) for the 16 Brazilian PBCRs demonstrated a marked peak in incidence of ALL at age 3 years old, in both genders. This population-based study of childhood leukemia demonstrates that substantial regional differences exist regarding the incidence of acute leukemia in Brazil, which warrants further ecological study.

Significant Recent Declines In Adult Leukemia Incidence Rates In the United States

AbstractAbstract 873Each year in the United States, approximately 45,000 individuals are newly diagnosed with leukemia and 22,000 will die of the disease. Due to this poor survival, leukemia ranks fifth in person years of life lost among specific cancers. Little is known about causes, although exposure to solvents, radiation, pesticides and, to a modest extent, cigarette smoke has been implicated for some subtypes. The last comprehensive report of leukemia trends covered the period 1973–1998 [Xie Y et al, Cancer 2003]. Evaluation of recent leukemia incidence trends could provide important new etiologic insights.Using Surveillance, Epidemiology and End Results (SEER) Program data, we analyzed leukemia incidence trends in U.S. adults (≥ 20 years of age) by age, leukemia subtype (acute myeloid (AML), acute lymphoid (ALL), chronic myeloid (CML), chronic lymphoid (CLL)) sex, race, and ethnicity for the period 1987–2007. Frequencies, age-adjusted incidence rates (IR, per million), and trends were calculated along with annual percent change (APC) and corresponding 95% confidence intervals (CI). Joinpoint analyses were used to detect any significant directional changes in IRs over the period.Of 43,970 newly diagnosed cases identified, IRs increased with age and were consistently higher in males than females for all four subtypes. The highest IRs occurred for CLL (54.4), followed by AML (38.3), CML (20.6) and ALL (7.0). With regard to trends, IRs for CLL (APC -0.5; CI: -0.9, -0.1) and CML (APC -1.2; CI: -1.6, -0.8) declined over the time period; declines were observed in males and females, and by race and ethnicity. Male(M):Female(F) IR ratios remained relatively constant at approximately 2.0 and 1.7, respectively. For ALL, IRs decreased in males (APC -0.9; CI: -1.9, 0.2) but slightly increased in females (APC 0.4; CI: -1.0, 1.7), which was most notable in Hispanics (APC 4.0; CI: 1.2, 6.8). In contrast to CML and CLL, the overall M:F rate ratio for ALL decreased, although it did not reach statistical significance (p=0.08). For AML, IRs increased significantly for males (APC 1.0; CI: 0.3,1.6) and females (APC 1.7; CI: 0.7, 2.7) from 1987–2000 and 1987–2001, respectively. However, since then, AML IRs for males have been significantly decreasing by 4.2% per year (CI: -6.4, -2.1), while IRs for females have been decreasing by 1.6% per year (CI: -4.1, 0.9). Across the entire time period 1987–2007, there was a statistically significant negative trend (p=0.002) in the M:F IR ratio for AML.Decreasing IRs across many leukemias since 1987 are unlikely to reflect changes in screening or diagnostic coding practices. Instead, these observations may reflect temporal changes in etiologically relevant environmental exposures. Of note, the prevalence of cigarette smoking in the population has decreased and occupational safety practices (e.g., reducing solvent/radiation/pesticide exposure) have improved over the last several decades, which could contribute to the gradual decreases in some IRs observed. In contrast, the rapid and significant decrease noted for AML since 2000, especially following a significant increase, was striking and deserved additional scrutiny. We further consulted with our cancer registry colleagues to determine whether the introduction of myelodysplastic syndrome (MDS) as a new malignancy in SEER in 2001 could be influencing recent AML trends given the (apparently) coincidental overlap in time periods. Of note, approximately one third of MDS patients subsequently develop AML. We learned that AML following an MDS diagnosis from 2001–2009 was not reportable to SEER and therefore not counted. We are not aware that this has been documented in the literature. However, beginning for 2010 diagnoses, SEER changed this practice such that AML following MDS will be captured as a second malignancy. Based on these changes in AML surveillance, it will especially be important to monitor future trends for this malignancy. Overall, this study demonstrates the value of in-depth analyses of SEER cancer IRs and trends; analyses may reveal patterns of clinical and/or etiological importance, or, in the instance of AML, unpublished coding rule changes. Disclosures:No relevant conflicts of interest to declare.

Comparison of NTP Historical Control Tumor Incidence Rates in Female Harlan Sprague Dawley and Fischer 344/N Rats

The National Toxicology Program (NTP) has historically used Fischer 344/N (F344/N) rats for the majority of its bioassays. Recently the NTP began using the Harlan Sprague Dawley (SD) as the primary rat model for NTP studies. The NTP had previously used female SD rats in nine bioassays. This article compares historical control (HC) tumor incidence rates from these nine SD rat studies with HC tumor rates from matched NTP F344/N rat bioassays to identify similarities and differences. Matching on sex, laboratory, diet, and route led to nine comparable F344/N rat studies. Our analyses revealed statistically significant strain differences, with female SD rats having lower incidence rates for clitoral gland adenoma (0.2% vs. 5.8%) and mononuclear cell leukemia (0.9% vs. 16.7%) and higher incidence rates for mammary gland fibroadenoma (67.4% vs. 48.4%), mammary gland carcinoma (10.2% vs. 2.4%), and thyroid gland C cell adenoma (25.4% vs. 13.6%) relative to female F344/N rats. These represent five of the seven most common tumor types among female SD and F344/N rats in the NTP HC database. When vehicle was included as an additional matching criterion, the number of comparable F344/N rat studies dropped to four, but similar results were obtained.

Childhood Cancer in Iran

This study tries to define the incidence, survival, and risk factors of childhood cancer in Iran. A literature review on published articles was conducted by using different search engine from November 1974 to October 2008. The incidence rate of childhood cancer in Iran was 48 to 112 and 51 to 144 per million among girls and boys in multi geographical settings, respectively. The most common cancer in children from 0 to 14 years old were leukemia (incidence rate=8 to 62/million), lymphoma (3 to 23), and central nervous system tumors (3 to 22). The mortality rate of childhood cancers was 42 and 49 per million among girls and boys, respectively in 2004. A positive association between ABO blood groups, family history of cancer, drug usage during pregnancy, fathers' job, history of radiation, and parental smoking habit were found with childhood leukemia. It is essential that the effect of geographical differences on childhood cancer incidence rates and high mortality rate to be investigated in future studies.

An epidemiological investigation of leukemia incidence between 2003 and 2007 in Nanjing, China

BackgroundThere has been little literature about leukemia epidemiology in Nanjing in recent years. We aimed to explore the incidence rate, gender and age distribution of leukemia in Nanjing using the leukemia database of the city.ResultsThe average yearly incidence rate of leukemia was 3.68/105 during 2003 - 2007 in Nanjing. There were no significant difference in gender (x2 = 3.266, p > 0.05) or seasons (x2 = 11.36, p > 0.05). The incidence rate was the highest in group aged 80~ years (18.64/105). AML accounted for approximately 36.8% of all leukemias.ConclusionsThe incidence rate of leukemia, especially in the aged population, was relatively high in Nanjing. Leukemia is the major malignant tumor in children. Therefore, more attention should be paid to leukemia in children and the aged people.

Gender Differences in Incidence Rates of Childhood B-Precursor Acute Lymphocytic Leukemia in Mississippi

The authors studied pediatric patients with B-precursor acute lymphocytic leukemia (ALL) to determine whether Mississippi's gender incidences correlate with national statistics. Furthermore, data on gender incidences in each of the risk categories of low, standard, and high were collected. A retrospective chart review was performed of pediatric B-precursor ALL patients diagnosed at the Children's Cancer Clinic at the University of Mississippi Medical Center from 1995 to 2005. The gender incidences in Mississippi were found to be comparable with the national average for ALL (1.34:1 vs 1.3:1) overall. However, the national average includes T-cell ALL, which is known to be significantly more prevalent in boys. Of greater significance, boys were noted to present with high-risk B-precursor ALL 4 times more than girls, suggesting the need for further investigation into possible causes of this phenomenon.

Evaluation of childhood acute leukemia incidence and underreporting in Brazil by capture–recapture methodology

Background: Population-based cancer registries (PBCR) are important in cancer epidemiology as they provide the basis for monitoring cancer incidence. Childhood acute lymphoblastic leukemia (ALL) is said to have lower incidence in developing countries, which has implications for its pathogenesis, but there are few studies concerning the completeness of cancer registries in developing countries. This study analyzes the number of cases and incidence of childhood acute lymphoblastic leukemia in three different cities in Brazil and estimates underreporting cases and possible PBCR failures. Methods: We evaluated the completeness of PBCR and the incidence rates of childhood ALL from three different Brazilian cities using the two-source capture–recapture method. The sources used were a population-based registry and databases from a diagnosis reference laboratory in 2001 and the Chapman's formula was used to calculate the estimates. Results: The estimated incidence was 5.76, 6.32 and 5.48 per 100,000 inhabitants for Salvador, Recife and Belo Horizonte, respectively. The estimated completeness of childhood ALL in PBCRs was 15.5%, 35.4% and 29.2%, respectively, for Salvador, Recife and Belo Horizonte. Conclusions: There was a high estimated underreporting of childhood leukemia cases in some Brazilian cities. The relationship between information systems and the capture–recapture method application improved epidemiological estimates. Childhood acute lymphoblastic leukemia incidence rates are similar to those of developed countries.

Cancer incidence among children and adolescents in Brazil: First report of 14 population‐based cancer registries

The Brazilian Population-Based Cancer Registry (PBCR) was started in 1967; today there are 20 PBCRs in Brazil. We report the first descriptive analysis of the incidence of childhood cancer based on data from 14 PBCRs, corresponding to 15% of the child and adolescent population in Brazil. Data were obtained from registry databases, including information on population coverage and data quality indicators. The International Classification of Childhood Cancer was used. Age-adjusted rates were calculated by world population. Incidence by cancer registry, age, sex, and cancer type were calculated per 1,000,000 children. Age-adjusted rates per 1,000,000 children/adolescents ranged from 92 to 220 among the 14 PBCRs. The principal groups of cancers were leukemia, lymphoma and central nervous tumors. The median incidence rate of childhood cancer in the 14 PBCRs was 154.3 per million; children 1-4 years of age had the highest incidence rates. The Brazilian PBCRs provide important information about pediatric cancer incidence in an emerging country. The observed incidence rates of childhood leukemia were similar to previous reported rates, and the age-specific incidence rates of retinoblastoma (0-4 years of age) were higher than those for developed countries. These data can be used as baseline incidence rates of childhood and adolescent cancer in Brazil in future epidemiological studies.

Trends in adult leukemia incidence and survival in Denmark, 1943–2003

The etiology of leukemia is largely unknown. Ecological data indicating trends in incidence and survival can provide information about changes in risk factors, can reflect underlying changes in diagnostic classification, and can measure therapeutic advances. From the records of the Danish Cancer Registry with registration starting from 1943, we calculated age-specific, period-specific, and age-standardized (world standard) incidence rates of chronic lymphoid leukemia (CLL), acute lymphoid leukemia (ALL), chronic myeloid leukemia (CML), and acute myeloid leukemia (AML) for persons above the age of 18. Kaplan-Meier survival curves and median survival times were calculated. Between 1943 and 2003, there were 26,036 cases of leukemia reported. The age-specific incidence rates of CLL, CML, and AML were higher for older men and women, while the incidence rates of ALL by age were more homogeneous. The age-standardized incidence rates during the study period increased for CLL and AML, increased less strongly for ALL, and decreased for CML in both men and women, although the incidence rates for women were almost always lower. Patients with CLL had the longest survival time in all age groups. The median survival time increased for all leukemia subtypes throughout the period of study most pronounced for CLL since 1950 and CML since 1990.

Geographical variations in the incidence of childhood acute leukaemia in France over the period 1990–2004

Spatial variations in childhood acute leukaemia (AL) incidence rates were investigated by département, in mainland France, over the period 1990-2004. This is the first spatial study of this incidence to cover a 15-year period. French National Registry of Childhood Haematological Malignancies data and population counts by type of leukaemia (AL, acute lymphoblastic leukaemia, acute myeloblastic leukaemia), time period (1990-2004, 1990-1994, 1995-1999 and 2000-2004), sex, and age group (0-14, 0-4, 5-9 and 10-14 years of age) were considered. The overall homogeneity of the relative risks of leukaemia was tested, as well as comparison to 1 of each relative risk by the exact Poisson test. To give a more stable estimate of the underlying relative risk pattern than that provided by the local standardized incidence ratios (SIRs), Bayesian hierarchical models using four different spatial priors have been produced: the parametric BYM and CAR models, and two semiparametric models. Very slight overall heterogeneity was observed on the whole AL data set (SIR overdispersion 18.6%, P=0.10). Irrespective of the model, the ranges of the smoothed SIRs exhibited considerable shrinkage relative to the ranges of the local SIRs. The associated maps were slightly heterogeneous; the smoothed SIRs of overall acute lymphoblastic leukaemia of the south-west départements were slightly higher than those of the north-east. The results, however, did not remain stable when investigated by leukaemia type, time period, sex or age group. No spatial heterogeneity of childhood AL incidence on the département scale was observed but that does not exclude spatial heterogeneity on other scales.

Re: BAKER P.J. &amp; HOEL D.G. (2007)European Journal of Cancer Care16, 355-363. Meta-analysis of standardized incidence and mortality rates of childhood leukaemia in proximity to nuclear facilities

Re: BAKER P.J. &amp; HOEL D.G. (2007)<i>European Journal of Cancer Care</i>16, 355-363. Meta-analysis of standardized incidence and mortality rates of childhood leukaemia in proximity to nuclear facilities

Changes in cancer incidence in teenagers and young adults (ages 13 to 24 years) in England 1979‒2003

Cancer for teenagers and young adults represents a major source of morbidity and mortality. Trends in cancer incidence can provide pointers concerning how changes in the environment and in personal behavior affect cancer risks. Data on 39,129 neoplasms in individuals ages 13 to 24 years who were diagnosed in England from 1979 to 2003 were analyzed. Variability in incidence by time period and differences in the time trends by age group, sex, and geographic region were analyzed using generalized linear models. Incidence rates of leukemias, lymphomas, central nervous system, bone, and germ cell tumors; melanoma; and carcinomas of the thyroid, ovary, cervix, and colon/rectum increased over time (all P < .01); whereas the incidence of carcinomas of the stomach and bladder decreased (both P < .01). These changes were consistent by age, sex, and region for most neoplasms. Melanoma incidence stabilized in southern England by 1993 but continued to increase in northern England (P = .001). The increase in non-Hodgkin lymphoma was greater in individuals ages 20 to 24 year than in younger individuals, but the increase in Hodgkin lymphoma was confined to individuals ages 13 to 14 years. The changes in incidence rates may have been caused in part by environmental changes and in part by behavioral changes in young individuals. Some of these results can be used to inform public health campaigns, which can be constructed to encourage better lifestyle choices by young individuals.

Herpes Simplex Virus Type 1 Promoted the Possibility of Leukemia Caused by L6565 Murine Leukemia Virus

Herpes Simplex Virus Type 1 (HSV-1) is a virus commonly existent in nature. Others reported that herpesvirus DNA probably activates type C virus in vitro. L6565 Murine Leukemia Virus (L6565 MuLV) is a kind of virus inducing the murine Leukemia. The main aim of the study was to explore the activation of HSV-1 to the pathogenicity of L6565 MuLV in vivo. Suckling mice were inoculated with either L6565 MuLV & inactivated HSV-1, or L6565 MuLV alone. In order to determine the infection of the mice, HE staining and RT-PCR techniques were applied. The result shows that the L6565 MuLV RNA was detected in 8 th week in the mice of MuLV plus HSV-1 group, while delayed to 10 th week in the L6565 MuLV alone group. The infection rates of the two groups were 74.3% and 41.7%, respectively. Also, L6565 MuLV RNA was detected in the thymus one week after the inoculation, and it was detected in both thymus and spleen two weeks after inoculation. It is obvious that HSV-1 promoted the infection of L6565 MuLV and increased the incidence rate of murine leukemia induced by L6565 MuLV.

Meta-analysis of standardized incidence and mortality rates of childhood leukaemia in proximity to nuclear facilities

The meta-analysis combined and statistically analysed studies of childhood leukaemia and nuclear facilities. Focus was on studies that calculated standardized rates for individual facilities. Due to variability between study designs, eight separate analyses were performed stratified by age and zone. One hundred and thirty-six sites were used in at least one analysis. Unadjusted, fixed effects and random effects models were used. Meta-rates greater than one were found in all models at all stratification levels often achieving statistical significance. Caution must be used when interpreting these results. The meta-analysis was able to show an increase in childhood leukaemia near nuclear facilities, but does not support a hypothesis to explain the excess. Each type of model utilized has limitations. Fixed effects models give greater weight to larger studies; however, population density may be a risk factor. Random effects models give greater weight to smaller studies that may be more likely to be affected by publication bias. A limitation of the overall study design is that standardized rates must be available for individual sites which led to exclusion of studies that only calculated rates for multiple sites and those that presented other statistical methods. Further, dose-response studies do not support excess rates found near nuclear facilities. However, it cannot be ignored that the majority of studies have found elevated rates, although not usually statistically significant.