The causes of acute leukemia

Although impressive biologic advances have increased understanding of leukemogenesis, we know little about the causes of the acute leukemias. Epidemiologic studies have focused primarily on children. Higher birth weight is associated with an increased risk of childhood acute leukemia. Several theories have been advanced that may account for these observations, and additional biologic studies are needed. Some epidemiologic studies suggest that the acute leukemias in children may have an infectious component. Again, further work, especially in the area of specific causative agents, is necessary. Another area for future epidemiologic study includes investigation of exposure to natural and synthetic DNA topoisomerase II inhibitors. Preliminary evidence suggests that exposure to these agents, which are found in certain foods and medications, may be related to the subsequent development of acute leukemia in infants.

Relationship of serum levels of interleukin-6, soluble interleukin-6 receptor and tumour necrosis factor receptors to the acute-phase protein response in advanced pancreatic cancer

The level of the acute-phase response is a major predictor of survival in patients with advanced pancreatic cancer. This study examines the association between the acute-phase protein response, as determined by serum C-reactive protein, and serum levels of interleukin-6, soluble interleukin-6 receptor and the soluble tumour necrosis factor receptors in patients with pancreatic cancer. Thirty-four blood samples were collected from 13 patients with advanced pancreatic cancer. Samples were also collected from six healthy subjects. Levels of C-reactive protein, interleukin-6, soluble interleukin-6 receptor and soluble tumour necrosis factor receptors 55 and 75 were measured by indirect ELISA. Serum levels of C-reactive protein, interleukin-6 and soluble tumour necrosis factor receptors 55 and 75 were significantly higher in cancer patients than in controls. Levels of serum soluble interleukin-6 receptor were not significantly different between the two groups. In cancer patients, a significant positive association was found between the level of the acute-phase protein response and serum levels of interleukin-6, soluble tumour necrosis factor receptor 55 and soluble tumour necrosis factor receptor 75. No association was found between levels of soluble interleukin-6 receptor and any other factor. There is no significant relationship between the level of soluble interleukin-6 receptor and the acute-phase protein response in vivo and the biological role of soluble interleukin-6 receptor in the chronic inflammatory component of cachexia remains unclear.

Epidemiologic studies of childhood leukemia: where do we go from here?

Much of our knowledge of the mechanisms of carcinogenesis has resulted from the study of rare cancers, including retinoblastoma, angiosarcoma, and vaginal clear cell carcinoma. Due to the heterogeneity of childhood leukemia, epidemiologic studies that focus on children with unique clinical and genetic manifestations of the disease could potentially lead to further understanding of leukemogenesis.

Lung tumorigenic interactions in strain A/J mice of five environmental polycyclic aromatic hydrocarbons

The binary, ternary, quaternary, and quintary interactions of a five-component mixture of carcinogenic environmental polycyclic aromatic hydrocarbons (PAHs) using response surface analyses are described. Initially, lung tumor dose-response curves in strain A/J mice for each of the individual PAHs benzo[a]pyrene (B[a]P), benzo[b]fluoranthene (B[b]F), dibenz[a,h]anthracene (DBA), 5-methylchrysene (5MC), and cyclopenta[cd]pyrene (CPP) were obtained. From these data, doses were selected for the quintary mixture study based on toxicity, survival, range of response, and predicted tumor yields. The ratios of doses among PAHs were designed to simulate PAH ratios found in environmental air and combustion samples. Quintary mixtures of B[a]P, B[b]F, DBA, 5MC, and CPP were administered to male strain A/J mice in a 2(5) factorial 32-dose group dosing scheme (combinations of five PAHs each at either high or low doses) and lung adenomas were scored. Comparison of observed lung adenoma formation with that expected from additivity identified both greater than additive and less than additive interactions that were dose related i.e., greater than additive at lower doses and less than additive at higher doses. To identify specific interactions, a response surface analysis using response addition was applied to the tumor data. This response surface model contained five dose, ten binary, ten ternary, five quaternary, and one quintary parameter. This analysis produced statistically significant values of 16 parameters. The model and model parameters were evaluated by estimating the dose-response relationships for each of the five PAHs. The predicted dose-response curves for all five PAHs indicated a good estimation. The binary interaction functions were dominated for the most part by DBA and were inhibitory. The response surface model predicted, to a significant degree, the observed lung tumorigenic responses of the quintary mixtures. These data suggest that although interactions between PAHs do occur, they are limited in extent.

Effect of interleukin-4 on pro-inflammatory cytokine production and the acute phase response in healthy individuals and in patients with cancer or multiple organ failure

1. This study investigates whether previously documented effects of interleukin-4 in down-regulating pro-inflammatory cytokine production by peripheral blood mononuclear cells (PBMCs) from healthy individuals would be reproducible in PBMCs isolated from patients with multiple organ failure (acute disease model) and gastrointestinal cancer (chronic disease model). The effects of interleukin-4 on the ability of PBMC supernatants to elicit an acute phase protein response from isolated human hepatocytes were also studied. 2. Incubation of PBMCs with interleukin-4 significantly reduced both spontaneous and lipopolysaccharide-induced production of tumour necrosis factor and lipopolysaccharide-induced interleukin-6 production, demonstrating that the PBMCs from patients with acute and chronic disease are not refractory to the effects of interleukin-4. The effects of interleukin-4 on the ability of PBMCs from the groups studied to elicit an acute phase response were complex and varied both between patient groups and individual acute phase proteins. Overall, interleukin-4 reduced the potential of PBMCs to stimulate production of the positive acute phase proteins C-reactive protein, alpha1-antichymotrypsin and alpha1-acid glycoprotein.3. This work emphasizes the pleiotropic nature of cytokines and the complex regulatory mechanisms which exist. The study illustrates the difficulties in devising in vivo intervention strategies using cytokines such as interleukin-4.

Mechanistic relationships between DNA adducts, oncogene mutations, and lung tumorigenesis in strain A mice

This paper describes a series of studies on the lung tumorigenic activities of polycyclic aromatic hydrocarbons (PAHs) in strain A/J mice, their ability to form PAH-DNA adducts in lung tissues, and their ability to mutate the Ki-ras oncogene in PAH-induced tumors. Seven PAHs were studied: cyclopenta[cd]pyrene (CPP), benzo[a]pyrene (B[a]P), benzo[b]fluoranthene (B[b]F), dibenz[a,h] anthracene (DBA), 5-methylchrysene (5MC), benz[j]aceanthrylene (B[j]A), and dibenzo[a,l]pyrene (DB[a,l]P). The dose-response data for the PAHs revealed 100-fold differences in tumor potency based on dose, with the order of activity DB[a,l]P, DBA > B[j]A > 5MC > CPP B[a]P > B[b]F. Large differences in tumor multiplicity were also observed between the PAHs. DNA adducts were measured by 32P-postlabeling techniques on DNA from lungs of mice treated with these PAH's. DB[a,l]P gave syn- and anti-fjord-region diol-epoxide adducts of dAdo and dGuo; DBA gave both bay-region diol-epoxide-dGuo and bisdihydrodiol-epoxide adducts; CPP gave cyclopenta-ring-dGuo adducts; B[j]A gave a mixture of cyclopenta-ring-dGuo and -dAdo adducts; 5MC gave anti-bay-region diol-epoxide-dGuo adducts; B[a]P gave bay-region diol-epoxide-dGuo adducts; and B[b]F gave 5-hydroxy-B[b]F-diol-epoxide-dGuo adducts. Ki-ras codon 12 and 61 mutation analysis of PAH induced tumors was performed using PCR and dideoxy sequencing methods. DB[a,l]P gave both codon 12 and codon 61 mutations. High proportions of codon 12 TGT mutations from B[a]P-, B[b]F- and 5MC-, induced tumors and CGT mutations from CPP- and B[j]A-induced tumors were observed. DBA produced no mutations in Ki-ras codons 12 or 61 by direct sequencing. The interrelationships between the tumorigenesis, DNA adduct, and oncogene mutation data are discussed.

Expectant management of missed miscarriage

The option of expectant management was offered 221 women with ultrasound diagnosis of missed miscarriage. Eighty-five women (38%) accepted; the remaining 136 women chose surgical evacuation of retained products of conception. In the expectant management group 21 women (24.7%) had a complete miscarriage, 14 (16.5%) had incomplete miscarriage necessitating surgery, and 50 (58.8%) requested surgery within 48 days from the original diagnosis. These results suggest that the success of expectant management of missed miscarriage is too low to justify its use in routine clinical practice.

Proinflammatory mediator activity, endogenous antagonists and the systemic inflammatory response in intra-abdominal sepsis. Scottish Sepsis Intervention Group

BACKGROUND

Severe intra-abdominal sepsis continues to carry a high mortality rate. The physiological response to sepsis in this condition and its relationship with proinflammatory mediators and their endogenous antagonists require further clarification.

METHODS

Fifty-seven patients were stratified by Acute Physiology And Chronic Health Evaluation (APACHE) II score at the time of admission to an intensive care unit (group 1, score of less than 20; group 2, score of 20 or more). Serial measurements of clinical and immunological variables were made.

RESULTS

Non-survivors from group 2 had a raised acute physiology score (P = 0.01), a higher peak serum interleukin (IL) 6 concentration (P = 0.03) and a depressed level of endogenous immunoglobulin (Ig) G class antiendotoxin core antibody (P = 0.005). In group 1, although organ failure score increased progressively in non-survivors, physiology score and peak IL-6 level were similar to those in survivors, and endogenous IgG class antiendotoxin core antibody titre rose (P = 0.02). In both groups IL-1 and tumour necrosis factor alpha were detected infrequently, but their natural antagonists were present in much higher concentrations in both survivors and non-survivors. Levels of C-reactive protein were raised in both but were not significantly different between survivors and non-survivors.

CONCLUSION

During the development of organ failure and death, the pattern of proinflammatory mediators and their endogenous antagonists can vary markedly and may in part be determined by the extent of the initial physiological disturbance.

Voice disorders in patients with suspected laryngo-pharyngeal reflux disease

Many symptoms have been recognized in association with laryngo-pharyngeal reflux disease (LPRD), but reports of perceptual voice disorders in this condition have been lacking to date. Forty-nine patients with suspected LPRD were studied for five specific perceptual voice characteristics, and these characteristics were compared to the same characteristics in individuals who had never seen an Otolaryngologist for a voice disorder or throat problem (controls). Sixteen of the suspected LPRD patients also underwent 24-hour pH probe studies. All patients with suspected LPRD had significantly increased abnormal perceptual voice characteristics (musculoskeletal tension, hard glottal attack, glottal fry, restricted tone placement, and hoarseness) compared to the controls. Statistical objective differences between the two groups was demonstrated by the presence of increased shimmer in patients with suspected LPRD compared to controls. The differential diagnosis between functional voice disorders and LPRD may be complex, and perceptual parameters may overlap. Interdisciplinary evaluation is advocated.

Pro-inflammatory cytokine release and mediation of the acute phase protein response in fulminant hepatic failure

OBJECTIVE

To study the relationship between interleukin-6 (IL-6), tumour necrosis factor (TNF) and the acute phase protein C-reactive protein (CRP) in patients with fulminant hepatic failure (FHF) and to investigate the potential of peripheral blood mononuclear cells (PBMC) isolated from these patients to stimulate CRP production by isolated human hepatocytes in vitro.

SETTING

Patients with FHF were studied at the time of their admission to the intensive care unit.

STUDY DESIGN

Serum TNF and IL-6 were measured in 12 patients with FHF, PBMC from 6 of these patients were then cultured in the presence and absence of lipopolysaccharides (LPS). TNF and IL-6 in serum and supernatants were measured by ELISA. PBMC supernatants were added to isolated human hepatocytes and CRP production was measured.

RESULTS

Serum IL-6 (348 +/- 172 pg/ml) and TNF (118.5 +/- 15.5 pg/ml) were elevated compared with healthy controls (not detected) and these observations were matched by elevated serum CRP in patients with FHF (38.9 +/- 7 mg/l). Both the production of IL-6 and TNF by PBMC isolated from patients with FHF and the potential of supernatants from these cells to stimulate CRP production by hepatocytes in vitro was significantly reduced compared with controls.

CONCLUSION

Despite the observation that patients with FHF have an elevated hepatic acute phase response, PBMC from patients with FHF have reduced potential to produce IL-6 and TNF and elicit an acute phase response in vitro by the time of patient admission to the intensive care unit. One explanation for this observation is early activation and exhaustion of PBMC in vivo.

Hepatoblastoma incidence in the United States from 1973 to 1992

BACKGROUND

There is recent evidence to suggest that extremely low birth weight is associated with the occurrence of hepatoblastoma.

PROCEDURE

In light of this possibility, we evaluated trends in hepatoblastoma incidence in the United States among children age 4 years and younger.

RESULTS

We found an increasing trend (5.2%) in hepatoblastoma incidence over the past two decades, a period that corresponds with improved survival of very low birth weight children.

CONCLUSION

Future studies of hepatoblastoma that incorporate birth weight are appropriate.

Induction of mutations by 2-acetylaminofluorene in lacI transgenic B6C3F1 mouse liver

Mutations induced in liver cells by the hepatocarcinogen 2-acetylaminofluorene (2-AAF) were characterized after i.p. administration on 4 consecutive days at 100 mg/kg per injection in male B6C3F1 Big Blue transgenic mice that harbored the Escherichia coli lacI reporter gene. Animals were sacrificed at 5, 10 or 60 weeks following the last injection, livers removed and DNA packaged in vitro into bacteriophage lambda particles. The bacteriophage were assayed for lacI function by plating on E. coli in the presence of X-gal. Approximately 3 x 10(5) plaques were assayed per animal. Solvent-treated control mice exhibited a slight increase in mutant frequency over time, from 3.93 x 10(-5) at 5 weeks to 5.02 x 10(-5) at 60 weeks. In contrast, treatment with 2-AAF yielded an approximately 2-fold increase in mutant frequency at 5 and 10 weeks after treatment relative to controls, with frequencies of 8.13 x 10(-5) and 7.43 x 10(-5) respectively. However, by 60 weeks post-treatment the mutant frequency was not significantly increased over concurrent controls. Similar to results in other systems, 2-AAF induced predominantly single base changes targeted to G:C base pairs, primarily G:C-->T:A transversions (27%). In contrast to results in other bacterial and eukaryotic systems, no deletions were observed among the 2-AAF-induced mutations and the 4 base hot spot deletion that is frequently observed in lacI in E. coli was not observed in this system, suggesting that the lacI transgene may be relatively refractory to frameshift mutations in vivo in the mouse.

Glutamine-supplemented total parenteral nutrition reduces blood mononuclear cell interleukin-8 release in severe acute pancreatitis

Glutamine, a conditionally essential amino acid, is important for immune function. It is now being formulated for incorporation into total parenteral nutrition (TPN). The aims of this study were to examine the effect of glutamine administration on lymphocyte proliferation and proinflammatory cytokine release in patients with severe acute pancreatitis. Fourteen patients were randomized (in a double-blind fashion) to receive either conventional or isocaloric, isonitrogenous glutamine-supplemented (0.22 g glutamine x kg(-1) x d(-1) as glycyl-glutamine) TPN for 7 d. DNA synthesis (index of lymphocyte proliferation) and the 24-h release of tumor necrosis factor (TNF), interleukin (IL)-6, and IL-8 from peripheral blood mononuclear cells were measured in vitro on days 0, 4, and 7. Thirteen patients completed the study protocol (6 glutamine TPN, 7 conventional TPN). Glutamine supplementation increased median DNA synthesis by 3099 cpm over the study period against 219 cpm in the conventional group (increase not significantly different between the two groups) . Glutamine supplementation did not significantly influence TNF or IL-6 release, but, in contrast, median IL-8 release was reduced by day 7 in the glutamine group while it was increased in the conventional group (-17.7 ng/mL (median change over study period) versus +43.3 ng/mL, respectively; P=0.045). Small patient numbers and substantial interindividual variation limit the conclusions, but there is a trend for the glutamine group to have improved lymphocyte proliferation, and in the case of IL-8, reduced proinflammatory cytokine release.

Albumin synthesis rates are not decreased in hypoalbuminemic cachectic cancer patients with an ongoing acute-phase protein response

OBJECTIVE

To determine whether suppression of albumin synthesis contributes to the hypoalbuminemia observed in weight-losing cancer patients with evidence of an ongoing acute-phase protein response (APPR).

BACKGROUND DATA

Proinflammatory cytokines such as tumor necrosis factor (TNF) and interleukin 6 (IL-6) are known to downregulate albumin synthesis and increase acute-phase protein production in isolated hepatocytes. However, whether albumin synthesis is suppressed in hypoalbuminemic cancer patients with evidence of an ongoing acute-phase response is unknown.

METHODS

Albumin synthesis rates were determined in six healthy controls and in six weight-losing pancreatic cancer patients with an ongoing APPR using a flooding dose technique with [2H5]-phenylalanine. The presence of an APPR was defined as a serum C-reactive protein concentration >10 mg/L. Serum cytokines (TNF, IL-6) and soluble TNF receptors (sTNF-R 55 and 75), along with serum cortisol and insulin, were also measured in both groups.

RESULTS

Cancer patients had reduced serum albumin (median 32 [range, 23-36] vs. 42 g/L [40-45]; p < 0.01) and increased serum C-reactive protein concentrations (72 [23-126] vs. <5 mg/L; p < 0.01) when compared with controls. TNF was not detected in either group. sTNF-R 55 levels were significantly elevated in the cancer patients (3.8 [1.9-8.1] vs. 1.2 pg/mL [0.9-2.2]; p < 0.01). Circulating IL-6, insulin, and cortisol concentrations were not significantly different between the groups. The intravascular albumin mass was lower (88 [56-93] vs. 133 g [105-177]; p < 0.01), but the intravascular albumin fractional synthetic rate was higher (13.9 [13.5-18.5] vs. 10.3%/d [71-11.3]; p < 0.01) in the cancer patients compared with the controls. The total intravascular albumin synthetic rate was, however, similar between the two groups (12.7 [7.7-15.7] vs. 11.7 g/d [8.5-18.7]; p NS).

CONCLUSIONS

In weight-losing pancreatic cancer patients with evidence of an ongoing APPR, hypoalbuminemia is not caused by a decreased rate of albumin synthesis.

National cancer clinical trials: children have equal access; adolescents do not

PURPOSE

To determine whether adolescents with cancer, who in comparison to younger patients have a higher cancer incidence and lower mortality reduction, have equal access to national cancer clinical trials.

METHODS

The ethnic/racial distribution of 29,859 subjects < 20 years of age entered onto National Cancer Institute-sponsored clinical trials between January 1, 1991, and June 30, 1994, was compared with the expected distribution of patients of the same age in the United States.

RESULTS

The Children's Cancer Group and Pediatric Oncology Group had 29,134 (97.6%) of the total study entries among < 20-year-old subjects during the 3.5 years of surveillance. The adult cooperative groups accounted for < 3% of the clinical trials entries in the 15-19-year age range. When analyzed nationally by region, the under-representation of the older adolescent subjects was universal. From other analyses, the two pediatric cooperative groups were estimated to have registered > 94% of the children < 15 years of age who were expected to have been diagnosed to have cancer, but only 21% of the cancer patients in the 15-19-year age group.

CONCLUSIONS

The national pediatric cancer cooperative groups allow the majority of American children < 15 years of age and their families equal opportunity to access clinical cancer trials, regardless of race or ethnicity. Among patients 15-19 years of age, however, > 75% are not being enrolled by any cooperative group sponsored by the National Cancer Institute. Thus, older adolescents are disadvantaged with respect to access to the national clinical trials, regardless of their race or ethnicity.

Women's perception. Breast cancer treatment and sexuality

PURPOSE

The authors describe women's perceptions of how their sexuality was affected by treatment for breast cancer. This description is part of a larger study that tested the psychometric properties of a sexuality measure.

DESCRIPTION OF STUDY

This exploratory study analyzed 105 women's responses to one question that asked them to describe how their sexuality had changed since their breast cancer diagnosis. Two researchers independently used content analytic procedures to identify themes that emerged from the data.

RESULTS

Four themes emerged: Physical Sexual Functioning, Relationship Quality, Psychological Self, and Self as Female. Women who had reconstructive surgery indicated that the loss of feeling in the reconstructed breast was sexually troublesome and disappointing. Comparison of the qualitative data with quantitative data (triangulation) provided support for the finding of no significant differences in sexual functioning before women treated by lumpectomy versus mastectomy.

CLINICAL IMPLICATIONS

Breast cancer affects many aspects of a woman's sexuality, including changes in physical functioning and in perception of femaleness. Informed healthcare decisions cannot be made until patients are knowledgeable about the sexual outcomes of cancer therapies. Healthcare professionals must acknowledge the scope of the impact of cancer treatment on sexuality, include such information as part of the informed consent process, and provide appropriate education and referral.