The frequency of febrile neutropenia in oncology patients receiving chemotherapy

e20691

Background:Febrile neutropenia (F/N) is a relatively common and serious side effect for oncology patients undergoing chemotherapy. Due to varying dosages and frequency of cytotoxic agents administered to oncology patients, the incidence and grade of neutropenia varies. The purpose of this study was to establish the frequency of febrile neutropenia in different chemotherapy regimens. Methods: Data was collected on 343 patients who underwent chemotherapy over a 9 month period. Regimens that caused at least one episode of febrile neutropenia in patients within that period were assessed in the study. A list of the patients on identified chemotherapy regimens during the time period was generated by the pharmacy department. Data on patients who had febrile neutropenia was obtained from their clinical notes. Clinical data was then obtained on all those patients. This information was then used to compare the frequency of febrile neutropenia in the included chemotherapy regimens. Results: 343 patients were included in this study. Of those, 41 patients developed febrile neutropenia within the 9 month period (11%); there were 49 cases of febrile neutropenia (14%) in total as some patients had more than one episode. Conclusions: Febrile neutropenia (FN) is a known potential side-effect from treatment with chemotherapy. This study highlights the rates of FN in patients treated within one centre. In patients being treated with specific chemotherapy regimens this study may guide the increased use of G-CSF and better outline the risk profile of such therapy to patients.

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No significant financial relationships to disclose.

Association studies of ALOX5 and bone mineral density in healthy adults

Animal studies suggest that arachidonate 5-lipoxygenase (encoded by ALOX5) may be a genetic determinant of bone mineral density. We tested this hypothesis in a sample of healthy men and women and did not find consistent evidence for an association between variation in this gene and either lumbar spine or femoral neck BMD.

INTRODUCTION

Phenotypic variation in bone mineral density (BMD) among healthy adults is influenced by both genetic and environmental factors. A recent mouse study implicated ALOX5, which encodes arachidonate 5-lipoxygenase, as a contributing factor to areal BMD (aBMD).

METHODS

Fifteen single nucleotide polymorphisms (SNPs) distributed throughout ALOX5 were genotyped in three healthy groups: 1,688 European American, premenopausal sisters, 512 African American premenopausal sisters and 715 European American brothers. Statistical analyses were performed in the three groups to test for association between these SNPs and femoral neck and lumbar spine aBMD.

RESULTS

Significant (p < or = 0.05) evidence of association was observed with three of the SNPs. However, despite the linkage disequilibrium between SNPs, adjacent SNPs did not provide statistical evidence of association in any of the three study groups.

CONCLUSIONS

These data do not provide consistent evidence of association between genomic variation in ALOX5 and clinical variability in aBMD in healthy subjects.

Validation of an asthma questionnaire for use in healthcare workers

BACKGROUND

Previous studies have described increased occurrence of asthma among healthcare workers, but to our knowledge there are no validated survey questionnaires with which to study this occupational group.

AIMS

To develop, validate, and refine a new survey instrument on asthma for use in epidemiological studies of healthcare workers.

METHODS

An initial draft questionnaire, designed by a multidisciplinary team, used previously validated questions where possible; the occupational exposure section was developed by updating health services specific chemical lists through hospital walk-through surveys and review of material safety data sheets. A cross-sectional validation study was conducted in 118 non-smoking subjects, who also underwent bronchial challenge testing, an interview with an industrial hygienist, and measurement of specific IgE antibodies to common aeroallergens.

RESULTS

The final version consisted of 43 main questions in four sections. Time to completion of the questionnaire ranged from 13 to 25 minutes. Test-retest reliability of asthma and allergy items ranged from 75% to 94%, and internal consistency for these items was excellent (Cronbach's alpha > or = 0.86). Against methacholine challenge, an eight item combination of asthma related symptoms had a sensitivity of 71% and specificity of 70%; against a physician diagnosis of asthma, this same combination showed a sensitivity of 79% and specificity of 98%. Agreement between self-reported exposures and industrial hygienist review was similar to previous studies and only moderate, indicating the need to incorporate more reliable methods of exposure assessment. Against the aerollergen panel, the best combinations of sensitivity and specificity were obtained for a history of allergies to dust, dust mite, and animals.

CONCLUSIONS

Initial evaluation of this new questionnaire indicates good validity and reliability, and further field testing and cross-validation in a larger healthcare worker population is in progress. The need for development of more reliable occupational exposure assessment methods that go beyond self-report is underscored.

Polymorphisms in the bone morphogenetic protein 2 (BMP2) gene do not affect bone mineral density in white men or women

INTRODUCTION

Peak bone mineral density (BMD) achieved during adulthood is a major determinant of osteoporotic fracture in later life. Although environmental factors affect peak BMD, it is a highly heritable trait. Recently, bone morphogenetic protein 2 (BMP2) was reported as a susceptibility gene for osteoporotic fractures and low BMD in Icelandic and Danish populations.

METHODS

To determine whether polymorphisms in the BMP2 gene contribute to BMD variation in our population of healthy American whites, we tested seven single nucleotide polymorphisms (SNPs), four of which were associated with osteoporotic phenotypes in the previous study. BMD at the femoral neck and lumbar spine (L2-L4) were measured by dual energy X-ray absorptiometry (DXA) in 411 men (age 18-61) and 1,291 pre-menopausal women (age 20-50). SNP genotypes/haplotypes were tested for population-based association with BMD using analysis of variance.

RESULTS

None of the polymorphisms tested reached statistical significance (all p values >0.05) for BMD at the femoral neck or lumbar spine in either gender. Two of the SNP haplotypes spanning the entire BMP2 gene were marginally associated with BMD in men (p values=0.019-0.043). However, these haplotypes would account for only a small, if any, portion of BMD variation and would not be significant after adjustment for multiple comparisons.

CONCLUSIONS

These results demonstrate that genetic variations in BMP2 do not substantially contribute to BMD variation in our population of healthy American whites.

Resistance exercise as a countermeasure to disuse-induced bone loss

During spaceflight, skeletal unloading results in loss of bone mineral density (BMD). This occurs primarily in the spine and lower body regions. This loss of skeletal mass could prove hazardous to astronauts on flights of long duration. In this study, intense resistance exercise was used to test whether a training regimen would prevent the loss of BMD that accompanies disuse. Nine subjects (5 men, 4 women) participated in a supine maximal resistance exercise training program during 17 wk of horizontal bed rest. These subjects were compared with 18 control subjects (13 men, 5 women) who followed the same bed rest protocol without exercise. Determination of treatment effect was based on measures of BMD, bone metabolism markers, and calcium balance obtained before, during, and after bed rest. Exercisers and controls had significantly (P < 0.05) different means, represented by the respective following percent changes: lumbar spine BMD, +3% vs. -1%; total hip BMD, +1% vs. -3%; calcaneus BMD, +1% vs. -9%; pelvis BMD, -0.5% vs. -3%; total body BMD, 0% vs. -1%; bone-specific alkaline phosphatase, +64% vs. 0%; alkaline phosphatase, +31% vs. +5%; osteocalcin, +43% vs. +10%; 1,25 dihydroxyvitamin D, +12% vs. -15%; parathyroid hormone intact molecule, +18% vs. -25%; and serum and ionized calcium, -1% vs. +1%. The difference in net calcium balance was also significant (+21 mg/day vs. -199 mg/day, exercise vs. control). The gastrocnemius and soleus muscle volumes decreased significantly in the exercise group, but the loss was significantly less than observed in the control group. The results indicate that resistance exercise had a positive treatment effect and thus might be useful as a countermeasure to prevent the deleterious skeletal changes associated with long-duration spaceflight.

Hearing impairment in essential tremor

OBJECTIVE

To assess hearing in patients with essential tremor (ET) vs patients with Parkinson disease (PD) and normal controls.

METHODS

The authors assessed demographic and clinical information including use of hearing aids in 250 patients with ET, 127 patients with PD, and 127 normal controls. The authors administered the Nursing Home Hearing Handicap Index (NHHI), a validated measure of hearing disability. Regression techniques were used to adjust for factors such as age and sex. The authors assessed a complete audiologic evaluation in a subset of patients with ET.

RESULTS

Patients with ET had worse adjusted NHHI scores when compared to patients with PD (p < 0.001), controls (p < 0.001), and both (p < 0.001). A higher percentage of patients with ET also used hearing aids (p < 0.0001). In the ET group, hearing loss was associated with tremor severity (p = 0.02) and tended to be associated with older age (p = 0.06), male sex (p = 0.06), and the absence of dystonia (p = 0.18). Audiology testing was consistent with high-frequency sensorineural hearing loss. Central processing was not disproportionally greater than peripheral loss.

CONCLUSION

Patients with ET have increased hearing disability compared to patients with PD and normal controls, which correlates with tremor severity.

Health care service use by Chinese seniors in British Columbia, Canada

This paper assesses whether the same factors are predictive of health service utilization among this ethnic group as is true of the general population of seniors. The data suggest that the health of Chinese elders is just as bad as other seniors, and their utilization is very similar. They have a strong preference for Western over Chinese medicine and for Western trained doctors over Chinese practitioners, and use services with Chinese staff, probably because of language. Similarly, the predictors of service use are strikingly similar to predictors revealed in utilization studies throughout the industrialized world. Ability to speak English, immigration history, and country of origin are unrelated to the use of these services. However, approximately half of Chinese seniors also engage in traditional Chinese care. Religious beliefs and a preference for traditional Chinese medicine are strongly predictive of the use of traditional care. It would appear that distinctive culture is related to the use of traditional care, but not the use of the western health care system.

Effect of follow-up time on risk estimates: a longitudinal examination of the relative risks of leukemia and multiple myeloma in a rubber hydrochloride cohort

BACKGROUND

Choice of follow-up time for an occupational cohort can influence risk estimates. We examined the effects of follow-up time on relative risk estimates for leukemia and multiple myeloma in a cohort of 1,845 rubber hydrochloride workers.

MATERIALS AND METHODS

We generated standardized mortality ratios (SMRs) for yearly follow-ups, beginning each study in 1940 and increasing study end dates from 1950 through 1996. We used Cox proportional hazards modeling to explore the effects of follow-up time on the exposure-response relationship.

RESULTS

The SMR for leukemia rose to 13.55 in 1961 and fell nearly monotonically to 2.47 by 1996. Cox modeling suggested interaction between cumulative exposure and time since exposure. A longer time to peak risk was seen for multiple myeloma.

CONCLUSIONS

Because summary risk estimates change with follow-up time, exposure limits set using these estimates may not adequately protect workers. Consideration of appropriate follow-up time and use of more complex temporal models are critical to the risk assessment process.

Alendronate as an effective countermeasure to disuse induced bone loss

Microgravity, similar to disuse immobilization on earth, causes rapid bone loss. This loss is believed to be an adaptive response to the reduced musculoskeletal forces in space and occurs gradually enough that changes occurring during short duration space flight are not a concern. Bone loss, however, will be a major impediment for long duration missions if effective countermeasures are not developed and implemented. Bed rest is used to simulate the reduced mechanical forces in humans and was used to test the hypothesis that oral alendronate would reduce the effects of long duration (17 weeks) inactivity on bone. Eight male subjects were given daily oral doses of alendronate during 17 weeks of horizontal bed rest and compared with 13 male control subjects not given the drug. Efficacy was evaluated based on measurements of bone markers, calcium balance and bone density performed before, during and after the bed rest. The results show that oral alendronate attenuates most of the characteristic changes in bone that are associated with long duration bed rest and presumably space flight.

Association of homozygous 7048G7049 variant in the intron six of Nurr1 gene with Parkinson's disease

OBJECTIVE

To determine whether the Nurr1 gene, which is critical for the development and maintenance of nigral dopaminergic neurons, is a risk factor associated with PD.

BACKGROUND

The Nurrl gene is highly expressed in the dopaminergic neurons in the midbrain. Knockout of the gene results in agenesis of nigral dopaminergic neurons and heterozygous knockout mice increases 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity.

METHODS

This study included 105 patients with familial PD (fPD) and 120 patients with sporadic PD (sPD) and 221 age-matched healthy control subjects. The polymorphisms and mutations of the Nurr1 gene in patients with PD were initially examined by heteroduplex analysis and sequencing analysis from PCR-amplified Nurr1 gene fragments. A polymorphism in the BseRI restriction site was identified, and a relatively large-scale analysis then was conducted by three independent investigators who were blinded to the clinical status of the subjects.

RESULTS

A homozygous 7048G7049 polymorphism was found in intron 6 of the Nurr1 gene, which was significantly higher in fPD (10/105; 9.5%) and in sPD (5/120; 4.2%) compared with healthy control subjects (2/221; 0.9%). The mean age and the SD at onset of these homozygote patients with PD was 52 +/- 15 years for fPD and 46 +/- 7 years for sPD. The clinical features of these homozygote patients with PD did not differ from those of typical PD.

CONCLUSIONS

The homozygote polymorphism of 7048G7049 in intron 6 of the Nurr1 gene is associated with typical PD.

Cytokine-induced p38 activation feedback regulates the prolonged activation of AKT cell survival pathway initiated by reactive oxygen species in response to UV irradiation in human keratinocytes

A previous study has shown that UV activates the PI3K/AKT cell survival pathway while inducing cell death in human skin in vivo and cultured human keratinocytes in vitro, and yet the upstream pathway leading to the activation of AKT has not been thoroughly investigated. In this study we found that UV-induced phosphorylation of p38 and AKT in a time-dependent manner. The phosphorylation of p38 started at 5 min post UV irradiation, peaked at about 30 min, and remained elevated up to 2 h. The phosphorylation of AKT started at 15 min post UV treatment, peaked at about 1 h, and remained elevated up to 2 h. We also found that H2O2 induced phosphorylation of p38 and AKT in a time- dependent manner. Pretreatment with NAC abolished UV-induced AKT phosphorylation, suggesting the involvement of reactive oxygen species in AKT activation. Interestingly, SB203085, a known p38 inhibitor, had partially inhibited UV-induced AKT phosphorylation. Further studies showed that cytokines such as TNF-alpha and IL-1beta induced AKT phosphorylation in a time-dependent manner. Pretreatment with SB203085 inhibited IL-1beta-induced p38 and AKT phosphorylation. Collectively, our data suggest that UV activation of PI 3-kinase/AKT pathway is initiated by ROS and prolonged by feedback activation of p38 induced by released cytokines in response to UV irradiation in cultured human keratinocytes.

Pseudodicentric (16;12)(q11;p11.2) in a type AB (mixed) thymoma

Genetic alterations of thymomas are rarely described in the literature. In this study, a previously unreported instance of aberrant karyotypic change consisting of 45,XX,pseu dic(16;12) (q11;p11.2) [cp23]/87-90,idemx2[cp4] in a Masaoka Stage II mixed thymoma or type AB thymoma affecting a 56-year-old Chinese woman is detailed. Abnormalities involving 12p containing important tumor suppressor-like genes have been documented especially in hematological malignancies. Recently, recurrent losses involving 16q, a locus known to harbor several tumor suppressor genes, have been described in type C thymomas (squamous cell carcinoma), suggesting a possible relationship between type AB thymoma and type C thymoma. Whether these genes are involved in the pathogenesis of type AB thymoma remain to be clarified and it is currently unclear if cytogenetic studies may eventually play a role in the classification of thymic tumors.

Inhibitors of mitogen-activated protein kinases differentially regulate eosinophil-activating cytokine release from human airway smooth muscle

Airway smooth muscle (ASM) is a potential source of multiple proinflammatory cytokines during airway inflammation. In the present study, we examined a requirement for mitogen-activated protein (MAP) kinase activation for interleukin (IL)-1beta-stimulated GM-CSF, RANTES, and eotaxin release. IL-1beta induced concentration-dependent phosphorylation of p42/p44 extracellular signal-regulated kinases (ERKs), p38 MAP kinase, and c-Jun amino-terminal kinase (SAPK/JNK). p42/p44 ERK and p38 MAP kinase phosphorylation peaked at 15 min and remained elevated up to 4 h. SAPK/JNK phosphorylation also peaked at 15 min but fell to baseline within 60 min. SB 203580 selectively inhibited IL-1beta-stimulated activation of p38 MAP kinase; U 0126 was selective against p42/p44 ERK activity. SB 202474, an inactive analog, had no effect on p42/p44 ERK, p38 MAP kinase, or SAPK/JNK activation, or on eotaxin or RANTES release. Eotaxin release was inhibited by SB 203580 and U 0126, whereas RANTES release was prevented by U 0126 only. GM-CSF release was inhibited by U 0126 but enhanced by SB 203580. These data indicate that RANTES release is dependent on p42/p44 ERK activation but occurs independently of p38 MAP kinase activity. Eotaxin release, however, is dependent on both p38 MAP kinase- and p42/p44 ERK-dependent mechanisms. GM-CSF release is p42/p44 ERK dependent and is tonically suppressed by a mechanism that is partially dependent on p38 MAP kinase, though direct inhibition of cyclooxygenase (COX) activity due to poor inhibitor selectivity may also contribute.

[The expression of HCV RNA polymerase in E.coli and the study of its solubility and antigenicity]

OBJECTIVE

To express HCV RNA polymerase and study its soluble condition and antigenicity.

METHODS

We constructed expression vectors pQE-5B-Fl and pQE-5B-C21 and expressed them in E.coli (M15). We analyzed their solubility in different conditions and purified soluble pQE-5B-C21 protein by Ni-NTA column, then detected its antigenicity by ELISA and western blot.

RESULTS

We obtained the purified soluble pQE-5B-C21 protein in the induction conditions of 18 degrees C and the protein was proved to be of good antigenicity by ELISA and western blot.

CONCLUSIONS

The RNA polymerase of HCV expressed in E.coli has good solubility and antigenicity.

Stabilization of heavy metals on spent fluid catalytic cracking catalyst using marine clay

Spent fluid catalytic cracking catalyst is a hazardous solid waste generated by petroleum refineries containing vanadium and nickel. The marine clay was used as a matrix to stabilize vanadium and nickel and produce bricks which were then fired at various temperatures. TCLP leaching tests indicated that stabilizing brick had low metal leaching, with a maximum of 6.4 mg/l for vanadium and 19.8 microg/l for nickel. Compressive strength of stabilizing brick was found to range between 20 N/mm2 and 47 N/mm2. It is believed that stabilization and encapsulation mechanisms are responsible for the stabilization of vanadium and nickel. Encapsulation is a process whereby the marine clay matrix forms a physical barrier around the heavy metals which are thus prevented from leaching out into the environment. Incorporation involves the formation of bonds between the marine clay matrix and the heavy metals which thus become incorporated in the clay microstructure.

Coordinate-free analysis of mitral valve dynamics in normal and ischemic hearts

BACKGROUND

The purpose of this investigation was to study mitral valve 3D geometry and dynamics by using a coordinate-free system in normal and ischemic hearts to gain mechanistic insight into normal valve function, valve dysfunction during ischemic mitral regurgitation (IMR), and the treatment effects of ring annuloplasty.

METHODS AND RESULTS

Radiopaque markers were implanted in sheep: 9 in the ventricle, 1 on each papillary tip, 8 around the mitral annulus, and 1 on each leaflet edge midpoint. One group served as a control (n=7); all others underwent flexible Tailor partial (n=5) or Duran complete (n=6) ring annuloplasty. After an 8+/-2-day recovery, 3D marker coordinates were measured with biplane videofluoroscopy before and during posterolateral left ventricular ischemia, and MR was assessed by color Doppler echocardiography. Papillary to annular distances remained constant throughout the cardiac cycle in normal hearts, during ischemia, and after ring annuloplasty with either type of ring. Papillary to leaflet edge distances similarly remained constant throughout ejection. During ischemia, however, the absolute distances from the papillary tips to the annulus changed in a manner consistent with leaflet tethering, and IMR was observed. In contrast, during ischemia in either ring group, those distances did not change from preischemia, and no IMR was observed.

CONCLUSIONS

This analysis uncovered a simple pattern of relatively constant intracardiac distances that describes the 3D geometry and dynamics of the papillary tips and leaflet edges from the dynamic mitral annulus. Ischemia perturbed the papillary-annular distances, and IMR occurred. Either type of ring annuloplasty prevented such changes, preserved papillary-annular distances, and prevented IMR.

Functional role of residues corresponding to helical domain II (amino acids 35 to 46) of human immunodeficiency virus type 1 Vpr

Vpr, encoded by the human immunodeficiency virus type 1 genome, contains 96 amino acids and is a multifunctional protein with features which include cell cycle arrest at G(2), nuclear localization, participation in transport of the preintegration complex, cation channel activity, oligomerization, and interaction with cellular proteins, in addition to its incorporation into the virus particles. Recently, structural studies based on nuclear magnetic resonance and circular dichroism spectroscopy showed that Vpr contains a helix (HI)-turn-helix (HII) core at the amino terminus and an amphipathic helix (HIII) in the middle region. Though the importance of helical domains HI and HIII has been defined with respect to Vpr functions, the role of helical domain HII is not known. To address this issue, we constructed a series of mutants in which the HII domain was altered by deletion, insertion, and/or substitution mutagenesis. To enable the detection of Vpr, the sequence corresponding to the Flag epitope (DYKDDDDK) was added, in frame, to the Vpr coding sequences. Mutants, expressed through the in vitro transcription/translation system and in cells, showed an altered migration corresponding to deletions in Vpr. Substitution mutational analysis of residues in HII showed reduced stability for VprW38S-FL, VprL42G-FL, and VprH45W-FL. An assay involving cotransfection of NLDeltaVpr proviral DNA and a Vpr expression plasmid was employed to analyze the virion incorporation property of Vpr. Mutant Vpr containing deletions and specific substitutions (VprW38S-FL, VprL39G-FL, VprL42G-FL, VprG43P-FL, and VprI46G-FL) exhibited a negative virion incorporation phenotype. Further, mutant Vpr-FL containing deletions also failed to associate with wild-type Vpr, indicating a possible defect in the oligomerization feature of Vpr. Subcellular localization studies indicated that mutants VprDelta35-50-H-FL, VprR36W-FL, VprL39G-FL, and VprI46G-FL exhibited both cytoplasmic and nuclear localization, unlike other mutants and control Vpr-FL. While wild-type Vpr registered cell cycle arrest at G(2), mutant Vpr showed an intermediary effect with the exception of VprDelta35-50 and VprDelta35-50-H. These results suggest that residues in the HII domain are essential for Vpr functions.