Single-Center Experience of Control of Ventilator-Circuit-Transmitted Burkholderia cepacia Outbreak in an Intensive Care Unit

Burkholderia cepacia is an emerging nosocomial pathogen frequently associated with outbreaks, but the exact transmission route of this pathogen can at times be elusive in spite of extensive environmental investigative cultures. Active surveillance for sputum cultures was performed for all patients from September 2008 to September 2009 in an intensive care unit (ICU) with B. cepacia outbreak. With evidence of persistent positive conversion of sputum cultures (colonization) and infections among patients, discontinuing re-usable ventilator circuits was introduced. A total of 689 patients were admitted to this unit for a mean duration of 8.7 ± 7.5 days. There were 489 patients (71.0%) with a stay for one to ten days; 161 (23.4%) patients for 11 to 20 days; and 39 (5.7%) with over 20 days. In the first group, 13.5% of patients had cultures converting from negative to positive, in contrast to 66.7% in the last group (p < 0.01). With intervention of using disposable ventilator circuits since June 2009, the incidence of isolated B. cepacia decreased gradually. The estimated 30-day isolation-free probabilities of the groups before, during, one month (August 2009) after, and two months (September 2009) after this intervention were 38.5%, 47.3%, 66.5%, and 96.0%, respectively (p < 0.01). Furthermore, the effect of discontinuing reusable ventilator circuit persisted in the following 6 years; both total isolates of B. cepacia and the infection caused by it were much lower compared to the outbreak period. In summary, this six-year outbreak in a medical ICU persisted until reusable ventilator circuits were discontinued in 2009. The effect of disposable circuits on the decreased incidence of B. cepacia infection maintained in the following years.

Time-dependent association between cancer and risk of tuberculosis: A population-based cohort study

BACKGROUND

We aimed to investigate the time-dependent association between cancer and the risk of tuberculosis (TB) before and after cancer diagnosis.

METHODS

This population-based cohort study incorporated the National Health Insurance Research Database and the National Health Interview Survey in Taiwan to estimate TB risk in cancer and noncancer populations. We estimated the period-specific incidence rate ratio (IRR) between cancer and risk of TB and used Cox proportional hazards models to estimate the average hazard ratio between cancer and TB during the peridiagnostic period.

RESULTS

From 2001 to 2015, 457 673 cancer and 3 738 122 noncancer individuals were enrolled. After stratifying the IRR of TB by year relative to the date of cancer diagnosis, the peak IRRs clustered in the year before and after the index date. In the peridiagnostic period of cancer, the adjusted hazard ratio was 2.29 (95% CI, 2.22-2.35) using the Cox model and 2.20 (95% CI, 2.09-2.32) after adjustment for missing confounders. Patients with cancers in the respiratory tract, upper digestive tract, and hematologic system were at the highest risk for TB.

CONCLUSIONS

Cancer is an independent risk factor for TB, with the highest risk observed around the time of cancer diagnosis.

Global burden of tuberculosis attributable to cancer in 2019: Global, regional, and national estimates

BACKGROUND

Cancer is an independent risk factor for tuberculosis (TB). The global burden of incident TB attributable to cancer has never been explored. We aimed to evaluate the cancer-attributable burden of TB.

METHODS

We estimated the population attributable fraction (PAF) by Levin's formula. The cancer prevalence rates were derived from the Institute for Health Metrics and Evaluation. The relative risk of TB in cancer patients was estimated by using the National Health Insurance Research Database in Taiwan. The global burden of incidence TB attributable to cancer was the weighted sum of PAFs multiplied by the incidence of TB retrieved from the World Health Organization.

RESULTS

Worldwide, the total of incident TB cases attributable to cancer was 115,478 cases with a 95% confidence interval (CI), 110,482-123,007, in 2019. The global PAF of TB due to cancer was 1.85% (95% CI, 1.77-1.97%). The three countries with the highest PAFs were Greenland (7.77%), Canada (7.75%), and the United States of America (6.79%), while the three countries with the highest attributable TB cases due to cancer were China (25,240), India (21,629), and Indonesia (13,917). Cancer of respiratory system contributed to 60,257 of TB cases.

CONCLUSIONS

This study comprehensively explored the impact of cancer on the global burden of TB. Efforts to reduce cancer risk, delay the occurrence of cancer, or treat latent TB infection in the cancer population could potentially reduce the burden of TB and rely on formulating integrated strategies.

Hierarchical measurement structure in the Women's Health Questionnaire: a confirmatory factor analysis

Purpose: This study conducted confirmatory factor analysis (CFA) to examine the measurement structure of the Women's Health Questionnaire (WHQ) and how its components were organized. Methods: Participants were 448 postmenopausal women, with a mean age of 63.3 years. CFA was conducted to test how well several proposed measurement models fit the data. Results: The single-factor model performed poorly, indicating the presence of multiple factors. The model with seven correlated factors fit the data well, although the varying degrees of inter-factor correlations suggested grouping of similar factors. The hierarchical measurement structure, with seven first-order factors organized under two second-order factors of physical health and mental health functioning, demonstrated a good fit with the data (χ²(367) = 694.05, p < 0.001; root mean square error of approximation = 0.05; comparative fit index = 0.95) and a meaningful pattern. The Mental Health factor was represented by Depressed Mood, Anxiety/Fear, Memory/Concentration Problems, and Sleep Problems. The Physical Health factor was manifested mainly by Somatic Symptoms, Menstrual Symptoms, and Vasomotor Symptoms, and, to a lesser extent, also by Sleep Problems and Memory/Concentration Problems. Conclusion: Findings suggested that, in addition to a global index and subscale scores, the WHQ may produce summary scores of physical health and mental health functioning in evaluation of well-being among postmenopausal women.

Leukemia Risk After Cardiac Fluoroscopic Interventions Stratified by Procedure Number, Exposure Latent Time, and Sex: A Nationwide Population-Based Case-Control Study

A number of cardiac fluoroscopic interventions have increased rapidly worldwide over the past decade. Percutaneous transluminal coronary angioplasty (PTCA) and stent implantation have become increasingly popular, and these advancements have allowed patients to receive repetitive treatments for restenosis. However, these advancements also significantly increase radiation exposure that may lead to higher cumulative doses of radiation. In the present study, a nationwide population-based case-controlled study was used to explore the risk of leukemia after cardiac angiographic fluoroscopic intervention.A total of 5026 patients with leukemia and 100,520 control patients matched for age and sex (1:20) by a propensity score method without any cancer history were enrolled using the Registry Data for Catastrophic Illness and the National Health Insurance Research Database (NHIRD) of Taiwan between 2008 and 2010. All subjects were retrospectively surveyed (from year 2000) to determine receipt of cardiac fluoroscopic interventions. Data were analyzed using conditional logistic regression models, and estimated crude and adjusted odds ratios (95% confidence interval).After adjusting for age, gender, and comorbidities, PTCA was found to be associated with an increased risk of leukemia with an adjusted OR of 1.566 (95% CI, 1.282-1.912), whereas coronary angiography alone without PTCA and cardiac electrophysiologic study were not. Our results also showed that an increased frequency of PTCA and coronary angiography was associated with a higher risk of leukemia (adjusted OR: 1.326 to 1.530 [all P < 0.05]). Gender subgroup analyses demonstrated that men were associated with a higher risk of leukemia compared with women.These results provide additional data in the quantification of the long-term health effects of radiation exposure derived from the cardiac fluoroscopic diagnostic and therapeutic intervention. PTCA alone or PTCA with coronary angiography was associated with an elevated risk of leukemia. Continued follow-up of existing cohorts will be valuable to help assess lifetime risks of cancer.

Effect of 23-Valent Pneumococcal Polysaccharide Vaccine Inoculated During Anti-Cancer Treatment Period in Elderly Lung Cancer Patients on Community-Acquired Pneumonia Hospitalization: A Nationwide Population-Based Cohort Study

To evaluate effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPSV23) inoculated during defined "vaccination period," first 6 months post cancer diagnosis (ie, an anti-cancer treatment period), in elderly lung cancer patients on community-acquired pneumonia (CAP) hospitalization incidence.This was a nationwide population-based cohort study of 157 newly diagnosed elderly lung cancer patients receiving PPSV23 during "vaccination period", and 628 age and sex one-to-one matched controls enrolled in the National Health Insurance Research Database (NHIRD) of Taiwan between 2007 and 2010. All patients were ≥75 years old and still survival post "vaccination period." Incidence density (ID) of all-cause inpatient CAP and cumulative survival risk were analyzed by multivariate Poisson regression and Kaplan-Meier method, respectively.After a 4-year follow-up, IDs of all-cause inpatient CAP for vaccination and control cohorts were 297 and 444 per 1000 PYs, respectively. Less vaccinated patients had CAP incidence density >1 time per PY (12.7% vs 21.2%) than non-vaccinated patients. After adjusting for potential confounding variables, like influenza vaccination, comorbidities, cancer treatment modalities, and socioeconomic status, adjusted inpatient CAP incidence rate in PPSV23 vaccination cohort was 0.74 times lower than control cohort (incidence rate ratio [IRR] = 0.740, P = 0.0339). Two-year cumulative CAP hospitalization rates and overall survival rates were 37.1% vs. 55.4%, and 46.6% vs. 26.2%, respectively, for lung cancer patients with and without PPSV23 (both P < 0.001). Subgroup analysis showed that for elderly lung cancer patients not ever receiving influenza vaccine, PPSV23 still had trend to reduce all-cause inpatient CAP.For elderly lung cancer patients aged ≥75 years, PPSV23 inoculated during anti-cancer treatment period could reduce CAP hospitalizations and improve survival.

Pseudomembranous colitis within radiotherapy field following concurrent chemoradiation therapy: a case report

Development of nonantibiotic-associated pseudomembranous colitis has been reported in patients receiving chemotherapy. Herein, we report a case of a 70-year-old man with diabetes mellitus and hypertension who received concurrent chemoradiation therapy after surgery for stage III pT3N1M0 rectal cancer. After completion of the therapy, the patient presented with a 2-week history of intermittent watery diarrhea (seven to nine times per day). However, the patient was afebrile and laboratory examination revealed no evidence of leukocytosis. Computed tomography disclosed inflammation of the sigmoid colon, infiltrative changes around the anastomotic site, and edematous changes straddling the serosal surface. Colonoscopic examination revealed multiple whitish patches within the radiation field, a finding suggestive of pseudomembranous colitis. No concomitant antibiotics were used during the period of concurrent chemoradiation therapy. Empirical oral metronidazole (500 mg every 8 hours) was administrated for 2 weeks. At the end of this treatment, stool culture was negative for Clostridium difficile. Physicians should be aware of the potential for the development of pseudomembranous colitis following concurrent chemoradiation therapy.

Concurrent image-guided intensity modulated radiotherapy and chemotherapy following neoadjuvant chemotherapy for locally advanced nasopharyngeal carcinoma

BACKGROUND

To evaluate the experience of induction chemotherapy followed by concurrent chemoradiationwith helical tomotherapy (HT) for nasopharyngeal carcinoma (NPC).

METHODS

Between August 2006 and December 2009, 28 patients with pathological proven nonmetastatic NPC were enrolled. All patients were staged as IIB-IVB. Patients were first treated with 2 to 3 cycles of induction chemotherapy with EP-HDFL (Epirubicin, Cisplatin, 5-FU, and Leucovorin). After induction chemotherapy, weekly based PFL was administered concurrent with HT. Radiation consisted of 70 Gy to the planning target volumes of the primary tumor plus any positive nodal disease using 2 Gy per fraction.

RESULTS

After completion of induction chemotherapy, the response rates for primary and nodal disease were 96.4% and 80.8%, respectively. With a median follow-up after 33 months (Range, 13-53 months), there have been 2 primary and 1 nodal relapse after completion of radiotherapy. The estimated 3-year progression-free rates for local, regional, locoregional and distant metastasis survival rate were 92.4%, 95.7%, 88.4%, and 78.0%, respectively. The estimated 3-year overall survival was 83.5%. Acute grade 3, 4 toxicities for xerostomia and dermatitis were only 3.6% and 10.7%, respectively.

CONCLUSION

HT for locoregionally advanced NPC is feasible and effective in regard to locoregional control with high compliance, even after neoadjuvant chemotherapy. None of out-field or marginal failure noted in the current study confirms the potential benefits of treating NPC patients by image-guided radiation modality. A long-term follow-up study is needed to confirm these preliminary findings.

Efficient simulation of the spatial transmission dynamics of influenza

Early data from the 2009 H1N1 pandemic (H1N1pdm) suggest that previous studies over-estimated the within-country rate of spatial spread of pandemic influenza. As large spatially resolved data sets are constructed, the need for efficient simulation code with which to investigate the spatial patterns of the pandemic becomes clear. Here, we present a significant improvement to the efficiency of an individual-based stochastic disease simulation framework commonly used in multiple previous studies. We quantify the efficiency of the revised algorithm and present an alternative parameterization of the model in terms of the basic reproductive number. We apply the model to the population of Taiwan and demonstrate how the location of the initial seed can influence spatial incidence profiles and the overall spread of the epidemic. Differences in incidence are driven by the relative connectivity of alternate seed locations. The ability to perform efficient simulation allows us to run a batch of simulations and take account of their average in real time. The averaged data are stable and can be used to differentiate spreading patterns that are not readily seen by only conducting a few runs.

Efficient simulation of the spatial transmission dynamics of influenza

Early data from the 2009 H1N1 pandemic (H1N1pdm) suggest that previous studies over-estimated the within-country rate of spatial spread of pandemic influenza. As large spatially-resolved data sets are constructed, the need for efficient simulation code with which to investigate the spatial patterns of the pandemic becomes clear. Here, we describe a significant improvement in the efficiency of an individual-based stochastic disease simulation framework that has been used for multiple previous studies. We quantify the efficiency of the revised algorithm and present an alternative parameterization of the model in terms of the basic reproductive number. We apply the model to the population of Taiwan and demonstrate how the location of the initial seed can influence spatial incidence profiles and the overall spread of the epidemic. Differences in incidence are driven by the relative connectivity of alternate seed locations.

Psychosocial factors and assessment in cardiac rehabilitation

Understanding the unique impact of psychosocial factors on the development and progression of coronary heart disease (CHD) has significant implications for cardiac rehabilitation (CR). Recent guidelines for CR strongly recommend the assessment of psychosocial factors and provision of behavioral interventions for CR participants. In this review, we focus on the most prominent psychosocial issues in CR literature, namely depression, anxiety, social support, and cardiac-prone personality. First, we summarize the current empirical findings with regard to each of the psychosocial issues in CR. In addition, we provide recommendations for some of the most common or useful instruments for assessing these psychosocial factors in CR settings. The results show that anxiety and depression are, in general, prevalent among CR participants, and that CR appears to be effective in reducing these distressful symptoms as well as coronary-prone behaviors. There is some evidence suggesting that higher anxiety and depression as well as a lack of social support may prevent cardiac patients from attending CR or predict non-adherence and premature dropout in CR participants. The generalizability of these findings, however, may be compromised by several methodological issues, including relatively small samples, low representation of women in studies, and lack of rigorous statistical controls. Future research is needed to investigate the specific role of each psychosocial factor in the context of rehabilitation.

Changes in serum interleukin-8 and interleukin-12 levels in patients with ischemic heart disease in a Chinese population

Increasing evidence has indicated the important roles of inflammation and immune response in the development of atherosclerosis and ischemic heart disease (IHD). We measured the serum interleukin (IL)-8 and IL-12 levels of patients with unstable angina pectoris (UAP) and patients with acute myocardial infarction (AMI), and compared findings with those of normal subjects. The results showed that the serum level of IL-8 was significantly higher in patients with UAP and patients with AMI than in healthy control subjects. To our knowledge, this is the first report that serum IL-12 level was elevated in patients with AMI but not in patients with UAP. These findings suggest that IL-8 and IL-12 are involved in the process of IHD, and serum IL-12 may be a marker for differentiating AMI from UAP.

A structural model of acculturation and mental health status among Chinese Americans

This study examined the role of acculturation and its direct and indirect impact on depressive symptom severity through various correlates, including socioeconomic status (SES), stress, social support, personality negativity, and physical health perception. Using structural equation modeling, the proposed model was tested with 983 employed Chinese Americans from a representative community sample, the majority of whom were immigrants. The results demonstrated that acculturation, correlated with SES, contributed to depressive symptom severity only through indirect pathways. Higher acculturation was found associated with higher stress that in turn contributed to more elevated depressive symptoms. On the other hand, higher acculturation was also found strongly correlated with higher SES, which was associated with lower depressive symptoms directly or indirectly through several mediators. Better support, lower personality negativity, better health perception, and lower stress were found mediating the relationship between higher SES and lower depressive symptom severity. The simultaneous multigroup analysis showed that the final model was comparable for both men and women with very few differences.

A strategy for identification and quantitation of phosphopeptides by liquid chromatography/tandem mass spectrometry

Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is a state-of-the-art method of structural analysis of peptides/proteins. Here, using activating transcription factor-2 (ATF2) as an example, we report how LC/MS/MS data were processed to generate selected ion tracings for identification of phosphorylated peptides based on their parallel elution behavior with their nonphosphorylated analogs. Via this approach, we verified that amino acid residues Thr-69, Thr-71, and Ser-90 of ATF2 were the in vitro targets for c-Jun kinase. Selected ion tracing method was also used to quantitatively determine phosphorylation states of peptides. We demonstrated that the phosphorylation of Thr-69/Thr-71 was increased in response to ultraviolet irradiation specifically in subconfluent but not in confluent cultures. About 24% of Thr-69/Thr-71-containing segment were singly phosphorylated in subconfluent cultures, while minimal phosphorylation occurred in confluent cultures. In contrast, Ser-112 phosphorylation remained unaffected by cell densities. This strategy could be applied to the studies of a variety of modifications seen in various regulated cellular processes.

Identification of heterogeneous nuclear ribonucleoprotein K (hnRNP K) as a repressor of C/EBPbeta-mediated gene activation

Transcription factor C/EBPbeta has been known to regulate a wide array of genes including those involved in the acute-phase response. One of the molecular mechanisms underlying transcription activation by C/EBPbeta is through protein-protein interaction with other transcription factors. Here we report the identification and characterization of physical and functional interactions between C/EBPbeta and heterogeneous nuclear ribonucleoprotein (hnRNP) K. This interaction results in the repression of C/EBPbeta-dependent trans-activation of the agp gene. Footprinting assays indicate that hnRNP K cannot bind to the promoter region of agp gene or interfere with the binding of C/EBPbeta to its cognate DNA site. Furthermore, agp gene activation by the synergistic interaction of Nopp140 and C/EBPbeta is abolished by hnRNP K. The kinetics of appearance of C/EBPbeta-hnRNP K complex in the nuclear extract after initiation of acute-phase reaction indicates that hnRNP K functions as a negative regulator of C/EBPbeta-mediated activation of agp gene.

Transcriptional induction of the agp/ebp (c/ebp beta) gene by hepatocyte growth factor

Hepatocyte growth factor (HGF) is a pleiotropic factor with mitogenic, morphogenic, motogenic, cytotoxic, or growth inhibitory activity. Although the signaling of HGF is mediated through the cell membrane receptor c-Met, the molecular mechanism of downstream signal transduction remains obscure. In this report, we present evidence that shows HGF can stimulate the expression of AGP/EBP (C/EBP beta) and NF-kappaB, which are both key transcription factors responsible for the regulation of many genes under stress conditions or during the acute-phase response. Biochemical and functional analysis indicates that the HGF-responsive element is located in the region -376 to -352 (URE1) of the 5'-upstream regulatory sequence of agp/ebp. Activation of NF-kappaB by HGF was observed to precede the induction of agp/ebp. Further studies indicate that NF-kappaB can cooperate with AGP/EBP or other members of the C/EBP family to activate the agp/ebp gene in both URE1 and URE2-dependent manner. These results suggest that the induction of the agp/ebp gene by HGF is mediated at least in part by its activation of NF-kappaB. The activated NF-kappaB then interacts with AGP/EBP, resulting in the induction of agp/ebp.

A mixed-charge pair in human interleukin 4 dominates high-affinity interaction with the receptor alpha chain

Human interleukin 4 (IL-4) binds to its cellular receptor with a Kd in the subnanomolar range, similar to many other 4-helix-bundle proteins interacting with members of the hematopoietin (cytokine) receptor superfamily. In the IL-4 system this interaction is predominantly determined by the extracellular domain (IL4-BP) of the receptor alpha chain (Kd approximately 150 pM). Now a high-resolution mutational and kinetic analysis has revealed that the high-affinity binding of IL-4 originates from a continuous patch of a few mostly polar or charged amino acid side chains located on helices A and C. The binding epitope comprises (i) a set of side chains determining the dissociation rate (k(off)) and (ii) a partially overlapping set determining the association rate constant (k(on)) of the IL-4/IL4-BP complex. The k(off) epitope is assembled from two juxtaposed main determinants (Glu-9 and Arg-88) surrounded by five side chains (Ile-5, Thr-13, Arg-53, Asn-89, and Trp-91) of lower importance. The cumulative increase in k(off) after alanine substitution is 10(5)-fold for the central mixed-charge pair and 3 x 10(3)-fold for the satellites. The k(on) epitope is formed by five positively charged residues on helix C (Lys-77, Arg-81, Lys-84, Arg-85, and Arg-88) and two neighboring residues on helix A (Glu-9 and Thr-13). The cumulative loss in k(on) of the alanine variants is only about 10-fold. These results provide the basis for an understanding of molecular recognition in cytokine receptor complexes and for an IL-4 antagonist design.

Global and local determinants for the kinetics of interleukin-4/interleukin-4 receptor alpha chain interaction. A biosensor study employing recombinant interleukin-4-binding protein

An engineered interleukin-4-binding protein (IL4-BP) representing the extracellular domain of the human interleukin-4 (IL-4) receptor alpha chain was expressed in Sf9 cells. The purified IL4-BP was immobilized via a single biotinylated SH group near the carboxyl end to a biosensor matrix and analysed in real time for interaction with IL-4 and IL-4 variants. IL-4 was bound to IL4-BP at a molar ratio of approximately 1:1. The association and dissociation at pH 7.4 and 150 mM NaCl had rate constants of 1.9 +/- 0.3 x 10(7) M-1 s-1 and 2 +/- 1 x 10(-3) s-1, respectively. Glycosylation and engineered amino acid substitutions of IL4-BP did not alter the kinetic constants as shown by a parallel analysis of IL4-BP variants produced in Escherichia coli or Chinese hamster ovary cells. The rate of association was only slightly affected in binding-deficient variants [E9Q]IL-4 and [R88Q]IL-4 and by acidic pH down to values of 4.5, but it was reduced up to fivefold at higher ionic strength. The rate of dissociation was increased 70-fold and 150-fold with the IL-4 variants and fivefold at an acidic pH of 4.5, but it was not affected by high ionic strength. Temperatures between 6 degrees C and 37 degrees C yielded similar rates of IL-4 dissociation and only a marginally reduced rate of IL-4 association at 6 degrees C. These results indicate that the high-affinity binding of IL-4 to its receptor (Kd approximately 100 pM) is mainly the result of an unusually high association rate. The IL-4/IL4-BP interaction appears to be dominated by charge effects. The exceedingly high rate of IL-4/IL4-BP association is augmented by the overall electrostatic potentials of both proteins (electrostatic steering). Localized charges and the formation of ion pairs may control the rate of complex dissociation.

Identification of a novel variant hepatocyte growth factor secreted by spleen-derived stromal cells

Stromal cells can interact with parenchymal cells by secreting various cytokines to affect the growth, differentiation or movement of the latter. Here we report the identification and characterization of a novel variant hepatocyte growth factor (HGF) from the conditioned medium of stromal cells derived from mouse spleen. Compared to human HGF, it has much lower heparin-binding activity and lacks the beta-chain. Its molecular weight, 70 kDa, is very close to that of the alpha-chain of HGF. Human HGF homologue was not found in the conditioned medium. The conditioned medium of stromal cells, like recombinant HGF, could inhibit the growth of rat hepatoma cells. The inhibitory activity was presumably attributed to this novel HGF because the inhibitory activity, as the existence of this novel HGF, was confined to the identical fractions after heparin-column chromatography. Furthermore, this activity could be specifically abrogated by neutralizing anti-HGF antibodies.

Autoregulated induction of the acute-phase response transcription factor gene, agp/ebp

AGP/EBP (C/EBP beta) is a key transcription factor responsible for transcriptional induction of many acute-phase protein genes. To characterize the regulation of this gene, we have isolated the mouse genomic DNA and sequenced the 5'-regulatory region. Using nuclear extracts from lipopolysaccharide (LPS)-stimulated or unstimulated mouse liver, three protein factor-binding motifs, UF1(-376 to -352), UF2(-254 to -223), and UF3(-220 to -190), as well as two Sp1 motifs (-309 to -277, and -264 to -241) were identified by DNase I footprinting assays. Biochemical analysis has shown that the AGP/EBP protein can bind to UF1 and UF2 sites, whereas an ubiquitous factor of unknown identity can bind to the UF3 site. Functional characterizations indicate that all of these factors play a major role in AGP/EBP induction. Thus, the agp/ebp gene is autoregulated during the acute-phase response.

Design of human interleukin-4 antagonists inhibiting interleukin-4-dependent and interleukin-13-dependent responses in T-cells and B-cells with high efficiency

Human interleukin-4 possesses two distinct sites for receptor activation. A signalling site, comprising residues near the C-terminus on helix D, determines the efficacy of interleukin-4 signal transduction without affecting the binding to the interleukin-4 receptor alpha subunit. A complete antagonist and a series of low-efficacy agonist variants of human interleukin-4 could be generated by introducing combinations of two or three negatively charged aspartic acid residues in this site at positions 121, 124, and 125. One of the double variants, designated [R121D,Y124D]interleukin-4, with replacements of both Arg121 and Tyr124 by aspartic acid residues was completely inactive in all analysed cellular responses. The loss of efficacy in [R121D,Y124D]interleukin-4 is estimated to be larger than 2000-fold. Variant [R121D,Y124D]interleukin-4 was also a perfect antagonist for inhibition of interleukin-13-dependent responses in B-cells and the TF-1 cell line with a Ki value of approximately 100 pM. In addition, inhibition of both interleukin-4-induced and interleukin-13-induced responses could be obtained by monoclonal antibody X2/45 raised against interleukin-4Rex, the extracellular domain of the interleukin-4 receptor alpha subunit. These results indicate that efficient interleukin-4 antagonists can be designed on the basis of a sequential two-step activation model. In addition, the experiments indicate the functional participation of the interleukin-4 receptor alpha subunit in the interleukin-13 receptor system.

Two distinct functional sites of human interleukin 4 are identified by variants impaired in either receptor binding or receptor activation

Interleukin 4 (IL-4) exerts a decisive role in the coordination of protective immune responses against parasites, particularly helminths. A disregulation of IL-4 function is possibly involved in the genesis of allergic disease states. The search for important amino acid residues in human IL-4 by mutational analysis of charged invariant amino acid positions identified two distinct functional sites in the 4-helix-bundle protein. Site 1 was marked by amino acid substitutions of the glutamic acid at position 9 in helix A and arginine at position 88 in helix C. Exchanges at both positions led to IL-4 variants deficient in binding to the extracellular domain of the IL-4 receptor (IL-4R(ex)). In parallel, up to 1000-fold increased concentrations of this type of variant were required to induce T-cell proliferation and B-cell CD23 expression. Site 2 was marked by amino acid exchanges in helix D at positions 121, 124 and 125 (arginine, tyrosine and serine respectively in the wild-type). IL-4 variants affected at site 2 exhibited partial agonist activity during T-cell proliferation; however, they still bound with high affinity to IL-4R(ex). [The generation of an IL-4 antagonist by replacing tyrosine 124 with aspartic acid has been described before by Kruse et al. (1992) (EMBO J., 11, 3237-3244)]. These findings indicate that IL-4 functions by binding IL-4R(ex) via site 1 which is constituted by residues on helices A and C.(ABSTRACT TRUNCATED AT 250 WORDS)

[Human umbilical cord blood transplantation in 4 cases with advanced solid tumors]

Four patients with solid tumors were treated with high dose chemotherapy and HLA-mismatched multi-cord blood transplantation. Of them, 3 reached complete remission, 1 got fair response. The side effects were tolerable. Little or no graft-versus-host reaction (GVHR) was observed. Donor cell engraftment was documented in 2 patients by cytogenetic analysis and determination of hemoglobin F of the peripheral blood. Recurrent diseases were confirmed clinically on day 210 (4 year-old girl with liposarcoma) and day 90 (11 year-old boy with non-Hodgkin's lymphoma). These results demonstrated that HLA-mismatched multicord blood transfusion could rescue myelo-suppression of patients treated with myeloablative chemotherapy. Therefore, cord blood may serve as a rich source of hematopoietic stem cells.

Left shift in the peripheral blood count at diagnosis in acute lymphocytic leukemia is significantly correlated with duration of complete remission

The prognostic significance of a left shift in the peripheral blood at the time of diagnosis of acute lymphocytic leukemia was investigated by a retrospective analysis of 109 patients treated on the same protocol in a single institution. Left shift was defined as the presence of 1% or more of metamyelocytes, myelocytes, or promyelocytes. All peripheral blood films were checked at the time of diagnosis by one of the authors. It was found that the duration of complete remission at 92 mo was 74% in patients with left shift and 42% in those without left shift (p less than 0.05, log-rank test). By Cox regression analysis, only the total white cell count (p less than 0.001) and the presence or absence of left shift (p less than 0.01) were independently significant in determining the proportion of patients in complete remission. Patients with a left shift had a significantly higher granulocyte count at diagnosis (p less than 0.05). We postulate that left shift in the peripheral blood count at the time of diagnosis may be an indirect measure of the total leukemia cell load. It is a new prognostic factor of significance in determining the likely outcome of the disease.

CFU-c enrichment from human bone marrow using a discontinuous Percoll gradient and soybean agglutinin in comparison with Ficoll-paque

This study compares the efficiency of different methods of separation of human bone marrow in vitro prior to transplantation. Separation on Ficoll-paque resulted in a median recovery of 11.3 X 10(4) CFU-c/10(9) nucleated cells harvested. The recovery from the major CFU-c containing fraction following separation on a discontinuous Percoll gradient was 10.8 X 10(4) CFU-c/10(9) nucleated cells. The CFU-c recovered from Percoll were contained in a smaller number of cells, resulting in enrichment for CFU-c of 1.6 times that of Ficoll-paque. Further CFU-c enrichment to approximately three times that of Ficoll-paque separation was possible by treatment of Percoll fractionated cells with soybean agglutinin (SBA). However this caused an overall loss of 67% of CFU-c. Cells remaining after SBA treatment of the CFU-c containing Percoll fraction had increased spontaneous DNA synthesis and decreased PHA responses. There was no significant change in the mixed lymphocyte reaction in comparison with Ficoll-paque.