Screening for Comorbidity of Sleep Disorders in Career Firefighters

BACKGROUND

The purpose of this study was to assess the prevalence and sequelae of insomnia, obstructive sleep apnea (OSA), and comorbid OSA and insomnia (COMISA).

METHOD

In the morning, after a shift end, Midwest career firefighters ( N = 89) in a midsized city completed an electronic battery of questionnaire to screen for OSA, daytime sleepiness, insomnia, presleep arousal, nightmares, mental and physical health symptoms, and a one-night sleep diary.

RESULTS

Prevalence of firefighters exceeding screening thresholds: OSA: 54%; insomnia: 30%; COMISA: 17%; four or more nightmares per month: 15%. Firefighters who met criteria for COMISA had shorter total sleep time, less restful and worse sleep quality, higher depression and anxiety symptoms, and presleep arousal symptoms than firefighters without self-reported sleep problems.

CONCLUSIONS

Many firefighters are at elevated risk of individual behavioral sleep disorders, COMISA, and daytime dysfunction.

[Morbidity of extended pelvic lymphadenectomy during robot-assisted laparoscopic prostatectomy for localized cancer prostate]

OBJECTIVES

To assess the morbidity specific of extended pelvic lymphadenectomy during robot-assisted laparoscopic radical prostatectomy in a 8 year retrospective study.

MATERIAL

We carried out a single-center, single-surgeon retrospective study on 342 consecutive patients who underwent a robot-assisted laparoscopic radical prostatectomy and extended pelvic lymphadenectomy, from July 2010 to March 2018. Postoperative complications were recorded up to 3 months after the operation.

RESULTS

Thirty (8.8%) patients had at least one complication related to lymphadenectomy including 1 vascular injury (0.3%), 7 injuries of the obturator nerve (2%), 5 venous thromboembolic complications (1.5%) including 4 pulmonary embolisms, 10 symptomatic lymphoceles (2.9%) and 8 lymphoedemas (2.3%). Of these complications, 13 were classified Clavien 1 (43.3%), 8 Clavien 2 (26.7%), 7 Clavien 3a (23.3%) and 2 Clavien 3b (6.7%). In univariate analysis a high age (P=0.04), high BMI (P<0.01) and pT stage (P=0.02) were significantly associated with complication whereas in multivariate analysis, only age (P=0.02) and BMI (P<0.01) lived were. In univariate analysis high BMI (P=0.04) and lymph node involvement (P=0.04) were associated with lymphatic complication. We did not find any other specific risk factor for the other complications.

CONCLUSION

With 8.8% of overall complications related to lymphadenectomy and 5% of complication classified Clavien grade 2 or higher, extended pelvic lymphadenectomy was not very morbid. Age and BMI were risk factors for a overall complication. BMI and lymph node involvement were risk factors for lymphatic complications.

LEVEL OF PROOF

4.

Characteristics of severe malaria in hospitalized children in Ho Chi Minh City from 2012 to 2019

In Vietnam, severe malaria is currently rare but is a life-threatening disease. It may be misdiagnosed with other common diseases. This descriptive study aimed to characterize severe malaria and its clinical aspects, as well as outcomes of infected pediatric patients to improve case management. The case-series study was carried out based on medical records of children aged between one month and 15 years with malaria diagnosed by blood smear or rapid diagnostic test. Chi-squared test with the p values less than 0.05 were considered statistically significant. There were 47 cases enrolled in the study. The prevalence of severe malaria was 29.8% (57.1% in children under five). The morbidity was 71.4% in male and 28.6% in female. Common clinical signs of severe malaria were fever (100%), severe anemia (21.4%), hepatomegaly (85.7%), and splenomegaly (71.4%). Common biological abnormalities in severe malaria were anemia, thrombocytopenia, increased liver enzymes, and high CRP level. The severe malaria was mainly caused by P. falciparum (100%). The age range for those infected with P. falciparum was 6.5 ± 4.5 years (min 0.3; max 14.9). The successful rate of treatment was 92.9% with artesunate. Antimalarial treatment time was 9.0 (6 - 12) days for severe malaria, which was twice as many as that for non-severe malaria (p = 0.067). The current clinical and biological findings of severe malaria are different from those in previous times, which make it easy to be overlooked. Therefore, it's important to perform malaria diagnostic tests when there're clinical suggestions of severe malaria, including fever, hepatomegaly or splenomegaly.

Depression, stigma and quality of life in people with drug-susceptible TB and drug-resistant TB in Vietnam

BACKGROUND: Drug resistance poses a major barrier to global control of TB - a leading infectious cause of death. Depression and stigma occur commonly among people with TB. However, the relationship between drug-resistant forms of TB, depression and stigma are not well understood.OBJECTIVE: To compare depression, stigma and health-related quality of life (HRQoL), among people with drug-susceptible TB (DS-TB) and multidrug-resistant TB (MDR-TB).METHODS: A cross-sectional study of people treated for DS-TB and MDR-TB in four provinces of Vietnam. The survey included a stigma scale (Vietnamese Tuberculosis Stigma Scale), depression scale (9-item Patient Health Questionnaire) and HRQoL scale (Functional Assessment of Chronic Illness Therapy - Tuberculosis). Differences between the two populations were compared using linear regression.RESULTS: Eighty-one people with DS-TB and 315 people with MDR-TB participated in the study. People with MDR-TB had a higher prevalence of depression than those with DS-TB (difference 17.8%, χ² 8.64). The mean depression and stigma scores were higher for people with MDR-TB than those with DS-TB (adjusted difference [AD] 8.6 and 7.6 respectively). People with MDR-TB reported lower HRQoL than those with DS-TB (AD -23.8).CONCLUSION: Depression and stigma are common among people with TB in Vietnam. Strategies to prevent and treat depressive symptoms and stigma in people with TB are critical to a holistic, patient-centred approach to care.

Active case-finding in contacts of people with TB

BACKGROUND: Exposure to people with TB substantially elevates a person's risk of tuberculous infection and TB disease. Systematic screening of TB contacts enables the early detection and treatment of co-prevalent disease, and the opportunity to prevent future TB disease. However, scale-up of contact investigation in high TB transmission settings remains limited.METHODS: We undertook a narrative review to evaluate the evidence for contact investigation and identify strategies that TB programmes may consider when introducing contact investigation and management.RESULTS: Selection of contacts for priority screening depends upon their proximity and duration of exposure, along with their susceptibility to develop TB. Screening algorithms can be tailored to the target population, the availability of diagnostic tests and preventive therapy, and healthcare worker expertise. Contact investigation may be performed in the household or at communal locations. Local contact investigation policies should support vulnerable patients, and ensure that drop-out during screening can be mitigated. Ethical issues should be anticipated and addressed in each setting.CONCLUSION: Contact investigation is an important strategy for TB elimination. While its epidemiological impact will be greatest in lower-transmission settings, the early detection and prevention of TB have important benefits for contacts and their communities.

What to expect from a non-suspicious prostate MRI? A review

BACKGROUND

Many guidelines now recommend multiparametric MRI (mpMRI) prior to an initial or repeat prostate biopsy. However, clinical decision making for men with a non-suspicious mpMRI (Likert or PIRADS score 1-2) varies.

OBJECTIVES

To review the most recent literature to answer three questions. (1) Should we consider systematic biopsy if mpMRI is not suspicious? (2) Are there additional predictive factors that can help decide which patient should have a biopsy? (3) Can the low visibility of some cancers be explained and what are the implications?

SOURCES

A narrative review was performed in Medline databases using two searches with the terms "MRI" and "prostate cancer" and ("diagnosis" or "biopsy") and ("non-suspicious" or "negative" or "invisible"); "prostate cancer MRI visible". References of the selected articles were screened for additional articles.

STUDY SELECTION

Studies published in the last 5 years in English language were assessed for eligibility and selected if data was available to answer one of the three study questions.

RESULTS

Considering clinically significant cancer as ISUP grade≥2, the negative predictive value (NPV) of mpMRI in various settings and populations ranges from 76% to 99%, depending on cancer prevalence and the type of confirmatory reference test used. NPV is higher among patients with prior negative biopsy (88-96%), and lower for active surveillance patients (85-90%). The PSA density (PSAd) with a threshold of PSAd<0.15ng/ml/ml was the most studied and relevant predictive factor used in combination with mpMRI to rule out clinically significant cancer. Finally, mpMRI-invisible tumours appear to differ from a histopathological and genetic point of view, conferring clinical advantage to invisibility.

LIMITATIONS

Most published data come from expert centres and results may not be reproducible in all settings.

CONCLUSION

mpMRI has high diagnostic accuracy and in cases of negative mpMRI, PSA density can be used to determine which patient should have a biopsy. Growing knowledge of the mechanisms and genetics underlying MRI visibility will help develop more accurate risk calculators and biomarkers.

A comparison of digital chest radiography and Xpert® MTB/RIF in active case finding for tuberculosis

OBJECTIVE: To compare two community screening tests for TB: sputum examination using Xpert^® MTB/RIF and chest radiography (CXR).METHOD: Men aged ≥15 years and women aged >45 years living in 96 sub-communes in Ca Mau, Viet Nam, were invited to provide a single sputum specimen that was tested using Xpert. Participants were also invited to attend a nearby location for digital radiography. Participants whose sputum was Xpert MTB-positive or whose CXR was reported as 'consistent with TB´ were requested to provide two further sputum specimens for culture. The sensitivities of the two tests for detecting TB (defined as sputum culture-positive for Mycobacterium tuberculosis) were compared.RESULTS: There were 72 985 eligible participants, of whom 57 597 (78.9%) participated in Xpert screening, 12 752 (17.5%) had CXR and 11 235 (15.4%) had both tests. We estimated that there were 59 cases of TB, of whom 20 were Xpert MTB-positive (programmatic sensitivity 34.0%) and 47 had CXR reported as 'consistent with TB´ (sensitivity 80.0%, P < 0.0001).CONCLUSION: In community-wide screening for TB, CXR is more sensitive than a single spontaneously expectorated sputum sample tested using Xpert, but it has a substantially lower participation rate.

Post-treatment Mortality Among Patients With Tuberculosis: A Prospective Cohort Study of 10 964 Patients in Vietnam

BACKGROUND

Tuberculosis is the leading infectious cause of death. Steep reductions in tuberculosis-related mortality are required to realize the World Health Organization's "End Tuberculosis Strategy." However, accurate mortality estimates are lacking in many countries, particularly following discharge from care. This study aimed to establish the mortality rate among patients with pulmonary tuberculosis in Vietnam and to quantify the excess mortality in this population.

METHODS

We conducted a prospective cohort study among adult patients treated for smear-positive pulmonary tuberculosis in 70 clinics across Vietnam. People living in the same households were recruited as controls. Participants were re-interviewed and their survival was established at least 2 years after their treatment with an 8-month standardized regimen. The presence of relapse was established by linking identifying data on patients and controls to clinic registries. Verbal autopsies were performed. The cumulative mortality among patients was compared to that among a control population, adjusting for age and gender.

RESULTS

We enrolled 10964 patients and 25707 household controls. Among enrolled tuberculosis patients, 9% of patients died within a median follow-up period of 2.9 years: 342 (3.1%) during treatment and 637 (5.8%) after discharge. The standardized mortality ratio was 4.0 (95% confidence interval 3.7-4.2) among patients with tuberculosis, compared to the control population. Tuberculosis was the likely cause of death for 44.7% of these deceased patients.

CONCLUSIONS

Patients treated for tuberculosis had a markedly elevated risk of death, particularly in the post-treatment period. Interventions to reduce tuberculosis mortality must enhance the early detection of drug-resistance, improve treatment effectiveness, and address non-communicable diseases.

Resource implications of the latent tuberculosis cascade of care: a time and motion study in five countries

BACKGROUND

The End TB Strategy calls for global scale-up of preventive treatment for latent tuberculosis infection (LTBI), but little information is available about the associated human resource requirements. Our study aimed to quantify the healthcare worker (HCW) time needed to perform the tasks associated with each step along the LTBI cascade of care for household contacts of TB patients.

METHODS

We conducted a time and motion (TAM) study between January 2018 and March 2019, in which consenting HCWs were observed throughout a typical workday. The precise time spent was recorded in pre-specified categories of work activities for each step along the cascade. A linear mixed model was fit to estimate the time at each step.

RESULTS

A total of 173 HCWs in Benin, Canada, Ghana, Indonesia, and Vietnam participated. The greatest amount of time was spent for the medical evaluation (median: 11 min; IQR: 6-16), while the least time was spent on reading a tuberculin skin test (TST) (median: 4 min; IQR: 2-9). The greatest variability was seen in the time spent for each medical evaluation, while TST placement and reading showed the least variability. The total time required to complete all steps along the LTBI cascade, from identification of household contacts (HHC) through to treatment initiation ranged from 1.8 h per index TB patient in Vietnam to 5.2 h in Ghana.

CONCLUSIONS

Our findings suggest that the time requirements are very modest to perform each step in the latent TB cascade of care, but to achieve full identification and management of all household contacts will require additional human resources in many settings.

Phenobarbital and symptom-triggered lorazepam versus lorazepam alone for severe alcohol withdrawal in the intensive care unit

A symptom-triggered lorazepam regimen is the standard for treating alcohol withdrawal syndrome (AWS) in an inpatient setting. However, in severe AWS, lorazepam requirements can reach significant amounts and lead to risk of delirium and propylene glycol toxicity. Phenobarbital has been shown to be an effective adjunctive therapy for AWS, reducing benzodiazepine use, in the emergency department. The purpose of this study is to determine the efficacy and safety of phenobarbital in adjunct to symptom-triggered lorazepam for severe AWS vs. lorazepam alone in the intensive care unit (ICU). A retrospective cohort was conducted at Cleveland Clinic hospitals from 2013 to 2018 of ICU patients with AWS receiving either phenobarbital adjunct to symptom-triggered lorazepam or lorazepam alone. The primary outcome was the total duration of treatment. Secondary outcomes include ICU length of stay, change in CIWA-Ar score at 24 h, incidence of hypotension, mechanical ventilation, and serum osmolar gap. A total of 72 ICU patients were included with 36 patients in each arm. The median duration of treatment in the phenobarbital adjunct arm was 2.7 days (IQR = 1.7-6.4), compared to 3.1 days (IQR = 1.6-4.8) in the lorazepam arm (p = 0.578). The median ICU length of stay was similar between both arms [4.1 days (IQR = 2.4-8.4) vs. 4.5 days (IQR = 2.8-6.1), p = 0.727]. The average change in CIWA-Ar from baseline at 24 h was significantly lower for those who received phenobarbital (1.8 ± 9.0 vs. 6.5 ± 8.5, p = 0.028). Three patients in the phenobarbital-adjunct group received mechanical ventilation after starting phenobarbital treatment. There were no new incidences of hypotension or increased osmol gap >10 mmol/L after starting treatment in both groups. In conclusion, phenobarbital is an effective adjunct to symptom-triggered lorazepam in severe alcohol withdrawal in the ICU with no significant difference in adverse events.

Epigenetic silencing of a multifunctional plant stress regulator

The central regulator of the ethylene (ET) signaling pathway, which controls a plethora of developmental programs and responses to environmental cues in plants, is ETHYLENE-INSENSITIVE2 (EIN2). Here we identify a chromatin-dependent regulatory mechanism at EIN2 requiring two genes: ETHYLENE-INSENSITIVE6 (EIN6), which is a H3K27me3 demethylase also known as RELATIVE OF EARLY FLOWERING6 (REF6), and EIN6 ENHANCER (EEN), the Arabidopsis homolog of the yeast INO80 chromatin remodeling complex subunit IES6 (INO EIGHTY SUBUNIT). Strikingly, EIN6 (REF6) and the INO80 complex redundantly control the level and the localization of the repressive histone modification H3K27me3 and the histone variant H2A.Z at the 5’ untranslated region (5’UTR) intron of EIN2. Concomitant loss of EIN6 (REF6) and the INO80 complex shifts the chromatin landscape at EIN2 to a repressive state causing a dramatic reduction of EIN2 expression. These results uncover a unique type of chromatin regulation which safeguards the expression of an essential multifunctional plant stress regulator.

The role of macroscopic sputum quality assessments to optimise sputum testing for tuberculosis

SETTING

Community-wide active case finding for tuberculosis (TB) using Xpert® MTB/RIF as the primary screening tool, Ca Mau Province, Viet Nam.

OBJECTIVES

To determine whether macroscopic sputum quality characteristics (sputum colour and volume) can be used to predict Xpert MTB-negative sputum and hence exclude sputum samples from testing.

DESIGN

Field staff conducted household visits to approximately 51,200 adults in 58 villages randomly selected from throughout the province. Sputum samples from all screened participants who were able to produce ⩾1 ml sputum underwent macroscopic sputum assessment and were tested with Xpert.

RESULTS

Of the 21,624 sputum samples tested, 159 (0.74%) were Xpert MTB-positive; 93% of the samples were 1-2 ml and nearly all were mucoid (93%) or mucopurulent (5.7%). One salivary sample was Xpert MTB-positive (2.0% of all salivary samples). The lowest positive predictive value for any sputum volume or colour characteristic was 0.66%. This was not substantially different from the overall prevalence of positive sputum Xpert MTB (0.74%).

CONCLUSION

Sputum colour and volume cannot be used to predict the presence or absence of M. tuberculosis in sputum detected using Xpert. These sputum quality parameters cannot therefore be used to exclude sputum samples from testing for TB.

Cutaneous skeletal hypophosphatemia syndrome: clinical spectrum, natural history, and treatment

Cutaneous skeletal hypophosphatemia syndrome (CSHS), caused by somatic RAS mutations, features excess fibroblast growth factor-23 (FGF23) and skeletal dysplasia. Records from 56 individuals were reviewed and demonstrated fractures, scoliosis, and non-congenital hypophosphatemia that in some cases were resolved. Phosphate and calcitriol, but not skin lesion removal, were effective at controlling hypophosphatemia. No skeletal malignancies were found.

PURPOSE

CSHS is a disorder defined by the association of epidermal and/or melanocytic nevi, a mosaic skeletal dysplasia, and an FGF23-mediated hypophosphatemia. To date, somatic RAS mutations have been identified in all patients whose affected tissue has undergone DNA sequencing. However, the clinical spectrum and treatment are poorly defined in CSHS. The purpose of this study is to determine the spectrum of the phenotype, natural history of the disease, and response to treatment of hypophosphatemia.

METHODS

Five CSHS subjects underwent prospective data collection at clinical research centers. A review of the literature identified 45 reports that included a total of 51 additional patients, in whom the findings were compatible with CSHS. Data on nevi subtypes, bone histology, mineral and skeletal disorders, abnormalities in other tissues, and response to treatment of hypophosphatemia were analyzed.

RESULTS

Fractures, limb deformities, and scoliosis affected most CSHS subjects. Hypophosphatemia was not present at birth. Histology revealed severe osteomalacia but no other abnormalities. Skeletal dysplasia was reported in all anatomical compartments, though less frequently in the spine; there was no clear correlation between the location of nevi and the skeletal lesions. Phosphate and calcitriol supplementation was the most effective therapy for rickets. Convincing data that nevi removal improved blood phosphate levels was lacking. An age-dependent improvement in mineral abnormalities was observed. A spectrum of extra-osseous/extra-cutaneous manifestations that included both benign and malignant neoplasms was present in many subjects, though osteosarcoma remains unreported.

CONCLUSION

An understanding of the spectrum, natural history, and efficacy of treatment of hypophosphatemia in CSHS may improve the care of these patients.

Critical Casimir forces for colloidal assembly

Critical Casimir forces attract increasing interest due to their opportunities for reversible particle assembly in soft matter and nano science. These forces provide a thermodynamic analogue of the celebrated quantum mechanical Casimir force that arises from the confinement of vacuum fluctuations of the electromagnetic field. In its thermodynamic analogue, solvent fluctuations, confined between suspended particles, give rise to an attractive or repulsive force between the particles. Due to its unique temperature dependence, this effect allows in situ control of reversible assembly. Both the force magnitude and range vary with the solvent correlation length in a universal manner, adjusting with temperature from fractions of the thermal energy, k B T, and nanometre range to several ten kT and micrometer length scale. Combined with recent breakthroughs in the synthesis of complex particles, critical Casimir forces promise the design and assembly of complex colloidal structures, for fundamental studies of equilibrium and out-of-equilibrium phase behaviour. This review highlights recent developments in this evolving field, with special emphasis on the dynamic interaction control to assemble colloidal structures, in and out of equilibrium.

Induction of Apoptosis by PQ1, a Gap Junction Enhancer that Upregulates Connexin 43 and Activates the MAPK Signaling Pathway in Mammary Carcinoma Cells

The mechanism of gap junction enhancer (PQ1) induced cytotoxicity is thought to be attributed to the change in connexin 43 (Cx43) expression; therefore, the effects of Cx43 modulation in cell survival were investigated in mammary carcinoma cells (FMC2u) derived from a malignant neoplasm of a female FVB/N-Tg(MMTV-PyVT)634Mul/J (PyVT) transgenic mouse. PQ1 was determined to have an IC₅₀ of 6.5 µM in FMC2u cells, while inducing an upregulation in Cx43 expression. The effects of Cx43 modulation in FMC2u cell survival was determined through transfection experiments with Cx43 cDNA, which induced an elevated level of protein expression similar to that seen with PQ1 exposure, or siRNA to silence Cx43 protein expression. Overexpression or silencing of Cx43 led to a reduction or an increase in cell viability, respectively. The mitogen-activated protein kinase (MAPK) family has been implicated in the regulation of cell survival and cell death; therefore, the gap junctional intercellular communication (GJIC)-independent function of PQ1 and Cx43 in the Raf/Mitogen-activated protein kinase/ERK kinase/extracellular-signal-regulated kinase (Raf-MEK-ERK) cascade of cellular survival and p38 MAPK-dependent pathway of apoptosis were explored. PQ1 treatment activated p44/42 MAPK, while the overexpression of Cx43 resulted in a reduced expression. This suggests that PQ1 affects the Raf-MEK-ERK cascade independent of Cx43 upregulation. Both overexpression of Cx43 and PQ1 treatment stimulated an increase in the phosphorylated form of p38-MAPK, reduced levels of the anti-apoptotic protein Bcl-2, and increased the cleavage of pro-caspase-3. Silencing of Cx43 protein expression led to a reduction in the phosphorylation of p38-MAPK and an increase in Bcl-2 expression. The mechanism behind PQ1-induced cytotoxicity in FMC2u mammary carcinoma cells is thought to be attributed to the change in Cx43 expression. Furthermore, PQ1-induced apoptosis through the upregulation of Cx43 may depend on p38 MAPK, highlighting that the effect of PQ1 on gap junctions as well as cellular survival via a MAPK-dependent pathway.

Quantitative electrochemical detection of cathepsin B activity in breast cancer cell lysates using carbon nanofiber nanoelectrode arrays toward identification of cancer formation

The proteolytic activity of cathepsin B in complex breast cell lysates has been measured with alternating current voltammetry (ACV) using ferrocene (Fc)-labeled-tetrapeptides immobilized on nanoelectrode arrays (NEAs) fabricated with vertically aligned carbon nanofibers (VACNFs). Four types of breast cells have been tested, including normal breast cells (HMEC), transformed breast cells (MCF-10A), breast cancer cells (T47D), and metastatic breast cancer cells (MDA-MB-231). The detected protease activity was found increased in cancer cells, with the MDA-MB-231 metastatic cancer cell lysate showing the highest cathepsin B activity. The equivalent cathepsin B concentration in MDA-MB-231 cancer cell lysate was quantitatively determined by spiking recombinant cathepsin B into the immunoprecipitated MDA-MB-231 lysate and the HMEC whole cell lysate. The results illustrated the potential of this technique as a portable multiplex electronic device for cancer diagnosis and treatment monitoring through rapid profiling the activity of specific cancer-relevant proteases.

FROM THE CLINICAL EDITOR

Breast cancer is the most common cancer in women. In this report, the authors applied the technique of nanoelectrode arrays to try to detect and compare cathepsin B activities in normal and breast cancer cells. It was found that protease activity correlated positively with the degree of malignancy cancer cells. Taking this further, this technique may be useful for rapid diagnosis of cancer in the future.

General practitioner management plans delaying time to next potentially preventable hospitalisation for patients with heart failure

BACKGROUND

Several studies have shown that the Australian Medicare-funded chronic disease management programme can lead to improvements in care processes. No study has examined the impact on long-term health outcomes.

AIMS

This retrospective cohort study assessed the association between provision of a general practitioner management plan and time to next potentially preventable hospitalisation for older patients with heart failure.

METHODS

We used the Australian Government Department of Veterans' Affairs (DVA) claims database and compared patients exposed to a general practitioner management plan with those who did not receive the service. Kaplan-Meier analysis and Cox proportional hazards models were used to compare time until next potentially preventable hospitalisation for heart failure between the exposed and unexposed groups.

RESULTS

There were 1993 patients exposed to a general practitioner management plan and 3986 unexposed patients. Adjusted results showed a 23% reduction in the rate of potentially preventable hospitalisation for heart failure at any time (adjusted hazard ratio, 0.77; 95% confidence interval, 0.64 to 0.92; P = 0.0051) among those with a general practitioner management plan compared with the unexposed patients. Within one year, 8.6% of the exposed group compared with 10.7% of the unexposed group had a potentially preventable hospitalisation for heart failure.

CONCLUSIONS

A general practitioner management plan is associated with delayed time to next potentially preventable hospitalisation for heart failure.

Increase of gap junction activities in SW480 human colorectal cancer cells

Background

Colorectal cancer is one of the most common cancers in the United States with an early detection rate of only 39%. Colorectal cancer cells along with other cancer cells exhibit many deficiencies in cell-to-cell communication, particularly gap junctional intercellular communication (GJIC). GJIC has been reported to diminish as cancer cells progress. Gap junctions are intercellular channels composed of connexin proteins, which mediate the direct passage of small molecules from one cell to the next. They are involved in the regulation of the cell cycle, cell differentiation, and cell signaling. Since the regulation of gap junctions is lost in colorectal cancer cells, the goal of this study is to determine the effect of GJIC restoration in colorectal cancer cells.

Methods

Gap Junction Activity Assay and protein analysis were performed to evaluate the effects of overexpression of connexin 43 (Cx43) and treatment of PQ1, a small molecule, on GJIC.

Results

Overexpression of Cx43 in SW480 colorectal cancer cells causes a 6-fold increase of gap junction activity compared to control. This suggests that overexpressing Cx43 can restore GJIC. Furthermore, small molecule like PQ1 directly targeting gap junction channel was used to increase GJIC. Gap junction enhancers, PQ1, at 200 nM showed a 4-fold increase of gap junction activity in SW480 cells. A shift from the P0 to the P2 isoform of Cx43 was seen after 1 hour treatment with 200 nM PQ1.

Conclusion

Overexpression of Cx43 and treatment of PQ1 can directly increase gap junction activity. The findings provide an important implication in which restoration of gap junction activity can be targeted for drug development.

Quantitative electrochemical detection of cathepsin B activity in complex tissue lysates using enhanced AC voltammetry at carbon nanofiber nanoelectrode arrays

The proteolytic activity of a cancer-related enzyme cathepsin B is measured with alternating current voltammetry (ACV) using ferrocene (Fc) labeled tetrapeptides attached to nanoelectrode arrays (NEAs) fabricated with vertically aligned carbon nanofibers (VACNFs). This combination enables the use of high AC frequencies (~1kHz) with enhanced electrochemical signals. The specific proteolysis of the Fc-peptide by cathepsin B produces decay in the ACV peak current versus the reaction time. The exponential component of the raw data can be extracted and defined as the "extracted proteolytic signal" which allows consistent quantitative analyses using a heterogeneous Michaelis-Menten model. A "specificity constant" kcat/KM = (3.68 ± 0.50) × 10(4)M(-1)s(-1) for purified cathepsin B was obtained. The detections of cathepsin B activity in different concentrations of whole lysate of human breast tissue, tissue lysate spiked with varied concentrations of cathepsin B, and the tissue lysate after immunoprecipitation showed that there is ~13.4 nM higher cathepsin B concentration in 29.1 µg mL(-1) of whole tissue lysate than the immunoprecipitated sample. The well-defined regular VACNF NEAs by e-beam lithography show a much faster kinetics for cathepsin B proteolysis with kcat/KM = 9.2 × 10(4)M(-1)s(-1). These results illustrate the potential of this technique as a portable multiplex electronic system for cancer diagnosis by rapid protease profiling of serum or blood samples.

The effect of antineoplastic drugs in a male spontaneous mammary tumor model

Male breast cancer is a rare disease. The limited number of clinical cases has led to the primary treatments for men being derived from female breast cancer studies. Here the transgenic strain FVB/N-Tg(MMTV-PyVT)634Mul/J (also known as PyVT) was used as a model system for measuring tumor burden and drug sensitivity of the antineoplastic drugs tamoxifen, cisplatin, and paclitaxel on tumorigenesis at an early stage of mammary carcinoma development in a male mouse model. Cisplatin treatment significantly reduced tumor volume, while paclitaxel and tamoxifen did not attenuate tumor growth. Cisplatin treatment was shown to induce apoptosis, grossly observed by reduced tumor formation, through reduced Bcl-2 and survivin protein expression levels with an increase in caspase 3 expression compared to control tumors. Tamoxifen treatment significantly altered the hormone receptor expression levels of the tumor, while additionally upregulating Bcl-2 and Cyclin D1. This suggests an importance in hormonal signaling in male breast cancer pathogenesis. The results of this study provide valuable information toward the better understanding of male breast cancer and may help guide treatment decisions.

Multistate outbreak of Escherichia coli O145 infections associated with romaine lettuce consumption, 2010

Non-O157 Shiga toxin-producing Escherichia coli (STEC) can cause severe illness, including hemolytic uremic syndrome (HUS). STEC O145 is the sixth most commonly reported non-O157 STEC in the United States, although outbreaks have been infrequent. In April and May 2010, we investigated a multistate outbreak of STEC O145 infection. Confirmed cases were STEC O145 infections with isolate pulsed-field gel electrophoresis patterns indistinguishable from those of the outbreak strain. Probable cases were STEC O145 infections or HUS in persons who were epidemiologically linked. Case-control studies were conducted in Michigan and Ohio; food exposures were analyzed at the restaurant, menu, and ingredient level. Environmental inspections were conducted in implicated food establishments, and food samples were collected and tested. To characterize clinical findings associated with infections, we conducted a chart review for case patients who sought medical care. We identified 27 confirmed and 4 probable cases from five states. Of these, 14 (45%) were hospitalized, 3 (10%) developed HUS, and none died. Among two case-control studies conducted, illness was significantly associated with consumption of shredded romaine lettuce in Michigan (odds ratio [OR] = undefined; 95% confidence interval [CI] = 1.6 to undefined) and Ohio (OR = 10.9; 95% CI = 3.1 to 40.5). Samples from an unopened bag of shredded romaine lettuce yielded the predominant outbreak strain. Of 15 case patients included in the chart review, 14 (93%) had diarrhea and abdominal cramps and 11 (73%) developed bloody diarrhea. This report documents the first foodborne outbreak of STEC O145 infections in the United States. Current surveillance efforts focus primarily on E. coli O157 infections; however, non-O157 STEC can cause similar disease and outbreaks, and efforts should be made to identify both O157 and non-O157 STEC infections. Providers should test all patients with bloody diarrhea for both non-O157 and O157 STEC.

Abstract 519: Attenuation of mammary tumor growth by gap junction enhancer

Normal cells have functional gap junctional intercellular communication (GJIC), while cancer cells exhibit many defects in cellular communication that contribute to the loss of tissue homeostasis. It is believed that restoring GJIC is linked to drug sensitivity and reduction of tumorigenicity. Previous studies show that GJIC and neoplastic cellular growth are inversely related and small molecule targeting gap junction can alter tumor growth. A dose of 25 mg/kg gap junction enhancer (PQ) can cause a 77% decrease of xenograft T47D breast tumors. In addition these small molecules can induce a decrease of tumor growth by 110%, 129%, and 73% in the pre, early, and late stages of tumor development of the transgenic mouse strain, FVB/N-Tg(MMTV-PyVT)634Mul/J. Western blot analysis shows that the gap junction protein, Cx43, was highly expressed in the PQ-treated tumors compared to the controls. Data suggests that enhancement of GJIC attenuates tumor growth; specifically Cx43 plays a significant role in tumorigenesis. Establishment of a continuous line of mammary tumor cells from the malignant neoplasm of a female transgenic mouse demonstrates that PQs can cause an increase of Cx43 expression and subsequently trigger a decrease of cell viability. Overall, targeting gap junction by small molecule PQ has shed light to the dynamic of connexins and gap junctions in mammary tumors.

Citation Format: Stephanie N. Shishido, Thu A. Nguyen. Attenuation of mammary tumor growth by gap junction enhancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 519. doi:10.1158/1538-7445.AM2013-519

Peptide hydrogelation and cell encapsulation for 3D culture of MCF-7 breast cancer cells

Three-dimensional (3D) cell culture plays an invaluable role in tumor biology by providing in vivo like microenviroment and responses to therapeutic agents. Among many established 3D scaffolds, hydrogels demonstrate a distinct property as matrics for 3D cell culture. Most of the existing pre-gel solutions are limited under physiological conditions such as undesirable pH or temperature. Here, we report a peptide hydrogel that shows superior physiological properties as an in vitro matrix for 3D cell culture. The 3D matrix can be accomplished by mixing a self-assembling peptide directly with a cell culture medium without any pH or temperature adjustment. Results of dynamic rheological studies showed that this hydrogel can be delivered multiple times via pipetting without permanently destroying the hydrogel architecture, indicating the deformability and remodeling ability of the hydrogel. Human epithelial cancer cells, MCF-7, are encapsulated homogeneously in the hydrogel matrix during hydrogelation. Compared with two-dimensional (2D) monolayer culture, cells residing in the hydrogel matrix grow as tumor-like clusters in 3D formation. Relevant parameters related to cell morphology, survival, proliferation, and apoptosis were analyzed using MCF-7 cells in 3D hydrogels. Interestingly, treatment of cisplatin, an anti-cancer drug, can cause a significant decrease of cell viability of MCF-7 clusters in hydrogels. The responses to cisplatin were dose- and time-dependent, indicating the potential usage of hydrogels for drug testing. Results of confocal microscopy and Western blotting showed that cells isolated from hydrogels are suitable for downstream proteomic analysis. The results provided evidence that this peptide hydrogel is a promising 3D cell culture material for drug testing.

Electrochemical Protease Biosensor Based on Enhanced AC Voltammetry Using Carbon Nanofiber Nanoelectrode Arrays

We report an electrochemical method for measuring the activity of proteases using nanoelectrode arrays (NEAs) fabricated with vertically aligned carbon nanofibers (VACNFs). The VACNFs of ~150 nm in diameter and 3 to 5 μm in length were grown on conductive substrates and encapsulated in SiO2 matrix. After polishing and plasma etching, controlled VACNF tips are exposed to form an embedded VACNF NEA. Two types of tetrapeptides specific to cancer-mediated proteases legumain and cathepsin B are covalently attached to the exposed VACNF tip, with a ferrocene (Fc) moiety linked at the distal end. The redox signal of Fc can be measured with AC voltammetry (ACV) at ~1 kHz frequency on VACNF NEAs, showing distinct properties from macroscopic glassy carbon electrodes due to VACNF's unique interior structure. The enhanced ACV properties enable the kinetic measurements of proteolytic cleavage of the surface-attached tetrapeptides by proteases, further validated with a fluorescence assay. The data can be analyzed with a heterogeneous Michaelis-Menten model, giving "specificity constant" kcat /Km as (4.3 ± 0.8) × 104 M-1s-1 for cathepsin B and (1.13 ± 0.38) × 104 M-1s-1 for legumain. This method could be developed as portable multiplex electronic techniques for rapid cancer diagnosis and treatment monitoring.

Gap junction enhancer increases efficacy of cisplatin to attenuate mammary tumor growth

Cisplatin treatment has an overall 19% response rate in animal models with malignant tumors. Increasing gap junction activity in tumor cells provides the targets to enhance antineoplastic therapies. Previously, a new class of substituted quinolines (PQs) acts as gap junction enhancer, ability to increase the gap junctional intercellular communication, in breast cancer cells. We examined the effect of combinational treatment of PQs and antineoplastic drugs in an animal model, showing an increase in efficacy of antineoplastic drugs via the enhancement of gap junctions. Mice were implanted with estradiol-17ß (1.7 mg/pellet) before the injection of 1×10⁷ T47D breast cancer cells subcutaneously into the inguinal region of mammary fat pad. Animals were treated intraperitoneally with DMSO (control), cisplatin (3.5 mg/kg), PQ (25 mg/kg), or a combining treatment of cisplatin and PQ. Cisplatin alone decreased mammary tumor growth by 85% while combinational treatment of cisplatin and PQ1 or PQ7 showed an additional reduction of 77% and 22% of tumor growth after 7 treatments at every 2 days, respectively. Histological results showed a significant increase of gap junction proteins, Cx43 and Cx26, in PQ-treated tissues compared to control or cisplatin. Furthermore, evidence of highly stained caspase 3 in tumors of combinational treatment (PQ and cisplatin) was seen compared to cisplatin alone. We have showed for the first time an increase in the efficacy of antineoplastic drugs through a combinational treatment with PQs, a specific class of gap junction enhancers.

C1B domain peptide of protein kinase Cγ significantly suppresses growth of human colon cancer cells in vitro and in an in vivo mouse xenograft model through induction of cell cycle arrest and apoptosis

Two peptides derived from the C1B domain of protein kinase Cγ (PKCγ) were shown to associate with classical PKC isozymes and modulate their activities. These C1B peptides are designated C1B1 (amino acid residues 101-112) and C1B5 (residues 141-151). Since PKC enzyme activity is shown to be involved in colon cancer development, the effect of C1B peptides on the growth of various human colon cancer cell lines was examined in vitro and in vivo. Sub-micromolar to micromolar levels of both C1B peptides induced approximately 60-70% growth attenuation in multiple colon cancer cell lines in a soft agar tumor colony assay; however, C1B5 peptide was not cytotoxic to normal colon epithelial cells in two dimensional culture. The effect of C1B5 peptide on colony growth of COLO205 cells was reversed by treatment with the PKCα/β inhibitor, Ro-32-0432. C1B peptide treatment attenuated COLO205 cells via two mechanisms: 1) cell cycle arrest and 2) stimulation of apoptosis. This is evident in G 2 arrest and increases in levels of cleaved caspase 3 and p53 phosphorylated at serine 20. Intratumoral injection of C1B5 peptide (20 mg/kg/day, every three days) markedly attenuated the growth of subcutaneous xenografts of COLO205 cells in SCID mice by 76% compared with the control. Taken together, these results strongly suggest that C1B peptides have negligible effects on normal tissues but are potentially effective chemotherapeutic agents for colon cancer.

Abstract 3712: Gap junction enhancer potentiates cytotoxic effect of cisplatin

Cisplatin is one of the most widely used anti-cancer drugs due to its highly effective apoptosis induction and DNA damage function. However, increasing reports of side effects and drug resistances indicate the limitation of cisplatin in cancer therapeutics. Recent studies showed that inhibition of gap junctions is one of the reasons that diminishes the cytotoxic efficiency and contributes to drug resistance. Therefore, identification of molecules that counteracts gap junctional inhibition without decreasing the anticancer effect of cisplatin in combinational treatment is essential to reverse resistance and potentiate drug efficacy. This study investigates the effects of combinational treatment of cisplatin and substituted quinoline PQ1, a gap junction enhancer, in T47D breast cancer cells. Cell viability was studied by both trypan blue method and morphology change. Ki67 was used as a marker to examine cell proliferation. Gap junction activity was examined by scrap load/dye transfer (SL/DT) and the expressions of connexins, the components of gap junction. Expressions of apoptotic factors, caspase-8, caspase-9, caspase-3, Bax, and Bcl-2, were measured by western blot analysis. Our results showed that compared with single cisplatin treatment, combinational treatment of PQ1 and cisplatin increased gap junctional intercellular communication (GJIC) as well as expressions of connexins (Cx26, Cx32 and Cx43), and subsequently decreased cell viability. Ki67 was greatly decreased by combinational treatment indicating the inhibition of proliferation. Expressions of pro-apoptotic factors, caspase-3, caspases-8, caspase-9, and bax, were activated or increased by pretreating T47D cells with PQ1; whereas, the pro-survival factor, bcl-2, was decreased by the pretreatment. Our studies imply that PQ1 has the potential to be used in the combinational treatment to counteract the drug resistance and potentiate the efficacy of cisplatin in breast cancer treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3712. doi:1538-7445.AM2012-3712

Evaluation of shellfish consumption in Nha Trang City, Southern coastal Vietnam

INTRODUCTION

Shellfish consumption may be a significant pathway to food contaminants such as heavy metals, pesticides and phycotoxins. Currently, little information exists about consumption of shellfish in Vietnam. Such data could be of interest in terms of nutritional value or risk assessment.

METHODS

Consumption of shellfish was assessed using a food frequency questionnaire and validated by a 7-day recall method. Approximately 1% of the city population of Nha Trang was selected yielding a final sample of 440 participants. The participants were above 18 years of age, in apparently good health and were shellfish consumers.

RESULTS

In South coastal Vietnam, the types of shellfish most consumed are green mussel, squid, crab and shrimp. The mean consumption rates of the bivalves, crustaceans, gastropods, cephalopods, echinoderms and all shellfish combined were 39.3, 20.9, 16.4, 11.2, 0.3 and 88.1 g/person/day, respectively. The consumption rate was slightly higher in the age group of 30-54 years, than in the younger (18-29 years) and older (55 years and above) age groups. Shellfish is essentially purchased in the markets and temporary markets, and mostly consumed during the dry season.

CONCLUSION

Shellfish consumption in the Southern coastal region of Vietnam is high compared to consumption levels in other countries; it is also high compared to consumption levels of Vietnamese emigrants. Such data may be useful for further investigation on nutrition perspectives and in term of risk assessment of shellfish contaminants.

Anti-breast cancer agents, quinolines, targeting gap junction

Cancer cells exhibit many defects in cell communication that contribute to the loss of tissue homeostasis (excess cell proliferation, invasion, and metastasis). The process of cancer formation causes a disruption in cell homeostasis, affecting the ability to respond to extracellular signals, as well as triggering some intracellular events which alter gap junctional intercellular communication (GJIC). Previous research has shown that the first two generations of substituted quinolines have anti-cancer effects in human breast cancer cells. This report presents the synthesis and bioactivities of third generation substituted quinolines. Scrape load/dye transfer studies showed that 100 nM of PQ15, a third generation substituted quinoline, causes a 4.5-fold increase of gap junction activity in T47D breast cancer cells. Furthermore, a significant decrease of cell proliferation and viability was observed in the presence of 200 nM PQ15 compared to control. The expression of α-survivin was reduced to <40% in the treatment of 200 nM PQ15 compared to solvent alone. Alpha-survivin expression is upregulated in human cancers and associated with resistance to chemotherapy, suggesting that α-survivin prolongs the survival of cancer cells. Thus, it has been shown that substituted quinolines stimulate gap junction activity, decrease alpha survivin expression, and subsequently inhibit cancer cell growth. Our findings demonstrate that PQ15 has a promising role in exerting anti-cancer activity in human breast cancer cells.

Second-generation substituted quinolines as anticancer drugs for breast cancer

Cancer cells have reduced capacity for gap junctional inter-cellular communication (GJIC). One feasible approach to reduce growth of cancer cells is to enhance GJIC. This report shows that a second-generation substituted quinoline, PQ7, has anti-tumor effect. Scrape load/dye transfer and colony growth assays were performed to measure GJIC and tumor formation of T47D breast cancer cells. PQ7 at 500 nM induced a 16-fold increase in the GJIC in T47D cells. In addition to an increase in GJIC, a 50% decrease of colony growth was observed with 100 nM of PQ7. PQ7-treated nu/nu mice showed a 100% regression of xenograft tumor growth of T47D cells. The results show that PQ7 has a promising role in exerting anti-tumor activity in human breast cancer cells.

Hydronephrosis and urine retention in estrogen-implanted athymic nude mice

Subcutaneous estrogen pellet implantation is commonly practiced to induce tumor promotion in nude (Nu-FOXn1(nu)) mice for xenograft tumor modeling. Twelve of 23, 18-week-old nude mice developed dysuria after estrogen pellet implantation. Physical examination revealed variably distended abdomens with palpable distended bladders. All mice were euthanatized and postmortem examinations were made. Blood samples of the mice were collected, and serum estrogen concentration was measured. Postmortem examination revealed variable dilation of the urinary bladder and unilateral or bilateral dilations of ureters and kidneys. Microscopically, 12 of 23 mice and 13 of 23 mice showed dilated urinary bladder and hydronephrosis, respectively.

Transkingdom RNA interference (tkRNAi): a novel method to induce therapeutic gene silencing

RNA interference is a phenomenon in which specific, endogenous genes are silenced by mRNA degradation. This technology is highly regarded as a potential therapeutic due to its high efficacy and low toxicity. However, the difficulty of delivering RNAi to target cells has impeded the development of RNAi-based therapies. One method to overcome this barrier is the use of a nonpathogenic bacteria vector, Escherichia coli, to deliver RNAi to target cells with high efficacy. In transkingdom interference RNAi (tkRNAi) delivery, E. coli were engineered to transcribe short RNA (shRNA) from a plasmid (TRIP) containing the invasin gene Inv and the listeriolysin O gene Hly. tkRNAi is successful in eliciting efficient gene silencing in vitro and in vivo.

Dealing with a positive result: routine HIV testing of pregnant women in Vietnam

HIV testing is an essential component of PMTCT. It can be offered to pregnant women through different testing models, ranging from voluntary counseling and testing (VCT) to routine and mandatory testing. This study was conducted in Hanoi, Vietnam, where HIV-prevalence is low among the general population, but high among young, urban, sexually active, male intravenous drug users. Women who want to deliver in a state hospital are routinely tested for HIV in the absence of well-defined opt-out procedures. In-depth interviews with a convenience sample of 38 seropositive pregnant women and mothers and 53 health workers explored the acceptability of routine testing. Patients and healthcare workers appeared to accept routine 'blood' tests (including HIV tests) because they feel uncomfortable discussing issues specific to HIV/AIDS. To avoid having to inform women directly about their HIV status, health workers at routine testing sites rely on the official notification system, shifting the responsibility from the hospitals to district and commune health staff. The notification system in Hanoi informs these local officials about the HIV status of people living in their catchment area without patients' consent. Our study shows that this non-confidential process can have serious social, economic and health consequences for the HIV-positive women and their children.

Synthesis and anti-breast cancer activities of substituted quinolines

Promising anti-breast cancer agents derived from substituted quinolines were discovered. The quinolines were readily synthesized in a large scale from a sequence of reactions starting from 4-acetamidoanisole. The Michael addition product was isolated as the reaction intermediate in the ring closing reaction of 4-amino-5-nitro-2-(3-trifluoromethylphenyloxy)anisole with methyl vinyl ketone leading to 6-methoxy-4-methyl-8-nitro-5-(3-trifluoromethylphenyloxy)quinoline (14). The amino function of 8-amino-6-methoxy-4-methyl-5-(3-trifluoromethylphenyloxy)quinoline, prepared from 14, was connected to various side chains via alkylation with N-(3-iodopropyl)phthalimide, Michael addition with acrylonitrile, and reductive amination with various heterocycle carboxaldehydes, such as imidazole-4-carboxaldehyde, thiophene-2-carboxaldehyde, and 2-furaldehyde. Effects of the substituted quinolines on cell viability of T47D breast cancer cells using trypan blue exclusion assay were examined. The results showed that the IC(50) value of 6-methoxy-8-[(2-furanylmethyl)amino]-4-methyl-5-(3-trifluoromethylphenyloxy)quinoline is 16+/-3nM, the lowest IC(50) out of all the quinolines tested. IC(50) values of three other quinolines are in the nanomolar range, a desirable range for pharmacological testing.

Changing distribution of group A rotavirus G-types and genetic analysis of G9 circulating in Japan

A total of 1,797 fecal specimens from infants and children with acute gastroenteritis in Japan from July 2000 to June 2003 were tested for group A rotavirus by ELISA, RT-PCR, RNA-PAGE and latex agglutination methods. Of these, 439 were found to be positive for group A rotavirus and this presented 24.4%. In 2000-2001, G1 was the most prevalent (45.5%) followed by G2 (32.5%), G3 (12.3%), G9 (5.9%) and G4 (2.6%). However, G2 was found predominant with 40% in the following year (2001-2002). Interestingly, G9 had a rapid increase of infection up to 17.8%. In 2002-2003, G3 dominated over other G-types with 34%. Another interesting feature of the study was the demonstration of great genetic diversity among G9 strains in Japan. Worth of note was the first prevalence pattern of rotavirus G-types with an increase of G2, G3 as well as G9 and a decrease of G1 during the 20 year-survey of rotavirus infection in Japan.

Existence of multiple outbreaks of viral gastroenteritis among infants in a day care center in Japan

A total of 921 fecal specimens collected from 44 infants in a day care center (DCC) in Tokyo, Japan during June 1999 to July 2000 were tested for the presence of rotavirus, norovirus, sapovirus, astrovirus and adenovirus by reverse-transcription-multiplex polymerase chain reaction (RT-multiplex PCR) and sequence analysis. Of 88 fecal specimens from infants with acute gastroenteritis, 51.1% (45) were found to be positive for diarrheal viruses. Astrovirus was the most prevalent (15.9%, 14 of 88), followed by norovirus GII (14.8%, 13 of 88), adenovirus (12.5%, 11 of 88), and sapovirus (2.3%, 2 of 88). Viral mixed infection accounted for 5.7% (5 of 88). Interestingly, 230 of 833 (27.6%) fecal specimens collected from asymptomatic infants were also infected with diarrheal viruses. Of these, astrovirus, norovirus GII, adenovirus and sapovirus were identified in 53, 46, 96 and 22 fecal specimens (23%, 20%, 41.7%, and 9.6%, respectively). Moreover, 13 of 833 (1.6%) normal specimens showed mixed viral infections. Surprisingly, no rotavirus (known as the most common causative agent of acute gastroenteritis in DCCs) was detected in those subjects. Another interesting feature was the demonstration of five separate outbreaks of acute gastroenteritis identified in a single DCC. Outbreak A was associated with both astrovirus serotype 1 and norovirus GII/3 (known as Toronto virus cluster); Outbreak B with adenovirus 12; Outbreak C with norovirus GII/4 (Lordsdale virus cluster); Outbreak D with sapovirus GIV and Outbreak E with astrovirus serotype 1. To our knowledge, this is the first proof of multiple outbreaks of viral gastroenteritis in Japanese infants in a single DCC. Our results confirm the presence as well as the importance of these viruses and warn of the threat they pose.

Etiologic agents of acute gastroenteritis among Japanese infants and children: virus diversity and genetic analysis of sapovirus

A total of 371 fecal specimens from infants and children with acute gastroenteritis in Maizuru, Tokyo and Osaka, Japan from July 2002 to June 2003 were tested for the presence of diarrheal viruses by reverse transcription-polymerase chain reaction (RT-PCR), reverse passive hemagglutination (PRHA), RNA-polyacrylamide gel electrophoresis (PAGE), latex agglutination and sequence analysis methods. Among diarrheal viruses detected, group A rotavirus was the most prevalent (42.2%) followed by norovirus (28.9%), group C rotavirus (8.4%), sapovirus (6.7%), adenovirus (5.3%) and astrovirus (0.9%), respectively. There was the high rate (7.6%) of viral mixed infections. Sapovirus was classified into 6 genotypes (GI/1, GI/4, GI/5, GI/6 and GII/1 and one novel tentatively called GII/5). It is noteworthy that genogroup II sapovirus can be classified into 5 genotypes. Our findings confirmed the presence of many diarrheal viruses co-circulating among Japanese infants and children and showed the great genetic diversity among sapoviruses.

A novel RT-multiplex PCR for enteroviruses, hepatitis A and E viruses and influenza A virus among infants and children with diarrhea in Vietnam

A novel reverse transcription-multiplex polymerase chain reaction (RT-multiplex PCR) assay that can detect enteroviruses, hepatitis A and E viruses and influenza A virus from various hosts (avian species, human, swine and horse) was developed. The identification of that group of viruses was performed with the mixture of four pairs of published specific primers (F1 and R1, P3 and P4, 2s and 2as, MMU42 and MMU43) for amplifying viral genomes and specifically generated four different amplicon sizes of 440, 267, 146 and 219 bp for enteroviruses, hepatitis A and E viruses and influenza A virus, respectively. A total of 276 fecal specimens (previously screened for rotavirus, adenovirus, norovirus, sapovirus and astrovirus-negative) from infants and children admitted into hospital with acute gastroenteritis in Ho Chi Minh city, Vietnam during October 2002 and September 2003 were collected and further tested for the presence of those viruses by RT-multiplex PCR. Enteroviruses were identified in 27 specimens and this represented 9.8%. No hepatitis A and E viruses and influenza A virus was found among these subjects. The sensitivity and specificity of RT-multiplex PCR were also assessed and demonstrated the strong validation against RT-monoplex PCR. Taken together, the findings clearly indicated that this novel RT-multiplex PCR is a simple and potential assay for rapid, sensitive, specific and cost-effective laboratory diagnosis to investigate molecular epidemiology of acute gastroenteritis caused by enteroviruses, hepatitis A and E viruses and influenza A virus. This report is the first, to our knowledge, detecting these kinds of viruses in diarrheal feces from infants and children in Vietnam.

Genetic diversity of sapovirus in fecal specimens from infants and children with acute gastroenteritis in Pakistan

A total of 517 fecal specimens collected from infants and children with acute gastroenteritis in Karachi city, Pakistan during 1990-1994 were examined for the presence of sapovirus by RT-PCR and sequence analysis methods. Sapovirus was identified in 17 of 517 (3.2%) specimens. Sapovirus was further clustered into three distinct genogroups (I, II and IV) and these presented 70.6%, 23.5% and 5.9%, respectively. Our results clearly indicated that sapovirus could be classified into 7 GI and 4 GII genotypes. It was noteworthy to point out that sapovirus detected among Pakistani infants and children with acute gastroenteritis demonstrated the great genetic diversity and presented novel sapovirus genotypes.

Exhaled breath condensate pH is a robust and reproducible assay of airway acidity

Exhaled breath condensate (EBC) pH is low in several lung diseases and it normalises with therapy. The current study examined factors relevant to EBC pH monitoring. Intraday and intraweek variability were studied in 76 subjects. The pH of EBC collected orally and from isolated lower airways was compared in an additional 32 subjects. Effects of ventilatory pattern (hyperventilation/hypoventilation), airway obstruction after methacholine, temperature (-44 to +13 degrees C) and duration of collection (2-7 min), and duration of sample storage (up to 2 yrs) were examined. All samples were collected with a disposable condensing device, and de-aerated with argon until pH measurement stabilised. Mean EBC pH (n=76 subjects, total samples=741) was 7.7+/-0.49 (mean+/-SD). Mean intraweek and intraday coefficients of variation were 4.5% and 3.5%. Control of EBC pH appears to be at the level of the lower airway. Temperature of collection, duration of collection and storage, acute airway obstruction, subject age, saliva pH, and profound hyperventilation and hypoventilation had no effect on EBC pH. The current authors conclude that in health, exhaled breath condensate pH is slightly alkaline, held in a narrow range, and is controlled by lower airway source fluid. Measurement of exhaled breath condensate pH is a simple, robust, reproducible and relevant marker of disease.

Malaria-associated cytokine changes in the placenta of women with pre-term deliveries in Yaounde, Cameroon

The prevalence of pre-term deliveries (PTDs) is increased in women who become infected with Plasmodium falciparum during pregnancy. Because prematurity is a risk factor for newborns, it is important to identify conditions that contribute to malaria-associated PTDs. Plasmodium falciparum-infected erythrocytes sequester in the placenta and attract activated mononuclear cells that secrete pro-inflammatory cytokines. Increased inflammatory cytokine levels in other microbial infections are associated with PTDs. To determine if such is the case in women with placental malaria, concentrations of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4), and IL-10 were measured in placental plasma of 391 malaria-infected and -uninfected Cameroonian women with premature and full-term deliveries. Risk factors for malaria-associated PTDs included peripheral and placental parasitemias greater than 1%, maternal anemia, elevated IL-10 levels, and low TNF-alpha:IL-10 ratios due to over-expression of IL-10. Alterations in cytokine levels may contribute to PTDs through the induction of anemia and/or altering cellular immune responses required for eliminating placental parasites.

Paclitaxel (Taxol) attenuates clinical disease in a spontaneously demyelinating transgenic mouse and induces remyelination

Treatment with paclitaxel by four intraperitoneal injections (20 mg/kg) 1 week apart attenuated clinical signs in a spontaneously demyelinating model, if given with onset of clinical signs. If given at 2 months of age (1 month prior to clinical signs), disease was almost completely prevented The astrogliosis, prominent in our model, was reversed by paditaxel as determined by astrocyte counts and quantitation of GFAP. Electron microscopic examination of affected regions at 2.5 months demonstrated that the myelin was generally normal. By 4 months of age, demyelination was common in the superior cerebellar peduncle, maximal at 6 months, but continued to 8 months. In addition to myelin vacuolation and nude axons, the presence of many thin myelin sheaths suggested remyelination or partial demyelination. Although no evidence of oligodendrocyte loss was seen, nuclear changes were observed. To substantiate that remyelination was occurring, we measured MBP (18.5 kDa), MBP-exon II, Golli-MBP, TP8, Golli-MBP-J37, platelet-derived growth factor alpha (PDGFR alpha) and sonic hedgehog (SHH). Of these TP8, PDGFR alpha and SHH were up-regulated in the untreated transgenic. After paditaxel treatment, MBP-Exon II, TP8, PDGFR alpha and SHH were further up-regulated. We concluded that some of the effects of paditaxel were to stimulate proteins involved in early myelinating events possibly via a signal transduction mechanism.

Importance of gender and sex hormones in regulation of susceptibility of the small intestine to peroral infection with Toxoplasma gondii tissue cysts

This study was performed to investigate whether the gender and sex hormones play a role in susceptibility of the small intestine of mice to peroral infection with Toxoplasma gondii tissue cysts. Female animals died significantly earlier than males, and early mortality of females was associated with greater numbers of tachyzoites and severe necrosis in their small intestines. Treatment of female mice with testosterone resulted in markedly reduced intestinal parasite numbers and pathology. Thus, the gender and sex hormones are important factors for determining susceptibility of the small intestine to T. gondii infection.

Risk factors for HIV-1 seropositivity in drug users under 30 years old in Haiphong, Vietnam

AIMS

To assess the prevalence of HIV infection among young drug users in Haiphong and, secondarily, to document the current patterns of drug use and sexual behavior in them. Design, setting and participants. A cross-sectional survey of drug users 15-30 years old, identified from police lists and by the snowballing method between March 15 and May 30, 1999, was conducted in Haiphong City.

MEASUREMENTS

Subjects (n = 520: 514 males and six females) were interviewed and donated blood specimens for HIV-1 antibody testing.

FINDINGS

Mean age of the subjects was 25 years (range 15-30 years). The prevalence of HIV among injecting drug users (IDUs) was 74% and among drug users not reporting injecting was 46% (92/201). Sixty-one per cent (319) reported injecting drugs. Among injectors, 72% used heroin, and 68% had shared needles. Factors related to the presence of HIV antibody among IDUs were sharing needles (OR: 4.12) and injecting more than 31 times per month (OR: 2.37). Extramarital sex within the last 6 months was reported by 44% of single and 24% of married IDUs.

CONCLUSION

The high HIV-1 prevalence in drug users and their frequent sexual mixing with the non-drug-using population suggests that preventive interventions for reduction of high-risk drug taking and sexual activities are urgently needed in these populations. Interventions through public sexually transmitted infection (STI) clinics are unlikely to have much impact, as only 16% of IDUs with an STI attended a public STI clinic.

Single-residue alteration in alpha-conotoxin PnIA switches its nAChR subtype selectivity

alpha-Conotoxins are disulfide-rich peptides that are competitive antagonists of nicotinic acetylcholine receptors (nAChRs). Despite their small size, different alpha-conotoxins are able to discriminate among different subtypes of mammalian nAChRs. In this report, the activity of two peptides from the venom of Conus pennaceus, alpha-conotoxins PnIA and PnIB, are examined. Although the toxins differ in only two residues, PnIA preferentially blocks alpha3beta2 nAChRs, whereas PnIB prefers the alpha7 subtype. Point mutation chimeras of these alpha-conotoxins were synthesized and their activities assessed on Xenopus oocytes expressing specific nAChRs. Change of a single residue, Ala10 to Leu, in PnIA (to form PnIA [A10L]) converts the parent peptide from alpha3beta2-preferring to alpha7-preferring; furthermore, PnIA [A10L] blocks the alpha7 receptor with an IC(50) (12.6 nM) that is lower than that of either parent peptide. Kinetic analysis indicates that differences in affinity among the analogues are primarily due to differences in off-rate, with PnIA [A10L]'s interaction with alpha7 having the smallest off-rate (k(off) = 0.17 min(-)(1)). Thermodynamic analysis indicates that Leu10 enhances the peptide's interaction with alpha7, but not alpha3beta2, receptors, whereas Ser11 (in PnIA [N11S]) reduces its affinity for both alpha7 and alpha3beta2 nAChRs.

Interactions of nuclear receptor coactivator/corepressor proteins with the aryl hydrocarbon receptor complex

MCF-7 human breast cancer cells express the aryl hydrocarbon receptor (AhR), and treatment with AhR agonists such as 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) inhibits estrogen receptor (ER)-mediated responses. This study investigates physical and functional interactions of the AhR complex with a prototypical coactivator (estrogen receptor associating protein 140, ERAP 140) and corepressor (silencing mediator for retinoic acid and thyroid hormone receptor, SMRT) for ER and other members of the nuclear receptor superfamily. The AhR, AhR nuclear translocator (Arnt), and AhR/Arnt proteins were coimmunoprecipitated with 35S-ERAP 140 and 35S-SMRT and, in gel mobility shift assays, AhR/Arnt binding to 32P-dioxin response element (DRE) was enhanced by ERAP-140 and inhibited by SMRT; supershifted bands were not observed. In transactivation assays, coactivator and corepressor proteins enhanced or inhibited AhR-mediated gene expression; however, these responses varied with the amount of coactivator/corepressor expression. These results confirmed functional and physical interactions of AhR/Arnt with ERAP 140 and SMRT in breast cancer cells.

TNF-alpha, nitric oxide and IFN-gamma are all critical for development of necrosis in the small intestine and early mortality in genetically susceptible mice infected perorally with Toxoplasma gondii

We previously reported that genetic susceptibility of mice to peroral infection with T. gondii is associated with CD4+ T cell-dependent, interferon (IFN)-gamma-mediated necrosis of their small intestine. We examined the role of tumour necrosis factor (TNF)-alpha and nitric oxide (NO), in addition to IFN-gamma. At 7 days after infection, a marked increase in CD4+ T cells was observed in lamina propria mononuclear cells (LPC) of the small intestine as compared with normal mice, and significantly greater amounts of mRNA for IFN-gamma, TNF-alpha, and inducible NO synthase (iNOS) were detected in LPC of the small intestine of infected than uninfected animals. Treatment of infected mice with anti-TNF-alpha monoclonal antibody (mAb) or the iNOS inhibitor, aminoguanidine, prevented necrosis and prolonged time to death. Infected iNOS-targeted mutant mice did not develop the disease whereas infected, control mice did. Treatment with anti-TNF-alpha mAb did not affect the expression of IFN-gamma in the LPC but inhibited expression of iNOS in the infected mice, indicating the role of TNF-alpha in the induction of iNOS. These results suggest that NO induced by a combination of IFN-gamma and TNF-alpha through activation of iNOS is a critical mediator of intestinal pathology and contributes to early mortality in genetically susceptible mice.

The developmental expression and activity of peptidylarginine deiminase in the mouse

We have measured the expression and activity of peptidylarginine deiminase (PAD, EC 3.5.3.15), the enzyme responsible for converting arginyl residues in proteins to citrullines, in normal mouse brain homogenate. PAD transcripts were detected as early as five days and were maximal at one month of age. The enzyme protein was also detected at 5 days in an antibody dependent assay and was maximal at 2 months of age, 1 month later than the maximum expression of transcripts. As expected, enzyme activity had a similar developmental profile to that of the enzyme protein. In isolated mouse brain compact myelin, the activity was highest at 15 days and fell rapidly to 15% of this level by 1-2 months. In the 'loose' myelin fraction (heavy myelin) it remained at the same high level form from 15 days to 8 months. The activity in compact myelin was about 15 times greater than the activity in brain homogenate, suggesting much of the enzyme was localized to myelin.