Economic evaluations of radioembolization with yttrium-90 microspheres in liver metastases of colorectal cancer: a systematic review

BACKGROUND

Transarterial radioembolization with yttrium-90 (Y-90 TARE) microspheres therapy has demonstrated positive clinical benefits for the treatment of liver metastases from colorectal cancer (lmCRC). This study aims to conduct a systematic review of the available economic evaluations of Y-90 TARE for lmCRC.

METHODS

English and Spanish publications were identified from PubMed, Embase, Cochrane, MEDES health technology assessment agencies, and scientific congress databases published up to May 2021. The inclusion criteria considered only economic evaluations; thus, other types of studies were excluded. Purchasing-power-parity exchange rates for the year 2020 ($US PPP) were applied for cost harmonisation.

RESULTS

From 423 records screened, seven economic evaluations (2 cost-analyses [CA] and 5 cost-utility-analyses [CUA]) were included (6 European and 1 USA). All included studies (n = 7) were evaluated from a payer and the social perspective (n = 1). Included studies evaluated patients with unresectable liver-predominant metastases of CRC, refractory to chemotherapy (n = 6), or chemotherapy-naïve (n = 1). Y-90 TARE was compared to best supportive care (BSC) (n = 4), an association of folinic acid, fluorouracil and oxaliplatin (FOLFOX) (n = 1), and hepatic artery infusion (HAI) (n = 2). Y-90 TARE increased life-years gained (LYG) versus BSC (1.12 and 1.35 LYG) and versus HAI (0.37 LYG). Y-90 TARE increased the quality-adjusted-life-year (QALY) versus BSC (0.81 and 0.83 QALY) and versus HAI (0.35 QALY). When considering a lifetime horizon, Y-90 TARE reported incremental cost compared to BSC (range 19,225 to 25,320 $US PPP) and versus HAI (14,307 $US PPP). Y-90 TARE reported incremental cost-utility ratios (ICURs) between 23,875 $US PPP/QALY to 31,185 $US PPP/QALY. The probability of Y-90 TARE being cost-effective at £ 30,000/QALY threshold was between 56% and 57%.

CONCLUSIONS

Our review highlights that Y-90 TARE could be a cost-effective therapy either as a monotherapy or when combined with systemic therapy for treating ImCRC. However, despite the current clinical evidence on Y-90 TARE in the treatment of ImCRC, the global economic evaluation reported for Y-90 TARE in ImCRC is limited (n = 7), therefore, we recommend future economic evaluations on Y-90 TARE versus alternative options in treating ImCRC from the societal perspective.

Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM

Transmission spectroscopy1-3 of exoplanets has revealed signatures of water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations' relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species-in particular the primary carbon-bearing molecules6,7. Here we report a broad-wavelength 0.5-5.5 µm atmospheric transmission spectrum of WASP-39b8, a 1,200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with the JWST NIRSpec's PRISM mode9 as part of the JWST Transiting Exoplanet Community Early Release Science Team Program10-12. We robustly detect several chemical species at high significance, including Na (19σ), H2O (33σ), CO2 (28σ) and CO (7σ). The non-detection of CH4, combined with a strong CO2 feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4 µm is best explained by SO2 (2.7σ), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST's sensitivity to a rich diversity of exoplanet compositions and chemical processes.

Economic evaluations of radioembolization with Itrium-90 microspheres in hepatocellular carcinoma: a systematic review

Background

Transarterial radioembolization (TARE) with yttrium-90 microspheres is a clinically effective therapy for hepatocellular carcinoma (HCC) treatment. This study aimed to perform a systematic review of the available economic evaluations of TARE for the treatment of HCC.

Methods

The Preferred Reported Items for Systematic reviews and Meta-Analyses guidelines was followed by applying a search strategy across six databases. All studies identified as economic evaluations with TARE for HCC treatment in English or Spanish language were considered. Costs were adjusted using the 2020 US dollars based on purchasing-power-parity ($US PPP).

Results

Among 423 records screened, 20 studies (6 cost-analyses, 3 budget-impact-analyses, 2 cost-effectiveness-analyses, 8 cost-utility-analyses, and 1 cost-minimization analysis) met the pre-defined criteria for inclusion. Thirteen studies were published from the European perspective, six from the United States, and one from the Canadian perspectives. The assessed populations included early- (n = 4), and intermediate-advanced-stages patients (n = 15). Included studies were evaluated from a payer perspective (n = 20) and included both payer and social perspective (n = 2). TARE was compared with transarterial chemoembolization (TACE) in nine studies or sorafenib (n = 11). The life-years gained (LYG) differed by comparator: TARE versus TACE (range: 1.3 to 3.1), and TARE versus sorafenib (range: 1.1 to 2.53). Of the 20 studies, TARE was associated with lower treatment costs in ten studies. The cost of TARE treatment varied widely according to Barcelona Clinic Liver Cancer (BCLC) staging system and ranged from 1311 $US PPP/month (BCLC-A) to 71,890 $US PPP/5-years time horizon (BCLC-C). The incremental cost-utility ratio for TARE versus TACE resulted in a 17,397 $US PPP/Quality-adjusted-Life-Years (QALY), and for TARE versus sorafenib ranged from dominant (more effectiveness and lower cost) to 3363 $US PPP/QALY.

Conclusions

Economic evaluations of TARE for HCC treatment are heterogeneous. Overall, TARE is a cost-effective short- and long-term therapy for the treatment of intermediate-advanced HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02396-6.

Disparities in post-operative surveillance testing for metastatic recurrence among colorectal cancer survivors

PURPOSE

Among colorectal cancer (CRC) survivors, treatment for metastatic recurrence is most effective when malignancies are detected early through surveillance with carcinoembryonic antigen (CEA) level test and computer tomography (CT) imaging. However, utilization of these tests is low, and many survivors fail to meet the recommended guidelines. This population-based study assesses individual- and neighborhood-level factors associated with receipt of CEA and CT surveillance testing.

METHODS

We used the Surveillance, Epidemiology and End Results (SEER)-Medicare data to identify Medicare beneficiaries diagnosed with CRC stages II-III between 2010 and 2013. We conducted multivariate logistic regression to estimate the effect of individual and neighborhood factors on receipt of CEA and CT tests within 18 months post-surgery.

RESULTS

Overall, 78% and 58% of CRC survivors received CEA and CT testing, respectively. We found significant within racial/ethnic differences in receipt of these surveillance tests. Medicare-Medicaid dual coverage was associated with 39% lower odds of receipt of CEA tests among non-Hispanic Whites, and Blacks with dual coverage had almost two times the odds of receiving CEA tests compared to Blacks without dual coverage.

CONCLUSIONS

Although this study did not find significant differences in receipt of initial CEA and CT surveillance testing across racial/ethnic groups, the assessment of the factors that measure access to care suggests differences in access to these procedures within racial/ethnic groups.

IMPLICATIONS FOR CANCER SURVIVORS

Our findings have implications for developing targeted interventions focused on promoting surveillance for the early detection of metastatic recurrence among colorectal cancer survivors and improve their health outcomes.

A Cell Culture-Adapted Vaccine Virus against the Current African Swine Fever Virus Pandemic Strain

African swine fever virus (ASFV) causes a virulent, deadly infection in wild and domestic swine and is currently causing a pandemic covering a contiguous geographical area from Central and Eastern Europe to Asia. No commercial vaccines are available to prevent African swine fever (ASF), resulting in devastating economic losses to the swine industry. The most advanced vaccine candidates are live attenuated strains developed using a genetically modified virulent parental virus. Recently, we developed a vaccine candidate, ASFV-G-ΔI177L, by deleting the I177L gene from the genome of the highly virulent ASFV pandemic strain Georgia (ASFV-G). ASFV-G-ΔI177L is safe and highly efficacious in challenge studies using parental ASFV-G. Large-scale production of ASFV-G-ΔI177L has been limited because it can replicate efficiently only in primary swine macrophages. Here, we present the development of an ASFV-G-ΔI177L derivative strain, ASFV-G-ΔI177L/ΔLVR, that replicates efficiently in a stable porcine cell line. In challenge studies, ASFV-G-ΔI177L/ΔLVR maintained the same level of attenuation, immunogenic characteristics, and protective efficacy as ASFV-G-ΔI177L. ASFV-G-ΔI177L/ΔLVR is the first rationally designed ASF vaccine candidate that can be used for large-scale commercial vaccine manufacture. IMPORTANCE African swine fever is currently causing a pandemic resulting in devastating losses to the swine industry. Experimental ASF vaccines rely on the production of vaccine in primary swine macrophages, which are difficult to use for the production of a vaccine on a commercial level. Here, we report a vaccine for ASFV with a deletion in the left variable region (LVR). This deletion allows for growth in stable cell cultures while maintaining the potency and efficacy of the parental vaccine strain. This discovery will allow for the production of an ASF vaccine on a commercial scale.

A nearby transiting rocky exoplanet that is suitable for atmospheric investigation

Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. The planet Gliese 486 b is 2.81 Earth masses and 1.31 Earth radii, with uncertainties of 5%, as determined from RV data and photometric light curves. The host star is at a distance of ~8.1 parsecs, has a J-band magnitude of ~7.2, and is observable from both hemispheres of Earth. On the basis of these properties and the planet's short orbital period and high equilibrium temperature, we show that this terrestrial planet is suitable for emission and transit spectroscopy.

Evaluation of the immunogenicity and protective efficacy of a recombinant CS6-based ETEC vaccine in an Aotus nancymaae CS6 + ETEC challenge model

Colonization factors or Coli surface antigens (CFs or CS) are important virulence factors of Enterotoxigenic E. coli (ETEC) that mediate intestinal colonization and accordingly are targets of vaccine development efforts. CS6 is a highly prevalent CF associated with symptomatic ETEC infection both in endemic populations and amongst travelers. In this study, we used an Aotus nancymaae non-human primate ETEC challenge model with a CS6 + ETEC strain, B7A, to test the immunogenicity and protective efficacy (PE) of a recombinant CS6-based subunit vaccine. Specifically, we determined the ability of dscCssBA, the donor strand complemented recombinant stabilized fusion of the two subunits of the CS6 fimbriae, CssA and CssB, to elicit protection against CS6 + ETEC mediated diarrhea when given intradermally (ID) with the genetically attenuated double mutant heat-labile enterotoxin LT(R192G/L211A) (dmLT). ID vaccination with dscCssBA + dmLT induced strong serum antibody responses against CS6 and LT. Importantly, vaccination with dscCssBA + dmLT resulted in no observed diarrheal disease (PE = 100%, p = 0.03) following B7A challenge as compared to PBS immunized animals, with an attack rate of 62.5%. These data demonstrate the potential role that CS6 may play in ETEC infection and that recombinant dscCssBA antigen can provide protection against challenge with the homologous CS6 + ETEC strain, B7A, in the Aotus nancymaae diarrheal challenge model. Combined, these data indicate that CS6, and more specifically, a recombinant engineered derivative should be considered for further clinical development.

Frequency of the CYP2C19*17 polymorphism in a Chilean population and its effect on voriconazole plasma concentration in immunocompromised children

Invasive fungal infections (IFIs) are the most frequent cause of morbidity and mortality in immunocompromised children. Voriconazole is the first-line antifungal choice in the treatment of IFIs like aspergillosis. Voriconazole pharmacokinetics vary widely among patients and voriconazole is metabolized mainly in the liver by the CYP2C19 enzyme, which is highly polymorphic. The CYP2C19*17 allele is characterized by the presence of four single nucleotide polymorphisms expressing an ultra-rapid enzyme phenotype with an accelerated voriconazole metabolism, is associated with low (sub-therapeutic) plasma levels in patients treated with the standard dose. Considering that in our center a high percentage of children have sub-therapeutic levels of voriconazole when treated with standard doses, we sought to determine the frequency of the CYP2C19*17 polymorphism (rs12248560) in a Chilean population and determine the association between voriconazole concentrations and the rs12248560 variant in immunocompromised children. First, we evaluated the frequency of the rs12248560 variant in a group of 232 healthy Chilean children, and we found that 180 children (77.6%) were non-carriers of the rs12248560 variant, 49 children (21.1%) were heterozygous carriers for rs12248560 variant and only 3 children (1.3%) were homozygous carriers for rs12248560 variant, obtaining an allelic frequency of 12% for variant in a Chilean population. To determine the association between voriconazole concentrations and the rs12248560 variant, we analyzed voriconazole plasma concentrations in a second group of 33 children treated with voriconazole. In these patients, carriers of the rs12248560 variant presented significantly lower voriconazole plasma concentrations than non-carriers (p = 0,011). In this study, we show the presence of the rs12248560 variant in a Chilean population and its accelerating effect on the pharmacokinetics of voriconazole in pediatric patients. From these data, it would be advisable to consider the variant of the patient prior to calculating the dosage of voriconazole.

The role of diet in children's exposure to organophosphate pesticides

BACKGROUND

Studies suggest that some of the greatest exposure to OPs in children occurs in agricultural communities and various pathways of exposure including the take-home pathway, proximity to orchards, and diet have been explored. However, the importance of the dietary pathway of exposure for children in agricultural communities is not well understood.

OBJECTIVES

Our goal was to ascertain whether there were associations between measures of OP exposure and apple juice, fruit, and vegetable consumption across growing seasons by children of farmworkers and non-farmworkers in a rural agricultural setting.

METHODS

Study participants were children of farmworker (N=100) or non-farmworker (N=100) households from a longitudinal cohort study. Dietary intake of fruits and vegetables was assessed using a "5-A-Day" abbreviated food frequency questionnaire, and exposure to OPs was characterized using three urinary di-methyl and three di-ethyl metabolite measurements per child for each of three growing seasons. We used generalized estimating equations to examine data.

RESULTS

Consumption frequency of fruits and vegetables was similar between children of farmworkers and non-farmworkers and across seasons. There were a few significant trends between dimethyl metabolites (DMAP) and fruit, vegetable or apple juice consumption; however, no clear pattern held across seasons or occupation. One difference was found in vegetable consumption during the harvest season, where the farmworker families showed a significant relationship between vegetable consumption and dimethyl metabolite levels (p=0.002). We also found a significant difference in this relationship between farmworkers and non-farmworkers (p=0.001). No significant trends between fruit and vegetable consumption and diethyl (DEAP) metabolites were found.

CONCLUSIONS

Our study shows the importance of considering season and parents' occupation in understanding OP exposure routes among children in an agricultural community. The impact of these factors on dietary OP exposure requires a more thorough analysis of the availability and consumption of produce from different sources including farms using pesticides where parents worked.

An innovative strategy to reach the underserved for colorectal cancer screening

Hispanics are an underserved population in terms of colorectal cancer (CRC). CRC is the second leading cause of cancer incidence among Hispanic men and women, and Hispanics have lower screening rates than non-Hispanic whites. The overall purpose of this project was to provide CRC information, education, and fecal occult blood test (FOBT) kits to Hispanics in a rural three-county region of Washington State. We held a series of 47 community health fair events that incorporated the use of a giant inflatable, walk-through colon model with physical depictions of healthy tissue, polyps, and CRC. We used a pre/post-design to look for changes in familiarity with CRC before and after walking through the colon among adults aged 18 and older (n = 947). McNemar's test analysis indicated significant differences in the distribution of the percentage of correct participant responses to CRC-related questions from pre- to post-test after an educational tour of the colon. Results from logistic regression analysis identified multiple participant characteristics associated with self-reported likelihood of being screened for CRC in 3 months following post-test. We distributed 300 free FOBT kits to be analyzed at no charge to the end user and to attendees aged 50 and older who toured the inflatable colon; 226 FOBT kits (75.3%) were returned for analysis. The use of the inflatable colon was an innovative way to attract people to learn about CRC and CRC screening modalities. Furthermore, the response to our distribution of FOBT kits indicates that if given the opportunity for education and access to services, this underserved population will comply with CRC screening.

Psychological distress, social withdrawal, and coping following receipt of an abnormal mammogram among different ethnicities: a mediation model

PURPOSE/OBJECTIVES

To explore ethnic differences in psychological distress and social withdrawal after receiving an abnormal mammogram result and to assess if coping strategies mediate ethnic differences.

DESIGN

Descriptive correlational.

SETTING

Two urban mobile mammography units and a rural community hospital in the state of Washington.

SAMPLE

41 Latina and 41 non-Latina Caucasian (NLC) women who had received an abnormal mammogram result.

METHODS

Women completed standard sociodemographic questions, Impact of Event Scale-Revised, the social dimension of the Psychological Consequences Questionnaire, and the Brief COPE.

MAIN RESEARCH VARIABLES

Ethnicity, psychological distress, social withdrawal, and coping.

FINDINGS

Latinas experienced greater psychological distress and social withdrawal compared to NLC counterparts. Denial as a coping strategy mediated ethnic differences in psychological distress. Religious coping mediated ethnic differences in social withdrawal.

CONCLUSIONS

Larger population-based studies are necessary to understand how ethnic differences in coping strategies can influence psychological outcomes. This is an important finding that warrants additional study among women who are and are not diagnosed with breast cancer following an abnormal mammogram.

IMPLICATIONS FOR NURSING

Nurses may be able to work with Latina patients to diminish denial coping and consequent distress. Nurses may be particularly effective, given cultural values concerning strong interpersonal relationships and respect for authority figures.

Breast cancer interventions serving US-based Latinas: current approaches and directions

Despite efforts to reduce morbidity and mortality in breast cancer, Latinas continue to have lower 5-year survival rates than their non-Latina white counterparts. All along the cancer continuum from screening to follow-up of abnormal screening to diagnosis and treatment to survivorship, Latinas fare poorer than non-Latina whites. To close this gap, a number of research projects across the continuum have attempted to improve breast cancer outcomes. In this review, we examine studies that have been carried out in breast cancer along the cancer continuum. We focus not only on randomized, controlled trials, but also on quasi-experimental, and pre- and post-test studies that provided interventions for positive breast cancer outcomes. We examine not only the intervention outcomes, but also the type of intervention targets and type of intervention implementation. In future breast cancer research among Latinas, more emphasis should be placed on the steps in detection and treatment that occur after screening.

Issues in biomedical research: what do Hispanics think?

OBJECTIVE

To examine barriers and facilitators of biomedical research participation among Hispanics in a rural community in Washington State.

METHODS

Questionnaires addressed socio-demographics, health care access, and barriers and facilitators of participation in biomedical studies. This is a descriptive analysis of the findings.

RESULTS

Barriers include the need to care for family members (82%), fear of having to pay for research treatments (74%), cultural beliefs (65%), lack of time (75%) and trust (71%), and the degree of hassle (73%). Facilitators include having a friend/relative with the disease being researched (80%) and monetary compensation (73%).

CONCLUSION

Researchers should be mindful of these facilitators and barriers when recruiting for biomedical research studies.

Abstract A19: CASPER the colon: An innovative way to influence colorectal cancer screening

Introduction: Hispanics are an underserved population in terms of cancer screening. In colorectal cancer (CRC) screening, for example, recent national data shows that only 7.8% of Hispanics have had a fecal occult blood test (FOBT) within the past year compared to 10.3% for non-Hispanic whites . Similarly, rates for CRC screening with endoscopy (sigmoidoscopy within past 5 years or colonoscopy within past 10 years) are 34.6% for Hispanics and 52.7% for non-Hispanic whites. Hispanics have lower CRC screening rates than any other minority group in the U.S. and therefore are more likely to be diagnosed with advanced stage CRC than their non-Hispanic white counterparts. As a result, Hispanics have poorer survival outcomes from CRC.

Description: In the Lower Yakima Valley of Washington State, a largely rural area with an emphasis on agriculture, a high proportion of the population is Hispanic (~79%). As part of our National Cancer Institute (NCI)-sponsored Community Networks Program Center (CNPC), based on a community needs assessment, we have been emphasizing CRC screening among this population over the last year. In a series of health fairs (N=45), we used a walk-through inflatable colon with physical depictions of polyps and cancers to educate the population about CRC and the importance of early detection through regular screening. Through a collaboration with a local community hospital, we were able to distribute FOBT kits to be analyzed at no charge to the end-user to attendees aged 55 and older.

Data Summary: Within less than a year, over 2000 people have walked through the colon. Over 700 have completed pre- and post-tests on knowledge about CRC as well as intention to be screened for CRC. Significant advances in knowledge were seen (from a combined knowledge score of 0.395 (low) at pre-test to 0.869 (high) at post-test). Similar results were seen for intention to be screened (64.3% likely at pre-test and 75.8% likely at post-test). To date, of the 300 FOBT kits distributed, 202 (67.3%) have been returned for analysis. Of those 7 were abnormal. Various sites in the community have offered low-cost or free colonoscopies for follow-up of the abnormal tests.

Conclusions: Health fairs serve as an effective venue to reach Hispanics in this rural area of Washington State. The use of CASPER the “colossal” colon is an innovative way to attract people to learn about CRC and CRC screening modalities. The response to our distribution of FOBT kits indicates that if given the opportunity for education and access to services, this population will comply with CRC screening.

Citation Format: Katherine J. Briant, Elizabeth Carosso, Avigail Galvan, Adriana Moya, Noah Espinoza, Ilda Islas, Genoveva Ibarra, Sandra Linde, Beti Thompson. CASPER the colon: An innovative way to influence colorectal cancer screening. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr A19.

Educating Hispanic women about breast cancer prevention: evaluation of a home-based promotora-led intervention

OBJECTIVES

Trained community health promoters (i.e., promotoras) conducted home-based group educational interventions (home health parties) to educate Hispanic women from the Lower Yakima Valley of Washington state about breast cancer and mammography screening.

METHODS

Women aged 40-79 participating in the parties completed baseline and follow-up surveys 6 months postintervention (n = 70). Changes in general cancer knowledge, breast cancer screening practices, and intentions to be screened among participants from baseline to follow-up were measured using McNemar's test for marginal homogeneity to evaluate the effectiveness of the parties.

RESULTS

The average age of the sample was 50.0 years (standard deviation [SD] 10.0), 84% reported less than an eighth grade education, and 54% were covered by the state's Basic Health Care Plan. Significant changes between baseline and follow-up were observed with respect to (1) believing that risk of cancer could not be reduced (41% vs. 15%, respectively, p = 0.001), (2) ever having a mammogram (83% vs. 91%, p = 0.014), (3) discussing a mammogram with a doctor (37% vs. 67%, p < 0.001), and (4) intending to have a mammogram within the next few months among women who did not report having a mammogram between baseline and follow-up (61% vs. 81%, p = 0.046).

CONCLUSIONS

Participation in home-based group educational interventions delivered by promotoras may be associated with improved breast cancer screening practices among Hispanic women.

Progesterone pre-treatment potentiates EGF pathway signaling in the breast cancer cell line ZR-75

Progesterone in hormone replacement therapy (HRT) preparations increases, while hysterectomy greatly reduces, the incidence of breast cancer. Cross-talk between the progesterone and growth factor signaling pathways occurs at multiple levels and this maybe a key factor in breast cancer survival and progression. To test this hypothesis, we characterized the effect of progesterone pre-treatment on the sensitization of the epidermal growth factor (EGF) signaling pathway to EGF in the breast cancer cell line ZR-75. For the first time in ZR-75 cells and in agreement with previous work using synthetic progestins, we demonstrate that pre-treatment with the natural ligand progesterone increases EGF receptor (EGFR) levels and subsequent ligand-dependent phosphorylation. Downstream we demonstrate that progesterone alone increases erk-1 + 2 phosphorylation, potentiates EGF-phosphorylated erk-1 + 2 and maintains these levels elevated for 24 h; over 20 h longer than in vehicle treated cells. Additionally, progesterone increased the levels of STAT5, another component of the EGF signaling cascade. Progesterone increased EGF mediated transcription of a c-fos promoter reporter and the nuclear localization of the native c-fos protein. Furthermore, progesterone and EGF both alone and in combination, significantly increase cell proliferation. Several results presented herein demonstrate the conformity between the action of the natural ligand progesterone with that of synthetic progestins such as MPA and R5020 and allows the postulation that the progestin/progesterone-dependent increase of EGF signaling provides a survival advantage to burgeoning cancer cells and may contribute to the breast cancer risk associated with endogenous progesterone and with progestin-containing HRT.

Cross-resistance to ACCase inhibitors of Lolium multiflorum, Lolium perenne and Lolium rigidum found in Chile

APPs (aryloxyphenoxypropionates) and CHDs (cyclohexanediones) are two of the most important groups used post-emergence for the control of grass weeds. They inhibit the lipid synthesis in plants by interfering with the activity of the enzyme Acetyl-coenzyme A carboxylase (ACCase), acting at a meristematic level. The resistance patterns of the biotypes characterized seem to indicate the existence of different degrees of resistance. It is thus possible to identify biotypes presenting cross-resistance only to certain APPs, to APPs and CHDs, or only to CHDs. The objective of this work was to evaluate the cross-resistance to fenoxaprop-P-ethyl, fluazifop-P-butyl, propaquizafop, cyhalofop-butyl, haloxyfop-R-methyl, tralkoxydim and tepraloxydim in three species of Lolium (L. multiflorum, L. perenne, and L. rigidum) resistant to diclofop-methyl. The assays were conducted with petri-dishes in which, over increasing doses, fifty seeds per biotype and dose were located in each dish. Two weeks later, the following parameters were evaluated: germination (%), number of roots, radicle length, plumule length, and fresh weight reduction (%). Based on plumule length and fresh weight reduction (%), diclofop-methyl resistant biotypes showed cross-resistance to fenoxaprop-P-ethyl, fluazifop-P-butyl, cyhalofop-butyl, haloxyfop-R-methyl, but not to propaquizafop, tralkoxydim and tepraloxydim. The parameters germination (%), number of roots or root length did not show a good relation between the dose and its efficacy (curves of dose response) for any of the susceptible and resistant biotypes studied.

[Auditory brainstem evoked potentials in hearing loss after bacterial meningitis]

Fourteen children with acute bacterial meningitis, were examined for auditory brainstem evoked potentials (ABEP) during their initial hospital course (days 3 to 24 from admission). Different degrees of neurosensory hypoacusia were detected in 8 patients (57.14%). Children aged less than one year seemed to be more susceptible to auditory deficit. In 6 children a second ABEP was done after a time interval which ranged from 20 to 570 days after the first one and all them showed residual hypoacusia. The short term evolution suggests that the acute process can be prolonged for more than 1 month after hospital admittance, and the altered auditory function tends to persist over the mid term. It is concluded that despite this research's methodological limitations. ABEP seem useful for early detection of postmeningitical neurosensory hypoacusia and follow-up of these patients.