Perinatal health in Spain during and after the Great Recession: Educational selection into fertility as a protective factor in high unemployment contexts

Higher maternal resources have long been associated with superior birth outcomes. This study analyzes the potentially protective role of maternal educational selection into fertility in adverse macroeconomic contexts. We focus on the case of Spain, a country reaching record-high unemployment levels during the Great Recession starting in 2008. First, we examine whether selection into fertility of more educated mothers took place as province-level unemployment rates rose. Secondly, we assess whether maternal education mitigated the impact of higher unemployment levels on different birth outcomes. The analysis combines register data on the universe of live births with aggregate data on province-level unemployment. We cover the period 2007-2019 to ensure sufficient variability of unemployment rates and perform linear regression and linear probability models with fixed effects to hold constant unobserved heterogeneity across provinces. Findings indicate selection into fertility of mothers with university-level education in times of high unemployment. In addition, while unemployment rates did show an adverse impact on certain birth outcomes -birthweight, the occurrence of low and very low birthweight, and the risk of stillbirth - maternal education mitigated the observed relations. It was itself, moreover, consistently and independently associated with better perinatal health. We thus conclude that fertility selectivity by maternal education cushioned the impact of the adverse economic context derived from the Great Recession through two separate pathways.

PFO closure for the prevention of cerebrovascular events in high-risk individuals: an updated and across-the-board meta-analysis

Introduction

Patent foramen ovale (PFO) closure has emerged as a secondary prevention option in patients with PFO and cerebrovascular events. Despite its seemingly established efficacy, its associated long-term outcomes – including safety – remain unclear.

Purpose

To ascertain the extent to which PFO percutaneous closure is able to improve long-term clinical outcomes in patients with cryptogenic vascular events.

Methods

We systematically searched MEDLINE, Embase and Cochrane CENTRAL for randomized controlled trials (RCTs) and observational studies comparing PFO percutaneous closure with antithrombotic therapy, in what concerns recurrent cerebrovascular and serious adverse events, as well as mortality. A composite of stroke and transient ischemic attack (TIA) was the primary endpoint. Data related to RCTs, patients with high-risk PFO features, subjected to PFO closure with the most represented device and with antiplatelet therapy as control were further investigated separately. Study-specific odds ratios (ORs) were pooled using traditional meta-analytic techniques, under a random- (DerSimonian-Laird method) or a fixed-effects (Mantel-Haenszel method) model.

Results

Literature search yielded 2145 references, of which 26 – 8 regarding RCTs – were included. Patients undergoing PFO closure reached 4304, whereas 4180 were treated with antithrombotic therapy. PFO closure was significantly associated with lower stroke/TIA recurrence (OR 0.35 [0.24–0.53], I2=58%). Moreover, such reduction met statistical significance for both stroke (OR 0.34 [0.21–0.54], I2=29%) and TIA (OR 0.53 [0.34–0.82], I2=39%), individually. Subgroup analyses focusing only on RCTs and on studies featuring the most represented device confirmed these trends, while the effects were even more pronounced in patients with high-risk PFO characteristics and in those controlled with antiplatelet therapy. On the other hand, PFO closure was not associated with neither lower all-cause (OR 0.76 [0.46–1.27], I2=0%) nor lower cardiovascular mortality (OR 0.92 [0.37–2.29], I2=0%). Moreover, neither a composite of serious adverse events (SAEs) (OR 1.10 [0.94–1.29], I2=0%) nor major bleeding episodes (OR 0.75 [0.40–1.38], I2=23%) differed significantly between groups. However, PFO closure was associated with increased odds of procedure- or device-related complications (OR 12.94 [5.56–30.13], I2=0%) and atrial fibrillation or flutter (OR 3.35 [1.78–6.30], I2=30%).

Conclusion

In patients with history of cryptogenic vascular events, when compared with medical management, PFO percutaneous closure is indeed associated with a reduction in the odds of recurrent stroke and TIA. However, mortality seems not to be impacted by this apparently enhanced effect. While general SAEs and major bleeding are comparable between both approaches, PFO closure may bring upon procedure- or device-related complications and increase the odds of atrial fibrillation or flutter.

Funding Acknowledgement

Type of funding sources: None.

Fetal neurosonography at 31-35 weeks reveals altered cortical development in pre-eclampsia with and without small-for-gestational-age fetus

OBJECTIVE

To explore the pattern of fetal cortical development in pregnancies complicated by pre-eclampsia (PE), with and without a small-for-gestational-age (SGA) fetus, compared to uncomplicated pregnancies.

METHODS

This was a prospective observational study including singleton pregnancies complicated by normotensive SGA (birth weight < 10^th centile) (n = 77), PE with an appropriate-for-gestational-age (AGA) fetus (n = 76) or PE with a SGA fetus (n = 67), and 128 uncomplicated pregnancies (normotensive AGA) matched by gestational age at ultrasound. All pregnancies underwent detailed neurosonography, using a transabdominal and transvaginal approach, at 31-35 weeks' gestation to assess the depth of the insula, Sylvian fissure, parieto-occipital sulcus, cingulate sulcus and calcarine sulcus. All measurements were adjusted for biparietal diameter (BPD). In addition, a grading score of cortical development was assigned to each brain structure, ranging from Grade 0 (no development) to Grade 5 (maximum development). Univariate and multiple regression analyses were conducted.

RESULTS

Similar to findings in previous studies, normotensive pregnancies with a SGA fetus showed significant differences in cortical development compared with controls, with reduced Sylvian fissure depth adjusted for BPD (14.5 ± 2.4 vs 16.6 ± 2.3; P < 0.001) and increased insula depth adjusted for BPD (33.2 ± 2.0 vs 31.8 ± 2.0; P < 0.001). Interestingly, a similar cortical development pattern was observed in PE pregnancies with a SGA fetus and in PE pregnancies with an AGA fetus, manifested by reduced Sylvian fissure depth adjusted for BPD (14.2 ± 2.3 and 14.3 ± 2.3 vs 16.6 ± 2.3; P < 0.001 for both) and greater insula depth adjusted for BPD (33.2 ± 2.1 and 32.8 ± 1.7 vs 31.8 ± 2.0; P < 0.001 for both) compared with controls. No significant differences were observed in parieto-occipital, cingulate sulcus or calcarine sulcus depth across the study groups. The Sylvian fissure was scored as Grade 4 in significantly more (93.2% vs 59.5%) and as Grade 5 in significantly fewer (2.7% vs 37.3%) PE pregnancies with an AGA fetus compared with controls (P < 0.05 for both). These differences remained significant even after statistical adjustment for potential confounders, including ethnicity, low socioeconomic status, nulliparity, chronic hypertension, pregestational diabetes, assisted reproductive technologies, smoking and fetal gender, with the application of Benjamini-Hochberg procedure for multiple comparisons.

CONCLUSIONS

PE with or without SGA is associated with a differential fetal cortical development pattern which is similar to that described previously in small fetuses. Future research is warranted to elucidate better the mechanism(s) underlying these changes. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal endoscopic tracheal occlusion reverses the natural history of right-sided congenital diaphragmatic hernia: European multicenter experience

OBJECTIVE

To evaluate the neonatal outcome of fetuses with isolated right-sided congenital diaphragmatic hernia (iRCDH) based on prenatal severity indicators and antenatal management.

METHODS

This was a retrospective review of prospectively collected data on consecutive cases diagnosed with iRCDH before 30 weeks' gestation in four fetal therapy centers, between January 2008 and December 2018. Data on prenatal severity assessment, antenatal management and perinatal outcome were retrieved. Univariate and multivariate logistic regression analysis were used to identify predictors of survival at discharge and early neonatal morbidity.

RESULTS

Of 265 patients assessed during the study period, we excluded 40 (15%) who underwent termination of pregnancy, two cases of unexplained fetal death, two that were lost to follow-up, one for which antenatal assessment of lung hypoplasia was not available and six cases which were found to have major associated anomalies or syndromes after birth. Of the 214 fetuses with iRCDH included in the neonatal outcome analysis, 86 were managed expectantly during pregnancy and 128 underwent fetal endoscopic tracheal occlusion (FETO) with a balloon. In the expectant-management group, lung size measured by ultrasound or by magnetic resonance imaging was the only independent predictor of survival (observed-to-expected lung-to-head ratio (o/e-LHR) odds ratio (OR), 1.06 (95% CI, 1.02-1.11); P = 0.003). Until now, stratification for severe lung hypoplasia has been based on an o/e-LHR cut-off of 45%. In cases managed expectantly, the survival rate was 15% (4/27) in those with o/e-LHR ≤ 45% and 61% (36/59) for o/e-LHR > 45% (P = 0.001). However, the best o/e-LHR cut-off for the prediction of survival at discharge was 50%, with a sensitivity of 78% and specificity of 72%. In the expectantly managed group, survivors with severe pulmonary hypoplasia stayed longer in the neonatal intensive care unit than did those with mildly hypoplastic lungs. In fetuses with an o/e-LHR ≤ 45% treated with FETO, survival rate was higher than in those with similar lung size managed expectantly (49/120 (41%) vs 4/27 (15%); P = 0.014), despite higher prematurity rates (gestational age at birth: 34.4 ± 2.7 weeks vs 36.8 ± 3.0 weeks; P < 0.0001). In fetuses treated with FETO, gestational age at birth was the only predictor of survival (OR, 1.25 (95% CI, 1.04-1.50); P = 0.02).

CONCLUSIONS

Antenatal measurement of lung size can predict survival in iRCDH. In fetuses with severe lung hypoplasia, FETO was associated with a significant increase in survival without an associated increase in neonatal morbidity. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

P4396Patients explanations of self-care in chronic heart failure: a grounded theory analysis of qualitative data from PANACEA-HF Phase 1

Background

Sub-optimal self-care and non-adherence to treatments are important predictors of poor clinical outcomes in patients with heart failure. Task-sharing and technology have each contributed modest improvements, but the combined effect on outcomes is unknown. We aim to develop a complex intervention package to improve self-care predicated on task sharing and smartphone based remote monitoring among heart failure patients.

Purpose

As a formative step, we conducted a qualitative study among heart failure patients and their caregivers to explore self-care and to inform the development of a contextualized intervention package.

Methods

We conducted in-depth interviews among 22 patients admitted to in-patient wards with a clinical diagnosis of chronic heart failure (diagnosis made at least 1 month prior to index hospitalization) and 18 caregivers (n=40), sampled from 4 states in southern India. Patients were purposively sampled based on sex, socioeconomic status, health literacy and past one month's history of adherence to heart failure medications. The middle range theory of self-care informed the drafting of the interview guide. We recorded and transcribed interviews translated from 5 regional languages. We inductively coded the data from a social constructionist viewpoint, created categories, prepared memos, compared extreme cases, identified key emergent themes and their inter-relationships.

Results

Patients' mean age was 60.5 (±13.4), with representation from socioeconomic strata, urban and rural areas. Patients had a high pill burden [median 10; IQR (6, 31)] and 8 (44%) reported irregular adherence to prescribed medications in the last month. Key categories associated with sub-optimal self-care included “Passivity”, “Entrenched Belief systems”, “Negative Emotions/Affect”, “Ageing causes disease”, and “inability to control situations” across all socioeconomic strata. These themes appear to impair self-actualization that negatively impacts self efficacy/confidence and in turn self-care reciprocally (Refer Figure). Key facilitators of self-care were: Intrinsic patient distinctive facilitators (situational awareness, resilience) and extraneous facilitators (insurance/financial protection, positive caregiver relationships and ease of healthcare access). Patients and caregivers generally expressed their readiness to use mobile technology for remote monitoring and to be counseled by trained lay workers to address beliefs and be trained on self-care.

Framework explaining self-care in HF

Conclusions

Findings from this formative study show opportunities for providers and community-based care workers to address task-sharing of beliefs by educating patients on self-care, including through the use of technology-based solutions. These findings regarding a self-care framework identify opportunities to improve self-care among heart failure patients using task-sharing and technology to support the patient-caregiver-provider triad.

Acknowledgement/Funding

India Alliance - Wellcome Trust and Department of Biotechnology

Abstract P1-14-02: A phase 2 study of low dose metronomic eribulin in metastatic breast cancer

Background: Eribulin mesylate is a non-taxane microtubule dynamics inhibitor approved by FDA in treatment of metastatic breast cancer (MBC) based on improvements in overall survival in the pivotal EMBRACE trial. Eribulin is approved at 1.4mg/m2 administered D1,8 of q21d cycle. However, this dose and schedule may have significant myelosuppression and peripheral neuropathy requiring dose reductions and treatment delays for some patients. We hypothesized that a low dose metronomic schedule will allow responding patients to remain on treatment, resulting in longer TTP (time to progression) and decreased incidence of toxicities and treatment-related discontinuations.

Methods: A multi-site prospective open-label phase II trial of metronomic dosing of eribulin in patients with MBC has completed accrual of 60 patients, outcomes will be updated at presentation. Patients whose disease had progressed following 1-6 prior regimens with prior exposure to a taxane, ECOG performance status of 0 – 2, measurable disease per RECIST 1.1, with normal marrow and organ function were eligible. Eribulin was administered at 0.9mg/m2 weekly for 3 out of 4 weeks. For patients with HER2 positive disease, concurrent trastuzumab administration was allowed. Concurrent denosumab or bisphosphonates were allowed for patients with bone disease.

Results: 60 patients were enrolled, average age 58 (range 34-83). Majority were postmenopausal Caucasian females, but the study included African American, Hispanic, native American, male patients. The majority of tumors were ER+, infiltrating ductal, but the study included 13 HER2+, and 12 TN tumors, with 5 ILC, and 5 mixed ILC/IDC. Nearly half of the enrolled patients had clinical benefit from the regimen, remaining on therapy for 6 months or longer, with stable disease or response; 50% had progression PD at 3 months 32% had stable disease and 18% had a partial or complete response (1, long term). Overall Survival, OS, for the entire group of heavily pre-treated patients was 1.2 years, with TN and HER2 positive patients faring better than ER+ in this small study. One HER2+ patient remains in long-term remission, off chemotherapy.

The regimen was extremely well tolerated. The majority of the patients experienced grade 0 or 1 toxicity for alopecia (48/60) and peripheral neuropathy (7 with grade 2 neuropathy, 5 pre-existing, 2 with grade 3 neuropathy). There were few dose reductions (n=15), thrombocytopenia (11 grade 1 only), or use of G-CSF (14).

Conclusions: Metronomic weekly low dose eribulin appears to be an active and tolerable regimen with less myelosuppression, alopecia and peripheral neuropathy than is seen with approved dose, allowing longer duration of use and disease control, with similar outcomes compared to the standard dose regimen. Outcomes will be updated at presentation.

Citation Format: Chalasani P, Liu AJ, Khanjian JA, Peha M, Buening BJ, Gadi VK, Specht JM, Salazar L, Linden HM. A phase 2 study of low dose metronomic eribulin in metastatic breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-14-02.

Paediatric interventional cardiology in Costa Rica: diagnostic reference levels and estimation of population dose

The goal of the present study was to propose a set of national diagnostic reference levels (DRLs) in Costa Rica for paediatric interventional cardiology (IC) procedures classified by age and weight and to estimate the collective dose of the paediatric population from these intervention practices. The data collection period was May 2016 to May 2017. The third quartile of patient dose data distributions for kerma-area product (KAP) values was set as the national DRLs. A sample of 154 paediatric IC procedures (collected in the national paediatric hospital with a single x-ray system) was used and divided into four age ranges and five weight ranges. The national DRLs obtained for KAPs by age range were 1.79 Gy cm² (<1 year) to 23.0 Gy cm² (10-15 years). The national DRLs obtained for KAPs by weight range were 1.0 Gy cm² (<10 kg) to 49.6 Gy cm² (50-79 kg). The contribution to the collective dose of the population of Costa Rica amounted to 0.78 person Sv.

Avoiding selection bias without random assignment? The effect of breastfeeding on cognitive outcomes in China

OBJECTIVES

Recent studies suggest that some of the health benefits traditionally attributed to breastfeeding may be overstated due to selection bias problems, since typically breastfeeding is more prevalent in more resourceful households. In this paper we argue that an important antidote against selection bias consists in analyzing data from contexts in which breastfeeding is not normativised, or where it is not systematically associated to socioeconomic advantage and best parenting practices. We estimate the effect of breastfeeding on the cognitive outcomes of Chinese children.

METHODS

We use observational data from a representative sample of children aged 10-15 from the China Family Panel Study. We estimate province fixed effect linear regression models to predict the impact of breastfeeding on test scores.

RESULTS

Our paper shows that there are no advantages in the results obtained by breastfed children when compared with those who were not breastfed, regardless of the duration of breastfeeding.

CONCLUSIONS

Some of the cognitive benefits associated to breastfeeding can be attributed to flaws inherent to the research designs usually adopted.

The burden and epidemiology of community-acquired central nervous system infections: a multinational study

Risk assessment of central nervous system (CNS) infection patients is of key importance in predicting likely pathogens. However, data are lacking on the epidemiology globally. We performed a multicenter study to understand the burden of community-acquired CNS (CA-CNS) infections between 2012 and 2014. A total of 2583 patients with CA-CNS infections were included from 37 referral centers in 20 countries. Of these, 477 (18.5%) patients survived with sequelae and 227 (8.8%) died, and 1879 (72.7%) patients were discharged with complete cure. The most frequent infecting pathogens in this study were Streptococcus pneumoniae (n = 206, 8%) and Mycobacterium tuberculosis (n = 152, 5.9%). Varicella zoster virus and Listeria were other common pathogens in the elderly. Although staphylococci and Listeria resulted in frequent infections in immunocompromised patients, cryptococci were leading pathogens in human immunodeficiency virus (HIV)-positive individuals. Among the patients with any proven etiology, 96 (8.9%) patients presented with clinical features of a chronic CNS disease. Neurosyphilis, neurobrucellosis, neuroborreliosis, and CNS tuberculosis had a predilection to present chronic courses. Listeria monocytogenes, Staphylococcus aureus, M. tuberculosis, and S. pneumoniae were the most fatal forms, while sequelae were significantly higher for herpes simplex virus type 1 (p < 0.05 for all). Tackling the high burden of CNS infections globally can only be achieved with effective pneumococcal immunization and strategies to eliminate tuberculosis, and more must be done to improve diagnostic capacity.

Does Living in a Fatherless Household Compromise Educational Success? A Comparative Study of Cognitive and Non-cognitive Skills

This study addresses the relationship between various family forms and the level of cognitive and non-cognitive skills among 15- to 16-year-old students. We measure cognitive skills using standardized scores in mathematics; non-cognitive abilities are captured by a composite measure of internal locus of control related to mathematics. A particular focus lies on father absence although we also examine the role played by co-residence with siblings and grandparents. We use cross-nationally comparable data on students participating in the Programme for International Student Assessment’s release for 2012. By mapping inequalities by family forms across 33 developed countries, this study provides robust cross-country comparable evidence on the relationship of household structure with both cognitive and non-cognitive skills. The study produces three key results: first, the absence of fathers from the household as well as co-residence with grandparents is associated with adverse outcomes for children in virtually all developed countries. Second, this is generally true in terms of both cognitive and non-cognitive skills, although the disadvantage connected to both family forms is notably stronger in the former than in the latter domain. Finally, there is marked cross-national diversity in the effects associated with the presence in the household of siblings and especially grandparents which furthermore differs across the two outcomes considered.

Abstract P2-11-05: Overall survival in inflammatory breast cancer patients receiving Her-2 Neu directed tumor vaccine therapy: Matched comparison with SEER registry patients

Background

Patients with inflammatory breast cancer (IBC) have a poor prognosis, primarily due to distant dissemination. Additionally, IBC patients have an increased rate of HER2 overexpression when compared to patients with non-inflammatory breast cancer. The forms the rationale for HER2 directed tumor vaccine therapy in these patients. The purpose of this study was to examine overall survival in IBC patients receiving HER2 directed tumor vaccine therapy when compared with matched control patients from the SEER Registry.

Methods

Patients with diagnosis of Stage III or IV HER2 positive IBC having completed standard initial therapy and without evidence of disease received HER2 vaccinations after being enrolled on 5 prospective clinical trials. Overall survival data were pooled and analyzed. A control group of matched IBC patients were identified by querying the SEER database from 1997-2011. The control group was identified as any individual in the database with a code for IBC. A secondary analysis comparing survival in HER2 positive IBC vs HER2 negative IBC patients was performed by querying the SEER database from 2010 onwards, the time point when the HER2 status was coded in the database. Propensity score adjustment were made to the control group to account for any imbalances between groups in measured covariates such as stage, race, age, sex, and era of enrollment and the time interval from diagnosis to enrollment on vaccine trial (median ∼2 years).

Results

A total of 37 IBC patients received HER2 directed vaccine therapy and 676 patients were identified for the SEER control group; Stage at enrollment: stage IIIB: 30 patients in the vaccine group and 639 patients in the control group; stage IIIC: 1 patient in the vaccine group and 15 patients in the control group; stage IV 6 patients in the vaccine group and 22 in the control group. The median survival of the overall population was 112 months for the vaccine group and 47 months for the control group (p=0.04). After using propensity scores to adjust the control for imbalances in measured covariates, the median survival for the overall population was 112 months for the vaccine group and 37 months for the control group (p=0.03). There was no difference in survival between HER2 positive and HER2 negative IBC patients in the control group (p=0.6).

Conclusion

These results demonstrate promising overall survival in HER2 positive IBC patients receiving HER2 directed vaccine therapy after initial therapy. Propensity matching was performed to adjust for imbalances in measured covariates and resulted in a modest decrease in survival of the control group after adjustment, suggesting that the vaccine trial group had relatively unfavorable pre-treatment characteristics. Despite these unfavorable characteristics, patients receiving vaccine had a median survival of 112 months. These results must be further confirmed in a prospective randomized trial.

Citation Format: Rengan R, Baker K, Salazar L, Childs J, Higgins D, Redman M, Reichow J, Disis ML. Overall survival in inflammatory breast cancer patients receiving Her-2 Neu directed tumor vaccine therapy: Matched comparison with SEER registry patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-05.

Tumour cell lysate-loaded dendritic cell vaccine induces biochemical and memory immune response in castration-resistant prostate cancer patients

Background:

Recently, we produced a tumour antigen-presenting cells (TAPCells) vaccine using a melanoma cell lysate, called TRIMEL, as an antigen source and an activation factor. Tumour antigen-presenting cells induced immunological responses and increased melanoma patient survival. Herein, we investigated the effect of TAPCells loaded with prostate cancer cell lysates (PCCL) as an antigen source, and TRIMEL as a dendritic cell (DC) activation factor; which were co-injected with the Concholepas concholepas haemocyanin (CCH) as an adjuvant on castration-resistant prostate cancer (CRPC) patients.

Methods:

The lysate mix capacity, for inducing T-cell activation, was analysed by flow cytometry and Elispot. Delayed-type hypersensitivity (DTH) reaction against PCCL, frequency of CD8⁺ memory T cells (Tm) in blood and prostate-specific antigen (PSA) levels in serum were measured in treated patients.

Results:

The lysate mix induced functional mature DCs that were capable of activating PCCL-specific T cells. No relevant adverse reactions were observed. Six out of 14 patients showed a significant decrease in levels of PSA. DTH⁺ patients showed a prolonged PSA doubling-time after treatment. Expansion of functional central and effector CD8⁺ Tm were detected.

Conclusion:

Treatment of CRPC patients with lysate-loaded TAPCells and CCH as an adjuvant is safe: generating biochemical and memory immune responses. However, the limited number of cases requires confirmation in a phase II clinical trial.

First Report of Meloidogyne marylandi Infecting Bermudagrass in Costa Rica

Bermudagrass plants (Cynodon dactylon cv. 419) from a soccer field in Santa Ana, San Jose Province, Costa Rica, were found with symptoms of decline with dried leaves and leaf yellowing in patches in February 2012. Roots of the affected plants presented small and smooth galls and protruding egg masses similar to those associated with root-knot nematodes (RKN), Meloidogyne spp. Morphometric and molecular analyses were conducted to identify the species present. Morphological measurements from 30 second-stage juveniles and perineal patterns from 10 adult females matched the description of Meloidogyne marylandi Jepson and Golden. Body length averaged 429.5 ± 18.5 (range: 392 to 459) μm, mean width averaged 16.0 ± 1.3 (range: 13.2 to 18.0) μm, stylet lengths averaged 10.7 ± 1.0 (range: 9.1 to 13.4) μm, dorsal gland orifice from stylet base averaged 2.8 ± 0.3 (range: 2.4 to 3.4) μm, tail lengths averaged 60.9 ± 4.9 (range: 45.5 to 74.7) μm, and the hyaline region of the tails averaged 12.4 ± 1.4 (range: 8.6 to 14.8) μm. Lower average tail length and hyaline tail terminal differentiate M. marylandi from the closely related species M. graminis, the grass root-knot nematode, that can also parasitize bermudagrass (1). Hemizonid position was posterior to the excretory pore. The overall shape of the perineal patterns was ovoid, and the dorsal arch was medium high with lateral lines and coarse striae. Males were rarely observed. DNA was extracted from 10 single mature females. Amplification and sequencing of the mitochondrial DNA region between COII and the lRNA gene was accomplished with primers C2F3 (5'-GGTCAATGTTCAGAAATTTGTGG-3') and 1108 (5'-TACCTTTGACCAATCACGCT-3') (2). A PCR product approximately 520 bp in length was obtained and the sequence (GenBank Accession Nos. KC473862 and KC473863) was compared with those in GenBank using BLAST and showed 99 to 100% identity with known sequences of M. marylandi (JN241916.1, JN241905.1, JN241917.1, JN241921.1, and JN241955.1) (3). Phylogenetic analysis with maximum likelihood (MEGA v.5.0) (4) of those sequences placed the Meloidogyne sp. from Costa Rica in a clade (100% bootstrap support) that included only M. marylandi sequences available from the GenBank database, thus confirming its identity. In addition, digestion of the PCR product with SspI restriction enzyme produced a four band pattern similar to what has been reported for M. marylandi from Israel and United States (Maryland) and this approach is considered useful for the separation of M. marylandi from M. graminis (3). To our knowledge, this is the first report of the root-knot nematode M. marylandi in Costa Rica. References: (1) A. M. Golden. J. Nematol. 21:453, 1989. (2) T. O. Powers and T. S. Harris. J. Nematol. 25:1, 1993. (3) M. A. McClure et al. Plant Dis. 96:635, 2012. (4) K. Tamura et al. Mol Biol Evol. 28:2731, 2011.

First isolation and molecular characterization of Ehrlichia canis in Costa Rica, Central America

The present study investigated Ehrlichia species in blood samples from dogs suspected of clinical ehrlichiosis, using molecular and isolation techniques in cell culture. From a total of 310 canine blood samples analyzed by 16S rRNA nested PCR, 148 (47.7%) were positive for Ehrlichia canis. DNA from Ehrlichia chaffeensis or Ehrlichia ewingii was not detected in any sample using species-specific primers in separated reactions. Leukocytes from five PCR-positive dogs were inoculated into DH82 cells; successful isolation of E. canis was obtained in four samples. Partial sequence of the dsb gene of eight canine blood samples (including the five samples for in vitro isolation) was obtained by PCR and their analyses through BLAST showed 100% of identity with the corresponding sequence of E. canis in GenBank. This study represents the first molecular diagnosis, isolation, and molecular characterization of E. canis in dogs from Costa Rica.

Phase I-II Study of Denileukin Diftitox (ONTAK®) in Patients with Advanced Refractory Breast Cancer

Background: CD4+CD25+Foxp3+ regulatory T cells (Tregs) are potent suppressors of CD4+ and CD8+ T cells, produce the immunosuppressive cytokine TGF-β; and as such, may down-regulate immune responses to tumor antigens. Additionally, Tregs are increased in the peripheral blood (PB) and tumors of breast cancer patients; and are associated with poor prognosis. Depletion of PB and tumor-associated Tregs may induce anti-tumor immunity by augmenting anti-tumor effector T cells and enhancing endogenous tumor specific immunity. ONTAK®, a diphtheria/IL-2R fusion protein depletes PB Tregs when given intravenously (IV) and selectively targets tumor cells that overexpress IL-2R. Breast tumors have been shown to overexpress IL-2R which is associated with their malignant potential. We hypothesized that ONTAK® could (1) have direct anti-tumor activity in breast cancers that overexpress IL-2R, and (2) deplete Tregs resulting in generation of functional immune effector cells and enhanced anti-tumor immunity. A phase I-II study was conducted to evaluate the safety of IV ONTAK® and assess its effect on Tregs and endogenous immunity in patients with advanced refractory breast cancer.Materials and Methods: 15 patients with progressive stage IV breast cancer following standard therapy were sequentially enrolled and received IV ONTAK® 18 mcg/kg/day on Days1-5 every 21 days for a total of 6 cycles and/or maximal tumor response. Toxicity was evaluated on Days 1 8, and 14 of each cycle per CTEP CTCAE v3.0. Tumor response was evaluated per RECIST at baseline, and after cycles 3 and 6. PB was collected at baseline and after cycles 2, 4, and 6 for evaluation of Tregs, sIL-2R, and endogenous tumor-antigen specific T cell immunity to HER-2/neu (HER2), CEA, and MAGE-3 via RT-PCR, LUMINEX and IFN-γ ELISPOT assay, respectively. Expression of IL-2R in patient paraffin embedded tumor samples was analyzed by IHC analysis.Results: 15 subjects have been enrolled and 14/15 have completed treatment; median age is 58 years (range, 32-69) and median salvage regimens is 3 (range, 2-8). 7/14 subjects had triple negative tumors. 7 subjects completed 1-2 and 7 completed 3-6 ONTAK® cycles, respectively. 4 subjects who completed 6 cycles of ONTAK® had SD or PR per RECIST. ONTAK®-related toxicities have been primarily grade I and II fatigue, nausea, and headache; and transient grade 3 hypoalbuminemia and lymphopenia. Preliminary data in 2 subjects shows enhanced tumor-antigen specific T cell immunity defined as mean tumor antigen-specific T cell precursors:PBMC to CEA (pre- ONTAK® 1:250,000; post- ONTAK® 1:15,000) and HER2 (pre- ONTAK® 1:63,000; post- ONTAK® 1:6,312). Immunologic analyses are ongoing and will be presented along with clinical data on all patients.Conclusions: ONTAK® is well-tolerated when used as a salvage regimen in heavily pretreated breast cancer patients. Additionally, ONTAK® treatment can enhance endogenous immunity to known breast cancer antigens and potentially lead to more effective eradication of tumor.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4130.

Phase II Study of a HER-2/Neu (HER2) Intracellular Domain (ICD) Vaccine Given Concurrently with Trastuzumab in Patients with Newly Diagnosed Advanced Stage Breast Cancer

HER2 is a tumor antigen in breast cancer and several trials have demonstrated that breast cancer patients can be immunized against this protein. We have developed HER2 peptide based vaccines that are aimed at eliciting CD4+ Th1 tumor antigen specific T cell responses. Th1 effectors provide immunologic memory, enhance cross priming which will allow the elaboration of tumor specific CD8+ T cells, and stimulate epitope spreading which we have shown to be a potential biomarker of clinical response. 52 patients will be enrolled with the primary objective to determine relapse free survival after active immunization. Eligible patients are newly diagnosed with Stage III (B or C) or Stage IV breast cancer and begin vaccination within 6 months of starting maintenance trastuzumab. This interim report will present data on the first 25 patients enrolled; 21 stage IV and 4 locally advanced patients. The vaccine is well tolerated with all adverse events (AE) being Grade I or 2. The most common AE is injection site reaction. Moreover, the combination of HER2 vaccination with trastuzumab did not result in additive cardiac toxicity in these patients. Immune responses were evaluated by IFN-gamma ELISPOT. To date, 88% of patients immunized developed significant immunity to the components of the ICD vaccine. The majority, 75%, developed robust immunity to the HER2 protein. Our group has recently demonstrated that a broadening of immunity throughout the HER2 protein, to components of the protein that weren't in the vaccine, i.e. epitope spreading, may be associated with improved survival in vaccinated patients. 63% of immunized patients demonstrated evidence of intramolecular epitope spreading. We questioned whether such high frequencies of homing Type 1 T cells might modulate the immunosuppressive tumor microenvironment, so we evaluated whether circulating serum immunosuppressive cytokines were impacted by immunization. TGF-beta is an immunosuppressive cytokine secreted by tumor stroma and regulatory T cells. We found that the levels of serum TGF-beta decreased significantly in the majority of patients after vaccination. We further analyzed the correlation between the change of serum levels of TGF-beta post vaccination and HER2 ICD vaccine-induced T cell responses. We found that the greater the magnitude of the HER2 specific T cell response, as demonstrated by IFN-gamma secretion, the greater the decrease in serum TGF-beta (p=0.0045, r=0.742). The correlation between the increased epitope spreading T cell response and decreased levels of TGF-beta was even more significant (p=0.0003). The median overall survival has not been reached with 100% of patients alive at this time. Relapse free survival data will be presented.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5102.

The Impact of National Press Coverage on Early Phase Clinical Trial Recruitment and Enrollment

The American Society of Clinical Oncologists reports that only 5% of cancer patients ultimately enroll in a clinical trial. According to the National Cancer Institute, one key barrier to participation is a lack of knowledge about clinical trials, both on behalf of oncologists and the patients themselves. Unfortunately, many investigator-initiated and academic clinical trials simply do not have budgets that permit implementation of large-scale recruitment efforts. Recent experience by our group demonstrates that press coverage by national media is a particularly effective tool for generating public interest in clinical research, as well as increasing trial enrollment.In the third quarter of 2008, our academic translational research group was featured on a national news program. In the week following the broadcast, our group's website, which had been listed in the broadcast and accompanying web story, received an unprecedented number of hits. Not only did the broadcast generate interest in our group's research; more specifically, it translated to substantial increases in potential clinical trial candidates, and subsequently, increased trial enrollment. In the month following the broadcast, our group received 125 new clinical trial inquiries as a result of the feature. That number represented a seven-fold increase in new inquiries during the same period in 2007. Of those 125 contacts, more than half of patients were potentially eligible for one of our clinical trials based on an initial screening. From November 2008 to the present, nearly one-third of all clinical trial enrollments can be attributed to the news story. Enrollment to the vaccine trial specifically described in the news feature increased four fold in comparison to the same 6-month period in 2008-2009, with half of all new enrollments attributable to the news feature.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6078.

Association of the level of HER2/neu (HER2) gene amplification in breast cancer and the magnitude of antigen specific T-cell immunity achieved after HER2 vaccination

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Background: Studies have demonstrated that the level of HER2 gene amplification in breast cancer, assessed by fluorescence in situ hybridization (FISH), correlates with favorable clinical response after treatment with trastuzumab. We questioned whether HER2 gene amplification impacted the development of HER2-specific T-cell immunity following immunization with a HER2 vaccine. Methods: Patients with HER2+ stage III or IV breast cancer, treated to complete remission or stable bone only disease, were enrolled in one of two concurrent clinical trials of HER2-specific vaccines. Eligibility criteria between the two studies were similar. Patients received either a plasmid DNA-based vaccine encoding the HER2 intracellular domain or a peptide-based vaccine composed of 3 HER2 class II epitopes. Peripheral blood was assessed for HER2-specific T-cell responses by interferon gamma (IFN-g) ELISPOT prior to, immediately after, and 6 months to 1 year after the end of vaccinations. Both immune response and FISH data were available on 31 patients. Results: Correlation of FISH levels to IFN-g spots/well in evaluable patients revealed the level of HER2 gene amplification was not related to the presence of pre-existent HER2-specific T-cell immunity prior to vaccination (p=0.43), the generation of a HER2-specific immune response after vaccination (p=0.35), or the persistence of the HER2-specific T-cell response (p=0.33). However, the magnitude of the T-cell response achieved was less as HER2 gene amplification increased (p=0.05). Conclusions: The level of HER2 gene amplification in the primary tumor can adversely impact the magnitude of HER2-specific T-cell immunity achieved after vaccination.

No significant financial relationships to disclose.

Fluctuating asymmetry in quantitative dermatoglyphic traits: twins and singletons

Fluctuating asymmetry for the digital quantitative value was analyzed in a sample of twins (mono and dizygotic) and singletons. The aim was to check if the influence of twinning on the development is expressed in a higher fluctuating asymmetry in twins than in singletons. The results have shown that significant differences exist among the three groups studied, and these differences are fundamentally expressed when the radial and ulnar counts are considered separately.

Modulation of established murine collagen-induced arthritis by a single inoculation of short-term lipopolysaccharide-stimulated dendritic cells

BACKGROUND

The use of regulatory or immature dendritic cells (DCs) as tools for modulating experimental rheumatoid arthritis is very recent. Tumour necrosis factor (TNF)-stimulated DCs have been shown to restore tolerance in experimental autoimmune encephalomyelitis and collagen-induced arthritis (CIA).

OBJECTIVE

We investigated the capacity of short-term lipopolysaccharide (LPS)-stimulated DCs pulsed with type II collagen (CII) to induce tolerance against established CIA.

METHODS

Bone marrow-derived DCs were generated in the presence of granulocyte monocyte colony-stimulating factor (GM-CSF). After CIA induction, mice were injected at day 35 with a single dose of 4- or 24-h LPS-stimulated DCs that had been loaded with CII (4hLPS/CII/DCs or 24hLPS/CII/DCs). Arthritis progression was monitored by clinical and histological evaluations.

RESULTS

Flow cytometry of 4hLPS/CII/DCs showed intermediate CD40 and CD86 expression, lower than that of 24hLPS/CII/DCs (fully mature) and higher than that of CII/DCs (immature). A functional assay showed that 4hLPS/CII/DCs display increased endocytosis ability with respect to 24hLPS/CII/DCs, indicating a semimature state. The single inoculation of 4hLPS/CII/DCs in mice with established CIA reduced disease severity significantly over time. Histological evaluation of mice treated with 4hLPS/CII/DCs revealed diminished inflammatory synovitis, cartilage damage and fibrosis. Co-cultures of DCs with splenocytes from CIA mice showed that collagen-specific interferon (IFN)gamma production was dramatically inhibited by 4hLPS/CII/DCs. 4hLPS/CII/DCs were high IL10 producers, which could explain the inhibition of arthritis progression in mice receiving this treatment because neither antibodies nor regulatory CD4+CD25+Foxp3+ T lymphocytes were demonstrated to be involved.

CONCLUSION

Short-term LPS-modulated DCs inoculation interferes with CIA progression when loaded with CII.

Identification of fatty acid esters and hydrocarbon derivatives fromCyrtocarpa proceraKunth by GC–MS

Extracts obtained from Cyrtocarpa procera Kunth were evaluated to determine their toxicity on Artemia salina Leach. All the extracts showed a significant activity. Bioguided fractionation of these extracts led to the isolation of beta-sitosterol and the identification of 1,3-propyl-dipentadecanoate, 3-hydroxypropyl-9-octadecenoate, pentadecylbenzene, eicosylbenzene, docosane, heptacosane, dotriacontane and 2,6,10-trimethyltetradecane by GC-MS.

The ambrosanolide cumanin inhibits macrophage nitric oxide synthesis: some structural considerations

Since its role in inflammatory diseases was recognized, nitric oxide (NO) has become an important mediator to evaluate anti-inflammatory agents. Sesquiterpene lactones, which occur in several medicinal plants, inhibit the NO production in macrophage-like cells. This action is probably due to a 1,4 addition reaction between its alpha,beta-unsaturated carbonyl group with sulfhydryl (SH)-containing compounds. For this reason it is believed that these compounds are cytotoxic, which restricts their therapeutic use. In this contribution, the ability of the ambrosanolide-type sesquiterpene lactone cumanin (from the Asteraceae Ambrosia psilostachya) to inhibit NO biosynthesis was evaluated in lipopolisaccharide-induced peritoneal murine macrophages and its cytotoxicity was assessed in the MTT assay. Cumanin showed a potent inhibitory effect in NO production (IC(50) = 9.38+/-0.38 microM) with low cytotoxicity. The 1,4-addition reaction of thiols was slow, which does not explain the inhibition of NO production but does explain the low cytotoxicity of cumanin with respect to other lactones.

Spasmolytic activity of several extracts obtained from some Mexican medicinal plants

A total of ten extracts from different parts of eight medicinal plants that are used in the treatment of gastrointestinal disorders, were evaluated to determine their spasmolytic action on in vitro isolated rat ileum. All extracts were less potent than papaverine, which was used as a positive control.

Psychosocial impact of serological diagnosis of herpes simplex virus type 2: a qualitative assessment

OBJECTIVES

To assess the emotional and psychosocial responses to a serological diagnosis of HSV-2 infection in individuals without previous history of genital herpes.

METHODS

24 individuals who had a positive HSV-2 serology by western blot and no clinical history of disease were recruited from four clinics (sexually transmitted disease, maternal and infant care, family medicine, and virology research) over a 10 month period. In-depth qualitative interviews were conducted to elicit an individual's responses to the HSV-2 diagnosis.

RESULTS

Three categories of themes were identified from the interviews. Short term emotional responses included surprise, denial, confusion, distress, sadness, disappointment, and relief to know. Short term psychosocial responses included fear of telling sex partners, anger at the source partner, guilt about acquiring or transmitting, and concern about transmitting to a child. Perceived ongoing responses included fear of telling future partners, concern about transmitting to a sex partner, feeling sexually undesirable, feeling socially stigmatised, feeling like "damaged goods," sex avoidance due to social responsibility, fear of transmitting to a newborn, and relationship concerns relating to the diagnosis.

CONCLUSIONS

Individuals exhibit strong emotional and psychosocial responses to a serological diagnosis of HSV-2 infection. Many of the negative responses may be time limited and influenced by factors that are potentially amenable to counselling.

[Cellular cycle control in mycobacteria]

Possibly the failure to eradicate the tuberculosis is linked to the pathogenesis of the causative organism, Mycobacterium tuberculosis. These bacteria can lie quiescent in the human host and later multiplies leading to a higher density of bacteria to increase and, hence at progressive tuberculosis. Particularly unknown is how the mechanism work and which are the molecules responsible for determining if the cells goes to an active replicate process, or in contrast to establish a dormant state. Many genes involved in DNA replication, chromosome segregation and cellular division have been cloned and analysed, and in some bacteria, as E. coli, the cellular cycle events have been described. However, the factors coupling these events are unknown.

[Chromosome replication in mycobacteria]

Variation in growth rate has provided a basis for the broad classification of Mycobacterium: (i) the slow-growing class includes the human pathogens Mycobacterium tuberculosis and M. leprae, and (ii) the fast-growing class includes saprophytic nonpathogens, such as M. smegmatis. An intimate association between DNA chromosomal replication and growth rate have been suggested. However, the molecular basis of this relation is unknown. In this article, we summarise our recent work on the study of the origin replication region of some species of mycobacteria, determination of the factors regulating the initiation of DNA replication and the characterisation of the main factor of the replicative machinery, the DnaA protein.

[Characterization of the expression and function of SigM an ECF sigma factor in mycobacteria]

The survival of M. tuberculosis within the macrophage depends on its ability to respond to oxidative stress, and the ECF subfamily of sigma factors likely play an important role. We studied SigM, a sigma factor whose gene is located near the origin of DNA replication. In both M. smegmatis and M. bovis BCG, the expression of sigM was induced at high temperature and in stationary phase. Mutants of M. smegmatis without an intact sigM were defective for survival in oxidative stress and also for the induction of thioredoxin reductase activity in oxidative stress. The thioredoxin system reduces disulfide bonds that are formed in oxidative stress. SigM thus appears to regulate thioredoxins and forms part of the bacteria's complex protective responses.

Vaccination against the HER-2/neu oncogenic protein

The HER-2/neu oncogenic protein is a well-defined tumor antigen. HER-2/neu is a shared antigen among multiple tumor types. Patients with HER-2/neu protein-overexpressing breast, ovarian, non-small cell lung, colon, and prostate cancers have been shown to have a pre-existent immune response to HER-2/neu. No matter what the tumor type, endogenous immunity to HER-2/neu detected in cancer patients demonstrates two predominant characteristics. First, HER-2/neu-specific immune responses are found in only a minority of patients whose tumors overexpress HER-2/neu. Secondly, immunity, if detectable, is of low magnitude. These observations have led to the development of vaccine strategies designed to boost HER-2/neu immunity in a majority of patients. HER-2/neu is a non-mutated self-protein, therefore vaccines must be developed based on immunologic principles focused on circumventing tolerance, a primary mechanism of tumor immune escape. HER-2/neu-specific vaccines have been tested in human clinical trials. Early results demonstrate that significant levels of HER-2/neu immunity can be generated with active immunization. The T-cell immunity elicited is durable after vaccinations have ended. Furthermore, despite the generation of CD8(+) and CD4(+) T-cells responsive to HER-2/neu in a majority of patients, there is no evidence of autoimmunity directed against tissues that express basal levels of the protein. Cancer vaccines targeting the HER-2/neu oncogenic protein may be useful adjuvants to standard therapy and aid in the prevention of relapse in patients whose tumors overexpress the protein. Furthermore, boosting HER-2/neu-specific T-cell frequencies via active immunization may allow the ex vivo expansion of HER-2/neu-specific T-cells for use in adoptive immunotherapy, a therapeutic strategy directed against the treatment of established disease.

Microbiological condition of ground meat retailed in Monterrey, Mexico

Eighty-eight samples of ground meat were randomly collected from retail stores in the metropolitan area of Monterrey, Mexico, and were analyzed for microbial contamination. Methods were those recommended by the Mexican regulation and/or the U.S. Food and Drug Administration. Over 75% of the samples contained > 10(5) total mesophilic microorganisms per g, and over 40% had >10(6) total coliforms per g. Fecal coliforms were present in most samples. Staphylococcus aureus was detected in 2.3% of the samples, Salmonella spp. in 11.4%, Listeria spp. in 62%, and L. monocytogenes in 16%. Escherichia coli was detected in 76% of samples, but none was serotype O157:H7. Shigella spp. was not found in any sample. Fusarium spp. and Mucor spp. were detected in 3.4% of the samples, and low levels of yeast in 93%. The microbiological quality of the ground meat analyzed was unsatisfactory, and the product could be an important cause of food poisoning.

Monoclonal antibodies to human apolipoproteins: application to the study of high density lipoprotein subpopulations

We produced, selected and cloned hybridomas that secrete monoclonal antibodies against human apolipoprotein (apo) A-I. All of the antibodies corresponded to the IgG(1) subclass and were named 1C11, 2B4, 2C10, 7C5, 8A4 and 8A5. The antibodies were characterized by their reactivity with whole lipoproteins, apolipoproteins, synthetic peptides and fragments generated by cleavage of the apo A-I. Three of the monoclonal antibodies studied (2B4, 2C10 and 7C5) were similarly inhibited by an amino-terminal peptide (amino acid sequence 1-20) of apo A-I, whereas antibodies 1C11, 8A4 and 8A5 had no reaction. Other results show that monoclonal antibody 1C11 recognizes an epitope located between amino acids 135-148. We evaluated the monoclonal antibody 8A4 against different HDL subpopulations by competitive displacement analysis and it showed a similar reactivity with the HDL particles: LpA-I and LpA-I:A-II. This antibody was used to standardize a sandwich ELISA to quantitate LpA-I in plasma. We conclude that these monoclonal antibodies are relevant for the study of apo A-I epitope expression and for quantitating apo A-I containing lipoparticles.

Survey of drug resistance of Mycobacterium tuberculosis in 3 Mexican states, 1997

BACKGROUND

Drug resistance threatens global tuberculosis (TB) control efforts. Population-based estimates of drug resistance are needed to develop strategies for controlling drug-resistant TB in Mexico.

OBJECTIVE

To obtain population-based data on Mycobacterium tuberculosis drug resistance in Mexico.

METHODS

To obtain drug resistance data, we conducted a population-based study of TB cases in the states of Baja California, Sinaloa, and Oaxaca, Mexico. We performed cultures and drug susceptibility testing on M tuberculosis isolates from patients with newly diagnosed, smear-positive TB from April 1 to October 31, 1997.

RESULTS

Mycobacterium tuberculosis was isolated from 460 (75%) of the 614 patients. Levels of resistance in new and retreatment TB cases to 1 or more of the 3 current first-line drugs used in Mexico (isoniazid, rifampin, and pyrazinamide) were 12.9% and 50.5%, respectively; the corresponding levels of multi-drug-resistant TB were 2.4% and 22.4%. Retreatment cases were significantly more likely than new cases to have isolates resistant to 1 or more of the 3 first-line drugs (relative risk [RR], 3.9; 95% confidence interval [CI], 2.8-5.5), to have isoniazid resistance (RR, 3.6; 95% CI, 2.5-5.2), and to have multi-drug-resistant TB (RR, 9.4; 95% CI, 4.3-20.2).

CONCLUSIONS

This population-based study of M tuberculosis demonstrates moderately high levels of drug resistance. Important issues to consider in the national strategy to prevent M tuberculosis resistance in Mexico include consideration of the most appropriate initial therapy in patients with TB, the treatment of patients with multiple drug resistance, and surveillance or periodic surveys of resistance among new TB patients to monitor drug resistance trends.