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Influence of the blood meal source on life cycle, mortality, and fecundity of 2 cohorts of recently colonized Mexican Meccus longipennis, fed on hens (H-cohort) or rats (R-cohort) were evaluated in laboratory conditions. One hundred twelve nymphs (56%) (H-cohort) and 102 nymphs (51%) (R-cohort), completed the cycle. The average time from Nymph I to adult was 209+/-41 days (H-cohort) and 239+/-28 days (R-cohort), taking an average of 1.8 (H-cohort) and 1.9 (R-cohort) blood meals per nymphal stage (range 1-6). The average span in days for each stage from the H-cohort was 20.8 for Nymph I, 24.5 for Nymph II, 38.8 for Nymph III, 56.1 for Nymph IV, and 72.5 for Nymph V, and it was 20.2 for Nymph I, 23.1 for Nymph II, 43.2 for Nymph III, 68.8 for Nymph IV, and 75.4 for Nymph V from the R-cohort. The mortality percentage was 44% (H-cohort) and 49% (R-cohort). The average number of eggs laid per female in a 9-month period was 484.1 (range 351.1-847.8) in the H-cohort, whereas the average number of eggs was 442.3 (range 288.5-720.5) in the R-cohort. No significant differences (P > 0.05) were recorded among cohorts fed on the studied blood meal sources, different from most previously studied Triatominae species, perhaps due to a high degree of association of M. longipennis with chickens and hens as much as with mammals under natural conditions on human dwellings.

Bacterial pathogenicity islands (PAI) often encode both effector molecules responsible for disease and secretion systems that deliver these effectors to host cells. Human enterohemorrhagic Escherichia coli (EHEC), enteropathogenic E. coli, and the mouse pathogen Citrobacter rodentium (CR) possess the locus of enterocyte effacement (LEE) PAI. We systematically mutagenized all 41 CR LEE genes and functionally characterized these mutants in vitro and in a murine infection model. We identified 33 virulence factors, including two virulence regulators and a hierarchical switch for type III secretion. In addition, 7 potential type III effectors encoded outside the LEE were identified by using a proteomics approach. These non-LEE effectors are encoded by three uncharacterized PAIs in EHEC O157, suggesting that these PAIs act cooperatively with the LEE in pathogenesis. Our findings provide significant insights into bacterial virulence mechanisms and disease.

Aspects related to hatching, time-lapse between presenting the blood-meal and beginning of feeding, feeding time, postfeed defecation delay, mortality, and fecundity for each stage of Meccus longipennis life-cycle were evaluated. The bugs were maintained in a dark incubator at 27 1 C and 80 5% rh, were fed weekly and checked daily for ecdysis or death. The hatching rate observed for 300 eggs was 76.7% and the average time of hatching was 19.8 days. Mean time-lapse between presentation of the blood meal and the beginning of feeding was under 5 min in nymphal stages and postfeed defecation delay was under 10 min in most stages, except in fourth and fifth stages. Mean feeding time was longer than 10 min in most stages, except in fourth stage. One hundred thirty-one nymphs (N) (65.5%) completed the cycle and the average time from NI to adult was 192.6 34.8 days. The average span in days for each stage was 18.1 for NI, 21.4 for NII, 29.5 for NIII, 45.5 for NIV and 55.9 for NV. The number of bloodmeals at each nymphal stage varied from 1 to 5. The mortality rate was 3.29 for NI, 6.8 for NII, 2.92 for NIII 3.76 for NIV, and 10.16 for NV nymphs. The average number of eggs laid per female in a 9-month period was 615.6. Based on our results, we conclude that M. longipennis has some biological and behavioral characteristics which influence its capacity of becoming infected and transmitting Trypanosoma cruzi to human populations in those areas of Mexico where it is currently present.

Accurate diagnosis is a necessary step in the management of breast cancer. In women with breast cancer, diagnosis can confirm the presence of the disease, reduce treatment delays, and clarify the predictive and prognostic features of the cancer, which help in planning treatment and counseling women. In women with benign breast conditions, accurate diagnosis avoids erroneous treatment for breast cancer, which can have devastating consequences for the woman and unnecessarily consumes resources. The panel distinguishes between a "clinical diagnosis" of breast cancer (one based on signs and symptoms and imaging findings) and a "pathologic diagnosis" of breast cancer (one based on microscopic examination of cellular or tissue samples). The panel agrees that all women should have a pathologic diagnosis of breast cancer before they are given definitive treatment for the disease, no matter how strongly their clinical findings suggest cancer. The tools for clinical diagnosis include history, clinical breast examination, ultrasound, and diagnostic mammography; these tools provide valuable information and play important supplemental roles in ascertaining the presence of breast cancer. Mammography and ultrasound also help determine the extent of disease within the breast, which is essential when breast-conserving therapy can be offered to women. The tools for pathologic diagnosis include fine-needle aspiration biopsy, core needle biopsy, and standard surgical biopsy. The panel noted that each of these tools has potential benefits and limitations in the limited-resource setting, and concluded that the choice among them must be based on the available tools and expertise. The triple test-checking for correlation of pathology findings, imaging findings, and clinical findings-was identified as a critical practice in diagnosing breast cancer. Panelists uniformly agreed that mastectomy should not be used to diagnose breast cancer, noting that accurate diagnosis can be made by less invasive means. Expertise in pathology was identified as a key requirement for ensuring reliable diagnostic findings. Several approaches were proposed for improving breast pathology, including training pathologists, establishing pathology services in centralized facilities, and organizing international pathology services.

The bundle-forming pilus (BFP) is an important virulence factor for enteropathogenic Escherichia coli (EPEC). Genes involved in its biogenesis and regulation are tightly regulated by PerA (BfpT), a member of the AraC/XylS family of transcriptional regulators. The aim of this work was to purify PerA and determine its association with bfpA and perA (bfpT) regulatory regions by electrophoretic mobility shift and DNase I footprinting assays. PerA was purified as a maltose-binding protein (MBP) fusion, which was capable of complementing bfpA expression and which was able to restore the localized adherence phenotype of an EPEC perA mutant strain. Upstream of bfpA and perA, MBP-PerA recognized with similar affinity asymmetric nucleotide sequences in which a 29-bp-long AT-rich consensus motif was identified. These DNA motifs share 66% identity and were previously shown, by deletion analysis, to be involved in the PerA-dependent expression of both genes. Interestingly, in perA, this motif spans the sequence between positions -75 and -47, approximately one helix turn upstream of the -35 promoter sequence, while in bfpA, it spans the sequence between positions -83 and -55, approximately two helix turns upstream from the promoter. An additional PerA binding site was identified at the 5' end of the bfpA structural gene, which was not required for its activation. Experiments with LexA-PerA fusions suggested that PerA acts as a monomer to activate the transcription of both perA and bfpA, in contrast to what has been documented for other members of this family of transcriptional regulators.

Aspects related to hatching, time-lapse between presenting the blood meal and beginning of feeding, feeding time, postfeed defecation delay,life time, mortality and fecundity for each stage of Meccus picturatus, life-cycle were evaluated and compared in two cohorts of M. picturatus fed on hens or rabbits. The hatching rate observed for each of the two studied groups of eggs was 78.1% (n = 2298) on the group fed on hens and 82.1% (n = 2704) on that fed on rabbits, and the average time of hatching was 20 days. Mean time-lapse for beginning feeding was under 3 min in nymphal stages and postfeed defecation delay was under 10 min in all stages, in both cohorts. Mean feeding time was significantly (P < 0.05) shorter in triatomines fed on hens than on rabbits. A similar number of nymphs of each cohort, 69 fed on hens (34.5%) and 68 fed on rabbits (34%), completed the cycle. No significantly (P > 0.05) differences were recorded among the average times from NI to adult in the cohort fed on hens (196.8 15.8 days) and the average time in the cohort fed on rabbits (189.5 22.9). The average span in days for each stage fed on hens was not significantly different to the average span for each stage fed on rabbits. The number of blood meals at each nymphal stage varied from 1 to 6 in both cohorts. The mortality rates were higher on fifth nymphal stage, in both cohorts. No significant (P > 0.05) differences were recorded on mortality rates on most nymphal stages of both cohorts. The average number of eggs laid per female from the cohort fed on hens in a 9-month period was 791.1, whereas the average number of eggs in the cohort fed on rabbits was 928.3.

Feeding time, postfeeding defecation delay, and life cycle for each stage of a cohort of recently colonized Mexican Triatoma dimidiata were evaluated, and results were compared to existing published information on this species. Seventy-five nymphs (41.7%) completed a cycle with an average time from N-I to adult of 142 +/- 64 days. The average span in days for each stage was 20.2 for N-I, 17.9 for N-II, 10.1 for N-III, 43.6 for N-IV, and 55.1 for N-V. First-stage nymphs had the highest mean feeding time (25 min) and the longest postfeeding defecation delay (45 min). Differences among biological data from previous studies and the present study confirm the importance of conducting research on the behavior of the indigenous triatomine species from various countries.

From August 1997 to August 1998, 334 specimens of Triatoma longipennis and 62 of T. picturata were collected in four groups of localities placed in the zone from Guadalajara, Jalisco to Tepic, Nayarit, in the West Coast of Mexico. Most T. longipennis were collected outdoors (69.2%) while most T. picturata (58.1%) were collected indoors. All collected specimens were examined for Trypanosoma cruzi infection, which was detected on 98 (29.3%) T. longipennis and 17 (27.4%) T. picturata. This study confirms the role of T. longipennis and T. picturata as some of the main T. cruzi vectors to humans in Mexico. Habitation Infestation Rate with T. longipennis was of 0.09 and with T. picturata was of 0.03 and the predominating ecotopes were pile of blocks, chicken coops, pigsties, wall crawls and beds.

The pathologist's contribution to the interdisciplinary team approach in breast cancer management is a cornerstone for decision-making. Continuous communication with the radiologist, surgeon, oncologist, and radiation oncologist is essential. Preoperative diagnosis, surgical specimen work-up with size determination, sentinel lymph node examination, processing forms to facilitate the work-up, and diagnostic templates are some of the items covered in this review of the pathologist's contribution to the interdisciplinary team in breast cancer. Use of diagnostic templates or synoptic reports routinely provide the complete diagnostic information required for treatment decisions.

Aspects related to hatching, life time, mortality, feeding behaviour and fecundity for each stage of Triatoma pallidipennis life-cycle were evaluated. The hatching rate observed for 200 eggs was 60% and the average time of hatching was 18 days. Eighty nymphs (N) (40%) completed the cycle and the average time from NI to adult was 168. 7+/-11.7days. The average span in days for each stage was 18.0 for NI, 18.5 for NII, 30.0 for NIII, 35.7 for NIV and 50.1 for NV. The number of bloodmeals at each nymphal stage varied from 1 to 5. The mortality rate was 9.17 for NI, 5.5 for NII, 6.8 for NIII 4.17 for NIV and 13.04 for NV nymphs. The average number of eggs laid per female in a 9-month period was 498.6. The survival rates of adults were 357+/-217.9 and 262.53+/-167.7 for males and females respectively.

The availability of flowering plants affected the sugar feeding rates of female Aedes aegypti (L.) in 4 areas of a small city in southern Mexico. The proportion of mosquitoes containing sugar varied from 8 to 21% in 4 areas in direct relation to blooming plant abundance. Human density was similar in the 4 areas (range, 3.9-5.4 per house), whereas the number of flowering plants per house increased on the outskirts (range, 3.1-5.4 plants per house). Equal proportions of sugar positive females were nulliparous or parous, indicating similar sugar feeding at any age. In addition, nearly 60% of positive females were at the Christophers stage II, indicating a greater need for flight fuel during the early stages of egg development. We conclude that Ae. aegypti feeds frequently on nectar and that this activity is modulated by nectar availability.

At routine screening mammography, asymmetrically enlarged left axillary lymph nodes were seen in a healthy 70-year-old woman. Ultrasound (US)-guided fine-needle aspiration biopsy of the largest node revealed a foreign body reaction. The patient recalled a previous silicone implantation in her wrist. On the basis of cytologic study, normal findings of physical examination, and clinical history, a benign foreign body reaction to silicone implant material was diagnosed. Consideration of regional silicone lymphadenopathy is recommended in the differential diagnosis of unilateral enlarged lymph nodes noted on mammograms. US-guided fine-needle aspiration biopsy is a simple, rapid, inexpensive, and relatively nontraumatic means of ruling out malignancy.

The outcome of 100 consecutive newly diagnosed breast cancer patients treated between 1975 and 1985 within a protocol of planned segmental mastectomy and radiation therapy that included an initial brachytherapy boost is reported. Margins were not routinely inked in this study and the tumor bed was determined with the operating surgeon at the time of brachytherapy. There were 30 T1 tumors, 61 T2, and 9 T3. Segmental mastectomy was followed 2 weeks later by an interstitial implant with iridium-192 sources given as initial boost dose to the tumor bed, at the time of axillary dissection. All patients received at least 20 Gy as boost dose followed by external beam radiation to a total dose of 45-50 Gy to the breast and regional nodes delivered over a period of 4-5 weeks. With a median follow-up of 7 years a total of 3 (3%) breast recurrences were detected (1/30 in T1 tumors, 2/61 in T2 tumors). Only one of the three recurrences was at the initial tumor bed. None of the nine T3 patients included in this series recurred locally. There were 4 severe complications (2 soft tissue necroses and 2 osteonecroses) occurring in 2/30 T1 and in 2/61 T2. Cosmetic results were good to excellent in 77% of the cases and fair to poor in 23%. The actuarial local control and survival probability rate were, respectively, 95% and 85% at 5 years and 93% and 73% at 10 years. Initial brachytherapy boost to a target volume accurately determined with the operating surgeon followed by subsequent external beam radiotherapy achieved excellent local control in the breast even for lesions larger than 2 cm (70% of the reported cases).

Since a great number of teeth could be rehabilitated and not extracted, in this paper we analyze the relation Perio-protesis by the point of the biology of marginal periodontal ligament, and the different options to establish this relations when are lost by decay or traumatism. We discuss the contraindications to avoid greater problems than benefits when intend to rehabilitate lost teeth.