Stem Cell-Secreted Allogeneic Elastin-Rich Matrix with Subsequent Decellularization for the Treatment of Critical Valve Diseases in the Young

Critical valve diseases in infants have a very poor prognosis for survival. Particularly challenging is for the valve replacement to support somatic growth. From a valve regenerative standpoint, bio-scaffolds have been extensively investigated recently. While bio-scaffold valves facilitate acute valve functionality, their xenogeneic properties eventually induce a hostile immune response. Our goal was to investigate if a bio-scaffold valve could be deposited with tissues derived from allogeneic stem cells, with a specific dynamic culture protocol to enhance the extracellular matrix (ECM) constituents, with subsequent stem cell removal. Porcine small intestinal submucosa (PSIS) tubular-shaped bio-scaffold valves were seeded with human bone marrow-derived mesenchymal stem cells (hBMMSCs), cultured statically for 8 days, and then exposed to oscillatory fluid-induced shear stresses for two weeks. The valves were then safely decellularized to remove the hBMMSCs while retaining their secreted ECM. This de novo ECM was found to include significantly higher (p < 0.05) levels of elastin compared to the ECM produced by the hBMMSCs under standard rotisserie culture. The elastin-rich valves consisted of ~8% elastin compared to the ~10% elastin composition of native heart valves. Allogeneic elastin promotes chemotaxis thereby accelerating regeneration and can support somatic growth by rapidly integrating with the host following implantation. As a proof-of-concept of accelerated regeneration, we found that valve interstitial cells (VICs) secreted significantly more (p < 0.05) collagen on the elastin-rich matrix compared to the raw PSIS bio-scaffold.

Effects of crowding on the three main proteolytic mechanisms of skeletal muscle in rainbow trout (Oncorhynchus mykiss)

Background

Skeletal muscle is one of the tissues most affected by stress conditions. The protein degradation in this tissue is vital for the supply of energy mediated by different proteolytic pathways such as the ubiquitin-proteasome (UPS), autophagy-lysosome (ALS) and the calpain/calpastatin system (CCS). Nevertheless, the regulation of this proteolytic axis under stress conditions is not yet completely clear. Chile is the main producer of rainbow trout (Oncorhynchus mykiss) in the world. This intensive fish farming has resulted in growing problems as crowding and stress are one of the major problems in the freshwater stage. In this context, we evaluated the crowding effect in juvenile rainbow trout kept in high stocking density (30 kg/m³) for 15, 45 and 60 days, using a control group of fish (10 kg/m³).

Results

Plasmatic cortisol and glucose were evaluated by enzyme immunoassay. The mRNA levels of stress-related genes (gr1, gr2, mr, hsp70, klf15 and redd1), markers of the UPS (atrogin1 and murf1) and CCS (capn1, capn1, cast-l and cast-s) were evaluated using qPCR. ALS (LC3-I/II and P62/SQSTM1) and growth markers (4E-BP1 and ERK) were measured by Western blot analysis. The cortisol levels increased concomitantly with weight loss at 45 days of crowding. The UPS alone was upregulated at 15 days of high stocking density, while ALS activation was observed at 60 days. However, the CCS was inactivated during the entire trial.

Conclusion

All these data suggest that stress conditions, such as crowding, promote muscle degradation in a time-dependent manner through the upregulation of the UPS at early stages of chronic stress and activation of the ALS in long-term stress, while the CCS is strongly inhibited by stress conditions in the rainbow trout muscle farmed during freshwater stage. Our descriptive study will allow perform functional analysis to determine, in a more detailed way, the effect of stress on skeletal muscle physiology as well as in the animal welfare in rainbow trout. Moreover, it is the first step to elucidate the optimal crop density in the freshwater stage and improve the standards of Chilean aquaculture.

PSXIII-12 Effects of altitudinal floor on nutrient digestibility, energy efficiency, visceral organ mass, and performance by guinea pigs

An experiment was conducted to evaluate the effect of altitude on nutrient digestibility, energy efficiency, performance, and, visceral organ mass by guinea pigs. Twenty male guinea pigs (initial BW 1.011 ± 0.096 kg) were selected in a crossover design experiment, maintained at metabolic cages (2 animals per cage) during a total digestibility period of 25 d (2 periods of 13-d). Animals were randomly assigned at 1 of 2 altitudinal sites, 2986 and 2480 m. above the sea level (masl; 5 cages per altitude). Animals were fed 45 g of alfalfa (DM) to meet energy requirements at maintenance levels. At the end of the digestion phase, an animal from each cage was slaughter to determine body fat content from body specific gravity and visceral organ mass. A subsequent performance phase was evaluated as completely randomized design, and animals were kept at the same altitudinal floor in which they ended period 2 of the crossover period. Animals were fed ad libitum with alfalfa. At the end of the performance phase, all remaining animals were slaughtered and visceral organ mass was measured. Energy intake and Dry matter, were increased by animals at 2986 compared to animals at 2480 masl (P<0.001). Metabolizable energy tended to be lower for animals kept at 2986 masl (P=0.053). Nutrient digestibility was lower for animals kept at 2986 compared to 2480 masl. Liver, kidneys and spleen mass were greater for animals maintained at 2986 masl (P<0.012). Heart mass tended to be greater for animasl kept at 2480 masl (P=0,060). Body fat was not alterd by altitudinal site (P>0.345). Final BW, ADG, and feed conversion rate was decreased by animals fed at 2986 masl (P<0.002). Results from this experiment suggest a novel approach to determine Energy efficiency as affected by altitudinal site. Data from this experiment evidenced a 7% increase on energy requirements on ME for animals kept 516 masl higher. Further research is requiered to apply to other biological models.

Abstract P6-09-09: Meta-analysis of ESR1 mutation prevalence in metastatic breast cancer

Introduction: ESR1 mutations were described for the first time in 1996 when different tyrosine 537 mutations were found to confer constitutive activation of the receptor, describing this region as a key factor in the ligand regulation of ER transcriptional activity. However, due to the low prevalence of this mutation in primary breast tumors its clinical significance maintained unknown. With the advent of large scale genomic analysis, a new understanding of breast cancer molecular characteristics has gained relevance. The low prevalence of ESR1 mutations in primary breast cancer has been confirmed but mutations in metastatic ER-positive breast cancers has been proved to be a completely different scenario. Nevertheless, information regarding real prevalence of ESR1 mutation in metastatic breast cancer is not known as selection of patients and molecular technique used are heterogeneous.

Sources: Search was carried by corresponding clinical oncologists of the Breast Cancer Unit of Alexander Fleming Institute. In March 2017, key words “ESR1 mutations”, “Estrogen receptor mutations” and “Breast cancer” were used as search strategy for the present meta-analysis in PubMed. Furthermore, abstracts from congress presentations were analyzed and hand searching from reference list of obtained articles was executed. Online search retrieved 60 articles published, 3 abstracts related were found and 3 further studies were detected by hand search. Articles were excluded if they only included primary tumors and not metastatic cases and if they were undertaken before 2000 due to important technical differences of mutation detection, including finally 23 cohorts.

Study Selection: Studies considered were prospective or retrospective cohorts of metastatic breast cancer patients with mutation analysis of tissue or circulating DNA. A data form was used by the primary reviewer to extract equivalent information from each article. Information extracted included population sampled, prevalence estimates, clinical characteristics of cohort, sample analyzed and technical procedure for mutation detection. A second reviewer blinded to the primary reviewer's decisions checked the article selection and data extraction. Any differences of opinion were discussed, and a third reviewer was available to arbitrate any issues.

Meta-analysis was undertaken using a random-effects model conducted using the metaprop function in Meta package of R studio Version 1.0.136 (© 2009-2016 RStudio, Inc.). PRISMA guidelines were followed in conducting and reporting the results.

Results and Discussion: Results show a prevalence of ESR1 mutation of 24% (CI95% 19-30%) in the 3607 patients included. Nevertheless, important heterogeneity (I2 =90%) is observed due to great differences in the articles published of this topic. This heterogeneity is attributed to the type of cohorts presented, the selection of patients, the technique used and type of sample studied, but another source of heterogeneity must be present as it still persists after grouping studies according to this variables. The importance of this analysis resides in the fact that it is the most complete information of the prevalence of this mutation that may have future importance in therapeutic decisions in metastatic breast cancer.

Citation Format: Mandó P, Rizzo MM, Perez de la Puente C, Costanzo MV, Nervo A, Nadal J, Colo F, Loza CM, Loza J, Fabiano V, Ponce C, Chacon R. Meta-analysis of ESR1 mutation prevalence in metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-09-09.

Colour change in a structural ornament is related to individual quality, parasites and mating patterns in the blue tit

Carry-over effects refer to processes that occur in one season and influence fitness in the following. In birds, two costly activities, namely reproduction and moult, are restricted to a small time window, and sometimes overlap. Thus, colour in newly moulted feathers is likely to be affected by the costs of reproduction. Using models of bird vision we investigated male colour change in a free-living population of blue tits (Cyanistes caeruleus) in three sampling occasions: spring 1, winter and spring 2. We related crown, tail, breast and cheek feather colouration after the moult (winter) to the intensity of infections by blood parasites during reproduction (spring 1). In the following spring (spring 2), we explored mating patterns with respect to changes in feather colour (springs 1 vs. 2). Males that were less intensely infected by the malaria parasite Plasmodium while breeding showed purer white cheek feathers in winter, which may indicate higher feather quality. Increased brightness in the white cheek was associated with better body condition during reproduction. In the following season, males with brighter cheeks paired with females that had noticeably brighter cheek patches compared to the male's previous mate. These results suggest that the conditions experienced during reproduction are likely to affect moult and thus feather colouration, at least in the white patch. High quality individuals may allocate resources efficiently during reproduction increasing future reproductive success through variation in mating patterns. Carry-over effects from reproduction might extend not only to the non-breeding phase, but also to the following breeding season.

Importance of tissue sampling, laboratory methods, and patient characteristics for detection of Pneumocystis in autopsied lungs of non-immunosuppressed individuals

To understand the epidemiological significance of Pneumocystis detection in a lung tissue sample of non-immunosuppressed individuals, we examined sampling procedures, laboratory methodology, and patient characteristics of autopsy series reported in the literature. Number of tissue specimens, DNA-extraction procedures, age and underlying diagnosis highly influence yield and are critical to understand yield differences of Pneumocystis among reports of pulmonary colonization in immunocompetent individuals.

Abstract P6-09-40: Her2 and hormonal receptor analysis in breast cancer synchronic node metastases could add therapeutic information

Introduction: Breast cancer is the tumor with highest incidence and mortality in women in Argentina. Hormonal receptors (HR) and HER2 are the most important prognostic and predictive factors. It is suggested that estrogen receptors (ER), progesterone receptors (PR) and HER2 expression can vary during tumor progression and metastases development. Published evidence has reported discordance between primary tumors and its metastases ranging from 15-54% for HR and HER2 overexpression. A similar discordance situation may exist among primary tumor (PT) and its axillary nodal metastases (NM)

Objective: To describe the expression and discordance of ER, PR and HER2 in PT and its synchronic NM

Material and methods: Prospective analysis of surgical breast cancer patients (pts) at Instituto Alexander Fleming (Sept 2013 to Feb 2016). HR were analyzed by immunohistochemistry (IHC) according to CAP protocols; values ≥ 10% were considered positive. HER2 overexpression was defined by 3+ IHC or positive FISH. Paired t test was used to compare mean using Prims 5 software.

Results: In 587 breast cancer surgeries, 190 pts presented NM. HR and HER2 analysis was performed in 101 paired samples. Median age was 51 years (r 25-83). Mean tumor size was 3,3 ± 0,2 cm. 0,99% (1) were stage I, 68,3% (69) stage II and 30,7% (31) stage III. Most frequent histologic subtype was ductal carcinoma (66.3%). 78.2% presented lymphovascular invasion. Median positive nodes were 2 (r 1-21). Paired samples allowed ER analysis in 99 cases, PR in 98 and HER2 in 96; 8 NM were Her2++; FISH analysis was inconclusive in 4 of them due to insufficient tissue. No differences were observed on ER between PT and NM (72% vs 71.1%, OR: 0,91, IC95 -3.2-5.1; p&gt;0,05), nor PR expression (52.1% vs 54,5%, OR: -2.1, IC95 -7.1-3.01; p&gt;0,05). PT were ER+ in 86.1% of the cases; NM were ER+ in 82.2%. Regarding PR, PT were 74.3% PR+ and NM were 76.2% PR+. 28 of the 101 pts (27.7%) were discordant. 5 pts with ER+ PT had ER- NM, and 3 pts had PT ER- but ER+ NM, representing a 7.9% of discordance. 4 of 75 pts with PR+ in PT were PR- in NM, while 8 of 26 pts were PR- in PT but PR+ in NM. Of the 13 HER2+ pts, 2 (15%) did not present overexpression in NM. On the other hand, 6 (7%) of the 83 HER2- PT were HER2+ in NM. 4 of 9 pts had PT RH and Her2- (TN), but NM RH and/or Her2+.

Discussion: Tumor heterogeneity is an important issue that may affect clinical decisions. Axillary nodes are the first metastatic site for breast cancer and different studies have shown discrepancy between PT and NM. We described a discordant expression in ER, PR and HER2 of 8%, 12% and 9% respectively. These differences could be due to technical reasons, intratumor heterogeneity and/or a different cellular phenotype. Although the clinical importance of these changes are not completely understood, NM status could bring important prognostic and therapeutic information defining a particular group of patients in which a specific therapeutic strategy could influence long term results. In fact, in our series 44% of TN tumors presented NM with a therapeutic target, either HR or HER2. We therefore confirm that pathological analysis of NM may bring up additional information that could be useful in a prognostic or therapeutic point of view.

Citation Format: Rizzo MM, Mando P, Perez de la Puente C, Maino M, Ponce C, Fabiano V, Pombo MT, Loza CM, Costanzo MV, Nervo A, Nadal J, Colo F, Chacon RD. Her2 and hormonal receptor analysis in breast cancer synchronic node metastases could add therapeutic information [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-40.

Abstract P3-01-07: Second axillary sentinel lymph node biopsy for breast tumor recurrence: Instituto Alexander Fleming experience in Buenos Aires, Argentina

Sentinel Lymph Node Biopsy (SLNB) is the standard technique for axillary staging of patients with operable breast cancer and a clinically negative axilla because it avoids unwarranted axillary dissection and consequently reduces postoperative morbidity.

Purpose: The aim of this study is to determinate the feasibility and accuracy of the second SLNB for patients with ipsilateral breast cancer recurrences with clinically negative axilla, who were treated previously with breast surgery and study of the axilla.

Methods: Retrospective review of the database of the Instituto Alexander Fleming. Between October 2009 and October 2014, 1029 patients with diagnosis of breast cancer required surgery. The study included 26 patients with the diagnosis of operable local breast cancer recurrence, who had previously undergone axillary surgery either as SLNB, sampling or axillary lymph node dissection (ALND). They subsequently underwent additional breast surgery and a second SLNB.

Results: The mean age of the ipsilateral breast cancer recurrences was 59.23 years (range: 32-87) and the most common histologic subtype was invasive ductal carcinoma in 22 patients (84.6%) and 4 patients (15.4%) with invasive lobular carcinoma. 4 patients (15.4%) had previously ALND or sampling and 22 patients (84.6%) SLNB. The identification rate of the second SLNB was 92.31%. Only 2 patients were not identify, one patient with a previous axillary sampling and another one with previous SLNB. In those patients the ALND was performed and the axilla was negative. Lymphoscintigraphy failed to identify any SLN in 6 patients (23%), 2 patients which were not identify and 4 patients only detected with patent blue. The average number of nodes removed at second SLNB was 1.8 (range: 1-5). Second SLNBs were negative in 21 patients (80.8%), and macrometastasis disease was identified in 2 patients and complete ALND was performed.

In 1 patients additional extra-axillary aberrant drainages was observed in the contralateral axilla and interpectoral, and other 3 patients had aberrant drainage in the contralateral axilla (1 patient), internal mammary regions (1 patient), and interpectoral (1 patient). Aberrant drainage pathways were not routinely dissected. Only those accessible during surgery were removed.

The median time between first surgery and ipsilateral breast tumor recurrence was 7.19 years (range: 1-22). The disease free survival (DFS) was 9.16 years (range: 2.25-24).

Conclusion: In the present serie we show a high identification rate of 92.31% in the second SLNB, comparable with other international series published in the literature (range: 51-97%). A second SLNB should be considered for patients with ipsilateral breast tumor recurrence who underwent conservative surgery and have clinically negative axilla. The procedure is technically feasible and accurate for selected patients, and avoids unnecessary ALND. Extra-axillary sentinel lymph node localization rates are higher than for primary SLNB but the clinical significance and management of extra-axillary nodes needs to be clarified.

Citation Format: Maino M, Fabiano V, Ponce C, Loza M, Costanzo V, Nervo A, Nadal J, Mysler D, Amat M, Coló F, Loza J, Chacón R. Second axillary sentinel lymph node biopsy for breast tumor recurrence: Instituto Alexander Fleming experience in Buenos Aires, Argentina. [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 P3-01-07.

[Embolic stroke by thrombotic non bacterial endocarditis in an Antiphospholipid Syndrome patient]

The antiphospholipid syndrome (APS) is an acquired thrombophilia, considered a systemic autoimmune disorder. We report a patient with APS who presented multiple cerebral infarcts (stroke) as a complication of a thrombotic non bacterial endocarditis. We review the literature focused on the physiological mechanism that produce this disease and its complications. Clinical features and their prognostic value and the different therapeutic options were also studied.

Side effects of rodent control on non-target species: Rodenticides increase parasite and pathogen burden in great bustards

For many years anticoagulant rodenticides have been used in vole control campaigns, in spite of the proven risk of secondary poisoning of non-target predators and scavengers. In this paper we analyse for the first time great bustard exposure and intoxication by anticoagulant rodenticides in Spain, based on residues found in the livers of 71 bustard carcasses collected during 1991-2010. Ten individuals contained chlorophacinone and one flocoumafen. Chlorophacinone level was significantly correlated with the pathogen and parasite burden of intoxicated birds. Moreover, through the last 12 years the annual number of great bustards that present chlorophacinone in liver collected in our study areas was correlated with vole peaks at a nearby area, suggesting that the ingestion of rodenticide was proportional to the amounts spread in the fields. We conclude that rodenticide consumption is a regular event among great bustards when baited cereal is spread on fields, and that this may cause chronic weakening of intoxicated individuals, possibly affecting their survival. Future rodent control actions should consider these negative side effects on non target granivorous steppe and farmland species, particularly when they are globally threatened.

Leishmania chagasi/infantum: further investigations on Leishmania tropisms in atypical cutaneous and visceral leishmaniasis foci in Central America

In Central America, apparently genetically identical Leishmania chagasi/infantum parasites cause cutaneous (CL) and visceral leishmaniasis (VL), the latter being more frequent in young children. The present study investigated if there were pathology-related differences in virulence between Honduran CL and VL strains using Mediterranean L. infantum strains as a reference. Macrophage infectivity and serum sensitivity, properties thought to be associated with virulence, were similar between CL and VL strains from both regions. Attention focused on the genome organisation of genes for two candidate virulence factors: Leishmania mitogen activated protein kinase (LMPK) and cysteine proteinase b (Cpb). Interestingly, the Mediterranean strains exhibited restriction enzyme polymorphisms associated with tropism for both LMPK and Cpb genes whereas no differences were observed for the Honduran strains. We also report relative genetic homogeneity of the Honduran strains as compared to the Mediterranean strains and discuss it in terms of the probable origin for the Central American L. chagasi/infantum.

[Bilateral vocal cords paresis following iodine therapy]

We present a case of a 33 year old man who underwent a thyroidectomy due to papillary thyroid carcinoma, with a reversible paresis of both vocal cords after radioiodine therapy. The patient had no previous lesion in laryngeal nerves. Paralysis of the vocal cords is a rare complication of the 131I administration and generally occurs more frequently when there is already some type of lesion in the recurrent laryngeal nerves. The paper reviews the literature on this type of complications.

[Transfusion transmission of Chagas disease in Honduras and other Central American countries]

The transmission of Trypanosoma cruzi through blood transfusion is the second most important way of acquiring Chagas disease. This form of transmission transcends the vectorial transmission in many geographical areas. Honduras has developed a successful program for the control of transfusional transmission, based on the serological screening of blood donors, which is supported by law, making it mandatory. This experience has been extended to other Central American countries, supported by PAHO. Actually in the framework of the Initiative of the Central American countries for the elimination of the transmission of Chagas disease, launched in 1997, the control of transfusional transmission is becoming a reality.

[Towards the elimination of the transmission of Trypanosoma cruzi in Honduras and Central American countries]

Central America is composed of seven countries: Belice, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama. Chagas disease exists in all seven countries, but with major prevalence in El Salvador, Guatemala, Honduras and Nicaragua. The main species of triatomine vectors are: Rhodnius prolixus, Triatoma dimidiata y Rhodnius pallescens. In 1997 the Central American countries launched an Initiative for the Vectorial and Transfusion Transmission Control of Chagas disease. The objectives of the Initiative are: 1. elimination of Rhodnius prolixus, 2. control of Triatoma dimidiata and 3. serological screening for Trypanosoma cruzi of 100% of the blood donors. This Initiative is supported by the Resolution for "The Elimination of Transmission of Chagas Disease", of the World Health Assembly in 1998.

Insecticidal paint and fumigant canisters for Chagas' disease control: community acceptance in Honduras

This study assessed public acceptance for two new vectorial control techniques for Chagas' disease: insecticidal paint and fumigant canisters. The study compared the two with traditional fenitrothion insecticide spraying. An experimental field study was performed in an endemic area of central Honduras from August to November 1992, a year after the initial application of the treatments. The objectives of the study were to determine the acceptability of the tools on the part of the population whose homes were treated, and on the part of the personnel applying the treatments. The sample size was drawn up according to a uniform protocol applied in six Latin American countries. For this study a total of 651 persons were surveyed in 15 rural communities. Along with the surveys, focus groups were used to collect information to learn the reasons for accepting or rejecting particular treatments. The survey was done with heads of households. Focus groups were done with heads of households and also with the field operators who applied the treatments. The research showed that insecticidal paint had a low level of community acceptance (28.8%). Field operators strongly disliked the paint because of problems with its transport, application, unpleasant smell, and very low effectiveness against triatomines and pest insects. The traditional insecticide was more acceptable to the community (93.9%) and to the field operators, especially for its strong effect against the triatomines and pest insects. The results showed that in order to increase the public acceptance for insecticidal paint, it would be necessary to make the paint easier to transport and apply and to increase its effectiveness. Because of their very low effectiveness, fumigant canisters did not represent an acceptable alternative for triatomine vector control. A public educational effort should be a component of any new control method developed.

N-glycosylation requirements for the AT1a angiotensin II receptor delivery to the plasma membrane

The purpose of this work was to investigate the role of N-glycosylation in the expression and pharmacological properties of the the rat AT1a angiotensin II (AII) receptor. Glycosylation-site suppression was carried out by site-directed mutagenesis (Asn-->Gln) of Asn176 and Asn188 (located on the second extracellular loop) and by the removal of Asn4 at the N-terminal end combined with the replacement of the first four amino acids by a 10 amino acid peptide epitope (c-Myc). We generated seven possible N-glycosylation-site-defective mutants, all tagged at their C-terminal ends with the c-Myc epitope. This double-tagging strategy, associated with photoaffinity labelling, allowed evaluation of the molecular masses and immunocytochemical cellular localization of the various receptors transiently expressed in COS-7 cells. We showed that: (i) each of the three N-glycosylation sites are utilized in COS-7 cells; (ii) the mutant with three defective N-glycosylation sites was not (or was very inefficiently) expressed at the plasma membrane and accumulated inside the cell at the perinuclear zone; (iii) the preservation of two sites allowed normal receptor delivery to the plasma membrane, the presence of only Asn176 ensuring a behaviour similar to that of the wild-type receptor; and (iv) all expressed receptors displayed unchanged pharmacological properties (Kd for 125I-sarcosine1-AII; sarcosine1-AII-induced inositol phosphate production). These results demonstrate that N-glycosylation is required for the AT1 receptor expression. They are discussed in the light of current knowledge of membrane-protein maturation and future prospects of receptor overexpression for structural studies.

Behaviour of Lutzomyia longipalpis in an area of southern Honduras endemic for visceral/atypical cutaneous leishmaniasis

The predominant sandfly in Las Maria de Pavana, Choluteca, Honduras, was found to be Lutzomyia longipalpis, most (69%) of the 791 specimens of this species caught being male. When local Lu. longipalpis were studied over 1 year (1986-1987) using CDC traps, peaks in the size of the adult population were observed in December and July, each after a period of rain. Most [51% (24/47)-67% (97/144)] of the flies caught inside houses were female whereas most [55% (6/11)-56% (37/66)] of those caught outside were male. Far more Lu. longipalpis of both sexes were collected, per h of collection, from cattle and horses than from dogs or pigs, the vast majority (83%-93%) of the flies caught on each type of animal being male. The males may benefit from resting on the mammals because the females with which they mate come to the same animals for blood. The females may benefit by the presence of the males, not only by the increased chance of finding a mate but also because pheremones from the males may attract the females both to the males and to a bloodmeal source. The adult Lu. longipalpis only appeared to be active during the hours of darkness, none alighting in the twilight of dawn (04.00-06.00 hours) or dusk (18.00-20.00 hours) on the large mammals investigated.

Enhanced differentiation of HL-60 leukemia cells to macrophages induced by ciprofibrate

Ciprofibrate, an hypolipidaemic peroxisome proliferator, induced differentiation of HL-60 cells. The effect was greatly potentiated by phorbol 12-myristate 13-acetate at a concentration where neither phorbol ester nor ciprofibrate alone had any effect on these cells. As occurs for HL-60 cell differentiation induced by high phorbol ester concentration, the ciprofibrate-induced phorbol ester-dependent differentiation of HL-60 cells proceeded through the monocytic/macrophage pathway and induced the phosphorylation of proteins with similar molecular weights suggesting that increased protein kinase C activity may be involved in the effect. The peroxisome proliferator-activated receptor (PPARalpha) transcription factor is expressed in HL-60 cells, but no changes were observed in its expression upon HL-60 cell differentiation.

[Chagas disease in the central region of Honduras: knowledge, beliefs, and practices]

From November to December 1991 and in March 1993 a survey was conducted in 17 rural communities located in Central Honduras. The communities belonged to two areas where Chagas' disease is endemic. In one of them, disease control activities had been conducted. A total of 849 adults, one in each of an equal number of households, was interviewed. The objective of the survey was to investigate and compare in both locations knowledge about Chagas' disease and its routes of transmission, measures aimed at avoiding the presence of triatomines within households, beliefs surrounding the vector and its control, and the population's sources of information about the disease. A 23-item questionnaire was tested and precoded. Almost 100% of the subjects who were surveyed were able to identify the vector and to describe its habits, but only 30.1% knew that Triatoma is the vector for the disease and only about 6% associated it with a chronic heart condition. Around 47.9% of survey subjects indicated that eliminating triatomines from households is a personal responsibility, although 78% identified as the control measure the institutional application of insecticides. Personal contact between a health worker and community members was the chief source of information for those who mentioned having heard of Chagas' disease (41.0%). These results suggest that health education should be included as a component in the planification of control programs. The role played by triatomines in disease transmission should be emphasized, as well as the importance of carrying out household improvements, with community participation, as an effective and sustainable measure. To achieve greater impact, this component should be developed through interpersonal communication channels.

Genetic variability among populations of the sand fly Lutzomyia (Lutzomyia) longipalpis (Diptera: Psychodidae) from Central America

Eleven Central American populations of Lutzomyia longipalpis (Lutz & Neiva) were analyzed for genetic variation at 16 enzyme loci. The aim was to study the genetic structure among populations within this region and to identify demes that may represent different sibling species. Genotypic frequencies within populations agreed with Hardy-Weinberg expectations, indicating that there were no sympatric sibling species among these 11 populations. Levels of genetic distance between pairs of populations were very low (< 0.02). Some substructing was evident, because after genotypes of all populations mere pooled, 7 of the 16 enzyme loci deviated from Hardy-Weinberg expectations. Estimates of effective migration rates among populations (Nm) were low (3.7), indicating that gene flow was restricted. These data explained observed genetic substructuring when all genotypes were pooled.

Non-ulcerative cutaneous leishmaniasis in Honduras fails to respond to topical paromomycin

A double-'blind', placebo-controlled trial of topical therapy with 15% paromomycin (aminosidine) and 10% urea in white paraffin was carried out on 53 patients with non-ulcerating cutaneous leishmaniasis in Honduras. Although the treatment was not effective, several unexpected findings emerged from the trial. Leishmania mexicana was found to be the cause of many of the skin lesions in one of the 2 study sites. These lesions were clinically indistinguishable from those caused by L. chagasi, the aetiologic agent previously found for this form of leishmaniasis. This is the first documented report of L. mexicana in Honduras.

Leishmania chagasi: genotypically similar parasites from Honduras cause both visceral and cutaneous leishmaniasis in humans

In the Mediterranean region Leishmania infantum causes both visceral and cutaneous leishmaniasis. These two pathologies tend to be caused by distinct parasite zymodemes. We have studied 33 isolates of Leishmania, 2 from sandflies, 5 from visceral cases, and 26 from cutaneous cases in Honduras, to determine if there is a correlation between pathology and parasite type in the New World similar to that in the Mediterranean region. Nine of the 26 cutaneous cases were caused by L. mexicana parasites, which have not been previously reported from Honduras; the remaining 17 cutaneous cases were due to L. chagasi. Only minor differences were found between the Honduran L. chagasi parasites by random amplified polymorphic DNA, differential display, pulsed-field gel electrophoresis, and schizodemes. This suggests that in Honduras the parasite type may not be the only factor determining the clinical outcome of L. chagasi infections.

Neurologic complications after allogeneic bone marrow transplantation

Neurological complications are not usually considered among the most important complications that may appear after allogeneic bone marrow transplantation (BMT). We have analyzed the occurrence of neurological manifestation in 27 recipients of allogeneic BMT. Ten patients (37%) developed neurological symptoms, and 14 episodes were registered. The most frequent manifestations were due to the use of cyclosporin A or prednisone for prophylaxis or treatment of graft-versus-host disease (GVHD). Cerebrovascular events (infarction or hemorrhage) and CNS infections were the most severe complications: they represented 26% of cause of death in our series. In conclusion, neurological complications are frequent in these patients, and represent an important cause of morbidity and mortality.

Comparison of the sex-pheromone components of Lutzomyia longipalpis (Diptera:Psychodidae) from areas of visceral and atypical cutaneous leishmaniasis in Honduras and Cost Rica

The terpene components of extracts prepared from male Lutzomyia longipalpis (Diptera: Psychodidae) collected from four sites in Honduras and one in Costa Rica were analysed by high-performance liquid chromatography, gas chromatography and coupled gas chromatography--mass spectrometry. The terpene components of Lu. longipalpis from other regions of South America have previously been shown to be sex pheromones. The flies from the four areas of Honduras, where Leishmania chagasi infection may lead to visceral or atypical cutaneous leishmaniasis, were found to be homogenous, all producing 9-methylgermacrene-B. Three types of terpene (9-methylgermacrene-B, a novel homosesquiterpene and a small amount of diterpene) were detected in pools of flies from Liberia, Costa Rica, where only atypical cutaneous leishmaniasis has been found. These results indicate that there are probably at least two and possibly three distinct populations of Lu. longipalpis in this region. The clinical manifestation of Leishmania chagasi infection does not appear to be dependent on which population of Lu. longipalpis transmitted the parasite.

Oligoblastic leukaemia with (8;21) translocation and haemophagocytic syndrome and granulocytic cannibalism

We report a 47-year-old man with oligoblastic leukaemia (8;21) translocation, phenomenon of cannibalism by granulocytic cells and haemophagocytic syndrome. The patient responded to intensive chemotherapy with disappearance of haemophagocytosis, granulocytic and histiocytic. We conclude that: (1) granulocytic cannibalism and haemophagocytic syndrome can be unusual myelodysplastic features; (2) the oligoblastic leukaemia with presence of cytogenetic abnormalities related to AML in young patients are probably more close to acute leukaemia than to myelodysplastic syndrome.

Molecular techniques in the characterization of Leishmania isolates from Central America

The public-health problems caused by leishmaniasis in most countries in Central America are becoming more severe. This is partly because of the increasing size of the human populations that are at risk and their migratory patterns. Annual incidence of the disease in Costa Rica, Honduras, Guatemala, Panama and Nicaragua is estimated to be as high as 20,000 cases. Regional changes in the epidemiology of the various Leishmania spp. present have emphasized the need for innovative, sensitive and accurate diagnostic tools. PCR and isoenzyme, monoclonal antibody, schizodeme, DNA-probe and random-amplified, polymorphic DNA analyses have been tested. Preliminary indications that Leishmania chagasi was present in Costa Rica and Honduras and that interspecific hybrids occurred in Nicaragua have been confirmed using these methods. The distribution of the mexicana complex was also found to be broader and more heterogeneous than initially expected. Overall, there was 87% concordance between the results produced using the different techniques.

Dose response of succinylcholine at the adductor pollicis of children with cerebral palsy during propofol and nitrous oxide anesthesia

Children with cerebral palsy may be resistant to paralysis induced by nondepolarizing neuromuscular blocking drugs. Potency of a bolus of succinylcholine in children with cerebral palsy has not been studied previously. Therefore, we measured the response of the adductor pollicis to succinylcholine in children with cerebral palsy anesthetized with propofol and nitrous oxide. Forty children between the ages of 2 and 10.2 yr with spastic quadriplegic cerebral palsy were randomly assigned to receive 100, 175, 250, or 375 micrograms/kg of succinylcholine during anesthesia with propofol and nitrous oxide. The ulnar nerve was stimulated with a train-of-four supramaximal stimulus every 10 s and the compound electromyogram of the adductor pollicis recorded by a Datex NMT monitor. Plasma cholinesterase activity was measured in all patients with three different substrates (propionylthiocholine, benzoylcholine, and succinylcholine). Dibucaine number was also determined using inhibition of benzoylcholine degradation. ED50 of succinylcholine was 146.8 micrograms/kg with 95% confidence intervals of 111.4-193.7 micrograms/kg. ED95 of succinylcholine was 360.5 micrograms with 95% confidence intervals of 273.3-475.5 micrograms/kg. We conclude that children with cerebral palsy are slightly sensitive to succinylcholine, but probably not sufficiently to be clinically important.

The characterization of Leishmania parasites and their vectors from Central America using molecular techniques

The disfiguring cutaneous and mucocutaneous and often fatal visceral forms of leishmaniasis are an increasing public health problem in Central America. There are some evidences of a highest prevalence of L. braziliensis and L. mexicana in Guatemala; L. braziliensis, L. panamensis and L. infantum (L. chagasi) in Honduras and Nicaragua, and L. panamensis in Costa Rica and Panamá. Our research project, just starting, attempts to use molecular approaches for a more rapid and accurate diagnosis and to identify the parasites. The techniques include non-radioactive DNA probes, PCR, schizodeme, isoenzyme analysis and monoclonal antibodies; and specific recombinant peptides will be used to improve immunodiagnosis of the visceral form. Intra-specific heterogeneity in Leishmania isolates will be examined by pulsed field electrophoresis and random amplified polymorphic DNA. Using selected strains, the techniques will be compared on a regional basis leading to a better knowledge of parasite distribution and the related clinical entities. Furthermore, DNA probes for the identification of parasites in vectors and for sibling species of vectors, are also to be applied; chemical identification of sandfly male pheromones will be attempted possibly leading to potential novel control measures.

Leishmania donovani chagasi: new clinical variant of cutaneous leishmaniasis in Honduras

During surveillance for endemic visceral leishmaniasis on an island off the Pacific coast of Honduras, an unusual form of cutaneous leishmaniasis was encountered. By clinical and laboratory criteria, 17 cases were identified over 5 months; children aged 4 to 15 years were primarily affected. Lesions were generally few in number, small, always papular, and non-ulcerative, even when present for several years. Patients with skin lesions seemed otherwise healthy and were well nourished. Montenegro skin tests with Leishmania mexicana and L major antigens were positive in 10 of 17 patients tested, and lesions from 9 patients were positive by culture. Since the summer of 1988, cases of atypical cutaneous leishmaniasis continue to occur on the island (8) as well as on the mainland of southern Honduras (23). A total of 9 parasite isolates from skin lesions, 4 from bone marrow of patients with kala-azar, and 2 from sandflies were identified as L donovani chagasi and were indistinguishable from one another by isoenzyme analysis.

Distinct quality of depressed mood: an attempt to develop an objective measure

Since the time of Kraepelin, in continental Europe the sadness of depression has been considered to have a "distinct quality' basic to the diagnosis of pathological depression. This distinct quality has been interpreted by observers but patients have been noted to have difficulty verbalizing differences from normal sadness. The authors have used a discriminant analysis to study how patients define pathological sadness and as a result have developed a Pathological Sadness Index with a sensitivity of 0.94, a specificity of 0.96 and a total misclassification rate of 5% (kappa w = 0.90).

Cutaneous paragonimiasis in man in Honduras

A worm found in histopathologic sections of the skin of a 31-year-old man in Honduras was identified as Paragonimus sp. The worm was immature, and specific identification was not possible. This is the second human case of paragonimiasis in Honduras.