Memory support training and lifestyle modifications to promote healthy aging in persons at risk for Alzheimer's disease: a digital application supported intervention (Brain Boosters)

BACKGROUND

Evidence-based interventions to protect against cognitive decline among older adults at risk for Alzheimer's disease and related dementias (ADRD) are urgently needed. Rehabilitation approaches to support memory and behavioral/lifestyle interventions are recognized as promising strategies for preserving or improving cognitive health, although few previous interventions have combined both approaches. This paper describes the protocol of the Brain Boosters intervention, which synergistically combines training in compensatory and healthy lifestyle behaviors and supports implementation and tracking of new behaviors with a digital application.

METHODS

The study utilizes a single-site, single-blinded, randomized controlled design to compare a structured lifestyle and compensatory aid intervention to an education-only self-guided intervention. We plan to enroll 225 community-dwelling adults (25% from underrepresented groups) aged 65 + who endorse subjective cognitive decline (SCD) and low baseline levels of healthy lifestyle behaviors. Both interventions will be administered in group format, consisting of 15 two-hour classes that occur weekly for ten weeks and taper to bi-monthly and monthly, for an intervention duration of 6 months. Participants in both interventions will receive education about a variety of memory support strategies and healthy lifestyle behaviors, focusing on physical and cognitive activity and stress management. The structured intervention will also receive support in adopting new behaviors and tracking set goals aided by the Electronic Memory and Management Aid (EMMA) digital application. Primary outcomes include global cognition (composite of memory, attention, and executive function tests) and everyday function (Everyday Cognition Questionnaire). Data will be collected at baseline and outcome visits, at approximately 6, 12, and 18 months. Qualitative interviews, self-report surveys (e.g., indicators of self-determination, health literacy) and EMMA data metrics will also be used to identify what components of the intervention are most effective and for whom they work.

DISCUSSION

Successful project completion will provide valuable information about how individuals with SCD respond to a compensation and preventative lifestyle intervention assisted by a digital application, including an understanding of factors that may impact outcomes, treatment uptake, and adherence. The work will also inform development, scaling, and personalization of future interventions that can delay disability in individuals at risk for ADRD.

TRIAL REGISTRATION

ClinicalTrials.gov. (NCT05027789, posted 8/30/2021).

Prognostic value of static and dynamic biomarkers in COVID-19 patients: a prospective cohort study

OBJECTIVE

The aim of this study was to analyze in a prospective cohort of hospitalized COVID-19 patients the relationship between biomarkers levels and their variation within the first 4 days since admission, and prognosis.

METHODS

Prospective cohort study. Individuals with confirmed diagnosis of covid-19 admitted in our hospital were included. Blood samples were obtained systematically on days 1 and 4 of hospitalization. Levels of RCP, LDH, Ferritin and D-dimer, together with platelets, lymphocytes and neutrophils counts were measured. A combined outcome that included ICU admission and death was considered the primary outcome. Logistic regression analysis was performed.

RESULTS

We included 335 patients with confirmed COVID-19. During their hospitalization, 23 (6.8%) needed ICU admission, and 10 (2.9%) died. In the multivariate analysis, a value of RCP greater than 10 mg/dl (OR 8.69, CI95% 1.45-52), an increase in RCP greater than 20% (OR 26.08, CI 95% 3.21-211.3), an increase in LDH greater than 20% (OR 6.29, CI 95% 1.84-21.44), a count of lymphocytes lower than 1500/mm3 (OR 2.74, CI 95% 1.04-7.23), a D-dimer value greater than 550 ng/ml (OR 9.8, CI 95% 1.78-53.9) and a neutrophil/lymphocyte index greater than 3(OR 4.5, CI 95% 1.43-14.19) were all associated with the primary outcome.

CONCLUSIONS

Our study shows that the utilization of static and dynamic biomarkers may represent an important tool to assess prognosis of COVID-19 patients.

Brimonidine-LAPONITE® intravitreal formulation has an ocular hypotensive and neuroprotective effect throughout 6 months of follow-up in a glaucoma animal model

Intravitreal administration is widely used in ophthalmological practice to maintain therapeutic drug levels near the neuroretina and because drug delivery systems are necessary to avoid reinjections and sight-threatening side effects. However, currently there is no intravitreal treatment for glaucoma. The brimonidine-LAPONITE® formulation was created with the aim of treating glaucoma for extended periods with a single intravitreal injection. Glaucoma was induced by producing ocular hypertension in two rat cohorts: [BRI-LAP] and [non-bri], with and without treatment, respectively. Eyes treated with brimonidine-LAPONITE® showed lower ocular pressure levels up to week 8 (p < 0.001), functional neuroprotection explored by scotopic and photopic negative response electroretinography (p = 0.042), and structural protection of the retina, retinal nerve fibre layer and ganglion cell layer (p = 0.038), especially on the superior-inferior axis explored by optical coherence tomography, which was corroborated by a higher retinal ganglion cell count (p = 0.040) using immunohistochemistry (Brn3a antibody) up to the end of the study (week 24). Furthermore, delayed neuroprotection was detected in the contralateral eye. Brimonidine was detected in treated rat eyes for up to 6 months. Brimonidine-LAPONITE® seems to be a potential sustained-delivery intravitreal drug for glaucoma treatment.

Antioxidant and pro-oxidant actions of resveratrol on human serum albumin in the presence of toxic diabetes metabolites: Glyoxal and methyl-glyoxal

Methylglyoxal (MGO) and glyoxal (GO) are attracting considerable attention because of their role in the onset of diabetes symptoms. Therefore, to comprehend the molecular fundamentals of their pathological actions is of the utmost importance. In this study, the molecular interactions between resveratrol (RES) and human serum albumin (HSA) and the ability of the stilbene to counteract the oxidative damage caused by pathological concentrations of MGO and GO to the human plasma protein, was assessed. The oxidation of Cys34 in HSA as well as the formation of specific protein semialdehydes AAS (α-aminoadipic), GGS (γ-glutamic) and the accumulation of Advanced Glycation End-products (AGEs) was investigated. Resveratrol was found to neutralize both α-dicarbonyls by forming adducts detected by HESI-Orbitrap-MS. This antioxidant action was manifested in a significant reduction of AGEs. However, RES-α-dicarbonyl conjugates oxidized Cys34 and lysine, arginine and/or proline by a nucleophilic attack on SH and ε-NH groups in HSA. The formation of specific semialdehydes in HSA after incubation with GO and MGO at pathological concentrations was reported for the first time in this study, and may be used as early and specific biomarkers of the oxidative stress undergone by diabetic patients. The pro-oxidative role of the RES-α-dicarbonyl conjugates should be further investigated to clarify whether this action leads to positive or harmful clinical consequences. The biological relevance of human protein carbonylation as a redox signaling mechanism and/or as a reflection of oxidative damage and disease should also be studied in future works.

Microwave Assisted Synthesis of Iron(III) Oxyhydroxides/Oxides Characterized Using Transmission Electron Microscopy, X-ray Diffraction, and X-ray Absorption Spectroscopy

Microwave assisted synthesis of iron oxide/oxyhydroxide nanophases was conducted using iron(III) chloride titrated with sodium hydroxide at seven different temperatures from 100 degrees C to 250 degrees C with pulsed microwaves. From the XRD results, it was determined that there were two different phases synthesized during the reactions which were temperature dependent. At the lower temperatures, 100 degrees C and 125 degrees C, it was determined that an iron oxyhydroxide chloride was synthesized. Whereas, at higher temperatures, at 150 degrees C and above, iron(III) oxide was synthesized. From the XRD, we also determined the FWHM and the average size of the nanoparticles using the Scherrer equation. The average size of the nanoparticles synthesized using the experimental conditions were 17, 21, 12, 22, 26, 33, 28 nm, respectively for the reactions from 100 degrees C to 250 degrees C. The particles also had low anisotropy indicating spherical nanoparticles, which was later confirmed using TEM. Finally, XAS studies show that the iron present in the nanophase was present as iron(III) coordinated to six oxygen atoms in the first coordination shell. The higher coordination shells also conform very closely to the ideal or bulk crystal structures.

Expression of immune responsive genes in cell lines from two different Anopheline species

Malaria infection results in increased expression of immune responsive genes, including those encoding antimicrobial peptides such as Gambicin (Gam1) and Cecropin A (Cec1). Understanding how these genes are regulated will provide insights how the mosquito immune system is activated by Plasmodium. We previously have shown that Cec1 was primarily regulated by the Imd-Relish (REL2) pathway in the Anopheles gambiae Sua1B cell line. We show here that expression of Defensin A (Def1) and Gam1 was reduced after RNA interference against components of the Imd-REL2 pathway in An. gambiae cell lines. Interestingly, promoter reporters of these antimicrobial peptides were expressed at very low level in the cell line MSQ43 from Anopheles stephensi. Surprisingly, over-expression of either NF-kappaB transcription factor REL1 or REL2 alone is sufficient to induce the expression of Cec1, Gam1 and Def1. These results suggest that expression of these antimicrobial peptides (AMP) in vivo may be regulated by both the Toll and Imd pathways. We also show here for the first time that Tep4, a gene encoding a thioester containing protein, is regulated by REL2. Taken together, these results suggest that there are significant overlaps of genes regulated by the Toll-Rel1 and Imd-Rel2 pathways. Further, the different expression patterns in two different Anopheline cell lines provide a platform to identify other key positive and negative regulators of the antimicrobial peptide genes.

The pneumonia severity index predicts time to clinical stability in patients with community-acquired pneumonia

SETTING

A total of 33 hospitals in 13 countries in North America, Europe, Africa, Asia and Latin America.

OBJECTIVE

To investigate the relationship between the pneumonia severity index (PSI) and the time to clinical stability from intravenous to oral antibiotic therapy in hospitalized adult patients with community-acquired pneumonia (CAP).

DESIGN

An international, retrospective, observational study of random adult patients meeting the definition of CAP between June 2001 and May 2004.

RESULTS

The risk class (RC) according to the PSI was calculated for all patients. The criteria to define when a patient is clinically stable were evaluated daily during the first 7 days of hospitalization in all patients. The mean time to clinical stability for 254 patients in RC I was 4.2 days, for 233 patients in RC II it was 3.9 days, for 395 patients in RC III it was 4.6 days, for 644 patients in RC IV it was 5.0 days and for 296 patients in RC V it was 6.0 days. Significant positive correlations were observed between RC and time to clinical stability (P < 0.0001).

CONCLUSION

The PSI is a tool that can be used to predict time to clinical stability (i.e., time to antimicrobial switch therapy) in hospitalized patients with CAP.

Characterization of free-floating spheres from human trabecular meshwork (HTM) cell culture in vitro

It has been observed in several tissues that direct isolation of cells in serum-free media and on nonadhesive substrates results in the formation of spherical clusters of cells known as free-floating spheres. Such free-floating spheres have been hypothesized to contain undifferentiated multipotent progenitor cells. Our goal was to isolate and characterize such free-floating spheres from HTM cell primary cultures. For this purpose, HTM cells were incubated in serum-free media and on a nonadhesive substrate. Individual free-floating spheres generated in these conditions were isolated in 96-well plates, and their proliferative capacity was evaluated by monitoring their size increase over time. The expression of the TM markers, MGP and CHI3L1, was examined using recombinant adenoviruses containing the respective promoters. Morphology of the free-floating spheres was analysed in semithin sections, and the gene expression profile was obtained using Human Genome U133 Plus 2.0 Affymetrix microarrays. HTM cells incubated in serum-free media and on nonadhesive substrate generated free-floating spheres that could be grown for more than 3 months. Addition of serum to the culture media promoted the attachment of the spheres to the substrate, migration of cells from the spheres, and differentiation into cells phenotypically similar to normal TM cells. Gene profiling analysis demonstrated strong similarities between the gene expression profiles of the spheres and HTM cell monolayers. Both infection with the recombinant adenoviruses and gene array analysis demonstrated the expression of CHI3L1 and MGP, indicating that free-floating spheres likely originate from HTM cells. Gene array analysis also showed expression of the marker for neural precursor cells nestin, as well as leukemia inhibitory factor, a gene involved in the maintenance of the undifferentiated state of progenitor cells. Analysis of semithin sections indicated that these TM free-floating spheres were highly dynamic structures demonstrating a distinct radial gradient of cell proliferation, survival, and apoptosis. Extensive up- and down-regulation of gene expression was associated with the processes of sphere attachment and cell migration after the addition of serum. These results suggest that HTM primary cultures might contain relatively undifferentiated or progenitor cells. The availability of TM progenitor cell cultures could constitute a useful tool to investigate cell therapy approaches targeting the TM in glaucoma.

HIV infection does not influence clinical outcomes in hospitalized patients with bacterial community-acquired pneumonia: results from the CAPO international cohort study

In a case-control study, outcomes for 58 human immunodeficiency virus (HIV)-positive patients with community-acquired pneumonia (CAP) were compared with outcomes for 174 HIV-negative patients with CAP. No differences were found in the time to clinical stability, the length of hospitalization, and mortality. Clinical outcomes for hospitalized patients with CAP may not be influenced by HIV infection.

Chagas disease in bone marrow transplantation: an approach to preemptive therapy

The efficacy of preemptive therapy was evaluated in bone marrow transplantation (BMT) recipients associated with Chagas disease (CD). The criterion to include patients in the protocol was the serological reactivity for CD in recipients and/or donors before transplant. After BMT, the monitoring was performed using the direct Strout method (SM), which detects clinical levels of Trypanosome cruzi parasitemia, and CD conventional serological tests. Monitoring took place during 60 days in ABMT and throughout the immunosuppressive period in allogeneic BMT. Reactivation of CD was diagnosed by detecting T. cruzi parasites in blood or tissues. In primary T. cruzi infection, an additional diagnostic criterion was the serological conversion. A total of 25 CD-BMT patients were included. Two ABMT and four allogeneic BMT recipients showed CD recurrences diagnosed by SM. One patient also showed skin lesions with T. cruzi amastigotes. Benznidazole treatment (Roche Lab), an antiparasitic drug, was prescribed at a dose of 5 mg/kg/day during 4-8 weeks with recovery of patients. Primary T. cruzi infection was not observed. This report proves the relevance of monitoring CD in BMT patients and demonstrates that preemptive therapy was able to abrogate the development of clinical and systemic disease.

Severe reversible cardiomyopathy in four unrelated infants associated with mitochondrial DNA D-loop heteroplasmy

Inherited disorders of energy metabolism are increasingly being recognized as important causes of cardiomyopathy in children. We previously reported that heteroplasmic point substitutions in the mitochondrial DNA D-loop were found in 15 of 75 children at risk for mitochondrial disease (vs 0/95 controls). Four of these cases presented with severe cardiomyopathy in congestive failure in addition to other anomalies and are presented here. In each case, myocardial dysfunction greatly improved following supportive therapy aimed at reversing both congestive failure and catabolism. D-loop point heteroplasmy may be a marker for severe, reversible, infantile multisystem disease that can present with cardiomyopathy.

Micropropagation of Ilex dumosa (Aquifoliaceae) from nodal segments in a tissue culture system

Micropropagation of Ilex dumosa var. dumosa R. ("yerba señorita") from nodal segments containing one axillary bud was investigated. Shoot regeneration from explants of six-year-old plants was readily achieved in 1/4 strength Murashige and Skoog medium (1/4 MS) plus 30 gr x L(-1) sucrose and supplemented with 4.4 microM BA. Further multiplication and elongation of the regenerated shoots were obtained by subculture in a fresh medium of similar composition with 1.5 gr x L(-1) sucrose. Rooting induction from shoots were achieved in two steps: 1) 7 days in 1/4 MS (30 gr x L(-1) sucrose, 0.25% Phytagel) with 7.3 microM IBA and 2) 21 days in the same medium without IBA and 20 microM of cadaverine added. Regenerated plants were successfully transferred to soil. This micropropagation schedule can be implemented in breeding programs of Ilex dumosa.

Characterization of three Toll-like genes from mosquito Aedes aegypti

Three Toll-related genes (AeToll1A, AeToll1B and AeToll5) were cloned and characterized from the yellow fever vector mosquito, Aedes aegypti. All three genes exhibited high levels of amino acid sequence similarity with Drosophila melanogaster (Dm)Toll1 and DmTehao (Toll5). AeToll1A and AeToll1B are 1124 and 1076 amino acid residues long, respectively. Both contain a carboxyl extension downstream of the Toll/interleukin-1 receptor (TIR) domain. AeToll5 is 1007 residues long and, like DmTehao, lacks the carboxyl terminal extension. Expression of these three genes was examined throughout development and after immune challenge. Both AeToll1A and AeToll5, like their Drosophila counterparts, activate transcription of drosomycin promoter in both Aedes and Drosophila cell lines. Deletion of the carboxyl extension of AeToll1A did not result in a further elevated level of the antifungal response. The intracellular signalling process appears to be species specific based on two observations. (1) DmToll is completely inactive in an Aedes cell line, suggesting a higher specificity requirement for DmToll in the intracellular signalling process. (2) Only one of three amino acid residues essential for DmToll function is required for AeToll1A function.

Midterm results of the Ross procedure

BACKGROUND

The optimal hemodynamic performance and potential growth of the pulmonary autograft has led to expanded indications for the Ross procedure. We reviewed our institutional experience to assess midterm results with the Ross operation.

METHODS

In a 7-year period (1992 to 1999), 111 patients with a median age of 15.7 years (range 2 days to 67 years), underwent the Ross procedure. Ninety-five patients had isolated aortic valve disease and 16 pediatric patients had a more complex left ventricular outflow tract obstruction.

RESULTS

There were 3 early (2.7%) and 3 late deaths over a median follow-up of 3.6 years (range 6 months to 7.6 years). Actuarial survival at 5 years was 94%+/-2%. In pediatric patients, the pulmonary autograft annulus enlarged from 14.7+/-6.2 mm to 22+/-6.3 mm. This growth followed the expected increase in pulmonary valve diameter based on body surface area. Eight reoperations were necessary for autograft insufficiency at a median interval of 14 months (range 2 days to 31 months). Freedom from replacement of the pulmonary autograft was 91%+/-3% at 5 years. Three patients developed important obstruction of the pulmonary homograft requiring reoperation at a median of 29 months (range 9 to 31 months).

CONCLUSIONS

The Ross procedure can be performed with good midterm results. In pediatric patients, autograft growth has been appropriate. The potential for development of important autograft insufficiency suggests close follow-up through the intermediate and late term.

Microsatellite polymorphism in tsetse flies (Diptera: Glossinidae)

In sub-Saharan Africa, tsetse flies are the vectors of trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals. Certain wild populations of the palpalis group exhibit intraspecific variation and are suspect of manifest differences in vectorial capacity. The current study reports the identification of 13 polymorphic microsatellite loci from Glossina palpalis palpalis Robinean-Desvoidy. The majority of these markers amplify corresponding loci from the related species C. p. gambiensis Vanderplank, G. f. fuscipes Newstead, and G. tachinoides Westwood. Only seven of 13 loci were amplified from G. austeni Newstead. Genetic variability was estimated in one field population of G. p. gambiensis. These results confirmed that microsatellite markers may be used to examine the subpopulation structure of tsetse flies.

Troponin I elevation after supraventricular tachycardia in a child with hypertrophic cardiomyopathy

An 11-year-old patient with diagnosis of hypertrophic cardiomyopathy (HCM) developed marked elevation of troponin I in the absence of electrocardiographic signs of ischemia after two episodes of supraventricular tachycardia. At follow-up the level of troponin I returned to normal. The role of troponin I in patients with HCM as a risk marker deserves further evaluation.

[Physiological significance of zinc: perinatal approximation]

Zinc is a very important micronutrient in several biological functions. During pregnancy, zinc deficiency causes fetal-growth retardation, malformations and others poor pregnancy outcomes. The additional need for zinc during pregnancy can be met by an increase in zinc intake, bioavailability or by physiologic adjustments in zinc homeostasis. However, there are factors associated with low intestinal zinc absorption such as diets high in phytate, and iron or calcium supplementation. Further studies of maternal zinc status are necessary to define a prophylactic supplementation to prevent zinc deficiency during pregnancy.

Physiological causes for decreased productivity under high salinity in Boma, a tetraploid Chloris gayana cultivar

Rhodes grass (Chloris gayana Kunth) is widely cultivated in the semi-arid tropics and favoured for salt tolerance; nevertheless, productivity decreases significantly under saline conditions, especially in tetraploid cultivars. The purpose of this work was to explore, in the tetraploid cultivar Boma, the physiological causes for such decrease. Experiments were carried out in vegetative plants in the greenhouse. At high salinity (200 mM NaCl), an early reduction in leaf area expansion was observed, and, later, decreased dry matter accumulation, suggesting that the central effect of salinity was a limitation of leaf growth. This was evaluated in 2 closely related Boma clones, exhibiting different degrees of salt tolerance. Growth, ion accumulation and excretion, sugars, and proline concentrations were measured under a range of salt concentrations (0–200 mM NaCl). Differences between the clones in leaf expansion were expressed only at high salinity, but were not associated with differences in water potential or hydraulic conductance in the expanding region. At all salinity levels, the proportion of dry leaves was higher in the clone which also had lower salt gland density and Na excretion rates. Less efficient Na extrusion, associated with high oxidative stress, may be the main cause for leaf senescence and differences in productivity between these clones.

Plant regeneration of Ilex paraguariensis (Aquifoliaceae) by in vitro culture of nodal segments

In vitro regeneration of complete plants from nodal single bud segments of "yerba mate" (Ilex paraguariensis St. Hil.) was studied under defined nutritional and environmental conditions. Nodal segments harvested from actively growing shoots of conventionally raised plants were cultured on nutrient medium with the mineral salts and vitamins of Murashige and Skoog medium at 1/4 strength, supplemented with various concentrations of sucrose and 6-benzyladenine (BAP). Shoot regeneration from explants of both young (2 years old) and adult (20 years old) mother plants were readily achieved in the medium supplemented with 0.04-0.09 M sucrose with or without BAP. As many as 60-65% of the nodal segments cultured formed shoots. Rooting of regenerated shoots was observed in 50% of the explants harvested from young plants, whereas 25% of the explants rooted when the nodal explants were harvested from adult plants. The best rooting induction was achieved on 1/4 strength MS medium with vermiculite as the substrate and supplemented with 1-1.5% IBA (indolebutyric acid) and 1-2% PPZ (3-methyl-1-phenyl-2 pyrazolin-5-one). Plantlets were successfully transferred to soil.

Systemic to pulmonary collaterals in very low birth weight infants: color doppler detection of systemic to pulmonary connections during neonatal and early infancy period

OBJECTIVE

Angiographic visualization of systemic to pulmonary collaterals (SPC) has been documented in premature infants needing prolonged ventilatory support. Noninvasive identification of such communications in premature infants was reported recently. The purpose of this study was to describe: 1) incidence, 2) clinical findings and implications, and 3) short-term follow-up of SPC diagnosed by echocardiography in very low birth weight (VLBW) infants admitted to the neonatal intensive care unit.

METHODS

From December 1, 1994 to August 31, 1996, 196 infants with birth weight <1500 g were admitted to the neonatal intensive care unit; 133 of them received serial echocardiographic evaluations at 1 to 2 days, at 2 weeks, and at 1, 2, and 3 months of life. Follow-up echocardiograms were scheduled at 6 months and 1 year of age for patients with SPC persisting at 3 months of age.

RESULTS

SPC were demonstrated in 88 patients (66%) at 1 to 90 days of life (mean 28 days). In most cases, the SPC originated at the distal aortic arch or the proximal descending aorta. Ten patients (11%) were treated for congestive heart failure. The symptoms improved and anticongestive therapy was discontinued in 9. One patient with persistent congestive heart failure underwent therapeutic cardiac catheterization and 1 prominent SPC was embolized.

CONCLUSIONS

The incidence of SPC in VLBW infants is much higher than previously reported. We postulate that SPC are bronchopulmonary communications that enlarge and/or proliferate in response to a given stimulus. These communications are associated with increased time on positive pressure ventilation and length of stay in the hospital. SPC may lead to pulmonary edema and should be searched for in VLBW infants with a more complicated course. Echocardiographic examination with color Doppler performed in premature infants to evaluate left to right shunts should include careful search for systemic to pulmonary collaterals.echocardiography, systemic to pulmonary collaterals, aortopulmonary collaterals, prematurity, pulmonary edema.

Chagas' disease in patients with kidney transplants: 7 years of experience 1989-1996

Chagas' disease was present in 17.22% of persons undergoing kidney transplantation in an Argentine Hospital. The criterion for attributing reactivation of chronic Chagas' disease and transmission of Trypanosoma cruzi to grafts was detection of parasites in blood (patent parasitemia) or tissues. Reactivation was diagnosed in 5 (21.7%) of 23 recipients. Ten (43.4%) of 23 chagasic recipients without reactivation of chronic Chagas' disease had abrogation of serological reactivity. T. cruzi infection was transmitted to 3 (18.7%) of 16 non-chagasic recipients. Reactivation and infection were diagnosed by patent parasitemia or cutaneous panniculitis. For diagnosis, detection of parasites in blood and tissues had more relevance than serology. Sequential monitoring detected early reactivation and infection, permitting application of preemptive or therapeutic therapy with benznidazole, thus inhibiting, in all patients, severe clinical disease produced by a progressive and systemic replication of the parasite.

Reverse aortic arch flow secondary to severe pulmonary hypertension in the neonate

The purpose of this study is to determine the incidence of reverse aortic arch flow in newborn infants with pulmonary hypertension, and no other identifiable cause for flow reversal, being considered for extracorporeal membrane oxygenation (ECMO) 2) compare the left ventricular output, and 3) outcomes, of these infants, with those in the group of patients with normal arch flow. We reviewed the medical records and echocardiograms of all infants referred to our institution for extracorporeal membrane oxygenation support for pulmonary hypertension, between August 1994 and April 1996. Neonates with pulmonary hypertension and reverse aortic arch flow had significantly lower left ventricular output (p = 0.005), and had significantly higher mortality (p = 0.04), than those with normal aortic arch flow. They required significantly higher ventilatory support (p = 0.01) and tended to need more inotropic support. Reverse aortic arch flow in newborn infants with pulmonary hypertension, and no other cause for the reverse flow, indicates significantly decreased left ventricular output, and may be a marker for a more difficult clinical course and poor prognosis. In this group of patients with pulmonary hypertension, the survival was significantly higher in infants with no PDA or with pure left to right shunt across a PDA.

Reactivation of chronic Chagas' disease following allogeneic bone marrow transplantation and successful pre-emptive therapy with benznidazole

This report shows the early detection of reactivation of chronic Chagas' disease (CCd) in a 27-year-old man with chronic myelogenous leukemia undergoing allogeneic bone marrow transplantation (ABMT). Pre-emptive therapy with benznidazole during a period of 7 weeks led to a rapid recovery of the patient, who remains free of parasitemia 2 years after the bone marrow transplantation.

[Clinical features and diagnosis of mucocutaneous leishmaniasis in patients of an endemic area in Salta]

A total of 39 patients with a clinical diagnosis of mucocutaneous leishmaniasis, in an endemic area for leishmaniasis in Salta, Argentina, were examined between June 1990 and December 1992. Of these cases, 87% (34/39) presented the cutaneous simple form, 10.3% the cutaneous multiple form and 2.6% the mucosal form. Lesions were more frequently located in legs and arms (71.8%), followed by trunk and multiple location (10.3%). Of the patients, 43% were housewives, students or children, suggesting that the infection could be contracted in the domestic or peridomestic environment. Of 39 patients diagnosed, in 22 (56.4%) the parasite was found. Direct microscopy (smear) permitted a diagnosis in 13 (59.4%) of these 22 patients. Among these, 5 (22.7%) had positive diagnosis by culture, and 9 (40.9%) by inoculation in hamsters. Ten parasite isolates (45.4%) were obtained. The smear is recommended as a diagnostic method for epidemiological surveillance due to the sensibility demonstrated herein and its easy application in the endemic area. The time of clinical evolution, from the appearance of the lesion up to the detection of the patient by Sanitary Agents, was approximately 90 days. This would be related to the frequency of the visits, usually every 3 months. Only one of 30 treated patients had a relapse at 6 months, due to non fulfillment of the treatment.

Recipients and donors of bone marrow transplants suffering from Chagas' disease: management and preemptive therapy of parasitemia

We report the clinical course of five adult patients with chronic Chagas' disease (Cd) who underwent BMT. Two patients with non-Hodgkin's lymphoma and one with ALL received an ABMT. Allogeneic BMT was performed in two patients with AML and CML respectively. One donor had chronic Cd. Samples of peripheral blood for parasite investigation by the Strout method, blood culture, and immunological studies by indirect immunofluorescent assay, ELISA and indirect hemagglutination tests were performed weekly from the start of chemotherapy until day +60 for ABMT and during the period of immunosuppression for allogeneic BMT. No prophylaxis was given to any of these patients. In only one ABMT patient were trypomastigotes detected early by blood culture without symptoms of reactivation. Benznidazole as preemptive treatment was administered at 5-8 mg/kg/daily for 30 days. Parasitemia was rapidly cleared and at the end of therapy xenodiagnosis was negative. The other Cd patients showed no evidence of relapse of parasitemia or signs and symptoms of reactivation. In brief, evidence of Cd should be sought in all BMT patients coming from endemic areas because parasitemia and reactivation are potential complications during the period of neutropenia and immunosuppression. The strategy used for early detection and treatment of parasitemia and reactivation was safe and effective.

Leishmania (Viannia) braziliensis: biological behavior in golden hamsters of isolates from Argentine patients

This study reports intraspecific variations of native isolates of Leishmania (Viannia) braziliensis from patients with leishmaniasis from Salta, Argentina. These isolates induced skin lesions in golden hamsters, initially showing rapid development, reaching their largest size between 28 and 35 days postinfection (PI). Thereafter, the infections were self-limiting and total regression was observed at 80-150 days PI. The majority of the native isolates were characterized by low infectivity in the experimental animals, and a classic pattern of dissemination to systemic organs was established. However, unusual features for L. braziliensis were displayed by two isolates; one showed evidence of high infectivity in hamsters characterized by a short prepatent period and larger, severe and persistent lesions at the inoculation site. The other isolate, of low infectivity, showed cutaneous metastasis and recurrent systemic dissemination in the same animals, suggesting dissociation between infectivity and pathogenicity. Metastasis has been frequently described in hamsters infected with L. (V) guyanensis and L. (V) panamensis, but not in infections induced by L. (V) braziliensis, as was observed in this study. Active and/or regressive histopathologic lesions were observed, depending on the stage of the infection. An exudative and mixed inflammatory pattern with microabscesses and necrotic areas was observed during early infection, while well-defined granulomas and collagen formation were the predominant features detected at a later time. Amastigotes were easily detected in the tissues, although in low numbers. Schaumann bodies were always detected. The characterization of the unique features of these native isolates, and the verification of their reproducibility in vitro and in vivo will be useful tools in tests related to immunoprophylaxis and chemotherapy.

Antibacterial effect of 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1, 4-naphthoquinone-4-imine on Staphylococcus aureus

The mechanism by which a new naphthoquinone derivative, the 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1, 4-naphthoquinone-4-imine (INQI-E) has antibacterial effect against Staphylococcus aureus was studied. The interaction of INQI-E with the bacteria was followed by absorption spectroscopy at 323 and 490 nm. The absorption band of INQI-E at 490 nm undergoes a hypochromic shift with a decrease of intensity. This effect was found to be reversible by oxygenation during the first hours of incubation. The participation of an oxidation-reduction process related to the respiratory chain was demonstrated by oxygen consumption. An increase in O2 uptake and inhibition of S. aureus growth was observed. Experiments with three inhibitors of the respiratory chain demonstrated that the pathway induced by INQI-E was antimycin-resistant and KCN- and salicylhydroxamic acid (SHAM)-sensitive, which suggests that INQI-E is capable of diverting the normal electron flow to an alternate superoxide-producing route. On the other hand, experiments with Tiron, a specific scavenger of superoxide, hindered the effect of INQI-E against S. aureus, indicating that the inhibitory growth effect of this quinone-imine is mainly due to the production of the cytotoxic superoxide radical.

[Acute effect of lorazepam on respiratory muscles in stable patients with chronic obstructive pulmonary disease]

Benzodiazepines are known to cause muscle hypotonia, but their effects on respiratory muscle function, particularly on diaphragm, have not yet been studied. Our aim was to look for any effect of lorazepam on respiratory muscle function in patients with chronic obstructive pulmonary disease (COPD). Nine stable COPD patients (mean +/- SD forced expiratory volume in one second (FEV1) 0.91 +/- 0.31 l) were included in the study. The following measurements were performed before and 1 hour after lorazepam administration (doses: 1.5 to 2 mg) by sublingual route: forced vital capacity (FVC), FEV1, maximal voluntary ventilation (MVV), arterial oxygen tension (PaO2), arterial carbon dioxide tension (PaCO2), minute ventilation (Ve), tidal volume (Vt), respiratory rate (f), inspiratory time/inspiratory plus expiratory time (Ti/Ttot)-, mean inspiratory flow (Vi), maximal inspiratory (MIP) and expiratory (MEP) pressures, maximal pleural pressure (Pplmax), transdiaphragmatic pressures (Pdi) and skeletal muscle strength and endurance. As expected, no change was noted in FVC, FEV1, FEV1/FVC (Table-1). Besides stability of expiratory flows, this denotes no change in collaboration in spite of the sedative effects of lorazepam. There was a 20% decrease in Ve, due to a Vt reduction and a small increase in PaCO2. These could be explained by the central effects of benzodiazepines. Skeletal muscle strength and endurance decreased significantly (22 and 50% respectively-Table 2), in accordance with the previously reported muscular actions of this pharmacological group. Respiratory muscle function parameters, MIP, MEP, MVV and Ppl showed significant reductions (10 to 20 per cent), as was the case with diaphragmatic function measured by Pdi (Muller maneuver with abdominal protrussion and maximal open-glottis expulsive maneuver) (Table 3). This study demonstrates that a single lorazepam dose reduces strength and endurance of respiratory muscle in chronic stable COPD patients.

Invasive micropapillary carcinoma of the breast. A new special type of invasive mammary carcinoma

After reviewing 986 consecutive cases of breast carcinoma from our files, 27 ductal infiltrating cancers showing micropapillary differentiation in invasive areas (MP) were selected. Special immunohistological and ultrastructural techniques were used, and their characteristics compared to those of the Not Otherwise Specified type of carcinomas (NOS). Diagnostic areas of MP were easily identified in H&E sections and were composed of solid or tubular neoplastic cell groups inside a spongy background, where they appeared to swim in aqueous or mucinous material. Neoplastic cells displayed the reverse polarity typical of the papillary phenotype. This was revealed by the detection of acid mucinous rims, lineal deposits of EMA substances, and microvilli in a peripheral position, even in areas where the micropapillae resembled tubules. Histologically, most MP were mixed with N0S, Papillary, or Mucinous patterns, but regardless of the extension of their micropapillary diagnostic component, their tumour size, or their WHO histological grade, two thirds had extensive lymphatic vessel invasion and all the cases presented massive axillary lymph node metastasis. Six of the twelve patients followed died within a mean of 22 months. In conclusion, we propose the recognition of "Invasive Micropapillary Carcinoma of the Breast" as a new special entity with a potentially high degree of aggressiveness.

Measles, mumps, and rubella antibodies in vaccinated Baltimore children

OBJECTIVE

To determine quantitative measles, mumps, and rubella serum antibody levels as a function of time since vaccination in a sample of vaccinated Baltimore children.

DESIGN

Cross-sectional serologic survey.

SETTING

Pediatric outpatient departments at the University of Maryland Medical Center, Baltimore.

PARTICIPANTS

One hundred seventy children, ranging in age from 1.5 through 16 years, who had measles, mumps, and rubella vaccination between ages 12 and 18 months.

RESULTS

Serum antibody levels to measles and rubella declined with increasing time since vaccination. However, no such decline in antibody levels to mumps was observed. Children who were vaccinated between ages 12 and 14 months did not have lower antibody levels than children who were vaccinated at age 15 months or older.

CONCLUSIONS

In areas free from natural disease, antibody levels resultant from measles, mumps, and rubella vaccine are likely to decline with advancing age. Revaccination with measles, mumps, and rubella vaccine may boost falling antibody titers.