Overexpression of BCL2, BCL6, VEGFR1 and TWIST1 in Circulating Tumor Cells Derived from Patients with DLBCL Decreases Event-Free Survival

Purpose

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous malignant lymphoid neoplasm and is the most common subtype of non-Hodgkin lymphoma in adults. More than half of patients with DLBCL can achieve remission with standard R-CHOP regimes; however, approximately 30-40% of patients are still failing this standard therapy, which remains as an important cause of progression and mortality of this disease. It is necessary to have diagnostic and monitoring tools that allow us to improve the accuracy of prognosis in these patients. Circulating tumor cells (CTCs) identification through molecular biomarkers is one of the novel strategies that have been used in other types of cancer, and we aim to use this tool to analyze the potential role in DLBCL.

Patients and Methods

We analyzed 138 blood samples of patients with DLBCL, of which CTCs were isolated by density gradient for subsequent detection and quantitation of molecular biomarkers using RT-qPCR with TaqMan probes. Survival analysis was performed using Kaplan-Meier curves.

Results

We found overexpression of ABCB1, αSMA, BCL2, BCL6 and VEGFR1 genes, as well as the presence of CK19, EpCAM, KI67, MAGE-A4, SNAIL and TWIST1 genes. CK19 and EpCAM expression were associated with a minor OS (85.7% vs 98.1%, p = 0.002). The overexpression of BCL2, BCL6, VEGFR1 and TWIST1 was related to a minor EFS (p = 0.001).

Conclusion

This study showed that in liquid biopsies analyzed, the presence of CTCs can be confirmed through molecular biomarkers, and it has an impact on OS and EFs, making this detection useful in the follow-up and prognosis of patients with DLBCL.

Atrioventricular nodal ablation with pacemaker implant is associated with improved safety outcomes compared to pulmonary vein isolation of atrial fibrillation with heart failure

Background

Pulmonary vein isolation (PVI) and atrioventricular nodal ablation (AVNA) with pacemaker implant have both been advocated for patients with atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF). Direct comparisons between the two are limited.

Purpose

We sought to compare outcomes and complications following PVI versus AVNA with implant of a cardiac implantable electronic device (CIED) among patients with AF and HFrEF.

Methods

We queried the National Inpatient Sample from 2011 to 2019, using relevant ICD-9 and -10 diagnostic and procedural codes for AF, HFrEF, ablation, and CIED implant to identify our study cohort. Exclusion criteria included presence of a pre-existing CIED, ventricular arrhythmias, non-AF supraventricular arrhythmias, and surgical AF ablation. Baseline characteristics included age, sex, race, and comorbidities related to AF and cardiovascular disease. Severity of comorbidities was assessed via Deyo-Charlson Comorbidity Index (Deyo-CCI). Outcomes investigated include all-cause mortality, major adverse cardiovascular events (MACE), extra-cardiac procedural complications, length of stay, and total hospital charges. Outcomes associations were analyzed using multivariate logistic regression adjusted for baseline characteristics that were significantly different (P<0.05) between cohorts expressed as adjusted odds ratios (aOR) and 95% confidence intervals (CI). SPSS v28.0 (IBM, Armonk, NY) was used to carry out all calculations.

Results

We identified 3,565 encounters for PVI and 1,355 for AVNA with CIED implant among hospitalized patients with AF and HFrEF. Patients who underwent AVNA were more often older (73.8 vs 66.2 years), with more severe comorbidities (mean Deyo-CCI score 2.9 vs 2.6) and were more likely to have an emergent procedure performed (81.3% vs 69.7%; p<0.001 for all). However, the AVNA cohort had less mortality (0.5% vs 1.2%, p=0.03), MACE (6.1% vs 7.8%, p=0.04), and total complications (12.7% vs 16.3%, p=0.002), but longer hospital stay (8.0 vs 6.5 days) and higher total charges ($201,100 vs $159,382; p<0.001 for both). After adjusting for confounders, AVNA remained independently associated with decreased odds of mortality (aOR: 0.370; 95% CI [0.159–0.862], p=0.02), MACE (aOR: 0.552; 95% CI [0.420–0.726], p<0.001), and total complications (aOR: 0.708; 95% CI [0.589–0.852], p<0.001).

Conclusion

Despite older age with more severe comorbidities and less elective procedures, hospitalized patients with AF and HFrEF who underwent AVNA with CIED implant had improved safety outcomes compared to PVI. Further studies comparing the intermediate and long-term outcomes and efficacy between therapies are needed to better delineate which would best serve this population.

Funding Acknowledgement

Type of funding sources: None.

Stay out (almost) all night: contrasting responses in flight activity among tropical moth assemblages

Variations in diel activity among hyperdiverse tropical communities of moths, despite representing a key component of niche partitioning between species, have barely been studied so far. Using light trapping from dawn to sunset over a 1-year period in French Guiana, we investigated these variations within and between two families of moths (Sphingidae and Saturniidae). Our results revealed contrasting patterns in flight activity at night between Sphingidae and Saturniidae. Sphingidae reached their peak in species richness and abundance between 7:00 and 8:00 p.m., followed by a decrease around 11:00 p.m. to midnight, whereas Saturniidae were continuously present throughout the night, with a peak around midnight. In addition, we found changes in diel activity among some of the most common genera in each family, highlighting distinct behavioral, physiological, and functional traits among taxa. Given differences in flight activity at different taxonomic levels, it is strongly recommended to monitor by light trapping throughout the night to effectively sample saturniid and sphingid assemblages, even though the activity of Sphingidae sharply declines after midnight. These results improve the general natural history information of tropical moths and reinforce the need of further research on the ecological and taxonomic consequences of differences in diel activity.

Diffuse (anergic) cutaneous leishmaniasis responding to amphotericin B

American cutaneous leishmaniasis is an important endemic zoonotic disease in the New World that comprises a spectrum of clinical manifestations. Diffuse cutaneous leishmaniasis (DCL) is a rare form of the disease characterized by antigen-specific immunodeficiency that often presents with multiple disfiguring non-ulcerated confluent nodules or plaques that involve large areas of the skin, resembling lepromatous leprosy. Relapse is invariable in advanced stages, despite aggressive chemotherapy, and a plethora of drugs has been tested with unchanging results. We report on a severe an exceptional case that resolved after treatment with amphotericin B, a drug considered only mildly effective, and discuss the therapeutic approach to this disease.

Diffuse cutaneous leishmaniasis responds to miltefosine but then relapses

BACKGROUND

Diffuse cutaneous leishmaniasis (DCL), although rare, is profoundly incapacitating. At present there is no successful treatment for this progressive protozoan infection, which is associated with the absence of specific cell-mediated immunity (CMI) to Leishmania. This disease shares features with visceral leishmaniasis (VL), including specific CMI inactivity during active disease and a heavy parasitic burden, but VL responds well to treatment. Miltefosine is the first orally administered drug which has shown efficacy in the treatment of VL; it has not been adequately evaluated in the treatment of DCL.

OBJECTIVES

To evaluate the efficacy of miltefosine in the treatment of DCL, using clinical, parasitological, histopathological and immunological criteria.

METHODS

Sixteen patients with DCL were treated with miltefosine, 2.0-2.5 mg kg(-1) daily, for variable periods of time (75-218 days). Patients were hospitalized for the first month and evaluated every 2 weeks until the termination of treatment with routine laboratory chemistry, percentage clinical improvement, presence of parasites in skin smears, growth of parasites in culture medium and in hamsters, histopathological characteristics of the granulomas, adverse side-effects, and reactivity to leishmanin skin test antigen. Further cycles of treatment were given in some of these patients, particularly after suspension of treatment was followed by relapse.

RESULTS

Patients showed dramatic clinical improvement and reduction in the parasite burden by day 15 after the initiation of treatment, which continued while treatment was maintained. By day 45, 15 patients showed 80-90% clinical improvement. Nevertheless, suspension of treatment was followed by the development of new lesions in all but one patient. Inoculation in hamsters was observed to be the most sensitive technique to detect persisting parasites. Adverse events were very mild.

CONCLUSIONS

Miltefosine produced a dramatic clinical and parasitological response in patients with DCL and improvement continued during drug administration, but with a single exception all patients presented new lesions after suspension of treatment. There was no histological or skin test evidence to suggest the development of CMI during treatment, which may be an indispensable criterion for the evaluation of potentially effective drugs against DCL.

Self-rated health and its relationship to functional status and well-being in a group of elderly Guatemalan subjects

This study examined the association of self-rated health with physical function and emotional well-being, while controlling for differences in sex, age and anthropometry. Subjects were participants in a multicentre study originated by the International Union of Nutritional Sciences (IUNS). A total of 151 elderly Guatemalan subjects were examined using a questionnaire which included information on self-rated health, activities of daily living, well-being, and a common battery of anthropometric variables. Adjusted odds ratios (OR) obtained with polytomous logistic regression showed that subjects with the highest score on the well-being index compared with those with the lowest were 1.67 times more likely (P-value <0.001, confidence interval (C.I.) = 1.31-2.14) to rate themselves in 'good' health versus 'fair' and 'poor' health. Subjects with the highest score versus those with the lowest on the mobility index were 1.15 times more likely (P-value <0.05, (C.I.) = 1.00-1.32) to rate themselves in 'good' health versus the other health ratings. These are the first results to examine the relationship of self-rated health to physical function and emotional well-being of elderly, free-living Guatemalans.

Can the degree of concordance with recommendations for a cancer prevention diet and lifestyle be assessed from existing survey information data?

BACKGROUND

The World Cancer Research Fund convened an expert committee who analyzed the literature related to the causation of human cancers. Recommendations for preventing cancer through behavioral practices were formatted into a 14-point guideline.

OBJECTIVE

We parsed the cancer prevention guidelines to determine to what extent relevant information on individual behavior could be assessed from conventional food-frequency questionnaires, which are being used in surveys conducted in developing countries.

DESIGN

We examined a convenience sample of archival forms completed during 2 independent studies (a case-control and a field study) that used an adapted Willett food-frequency questionnaire that was translated into Spanish for use in Guatemala.

RESULTS

All dietary related guidelines, except for salt, were evaluated by both questionnaires. Physical activity, food handling, and food preparation were not addressed by either of the questionnaires, although body mass index and dietary supplements were addressed in the case-control study and field-study questionnaires, respectively.

CONCLUSIONS

Although concordance with some of the cancer prevention goals and guidelines can be evaluated from the existing questionnaires, adjustments and additions must be made with respect to salt and supplement use, physical activity, and food handling. Actual weight and height measurements are also needed, particularly in low-income populations.

Paradoxical behavior of PR interval dynamics during exercise and recovery and its relationship to cardiac memory at the atrioventricular node

This preliminary study deals with the dynamics of the PR interval during exercise testing by using a Bruce protocol in 31 nonmedicated, normal patients with ages of 33 +/- 14 years. The behavior of the PR interval permitted its categorization into 2 groups. In Group I (27 of 31, 87.1% of patients) the PR interval showed the expected biphasic behavior with a gradual shortening with increasing exercise and a gradual lengthening during recovery. In contrast, the PR interval in Group II (4 of 31, 12.9% of patients) showed a triphasic behavior since, toward the end of recovery, there was a second decrease in duration. Because of this temporal relation to the phases of exercise, this paradoxical response, in analogy to what happened to the QT interval during exercise, could have been caused by a form of short-term memory or to varying, but normal, intergroup differences in autonomic function. However, further studies involving a greater number of patients are required to reach definite conclusions.

[Introduction of Bacillus sphaericus strain-2362 (GRISELESF) for biological control of malaria vectors in Guatemala]

Malaria continues to be an important health problem in a number of countries of Central and South America where it is considered as a highly prevent endemic disease. The objective of this paper is to assess the entomo-epidemiological impact of a pilot program for the biological control of malaria-transmitting vectors, which was implemented in 1998 in Escuintla, Republic of Guatemala. This program was based on the use of 20,000 L of biolarvicide Bacillus sphaericus- strain-2362 (GRISELESF) which was applied in the 46 localities of highest epidemiological risk at a rate of 10 mL/m2 of effective area of breeding. The entomologic effectiveness of this biolarvicide was monitored from the first 72 hours to 4 months after the application. There was a total larval reduction of 94.57 in the maturity stage of the water phase of Anopheles albimanus vector. The epidemiological analysis was carried out by comparing the rate of malaria prevalence (per 1000 pop) during 1997 and 1998. The five treated municipalities showed a statistically significant reduction of 50% (p 0.01). The results obtained in this paper coincided with those reported by comparable studies, so, this allowed us to recommend the use of the biolarvicide Bacillus sphaericus (strain-2362) as part of a comprehensive program of malaria-transmitting vector control in the Republic of Guatemala and other countries of the region.

Paradoxical behavior of the QT interval during exercise and recovery and its relationship with cardiac memory

BACKGROUND

Few studies have dealt with the behavior of the corrected (QTc) and uncorrected QT intervals during exercise and recovery.

HYPOTHESIS

Based on previously published dynamics of the QT interval during treadmill testing, this study attempted to reevaluate the computer-proposed underlying mechanisms of these dynamics and to determine whether the so-called memory phenomenon could be operative in some subjects without evidence of structural heart disease.

METHODS

This study included 42 unmedicated healthcare volunteers, 23 men and 19 women aged between 20 and 42 (mean 31.7) years. All had normal physical examinations, x-rays, and transthoracic echocardiograms. The electrocardiograms were also normal with 12-lead QT interval dispersions of < 90 ms.

RESULTS

During exercise and recovery, the behavior of the QT intervals permitted the categorization into two groups. In Group 1 (31/42; 73.8% of subjects) the uncorrected QT interval showed a biphasic pattern consisting of a gradual decrease during incremental exercise followed by a gradual increase during recovery. In contrast, the QTc interval had a triphasic pattern resulting from a slight increase during the early phase of exercise, a gradual decrease at the highest rates, and a final increase during recovery as the rate slowed to control values. In Group 2 (11/42; 36.2% of subjects) the behavior was considered as paradoxical since the uncorrected QT interval displayed in a triphasic pattern whereas the QTc interval yielded a tetraphasic pattern due to the fact that both showed a second decrease during recovery while the rate was decreasing.

CONCLUSIONS

Analysis of dynamics behavior of the QTc and the uncorrected QT intervals during exercise showed that some normal subjects had a paradoxical behavior which, because of its temporal relation to the phases of exercise, could be an expression of the so-called memory phenomenon.

Bioelectrical impedance spectroscopy (BIS) in young children with acute and semi-acute hydration disorders: potentials and limitations

This study aimed to evaluate the feasibility and reliability of bioelectrical impedance spectroscopy in young children suffering of acute hydrational disorders. Whole body and segmental measurements were carried out in a group of 42 of children aged 4 to 147 months, using a BIS analyzer (Xitron 4000B). This phase of the study involved several hundred of BIS measurement, which showed the feasibility of using this technique in young children. Using the sweep mode and the modeling software provided for the manufacturer of the instrument, the resistance of the extracellular (RECW) and intracellular (RICW) compartment was calculated. Correlation coefficient (r) and technical error of measurement (TEM) were obtained from paired BIS measurements. RECW showed to be highly reproducible (r = 0.99), with a relatively low TEM (from 1 to 3.5%), across all segments. The reliability was markedly lower respect to RICW, which shows the potential application of BIS technique even in critically ill young child populations.

Progressive sensorineural hearing loss, subjective tinnitus and vertigo caused by elevated blood lipids

The otologist frequently sees patients with progressive sensorineural hearing loss, subjective aural tinnitus and vertigo with no apparent cause. Elevated blood lipids may be a cause of inner ear malfunction on a biochemical basis. To establish the true incidence of this condition, all new patients (4,251) seen during an eight-year period were evaluated; of these, 2,332 patients had complaints of inner ear disease. All had a complete neurotologic examination, appropriate audiometric and vestibular studies and imaging, and blood tests including lipid phenotype studies. Hyperlipoproteinemia was found in 120 patients (5.1%). Most patients were found to be overweight and had additional coexisting conditions such as diabetes mellitus. Treatment with vasodilators and a 500-calorie, high-protein, low-carbohydrate diet yielded improvement of symptoms in 83% of patients within five months of initiation of treatment.

Activated calcineurin confers high tolerance to ion stress and alters the budding pattern and cell morphology of yeast cells

The PP2B protein phosphatase, also known as calcineurin, is a regulator of ion homeostasis in yeast cells. We have investigated the physiological consequences of constitutive expression of a recombinant form of calcineurin in which the Ca2+/calmodulin-binding and autoinhibitory domains of the catalytic subunit were deleted. The concomitant expression of the regulatory subunit along with the truncated catalytic subunit resulted in high tolerance to toxic levels of Na+ and Li+. This activated form of calcineurin substituted for the Na+ stress signal to promote the expression of the ENA1 gene, encoding a P-ATPase pump, and to induce the transition of the K+ uptake system to the high affinity mode that restricts influx of Na+ and Li+. In addition, the transcriptional responsiveness of ENA1 to Na+ stress was enhanced. These results demonstrate that calcineurin has a pivotal role in a signaling cascade activated by ion stress in yeast. Moreover, we found that changes in the level of calcineurin activity affected budding pattern and cell morphology. Cells expressing the truncated calcineurin were elongated and budded in an unipolar pattern, whereas calcineurin-deficient mutants budded randomly. These results suggest that calcineurin may also act in the establishment of cell polarity.

Characterization of spontaneous recurrent ventricular arrhythmias detected by electrogram-storing defibrillators in sudden cardiac death survivors with no inducible ventricular arrhythmias at baseline electrophysiologic testing

This retrospective study characterized the recurring ventricular arrhythmias with an electrogram-storing defibrillator in survivors of sudden cardiac death who had no inducible sustained ventricular arrhythmias at baseline electrophysiologic testing (EPS). The study group was composed of 24 selected patients with documented ventricular fibrillation (VF) without need of revascularization or chronic antiarrhythmic therapy. The EPS protocol usually consisted of three extrastimuli at two drive cycles at two right ventricular sites. Nonischemic cardiomyopathy was the most frequent structural abnormality (n = 11) followed by coronary artery disease (n = 7). The mean ejection fraction was 0.37 +/- 0.13. Cardiac status did not appear to change during a mean follow-up period of 16.4 +/- 12.5 months, and eight (33%) patients received appropriate shocks in that time period. On the basis of intracardiac electrograms, 7 (88%) patients experienced VF and 1 (12%) patient had ventricular tachycardia as the first recurring arrhythmia. Four patients had additional recurrences and all were VF episodes. VF was usually present from the onset of the arrhythmia. In addition, 9 (38%) patients had nonsustained ventricular arrhythmias that were solely VF in 6 (67%). In conclusion, VF of sudden onset was the most frequent recurring sustained ventricular arrhythmia in this group.

A comparison of body fat estimates using anthropometry and bioelectrical impedance analysis with distinct prediction equations in elderly persons in the Republic of Guatemala

Bioelectrical impedance analysis (BIA) has been proposed as a technique to estimate body composition. Its application has extended beyond the clinical setting, however, it remains to be determined if the BIA prediction formulas published to date provide comparable body composition estimates in elderly populations. The objective of this study was to compare the estimates of body fat derived from published prediction equations in a developing country's population such as Guatemala. A total of 234 elderly persons were studied (108 males and 126 females), with ages of 78 +/- 7 and 77 +/- 8 (mean +/- SD) yr, respectively. The height and weight averaged 156.4 +/- 7.9 and 144.0 +/- 7.0 cm, and 54.5 +/- 9.4 and 49.4 +/- 10.6 kg, for males and females, respectively. Measurements included skinfolds (triceps, biceps, subscapular, and suprailiac), and body resistance (BIA). Body fat estimates were derived from four BIA-prediction formulas and three equations based on anthropometry. Mean percent body fat estimates for the overall population obtained from anthropometry and BIA prediction formulas ranged from 22 to 50%. Females had higher estimates compared to males without regard for the method used. Highly significant intermethod correlations were seen, but differences in fat estimation among prediction formulas were noticed and the magnitude of the differences were BIA-formula dependent.

Blood retinol and beta-carotene levels in rural Guatemalan preschool children

Plasma retinol and beta-carotene levels were measured in 502 preschool Guatemalan children from five rural hamlets. Their ages ranged from 6 to 78 months (mean: 42.9 +/- 19.2 months); 45% males and 55% females. The mean retinol value in the whole group was 0.9 +/- 0.4 mumol/l (range: 0.1 to 8.4 mumol/l). There was no significant difference between sexes in retinol mean values nor in the incidence of retinol values less than 0.7 mumol/l (22% in males, 18% in females). When grouped by age and community, significant low retinol mean values were found in two hamlets in the youngest age group (12 to 23 months) as compared to the other age-groups (p < 0.05). In the other two hamlets, there were no significant differences among retinol means by age-group. The highest prevalence of deficient retinol values by age-group was in the 12 to 23 months group (40%), and decreased as age increased. The mean value for beta-carotene in the whole group was 0.13 +/- 0.18 mumol/l (range: 0.01 to 2.23 mumol/l). There were no significant differences in beta-carotene means between sexes in the whole group. Stratifying the beta-carotene data by age-groups and community, values were significantly higher in the 48-59 months and 72-83 months groups, as compared with the other age groups in two of the communities (p < 0.05). Significant differences across communities for beta-carotene were found only in the 12 to 23 months group.

[Relationship between plasmatic lipids and fat soluble vitamins in Guatemalan periurban elderly]

The levels of plasmatic lipids and fat liposoluble vitamins were measured in 107 elderlies (29% males, 71% females) who were residents of a poor periurban neighborhood of Guatemala City. The age ranged between 60-103 years (means +/- sd 69 +/- 8). The mean and sd for the plasmatic levels of lipids and vitamins were (ranges in parenthesis): cholesterol 220 +/- 42 mg/dl (128 to 428); triglycerides: 189 +/- 92 mg/dl (54 to 513); retinol 50 +/- 16 ug/dl (4.5 to 103); beta-carotene 17 +/- 12 ug/dl (12 to 60), tocopherol 1.32 +/- 0.36 mg/dl (0.54 to 2.46). A significant correlation was found in both sexes between cholesterol and retinol (r = 0.3, p < 0.05) and cholesterol and tocopherol (r = 0.4, p < 0.05), triglycerides and retinol (r = 0.3, p < 0.05). Cholesterol and beta-carotene was also significant in women (r = 0.5, p < 0.05). The correlation between triglycerides and beta-carotene by gender was not significant.

The protein phosphatase calcineurin is essential for NaCl tolerance of Saccharomyces cerevisiae

NaCl-sensitive yeast mutants were isolated to identify genes essential for NaCl tolerance. Complementation of a mutant highly sensitive to Na+ and Li+ led to the isolation of the CNB1 gene. This gene encodes the regulatory subunit (CNB) of the Ca2+/calmodulin-dependent protein phosphatase calcineurin. Cells deficient in CNB accumulated Li+ due to reduced expression of ENA1, a gene encoding a P-type ATPase involved in Na+ and Li+ efflux. In addition, the K+ transport system of cnb1 delta cells was not converted to the high affinity state that facilitates better discrimination of K+ over Na+. Thus the cnb1 delta strain resembled a trk1 mutant. These results indicate that adaptation to NaCl stress in Saccharomyces cerevisiae requires a signal transduction pathway involving Ca2+ and protein phosphorylation-dephosphorylation. In this pathway, calcineurin would coordinate gene expression and activity of ion transporters to facilitate ion homeostasis.

Prevalence of riboflavin deficiency among Guatemalan elderly people and its relationship to milk intake

Six groups of elderly subjects from central Guatemala were assessed for riboflavin status by using the erythrocyte glutathione reductase activity coefficient (EGRAC). The prevalence of riboflavin deficiency ranged from 50% to 76% among the free-living rural elderly subjects. Milk intake data that were collected from some of the subjects showed a significant correlation (P < 0.0001) between frequency of milk intake and riboflavin status. In a short-term riboflavin supplementation experiment in which nine riboflavin-deficient subjects were given 10 mg riboflavin/d for 3 d, all the subjects' EGRACs were normalized by the supplementation. However, they returned to a state of deficiency within 2 wk while consuming their usual diets without supplementation. It appears that the high prevalence of riboflavin deficiency in elderly Guatemalan people is caused by inadequate intake of riboflavin-rich foods such as dairy products, and that sufficient amounts of riboflavin need to be ingested regularly to maintain satisfactory riboflavin status.

Riboflavin requirement of healthy elderly humans and its relationship to macronutrient composition of the diet

The riboflavin requirements of two groups of riboflavin-deficient, but otherwise healthy, Guatemalan elderly persons over the age of 60 y were studied by varying the fat:carbohydrate ratio in two diets. The first group consumed a diet similar in macronutrient content to a Western-type diet with low carbohydrate and high fat; the second group consumed a typical Guatemalan diet with high carbohydrate and low fat. Energy and protein intakes of both groups were similar. Riboflavin status was monitored by weekly measurements of erythrocyte glutathione reductase activity coefficient (EGRAC) and urinary riboflavin excretion. Increasing increments of riboflavin were added to the subjects' diets until their status was normalized, as indicated by EGRAC of < 1.34 and a sharp increase in urinary riboflavin excretion. Using the EGRAC method, the mean value of riboflavin intake at which the subjects' EGRAC reached the limit of normality was 1.37 +/- 0.03 mg/d in the first phase and 1.29 +/- 0.03 mg/d in the second phase. The sharp increase in urinary excretion occurred at riboflavin intakes of 1.13 and 1.03 mg/d for Groups 1 and 2, respectively. Thus, the differences between the two groups suggest that diets with a lower fat:carbohydrate ratio can decrease the dietary need for riboflavin. The dietary requirement of riboflavin, as estimated by the more reliable urinary excretion method, was 1.1-1.3 mg/d for those consuming the Western-type diet, which is similar to values found over 40 y ago in young adults. We conclude that the dietary requirements of riboflavin in the elderly do not differ from those of young adults.

Uses of anthropometry in the elderly in the field setting with notes on screening in developing countries

A field setting can be defined as any setting outside of a fixed, permanent, and sophisticated health facility or research laboratory. The most important applications of anthropometry at field level include biological anthropology, epidemiology, clinical application, and metabolic research. Data collecting in the field setting requires different levels of accuracy and precision; the standardization should also consider intra- and inter-observer variability due to the possibility of more than one observer participating in a given survey. A field setting, in contrast to the laboratory setting, involves special conditions that challenge the application of anthropometry. The required equipment is different and the conditions of data collection are less rigorous. Issues intrinsic to the target group - of education, culture and sophistication - might be limiting factors for carrying out anthropometric surveys in field settings. Another issue is related to interpretation of the biological, nutritional and health significance of anthropometric findings in relationship to the elderly. Uncertainty regarding the accuracy of chronological age, and geography and differential survival of the elderly should be considered when designing a survey. In addition, because the majority of the elderly now live in developing countries, short stature should be a common finding in the age groups from these regions. It is in these short-stature elderly populations, that there is a problem interpreting and applying anthropometric norms or references for height or weight derived from elderly populations of developed countries. In conclusion, although the application of anthropometry to the field setting is feasible, given its enormous importance to gerontological biology, nutrition and health, researchers should consider a series of factors and paradigms when designing and carrying out anthropometric surveys at the field level.

Sustained ventricular tachycardia in chronic chagasic myocarditis: electrophysiologic and pharmacologic characteristics

Sustained ventricular tachycardia (VT) develops in many patients with chronic Chagasic myocarditis. Programmed stimulation was used to study the electrophysiologic characteristics of VT in 15 patients with Chagas' cardiomyopathy. Nine patients were in New York Heart Association functional class I, 5 were in class II and 1 patient was in class III. The average ejection fraction was 56 +/- 7%, which is somewhat better than that reported in patients with VT owing to idiopathic cardiomyopathy. In 11 patients VT could be reproducibly initiated and terminated by programmed stimulation. Intravenous mexilitene prevented induction of VT in 7 of 8 patients; amiodarone did not prevent induction in 3 of 4 patients. Our data indicate that the mechanism of VT is likely to be reentrant in many patients, and therefore VT can be produced by extrastimuli. Electrophysiologic study is therefore useful for establishing the diagnosis of sustained VT and may be useful for guiding initial therapy in selected cases of Chagas' disease.

[Suppression, capture and modulation of ventricular parasystole]

Few clinical studies have dealth with annihilation, entrainment and modulation of ventricular parasystolic rhythm. Parasystolic modulation was diagnosed in 9 nonmedicated patients because single, nonparasystolic beats falling during the initial 59% of the cycle prolonged the parasystolic cycle length (by 12 to 37.5%), whereas those that fell later in the cycle shortened it (by 9 to 25%). Plotting this prolongation or shortening as a function of the temporal position of the nonparasystolic beats in the cycle, yielded biphasic response curves. In two patients, episodes of concealed one-to-one entrainment were initiated by late nonparasystolic (sinus) beats and, later on, terminated by early ventricular extrasystoles. In 2 other patients, (and in 2 separate occasions) nonparasystolic beats, falling in part of the cycle located in between those of maximal delay and acceleration, produced pacemaker annihilation (cessation of automatic activity for the remaining monitoring time). Parasystolic annihilation and concealed entrainment may be one of the causes that can explain the large, spontaneous, day-to-day variability in the incidence of ectopic ventricular beats reported in Holter recordings.

Radionuclide evaluation of left-ventricular function in chronic Chagas' cardiomyopathy

Left-ventricular ejection fraction (LVEF) and abnormalities of regional wall motion (WMA) were studied by means of radionuclide ventriculography in 41 patients prospectively diagnosed as having chronic Chagas' disease. Thirteen patients were asymptomatic (ASY), 16 were arrhythmic (ARR), and 12 had congestive heart failure (CHF). Mean LVEF was normal in ASY (0.64 +/- 0.06) but markedly depressed in CHF (0.28 +/- 0.08). Regional WMAs were minimal in ASY and their severity increased in ARR. Most CHFs (75%) had diffuse hypokinesia of the left ventricle. The region most frequently affected was the infero-apical (63%). Seven patients had a distinct apical aneurysm. Correlation between radionuclide and contrast ventriculography data was good in 17 patients. For LVEF, r = 0.90. For WMA there was agreement between the two techniques in 77% of 65 segments compared. Best agreement occurred with infero-apical lesions (88%), and worst with septal (69%). Selective coronary arteriography showed normal arteries in all patients. Therefore, chronic Chagas' heart disease joins ischemic heart disease as a cause of regional WMA.

[Electrophysiological evaluation of the treatment of patients with recurrent ventricular tachycardia]

In order to asses the predictive value of serial electrophysiologic studies in the selection of an effective long-term effective antiarrhythmic regimen, we studied 16 patients with recurrent sustained ventricular tachycardia (VT), resistant to conventional medical treatment. (group 1) Eleven patients in this group had chronic chagas myocarditis, and several hospitalizations and cardioversions had been required for therapy of VT. In addition, 35 patients (group 2: control) underwent electrophysiological studies to evaluate rhythm disturbances differences to TV. Ventricular Tachycardia was successfully initiated and terminate with programmed electrical stimulation of the right ventricle only in the group 1. After control studies, the effects of several drugs (ajmalin, amiodarone, carbamazepine, disopyramide, diphenilhydantoin, mexiletine, procainamide, propranolol, quinidine and verapamil on the ability to initiate VT were assessed. A drug was considered effective only if it prevented the initiation of VT and allowed long-term suppression o clinical VT. All the patients of group 1 were placed on chronic oral therapy with the effective agent and were followed for an average period of 16 months (range 5 to 47 months). In all 16 patients we could document complete long-term prophylaxis against VT. This method offers advantage in terms of morbidity, mortality, duration of therapy, and promptness of choosing an effective drug add expense to the patient over traditional empirical methods of drug selection.

[Simultaneous maternal and infant care or rooming-in care in the General Hospital of Mexico of the S.S.A]

This paper presents the preliminary results of a prospective study undertaken at the Neonatal Unit of the Hospital General de México, S.S.A. (Méx.) conducted to evaluate the possibilities offered by the rooming-in system in this hospital. In both groups, having 250 patients, most of them eutrophic, it was noticed that none of the babies assisted by their mothers showed severe infections, as compared to four babies that showed clinical data compatible with septicemia; these babies were assisted in the nursery in a traditional way, but three of them died. Many of the aspects about the rooming-in system are reviewed, concerning the mothers as well as the babies, and it is finally determined that it is a practical, accessible system that optimizes resources and seems to offer immediate benefits to the mothers as well as to the babies.

Left anterior hemiblock of the 2:1 type in the presence of inferior wall myocardial infarction

A case of inferior wall myocardial infarction (IWMI) with left anterior hemiblock (LAH) is presented. The LAH became type 2:1 in the course of the disease. Electrocardiographic signs of LAH in the presence of IWMI are outlined, and the behavior and etiology of the T-wave changes are analyzed.