Implementation and scalability of a digital intervention to reduce depressive symptoms in people with diabetes, hypertension or both in Brazil and Peru: a qualitative study of health system's stakeholders' perspectives

Two randomized controlled trials (RCTs) in Brazil and Peru demonstrated the effectiveness of CONEMO, a digital intervention supported by trained nurses or nurse assistants (NAs), to reduce depressive symptoms in people with diabetes and/or hypertension. This paper extends the RCTs findings by reflecting on the conditions needed for its wider implementation in routine care services. A qualitative study using semi-structured interviews and content analysis was conducted with nurses/NAs, clinicians, healthcare administrators, and policymakers. Informants reported that CONEMO would be feasible to implement in their health services, but some conditions could be improved before its scale-up: reducing workloads of healthcare workers; raising mental health awareness among clinicians and administrators; being able to inform, deliver and accompany the intervention; assuring appropriate training and supervision of nurses/NAs; and supporting the use of technology in public health services and by patients, especially older ones. We discuss some suggestions on how to overcome these challenges.

Intermediate hyperglycaemia and 10-year mortality in resource-constrained settings: the PERU MIGRANT Study

AIM

To determine whether intermediate hyperglycaemia, defined by fasting plasma glucose and HbA_1c criteria, is associated with mortality in a 10-year cohort of people in a Latin American country.

METHODS

Analysis of the PERU MIGRANT Study was conducted in three different population groups (rural, rural-to-urban migrant, and urban). The baseline assessment was conducted in 2007/2008, with follow-up assessment in 2018. The outcome was all-cause mortality, and the exposure was intermediate hyperglycaemia, using three definitions: (1) impaired fasting glucose, defined according to American Diabetes Association criteria [fasting plasma glucose 5.6-6.9 mmol/l (100-125 mg/dl)]; (2) intermediate hyperglycaemia defined according to American Diabetes Association criteria [HbA_1c levels 39-46 mmol/mol (5.7-6.4%)]; and (3) intermediate hyperglycaemia defined according to the International Expert Committee criteria [HbA_1c levels 42-46 mmol/mol (6.0-6.4%)]. Crude and adjusted hazard ratios and 95% CIs were estimated using Cox proportional hazard models.

RESULTS

At baseline, the mean (sd) age of the study population was 47.8 (11.9) years and 52.5% of the cohort were women. The study cohort was divided into population groups as follows: 207 people (20.0%) in the rural population group, 583 (59.7%) in the rural-to-urban migrant group and 198 (20.3%) in the urban population group. The prevalence of intermediate hyperglycaemia was: 6%, 12.9% and 38.5% according to the American Diabetes Association impaired fasting glucose definition, the International Expert Committee HbA_1c -based definition and the American Diabetes Association HbA_1c -based definition, respectively, and the mortality rate after 10 years was 63/976 (7%). Intermediate hyperglycaemia was associated with all-cause mortality using the HbA_1c -based definitions in the crude models [hazard ratios 2.82 (95% CI 1.59-4.99) according to the American Diabetes Association and 2.92 (95% CI 1.62-5.28) according to the International Expert Committee], whereas American Diabetes Association-defined impaired fasting glucose was not [hazard ratio 0.84 (95% CI 0.26-2.68)]. In the adjusted model, however, only the American Diabetes Association HbA_1c -based definition was associated with all-cause mortality [hazard ratio 1.91 (95% CI 1.03-3.53)], whereas the International Expert Committee HbA_1c -based and American Diabetes Association impaired fasting glucose-based definitions were not [hazard ratios 1.42 (95% CI 0.75-2.68) and 1.09 (95% CI 0.33-3.63), respectively].

CONCLUSIONS

Intermediate hyperglycaemia defined using the American Diabetes Association HbA_1c criteria was associated with an elevated mortality rate after 10 years in a cohort from Peru. HbA_1c appears to be a factor associated with mortality in this Peruvian population.

Prevalence and risk factors of restrictive spirometry in a cohort of Peruvian adults

INTRODUCTION

Few studies have described the prevalence of and lung function decline among those with a restrictive spirometric pattern (RSP) in low- and middle-income countries.

METHODS

We analyzed prospective data from 3055 adults recruited across four diverse settings in Peru over a 3-year period. Multivariable logistic regression was used to study the association between the presence of restriction and associated risk factors. Multivariable linear mixed models were used to determine lung function decline.

RESULTS

Among 3055 participants, the average age was 55.4 years (SD 12.4); 49% were male. Overall prevalence of RSP was 4.7%, ranging from 2.8% (Lima) to 6.9% (Tumbes). The odds of having RSP were higher among those who lived in a rural environment (OR 2.19, 95%CI 1.43-3.37), had a diagnosis of diabetes (OR 1.94, 95%CI 1.10-3.40) and among women (OR 2.09, 95%CI 1.41-3.09). When adjusting for baseline lung function, adults with RSP had accelerated decline in forced expiratory volume in 1 s (FEV1) compared with non-obstructed, non-restricted individuals.

DISCUSSION

RSP is prevalent particularly among women and in individuals living in rural settings of Peru. When adjusted for baseline lung function, participants with RSP had accelerated rates of FEV1 decline. Our findings are consistent with the notion that RSP is an insidious inflammatory condition with deleterious effects of lung function decline.

Chronic respiratory disease and high altitude are associated with depressive symptoms in four diverse settings

SETTING

Depression is a prevalent comorbidity of chronic respiratory disease (CRD), and may indicate worse clinical outcomes. The relationship between depression and living with chronic hypoxia due to CRD or residence at altitude has received little attention in resource-poor settings.

OBJECTIVE

To investigate the association between CRD conditions and depressive symptoms in four settings in Peru.

DESIGN

We collected data on CRD and depressive symptoms in adults aged ⩾35 years. Depressive symptoms were measured according to the Center for Epidemiologic Studies Depression scale. Multivariable ordinal logistic regression was used to assess the adjusted odds of being in a higher category of depressive symptoms as a function of CRD.

RESULTS

We analyzed data from 2953 participants (mean age 55.3 years, 49% male). The prevalence of major depressive symptoms was 19%, with significant variation according to setting. Participants with at least one CRD (OR 1.34, 95%CI 1.06-1.69) and those living at altitude (OR 1.64, 95%CI 1.10-2.43) had an increased adjusted odds of being in a higher category of depressive symptoms.

CONCLUSION

We found a high prevalence of depressive symptoms, and a positive association between depressive symptoms with CRD and with living at altitude, both of which cause chronic hypoxia.

Design and content validation of a set of SMS to promote seeking of specialized mental health care within the Allillanchu Project

BACKGROUND

The aim of this study was to design and develop a set of, short message service (SMS) to promote specialized mental health care seeking within the framework of the Allillanchu Project.

METHODS

The design phase consisted of 39 interviews with potential recipients of the SMS, about use of cellphones, and perceptions and motivations towards seeking mental health care. After the data collection, the research team developed a set of seven SMS for validation. The content validation phase consisted of 24 interviews. The participants answered questions regarding their understanding of the SMS contents and rated its appeal.

RESULTS

The seven SMS subjected to content validation were tailored to the recipient using their name. The reminder message included the working hours of the psychology service at the patient's health center. The motivational messages addressed perceived barriers and benefits when seeking mental health services. The average appeal score of the seven SMS was 9.0 (SD±0.4) of 10 points. Participants did not make significant suggestions to change the wording of the messages.

CONCLUSIONS

Five SMS were chosen to be used. This approach is likely to be applicable to other similar low-resource settings, and the methodology used can be adapted to develop SMS for other chronic conditions.

Nutrition status of children in Latin America

The prevalence of overweight and obesity is rapidly increasing among Latin American children, posing challenges for current healthcare systems and increasing the risk for a wide range of diseases. To understand the factors contributing to childhood obesity in Latin America, this paper reviews the current nutrition status and physical activity situation, the disparities between and within countries and the potential challenges for ensuring adequate nutrition and physical activity. Across the region, children face a dual burden of undernutrition and excess weight. While efforts to address undernutrition have made marked improvements, childhood obesity is on the rise as a result of diets that favour energy-dense, nutrient-poor foods and the adoption of a sedentary lifestyle. Over the last decade, changes in socioeconomic conditions, urbanization, retail foods and public transportation have all contributed to childhood obesity in the region. Additional research and research capacity are needed to address this growing epidemic, particularly with respect to designing, implementing and evaluating the impact of evidence-based obesity prevention interventions.

Biomass fuel smoke exposure was associated with adverse cardiac remodeling and left ventricular dysfunction in Peru

While household air pollution from biomass fuel combustion has been linked to cardiovascular disease, the effects on cardiac structure and function have not been well described. We sought to determine the association between biomass fuel smoke exposure and cardiac structure and function by transthoracic echocardiography. We identified a random sample of urban and rural residents living in the high-altitude region of Puno, Peru. Daily biomass fuel use was self-reported. Participants underwent transthoracic echocardiography. Multivariable linear regression was used to examine the relationship of biomass fuel use with echocardiographic measures of cardiac structure and function, adjusting for age, sex, height, body mass index, diabetes, physical activity, and tobacco use. One hundred and eighty-seven participants (80 biomass fuel users and 107 non-users) were included in this analysis (mean age 59 years, 58% women). After adjustment, daily exposure to biomass fuel smoke was associated with increased left ventricular internal diastolic diameter (P=.004), left atrial diameter (P=.03), left atrial area (four-chamber) (P=.004) and (two-chamber) (P=.03), septal E' (P=.006), and lateral E' (P=.04). Exposure to biomass fuel smoke was also associated with worse global longitudinal strain in the two-chamber view (P=.01). Daily biomass fuel use was associated with increased left ventricular size and decreased left ventricular systolic function by global longitudinal strain.

Glycated haemoglobin (HbA1c ) and fasting plasma glucose relationships in sea-level and high-altitude settings

AIM

Higher haemoglobin levels and differences in glucose metabolism have been reported among high-altitude residents, which may influence the diagnostic performance of HbA_1c . This study explores the relationship between HbA_1c and fasting plasma glucose (FPG) in populations living at sea level and at an altitude of > 3000 m.

METHODS

Data from 3613 Peruvian adults without a known diagnosis of diabetes from sea-level and high-altitude settings were evaluated. Linear, quadratic and cubic regression models were performed adjusting for potential confounders. Receiver operating characteristic (ROC) curves were constructed and concordance between HbA_1c and FPG was assessed using a Kappa index.

RESULTS

At sea level and high altitude, means were 13.5 and 16.7 g/dl (P > 0.05) for haemoglobin level; 41 and 40 mmol/mol (5.9% and 5.8%; P < 0.01) for HbA_1c ; and 5.8 and 5.1 mmol/l (105 and 91.3 mg/dl; P < 0.001) for FPG, respectively. The adjusted relationship between HbA_1c and FPG was quadratic at sea level and linear at high altitude. Adjusted models showed that, to predict an HbA_1c value of 48 mmol/mol (6.5%), the corresponding mean FPG values at sea level and high altitude were 6.6 and 14.8 mmol/l (120 and 266 mg/dl), respectively. An HbA_1c cut-off of 48 mmol/mol (6.5%) had a sensitivity for high FPG of 87.3% (95% confidence interval (95% CI) 76.5 to 94.4) at sea level and 40.9% (95% CI 20.7 to 63.6) at high altitude.

CONCLUSION

The relationship between HbA_1c and FPG is less clear at high altitude than at sea level. Caution is warranted when using HbA_1c to diagnose diabetes mellitus in this setting.

Rural-to-urban migration and risk of hypertension: longitudinal results of the PERU MIGRANT study

Urbanization can be detrimental to health in populations due to changes in dietary and physical activity patterns. The aim of this study was to determine the effect of migration on the incidence of hypertension. Participants of the PERU MIGRANT study, that is, rural, urban and rural-to-urban migrants, were re-evaluated after 5 years after baseline assessment. The outcome was incidence of hypertension; and the exposures were study group and other well-known risk factors. Incidence rates, relative risks (RRs) and population attributable fractions (PAFs) were calculated. At baseline, 201 (20.4%), 589 (59.5%) and 199 (20.1%) participants were rural, rural-to-urban migrant and urban subjects, respectively. Overall mean age was 47.9 (s.d.±12.0) years, and 522 (52.9%) were female. Hypertension prevalence at baseline was 16.0% (95% confidence interval (CI) 13.7-18.3), being more common in urban group; whereas pre-hypertension was more prevalent in rural participants (P<0.001). Follow-up rate at 5 years was 94%, 895 participants were re-assessed and 33 (3.3%) deaths were recorded. Overall incidence of hypertension was 1.73 (95%CI 1.36-2.20) per 100 person-years. In multivariable model and compared with the urban group, rural group had a greater risk of developing hypertension (RR 3.58; 95%CI 1.42-9.06). PAFs showed high waist circumference as the leading risk factor for the hypertension development in rural (19.1%), migrant (27.9%) and urban (45.8%) participants. Subjects from rural areas are at higher risk of developing hypertension relative to rural-urban migrant or urban groups. Central obesity was the leading risk factor for hypertension incidence in the three population groups.

Chronic exposure to biomass fuel smoke and markers of endothelial inflammation

Indoor smoke exposure may affect cardiovascular disease (CVD) risk via lung-mediated inflammation, oxidative stress, and endothelial inflammation. We sought to explore the association between indoor smoke exposure from burning biomass fuels and a selected group of markers for endothelial inflammation. We compared serum concentrations of amyloid A protein, E-selectin, soluble intercellular adhesion molecule 1 (ICAM-1) and VCAM-1, von Willebrand factor (vWF), and high-sensitivity C-reactive protein (hs-CRP) in 228 biomass-exposed vs. 228 non-exposed participants living in Puno, Peru. Average age was 56 years (s.d. = 13), average BMI was 26.5 kg/m(2) (s.d. = 4.4), 48% were male, 59.4% completed high school, and 2% reported a physician diagnosis of CVD. In unadjusted analysis, serum levels of soluble ICAM-1 (330 vs. 302 ng/ml; P < 0.001), soluble VCAM-1 (403 vs. 362 ng/ml; P < 0.001), and E-selectin (54.2 vs. 52.7 ng/ml; P = 0.05) were increased in biomass-exposed vs. non-exposed participants, respectively, whereas serum levels of vWF (1148 vs. 1311 mU/ml; P < 0.001) and hs-CRP (2.56 vs. 3.12 mg/l; P < 0.001) were decreased, respectively. In adjusted analyses, chronic exposure to biomass fuels remained positively associated with serum levels of soluble ICAM-1 (P = 0.03) and VCAM-1 (P = 0.05) and E-selectin (P = 0.05), and remained negatively associated with serum levels of vWF (P = 0.02) and hs-CRP (P < 0.001). Daily exposure to biomass fuel smoke was associated with important differences in specific biomarkers of endothelial inflammation and may help explain accelerated atherosclerosis among those who are chronically exposed.

Can a simple test of functional capacity add to the clinical assessment of diabetes?

AIM

To identify impairment in functional capacity associated with complicated and non-complicated diabetes using the 6-min walk distance test.

METHODS

We enrolled 111 adults, aged ≥40 years, with Type 2 diabetes from a hospital facility and 150 healthy control subjects of similar age and sex from a community site in Lima, Peru. All participants completed a 6-min walk test.

RESULTS

The mean age of the 261 participants was 58.3 years, and 43.3% were male. Among those with diabetes, 67 (60%) had non-complicated diabetes and 44 (40%) had complications such as peripheral neuropathy, retinopathy or nephropathy. The mean unadjusted 6-min walk distances were 376 m and 394 m in adults with and without diabetes complications, respectively, vs 469 m in control subjects (P<0.001). In multivariable regression, the subjects with diabetes complications walked 84 m less far (95% CI -104 to -63 m) and those without complications walked 60 m less far (-77 to -42 m) than did control subjects. When using HbA1c level as a covariate in multivariable regression, participants walked 13 m less far (-16.9 to -9.9 m) for each % increase in HbA1c .

CONCLUSIONS

The subjects with diabetes had lower functional capacity compared with healthy control subjects with similar characteristics. Differences in 6-min walk distance were even apparent in the subjects without diabetes complications. Potential mechanisms that could explain this finding are early cardiovascular disease or deconditioning.

Delivery of Type 2 diabetes care in low- and middle-income countries: lessons from Lima, Peru

AIMS

The health system's response is crucial to addressing the increasing burden of diabetes, particularly that affecting low- and middle-income countries. This study aims to assess the facilitators and barriers that help or hinder access to care for people with diabetes in Peru.

METHODS

We used a survey tool to design and collect qualitative and quantitative data from primary and secondary sources of information at different levels of the health system. We performed 111 interviews in Lima, the capital city of Peru, with patients with diabetes, healthcare providers and healthcare officials. We applied the six building blocks framework proposed by the World Health Organization in our analysis.

RESULTS

We found low political commitment, as well as several barriers that directly affect access to medicines, regular laboratory check-ups and follow-up appointments for diabetes, especially at the primary healthcare level. Three major system-level barriers were identified: (1) the availability of information at different healthcare system levels that affects several processes in the healthcare provision; (2) insufficient financial resources; and (3) insufficient human resources trained in diabetes management.

CONCLUSION

Despite an initial political commitment by the Peruvian government to improve the delivery of diabetes care, there exist several key limitations that affect access to adequate diabetes care, especially at the primary healthcare level. In a context in which various low- and middle-income countries are aiming to achieve universal health coverage, this study provides lessons for the implementation of strategies related to diabetes care delivery.

Molecular structures and interactions in the yeast kinetochore

Kinetochores are the elaborate protein assemblies that attach chromosomes to spindle microtubules in mitosis and meiosis. The kinetochores of point-centromere yeast appear to represent an elementary module, which repeats a number of times in kinetochores assembled on regional centromeres. Structural analyses of the discrete protein subcomplexes that make up the budding-yeast kinetochore have begun to reveal principles of kinetochore architecture and to uncover molecular mechanisms underlying functions such as transmission of tension and establishment and maintenance of bipolar attachment. The centromeric DNA is probably wrapped into a compact organization, not only by a conserved, centromeric nucleosome, but also by interactions among various other DNA-bound kinetochore components. The rod-like, heterotetrameric Ndc80 complex, roughly 600 Å long, appears to extend from the DNA-proximal assembly to the plus end of a microtubule, to which one end of the complex is known to bind. Ongoing structural studies will clarify the roles of a number of other well-defined complexes.

The Latin American Consortium of Studies in Obesity (LASO)

Current, high-quality data are needed to evaluate the health impact of the epidemic of obesity in Latin America. The Latin American Consortium of Studies of Obesity (LASO) has been established, with the objectives of (i) Accurately estimating the prevalence of obesity and its distribution by sociodemographic characteristics; (ii) Identifying ethnic, socioeconomic and behavioural determinants of obesity; (iii) Estimating the association between various anthropometric indicators or obesity and major cardiovascular risk factors and (iv) Quantifying the validity of standard definitions of the various indexes of obesity in Latin American population. To achieve these objectives, LASO makes use of individual data from existing studies. To date, the LASO consortium includes data from 11 studies from eight countries (Argentina, Chile, Colombia, Costa Rica, Dominican Republic, Peru, Puerto Rico and Venezuela), including a total of 32,462 subjects. This article describes the overall organization of LASO, the individual studies involved and the overall strategy for data analysis. LASO will foster the development of collaborative obesity research among Latin American investigators. More important, results from LASO will be instrumental to inform health policies aiming to curtail the epidemic of obesity in the region.

Interethnic differences in the accuracy of anthropometric indicators of obesity in screening for high risk of coronary heart disease

BACKGROUND

Cut points for defining obesity have been derived from mortality data among Whites from Europe and the United States and their accuracy to screen for high risk of coronary heart disease (CHD) in other ethnic groups has been questioned.

OBJECTIVE

To compare the accuracy and to define ethnic and gender-specific optimal cut points for body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) when they are used in screening for high risk of CHD in the Latin-American and the US populations.

METHODS

We estimated the accuracy and optimal cut points for BMI, WC and WHR to screen for CHD risk in Latin Americans (n=18 976), non-Hispanic Whites (Whites; n=8956), non-Hispanic Blacks (Blacks; n=5205) and Hispanics (n=5803). High risk of CHD was defined as a 10-year risk > or =20% (Framingham equation). The area under the receiver operator characteristic curve (AUC) and the misclassification-cost term were used to assess accuracy and to identify optimal cut points.

RESULTS

WHR had the highest AUC in all ethnic groups (from 0.75 to 0.82) and BMI had the lowest (from 0.50 to 0.59). Optimal cut point for BMI was similar across ethnic/gender groups (27 kg/m(2)). In women, cut points for WC (94 cm) and WHR (0.91) were consistent by ethnicity. In men, cut points for WC and WHR varied significantly with ethnicity: from 91 cm in Latin Americans to 102 cm in Whites, and from 0.94 in Latin Americans to 0.99 in Hispanics, respectively.

CONCLUSION

WHR is the most accurate anthropometric indicator to screen for high risk of CHD, whereas BMI is almost uninformative. The same BMI cut point should be used in all men and women. Unique cut points for WC and WHR should be used in all women, but ethnic-specific cut points seem warranted among men.

Non-communicable diseases in low- and middle-income countries: context, determinants and health policy

The rise of non-communicable diseases and their impact in low- and middle-income countries has gained increased attention in recent years. However, the explanation for this rise is mostly an extrapolation from the history of high-income countries whose experience differed from the development processes affecting today's low- and middle-income countries. This review appraises these differences in context to gain a better understanding of the epidemic of non-communicable diseases in low- and middle-income countries. Theories of developmental and degenerative determinants of non-communicable diseases are discussed to provide strong evidence for a causally informed approach to prevention. Health policies for non-communicable diseases are considered in terms of interventions to reduce population risk and individual susceptibility and the research needs for low- and middle-income countries are discussed. Finally, the need for health system reform to strengthen primary care is highlighted as a major policy to reduce the toll of this rising epidemic.

Highly reactive cysteine residues in rodent hemoglobins

Two hemoglobins with cysteine residues highly reactive toward electrophiles have been identified and characterized. Cys-125beta of guinea pig hemoglobin has a low pK(a) and forms conjugates with electrophiles more quickly than glutathione and several orders of magnitude more quickly than other protein thiols. This cysteine is capable of intercepting benzoquinone, a known carcinogenic metabolite, before other protein nucleophiles can be modified. Cys-13beta of mouse hemoglobin was observed to conjugate with electrophiles as quickly as glutathione. The structural basis of reactivity is different in the two hemoglobins and is analyzed in terms of hydrogen-bonding, solvent accessibility, and helix-dipole contributions. Complementing a previously characterized highly reactive cysteine in rat hemoglobin, identification of these cysteines suggests that the reactivity of these hemoglobins could represent a common function as a detoxification sink against carcinogens.

Structural characterization of human hemoglobin crosslinked by bis(3,5-dibromosalicyl) fumarate using mass spectrometric techniques

Diaspirin crosslinked hemoglobin (DCLHb) was analyzed by mass spectrometric-based techniques to identify the protein modifications effected by the crosslinking reaction with bis(3,5-dibromosalicyl) fumarate. DCLHb consists of two principal components. These components were isolated by size-exclusion chromatography and identified by measurement of their molecular weight using electrospray mass spectrometry and subsequent peptide mass mapping and mass spectrometric sequence analysis of their individual digests. Three major RP-HPLC fractions were observed from the major hemoglobin in DCLHb. Their MWs matched the MW of heme, intact hemoglobin beta-chain, and two hemoglobin alpha-chains crosslinked by a fumarate moiety, respectively. The minor HPLC peaks of DCLHb were also separated, and characterized by mass spectrometric methods. These minor components revealed additional details of the structural nature of covalent modification of DCLHb.

Studies on immunological paralysis. X. Cellular characteristics of the induction and loss of tolerance to levan (Polyfructose)

The induction and loss of tolerance to native and depolymerized fractions of levan, a thymus-independent antigen, have been studied in (DBA/1×CBA-T6T6)F₁ mice by a direct plaque-forming cell (PFC) assay. Tolerance following 1 mg native levan began to break by 80 days, whereas mice remained specifically unresponsive 150 days after 10 mg. Effects attributable to long persistence of antigen have been demonstrated. The following main features of levan tolerance were established by transfer of spleen cells to 900 R-irradiated recipients: (1) the induction period is very short—less than 24 hours. (2) No detectable immunity accompanies or precedes induction. (3) The fall in immunogenicity with reduction in molecular weight (mol. wt) of levan is not accompanied by loss of tolerogenicity. An effectively tolerogenic, non-immunogenic fraction (mol. wt<10,000) was found. (4) There is no rapid loss of tolerance following cell transfer (reactivity is only regained after 50 days), arguing against the existence of tolerant cells in this model.

As these results and those from corresponding investigations with SIII and HGG all show major dissimilarities, it is considered imprudent to base generalizations concerning the nature of B cell tolerance on studies with only one type of antigen. Whether or not two different kinds of specific unresponsiveness might be implicated with these cells is discussed.