A method for rapid flow-cytometric isolation of endothelial nuclei and RNA from archived frozen brain tissue

Endothelial cells are important contributors to brain development, physiology, and disease. Although RNA sequencing has contributed to the understanding of brain endothelial cell diversity, bulk analysis and single-cell approaches have relied on fresh tissue digestion protocols for the isolation of single endothelial cells and flow cytometry-based sorting on surface markers or transgene expression. These approaches are limited in the analysis of the endothelium in human brain tissues, where fresh samples are difficult to obtain. Here, we developed an approach to examine endothelial RNA expression by using an endothelial-specific marker to isolate nuclei from abundant archived frozen brain tissues. We show that this approach rapidly and reliably extracts endothelial nuclei from frozen mouse brain samples, and importantly, from archived frozen human brain tissues. Furthermore, isolated RNA transcript levels are closely correlated with expression in whole cells from tissue digestion protocols and are enriched in endothelial markers and depleted of markers of other brain cell types. As high-quality RNA transcripts could be obtained from as few as 100 nuclei in archived frozen human brain tissues, we predict that this approach should be useful for both bulk analysis of endothelial RNA transcripts in human brain tissues as well as single-cell analysis of endothelial sub-populations.

A mysterious sensation about sleep and health: the role of interoception

Background

Interoception is mental awareness, recognition and acknowledgement of physiological body signals. Understanding the role of sleep and interoception may provide a better understanding surrounding the sleep-health connection. Our primary objective was to examine the potential relationships between subjective sleep quality and multiple dimensions of interoceptive abilities in a large sample of young adults, a group who are vulnerable to sleep impairment and its widespread health consequences.

Methods

We conducted an online cross-sectional survey targeting young adults, aged 18–25 years. The Pittsburgh Sleep Quality Index (PSQI) was used to identify subjective sleep quality and the Multidimensional Assessment of Interoceptive Awareness Version 2 was used to assess eight domains of interoception. We conducted a series of Spearman’s bivariate correlations to assess the relationships between global sleep quality as well as the seven PSQI sub-components in relation to the eight interoception outcomes. We then conducted quantile regression to assess if global PSQI score was an independent predictor of interoception. Participants (n = 609) consented and provided data.

Results

After adjustment, the global PSQI was a significant predictor of ‘Non-Distracting’, ‘Emotional Awareness’ and ‘Trusting’, where β = − 0.10 (95% CI: − 0.14, − 0.07), β = 0.05 (0.01, 0.09), and β = − 0.10 (− 0.14, − 0.05), respectively.

Conclusions

Our findings reveal a small, significant relationship between sleep quality and interoceptive abilities amongst young adults. Sleep impairment may inhibit interoceptive skills, thus adding value to the mechanistic explanation of the sleep-health relationship. Experimental and prospective studies are needed to determine temporal associations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11603-0.

Prescribing laughter to ameliorate mental health, sleep, and wellbeing in university students: A protocol for a feasibility study of a randomised controlled trial

Objectives

This research is the first study to investigate the potential effects of a laughter prescription on both psychological health and objective sleep parameters in university students. The primary objective is to evaluate the feasibility of prescribing laughter to inform a larger randomised controlled trial. Secondary objectives are to assess if a two-week laughter prescription improves subjective and objective sleep outcomes, wellbeing, and/or psychological health outcomes.

Trial design

To assess the feasibility of a randomised controlled trial for laughter prescription in relation to sleep, psychological health, and wellbeing. Forty university students will be recruited and randomised to one of two conditions (control/experimental).

Methods

Wrist actigraphy and sleep diaries will be used to estimate sleep outcomes during a one-week baseline testing phase and across the two-week intervention. The experimental group will be shown how to record a Laughie (a 1-min recording of their joyful laughter on their smartphone) and prescribed to laugh with it three times daily for 14 days (the control group will only track sleep). All participants will complete the WHO (Five) Well-being Index, and Hospital Anxiety and Depression Scale pre- and post-intervention. The CONSORT checklist, and the Feasibility, Reach-out, Acceptability, Maintenance, Efficacy, Implementation, and Tailorabilty (FRAME-IT) framework will guide intervention planning and evaluation. Participant interviews will be analysed using Differential Qualitative Analysis (DQA).

Results

The feasibility of a two-week laughter prescription in university students and its impact on sleep, wellbeing, and/or psychological health outcomes will be assessed.

Conclusions

Zayed University Research Ethics Committee approved the study in July 2019. The research will be completed following protocol publication.

Trial registration

ClinicalTrials.gov. ID: NCT04171245. Date of registration: 18 October 2019.

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First study to explore the feasibility of a laughter only prescription for university students.

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First assessment of the impact of laughter on psychological health and objective sleep outcomes.

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A combination of wrist actigraphy and the Laughie enables clear measurements of sleep and laughter.

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Provision of a detailed description of the Laughie and how to use it and prescribe it.

The prevalence of psychological consequences of COVID-19: A systematic review and meta-analysis of observational studies

A systematic review and a meta-analysis were conducted to examine the overall prevalence of psychological health outcomes during COVID-19. Seven databases were systematically searched to include studies reporting on at least one psychological outcome. The pooled prevalence of primary psychological outcomes was 26% (95%CI: 21-32). Pooled prevalence for symptoms of PTSD was 33% (0-86), anxiety 28% (21-36), stress 27% (14-43), and depression 22% (13-33). The prevalence of psychological outcomes was similar in healthcare workers and in the general population (34% [24-44] and 33% [27-40] respectively). High prevalence figures support the importance of ensuring adequate provision of resources for mental health.

Jaw bones' involvement and dental features of type I and type III Gaucher disease: a radiographic study of 42 paediatric patients

PURPOSE

Gaucher disease (GD) is a lysosomal storage disease caused by an autosomal recessive inherited deficiency of the lysosomal enzyme glucocerebrosidase. The aim of this study is to describe jaw bones' involvement and dental radiographic features in paediatric Gaucher disease patients (type I and type III).

METHODS

The study population of this case-control study included: 42 Gaucher patients (study group) and 84 medically free children (control group). The radiographic images of both groups were analysed for the following findings: generalised bone rarefaction, localised rarefaction and enlarged bone marrow spaces, thinning of cortex, pseudocystic radiolucent lesions, anodontia and dental anomalies. Dental age assessment of Gaucher patients using the Demirjian's method was also performed.

RESULTS

Generalised rarefaction showed almost similar percentages in both types of Gaucher disease cases. Localised rarefaction was noted in 30.77% and 18.75% of Gaucher disease type III and type I, respectively. Pseudocystic radiolucent lesions, thinning of cortex, anodontia and dental anomalies were more prevalent in type III Gaucher patients. The mean chronological and mean dental ages in both sexes of Gaucher patients were not statistically significant.

CONCLUSION

Thinning of cortex, localised rarefaction and generalised rarefaction are the most common jaw bone findings in Gaucher patients.

Abstract 4354: A human bronchial epithelial cell model demonstrates a role for glutamine regulation in genomic instability and oncogenic transformation

Background: Previous work from our laboratory has investigated the role of solute carrier family A1 member 5 (SLC1A5) as a critical modulator of glutamine (Gln) uptake, cell growth and tumor progression in non-small cell lung cancer (NSCLC). In addition, remarkable metabolic reprogramming was observed in cells from individuals at high risk of lung cancer, including an increased dependence on Gln. However, it remains unclear how these changes in Gln metabolism and other metabolic dysregulations contribute to early events of tumorigenesis such as genomic instability. Given the emerging role of Gln metabolism in cancer and the differential expression of SLC1A5 in NSCLC, we tested the hypothesis that Gln uptake is a key mechanism by which cells with oncogenic potential can transform into a malignant phenotype.

Aims & Strategy: The aim of this study is to evaluate the involvement of SLC1A5 in the process of early oncogenic transformation and survival. To address this aim, we utilized four HBECs immortalized by over-expressing Cdk4 and human telomerase reverse transcriptase (hTERT), along with a series of canonical oncogenic drivers, P53-knocdown, KRAS and MYC overexpression, which drove these cells to exhibit a malignant phenotype. This successful transformation of an in vitro model could be useful in studying the metabolic dysregulation and, in particular, the role of Gln metabolism in contributing to genomic instability in an accessible and employable cell model representative of the oncogenic transformation process.

Results: We found that oncogene driven HBECs exhibited a substantially higher expression of SLC1A5 than unaltered HBEC cells. Inhibition of SLC1A5 by a small molecule inhibitor, gamma-l-Glutamyl-P-NitroAnilide (GPNA), decreased cell survival, Gln uptake and markers of genotoxic stress. The sensitivity to GPNA treatment was significantly correlated with SLC1A5 RNA expression (R2=0.96, P<0.05). We tested the effect of SLC1A5 inhibition on two markers of genomic instability, gamma-H2Ax and 8oxoGuanine, and discovered that GPNA treated cells exhibited higher degree of gamma-H2Ax and 8oxoGuanine staining suggesting that Gln uptake has a protective role against DNA damage. We further investigated the effect of effect of GPNA treatment on apoptotic signaling and found that SLC1A5 inhibition is associated with the activation of Caspase-9.

Conclusion: Overall, Our results indicate that oncogene-transformed HBECs exhibited higher dependence on Gln uptake through SLC1A5 relative to the non-oncogenic clones. Tumor-forming HBECs exhibited higher sensitivity to SLC1A5 inhibition than non-tumorigenic ones. Furthermore, Gln deprivation was implicated in regulation of genomic integrity and apoptosis in this cell model. This works suggests that Gln metabolism regulates aspects of genomic instability and implicates its function in lung tumorigenesis.

Citation Format: Omar M. Omar, Jamshedur Rahman, Pierre Massion. A human bronchial epithelial cell model demonstrates a role for glutamine regulation in genomic instability and oncogenic transformation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4354.

Aspirin Use and Cardiovascular Outcome in Patients With Type 2 Diabetes Mellitus and Heart Failure: A Population-Based Cohort Study

Background

Aspirin is of uncertain benefit for primary prevention in patients with type 2 diabetes mellitus (T2D). We assessed whether primary prevention with aspirin is beneficial in patients with T2D and heart failure (HF).

Methods and Results

Data from The Health Improvement Network, a UK multicenter prospective primary care database, were analyzed. Those with T2D and HF, age ≥55 years, and no previous history of myocardial infarction and/or coronary artery disease, stroke, peripheral artery disease, or atrial fibrillation were included. We compared outcomes for those on aspirin to no aspirin after diagnosis of HF and T2D and assessed the role of a >75‐mg dose. The primary outcome was a composite of all‐cause mortality and hospitalization for HF; secondary outcomes were nonfatal stroke, nonfatal myocardial infarction, or major bleeding. There were 5967 participants on aspirin and 6567 not on aspirin. The mean age (SD) was 75.3 (9.6) years, 53.9% were men, and the mean follow‐up (SD) was for 5 (4.2) years. After propensity‐score matching and further multivariable adjustment, aspirin was significantly associated with a decrease in the primary outcome and all‐cause mortality (hazard ratio=0.88, 95% confidence interval 0.82‐0.93; 0.88, 0.83‐0.94], respectively); and an increased risk of nonfatal myocardial infarction (hazard ratio=1.66; 95% confidence interval 1.49‐1.85) and nonfatal stroke (hazard ratio=1.23, 1.01‐1.50). Major bleedings and hospitalization for HF were not significantly higher with aspirin (hazard ratio=0.68, 0.45‐1.03; 0.87, 0.66‐1.15, respectively). There was no additional benefit for a dose >75 mg.

Conclusions

Primary prevention with aspirin in patients with T2D and HF is associated with lower all‐cause mortality.

The Prospective Association Between Electronic Device Use Before Bedtime and Academic Attainment in Adolescents

PURPOSE

To examine longitudinal associations between five commonly used technology devices prior to bedtime and real-life academic outcomes in adolescents.

METHODS

A total of 853 adolescents were recruited to a three-year prospective cohort study, with annual assessments. Academic grades/levels for three core subjects (English, Mathematics, and Science) were extracted from school records, and standardized (z-scores) were derived at the end of each academic year. A validated questionnaire was used to determine the frequency of using five types of technology (television viewing, video gaming, mobile telephone use, listening to music, and social networking) before bedtime.

RESULTS

After adjustment, English attainment was the subject most affected by prebedtime technology use, where three of five technologies assessed were negatively and prospectively associated (social networking [β = -.07 and p = .024], video gaming [β = -.10 and p = .008], and mobile telephone [β = -.07 and p=.017]). Social networking (β = -.07and p = .042), television viewing (β = -.08 and p = .044), and mobile telephones (β = -.07 and p = .031) were associated with significant impairment in English for girls whereas attainment in boys was most impaired by video gaming (β = -.12 and p = .014).

CONCLUSIONS

The use of electronic devices by adolescents before bedtime may reduce their academic attainment, but apart from video gaming for boys, the negative impact of near bedtime technology use on academic performance is small.

TFF1 antagonizes TIMP-1 mediated proliferative functions in gastric cancer

Tissue inhibitor matrix metalloproteinase-1 (TIMP1) is one of four identified members of the TIMP family. We evaluated the role of TIMP1 in gastric cancer using human and mouse tissues along with gastric organoids and in vitro cell models. Using quantitative real-time RT-PCR, we detected significant overexpression of TIMP1 in the human gastric cancer samples, as compared to normal stomach samples (P < 0.01). We also detected overexpression of Timp1 in neoplastic gastric lesions of the Tff1-knockout (KO) mice, as compared to normal stomach tissues. Reconstitution of TFF1 in human gastric cancer cell lines led to a significant decrease in the mRNA expression level of TIMP1 (P < 0.05). In vitro analysis demonstrated that TIMP1 mRNA expression is induced by TNF-α and activation of NF-κB whereas inhibition of NF-κB using BAY11-7082 led to inhibition of NF-κB and downregulation of TIMP1. Western blot analysis confirmed the decrease in TIMP1 protein level following reconstitution of TFF1. By using immunofluorescence, we showed nuclear localization of NF-κB and expression of TIMP1 in gastric organoids established from the Tff1-KO stomach where reconstitution of Tff1 using recombinant protein led to a notable reduction in the expression of both NF-κB and TIMP1. Using EDU assay, as a measure of proliferating cells, we found that TIMP1 promotes cellular proliferation whereas TFF1 reconstitution leads to a significant decrease in cellular proliferation (P < 0.05). In summary, our findings demonstrate overexpression of TIMP1 in mouse and human gastric cancers through NF-kB-dependent mechanism. We also show that TFF1 suppresses NF-κB and inhibits TIMP1-mediated proliferative potential in gastric cancer.

Activation of EIF4E by Aurora Kinase A Depicts a Novel Druggable Axis in Everolimus-Resistant Cancer Cells

Purpose: Aurora kinase A (AURKA) is overexpressed in several cancer types, making it an attractive druggable target in clinical trials. In this study, we investigated the role of AURKA in regulating EIF4E, cap-dependent translation, and resistance to mTOR inhibitor, RAD001 (everolimus).Experimental Design: Tumor xenografts and in vitro cell models of upper gastrointestinal adenocarcinomas (UGC) were used to determine the role of AURKA in the activation of EIF4E and cap-dependent translation. Overexpression, knockdown, and pharmacologic inhibition of AURKA were used in vitro and in vivoResults: Using in vitro cell models, we found that high protein levels of AURKA mediate phosphorylation of EIF4E and upregulation of c-MYC. Notably, we detected overexpression of endogenous AURKA in everolimus-resistant UGC cell models. AURKA mediated phosphorylation of EIF4E, activation of cap-dependent translation, and an increase in c-MYC protein levels. Targeting AURKA using genetic knockdown or a small-molecule inhibitor, alisertib, reversed these molecular events, leading to a decrease in cancer cell survival in acquired and intrinsic resistant cell models. Mechanistic studies demonstrated that AURKA binds to and inactivates protein phosphatase 2A, a negative regulator of EIF4E, leading to phosphorylation and activation of EIF4E in an AKT-, ERK1/2-, and mTOR-independent manner. Data from tumor xenograft mouse models confirmed that everolimus-resistant cancer cells are sensitive to alisertib.Conclusions: Our results indicate that AURKA plays an important role in the activation of EIF4E and cap-dependent translation. Targeting the AURKA-EIF4E-c-MYC axis using alisertib is a novel therapeutic strategy that can be applicable for everolimus-resistant tumors and/or subgroups of cancers that show overexpression of AURKA and activation of EIF4E and c-MYC. Clin Cancer Res; 23(14); 3756-68. ©2017 AACR.

Assessment for the possibility of a first night effect for wrist actigraphy in adolescents

OBJECTIVES

Evidence of a 'first night effect' has been documented for polysomnography. The possibility of this has not been previously assessed in wrist actigraphy, yet may have important implications for the study design of future sleep research. We sought to examine potential evidence of a 'first night effect' for wrist actigraphy in adolescents across weekdays and weekend nights for multiple sleep outcomes.

DESIGN

3-year prospective cohort study (Midlands Adolescent Schools Sleep Education Study).

SETTING

8 secondary schools in the Midlands region of the UK.

PARTICIPANTS

Adolescents (aged 11-13 years at baseline) were recruited to the study and were requested to wear a wrist actigraph for 7 consecutive days/nights at baseline and then annually for 2 years during the second term of the academic year.

PRIMARY OUTCOME MEASURES

We compared multiple sleep outcomes (total sleep time, wake after sleep onset, sleep efficiency, sleep onset latency, number of awakenings, length of awakenings, sleep onset time) when the device was worn on a weekday and weekend and compared these to other nights to identify possible evidence of a 'first night effect' for wrist actigraphy.

RESULTS

No significant differences were found between any sleep outcomes when the first night of wrist actigraphy was on a weekday compared with other weekdays. When the first night was measured on a weekend (Friday), average total sleep time was significantly greater (486±5 min) compared with the second night (Saturday; 469±6 min), p=0.01.

CONCLUSIONS

We found no evidence to support a 'first night effect' for wrist actigraphy in our adolescent sample. The first night of actigraphy data should not be disregarded in future studies that deploy this technique to measure sleep over prolonged time periods.

An investigation of the associations among sleep duration and quality, body mass index and insulin resistance in newly diagnosed type 2 diabetes mellitus patients

OBJECTIVES

To examine direct and indirect associations of sleep duration and quality with insulin resistance, considering body mass index (BMI) as a potential mediator in newly diagnosed type 2 diabetes mellitus patients.

METHODS

Cross-sectional data from patients enrolled in the Early Activity in Diabetes study. We studied 522 newly diagnosed type 2 diabetes mellitus patients, 65.9% male, mean age 63.5 ± 10.1 years. Of the total sample 53% had a BMI of ⩾30 kg/m(2). Participants completed a 7-day sleep diary and sleep questionnaire. Average sleep duration (minutes), average nap duration (minutes) and average number of night awakenings were derived. Objective measures of height and body weight were obtained for the BMI calculation (kg/m(2)). Insulin resistance was obtained using the homeostatic model assessment - insulin resistance (HOMA2-IR) standardized technique.

RESULTS

Average number of night awakenings was positively correlated with BMI (r= 0.22, p < 0.001) and negatively associated with logged HOMA2-IR (r= -0.16, p = 0.04). Path analysis demonstrated night awakenings were directly associated with BMI and indirectly associated with insulin resistance, whilst considering BMI as a potential mediator (p < 0.05). Sleep duration was not associated with BMI or insulin resistance (p > 0.05).

CONCLUSIONS

Sleep quality, not sleep duration, plays an important role in insulin resistance in newly diagnosed type 2 diabetes mellitus patients. BMI may mediate the relationship between indicators of sleep quality and insulin resistance. There is a need to examine the impact of improving sleep quality on obesity and insulin resistance in patients with type 2 diabetes mellitus.

The effects of a systemic single dose of zoledronic acid on post-implantation bone remodelling and inflammation in an ovariectomised rat model

Bisphosphonates reverse the negative effects of ovariectomy on bone, but they have also been associated with adverse processes in human jawbone. The molecular events determining bone regeneration and implant integration in osteoporotic conditions, with and without bisphosphonate treatment, are unclear. In this study, ovariectomised rats, to which a single dose of saline (NaCl) or zoledronic acid (Zol) was administered, received titanium alloy implants in their tibiae and mandibles. An enzyme-linked immunosorbent assay, gene expression analysis and histomorphometry were performed. The results show that ovariectomy, per se, upregulated the expression of genes denoting bone formation in the tibia, bone remodelling in the mandible and apoptosis in the tibia and mandible. Zoledronic acid administration resulted in lower levels of a remodelling marker in serum and downregulated gene expression for inflammation, bone formation, angiogenesis and apoptosis, mainly in the mandible, after 28 d of healing. Histomorphometry revealed improved bone-to-implant contact in the tibia, while the opposite was observed in the mandible. The present data show that a systemic single dose of zoledronic acid, in ovariectomised animals, results in site-specific differences in the regulation of genes involved in bone healing and regeneration in association with implant installation. These events occur in parallel with site-specific differences in the rate of osseointegration, indicating diverse tissue responses in the tibia and mandible after zoledronic acid treatment. The zoledronic acid effect on gene expression, during the late phase of healing in the mandible, suggests negative effects by the anti-resorptive agent on osseointegration at that particular site.

The stimulation of an osteogenic response by classical monocyte activation

The monocyte/macrophage system plays a central role in host defense, wound healing and immune regulation at biomaterial surfaces. Monocytes can be classically and alternatively activated, and can be stimulated differently in response to variations in biomaterial surface properties. In this study, human monocytes, cultured on polystyrene surfaces (Ps), were activated either classically, by lipopolysaccharide (LPS), or alternatively, by interleukin-4 (IL-4). Monocytes were also cultured on anodically oxidized (Ox) and machined (Ma) titanium surfaces, with and without LPS stimulation. Cells were cultured for 1 and 3 days and their conditioned media (CM) were collected. The osteogenic response of hMSCs to the monocyte CM was determined by analyzing the gene expression of key osteogenic markers. The CM from classically activated monocytes increased the hMSCs expression of runt-related transcription factor 2 (Runx2) and alkaline phosphatase (ALP). Furthermore, CM from monocytes cultured on Ox surface resulted in a modest increase of the expression of bone morphogenetic protein-2 (BMP-2). LPS stimulation of the surface-seeded monocytes overwhelmed the effect of the surface properties and resulted in significant upregulation of BMP-2 and Runx2 for all samples. The results show that human monocytes, cultured on different surfaces and/or under different activation pathways, communicate pro-osteogenic signals to hMSCs. The signals involve regulation of autologous BMP-2 in the hMSCs. The classical activation results in profound and prolonged osteogenic effect compared to the effect of the investigated surface properties.

Titanium oral implants: surface characteristics, interface biology and clinical outcome

Bone-anchored titanium implants have revolutionized oral healthcare. Surface properties of oral titanium implants play decisive roles for molecular interactions, cellular response and bone regeneration. Nevertheless, the role of specific surface properties, such as chemical and phase composition and nanoscale features, for the biological in vivo performance remains to be established. Partly, this is due to limited transfer of state-of-the-art preparation techniques to complex three-dimensional geometries, analytical tools and access to minute, intact interfacial layers. As judged by the available results of a few randomized clinical trials, there is no evidence that any particular type of oral implant has superior long-term success. Important insights into the recruitment of mesenchymal stem cells, cell-cell communication at the interface and high-resolution imaging of the interface between the surface oxide and the biological host are prerequisites for the understanding of the mechanisms of osseointegration. Strategies for development of the next generation of material surface modifications for compromised tissue are likely to include time and functionally programmed properties, pharmacological modulation and incorporation of cellular components.

Immunity to schistosomiasis before puberty: humeral or cell mediated

To determine if the cell mediated immunity, induced by T-helper type-1 lymphocytes (Th1) response, during schistosomiasis mansoni has the potential to protect against infection, intensities of infections and re-infections, reflected in the egg count were followed up to 20 months among 119 individuals aged 5-22 years (Ys) with different number of previous infections whose yearly levels and pattern of water contact were similar. They were classified into 5 groups. Delayed hypersensitivity skin tests (DHT) to adult schistosome excretory-secretary antigens (ESAgs) and anti-schistosomula (ESAgs) isotypes were measured on detecting re-infection. The group with a mean age of (8.6 +/- 2.6 Ys) and infected less than 5 times showed only 6.5 percentage reduction of the egg count (PREC) and low cellular and humoral responses. Th1-associated cellular (DHT) and antibody responses (IgG2, IgG3) to the five infections were significantly higher in the (13.5 +/- 1.4 Ys) than in (18 +/- 2.2 Ys) age group. This was reflected in significant difference in PREC; being 41.5% among the first and 13.5% among the second. Th2-associated antibody responses (IgG1, IgG4, IgE) went on rising as patients allowed for age and number of infections increased over 5, being significantly higher in the (19 +/- 1.8 Ys) than in (14 +/- 1.1 Ys) age groups with PREC 45.5% and 12.9% respectively. These results imply a substantial protective role for cell mediated immunity in the pre-puberty stage and provide evidence that Th1-based vaccination strategy can work if augmented.