Co-administration of l-cystine and l-theanine enhances efficacy of influenza vaccination in elderly persons: nutritional status-dependent immunogenicity

Cystine and theanine for chemoradiotherapy-induced esophagitis in non-small cell lung cancer: a prospective observational study

PURPOSE

Although several potential radioprotectants have been explored, radiation esophagitis is still difficult to control. Further development of supportive therapies is required. Our purpose was to investigate the efficacy and safety of cystine and theanine for esophagitis in non-small cell lung cancer (NSCLC) patients undergoing chemoradiotherapy (CRT).

METHODS

This study is a prospective observational study. The participants were recruited from unresectable locally advanced NSCLC who had scheduled to receive weekly paclitaxel or nab-paclitaxel/carboplatin plus radiation therapy (60 Gy in 30 fractions) for 6 weeks. They took an oral amino acid supplement containing 700 mg cystine and 280 mg theanine once daily regardless of CRT timing from the start of CRT until completion. The primary endpoint was the incidence of any grade esophagitis. The secondary endpoints were quality of life (QoL) and adverse events (AEs).

RESULTS

A total of 26 patients were evaluated. All participants completed 60 Gy of RT in 30 fractions. The overall incidence of esophagitis was 73%; however, no ≥ grade 3 was reported. There were no AEs likely to be related to cystine and theanine. The mean EuroQoL 5-Dimension 5-Level health index score before and after chemoradiotherapy was 0.952 ± 0.0591 and 0.952 ± 0.0515 (P = 0.89), and the mean Visual Analogue Scale scores before and after treatment were 67.9 ± 15.4 and 79.4 ± 13.2 (P = 0.0047), respectively.

CONCLUSION

Our study showed no severe esophagitis, any AEs, nor QoL decrease in NSCLC patients receiving CRT. Cystine and theanine are potentially effective to reduce severe CRT-induced esophagitis.

TRIAL REGISTRATION

UMIN000052622, 26 October 2023, retrospectively registered.

Antidiabetic Potential of Tea and Its Active Compounds: From Molecular Mechanism to Clinical Evidence

Diabetes mellitus (DM) is a chronic endocrine disorder that poses a long-term risk to human health accompanied by serious complications. Common antidiabetic drugs are usually accompanied by side effects such as hepatotoxicity and nephrotoxicity. There is an urgent need for natural dietary alternatives for diabetic treatment. Tea (Camellia sinensis) consumption has been widely investigated to lower the risk of diabetes and its complications through restoring glucose metabolism homeostasis, safeguarding pancreatic β-cells, ameliorating insulin resistance, ameliorating oxidative stresses, inhibiting inflammatory response, and regulating intestinal microbiota. It is indispensable to develop effective strategies to improve the absorption of tea active compounds and exert combinational effects with other natural compounds to broaden its hypoglycemic potential. The advances in clinical trials and population-based investigations are also discussed. This review primarily delves into the antidiabetic potential and underlying mechanisms of tea active compounds, providing a theoretical basis for the practical application of tea and its active compounds against diabetes.

Establishment of an efficient transformation system and its application in regulatory mechanism analysis of biological macromolecules in tea plants

Tea (Camellia sinensis), one of the most important beverage crops originated from China and is now cultivated worldwide, provides numerous secondary metabolites that account for its health benefits and rich flavor. However, the lack of an efficient and reliable genetic transformation system has seriously hindered the gene function investigation and precise breeding of C. sinensis. In this study, we established a highly efficient, labor-saving, and cost-effective Agrobacterium rhizogenes-mediated hairy roots genetic transformation system for C. sinensis, which can be used for gene overexpression and genome editing. The established transformation system was simple to operate, bypassing tissue culture and antibiotic screening, and only took two months to complete. We used this system to conduct function analysis of transcription factor CsMYB73 and found that CsMYB73 negatively regulates L-theanine synthesis in tea plant. Additionally, callus formation was successfully induced using transgenic roots, and the transgenic callus exhibited normal chlorophyll production, enabling the study of the corresponding biological functions. Furthermore, this genetic transformation system was effective for multiple C. sinensis varieties and other woody plant species. By overcoming technical obstacles such as low efficiency, long experimental periods, and high costs, this genetic transformation will be a valuable tool for routine gene investigation and precise breeding in tea plants.

L-Theanine and Immunity: A Review

L-theanine (N-ethyl-γ-glutamine) is the main amino acid in tea leaves. It not only contributes to tea flavor but also possesses several health benefits. Compared with its sedative and calming activities, the immunomodulatory effects of L-theanine have received less attention. Clinical and epidemiological studies have shown that L-theanine reduces immunosuppression caused by strenuous exercise and prevents colds and influenza by improving immunity. Numerous cell and animal studies have proven that theanine plays an immunoregulatory role in inflammation, nerve damage, the intestinal tract, and tumors by regulating γδT lymphocyte function, glutathione (GSH) synthesis, and the secretion of cytokines and neurotransmitters. In addition, theanine can be used as an immunomodulator in animal production. This article reviews the research progress of L-theanine on immunoregulation and related mechanisms, as well as its application in poultry and animal husbandry. It is hoped that this work will be beneficial to future related research.

Perioperative Administration of Cystine and Theanine Suppresses Inflammation and Facilitates Early Rehabilitation and Recovery after Esophagectomy: A Randomized, Double-Blind, Controlled Clinical Trial

Oral administration of cystine and theanine (CT) increases glutathione levels to modulate the inflammatory response, which has yet to be sufficiently explored for patients’ recovery and early rehabilitation. We planned a randomized, double-blind, placebo-controlled trial to determine whether perioperative oral administration of CT promotes recovery after esophagectomy. Patients were randomized into either CT or placebo groups, who received preoperative and postoperative treatments for 4 and 13 days, respectively. The main outcome measures were triaxial accelerometer readings, inflammation indicators, a 6 min walk test (6MWT), and a quality of life questionnaire (QoR-40). The study involved 32 patients. Although the CT group (n = 16) showed better patient activity across the investigated period, there was no significant difference between the two groups. However, white blood cell count on postoperative days (POD) 2 and 10, neutrophil count (POD 2, 7, and 10), and C-reactive protein level (POD 13) in the CT group were significantly lower than in the placebo group. Furthermore, 6MWT on POD 7 and QoR-40 on POD 13 were significantly higher in the CT group than those in the placebo group. This study suggests that perioperative administration of CT may contribute to early recovery and rehabilitation after esophagectomy via suppression of inflammatory response.

Bacterial Gamma-Glutamyl Transpeptidase, an Emerging Biocatalyst: Insights Into Structure-Function Relationship and Its Biotechnological Applications

Gamma-glutamyl transpeptidase (GGT) enzyme is ubiquitously present in all life forms and plays a variety of roles in diverse organisms. Higher eukaryotes mainly utilize GGT for glutathione degradation, and mammalian GGTs have implications in many physiological disorders also. GGTs from unicellular prokaryotes serve different physiological functions in Gram-positive and Gram-negative bacteria. In the present review, the physiological significance of bacterial GGTs has been discussed categorizing GGTs from Gram-negative bacteria like Escherichia coli as glutathione degraders and from pathogenic species like Helicobacter pylori as virulence factors. Gram-positive bacilli, however, are considered separately as poly-γ-glutamic acid (PGA) degraders. The structure-function relationship of the GGT is also discussed mainly focusing on the crystallization of bacterial GGTs along with functional characterization of conserved regions by site-directed mutagenesis that unravels molecular aspects of autoprocessing and catalysis. Only a few crystal structures have been deciphered so far. Further, different reports on heterologous expression of bacterial GGTs in E. coli and Bacillus subtilis as hosts have been presented in a table pointing toward the lack of fermentation studies for large-scale production. Physicochemical properties of bacterial GGTs have also been described, followed by a detailed discussion on various applications of bacterial GGTs in different biotechnological sectors. This review emphasizes the potential of bacterial GGTs as an industrial biocatalyst relevant to the current switch toward green chemistry.

Elderly Subjects Supplemented with L-Glutamine Shows an Improvement of Mucosal Immunity in the Upper Airways in Response to Influenza Virus Vaccination

BACKGROUND

Although glutamine is able to improve the immune response, its action in the upper airway immunity against the influenza virus vaccine remains unclear. Therefore, we aimed to evaluate the L-glutamine supplementation effect on the mucosal immune/inflammatory response of elderly subjects vaccinated against the influenza virus.

METHODS

Saliva sampling from 83 physically active elderly volunteers were collected pre- and 30 days after influenza virus vaccination and supplementation with L-glutamine (Gln, n = 42) or placebo (PL, n = 41).

RESULTS

Gln group showed higher salivary levels of interleukin (IL)-17, total secretory immunoglobulin A (SIgA), and specific-SIgA post-vaccination than values found pre-vaccination and in the PL group post-vaccination. Whereas higher salivary levels of IL-6 and IL-10 were observed post-vaccination in the Gln group, IL-37 levels were lower post-vaccination in both groups than the values pre-vaccination. Tumor necrosis factor (TNF)-α levels were unchanged. Positive correlations between IL-6 and IL-10 were found in all volunteer groups pre- and post-vaccination and also between IL-17 and IL-6 or IL-10 in the Gln group post-vaccination. A negative correlation between IL-37 and IL-10 was found pre- and post-vaccination in the PL group.

CONCLUSION

Gln supplementation was able to modulate salivary cytokine profile and increase SIgA levels, both total and specific to the influenza virus vaccine, in physically active elderly subjects.

γ-Glutamyltranspeptidase from Bacillus amyloliquefaciens: transpeptidation activity enhancement and L-theanine production

L-theanine, a unique amino acid in green tea with health benefits, can be enzymatically synthesized by γ-glutamyltranspeptidase (γ-GT; EC 2.3.2.2). Here, a salt-tolerant γ-glutamyltranspeptidase from a marine bacterium Bacillus amyloliquefaciens was expressed in Escherichia. coli BL21 (DE3) and was shown to be optimally active at 55 °C, pH 8.5 and alkali stable. A mutant, with higher transpeptidation activity, was obtained following two rounds of directed evolution using error-prone PCR and site-saturation mutagenesis. The mutation increased the ratio of transpeptidation to hydrolysis from 1.6 to 35.6. Additionally, Kinetic analysis exhibited 17.5% decrease of K_m, 13.0-fold increase of K_cat, and 16.3-fold increase of K_cat/K_m in mutant V319A/S437 G versus the wild-type. The 3-D modelling analysis revealed a tighter binding pocket in mutant V319A/S437 G. The frequency of hydrogen bond between donor substrate and two residues in the catalytic pocket (Gly437 and Thr375) was enhanced, which stabilized the ligand binding and thus improved the catalytic efficiency. The optimal conditions for the biocatalytic synthesis were determined as pH 10.0, 20 μg mL^-1BaGT, 200 mM L-glutamine, 2 M ethylamine, and a reaction time of 5 h. The V319A/S437 G mutant was shown to increase the percentage yield of L-theanine from 58% to 83%. These results indicate the great potential of V319A/S437 G in L-theanine production after further study.

Efficacy of oral administration of cystine and theanine in colorectal cancer patients undergoing capecitabine-based adjuvant chemotherapy after surgery: a multi-institutional, randomized, double-blinded, placebo-controlled, phase II trial (JORTC-CAM03)

Purpose

Capecitabine-based adjuvant chemotherapy for colorectal cancer patients often causes adverse events (AEs), such as diarrhea, stomatitis, anorexia, and hand-foot syndrome (HFS). Cystine and theanine were reported to attenuate some chemotherapy-associated AEs, and hence are also expected to attenuate capecitabine-induced AEs. Therefore, we aimed to investigate the safety and efficacy of cystine/theanine treatment in colorectal cancer patients undergoing capecitabine-based adjuvant chemotherapy after surgery.

Methods

A total of 100 colorectal cancer patients treated with capecitabine as an adjuvant chemotherapy after surgery were randomly allocated into the cystine/theanine group (n = 52) or the placebo group (n = 48). The primary endpoint was incidence rate of diarrhea of grade 1 or higher in accordance with the Common Terminology Criteria for AEs (CTCAE) v.4.0, Japanese Clinical Oncology Group (JCOG) version. The secondary endpoints included incidence rates of other AEs (CTCAE v.4.0-JCOG), as well as the incidence rate of HFS according to the HFS grading scale.

Results

There were no significant differences in capecitabine-induced AEs between the two groups. However, the incidence rate of diarrhea of grade 1 or higher tended to be lower in the cystine/theanine group than the placebo group (18.4% vs. 28.9%, p = 0.169) as well as the incidence rate of HFS of grade 1 or higher (CTCAE v.4.0-JCOG or HFS grading scale) (67.4% vs. 77.8%, p = 0.185, 67.3% vs. 80.0%, p = 0.124, respectively).

Conclusion

This trial demonstrated that cystine/theanine treatment of colorectal cancer patients undergoing capecitabine-based adjuvant chemotherapy after surgery is safe and has the tendency to reduce the incidence rate of diarrhea or HFS.

Trial registration

UMIN000024784

Electronic supplementary material

The online version of this article (10.1007/s00520-019-05205-1) contains supplementary material, which is available to authorized users.

Mercury Exposure and Poor Nutritional Status Reduce Response to Six Expanded Program on Immunization Vaccines in Children: An Observational Cohort Study of Communities Affected by Gold Mining in the Peruvian Amazon

Background: Poor nutritional status combined with mercury exposure can generate adverse child health outcomes. Diet is a mediator of mercury exposure and evidence suggests that nutritional status modifies aspects of mercury toxicity. However, health impacts beyond the nervous system are poorly understood. This study evaluates antibody responses to six vaccines from the expanded program on immunization (EPI), including hepatitis B, Haemophilus influenzae type B, measles, pertussis, tetanus, and diphtheria in children with variable hair mercury and malnutrition indicators. Methods: An observational cohort study (n = 98) was conducted in native and non-native communities in Madre de Dios, Peru, a region with elevated mercury exposure from artisanal and small-scale gold mining. Adaptive immune responses in young (3–48 months) and older children (4–8 year olds) were evaluated by vaccine type (live attenuated, protein subunits, toxoids) to account for differences in response by antigen, and measured by total IgG concentration and antibody (IgG) concentrations of each EPI vaccine. Mercury was measured from hair samples and malnutrition determined using anthropometry and hemoglobin levels in blood. Generalized linear mixed models were used to evaluate associations with each antibody type. Results: Changes in child antibodies and protection levels were associated with malnutrition indicators, mercury exposure, and their interaction. Malnutrition was associated with decreased measles and diphtheria-specific IgG. A one-unit decrease in hemoglobin was associated with a 0.17 IU/mL (95% CI: 0.04–0.30) decline in measles-specific IgG in younger children and 2.56 (95% CI: 1.01–6.25) higher odds of being unprotected against diphtheria in older children. Associations between mercury exposure and immune responses were also dependent on child age. In younger children, one-unit increase in log₁₀ child hair mercury content was associated with 0.68 IU/mL (95% CI: 0.18–1.17) higher pertussis and 0.79 IU/mL (95% CI: 0.18–1.70) higher diphtheria-specific IgG levels. In older children, child hair mercury content exceeding 1.2 µg/g was associated with 73.7 higher odds (95% CI: 2.7–1984.3) of being a non-responder against measles and hair mercury content exceeding 2.0 µg/g with 0.32 IU/mL (95% CI: 0.10–0.69) lower measles-specific antibodies. Log₁₀ hair mercury significantly interacted with weight-for-height z-score, indicating a multiplicative effect of higher mercury and lower nutrition on measles response. Specifically, among older children with poor nutrition (WHZ = −1), log₁₀ measles antibody is reduced from 1.40 to 0.43 for low (<1.2 µg/g) vs. high mercury exposure, whereas for children with good nutritional status (WHZ = 1), log₁₀ measles antibody is minimally changed for low vs. high mercury exposure (0.72 vs. 0.81, respectively). Conclusions: Child immune response to EPI vaccines may be attenuated in regions with elevated mercury exposure risk and exacerbated by concurrent malnutrition.

The effect of L-theanine supplementation on the immune system of athletes exposed to strenuous physical exercise

Background

The aim of this study was to analyze the response of selected components of the immune system in rowers to maximal physical exercise, and to verify if this response could be modulated by supplementation with L-theanine.

Method

The double-blind study included 20 members of the Polish Rowing Team. The subjects were randomly assigned to the supplemented group (n = 10), receiving 150 mg of L-theanine extract for 6 weeks, or to the placebo group (n = 10). The participants performed a 2000-m test on a rowing ergometer at the beginning (1st examination) and at the end of the supplementation period (2nd examination). Blood samples were obtained from the antecubital vein before each exercise test, 1 min after completing the test, and after a 24-h recovery. Subpopulations of T regulatory lymphocytes (Tregs) (CD4+/CD25+/CD127-), cytotoxic lymphocytes (CTLs) (CD8+/TCRαβ+), natural killer (NK) cells (CD3-/CD16+/CD56+) and TCRδγ-positive (Tδγ) cells were determined by means of flow cytometry. The levels of interleukin 2 (IL-2), interleukin 4 (IL-4), interleukin 10 (IL-10), interferon gamma (INF-ɤ) and total antioxidant capacity (TAC) were determined with commercially available diagnostic kits.

Results

Supplementation with L-theanine contributed to a significant post-exercise decrease in IL-10 concentration, which was reflected by higher values of IL-2 to IL-10 and IFN-γ to IL-10 ratios. Moreover, a significant post-recovery decrease in CTL count, Treg to NK and Treg to CTL ratios was observed in the supplemented group.

Conclusion

Despite the decrease in the number of some cytotoxic cells (CTLs) and an increase in the proportion of Tregs to CTLs, supplementation with LTE seems to exert a beneficial effect on a disrupted Th1/Th2 balance in elite athletes, as shown by the decrease in IL-10 concentration.

Efficacy of oral administration of cystine and theanine in patients with colorectal cancer undergoing capecitabine-based adjuvant chemotherapy after surgery: study protocol for a multi-institutional, randomised, double-blinded, placebo-controlled, phase II trial

INTRODUCTION

Although adjuvant capecitabine therapy for patients with colorectal cancer after surgery often causes adverse events (AEs), such as diarrhoea, stomatitis, anorexia and hand-foot syndrome (HFS), there are no standard prevention therapies. Cystine and theanine were reported to attenuate some chemotherapy-associated AEs, and are also expected to attenuate the AEs caused by capecitabine treatment. Therefore, our present study aimed to determine the safety and efficacy of cystine/theanine therapy in patients with colorectal cancer undergoing capecitabine-based adjuvant chemotherapy after surgery.

METHODS AND ANALYSIS

A multi-institutional, prospective, randomised, double-blinded, placebo-controlled, phase II trial is being planned. Patients with colorectal cancer treated with capecitabine as an adjuvant chemotherapy will be randomised into either the cystine/theanine group (n=50) or placebo group (n=50). Data will be collected during four courses of capecitabine therapy. The primary endpoint will be incidence rate of diarrhoea of grade 1 or higher in accordance with the Common Terminology Criteria for AEs (CTCAE) v.4.0, Japanese Clinical Oncology Group (JCOG) version. The secondary endpoints are incidence rates of other AEs (CTCAE v.4.0-JCOG), scores of the Japanese version of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire module for all patients with cancer (QLQ-C30) and for patients with colorectal cancer (QLQ-CR29), incidence rate of HFS according to the HFS grading scale, protocol adherence, completion rate of four courses of capecitabine therapy and the proportion of completion without delay or dose reduction, time to completion of four courses of capecitabine and total dose of capecitabine. A sample size of 100 patients will be analysed between November 2016 and April 2018.

ETHICS AND DISSEMINATION

Ethical approval was obtained at all participating institutions. The results of this study will be submitted for publication in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

UMIN000024784; Pre-results.

Topical delivery of l-theanine ameliorates TPA-induced acute skin inflammation via downregulating endothelial PECAM-1 and neutrophil infiltration and activation

l-theanine, the most abundant free amino acid in tea, has been documented to possess many different bioactive properties through oral or intragastrical delivery. However, little is known about the effect of topical delivery of l-theanine on acute inflammation. In the present study, by using 12-O-tetradecanoylphorbol-13-acetate (TPA, 2.5 μg/ear)-induced ear edema model in mice, we first found that single-dose local pretreatment of l-theanine 30 min before TPA time- and dose-dependently suppressed the increases in both skin thickness and weight. Subsequently l-theanine ameliorated TPA-induced erythema, vascular permeability increase, epidermal and dermal hyperplasia, neutrophil infiltration and activation via downregulating the expression of PECAM-1 (a platelet endothelial adhesion molecule-1) in blood vessels and the production of pro-inflammatory cytokines IL-1β, TNF-α, and mediator cyclooxygenase-2 (COX-2), which is mainly expressed in neutrophils. It highlighted the potential of l-theanine as a locally administrable therapeutic agent for acute cutaneous inflammation.

Serum C-Reactive Protein and Congestive Heart Failure as Significant Predictors of Herpes Zoster Vaccine Response in Elderly Nursing Home Residents

Background

Elderly long-term care residents often exhibit a myriad of risk factors for immune dysfunction, including chronic inflammation and multiple comorbid conditions, which undoubtedly contribute to their enhanced susceptibility to infection. Hence, understanding the factors required for optimal vaccine responsiveness is critical.

Methods

We examined 187 elderly nursing home residents (aged 80-102 years) and 50 community-dwelling seniors (aged 60-75 years) immunized with the live-attenuated varicella-zoster virus (VZV) vaccine. Specifically, we examined whether vaccine responsiveness was associated with serum C-reactive protein (CRP), tumor necrosis factor, interleukin 1β, 6, and 10, leukocyte telomere length, chronic disease status, and frailty.

Results

Elderly participants had significantly higher levels of CRP, tumor necrosis factor, and interleukin 6 and shorter leukocyte telomere length. Vaccine responsiveness was inversely related to the CRP level in elderly participants, but not seniors, and those with congestive heart failure were less likely to achieve a 2-fold response (odds ratio, 0.08). The latter relationship is probably due to immunosenescence, because heart failure was associated with increased senescent CD4+ T cells, and reduced naive and effector and central memory CD8+ T cells.

Conclusions

In summary, these data improve our understanding of vaccine responsiveness for those in long-term care, suggesting that certain risk factors are associated with a greater likelihood of vaccine failure.

Cystine and theanine: amino acids as oral immunomodulative nutrients

The decreases in the glutathione (GSH) level in the mouse spleen and liver after immune stimulation are suppressed by the oral administration of cystine and theanine (CT). GSH is considered to be important for the control of immune responses. Antibody production in mice after infection is enhanced by the oral administration of CT. In humans, also, the oral administration of CT has been confirmed to enhance antibody production after vaccination against Flu and also reduce the incidence of cold. However, the GSH level is reduced by intense exercise and surgery. In clinical studies of body-builders and long-distance runners, the intake of CT suppressed excessive inflammatory reactions and a decline in immune functions after intense training. Surgery as well as intense exercise induces excessive inflammatory reactions. In mice, the preoperative administration of CT suppressed excessive inflammatory reactions associated with surgery and promoted the postoperative recovery. Moreover, in clinical studies of gastrectomized patients, CT intake suppressed excessive postoperative inflammatory reactions and induced early recovery. If infection is regarded as invasive stress, CT intake is considered to exhibit an immunomodulatory effect by suppressing the decrease in GSH due to invasive stress. The clarification of their detailed action mechanisms and their application as medical or function foods is anticipated.

A review of the evidence to support influenza vaccine introduction in countries and areas of WHO's Western Pacific Region

Background

Immunization against influenza is considered an essential public health intervention to control both seasonal epidemics and pandemic influenza. According to the World Health Organization (WHO), there are five key policy and three key programmatic issues that decision-makers should consider before introducing a vaccine. These are (a) public health priority, (b) disease burden, (c) efficacy, quality and safety of the vaccine, (d) other inventions, (e) economic and financial issues, (f) vaccine presentation, (g) supply availability and (h) programmatic strength. We analyzed the body of evidence currently available on these eight issues in the WHO Western Pacific Region.

Methodology/Principal Findings

Studies indexed in PubMed and published in English between 1 January 2000 and 31 December 2010 from the 37 countries and areas of the Western Pacific Region were screened for keywords pertaining to the five policy and three programmatic issues. Studies were grouped according to country income level and vaccine target group. There were 133 articles that met the selection criteria, with most (90%) coming from high-income countries. Disease burden (n = 34), vaccine efficacy, quality and safety (n = 27) and public health priority (n = 27) were most frequently addressed by studies conducted in the Region. Many studies assessed influenza vaccine policy and programmatic issues in the general population (42%), in the elderly (24%) and in children (17%). Few studies (2%) addressed the eight issues relating to pregnant women.

Conclusions/Significance

The evidence for vaccine introduction in countries and areas in this Region remains limited, particularly in low- and middle-income countries that do not currently have influenza vaccination programmes. Surveillance activities and specialized studies can be used to assess the eight issues including disease burden among vaccine target groups and the cost-effectiveness of influenza vaccine. Multi-country studies should be considered to maximize resource utilization for cross-cutting issues such as vaccine presentation and other inventions.

Immune response to hepatitis B virus vaccination among HIV-1 infected and uninfected adults in Kenya

BACKGROUND

In studies from high-income countries, human immunodeficiency virus type 1 (HIV-1)-infected persons have diminished responses to hepatitis B virus (HBV) vaccination, compared with HIV-1-uninfected persons, but data from other settings are limited.

METHODS

We compared the immune response to HBV vaccination among HIV-1-infected and HIV-1-uninfected Kenyan adults and assessed the response of HIV-1-infected initial nonresponders to revaccination with a standard HBV vaccine series.

RESULTS

Of 603 participants, 310 (51.4%) were HIV-1-infected, for whom the median CD4(+) T-cell count was 557 cells/μL (interquartile range, 428-725 cells/μL); none were receiving antiretroviral therapy. Nonresponse to HBV vaccine was higher among HIV-1-infected participants, compared with HIV-1-uninfected participants (35.8% vs 14.3%; odds ratio, 3.33; P < .001). Of 102 HIV-1-infected initial nonresponders, 88 (86.3%) responded to revaccination, for an overall response, including to revaccination, of 94.9%. Among HIV-1-infected individuals, lower CD4(+) T-cell counts and male sex were independent predictors of nonresponse to initial vaccination, and lower body mass index, higher plasma HIV-1 RNA levels, and longer time to revaccination predicted nonresponse to revaccination.

CONCLUSIONS

Kenyan adults had similar HBV vaccination responses as persons from high-income countries. Timely revaccination of HIV-1-infected nonresponders increased response to the vaccine to 95%.

A systematic mapping review of randomized controlled trials (RCTs) in care homes

Background

A thorough understanding of the literature generated from research in care homes is required to support evidence-based commissioning and delivery of healthcare. So far this research has not been compiled or described. We set out to describe the extent of the evidence base derived from randomized controlled trials conducted in care homes.

Methods

A systematic mapping review was conducted of the randomized controlled trials (RCTs) conducted in care homes. Medline was searched for “Nursing Home”, “Residential Facilities” and “Homes for the Aged”; CINAHL for “nursing homes”, “residential facilities” and “skilled nursing facilities”; AMED for “Nursing homes”, “Long term care”, “Residential facilities” and “Randomized controlled trial”; and BNI for “Nursing Homes”, “Residential Care” and “Long-term care”. Articles were classified against a keywording strategy describing: year and country of publication; randomization, stratification and blinding methodology; target of intervention; intervention and control treatments; number of subjects and/or clusters; outcome measures; and results.

Results

3226 abstracts were identified and 291 articles reviewed in full. Most were recent (median age 6 years) and from the United States. A wide range of targets and interventions were identified. Studies were mostly functional (44 behaviour, 20 prescribing and 20 malnutrition studies) rather than disease-based. Over a quarter focussed on mental health.

Conclusions

This study is the first to collate data from all RCTs conducted in care homes and represents an important resource for those providing and commissioning healthcare for this sector. The evidence-base is rapidly developing. Several areas - influenza, falls, mobility, fractures, osteoporosis – are appropriate for systematic review. For other topics, researchers need to focus on outcome measures that can be compared and collated.

Enhancement of postoperative recovery by preoperative oral co-administration of the amino acids, cystine and theanine, in a mouse surgical model

BACKGROUND & AIMS

Glutathione (GSH) is important in the control of immune responses, and its levels decline following trauma. We previously reported that the oral administration of cystine/theanine (CT) increased GSH synthesis and that CT intake inhibited intense exercise-induced inflammation. Based on these results, we hypothesised that CT inhibits surgically induced inflammation and promotes postoperative recovery. Our aim was to confirm this hypothesis using a mouse surgical model.

METHODS

CT or a vehicle (V) was administered orally to mice once a day for 5 days, until the day of surgery. On the day of surgery, a sham operation or an intestinal manipulation was performed 2 h after the oral administration of CT or V. Levels of IL-6 in the blood and GSH in the intestine were analysed 2 h after surgery. Behavioural analysis was also undertaken after surgery.

RESULTS

Treatment with CT inhibited the manipulation-induced increase in IL-6 in the blood and decrease in GSH in the intestine. There was a significant negative correlation between IL-6 in the blood and GSH in the intestine. In addition, behavioural analysis revealed that CT administration improved locomotor activity and food intake after surgery.

CONCLUSION

These results suggest that CT suppresses inflammatory responses by inhibiting the surgically induced decrease in GSH in the small intestine and promotes postoperative recovery.

L-Theanine: properties, synthesis and isolation from tea

Theanine is a non-protein amino acid that occurs naturally in the tea plant (Camellia sinensis) and contributes to the favourable taste of tea. It is also associated with effects such as the enhancement of relaxation and the improvement of concentration and learning ability. It is also linked with health benefits including the prevention of certain cancers and cardiovascular disease, the promotion of weight loss and enhanced performance of the immune system. Thus, there has been a significant rise in the demand for theanine. While theanine has been chemically and biologically synthesised, techniques to isolate theanine from natural sources remain an important area of research. In this review article, the properties and health benefits of theanine are summarised and the synthesis and isolation of theanine are reviewed and discussed. Future perspectives for the isolation of theanine from natural sources are also outlined.

Neuroendocrine-immune interactions in healthy aging

AIM

The nervous, endocrine and immune systems are connected by shared neurotransmitters, hormones and cytokines. The function of these systems shows patterns of circadian rhythmicity and a number of age-related changes in the 24-h hormonal and non-hormonal rhythms have been found in older human beings. The aim of this study was to evaluate integration among the nervous, endocrine and immune systems in the elderly.

METHODS

Cortisol and melatonin serum levels were measured and lymphocyte subpopulation analyses were performed on blood samples collected every 4 h for 24 h from 15 healthy young-middle-aged subjects (range 36-55 years, mean age±standard error [SE] 44.08±1.76) and 15 healthy old-aged subjects (range 67-79 years, mean age±SE 68.52±1.27).

RESULTS

There was a statistically significant difference between the groups in the observed values of CD20 (total B cells higher in young-middle-aged subjects, P=0.02), CD25 (activated T cells with expression of the α-chain of interleukin-2 receptor, higher in elderly subjects, P=0.04) and DR+ T cells (activated T cells higher in elderly subjects, P=0.01). There were different correlations among lymphocyte subpopulations and hormone serum levels in young and middle-aged subjects in compared to old-aged subjects. In the group of young-middle-aged subjects, a clear circadian rhythm was validated for the time-qualified changes of all the factors studied. In the group of elderly subjects, a clear circadian rhythm was validated for the nyctohemeral changes of CD3 (with a phase delay of 3 h), CD8, CD4/CD8 ratio, CD16, CD25 (in opposite phase), cortisol (with a phase delay of 1 h) and melatonin.

CONCLUSION

The results of the current study show that aging is associated with enhanced responsiveness of the T-cell compartment, impairment of B-cell compartment and alterations in temporal architecture and correlations of neuroendocrine-immune parameters.

Suppression of exercise-induced neutrophilia and lymphopenia in athletes by cystine/theanine intake: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Intense exercise induces increased blood neutrophil counts and decreased lymphocyte counts, and leads to inflammation and immunosuppression. It was previously reported that cystine and theanine (CT) supplementation by long-distance runners before a training camp suppressed the changes of these blood parameters observed in un-supplemented control subjects after the camp. The purpose of the present study was to determine the effects of CT supplementation on the inflammatory response and immune state before and after intense endurance exercise in long-distance runners at a training camp.

METHODS

Sixteen long-distance runners were allocated to one of two groups given CT supplements (700 mg cystine + 280 mg theanine daily) or placebo (8 in each group) for 7 days prior to and during a 9-day training camp. Daily run training averaged 19.9 km/day prior to the camp and 28.6 km/day during the camp. On the initial and final days of the camp, blood samples were collected before and after 15 km morning interval running workouts (1000 m x 15 times) and analyzed for neutrophil and lymphocyte counts and myoglobin.

RESULTS

The relative change in exercise-induced blood neutrophil count (% of pre-exercise values) was significantly lower in the CT group than in the placebo group (163.3 +/- 43.2% vs. 200.4 +/- 19.6%, p = 0.044) on the initial day of camp, but not on the last day. The decline in lymphocyte count (% of pre-exercise values) was significantly less in the CT group than in the placebo group (60.2 +/- 19.2% vs. 36.2 +/- 12.0%, p = 0.010) on the initial day of camp, but not on the last day. In blood myoglobin, there was a trend toward lower % of pre-exercise values in the CT group (p < 0.09) on both measurement days.

CONCLUSION

CT supplementation significantly attenuated the increase in neutrophil count and the reduction in lymphocyte count induced by intense endurance exercise. These results suggest that CT supplementation may suppress the exercise-induced fluctuation of the blood immunocompetent cells and may help to reduce the alteration of the immune state.

Effects of (L)-cystine and (L)-theanine supplementation on the common cold: a randomized, double-blind, and placebo-controlled trial

The common cold is one of the most frequent illnesses caused by viral infection. Recently, we have reported that oral administration of cystine and theanine (CT) to mice enhanced the humoral immune response associated with antibody production. Based on this mouse study, we investigated the effects of CT supplementation on the common cold in humans as a pilot study. A total of 176 healthy male volunteers were randomized to receive either placebo or CT (490 mg) tablets twice daily for 35 days. The incidence outcome was assessed using the definition in our laboratory based on questionnaires regarding cold symptoms. The incidence of subjects with colds during the trial was significantly lower in the CT group than in the placebo group, although the duration of the colds was not significantly different between the groups. These results suggest that CT supplementation may be useful for the prevention of the common cold.

Effects of oral supplementation with cystine and theanine on the immune function of athletes in endurance exercise: randomized, double-blind, placebo-controlled trial

Athletes become increasingly susceptible to infection with intense training that results in immune suppression. The immune state was investigated after administering cystine/theanine (CT), which has been reported to have an immune reinforcement effect, to athletes before training involving a prolonged period of intense exercise. Fifteen long-distance runners were each allocated to the CT or placebo group, and the test food was ingested for 10 d prior to the start of training. Clinical examinations were performed before and after the training. The results indicate a significant increase in the high-sensitivity C-reactive protein (hs-CRP) and neutrophil count in the blood, as well as a decreasing tendency for lymphocytes in the placebo group, but not the CT group. These observations suggest that the ingestion of CT contributed to suppressing the change in inflammatory response, prevented a decrease in the immune function, and prevented infection and reduced symptoms when infected associated with continuous intense exercise.