The impact of malnutrition on the effectiveness of intradialytic exercise in hemodialysis patients: amulticenter cohort study.

PURPOSE: Low physical function can be effectively improved via intradialytic exercise. However, the association between the effects of intradialytic exercise on physical function and malnutrition severity has not been studied extensively. This study aimed to investigate the impact of nutritional status severity on physical function in patients undergoing hemodialysis with low physical function to whom intradialytic exercise was prescribed. METHODS: The participants were patients with decreased mobility [walking speed < 1.0 m/s and/or Short Physical Performance Battery (SPPB) < 12] who had been undergoing hemodialysis thrice a week for 6 months and performing intradialytic exercise program. Patients were divided into groups based on the Geriatric Nutritional Risk Index (GNRI) [Non-malnutrition group (GNRI > 98), Gentle/slim malnutrition group (GNRI ≤ 98, GNRI ≥ 92), Mild malnutrition group (GNRI < 92, GNRI ≥ 82), Severe malnutrition group (GNRI < 82)]. The primary outcomes were Grip strength, isometric knee extension strength (IKES), SPPB, and 10-m walking speed measured at baseline and at 6 months. Statistical analyses were performed using a linear mixed-effects model with the intention-to-treat analysis, including within-group analysis and between-group comparison. RESULTS: A total of 805 participants were included in the study. Within-group comparisons showed significantly improved IKES, 10-m walking speed, and SPPB improved, except in the Severe malnutrition group. Grip strength significantly improved in the Gentle/slim and mild malnutrition groups. Between-group comparison with controls showed that the improvement in Grip strength was significantly bigger in the Gentle/slim malnutrition group [0.98 (0.15 to 1.82) kg] than in the non-malnutrition group. However, IKES in the Severe malnutrition group [- 5.14 (- 9.18 to - 1.10) %] less significantly improve than that in the non-malnutrition group. No significant differences were found in the other indices. CONCLUSION: In patients with severe malnutrition, the changes in IKES scores resulting from Intradialytic exercise were significantly smaller than those observed in non-malnourished patients. Therefore, it is necessary to initiate suitable nutritional and exercise therapy based on the severity of malnutrition.

Factors associated with improved health-related quality of life due to improvements in physical function and dialysis-related symptoms following intradialytic exercise in outpatients undergoing haemodialysis.

PURPOSE: Exercise therapy is a crucial intervention for improving health-related quality of life (HRQOL) in patients undergoing haemodialysis. However, factors that improve HRQOL by improving physical function and dialysis-related symptoms remain unknown. This study aimed to examine the physical function parameters and dialysis-related symptoms that improve HRQOL following intradialytic exercise. METHODS: This multicentre cohort study included 596 patients who participated in an intradialytic exercise program three times per week for a period of 6 months, which comprised of stretching and resistance training. EuroQol 5 dimensions 5-level (EQ5D-5L), grip strength, isometric knee extension strength, 10-m walking speed, Short Physical Performance Battery (SPPB), and improvement in dialysis-related symptoms were measured at the baseline and post-intervention. A linear mixed model was used to analyse the effects of improved physical function and dialysis-related symptoms on improvements in EQ5D-5L. RESULTS: As a physical function index affecting ΔEQ5D-5L, only SPPB showed a significant increase in ΔEQ5D-5L compared with the non-improved group [difference in ΔEQ5D-5L, 0.05 (0.004 to 0.092) point; p < 0.05]). In addition, dialysis-related symptoms with Improved physical conditions [difference in ΔEQ5D-5L, 0.07 (0.02 to 0.13) point] and an Extended walking distance [difference in ΔEQ5D-5L was 0.07 (0.01 to 0.12) point] significantly influenced ΔEQ5D-5L (p < 0.05, both). CONCLUSIONS: The improvements observed in the SPPB scores and self-percieved physical fitness and ambulation range, attributable to intradialytic exercise, may potentially improve HRQOL.

Age-associated effects of intradialytic exercise on physical function and nutritional status in patients receiving ambulatory hemodialysis: A multicenter cohort study.

INTRODUCTION: Intradialytic exercise is essential for improving physical function for older patients. This study aimed to examine the relationship between the effects of exercise therapy and aging. METHODS: This multicenter cohort study included 1176 patients aged 40-89 years, who participated in an intradialytic exercise program, comprising stretching and resistance training, three times per week for 12 months. Isometric knee extension strength (IKES), 10-m walking speed, Short Physical Performance Battery (SPPB), and Geriatric Nutritional Risk Index (GNRI) were measured at baseline and after 12 months. The patients were divided according to age as follows: 40-59, 60-69, 70-79, and 80-89 years. A linear mixed-effects model examined the improvement within-group and between-control differences, as the 40-59 age group was the control group. FINDINGS: The 40-59, 60-69, 70-79, and 80-89 age groups comprised 180, 317, 466, and 213 participants, respectively. Within-group differences, all the age groups significantly improved IKES and SPPB. The 10-m walking speed [0.02 (0.02) m/s] and GNRI [0.38 (0.33)] did not improved only in the 80-89 age group despite other age groups significantly improved. Between-control differences, IKES of the 70-79 age group [-0.24 (-0.42 to -0.06) %] was significantly lower improvement than control. GNRI of all the older groups were significantly smaller improvement than control (p < 0.05). DISCUSSION: The older group demonstrated difficulty in improving walking ability and nutritional status compared with the younger groups. Clinicians need to consider the difference in effectiveness due to age and prescribe intradialytic exercises accordingly.

The study of exercise therapy using a virtual reality system on healthy subjects assuming hospital use and intradialytic exercise.

This study aimed to investigate the basic data on the effectiveness and safety of the system in healthy subjects using an immersive virtual reality (VR) exercise system specialized for therapeutic exercise therapy during dialysis or hospital use. A total of 15 healthy adult subjects performed four exercises, namely lifting and rowing exercises using VR and each movement exercise without VR (control). The simulator sickness questionnaire (SSQ) was administered pre- and post-operatively to assess for VR sickness. Blood pressure, heart rate (HR), rating of perceived exhaustion, Profile of Mood States 2nd Edition Japanese version, and muscle activity (iEMG) were measured using electromyography. The correlation between changes in mood states and HR or iEMG results was examined. The SSQ measured post-VR exercise was 11.2 (18.7-7.5) and 11.2 (7.5-29.9) points in the lifting and rowing VR, respectively. The HR in lifting (VR, 82.5 ± 12.7 vs control, 71.6 ± 10.6 bpm, P<0.05) and rowing (VR, 94.2 ± 13.1 vs control, 83.5 ± 12.0, P<0.05) with VR exercise was significantly higher than in control. No significant differences were observed between the other variables. There was a positive correlation between HR and negative mood in the lifting VR condition (r=0.64, P<0.05), but not in the control group. Contrastingly, there was a positive correlation between iEMG and negative mood in rowing control (r=0.56), but not VR. Safety was confirmed, with no VR sickness or discontinuation of the system. Exercise therapy using VR resulted in a higher exercise load. This VR system has the potential for additional effective intradialytic exercises and hospital use.

Active role of the protein translation machinery in protecting against stress tolerance in Synechococcus elongatus PCC7942.

In vivo protein synthesis is crucial for all domains of life. It is accomplished through translational machinery, and a key step is the translocation of tRNA-mRNA by elongation factor G (EF-G). Genome-based analysis revealed two EF-G encoding genes (S0885 and S2082) in the freshwater cyanobacterium model Synechococcus elongatus PCC7942. S0885 is the essential EF-G gene for photosynthesis. We generated a strain of S. elongatus PCC7942 that overexpressed S0885 (OX-S0885) to identify EF-G functionality. RT-PCR and Western blot analyses revealed increased transcriptional and translational levels in OX-S0885 at 10.5-13.5 and 2.0-3.0 fold, respectively. Overexpression of S0885 led to an increase in specific growth rate. Additionally, polysome-to-monosome ratio (P/M) and RNA-to-protein ratio (R/P) were elevated in OX-S0885 compared with the empty vector. Interestingly, R/P in OX-S0885 was retained at more than 70% under oxidative stress while R/P in the empty vector was severely depleted, suggesting the maintenance of translation. Thus, S0885 appeared to be the important target of oxidative stress because it was protected by the stress response system to maintain its function. These results suggest that cyanobacterial EF-G has a primary function in translation and an unrelated activity during stress conditions. These findings support the substantial role of EF-G in the formation and maintenance of cellular protein formation, and in the protection of the global translational mechanism under oxidative stress condition.

Influence of Malnutrition on the Improvement of Physical Function by Intradialytic Resistance Exercise in Patients Undergoing Hemodialysis.

OBJECTIVE: Intradialytic exercise improves physical function. However, malnutrition may be an essential factor affecting the effectiveness of exercise to improve physical function. Few studies of the relationship between malnutrition and the effectiveness of intradialytic exercise to improve physical function exist. Therefore, this study investigated malnutrition at the beginning of intradialytic exercise and how it affects the subsequent improvement in physical function. METHODS: Patients who performed intradialytic exercise for 12 months were enrolled in this study. A Geriatric Nutritional Risk Index of 91.2 was defined as malnutrition. Patients were assigned to 2 groups using propensity score matching to adjust for confounding factors. Physical function outcomes were handgrip strength, isometric knee extension strength, short physical performance battery, and 10-m walking speed; these were compared at baseline, 3 months, 6 months, and 12 months. The 2 groups were further divided into another 2 groups as per whether the nutritional status had improved after 12 months; therefore, a total of 4 groups were analyzed. RESULTS: After matching, the data of 154 patients in each group were analyzed. During the intragroup comparison, isometric knee extension strength, short physical performance battery, and 10-m walking speed improved significantly in both groups after intradialytic exercise was started compared with before intradialytic exercise was started. However, there was no significant improvement in handgrip strength in the malnutrition group. There were no significant differences in any of the physical function measurements or changes from the baseline values among the 4 groups divided as per subsequent recovery of the nutritional status. CONCLUSION: Malnutrition may not impact the effectiveness of intradialytic exercise to improve lower-leg physical function. Its effect on the improvement of handgrip strength requires further investigation.

Oral Supplementation with Z-Isomer-Rich Astaxanthin Inhibits Ultraviolet Light-Induced Skin Damage in Guinea Pigs.

The effect of oral supplementation with astaxanthin of different Z-isomer ratios on ultraviolet (UV) light-induced skin damage in guinea pigs was investigated. Astaxanthin with a high Z-isomer content was prepared from the all-E-isomer via thermal isomerization. Intact (all-E)-astaxanthin and the prepared Z-isomer-rich astaxanthin were suspended in soybean oil and fed to guinea pigs for three weeks. The UV-light irradiation was applied to the dorsal skin on the seventh day after the start of the test diet supplementation, and skin parameters, such as elasticity, transepidermal water loss (TEWL), and pigmentation (melanin and erythema values), were evaluated. The accumulation of astaxanthin in the dorsal skin was almost the same after consumption of the all-E-isomer-rich astaxanthin diet (E-AST-D; total Z-isomer ratio = 3.2%) and the Z-isomer-rich astaxanthin diet (Z-AST-D; total Z-isomer ratio = 84.4%); however, the total Z-isomer ratio of astaxanthin in the skin was higher in the case of the Z-AST-D supplementation. Both diets inhibited UV light-induced skin-damaging effects, such as the reduction in elasticity and the increase in TEWL level. Between E-AST-D and Z-AST-D, Z-AST-D showed better skin-protective ability against UV-light exposure than E-AST-D, which might be because of the greater UV-light-shielding ability of astaxanthin Z-isomers than the all-E-isomer. Furthermore, supplementation with Z-AST-D resulted in a greater reduction in skin pigmentation caused by astaxanthin accumulation compared to that of E-AST-D. This study indicates that dietary astaxanthin accumulates in the skin and appears to prevent UV light-induced skin damage, and the Z-isomers are more potent oral sunscreen agents than the all-E-isomer.

Effectiveness and safety of rehabilitation on minimal change nephrotic syndrome in remission for elderly patients with low activity of daily living: a case report.

There are few reports on the rehabilitation of elderly patients with minimal change nephrotic syndrome (MCNS). The purpose of this case study was to evaluate the efficacy and safety of rehabilitation for an elderly patient with MCNS in remission. The patient was an 86-year-old woman. She was admitted to the hospital with a diagnosis of MCNS, and steroid treatment was initiated. She was weaned from dialysis 2 weeks later; however, her activities of daily living (ADL) decreased, and she developed disuse syndrome. After rehabilitation, the patient's ADL, maximum hand grip strength, and gait function improved. There was no recurrence of weight gain or increased proteinuria during rehabilitation, but the estimated glomerular filtration rate decreased. This case suggests that rehabilitation for elderly patients with MCNS in remission can be effective for physical and ADL functions without relapse of MCNS. The effect of exercise therapy on the relationship between exercise therapy and renal function needs to be further investigated by collecting more cases.

Evaluation and improvement of storage stability of astaxanthin isomers in oils and fats.

Astaxanthin Z-isomers potentially have greater bioavailability and biological activity than (all-E)-astaxanthin. However, the stability of the Z-isomers is lower than the all-E-isomer, which is a serious problem affecting its practical use. In this study, we investigated the impacts of different suspension media (oils and fats) and additives on astaxanthin isomer stability and identified suitable ones for astaxanthin stabilization. The evaluations showed that several vegetable oils and antioxidants significantly improved astaxanthin isomer stability, e.g., when soybean and sunflower oils were used as the suspension medium, astaxanthin isomers were hardly degraded; however the total Z-isomer ratio decreased from ~80% to ~50% during 6-week storage at 30 °C. Moreover, it was revealed that (9Z)-astaxanthin showed higher stability than the 13Z- and 15Z-isomers. Hence, to maintain astaxanthin concentration and the Z-isomer ratio over long periods, it is important to use suitable suspension mediums and antioxidants, and select a Z-isomerization method that increases (9Z)-astaxanthin ratio.

Synergistic Effects of Food Ingredients and Vegetable Oils on Thermal Isomerization of Lycopene.

Recent investigations have demonstrated that some food ingredients and vegetable oils, such as onion, garlic, and sesame oil, enhanced thermal Z-isomerization of (all-E)-lycopene in tomatoes. However, the synergistic effects of these ingredients and oils have not yet been investigated. This study aims at clarifying how the combined use of lycopene Z-isomerization-promoting food ingredients and vegetable oils impacts thermal Z-isomerization of (all-E)-lycopene in tomato puree. Apart from a few exceptions, when olive oil was used as a reaction medium, the combined use of garlic, cabbage, broccoli, shiitake mushroom, and makonbu improved the total Z-isomer ratio of lycopene after heating compared to the separate use of the tested ingredients. However, when onion was used together with the other ingredients, the Z-isomer ratio significantly decreased compared to its individual use. Moreover, when garlic, cabbage, broccoli, shiitake mushroom, and makonbu were used with sesame and mustard oils, that exhibit higher Z-isomerizationpromoting effect than that of olive oil, the lycopene Z-isomerization reaction was further enhanced. However, when onion was combined with these oils, the Z-isomer ratio decreased compared to that measured upon the combined use of onion with olive oil. Our results on these synergistic effects are not only important for the food and drink manufacturing industries but also for daily home cooking.

A NiRhS fuel cell catalyst - lessons from hydrogenase.

We present a novel fuel cell heterogeneous catalyst based on rhodium, nickel and sulfur with power densities 5-28% that of platinum. The NiRhS heterogeneous catalyst was developed via a homogeneous model complex of the [NiFe]hydrogenases (H2ases) and can act as both the cathode and anode of a fuel cell.

Antioxidative and Antiglycative Properties of Mycosporine-Like Amino Acids-Containing Aqueous Extracts Derived from Edible Terrestrial Cyanobacteria.

The terrestrial filamentous cyanobacterium, Nostoc commune, has been used as a food source in many countries, especially countries in Asia. In this study, N. commune-derived aqueous extracts were evaluated with regard to their antioxidative and antiglycative properties. The antioxidative activity was significantly higher in N. commune colonies isolated from the field than in extracts from colonies cultured in the laboratory. The antioxidative compound content of extracts, including phenolic compounds and phycobiliproteins, was correlated with their antioxidative power. In addition, two mycosporine-like amino acids (MAAs), specifically detected in colonies isolated from the field, were purified. In addition to assessing their antioxidative properties, the antiglycative activity of these MAAs was also assessed. Their inhibitory effects on glycation-dependent protein cross-linking might contribute to the antiglycative power of the extract prepared from field colonies. Taken together, the results from this study revealed that N. commune may have beneficial properties for functional food applications, both by preventing oxidative stress and suppressing the formation of advanced glycation end-products.

Morphological plasticity of hyperelongated cells caused by overexpression of translation elongation factor P in Synechococcus elongatus PCC7942.

Translation elongation factors (EFs) are proteins that play important roles during the elongation stage of protein synthesis. In prokaryotes, at least four EFs function in repetitive reactions (EF-Tu, EF-Ts, EF-G, and EF-P). EF-P plays a vital role in the specialized translation of consecutive proline amino acid motifs. It was also recently recognized that EF-P acts throughout translation elongation. Here, we demonstrated for the first time that cell division and morphology are intimately linked to the control of EF-P in the model cyanobacterium Synechococcus elongatus PCC7942. We constructed the overexpression of a wild-type gene product for EF-P (Synpcc7942_2565) as a tool to identify EF-P functionality. The overexpression of EF-P resulted in the morphological plasticity of hyperelongated cells. During the stationary phase, EF-P overexpressors displayed cell lengths of 150 µm or longer, approximately 35 times longer than the control. Total cellular protein and amino acid content were also increased in overexpressors. To explore the molecular mechanisms underlying hyperelongation, gene expression analysis was performed. The results revealed that cell division genes, including ftn6, minD, mreB, mreC, and ftsZ, were modulated in overexpressors. Strikingly, ftn6 was severely down-regulated. Little is known regarding EF-P in prokaryotic photosynthetic organisms. Our results suggest that cyanobacterial EF-P participates in the acceleration of protein synthesis and also regulates cell division processes. These findings suggest new ways to modify translation and metabolism in cyanobacteria. Phenotypic and metabolic alterations caused by overexpressing EF-P may also be beneficial for applications such as low-cost, green molecular factories. KEY POINTS: • Cell division and cell morphology in the cyanobacterium Synechococcus elongatus PCC7942 are closely linked with the control of translation elongation factor P (EF-P). • Overexpression of EF-P leads to morphological plasticity in hyperelongated cells. • Cyanobacterial EF-P is involved in the acceleration of protein synthesis and the regulation of cell division processes.

The Effects of Salts and Osmoprotectants on Enzyme Activities of Fructose-1,6-biphosphate Aldolases in a Halotolerant Cyanobacterium, Halothece sp. PCC 7418.

The halotolerant cyanobacterium, Halothece sp. PCC 7418, possesses two classes of fructose-1,6-bisphosphate aldolase (FBA): H2846 and H2847. Though class I (CI)-FBA H2846 is thought to be associated with salt tolerance, the regulatory mechanisms, molecular characteristics, and expression profiles between H2846 and class II (CII)-FBA H2847 have scarcely been investigated. Here, we show that the accumulation of the H2846 protein is highly responsive to both up- and down-shock with NaCl, whereas H2847 is constitutively expressed. The activity of CI- and CII-FBA in cyanobacterial extracts is correlated with the accumulation patterns of H2846 and H2847, respectively. In addition, it was found that these activities were inhibited by NaCl and KCl, with CII-FBA activity strikingly inhibited. It was also found that the CI-FBA activity of recombinant H2846 was hindered by salts and that this hindrance could be moderated by the addition of glycine betaine (GB), whereas no moderation occurred with other potential osmoprotectant molecules (proline, sucrose, and glycerol). In addition, a phylogenetic analysis showed that CI-FBAs with higher similarities to H2846 tended to be distributed among potential GB-synthesizing cyanobacteria. Taken together, our results provide insights into the independent evolution of the CI- and CII-FBA gene families, which show distinct expression profiles and functions following salt stress.

The evolutionarily conserved HtrA is associated with stress tolerance and protein homeostasis in the halotolerant cyanobacterium Halothece sp. PCC7418.

The HtrA protein family represents an important class of serine proteases that are widely distributed across taxa. These evolutionarily conserved proteins are crucial for survival and function as monitors of protein synthesis during various stresses. Here, we performed gene expression analysis of the entire set of putative serine protease genes in Halothece sp. PCC7418 under salt stress conditions. The gene-encoding HtrA2 (H3553) was highly upregulated. This gene was cloned and functionally characterized, and its sub-cellular localization was determined. The recombinant H3553 protein (rH3553) displayed a pH optimum of 8.0, remained stable at 45 °C, and its proteolytic activity was not affected by salts. H3553 completely degraded the unfolded model protein, ß-casein. In contrast, the folded model substrates (lysozyme or BSA) were not degraded by rH3553. Denaturation of BSA at a high temperature significantly increased its degradation by rH3553. H3553 was detected in the soluble protein fraction as well as the plasma membrane and thylakoid membrane fractions. Interestingly, the majority of H3553 was present in the plasma membrane under salt and heat stress conditions. Thus, H3553 resides in multiple sub-cellular locations and its localization drastically changes after exposure to stresses. Taken together, H3553 underpins protein quality-control process and is involved in the response and adaptation to salinity and heat stresses.

Isomerization of Commercially Important Carotenoids (Lycopene, ß-Carotene, and Astaxanthin) by Natural Catalysts: Isothiocyanates and Polysulfides.

Effects of natural catalysts, isothiocyanates and polysulfides, on Z-isomerization and decomposition of (all-E)-carotenoids (lycopene, ß-carotene, and astaxanthin) after heat treatment were investigated. When isothiocyanates were added to (all-E)-carotenoid solutions and heated, Z-isomerization and decomposition of carotenoids were enhanced and the degree differed depending on the isothiocyanate type. Interestingly, when polysulfides were applied in the same manner, in addition to promoting the Z-isomerization reaction, they markedly improved the thermal stability of carotenoids. Successively, we investigated the reaction characteristics of allyl isothiocyanate (AITC) and diallyl disulfide (DADS) using (all-E)-lycopene; that is, effects of the amount added, solvent used, and reaction temperature and time, as well as the combination use on Z-isomerization and decomposition of lycopene, were investigated. With increases in the amount added and reaction temperature and time, Z-isomerization of lycopene was promoted for both catalysts. The high-temperature treatment tests clearly showed that AITC induced thermal decomposition of lycopene, whereas DADS improved the lycopene stability. Moreover, the simultaneous use of AITC and DADS resulted in a synergetic effect on the Z-isomerization efficiency.

Fuel cell and electrolyzer using plastic waste directly as fuel.

The effective utilization of plastic waste, including its use as an energy or chemical resource, has attracted much attention. Nevertheless, energy recovery from plastics via incineration generates air pollutants and toxic compounds, while chemical conversion requires significant energy inputs, especially in the case of gasification. Herein, we report the electrochemical conversion of plastics into electricity or hydrogen without the use of special procedures. When a mixture of plastic solid combined with an acidic solution was fed into an electrochemical cell, the solid was found to dissolve in the solution at 100 °C or higher, followed by the release of protons from the anode to the cathode according to a multi-electron oxidation reaction. This oxidation reaction required an anode that was sufficiently porous so as to allow transport of the reactants. Taking the sponge sample as an example, the dissolved polyurethane had a molecular weight of 2000 or higher, the transport of which was facilitated using a carbon support with a pore diameter of approximately 10 nm. In addition, carbon black having an ordered porous structure exhibited better reagent transport compared to a disordered porous carbon black with similar pore diameters. As a consequence, this cell continuously provided power densities on the order of mW cm-2 in the fuel cell mode and generated hydrogen at a low cell voltage of 0.55 V in the electrolyzer mode, using plastics as fuels at an operational temperature of 200 °C.

Humidity Driven Transition from Insulator to Ionic Conductor in Portland Cement.

This work aims to assess ionic conduction in anhydrous cement particles and hydrated cement pastes with aging periods of 5-25 days. When a cement sample was humidified (relative humidity = 100%) over the range of 50-100 °C, it exhibited bulk conductivities of 10-3-10-2 S cm-1, regardless of the hydration level, whereas the interfacial conductivities varied in the range of 10-7-10-3 S cm-1, depending on the structural defects or conduction pathways of the sample. Both the bulk and interfacial conductivities were increased to 0.01 S cm-1 or higher at 100 °C, although the sample required previous moistening with water mist. The major charge carrier in the sample was determined to be hydroxide ions, and the total ion transport number was approximately 1. Exposing the sample to a mixture of carbon dioxide and water vapor caused a decrease in the bulk and interfacial conductivities; however, the bulk conductivity was returned to the initial value by treatment with an acid.

Overexpressing the HD-Zip class II transcription factor EcHB1 from Eucalyptus camaldulensis increased the leaf photosynthesis and drought tolerance of Eucalyptus.

Alteration in the leaf mesophyll anatomy by genetic modification is potentially a promising tool for improving the physiological functions of trees by improving leaf photosynthesis. Homeodomain leucine zipper (HD-Zip) transcription factors are candidates for anatomical alterations of leaves through modification of cell multiplication, differentiation, and expansion. Full-length cDNA encoding a Eucalyptus camaldulensis HD-Zip class II transcription factor (EcHB1) was over-expressed in vivo in the hybrid Eucalyptus GUT5 generated from Eucalyptus grandis and Eucalyptus urophylla. Overexpression of EcHB1 induced significant modification in the mesophyll anatomy of Eucalyptus with enhancements in the number of cells and chloroplasts on a leaf-area basis. The leaf-area-based photosynthesis of Eucalyptus was improved in the EcHB1-overexpression lines, which was due to both enhanced CO2 diffusion into chloroplasts and increased photosynthetic biochemical functions through increased number of chloroplasts per unit leaf area. Additionally, overexpression of EcHB1 suppressed defoliation and thus improved the growth of Eucalyptus trees under drought stress, which was a result of reduced water loss from trees due to the reduction in leaf area with no changes in stomatal morphology. These results gave us new insights into the role of the HD-Zip II gene.