Mind the cell: Seasonal variation in telomere length mirrors changes in leucocyte profile

Leucocytes are typically considered as a whole in studies examining telomere dynamics in mammals. Such an approach may be precarious, as leucocytes represent the only nucleated blood cells in mammals, their composition varies temporally, and telomere length differs between leucocyte types. To highlight this limitation, we examined here whether seasonal variation in leucocyte composition was related to variation in telomere length in free‐ranging mandrills (Mandrilllus sphinx). We found that the leucocyte profile of mandrills varied seasonally, with lower lymphocyte proportion being observed during the long dry season presumably because of the combined effects of high nematode infection and stress at that time of the year. Interestingly, this low lymphocyte proportion during the long dry season was associated with shorter telomeres. Accordingly, based on longitudinal data, we found that seasonal changes in lymphocyte proportion were reflected by corresponding seasonal variation in telomere length. Overall, these results suggest that variation in lymphocyte proportion in blood can significantly affect telomere measurements in mammals. However, lymphocyte proportion did not entirely explain variation in telomere length. For instance, a lower lymphocyte proportion with age could not fully explain shorter telomeres in older individuals. Overall, our results show that telomere length and leucocyte profile are strongly although imperfectly intertwined, which may obscure the relationship between telomere dynamics and ageing processes in mammals.     

The relationships between oral status, physical and mental health, nutritional status and diet type in elderly Japanese women with dementia

Objectives: To suggest methods for maintaining an adequate nutritional status for elderly patients with dementia by evaluating the relationships between oral status, physical and mental health, and feeding conditions. Background: Feeding difficulties in dementia patients are related to food intake, and failure to eat may be associated with weight loss in long‐term care facilities. The relationship between compromised oral function and diet is still unclear. Materials and methods: A cross‐sectional study of 94 elderly women with dementia (mean age 89.6 ± 5.6 years) from a nursing home was undertaken to investigate their oral, physical and mental and nutritional status. Results: There were significant differences in serum albumin (p = 0.0284), N‐ADL (p = 0.0005), NM scale (p = 0.0004) and HDS‐R (p = 0.0004) between denture wearers and non‐denture wearers. However, there were no significant differences in body mass index between denture wearers and non‐denture wearers. Conclusion: A suitable type of diet and assistance with feeding could maintain the nutritional status of elderly patients with dementia if they are still feeding themselves. The nutritional support team will benefit from the participation of a dentist.     

Association between nutrition and the prosthetic condition in edentulous elderly

Objectives: The aim of this study was to assess the possible risk of malnutrition among the elderly population. Subjects: twenty‐three pairs of complete dentures were made for a group of patients and 17 upper complete dentures with implant‐supported lower dentures were made for a different group. Methods: The study was performed at the University of São Paulo – Dental Branch, Brazil. The patients were submitted to a nutritional test, as well as to a clinical examination and interview. Chewing ability and patient's satisfaction with their prostheses were evaluated. The nonparametric statistics proof of chi‐squared, level 0.05 was performed and because of the low frequencies. The Fischer test was also used. Results: Patients wearing mandibular implant‐supported dentures were considered well nourished (76.47%) when compared with complete dentures users (43.48%). There was a significant difference between the two groups, concerning to chewing ability (χ² = 5.79) and nutritional status (χ² = 4.35). Conclusion: The risk of malnutrition was higher for elderly wearing complete dentures. The psychological state influences the interest in diet and choice of food.     

Inhibition of frog antimicrobial peptides by extracellular products of the bacterial pathogen Aeromonas hydrophila

Aims:  To determine whether the extracellular products (ECPs) from Aeromonas hydrophila , a frog bacterial pathogen that is resistant to skin antimicrobial peptides of three different frog species Xenopus laevis , Litoria aurea and Litoria raniformis , can modulate the activity of these peptides.
Methods and Results:  ECPs were collected from cultures of Klebsiella pneumoniae , a pathogen susceptible to skin antimicrobial peptides of all three tested frog species, and from cultures of Aer .  hydrophila . They were tested for protease activity and for inhibition of the antimicrobial activity of natural peptide mixtures and single peptides of all three frog species against Escherichia coli ATCC 25922. ECPs from cultures of Aer .  hydrophila grown for 16, 24 and 36 h showed protease activity and inhibited the antibacterial activity of all peptides against E .  coli ATCC 25922. In contrast, the ECPs from cultures of Kl .  pneumoniae neither had protease activity nor inhibited the activity of any peptides.
Conclusion:  The proteolytic ECPs of Aer .  hydrophila have the ability to inhibit the skin antimicrobial peptides of frogs.
Significance and Impact of the Study:  The results of this study provide new information on the association of ECPs with the resistance of Aer .  hydrophila to frog antimicrobial peptides.     

Female weight and reproductive condition in a population of olive baboons (Papio anubis)

The study reported here tested Altmann's prediction [Baboon Mothers and Infants. Cambridge, Harvard University Press, 1980] that lactating female baboons endure a weight loss. Data from 64 adult female olive baboons (Papio anubis) residing in six troops in Kenya revealed that reproductive condition was related to weight. Lactating females weighed less and pregnant females weighed more than cycling females. There was a negative correlation between the weight of cycling females and the number of months postweighing to their next conception. These results indicate that lactation in wild baboons imposes energy costs that result in lost weight. It is suggested that female baboons may have to surpass a minimum weight threshold prior to resumption of postlactational cycling and that nutritional status is more influential than rank in affecting female reproductive success.     

Nutritional status assessment in complete denture wearers

doi: 10.1111/j.1741‐2358.2011.00620.x Nutritional status assessment in complete denture wearers Background and objectives: The relationship between oral health and the nutritional status in the elderly is complex and controversial. It has been suggested that poor oral health and a decreased ability to chew have a profound influence on food selection, diet and thereby the nutritional status of the individual. This study aimed to evaluate the effect of edentulousness and prosthetic treatment on the nutritional status of the individual. Methods: A total of 94 patients were selected for the study, which was conducted over a period of 16 months. The nutritional status was assessed using the Mini Nutritional Assessment Form (MNA) before the complete denture treatment and after an interval of 6 months and 9 months following the treatment. The individual scores obtained for each question and the total scores at the baseline study were compared with those obtained after 6 and 9 months. Proportions were compared using chi‐squared test of significance. Results: The results showed statistically significant differences in the total MNA scores between the baseline study and after 6 and 9 months. The edentulous patients without complete dentures had significantly lower MNA scores. Conclusion: Prosthetic rehabilitation of the edentulous patients with complete dentures, along with the dietary counselling, improved the nutritional status of these patients.     

Plasma zinc levels during pregnancy and its relationship to maternal and neonatal characteristics: a longitudinal study

Forty consecutive healthy pregnant women aged 17–38 yr who attended the antenatal clinic of the Department of Obstetrics and Gynecology, Ankara University in their first trimester participated in the study. The pregnant women were followed up longitudinally until the end of their pregnancy. Forty healthy age-matched nonpregnant women were used as a control group. Each pregnant woman was interviewed and a special questionnaire recording dietary history (3-d recall) and socioeconomic status (SES) was used. Birth weight, height, and head circumference of the newborn were measured and a complete physical examination was done for each neonate by the same observer. Blood samples were obtained at each trimester and zinc determinations were made using flame atomic absorption spectrophotometer. The results of plasma Zn measurements were available in 39 pregnant women. There were 23 women of low SES (mean plasma Zn level: 59.0 ± 6.9 μg/dL) and 16 of high SES (mean plasma Zn: 70.3 ± 5.2 μg/dL). The difference between the mean plasma Zn levels of these two groups was significant (p<0.001). The nutritional status in our study appeared to be an important factor responsible for low plasma Zn levels during pregnancy. However, we did not find any correlation between plasma Zn levels and anthropometric parameters of the newborn and pregnancy outcome. Further studies using larger sample sizes are needed to clarify the role of plasma Zn levels on maternal features and fetal outcomes in Turkey.     

Root colonization and iron nutritional status of a Pseudomonas fluorescens in different plant species

Root colonization and induction of an iron stress regulated promoter for siderophore production by Pseudomonas fluorescens 2-79RLI was studied in vitro and in the rhizosphere of different plant species. P. fluorescens 2-79RLI was previously genetically modified with an iron regulated ice nucleation reporter, which allowed calibration of ice nucleation activity with siderophore production. Initial experiments examined ice nucleation activity and siderophore production under different growth conditions in vitro. These studies demonstrated that P. fluorescens 2-79RLI could utilize both Fe-citrate and Fe-phytosiderophore as iron sources, suggesting that production of these compounds by plants would increase iron availability for P. fluorescens 2-79RLI in the rhizosphere. Fe demand and Fe stress were further shown to be a function of nutrient availability and were reduced when carbon was limiting for growth. Subsequent experiments extended these observations to rhizosphere cells. Cells were sampled from the rhizosphere and the rhizoplane. Results of a soil microcosm experiment showed that Fe stress was reduced for P. fluorescens 2-79RLI in the barley rhizosphere as compared to the cells in the rhizosphere.of lupin. In lupin, relative Fe stress of P. fluorescens 2-79RLI was greater at the root tip than in the lateral root zone. In a second experiment comparing zucchini and bean, iron stress was greater for P. fluorescens 2-79RLI associated with zucchini than with bean. In a third experiment with rape plants under P deficient conditions, addition of soluble P was shown to increase Fe stress for P. fluorescens 2-79RLI located at the root tip, but not in the lateral root zone. This study showed that Fe stress of P. fluorescens 2-79RLI in the rhizosphere may be influenced by plant species, P source, root zone and localization of the cells within the rhizosphere.     

南亚热带森林两种优势树种幼苗的元素含量对模拟氮沉降增加的响应

氮沉降是当前全球变化的一个重要方面,它对各类森林生态系统和植物的影响及其机制的研究是当前国际生态学界关注的问题之一。探讨了南亚带森林两种优势树种荷木(Schimasuperba)和黄果厚壳桂(Cryptocaryaconcinna)幼苗的养分状况对模拟氮沉降增加的响应。实验随机分为对照(Control)、T5、T10、T15和T305个样方,每个样方包括3个重复。所施氮肥为NH4NO3,每次溶解在10L自来水中,5个样方喷施的浓度分别为0、0.12、0.24、0.36和0.72mol·L-1。每月喷施2次,5个样方一年喷施的总氮量分别相当于氮沉降率0、5、10、15和30g·m-2·a-1。经过11个月的处理,土壤中速效氮水平明显提高,而pH值下降。两种幼苗叶、枝干和根的氮含量随处理水平的增加而升高,但P、K、Ca和Mg的含量与对照相比普遍下降。荷木幼苗的单株氮贮量除T5处理外,所有处理样方均高于对照,但以T10样方最高;黄果厚壳桂幼苗的单株氮贮量随处理水平增加而增加,在T15样方达最大值,之后下降。氮处理引起两种幼苗体内的氮分配到枝干的比例增加,但分配到叶中的比例下降。两种幼苗叶、枝和根3器官中N与其他营养元素的比值随氮处理水平增加而显著增加。     

Mg2+ as an indicator of nutritional status in marine bacteria

Cells maintain an osmotic pressure essential for growth and division, using organic compatible solutes and inorganic ions. Mg²⁺, which is the most abundant divalent cation in living cells, has not been considered an osmotically important solute. Here we show that under carbon limitation or dormancy native marine bacterial communities have a high cellular concentration of Mg²⁺ (370–940 m) and a low cellular concentration of Na⁺ (50–170 m). With input of organic carbon, the average cellular concentration of Mg²⁺ decreased 6–12-fold, whereas that of Na⁺ increased ca 3–4-fold. The concentration of chlorine, which was in the range of 330–1200 m and was the only inorganic counterion of quantitative significance, balanced and followed changes in the concentration of Mg²⁺+Na⁺. In an osmotically stable environment, like seawater, any major shift in bacterial osmolyte composition should be related to shifts in growth conditions, and replacing organic compatible solutes with inorganic solutes is presumably a favorable strategy when growing in carbon-limited condition. A high concentration of Mg²⁺ in cells may also serve to protect and stabilize macromolecules during periods of non-growth and dormancy. Our results suggest that Mg²⁺ has a major role as osmolyte in marine bacteria, and that the [Mg²⁺]/[Na⁺] ratio is related to its physiological condition and nutritional status. Bacterial degradation is a main sink for dissolved organic carbon in the ocean, and understanding the mechanisms limiting bacterial activity is therefore essential for understanding the oceanic C-cycle. The [Mg²⁺]/[Na⁺]-ratio in cells may provide a physiological proxy for the transitions between C-limited and mineral nutrient-limited bacterial growth in the ocean''s surface layer.