Structural Reconstruction of the Perivascular Space in the Adult Mouse Neurohypophysis During an Osmotic Stimulation

Oxytocin (OXT) and arginine vasopressin (AVP) neuropeptides in the neurohypophysis (NH) control lactation and body fluid homeostasis, respectively. Hypothalamic neurosecretory neurones project their axons from the supraoptic and paraventricular nuclei to the NH to make contact with the vascular surface and release OXT and AVP. The neurohypophysial vascular structure is unique because it has a wide perivascular space between the inner and outer basement membranes. However, the significance of this unique vascular structure remains unclear; therefore, we aimed to determine the functional significance of the perivascular space and its activity-dependent changes during salt loading in adult mice. The results obtained revealed that pericytes were the main resident cells and defined the profile of the perivascular space. Moreover, pericytes sometimes extended their cellular processes or 'perivascular protrusions' into neurohypophysial parenchyma between axonal terminals. The vascular permeability of low-molecular-weight (LMW) molecules was higher at perivascular protrusions than at the smooth vascular surface. Axonal terminals containing OXT and AVP were more likely to localise at perivascular protrusions than at the smooth vascular surface. Chronic salt loading with 2% NaCl significantly induced prominent changes in the shape of pericytes and also increased the number of perivascular protrusions and the surface area of the perivascular space together with elevations in the vascular permeability of LMW molecules. Collectively, these results indicate that the perivascular space of the NH acts as the main diffusion route for OXT and AVP and, in addition, changes in the shape of pericytes and perivascular reconstruction occur in response to an increased demand for neuropeptide release.

Dietary Variety and Decline in Lean Mass and Physical Performance in Community-Dwelling Older Japanese: A 4-year Follow-Up Study

OBJECTIVES

To examine associations of dietary variety with changes in lean mass and physical performance during a 4-year period in an elderly Japanese population.

DESIGN

Four-year prospective study.

SETTING

The Hatoyama Cohort Study and Kusatsu Longitudinal Study, Japan.

PARTICIPANTS

935 community-dwelling Japanese aged 65 years or older.

MEASUREMENTS

Dietary variety was assessed using a 10-item food frequency questionnaire. Body composition was determined by multifrequency bioelectrical impedance analysis, and physical performance (grip strength and usual gait speed) was measured in surveys at baseline and 4 years later. Longitudinal analysis included only participants who were originally in the upper three quartiles of lean body mass, appendicular lean mass, grip strength, and usual gait speed. The outcome measures were decline in lean body mass, appendicular lean mass, grip strength, and usual gait speed, defined as a decrease to the lowest baseline quartile level at the 4-year follow-up survey. Associations of dietary variety with the outcome measures were examined by logistic regression analysis adjusted for potential confounders.

RESULTS

In the fully adjusted model, the odds ratios for decline in grip strength and usual gait speed were 0.43 (95% confidence interval, 0.19-0.99) and 0.43 (confidence interval, 0.19-0.99), respectively, for participants in the highest category of dietary variety score as compared with those in the lowest category. Dietary variety was not significantly associated with changes in lean body mass or appendicular lean mass.

CONCLUSION

Among older adults, greater dietary variety may help maintain physical performance, such as grip strength and usual gait speed, but not lean mass.

Transplantation of Restored Kidneys From Unrelated Donors After Resection of Renal Cell Carcinoma: Results From 10 Patients

PURPOSE

To relieve the chronic shortage of donor kidneys, we conducted a prospective kidney transplantation trial using kidneys removed from 10 unrelated patients (51 to 79 years of age) who had undergone nephrectomy for small renal cell carcinoma (1.5 to 3.9 cm) of low-to-moderate complexity based on RENAL (radius, exophytic/endophytic properties, nearness of tumor to the collecting system or sinus in millimeters, anterior/posterior location relative to polar lines) nephrometry (objective description helpful for operative indication and planning).

METHODS

Donors were selected from among 15 patients who opted to undergo nephrectomy for small renal cell carcinoma. A total of 76 dialysis patients 34 to 85 years of age who agreed to undergo restored kidney transplantation were recruited as transplant candidates.

RESULTS

In stage 1 (5 cases), high-risk patients were selected without human leukocyte antigen testing, and accelerated acute rejection occurred in 4 of 5 recipients. This trial was subsequently extended with human leukocyte antigen testing, and an additional 5 patients were enrolled in stage 2. Eight recipients, including 4 recipients with a history of renal transplantation, experienced rejection; 1 patient resumed dialysis 35 months after transplantation. The most recent serum creatinine levels ranged from 1.10 to 3.19 mg/dL in the 9 recipients with functioning grafts and from 0.84 to 4.68 mg/dL in the 10 donors. No tumor recurrence was noted at 32 to 58 months after surgery in either the recipients or the donors.

CONCLUSIONS

Restored kidney transplantation using kidneys with a small renal tumor seems suitable for carefully selected high-risk recipients and, in particular, elderly kidneys can also function well. Avoiding cancer transmission, fair recipient selection, close follow-up, and a well-organized tracking system warrant further study.

Association of Dietary Variety with Body Composition and Physical Function in Community-dwelling Elderly Japanese

OBJECTIVES

To examine the associations of dietary variety with body composition and physical function in community-dwelling elderly Japanese.

DESIGN

Cross-sectional study.

SETTING

Community-based.

PARTICIPANTS

A total of 1184 community-dwelling elderly adults aged 65 and over.

MEASUREMENTS

Dietary variety was assessed with a food frequency questionnaire (maximum, 10 points) that encompassed the 10 main food components of Japanese meals (meat, fish/shellfish, eggs, milk, soybean products, green/yellow vegetables, potatoes, fruit, seaweed, and fats/oils). Body composition was determined by multifrequency bioelectrical impedance analysis. Physical function was assessed by measuring grip strength and usual walking speed. Multiple linear regression analysis was used to examine the associations of dietary variety with body composition and physical function.

RESULTS

After adjusting for potential confounders, higher dietary variety scores were independently associated with higher lean mass (β (SE): 0.176 (0.049), p<0.001) and appendicular lean mass (β (SE): 0.114 (0.027), p<0.001) but not with body fat mass. Elders with a higher dietary variety score had greater grip strength and faster usual walking speed (β (SE): 0.204 (0.071), p=0.004, and β (SE): 0.008 (0.003), p=0.012, respectively).

CONCLUSION

Greater dietary variety was significantly associated with greater lean mass and better physical function in Japanese elders. The causal relationship warrants investigation in a prospective study.

Developmental changes in desensitisation of c-Fos expression induced by repeated maternal separation in pre-weaned mice

Early-life stress has long-lasting effects on neuroendocrine and behaviour in adulthood. Maternal separation (MS) is used as a model of early-life stress and daily repeated MS (RMS) for 3 h during the first two postnatal weeks is widely used in rodent studies. However, it is not fully understood whether early-life animals desensitise/habituate to repeated stress. In the present study, we investigated the effects of daily RMS for 3 h and acute/single time MS (SMS) for 3 h on the plasma corticosterone level and c-Fos expression in the brain in mice at different postnatal ages. Mice were subjected to: (i) RMS from postnatal day (PND) 1 to 14 (RMS14); (ii) RMS from PND14 to 21 (RMS21); (iii) SMS on PND14 (SMS14); and (iv) SMS on PND21 (SMS21). Plasma corticosterone and c-Fos expression were examined on the final day in each experiment. The basal corticosterone levels in RMS14 and RMS21 were equal to those in respective age-matched controls. After the final separation, the levels were significantly increased and were comparable with those after SMS14 and SMS21, respectively. Histological analysis indicated that c-Fos expression significantly increased in many brain regions, including the paraventricular nucleus, prefrontal cortex, hippocampus, and basolateral and medial amygdale in both SMS14 and SMS21 mice. However, c-Fos expression in RMS14 mice significantly increased in many regions, whereas such increases were hardly seen in RMS21 mice. These results indicate that repeated early-life stress neither increases basal corticosterone, nor decreases the magnitude of the corticosterone response during the first three postnatal weeks, although desensitisation of c-Fos expression induced by repeated stress is changed during postnatal development.

Job stress and temperaments in female nurses

BACKGROUND

According to previous studies, temperament predicts a large share of the variance in job stress. It may be necessary for mental health practitioners to offer intervention strategies in accordance with individual temperament.

AIMS

To investigate the relationship between job stress and temperament among nurses in a general hospital and to provide insight into personality traits influencing their mental or physical health.

METHODS

A questionnaire survey of nurses in a general hospital. Work stress was measured using the Japanese version of the Effort-Reward Imbalance (ERI) scale. Temperament was assessed by a Japanese version of Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Autoquestionnaire (TEMPS-A). Hierarchical multiple regression analysis was used to determine the independent contribution of temperament to effort-reward ratio and over-commitment.

RESULTS

Response rate was 48% (326/685). Temperament predicted part of the variance of the four ERI ratios (effort-reward ratio 26%; effort-esteem ratio 27%; effort-promotion ratio 26%; and effort-security ratio 18%) and also of over-commitment (38%). Depressive temperament influenced all four ERI ratios and over-commitment. Anxious temperament influenced only over-commitment.

CONCLUSIONS

Nurses with depressive or anxious temperaments should be identified, monitored for signs of job stress and offered interventions to prevent adverse physical and mental effects.

Eating habits and colorectal cancer

In order to investigate the relation between the occurrence of colorectal cancer and food consumption in Hokkaido, Japan, etiological factors of colorectal cancer were investigated through an ecologic study using official food consumption and mortality statistics concerning colorectal cancer, and through a community-based case-control study. The ratio of 'animal foods' to 'plant foods' and that of 'animal protein' to 'plant protein' had a significant correlation with the mortality rate in colorectal cancer. The percentage of fat energy was much more contributory than the absolute amount of fat. Traditional Japanese foods tended to prevent while Western foods tended to promote colorectal cancer. Odds ratios for Japanese foods were low for colon cancer, and those for Western foods were high for rectum cancer. Relative amounts of foods are more contributory than their absolute amounts. An increase of colorectal cancer in Japanese people may be attributable to the increase in the relative amounts of Western foods. Reduction of the ratio of animal foods to plant foods (i.e., a reduction in relative amounts of Western foods or an increase in relative amounts of Japanese foods) may lend to the prevention of colorectal cancer.