Astragalus membranaceus flavonoids (AMF) ameliorate chronic fatigue syndrome induced by food intake restriction plus forced swimming

Aim of the study

Alteration of immune function may be associated with chronic fatigue syndrome (CFS) and this study reveals the immunoregulatory effect of Astragalus membranaceus flavonoids (AMF).

Materials and methods

CF rats were induced by food intake restriction plus forced swimming for 6 weeks.

Results

An atrophied spleen associated with a significantly decreased spleen/body weight ratio and a reduced spleen cells proliferation was found in CF rats when compared with home cage controls. AMF given orally at 20, 50 and 100 mg/kg body weight once a day consecutively for 6 weeks could recover the reduced cell proliferation. A switch to Th1-dominated immune regulation was observed in CF rats as the cultured splenocytes produced more interleukin-2 (IL-2) but less IL-4 when compared with controls. Supplementation with AMF could significantly counteract the aberrant cytokine production and rats received AMF exhibited higher endurance capacity to swim when compared with those without AMF administration. Checking the spectrum signals confirmed that the three major isoflavones contained in AMF were ononin, formononetin, and demethylhomopterocarpin.

Conclusion

Alterations of immune function may be associated with CFS and the tonic effects of AMF against CF may be attributable to balance the abnormal cytokine level by isoflavones.     

Establishment of the Psychometric Properties of a Disaster Resilience Measuring Tool for Healthcare Rescuers in China:A Cross-Sectional Study

The aim of this study was to test the validity and reliability of a tool for measuring the disaster resilience of healthcare disaster rescuers.A cross-sectional...     

Alternatively activated macrophages induced by nematode infection inhibit proliferation via cell-to-cell contact

The cytokine microenvironment is thought to play an important role in the generation of immunoregulatory cells. Nematode infections are commonly associated with Th2 cytokines and hyporesponsive T cells. Here we show that IL-4-dependent macrophages recruited in vivo by the nematode parasite Brugia malayi actively suppress the proliferation of lymphocytes on co-culture in vitro. These alternatively activated macrophages block proliferation by cell-to-cell contact, implicating a receptor-mediated mechanism. Further, the proliferative block is reversible and is not a result of apoptosis. Suppressed cells accumulate in the G1 and G2/M phase of the cell cycle. Interestingly, the G1 and G2/M block correlates with increased levels of Ki-67 protein, suggesting a mechanism that affects degradation of cell cycle proteins. We also show that, in addition to lymphocyte cell lines of murine origin, these suppressive cells can inhibit proliferation of a wide range of transformed human carcinoma lines. Our data reveal a novel mechanism of proliferative suppression induced by a parasitic nematode that acts via IL-4-dependent macrophages. These macrophages may function as important immune regulatory cells in both infectious and noninfectious disease contexts.     

Left ventricular assist device implantation augments nitric oxide dependent control of mitochondrial respiration in failing human hearts

OBJECTIVES: The objective of the study was to evaluate nitric oxide (NO) mediated regulation of mitochondrial respiration after implantation of a mechanical assist device in end-stage heart failure. BACKGROUND: Ventricular unloading using a left ventricular assist device (LVAD) can improve mitochondrial function in end-stage heart failure. Nitric oxide modulates the activity of the mitochondrial electron transport chain to regulate myocardial oxygen consumption (MVO2). METHODS: Myocardial oxygen consumption was measured polarographically using a Clark-type oxygen electrode in isolated left ventricular myocardium from 26 explanted failing human hearts obtained at the time of heart transplantation. RESULTS: The rate of decrease in oxygen concentration was expressed as a percentage of baseline. Results of the highest dose of drug are shown. Decrease in MVO2 was greater in LVAD hearts (n = 8) compared with heart failure controls (n = 18) in response to the following drugs: bradykinin (-34+/-3% vs. -24+/-5%), enalaprilat (-37+/-5% vs. -23+/-5%) and amlodipine (-43+/-13% vs. -16+/-5%; p<0.05 from controls). The decrease in MVO2 in LVAD hearts was not significantly different from controls in response to diltiazem (-22+/-5% in both groups) and exogenous NO donor, nitroglycerin (-33+/-7% vs. -30+/-3%). N(w)-nitro-L-arginine methyl ester, inhibitor of NO synthase, attenuated the response to bradykinin, enalaprilat and amlodipine. Reductions in MVO2 in response to diltiazem and nitroglycerin were not altered by inhibiting NO. CONCLUSIONS: Chronic LVAD support potentiates endogenous NO-mediated regulation of mitochondrial respiration. Use of medical or surgical interventions that augment NO bioavailability may promote myocardial recovery in end-stage heart failure.     

Normal standard of pubertal development in Singapore school children.

A cross sectional study of the pubertal status of normal school children in Singapore was performed in 1987. The results of the data analysis are presented as an update from the last survey performed in 1977. The norms of pubertal development in boys and girls are thus defined.     

Growth and pubertal assessment after treatment in acute leukemia.

To evaluate the effect of leukaemia and its treatment on growth and puberty, we studied retrospectively the serial heights and pubertal development of 37 children with acute leukaemia. The age of diagnosis ranged from 10 months to 13 years, with a duration of follow-up varying from 2 years to 14 years. The SDS (Z score) which reflects the deviation of height measurements from the population mean was used to assess height change at yearly intervals. Pubertal assessment was also made using the Tanner standards. 25 (69%) children showed a falling trend in mean Z scores over a 5 year follow-up period. The difference between the mean Z scores at 0 and 5 years was statistically significant (p < 0.035). However, there was no significant correlation between age of onset of disease and duration of survival with the deviation in the Z score. 11 children did not demonstrate a fall in the Z scores. There were, however, no defined factors such as age of onset, duration of follow-up, and sex distribution which could predict growth failure. Pubertal assessment showed normal development in all children with the pubertal age group (n = 11), except for 3 boys, two of whom had received testicular irradiation.     

Long term endocrine complications of acute leukemia therapy--a case report.

We report a patient with acute lymphoblastic leukemia who underwent treatment comprising chemotherapy, radiotherapy (cranial and testicular) and then a bone marrow transplant from an identical twin. He was cured of his leukemia and has been disease-free for nine years. With long term survival, there were problems, notably those of growth and endocrine insufficiency, which needed special considerations in management.