Branched‐chain amino acids protect against dexamethasone‐induced soleus muscle atrophy in rats

We investigated the utility of branched‐chain amino acids (BCAA) in dexamethasone‐induced muscle atrophy. Dexamethasone (600 μg/kg, intraperitoneally) and/or BCAA (600 mg/kg, orally) were administered for 5 days in rats, and the effect of BCAA on dexamethasone‐induced muscle atrophy was evaluated. Dexamethasone decreased total protein concentration of rat soleus muscles. Concomitant administration of BCAA reversed the decrease. Dexamethasone decreased mean cross‐sectional area of soleus muscle fibers, which was reversed by BCAA. Dexamethasone increased atrogin‐1 expression, which has been reported to play a pivotal role in muscle atrophy. The increased expression of atrogin‐1 mRNA was significantly attenuated by BCAA. Furthermore, dexamethasone‐induced conversion from microtubule‐associated protein 1 light chain 3 (LC3)‐I to LC3‐II, which is an indicator of autophagy, was blocked by BCAA. These findings suggest that BCAA decreased protein breakdown to prevent muscle atrophy. BCAA administration appears to be useful for prevention of steroid myopathy. Muscle Nerve, 2010     

Primary undifferentiated carcinoma of the small intestine: an immunohistochemical study and review of the literature

Primary undifferentiated carcinoma of the small intestine is an extremely rare neoplasm. Here, we report a case of primary undifferentiated carcinoma that arose from the ileum in a 65-year-old woman. Laboratory data revealed anemia and slightly elevated inflammatory parameters. Computed tomography showed a heterogeneous mass in the pelvic cavity, and magnetic resonance imaging revealed that the margin of the tumor mass was clear. Positron emission tomography using ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) showed accumulation of FDG on the tumor mass with a standardized uptake value of 8.3. Partial resection of the ileum to remove the tumor was performed under a clinical diagnosis of small intestinal carcinoma. The tumor was nodulated and had a circumscribed margin 6.5 × 5.5 × 4 cm in diameter. Microscopically, the tumor was composed of giant polygonal cells with cellular atypia. Immunohistochemical examination revealed that the tumor cells expressed epithelial markers including AE1/AE3, CAM5.2, and EMA; however, lymphocytic, mesenchymal, and gastrointestinal stromal tumor markers were not expressed. We made a final diagnosis of primary undifferentiated carcinoma of the small intestine. The prognosis of patients with undifferentiated carcinoma of the small intestine is very poor. To improve the outcome of treatment, early and accurate diagnosis is essential, and additional therapy, including multimodality adjuvant therapy or the administration of novel molecular targeted drugs, should be considered.     

An SNP in protamine 1: a possible genetic cause of male infertility?

Gene targeting of the sperm nuclear proteins, the protamines, in mice leads to haploinsufficiency, abnormal chromatin compaction, sperm DNA damage, and male infertility. In order to investigate whether changes in amount or structure of the protamines could be a cause of human infertility, we sequenced the protamine genes of infertile men whose sperm appeared phenotypically similar to those of protamine deficient mice. We identified a heterozygous single nucleotide polymorphism (SNP) in the protamine (PRM1) gene in three infertile men (10% of the total infertile men analysed). This SNP disrupts one of the highly conserved arginine clusters needed for normal DNA binding. To rapidly screen for this SNP in infertile patients, we developed a simple PCR restriction fragment length polymorphism assay. This is the first report of a SNP in the PRM1 gene that appears associated with human male infertility.     

The effect of zoledronic acid and osteoprotegerin on growth of human lung cancer in the tibias of nude mice

The pathogenesis of bone metastases may require the activation of osteoclasts by tumor-secreted factors, which promote important interactions with the bone microenvironment. We utilized an intratibial model of bone metastasis with bioluminescent imaging (BLI) to measure the effect of osteoclast inhibition on the interaction of human lung cancer cells with bone, and on tumor growth. Mice were injected with luciferase-transduced tumor cells (HARA, human pulmonary squamous carcinoma) and divided into three groups: (1) untreated, (2) twice weekly treatment with the bisphosphonate zoledronic acid (ZOL), or (3) osteoprotegerin (OPG). Histomorphometry and imaging were used to evaluate tumor burden, and parameters of osteoclast activity. Mice in the treated groups had increased bone density and decreased osteoclast numbers in nontumor-bearing tibiae. There was greater than 60% reduction in mean tumor volume in both treatment groups when evaluated by histomorphometry (P = 0.06 [OPG], P = 0.07 [ZOL]). However, bioluminescent imaging failed to show a reduction in tumor burden due to wide variability in the data. Osteoclast numbers along tumor-associated bone were significantly increased compared to tumor-free bone, and were not reduced by either treatment. Plasma calcium concentration was increased in all groups. Plasma tartrate-resistant acid phosphatase 5b was reduced in both treatment groups. Plasma PTHrP was significantly increased in the untreated tumor-bearing group, but was not significantly different in the two treatment groups compared to normal mice. OPG or ZOL did not change tumor cell proliferation, but ZOL increased HARA cell apoptosis. OPG and ZOL reduced tumor growth in the tibiae of treated mice, however, PTHrP production by HARA cells may have resulted in a high concentration in the bone microenvironment, partially overriding the antiosteoclast effects of both OPG and ZOL.     

Underuse of medications for chronic diseases in the oldest of community-dwelling older frail Japanese

OBJECTIVES: To test the following hypotheses: (1) the rate of polypharmacy, defined as six or more prescribing medications, is lower in the oldest old (> or =85) than in younger older people (65-84); (2) beneficial medication use is lower in the oldest old; (3) the underuse of these medications in the oldest old is associated with physical or cognitive impairment or comorbid conditions. DESIGN: A cross-sectional study of the baseline data from the Nagoya Longitudinal Study for Frail Elderly. SETTING: Community-based. PARTICIPANTS: One thousand eight hundred seventy-five community-dwelling older people (632 men, 1,243 women). MEASUREMENTS: The data, which were collected at the patients' homes or from care-managing center records, included the clients' demographic characteristics, depression status as assessed using the short version of the Geriatric Depression Scale, a rating for basic activities of daily living (ADLs), prescribed medications, and physician-diagnosed chronic diseases. RESULTS: The oldest old had less polypharmacy even after controlling for ADLs and comorbid conditions. The underuse of beneficial medications for the oldest old was observed after adjusting for ADLs, cognitive impairment, comorbid conditions, antithrombotic agents for subjects with a history of cardiovascular diseases, acetylcholinesterase inhibitors for those with dementia, and antidepressants for those with depression. However, being aged 85 and older was not associated with the underuse of hypoglycemic and antihypertensive agents by those with diabetes mellitus and hypertension, respectively. CONCLUSION: Among community-dwelling frail older people, the rate of polypharmacy is lower in the oldest members than in the younger ones. The underuse of prescribed medications for chronic diseases/conditions of frail older people is common but not for all conditions.     

Depletion of cholinergic neurons in the nucleus of the medial septum and the vertical limb of the diagonal band in dementia with Lewy bodies

The cholinergic basal forebrain is divided into four subregions (Ch1–4), and cholinergic neuronal loss in the nucleus basalis of Meynert (Ch4) has been correlated with cognitive impairments in both Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB). However, the Ch1–2 regions, which provide the major cholinergic innervation to the hippocampus, have not been investigated in DLB. The purpose of this study was to reveal the cholinergic neuronal changes in the medial septum (Ch1) and the nucleus of the vertical limb of the diagonal band (Ch2) of DLB brains. Using choline acetyltransferase (ChAT) immunohistochemistry, we showed that the number of ChAT-immunoreactive neurons in DLB brains was significantly lower than the numbers in AD and non-demented (control) brains. No significant difference in the number of ChAT-immunoreactive neurons was found between the AD and control brains. Moreover, the size of the ChAT-immunoreactive neurons was significantly smaller in the AD and DLB brains than in the control brains. These results show that cholinergic neurons of the Ch1-2 regions are more severely affected in DLB than in AD. Our DLB cases did not fulfill the neuropathologic criteria for definite AD. Furthermore, some Lewy bodies were observed in the Ch1-2 regions. Thus, cholinergic neuronal loss in the Ch1-2 regions might be specific to the pathology of DLB. Taking the distribution of cholinergic fibers in the hippocampus into consideration, this study suggests a possibility that hippocampal cholinergic projection is involved in Lewy-related neurites in the CA2–3 regions, the origin of which remains unclear.     

Pamidronate inhibits antiapoptotic bcl-2 expression through inhibition of the mevalonate pathway in prostate cancer PC-3 cells

Bisphosphonates are expected to be efficacious to prevent the growth of metastatic cancer in bone tissue. Bone metastases often occur in patients with various cancers, such as breast, lung and prostate cancer. Bcl-2 is a potent antiapoptotic protein and its expression is known to be closely related to its function. In this study, to investigate the effect of bisphosphonates on cancer cells, we focused on bcl-2 expression in bisphosphonate-treated prostate cancer cells. First, we observed that bcl-2 mRNA expression in PC-3 was significantly inhibited to 12% of the control level by treatment with 100 μM pamidronate for 12 h. Inhibition was seen in cells treated with nitrogen-containing bisphosphonates, which have the ability to inhibit isoprenoid biosynthesis via the mevalonate pathway, but not in non-nitrogen-containing etidronate. Simultaneous treatment with geranylgeraniol, an intermediate of the mevalonate pathway, significantly blocked inhibition by pamidronate, and treatment with geranylgeranyl transferase inhibitor GGTI-286 also suppressed bcl-2 mRNA expression. Furthermore, pamidronate inhibited the translocation of Rap1 protein to the membrane fraction, suggesting that a change in posttranslational modification of Rap1 occurred in treated cells. Finally, knockdown of Rap1 by siRNA resulted in the inhibition of bcl-2 expression. These results strongly indicate that bcl-2 reduction in bisphosphonate-treated PC-3 cells is dependent on inhibition of the mevalonate pathway. The inhibitory effect of bisphosphonates on bcl-2 expression shown in prostate cancer cell line should be tested in animal experiments and clinical studies.