Tamoxifen: Friend or Foe?

This paper will discuss the effects of Tamoxifen on the breast, reproductive tract, skeletal system, and cardiovascular system.     

苏州市某社区老年肌少症人群血脂状况及其与肌少症发生的相关性

目的 探讨血脂水平与肌少症诊断指标及肌少症发生的相关性。方法 采用方便抽样,收集1 534例苏州市社区老年人的一般资料、血脂水平及身体成分,进行握力及6米步速测试,依据亚洲肌少症工作组2019年诊断标准,分为肌少症人群与非肌少症人群,比较两类人群血脂状况差异,探讨血脂与肌少症相关性。采用SPSS 23.0软件进行数据分析。根据数据类型,组间比较分别采用t检验、Mann-Whitney U检验,χ²检验以及相关和回归分析。结果 与非肌少症人群相比,肌少症人群的极低密度脂蛋白胆固醇[(0.49±0.18)和(0.53±0.29)mmol/L]、甘油三酯[TG,(1.57±0.92)和(1.76±1.22)mmol/L]、甘油三酯/高密度脂蛋白胆固醇比值[TG/HDL-C,(1.26±1.10)和(1.52±1.39)]显著较低(均P<0.05);而HDL-C[(1.45±0.37)和(1.31±0.32)mmol/L;P<0.01]、总胆固醇[TC,(5.17±1.03)和(4.97±0.96)mmol/L;P<0.05]显著更高;高TG发生率[29...     

Activity‐induced fiber regeneration in rat soleus muscle

In an attempt to understand why muscle recovery is limited following atrophy due to limb immobilization, satellite cell activity and muscle fiber regeneration were analyzed in rat soleus muscles. Adult rat hindlimbs were immobilized in plaster casts for a period of two to ten weeks. Soleus muscles were examined by electron microscopy for evidence of fiber degeneration or regeneration, and to quantify satellite cell nuclei. Immunocytochemical localization of embryonic myosin was used to identify regenerating myofibers. Soleus muscle wet weight to body weight ratios for the casted muscles significantly decreased over the 10‐week immobilization period. The casted muscles displayed ultrastructural evidence of minor fiber damage, including myofibrillar atrophy, Z‐disc disruption, and abnormal triadic junctions. No ultrastructural evidence of regeneration was seen in the casted animals. The number of satellite cells in the casted muscles significantly decreased from 6.4% to 3.3% by eight to 10 weeks of immobilization. Approximately 1.0% of extrafusal fibers in the control soleus muscles appeared to be regenerating since they expressed embryonic myosin and were of a small diameter, while in casted muscles, only 0.1% of the fibers were embryonic myosin‐positive. Following release from immobilization, a reappearance of embryonic myosin‐positive fibers was noted within four days of renewed activity. In contrast to control muscles, embryonic myosin‐positive fibers in the recovery muscles included both small and large diameter fibers. Subtle changes in functional activity influence muscle damage and subsequent myofiber regeneration. Reduced activity reduces muscle fiber regeneration, while increased activity, as seen by increased hindlimb weight bearing and return to normal activity following immobilization, increase regenerating fibers and also the expression of embryonic myosin in adult fibers. Anat Rec 258:176–185, 2000. © 2000 Wiley‐Liss, Inc.     

LAT1 and SNAT2 Protein Expression and Membrane Localization of LAT1 Are Not Acutely Altered by Dietary Amino Acids or Resistance Exercise Nor Positively Associated with Leucine or Phenylalanine Incorporation in Human Skeletal Muscle

The influx of essential amino acids into skeletal muscle is primarily mediated by the large neutral amino acid transporter 1 (LAT1), which is dependent on the glutamine gradient generated by the sodium-dependent neutral amino acid transporter 2 (SNAT2). The protein expression and membrane localization of LAT1 may be influenced by amino acid ingestion and/or resistance exercise, although its acute influence on dietary amino acid incorporation into skeletal muscle protein has not been investigated. In a group design, healthy males consumed a mixed carbohydrate (0.75 g·kg⁻¹) crystalline amino acid (0.25 g·kg⁻¹) beverage enriched to 25% and 30% with LAT1 substrates L-[1-¹³C]leucine (LEU) and L-[ring-²H₅]phenylalanine (PHE), respectively, at rest (FED: n = 7, 23 ± 5 y, 77 ± 4 kg) or after a bout of resistance exercise (EXFED: n = 7, 22 ± 2 y, 78 ± 11 kg). Postprandial muscle biopsies were collected at 0, 120, and 300 min to measure transporter protein expression (immunoblot), LAT1 membrane localization (immunofluorescence), and dietary amino acid incorporation into myofibrillar protein (ΔLEU and ΔPHE). Basal LAT1 and SNAT2 protein contents were correlated with each other (r = 0.55, p = 0.04) but their expression did not change across time in FED or EXFED (all, p > 0.05). Membrane localization of LAT1 did not change across time in FED or EXFED whether measured as outer 1.5 µm intensity or membrane-to-fiber ratio (all, p > 0.05). Basal SNAT2 protein expression was not correlated with ΔLEU or ΔPHE (all, p ≥ 0.05) whereas basal LAT1 expression was negatively correlated with ΔPHE in FED (r = −0.76, p = 0.04) and EXFED (r = −0.81, p = 0.03) but not ΔLEU (p > 0.05). Basal LAT1 membrane localization was not correlated with ΔLEU or ΔPHE (all, p > 0.05). Our results suggest that LAT1/SNAT2 protein expression and LAT1 membrane localization are not influenced by acute anabolic stimuli and do not positively influence the incorporation of dietary amino acids for de novo myofibrillar protein synthesis in healthy young males.     

Using Dietary Macronutrient Patterns to Predict Sarcopenic Obesity in Older Adults: A Representative Korean Nationwide Population-Based Study

Older adults with sarcopenic obesity (SO) are at increased risk of adverse health outcomes. It has not been identified which pattern of macronutrient intake is appropriate in relation to SO. We aimed to compare the patterns of macronutrient intake for predicting SO in older adults. Data from a total of 3828 older adults who participated in the 2008–2011 Korea National Health and Nutrition Examination Survey were analyzed. The one-day 24 h dietary recall method was used to assess macronutrient intake. SO was defined by a combination of body mass index (BMI) ≥ 25 kg/m² and BMI adjusted-appendicular skeletal muscle mass <0.789 for men and <0.512 for women. Weighted logistic regression analysis revealed the odds ratio (95% confidence interval) for SO of total calorie intake per 100 increments and carbohydrate (CHO) intake (g/kg/day) per 1 increment to be 0.95 (0.91–0.99) and 0.83 (0.74–0.94), respectively, after adjusting for confounding variables in women. The predictive power for SO of CHO intake (g/kg/day) was higher compared with the other patterns of macronutrient intake both in men and women. In conclusion, total calorie intake and CHO intake (g/kg/day) are inversely related to SO in women. CHO intake (g/kg/day) could be the best index for determining SO.     

小鼠胎肝Sca-1+细胞分化为骨骼肌细胞

探讨小鼠胚胎肝组织中干细胞抗原-1阳性的细胞(Sca-1+细胞)向骨骼肌细胞分化的潜能.取14.5d的小鼠胎肝,制作细胞悬液;用单克隆免疫磁珠细胞分离技术分离Sca-1+细胞;用PCR鉴别Y染色体性别决定区域(SRY)基因序列;将2×103个雄性小鼠Sca-1+细胞输注给经致死剂量(10Gy)60钴全身照射的雌性小鼠体内;于移植后2个月,处死受体小鼠,取骨骼肌组织固定、制片;用免疫组织化学染色和荧光原位杂交检测雌性受体小鼠骨骼肌组织内供体小鼠胎肝Sca-1+细胞向骨骼肌细胞分化情况.结果在骨骼肌组织内发现存在Y染色体阳性的供体来源的细胞,同时呈现骨骼肌组织的部分特征,表型为Dystrophin+/Flt-1-/CD45-F4/80-.提示小鼠胎肝Sca-1+细胞(其中绝大部分是造血干细胞)具有向骨骼肌组织细胞分化的潜能.     

Ameliorating Effects of Coriander on Gastrocnemius Muscles Undergoing Precachexia in a Rat Model of Rheumatoid Arthritis: A Proteomics Analysis

Coriander is a commonly used vegetable, spice, and folk medicine, possessing both nutritional and medicinal properties. Up to two-thirds of patients with rheumatoid arthritis (RA) exhibit loss of body mass, predominately skeletal muscle mass, a process called rheumatoid cachexia, and this has major effects of the quality of life of patients. Owing to a lack of effective treatments, the initial stage of cachexia has been proposed as an important period for prevention and decreasing pathogenesis. In the current study, we found that cachexia-like molecular disorders and muscle weight loss were in progress in gastrocnemius muscle after only 5 days of RA induction in rats, although rheumatoid cachexia symptoms have been reported occurring approximately 45 days after RA induction. Oral administration of coriander slightly restored muscle loss. Moreover, iTRAQ-based quantitative proteomics revealed that coriander treatment could partially restore the molecular derangements induced by RA, including impaired carbon metabolism, deteriorated mitochondrial function (tricarboxylic acid cycle and oxidative phosphorylation), and myofiber-type alterations. Therefore, coriander could be a promising functional food and/or complementary therapy for patients with RA against cachexia.     

Previously undescribed spondyloepiphyseal dysplasia associated with craniosynostosis,cataracts, cleft palate,and mental retardation: Report of four sibs

We report on four Japanese sibs (three brothers and one sister) with a previously unreported syndrome of spondyloepiphyseal dysplasia, craniosynostosis, cataracts, cleft palate, and mental retardation. Most clinical manifestations were evident neonatally, but skeletal changes and cataracts became substantial in early childhood. Radiological anomalies comprised coronal synostosis, mild epiphyseal dysplasia, particularly in the distal tibiae, strikingly delayed patellar ossification, mild metaphyseal splaying, hypoplastic ilia with iliac flare, and platyspondyly with ovoid-shaped or posteriorly humped vertebral bodies. The nonconsanguineous parents were mildly mentally retarded, and sibs of both gender were equally affected; thus, inheritance was likely autosomal recessive. Am. J. Med. Genet. 77:1–7, 1998. © 1998 Wiley-Liss, Inc.     

The dose-related response of rabbit fast muscle to long-term low-frequency stimulation

Rabbit tibialis anterior muscles were stimulated continuously at 2.5 Hz, 5 Hz, or 10 Hz for 10 months. The resulting adaptive transformation was dose-related for contractile speed, myosin isoform composition, and enzyme activities. The “fast-oxidative” state produced by stimulation at 2.5 Hz was stable: even after 10 months, 84% of the fibers were of type 2A. Absence of a secondary decline in oxidative activity in these muscles provided strong evidence of a causal link between myosin transitions and metabolic adaptation. Significant fiber loss occurred only after prolonged stimulation at 10 Hz. The myosin isoform composition of individual muscles stimulated at 5 Hz resembled that of muscles stimulated at either the lower or the higher frequency, behavior consistent with a threshold for fiber type change. In clinical applications such as cardiomyoplasty, muscles could be used more effectively by engineering their properties to combine speed and power of contraction with the necessary resistance to fatigue. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21: 1632–1646, 1998