ABSTRACT
BACKGROUND: Medical comorbidities in people with mental disorders have recently gained more attention. People with bipolar disorder (BD) often have comorbid low bone mass, which is associated with increased fracture risk and related severe outcomes. However, few clinical studies on bone metabolism in BD patients are available. This study was designed to assess bone mineral density (BMD) and related influencing factors in a sample of newly diagnosed, drug-naïve individuals with BD and age- and sex-matched healthy controls. METHODS: Sixty-one drug-naïve individuals with BD (DSM-V) and 95 healthy volunteers had their lumbar spine (L1-L4) and left hip (Neck/Troch/Ward's) BMD determined by dual-energy X-ray absorptiometry. Besides, sociodemographic and clinical assessment were collected. Between-group comparisons and within subgroup analysis were performed. RESULTS: Drug-naïve patients with BD had significantly lower BMD in comparison to healthy controls in multiple sites (L1, L3, Neck, Troch, Ward's, and total hip). On subgroup analysis, overweight individuals with BD had higher bone mass, while females presented reduced BMD. Binary logistic regression showed that low BMD in multiple regions was associated with BD diagnosis, body mass index (BMI), gender, and age. CONCLUSION: Drug-naïve individuals with BD have lower BMD when compared to an age- and gender-matched healthy control sample. Low BMI and female gender are factors associated with this outcome. The underlying pathological mechanisms of BD comorbid with osteoporosis should be further explored. CLINICAL TRIAL REGISTRATION: www.chictr.org.cn, identifier ChiCTR190002137.
ABSTRACT
In most animals, fertilized eggs inherit one centrosome from a meiosis-II spindle of oocytes and another centrosome from the sperm. However, since first proposed by Boveri [Sitzungsber. Ges. Morph. Phys. Münch. 3 (1887) 151-164] at the turn of the last century, it has been believed that only the paternal (sperm) centrosome provides the division poles for mitosis in animal zygotes. This uniparental (paternal) inheritance of centrosomes is logically based on the premise that the maternal (egg) centrosome is lost before the onset of the first mitosis. For the processes of the selective loss of the maternal centrosome, three models have been proposed: One stresses the intrinsic factors within the centrosome itself; the other two emphasize external factors such as cytoplasmic conditions or the sperm centrosome. In the present study, we have examined the validity of one of the models in which the sperm centrosome overwhelms the maternal centrosomes. Because centrosomes cast off into both the first and the second polar bodies (PB) are known to retain the capacity for reproduction and cell-division pole formation, we observed the behavior of those PB centrosomes with reproductive capacity and the sperm centrosome in the same zygotic cytoplasm. We prepared two kinds of fertilized eggs that contain reproductive maternal centrosomes, (1) by micromanipulative transplantation of the PB centrosomes into fertilized eggs, and (2) by suppression of the PB extrusions of fertilized eggs with cytochalasin B. In both types of eggs, the PB centrosomes could double and form cell-division poles, indicating that they are not suppressed by the sperm centrosome, which in turn indicates that selective loss of the maternal centrosome is due to intrinsic factors within the centrosomes themselves.
