Decreased testicular expression of cAMP response element modulator (CREM) in rat with varicocele

This study examines the hypothesis that varicocele would impair the testicular expression of cAMP response element modulator (CREM) in experimental rats. Thirty (30) rats were selected at random, of 20 were operated as varicocele's group; of 10 were for sham-operation as controlled group, testes were removed, fixed and stained in three months. Makler Score was adopted to analyze the bore, limitan's thickness, layer number of cell, the degree of cell's maturity and average score in 200 and 100 seminiferous tubulae, respectively. CREM, HSP60 was determinated by hybridization in situ, the difference between two groups were compared. In varicocele group, seminiferous tubule's bore was decreased (101 +/- 2.2) vs 146 +/- 4.1), limitan became thicker (3.5 +/- 0.1 vs 1.9 +/- 0.2), cell's layer number was reduced (3.0 +/- 0.2 vs 5.5 +/- 0.1), cell's maturity turned to disturbance (3.6 +/- 0.3 vs 4.9 +/- 0.1), the average score was lower than controlled group (8.5 +/- 0.6 vs 16.0 +/- 1.2), they had significant differences (P < 0.001). The testicular CREM expression was significantly lower in varicocele group than in controlled one (VG2.0 +/- 0.32, SoG3.90 +/- 0.32) (p < 0.001), which was located in spermatogenous cell to spermatocyte stage. However, HSP60 expression in VG was higher than in SoG (3.85 +/- 0.3 versus 2.1 +/- 0.32) with significant differences (P < 0.001), the expression located in spermatid. Varicocele could lead to lower testicular CREM expression and breeding sperm functional lesion.     

Study on biocompatibility of complexes of collagen-chitosan-sodium hyaluronate and cornea

In this study we investigated the biocompatibility of collagen-chitosan-sodium hyaluronate (Col-Chi-NaHA) complexes and cornea tissue, and the feasibility of Col-Chi-NaHA complexes as substrates for cultivating rabbit corneal cells. Different components of Col-Chi-NaHA complexes were prepared and tested. A circular complex film with a diameter of 6 mm was inserted into rabbit stomal pocket and traced for a period of 5 months. Clinical examination was made. Rabbit limbal corneal epithelial cells, corneal endothelial cells, and keratocytes were cultured primarily on complexes. Phase contrast microscope examination was made daily. Histological, immunohistochemical, and scanning electron microscopic examinations were carried out. The complexes of 20% collagen, 10% chitosan, and 0.5% sodium hyaluronate showed rather weak corneal edema and other responses. The degradation of materials was obvious after 5 months. Corneas were transparent and translucent. Cells seeded on Col-Chi-NaHA were allowed to proliferate and partly form confluent monolayer after 9 days in culture. Cultured cells were well attached to the complexes of 20% collagen, 10% chitosan, and 0.5% sodium hyaluronate, or 10% chitosan and 0.5% sodium hyaluronate. The results showed that Col-Chi-NaHA complexes had good biocompatibility with cornea. The complexes can degrade and be absorbed in cornea. Col-Chi-NaHA complex may be a suitable substrate for cultivating corneal cells and a feasible material as a scaffold of tissue-engineered cornea.     

Relationships Between the Changes of Serum Levels of OPG and RANKL with Age, Menopause, Bone Biochemical Markers and Bone Mineral Density in Chinese Women Aged 20-75

The correlations between the serum levels of OPG, RANKL with age, menopause, bone markers, and bone mineral densities (BMDs) at the lumbar spine and proximal femur were studied in 504 pre- and postmenopausal Chinese women aged 20–75 years. We found that age was positively and negatively correlated with serum concentrations of OPG (r = 0.442, P < 0.001) and RANKL (r = –0.263, P < 0.001), respectively. Compared with premenopausal women, postmenopausal women showed higher serum OPG levels (107.6 ± 3.0 vs 72.0 ± 1.8 pg/ml, P < 0.001), lower serum RANKL concentrations (4.7 ± 0.4 vs. 5.8 ± 0.3 pg/ml, P < 0.001) and RANKL/OPG ratios (0.045 ± 0. 004 vs. 0.099 ± 0.008, P < 0.001). Neither serum levels of OPG nor RANKL or RANKL/OPG ratio correlated with BMDs after adjustment of age and menopause. They also showed no differences among normal, osteopenic and osteoporotic postmenopausal women. Serum levels of OPG were positively correlated with urinary excretion of NTx (r = 0.1453, P = 0.006). Serum levels of RANKL (r = –0.1928, P < 0.001) and RANKL/OPG ratio (r = –0.1303, P = 0.013) were inversely correlated with serum concentrations of OC. In multiple regression analysis, up to 20% variance (R² = 0.106–0.224) of the OPG-RANKL system in peripheral circulation can be explained by age, menopause and bone markers.These results suggest that although serum OPG and RANKL concentrations were unrelated with BMDs, the age– and menopause– dependent changes of serum OPG and RANKL might be a protective mechanism against the accelerated bone loss in postmenopausal women.     

Hydrophobicity of reactive site loop of SCCA1 affects its binding to hepatitis B virus

AIM: To investigate the role of SCCA2 and other SCCA1 molecules in the process of hepatitis B virus (HBV) binding to mammalian cells. METHODS: SCCA1 and SCCA2 were isolated from HepG2. Binding protein (BP) genes were obtained through PCR. Recombinant baculoviruses expressing SCCA1, SCCA2, BP, and different mutants were constructed and utilized to infect mammalian cells to investigate the binding ability of infected cells to HBV. RESULTS: A SCCA1 gene (A1) was isolated from HepG2, but it appeared to lack the binding ability of infected cells to HBV. Two mutants, A1-BP and BP-A1, were constructed by interchanging the carboxyl terminal of A1 and BP. Cells expressing A1-BP showed an increased virus binding capacity, but not BP-A1. Comparison of A1 sequence with the sequence of BP indicated the presence of only three amino acid changes in the carboxyl terminal, two of them were found in the reactive site loop (RSL) of SCCA1. Primary structure assay revealed that the hydrophobicity of BP and AJ515706 in this domain was strong, but A1 was relatively weak. Changing the aa349 of A1 from low hydrophobic glutamic add to high hydrophobic valine enhanced HBV binding. In contrast, HBV binding was reduced by changing the aa349 of BP from valine to glutamic acid. CONCLUSION: The results suggest that the hydrophobicity of RSL of SCCA1 may play an important role in HBV binding to cells.     

Visceral response to acute retrograde gastric electrical stimulation in healthy human

AIM: To investigate the visceral response to acute retrograde gastric electrical stimulation (RGES) in healthy humans and to derive optimal parameters for treatment of patients with obesity. METHODS: RGES with a series of effective parameters were performed via a bipolar mucosal electrode implanted along the great curvature 5 cm above pylorus of stomach in 12 healthy human subjects. Symptoms associated with dyspepsia and other discomfort were observed and graded during RGES at different settings, including long pulse and pulse train. Gastric myoelectrical activity at baseline and during different settings of stimulation was recorded by a multi-channel electrogastrography. RESULTS: The gastric slow wave was entrained in all the subjects at the pacing parameter of 9 cpm in frequency, 500 ms in pulse width, and 5 mA in amplitude. The frequently appeared symptoms during stimulation were satiety, bloating, discomfort, pain, sting, and nausea. The total symptom score for each subject significantly increased as the amplitude or pulse width was adjusted to a higher scale in both long pulse and pulse train. There was a wide diversity of visceral responses to RGES among individuals. CONCLUSION: Acute RGES can result in a series of symptoms associated with dyspepsia, which is beneficial to the treatment of obesity. Optimal parameter should be determined according to the individual sensitivity to electrical stimulation.     

BAFF overexpression and accelerated glomerular disease in mice with an incomplete genetic predisposition to systemic lupus erythematosus

OBJECTIVE: To determine whether overexpression of BAFF can accelerate the development of systemic lupus erythematosus-associated end-organ disease in hosts with an underlying autoimmune diathesis. METHODS: We introduced a BAFF transgene (Tg) into autoimmune-prone B6.Sle1 and B6.Nba2 mice and evaluated these mice for serologic autoimmunity and renal pathology. RESULTS: B6.Sle1.BAFF and B6.Nba2.BAFF mice, but not non-Tg littermates, frequently developed severe glomerular pathology by 3 months of age. Age-matched B6.BAFF mice, despite renal Ig deposits and increases in B cells and Ig production similar to those in B6.Sle1.BAFF and B6.Nba2.BAFF mice, did not develop glomerular pathology. In B6.Sle1.BAFF and B6.Nba2.BAFF mice, severity of glomerular disease did not obligately correlate with circulating levels of IgG anti-chromatin and/or anti-double-stranded DNA antibodies or with amounts of these autoantibodies deposited in the kidneys. Even in mice with severe glomerular disease, renal tubulointerstitial infiltrates were very limited, and increased proteinuria was not detected. CONCLUSION: BAFF-driven effects on glomerular pathology may be mediated, at least in part, by autoantibodies with specificities other than chromatin and/or by autoantibody-independent means. There is an uncoupling of BAFF-driven precocious glomerular pathology from concomitant development of clinically apparent renal disease, strongly suggesting that BAFF overexpression works in concert with other factors to promote overt renal disease.     

Do cyclooxygenase-2 knockout mice have primary hyperparathyroidism?

The absence of cyclooxygenase-2 (COX-2) activity in vitro reduces differentiation of both bone-forming and bone-resorbing cells. To examine the balance of COX-2 effects on bone in vivo, we studied COX-2 knockout (KO) and wild-type (WT) mice. After weaning, KO mice died 4 times faster than WT mice, consistent with reports of progressive renal failure in KO mice. Among KO mice killed at 4 months of age, some had renal failure with marked secondary hyperparathyroidism, but others appeared healthy. On the assumption that renal failure was not inevitable in COX-2 KO mice and that phenotypic differences might increase with age, we studied KO mice surviving to 10 months of age with serum creatinine levels similar to those of WT mice. In 10-month-old male KO mice, serum calcium and PTH, but not phosphorus, levels were increased compared with those in WT mice. 1,25-Dihydroxyvitamin D(3) levels were markedly elevated in KO mice. Skeletal analysis showed small nonsignificant decreases in cortical bone density by BMD and either an increase (distal femur, by microcomputed tomography) or no difference (distal femur, by static histomorphometry) in trabecular bone density in KO mice. There was a trend toward increased percent osteoblastic and osteoclastic surfaces, and on dynamic histomorphometry, the rates of trabecular bone formation and mineral apposition were increased in KO mice relative to WT mice. Similar trends were observed for most parameters in 10-month-old female COX-2 KO mice. However, rates of trabecular bone formation and mineral apposition were increased in 10-month-old WT females compared with males and did not increase further in female KO mice. These data suggest that COX-2 KO mice with intact renal function have primary hyperparathyroidism, and that effects of increased PTH and 1,25-dihydroxyvitamin D(3) to increase bone turnover may compensate for the absence of COX-2.     

Tissue-engineered vessel strengthens quickly under physiological deformation: application of a new perfusion bioreactor with machine vision

In order to develop a patent tissue-engineered blood vessel that grossly resembles native tissue, required culture times in most studies exceed 8 weeks. For the sake of shortening the maturation period of the constructs, we have used deformation as the basic index for mechanical environment control. A new bioreactor with a machine vision identifier was developed to accurately control the deformation of the construct during the perfusion process. Two groups of seeded constructs (n = 4 per group) were investigated in this study, with one group stimulated by a cyclic deformation of 10% and the other by a pulsatile pressure that gradually increased to 120 mm Hg (the control group). After 21 days of culture, the mechanical properties of the constructs were examined. The average burst strength and suture retention strength in the two groups were significantly different (t test, p < 0.05). For the experimental group, the average burst strength and suture retention strength were higher than those of the control group, by 31.6 and 23.4%, respectively. Specifically, the average burst strength of the constructs reached 1,402 mm Hg (close to that of the native vessel, i.e. 1,680 mm Hg) within a relatively short period of 21 days. In conclusion, deformation is an observable, controllable and very valuable index for mechanical environment control in vascular tissue engineering. It makes the control of mechanical stimuli more essential and experiments more comparable.