[Research progress in the regulation of pathogenesis and the transformation of chronic liver disease by short-chain fatty acids].

Short-chain fatty acids are metabolites of the intestinal flora and serve as the main energy source for intestinal epithelial cells. At the same time, as important signaling molecules, it regulate a variety of cellular inflammatory responses and homeostatic proliferation through receptor-dependent and independent pathways. Short-chain fatty acids regulate the gut-liver axis and thereby directly act on the liver, participating in the pathogenesis and transformation of various liver diseases, including alcoholic liver disease, metabolic dysfunction-related liver disease, autoimmune liver disease, liver fibrosis, and hepatocellular carcinoma. In addition, short-chain fatty acids can inhibit HBV DNA replication. This article reviews the research progress on the role of short-chain fatty acids in aspects of the pathogenesis and transformation of chronic liver diseases.

[Relationship between screening and colorectal cancer incidence: a systematic review and meta-analysis].

Objective: To explore a relationship between screening and incidence for colorectal cancer (CRC). Methods: Medline, Scopus, BIOSIS Previews, and the Cochrane Library were searched for studies, which included any randomized controlled trial (RCT) about CRC screening with a report on using endoscopy in screening arms and a usual care in control arms. Results: Nine qualified trials, four one-time and five two-or-more-time screening programs, were included in this review with 997 131 persons randomized and a median follow-up of 10-28 years. In an intention-to-screen analysis, screening was associated with a reduced incidence of advanced CRCs by 10%-60%. Compared with control groups, incidence of CRC firstly increased and then decreased following a screening procedure. Five RCT with six screening arms reported incidences at different follow-up time points, and the incidence ratios at the last time of follow-up were 0.96 (95%CI: 0.86-1.06), 0.80 (95%CI: 0.70-0.92), 1.02 (95%CI: 0.91-1.14), 0.80 (95%CI: 0.70-0.90), 0.83 (95%CI: 0.73-0.94) and 0.94 (95%CI: 0.85-1.05) at the 9.0th, 10.9th, 13.0th, 18.0th, 18.0th, and 19.5th year after baseline, respectively. Compared with population-based screening, people in the hospital/clinic-based screenings had more benefits from CRC incidence reduction, particularly for those with high endoscopy rates, more lesions detected and resected by screening. Conclusions: This study indicates that screening is likely associated with reduction of CRC incidence after 10 years since baseline screening, and this reduction seems to be highly affected by CRC risk of population screened, screening procedure program, and compliance to screening program including accepting endoscopy.

[Study on the association between social isolation and cognitive function among elderly in Daqing city, Heilongjiang province].

Objective: To examine the association between social isolation and cognitive function among the elderly living in the communities of Daqing city. Methods: A total of 981 community residents aged 60 years or over, were surveyed with a questionnaire. Both Lubben Social Network Scale-6 (LSNS-6) and Montreal Congnitive Assessment (MoCA) Changsha Versions were used to respectively screen the status of social isolation and cognitive function, on these elderly. Results: The average age was 71 years old for the 981 study participants. 10.60% (104/981) of the participants were assessed as having the status of social isolation, 9.48% (93/981) as having marginal family ties and 13.97% (137/981) as having marginal friendship ties. Results from the multivariate linear regression analysis revealed that participants with higher scores of LSNS-6 presenting better cognitive function score, with a partial regression coefficient as 0.10 (P<0.01). The MoCA scores in participants with social isolation (20.38±5.54) were significantly lower than the ones without social isolation (22.10±5.01) and the difference was statistically significant (P<0.01). Social isolation was significantly related to the domain scores on visuo-spatial constructional executive functions (P=0.02), naming (P=0.03), language (P=0.01) and delayed memory functions (P<0.01), but not with other domains as concentration (P=0.33), orientation (P=0.27) or abstraction (P=0.49). Conclusion: The findings suggested that social isolation was mainly caused by the lack of friendship ties and associated with cognitive function and among the elderly in Daqing city, Heilongjiang province.

[The establishment of Ting Hsien Experimental Project of Rural Health Service and its influence].

Founded by the Chinese Mass Education Movement (MEM) led by Dr.James Yen and Peking Union Medical College(PUMC), the Ting Hsien Experimental Project was a demonstration program for health service in a rural county. Through a 8-year endeavor (1929-1937) and using a bottom-up approach, Dr. Chen Chih-chien and Dr.YaoHsun-yuan took the leadership of a group of dedicated PUMC graduates and students, and created a three-level(village-district-county) system to deliver both curative as well as preventive medical service for rural population. This project, under the full support of MEM and Dr. John Black Grant, Director of the Department of Public Health of PUMC, offered an important example for rural community health care in contemporary China. Moreover, it demonstrated and inspired the concepts of the primary health care advocated by World Health Organization 40 years later.

A comprehensive, multispecialty approach to an acute exacerbation of chronic central pain in a tetraplegic.

STUDY DESIGN: We present a case report describing the multidisciplinary treatment of a tetraplegic spinal cord injury (SCI) patient who developed an acute exacerbation of chronic central pain. OBJECTIVE: To bring further awareness to the importance of using a comprehensive, multidisciplinary approach in treating acute exacerbation of chronic central pain in SCI patients. SETTING: University of California Irvine Medical Center, Orange, CA, USA. CASE REPORT: We present a 34-year-old man with a past medical history of C5 American Spinal Injury Association B tetraplegia secondary to a surfing accident 8 years prior, central pain syndrome, spasticity, autonomic dysreflexia and anxiety who arrived at the emergency room with a 1-month history of worsening acute on chronic pain refractory to opioid escalation. The multispecialty treatment plan included treatment of the patient's urinary tract infection by the primary medicine service, management of the patient's depression by the psychiatric service, treatment of bowel obstruction by general surgery and adjustment of pain medications by pain management. The patient was found to have stable neurological findings, neuroimaging unchanged from prior imaging and a urinary tract infection. Hospitalization was complicated by severe colonic dilation that required disimpaction by general surgery. CONCLUSION: The treatment of this patient's acutely worsened central pain highlights the importance of applying a multidisciplinary approach to SCI patients with an acute exacerbation of chronic central pain. In this case, the multispecialty treatment plan included treatment of the patient's urinary tract infection by the primary medicine service, management of the patient's depression by the psychiatric service, treatment of bowel obstruction by general surgery, and adjustment of pain medications by pain management.

Hierarchically biomimetic bone scaffold materials: nano-HA/collagen/PLA composite.

A bone scaffold material (nano-HA/ collagen/PLA composite) was developed by biomimetic synthesis. It shows some features of natural bone both in main composition and hierarchical microstructure. Nano-hydroxyapatite and collagen assembled into mineralized fibril. The three-dimensional porous scaffold materials mimic the microstructure of cancellous bone. Cell culture and animal model tests showed that the composite material is bioactive. The osteoblasts were separated from the neonatal rat calvaria. Osteoblasts adhered, spread, and proliferated throughout the pores of the scaffold material within a week. A 15-mm segmental defect model in the radius of the rabbit was used to evaluate the bone-remodeling ability of the composite. Combined with 0.5 mg rhBMP-2, the material block was implanted into the defect. The segmental defect was integrated 12 weeks after surgery, and the implanted composite was partially substituted by new bone tissue. This scaffold composite has promise for the clinical repair of large bony defects according to the principles of bone tissue engineering.

In vitro and in vivo degradation of mineralized collagen-based composite scaffold: nanohydroxyapatite/collagen/poly(L-lactide).

The objective of this article was to investigate the in vitro and in vivo biodegradation of a novel biomimetic bone scaffold composite, nanohydroxyapatite/collagen/poly(L-lactide), that could be used for bone tissue engineering. For evaluation of in vitro degradation specimens were immersed into 1% trypsin/phosphate-buffered saline solution at 37 degrees C. In vivo evaluation involved the implantation of samples into the posterolateral lumbar spine of rabbits, and the retrieved specimens were analyzed by Fourier transform-infrared spectroscopy. The results demonstrated that weight loss increased continuously in vitro with a reduction in mass of 19.6% after 4 weeks. During the experimental period in vitro, the relative rate of reduction of the three components in this material was shown to differ greatly: collagen decreased the fastest, from 40% by weight to 20% in the composite; hydroxyapatite content increased from 45 to 60%; and PLA changed little. The pore structure was maintained throughout the whole experimental period in vitro; however, the thickness of the walls of the pores decreased and the surface of the walls increased in roughness. In vivo, the ratio of collagen to hydroxyapatite appeared to be slightly higher near the transverse process than in the central part of the intertransverse process. This finding may have been due to new bone matrix formation extending from the transverse to the intertransverse process.

Lumbar spinal fusion with a mineralized collagen matrix and rhBMP-2 in a rabbit model.

STUDY DESIGN: A new mineralized collagen matrix combined with or without growth factor was used for the posterolateral spinal fusion in the rabbit lumbar spine. OBJECTIVES: The availability of a new osteoconductive matrix with or without recombinant osteoinductive growth factors offers a possible alternative to the use of autogenous bone for grafting indications. This study evaluated the bone-forming activity of the biomimetic matrix: nano-hydroxyapatite/collagen/polylactic acid (nHAC/PLA) combined without or with recombinant human bone morphogenetic protein-2 (rhBMP-2) in a rabbit posterolateral spinal fusion. SUMMARY OF BACKGROUND DATA: Many bone grafting materials such as titanium alloy, ceramics, and polymers were used to repair bony defects. However, each has specific disadvantaged. The permanent implantation still has possibility to be eroded in vivo, which is caused by late breakdown and abscess formation. The acidic outcome of polymer biodegradation was also negatively affected in the later-stage results of bone repair. It needed a promising material for an alternative to the use of autogenous bone for grafting indications. MATERIALS AND METHODS: Sixty-four rabbits were randomly divided into four groups: autologous iliac crest bone group (ACB), nHAC/PLA composite group (nHAC/PLA), autologous iliac crest bone mixed with nHAC/PLA composite group (ACB + nHAC/PLA), nHAC/PLA composite with recombinant human BMP-2 group (nHAC/PLA + rhBMP-2). The lumbar intertransverse process fusions were assessed by manual palpation, radiographic, histologic, and mechanical strength, and scanning electronic microscopy (SEM) in a 10-week observation. RESULTS: Optimal formulations of the ACB + nHAC/PLA and nHAC/PLA + rhBMP-2 groups were shown to perform similar to ACB in both the fusion ratio and mechanical strength in the 6 and 10 weeks after surgery. From the microstructure analysis of the samples, there was no negative effect when the compound implanted this composite with autogenous iliac crest, and there was also new bone-like tissue formation implanted this composite without combined rhBMP-2 early at the second week after surgery. CONCLUSIONS: This study shows the effective results of nHAC/PLA in rabbit posterolateral spinal fusion combined with rhBMP-2. It is an alternative method to autograft by compounding this osteoconductive matrix with growth factors.

Synthesis and biocompatibility of porous nano-hydroxyapatite/collagen/alginate composite.

Porous nano-hydroxyapatite/collagen/alginate (nHAC/Alginate) composite containing nHAC and Ca-crosslinked alginate is synthesized biomimetically. This composite shows a significant improvement in mechanical properties over nHAC material. Mechanical test results show that the compressive modulus and yield strength of this composite are in direct proportion to the percentage of Ca-crosslinked alginate in the composite. Primary biocompatibility experiments in vitro including fibroblasts and osteoblasts co-culture with nHAC/alginate composite indicated the high biocompatibility of this composite. Therefore the composite can be a promising candidate of scaffold material for bone tissue engineering.

Long-term efficacy of plasma-derived hepatitis B vaccine: a 15-year follow-up study among Chinese children.

To determine necessity and timing of booster of hepatitis B vaccine, we need to observe the duration of its protection. We report the results of a 15-year follow-up of a cohort of 649 children who participated a randomized, double blind, placebo-controlled trial on a plasma-derived hepatitis B vaccine in 1982. During the 15 years after vaccination, more vaccinated children had anti-HBs of 10 S/N ratios or over, compared with the controls, at all nine observations. At 15 years 50.0% (26/52) of the participants studied in the vaccinated group and 33.3% of the tested controls (18/54) retained anti-HBs levels of S/N ratios> or =10 (P < 0.09). However, since 5 years after vaccination, median S/N ratios of anti-HBs among the vaccinated children with detectable anti-HBs were lower than those of the controls except that detected at 15 years. 16.7% (9/54) of the tested children in the control group were HBsAg positive at 15 years after vaccination, in comparison with 1.9% (1/52) of the tested children in the vaccinated (P < 0.02). 28 chronic HBsAg carriers were identified in the control cohort over the 15 years, whereas only 1 case was noted in the vaccinated group (8.2% vs. 0.3%, P < 0.00001), corresponding to an efficacy of 96%.

Effect of trilinolein on the activity and gene expression of superoxide dismutase in cultured rat brain astrocytes.

Cerebrovascular disease is one of the major causes of morbidity and mortality in recent. Oxygen free radicals produced during cerebral infarction increases the damage to neurons. Superoxide dismutase (SOD) is the endogenous antioxidant enzyme that can effectively scavenge superoxide radicals. Trilinolein is a lipophilic antioxidant purified from the herb of Panax pseudoginseng. In the cultured rat brain astrocytes (RBA), the activity of SOD (both Cu,Zn-SOD and Mn-SOD subtypes) was markedly increased by incubation with trilinolein at low concentration (0.1 microM) for 2 days. This stimulatory effect of trilinolein was not related to the incubating concentration. However, long-term (7 days) incubation with trilinolein at same concentration decreased the activity. Similar changes were also observed in the gene expression of SOD in RBA; short-term (2 days) incubation of RBA by 0.1 microM trilinolein increased the mRNA level that was lowered in RBA received a long-term incubation with 0.1 microM trilinolein. This result shows that trilinolein is an effective antioxidant to increase the activity of SOD in RBA which would be beneficial to neurons subjected to oxygen free radical damage. However, long-term medication of antioxidant shall be concerned.

Superoxide dismutase gene expression and activity in the brain of spontaneously hypertensive rats and normotensive rats.

OBJECTIVE: To determine if changes in superoxide dismutase (SOD) in the brain occur in the hypertensive state. METHODS: We compared the levels of the two main subtypes of this enzyme in spontaneously hypertensive rats (SHR) with age-matched normotensive Wistar Kyoto (WKY) rats using enzyme activity estimation, Western blotting for enzyme contents, and Northern blotting of mRNA level. Five discrete brain regions, cerebrocortex, hypothalamus, hippocampus, the remaining non-cortex cerebrum (NCC area), and cerebellum, were employed for comparison in 30-31 weeks old rats. RESULTS: A lower level of both Mn-SOD activity and Mn-SOD mRNA expression was found in all areas of the brain of SHR as compared with WKY rats. Also, the mRNA levels of Cu, Zn-SOD in the brain of SHR differed from WKY rats in parallel to the enzyme activities. The activity and mRNA expression of Cu, Zn-SOD were lower in the hypothalamus and cerebellum of SHR but the mRNA level and the activity in hippocampus were significantly higher in the SHR compared to WKY rats. No differences for Cu, Zn-SOD were observed in cerebrocortex or NCC area in the two species. However, the amount of SOD enzyme subtypes, determined by Western blotting analysis, was not different between SHR and WKY rats. CONCLUSIONS: The results indicate a lower gene expression and less activity of Mn-SOD in SHR brain. This alternation of SOD may be one of the important factors for the vulnerability of the brain from oxygen free radicals or may be related to the pathogenesis of hypertension in this species.

Modification of superoxide dismutase (SOD) mRNA and activity by a transient hypoxic stress in cultured glial cells.

In order to understand the role of superoxide dismutase (SOD) in response to transient hypoxia or hypoxia-reperfusion in astrocytes, the present study performed an in vitro investigation using rat glial cells in culture. Hypoxia was induced by an incubation with nitrogen gas for 10 min and that followed a further reperfusion with air for 10 min was indicating as hypoxia-normoxia. Activity of SOD was determined by the reduction of nitroblue tetrazolium (NTB). Changes of mRNA for Cu,Zn-SOD or Mn-SOD were also characterized using Northern blotting analysis. Transient hypoxia increased the activity of Mn-SOD but not that of Cu,Zn-SOD in glial cells. Expression of mRNA for SOD was also elevated in cells received hypoxia and the mRNA level for Mn-SOD raised higher than that for Cu,Zn-SOD. In cells received hypoxia-reperfusion, these changes of SOD both the activity and the mRNA level were not observed. Otherwise, the SOD protein amount, both Cu,Zn-SOD and Mn-SOD, identified by Western blotting was not changed in glial cells receiving hypoxic stress or not. The obtained results suggest that gene expression and activity of Mn-SOD in glial cells can be activated in response to the transient hypoxic stress.

HIV in China: epidemiology and risk factors.

Despite the low prevalence of HIV infection in most areas of China that should allow control of the epidemic, the fast developing risk environments and behaviors are reducing this opportunity. China is sitting on an 'active volcano' with respect to the HIV epidemic. A true volcano cannot yet be controlled by humans, but an HIV epidemic can. To confront the risks, a consensus of governments and the general public in concert with the efforts of health workers is most important. Above all, education targeting the general population, including policy makers, needs to be significantly promoted.

Changes of superoxide dismutase (SOD) mRNA and activity in response to hypoxic stress in cultured Wistar rat glioma cells.

In an attempt to understand the change of superoxide dismutase (SOD) in tumor cells by hypoxia and hypoxia-normoxia exposure, the present study performed an in vitro investigation using rat glioma cell line in culture. Hypoxia was induced by an incubation with nitrogen gas for 15 h followed the normoxia exposure with air for 30 min. Activity of SOD in cytosolic and particulate of cells was determined by the reduction of nitroblue tetrazolium. Changes of mRNA for Cu,Zn-SOD or Mn-SOD were also characterized using Northern blotting analysis. Hypoxic stress decreased the activity of SOD, both Cu,Zn-SOD and Mn-SOD, in glioma cells. Expression of mRNA for SOD was elevated by hypoxic stress and the increase of mRNA level for Cu,Zn-SOD was more marked than that for Mn-SOD. In response to hypoxia-normoxia exposure, an increase of activity with a lower mRNA level for Mn-SOD was observed in glioma cells. However, changes of Cu,Zn-SOD both the activity and the level of mRNA were not found in glioma cells by hypoxia-normoxia. The obtained results suggest that the SOD in glioma cells can be activated to compensate the damage from free radicals during hypoxic stress.

[Factors affecting young children's mental development and their significance in intervention].

Factors affecting their developmental quotients (DQ) in 48 normal young children, who were involved in regular development assessments at child health care outpatient visits and whose parents received child-rearing guidance at Chaoyangmen Subdistrict of Dongcheng District, Beijing, and 43 controls aged 36 months were analyzed. Factors, such as their parents' receiving child-rearing guidance, paternal education, maternal education, paternal occupation, type of nursery schools, home environment quality score (HEQS) at 24 and 36 months of age, and mothers' knowledge of child-rearing were associated with children's DQ at their age of 36 months, with statistical significance at a level of 0.05 in univariate analysis. With multiple regression analysis, HEQS at the age of 36 months, family size at the age of 24 months, paternal education, children's sex, and mothers' age had influences on DQ at age of 36 months with statistical significance, and the degree of correlation of HEQS with DQ at 36 months was much higher than that of other factors, and it suggested that HEQS was an important link in child developmental intervention.

Androgens up-regulate the human prostate-specific antigen messenger ribonucleic acid (mRNA), but down-regulate the prostatic acid phosphatase mRNA in the LNCaP cell line.

To better understand androgen-regulated gene expression in the prostate, we have used Northern blot analysis to study the effects of androgens and other steroid hormones on the steady state levels of several human prostatic mRNAs in the LNCaP cell line. Dihydrotestosterone (40 nM) as well as a synthetic androgen, R1881 (0.1 nM), increased the amounts of prostate-specific antigen (PSA) and human glandular kallikrein mRNAs; at the same time, the level of prostatic acid phosphatase (PAP) mRNA was down-regulated. Incubation of LNCaP cells with medium containing 0.1 or 1 microM R1881 for 3, 7, or 13 days resulted in up-regulation of PSA and human glandular kallikrein mRNAs and down-regulation of PAP mRNA. Thus, the two clinically important prostate-specific marker proteins are inversely regulated in this cell line. The level of human androgen receptor mRNA was also repressed by the androgen treatments. 17 beta-Estradiol and progesterone had effects similar to those of R1881 on gene expression in LNCaP cells. Our results show that the decrease in the amount of secreted PAP and the increase in the amount of secreted PSA caused by androgens and other steroid hormones in the LNCaP cells of epithelial origin are mediated by changes in the levels of the corresponding mRNAs.

Localization and regulation of estrogen, progestin and androgen receptors in the seminal vesicle of the rhesus monkey.

We have used monoclonal antibodies against the estrogen (E), progestin (P) and androgen (A) receptors (R) to study receptor localization and regulation in the seminal vesicles of rhesus monkeys under different hormonal conditions. The antibodies caused substantial shifts of the appropriately labeled receptors on sucrose gradients. ER levels were lower in intact males than in immature, castrate, and estrogen-treated castrates. With immunocytochemistry, ER were detectable only in stromal and smooth muscle cells, not the epithelium. The number of ER-positive stromal cells was significantly lower in intact males than in immature, castrate, and estrogen-treated castrates, and low in a DHT-treated castrate animal. Androgen receptors were localized in epithelial as well as stromal and smooth muscle cells, and the number of AR-positive stromal cells was highest in intact adults and lowest in castrated and immature animals. Estrogen treatment at the time of castration induced PR in the ER-positive stromal cells, prevented a decline in the number of AR-positive stromal cells, and caused stromal hypertrophy. In summary, in the seminal vesicle, as in the prostate, ER is restricted to the fibromuscular stroma, is suppressed by androgens, and can mediate induction of PR on estrogen treatment. Androgen receptors are present in epithelial as well as stromal and smooth muscle cells, but variations in hormonal state appear to affect regulation of AR more in the stroma than the epithelium.

[A study of the growth changes of the alveolar arch in Chinese infants].

Sillman, Abe, and Ichilkawa demonstrated that the alveolar arches of infants change with growth and development. They considered that the shape and dimensions of the dental arch will change as the growth of the alveolar arch in infants proceed. They also suggested that recording the growth pattern of the alveolar arch might help us predict the future development of the dental arch. Our material consisted of maxillary and mandibular casts of 164 Kaohsiung infants. It was obtained after pooling the data of studies of Child Dental Growth and Development for research conducted under the direction of Dr. Tien-Yu Shieh of the School of Dentistry, Kaohsiung Medical College. After being examined at the Pediatric Health Center, Chung Ho Memorial Hospital, K.M.C., 106 male infants and 58 female infants from two months to twelve months of age were selected. All individuals were free of abnormalities, chronic disease, or cleft lip and palate. The dimensions of the upper and lower arches were measured with a vernier in combination with other special devices. The growth and developmental curves of the lengths and widths of the alveolar arches were plotted using the means of the alveolar lengths and widths. Results demonstrated that the dimensional coefficients of variance of the anterior alveolar length were greater than those of the other dimensions. The anterior alveolar length varied the most for any given age (in months). The posterior alveolar width and mandibular whole alveolar length showed the least amount of change from two months to twelve months of age. Comparison of the right and left side of the alveolar vector dimension showed no significant difference. It was noted that the alveolar arches of male and female infants grew rapidly. The growth and developmental curves of the alveolar arches of male infants were more steep and rapid than those of female infants. As compared with previous investigations of the Japanese population, the maxillary anterior alveolar lengths and anterior alveolar widths of the present investigation were greater than those of Japanese infants.