Fruit but not vegetable consumption is beneficial for low prevalence of colorectal polyps in a high-risk population: findings from a Chinese Lanxi Pre-colorectal Cancer Cohort study

PURPOSE

The available evidence regarding the role of fruit and vegetable consumption in the development of colorectal polyps remains inconclusive, and there is a lack of data on different histopathologic features of polyps. We aimed to evaluate the associations of fruit and vegetable consumption with the prevalence of colorectal polyps and its subtypes in a high-risk population in China.

METHODS

We included 6783 Chinese participants aged 40-80 years who were at high risk of colorectal cancer (CRC) in the Lanxi Pre-colorectal Cancer Cohort (LP3C). Dietary information was obtained through a validated food-frequency questionnaire (FFQ), and colonoscopy screening was used to detect colorectal polyps. Dose-response associations of fruit and vegetable intake with the prevalence of polyps were calculated using multivariate-adjusted regression models, which was reported as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

2064 cases of colorectal polyps were ascertained in the LP3C during 2018-2019. Upon multivariable adjustments, including the diet quality, fruit consumption was inversely associated with the prevalence of polyps (P trend = 0.02). Participants in the highest tertile of fruit intake had a 25% lower risk (OR: 0.75; 95% CI 0.62‒0.92) compared to non-consumers, while vegetable consumption had no significant association with polyp prevalence (P trend = 0.86). In terms of colorectal histopathology and multiplicity, higher fruit intake was correlated with 24, 23, and 33% lower prevalence of small polyps (OR: 0.76; 95% CI 0.62‒0.94; P trend = 0.05), single polyp (OR: 0.77; 95% CI 0.62‒0.96; P trend = 0.04), and distal colon polyps (OR: 0.67; 95% CI 0.51‒0.87; P trend = 0.003), respectively.

CONCLUSIONS

Fresh fruit is suggested as a protective factor to prevent colorectal polyps in individuals at high risk of CRC, and should be underscored in dietary recommendations, particularly for high-risk populations.

Fried food consumption, genetic risk, and incident obesity: a prospective study

Background and aims: Genetic and dietary factors contribute to adiposity risk, but little evidence supports genetic personalization of fried food intake recommendations for the management of obesity. This study aimed to assess the associations between fried food consumption and adiposity incidence and whether the associations were modified by an individual's genotype. Methods: We included 27 427 participants who had dietary data assessed by a validated 24 h dietary recall and available anthropometric information from the UK Biobank study. The genetic risk score (GRS) was calculated using 940 BMI associated variants. Results: With an average of 8.1 years of follow-up, 1472 and 2893 participants were defined as having overall obesity and abdominal obesity, respectively. Individuals in the highest categories of fried food consumption were positively associated with the risk of obesity (HR = 1.31; 95% CI 1.10-1.56) and abdominal obesity (HR = 1.27; 95% CI 1.12-1.45) compared with the lowest categories. Moreover, fried food consumption had a significant interatction with obesity GRS for abdominal obesity risk (P interaction = 0.016). Fried food intake was associated with a higher abdominal obesity risk (HR = 1.59, 95% CI: 1.25-2.00) among participants with a lower genetic risk. Conclusions: Our findings indicated that fried food consumption had a higher abdominal obesity risk among individuals with a lower genetic risk, suggesting the restriction of fried food intake for this group of people.

Water use efficiency of China's karst ecosystems: The effect of different ecohydrological and climatic factors

Water use efficiency (WUE) is an important indicator for understanding the coupled ecosystem carbon and water cycles. However, the effect and contributions of factors on WUE variations in China's karst ecosystems for different climatic conditions have not been extensively studied. Our studies on WUE variations of China's karst ecosystems from 2001 to 2021 based on evapotranspiration and net primary productivity (NPP) from Moderate-resolution imaging spectroradiometer revealed the contributions of soil moisture (SM), leaf area index (LAI), precipitation (P), temperature (T), vapor pressure deficit (VPD), and CO2 concentration (CO2). Results showed that the trend of WUE was similar to that of NPP in terms of the latitude, longitude, and elevation, and WUE started abruptly decreasing after an elevation >3000 m until it reached 0 at 4500 m. WUE was primarily "slightly increased" in the humid region (H) and "slightly decreased" in the semi-humid region (SH), arid and semi-arid regions (ASA), and Qinghai-Tibet plateau region (QTP). CO2 (0.34), LAI (0.60), P (0.58), and LAI (0.55) exhibited the strongest positive direct effects on WUE in H, SH, ASA, and QTP, while VPD exhibited the strongest negative direct effect. VPD (0.26), VPD (0.28), SM (0.47), and P (0.39) had the strongest positive indirect effect, while T (-0.24), T (-0.18), VPD (-0.35), and P (-0.03) had the strongest negative indirect effect on WUE. The positive contributions of WUE variations in H, SH, ASA, and QTP were dominated by T (47.96 %), CO2 (26.36 %), P (8.81 %), and CO2 (52.97 %), whereas the negative contributions were dominated by P (-7.95 %), LAI (-26.57 %), CO2 (-35.98 %), and VPD (-9.59 %), respectively. This study quantifies the spatial and temporal distribution patterns of WUE in China's karst ecosystems and the regional differences between the multiple ecohydrological factors, thereby facilitating in-depth understanding and effective regulation for the carbon and water cycles in karst ecosystems.

Resource allocation of rural institutional elderly care in China's new era: spatial-temporal differences and adaptation development

OBJECTIVES

In the new era of China, to ensure that rural residents can get the corresponding institutional elderly services equally, it is necessary to investigate the current situation of resource allocation of rural institutional elderly care and make corresponding adaptation suggestions.

STUDY DESIGN

This research discusses the characteristics and evolution pattern of rural aging, the resource allocation of rural elderly care institutions, and the adaptation degree of rural institutional elderly care resource and aging.

METHODS

The research methodology consists of the following stages: entropy-based Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), kernel density estimation, coupling coordination, spatial autocorrelation, and Theil index decomposition.

RESULTS

The degree of aging in rural areas of China is rising, and the whole population has entered a moderate aging society, showing the spatial characteristics of 'high in the east and low in the west'. The resource allocation of rural institutional elderly care in China is at a low level, and the absolute differences among provinces tend to reduce over time, and the overall resource allocation level tends to decline. The provinces that were in the mismatched adaptation relationship in the early stage have improved; however, the number of provinces with mismatched adaptability has continued to increase. The local spatial autocorrelation of resource adaptation verifies that the middle and lower reaches of the Yangtze River as the core form a hot spot, and during the observation period, the spatial agglomeration effect of the core is strengthened. The Theil index decomposition of resource adaptation indicates that the within-group differences between the eastern and western regions is significantly higher than that between the northeastern and central regions.

CONCLUSIONS

First, special attention should be paid to preventing the resource allocation of rural institutional elderly care in the eastern and western regions from falling again. Second, to avoid more and more low-adapted provinces falling into the 'mismatch dilemma' with the deepening of the aging degree. Third, strengthen cooperation among regions and promote the coordinated development of resource allocation of institutional elderly care in various regions. Fourth, the priority of institutional elderly care balanced development should be given to the eastern region and western region, thus weakening the overall difference.

Healthy dietary patterns and risk of cardiovascular disease in diabetic patients: a prospective cohort study

Purpose: Evidence is limited regarding the associations of different dietary patterns with cardiovascular disease (CVD) risk among the population with diabetes. Thus, we aimed to explore the associations between three dietary patterns and CVD incidence among the population with diabetes. Materials and methods: We prospectively followed 22 473 diabetic patients from the UK Biobank at the baseline. The healthy dietary pattern was derived from a food frequency questionnaire; meanwhile, the Alternate Mediterranean Diet (AMED) and the Dietary Approaches to Stop Hypertension (DASH) diet were assessed based on the Oxford WebQ online 24 h dietary questionnaire. Results: During an average of 10.8 years of follow-up, 5209 incident CVD cases, including 3552 coronary heart disease (CHD) events and 881 strokes, were documented. After multivariate adjustment, a higher healthy diet score was negatively associated with CVD, CHD, and stroke incidence. The hazard ratios and 95% confidence intervals across increasing quintiles of healthy diet score were 0.86 (0.79-0.95), 0.83 (0.75-0.93), and 0.71 (0.57-0.88) for CVD, CHD, and stroke, respectively. A similar protective association with CVD incidence was found for the AMED but not the DASH diet. Conclusions: Adherence to healthy dietary patterns is related to a lower risk of developing CVD among diabetic patients. Our findings further provide vigorous evidence for formulating dietary adherence guidelines for diabetic patients to reduce the burden of CVD complications.

Association of Fish Oil Supplementation with Risk of Coronary Heart Disease in Individuals with Diabetes and Prediabetes: A Prospective Study in the UK Biobank

This study aimed to explore the association between habitual intake of fish oil supplementation and the risk of developing CHD in patients with prediabetes and diabetes. Habitual use of fish oil was assessed by repeated questionnaires. Cox proportional hazard models were applied to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Over a median follow-up of 11.6 years, 4304 and 3294 CHD cases were documented among 47,663 individuals with prediabetes and 22,146 patients with diabetes in the UK Biobank, respectively. After multivariable adjustment, the HRs (95% CI) of CHD were 0.91 (0.85-0.98) and 0.87 (0.80-0.95) for individuals utilizing fish oil supplementation compared with non-users among the participants with prediabetes and diabetes, respectively. Furthermore, we identified an inverse relationship between fish oil use and CHD incidence, which was significantly mediated by serum C-reactive protein (CRP) levels in individuals with prediabetes and by very-low-density lipoprotein cholesterol (VLDL-C) in patients with diabetes at baseline. The inverse associations were consistent in the analyses stratified by potential confounders. In conclusion, the consumption of fish oil supplements was linked to decreased serum CRP and VLDL-C levels and subsequent CHD risk among adults with prediabetes and diabetes. Our findings highlight the important role of the habitual intake of fish oil supplements in preventing CHD in individuals with impaired glucose metabolism.

Associations of specific dietary unsaturated fatty acids with risk of overweight/obesity: population-based cohort study

Background

The role of specific unsaturated fatty acids (FAs) in the development of overweight/obesity remains unclear in the general population. Here, we aimed to explore the associations of different types of unsaturated FAs with overweight/obesity risk among the Chinese population.

Methods

Eight thousand seven hundred forty-two subjects free of overweight/obesity at entry in the China Health and Nutrition Survey (CHNS) were followed up until 2015. Dietary unsaturated FAs were assessed by 3-day 24-h recalls with a weighing method in each wave. Cox regression models were used to obtain the hazard ratios (HRs) and 95% confidence intervals (CIs) for overweight/obesity risk associated with unsaturated FAs.

Results

During a median follow-up of 7 years, 2,753 subjects (1,350 males and 1,403 females) developed overweight/obesity. Consuming more monounsaturated FAs (MUFAs) was associated with a lower risk of overweight/obesity (highest vs. lowest quartile: HR 0.80, 95% CI 0.67-0.96; P-trend = 0.010). Similar inverse associations were observed for plant-MUFAs (HR_Q4vsQ1 0.83, 95% CI: 0.73-0.94; P-trend = 0.003) and animal-MUFAs (HR_Q4vsQ1 0.77, 95% CI: 0.64-0.94; P-trend = 0.004), total dietary oleic acid (OA) (HR_Q4vsQ1 0.66, 95% CI: 0.55-0.79; P-trend <0.001), plant-OA (HR_Q4vsQ1 0.73, 95% CI: 0.64-0.83; P-trend <0.001) and animal-OA (HR_Q4vsQ1 0.68, 95% CI: 0.55-0.84; P-trend <0.001). In addition, the intakes of n-3 polyunsaturated FAs (PUFAs) (HR_Q4vsQ1 1.24, 95% CI: 1.09-1.42; P-trend = 0.017) and α-linolenic acid (ALA) (HR_Q4vsQ1 1.22, 95% CI: 1.07-1.39; P-trend = 0.039) but not marine n-3 PUFAs were positively linked to overweight/obesity risk. Consumption of n-6 PUFAs (HR_Q4vsQ1 1.13, 95% CI: 0.99-1.28; P-trend = 0.014) and linoleic acid (LA) (HR_Q4vsQ1 1.11, 95% CI: 0.98-1.26; P-trend = 0.020) had marginal and positive relationships with the incidence of overweight/obesity. N-6/n-3 PUFA ratio ranging from 5.7 to 12.6 was related to higher risk of overweight/obesity.

Conclusion

Higher dietary intake of MUFAs was associated with lower overweight/obesity risk, which was mainly driven by dietary OA from either plant or animal sources. Intakes of ALA, n-6 PUFAs and LA were related to higher risk of overweight/obesity. These results support consuming more MUFAs for maintaining a healthy body weight among the Chinese population.

High fried food consumption impacts anxiety and depression due to lipid metabolism disturbance and neuroinflammation

Western dietary patterns have been unfavorably linked with mental health. However, the long-term effects of habitual fried food consumption on anxiety and depression and underlying mechanisms remain unclear. Our population-based study with 140,728 people revealed that frequent fried food consumption, especially fried potato consumption, is strongly associated with 12% and 7% higher risk of anxiety and depression, respectively. The associations were more pronounced among male and younger consumers. Consistently, long-term exposure to acrylamide, a representative food processing contaminant in fried products, exacerbates scototaxis and thigmotaxis, and further impairs exploration ability and sociality of adult zebrafish, showing anxiety- and depressive-like behaviors. Moreover, treatment with acrylamide significantly down-regulates the gene expression of tjp2a related to the permeability of blood-brain barrier. Multiomics analysis showed that chronic exposure to acrylamide induces cerebral lipid metabolism disturbance and neuroinflammation. PPAR signaling pathway mediates acrylamide-induced lipid metabolism disorder in the brain of zebrafish. Especially, chronic exposure to acrylamide dysregulates sphingolipid and phospholipid metabolism, which plays important roles in the development of anxiety and depression symptoms. In addition, acrylamide promotes lipid peroxidation and oxidation stress, which participate in cerebral neuroinflammation. Acrylamide dramatically increases the markers of lipid peroxidation, including (±)5-HETE, 11(S)-HETE, 5-oxoETE, and up-regulates the expression of proinflammatory lipid mediators such as (±)12-HETE and 14(S)-HDHA, indicating elevated cerebral inflammatory status after chronic exposure to acrylamide. Together, these results both epidemiologically and mechanistically provide strong evidence to unravel the mechanism of acrylamide-triggered anxiety and depression, and highlight the significance of reducing fried food consumption for mental health.

Association of egg consumption with colorectal polyp prevalence: findings from the Lanxi Pre-Colorectal Cancer Cohort (LP3C) in China

Eggs contain high-quality protein, lavish vitamins and other bioactive nutrients but are rich in cholesterol. Our study is designed to assess the association of egg intake with polyp prevalence. A total of 7068 participants at a high risk of CRC from the Lanxi Pre-Colorectal Cancer Cohort Study (LP3C) were recruited. A food frequency questionnaire (FFQ) was utilized to obtain dietary data through a face-to-face interview. Cases of colorectal polyps were identified by electronic colonoscopy. The logistic regression model was exploited to achieve odds ratios (ORs) and 95% confidence intervals (CIs). Overall 2064 cases of colorectal polyps were identified in the 2018-2019 survey of LP3C. A positive association of egg consumption with colorectal polyp prevalence was found after the multivariable adjustment [OR_{Q4 vs. Q1} (95% CI): 1.23 (1.05-1.44); P_trend = 0.01]. However, a positive relationship disappeared after further adjustment for dietary cholesterol (P_trend = 0.37), which explained that the harmful role of eggs could be ascribed to the high content of dietary cholesterol. Besides, a positive trend was found between dietary cholesterol and polyp prevalence [OR (95% CI): 1.21 (0.99-1.47); P_trend = 0.04]. Furthermore, replacing 1 egg (50 g d^-1) with an equal amount of total dairy products was related to 11% lower colorectal polyp prevalence [OR (95% CI): 0.89 (0.80-0.99); P = 0.03]. In summary, higher egg consumption was correlated with a higher polyp prevalence among the Chinese population at a high risk of CRC, which was ascribed to the high content of dietary cholesterol in eggs. Besides, individuals with the highest dietary cholesterol tended to have a higher polyp prevalence. Reducing the consumption of eggs and replacing eggs with total dairy products as alternative protein sources may prevent the occurrence of polyps in China.

The sulfur microbial diet and increased risk of obesity: findings from a population-based prospective cohort study

BACKGROUND & AIMS

Gut-produced hydrogen sulfide (H₂S) has been associated with increased gut permeability and inflammation, which may be related to higher obesity risk. We investigated the association of sulfur microbial diet, a dietary index associated with 43 sulfur-metabolizing bacteria, with the incident obesity and whether the relationship was modified by the genetic predisposition to obesity.

METHODS

We included 27,429 participants with available body mass index (BMI) data from the UK Biobank. The sulfur microbial diet score was assessed using the 24-h dietary assessment method. Obesity and abdominal obesity were defined according to the World Health Organization criteria. Body fat percentage was assessed using a body composition analyzer. The genetic risk score (GRS) was calculated by 940 BMI-related variants.

RESULTS

We documented 1472 and 2893 cases of obesity and abdominal obesity during a mean follow-up of 8.1 years. After multivariable adjustment, the sulfur microbial diet score was positively associated with obesity (HR_Q4vsQ1 = 1.63; 95% CI = 1.40-1.89, P-trend = 0.001) and abdominal obesity risk (HR_Q4vsQ1 = 1.17; 95% CI = 1.05-1.30, P-trend = 0.002). We also observed that increased sulfur microbial diet score was positively related to several adiposity indicators, including a 5% increase in BMI, WC, and body fat percentage. Moreover, the sulfur microbial diet had no significant interactions with genetic risk on obesity incidence.

CONCLUSIONS

Our results emphasized the significance of avoiding the sulfur microbial diet for obesity prevention across all levels of genetic risk.

The functional difference of eight chitinase genes between male and female of the cotton mealybug, Phenacoccus solenopsis

The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is a polyphagous insect that attacks tens of plant and causes substantial economic loss. Insect chitinases are required to remove the old cuticle to allow for continued growth and development. Though insect chitinases have been well studied in tens of insects, their functions in mealybug are still not addressed. Here, we sequenced the transcriptomes of adult males and females, from which eight chitinase genes were identified. We then used the method of rapid amplification of cDNA ends to amplify their full length. Phylogenetic analysis indicated that these genes clustered into five subgroups. Among which, group II PsCht2 had the longest transcript and was highly expressed at second instar nymph. PsCht10, PsCht3-3 and PsIDGF were highly expressed in the adult females, whereas PsCht4 and PsCht4-1 were significantly expressed at the male pupa and adult male. Next, we knocked down all eight chitinase genes by feeding the double-stranded RNA. Knockdown of PsCht4 or PsCht4-1 led to the failure of moult and, silencing PsCht5 resulted in pupation defect, while silencing PsCht10 led to small body size, suggesting these genes have essential roles in development and can be used as a potential target for pest control.

Characterization and comparison of flower bud microRNAs from yellow-horn species

An increasing number of microRNAs (miRNAs) are known to play crucial regulatory roles in floral organ differentiation and development. Yellow-horn (Xanthoceras sorbifolia Bunge) is an oil-rich seed shrub that has great potential for biodiesel production. To evaluate the roles of miRNAs in the regulation of flower development, we used high-throughput sequencing to characterize them from flower buds of double-flower yellow-horn mutant and wild-type plants. Approximately 33 million raw reads were obtained through Solexa sequencing of two small RNA libraries, and the conserved and novel miRNA locations were annotated. Nineteen conserved miRNAs (belonging to nine families) and eight novel miRNAs were identified from the two libraries. Twelve conserved and eight novel miRNA-star sequences were also discovered, providing additional evidence for the existence of miRNAs in this species. Thirteen miRNAs were differentially expressed between wild-type and mutant plants. Real-time reverse transcription-polymerase chain reaction analysis revealed the expression patterns of eight microRNAs, which were confirmed by sequencing. The assessed targets of these miRNAs are involved in transcriptional regulation, disease resistance, antioxidative metabolism, nucleobase regulation, and nucleic acid metabolism. This study opens up new avenues for understanding the roles of miRNAs in X. sorbifolia.

Intra-articular delivery of anti-Hif-2α siRNA by chondrocyte-homing nanoparticles to prevent cartilage degeneration in arthritic mice

Hypoxia-inducible factor-2α (Hif-2α) is a potential therapeutic target for osteoarthritis (OA), but the application of this target in the delivery of therapeutic agents to chondrocytes remains a challenge. A chondrocyte-targeting vector was constructed in a previous study to enhance transfection efficiency and specificity of chondrocytes in vivo. This study used vectors to deliver small-interfering RNA (siRNA) and silenced Hif-2α expression to prevent cartilage degeneration in OA-affected mice. After siRNA transfection was conducted by cartilage-targeting nanoparticles, the protein levels of Hif-2α, matrix metalloproteinases (MMP-13, -9), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-4, -5), vascular endothelial growth factor (VEGF), type X collagen and nuclear factor (NF)-κB in interleukin-1-beta (IL-1β)-stimulated chondrocytes were determined. Chondrocyte-targeting ability was also determined by fluorescein isothiocyanate (FITC)-labeled siRNA tracking under a confocal microscope. OA model was established by surgically destabilizing the knee joints of a mouse. Hif-2α siRNA was then delivered intra-articularly with nanoparticles in vivo. Cartilage degeneration and synovium inflammation in the knee joints were analyzed by histomorphometry. IL-1β levels in the synovial fluid were also measured by enzyme-linked immunosorbent assay. In vitro assay results showed that catabolic factors, including Hif-2α, MMP-13 and -9, ADAMTS-4, VEGF, collagen type X and NF-κB, were downregulated after Hif-2α-siRNA transfection by chondrocyte-targeting nanoparticles. In vivo assay results with FITC-labeled siRNA tracking also confirmed that nanoparticles promoted the local concentration and prolonged the retention time of siRNA in the cartilage. Histological analysis results confirmed that nanoparticle-mediated siRNA maintained cartilage integrity and alleviated synovium inflammation. IL-1β levels decreased after siRNA was silenced by nanoparticles. Thus, chondrocyte-targeting nanoparticles could deliver Hif-2α siRNA to cartilage and specifically inhibit the expression of catabolic proteins.

Food-intake dysregulation in type 2 diabetic Goto-Kakizaki rats: hypothesized role of dysfunctional brainstem thyrotropin-releasing hormone and impaired vagal output

Thyrotropin-releasing hormone (TRH), a neuropeptide contained in neural terminals innervating brainstem vagal motor neurons, enhances vagal outflow to modify multisystemic visceral functions and food intake. Type 2 diabetes (T2D) and obesity are accompanied by impaired vagal functioning. We examined the possibility that impaired brainstem TRH action may contribute to the vagal dysregulation of food intake in Goto-Kakizaki (GK) rats, a T2D model with hyperglycemia and impaired central vagal activation by TRH. Food intake induced by intracisternal injection of TRH analog was reduced significantly by 50% in GK rats, compared to Wistar rats. Similarly, natural food intake in the dark phase or food intake after an overnight fast was reduced by 56-81% in GK rats. Fasting (48h) and refeeding (2h)-associated changes in serum ghrelin, insulin, peptide YY, pancreatic polypeptide and leptin, and the concomitant changes in orexigenic or anorexigenic peptide expression in the brainstem and hypothalamus, all apparent in Wistar rats, were absent or markedly reduced in GK rats, with hormone release stimulated by vagal activation, such as ghrelin and pancreatic polypeptide, decreased substantially. Fasting-induced Fos expression accompanying endogenous brainstem TRH action decreased by 66% and 91%, respectively, in the nucleus tractus solitarius (NTS) and the dorsal motor nucleus of the vagus (DMV) in GK rats, compared to Wistar rats. Refeeding abolished fasting-induced Fos-expression in the NTS, while that in the DMV remained in Wistar but not GK rats. These findings indicate that dysfunctional brainstem TRH-elicited vagal impairment contributes to the disturbed food intake in T2D GK rats, and may provide a pathophysiological mechanism which prevents further weight gain in T2D and obesity.

X-linked congenital hypertrichosis syndrome is associated with interchromosomal insertions mediated by a human-specific palindrome near SOX3

X-linked congenital generalized hypertrichosis (CGH), an extremely rare condition characterized by universal overgrowth of terminal hair, was first mapped to chromosome Xq24-q27.1 in a Mexican family. However, the underlying genetic defect remains unknown. We ascertained a large Chinese family with an X-linked congenital hypertrichosis syndrome combining CGH, scoliosis, and spina bifida and mapped the disease locus to a 5.6 Mb critical region within the interval defined by the previously reported Mexican family. Through the combination of a high-resolution copy-number variation (CNV) scan and targeted genomic sequencing, we identified an interchromosomal insertion at Xq27.1 of a 125,577 bp intragenic fragment of COL23A1 on 5q35.3, with one X breakpoint within and the other very close to a human-specific short palindromic sequence located 82 kb downstream of SOX3. In the Mexican family, we found an interchromosomal insertion at the same Xq27.1 site of a 300,036 bp genomic fragment on 4q31.2, encompassing PRMT10 and TMEM184C and involving parts of ARHGAP10 and EDNRA. Notably, both of the two X breakpoints were within the short palindrome. The two palindrome-mediated insertions fully segregate with the CGH phenotype in each of the families, and the CNV gains of the respective autosomal genomic segments are not present in the public database and were not found in 1274 control individuals. Analysis of control individuals revealed deletions ranging from 173 bp to 9104 bp at the site of the insertions with no phenotypic consequence. Taken together, our results strongly support the pathogenicity of the identified insertions and establish X-linked congenital hypertrichosis syndrome as a genomic disorder.

Mutations in HOXD13 underlie syndactyly type V and a novel brachydactyly-syndactyly syndrome

HOXD13, the homeobox-containing gene located at the most 5' end of the HOXD cluster, plays a critical role in limb development. It has been shown that mutations in human HOXD13 can give rise to limb malformations, with variable expressivity and a wide spectrum of clinical manifestations. Polyalanine expansions in HOXD13 cause synpolydactyly, whereas amino acid substitutions in the homeodomain are associated with brachydactyly types D and E. We describe two large Han Chinese families with different limb malformations, one with syndactyly type V and the other with limb features overlapping brachydactyly types A4, D, and E and mild syndactyly of toes 2 and 3. Two-point linkage analysis showed LOD scores >3 (theta =0) for markers within and/or flanking the HOXD13 locus in both families. In the family with syndactyly type V, we identified a missense mutation in the HOXD13 homeodomain, c.950A-->G (p.Q317R), which leads to substitution of the highly conserved glutamine that is important for DNA-binding specificity and affinity. In the family with complex brachydactyly and syndactyly, we detected a deletion of 21 bp in the imperfect GCN (where N denotes A, C, G, or T) triplet-containing exon 1 of HOXD13, which results in a polyalanine contraction of seven residues. Moreover, we found that the mutant HOXD13 with the p.Q317R substitution was unable to transactivate the human EPHA7 promoter. Molecular modeling data supported these experimental results. The calculated interactions energies were in agreement with the measured changes of the activity. Our data established the link between HOXD13 and two additional limb phenotypes--syndactyly type V and brachydactyly type A4--and demonstrated that a polyalanine contraction in HOXD13, most likely, led to other digital anomalies but not to synpolydactyly. We suggest the term "HOXD13 limb morphopathies" for the spectrum of limb disorders caused by HOXD13 mutations.

Two novel mutations and evidence for haploinsufficiency of the ADAR gene in dyschromatosis symmetrica hereditaria

BACKGROUND

Dyschromatosis symmetrica hereditaria (DSH, MIM 127400) is a dominantly inherited skin disease associated with mutations in ADAR, the gene that encodes a double-stranded RNA-specific adenosine deaminase. We previously reported two novel ADAR mutations (p.Q513X and p.R916W) and confirmed the role of ADAR in Chinese patients with DSH. Both haploinsufficiency and a dominant-negative effect have been suggested as the potential mechanism by which ADAR mutations cause DSH.

OBJECTIVES

To identify ADAR mutations in two additional Chinese DSH families and to obtain insight into the pathogenic mechanism of heterozygous ADAR mutations.

METHODS

For mutation detection, all ADAR exons and their flanking intronic sequences were amplified and sequenced. Mutations were further confirmed by restriction analysis. Direct sequencing of cDNA fragments produced by reverse transcription-polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR were used to examine the expression of ADAR in peripheral lymphocytes isolated from affected individuals.

RESULTS

A small deletion, c.1555delT (p.C519fs), and a missense mutation, c.3116A>G (p.K1039R), were found in families A and B, respectively. In individuals carrying p.Q513X or p.C519fs, sequencing of cDNA fragments indicated almost total loss of mRNA expression from the mutant alleles, and real-time quantitative RT-PCR showed an approximately 50% reduction of ADAR expression. However, equal abundance of the wild-type and mutant cDNA sequences without reduction of ADAR expression was found in a patient with the missense p.R916W mutation. These results suggest that both the nonsense p.Q513X and frameshift p.C519fs mutations have generated null alleles probably by nonsense-mediated mRNA decay.

CONCLUSIONS

Two novel ADAR mutations were found in Chinese patients with DSH. Evidence for ADAR haploinsufficiency as a mechanism underlying the molecular pathogenesis of DSH was obtained.

A novel deletion in TNNI2 causes distal arthrogryposis in a large Chinese family with marked variability of expression

Distal arthrogryposis (DA) is composed of a group of clinically and genetically heterogeneous disorders, characterized by multiple congenital contractures of the limbs. Point mutations in three genes encoding contractile fast-twitch myofibers, TPM2, TNNI2 and TNNT3, were recently identified in DA type 1 (DA1; MIM 108120) and DA type 2B (DA2B; MIM 601680). We have described a large Chinese DA family in which different individuals had phenotypes similar to DA1 or DA2B. To map the disease locus in this family, two-point linkage analysis was first performed using microsatellite markers selected from the genomic regions close to the TPM2, TNNI2/TNNT3 and TNNC2 genes. A positive LOD score of 3.61 at theta = 0 was obtained with the marker close to the TNNI2/TNNT3 genes, corresponding to the genetic mapping site of DA2B. Direct sequencing of the PCR-amplified DNA fragment spanning exon 8 of the TNNI2 gene showed a heterozygous deletion, c.523_525delAAG (p.K175del), in the proband. This novel mutation was confirmed to cosegregate with the DA phenotype in affected individuals but not detected in all unaffected individuals of the family and not in 50 healthy controls. In summary, we have found a novel TNNI2 mutation in a Chinese family with DA2B. Our work represents the first report on the link between TNNI2 and the DA phenotype in Chinese.

[A DNA duplication at chromosome 10q24.3 is associated with split-hand split-foot malformation in a Chinese family]

OBJECTIVE

To identify the disease-causing genetic alteration of split-hand/split-foot malformation (SHFM) in a Chinese family.

METHODS

Three of the 5 affected individuals from a four-generation Chinese SHFM family were examined physically and radiologically. Peripheral blood samples were collected from Digital photographs of the malformed hands and feet were taken. Peripheral blood samples were collected from 2 affected individuals, and lymphocytes were isolated to undergo high resolution G-banding. Genomic DNA was extracted from the whole blood samples of 4 available family members, including the 3 affected individuals. All 16 exons and their flanking intronic sequences of the TP63 gene were amplified using polymerase chain reaction (PCR) and sequenced directly. Microsatellite markers from the five SHFM loci were analyzed in the available family members by PCR, polyacrylamide gel electrophoresis and silver staining. For semi-quantitative determination of the allele copy number, the polymorphic PCR-amplified fragments representing genetic markers from the SHFM3 locus at chromosome 10q24.3 were sequenced in the affected individuals using normal individuals with identical genotypes as controls.

RESULTS

All 3 existing affected individuals showed absence of 3 radial fingers, 2 affected individuals had a deep central cleft and central ray deficiency in the feet, and 1 affected individual had a fibular monodactyli, all limb malformations being bilateral and consistent with the phenotype of typical SHFM. G-banding showed normal karyotypes in the 3 affected individuals and no visible cytogenetic abnormality was found. Moreover, no mutation was identified in the TP63 gene. While no haplotype sharing was observed in the markers from loci SHFM1, SHFM4 and SHFM5, potential haplotype sharing was detected in the markers from two loci, SHFM2 and SHFM3, indicating possible causative mutation at SHFM2 or SHFM3. Furthermore, obviously biased silver density toward the allele fragments shared by the 3 affected individuals was observed in the markers from the SHFM3 locus. Comparative sequencing showed roughly one-fold increase of fluorescent signal of the shared fragments in the affected individuals. These results suggested a large-scale DNA duplication within the SHFM3 locus.

CONCLUSION

A large-scale DNA duplication within the SHFM3 locus at chromosome 10q24.3 has been identified as the pathogenic genetic change in Chinese patients with SHFM.

[HOXD13 polyalanine tract expansion in synpolydactyly: mutation detection and prenatal diagnosis in a large Chinese family]

OBJECTIVE

Synpolydactyly (SPD, MIM 186000), also known as syndactyly type II, is a dominantly inherited limb malformation with incomplete penetrance and variable expressivity. Polyalanine tract expansion in HOXD13 has been shown to be the disease-causing mutation in SPD. The present study was designed to identify mutation in HOXD13 and to provide prenatal diagnosis, in a large Chinese SPD family consisting of 54 individuals.

METHODS

The proband and 4 other affected individuals in the family were evaluated physically and radiologically to ascertain the SPD phenotype. Genomic DNA was extracted from peripheral blood samples obtained from 18 family members (9 affected and 9 unaffected), and from amniotic fluid and chorionic villus samples obtained from the proband during her two consecutive pregnancies. With the use of a pair of specific primers, a fragment of 161bp was amplified by polymerase chain reaction (PCR) to cover the imperfect GCN triplet repeat sequence in exon 1 of HOXD13 encoding the 15-residue polyalanine tract. The PCR products were detected by agarose gel electrophoresis, and sequenced after cloning into pMD18T vector. To confirm prenatal diagnosis, haplotype analysis was also performed by allele-typing three microsatellite markers, including the intronic CA repeats in HOXD13.

RESULTS

Digital and radiographic findings indicated a typical SPD phenotype in the family. These included 3/4 finger syndactyly and 4/5 toe syndactyly with an extra digit in the syndactylous web. Unilateral finger syndactyly in the proband, unilateral toe syndactyly in 2 individuals, bilateral brachydactyly of the fifth toes in 1 individual, and clinodactyly of the fifth fingers in 4 individuals were also observed, indicating variable expressivity. Gel electrophoresis of the PCR products showed an additional longer fragment in all 9 affected individuals but not in the unaffected ones. Sequence analysis of the longer fragment revealed a 9-alanine expansion. The expansion was detectable in DNA from the amniotic fluid and chorionic villus samples. Furthermore, haplotype analysis ruled out potential contamination of the maternal DNA. These suggested that the two fetuses carried the same polyalanine expansion.

CONCLUSION

HOXD13 polyalanine expansion was detected in a large Chinese family with SPD and prenatal diagnosis of two affected fetuses was achieved. This is the first report on prenatal diagnosis of SPD by detecting the HOXD13 polyalanine expansion in the Han population of the Chinese mainland.

Peripheral secretin-induced Fos expression in the rat brain is largely vagal dependent

I.v. injection of secretin activates neurons in brain areas controlling autonomic function and emotion. Peripheral administration of secretin inhibits gastric functions through a central mechanism that is mediated by vagal dependent pathways. We investigated whether the vagus nerve is involved in i.p. injection of secretin-induced brain neuronal activation in conscious rats as monitored by Fos immunohistochemistry. Secretin (40 or 100 microg/kg, i.p., 90 min) induced a dose-related increase in the number of Fos positive neurons in the central nucleus of the amygdala (CeA), and a plateau Fos response in the area postrema (AP), nucleus tractus solitarii (NTS), locus coeruleus (LC), Barrington's nucleus (Bar), external lateral subnucleus of parabrachial nucleus (PBel) and arcuate nucleus, and at 100 microg/kg, in the dorsal motor nucleus of the vagus (DMV) compared with i.p. injection of vehicle. Double immunohistochemistry showed that secretin (40 microg/kg, i.p.) activates tyrosine hydroxylase neurons in the NTS. Subdiaphragmatic vagotomy (7 days) abolished Fos expression-induced by i.p. secretin (40 microg/kg) in the NTS, DMV, LC, Bar, PBel and CeA, while a significant rise in the AP was maintained. In contrast, s.c. capsaicin (10 days) did not influence the Fos induction in the above nuclei. Reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR showed that secretin receptor mRNA is expressed in the nodose ganglia and levels were higher in the right compared with the left ganglion. These results indicate that peripheral secretin activates catecholaminergic NTS neurons as well as neurons in medullary, pontine and limbic nuclei regulating autonomic functions and emotion through vagal-dependent capsaicin-resistant pathways. Secretin injected i.p. may signal to the brain by interacting with secretin receptors on vagal afferent as well as on AP neurons outside the blood-brain barrier.

[A Chinese girl with cleidocranial dysplasia (CCD) caused by the recurrent R190W mutation in RUNX 2]

OBJECTIVE

Cleidocranial dysplasia (CCD) is a rare skeletal disease with autosomal dominant inheritance associated with mutation in RUNX 2. The authors report a Chinese girl with CCD in whom the mutation in RUNX 2 was identified.

METHODS

Clinical diagnosis was based on physical examination, radiological findings, and biochemical tests. For mutation detection, genomic DNA was extracted from peripheral blood using standard method. All 7 coding exons of RUNX 2 and their flanking intronic sequences were amplified by polymerase chain reaction (PCR), and the PCR products were then subjected to automatic DNA sequencing.

RESULTS

The affected girl showed typical clinical manifestations of CCD, including patent fontanelles, absent clavicles, short stature and dental anomalies. Direct sequencing of PCR-amplified fragments revealed a recurrent missense mutation, R190W (568 C > T), in RUNX 2. The mutation was further confirmed by Hae III restriction analysis.

CONCLUSION

A Chinese case of CCD was confirmed and the disease-causing mutation was linked to a recurrent point mutation in RUNX 2.

Novel Mutations of the RNA-Specific Adenosine Deaminase Gene (DSRAD) in Chinese Families with Dyschromatosis Symmetrica Hereditaria

Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant skin disorder. It is also called "reticulate acropigmentation of Dohi" or "symmetric dyschromatosis of the extremities". The DSH locus has recently been mapped to chromosome 1q21 and pathogenic mutations were identified in the DSRAD gene encoding double-stranded RNA-specific adenosine deaminase in Japanese patients with DSH. We report here two novel point mutations, Q513X(1537C>T) and R916W(2746C>T) in the DSRAD gene identified in two Chinese families, respectively. These data suggest that mutations in DSRAD were also associated with DSH in Chinese. This is the first report on DSRAD as the causative gene of DSH in the Chinese population.

Somatic mutation analysis of p53 and ST7 tumor suppressor genes in gastric carcinoma by DHPLC

AIM: To verify the effectiveness of denaturing high-performance liquid chromatography (DHPLC) in detecting somatic mutation of p53 gene in gastric carcinoma tissues. The superiority of this method has been proved in the detection of germline mutations, but it was not very affirmative with respect to somatic mutations in tumor specimens. ST7 gene, a candidate tumor suppressor gene identified recently at human chromosome 7q31.1, was also detected because LOH at this site has also been widely reported in stomach cancer.

METHODS: DNA was extracted from 39 cases of surgical gastric carcinoma specimen and their correspondent normal mucosa. Seven fragments spanning the 11 exons were used to detect the mutation of p53 gene and the four exons reported to have mutations in ST7 gene were amplified by PCR and directly analyzed by DHPLC without mixing with wild-type allele.

RESULTS: In the analysis of p53 gene mutation, 9 aberrant DHPLC chromatographies were found in tumor tissues, while their normal-adjacent counterparts running in parallel showed a normal shape. Subsequent sequencing revealed nine sequence variations, 1 polymorphism and 8 mutations including 3 mutations not reported before. The mutation rate of p53 gene (21%) was consistent with that previously reported. Furthermore, no additional aberrant chromatography was found when wild-type DNA was added into the DNA of other 30 tumor samples that showed normal shapes previously. The positivity of p53 mutations was significantly higher in intestinal-type carcinomas (40%) than that in diffuse-type (8.33%) carcinomas of the stomach. No mutation of ST7 gene was found.

CONCLUSION: DHPLC is a very convenient method for the detection of somatic mutations in gastric carcinoma. The amount of wild type alleles supplied by the non-tumorous cells in gastric tumor specimens is enough to form heteroduplex with mutant alleles for DHPLC detection. ST7 gene may not be the target gene of inactivation at 7q31 site in gastric carcinoma.

[Genomic variations in the locus for aminopeptidase N:a putative cellular receptor for SARS-CoV spike glycoprotein]

Aminopeptidase N has been identified as the cellular receptor for human coronavirus HCoV-229E and was a putative receptor for the spike glycoprotein encoded by the SARS-associated coronavirus (SARS-CoV). We report here identification of 9 single nucleotide polymorphisms (SNPs) in ANPEP, encoding human aminopeptidase N, in Chinese. All ANPEP exons and their flanking intronic sequences were amplified from unrelated normal individuals by polymerase chain reaction (PCR) and screened using denaturing high-performance liquid chromatography (DHPLC). Nine SNPs were revealed after direct sequencing of PCR amplified fragments which showed changes of DHPLC chromatogram. Four of these polymorphisms, T321M(962C > T), S651L(1952C > T), S752N(2255G > A) and G764R(2290G > A), were non-synonymous; the remaining exonic synonymous and intronic ones were T795T(2385C > T), IVS7 + 17G > A, IVS14-16A > G, IVS17 + 12C > G and IVS17 + 44C > T. Our data may be useful for studies to investigate the role of host genetic factors in SARS pathogenesis, especially for identifying SARS-susceptible and/or anti-SARS alleles.

Loss of heterozygosity on chromosome 18 in microdissected gastric cancer cells

AIM: To detect loss of heterozygosity (LOH) on chromosome 18 in primary gastric carcinomas.

METHODS: Short insertion deletion polymorphism (SIDP) markers on chromosome 18 were analyzed using high fidelity-whole genome amplification (HF-WGA) and denatured high pressure liquid chromotography (DHPLC) to detect LOH in gastric cancer cells purified by laser capture microdissection (LCM).

RESULTS: LOH in 3 (MID148, MID150 and MID352) of 9 SIDP loci was found. Three of 10 samples of gastric cancer showed LOH at the same SIDP locus (MID150) (30%) and one of them also demonstrated LOH at the other 2 SIDP loci (MID148, MID352). No LOH was detected in 6 of 9 SIDP loci.

CONCLUSION: Detection of LOH in cancer cells can be achieved by the combination of LCM, HF-WGA and the analysis of SIDP marker by DHPLC. This study provides an alternative new way to map tumor suppressor genes on chromosome 18.

p53-interacting protein 53BP2 inhibits clonogenic survival and sensitizes cells to doxorubicin but not paclitaxel-induced apoptosis

53BP2 was initially identified as a protein interacting with p53 in a yeast two-hybrid screen and subsequently shown to enhance p53 transcriptional transactivation and induce apoptosis when transiently overexpressed in cell lines. In order to further study the biologically relevant effects of 53BP2, we have constructed HEK293 stable cell lines where 53BP2 expression can be regulated using an ecdysone inducible expression system. Our results indicate that the response of cells is dependent on the amount of 53BP2 that is expressed. High levels of 53BP2 expression (>or=140-fold above endogenous) impede cell cycle progression and induce apoptosis. Lower levels of 53BP2 expression (6-11-fold above endogenous) suppress colony formation but do not lead to detectable perturbations in the cell cycle or apoptosis. Lower levels of 53BP2 expression sensitized cells to apoptosis induced by DNA damaging chemotherapy agents doxorubicin, ara-C and VP16, but not microtubule active agents paclitaxel and vinblastine. Our results demonstrate that high levels of 53BP2 expression have profound biological effects ultimately leading to apoptosis, whereas lower levels of 53BP2 expression have more subtle effects on growth and sensitize cells to some chemotherapy agents.

[Quantitative analysis for inheritance of quality characters in indica hybrid rice]

Nine quality characters of 3 sterile lines, 10 restorers and their 30 indica hybrid rice by NC II genetic design were studied. The results showed as follows: (1) No genetic segregation occurred in F2 grains in grain length, grain width, grain weight, brown rice% and head rice%, which indicated these traits are completely controlled by maternal plant genotypes. (2) Significant genetic segregation occurred in F2 grains in chalkiness score, amylose content, gelatinization temperature and gel consistency, which indicated the genetic expression of these traits is mainly controlled by endosperm genotypes. (3) The quality characters have relatively high heritabilities except brown rice % and chalkiness score. The genetic variation of quality characters was mainly caused by additive effect except grain weight.

Proapoptotic p53-interacting protein 53BP2 is induced by UV irradiation but suppressed by p53

p53 is an important mediator of the cellular stress response with roles in cell cycle control, DNA repair, and apoptosis. 53BP2, a p53-interacting protein, enhances p53 transactivation, impedes cell cycle progression, and promotes apoptosis through unknown mechanisms. We now demonstrate that endogenous 53BP2 levels increase following UV irradiation induced DNA damage in a p53-independent manner. In contrast, we found that the presence of a wild-type (but not mutant) p53 gene suppressed 53BP2 steady-state levels in cell lines with defined p53 genotypes. Likewise, expression of a tetracycline-regulated wild-type p53 cDNA in p53-null fibroblasts caused a reduction in 53BP2 protein levels. However, 53BP2 levels were not reduced if the tetracycline-regulated p53 cDNA was expressed after UV damage in these cells. This suggests that UV damage activates cellular factors that can relieve the p53-mediated suppression of 53BP2 protein. To address the physiologic significance of 53BP2 induction, we utilized stable cell lines with a ponasterone A-regulated 53BP2 cDNA. Conditional expression of 53BP2 cDNA lowered the apoptotic threshold and decreased clonogenic survival following UV irradiation. Conversely, attenuation of endogenous 53BP2 induction with an antisense oligonucleotide resulted in enhanced clonogenic survival following UV irradiation. These results demonstrate that 53BP2 is a DNA damage-inducible protein that promotes DNA damage-induced apoptosis. Furthermore, 53BP2 expression is highly regulated and involves both p53-dependent and p53-independent mechanisms. Our data provide new insight into 53BP2 function and open new avenues for investigation into the cellular response to genotoxic stress.

[Early arthroscopic reconstruction in treatment of acute complete rupture of anterior cruciate ligament]

OBJECTIVE

To early reconstruct acute and complete rupture of anterior cruciate ligament (ACL) and treat combined injuries for the recovery of knee joint stability.

METHODS

Ten cases of acute complete rupture of anterior cruciate ligament and medial collateral ligament were treated arthroscopically by anterior cruciate ligament reconstruction using patellar tendon autograft fixed with interference screw from February 1998 to March 1999.

RESULTS

Follow-up ranged from 5 months to 1 year and 3 months (average 10 months). Clinical results showed that the stability of knee joint was satisfactory in the early stage.

CONCLUSIONS

Acute the ACL rupture can be reconstructed arthroscopically in the early stage and the injuries were moderate, combined injuries could be treated at the same time, and the stability of knee joint could recover in the early stage after operation.

[Arthroscopically assisted anterior cruciate ligament reconstruction using patellar tendon autograft fixed with interference screw]

OBJECTIVES

To evaluate the optimal position of bony tunnel, the firmness of tendon graft fixation and the effectiveness of postoperative function recovery in an arthroscopic approach for the minimally invasive reconstruction of anterior cruciate ligament (ACL).

METHODS

In a single arthroscopic approach, the ACL was reconstructed by the bone-tendon-bone compound patellar tendon autograft with the fixation of an interference screw.

RESULTS

ACL reconstruction was performed in 49 patients, of whom 20 were followed up for over one year (average 1 year and 5 months). Among the 20 patients, 13 were rated as excellent, 5 good, and 2 fair. The excellent and good rate went up to 90%. Reconstructed ACLs were reevaluated arthroscopically in 9 patients, in whom, 6 had good remodeling of ACLs.

CONCLUSIONS

Our results indicated that this method has the advantages of less injury, optimal positioning of bone tunnel, firm graft fixation, and early rehabilitation. Compound bone-tendon-bone autograft allows firm fixation and biologic healing with good shape and tension remodeling.

[Acute rupture of anterior cruciate ligament: diagnosis and treatment by early arthroscopy]

OBJECTIVE

To early diagnose and treat acute rupture of anterior cruciate ligament (ACL).

METHODS

23 patients with acute rupture of ACL were examined and treated by early arthroscopy.

RESULTS

The preoperative diagnosis of ACL rupture was similar to that of in 18 patients. Three patients were confirmed by early arthroscopy and 2 patients were found to have ACL rupture, 16 patients were combined with meniscus injuries and 6 patients with cartilaginous injuries. Patholanatomical type of ACL were rupture of parenchymal part (21 patients) and avulsion rupture of attachment point (2 patients). In 6 patients ACL was reconstructed under arthroscope.

CONCLUSIONS

Early arthroscopy in the treatment of acute ACL rupture has advantages of minor injury, correct diagnosis, visible location of injury or combined injury and timely treatment. Early arthroscopy for acute ACL rupture is an important measure for diagnosis, treatment, and stabilization of the knee joint.

Activation of cAMP-dependent protein kinase is required for optimal alpha-melanocyte-stimulating hormone-induced pigmentation

The cAMP-dependent pathway has been long presumed to play a critical role in mediating alpha-melanocyte-stimulating hormone (alpha-MSH)-induced pigmentation, but it has never been demonstrated that this pathway is obligatory. In order to determine whether the cAMP-dependent pathway is required for a alpha-MSH-induced pigmentation, we inhibited the activity of cAMP-dependent protein kinase (PKA), the main kinase mediating in this pathway, by introducing a physiologic cAMP-dependent protein kinase inhibitor (PKI) into S91 murine melanoma cells and then measuring pigment response after alpha-MSH stimulation. Cells were stably transfected either with the pMXX-PKI expression vector that encodes the active part of PKI (the amino terminal 1-31 amino acids) under a metallothionein-inducible promoter and the pSV2-Neo expression vector alone. As expected, treatment of transfected cells with 1 microM CdCl2 for 24 h induced the expression of PKI mRNA in cells transfected with both vectors, but not in cells transfected with the pSV2-Neo expression vector alone. Subsequent treatment of these transfected cells with alpha-MSH for 5-6 days in the continual presence of 1 microM CdCl2 resulted in inhibition of PKA activity by 30-40% in cells expressing PKI. Parallel measurements revealed that alpha-MSH-increased melanin content five- to six-fold in control cells transfected with pSV2-Neo alone, while there was only a two-fold increase in PKI-expressing cells, a 40-50% inhibition in alpha-MSH-induced total melanin content. alpha-MSH-induced tyrosinase activity and tyrosinase mRNA and protein levels measured in parallel were also inhibited by 40-50% in PKI-expressing cells compared to control cells transfected with pSV2-Neo alone. Together, these results demonstrate for the first time that activation of PKA through the cAMP-dependent pathway is required for optimal alpha-MSH-induced pigmentation.

[Reconstruction of anterior cruciate ligament using bone-patellar tendon-prepatellar periosteum free graft with impacting bone technique]

In order to make full and effective use of patellar tendon (middle one-third) during reconstruction of anterior cruciate ligament, we designed bone-patellar tendon-tendon of quadriceps femoris free graft with impacting bone technique and 38 cases were treated by this method. Follow-up for 2 years and 7 months showed that the clinical results were good. The exellent and good rate was 89.7%. Clinical results indicated that the fixation of this reconstructive method was firm and grafts in the joint cavity were patellar tendon tissue. The anterior medial rotatory instability of the knee joint could be corrected with the same graft that have enough length. The experience of acute rupture of anterior cruciate ligament and the rupture of anterior cruciate ligament combined with injury of meniscus were reported.

Lysophosphatidic acid sensitises Ca2+ influx through mechanosensitive ion channels in cultured lens epithelial cells

We investigated the effect of lysophosphatidic acid (LPA), a bioactive phospholipid, on the response in cytosolic free Ca2+ concentration ([Ca2+]i) to mechanical stress in cultured bovine lens epithelial cells. Spritzing of bath solution onto cells as mechanical stress caused marked increase in [Ca2+]i in the presence of LPA and this increase was concentration-dependent (1-10 microM), whereas neither addition of LPA alone nor the mechanical stress in the absence of LPA affected [Ca2+]i. The mechanical stress-induced increase in [Ca2+]i in the presence of LPA was inhibited by removing extracellular Ca2+ or by addition of Gd3+, a blocker of mechanosensitive cation channels, but not by nicardipine, thapsigargin, an inhibitor of endoplasmic reticulum-ATPase pump, or U73122, a phospholipase C inhibitor. These results show that LPA sensitises Ca2+ influx through cation-selective mechanosensitive channels, but does not sensitise Ca2+ release from intracellular stores, triggered by changes in mechanical stress. On the other hand, phosphatidic acid had less of a sensitising effect than LPA, and neither lysophosphatidylcholine nor chlorpromazine had any effect. Also Ca2+ mobilising agonists, ATP, histamine and carbachol, did not sensitise Ca2+ response to the mechanical stress. These results show that LPA sensitises mechanoreceptor-linked response in lens epithelial cells, suggesting that it plays a role in the development of cataracts due to increases in [Ca2+]i induced by mechanical stress.

Rapid determination of ascorbate by ESR spectroscopy

Optimal conditions for the determination of ascorbate, based on the detection of its radical by ESR spectroscopy, were established. The optimal pH for the measurement of the ascorbate radical was 10, whereas that for the gallate and caffeate radical was much higher. This was due to the liability of the ascorbate radical at higher pH. When the radical intensity of ascorbate vs. concentration was plotted double logarithmically, a linear correlation was established between these two parameters within the ascorbate concentration of 0.03-10 mM. ESR analysis of the homogenates under alkaline condition demonstrated that ascorbate is distributed in various mouse organs and that the ascorbate radical is unstable at neutral pH in the brain and liver, suggesting the presence of metabolizing substances. The present study suggests the applicability of the present technique for the study of ascorbate metabolism and identification of physiological factors which regulate the radical intensity of ascorbate.

Alpha-melanocyte stimulating hormone-induced pigmentation is blocked by depletion of protein kinase C

We have explored the role of protein kinase C (PKC) in pigmentation induced by alpha-melanocyte stimulating hormone (alpha-MSH). Using the well-studied S91 Cloudman mouse melanoma model system in which 10(-7) M alpha-MSH is known to produce a time-dependent increase in pigmentation, we found an increase in the activity of tyrosinase, the key enzyme in pigmentation, between Days 2 and 6 accompanied by an increase in mRNA and protein levels of tyrosinase, as well as an increase in the level of specifically the beta isoform of PKC. When S91 cells were treated with phorbol dibutyrate, 95% of PKC activity was lost within 48 h and the alpha-MSH-induced melanogenesis was completely blocked, as was the induction of tyrosinase mRNA and protein. Serially passaged S91 cells no longer capable of responding to alpha-MSH had an undetectable level of PKC-beta, although the tyrosinase protein level was identical to that of alpha-MSH-responsive cells. Furthermore, in these S91 cells alpha-MSH also did not increase the level of tyrosinase mRNA. Thus, induction of murine melanogenesis by alpha-MSH involves up-regulation of tyrosinase mRNA and protein mediated in part by the PKC-dependent pathway, associated with an up-regulation of the beta isoform previously demonstrated to specifically activate tyrosinase in human melanocytes.