Micro-223 Promotes Diabetic Osteoarthritis Progression by Regulating Cartilage Degeneration and Subchondral Bone Remodeling

OBJECTIVE

Our study was performed to investigate whether micro-223 promotes diabetic Osteoarthritis (OA) progression by regulating cartilage degeneration and subchondral bone remodeling.

METHODS

The expression of miR-223 in human normal cartilage, OA cartilage, and subchondral bone tissue with or without DM was detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). miR-223 mimic or inhibitor was transfected into chondrocytes. Cell viability and apoptosis were assessed by 3-(4,5)-dimethylthiahiazo(-2)-3,5-diphenyltetrazolium bromide (MTT) and Terminal Deoxynucleotidyl Transferase(TdT)-mediated dUTP nick end labeling (TUNEL) assay, respectively.

RESULTS

miR-223 was significantly higher in human diabetic OA cartilage and subchondral bone compared with normal OA and healthy control. Overexpression of miR-223 accelerated cartilage degeneration and subchondral bone sclerosis in diabetic OA mice, whereas miR-223 inhibition had the opposite effect. In vitro upregulation of miR-223 decreased proliferation and enhanced apoptosis of chondrocytes. Meanwhile, downregulation of miR-223 promoted glycosaminoglycan (GAG) production in chondrocytes.

CONCLUSION

miR-223 promotes diabetic OA progression by regulating cartilage degeneration and subchondral bone remodeling both in vitro and in vivo.

[One case of severe exogenous lipoid pneumonia complicated with lung abscess caused by diesel inhalation]

Exogenous lipoid pneumonia is an inflammatory response to the lungs caused by inhaled lipid substances, which is prone to secondary bacterial infection, resulting in the formation of local abscesses, which can be life-threatening in severe cases. This paper reports a case of a 55-year-old patient with diesel aspiration, secondary to Klebsiella pneumoniae (ESBL positive) and Candida glabrata infection resulting in lung abscess formation. He was treated with a variety of antibacterial drugs for anti-infection, non-invasive ventilator ventilation, bronchoalveolar lavage, glucocorticoids, phlegm and other medical treatments. Finally, he underwent middle lobectomy for improvement and was discharged from the hospital, and he recovered well with regular follow-up.

[A case of corrosive digestive tract and lung injury caused by ingestion of pipeline dredging agent]

Ingestion of corrosive substances can severely burn the upper digestive tract leading to bleeding or perforation, and may even be life-threatening. Less commonly, damage to the trachea and bronchi is involved. In this paper, a case of corrosive digestive tract injury and lung injury after oral administration of pipeline dredging agent (the main components are hydroxide, sodium carbonate, sodium hypochlorite, etc.) was analyzed. After active rescue treatment, the patient died of massive hemoptysis. It is suggested that serious complications may occur after ingestion of corrosive substances. Timely diagnosis and reasonable medical management are needed to improve the level of recognition and treatment of such diseases.

[Clinical application of a classification based on crucial curvature of coronal imbalance in degenerative lumbar scoliosis]

Objective: To present efficacy of clinical application of a classification based on crucial curvature of coronal imbalance in degenerative lumbar scoliosis (DLS). Methods: A case series study. Clinical data of 61 cases (8 males, 53 females) who underwent posterior correction surgery for DLS from January 2019 to January 2021 were retrospectively analyzed. The mean age was (71.7±6.2) years (ranged 60-82 years). According to the direction of C₇ plumb line (C₇PL) deviated from central sacral vertical line (CSVL) and orientation of L₄ coronal tilt, the author determined which one was the crucial curve. If C₇PL deviated from CSVL in the same direction as concave side of the thoracolumbar curve and L₄ coronally tilts opposite direction of C₇PL deviates from CSVL, then the crucial curve was thoracolumbar curve (type 1). On the contrary, if C₇PL deviated from CSVL in the same direction as concave side of the lumbosacral curve and L₄ coronally tilts consist with direction of C₇PL deviates from CSVL, then the crucial curve was lumbosacral curve (type 2). According to absolute value of coronal balance distance (|CBD|), each type of patients was divided into two groups, respectively, namely coronal balance (CB) (|CBD|≤3 cm) and coronal imbalance (CIB) (|CBD|>3 cm). Changes of Cobb angles of thoracolumbar curve and lumbosacral curve and CBD were recorded and analyzed. Results: The rate of preoperative CIB was 55.7% (34/61) in all the patients. Of the patients, 23 cases were classified as type 1 and 38 cases as type 2. The rate of preoperative CIB was 34.8% (8/23) in type 1 patients and 68.4% (26/38) in type 2. The rate of postoperative CIB was 27.9% (17/61) in all the patients, with 13.0% (3/23) in type 1 and 36.8% (14/38) in type 2. The |CBD| of CB group in type 1 patients decreased from (2.6±1.4) cm before the operation to (1.5±1.0) cm after (P=0.015); and the correction rate of thoracolumbar curve (68.8%±18.4%) was significantly higher than that of lumbosacral curve (34.5%±23.9%) (P=0.005). The |CBD| of CB group in type 2 patients decreased from (2.6±3.0) cm before the operation to (1.6±1.2) cm after (P=0.027); the correction rate of lumbosacral curve (71.3%±18.6%) was higher than that of thoracolumbar curve (57.3%±21.1%), but the difference was not statistically significant (P=0.546). There was no significant difference in |CBD| of CIB group in type 2 patients before and after the operation (P=0.222); the correction rate of lumbosacral curve (38.3%±14.8%) was significantly lower than that of thoracolumbar curve (53.6%±16.0%) (P=0.001). There was a correlation between the change of CBD (3.8±1.5) cm and the difference in correction rate between thoracolumbar and lumbosacral curve (32.3%±19.6%) in CB group in type 1 patients after surgery (r=0.904, P<0.001). There was a correlation between the change of CBD (1.9±2.2) cm and the difference in correction rate between lumbosacral and thoracolumbar curve (14.0%±26.2%) in CB group in type 2 patients after surgery (r=0.960, P<0.001). Conclusion: Clinical application of a classification based on crucial curvature of coronal imbalance in DLS is satisfactory, and its combination with matching correction can effectively prevent the occurrence of coronal imbalance after spinal correction surgery.

[Willingness of receiving influenza vaccine and its influencing factors among health care workers in Yangtze River Delta region from 2020 to 2021]

Objective: To analyze the willingness of receiving influenza vaccine and its influencing factors among health care workers (HCWs) in Yangtze River Delta region from 2020 to 2021. Methods: Convenient sampling method was adopted. From July 2020 to March 2021, 76 hospitals in Jiangsu, Zhejiang, Anhui and Shanghai provinces were selected according to the hospital level and job position, and a questionnaire survey was conducted on the willingness of receiving influenza vaccination. Logistic regression model was used to analyze the influencing factors of vaccination intention. Results: A total of 1 332 HCWs were investigated, with a ratio of male to female about 1∶3.2, and the length of working years was (15.07±9.75) years. A total of 614 HCWs had received influenza vaccine in 2019, with a vaccination rate of 46.09%. About 63.21% (842/1 332) of HCWs were willing to be vaccinated with influenza vaccine. The results of binary logistic regression analysis showed that the willingness of receiving influenza vaccine among HCWs in primary hospitals was higher than that in secondary hospitals (OR=0.573) and tertiary hospitals (OR=0.357). The willingness of HCWs who had received influenza vaccine in 2019 was higher than that of HCWs who had not received influenza vaccine (OR=0.226) and had unknown history of influenza vaccination (OR=0.228). The willingness of HCWs in departments of prevention, health care and infection was higher than that in departments of pre-examination, outpatient, emergency, pediatrics and respiratory (OR=1.670). Conclusion: The willingness of receiving influenza vaccination among HCWs in Yangtze River Delta region is high, but it is still lower than that in developed countries. It is necessary to strengthen publicity and education to improve the influenza immunization level of HCWs.

[Malignant solitary fibrous tumors: a clinicopathological and molecular genetic analysis]

Objective: To explore the clinicopathological features, immunophenotype and molecular genetic characteristics of malignant solitary fibrous tumor (MSFT). Methods: Seven cases of MSFT were collected from the First Affiliated Hospital of Zhengzhou University from July 2018 to December 2020. Immunohistochemistry, RNA-based NGS and DNA-based NGS were performed. Results Among the 7 patients, there were 5 males and 2 females with a median age of 53 years (37-69 years). Two tumors located at skull base, and one in the tentorium of cerebellum, parietal occipital region, occipital area, chest and buttock respectively. The maximum diameter of the tumor was 2.5-20.0 cm. Microscopically, typical hemangiopericomatoid structures were noted; the tumor was cellular, fusiform or oval, very pleomorphic, with necrosis and high mitotic figures (>4/10 HPF). In some cases, classical solitary fibrous tumor morphology and dedifferentiated region were observed. Immunohistochemically, the tumor was positive for CD34 (6/7), STAT6 (7/7), bcl-2 (7/7), but negative for S-100 (7/7); CKpan or EMA was positive to varying degrees; mutated p53 was noted (3/7); Ki-67 positive index was more than 10%. NAB2-STAT6 gene fusion was typically detected in all the 7 cases. In 4 cases, ZNF415-FGFR1, COPG1-MET, IPO11-LRRC70_ncRNA-PLAG1 and Clorf198-CD274 (PD-L1) gene fusions were also detected. NOTCH1 mutation was found in 7 cases and TP53 mutation in 4 cases. TERT promoter mutations were not detected in all the cases. Conclusions: MSFT is rare and needs to be differentiated from many other spindle cell tumors. Especially when tumors express epithelial markers, they are easily misdiagnosed as sarcomatoid carcinoma and synovial sarcoma, etc. Immunohistochemistry and molecular detection of NAB2-STAT6 gene fusion have important diagnostic values. NOTCH1 and TP53 mutations may be associated with the progression of MSFT. Some patients have FGFR1 gene fusion and MET gene fusion, which may be potential therapeutic targets.

Genome-wide association study reveals a quantitative trait locus and two candidate genes on Sus scrofa chromosome 5 affecting intramuscular fat content in Suhuai pigs

Intramuscular fat content (IFC) is an essential quantitative trait of meat, affecting multiple meat quality indicators. A certain amount of IFC could not only improve the sensory score of pork but also increase the flavour, tenderness, juiciness and shelf-life. To dissect the genetic determinants of IFC, two methods, including genome-wide efficient mixed-model analysis (GEMMA) and linkage disequilibrium adjusted kinships (LDAKs), were used to carry out genome-wide association studies for IFC in Suhuai pig population. A total of 14 and 18 significant single nucleotide polymorphisms (SNPs) were identified by GEMMA and LDAK, respectively. The results of these two methods were highly consistent and all 14 significant SNPs in GEMMA were detected by LDAK. Seven of the 18 SNPs reached the genome-wide significance level (P < 9.85E-07) while 11 cases reached the suggestive significance level (P < 1.77E-05). These significant SNPs were mainly distributed on Sus scrofa chromosome (SSC) 5, 3, and 7. Moreover, one locus resides in a 2.27 Mb (71.37-73.64 Mb) region on SSC5 harbouring 13 significant SNPs associated with IFC, and the lead SNP (rs81302978) also locates in this region. Linkage disequilibrium (LD) analysis showed that there were four pairs of complete LD (r² = 1) among these 13 SNPs, and the remaining 9 SNPs with incomplete LD (r² ≠ 1) were selected for subsequent analyses of IFC. Association analyses showed that 7 out of 9 SNPs were significantly associated with IFC (P < 0.05) in 330 Suhuai pigs, and the other 2 SNPs tended to reach a significant association level with IFC (P < 0.1). The phenotypic variance explained (PVE) range of these 9 SNPs was 0.92-3.55%. Meanwhile, the lead SNP was also significantly associated (rs81302978) with IFC (P < 0.05) in 378 commercial hybrid pigs (Pietrain × Duroc) × (Landrace × Yorkshire) (PDLY), and the PVE was 1.38%. Besides, two lipid metabolism-relevant candidate genes, the leucine rich repeat kinase 2 (LRRK2) and PDZ domain containing ring finger 4 (PDZRN4) were identified in the 2.27 Mb region on SSC5. In conclusion, our results may provide a set of markers useful for genetic improvement of IFC in pigs and will advance the genome selection process of IFC on pig breeding programmes.

[One case report of pneumoconiosis in porcelain teeth workers]

Porcelain tooth technology is widely used in the treatment of oral diseases, but there are few reports on the possible occupational hazard factors in the process of porcelain tooth production. Porcelain teeth production will produced a large amount of silica dust and metal dust during the grinding process. The technical workers who have been engaged in this work for a long time are very prone to pneumoconiosis due to their poor personal protection awareness. This paper analyzed the clinical data of a pneumoconiosis patient engaged in porcelain tooth making, and analyzed the possible occupational hazard factors in the process of porcelain teeth production, so as to improve the understanding of relevant enterprises, technical workers and medical personnel on the disease and reduce the risk of porcelain teeth production workers suffering from pneumoconiosis.

Integrated microRNA-mRNA analysis reveals the roles of microRNAs in the muscle fat metabolism of Yanbian cattle

Fat deposition is an important economic trait in farm animals. However, it is difficult to genetically improve intramuscular fat deposition via trait-based cattle breeding. The main objectives of this study were to analyze the factors about beef flavor, and to detect functional microRNA (miRNA, miR) associated with intramuscular fat deposition in Yanbian cattle. Longissimus dorsi samples from six steers were separated into high- and low-fat groups (n = 3 each) based on the marbling score, and transcriptomic analysis was performed using miRNA sequencing. A total of 33 miRNAs and 38 genes were found to be differentially expressed in the high- and low-fat groups. Quantitative real-time polymerase chain reaction was performed to validate the sequencing results. Integrated miRNA-mRNA analysis revealed that miRNA-associated target genes were primarily associated with skeletal muscle development. However, some of the miRNAs (miR-424 etc.) and genes (ATF3 etc.) were also associated with fat metabolism. A targeted relationship between miR-22-3p and the WFIKKN2 gene and its involvement in adipocyte differentiation were confirmed experimentally. The study findings may provide potential candidate molecular targets for the selection of cattle with improved meat quality.

Determination of eddy current response with magnetic measurements

Accurate mutual inductances between magnetic diagnostics and poloidal field coils are an essential requirement for determining the poloidal flux for plasma equilibrium reconstruction. The mutual inductance calibration of the flux loops and magnetic probes requires time-varying coil currents, which also simultaneously drive eddy currents in electrically conducting structures. The eddy current-induced field appearing in the magnetic measurements can substantially increase the calibration error in the model if the eddy currents are neglected. In this paper, an expression of the magnetic diagnostic response to the coil currents is used to calibrate the mutual inductances, estimate the conductor time constant, and predict the eddy currents response. It is found that the eddy current effects in magnetic signals can be well-explained by the eddy current response determination. A set of experiments using a specially shaped saddle coil diagnostic are conducted to measure the SUNIST-like eddy current response and to examine the accuracy of this method. In shots that include plasmas, this approach can more accurately determine the plasma-related response in the magnetic signals by eliminating the field due to the eddy currents produced by the external field.

[Mutation analysis of GJB2 gene in 1 822 patients with nonsyndromic hearing loss in Zhejiang Province]

Objective:To analyze the genetic characteristics in nonsyndromic hearing impairment (NSHL) patients in Zhejiang province.Method:Peripheral blood samples were obtained from 1822 NSHL patients and 467 normal hearing controls in Zhejiang province. We carried out a systematic mutational screening of GJB2 gene in these subjects by amplifying the coding region of GJB2 gene and sequencing directly.Result:Thirty kinds of mutation were identified, including eleven pathogenic mutations, one hypomorphic allele, sixteen polymorphic mutations and two novel mutations. The c.235delC mutation was the most prevalent pathogenic mutation in this cohort (18.50%), and the rate of allele mutation was 12.16%. The frequency of c.299_300delAT,c.176_191del16,c.512_513insAACG,c.35delG,c.283G>A,c.427C>T,c.35insG,c.439G>A,c.571T>C,c.139G>T mutations were decreased in turn.Conclusion:c.235delC mutation is the hot spot of GJB2 gene mutation in NSHL patients in Zhejiang province and the most common mutational pattern is frame-shift mutation. The discovery of novel mutations enriches the spectrum and frequency of variants in GJB2 gene.

Effects of TiO2 nanoparticles on nutrition metabolism in silkworm fat body

Silkworm (Bombyx mori) is an important economic insect with a fat body that plays a crucial role in the storage and transfer of nutrients. It is also known that TiO₂ nanoparticles (NPs) can improve feed efficiency and promote silk protein synthesis in the silkworm. In this study, we profiled gene expression in the silkworm fat body after TiO₂ NP treatment, validated the major RNA-seq findings, and determined the contents of trehalose and triglyceride, the activity of lipase, and the amount of total proteins. RNA-seq analysis revealed that TiO₂ NP treatment caused significant expression changes in 341 genes (P≤0.01), 138 of which were upregulated while the other 203 were downregulated. The expression levels of two target genes in the insulin signaling pathway and two protein metabolism-related target genes, three lipid metabolism-associated target genes, two carbohydrate metabolism related target genes and expression levels of seven heat shock protein genes were increased, and that of threonine dehydratase gene and fatty acid transport protein gene were decreased. The RNA-seq results of 16 genes were validated by quantitative real-time PCR. The lipase activity, content of trehalose, and amount of total proteins were elevated by 3.86-fold, 1.34-fold, and 1.21-fold, respectively, and the content of triglyceride was decreased by 0.94-fold after TiO₂ NP treatment. These results indicated that TiO₂ NPs activated the insulin signaling pathway, promoted the metabolism of protein, fat, and carbohydrate, and improved nutrition metabolism. Our study provides new support for the understanding of the beneficial effect of TiO₂ NPs on silkworm nutrient metabolism.

Summary: Our study indicates that TiO₂ nanoparticles promote nutrient metabolism in the fat body of silkworms, and provide a reference for studies investigating the biological function of TiO₂ nanoparticles.

Mechanisms of TiO2 NPs-induced phoxim metabolism in silkworm (Bombyx mori) fat body

Silkworm is an important economic insect. Abuse of organophosphorus pesticides in recent years often leads to poisoning of silkworms, which significantly affects sericulture development by reducing silk production. Previous studies have shown that TiO2 NPs can effectively mitigate the damages caused by organophosphorus pesticides in silk glands and nerve tissues. The fat body is an important metabolic detoxification organ of silkworms, but it is unknown whether TiO2 NPs affect pesticide metabolism in fat body. In this study, we characterized the transcription of antioxidant genes and enzyme activity in fat body after TiO2 NPs and phoxim treatments using transcriptome sequencing, real-time PCR, and enzyme activity assay. Transcriptome sequencing detected 10 720, 10 641, 10 403, and 10 489 genes for control group, TiO2 NPs group, phoxim group, and TiO2 NPs+phoxim group, respectively. The TiO2 NPs+phoxim group had 705 genes with significantly differential expression (FDR<0.001), among which the antioxidant genes thioredoxin reductase 1 and glutathione S-transferase omega 3 were significantly upregulated. In phoxim group, the expression levels of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase delta (GSTd), and thioredoxin peroxidase (TPx) were increased by 1.365 -fold, 1.335 -fold, 1.642 -fold, and 1.765 -fold, respectively. The level changes of SOD, CAT, GSTd, and TPx were validated by real time PCR. The contents of reactive oxygen species (ROS), malondialdehyde (MDA), and hydrogen peroxide (H2O2) were increased by 1.598 -fold, 1.946 -fold, and 1.506 -fold, respectively, indicating that TiO2 NPs treatment can relieve phoxim-induced oxidative stress. To clarify the mechanism of TiO2 NPs's effect, the transcription levels of P450 gene family were measured for the TiO2 NPs+phoxim group; the expression levels of CYP4M5, CYP6AB4, CYP6A8, and CYP9G3 were elevated by 2.784 -fold, 3.047 -fold, 2.254 -fold, and 4.253 -fold, respectively, suggesting that high expression of P450 family genes can enhance the metabolism of phoxim in the fat body. The results of this study indicated that TiO2 NPs treatment promoted the transcriptional expression of the P450 family genes to improve the fat body's ability to metabolize phoxim and reduce phoxim-induced oxidative stress. This may be the main mechanism of TiO2 NPs' mitigation of phoxim-induced damages in the fat body.

Effects of mutations on the structure and function of silkworm type 1 acetylcholinesterase

AChE is the target of organophosphate (OP) and carbamate (CB) pesticides, and mutations in the gene can significantly reduce insects' sensitivity to these pesticides. Bombyx mori is highly sensitive to pesticides. To investigate the effects of mutations on AChE1 structure and function, we used a prokaryotic system to express B.mori wild type AChE1 (wAChE1) and mutant AChE1 (mAChE1) in this study. Active AChE1 proteins were obtained after refolding and purification, and wAChE1 and mAChE1 had similar activities. After incubation with 10(-6)M physostigmine and 10(-3)mg/mL phoxim, the remaining enzyme activity of mAChE1 was 4.42% and 8.86% higher than that of wAChE1's, respectively. Three-dimensional analysis of mutation AChE1 (mAChE1) revealed that the Ser and Ala side chains extended toward the central part of S285 with distances of just 2.80Å and 3.68Å, respectively, which changed the spatial structure of the active center and reduced its sensitivity to pesticides. These results indicated that the mutations altered the 3D structure of AChE1, which may affect the binding of physostigmine and phoxim to the serine residue at the active center, leading to reduced sensitivity. Our study helps understand the relationship between AChE1 mutations and pesticide resistance and provides a new direction for the cultivation of new pesticide-resistant varieties of B.mori.

Differentially expressed genes in the fat body of Bombyx mori in response to phoxim insecticide

The silkworm, Bombyx mori, is an economically important insect. However, poisoning of silkworms by organophosphate pesticides causes tremendous loss to the sericulture. The fat body is the major tissue involved in detoxification and produces antimicrobial peptides and regulates hormones. In this study, a microarray system comprising 22,987 oligonucluotide 70-mer probes was employed to examine differentially expressed genes in the fat body of B. mori exposed to phoxim insecticide. The results showed that a total of 774 genes were differentially expressed upon phoxim exposure, including 500 up-regulated genes and 274 down-regulated genes. The expression levels of eight detoxification-related genes were up-regulated upon phoxim exposure, including six cytochrome P450s and two glutathione-S-transferases. It was firstly found that eight antimicrobial peptide genes were down-regulated, which might provide important references for studying the larvae of B. mori become more susceptible to microbial infections after phoxim treatment. In addition, we firstly detected the expression level of metamorphosis-related genes after phoxim exposure, which may lead to impacted reproduction. Our results may facilitate the overall understanding of the molecular mechanism of multiple pathways following exposure to phoxim insecticide in the fat body of B. mori.

Major histocompatibility complex class II polymorphisms in forest musk deer (Moschus berezovskii) and their probable association with purulent disease

Genes of the major histocompatibility complex (MHC) family are crucial in immune responses because they present pathogenic peptides to T cells. In this study, we analysed the genetic variation in forest musk deer (Moschus berezovskii) MHC II genes and its potential association with musk deer purulent disease. In total, 53 purulent disease-susceptible and 46 purulent disease-resistant individuals were selected for MHC II exon 2 fragment analysis. Among them, 16 DQ alleles and four additional DR alleles were identified, with DQ exon 2 fragments displaying a low level of polymorphism. The nonsynonymous substitutions exceeded the synonymous substitutions in the peptide-binding sites of DQA2, DQB1 and DQB2. Then, 28 MHC II alleles were used to analyse the distribution patterns of purulent disease between the susceptible and resistant groups. Among them, three alleles (DQA1*01, DQA1*02 and DQA2*04) were found to be resistant, and five alleles (DRB3*07, DQA1*03, DQA1*04, DQA2*05 and DQA2*06) were found to increase susceptibility. Additionally, three haplotypes were found to be putatively associated with musk deer purulent disease. However, these three haplotypes were only found in the resistant or susceptible group, and their frequencies were low. The results from our study support a contributory role of MHC II polymorphisms in the development of purulent disease in forest musk deer.

Characteristics of phoxim-exposed gene transcription in the silk gland of silkworms

Silkworm (Bombyx mori), a model Lepidoptera insect, is an important economic insect. Its silk gland is the important organ for silk protein synthesis and secretion. Phoxim exposure causes deficient cocooning of silkworm and has become one of the major negative factors for the silk industry. To study the impact of phoxim exposure on silk gland, using gene chip technology, we examined differentially expressed genes in silk gland after silkworms were exposed to phoxim (4.0μg/mL) for 24h. Functional annotation, classification and KEGG signaling pathway analysis were performed. The results showed that out of 3206 genes detected in silk gland after phoxim exposure, 270 were differentially expressed significantly, including 249 up-regulated genes and 21 down-regulated genes. These differentially expressed genes related to apoptosis, detoxification and protein degradation were selected. Using qRT-PCR, the expression levels of 9 genes involved in apoptosis, detoxification and protein degradation were validated. In addition, the expression profiles of three related fibroin synthesis genes (Fib-H, Fib-L and P25) were analyzed. Our results showed that phoxim exposure induced apoptosis of silk gland cells and inhibition of fibroin synthesis. This may be the cause of deficient silkworm cocooning.

Changes in the activity and the expression of detoxification enzymes in silkworms (Bombyx mori) after phoxim feeding

Silkworm (Bombyx mori) is an economically important insect. However, non-cocoon caused by chemical insecticide poisoning has largely hindered the development of sericulture. To explore the roles of detoxification enzymes in B. mori after insecticide poisoning, we monitored the activity changes of cytochrome P450 monooxygenase, glutathione-S-transferase, and carboxylesterase in B. mori midgut and fatbody after phoxim feeding. At the same time, the expression levels of detoxification enzyme-related genes were also determined by real-time quantitative PCR. Compare to the control levels, the activity of P450 in the midgut and fatbody was increased to 1.72 and 6.72 folds; the activity of GST was no change in midgut, and in fatbody increased to 1.11 folds; the activity of carboxylesterase in the midgut was decreased to 0.69 folds, and in fatbody increased to 1.13 folds. Correspondingly, the expression levels of detoxifying enzyme genes CYP6ae22, CYP9a21, GSTo1 and Bmcce were increased to 15.99, 3.32, 1.86 and 2.30 folds in the midgut and to 3.58, 1.84, 2.14 and 4.21 folds in the fatbody after phoxim treatment. These results demonstrated the important roles of detoxification enzymes in phoxim metabolism. In addition, the detected activities of such enzymes were generally lower than those in cotton bollworms (Helicoverpa armigera), which may contribute to the high susceptibility of B. mori to insecticides. Our findings laid the foundation for further investigations of the molecular mechanisms of organophosphorus pesticide metabolism in B. mori.

Transcriptional characteristics of gene expression in the midgut of domestic silkworms (Bombyx mori) exposed to phoxim

Silkworm (Bombyx mori) is not only an economically important insect but also a model system for lepidoptera. As a vital organ of digestion and nutrient absorption, the midgut of insects also serves as the first physiological barrier to chemical pesticides. In this study, microarray was performed to profile the gene expression changes in the midgut of silkworms exposed to phoxim. After 24h of phoxim exposure (4.0μg/mL), 266 genes displayed at least 2.0-fold changes in expression levels. Among them, 192 genes were up-regulated, and 74 genes were down-regulated. The most significant changes were 14.88-fold up-regulation and 23.36-fold down-regulation. According to gene ontology annotation and pathway analysis, differentially expressed genes were mainly classified into different groups based on their potential involvements in detoxification, immunne response, stress response, energy metabolism and transport. Particularly, the transcription levels of detoxification-related genes were up-regulated, such as cytochrome P450s, esterases and glutathione-S-transferase (GST), indicating increased detoxification activity in the midgut. Our study provides new insights into the molecular mechanism of pesticide metabolism in the midgut of insects, which may promote the development of highly efficient insecticides.

Peripheral blood mRNA expression patterns to differentiate hepatocellular carcinoma from other hepatic diseases

Peripheral blood genes expressions profiling (GeXP) have been convinced to be more specific for the diagnosis of cancer and other diseases, and the GeXP system provides an ideal method to analyze multiple genes expression in one normalized and equable system. We aim to differentiate hepatocellular carcinoma from other hepatic diseases based on peripheral blood and the GeXP system. Fifteen selected hepatic diseases related genes with two house-keeping genes for normalization were detected by the GeXP system. The diagnosis model was based on K nearest neighbor classifier and cross validation, and software based on MATLAB software was built for differential diagnosis of hepatic diseases. Eight hepatic related genes were demonstrated to show an obvious statistic difference in expressions while the K nearest neighbors classifier showed that the accuracy for normal controls, hepatitis B, liver cirrhosis, hepatocellular carcinoma and the Other group was separately 80.57 %, 78.17 %, 84.48 %, 73.24 % and 85.85 %. The set of validation has been carried out to assess the accuracy of Model Two and the accuracy was even higher than the set of building for the model, except for the hepatitis B (HBV) group. A sensitive and specific GeXP system of eight genes has been developed for the accurate differential diagnosis of hepatic disease.

Peripheral blood mRNA expression patterns to differentiate hepatocellular carcinoma from other hepatic diseases

Peripheral blood genes expressions profiling (GeXP) have been convinced to be more specific for the diagnosis of cancer and other diseases, and the GeXP system provides an ideal method to analyze multiple genes expression in one normalized and equable system. We aim to differentiate hepatocellular carcinoma from other hepatic diseases based on peripheral blood and the GeXP system. Fifteen selected hepatic diseases related genes with two house-keeping genes for normalization were detected by the GeXP system. The diagnosis model was based on K nearest neighbor classifier and cross validation, and software based on MATLAB software was built for differential diagnosis of hepatic diseases. Eight hepatic related genes were demonstrated to show an obvious statistic difference in expressions while the K nearest neighbors classifier showed that the accuracy for normal controls, hepatitis B, liver cirrhosis, hepatocellular carcinoma and the Other group was separately 80.57 %, 78.17 %, 84.48 %, 73.24 % and 85.85 %. The set of validation has been carried out to assess the accuracy of Model Two and the accuracy was even higher than the set of building for the model, except for the hepatitis B (HBV) group. A sensitive and specific GeXP system of eight genes has been developed for the accurate differential diagnosis of hepatic disease.

Photochemical decomposition of perfluorodecanoic acid in aqueous solution with VUV light irradiation

The photochemical decomposition of perfluorodecanoic acid (PFDeA) in water in the presence of persulfate ion (S(2)O(8)(2-)) and sulfur ion (S(2-)) was investigated under vacuum ultraviolet (VUV) light irradiation. PFDeA was decomposed under VUV light irradiation. With the addition of S(2)O(8)(2-) or S(2-), the photo-decomposition and defluorination of PFDeA were enhanced significantly. Sulfate radical anion (SO(4)(*-)) generated from photolysis of S(2)O(8)(2-) initiated PFDeA oxidation. While the S(2-) ion, acting as a *OH scavenger, enhanced the role of reduction pathway induced by aqueous electrons (e(aq)(-)). The shorter-chain perfluorocarboxylic acids (PFCAs), formed in a stepwise manner from longer-chain PFCAs, were identified as products by HPLC/MS.

Photochemical decomposition of perfluorooctanoic acid in aqueous periodate with VUV and UV light irradiation

The photochemical decomposition of perfluorooctanoic acid (PFOA) in aqueous periodate (IO(4)(-)) was investigated under two types of low-pressure mercury lamps: one emits at 254nm light (UV light) and the other emits both 254 nm and 185 nm light (VUV light). PFOA decomposed efficiently under VUV light irradiation while it decomposed poorly under UV light irradiation. The addition of IO(4)(-) significantly increased the rate of decomposition and defluorination of PFOA irradiated with UV light whereas it decreased both processes under VUV irradiation. Reactive radical (IO(3)) generated by photolysis of IO(4)(-) initiated the oxidation of PFOA in UV process. Aquated electrons (e(aq)(-)), generated from water homolysis, scavenged IO(4)(-) resulting in decrease of reactive radical species production and PFOA decomposition. The shorter-chain perfluorocarboxylic acids (PFCAs) formed in a stepwise manner from long-chain PFCAs.

Utility of PDL progenitors for in vivo tissue regeneration: a report of 3 cases

OBJECTIVE

Periodontal disease is an inflammatory disorder with widespread morbidities involving both oral and systemic health. The primary goal of periodontal treatment is the regeneration of the lost or diseased periodontium. In this study, we retrospectively examined feasibility and safety of reconstructing the periodontal intrabony defects with autologous periodontal ligament progenitor (PDLP) implantation in three patients.

MATERIALS AND METHODS

In this retrospective pilot study, we treated 16 teeth with at least one deep intrabony defect of probing depth (PD) > OR = 6 mm with PDLP transplantation and evaluated clinical outcome measures in terms of probing depth, gingival recession and attachment gain for a duration of 32-72 months. Furthermore, we compare PDLPs with standard PDL stem cells (PDLSCs) and confirmed that PDLPs possessed progenitor characters.

RESULTS

Clinical examination indicated that transplantationof PDLPs may provide therapeutic benefit for the periodontal defects. All treated patients showed no adverse effects during the entire course of follow up. We also found that PDLPs were analogous to PDLSCs in terms of high proliferation, expression of mesenchymal surface molecules, multipotent differentiation, and in vivo tissue regain. However, PDLPs failed to express scleraxis, a marker of tendon, as seen in PDLSCs.

CONCLUSIONS

This study demonstrated clinical and experimental evidences supporting a potential efficacy and safety of utilizing autologous PDL cells in the treatment of human periodontitis.

Structure effects in angle-resolved high-order above-threshold ionization of molecules

We present energy-resolved angular distributions of photoelectrons generated in above-threshold ionization (ATI) of nonaligned diatomic molecules N2 and O2 in high-intensity short laser pulses, with emphasis on the most energetic part of the spectra. The angular distribution for photoelectrons with energy of 10U(p) (U(p): ponderomotive energy), i.e., the plateau cutoff in ATI spectra, is found to be broader in O2 than in N2. Resorting to the analyses from both an S-matrix theory and an intuitive semiclassical model, we attribute the observation to the effect of the ground state molecular orbital structure on high-energy electron emission in strong-field molecular ionization.

Disaster epidemiology and medical response in the Chi-Chi earthquake in Taiwan

STUDY OBJECTIVE

We examine the mortality and morbidity associated with earthquakes in the Chi-Chi earthquake in Taiwan in 1999.

METHODS

Crude casualty data were collected from the reports of the government, local health bureaus, and 97 hospitals. The demographic data from the annual report of the Department of Interior were also employed for data analysis. Cross tables showing incidence of deaths and injuries by age, sex, time, and geographic distribution were generated to compare the mortality among different subgroups. Multiple regression models were established to explore the risk factors related to the mortality caused by earthquakes.

RESULTS

The following results were found: the mortality rate increased with proximity to the epicenter, mortality was higher among the elderly than among young people, 30% of the victims died from head injuries caused by the collapse of dwellings, and the peak of medical demand was 12 hours after the earthquake and significantly increased demand for care lasted as long as 3 days. Furthermore, the regression model indicated that 78.5% of the variation of locality-age-sex-specific mortality was explained by the intensity of the earthquake, age, population density, distance to epicenter, medical beds per 10,000 people, and physicians per 10,000 people.

CONCLUSION

The results implied that fragile minorities, specifically the elderly and children, require special consideration and attention in regard to disaster rescue and emergency medical care allocation. Epidemiologic analysis can guide disaster response and preparation.

Managed care, vertical integration strategies and hospital performance

OBJECTIVE

The purpose of this study is to examine the association of managed care with hospital vertical integration strategies, as well as to observe the relationships of different types of vertical integration with hospital efficiency and financial performance.

DATA AND METHODS

The sample consists of 363 California short-term acute care hospitals in 1994. Linear structure equation modeling is used to test six hypotheses derived from the strategic adaptation model. Several organizational and market factors are controlled statistically.

PRINCIPAL FINDINGS

Results suggest that managed care is a driving force for hospital vertical integration. In terms of performance, hospitals that are integrated with physician groups and provide outpatient services (backward integration) have better operating margins, returns on assets, and net cash flows (p < 0.01). These hospitals are not, however, likely to show greater productivity. Forward integration with a long-term-care facility, on the other hand, is positively and significantly related to hospital productivity (p < 0.001). Forward integration is negatively related to financial performance (p < 0.05), however, opposite to the direction hypothesized.

CONCLUSIONS

Health executives should be responsive to the growth of managed care in their local market and should probably consider providing more backward integrated services rather than forward integrated services in order to improve the hospital's financial performance in today's competitive health care market.

Management strategies and financial performance in rural and urban hospitals

This study identifies the difference in financial performance between rural and urban hospitals and examines whether or not that difference may be attributed to the emphasis of revenue enhancement over cost management strategies. Hospitals in Virginia were included in this study except for the two state university medical centers. Rural and urban hospitals were compared on 10 performance indicators grouped into four categories: revenues, costs, profits, and productivity. The results suggest that rural hospital profitability is dependent on cost management. Since rural hospitals achieved lower cost, better efficiency and productivity level than urban hospitals in Virginia, they demonstrate a significant higher level of profit.

An evaluation of the performance of cDNA microarrays for detecting changes in global mRNA expression

The cDNA microarray is one technological approach that has the potential to accurately measure changes in global mRNA expression levels. We report an assessment of an optimized cDNA microarray platform to generate accurate, precise and reliable data consistent with the objective of using microarrays as an acquisition platform to populate gene expression databases. The study design consisted of two independent evaluations with 70 arrays from two different manufactured lots and used three human tissue sources as samples: placenta, brain and heart. Overall signal response was linear over three orders of magnitude and the sensitivity for any element was estimated to be 2 pg mRNA. The calculated coefficient of variation for differential expression for all non-differentiated elements was 12-14% across the entire signal range and did not vary with array batch or tissue source. The minimum detectable fold change for differential expression was 1.4. Accuracy, in terms of bias (observed minus expected differential expression ratio), was less than 1 part in 10 000 for all non-differentiated elements. The results presented in this report demonstrate the reproducible performance of the cDNA microarray technology platform and the methods provide a useful framework for evaluating other technologies that monitor changes in global mRNA expression.

Allitridum mimics effect of ischemic preconditioning by activation of protein kinase C

AIM

To investigate whether allitridum has the effect of pharmacological preconditioning and whether protein kinase C (PKC) plays a role in myocardial protection.

METHODS

Thirty-four isolated rabbit hearts which subjected to 30 min of regional myocardial ischemia and 2 h reperfusion, were randomly divided into 5 groups: control group, ischemic preconditioning (PC) group, allitridum (A) group, polymyxin B (Poly B) group, allitridum + polymyxin B (A + Poly B) group. Infarct size was determined by triphenyltetrazolium staining.

RESULTS

Pharmacological preconditioning in hearts with a 5 -min allitridum infusion 10 min before the prolonged regional ischemia resulted in significantly smaller infarcts (7 % +\- 6 % of risk area) than in control hearts (25 % +\- 7 %, P < 0.05). There is no significant difference in infarct size between (A+Poly B) group and control hearts (23 % +\- 5 % vs 25 % +\- 7 %, P > 0.05).

CONCLUSION

These data indicate that allitridum can precondition rabbit ischemic myocardium and this protection can be effectively blocked by administration of Poly B, an inhibitor of PKC, implying that PKC has an important role in preconditioning.

Exploiting polymerase promiscuity: A simple colorimetric RNA polymerase assay

We developed a convenient colorimetric assay for monitoring RNA synthesis from DNA-dependent RNA polymerases (DdRp) and viral RNA-dependent RNA polymerases (RdRp). ATP and GTP with a p-nitrophenyl moiety attached to the gamma-phosphate were synthesized (PNP-NTPs). These PNP-NTPs can be used for RNA synthesis by several RNA polymerases, including the RdRps from brome mosaic virus and bovine viral diarrhea virus and the DdRps from bacteriophage T7 and SP6. When the polymerase reactions were performed in the presence of alkaline phosphatase, which digests the p-nitrophenylpyrophosphate side-product of phosphoryl transfer to the chromogenic p-nitrophenylate, an increase in absorbence at 405 nm was observed. These nucleotide analogues were used in continuous colorimetric monitoring of polymerase activity. Furthermore, the PNP-NTPs were found to be stable and utilized by RNA polymerases in the presence of human plasma. This simple colorimetric polymerase assay can be performed in a standard laboratory spectrophotometer and will be useful in screens for inhibitors of viral RNA synthesis.

Assessment of similarity between dissolution profiles

In vitro dissolution equivalence has been assessed through profile comparison between the test and reference formulations for postapproval changes. Functions of the absolute mean difference and average squared mean differences were two of the often-used criteria to evaluate distance or similarity between general profiles. The two functions and their method of moment estimators are studied in this paper as an application to similarity assessment of two dissolution profile. Due to the complexity of the distributions of these estimators, the confidence intervals obtained from the bootstrap method were used for testing the hypothesis of dissolution similarity. The size and power of two procedures are examined with a simulation study. A numerical example is used to illustrate the application of the procedures.

Trends in hospital efficiency among metropolitan markets

This study evaluates trends in efficiency among American hospital markets. A total of 6010 hospitals were identified for use in the analysis from the American Hospital Association's Annual Surveys for 1989 and 1993. Using data envelopment analysis (DEA), a longitudinal study of hospital efficiency was conducted on all 314 metropolitan markets in the United States. Results suggest that large hospital markets generally demonstrated higher inefficiency. The major inefficiencies exist in the availability of hospital services, the number of operating beds, the utilization of hospital staffing and operating expenses. Consequently, the large hospital market had a significant excess of health manpower that resulted in inefficiency that amounted to approximately $23 billion. From a policy perspective, this study has shed some light on the need to establish more specific policies to address inefficiency in the health care industry.

Molecular and biochemical basis of galactosemia

Galactosemia is a clinically heterogeneous autosomal recessive inborn error of metabolism caused by deficiency of galactose-1-phosphate uridylyltransferase (GALT). Despite the numerous point mutations identified in the GALT gene, the prevalence of these mutations in different ethnic groups has not been studied. Reports on genotype/phenotype correlation are not consistent due to the small sample sizes studied and the lack of a sensitive enzyme assay. We applied multiplex PCR/ASO dot blot analysis to screen 293 galactosemic patients for 17 known point mutations in exons 5, 6, and 10. Our data demonstrate that only 7 of these mutations were detected in our patients, accounting for 65% of the GALT mutant alleles. Although Q188R is the most common mutation in Caucasian and Hispanic patients, the S135L mutation is most common in African-Americans. Another mutation, F171S, was observed only among African-American patients. An improved, sensitive, and accurate method was used to measure GALT activity in patient's red blood cells. The results indicated that patients homozygous for Q188R have no enzyme activity while those homozygous for S135L had residual enzyme activity. Interestingly, both Q188R/S135L and S135L/F171S compound heterozygotes demonstrated zero enzyme activity. Overall, 85% of Q188R compound heterozygotes also did not have any enzyme activity, whereas the remaining Q188R and the majority of S135L compound heterozygotes expressed variable amounts of GALT activity. We speculate that heterodimeric subunit interaction plays an important role in determining the overall enzymatic activity. Various genotypes thus result in biochemical and clinical heterogeneity among the patients.

Neutrophil rolling altered by inhibition of L-selectin shedding in vitro

The L-selectin adhesion molecule is involved in guiding leukocytes to sites of inflammation. L-selectin is cleaved by an unusual proteolytic activity at a membrane-proximal site resulting in rapid shedding from the cell surface. Although it has been demonstrated that L-selectin mediates, in part, the early event of leukocyte rolling under hydrodynamic flow, the contribution of shedding to L-selectin function has remained unknown. Here we show that hydroxamic acid-based metalloprotease inhibitors block L-selectin downregulation from the cell surface of stimulated neutrophils, without affecting Mac-1 mobilization or general neutrophil activation, and inhibit cleavage of L-selectin in a cell-free system. Unexpectedly, the hydroxamic acid-based inhibitors reduced neutrophil rolling velocity under hydrodynamic flow, resulting in increased neutrophil accumulation. These results suggest that L-selectin is cleaved in seconds--much faster than previously suspected--during the process of rolling under hydrodynamic flow, and that shedding of L-selectin may contribute significantly to the velocity of leukocyte rolling. L-selectin shedding during rolling interactions may be physiologically important for limiting leukocyte aggregation and accumulation at sites of inflammation.

Identification of a nuclear-specific cyclophilin which interacts with the proteinase inhibitor eglin c

We have identified a novel human cyclophilin (hCyP-60) which interacts with the proteinase inhibitor eglin c using the yeast two-hybrid system. A cDNA isolated from a Raji B lymphocyte library reveals a domain showing sequence similarity to known cyclophilins flanked by unique N- and C-terminal residues. In addition, hCyP-60 contains a tyrosine residue (Tyr 389) instead of a tryptophan residue found in most eukaryotic cyclophilins at a position important for cyclosporin binding. Northern and Western analysis reveal widespread expression with considerable tissue-specific variation. Specifically, the highest levels of mRNA are detected in the thymus, pancreas, testis, and K-562 cell line, while the most protein is detected in the kidney. Immunohistochemistry indicates a nuclear-specific localization both in transfected cells and tissue sections. hCyP-60's specific subcellular localization and conserved amino acid sequence suggest that it may play a specific role in the nucleus.

Human cathepsin O2, a matrix protein-degrading cysteine protease expressed in osteoclasts. Functional expression of human cathepsin O2 in Spodoptera frugiperda and characterization of the enzyme

Cathepsin O2, a human cysteine protease predominantly present in osteoclasts, has been functionally expressed in Spodoptera frugiperda Sf9 cells using the Autographa californica nuclear polyhedrosis virus. Following in vitro activation at pH 4.0 with pepsin, active enzyme with an apparent molecular weight of 29,000 was obtained. N-terminal sequencing revealed the typical processing site for cysteine proteases of the papain family with a proline in the position adjacent to the N-terminal alanine residue. The S2P2 subsite specificity of human cathepsin O2 is similar to cathepsin S but distinguished from cathepsins L and B. Similar to cathepsin S, cathepsin O2 is characterized by a bellshaped pH activity profile and is stable at pH 6.5 for 30 min at 37 degrees C. Cathepsin O2 is further distinguished by its potent collagenolytic activity against Type I collagen between pH 5 and 6, and elastinolytic activity against insoluble elastin at pH 7.9. Its capacity to efficiently degrade Type I collagen and its high expression in osteoclasts suggest that cathepsin O2 may play a major role in human osteoclastic bone resorption.

Prenatal identification of i(Yp) by molecular cytogenetic analysis

An i(Yp) is a rare marker chromosome. We present a case of de novo 46,X,i(Yp) detected prenatally in an amniotic fluid specimen. Fluorescence in situ hybridization (FISH) studies using a panel of Y-specific biotinylated DNA probes identified the marker chromosome as i(Yp). Comparative genomic hybridization (CGH) studies further confirmed the diagnosis. Upon pregnancy termination, external examination of the fetus revealed a generally well-developed male fetus with slight facial dysmorphism and prominent rocker-bottom feet. The molecular cytogenetic data in this case proved very useful in genetic counselling and served as a good example illustrating the important role of molecular techniques for accurate identification of marker chromosomes.

A homeotic gene cluster patterns the anteroposterior body axis of C. elegans

In insects and vertebrates, clusters of Antennapedia class homeobox (HOM-C) genes specify anteroposterior body pattern. The nematode C. elegans also contains a small cluster of HOM-C genes, one of which has been shown to specify positional identity. Here we show that two additional C. elegans HOM-C genes also specify positional identity and that together these three HOM-C genes function along the anteroposterior axis in the same order as their homologs in other organisms. Thus, HOM-C-based pattern formation has been conserved in nematodes despite the many differences in morphology and embryology that distinguish them from other phyla. Each C. elegans HOM-C gene is responsible for a distinct body region; however, where their domains overlap, two HOM-C genes can act together to specify the fates of individual cells.

Discrepancy in mosaic findings between chorionic villi and amniocytes: a diagnostic dilemma involving 45,X, 46,XY, and 47,XYY cell lines

Discrepancies between cytogenetic findings in chorionic villi (CV) and fetal tissue have been reported. Several embryogenic models have been proposed to explain such discrepancies. We describe a case in which analysis of the direct preparation showed 24% 45,X and 76% 46,XY, with 43% 45,X and 57% 46,XY cells in cultured villi. Amniocentesis results disclosed 97% 46,XY and 3% 47,XYY. No 45,X cells were found in cultured amniocytes. These findings suggest that nondisjunction occurred early in postzygotic cleavage resulting in 3 cell lines. It is postulated that through selection, the less viable 45,X cells died out among those destined to become fetus proper but persisted among the cytotrophoblast and extraembryonic mesoderm cells. While there is probably selection against all aneuploid cell lines, 47,XYY cells are more likely to survive in the fetus. An explanation for the lack of 47,XYY cells in the CV might be simply that the tissue sampled was not representative of the cytogenetic make up of the entire placenta.

Characterization of i(18p) in prenatal diagnosis by fluorescence in situ hybridization

A case is presented in which chorionic villus direct preparation and cultured chorionic villus cells revealed a 47,XX+mar karyotype. The marker was a small metacentric chromosome and appeared to be i(18p)--isochromosome 18p. Follow-up studies in both amniotic fluid and fetal fibroblasts confirmed the karyotype. In order to characterize the marker, a panel of biotinylated DNA probes was used, including a whole chromosome 18 probe, chromosome 18-specific alpha satellite DNA, Yac clones, and a pan-telomeric probe. These studies show that the marker is a monocentric i(18p) in which about 80 per cent of chromosome 18 alpha satellite DNA has been lost.

Mosaicism in chorionic villus sampling: an analysis of incidence and chromosomes involved in 2612 consecutive cases

The incidence of chromosome mosaicism was analysed in 2612 consecutive chorionic villus sampling (CVS) cases. True mosaicism was found in five cases (0.19 per cent). Confined placental mosaicism (CPM) occurred in 51 cases (1.9 per cent). The chromosomes most frequently encountered in CPM were 2, 7, 8, and the sex chromosomes. Three types of CPM as proposed by Kalousek et al. (1992) were observed. Cases with CPM had a statistically significant association with spontaneous abortion (chi 2 = 3.92, p < 0.05). Based on the data analysed, we conclude that (1) CPM is as likely to occur in cultured chorionic villi as in the direct preparation; (2) as with amniocyte culture, chromosome 2 mosaicism occurs commonly in villus culture; (3) the incidence of false-positive results can be greatly reduced and concern about maternal cell contamination can be alleviated by using both direct cytotrophoblast preparation and cultured chorionic stroma cells in all cases; and (4) follow-up cytogenetic and obstetrical studies, such as ultrasound and fetal monitoring, should always be considered in cases where CPM is suspected.

Chorionic villus sampling: experience with 3016 cases performed by a single operator

OBJECTIVE

To describe our experience with 3016 first-trimester chorionic villus sampling (CVS) procedures, all performed by a single operator, to assess the influence of operator experience on the safety and efficacy of CVS.

METHODS

Transcervical or transabdominal CVS procedures were performed on 3016 patients between the gestational ages of 9-12 weeks. The sampling success rate, procedure complications, cytogenetic results, and pregnancy outcomes were tabulated and analyzed.

RESULTS

Samples adequate for diagnosis were obtained in 99.7% of the cases. The mean (+/- standard deviation) number of insertions per procedure was 1.1 +/- 0.4. The percentage of procedures in which the sample was obtained with a single insertion increased from 51% in the first 100 cases to 96% in the last 2516 cases. There were 56 (1.94%) first- and second-trimester pregnancy losses among 2892 pregnancies intended to continue. This loss rate compares with published baseline risk figures for miscarriage of approximately 2-3%. No difference in pregnancy loss rate followed one or two catheter or needle insertions, but the need for three insertions was associated with a significantly increased loss rate (6.7 versus 1.9%; chi 2 = 4.35, P < .05).

CONCLUSION

Operator experience plays a significant role in the safety and efficacy of CVS.

Apparent non-mosaic trisomy 16 in chorionic villi: diagnostic dilemma or clinically significant finding?

A case is presented in which apparent non-mosaic trisomy 16 was found in chorionic villi (direct and culture) obtained from a patient undergoing first-trimester prenatal diagnosis. The fetal karyotype subsequently was determined to be 46,XX by follow-up amniocentesis. Serial ultrasonographic examinations revealed placental sonolucencies and intrauterine growth retardation. At 37 weeks, a small-for-gestational-age female was delivered by Caesarean section for fetal distress. Postnatal cytogenetic studies revealed a normal female karyotype in cord blood and mosaic trisomy 16 in placental tissues. These findings suggest that in cases where aneuploidy is confined to placental tissues, it may have biological significance, as evidenced by the apparent placental dysfunction and poor fetal growth in this case.