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Biomedical subjects

W W Cai

Publications and source records attributed to W W Cai.

At least 19 recordsLinked to original sources
PubMed2006

Congenital diaphragmatic hernia associated with duplication of 11q23-qter.

Congenital diaphragmatic hernia (CDH) is a relatively common birth defect with a high mortality. Although little is known about its etiology, there is increasing evidence for a strong genetic contribution. Both numerical and structural chromosomal abnormalities have been described in patients with CDH. Partial trisomy 11q and partial trisomy 22 associated with the common t(11;22) has been reported in several cases of CDH. It has been assumed that the diaphragmatic defect seen in these individuals was primarily due to duplication of material from chromosome 22q11. However, in this report we describe a family with a t(11;12) in which one of two brothers with partial trisomy 11q has a left sided posterolateral CDH. This is the second case of CDH in partial trisomy 11q due to an unbalanced translocation other than t(11;22). Using array-based comparative genomic hybridization and fluorescent in situ hybridization, we mapped the breakpoints in both brothers and their mother who is a balanced translocation carrier. Our results suggest that duplication of one or more genes on a approximately 19 Mb region of 11q23.3-qter predisposes to the development of CDH. These effects may be the primary cause of CDH in individuals t(11;22) or may be additive to effects from the duplication of chromosome 22 material. We also conclude that the partial trisomy 11q syndrome has a variable phenotype and that CDH should be added to the spectrum of anomalies that can be present in this syndrome.

Adult↗
PubMed2006

Array-based comparative genomic hybridization and copy number variation in cancer research.

Array-based comparative genomic hybridization (aCGH) is a molecular cytogenetic technique used in detecting and mapping DNA copy number alterations. aCGH is able to interrogate the entire genome at a previously unattainable, high resolution and has directly led to the recent appreciation of a novel class of genomic variation: copy number variation (CNV) in mammalian genomes. All forms of DNA variation/polymorphism are important for studying the basis of phenotypic diversity among individuals. CNV research is still at its infancy, requiring careful collation and annotation of accumulating CNV data that will undoubtedly be useful for accurate interpretation of genomic imbalances identified during cancer research.

Animals↗
PubMed2001

An SSLP marker-anchored BAC framework map of the mouse genome.

We have constructed a BAC framework map of the mouse genome consisting of 2,808 PCR-confirmed BAC clusters, using a previously described method. Fingerprints of BACs from selected clusters confirm the accuracy of the map. Combined with BAC fingerprint data, the framework map covers 37% of the mouse genome.

Animals↗
PubMed2001

A clone-array pooled shotgun strategy for sequencing large genomes.

A simplified strategy for sequencing large genomes is proposed. Clone-Array Pooled Shotgun Sequencing (CAPSS) is based on pooling rows and columns of arrayed genomic clones, for shotgun library construction. Random sequences are accumulated, and the data are processed by sequential comparison of rows and columns to assemble the sequence of clones at points of intersection. Compared with either a clone-by-clone approach or whole-genome shotgun sequencing, CAPSS requires relatively few library constructions and only minimal computational power for a complete genome assembly. The strategy is suitable for sequencing large genomes for which there are no sequence-ready maps, but for which relatively high resolution STS maps and highly redundant BAC libraries are available. It is immediately applicable to the sequencing of mouse, rat, zebrafish, and other important genomes, and can be managed in a cooperative fashion to take advantage of a distributed international DNA sequencing capacity.

Animals↗
PubMed1999

An integrated gene and SSLP BAC map framework of mouse chromosome 11.

Physical maps are important resources both in sequencing and in functional analyses of large genomes. Global contig-building approaches are regarded to be more efficient relative to the cumulative outcome of scattered and more localized physical mapping studies accompanying positional cloning. This work is part of an effort to assemble a complete physical map of mouse chromosome 11 in which selection of clones containing specific genetic markers from genomic libraries is the first step in the process. Using a previously developed strategy, we identified 361 bacterial artificial chromosomes (BACs) containing 88 gene markers. Since the linkage positions of markers chosen for these studies are known, the BAC framework obtained is anchored to the genetic map and represents about 13% of the length of the entire chromosome. Together with similar assignments of BACs generated previously using D11Mit markers (Cai et al., 1988, Genomics, 54: 387-397), 36-40% of the chromosome 11 is now assembled into contigs, and these contigs correlate through 51 clones carrying both gene and simple sequence length polymorphism markers.

Animals↗
PubMed1999

Engineering a mouse balancer chromosome.

Balancer chromosomes are genetic reagents that are used in Drosophila melanogaster for stock maintenance and mutagenesis screens. Despite their utility, balancer chromosomes are rarely used in mice because they are difficult to generate using conventional methods. Here we describe the engineering of a mouse balancer chromosome with the Cre-loxP recombination system. The chromosome features a 24-centiMorgan (cM) inversion between Trp53 (also known as p53) and Wnt3 on mouse chromosome 11 that is recessive lethal and dominantly marked with a K14-Agouti transgene. When allelic to a wild-type chromosome, the inversion suppresses crossing over in the inversion interval, accompanied by elevated recombination in the flanking regions. The inversion functions as a balancer chromosome because it can be used to maintain a lethal mutation in the inversion interval as a self-sustaining trans-heterozygous stock. This strategy can be used to generate similar genetic reagents throughout the mouse genome. Engineering of visibly marked inversions and deficiencies is an important step toward functional analyses of the mouse genome and will facilitate large-scale mutagenesis programs.

Animals↗
PubMed1998

An anchored framework BAC map of mouse chromosome 11 assembled using multiplex oligonucleotide hybridization.

Despite abundant library resources for many organisms, physical mapping of these organisms has been seriously limited due to lack of efficient library screening techniques. We have developed a highly efficient strategy for large-scale screening of genomic libraries based on multiplex oligonucleotide hybridization on high-density genomic filters. We have applied this strategy to generate a bacterial artificial chromosome (BAC) anchored map of mouse chromosome 11. Using the MIT mouse SSLP data, 320 pairs of oligonucleotide probes were designed with an "overgo" computer program that selects new primer sequences that avoid the microsatellite repeat. BACs identified by these probes are automatically anchored to the chromosome. Ninety-two percent of the probes identified positive clones from a 5.9-fold coverage mouse BAC library with an average of 7 positive clones per marker. An average of 4.2 clones was confirmed for 204 markers by PCR. Our data show that a large number of clones can be efficiently isolated from a large genomic library using this strategy with minimal effort. This strategy will have wide application for large-scale mapping and sequencing of human and other large genomes.

Animals↗
PubMed1998

Increased cesarean section rates and emerging patterns of health insurance in Shanghai, China.

OBJECTIVES: This study examined the trend in cesarean section deliveries and the factors associated with it in the Minhang District of Shanghai, China. METHODS: A representative sample of the members of 2716 households in the district were interviewed in the fall of 1993. This study analyzed the data from 1959 married women of reproductive age with at least one live birth. RESULTS: During the past 3 decades, the proportion of infants born by cesarean section increased from 4.7% to 22.5%. Logistic regression analysis revealed that the highest cesarean section rate, which occurred in the most recent period of 1988 through 1993, was associated with form of medical payment, self-reported complications during pregnancy, higher birthweight, and maternal age. Government insurance pays all costs of cesarean sections and accounted for the highest proportion of the cesarean section rate. CONCLUSIONS: The high rates of cesarean sections in China are surprising given the lack of the factors that usually lead to cesarean sections. The increasing cesarean section rates may be an early indication that emerging forms of health insurance and fee-for-service payments to physicians will lead to an excessive emphasis on costly, high-technology medical care in China.

Adolescent↗
PubMed1994

Birth defects in relation to threatened abortion.

The evidence for the association between threatened abortion and birth defects is limited and inconsistent. This study examined this relation using data from the Shanghai Birth Defects Monitoring Program. A total of 1,013 cases of birth defects and an equal number of controls were analyzed. Our study showed that women with threatened abortion had a 50% higher risk of having a baby with birth defects compared with those without this complication, controlling for other factors (adjusted odds ratio = 1.5; 95% confidence interval = 1.1-2.1). Threatened abortion was generally related to defects of the urogenital system, heart and circulatory system, and musculoskeleton and limbs and was specifically associated with polydactyly, undescended testicle, and hypospadias.

Abortion, Threatened↗
PubMed1994

[Multivariate analysis of relationship between breast feeding and infant physical development].

Longitudinal analysis with generalized estimating equation (GEE) revealed breast feeding can promote infant physical development and growth, and cross-sectional analysis with canonical correlation showed protein intake with breast milk as its main source brought about infants to develop physically tall and lean at first, which might support the theory that protein intake affects more on their development and growth. The extent of infant physical development and growth varied with the amount of breast milk of his or her mother, which should be caught attention in comparison of infant physical development with different feeding patterns. It is suggested that intervention of breast feeding should be implemented during perinatal period and 1-2 months after delivery with emphasis on health education.

Body Height↗
PubMed1993

Pregnancy-induced hypertension and early neonatal death: a case-control study.

Literature on the association between pregnancy-induced hypertension and early neonatal death is limited. The present case-control study consisted of 342 early neonatal deaths and 523 frequency-matched controls. After controlling for other factors such as infant sex, gravidity, maternal age, threatened abortion, and maternal anemia, moderate to severe pregnancy-induced hypertension was associated with an increased risk of early neonatal death with apparent dose-effect gradients (odds ratio = 1.8 for moderate and 2.2 for severe). The biologic plausibility of pregnancy-induced hypertension as a cause of neonatal mortality is discussed.

Abortion, Threatened↗
PubMed1993

Association of the common cold in the first trimester of pregnancy with birth defects.

OBJECTIVE: To examine the association between the common cold with or without fever in the first 3 months of pregnancy and birth defects in offspring. DESIGN: A case-control study. SETTING: Data are from the Shanghai Birth Defects Monitoring Program, conducted in 29 hospitals in Shanghai, China from October 1, 1986 to September 30, 1987. SUBJECTS: A total of 986 birth defects cases, 990 frequency-matched live birth controls, and 159 stillbirth controls. RESULTS: Modestly elevated risk of birth defects was identified among women who reported having a cold with or without fever in the first trimester of pregnancy. Notably increased relative risks were observed for anencephalus (odds ratio [OR] = 3.9, 95% confidence interval [CI] = 2.0 to 7.7), spina bifida (OR = 4.1, 95% CI = 1.7 to 9.7), hydrocephalus (OR = 2.3, 95% CI = 1.1 to 5.1), cleft lip (OR = 2.2, 95% CI = 1.4 to 3.4), and undescended testicle (OR = 1.8, 95% CI = 1.0 to 3.0). Our study further found that the overall relative risks were consistent by using two different control groups, suggesting that this association was unlikely to be due to recall or report bias. CONCLUSION: Common cold in the first trimester of pregnancy may be associated with an increased risk of birth defects in offspring. However, these findings should be interpreted cautiously.

Adult↗
PubMed1992

Occupational hazards and pregnancy outcomes.

This study examined the association between exposure to occupational hazards and pregnancy outcomes using data from a case-control study conducted in 29 hospitals in Shanghai, China. The sample included 1,875 perinatal deaths and newborns with birth defects and the same number of controls. Information on mother's exposure to occupational radiation, chemicals, noise, and pesticides was investigated. Logistic regression analysis controlling for potential confounders showed that exposure to radiation before/during pregnancy was associated with antepartum fetal death, birth defects, small-for-gestational-age (SGA), and threatened abortion. Exposure to chemicals before/during pregnancy was associated with antepartum fetal death, early neonatal death, birth defects, preterm birth, and threatened abortion. Women exposed to pesticides during pregnancy had an increased risk of SGA and threatened abortion. Exposure to occupational noise during pregnancy increased the risk of antepartum fetal death. Furthermore, higher than expected numbers of congenital anomalies in the central nervous system (CNS) were identified among women exposed to chemicals before pregnancy and to pesticides during the first trimester of pregnancy. No significant association was found between occupational exposure and intrapartum fetal death. Although recall bias may be possible in our study, the findings encourage further research.

Case-Control Studies↗
PubMed1992

A case-control study of paternal smoking and birth defects.

Although the influence of paternal smoking on birth defects is of great public interest, epidemiological evidence concerning this potential relationship is extremely limited. A stratified random sample of 29 hospitals in the Shanghai Municipality, China, was used to select 1012 birth defects cases and controls. Mothers of the cases and controls were interviewed in the hospitals from October 1986 to September 1987. A modest relationship between paternal smoking and overall birth defects in offspring was identified [odds ratio (OR) = 1.21, 95% confidence interval (CI): 1.01-1.45]. More markedly elevated risks were identified for anencephalus (OR = 2.1), spina bifida (OR = 1.9), pigmentary anomalies of the skin (OR = 3.3) and varus/valgus deformities of the feet (OR = 1.8). Our analysis also shows that paternal smoking is more likely to be associated with multiple rather than isolated malformations. A paternally-mediated effect of smoking on birth defects is suggested and further studies are encouraged.

Adult↗
PubMed1991

Perinatal mortality in Shanghai: 1986-1987.

The incidence of, and risk factors associated with, perinatal mortality in Shanghai during 1986-1987 are examined using data from a multi-site study conducted in 29 hospitals. The overall perinatal mortality rate was 14.96 per 1000 births. The mortality rates of antepartum fetal death, intrapartum fetal death and early neonatal death were 5.97, 2.06 and 6.94 per 1000 births, respectively. The perinatal mortality rates increased in winter and late spring. Male neonates were 1.5 times more likely to die than females. Low birthweight and preterm infants had 15 to 80 times higher risk of perinatal death. Higher parity, multiple pregnancy, and maternal age greater than or equal to 35 years were the risk factors for perinatal mortality. Asphyxia, cord complications, and congenital malformations were found to be the major causes of perinatal deaths. Comparison of mortality rates between Shanghai and the US suggests that the shortage of advanced technology in perinatal care (e.g. neonatal intensive care units) is a major obstacle to the reduction of perinatal mortality in Shanghai.

Adult↗