Sonographic findings in a case of congenital pyloric diaphragm.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
Y J Chan
Publications and source records attributed to Y J Chan.
Current awareness in prenatal diagnosis.
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of prenatal diagnosis. Each bibliography is divided into 17 sections: 1 Books, Reviews & Symposia; 2 General Interest; 3 Normal Fetal Development; 4 Gametogenesis and Pre-implantation Diagnosis; 5 First Trimester Diagnosis; 6 Second Trimester Diagnosis; 7 Fetal Diagnosis by Ultrasound and Other Imaging; 8 Maternal Screening; 9 Screening for Carriers of Genetic Abnormality; 10 Technological Developments; 11 Confined Placental Mosaicism and Uniparental Disomy; 12 Molecular Cytogenetics; 13 Fetal Cells in Maternal Circulation; 14 Fetal Therapy; 15 Psychosocial Aspects; 16 Epidemiology and Environmental Factors; 17 Developmental Pathology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
Humans↗
Detection and viral nucleotide sequence analysis of transfusion-transmitted virus infection in acute fulminant and non-fulminant hepatitis.
The impact of transfusion-transmitted virus (TTV) infection on acute fulminant and non-fulminant hepatitis is unclear. In this study, serum samples from 164 patients with acute hepatitis of various aetiologies, from 34 asymptomatic hepatitis B virus carriers and from 202 healthy adults were tested for TTV DNA by the semiconserved nested polymerase chain reaction. TTV viraemia was prevalent in patients with acute hepatitis C, in patients with acute hepatitis D virus superinfection and in patients with non-A-E hepatitis (27-30%) but the incidence was not significantly different from that of healthy controls (31 of 202, 15.3%). There were no significant differences in gender, age, presence of hepatitis G virus, the occurrence of fulminant hepatitis, or in serum albumin, bilirubin or alanine aminotransferase levels (9/30 vs 35/134) between patients with or without TTV viraemia. Seven of the nine TTV-positive patients with fulminant hepatitis were co-infected with hepatitis C, D or E. TTV clones from 18 subjects, with or without fulminant hepatitis, were sequenced and analysed phylogenetically. Eleven (61. 1%) belonged to TTV group 1, six (33.3%) to TTV group 2 and one to TTV group 3. No particular strain of TTV was associated with fulminant hepatitis. In summary, in Taiwan, TTV is prevalent in the general population as well as in patients with liver diseases. TTV plays an insignificant role in acute fulminant and non-fulminant hepatitis. Its influence on outcome requires a longitudinal study.
Acute Disease↗
Detection of human cytomegalovirus retinitis and monitoring of ganciclovir treatment using conjunctival swab with polymerase chain reaction in AIDS patients.
This report studies the accuracy of conjunctival swab polymerase chain reaction (CS-PCR) for the diagnosis of human cytomegalovirus retinitis (HCMV) in AIDS patients. PCR and virus culture were used for the detection of HCMV in conjunctival swab, serum, and urine specimens from 38 AIDS patients between April 1996 and April 1998. The clinical utility of the identification of HCMV retinitis by these 6 different methods was demonstrated by their prediction power to estimate AIDS patients at risk of contracting HCMV retinitis. The sensitivity, specificity, positive predictive value, and negative predictive value of CS-PCR for the detection of HCMV retinitis were 91.5%, 80.9%, 60.8%, and 92.7%, respectively; for serum PCR were 74.3%, 81.7%, 57.2%, and 90.3%; for urine PCR were 100%, 17.3%, 20.4%, and 100%; for conjunctival swab culture were 22.7%, 100%, 100%, and 86%; for serum culture were 27.3%, 98.1%, 75%, and 86.4%; and for urine culture were 90.9%, 44.2%, 25.6%, and 95.8%.
AIDS-Related Opportunistic Infections↗
Tubulocystic ovarian clear cell carcinoma with abundant fibrous stroma: malignant clear cell adenofibroma.
We report a case of tubulocystic ovarian clear cell carcinoma (OCCC) with abundant fibrous stroma associated with an endometriotic cyst. Most OCCC show a small amount of fibrous stroma; however, the tumor presented in this case had abundant stroma, that qualifies it as a malignant clear cell adenofibroma. This unusual type of clear cell carcinoma may be misinterpreted as a benign lesion or as metastatic carcinoma on frozen section. In permanent sections, the stromal invasive foci are focal, small and subtle. Therefore, extensive sampling of the specimen to search for evidence of invasion is recommended for a fibrous ovarian tumor that appears benign on gross examination.
Adenofibroma↗
TT virus infection among hemodialysis patients at a medical center in Taiwan.
Although the association between TT virus (TTV) infection and hepatitis is controversial, the high prevalence of TTV infection in healthy blood donors and even higher rate among frequently transfused patients poses a potential threat to public health and clinical care. In addition, there is a lack of data concerning the prevalence and mode of transmission of TTV infection in different subpopulations in Taiwan. In the present study, we investigated the prevalence of TTV infection in 111 uremic patients receiving regular hemodialysis in a single hospital in Taiwan. Blood samples were collected and analyzed using a seminested polymerase chain reaction (PCR) designed to amplify a 271 base-pair DNA fragment. The results show that the overall TTV positive rate in uremic patients in our hospital was 61% (68/111), which was much higher than the reported TTV prevalence rate among the normal population (ranging from 1%-12%). The results of analysis of the demographic and clinical characteristics of the patients indicate that blood transfusion may play an important role in TTV transmission (p < 0.05). In addition, the hepatitis B positive rate was significantly lower in TTV positive patients. However, liver function tests were not significantly different between TTV positive and TTV negative patients. The results of the present study suggest that blood transfusion plays an important role in TTV transmission in uremic patients.
Adult↗
Ophthalmic findings in patients with acquired immunodeficiency syndrome.
Ocular manifestations have been reported in up to 60% of individuals infected with human immunodeficiency virus (HIV) in the United States, and it is becoming increasing apparent that these ocular manifestations almost invariably reflect extent of progression of the disease. The prevalence of ocular abnormalities among acquired immunodeficiency syndrome (AIDS) patients in Taiwan has not been reported. In the present study, we examined and followed up the ophthalmic conditions of a total of 274 HIV-infected patients during the period from March 1993 to May 1999. The results show that cotton-wool spots was the most common ocular finding in this series of patients with AIDS, occurring in 22 (32.8%) of 67 AIDS patients. Cytomegalovirus (CMV) retinitis was the most commonly seen opportunistic ocular infection, occurring in 14 (20.8%) of 67 AIDS patients. These findings suggest that AIDS patients should be closely followed for signs of opportunistic ocular disease which may initially be asymptomatic. Close co-operation between the ophthalmologist and the internist is essential to ensure timely therapeutic intervention, which can decrease the risk of further complications including visual impairment and blindness.
Acquired Immunodeficiency Syndrome↗
Prenatal diagnosis of limb-body wall complex using two- and three-dimensional ultrasound.
Explore the source record for details and available documents.
Abdominal Muscles↗
Using buffy coat for reverse transcriptase-polymerase chain reaction in the diagnosis of dengue virus infection: preliminary study.
Using reverse transcriptase-polymerase chain reaction (RT-PCR) to detect and type from viremic human serum samples for dengue virus infection is widely used today. However, a few false-negative results were reported due to very low titers of the virus particle in serum samples. As mononuclear cells, macrophages or monocytes are target cells for dengue virus infection, and the replication of virions can be observed in peripheral leukocytes frequently, the amount of virus particle in buffy coat should be higher than those in serum samples. Here, we describe a procedure in which RNA extraction from the buffy coat of a patient with a false-negative serum sample yielded specific viral RNA amplifiable by RT-PCR, thereby providing an alternative choice for the accurate diagnosis of dengue infection.
Dengue↗
Factors affecting human cytomegalovirus gene expression in human monocyte cell lines.
To understand the mechanisms for establishing and reactivating monocytes and macrophages from latency by human cytomegalovirus (HCMV), human monocyte cell lines were infected and HCMV gene expression was investigated. Indirect immunofluorescence assay (IFA) with monoclonal antibody to HCMV major immediate early (MIE) IE1 or IE2 proteins revealed that HCMV MIE genes were expressed at low levels in relatively more differentiated THP-1 cells with TPA treatment after virus infection (posttreatment). Less differentiated cells such as U937 or HL60 did not support MIE gene expression even after TPA treatment. If THP-1 cells were pretreated before virus infection with TPA and became differentiated at the time of HCMV infection, MIE gene expression increased by 5-6 fold. Therefore, the relative degree of monocyte cell differentiation appears to be an important factor for regulating HCMV gene expression. Further IFA studies using monoclonal antibodies specific for IE1 or IE2 proteins indicate that the sequence and general pattern of IE1 and IE2 gene expression in THP-1 cells treated with TPA were similar to those in permissive human fibroblast cells with some delay in time. Formation of the replication compartment detected with monoclonal antibody to HCMV polymerase accessory protein UL44 in THP-1 cells suggests a fully productive replication process of HCMV in these cells. Monocytes are known to be induced to differentiate by hydrocortisone (HC), tumor necrosis factor (TNF)-alpha or interferon (IFN)-gamma. HC, which is known to stimulate HCMV replication in permissive human fibroblast (HF) cells, enhanced HCMV gene expression by 2-3 fold in TPA-pre or posttreated THP-1 cells, but TNF-alpha or IFN-gamma had little effect. Nitric oxide (NO) is released by immune cells in the defense against foreign stimuli and was shown to inhibit HCMV gene expression in HF cells. Increasing NO by nitroprusside significantly reduced HCMV gene expression in THP-1 cells. Therefore, it appears that the expression of HCMV immediate early genes in THP-1 cells treated with TPA closely resembles those in permissive HF cells.
Cell Line↗
Glycogen storage disease type IV: a case report.
Glycogen storage disease type IV (GSD-IV) is a rare autosomal recessive disease caused by a deficiency of glycogen branching enzyme (GBE) activity. This results in the accumulation of abnormal glycogen in the liver and other organs. We report the case of a 14-month-old female patient with typical hepatic pathologic findings of GSD-IV. The patient suffered from decreased muscle tone and progressive hepatosplenomegaly since birth. A wedge biopsy of the liver showed enlarged hepatocytes with colorless to faintly eosinophilic ground glass intracytoplasmic inclusions. Portal fibrosis and lobular, fibrous septa were present. Ultrastructure of the inclusions revealed non-membrane-bound fibrillar material 5 nm in maximal diameter. Enzyme study revealed a total deficiency of GBE activity.
Female↗
Synergistic interactions between overlapping binding sites for the serum response factor and ELK-1 proteins mediate both basal enhancement and phorbol ester responsiveness of primate cytomegalovirus major immediate-early promoters in monocyte and T-lymphocyte cell types.
Cytomegalovirus (CMV) infection is nonpermissive or persistent in many lymphoid and myeloid cell types but can be activated in differentiated macrophages. We have shown elsewhere that both the major immediate-early gene (MIE) and lytic cycle infectious progeny virus expression can be induced in otherwise nonpermissive monocyte-like U-937 cell cultures infected with either human CMV (HCMV) or simian CMV (SCMV) by treatment with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). Two multicopy basal enhancer motifs within the SCMV MIE enhancer, namely, 11 copies of the 16-bp cyclic AMP response element (CRE) and 3 copies of novel 17-bp serum response factor (SRF) binding sites referred to as the SNE (SRF/NFkappaB-like element), as well as four classical NFkappaB sites within the HCMV version, contribute to TPA responsiveness in transient assays in monocyte and T-cell types. The SCMV SNE sites contain potential overlapping core recognition binding motifs for SRF, Rel/NFkappaB, ETS, and YY1 class transcription factors but fail to respond to either serum or tumor necrosis factor alpha. Therefore, to evaluate the mechanism of TPA responsiveness of the SNE motifs and of a related 16-bp SEE (SRF/ETS element) motif found in the HCMV and chimpanzee CMV MIE enhancers, we have examined the functional responses and protein binding properties of multimerized wild-type and mutant elements added upstream to the SCMV MIE or simian virus 40 minimal promoter regions in the U-937, K-562, HL-60, THP-1, and Jurkat cell lines. Unlike classical NFkappaB sites, neither the SNE nor the SEE motif responded to phosphatase inhibition by okadaic acid. However, the TPA responsiveness of both CMV elements proved to involve synergistic interactions between the core SRF binding site (CCATATATGG) and the adjacent inverted ETS binding motifs (TTCC), which correlated directly with formation of a bound tripartite complex containing both the cellular SRF and ELK-1 proteins. This protein complex was more abundant in U-937, K-562, and HeLa cell extracts than in Raji, HF, BALB/c 3T3, or HL-60 cells, but the binding activity was altered only twofold after TPA treatment. A 40-fold stimulation of chloramphenicol acetyltransferase activity mediated by four tandem repeats of the SNE could be induced within 2 h (and up to 250-fold within 6 h) after addition of TPA in DNA-transfected U-937 cells, indicating that the stimulation appeared likely to be a true protein kinase C-mediated signal transduction event rather than a differentiation response. Slight differences in the sequence of the core SRF binding site compared with that of the classical c-Fos promoter serum response element, together with differences in the spacing between the SRF and ETS motifs, appear to account for the inability of the SCMV SNEs to respond to serum induction.
3T3 Cells↗
Two distinct upstream regulatory domains containing multicopy cellular transcription factor binding sites provide basal repression and inducible enhancer characteristics to the immediate-early IES (US3) promoter from human cytomegalovirus.
The US3 gene of human cytomegalovirus (HCMV) is expressed at immediate-early (IE) times in permissive HF cells, but not in nonpermissive rodent cells, and encodes several proteins that have been reported to have regulatory characteristics, although they are dispensable for growth in cell culture. Both spliced and unspliced forms of US3 IE transcripts are associated with the second of only two known large and complex upstream enhancer domains within the 229-kb HCMV genome, which we refer to as the IES cis-acting control region. Only the 260-bp proximal segment (from -313 to -55) of the 600-bp IES control domain, which contains multicopy NF-kappaB binding sites, proved to be necessary to transfer both high basal expression plus phorbol ester- and okadaic acid-inducible characteristics to heterologous promoters in transient assays in U-937 and K-562 cells. However, the IES control region contains a distinctive 280-bp distal domain, characterized by the presence of seven interspersed repeats of a 10-bp TGTCGCGACA palindromic consensus motif that encompasses a NruI site. This far upstream Nru repeat region (from -596 to -314) imparted up to 20-fold down-regulation effects onto strong basal heterologous promoters as well as onto the IES enhancer plus minimal promoter region in both U-937 and K-562 cells. Functional Nru repressor elements (NREs) could not be generated by multimerizing either the palindromic (P) Nru motifs alone or adjacent degenerate interrupted (I Nru motifs alone. However, multimerized forms of the combined P plus I elements reconstituted the full 20-fold cis-acting down-regulation phenotype of the intact NRE domain. The P and I forms of the Nru elements each bound independently and specifically to related cellular DNA-binding factors to form differently migrating A or B complexes, respectively, whereas the combined P plus I elements bound cooperatively to both the A and B complexes with high affinity. Interestingly, nuclear extracts from U-937, K-562, HeLa, and Vero cells all formed both the A and B NRE binding factor complexes, whereas those from HF cells produced only A complexes, and Raji, HL60, and BALB/c 3T3 cells lacked both types of binding factor complexes. The core pentameric CGACA and CGATA half sites present in both the P and I Nru motifs are related to recently described Drosophila chromosomal insulator binding sites. Therefore, in addition to its cis-repression or silencer characteristics, the NRE domain appears likely to act to shield adjacent segments of the viral genome from the chromatin-reorganizing effects of the IES-inducible enhancer. We speculate that differential expression and regulation of the IES enhancer-controlled US3 protein, either in concert with or separately from the major IE (MIE) enhancer-controlled IE1 and IE2 transactivator proteins, may play a critical role in determining HCMV permissiveness in some cell types and perhaps also in the establishment of or reactivation from latency.
Animals↗
Identification of a large bent DNA domain and binding sites for serum response factor adjacent to the NFI repeat cluster and enhancer region in the major IE94 promoter from simian cytomegalovirus.
The major immediate-early (MIE) transactivator proteins of cytomegaloviruses (CMV) play a pivotal role in the initiation of virus-host cell interactions. Therefore, cis- and trans-acting factors influencing the expression of these proteins through their upstream promoter-enhancer regions are important determinants of the outcome of virus infection. S1 nuclease analysis and in vitro transcription assays with the MIE (or IE94) transcription unit of simian CMV (SCMV) (Colburn) revealed a single prominent mRNA start site associated with a canonical TATATAA motif. This initiator region lies adjacent to a 2,400-bp 5'-upstream noncoding sequence that encompasses a newly identified 1,000-bp (A+T)-rich segment containing intrinsically bent DNA (domain C), together with the previously described proximal cyclic AMP response element locus (domain A) and a tandemly repeated nuclear factor I binding site cluster (domain B). Deleted MIE reporter gene constructions containing domain A sequences only yield up to 4-fold stronger basal expression in Vero cells than the intact simian virus 40 promoter-enhancer region, and sequences from position -405 to -69 (ENH-A1) added to a minimal heterologous promoter produced a 50-fold increase of basal expression in an enhancer assay. In contrast, neither the nuclear factor I cluster nor the bent DNA region possessed basal enhancer properties and neither significantly modulated the basal activity of the ENH-A1 segment. A second segment of domain A from position -580 to -450 was also found to possess basal enhancer activity in various cell types. This ENH-A2 region contains three copies of a repeated element that includes the 10-bp palindromic sequence CCATATATGG, which resembles the core motif of serum response elements and proved to bind specifically to the cellular nuclear protein serum response transcription factor. Reporter gene constructions containing four tandem copies of these elements displayed up to 13-fold increased basal enhancer activity and 18-fold tetradecanoyl phorbol acetate responsiveness in U937 cells, but an ENH-A2 DNA segment encompassing two of the core serum response transcription factor binding sites failed to respond to serum induction in NIH 3T3 cells. Although there are overall similarities in the organizations of both the MIE enhancers and MIE transcription units among human CMV, SCMV, and murine CMV, the specific arrangements of repetitive motifs are quite different, and the bent DNA and ENH-A2 domains appear to be unique to SCMV.
Base Sequence↗
Localization of the human cytomegalovirus 2.7-kb major early beta-gene transcripts by RNA in situ hybridization in permissive and nonpermissive infections.
During the early phase of a human cytomegalovirus (HCMV) infection, the 2.7-kb early gene is by far the most abundantly transcribed RNA. Using strand-specific 32P or digoxigenin-labeled riboprobes derived from a subgenomic fragment of the HCMV Towne 2.7-kb early gene, we have performed Northern blot analysis and RNA in situ hybridization on human and mouse fibroblasts infected with HCMV and on 23 formalin-fixed paraffin-embedded sections of tissue obtained at autopsy. By Northern blot analysis, expression of the 2.7 kb early gene was found only in permissive infections. In contrast, specific hybridization was detected in both permissive and nonpermissive cells by RNA in situ hybridization. In nonpermissive cells, hybridization was weak and predominantly nuclear. In permissive cells, strong nuclear and cytoplasmic hybridization was noted. Specific hybridization to cells with and without cytopathic changes was detected with the anti-sense probe in CMV infected tissue obtained at autopsy. When the sense riboprobe was employed, no specific hybridization was found under nondenaturing conditions. These results suggest that in situ hybridization with a probe directed at the 2.7-kb early gene is an effective method of detecting both permissive and nonpermissive HCMV infections in different stages of infection and in localizing the expression of the major early gene in various cell types.
Animals↗
[Pseudolymphoma of the lung: report of a case].
Explore the source record for details and available documents.
Diagnosis, Differential↗