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Biomedical subjects

C Y Chuang

Publications and source records attributed to C Y Chuang.

At least 19 recordsLinked to original sources
PubMed2001

Reciprocal regulatory interaction between human herpesvirus 8 and human immunodeficiency virus type 1.

Human herpesvirus 8 (HHV8) is the primary viral etiologic agent in Kaposi's sarcoma (KS). However, individuals dually infected with both HHV8 and human immunodeficiency virus type 1 (HIV-1) show an enhanced prevalence of KS when compared with those singularly infected with HHV8. Host immune suppression conferred by HIV infection cannot wholly explain this increased presentation of KS. To better understand how HHV8 and HIV-1 might interact directly in the pathogenesis of KS, we queried for potential regulatory interactions between the two viruses. Here, we report that HHV8 and HIV-1 reciprocally up-regulate the gene expression of each other. We found that the KIE2 immediate-early gene product of HHV8 interacted synergistically with Tat in activating expression from the HIV-1 long terminal repeat. On the other hand, HIV-1 encoded Tat and Vpr proteins increased intracellular HHV8-specific expression. These results provide molecular insights correlating coinfection with HHV8 and HIV-1 with an unusually high incidence of KS.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Experiences in thoracoscopic sympathectomy for axillary hyperhidrosis and osmidrosis: focusing on the extent of sympathectomy.

HYPOTHESIS: A more selective sympathectomy can improve the outcome of axillary hyperhidrosis and osmidrosis and minimize the potential sequelae. DESIGN: Retrospective cohort. SETTING: Tertiary care center. PATIENTS: Between July 1, 1996, and May 30, 2000, 171 patients with axillary hyperhidrosis and osmidrosis were studied. INTERVENTIONS: T3-4 sympathectomies were performed in 40 patients (group 1), T4 sympathectomies were performed in 56 patients (group 2), and T4-5 sympathectomies were performed in 75 patients (group 3). MAIN OUTCOME MEASURES: The surgical outcomes were evaluated by direct patient interview in the outpatient clinic or by telephone or mail questionnaires. The results were categorized as excellent (significant or complete disappearance of symptoms), good (>/=50% improvement), or poor (<50% improvement). RESULTS: There were no surgical mortalities in this study. Twenty-eight group 1 patients (70%), 16 group 2 patients (29%), and 22 group 3 patients (29%) developed compensatory perspiration (P<.001). Six group 1 patients (15%), 1 group 2 patient (2%), and 1 group 3 patient (1%) developed dry hands (P =.02). In the group 1 patients, the surgical outcomes were excellent in 21 (52%), good in 6 (15%), and poor in 13 (32%). In the group 2 patients, the surgical outcomes were excellent in 29 (52%), good in 10 (18%), and poor in 17 (30%). In the group 3 patients, the surgical outcomes were excellent in 53 (71%), good in 11 (15%), and poor in 11(15%) (P =.04). (Percentages may not sum to 100 because of rounding.) CONCLUSION: T4-5 sympathectomies provide higher patient satisfaction rates in treating axillary hyperhidrosis and osmidrosis, with fewer sequelae.

Adolescent↗
PubMed2001

Hydroxychloroquine sulphate inhibits in vitro apoptosis of circulating lymphocytes in patients with systemic lupus erythematosus.

The serological hallmark of systemic lupus erythematosus (SLE) is the presence of antibodies against double-stranded DNA. However, several studies have suggested that it is not DNA itself, but nucleosomes that are the immunogenic particles involved both in the induction of anti-DNA antibodies, and in the pathophysiology of SLE. Meanwhile, It has been demonstrated that there is an accelerated in vitro apoptosis of lymphocytes from patients with SLE. Therefore, one can postulate that the process of apoptosis may provide a source of nuclear antigens to drive the autoantibody response seen in SLE. Our study has demonstrated that hydroxychloroquine exhibits an anti-apoptotic action and this anti-apoptotic effect is dependent on monocyte coexistence. We used both morphology assessment and fluorescent antibody cell sorter (FACS) analysis to measure the apoptotic percentage of lymphocytes from 25 SLE patients in medium alone (control) or with the addition of different concentrations of hydroxychloroquine. Our results have shown that there is a significant decrease in the percentage of apoptosis at the therapeutic concentration (10(-6) M) as compared with the control (p < 0.05). It has been reported that the anti-rheumatic properties of hydroxychloroquine result from its interference with antigen processing in macrophages and other antigen-presenting cells. We propose that this results in decreased stimulation of autoreactive lymphocytes reactive with self-peptides, and consequently diminution of activation-induced cell death (apoptosis) of mature peripheral lymphocytes.

Acridine Orange↗
PubMed2001

Expression of apoptosis-regulating proteins p53, Bcl-2, and Bax in primary resected esophageal squamous cell carcinoma.

Apoptosis plays a key role in the pathogenesis, aggressiveness, and therapy responsiveness of cancer. Proteins of the Bcl-2 family as well as p53 are important regulators of apoptosis. The present study retrospectively examines the expression of apoptosis-regulating proteins in primary resected esophageal squamous cell carcinoma (ESCC) and the correlation between the outcome of patients' treatment and the expression of the proteins. We used antibodies specific for the human p53, Bcl-2 and Bax proteins to examine the expression of these apoptosis-regulating proteins in 40 archival specimens of patients with primary resected esophageal squamous cell carcinoma. The overall expression of p53, Bcl-2, and Bax was 73%, 18%, and 100%, respectively. No significant correlations were found between the expression of p53, Bcl-2, and Bax. The expression of Bcl-2 had a negative influence on survival in this population of primary resected ESCC patients (p=0.03). But no differences in survival were observed in relation to the expression of p53 or Bax. In conclusion, Bcl-2 expression may provide additional and prognostic information for the clinical course of the disease and therefore to be developed as a prognostic indicator for primary resected esophageal squamous cell carcinoma.

Apoptosis↗
PubMed2000

Endoscopy in acquired immunodeficiency syndrome patients with diarrhea and negative stool studies.

BACKGROUND: Diarrhea is a frequent gastrointestinal symptom in patients with acquired immuno-deficiency syndrome (AIDS) and is a major source of morbidity and mortality. A stepwise diagnostic approach is often recommended to search for treatable causes. However, whether the stepwise diagnostic approach is adequate for planning treatment and whether specific treatment for infectious etiologies will affect the survival of patients with AIDS remain unknown. METHODS: From March 1996 to September 1997, endoscopy was performed in AIDS patients with diarrhea, the etiology of which was not identified by noninvasive methods. Specific treatment was given according to the identified etiologies and symptomatic treatment was given for those without definite diagnosis. The clinical symptoms, signs, and duration of follow-up were recorded and survival patterns were analyzed. RESULTS: Etiologic diagnoses were made in 26 of 40 patients (65%) who underwent endoscopic studies. Amebic colitis and cytomegalovirus colitis were the 2 leading causes of prolonged diarrhea in patients with AIDS. Thirty-five patients (87.5%) recovered after treatment. The difference in survival time after diarrhea between patients whose symptoms resolved after treatment and those who continued to have diarrhea was statistically significant (p < 0.001). CONCLUSIONS: Endoscopic studies were helpful for the diagnosis of prolonged diarrhea in AIDS patients who had negative stool studies and did not respond to 2 weeks of empiric treatment. Specific treatment according to the results of endoscopy may improve survival in these patients.

AIDS-Related Opportunistic Infections↗
PubMed2000

Molecular biology of human immunodeficiency virus type 1.

Since the discovery of human immunodeficiency virus (HIV) as the etiologic agent of acquired immune deficiency syndrome (AIDS) more than a decade ago, tremendous progress has been made in various aspects of this virus and its interplay with the host immune system. The advent of potent combination therapy has made it possible to achieve effective and durable control of HIV-1 replication in vivo, yet the persistence of the latent reservoirs pose a new challenge. The recent identifications of several cellular proteins interacting with different viral gene products have not only shed new insights into our understanding of the HIV-1 and the host cell biology, but also provided the bases for developing novel strategies to block HIV-1 replication. It is from this perspective that we review the current understanding of the molecular mechanisms governing the HIV-1 life cycle.

Base Sequence↗
PubMed2000

Surgical management of substernal goiter.

PURPOSE: We describe the clinical results and complications associated with different surgical approaches to the treatment of substernal goiter. METHODS: We retrospectively reviewed the medical records of 56 patients treated for substernal goiter from 1983 through 1999. Eight had undergone previous thyroidectomy. Posterior mediastinal goiter was diagnosed in eight patients, hyperthyroidism in seven, acute respiratory failure in three, and superior vena cava syndrome in two. All but one of the patients underwent thyroidectomy. RESULTS: Thyroid scan revealed that 88% of patients had substernal goiter. A cervical incision alone was used in 46 of 55 patients. Nine patients underwent thyroidectomy via a thoracic approach. Both lobes were resected in 16 patients. Two deaths occurred: one patient suffered a stroke and another patient developed pneumonia after surgery. The most frequent complication was recurrent laryngeal nerve injury, followed by removal of a normal parathyroid gland and pneumonia. Multinodular goiter occurred in 52 patients. Resected goiter with occult malignancy was found in three patients, two of whom underwent lobectomy only. These three patients had survived at 5, 7, and 11 years postoperatively, respectively. All patients with tracheal lumen narrowing showed a normal sized tracheal lumen 2 to 3 months postoperatively. CONCLUSION: Our data indicate that the presence of a substernal goiter should be considered an indication for resection based on risk of acute respiratory distress, risk of malignancy, and lower surgical morbidity. Most secondary substernal goiters can be simply resected through cervical incision and curation.

Adult↗
PubMed1999

The effect of allergen immunotherapy on in vitro IL-4 and IFN-gamma production by peripheral mononuclear cells in house dust-sensitive Chinese patients with bronchial asthma.

The IFN-gamma produced by Th1 cells and IL-4 produced by Th2 cells are two most important cytokines in the regulation of IgE production. House dust immunotherapy has been tried in the treatment of house dust-sensitive Chinese asthmatic patients with good results. We examined the influence of such treatment on in vitro IL-4 and IFN-gamma production by peripheral blood mononuclear cells in house dust-sensitive asthmatic patients. Allergen immunotherapy in house-dust sensitive asthmatic patients can significantly decrease IL-4 production from peripheral mononuclear cells (p<0.05). The production levels of IL-4 in patients without treatment had higher levels than those in patients with hyposensitization (p<0.01). Such therapy also have some effect on promotion of IFN-gamma production in asthmatic patients. In conclusion, immunotherapy with house dust may have the potential ability to shift the Th1/Th2 balance of immune response to allergens and to create a favorable cytokine microenvironment to suppress the allergic reaction in the asthmatic airway.

Adolescent↗
PubMed1998

Sonographic findings in a fetus with megacystis-microcolon-intestinal hypoperistalsis syndrome.

We describe the perinatal findings in a female fetus with megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS). Prenatal sonography performed during 18-21 weeks' gestation showed a normal amount of amniotic fluid, but the fetus was seen to have a persistently distended stomach, a hugely distended bladder, and bilateral dilated renal calyces. Genetic analysis of amniotic fluid revealed a 46,XX karyotype. The pregnancy was terminated at 22 weeks' gestation. At necropsy, the fetus was found to have prune-belly syndrome, gastric dilatation, pronounced megacystis, bilateral hydronephrosis and megaureters, short bowel, microileum, microcolon, and malrotation of the intestines. This fetus showed the typical clinical and sonographic features of MMIHS, as well as the rare antenatal finding of persistent gastric distention.

Abnormalities, Multiple↗
PubMed1998

Kyphomelic dysplasia in two sib fetuses.

We present the in utero appearances and postmortem radiographic findings of two sib fetuses, a male and a female, with features suggestive of kyphomelic dysplasia. The fetuses had severe bowing of the long bones, short, flared ribs, platyspondyly, metaphyseal flaring, skin dimpling, with normal external genitalia and karyotypes and a normal pregnancy. They were born to a mother with features of brachydactyly type E. Prenatal ultrasonography of each case showed a normal amount of amniotic fluid, a normal brain, a normal biparietal diameter, symmetrical bowing and shortening of the long bones, and a narrow thorax. Our cases provide support for a familial mode of inheritance for both sexes in kyphomelic dysplasia. Prenatal ultrasound examination can be offered in subsequent pregnancies.

Abnormalities, Multiple↗
PubMed1998

Prenatal diagnosis of de novo isochromosome 13q associated with microcephaly, alobar holoprosencephaly and cebocephaly in a fetus.

We report on the prenatal diagnosis, genetic studies, and pathology of a case with de novo isochromosome 13q. A 31-year-old primigravida was referred for genetic counselling at 26 weeks' gestation due to the sonographic findings of intrauterine growth retardation and microcephaly. Level II ultrasonograms further demonstrated alobar holoprosencephaly, hypotelorism, polydactyly, a ventricular septal defect, and a single nostril. A diagnosis of cebocephaly was made. Genetic amniocentesis and cord blood sampling revealed translocation trisomy 13 with a de novo t(13q13q) rearrangement. Chromosomal analysis using G- and C-banding techniques and fluorescence in situ hybridization (FISH) showed an apparent monocentric isochromosome. Molecular analyses using polymorphic molecular markers showed that the rearrangement was consistent with an isochromosome of maternal chromosome 13q[46,XX,i(13)(q10)]. Necropsy confirmed cebocephaly and the prenatally detected anomalies.

Adult↗
PubMed1998

Prenatal diagnosis of de novo interstitial 16q deletion in a fetus associated with sonographic findings of prominent coronal sutures, a prominent frontal bone, and shortening of the long bones.

De novo interstitial 16q deletion diagnosed in utero has not previously been reported. We present a case of fetal de novo interstitial 16q deletion associated with the sonographic findings of prominent coronal sutures, a prominent frontal bone, and shortening of the long bones. Genetic amniocentesis at 23 weeks' gestation revealed a de novo deletion of 16q13-q22. At birth, the fetus manifested a dysmorphic phenotype correlated with monosomy 16q syndrome. Linkage analysis of the family confirmed the maternal origin and the extent of the deletion. We suggest that prenatal detection of a prominent frontal bone with prominent cranial sutures and shortening of the long bones should prompt cytogenetic analysis looking for a deletion in the long arm of chromosome 16.

Adult↗
PubMed1997

Prenatal diagnosis of partial trisomy 12 and partial trisomy 21 due to a 3:1 segregation of maternal reciprocal translocation t(12;21) (p13.3;q21).

We describe the prenatal diagnosis and fetal phenotype of partial trisomy 12 (p13.3-pter) and partial trisomy 21 (pter-q21) due to a 3:1 segregation with tertiary aneuploidy transmitted from a maternal reciprocal translocation 12;21. Genetic amniocentesis of a 39-year-old gravida 2, para 1 woman at 19 weeks' gestation due to advanced maternal age revealed an unusual karyotype of 47,XY,+der(21)t(12;21)(p13.3;q21)mat. The pregnancy was terminated at 24 gestational weeks. The proband postnatally displayed by dysmorphic features of a round flat face with prominent cheeks and high forehead, upward slanting palpebral fissures, epicanthic folds, hypertelorism, a short nose, a broad and depressed nasal bridge, anteverted nares, a deformed philtrum, an open mouth, thin upper vermilion and broad everted lower lip, low-set ears with prominent anthelix and deep concha, broad hands with simian creases, a short neck, and cryptorchidism. The association of the involved chromosomal segments with the phenotype of Down's syndrome and trisomy 12p syndrome is discussed.

Adult↗
PubMed1997

Measurement of synovial tumor necrosis factor-alpha in diagnosing emergency patients with bacterial arthritis.

Because of the high morbidity and mortality in patients with bacterial arthritis, rapidly and correctly diagnosing this critical condition is a challenge to emergency clinicians. Synovial fluid samples were obtained from 75 patients with arthritis disorders who presented to an emergency service, and levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and interleukin-6 (IL-6) were measured. Twenty patients with culture-proven bacterial arthritis had higher levels of synovial TNF-alpha than patients with osteoarthritis or with inflammatory arthritis, including gouty arthritis, rheumatoid arthritis, reactive arthritis, and lupus arthritis. There was a good sensitivity for synovial TNF-alpha level in diagnosing patients with bacterial arthritis. Nearly 100% of patients with bacterial arthritis had elevated synovial TNF-alpha levels. However, synovial IL-1 beta and IL-6 levels failed to discriminate bacterial arthritis from other inflammatory arthritis. Measurement of synovial TNF-alpha level may be useful as a diagnostic aid in emergency patients with bacterial arthritis disorders.

Adult↗