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Biomedical subjects

C Y Wang

Publications and source records attributed to C Y Wang.

At least 73 records · Page 4Linked to original sources
PubMed2001

The effect of prophylactic metaraminol on systemic hypotension caused by induction of anaesthesia with propofol in patients over 55 years old.

We conducted a double-blind, randomised, placebo-controlled study evaluating the efficacy of prophylactic metaraminol for preventing propofol-induced hypotension. Thirty patients aged 55-75 years undergoing general anaesthesia were randomly allocated to receive either metaraminol 0.5 mg or saline before administration of fentanyl 1 microg.kg(-1) and propofol 2 mg.kg(-1). Induction of anaesthesia was associated with a decrease in mean and systolic arterial pressure in both groups (p = 0.0001). However, there was no significant difference between the two groups. These results show that prophylactic use of metaraminol 0.5 mg does not prevent the decrease in blood pressure following fentanyl and propofol induction in older patients.

Adrenergic alpha-Agonists↗
PubMed2001

Colonoscopic manifestations of primary colorectal lymphoma.

BACKGROUND AND STUDY AIMS: Little is known about the colonoscopic manifestation of colorectal lymphoma. This article describes the use of colonoscopy for diagnosis of primary colorectal lymphoma. PATIENTS AND METHODS: We analyzed colonoscopic findings in 13 retrospectively collected cases of primary colorectal lymphoma diagnosed between 1990 and 1999 at our hospital. RESULTS: The primary colorectal tymphomas were distinguished into three colonoscopic types: a) the mucosal type, which included six lymphomas (46%), which were classified into two subtypes, erosive (two lymphomas) and ulcerative (four tymphomas); b) the polypoid type, which included three tymphomas (23%); and c) the massive type, which included four (31%). The proportion of patients with T-cell lineage lymphoma (5 of 12, 42%) was higher than in previous studies. Three cases were diagnosed as enteropathy-associated T-cell (EAT)-like lymphoma: one presenting with multicentric ulcerations, one as a massive type and another as a polypoid type. Of those with B-cell lineage lymphoma (7 of 12, 58%), three presented as massive type, two as polypoid type and two as erosive subtype. CONCLUSIONS: Based on the analysis of colonoscopic records, we have proposed three main types of primary colorectal lymphoma. An unusually high proportion of T-cell lineage lymphomas was noted, but as the number of cases was low, further study is still needed for confirmation.

Adult↗
PubMed2001

Augmented inverse probability weighted estimator for Cox missing covariate regression.

This article investigates an augmented inverse selection probability weighted estimator for Cox regression parameter estimation when covariate variables are incomplete. This estimator extends the Horvitz and Thompson (1952, Journal of the American Statistical Association 47, 663-685) weighted estimator. This estimator is doubly robust because it is consistent as long as either the selection probability model or the joint distribution of covariates is correctly specified. The augmentation term of the estimating equation depends on the baseline cumulative hazard and on a conditional distribution that can be implemented by using an EM-type algorithm. This method is compared with some previously proposed estimators via simulation studies. The method is applied to a real example.

Analysis of Variance↗
PubMed2001

Removal of cardiac beat artifact in esophageal pressure measurement via a modified adaptive noise cancellation scheme.

Information on volume-pressure relationships of human lungs is usually based on indirect determination of intrapleural pressure (P(ip)) obtained from the esophagus. Unfortunately, cardiac beat artifact frequently corrupts measurement of esophageal pressure (P(es)). In this study, we presented a modified adaptive noise cancellation (MANC) scheme for removing the cardiac beat artifact in the P(es) signal. The proposed methodology used an airflow signal as the reference signal with least-mean-square method as the adaptive algorithm. The results of six experiments on two Brown-Norway rats showed a significant reduction of the apparent cardiac pulsation with minimal distortion of the P(es) signal. The MANC filter also showed evidence of peak suppression at integer multiples of heart rate in the fast Fourier transform of the P(es) signal while leaving the remaining spectrum largely unperturbed. A t-test method and the ratio of standard deviation to mean (std/mean) statistics of airway resistance (R(aw)) values were used to evaluate the performance of the MANC filter. In all six experiments, a reduction of std/mean of R(aw) by 12.5%-68% was obtained, indicating the effectiveness of the proposed scheme.

Airway Resistance↗
PubMed2001

Prostate-specific antigen and human glandular kallikrein 2 are markedly elevated in urine of patients with polycystic ovary syndrome.

Prostate-specific antigen (PSA) is a well-established tumor marker of prostatic adenocarcinoma. Human glandular kallikrein 2 (hK2), another serine protease closely related to PSA, is also gaining ground as a promising diagnostic tool in prostate cancer. The expression of these 2 proteases is known to be regulated by androgens and progestins in hormonally responsive tissues, such as the male prostate and the female breast. Previously, we have shown that serum PSA levels in normal women are very low but still detectable by ultrasensitive PSA immunoassays. We have also demonstrated that some women with hyperandrogenic syndromes have elevated serum PSA levels. In this study, we have measured urinary PSA and urinary hK2 levels in 35 polycystic ovary syndrome (PCOS) patients and compared them to those of 41 age-matched controls. We found that urinary PSA levels were significantly higher (P < 0.0001) in PCOS patients (mean +/- SE = 820 +/- 344 ng/L) than in the controls (mean +/- SE = 4.3 +/- 1.8 ng/L). Similarly, the difference between urinary hK2 of patients (mean +/- SE = 8.2 +/- 3.1 ng/L) and controls (0.5 +/- 0.3 ng/L) was also significant (P < 0.001). A weak correlation was observed between urinary PSA and serum 3 alpha-androstanediol glucuronide (r(s) = 0.42, P = 0.03) as well as between urinary PSA and serum testosterone (r(s) = 0.40, P = 0.04). The results of this study indicate that urinary PSA, and possibly urinary hK2, are promising markers of hyperandrogenism in females suffering from PCOS.

Adult↗
PubMed2001

[Studies of FISH and karyotype of Gossypium barbadense].

Based on the fluorescent in situ hybridization (FISH) of somatic chromosome of Gossypium barbadense with the probe of genomic DNA (gDNA) of Gossypium arboreum, two sets of chromosomes were easily distinguished by signals hybridized or not. The FISH directly proved that G. barbadense originated from two different diploid species, but was not in concordance with the former point that every chromosome of A sub-genome of tetraploid species was bigger than that of other sub-genome (D genome). The karyotype formula of G. barbadense based on its FISH was 2n = 4x = 52 = 38 m + 14sm(6sat). There were three pairs of satellite chromosomes which were all sm types. Their satellites located in short arms but originated differently from their chromosomes of sub-genome. Fragment translocations occured in the long arms of homologous chromosomes of number 5, 6 and 9 of A sub-genome. It was suggested that the translated fragments come from D sub-genome. The fragments are fairly large with the relative lengths of 19.21%, 17.69% and 12.88% of their whole chromosomes, respectively. At least five pairs of chromosomes in D sub-genome show some hybridized signals of gDNA probe of G. arboreum in their centromere regions, which indicated that there would be chromatin introgressions from A sub-genome.

Gossypium↗
PubMed2001

Ataxia telangiectasia: report of two cases.

Ataxia telangiectasia (A-T) is a rare autosomal recessive multisystem disease. The diagnosis of A-T is based on the typical clinical picture: ataxia and telangiectasia. However, an increase in (alpha-fetoprotein (AFP) level and the identification of the A-T mutated gene (ATM) assist in an early diagnosis. Here we report two cases of A-T diagnosed in our hospital (case 1: a 7-year-old boy; case 2: an 8-year-old girl). Both of these patients had typical clinical pictures of ataxia and telangiectasia, AFP was also increased (case 1:471.2 ng/dL; case 2: 196 ng/dL). T-cell dysfunction was noted in both patients. Case 1 had IgG2 deficiency and case 2 had IgA, IgG2 and IgG3 deficiency. Case 2 developed malignant lymphoma at 9 years of age and died of pneumonia with respiratory failure at 10 years of age. Because of rhe rarity of A-T in Taiwan, we report two cases to help pediatricians make an early diagnosis of A-T if they have a patient with progressive ataxia and oculocutaneous telangiectasia.

Ataxia Telangiectasia↗
PubMed2001

Steroid allergy: report of two cases.

Corticosteroid preparations have anti-inflammatory and immunosuppressive properties and are widely used in the treatment of asthma and allergic disorders. Steroids themselves, however, can induce hypersensitivity reactions. The number of reports on contact allergy or anaphylactic reactions is increasing. Steroid hypersensitivity should be considered in any patient whose dermatitis becomes worse with topical steroid therapy, or in patients who develop systemic allergic reactions after the use of systemic steroids. The diagnosis can be confirmed by skin testing, in vitro evidence of specific IgE, oral or parenteral challenge, or an allergic patch test. The latter may be positive within 20 min, which indicates immediate contact urticaria, or at 72 to 96 h, which indicates delayed contact hypersensitivity. In this article we report two cases of steroid allergy. Case 1 was a 5-year-old asthmatic boy with an anaphylactic reaction to steroids and aspirin. Case 2 was a 2-year-old boy with atopic dermatitis and steroid contact urticaria. Both cases 1 and 2 showed positive results to triamcinolone, dexamethasone, hydrocortisone, and methylprednisolone in the immediate skin allergy test. Case 2 had immediate contact urticaria to hydrocortisone and clobetasone butyrate. Case 1 had a positive systemic allergic reaction to cortisone acetate, prednisolone, and dexamethasone on the oral steroid challenge test, and also had aspirin induced angioedema and urticaria 10 min after challenge with 50 mg aspirin.

Adrenal Cortex Hormones↗
PubMed2001

Thyroidectomy or radioiodine? The value of ultrasonography and cytology in the assessment of nodular lesions in Graves' hyperthyroidism.

Although diffuse toxic goiter is a classical feature of Graves' disease (GD) nodular goiters are occasionally found in some patients. The aim of the present study was to investigate the ultrasonographic and corresponding cytological manifestations in GD patients with nodular lesions to decide on a therapeutic strategy. Twenty-seven consecutive GD patients with nodular goiter were included in this study (21 women and six men, mean age 41.2 years, range 22-77 years). All underwent thyroid ultrasonography and fine-needle aspiration cytology. Of the 27 patients eight underwent surgical intervention because papillary thyroid carcinoma or follicular neoplasm was diagnosed by cytology; five of these were shown to have papillary thyroid carcinomas. Ultrasonography revealed the malignant nodules to be hypoechogenic, heterogeneous, and with ill-defined margins in four of these five thyroid cancers, whereas the remaining sonogram showed a cystic change and cauliflower-like tumor formation with microcalcification. The volume and maximal diameter of cancerous nodules were significantly larger than those of benign nodules. In conclusion our results reveal that ultrasonography and fine-needle aspiration cytology are reliable and quick methods for diagnosing nodular goiters in GD patients. If thyroid neoplasms are found ablative therapy with thyroidectomy is indicated instead of radioactive iodine.

Adult↗
PubMed2001

Childhood serum sickness: a case report.

Childhood serum sickness is a rare allergic disease that follows the administration of a foreign antigenic material, most commonly caused by injecting a protein or haptenic drug. The disease is a type III hypersensitivity reaction mediated by deposits of circulating immune complexes in small vessels, which leads to complement activation and subsequent inflammation. The clinical features are fever, cutaneous eruptions, lymphadenopathy, arthralgias, albuminuria, and nephritis. Serum sickness is an acute self-limited disease. We report a 3-year-old child who presented with fever and a rash; an invasive bacterial infection was strongly suspected. He was therefore given penicillin and gentamicin and responded well. At day 4 after admission, he developed a serum sickness reaction and showed symptoms of arthralgias, generalized edema, purpura, and gross hematuria. The white blood cell count was 12 190/mm3 with 7% eosinophils. Urinalysis revealed red blood cell above 100 per high power field, white blood cell 10 to 15 per high power field, and proteinuria. The antibiotics were discontinued and hydrocortisone (20 mg/kg/d), diphenhydramine HCl (4 mg/kg/d), aspirin (66 mg/kg/d) was administered, plus 1 dose of epinephrine (0.01 mL/kg) administered intramuscularly. On day 7, the 3rd day after withholding antibiotics, his condition dramatically improved. The clinical symptoms resolved progressively and his urinalysis returned to normal.

Child, Preschool↗
PubMed2001

Thyroid Doppler ultrasonography and resistive index in the evaluation of the need for ablative or antithyroid drug therapy in Graves' hyperthyroidism.

BACKGROUND AND PURPOSE: Graves' disease (GD) is the most common hyperthyroid disorder, but the therapeutic strategy for choosing between medical or ablative therapy has not been standardized. Thyroid hypervascularity is an important diagnostic feature in GD. This study collected Doppler ultrasonography data from patients with GD, Hashimoto's thyroiditis, and simple goiter to develop a hemodynamic index for use in the evaluation of when antithyroid drugs (ATDs) should be withdrawn or ablative therapy given in GD. MATERIAL AND METHODS: Thyroid Doppler ultrasonography was used to measure the resistive index (RI) and pulsatility index (PI) in various thyroid diseases. We studied 88 patients, including 13 untreated GD patients, 14 euthyroid GD patients after withdrawal of ATDs for more than 12 months, 14 euthyroid GD patients with normal thyroid stimulating hormone (TSH) concentrations after regular ATD treatment for 12 months (well controlled), 16 hyperthyroid GD patients with undetectable TSH concentrations after regular ATD treatment for more than 12 months (poorly controlled), 13 Hashimoto's thyroiditis patients, and 18 patients with simple goiters. RESULTS: The PI and RI were significantly different between patients with untreated (median PI/RI 1.36/0.79) or medically well-controlled (median PI/RI 0.66/0.51) GD, but no significant differences in PI and RI were found between patients with untreated or medically poorly controlled (median PI/RI 1.24/0.74) GD. An RI cut-off of at least 0.7 with undetectable TSH was found to be suggestive of the need for ablative therapy in GD patients who had received regular ATD treatment for more than 12 months, because of its statistically high sensitivity and specificity in all untreated and poorly controlled GD patients. An RI of less than 0.6 with normal TSH was suggestive of the need for withdrawal of ATDs in GD patients receiving regular medical treatment, because of its statistically high sensitivity and specificity in all treated euthyroid GD patients. CONCLUSIONS: This study has developed an RI-derived hemodynamic index that determines the need for ablative or ATD therapy in patients with GD. A large-scale, prospective study is needed to confirm its clinical value.

Adult↗
PubMed2000

IL-10, but not IL-4, suppresses infection-stimulated bone resorption in vivo.

Periapical bone resorption occurs following infection of the dental pulp and is mediated mainly by IL-1alpha in the murine model. The production and activity of IL-1alpha is modulated by a network of regulatory cytokines, including those produced by Th1 (pro-inflammatory) and Th2 (anti-inflammatory) subset T cells. This study was designed to assess the functional role of the Th2-type cytokines IL-4 and IL-10 in infection-stimulated bone resorption in vivo. The dental pulps of the first molars were exposed and infected with a mixture of four common endodontic pathogens, and bone destruction was determined by micro-computed tomography at sacrifice on day 21. The results demonstrate that IL-10(-/-) mice had significantly greater infection-stimulated bone resorption in vivo compared with wild-type mice (p < 0.001), whereas IL-4(-/-) exhibited no increased resorption. IL-10(-/-) had markedly elevated IL-1alpha production within periapical inflammatory tissues (>10-fold) compared with wild type (p < 0.01), whereas IL-4(-/-) exhibited decreased IL-1alpha production (p < 0.05). IL-10 also suppressed IL-1alpha production by macrophages in a dose-dependent fashion in vitro, whereas IL-4 had weak and variable effects. We conclude that IL-10, but not IL-4, is an important endogenous suppressor of infection-stimulated bone resorption in vivo, likely acting via inhibition of IL-1alpha expression.

Animals↗
PubMed2000

NF-kappaB-induced loss of MyoD messenger RNA: possible role in muscle decay and cachexia.

MyoD regulates skeletal muscle differentiation (SMD) and is essential for repair of damaged tissue. The transcription factor nuclear factor kappa B (NF-kappaB) is activated by the cytokine tumor necrosis factor (TNF), a mediator of skeletal muscle wasting in cachexia. Here, the role of NF-kappaB in cytokine-induced muscle degeneration was explored. In differentiating C2C12 myocytes, TNF-induced activation of NF-kappaB inhibited SMD by suppressing MyoD mRNA at the posttranscriptional level. In contrast, in differentiated myotubes, TNF plus interferon-gamma (IFN-gamma) signaling was required for NF-kappaB-dependent down-regulation of MyoD and dysfunction of skeletal myofibers. MyoD mRNA was also down-regulated by TNF and IFN-gamma expression in mouse muscle in vivo. These data elucidate a possible mechanism that may underlie the skeletal muscle decay in cachexia.

Animals↗
PubMed2000

Purification, cDNA cloning and function assessment of BmK abT, a unique component from the Old World scorpion species.

A new neurotoxic component named BmK abT was purified from the venom of Chinese scorpion Buthus martensi Karsch. The molecular weight of BmK abT was determined to be 7212 Da on a mass spectrum. The minimum lethal dose of BmK abT was tested to be about 1.5 microg per mouse by intracerebroventricular injection, and the dose induced significant paralysis effect on cockroach was about 5 microg by i.p. injection. The partial amino acid sequence indicated that it was a distinctive polypeptide in the scorpion neurotoxin family. Thereafter, the whole amino acid sequence of mature BmK abT was deduced from cDNA sequence by 5'- and 3'-rapid amplification of cDNA ends. Finally, it was defined to be composed of 63 residues with amidation at the C-terminal residue. By sequence comparison, BmK abT was found to be most similar to Ts VII, a beta-toxin from the New World scorpion. The patch-clamp recording on DRG neurons, unexpectedly, showed this toxin could prolong the action potential and increase the amplitude of the peak Na+ currents, which are the typical characters of alpha-toxin. These results suggested that BmK abT was a new toxic component found in the Old World scorpion species structurally similar to beta-toxins, but functionally similar to alpha-toxins.

Action Potentials↗
PubMed2000

Carcinogenicity of the N-hydroxy derivative of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 2-amino-3, 8-dimethyl-imidazo[4,5-f]quinoxaline and 3, 2'-dimethyl-4-aminobiphenyl in the rat.

Heterocyclic amines and carcinogenic aromatic amines are similarly metabolically activated suggesting that they may have similar organ specificity. Three day-old male ACI/seg rats were injected, i.p., twice a week for 10 weeks with 50 micromol/kg of N-hydroxy-3, 2'-dimethyl-4-aminobiphenyl (N-OH-DMABP; Group II), N-OH-2-amino-3, 8-dimethylimidazo[4,5-f]quinoxaline (N-OH-MeIQx; Group III) or N-OH-2-amino-1-methyl-6-phenylimidaza-[4,5-b]pyridine (N-OH-PhIP; Group IV). Animals in control group (Group I) were similarly injected with solvent alone. The animals were sacrificed at age 68 weeks, and 31, 30, 27 and 31 rats from Groups I, II, III and IV, respectively, were evaluated. Colon carcinomas were found in 0, 15 (P<0.001), 2 and 4 (P<0.06), and bladder transitional cell tumors in zero, two, two and four (P<0.06), in Group I, II, III and IV, respectively. The incidence of atypical hyperplasia of ventral prostate in Groups III and IV, and of anterior prostate and seminal vesicle in all treated groups was also significantly greater (P<0.05). These results suggest that N-OH-PhIP and N-OH-MeIQx may be potential carcinogens for the prostate. Since bladder tumor is rare in ACI rats, N-OH-PhIP may also be a potential carcinogen for the bladder.

Aminobiphenyl Compounds↗
PubMed2000

cAMP pulse during preservation inhibits the late development of cardiac isograft and allograft vasculopathy.

The causes of transplant-associated coronary artery disease remain obscure, and there is no known treatment. Preservation injury of murine heterotopic vascularized cardiac isografts caused a small, albeit significant, increase in neointimal formation; preservation injury of allografts markedly increased both the incidence and severity of transplant-associated coronary artery disease. As cAMP is an important vascular homeostatic mediator the levels of which decline during organ preservation, buttressing cAMP levels solely during initial preservation both improved acute allograft function and reduced the severity of transplant-associated coronary artery disease in grafts examined 2 months later. Inhibiting the cAMP-dependent protein kinase abrogated these beneficial effects. cAMP treatment was associated with an early reduction in leukocyte infiltration and a reciprocal decrease in superoxide and increase in NO levels. These data indicate that alloantigen-independent injury to the graft, which occurs at the time of cardiac preservation, can set in motion pathological vascular events that are manifest months later. Furthermore, a cAMP pulse during cardiac preservation reduces the incidence and severity of transplant-associated coronary artery disease.

Animals↗
PubMed2000

Antisense intercellular adhesion molecule-1 (ICAM-1) oligodeoxyribonucleotide delivered during organ preservation inhibits posttransplant ICAM-1 expression and reduces primary lung isograft failure.

Transiently increased expression of leukocyte adhesion receptors after lung preservation contributes to early graft demise by recruiting leukocytes, activating complement, and causing microcirculatory stasis. We hypothesized that inhibiting intercellular adhesion molecule-1 (ICAM-1) expression even briefly may significantly improve lung graft function and that the preservation period might provide a unique window to deliver a therapeutic pulse of antisense oligonucleotide ICAM-1 to inhibit ICAM-1 expression after transplantation. Interleukin-1beta-treated rat pulmonary endothelial cells given a 20-mer phosphorothioate oligonucleotide comprising an antisense span targeted to the 3'-untranslated region of rat ICAM-1 demonstrated an oligonucleotide dose-dependent reduction in ICAM-1 expression. Using a cationic liposomal carrier, this same antisense oligonucleotide (but not the sense control) instilled into the pulmonary vasculature at the time of preservation reduced subsequent graft ICAM-1 expression and graft leukostasis and markedly improved oxygenation, pulmonary blood flow, and graft survival. These experiments demonstrate that the preservation period presents a window during which to target an anti-ICAM-1 expression strategy to inhibit early adhesion receptor expression and improve functional outcome after lung transplantation.

Animals↗