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Biomedical subjects

C K Chen

Publications and source records attributed to C K Chen.

At least 91 records · Page 5Linked to original sources

Synchronous primary carcinomas of the endometrium and ovary.

OBJECTIVES: Synchronous carcinomas of the endometrium and ovary may indicate either independently developing neoplasms or metastatic disease. The clinical implications and prognosis of these two categories are quite different. The objectives of this study were to identify and evaluate the empirical criteria and significant therapeutic implications. METHOD: The National Taiwan University Hospital Cancer Registry records and pathological reports from 1977 to 1994 were reviewed. Empirical criteria were used to identify synchronous primary cancers. RESULTS: A total of 322 patients had endometrial cancer and 421 patients had ovarian cancer in our Cancer Registry records. Eleven patients had simultaneous cancer involvement of both the endometrium and ovary. Six cases fulfilled the criteria of synchronous primary carcinomas of the endometrium and ovary. Of these, five were alive and free of disease for 35-144 months (median 94.2 months). The disease-free survival rates between patients with synchronous primary and metastatic cancers of different histologic types showed a statistically significant difference (P = 0.013). No statistical significance was noted for different histologic types (P > 0.5). CONCLUSIONS: The empirical criteria used here were useful in identifying synchronous primary cancers of the endometrium and ovary. The favorable clinical outcome may relate to early detection of early-stage disease and low-grade malignancy with an indolent growth rate. Surgical management with or without adjuvant therapy has a satisfactory outcome in our experience.

Adult↗

Increased expressions of CD69 and HLA-DR but not of CD25 or CD71 on endometrial T lymphocytes of nonpregnant women.

To investigate lymphocyte subpopulations and the status of T-cell activation at different phases of the menstrual cycle, lymphocytes in endometrial tissue were analyzed by dual-color flow cytometry in 39 patients. Compared with peripheral blood, the lymphocytes in the endometrium had a higher CD3-/(CD56+ or CD16+) ratio (25.2% +/- 6.8% vs 11.1% +/- 7.0%), but an inverted CD3+ CD8-/CD3+ CD8+ ratio (0.5 vs 1.8) and a minimal amount of B cells (3.3% +/- 3.1%). TcR gamma delta + T cells accounted for a minor proportion (7.8% +/- 5.1%) in endometrium. The proportions of TcR alpha beta + (85.0% +/- 6.6%) and CD3+ CD56+ (7.4% +/- 4.4%) endometrial T lymphocytes were found significantly different from those in peripheral blood (89.1% +/- 5.6% and 3.8% +/- 3.4%, respectively). As the endometrium proceeded from proliferative phase to luteal phase, the proportion of CD3+ CD8+ T cells in peripheral blood increased from 35.6% +/- 6.9% to 41.3% +/- 8.4% and CD3+ CD8- T cells decreased from 64.4% +/- 6.9% to 58.7% +/- 8.4%. The endometrial T cells expressed high levels of CD69 (84.1% +/- 18.9%) and DR (75.9% +/- 9.7%), but rarely expressed CD25 (7.0% +/- 5.4%) and CD71 (2.8% +/- 1.8%). The patterns of expression of these activation markers were similar in both proliferative and luteal phases. Our observations suggest that endometrial T lymphocytes are in a state of recent and persistent activation. Lymphocytes expressing the NK cell markers (CD56 or CD16) and CD8+ accounted for a significant proportion, suggesting that they may play important roles in local defense.

Adult↗

Acute interstitial nephritis associated with ticlopidine.

Ticlopidine, a platelet aggregation inhibitor, has been approved to decrease the risk of thrombotic stroke. We describe a 75-year-old white woman who developed acute renal failure 10 days after initiating ticlopidine therapy. A renal biopsy revealed interstitial infiltrates containing lymphocytes and eosinophils. To our knowledge this is the first report of ticlopidine-induced acute interstitial nephritis.

Acute Kidney Injury↗

Is total abdominal hysterectomy with bilateral salpingo-oophorectomy adequate for new FIGO stage I endometrial carcinoma?

OBJECTIVE: The new FIGO staging for endometrial cancer cases complies with other forms of surgical staging and correlates better with clinical outcomes because it includes prognostic factors. This study was done to investigate whether total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH+BSO) is adequate for new FIGO Stage I endometrial carcinoma. SUBJECTS: Sixty-five cases of endometrial carcinoma defined according to the new FIGO Stage Ia (n = 26), Ib (n = 24) and Ic (n = 15) were analysed. They all received TAH+BSO only and were followed up for at least two years. METHODS: The histologic type, grade, depth of myometrial invasion, lympho-vascular tumour emboli and tumour size were analysed by t-test to correlate the risk factors for treatment failure. RESULTS: There were no recurrences after TAH+BSO in Ia and Ib cases. However, recurrences occurred in five cases (33%) of Stage Ic with deep myometrial invasion, high histologic grade, large tumour size and tumour emboli. CONCLUSIONS: TAH+BSO is inadequate in some Ic cases with a high histologic grade, deep myometrial invasion and tumour emboli. Thus, thorough pre-operative and intra-operative staging, adequate operation method and prompt post-operative adjuvant therapy are indispensable for successful treatment.

Adult↗

Immunoelectrophoretic differentiation of alpha-fetoprotein in disorders with elevated serum alpha-fetoprotein levels or during pregnancy.

Our study aims to make differential diagnosis by immunoelectrophoresis for some common conditions with elevated levels of serum alpha-fetoprotein (AFP). One hundred and nine cases with elevated AFP levels were included in this study: yolk sac tumor (n = 8), hepatocellular carcinoma (n = 26), gastric cancer (n = 12), chronic hepatitis (n = 27) and normal pregnancy (n = 36). Lectin agarose gel electrophoresis, antibody-affinity blotting, and immunoreaction were used to identify the specific patterns of AFP in the respective conditions. The results showed that there were three possible bands: L1, L2 and L3. Yolk sac tumor produced a prominent L2 band and a light L3 band. Hepatocellular carcinoma produced a prominent L1 band and a light L3 band. Gastric cancer produced only an L1 band. Chronic hepatitis had a light L1 band and a pronounced L3 band. In pregnancy, the AFP pattern is similar to that of hepatocellular carcinoma. Immunoelectrophoresis is a useful method facilitating the differentiation of AFP origins.

Biomarkers, Tumor↗

A highly conserved homologue of bovine neurocalcin in Drosophila melanogaster is a Ca(2+)-binding protein expressed in neuronal tissues.

Polymerase chain reaction was used to search for genes encoding recoverin-like proteins in Drosophila melanogaster. We identified a gene that codes for a cognate of bovine neurocalcin; hence, we have named it neurocalcin (nca). A cDNA of nca was isolated and sequenced. The deduced polypeptide product of the cDNA is 22 kDa in size, and its amino acid sequence is 88% identical to that of bovine neurocalcin. This deduced Drosophila neurocalcin (DrosNCa) protein has three putative EF-hands and has a sequence in its NH2 terminus required for fatty acylation. DrosNCa was expressed in Escherichia coli and subsequently purified by phenyl-Sepharose chromatography and Mono Q anion exchange fast protein liquid chromatography. This recombinant protein was capable of binding 45Ca2+ and exhibited Ca(2+)-dependent mobility shifts in both SDS-polyacrylamide gel electrophoresis and native gel electrophoresis. DrosNCa was tritiated when it was coexpressed in E. coli with N-myristoyl transferase in the presence of [3H]myristic acid. The nca transcript was approximately 1 kilobase long, and tissue in situ hybridization showed that this message was present in the brain of adult flies. Antibodies raised against recombinant DrosNCa cross-reacted with rat hippocalcin on an immunoblot but not with bovine recoverin. When immunohistochemical analysis was performed, staining was observed throughout the central nervous system of adult flies, particularly in the neuropil, where neurons synapse. The nca locus maps to or near 76F on the Drosophila third chromosome.

Amino Acid Sequence↗

A reverse transcription-polymerase chain reaction study of p75 nerve growth factor receptor gene expression in developing rat cerebellum.

The actions of the neurotrophins are mediated through specific receptors. Nerve growth factor (NGF), the prototypic neurotrophin, binds to receptors of both high and low affinity. A protein 75 kDa in size (p75NGFR) binds NGF, as well as brain-derived neurotrophic factor and neurotrophin 3, with low affinity. Recent investigations suggest that this protein may also be a component of the high affinity NGF receptor complex. To study gene expression of the p75NGFR molecule, we used a sensitive reverse transcription-polymerase chain reaction (RT-PCR) assay to measure levels of its messenger RNA (mRNA) in small samples of total RNA. The assay is based on using a shortened p75NGFR cRNA as an internal RNA standard to control for variability in reverse transcription and polymerase chain amplification. We measured p75NGFR mRNA levels in the rat cerebellum during ontogeny to further study the transient developmental increase in receptor gene expression known to occur in this brain region during the early postnatal period. We found that p75NGFR mRNA levels were most abundant at postnatal day 2, and then declined to lower levels throughout postnatal development and in the adult. Northern blot analysis of the same total RNA samples used in our RT-PCR assay verified that p75NGFR expression is highest in the early postnatal period. These results confirm those of previous studies accomplished with much larger amounts of RNA using ribonuclease protection or northern blot assays. The use of an RT-PCR assay that utilized an internal standard also controls against changes in RNA complexity which can affect the measurement of message abundance across developmental stages.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

Myoepithelial carcinoma of the breast with distant metastasis and accompanied by adenomyoepitheliomas.

A breast tumour in a 47-year-old female with axillary lymph node metastasis was interpreted as the rare malignant adenomyoepithelioma based on morphological and immunohistochemical studies. Multiple bone metastases developed and the patient died after 7 months. The malignant neoplasm consisted of cords and interlacing bundles of spindle cells with indistinct cell borders and clear cytoplasm. The cells stained positively for cytokeratin, S-100 protein, GFAP, and muscle-specific actin, and possessed basal lamina, pinocytic vesicles, tonofilaments, desmosomes, and intermediate filaments with dense bodies. In some areas, cells with microvillous projections enclosed small spaces. In the breast, foci of myoepithelioma with various morphological subtypes and infiltration coexisted, demonstrating the origin of the malignant tumour. The histogenesis of the myoepithelial tumours is discussed.

Biopsy↗

Characterization of galanin receptor in canine small intestinal circular muscle synaptosomes.

We used 125I-galanin (porcine) as ligand to study the galanin receptors in circular muscle and deep muscular plexus from canine small intestine. Specific binding sites were found in both nerve and muscle membranes. On synaptosomal membranes, the equilibrium binding study showed a high-affinity (dissociation constant, Kd = 1.1 +/- 0.13 nM; maximum binding capacity, Bmax = 244 +/- 2.1 fmol/mg) binding site. The specific binding of 125I-galanin to nerve membrane was inhibited by galanin or NH2-terminal galanin fragments but not by the COOH-terminal fragment. Computer analysis suggested a two-site model (inhibitor constants, Ki1 = 0.02 +/- 0.005 nM and Ki2 = 1.05 +/- 0.3 nM) for competition by galanin-(1-29). Kinetic and competition studies using guanosine 5'-O-(3-thiotriphosphate) or pertussis toxin (PTX) suggested that the high-affinity binding site involved a PTX-sensitive G protein which acted to slow dissociation of bound galanin from the receptor. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the galanin receptor complex revealed a radioactive band at 50 kDa. We conclude that, in canine small intestine, galanin may act as an inhibitory neuromodulator by a PTX-sensitive G protein-coupled interaction of galanin and its specific receptor on enteric nerve synaptosomes.

Animals↗

Galanin receptor in plasma membrane of canine small intestinal circular muscle.

High-affinity binding sites for galanin were identified and characterized in plasma membrane of circular muscle from canine small intestine using 125I-radioiodinated synthetic porcine galanin. Scatchard analysis indicated a high-affinity binding site on plasma membrane with a dissociation constant (Kd) of 0.58 nM and a binding capacity of 389 fmol/mg. Unlabeled galanin or NH2-terminal galanin fragments competitively inhibited the binding of 125I-galanin in a concentration-dependent manner, whereas the COOH-terminal fragment was inactive. Computer analysis of competitive binding data suggested a two-site model with a high-affinity (inhibitor constant, Ki = 0.01 nM) and a low-affinity (Ki = 2.8 nM) binding site. Guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) enhanced the dissociation of bound 125I-galanin. Cholera toxin (CTX) and GTP gamma S abolished the activity of the high-affinity binding site, leaving the low-affinity binding site. We conclude that galanin may act as an neurotransmitter to inhibit canine small intestinal smooth muscle contraction by interaction with a CTX-sensitive G protein-coupled specific receptor on muscle membrane. This receptor showed different G protein coupling from a synaptosomal receptor previously described in the same tissue preparations.

Animals↗

Evaluation of immunosuppressive acidic protein in human ovarian cancer.

This study was conducted to determine the levels of serum immunosuppressive acidic protein (IAP) in Chinese female controls and patients with ovarian tumors; and to examine the usefulness of serum IAP as an additional diagnostic test for ovarian cancer. Serum IAP was determined by a single radial immunodiffusion method. Blood samples were collected prior to surgery from patients with ovarian tumors and from female controls. A histologic diagnosis was made, and staging was performed on the basis of the FIGO staging system for ovarian cancer. The studied subjects included 33 healthy controls, 33 patients with benign ovarian tumors and 32 patients with ovarian cancer (stage I-III, and recurrent). The data were analyzed by Student's t test, Fisher's exact test and the one-way ANOVA test. The mean (+/- SD) level of serum IAP in controls was 330 +/- 61 micrograms/ml. The calculated normal upper limit (mean plus 2 SD) was 452 micrograms/ml. The mean value (867 +/- 392 micrograms/ml) in ovarian cancer was significantly higher than the controls (p < 0.001) or the benign ovarian tumors (333 +/- 95 micrograms/ml) (p < 0.001). Five (15.6%) of 32 patients with ovarian cancer had false-negative results. Three (9.1%) of 33 patients with benign ovarian tumors showed false-positive IAP levels. The pathologic diagnosis of these three patients revealed that two had endometrioma and one had mucinous cystadenoma with hemorrhagic necrosis. Three of four patients with epithelial ovarian cancer of borderline malignancy had IAP levels only slightly higher than the cut-off point of 452 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Linear growth response to recombinant human growth hormone in children with growth hormone deficiency.

BACKGROUND: This study was to evaluate the efficacy, safety and immunogenicity of recombinant human growth hormone (rhGH) in treatment of children with growth hormone deficiency (GHD). METHODS: We selected 15 children with GHD for a 12-month clinical trial and separated them into three groups with each 5 patients receiving one of the 3 tested rhGH (Saizen by Serono, Aubonne, Switzerland; Genotropin by KabiVitrum, Stockholm, Sweden and Humatrope by Eli Lilly, Indianapolis, USA). RESULTS: In Saizen group, 3 boys and 2 girls with a mean chronological age (CA) of 10.6 +/- 1.7 yrs and bone age (BA) of 6.7 +/- 1.2 yrs, at dose of 0.2 IU/kg sc tiw, gained an average BA of 2.1 +/- 1.3 yrs. The mean height velocity (HV) increased from 3.7 +/- 1.2 to 11.1 +/- 3.3 cm/yr. The height standard deviation score (SDS) increased from -4.2 +/- 3.1 to -3.1 +/- 2.9. In Genotropin group, 2 boys and 3 girls with a mean CA of 9.2 +/- 2.3 yrs and BA of 5.6 +/- 2.1 yrs, at dose of 0.1 IU/kg sc qd, gained an average BA of 0.8 +/- 0.2 yr. The mean HV increased from 3.4 +/- 0.7 to 11.3 +/- 2.0 cm/yr. The height SDS increased from -4.0 +/- 0.5 to -2.7 +/- 0.7. In Humatrope group, 4 boys and 1 girl with a mean CA of 10.3 +/- 3.5 yrs and BA of 5.8 +/- 2.9 yrs, at dose of 0.1 IU/kg sc qd, gained at average BA of 0.8 +/- 0.7 yr. The mean HV increased from 4.0 +/- 1.3 to 9.4 +/- 1.9 cm2yr, and the height SDS increased from -2.9 +/- 0.7 to -2.2 +/- 1.0. Very low titers of anti-rhGH antibodies were noted only in two patients, one in Saizen group (titer = 1:10) and the other in Genotropin group (titer = 1:6). Their HV was not affected (Saizen: 13.3 cm/yr, Genotropin: 11.2 cm/yr). One patient evolved subclinical hypothyroidism whereas no side effect at all was noted in the rest of patients. CONCLUSIONS: Three tested GH (Saizen, Genotropin, Humatrope) produced by recombinant DNA technology appear to make no significant difference in this clinical trial, and rhGH therapy is an effective and safe treatment for prepubertal GHD children.

Adolescent↗

Downregulation of cGMP phosphodiesterase induced by expression of GTPase-deficient cone transducin in mouse rod photoreceptors.

PURPOSE: Photoexcitation of vertebrate retinal rod photoreceptors stimulates GTP binding to the transducin alpha subunit. Like other GTP-binding proteins, transducin restores itself to an inactive form by hydrolyzing its bound GTP. The role of GTP hydrolysis in phototransduction was investigated. METHODS: A mutant form of cone transducin alpha deficient in its ability to hydrolyze bound GTP was expressed in mouse rod photoreceptors. RESULTS: Expression of the mutant cone transducin alpha at levels threefold to sixfold higher than endogenous rod transducin alpha led to a specific depletion of the transducin target, cGMP phosphodiesterase, and a decrease in the cGMP level. Suction electrode recordings revealed abnormally prolonged flash responses, decreased maximal response amplitudes, and a shift in the stimulus-response relation to higher flash strengths. CONCLUSIONS: Rods expressing high levels of GTPase-deficient cone transduction alpha have reduced levels of phosphodiesterase catalytic subunits and cGMP. These changes are associated with prolonged flash responses, reduced dark current, and decreased sensitivity to light.

3',5'-Cyclic-GMP Phosphodiesterases↗

Role of the acylated amino terminus of recoverin in Ca(2+)-dependent membrane interaction.

Recoverin, a calcium ion (Ca2+)-binding protein of vertebrate photoreceptors, binds to photoreceptor membranes when the Ca2+ concentration is greater than 1 micromolar. This interaction requires a fatty acyl residue covalently linked to the recoverin amino (NH2)-terminus. Removal of the acyl residue, either by proteolytic cleavage of the NH2-terminus or by production of nonacylated recoverin, prevented recoverin from binding to membranes. The acylated recoverin NH2-terminus could be cleaved by trypsin only when Ca2+ was bound to recoverin. These results suggest that the hydrophobic NH2-terminus is constrained in Ca(2+)-free recoverin and liberated by Ca2+ binding. The hydrophobic acyl moiety of recoverin may interact with the membrane only when recoverin binds Ca2+.

1,2-Dipalmitoylphosphatidylcholine↗

Phylogeny of species in the family Neisseriaceae isolated from human dental plaque and description of Kingella oralis sp. nov [corrected].

Fourteen human periodontal isolates recovered from a purported Eikenella corrodens-selective medium containing 1 microgram of clindamycin per ml displayed biochemical traits which differed from those described for E. corrodens. These organisms were gram-negative rods which corroded agar. The isolates were oxidase positive and urease, indole, and esculin negative. They differed from E. corrodens in catalase, nitrate reduction, lysine decarboxylase, and ornithine decarboxylase activities. One isolate, strain UB-294, was presumptively identified as Kingella denitrificans. A second isolate, strain UB-204, differed from E. corrodens by being catalase positive and nitrate reduction negative. Twelve isolates, including strain UB-38T (T = type strain), were phenotypically similar to Kingella kingae except that they did not produce acid from maltose and were not beta-hemolytic. Essentially complete (1,480-base) 16S rRNA sequences were determined for strains UB-38T, UB-204, and UB-294 and the type strains of Neisseria animalis, Neisseria canis, Neisseria denitrificans, Neisseria elongata, Neisseria flavescens, Neisseria macaca, and Neisseria polysaccharea. These sequences were compared with the previously published sequences of six other species belonging to the family Neisseriaceae. On the basis of the results of the comparative sequence analysis, UB-294 was confirmed as a K. denitrificans strain, UB-204 was identified as a member of a new species which may belong in the genus Eikenella, and UB-38T was identified as a member of a new species of the genus Kingella, for which we propose the name Kingella oralis [corrected]. Since strain UB-204 was the only representative of a new species, it was not named.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Proteins↗

Membrane protein expression by Actinobacillus actinomycetemcomitans in response to iron availability.

Iron-limited growth conditions under anaerobiosis were established for Actinobacillus actinomycetemcomitans strains Y4, JP2, and 75 by use of the ferrous ion chelator 2,2'-dipyridyl. Growth inhibition was reversible with both ferrous and ferric iron sources. Sarcosyl-insoluble membrane fractions of iron-stressed anaerobic A. actinomycetemcomitans cultures revealed a similar iron-repressible protein of approximately 70 kDa in A. actinomycetemcomitans strains Y4, JP2, and 75. This 70-kDa protein was recognized by serum from localized juvenile periodontitis patients and a periodontally healthy subject. This suggested that the 70-kDa iron-repressible protein may be expressed in vivo. When A. actinomycetemcomitans was grown under aerobic conditions, the ferric iron chelator, ethylenediamine di(o-hydroxyphenylacetic acid) (EDDA) was utilized for growth limitation. EDDA inhibition was reversible in strain Y4 with ferrous and ferric iron sources. An iron-repressible protein of approximately 70 kDa was also noted in iron-stressed aerobic cultures. The 70-kDa protein may be involved in iron transport by A. actinomycetemcomitans. Preliminary experiments were performed to examine potential iron transport systems for A. actinomycetemcomitans. Production of the two most common chemical types of siderophore was not detected in A. actinomycetemcomitans culture supernatants. Iron-starved A. actinomycetemcomitans cells did not bind transferrin or lactoferrin in a dot blot assay.

2,2'-Dipyridyl↗

Sexual precocity due to McCune-Albright syndrome: report of a case.

McCune-Albright syndrome is one of the causes of isosexual precocity in girls. Recurrent ovarian cysts are not uncommon in McCune-Albright syndrome; however, treatment for these cysts is still controversial. We report on a six-year-old girl with sexual precocity due to recurrent ovarian cysts. Initially, she received a left salpingo-ophorectomy for an ovarian cyst at the age of two years and one month; the postoperative course was uneventful. Unfortunately, sexual precocity and a cyst on the remaining ovary were noted four years later. A series of studies revealed a hyperpigmented area with an irregular margin on the back and probable fibrous dysplasia of the orbital bone. A luteinizing hormone-releasing hormone test showed a prepubertal response. Cyproterone acetate was tried under the diagnosis of McCune-Albright syndrome, and her secondary sexual characteristics disappeared after treatment.

Child↗

Cryptococcal infection of the vagina.

BACKGROUND: Cryptococcal infection is opportunistic and occurs most commonly in immunocompromised patients. Meningitis is the most frequent manifestation and causes marked morbidity and mortality. Other sites are less common. We report a case of vaginal cryptococcal infection. CASE: A 72-year-old patient who had undergone resection of the colon for cancer 9 years earlier was noted to have a suspicious lesion on the right vaginal wall after an abnormal Papanicolaou test. Biopsy of the lesion showed findings compatible with cryptococcal infection. Serial examinations revealed no evidence of systemic infection or immunocompromised condition. Empirical treatment was tried with fluconazole. Follow-up colposcopy showed almost complete disappearance of the vaginal lesion, and histologic section and culture of the tissue failed to reveal cryptococcus. CONCLUSION: Cryptococcal infection is rare, especially in a patient with no evidence of an immunocompromised condition. The preliminary result of fluconazole treatment was satisfactory. However, further follow-up and evaluation are needed to confirm the effectiveness of fluconazole in our patient.

Aged↗