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Biomedical subjects

C C Pan

Publications and source records attributed to C C Pan.

At least 37 records · Page 2Linked to original sources

Signet-ring cell carcinoma of the rectum with tonsillar metastasis: a case report.

A 36-year-old man was diagnosed as a case of mucinous adenocarcinoma of the rectum, Dukes' C. Pathologic examination revealed abundant signet-ring cells in the tumor. He did not receive adjuvant radiotherapy or chemotherapy after resection of the tumor. Two years later, a 3 x 5 cm mass over the right palatine tonsil was found with associated right neck lymphadenopathy. Right tonsillectomy was performed. Metastatic mucinous adenocarcinoma of the tonsil with abundant signet-ring cells similar to the primary tumor of the rectum was found. Signet-ring cell carcinoma of the rectum with tonsillar metastasis is extremely rare. No case has been reported in the English literature. To the best of our knowledge, this is the first case of signet-ring cell carcinoma of the rectum with tonsillar metastasis. The relevant literature on metastatic tonsillar tumors is reviewed.

Adult↗

A multivariate analysis of prognostic factors in thymoma.

BACKGROUND: Considering the prognostic factors of thymoma, the clinical stage is the most important, while controversies exist about other clinicopathologic factors. A multifactorial study was carried out to clarify the relationship between prognosis and sex, age, tumor size, presence of myasthenia gravis, staging, epithelial subtyping, lymphocyte/epithelial cell ratio (L/E ratio) and other adjuvant pathological features. METHODS: One hundred and thirty-seven cases were collected in Veterans General Hospital-Taipei from 1961 to 1993. The aforementioned features were studied. Kaplan-Meier's actuarial survival analysis was adopted, with Logrank test, to determine the significance of overall heterogeneity and trend. Cox proportional hazard model was also used for multivariate analysis. RESULTS: Among all tested prognostic factors, staging had the highest significance (relative risk = 3.00, p < 0.001) and age had only a moderate one (relative risk = 1.04, p = 0.011). No other clinicopathological factor showed any statistical significance for prognosis. CONCLUSIONS: Staging remains of greatest usefulness in predicting the biological behavior of thymoma. The effect of age requires more investigation. Other clinicopathological features have no definite influence in survival expectancy.

Adolescent↗

Mesoblastic nephroma: a case report.

Mesoblastic nephroma is a rare tumor of kidney characterized by interlacing bundles of spindle mesenchymal cells. The tumor usually occurs in the newborn, and scarcely in the old child. In this article, the authors report a case of an unusual age, a 12-year-old boy, with mesoblastic nephroma which was found by routine physical examination.

Child↗

The clinicopathological correlation of epithelial subtyping in thymoma: a study of 112 consecutive cases.

The clinicopathological features of 112 thymomas collected from the surgical pathological files of Taipei Veterans General Hospital from 1961 to 1991 were investigated to determinate the clinical efficacy of epithelial subtyping. All thymomas were categorized based on the Müller-Hermelink system into three subtypes: cortical thymoma, mixed thymoma, and medullary thymoma. The former was further subclassified into organoid thymoma, conventional cortical thymoma, and well differentiated thymic carcinoma (WDTC) according to the systems of Pescarmona and Kirchner. The association of each subtype with sex, age at diagnosis, clinical stage, presence of myasthenia gravis, and length of survival was studied. As classified by the Müller-Hermelink system, the cortical thymomas as a whole tended to occur in younger patients and were more frequently associated with myasthenia gravis than the medullary thymomas. The cortical thymomas also showed a propensity to be invasive in nature, whereas the medullary thymomas generally behaved as benign tumors. Further subclassification of cortical thymomas into organoid thymoma, conventional thymoma, and WDTC did not provide more information about clinical behavior. By Kaplan-Meier's actuarial survival analyses none of the epithelial subtypes displayed a statistically significant influence on prognosis. It is concluded that staging remains the most important factor affecting the patient's outcome. Because of the existence of many intermediate forms and the deficiency of clinical relevance, the subclassification of cortical thymomas should be interpreted as a morphological continuum rather than as distinct histological variants.

Adolescent↗

Electroejaculation for the treatment of idiopathic anejaculation: a case report.

Electroejaculation to produce semen from anejaculated males has been employed successfully in conjunction with intrauterine insemination (IUI), in vitro fertilization/embryo transfer, and gamete intrafallopian transfer. We herein report the use of IUI to achieve pregnancy following electroejaculation in a patient with primary idiopathic anejaculation. This 30-year-old patient had a history of anejaculation that was noted after marriage, but had normal sexual potency and occasional nocturnal emission. Electroejaculation was successfully used to obtain semen. The highly motile sperm was recovered from swim up procedure and used for IUI. The 25-year-old wife was given clomiphene citrate and Pergonal for ovulation induction. A triplet pregnancy was achieved. At 26 weeks of gestation, the first triplet was delivered after spontaneous rupture of membrane. We tried to delay delivery of this retained twin pregnancy. Thirty-two days later, the remaining two fetuses were delivered weighing 1100 gm and 900 gm. Ninety-three days after delivery, these two babies were discharged, putting on weight to 3564 gm and 3264 gm. This case represents the first success of using electroejaculation to achieve pregnancy from anejaculated patient in Taiwan.

Adult↗

Characterization of filamentous bacteriophage phi Lf from Xanthomonas campestris pv. campestris.

A filamentous phage, phi Lf, which specifically infects Xanthomonas campestris pv. campestris was isolated. The phage particle measured 1,000 (+/- 200) x 8 nm. It formed turbid plaques of about 1 mm in diameter. During multiplication, the progeny virions extruded into the medium without retarding host cell growth. Stocks were stable for 6 months at 4 degrees C and survived treatment at 80 degrees C for 10 min. Treatment with chloroform, ethanol or acetone completely destroyed infectivity; ethyl ether and methanol inactivated 98 to 99% of the phage. SDS-polyacrylamide gel electrophoresis showed a major coat protein band of approximate Mr 4000 whereas an immunoprecipitation test detected the existence of two coat protein species. The phage genome was shown to be a single-stranded DNA molecule. A physical map was constructed and the DNA size was calculated to be 5.9 kb. Cells treated with Tris-HCl containing CaCl2 and polyethylene glycol 6000 were transfected by replicative form DNA at a frequency of 3.4 x 10(3) p.f.u./micrograms.

Bacteriophages↗

Applicability of the product isolation and the radiometric aromatase assays for the measurement of low levels of aromatase: lack of aromatase activity in the human endometrium.

The purpose of this investigation was to assess the applicability of two well established procedures: (i) the product isolation assay and (ii) the radiometric 3H2O assay for the determination of very low levels of aromatase activity. The methods were validated and used to assess the capacity of normal and neoplastic human endometrium to synthesize oestrogens from androgens. Using the product isolation assay, various specimens (n = 27) of normal and neoplastic endometrium were incubated with [1,2,6,7-3H]testosterone either by a standard incubation procedure or by a superfusion technique. Following the incubation, carrier oestrone and oestradiol or [14C]oestrone and [14C]oestradiol were added, and the oestrogens were isolated and purified by paper chromatography and high-performance liquid chromatography. The radiochemical purity of oestrone and oestradiol was checked by the isotope dilution technique. In all samples, the 3H associated with oestrone and oestradiol failed to recrystallize as oestrone and oestradiol. No radioactivity was detectable in the oestrone and oestradiol crystals after acetylation. Similarly, 16 endometrial samples were tested for aromatase activity by the 3H2O release assay using [1 beta-3H]androstenedione as substrate. The results indicate that 3H2O was indeed released during these incubations, but this activity could not be inhibited by the aromatase inhibitor 4-hydroxyandrostenedione, by excess substrate or by heat inactivation of the tissue. Furthermore, the release of 3H2O from [1 beta-3H]androstenedione under the incubation conditions used (Dulbecco's modified Eagle's medium or RPMI-1640 containing fetal bovine serum and NADPH) also occurred in the absence of any tissue. This activity was not inhibited by 4-hydroxyandrostenedione nor by excess substrate. The results demonstrate that the human endometrium does not contain detectable levels of aromatase activity and that the radiometric assay can give rise to false-positive results if used for detection of very low levels of aromatase activity.

Androstenedione↗

Antigenic detection and prognosis of patients with transitional cell carcinoma of the urinary bladder.

We used the specific red cell adherence (SRCA) technique to detect the A, B, O cell surface antigen on 61 transitional cell carcinomas of the urinary bladder seen from 1979 to 1982 at the Urology Department of Kaohsiung Medical College Hospital. It was suggested in this study that the loss of surface antigen had good correlation with both the pathological grade and clinical stage of tumors. On the other hand, the patients deprived of the surface antigen were poorer in prognosis than those with positive surface antigens. Among the four groups of A, B, O and AB patients, patients with blood group O had higher mortality rates, and more susceptibility to loss of the surface antigen. This study also demonstrated that the activation of surface antigen will reduce as the age increased. Of 11 patients with recurrent stage A tumors in this study, 8 had positive surface antigen and 3 had negative surface antigen. In 8 cases of positive surface antigen, 1 (13%) subsequently developed an invasive tumor. In contrast, 2 (67%) among the 3 negative surface antigens developed invasive tumors and the statistics showed significant differences (p less than 0.05). Consequently, the SRCA technique may be valuable for predicting malignant potential in early stage cancer of the bladder.

ABO Blood-Group System↗

Metabolism of [3H]equilin-[35S]sulfate and [3H]equilin sulfate after oral and intravenous administration in normal postmenopausal women and men.

The absorption of equilin sulfate and equilin from the gastrointestinal tract was determined in normal men after the ingestion of [3H]equilin-[35S]sulfate or a mixture of [3H]equilin and equilin-[35S]sulfate, while the metabolism of equilin sulfate was investigated after iv administration of [3H]equilin sulfate to postmenopausal women. After the oral administration of [3H]equilin-[35S]sulfate, equilin sulfate containing both 3H and 35S was isolated from plasma; however, only in the first sample taken at 10 min was the 3H/35S ratio the same as that of the [3H]equilin-[35S]sulfate ingested. The 3H/35S ratio then increased, and by 12 h only traces of equilin-[35S]sulfate were detectable. Similarly, after the ingestion of [3H]equilin and equilin-[35S]sulfate, [3H]equilin-[35S]sulfate was isolated from plasma. The 3H/35S ratio was at all time points greater than the 3H/35S ratio of the ingested mixture. Analysis of urine indicated that over 98% of 35S was not associated with any steroid and was most likely inorganic sulfate. After iv administration of [3H] equilin sulfate to postmenopausal women, equilin, equilenin, 17 beta-dihydroequilin, and 17 beta-dihydroequilenin were isolated from the urine. These results indicate that 1) some of the orally administered equilin sulfate was absorbed from the gut without prior hydrolysis, 2) some equilin sulfate was hydrolyzed in the gut before absorption; 3) equilin was absorbed more efficiently than equilin sulfate; 4) equilin absorbed was readily sulfated and circulated in this form; and 5) equilin sulfate was extensively metabolized, and the metabolites were excreted in the urine mainly conjugated with glucuronic acid.

17-Ketosteroids↗

Congenital nephrotic syndrome. Gallium-67 imaging.

Congenital nephrotic syndrome is a rare disorder. Heavy proteinuria, hypoalbuminemia, and edema occur during the first 3 months of life. Initial cases were reported from Finland and sporadic cases have occurred elsewhere. Finnish cases demonstrated an autosomal recessive inheritance pattern; currently, Finnish and non-Finnish types are recognized. The clinical course consists of failure to thrive, frequent infections, declining renal function, and early death by age 4 years from sepsis or uremia. Recently renal transplantation has improved the prognosis of patients with this disease. An abnormal Ga-67 scan in a case of congenital nephrotic syndrome is presented.

Gallium Radioisotopes↗

Sequence duplication and internal deletion in the integrated human papillomavirus type 16 genome cloned from a cervical carcinoma.

Integrated human papillomavirus type 16 (HPV16) sequences were cloned from a cervical carcinoma and analyzed by restriction mapping and nucleotide sequencing. The viral integration sites were mapped within the E1 and E2 open reading frames (ORFs). The E4 and E5 ORFs were entirely deleted. An internal deletion of 376 base pairs (bp) was found disrupting the L1 and L2 ORFs. Sequencing analysis showed that an AGATGT/ACATCT inverted repeat marked the deletion junction with two flanking direct repeats 14 and 8 bp in length. A 1,330-bp sequence duplication containing the long control region (LCR) and the E6 and E7 ORFs was also found. The duplication junction was formed by two 24-bp direct repeats with 79% (19 of 24) homology located within the LCR and the E2 ORF of the prototype viral genome, respectively. This observation leads us to propose that the initial viral integration involved an HPV16 dimer in which the direct repeats in tandem units recombined, resulting in reiteration of only a portion of the original duplication. A guanosine insertion between nucleotides 1137 and 1138 created a continuous E1 ORF which was previously shown to be disrupted. Results from this study indicate that sequence reiteration and internal deletion in the integrated, and possibly in the episomal, HPV16 genome are influenced by specific nucleotide sequences in the viral genome. Moreover, reiteration of the LCR/E6/E7 sequences further supports the hypothesis that the E6/E7 ORFs may code for oncogenic proteins and that regulatory signals in the LCR may play a role in cellular transformation.

Base Sequence↗

Maternal diabetes and its effect on biochemical and functional development of rabbit fetal lung.

The effect of maternal diabetes on functional and biochemical maturation of the fetal lung was studied in a rabbit model. Pregnancy was initiated only after diabetes had been established. Both the pregnant doe and its fetuses were hyperglycemic. For comparison, the fetal heart and liver were also studied. In the diabetic group, the DNA content was lower in the fetal heart and lung while the protein content was higher in all three tissues. The glycogen levels were higher only in the fetal lung. Glycogen synthase was higher in the fetal lung and heart while phosphorylase activity was higher in all three tissues from the diabetic group. The activities of key enzymes involved in glycolysis were not affected. No difference was observed in the concentration of total phospholipids or in the ability of the airway fluid to reduce surface tension. In contrast, fetal lungs from diabetic does did not expand as well as the controls and retained less air on deflation. These findings suggest that the utilization of glycogen in fetal lungs from the diabetic does was not complete and that the increased incidence of respiratory distress in infants of diabetic mothers may not be due to a lack of surfactant.

Animals↗

Presence of episomal and integrated human papillomavirus DNA sequences in cervical carcinoma.

Thirty surgical samples of squamous cell carcinoma of the cervix obtained from Chinese women were analysed for the presence of human papillomavirus (HPV) types 16 and 18 using Southern blot hybridization procedure. HPV16 was detected in 53% while HPV18 was found in only 6% of the samples analyzed. When compared with other reports, variation in the geographic distribution of these two HPV types in association with cervical carcinoma is noted. Thirty-seven and a half percent of the HPV16-positive samples contained this HPV type in episomal form and an equal number in cellular DNA-integrated form. The simultaneous presence of both episomal and integrated forms was found in the remaining 25% of the positive samples. The two HPV18-positive cases harbored only episomal viral genome and were not superinfected by HPV16. Analysis of the HPV16 integration samples showed that single integration events had probably occurred and some of the viral sequences had been lost on or subsequent to integration.

Carcinoma, Squamous Cell↗

Integration of human papillomavirus type 16 into cellular DNA of cervical carcinoma: preferential deletion of the E2 gene and invariable retention of the long control region and the E6/E7 open reading frames.

The integration patterns of human papillomavirus (HPV) type 16 in the cellular DNA of six cervical carcinoma samples were analyzed by the Southern blot procedure. None of the HPV integrants retained the entire viral genome. Double HPV integration was found in one case while all other cases were single integrants. In some samples, internal deletion and selective amplification of the viral sequences were observed. On integration, the E2 open reading frame (ORF) was invariably lost but the E6/E7 ORFs and the long control region of the HPV-16 genome were retained in all seven integrations analyzed and may play a role in cellular transformation and/or maintenance of the transformed phenotype.

Base Sequence↗

Analysis of six distinct integrated hepatitis B virus sequences cloned from the cellular DNA of a human hepatocellular carcinoma.

Six distinct hepatitis B virus (HBV) integrations and the flanking cellular sequences were cloned from a hepatoma DNA preparation. None of the cloned fragments retains the entire HBV sequences but the surface antigen (HBsAg) gene and the HBV enhancer are retained in three of the six clones. The other three clones carry only short and possibly highly rearranged HBV genomic sequences and seem to contain some GC-rich clusters. Members of the repetitive Alu family are also found in the vicinity of five of the six integration regions which may have contributed to genome instability. In these six clones, the preferred integration sites are shown to lie within the single-strand region of the HBV genome. None of the clones carries in the flanking cellular sequences any of the 17 oncogenes tested, although the possibility still exists that an oncogene may be found on the side of the genome which has not been cloned. This work thus paves the way for detailed sequence analysis of virus-host junctions, for transfection studies of the HBV integration events, and for a search of genes in the flanking cellular sequences which may have been activated by the retained HBV enhancer using the clones described.

Base Sequence↗

Regulation of rabbit fetal glycogen: effect of in utero fetal decapitation on the metabolism of glycogen in fetal heart, lung, and liver.

To understand the control mechanisms involved in the regulation of fetal glycogen, we have studied the effect of in utero fetal decapitations on glycogen metabolism in rabbit fetal heart, lung, and liver. In utero fetal decapitations were performed between days 18 and 21 of gestation. Two to four fetuses on one side of the horn were decapitated. Fetuses were delivered between days 23 and 26 or between days 28 and 30 of gestation. Fetal heart, lungs, and liver were analyzed for DNA, protein, glycogen, glycogen synthase (I and D forms), glycogen phosphorylase (a and b forms), phosphofructokinase, pyruvate kinase, and lactic dehydrogenase. In fetal heart and lung, no difference was observed in any of the above measurements in the intact and decapitated fetuses. In contrast, fetal liver does not appear to develop the glycogen system as indicated by the very low levels of glycogen (0.02 mg/mg DNA) in decapitated fetuses as compared with intact fetuses (0.4 mg/mg DNA). Similarly the levels of glycogen synthase and phosphorylase were two to three times lower in livers from decapitated fetuses as compared with the livers from intact fetuses. The three enzymes phosphofructokinase, pyruvate kinase, and lactic dehydrogenase were not affected by fetal decapitation in all three tissues. These results indicate that the fetal hypothalamic-pituitary-adrenal (thyroid) axis is not required at least after day 18 of gestation for the normal accumulation and subsequent utilization of glycogen in fetal heart and lungs, while it is an absolute requirement for the development of the fetal liver glycogen system.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Report of a family with mal de Meleda in Taiwan: a clinical, histopathological and immunological study.

A family in Taiwan is reported to have Mal de Meleda with possibly autosomal recessive inheritance among 5 of its members. The glove- and sock-like erythrokeratosis and the hyperkeratotic plaques of the knees and elbows are the common features. Erythema of the nose, cheeks, and the perioral area in 4 affected members, actinic elastosis in 2 severely affected members, and partially impaired cell-mediated immunity in vitro in both affected and unaffected members are notable findings. Tigason (etretinate) treatment was beneficial in regard to hyperkeratinization, but not to erythema.

Adolescent↗