Biomedical subjects

C C Lin

Publications and source records attributed to C C Lin.

At least 235 records · Page 13Linked to original sources

PubMed1998

Radiotherapy in the treatment of duodenal bleeding due to hepatocellular carcinoma invasion.

Haemorrhage from an hepatocellular carcinoma (HCC) directly invading the gastrointestinal (GI) tract is uncommon. A 58-year-old man was admitted with upper gastrointestinal (UGI) bleeding and panendoscopy on examination revealed a large duodenal ulcerative bleeding mass. The mass was eventually diagnosed as HCC by pathological examination. The bleeding failed to respond to conventional management of haemostasis, but resolved with an external beam of radiotherapy with a total dose of 6000 cGy over a 5 week period. This unusual presentation of UGI bleeding, due to HCC invading the duodenum and treated by radiotherapy, has not been previously reported.

Carcinoma, Hepatocellular↗

PubMed1998

Antioxidant and hepatoprotective activity of punicalagin and punicalin on carbon tetrachloride-induced liver damage in rats.

Punicalagin and punicalin, isolated from the leaves of Terminalia catappa L., are used to treat dermatitis and hepatitis. Both compounds have strong antioxidative activity. The antihepatotoxic activity of punicalagin and punicalin on carbon tetrachloride (CCl4)-induced toxicity in the rat liver was evaluated. Levels of serum glutamate-oxalate-transaminase and glutamate-pyruvate-trans-aminase were increased by administration of CCl4 and reduced by drug treatment. Histological changes around the liver central vein and oxidation damage induced by CCl4 also benefited from drug treatment. The results show that both punicalagin and punicalin have anti-hepatotoxic activity but that the larger dose of punicalin induced liver damage. Thus even if tannins have strong antioxidant activity at very small doses, treatment with a larger dose will induce cell damage.

Alanine Transaminase↗

PubMed1998

Raffinee, a free radical scavenger, in the treatment of subacute stage brain and spinal cord lesions: a case report.

This report presents the effects of the natural antioxidant formulation "Raffinee" in treatment of a case with subacute cerebellar hemorrhage and a case with subacute incomplete cervical cord injury. Four days after onset of cerebellar hemorrhage, the regimen started and ameliorated severe headache and dizziness within 3 days. Forty-five days after incomplete spinal cord injury with marked edema of cervical cord, the regimen started. Excellent motor and sensory function recovery were obtained within one month with remission of cord edema. The dosage of "Raffinee" is equivalent to 2,280,000 units of superoxide radical scavenging activity and 47,000 units of hydroxyl radical scavenging activity. Based on the secondary injury theory, superoxide and hydroxyl radical scavengers may have a valuable use in subacute central nervous system (CNS) lesions. Further larger scale of randomized, placebo-controlled, double-blind clinical trials are indicated to verify the effect of "Raffinee" on subacute CNS lesions.

Adult↗

PubMed1998

Pharmacokinetic drug interaction study: administration of ceftibuten concurrently with the antacid mylanta double- strength liquid or with ranitidine.

This study investigated the influence of antacid (Mylanta Double-Strength Liquid; J & J-Merck Consumer, Fort Washington, PA) and the H2 antagonist ranitidine on the pharmacokinetics of ceftibuten, a once-daily oral cephalosporin. Eighteen male volunteers received, in a randomized, three-way, crossover design, a single oral 400-mg dose of ceftibuten after an overnight fast (1) alone, (2) with antacid (60 mL), and (3) with ranitidine (after 3 days of dosing, 150 mg/12 hours). Serial blood and urine samples were collected during a 24-hour period after each administration, with a 1-week washout between treatments. Ceftibuten, and its metabolite ceftibuten-trans, were analyzed in plasma and urine by high-performance liquid chromatography. Bioavailability parameters, maximum plasma concentration and area under the plasma concentration-time curve to infinity of ceftibuten were unaffected by treatment with antacid. These parameters were somewhat higher when ceftibuten was administered with ranitidine, but they were still within the ranges seen in normal healthy volunteers. The excretion of ceftibuten was independent of treatment. The concentrations of ceftibuten-trans were low in both plasma and urine with all three treatments. It is concluded that the co-administration of antacid and ranitidine are unlikely to affect the bioavailability and antibacterial efficacy of ceftibuten.

Administration, Oral↗

PubMed1998

Congenital renal arteriovenous malformations: two cases report.

Congenital arteriovenous malformation (AVM) of the kidney is a rare condition. Rupture of an AVM in the kidney may cause hematuria, flank pain, and urinary retention due to clots. We report 2 cases of congenital renal AVM. Both were treated with transcatheter renal arterial embolization. The signs and symptoms disappeared after embolization. On follow-up, renal function testing with a DMSA scan revealed only focal loss of renal cortical function. The clinical courses of 2 cases are reported and the literature is reviewed.

Adult↗

PubMed1998

The haemodynamic effect of thoracoscopic cardiac sympathectomy.

A patient with angina pectoris who had been successfully treated by thoracoscopic cardiac sympathectomy was scheduled to have scalp debridement under general anaesthesia for a scald burn. There were haemodynamic changes during and after the operation including anaesthetic induction, endotracheal intubation, maintenance, and early recovery period. The sympathetic denervated heart showed little chronotropic response to anaesthetic and surgical stimulation. On the contrary, the parasympathetic response was predominant. An episode of severe bradycardia occurred during endotracheal suctioning prior to extubation. The haemodynamic response to cardiac sympathetic denervation corresponded to the efferent effect of beta-receptor blockade

Aged↗

PubMed1998

Fetal congenital malformations. Biophysical profile evaluation.

OBJECTIVE: To study the association between various fetal congenital malformations and the biophysical profile (BPP), we tested the following hypotheses: (1) a specific organ system malformation is associated with the absence of one or more BPP parameters, and (2) four BPP parameters are not affected by the advancement of fetal maturation. STUDY DESIGN: From 1985 to 1995, 316 fetuses with congenital malformations and 351 controls were identified in a high-risk population undergoing ultrasound examinations of anatomic structures and biophysical profile evaluations. For investigation of the influence of fetal maturity on biophysical profile evaluations, both the malformed fetuses and the controls were stratified into two gestational-age groups, 26-34 weeks and > 34 completed weeks. Four parameters of the BPP, including (1) fetal breathing, (2) gross fetal movements, (3) fetal muscle tone, and (4) quantitative amniotic fluid volume, were divided into low (0-6) and high (8) total score subgroups. Tests of significance were done using chi 2 analysis, Student's t test or Fisher's exact test, as appropriate. Level of significance was set at P < .05. RESULTS: When comparing malformed fetuses to controls, the malformed group had a statistically significantly higher percentage of low BPP scores due to absent fluid, tone or breathing. Fetuses with a musculoskeletal anomaly were statistically significantly more likely to lose points for fetal movement (P < .02); fetuses with a genitourinary system anomaly lost points for fluid (P < .001), tone (P < .005) and breathing (P < .005); fetuses with a central nervous system anomaly lost points for tone (P < .02) and breathing (P < .001); and fetuses with a thoracic anomaly lost points for breathing (P < .002). There was no statistically significant difference in BPP scores between fetuses at 26-34 weeks' gestational age and fetuses > 34 completed weeks' gestational age. CONCLUSION: The two hypotheses were confirmed by the study results.

Amniotic Fluid↗

PubMed1998

Placenta previa percreta involving the left broad ligament and cervix. A case report.

BACKGROUND: Placenta previa percreta with invasion of the broad ligament and uterine cervix is an extremely rare condition and carries high maternal and fetal morbidity and mortality. CASE: A 39-year-old, multiparous woman with two previous cesarean sections presented in active labor at term with placenta previa percreta involving the left broad ligament and cervix. The patient was managed by antepartum diagnosis of placenta previa accreta, supracervical hysterectomy, and blood transfusion. CONCLUSION: This case was managed consistent with the literature, and favorable maternal and fetal outcomes were achieved.

Adult↗

PubMed1998

Osseous choristoma of oral cavity--report of two cases and review of the literature.

Osseous choristoma of the oral cavity is an extremely rare lesion. Two cases of osseous choristomas of oral cavity, representing two different natures of such lesions are reported. One was situated on the dorsal surface of posterior tongue just anterior to the circumvallate papillae and the other on the right buccal mucosa just below the orifice of the Stensen's duct. To date, about 73 cases of oral osseous choristoma have been reported in the literature including the two present cases, of which, 61 and 8 cases occurred in the tongue and buccal mucosa, respectively. The clinical and microscopic characteristics, and their common sites of these peculiar lesions are presented. The origin and pathogenesis of the lesion are discussed and the literature on the subject is reviewed.

Adult↗

PubMed1998

[Self-care behaviors, self-efficacy, and social support effect on the glycemic control of patients newly diagnosed with non-insulin-dependent diabetes mellitus].

The purpose of this study was to explore the glycemic control and influencing factors in outpatients newly diagnosed with non-insulin-dependent diabetes mellitus (NIDDM). By purposeful sampling, data were collected from 130 outpatients with NIDDM at one medical center in Kaohsiung. The results indicated: (1) the mean value for HbA1C was 7.12%; and 63.1% of the patients belonged to moderate to well controlled group; (2) male patient's HbA1C value was significantly lower than female patient's; patients with no religious belief also had a lower HbA1C value than patients with a religious background; (3) there were strongly negative correlations between self-care behaviors, social support, and self-efficacy and HbA1C; (4) using a multiple stepwise regression analysis, religious belief and self-care behaviors were found to explain 10.9% variance of HbA1C level. The results of this study could be used as a reference for diabetes health education program.

Adult↗

PubMed1997

DK phocomelia phenotype (von Voss-Cherstvoy syndrome) caused by somatic mosaicism for del(13q).

DK phocomelia (von Voss-Cherstvoy syndrome) is a rare condition characterized by radial ray defects, occipital encephalocoele, and urogenital abnormalities. Lubinsky et al. [1994: Am J Med Genet 52:272-278] pointed out similarities between this and the del(13q) syndrome. To date, all reported cases of DK phocomelia have been apparently normal chromosomally. We report on a case of DK phocomelia in which the proposita had normal lymphocyte chromosomes, but was mosaic in fibroblasts for del(13)(q12). Fibroblast chromosomes studies on other cases of DK phocomelia have not been reported: this raises the possibility that some cases of DK phocomelia may be somatic mosaics for del(13)(q12).

Adult↗

PubMed1997

Structure-activity relationship of 3-substituted N-(pyridinylacetyl)-4- (8-chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene )- piperidine inhibitors of farnesyl-protein transferase: design and synthesis of in vivo active antitumor compounds.

Novel tricyclic Ras farnesyl-protein transferase (FPT) inhibitors are described. A comprehensive structure-activity relationship (SAR) study of compounds arising from substitution at the 3-position of the tricyclic pyridine ring system has been explored. In the case of halogens, the chloro, bromo, and iodo analogues 19, 22, and 28 were found to be equipotent. However, the fluoro analogue 17 was an order of magnitude less active. Whereas a small alkyl substituent such as a methyl group resulted in a very potent FPT inhibitor (SCH 56580), introduction of bulky substituents such as tert-butyl, compound 33, or a phenyl group, compound 29, resulted in inactive FPT inhibitors. Polar groups at the 3-position such as amino 5, alkylamino 6, and hydroxyl 12 were less active. Whereas compound SCH 44342 did not show appreciable in vivo antitumor activity, the 3-bromo-substituted pyridyl N-oxide amide analogue 38 was a potent FPT inhibitor that reduced tumor growth by 81% when administered q.i.d. at 50 mpk and 52% at 10 mpk. These compounds are nonpeptidic and do not contain sulfhydryl groups. They selectively inhibit FPT and not geranylgeranyl-protein transferase-1 (GGPT-1). They also inhibit H-Ras processing in COS monkey kidney cells and soft agar growth of Ras-transformed cells.

3T3 Cells↗

PubMed1997

High-performance liquid chromatographic determination and stability of 5-(3-methyltriazen-1-yl)-imidazo-4-carboximide, the biologically active product of the antitumor agent temozolomide, in human plasma.

5-(3-Methyltriazen-1-yl)-imidazo-4-carboximide (MTIC) is a highly unstable compound which is believed to be the biologically active degradation product of the antitumor agent temozolomide. An HPLC method has been developed and validated for the analysis of MTIC in human plasma. Because of the instability of MTIC, sample processing was kept to minimal. The method involved precipitation of plasma protein with methanol followed by analysis of the supernatant using reversed-phase column and UV detection at 316 nm. The linearity (r>0.99), precision (C.V.<9%) and accuracy (bias<5%) were satisfactory. The lower limit of quantitation (LOQ) was 10 ng/ml. The recovery of MTIC and internal standard was > or = 86.7%. MTIC was stable in plasma though three freeze-thaw cycles, and was stable at 4 degrees C for 1 h and at -80 degrees C for at least 70 days. MTIC may be unstable at 10 degrees C in processed samples; therefore, samples were placed in the autosampler (10 degrees C) immediately prior to injection. By using this analytical method, MTIC was quantified in plasma of cancer patients (n=12) within 0.25-12 h after oral administration of temozolomide at 150 mg/m2. The mean maximum plasma concentration (Cmax) was 211 ng/ml which was observed at a mean Tmax of 1.88 h post dose. MTIC disappeared rapidly from plasma with an apparent in vivo half-life (t1/2) of 1.9 h similar to that of temozolomide. Following in vitro incubation of MTIC in human plasma at 25 degrees C, MTIC disappearance was bioexponential with estimated t1/2 values of 25 and 60 min for the first and second phases, respectively. Therefore, the elimination t1/2 of MTIC in human in vivo (1.9 h) was controlled by the rate of its formation from temozolomide.

Administration, Oral↗

PubMed1997

Loss of imprinting and overexpression of IGF2 gene in gastric adenocarcinoma.

Both insulin-like growth factor II (IGF2) and H19 gene are located on chromosome 11p15.5 in close vicinity to each other, and are imprinted on different parental alleles. Although the exact mechanism remains unclear, loss of imprinting (LOI) leading to the biallelic expression of IGF2 and H19 genes has recently been reported in a variety of tumors. To study the role of IGF2 and H19 genes in gastric carcinogenesis, the LOI and loss of heterozygosity (LOH) status of these two genes were determined in 70 patients with gastric cancer. Among them, 30 patients were heterozygous for IGF2, 28 patients were heterozygous for H19, and 42 patients were heterozygous for either IGF2 or H19 gene. Among the 30 patients who were heterozygous for IGF2, one exhibited LOH (1/30, 3.3%) and 10 exhibited LOI (10/29, 34.5%). None of the 28 patients heterozygous for H19 gene had either LOH or LOI. LOI of IGF2 was more frequently found in the diffuse type (8/15, 53.3%) than the intestinal type (2/14, 14.3%, P < 0.05) gastric cancer. Five out of the six tumors with LOI of IGF2 exhibited overexpression of mRNA, but no obvious alterations of expression of H19 were noted by Northern hybridization. These data suggest that LOI leading to overexpression of IGF2 plays an important role in carcinogenesis of diffuse type gastric cancer.

Adenocarcinoma↗

PubMed1997

Cephalosporin 3'-phloroglucide esters and 7-(phloroglucidamido) cephalosporins as novel antibacterial agents.

Two series of new phloroglucide derivatives were synthesized that possessed antibacterial activities. The first series includes cephalosporin 3'-phloroglucide esters 19 and 20, which were obtained by condensation of cephalosporin 16 with bioactive phloroglucides 14 and 15, respectively. They exhibited a dual mode of antibacterial action. In comparison with cephalosporins 26 and 27, bearing an acetoxy unit at the C-3' position, the bifunctional cephalosporins 19 and 20 showed a broadened spectrum of activity. Results from the consistent valence force field (CVFF) calculations indicate that the most stable conformational isomer of phenolic acid 14, holding a cis-syn-syn geometry, possessed a cavity. It provides an ideal environment to accommodate metal ions of holoenzymes. Phenolic keto acid 15, however, possessed a trans-anti-syn conformation, which allowed chelation between metal ions and the phenolic hydroxyl groups as well as the carbonyl functionalities. Our biological results show that the cavity formed in phloroglucides plays an important role. The second series includes 7-(phloroglucidamido)cephalosporins 24 and 25, which were synthesized by condensation of cephalosporin 21 with 14 and 15, respectively. Results from the CVFF calculations indicate that cephalosporin 24 also possessed a cavity. Unlike cephalosporin 3'-phloroglucide esters 19 and 20, cephalosporins 24 and 25 were found resistant to beta-lactamases from Staphylococcus aureus 95 and Pseudomonas aeruginosa 18S-H. These new compounds, however, showed notable activities against S. aureus FDA 209P, S. aureus 95, Candida albicans, P. aeruginosa 1101-75, and P. aeruginosa 18S-H.

Anti-Bacterial Agents↗

PubMed1997

Pharmacokinetic screening for the selection of new drug discovery candidates is greatly enhanced through the use of liquid chromatography-atmospheric pressure ionization tandem mass spectrometry.

Selection of a new drug discovery candidate from a series of compounds requires a means of performing rapid analytical method development and sensitive quantitation of each drug in serum, plasma or other biological matrices. Information on serum/plasma concentration, bioavailability and half-life can often aid the discovery process by selecting those candidates with the desired pharmacokinetic parameters. In one series of farnesyl protein transferase (FPT) inhibitors, gas chromatography with nitrogen-phosphorus detection (NPD) was initially used to analyze samples from pharmacokinetic studies in mice and monkeys. Typical turnaround times using this technique approached 2-4 weeks for method development, quantitation of study samples and calculation of pharmacokinetic parameters. Once LC-atmospheric pressure ionization (API) MS-MS analysis was implemented in these same studies, they could be completed in less than one week. The advantages of using LC-API-MS-MS to aid in the drug candidate selection process is demonstrated for one compound (SCH 44342) in this series of FPT inhibitors.

Administration, Oral↗

PubMed1997

cGMP-elevating agents suppress proliferation of vascular smooth muscle cells by inhibiting the activation of epidermal growth factor signaling pathway.

BACKGROUND: Abnormal proliferation of vascular smooth muscle cells (VSMC) is a key event in the pathogenesis of atherosclerosis and many vascular diseases. It is known that nitric oxide released from the endothelium participates in the regulation of VSMC proliferation via a cyclic 3',5'-guanosine monophosphate (cGMP)-mediated mechanism. In a series of experiments, sodium nitroprusside (SNP) and A02131-1 were evaluated for their antiproliferative effect and the mechanism of their cGMP-elevating action. METHODS AND RESULTS: The effect of SNP and A02131-1 on epidermal growth factor (EGF)-stimulated proliferation of rat aortic smooth muscle cells (VSMC) was examined. Cell proliferation was measured in terms of [3H]thymidine incorporation, flow cytometry, and the cell number. Further, their effect on the EGF-activated signal transduction pathway was assessed by measuring mitogen-activated protein kinases (MAPK), MAPK kinase (MEK). Raf-1 activity, and the formation of active form of Ras. SNP and A02131-1 inhibited EGF-induced DNA synthesis and subsequent proliferation of VSMC. These two increased cGMP but only a little cAMP in VSMC. A similar antiproliferative effect was observed with 8-bromo-cGMP. The antiproliferative effect of the two was reversed by KT5823 but not by dideoxyadenosine nor Rp-cAMPS. SNP and A02131-1 blocked the EGF-inducible cell cycle progression at the G1/S phase. Further experiments indicated that the two cGMP-elevating agents primarily blocked the activation of Raf-1 by EGF-activated Ras. CONCLUSIONS: These results demonstrate that cGMP-elevating agents inhibit [3H]thymidine incorporation and thus the growth of VSMC, and this inhibition appears to attenuate EGF-activated signal transduction pathway by preventing Ras-dependent activation of Raf-1.

Amino Acid Sequence↗

PubMed1997

Comparisons of geniposidic acid and geniposide on antitumor and radioprotection after sublethal irradiation.

The antitumor effects of two iridoid compounds, geniposidic acid (GA) and geniposide (GP), were investigated in mice along with their possible effects on radioprotection after sublethal X-irradiation. Decreases in the growth of the implanted tumor by ascitic cells were a result of intraperitoneal administration of GA and GP at high concentrated levels. This result was achieved by exerting the levels of dosage in a dose-dependent manner. Except on the 12th day after treatment by the dosage of 500 mg/kg, reduced radiation effects of mice treated with the drugs in the 30 min preirradiated period by GA and GP on peripheral leukocytes were not observed significantly by the sublethal whole-body X-irradiation. And except on the 7th day after treatment, when these two compounds were administered i.p. to mice 30 min before 4 Gy irradiation, neither GA nor GP enhanced significantly the postirradiation responses of splenic blastogenesis by PHA. In addition, GA might be a more potent tumor growth inhibitor than GP when combined with the X-irradiation, though there was no significant synergetic effect on their combined antitumor activity. The preliminary results of GA and GP on hematological and blastogenic observations in this study suggested that they may very well, partially, play a role in an effective anticancer product with the ability to decrease undesirable radiation damage to the hematologic tissue after high dose irradiation.

Animals↗