Search PubMed⌕ Search

Biomedical subjects

C C Lin

Publications and source records attributed to C C Lin.

At least 325 records · Page 18Linked to original sources

Experience in thoracoscopic sympathectomy for hyperhidrosis with concomitant pleural adhesion.

Thoracoscopic (transthoracic endoscopic) sympathectomy, known worldwide as the best method for treatment of hyperhidrosis, is regarded as having two major contraindications: pleural adhesion and coagulopathy. We embarked on this study to prove that it is possible and highly feasible to do thoracoscopic sympathectomy, even in the presence of severe pleural adhesion, as long as the surgeon knows anatomy and is well-trained in performing this procedure. From October 1, 1989, through December 31, 1992, we treated 719 cases of hyperhidrosis palmaris (325 male and 394 female patients), by the thoracoscopic method at Tainan Municipal Hospital. Among them, 24 cases (3.5%), 19 male and 5 female patients, had concomitant pleural adhesions. The causes of pleural adhesion were pulmonary tuberculosis, chronic bronchitis, previous operations for hyperhidrosis, and a few with uncertain origins. Except for the first encountered case of hyperhidrosis with pleural adhesion, which was treated by mini-thoracotomy after failure of a thoracoscopic approach through the right thoracic cavity, the remainder of the 23 cases were treated successfully by the thoracoscopic method. In cases with bilateral pleural adhesions, the right thoracic cavity was more frequently involved and more severely. The incidence of pleural adhesion in hyperhidrosis is 3.5% in our series; all, except the first case, were treated thoracoscopically. Coagulopathy is for us, therefore, the only remaining contraindication of thoracoscopic sympathectomy.

Adolescent↗

Clinical response of tuberculous pericarditis to medical treatment: a retrospective survey.

BACKGROUND: The prevalence of tuberculosis has declined with advanced antituberculous chemotherapy. However, the occurrence of subsequent constrictive pericarditis in tuberculosis has not reduced. Clinical progress of tuberculous pericarditis was investigated in patients receiving antituberculous chemotherapy. METHODS: Thirteen patients with tuberculous pericarditis (11 men and 2 women aged 14 to 86 years [mean 60.0 +/- 17.0]), treated initially with antituberculous medications were analyzed. All patients underwent pericardiocentesis on admission following echocardiography. RESULTS: Dyspnea was the most common clinical pictures. Bloody effusion fluids were noted in 10 patients. Moreover, the lymphocytic fluids were present in 78% of all patients. The neutrophilic fluids tended to have a bloody color, and there was progress to constrictive pericarditis even for those on anti-tuberculous chemotherapy. Five patients with subsequent constrictive pericarditis received pericardiectomy within 3.5 months of admission. Three of them received pericardiectomy later, despite pericardial window procedure. CONCLUSIONS: Follow-up by echocardiogram is necessary within three months after commencing medical treatment because of the high incidence of progression constrictive pericarditis despite aggressive medical treatment. Pericardiectomy seems to be the only solution to the catastrophic outcome of constrictive pericarditis.

Adolescent↗

Skin metastases from follicular thyroid carcinoma: a case report.

Thyroid carcinomas metastasizing to the skin are rare. We report a case of skin metastases from a follicular thyroid carcinoma. A 73-year-old man developed multiple painless skin nodules about 6 years after thyroidectomy for the primary thyroid carcinoma. A biopsy disclosed a dermal tumor composed of small thyroid follicular structures with colloid material. The diagnosis was confirmed by immunohistochemistry using monoclonal antithyroglobulin antibodies performed on the skin biopsy specimens. The patient died 9 months later with multiple metastases after the development of skin lesions.

Adenocarcinoma, Follicular↗

Propofol anesthesia in a patient with myasthenia gravis--a case report.

Experience with the use of propofol for induction and maintenance of anesthesia in patients with myasthenia gravis is limited in the literature. We report, in this case, the well prepared and successful use of continuous propofol infusion without conventional neuromuscular blocking agents in a patient with Ossermann stage IIb of myasthenia gravis undergoing laparoscopic cholecystectomy.

Anesthesia, Intravenous↗

Selective oxidative modification and affinity cleavage of pigeon liver malic enzyme by the Cu(2+)-ascorbate system.

Pigeon liver malic enzyme was rapidly inactivated by micromolar concentration of Fe2+ in the presence of ascorbate at neutral pH. The inactivated enzyme was subsequently cleaved by the Fe(2+)-ascorbate system at the chemical bond between Asp258 and Ile259 (Wei, C.H., Chou, W.Y., Huang, S.M., Lin, C.C., and Chang, G.G. (1994) Biochemistry, 33, 7931-7936), which was confirmed by site-specific mutagenesis (Wei, C.H., Chou, W.Y., and Chang, G.G. (1995) Biochemistry 34, 7949-7954). In the present study, at neutral pH, Cu2+ was found to be more reactive in the oxidative modification of malic enzyme and the enzyme was cleaved in a similar manner as Fe2+ did. At acidic pH, however, Fe2+ was found to be ineffective in oxidative modification of the enzyme. Nevertheless, Cu2+ still caused enzyme inactivation and cleaved the enzyme at Asp141-Gly142, Asp194-Pro195, or Asp464-Asp465. Mn2+ and L-malate synergistically protect the enzyme from Cu2+ inactivation at acidic pH. Cu2+ is also a competitive inhibitor versus Mn2+ in the malic enzyme-catalyzed reaction with Ki value 70.3 +/- 5.8 microM. The above results indicated that, in addition to the previously determined Asp258 at neutral pH, Asp141, Asp194, and Asp464 are also the coordination sites for the metal binding of malic enzyme. We suggest that the mechanism of affinity modification and cleavage of malic enzyme by the Cu(2+)-ascorbate system proceed in the following sequence. First, Cu2+ binds with the enzyme at the Mn2+ binding site and reduces to Cu+ by ascorbate. Next, the local oxygen molecules are reduced by Cu+, thereby generating superoxide or other reactive free radicals. These radicals interact with the susceptible essential amino acid residues at the metal-binding site, ultimately causing enzyme inactivation. Finally, the modified enzyme is cleaved into several peptide fragments, allowing the identification of metal site of the enzyme. The pH-dependent different specificities of metal-catalyzed oxidation system may be generally applicable for other enzymes or proteins.

Amino Acid Sequence↗

Radical scavenger and antihepatotoxic activity of Ganoderma formosanum, Ganoderma lucidum and Ganoderma neo-japonicum.

The free radical scavenging and antihepatotoxic activity from Ganoderma lucidum, Ganoderma formosanum and Ganoderma neo-japonicum were studied. Treatment with the water extract of Ganoderma lucidum, Ganoderma formosanum and Ganoderma neo-japonicum caused a marked decrease in the CCl4-induced toxicity in rat liver, made evident by their effect on the levels of glutamic oxaloacetic transaminase (GOT) and lactic dehydrogenase (LDH) in the serum. The scavenging potency of the water extracts of the crude drugs was evaluated in terms of their ability to reduce the peaks of spin adducts using electron spin resonance (ESR) spin-trapping techniques. The results indicated that Ganoderma formosanum showed the greatest antihepatotoxic activity and the greatest free radical scavenging activity.

Alanine Transaminase↗

Absence of a pharmacokinetic interaction between losartan and hydrochlorothiazide.

To support the use of a combination of losartan, a highly specific and selective AT1 angiotensin II receptor antagonist, and hydrochlorothiazide for treatment of hypertension, a pharmacokinetic drug interaction study was conducted. In this open-label, randomized, three-period, crossover study, patients with mild to moderate hypertension received a 12.5-mg tablet of hydrochlorothiazide, a 50-mg losartan tablet, or a combination tablet of 12.5 mg of hydrochlorothiazide and 50 mg of losartan for 7 days. Twelve patients (age range, 35-55 years; mean age, 44 years) were allocated to treatment. Drug interactions were evaluated by comparing the 24-hour area under the concentration-time curve (AUC24) for losartan and its active metabolite, E-3174, when losartan (50 mg) was given alone or in combination with 12.5 mg hydrochlorothiazide. The urinary recovery over the 24-hour period of hydrochlorothiazide was compared for hydrochlorothiazide (12.5 mg) given alone or in combination with 50 mg losartan. A clinically significant interaction was defined as a treatment difference of more than 35%. There was no evidence of a clinically significant effect of hydrochlorothiazide on the pharmacokinetics of losartan or E-3174, as the geometric mean AUC24 ratio (90% confidence interval [CI]) was 1.02 (0.95, 1.09) for losartan and 1.02 (0.96, 1.09) for E-3174. Based on urinary recovery over a 24-hour period of hydrochlorothiazide, losartan did not affect the pharmacokinetics of hydrochlorothiazide, as the geometric mean ratio of urinary hydrochlorothiazide recovery (90% CI) was 0.898 (0.79, 1.20). There was a minor (17%) decrease in the AUC24 of hydrochlorothiazide after administration of the combination tablet. Coadministration of hydrochlorothiazide and losartan was well tolerated.

Adult↗

Human gamma X satellite DNA: an X chromosome specific centromeric DNA sequence.

The cosmid clone, CX16-2D12, was previously localized to the centromeric region of the human X chromosome and shown to lack human X-specific alpha satellite DNA. A 1.2 kb EcoRI fragment was subcloned from the CX16-2D12 cosmid and was named 2D12/E2. DNA sequencing revealed that this 1,205 bp fragment consisted of approximately five tandemly repeated DNA monomers of 220 bp. DNA sequence homology between the monomers of 2D12/E2 ranged from 72.8% to 78.6%. Interestingly, DNA sequence analysis of the 2D12/E2 clone displayed a change in monomer unit orientation between nucleotide positions 585-586 from a "tail-to-head" arrangement to a "head-to-tail" configuration. This may reflect the existence of at least one inversion within this repetitive DNA array in the centromeric region of the human X chromosome. The DNA consensus sequence derived from a compilation of these 220 bp monomers had approximately 62% DNA sequence similarity to the previously determined gamma 8 satellite DNA consensus sequence. Comparison of the 2D12/E2 and gamma 8 consensus sequences revealed a 20 bp DNA sequence that was well conserved in both DNA consensus sequences. Slot-blot analysis revealed that this repetitive DNA sequence comprises approximately 0.015% of the human genome, similar to that found with gamma 8 satellite DNA. These observations suggest that this satellite DNA clone is derived from a subfamily of gamma satellite DNA and is thus designated gamma X satellite DNA. When genomic DNA from six unrelated males and two unrelated females was cut with SstI or HpaI and separated by pulsed-field gel electrophoresis, no restriction fragment length polymorphisms were observed for either gamma X (2D12/E2) or gamma 8 (50E4) probes. Fluorescence in situ hybridization localized the 2D12/E2 clone to the lateral sides of the primary constriction specifically on the human X chromosome.

Base Sequence↗

Obstructive sleep apnea syndrome and bronchial hyperreactivity.

This study was designed to investigate the prevalence of bronchial hyperreactivity (BH) in patients with obstructive sleep apnea syndrome (OSAS), heavy snorers, and light snorers; its correlation with OSAS severity; and its response to nasal CPAP therapy. Forty-eight age- and sex-matched subjects were selected on the basis of preentry sleep studies: Group I consisted of 16 patients with OSAS (hypopnea-apnea index (HAI) = 35 +/- 9); group II consisted of 16 cases of heavy snorers without OSAS; and group III, a control group, consisted of 16 subjects with only mild snoring. All 48 patients had normal pulmonary function (simple spirometry) prior to study entry and had no history of asthma or allergies. The prevalence of BH was prospectively assessed by giving each subject a methacholine challenge test (MCT). Patients with a positive MCT were treated with 2-3 months of nasal CPAP treatment, after which they had a second MCT. Four of 16 patients in group I had BH on MCT (PD20 = 88, 103, 109, 162 D.U.), whereas none of the group II or III subjects demonstrated BH. There was no correlation between BH and the severity of the OSAS. The 4 patients with BH in group I showed an increase in PD20M after 2-3 months of nasal CPAP treatment. In conclusion, BH may occur in patients with OSAS. It is unrelated to the severity of the OSAS, and nasal constant positive airway pressure (CPAP) therapy can decrease the hyperreactivity to methacholine in these patients.

Adult↗

Effects of felbamate on the pharmacokinetics of the monohydroxy and dihydroxy metabolites of oxcarbazepine.

The effects of felbamate on the multiple dose pharmacokinetics of the monohydroxy and dihydroxy metabolites of oxcarbazepine were assessed in a placebo-controlled, randomized, double-blind crossover study in 18 healthy male volunteers. Oxcarbazepine, 1200 mg/day, was administered on an open basis in combination with double-blind placebo or 2400 mg/day felbamate for two 10-day treatment periods separated by a 14-day washout period. Pharmacokinetic parameters of monohydroxyoxcarbazepine and dihydroxyoxcarbazepine were determined from plasma and urine samples obtained on the tenth day of each treatment period. Felbamate had no effect on monohydroxyoxcarbazepine plasma or urine pharmacokinetics compared with placebo, but it significantly increased values for dihydroxyoxcarbazepine maximum concentration and area under the curve from 0 to 12 hours, as well as urinary excretion of free and total dihydroxyoxcarbazepine. The mechanism that may account for the observations is the induction of oxidative metabolism of monohydroxyoxcarbazepine. Despite these changes, the relative amount of dihydroxyoxcarbazepine is small in comparison to monohydroxyoxcarbazepine, and antiepileptic activity is associated with monohydroxyoxcarbazepine rather than dihydroxyoxcarbazepine. Therefore we conclude that felbamate has no clinically relevant effects on the pharmacokinetics of oxcarbazepine in humans.

Adolescent↗

Effects of felbamate on the pharmacokinetics of a low-dose combination oral contraceptive.

The effects of felbamate on the pharmacokinetics of a low-dose combination oral contraceptive containing 30 micrograms ethinyl estradiol and 75 micrograms gestodene were assessed in a randomized, double-blind, placebo-controlled parallel-group study in healthy premenopausal female volunteers established in a regimen of oral contraceptive use. They received either placebo or 2400 mg/day felbamate from midcycle (day 15) to midcycle (day 14) of two consecutive oral contraceptive cycles (months 1 and 2). Pharmacokinetic assessments of ethinyl estradiol and gestodene were performed on day 14 of both cycles. To determine whether ovulation occurred, plasma progesterone and urinary luteinizing hormone levels were measured, and diaries recording vaginal bleeding were kept. Felbamate treatment resulted in a significant 42% decrease in gestodene area under the plasma concentration-time curve (0 to 24 hours) (p = 0.018) compared with baseline, whereas a minor but not clinically relevant effect was observed on the pharmacokinetic parameters of ethinyl estradiol. There were no changes in the pharmacokinetics of ethinyl estradiol or gestodene after placebo treatment. No volunteer showed hormonal evidence of ovulation; however, one volunteer reported the onset of intermenstrual bleeding during felbamate treatment. Because of the effect of felbamate on the pharmacokinetics of gestodene and the report of intermenstrual bleeding, it is possible that the contraceptive efficacy of low-dose combination oral contraceptives may be adversely affected during felbamate treatment.

Adult↗

Loratadine administered concomitantly with erythromycin: pharmacokinetic and electrocardiographic evaluations.

OBJECTIVE: To evaluate the effects of coadministration of loratadine and erythromycin on the pharmacokinetics and electrocardiographic repolarization (QTc) pharmacodynamics of loratadine and its metabolite descarboethoxyloratadine in healthy volunteers. METHODS: Twenty-four healthy volunteers were studied in a prospective, double-blind crossover design while confined in a Clinical Research Center. The primary pharmacodynamic end point of the study was the difference between baseline and day 10 mean QTc intervals obtained from surface electrocardiograms. Plasma concentrations of loratadine, descarboethoxyloratadine, and erythromycin were measured on treatment day 10 for pharmacokinetic analysis. Subjects received in random sequence the following three treatments for 10 consecutive days during three separate study periods: 10 mg loratadine every morning plus 500 mg erythromycin stearate every 8 hours, or 10 mg loratadine every morning plus placebo every 8 hours, or placebo every morning plus 500 mg erythromycin stearate. RESULTS: Concomitant administration of loratadine and erythromycin was associated with increased plasma concentrations of loratadine (40% increase in area under the plasma concentration-time curve [AUC]) and descarboethoxyloratadine (46% increase in AUC) compared with loratadine alone. Analysis of variance showed no difference between the treatment groups in effect on QTc intervals compared with baseline, and no significant change from baseline was observed. No clinically relevant changes in the safety profile of loratadine were observed, and there were no reports of sedation nor syncope. CONCLUSION: Although concomitant administration of loratadine and erythromycin was associated with increased plasma concentrations of loratadine and descarboethoxyloratadine, no clinically relevant changes in the safety profile of loratadine were observed. In this study, 10 mg loratadine administered orally for 10 consecutive days was well tolerated when coadministered with therapeutic doses of erythromycin stearate.

Adult↗

Effects of felbamate on the pharmacokinetics of phenobarbital.

The effects of felbamate on the pharmacokinetics of phenobarbital and one of its main metabolites, parahydroxyphenobarbital, were assessed in a parallel-group, placebo-controlled, double-blind study, in 24 healthy volunteers. Pharmacokinetic parameters of phenobarbital and parahydroxyphenobarbital were determined from plasma and urine samples obtained after 28 days of daily administration of 100 mg phenobarbital and after a further 9 days of phenobarbital plus 2400 mg/day felbamate or placebo. Felbamate increased phenobarbital values for area under the plasma concentration-time curve from 0 to 24 hours and maximum concentration by 22% and 24%, respectively, whereas placebo had no effect. This increase was caused by a reduction in parahydroxylation of phenobarbital and possibly through effects on other metabolic pathways. Because felbamate inhibits the S-mephenytoin hydroxylase (CYP2C19) isozyme in vitro, it appears that phenobarbital hydroxylation is mediated in part by this isozyme.

Adult↗

Mechanical properties and histological evaluation of sintered beta-Ca2P2O7 with Na4P2O7.10H2O addition.

The ultimate goal of implantation of biomaterials in the skeleton is to reach full integration of the non-living implant with the living bone. The biomaterial can be used much as a bone graft, resorbing or dissolving as bone growth occurs, and the end result is a new remoulded bone. Calcium pyrophosphate, Ca2P2O7, is one of the intermediate products of bone mineralization. beta-Dicalcium pyrophosphate (beta-DCP) doped with certain amounts of Na4P2O7.10H2O was prepared as the developed material. Na4P2O7.10H2O was used as a liquid-phase additive to improve the sintering process and promote physiological bioresorbability. Compressive strength and four-point bending strength were measured by the Bionix test system 858. The mechanical strength of the sintered beta-DCP increased with the addition of Na4P2O7.10H2O up to 5 wt%, but thereafter decreased. The microstructure and crystal structure were analysed by the techniques of SEM, EPMA, TEM and XRD. The relationship between the mechanical strength of the sintered bioceramics and the Na4P2O7.10H2O dopant was examined in terms of the presence of NaCa(PO3)3, grain growth and abnormal grain coalescence while the dopant increased. Preliminary in vivo evaluation was studied by rabbit femur condyle implantation. There was no inflammation or any toxic sign during the experimental period. The histological section of intraosseous implantation revealed that the new bone deposited directly on the surface of the material in the fourth week after operation. The implant gradually decreased in volume and was replaced by the surrounding regenerated bone in the rabbit condyle in vivo environment. The results led us to conclude that the developed material has great potential as a biodegradable bone substitute.

Animals↗

The evaluation of hepatoprotective effects of Taiwan folk medicine 'teng-khia-u'.

'Teng-khia-u' is a folk medicine of Taiwan, derived from the entire plants of Elephantopus scaber L., E. mollis H.B.K. and Pseudoelephantopus spicatus (Juss.) Rohr. The hepatoprotective effects of water extracts of these three plants against beta-D-galactosamine (D-GalN)- and acetaminophen (APAP)-induced acute hepatic damage were determined in rats. The results indicated that the serum glutamate-oxalate-transaminase (sGOT) and the serum glutamate-pyruvate-transaminase (sGPT) levels caused by D-GalN and APAP decreased after treatment with crude extracts of 'teng-khia-u' (P < 0.005). The pathological changes of hepatic lesions, caused by D-GalN and APAP, improved following treatment with the drug extracts mentioned above.

Acetaminophen↗

Scavenging effects of Mallotus repandus on active oxygen species.

The active oxygen species scavenging potencies of Mallotus repandus (Willd.) Muell.-Arg. extracts were evaluated by the electron spin resonance (ESR) spin-trapping technique. Superoxide radical (O2.-) and hydroxyl radical (OH.) were supplied enzymatically from hypoxanthine-xanthine oxidase (HPX-XOD) reaction and hydrogen peroxide-ferrous sulfate (Fenton reaction), respectively, to the assay system. The ethyl acetate fraction of Mallotus repandus (stem) showed the greatest superoxide radical scavenger activity and the n-hexane fraction of Mallotus repandus (stem as well as root) the greatest hydroxyl radical scavenger activity.

Antioxidants↗

A specific enzyme immunoassay (EIA) with selective extraction for quantitation of a topical anti-inflammatory agent, SCH 40120, in human plasma.

SCH 40120 is a potent anti-inflammatory agent under development for the topical treatment of dermal inflammatory and allergic disorders such as atopic dermatitis, contact dermatitis and psoriasis. We have previously described a sensitive enzyme immunoassay (EIA) for SCH 40120 in unextracted human plasma to support clinical studies. However, severe cross-reaction with unknown metabolites was observed during validation using samples from rats dosed with 14C-SCH 40120. Therefore, a selective extraction procedure was developed to remove the unknown plasma metabolites of SCH 40120 prior to EIA quantitation. The modified EIA using extracted plasma was cross-validated with an LC method using plasma samples from dosed subjects (human and rat), thereby confirming the specificity of the assay. The EIA can reliably quantitate SCH 40120 in plasma samples from 100 pg ml-1 to 10 ng ml-1 with good linearity, accuracy and precision, and is suitable for pharmacokinetic studies in man.

Administration, Topical↗