Biomedical subjects

M C Kao

Publications and source records attributed to M C Kao.

At least 73 records · Page 4Linked to original sources

PubMed1995

Mitochondrial alterations of skeletal muscle in a heat stress rat model.

The morphological and ultrastructural alterations of skeletal muscle in experimental rats with heat stress were investigated. Fifteen male Sprague-Dawley rats were exposed in a 42 degrees C constant temperature oven, resulting in a heat stress state; ten rats were used as controls. All treated rats had weakness of the 4 limbs associated with increased serum creatine kinase levels (p < 0.01). Soleus muscles were submitted to histological, histochemical, ultrastructural and quantitative-morphometric analysis. The group receiving heat stress showed many ragged-red fibers in Gomori trichrome stain and appeared hyper-reactive in succinate dehydrogenase and cytochrome C oxidase stains. The ultrastructure of ragged-red fibers showed increased mitochondrial aggregation as multiple small nests, which were particularly located in the subsarcolemmal space. The mitochondrial area was significantly increased in heat stress rats (p < 0.001). The consistently increased mitochondrial area and histochemical alterations of mitochondria are early pathological abnormalities in muscles with heat stress and indicate fundamental impairment of energy metabolism.

Animals↗

PubMed1994

Antibody against branched epitope as an affinity ligand to separate the parent protein.

A peptide that contained one of the continuous epitopes of recombinant human lymphotoxin (rhLT) (amino acid residues 139-154) has been located by epitope mapping. The branched form of this peptide was synthesized by the multiple antigen peptide procedure with an octameric branched resin and was subsequently used to elicit anti-epitope antibody in rabbits. The resulting anti-epitope was then used as an immunoaffinity ligand in affinity chromatography to purify the parent protein, rhLT, from the host cell lysate directly. It is suggested that this approach would be a general way to create novel biospecific ligands for affinity separations.

Amino Acid Sequence↗

PubMed1994

Palmar hyperhidrosis in children: treatment with video endoscopic laser sympathectomy.

Palmar hyperhidrosis (PH) often starts in childhood and can be a disabling condition for a significant number of young children at the age they begin primary school. There are few reports regarding the surgical treatment of PH in children. The authors report on 40 PH patients under 16 years of age treated with video thoracoscopic laser sympathectomy; there has been substantial experience with this procedure for the treatment of adults with PH. A satisfactory result, with very low morbidity, was achieved for all 40 children. The surgical technique is described briefly. With the technique, the proper sympathetic segment is visualized in almost all cases and then definitely ablated with a fiberoptic low-power laser while under the aid of sympathetic monitoring. Consequently, an adequate sympathectomy warranting a long-lasting therapeutic effect can be achieved without the need of tissue diagnosis. No case required conversion to open sympathectomy. Neither injury to the lung nor bleeding was encountered. Horner's syndrome did not occur in any case. Bilateral sympathectomy was accomplished generally within 30 minutes. All patients were discharged after an overnight stay and are doing well with normal activities. The most frequent complication was compensatory hyperhidrosis, which was tolerable after reassurance. Based on the accumulated experience, it is justified to recommend early surgery, with this refined technique, in cases of severe PH in children.

Adolescent↗

PubMed1994

Craniofacial hyperhidrosis treated with video endoscopic sympathectomy.

Craniofacial hyperhidrosis as well as palmar hyperhidrosis is an abnormal state of local excessive sweating of unclear etiology. The hyperhidrosis may be isolated in the craniofacial region or associated with palmar hyperhidrosis. The patient's face is so wet with sweat that their daily activities are often seriously disturbed. To the best of our knowledge, there has been no satisfactory medical therapy, nor any effective surgical treatment reported in the literature. In 1991, we started to treat a patient with such distress using endoscopic ablation of the sympathetic T2 segment, because we mastered the technique after treating a large series of palmar hyperhidrosis patients. Furthermore, we were impressed by concomitant reduction of craniofacial sweating after T2-3 sympathectomy resulting from the relatively different domination of sympathetic supply between the eye and face. It appears possible to relieve excessive sweating of the head and face, without producing ptosis or miosis by ablation of the T2 segment. During the past 2 years, 7 patients with severe craniofacial hyperhidrosis have been successfully treated with the method and all obtained a satisfactory result. No complete Horner's syndrome has been produced except in one patient, who showed a mild and transient left eye ptosis, in whom coagulation of the sympathetic trunk higher than the T2 segment was performed. Intraoperative monitoring of forehead skin perfusion and observation of the change of pupillary size is emphasized during the lesion making. The longest postoperative follow-up was 2 years, with a mean follow-up of 12.4 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Autonomic activities in hyperhidrosis patients before, during, and after endoscopic laser sympathectomy.

Three hundred palmar hyperhidrosis (PH) patients have been treated with video endoscopic laser sympathectomy during the last 2 years. Monitoring the palmar skin perfusion (PSP) and palmar skin temperature (PST) has been used intraoperatively to aid the confirmation of the correct sympathetic segment for laser ablation. The preoperative and postoperative PSP and PST and sympathetic skin response (SSR) also have been measured to evaluate the therapeutic effect of this method. An apparent increase of PSP would occur intraoperatively after the interruption of the T2 sympathetic segment, and then a gradual elevation of PST would follow after the extirpation of the segment. A rise of PST of about 3 degrees C after laser ablation of the appropriate segment indicated sufficient denervation of the hand and predicted long-lasting relief of PH. Furthermore, both PSP and PST also significantly increased after the operation. The postoperative elevation of the PST (usually about 3 degrees C) is similar to that recorded during intraoperative monitoring. The amplitude and the latency of SSR in the palm and sole were recorded both before and after sympathectomy. A remarkable decrease of palmar SSR amplitude and its ratio was found postoperatively by comparing it with that of plantar SSR in the same patient. These autonomic activity changes have correlated well with the postoperative satisfaction of the patients. Based on our study, the anatomic identification confirmed by the sympathetic monitorings has proved essential to achieve a definite and adequate sympathectomy leading to a satisfactory resolution of PH without the need of a tissue diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Continuous epitopes of human lymphotoxin and their topographies.

Human lymphotoxin (hLT or TNF-beta) is a lymphokine that is structurally and functionally related to tumor necrosis factor alpha (TNF-alpha). The continuous epitopes of hLT were located by examining the cross-reaction between rabbit anti-hLT antibody and peptides derived from proteolytic digestion and chemical synthesis. Three antigenic sites, corresponding to residues 40-48, 83-94 and 139-147, of the protein sequence, were located by this approach. Since residues 49-57 also exhibited trace antigenicity, but residues 45-52 displayed no reaction, the whole peptide fragment consisting of residues 40-57 might be necessary for antigenicity. A comparison of the antigenic determinants with the loop structures obtained from X-ray crystallographic studies of hLT showed that all of the epitopes are found on or adjacent to functionally important domains.

Amino Acid Sequence↗

PubMed1994

Percutaneous excimer laser coronary angioplasty: animal models and the first human experience in Taiwan.

BACKGROUND: Clinical studies with excimer laser coronary angioplasty (ELCA) have been published in USA and Germany for lesions too difficult for use of routine balloon angioplasty. The purpose of the study was to evaluate the safety and short-term effects of excimer laser radiation applied to canine coronary angioplasty, and to report the first experience with percutaneous coronary excimer laser angioplasty and adjunctive percutaneous transluminal coronary angioplasty (PTCA) in a human subject on Taiwan. METHODS: Twelve canine subjects were studied. An excimer laser (Technolas Inc. Max-10), 20 Hz, 35 mJ/mm2, and 60 ns pulse was used. RESULTS: There were no perforations, with minimal dissection on the arterial intimal layer after using the bare-tip (crude single fiber-optic) fiber laser. The human subject showed partially successful recanalization after ELCA, with no residual stenosis after adjunctive PTCA for an occluded left anterior descending (LAD) artery (proximal lesion). A 0.014-in guide wire was used. There were no complications except for premature ventricular contractions during the procedure. CONCLUSIONS: The percutaneous excimer laser angioplasty is an effective and safe tool for treating coronary artery disease.

Angioplasty, Balloon, Coronary↗

PubMed1994

Video thoracoscopic laser sympathectomy for palmar hyperhidrosis.

Palmar hyperhidrosis (PH) is common in Orientals from subtropical areas. Many therapeutic modalities are used in practice, but none has proved to be entirely satisfactory. We have developed a new therapeutic technique by combining a video thoracoscopic system with a surgical laser unit (both waveguide CO2 laser and fibre-optic Nd:YAG laser). The operation was performed under general anaesthesia with alternative one-lung ventilation. With this technique, we are able to identify the sympathetic trunk on the TV screen and confirm its proper level with accurate ablation by intraoperative vasomotor monitoring. Consequently, an adequate sympathectomy can be definitely achieved through laser extirpation. We have successfully treated 300 PH patients with this technique from 1990 to 1992. The ages ranged from six to 63 years with a mean of 26.6. There were 125 males and 175 females. Most patients underwent en bloc ablation of the T2 segment which includes a major part of the T2 ganglion with its adjacent trunk which overlays the T2 rib head. All of them obtained a satisfactory relief of PH except 13 patients. The procedure did not result in a change of vital signs. There was neither obvious injury to lung nor bleeding. No Horner's syndrome was produced. The commonest complication was compensatory hyperhidrosis in various degrees encountered in about half of the cases. Two-thirds of the patients were followed up for more than 12 months and only three had recurrence. Based on our experience, the technique is considered to be a minor and safe procedure and able to achieve a definite and long-lasting therapeutic effect. It causes minimal discomfort and scarring. Particularly, the operation time and hospital stay were markedly shortened in comparison with other conventional open sympathectomy procedures.

Adolescent↗

PubMed1994

[Alternative one lung ventilation anesthesia for bilateral thoracoscopic sympathectomy].

Palmar hyperhidrosis (PH) is a common disorder in the oriental subtropical area. There have been many therapeutic methods, such as: oral medication, local treatment and traditional surgical operation, but none of them has proved entirely satisfactory. Since the development of video endoscopic surgery, transthoracic endoscopic sympathectomy has been increasing day by day. This study consisted of 124 PH patients under alternative one lung ventilation anesthesia for bilateral thoracoscopic laser sympathectomy. The age of patients ranged from 13 to 64 years, male 45 and female 79. The average anesthesia duration was 60 min. We used glycopyrrolate 0.03 mg/kg, decardon 1 mg/10 kg for premedication. Induction was with fentanyl 0.07 ml/kg, atracurium 0.6 mg/kg and thiopental 4 mg/kg. Maintenance was with isoflurane in 3L/min. oxygen inhalation. The alternative one lung ventilation anesthesia was achieved with double-lumen endobronchial tube. Fr 37, Fr 35, Fr 28 Sheridan Lt. double-lumen bronchial tube were used depending upon the sex and fudgement of the individual patient. All patients tolerated the procedure well so that sympathectomy could be performed smoothly and uneventfully. Immediately after the operation, a transient mild to moderate degree of difficult breathing and substernal discomfort were experienced in the majority of patients. These suffering often relieved spontaneously or with some common analgesic.

Adolescent↗

PubMed1993

Pyridylethylation of cysteine residues in proteins.

A procedure is described for using an inert polyvinylidene difluoride type membrane (e.g., ProBlott) as a matrix for on-membrane gas-phase pyridylethylation and as a desalting (cleanup) support following the solution phase pyridylethylation of cysteine residues in proteins. As a desalting support for 200 pmol of cardiotoxin, the membrane-derived sample gave a better recovery of phenylthiohydantoin (PTH)-amino acids during N-terminal sequencing compared to the sample obtained by rpHPLC. Using on-membrane gas-phase pyridylethylation, followed by replacement of glass-fiber filter disc and membrane washing/drying in vacuo, it was possible to eliminate the broad background peak that coeluted with PTH-Ala in the HPLC chromatogram completely. Using this modified procedure, there was no evidence of N-terminal alkylation of the amino-termini of proteins.

Alkylation↗

PubMed1993

Fluorospectral study of the rat brain and glioma in vivo.

An animal model of cerebral glioma was utilized by implanting C6 glioma cells into the brains of adult Wistar rats. Once tumors developed to 7-12 mm in diameter, we conducted continuous fluorimetry monitoring of glioma up to 24 hours using a fibre-optic system connected to an intensified multichannel photodetector after an intravenous injection of hematoporphyrin derivative (HPD) into the rats. The intensity of the fluorescence in normal brain reached a plateau 6 hours after intravenous injection of HPD while that in glioma reached a plateau 80 minutes after injection. These fluorescence intensities of glioma, brain adjacent to tumor (BAT), and surrounding normal brain were measured in vivo 24 hours after intravenous administration of 5 mg/kg of HPD. The ratio of fluorescence intensities between glioma and brain was 6.1 while the ratio between BAT and brain was 3.9. There were no obvious differences in shapes between the spectra of the natural fluorescence (autofluorescence) of rat glioma and brain but the intensity of autofluorescence was much weaker in glioma. There are many problems in spectroscopic studies of biological tissues in vivo. It cannot be overemphasized that very strict criteria must be applied in order to get accurate data. Fluorescence from HPD administration may be used to discriminate tumor tissue from surrounding normal brain tissue during operation if the measuring conditions could be kept constant. It is important to understand the photospectral properties of glioma and brain tissue in order to get the most benefits in clinical application of light-induced fluorescence or photoradiation therapy.

Absorption↗

PubMed1993

Cloning and characterization of a cDNA encoding the cytosolic copper/zinc-superoxide dismutase from sweet potato tuberous root.

A full-length cDNA clone encoding a putative copper/zinc-superoxide dismutase (SOD) of sweet potato, Ipomoea batatas (L.) Lam. cv Tainong 57, was isolated from a cDNA library constructed in lambda gt10 from tuber root mRNA. Nucleotide sequence analysis of this cDNA clone revealed that it comprises a complete open reading frame coding for 152 amino acid residues. The deduced amino acid sequence showed higher homology (78-86%) with the sequence of the cytosolic SOD than that of the chloroplast SOD from other plant species. The residues required for coordinating copper and zinc are conserved as they are among all reported Cu/Zn-SOD sequences. In addition, it lacks recognizable plastic or mitochondrial targeting sequences. These data suggest that the isolated sweet potato clone encodes a cytosolic Cu/Zn-SOD.

Amino Acid Sequence↗

PubMed1993

Antihepatotoxic activity of phenolic flavan-3-ols and their derivatives.

The protective activity against carbon tetrachloride induced hepatotoxicity of several phenolic flavan-3-ols and their derivatives has been assessed. Our research showed that monomers possessing a pyrogallol moiety as the B-ring had greater activity and this was not directly related to the stereo-chemistry of the hydroxyl group at C-3 in the flavan unit. However, when a galloyl group was linked to the hydroxyl group to form a gallate, this product exhibited markedly more activity than other analogs. These results suggest that the antihepatotoxic activity of phenolic flavan-3-ols and their derivatives seem to be related to the galloylation at the C-3 hydroxyl group in the flavan skeleton rather than the structure of another moiety or the degree of condensation.

Animals↗

PubMed1993

Therapy for supratentorial malignant astrocytomas: survival and possible prognostic factors.

Maximum feasible resection of the tumor followed by 50 Gy whole brain irradiation was the routine management for patients with malignant glioma in this series. To determine treatment results and possible prognostic factors, a retrospective analysis was done of 116 patients with pathologically proven supratentorial malignant astrocytomas (71 glioblastoma multiforme and 45 anaplastic astrocytoma) from January 1981 to December 1990. The mean age of the patients at the time of diagnosis was 46 years for glioblastoma multiforme and 37 years for anaplastic astrocytoma. In 86% of the patients, their condition improved or was constant after surgery; in 14% of the patients, the conditions worsened. The median survival time was 10 months for patients with glioblastoma multiforme and 22 months for those with anaplastic astrocytoma. Cox regression analysis showed that the duration of symptoms, extent of resection, irradiation and tumor histology were significantly related to the survival time. However, gross total resection did not improve the survival time relative to a subtotal resection, although both were shown to be better than a partial resection or biopsy.

Adult↗

PubMed1993

Prognostic factors of intraspinal neurilemmoma and meningioma with severe preoperative motor deficits.

A total of 20 cases of intraspinal benign tumors (13 neurilemmomas and seven meningiomas) with severe motor deficits operated on from 1978 to 1991 were reviewed. Motor deficits were graded according to the classification of Cooper and Ebstein. Grade IV represented slight movement of the lower extremities, but no ability to walk or stand; grade V was complete paralysis. There were 16 patients classified as grade IV and four classified as grade V. All patients underwent total excision of the tumor and postoperative physical therapy. After various periods of follow-up, 13 patients could walk independently, five could walk with assistance, one could stand, and one was still restricted to a wheelchair. For the 13 patients who could walk independently, 11 were able to stand within one month after surgery. In contrast, of the seven patients who could not walk independently, only two managed to stand within one month of surgery. Statistically, age, duration of paraplegia and tumor location all had a significant influence on the recovery of motor function. Being able to stand within one month of surgery was predictive of a good recovery.

Adult↗

PubMed1992

Multidrug resistant HOB1 lymphoma cells express P-glycoprotein that does not play the major role in the development of drug resistance to adriamycin.

Two cell lines resistant to 0.1 microM vincristine (VCR) and 2.0 microM adriamycin (ADR), respectively, (designated HOB1/VCR0.1 and HOB1/ADR2.0) were established from a human immunoblastic B lymphoma cell line. These cell lines showed the typical MDR phenotype with overexpression of P-glycoprotein and decreased [3H]VCR accumulation. The retention amounts of intracellular [3H]VCR in these two cell lines could be augmented by verapamil. However, in spite of the overproduction of P-glycoprotein, both HOB1/VCR1.0 and HOB1/ADR2.0 cells did not exhibit decreased accumulation of intracellular [14C]ADR. And the retention of [14C]ADR was not affected by verapamil. Our data support that P-glycoprotein is a drug transporter more important for the development of drug resistance to VCR than to ADR.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1992

Laser endoscopic sympathectomy for palmar hyperhidrosis.

Hyperhidrosis palmaris is a common disorder among the Orientals. Despite numerous therapeutic modalities in practice, none has proved entirely satisfactory. With the introduction of video-endoscopic surgery, we combined this system with a fiber optic Nd-YAG laser unit, electrocautery, and a laser Doppler flowmeter to design a new and promising therapeutic technique for palmar hyperhidrosis. General anesthesia with alternating one-lung ventilation is essential for a safe and smooth endoscopic sympathectomy. An operating endoscope was introduced into thoracic cavity via the second intercostal space and then attached to a CCD camera video system, which provided clear visibility of the sympathetic trunk in most cases. The proper level of the sympathetic trunk was further confirmed with the aid of vasomotor response of the palmar skin resulting from electric stimulation on the related sympathetic trunk. Finally, the confirmed target was precisely vaporized with a low power Nd-YAG laser through an endoscope. Twenty patients underwent bilateral sympathectomy, mostly on T2 and its adjacent trunk. This technique did not cause any injury to the lung or bleeding. No Horner's syndrome was produced. It provided a precise ganglionectomy on a confirmed target under clear magnified vision. Consequently, a definite and long-lasting therapeutic effect seemed warranted. It was considered to be a relative minor and safe procedure causing minimal discomfort and an almost invisible scar without producing serious complications. It also shortened the operation time and hospital stay remarkably in comparison with other open sympathectomy procedures.

Adolescent↗

PubMed1992

Video endoscopic sympathectomy using a fiberoptic CO2 laser to treat palmar hyperhidrosis.

Palmar hyperhidrosis is a common disorder among orientals. A new therapeutic technique for this disorder has been designed by combining a computer compact disc video endoscopic system with a fiberoptic CO2 surgical laser unit. The operation is performed under general anesthesia with alternating one-lung ventilation. There are three important aids in localizing the correct sympathetic segment: 1) direct visualization of its magnified image on the television monitor; 2) identification with an electrode probe palpation at its presumed location; and 3) monitoring the microvasomotor changes on the skin of the finger resulting from electrical stimulation of the sympathetic trunk. Subsequently, the confirmed sympathetic target is vaporized using a low power CO2 laser under direct vision on the television monitor. The laser is delivered to the target by a small optical fiber passing through a throacoscope, which is introduced into the thoracic cavity via the intercostal space between the second and third ribs at the midclavicular line. Fourteen palmar hyperhidrosis patients were successfully treated by this method. No complications, such as Horner's syndrome, bleeding, or intercostal neuralgia, were encountered. Although the number of cases treated was small, and the follow-up period was short, the evidence indicates that a definite sympathectomy on a confirmed segment under magnified vision is possible with this procedure, and could warrant a definite and long-lasting therapeutic effect. Based on our experience, the method is considered a relatively minor and safe procedure, causing minimal discomfort and almost invisible scars. The operation time and hospital stay were remarkably shortened in comparison with other conventional sympathectomy procedures.

Adolescent↗