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Biomedical subjects

C S Lai

Publications and source records attributed to C S Lai.

At least 37 records · Page 2Linked to original sources

Endoscopically-assisted adipofascial flap harvest for soft tissue defects of the lower leg.

Five cases of soft tissue defect of the lower leg were reconstructed successfully with the distally based medial adipofascial flap which was harvested with endoscopically-assisted surgery. The size of these flaps ranged from 4.0 x 7.0 cm to 5.0 x 15.0 cm in size. All the flaps had good perfusion and uneventful course postoperatively. The donor site skin was intact except for an additional access-scar 2.5 cm in length. The donor site morbidity of the adipofascial flap was further minimised in this series.

Accidents, Traffic↗

The distally based lateral adipofascial flap.

The distally based lateral adipofascial flap can be based either on the lowermost perforator or the anterior perforating branch of the peroneal artery avoiding sacrifice of the main peroneal artery. It has been used successfully to resurface soft tissue defects either on the lateral or medial aspect of the lower third of the leg in 13 cases. The size of these flaps varied from 2.0 cm x 5.0 cm to 4.5 cm x 15.0 cm in size. These cases had minimal donor site morbidity and had positive aesthetic results. The advantages were: 1. Choice of either the lowermost perforator or the anterior perforating branch giving a wide arc of rotation; 2. Preservation of the superficial peroneal nerve; 3. Primary closure of the donor site.

Adult↗

Apparent digestibility of a debranched amylopectin-lipid complex and resistant starch incorporated into enteral formulas fed to ileal-cannulated dogs1.

The purpose of this study was to evaluate apparent digestibility in ileal-cannulated dogs fed enteral diets containing a debranched amylopectin-lipid complex (V-complex) or resistant starch. Six ileal-cannulated dogs were randomized into a replicated 3 x 3 Latin square design for determination of digestibility of three experimental treatments. Dietary treatments were as follows: 1) control; 2) V-complex; and 3) resistant starch. Diets were similar in chemical composition. Apparent digestibility of dry matter (DM), organic matter (OM) and carbohydrate by dogs fed the control diet was higher (P < 0.05) than for dogs consuming the other diets. Mean apparent digestibilities of carbohydrate for the control, V-complex and resistant starch diets were 89, 76 and 43%, respectively. Both DM and carbohydrate digestibility were lower (P < 0.05) for resistant starch compared with V-complex. Fecal dry and wet weights for dogs fed the control diet were lower (P < 0.05) than for those receiving either the resistant starch or V-complex treatments. Dogs fed the V-complex diet produced approximately 90 g less feces per day than dogs fed resistant starch. Dietary incorporation of V-complex to replace traditional carbohydrates may be beneficial for diabetic patients because of the decreased digestibility and subsequent glucose absorption rate. Furthermore, incorporation of resistant starch into enteral formulas may improve gastrointestinal tract health status as a result of increased fecal bulk, potential dilution of toxins in the intestinal lumen and greater production of short-chain fatty acids.

Amylopectin↗

The reverse lateral arm adipofascial flap for elbow coverage.

The reverse lateral arm adipofascial flap covered immediately with a skin graft has been used successfully for reconstruction of a cubital fossa defect (caused by avulsion injury) and an exposed olecranon (resulting from recurrent bursitis) in 2 patients. The flap is nourished by the septal perforators of the posterior radial collateral artery, which in turn obtains its blood supply from the interosseous recurrent artery. The distal vascular pedicle should contain a sufficient amount of subcutaneous fat and its underlying fascia to enhance the arterial input and the venous drainage of the flap. The primary benefit of this technique is that the thickness of the flap can be tailored to fit into the defect, and the donor site can be closed primarily without tension. The advantages include satisfactory cosmetic results, a rapid one-stage procedure, no sacrifice of the main artery or local muscle, and avoidance of any long-term immobilization of the involved elbow joint.

Adult↗

A mixture of allogeneic dermal tissue and autologous microskin grafting of rabbit skin wound.

In a rabbit model, transplantation of largely expanded microskin grafts (expansion ratio 25 X) were studied. In Group I, the autologous microskin grafts were transplanted onto the full-thickness skin defect on the back of a rabbit and were overlaid with Biobrane. In Group II, the autologous microskin grafts were mixed with allogeneic microdermal substance (expansion ratio 25 X) before the transplantation. The percentage of re-epithelialized area to the total grafted wound was analyzed by means of computerized planimetric analyses of photographs of the grafted wounds on days 11 and 13. Biopsies of the grafted wounds were done. On day 11, the mean percentage of Group I was 72.4% and that of Group II was 82.7%. On day 13, they were 82.3% in Group I and 92.3% in Group II. In Group II, the allogeneic dermal tissue did not cause obvious rejection in the neoepithelium. Histological features showed the existence of allogeneic dermal tissue in the grafted wound. The adding of largely expanded allogeneic dermal substance to autologous microskin grafts in Group II provided better circumstances than that in Group I for re-epithelialization of autologous mciroskin grafts.

Animals↗

[Chemical burn caused by hydrofluoric acid in Kaohsiung area--a 5-year experience].

Hydrofluoric acid (HF) has been used extensively in industry and laboratory, and also is a common agent for occupational chemical burn. Severe pain and destruction of deep tissue layers occurred when skin was injured by hydrofluoric acid. Some fatal change may happen especially when hydrocalcemia was induced. For presentation of its special character and the use of antidote, we report one outbreak and six individual victims of hydrofluoric acid injury during the previous 5 years in Kaohsiung area. We hope medical personnel could have more accurate management and clinical care for those who are injured by HF, and workers should pay attention to any chemical agents they use to prevent any further injury as a result of careless use of such chemicals.

Adult↗

Continuous monitoring of cellular nitric oxide generation by spin trapping with an iron-dithiocarbamate complex.

Nitric oxide (NO) generation in murine macrophages was determined in real time using the electron paramagnetic resonance (EPR) spin trapping method. An iron complex of N-methyl D-glucamine dithiocarbamate was utilized as the spin trap. This spin trapping compound reacts with NO in solution to form a specific room-temperature stable, mononitrosyl complex which is readily detected and identified by EPR spectroscopy. Mouse peritoneal macrophages were placed in an EPR sample-cell and activated by lipopolysaccharide and gamma-interferon at 37 degrees C, followed by an additional incubation in oxygenated medium without these activation agents. After various incubation periods, spin trap solution was infused to replace the medium in the sample-cell, and the time-evolution of the EPR signal of the spin adduct (NO-complex) was recorded. Rates of NO generation were calculated based upon the initial slopes of the increase in the EPR intensity with time. In comparison to the NO (or NO2-) generation rate obtained under similar experimental conditions using the Griess reaction assay, the spin trapping method was found to be more sensitive, with a lowest limit of the detection of 3 pmol/min. In addition, by using the spin trapping method, NO generation from the same cells could be measured consecutively during various stages of activation, because infusion of the spin trap solution did not affect the viability of macrophages.

Animals↗

Evaluation of vascular actions of the nitric oxide-trapping agent, N-methyl-D-glucamine dithiocarbamate-Fe2+, on basal and agonist-stimulated nitric oxide activity.

The NO scavenger, N-methyl-D-glucamine dithiocarbamate-Fe2+ (MGD-Fe), was used to characterize spontaneous and agonist-stimulated NO activity arising from rat aortic endothelium. Scavenging of NO in solution by MGD-Fe without tissue was confirmed by electron paramagnetic resonance spectroscopy. The addition of MGD-Fe to aortic ring segments suspended in vitro under resting tension did not cause any direct contraction, but when added to rings contracted with phenylephrine elicited a rapid additional increment in tension which was not altered by indomethacin. This increase in tension was absent in rings pretreated with L-nitroarginine or in rings without endothelium; however, the developed tension in both instances was similar in magnitude to that seen after MGD-Fe suggesting complete scavenging of basal NO production. Acetylcholine produced relaxation (maximum relaxation = 100 +/- 1%) which was completely eliminated in the presence of L-nitroarginine or upon removal of the endothelium. Relaxation to acetylcholine was reduced to 56 +/- 8% in the presence of MGD-Fe (3.0/0.6 mM ratio). Higher concentrations of MGD-Fe caused further decreases in the maximum relaxation to acetylcholine; however, a residual component (approx. 30%) of relaxation persisted. This effect was mimicked by using another NO trapping agent, carboxy-PTIO. These data suggest that MGD-Fe scavenges agonist-stimulated NO, but also reveals a NO synthase-dependent component which is unavailable to interact with MGD-Fe.

Acetylcholine↗

Adipofascial flap of the lower leg based on the saphenous artery.

The adipofascial flap of the lower leg based on the saphenous artery is a modification of the saphenous artery flap. It has been used successfully in 5 patients for reconstruction of soft tissue defects around the knee and superior third of the tibia. The size of these flaps ranged from 5 x 12 cm to 5 x 18 cm. All flaps survived completely. These cases had minimal donor site morbidity because their donor sites were closed primarily with the preserved overlying skin.

Adolescent↗

The lateral calcaneal artery adipofascial flap.

The lateral calcaneal artery adipofascial flap is a modification of the lateral calcaneal artery skin flap. It has been used successfully in five patients. In comparison to the skin flap, it has the advantages of more versatile clinical applications, better aesthetic result of the donor site and sural nerve preservation.

Adipose Tissue↗

Spirometry in life-long non-smoking, healthy Chinese women in Taiwan.

To establish the spirometric values for normal, healthy Chinese women in Taiwan, the spirometry of 506 life-long non-smoking, healthy Chinese women was examined, including 140 subjects over the age of 60 years. Significant correlations among age, height and forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC%, peak expiratory flow (PEF), Vmax75, Vmax50, Vmax25 were found. However, there were no significant correlations between age and FEV1/FVC%, nor age and Vmax25 in the elderly group. FEV1 (FEV1*) and FVC (FVC*) were standardized to the overall mean height for elderly women using Cole's formula. The decline in FEV1* and FVC* with age were observed. The predicted value for the average 70-year-old woman with a height of 1.5 m derived from the present study is compared with those from other surveys of the elderly. The values from the present study are somewhat higher than the values from the Hong Kong study. The authors believe the fact that all of the present subjects were life-long non-smokers might explain the differences.

Adult↗

Continuous thoracic epidural anesthesia for breast augmentation.

Thirty consecutive cases were scheduled for submuscular breast augmentation under continuous thoracic epidural anesthesia. The epidural tube was placed into the intervertebral space between the third and fourth thoracic vertebrae. An average of 15 ml of 2% lidocaine with 1:80,000 epinephrine was used as a primary anesthetic agent. There were no significant changes in respiratory function; only a transient elevation of blood pressure and increased heart rate were noted. All cases were successfully anesthetized, except one case (3%) who had a partial analgesic effect and needed to combine general anesthesia. One patient needed a single dose of ephedrine, 20 mg, to treat hypotension. Perioperative complications included transient shivering (33%), stuffy nose (20%), nausea (7%), and shortness of breath (13%). These symptoms were alleviated after reassurance or light sedation and oxygen inhalation. Immediate postoperative pain of the operative site was effectively controlled by injection of local anesthetics through the epidural tube. This study revealed that thoracic epidural anesthesia was feasible, effective, and even better than conventional alternative anesthetic techniques for breast augmentation.

Adult↗

Mitochondrial gene mutations in patients with insulin-dependent diabetes mellitus in Taiwan.

We studied the prevalence of mitochondrial gene mutations in subjects with insulin-dependent diabetes mellitus (IDDM) in a Chinese population living in Taiwan. Eighty-four subjects with insulin-dependent diabetes mellitus and 105 unrelated normal controls were recruited in the present study. Both an A-to-G mutation at position 3243 and a mutation at position 8,344 of the mitochondrial DNA were screened by polymerase chain reaction-restriction fragment length polymorphism methods and confirmed by direct DNA sequence analysis. The insulin secretory response was assessed by the C-peptide response to glucagon administration. Among 84 IDDM patients, two (2.4%) subjects were found to carry the 3,243 nucleotide pair (np) mutation. There was no np 8,344 mutation in this series. Of the two subjects carrying a mitochondrial gene mutation, case 1 manifested initially as gestational diabetes mellitus. Manifestation of case 2 was consistent with MELAS, a syndrome of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. The pancreatic beta cell reserve was reduced, as the glucagon-stimulated C-peptide response was very low in these two cases. HLA genotyping studies revealed that case 2 carried DRB1*0301-DQA1*0501-DQB*0201/ DRB1*0405-DQA1*0301-DQB1*0302, which was the most susceptible genotype to IDDM in our population. Anti-GAD65 antibody was also positive in this patient. In addition to the nuclear genes, a defective mitochondrial gene might contribute to some of the clinical cases with IDDM.

Adult↗

No association between the Gly971Arg variant of the insulin receptor substrate 1 gene and NIDDM in the Taiwanese population.

OBJECTIVE: To study the role of the Gly971Arg variant of the insulin receptor substrate 1 (IRS-1) gene in the development of NIDDM in the Chinese population living in Taiwan. RESEARCH DESIGN AND METHODS: A total of 82 unrelated normal control subjects, 89 subjects with NIDDM, and 23 multiplex families were recruited in Taiwan. All of them were Han Chinese. Pedigree members without a history of diabetes were studies by the standard 75-g oral glucose tolerance test. Detection of the Gly971Arg variant of the IRS-1 gene was performed by polymerase chain reaction and restriction fragment-length polymorphism analysis. RESULTS: The frequency of Gly971Arg variant of the IRS-1 gene in the normal population was 1.2% which was lower than frequencies reported in white populations. The prevalence of the Gly971Arg variant was not significantly increased in both the nonselected NIDDM population (1.1%) and the probands of the multiplex families (4.3%). More importantly, the Gly971Arg variant of the IRS-1 gene did not cosegregate with BMI and NIDDM in these families, CONCLUSIONS: The Gly971Arg variant of the IRS-1 gene is an infrequent normal allele among Taiwanese. This variant is neither associated nor cosegregated with NIDDM in the Taiwanese population and families. Gly971Arg of IRS-1 gene does not play an important role in the development of NIDDM in this population.

Adult↗

Early diagnosis of necrotizing fasciitis by utilization of ultrasonography.

Necrotizing fasciitis is a rare and rapid progression soft tissue infection. The only identifiable feature is tissue necrosis along a single fascia plane. Because the skin is initially spared, it is difficult for early recognition prior to extensive tissue destruction. Ultrasonography was used for early diagnosis of this infection in five cases. All 5 patients presented with severe cellulitis. Under the suspicion of necrotizing fasciitis, ultrasonography was performed before surgical debridement. Tissue biopsy was done for histological confirmation of the diagnosis. Three patients were proven to have necrotizing fasciitis and two cellulitis only. The ultrasonographic findings of necrotizing fasciitis included: 1) irregularity of the fascia; 2) abnormal fluid collections along the fascia plane; and 3) diffuse thickening of the fascia when compared with the control site in the normal limb. However, in severe infectious cellulitis, the above mentioned findings were not observed. Our results indicate the usefulness of the ultrasonography for early diagnosis of necrotizing fasciitis.

Adult↗

Squamous cell carcinoma of the nail bed.

Squamous cell carcinoma of the nail bed is a rare disorder. Metastasis is extremely unusual. A case of primary squamous cell carcinoma of the nail bed with metastasis to the regional lymph nodes is reported. The tumor was successfully treated by amputation of the involved finger, block dissection of the regional lymph nodes, postoperative irradiation of the involved axilla, and systemic chemotherapy. Early diagnosis by biopsy, especially in patients with recurrent and persistent disease of the nail bed, is recommended, so that treatment can be instituted early while the tumor is confined to its primary site.

Adult↗