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K C Huang

Publications and source records attributed to K C Huang.

At least 19 recordsLinked to original sources
PubMed1997

Characterization of a new ribotoxin gene (c-sar) from Aspergillus clavatus.

A new ribotoxin, c-sarcin, was isolated from a culture of Aspergillus clavatus. A full-length genomic DNA (c-sar) coding for c-sarcin was cloned and sequenced. The deduced amino acid sequence showed a high homology to restrictocin and alpha-sarcin. The native toxin as well as the recombinant protein hydrolysed ribosomes and naked RNA. The genomic structure of the c-sar gene had an intron located between the coding sequences for secretory signal peptide and the mature protein. The intron contained a stretch of 38 adenines. The intron sequence of c-sar was different from that of restrictocin but resembled that of alpha-sarcin. There was 34% identity between the intron of c-sarcin and alpha-sarcin, and this similarity was further increased to 83% if the stretch of polyadenine was omitted.

Aspergillus↗
PubMed1996

Percutaneous absorption of 2,4-dichlorophenoxyacetic acid from soil with respect to soil load and skin contact time: in vivo absorption in rhesus monkey and in vitro absorption in human skin.

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), used for control of weeds in agriculture, forestry, and rights of way, can accumulate as a residual chemical in soil. The objective was to determine percutaneous absorption of 2,4-D from soil, with emphasis on soil load and skin contact time. With control acetone vehicle, in vivo absorption of 2,4-D in the rhesus monkey was 8.6 +/- 2.1% of the dose, which compared closely to published human absorption of 6.0 +/- 2.4%. Percutaneous absorption from soil loads of 1 and 40 mg/cm2 were 9.8 +/- 4.0 and 15.9 +/- 4.7%, respectively, values similar to acetone vehicle. In vitro absorption in human skin calculated from skin contact accumulation over 24 h was 1.8 +/- 1.7, 1.7 +/- 1.3, and 1.4 +/- 1.2% for soil loads of 5, 10, and 40 mg/cm2, respectively. Thus, soil load did not affect 24-h percutaneous absorption. Current Environmental Protection Agency (EPA) recommended calculated reductions due to soil load are not supported by these results with 2,4-D. Percutaneous absorption of 2,4-D from acetone vehicle for 8 h dosing period was 3.2 +/- 1.0%, one-third the value of 8.6 +/- 2.1% over 24 h. With soil vehicle, absorption for 8 h was only 0.03 +/- 0.02% for 40 mg/cm2 soil load and 0.05 +/- 0/.004% for 1 mg/cm2 soil load. Absorption for 16 h was 2.2 +/- 1.2%. Absorption over time was linear for acetone vehicle, where total dose is deposited on skin, but not linear for soil vehicle, which had an 8-h delay (lag time). This equates with a normal 8-h work day where most of the contaminated soil can be washed off the skin. The apparent partition coefficient of 2,4-D between soil and water changed over time. This suggests there is a "mobility" phase for 2,4-D in soil that will change with time. For soil vehicle, percutaneous absorption of 2,4-D was not linear in respect to soil load or to skin contact time. Calculation based on assumed linearity can falsely estimate potential human health hazard. Clearly, the dermatokinetics with soil and skin represent complex interactive forces that require detailed evaluation before overgeneralizing rules for interpretation in terms of risk assessment.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1995

Production of type II ribotoxins by Aspergillus species and related fungi in Taiwan.

A molecular investigation was conducted on the production of type II ribotoxin of the species Aspergillus and related fungi in Taiwan. Species that carried ribotoxin were confirmed by (1) cross-reactivity to anti-alpha-sarcin serum; (2) Southern dot hybridization; (3) PCR amplification of genomic DNA with specific primers; and (4) analysis of ribotoxic activity. Five new strains, A. clavatus, A. oryzae var. effusus, A. ostianus, A. tamarii, and Neosartorya fischeri var. spinosa, were identified to contain an alpha-sarcin-like ribotoxin. These positive strains exhibit ribotoxic activity by cleaving ribosomes and generating an alpha-fragment.

Animals↗
PubMed1995

Cytogenetic mapping of lambda gt10 lacZ sequences in the transgenic mouse strain 40.6 (Muta Mouse).

The transgenic mouse strain 40.6 (Muta Mouse) was developed for the detection of gene mutations induced in vivo. Strain 40.6 was constructed by microinjecting the shuttle vector lambda gt10 lacZ into the male pronucleus of a single cell embryo resulting from a CD2 (i.e. BALB/c x DBA/2)F1 x CD2F1 cross. Approximately 40 concatenated copies of the shuttle vector were integrated per haploid genome. The resulting mice were bred to disomy for the insert for use in mutagenicity studies. Ultimately, it is hoped that transgenic rodent model systems such as this one will play an important regulatory role in hazard identification. Despite the increasing use of this strain in toxicological studies, relatively little is known about the site of integration of the target gene into the mouse genome. In this study, fluorescence in situ hybridization and DAPI chromosome banding were combined to determine the location of the transgenic element in the mouse genome. The results indicate that the lambda sequences containing the lacZ gene are located in the B region of mouse chromosome 3. No other major chromosomal rearrangements were evident in the genome of this mouse strain.

Animals↗
PubMed1993

Suitability of human chromosome-specific DNA libraries for mutagenicity studies in Macaca fascicularis.

The development and use of chromosome-specific DNA probes to label entire human chromosomes has been an important advance in molecular cytogenetics. Fluorescence in situ hybridization using whole chromosome-specific DNA probes has been used to study both numerical and structural chromosomal aberrations in many human cell types. It would be useful if this technology could be applied to other animal species. However, whole chromosome-specific DNA probes have been reported for only human chromosomes. In this study, experiments were conducted to determine whether human probes could be used to label chromosomes of the cynomolgus monkey, Macaca fascicularis. The results demonstrate that some human DNA probes are suitable for the study of chromosomal aberrations in the monkey. Monkey chromosomes 1 and 4 labelled with human DNA probes had a strong, chromosome-specific labelling pattern. The probe for human chromosome 21 labelled the short arm on the monkey chromosome 2 and the probe for human chromosome 2 could not be detected on any of the monkey chromosomes.

Animals↗
PubMed1992

Side effects during continuous epidural infusion of morphine and fentanyl.

Respiratory effects, nausea, somnolence, and pruritus were compared during a 48-hr period of continuous epidural morphine (n = 34) and fentanyl (n = 32) infusion in 66 patients following elective total replacement of the hip or knee joint. Respiratory effects were assessed by PaCO2. Side effects were assessed by visual analogue scale and considered to be present when the score was above 30. Assessment was made at preoperative visits then 3, 6, 12, 24, 36, and 48 hr after the epidural injection. The bolus dose and subsequent infusion rate were 3,900 +/- 1,300 micrograms and 427 +/- 213 micrograms.hr-1 for morphine, and 85 +/- 46 micrograms and 56 +/- 27 micrograms.hr-1 for fentanyl. Pain relief was similar in both groups. In the morphine group, PaCO2 elevation and nausea occurred over a period of more than 12 hr (P less than 0.05). In the fentanyl group, there was no PaCO2 change, and nausea was confined to the first few hours. Nausea was more severe (P less than 0.01 at six hours and more frequent (24 hr cumulative incidence, 53 vs 28%, P less than 0.05) in the morphine group. Somnolence was prominent within several hours in two-thirds of patients in both groups. Somnolence continued to decline thereafter in the morphine group, but it was demonstrable in approximately half of the patients throughout the second day in the fentanyl group. The incidence was higher in the fentanyl group at the 48th hr (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Second hip fracture].

During the period from 1982-1990, a total of 1644 patients were admitted to our hospital with proximal femoral fractures. Trochanteric fractures were encountered in 54 per cent of the cases (887/1644) with a mean age of 68 years. Cervical fractures were encountered in 46 per cent of the cases (757/1644) with a mean age of 62 years. We found 28 patients who had been readmitted with a second hip fracture in this retrospective study, including twenty three males and five females. Two of these second hip fractures occurred on the same side as the initial fracture and twenty six occurred on the opposite side. The time interval between the first and the second hip fracture was shorter in males than that in females (1.7 years V.S. 2.7 years) and the interval also was shorter in those with a previous trochanteric fracture as compared to those with a previous cervical fracture (1.5 years V.S. 2.6 years). It appeared that a hip fracture reduced the risk of a subsequent hip fracture on the same side, and almost all second hip fractures were located on the opposite side of the patient (93 per cent). A possible reason for this "protective mechanism" is increased strength of the bone due to callus formation. A significant symmetry (trochanteric-trochanteric or cervical-cervical) was found between the first and the second hip fractures (69 per cent). We believe the symmetrical fracture pattern is due to senile osteoporosis, a kind of ongoing systemic weakening of the skeletal system among the elderly.

Aged↗
PubMed1991

Cardiac sympathetic tone in anaesthetized diabetics.

To assess cardiac sympathetic nervous function in diabetics, the heart rates attained following a pharmacological dose of intravenous atropine, 23 micrograms.kg-1, were studied under N2O, isoflurane anaesthesia in diabetics (n = 21) and nondiabetics (n = 30). Atropine-induced heart rate in diabetics was significantly lower than that in nondiabetics (95 +/- 14 (SD) bpm vs 109 +/- 12 bpm, P less than 0.001) and were closely related to preoperative orthostatic diastolic blood pressure change (r = 0.60, P less than 0.01). There was some correlation between the atropine-induced heart rate and preoperative RR-variation in diabetics (r = 0.50, P less than 0.05). The findings suggest that cardiac sympathetic function may also be impaired in diabetics with orthostatic hypotension.

Adolescent↗
PubMed1991

[Acetabular roof reconstruction with femoral head bone-graft for severe acetabular deficiency in total hip replacement].

From July 1984 to September 1989 at Taichung Veterans General Hospital, 14 patients (15 hips) received femoral head bone-grafting by modified Harris method as a part of their total hip replacement for acetabular bony deficiencies. They were followed up for an average of 31.7 months (range from 7 to 66 months). The clinical results were classified as excellent (58.3%) and good (41.7%) by Harris hip scoring system. All the grafts presented as "solid incorporation" with the pelvic wall and only one of the grafts was assessed to be "definite resorption" (volume reduction greater than 50%) by radiologic study. The "biologic viability" of these grafts were proved to be positive by scintigraphy in three-dimensional technique (SPECT). According to our limited experience and primary follow-up studies, we found that good clinical results depend on ideal positioning of the acetabular component in the true acetabulum and femoral head bone-grafting is an ideal procedure for the reconstruction of severe acetabular dysplasia in total hip arthroplasty.

Acetabulum↗
PubMed1990

Stroke volume measurements by electrical bioimpedance and echocardiography in healthy volunteers.

To evaluate the validity of three equations for estimation of thoracic electrical field size in a new bioimpedance algorithm, stroke volume (SV) as calculated by these equations was compared with that calculated by Doppler echocardiography in 48 healthy volunteers, both lean and obese. When the volume of electrically participating tissue was estimated from body height (modified Sramek) or body height corrected for body habitus (Sramek-Bernstein), there was considerable variation between bioimpedance and Doppler stroke volumes. When the volume of electrically participating tissue was estimated from the actual measurement of the height of the thorax and the circumference at the base of the thorax, the variation in SV differences decreased substantially (Sramek equation), although still considerable for clinical use, and there was no relationship between SV thus obtained and body habitus. Analysis of calculated stroke indices derived by our Doppler echocardiographic standard, as compared with values in the literature, revealed a systematic underestimation. We conclude that the original Sramek equation systematically underestimates SV by 15% to 20%, and the modified Sramek and Sramek-Bernstein equations systematically underestimates SV by 15% to 20%, and the modified Sramek and Sramek-Bernstein equations systematically overestimate SV in females by about 15%, but provide SV values in males in the predicted range. Further studies on the current assumption that the electrical field size is a truncated cone may improve precision of the bioimpedance method.

Adult↗
PubMed1989

Peripheral somatic sensory neuropathy and skin galvanic response in the feet of patients with diabetes.

The relationship between abnormality in the peripheral sympathetic nervous system (skin galvanic response) and in the peripheral somatic sensory nerve fibers was studied in the lower extremities of 51 patients with diabetes. Deficits in temperature and pain sensations (the small sensory nerve fibers) were related to abnormal sympathetic nervous function (temperature sensation, p less than 0.001; pain sensation, p less than 0.05). The deficits in temperature sensation, in particular, predicted abnormal sympathetic nervous function reliably and vice versa. There was no relationship between deficits in touch and vibration sensations (the large sensory nerve fibers) and abnormal sympathetic nervous function. There was a relationship between skin galvanic response and RR-variation (p less than 0.01). However, abnormality in RR-variation was not related to the deficits in any of the four sensory modalities.

Adult↗
PubMed1988

Renal handling of adriamycin.

The excretion of the anticancer drug, adriamycin (ADR) was investigated in dogs. Its plasma half-life was found to be 8.4 hrs. 1. ADR was excreted in the bile against concentration gradient. The biliary clearance ratio between ADR and creatinine was ranged from 30-100. 2. Intra-arterial injection studies showed that ADR was both reabsorbed and secreted by the renal tubules. Stop-flow studies indicated that the secretion of ADR was localized at the proximal tubular section. 3. The tubular secretion of ADR is probably by an organic base secretory mechanism. Acidification of the urine would augment the urinary excretion of ADR and alkalinization reduces it. Probenecid has little effect on ADR excretion.

Absorption↗
PubMed1987

Dose-dependent elimination of 5-fluoro-2'-deoxyuridine in the monkey.

The kinetics of 5-fluoro-2'-deoxyuridine (FdUrd) and 5-fluorouracil (FUra) disposition after bolus intravenous injection were determined in anesthetized rhesus and cynomolgus monkeys. FdUrd disappearance from plasma was an apparent triexponential process with average half-lives of 0.5, 2, and 8 min; FUra disappearance was biphasic with average half-lives of 2 and 13 min. After FdUrd injection, FUra reached peak plasma concentrations of 15-30% of the initial FdUrd concentrations within 3 min, and then disappeared more slowly than FdUrd. Total FdUrd clearance fell from 105 to 73 to 56 ml/kg/min as the dose increased from 10 to 20 to 40 mg/kg. Metabolic clearance was about 85% of total clearance and fell similarly with increasing dosage. Total and metabolic FUra clearances were about 30% of FdUrd values at an equimolar dose. Renal FdUrd clearance exceeded glomerular filtration rate and was decreased by probenecid, indicating tubular secretion; renal FUra clearance was close to glomerular filtration rate. There was no apparent correlation between dose and renal clearance or volume of distribution. It was concluded that FdUrd, like FUra, is eliminated primarily by a dose-dependent process. The metabolic basis of the dose-dependent kinetics remains to be determined.

Animals↗