Biomedical subjects

C Tai

Publications and source records attributed to C Tai.

At least 19 recordsLinked to original sources

PubMed2026

[Genomic characteristics of multi-drug resistant of non-O1/non-O139 Vibrio cholerae ST1565 from sepsis cases].

To analyze the genomic characteristics of multi-drug resistant of non-O1/non-O139 Vibrio cholerae ST1565 from sepsis cases. An 88 years old male patient admitted to Huashan Hospital in Shanghai on July 2, 2025, who was retrospectively analyzed. The clinical diagnosis was severe bacterial enteritis and secondary NOVC sepsis. Blood culture confirmed the presence of non-O1/non-O139 group Vibrio cholerae. The strain was a multidrug-resistant isolated of ST1565 as determined by whole-genome sequencing. The ResFinder database predicted 11 resistance genes for 6 classes of antibiotics: qnrVC5, sul2, floR, tet(59), aph(6)-Id, aph(3'')-Ib, dfrA15, dfrA31, almE, almF, and almG. Except for the quinolone qnrVC5, which was not expressed, the other resistance genes were consistent matched the phenotypic results. Additionally, 8 insertion sequences were identified: ISVch1, ISVvu4, ISVch6, ISVvu8, ISVpa3, ISVpa4, ISVsa3, and ISShfr9. Important virulence factors included 3 secreted protein toxin genes: Vibrio cholerae hemolysin, repeat toxin, and Vibrio parahaemolyticus thermostable direct hemolysin. The patient was cured after sequential treatment with meropenem, levofloxacin, and doxycycline. NOVC/ST1565 is a newly identified sequence type in China, which exhibits multidrug-resistant and hypervirulent phenotypes.

Drug Resistance, Multiple, Bacterial↗

PubMed2006

Origin of spontaneous activity in neonatal and adult rat bladders and its enhancement by stretch and muscarinic agonists.

This study examined the origin of spontaneous activity in neonatal and adult rat bladders and the effect of stretch and muscarinic agonists and antagonists on spontaneous activity. Rats were anesthetized and their bladders were excised, cannulated, and loaded with voltage- and Ca(2+)-sensitive dyes. Intracellular Ca(2+) and membrane potential transients were mapped using photodiode arrays in whole bladders, bladder sheets, or cross-section preparations at 37 degrees C. Intravesical pressure was recorded from whole bladders. In neonatal bladders and sheets, spontaneous Ca(2+) and electrical signals arose at a site near the dome and spread in a coordinated manner throughout the bladder with different dome-to-neck conduction velocities (Ca(2+): 3.7 +/- 0.4 mm/s; membrane potential: 46.2 +/- 3.1 mm/s). In whole bladders, optical signals were associated with spontaneous contractions (10-20 cmH(2)O). By contrast, in adult bladders spontaneous Ca(2+) and electrical activity was uncoordinated, originating at multiple sites and was associated with smaller (2-5 cmH(2)O) contractions. Spontaneous contractions and optical signals were insensitive to tetrodotoxin (2 muM) but were blocked by nifedipine (10 muM). Stretch or low carbachol concentrations (50 nM) applied to neonatal whole bladders enhanced the amplitude (to 20-35 cmH(2)O) of spontaneous activity, which was blocked by atropine. Bladder cross sections revealed that Ca(2+) and membrane potential transients produced by stretch or carbachol began near the urothelial-suburothelial interface and then spread to the detrusor. In conclusion, spontaneous activity in neonatal bladders, unlike activity in adult bladders, is highly organized, originating in the urothelium-suburothelium near the dome. Activity is enhanced by stretch or carbachol and this enhancement is blocked by atropine. It is hypothesized that acetylcholine is released from the urothelium during bladder filling to enhance spontaneous activity.

Animals↗

PubMed2005

Selection responses in duration of fertility and its consequences on hatchability in the intergeneric crossbreeding of ducks.

1. From 1992 to 2003, selected (S) and control lines (C) of the laying Brown Tsaiya duck (Anas platyrhynchos) were simultaneously maintained under the same standardised conditions of feeding and management. 2. The selection objective was to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. From generations G1 to G11, 2452 and 2022 female ducks, in S and C lines, respectively, were measured and recorded. In the S line, the percentage selected varied between 20.2 and 34.3% in females and between 7.2 and 20.8% in males. 3. Selection for number of fertile eggs had a correlated effect of increasing the parameter tau of the logistic curves which fitted the daily variations (d 2 to 15) in fertility or hatchability on the basis of eggs set. The differences S-C for the estimates of the times of half maximal fertility and hatchability increased by 0.41 and 0.37 d per generation between G1 and G11, respectively. 4. The highest increases of fertility per day rates after a single AI were observed between d 5 and 11. Moreover, in the selected line, fertility rate was higher than, or equal to, 90% in d 2 from G8. The same tendencies were observed for the changes in the evolution of hatchability on the basis of eggs set. 5. Selection increased fertility and hatchability according to the egg set rates, especially for d 2 to 8 after AI. Hatchability of fertile eggs was not impaired, confirming that selection for one AI per week was possible in this strain of laying ducks.

Animal Husbandry↗

PubMed2004

Heritabilities and genetic correlations of laying performance in Muscovy ducks selected in Taiwan.

1. Genetic parameters in the base population of a closed experimental strain of Muscovy ducks, selected for body weight at 10 weeks of age, were estimated from data in 8 successive generations, for the following traits: age at first egg (AGE1EGG), total number of eggs laid at 40 and 52 weeks of age (NEGG40 and NEGG52), number of eggs laid during 15 and 22 weeks in the first laying cycle (NEGG15W and NEGG22W), and their Box-Cox transformed data. 2. The method of multi-trait restricted maximum likelihood with an animal model was used to estimate genetic parameters. Only the results obtained with non-transformed data are shown. 3. Heritability estimates for laying performance showed moderate values, increasing little with age: 0.20+/-0.03 (AGE1EGG), 0.23+/-0.03 (NEGG40), 0.27+/-0.03 (NEGG52), 0.20+/-0.03 (NEGG15W), and 0.22+/-0.03 (NEGG22W). 4. Genetic correlations between laying traits were high. Genetic correlation between AGE1EGG and egg number was negative, it was positive between total numbers of eggs at 40 and 52 weeks and egg numbers in the first laying cycle. 5. Body weight at 10 weeks of age exhibited positive genetic correlations (0.46+/-0.06) with age at first egg and negative with egg production traits (-0.28+/-0.06 to -0.41+/-0.06). 6. The cumulated predicted genetic gains, after 7 generations of selection, expressed per genetic standard deviation unit (sigma(g)) were 0.06 sigma(g), 0.07 sigma(g), 0.17 sigma(g), 0.23 sigma(g), and 0.25 sigma(g) for AGE1EGG, NEGG40, NEGG52, NEGG15W, and NEGG22W, respectively. 7. Selecting Muscovy ducks to improve laying in Taiwanese climatic conditions would be possible using the number of eggs laid up to 52 weeks of age as the selection criterion. Because unintended selection effects for laying traits were present, the selection experiment for body weight at 10 weeks of age was not antagonistic with laying traits.

Animals↗

PubMed2003

Pre-donated autologous blood transfusion in scoliosis surgery.

We studied the use of autologous pre-donatedblood transfusion in surgery for scoliosis in 45 patients who were divided into two groups; 27 who pre-donated autologous blood (group 1) and 18 who were planned recipients of allogenic blood (group 2). Normovolaemic haemodilution and intra-operative blood salvage was used in six patients in group 1 and three patients in group 2. The two groups did not differ significantly with respect to age, American Society of Anaesthesiologists score, mean operative time, number of vertebral segments fused, total blood loss, length of stay in intensive care and length of stay in hospital. The risk of requiring allogenic blood transfusion was found to be significantly less in group 1 (7.4% v 88.9%, p < 0.001). Only 5.21% of autologous units were wasted. Although intra-operative blood salvage reduced the total blood loss in both groups, it did not affect the need for subsequent allogenic transfusion or reduce the number of pre-donated autologous units which were given (p < 0.67). Autologous blood transfusion requiredextra time, personnel, resources and cost pounds sterling 28.88 per patient more than allogenic transfusion, however, the projected costs at May 2002 make this programme cost-effective by pounds sterling 51.54 per patient. Pre-donated autologous blood transfusion is acceptable and safe in scoliosis surgery. It significantly reduces the subsequent requirement of allogenic transfusion. Although the cost is currently more than allogenic transfusion, with the increase in the costs of the latter and the decrease in potential donors which is anticipated, pre-donation of autologous blood will become comparatively cost-effective.

Adolescent↗

PubMed2001

Colon and anal sphincter contractions evoked by microstimulation of the sacral spinal cord in cats.

The colon and anal sphincter contractions induced by microstimulation of the S2 spinal cord were investigated by measuring the intraluminal pressure change via saline filled balloons in alpha-chlorolose anesthetized cats. Stimulation of sacral ventral roots (S1-S3) revealed that the S2 efferent outflow usually produces the largest colon response. Stimulation of the S2 ventral root or the spinal cord both indicated that 15 Hz stimulation was the optimal frequency for evoking colon contractions. Colon and anal sphincter contractions were also influenced by stimulation intensity and pulsewidth. Locations in S2 spinal cord, where microstimulation evoked a distal/proximal colon pressure response that was greater than the anal sphincter response, included the area of sacral parasympathetic nucleus (SPN), the area medial to the SPN extending to the dorsal commissure, and areas deep in the ventral horn. Anal sphincter relaxation was evoked by microstimulation in more restricted locations in S2 spinal cord, which appeared to overlap with those evoking anal sphincter contractions. These results suggest a possible method to evoke colon contraction and defecation by microstimulation of the S2 spinal cord with multiple microelectrodes.

Adrenergic beta-Antagonists↗

PubMed2001

LIS1: cellular function of a disease-causing gene.

Brain development is severely defective in children with lissencephaly. The highly organized distribution of neurons within the cerebral cortex is disrupted, a condition that might arise from improper migration of neuronal progenitors to their cortical destinations. Type I lissencephaly results from mutations in the LIS1 gene, which has been implicated in the cytoplasmic dynein and platelet-activating factor pathways. Recent studies have identified roles for the product of LIS1 in nuclear migration, mitotic spindle orientation and chromosome alignment, where it appears to act in concert with cytoplasmic dynein. A unifying hypothesis for the subcellular function of LIS1 is presented.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

PubMed2001

Cryopreservation of gander semen.

1. The effect of dimethylacetamide (DMA) and dimethyl sulphoxide (DMSO) on the cryopreservation of gander semen were investigated. An improved survival rate of spermatozoa after freeze-thawing was obtained when semen was frozen by a fast-freezing procedure on dry ice with 9% DMA as the cryoprotectant. 2. Gander semen, which was frozen during mid season, was tested for fertilising ability in different times of the season. The percentage of fertility during d 3 to d 9 after 2 consecutive inseminations was 68% to 95%, depending on the date of artificial insemination.

Acetamides↗

PubMed2001

Neural control of the urethra.

Coordination between the urinary bladder and the urethra is mediated by multiple reflex pathways organized in the brain and spinal cord. Some reflexes promote urine storage; whereas other reflexes facilitate voiding. During bladder filling, activation of mechanoreceptor afferent nerves in the bladder wall triggers firing in the cholinergic efferent pathways to the external urethral sphincter (EUS) and in sympathetic adrenergic pathways to the urethral smooth muscle. These storage reflexes are dependent upon interneuronal circuitry in the spinal cord. During voiding the spinal storage reflexes are inhibited by supraspinal mechanisms which originate in the pontine micturition center. Glutamatergic, serotonergic and alpha, adrenergic excitatory transmission as well as GABAergic/glycinergic inhibitory transmission have been implicated in the central control of sphincter reflexes. During voiding, a parasympathetic nitrergic inhibitory input to the urethral smooth is activated. This reflex mechanism which is triggered by bladder afferents persists in paraplegic rats and therefore must be mediated at least in part by spinal interneuronal circuitry. In female rats, the parasympathetic nitrergic pathway is prominent; but in male rats it is obscured by a dominant parasympathetic cholinergic excitatory input to the urethral smooth muscle. The function of the cholinergic pathway in voiding is uncertain. Stimulation of urethral afferents can also influence bladder activity. Contraction of the external urethral sphincter activates afferents that inhibit reflex bladder contractions; whereas infusion of fluid through the urethra facilitates bladder contractions. These reflexes are also organized in the spinal cord and presumably play a role in urine storage and elimination. Alterations in primitive bladder-to-urethra and urethra-to-bladder reflex mechanisms may contribute to neurogenic bladder dysfunction.

Afferent Pathways↗

PubMed2001

Performance evaluation of the microPET P4: a PET system dedicated to animal imaging.

The microPET Primate 4-ring system (P4) is an animal PET tomograph with a 7.8 cm axial extent, a 19 cm diameter transaxial field of view (FOV) and a 22 cm animal port. The system is composed of 168 detector modules, each with an 8 x 8 array of 2.2 x 2.2 x 10 mm3 lutetium oxyorthosilicate crystals, arranged as 32 crystal rings 26 cm in diameter. The detector crystals are coupled to a Hamamatsu R5900-C8 PS-PMT via a 10 cm long optical fibre bundle. The detectors have a timing resolution of 3.2 ns, an average energy resolution of 26%, and an average intrinsic spatial resolution of 1.75 mm. The system operates in 3D mode without inter-plane septa, acquiring data in list mode. The reconstructed image spatial resolution ranges from 1.8 mm at the centre to 3 mm at 4 cm radial offset. The tomograph has a peak system sensitivity of 2.25% at the centre of the FOV with a 250-750 keV energy window. The noise equivalent count rate peaks at 100-290 kcps for representative object sizes. Images from two phantoms and three different types of laboratory animal demonstrate the advantage of the P4 system over the original prototype microPET. including its threefold improvement in sensitivity and a large axial FOV sufficient to image an entire mouse in a single bed position.

Animals↗

PubMed2001

Genetic parameters of reproductive traits in Brown Tsaiya ducks artificially inseminated with semen from Muscovy drakes.

A selection experiment on maximum duration of fertility of Brown Tsaiya ducks after artificial insemination (AI) with pooled Muscovy semen has been conducted since 1992. The Brown Tsaiya ducks were divided into two lines: a control line (T) with no selection and a selected line (S). The traits measured were the number of eggs set that were laid from Days 2 to 15 after one AI (NES), the number of fertile eggs at candling (NEF), the total number of dead embryos (NED), the maximum duration of fertility (MD), and the number of hatched mule ducklings (NEH). The selected trait was NEF. Six generations with a total of 2,127 females were measured. The variance components were estimated for each line in a multiple-trait animal model, using the restricted maximum likelihood (REML) methodology, which yields estimates free of bias caused by selection and inbreeding. Estimates of the heritability and genetic correlation from the two lines were very similar. Heritabilities in the S and T lines, respectively, were 0.14 and 0.10 for NES, 0.30 and 0.26 for NEF, 0.06 and 0.09 for NED, 0.28 and 0.21 for MD, and 0.18 and 0.19 for NEH. High and favorable genetic correlations existed between NEF and MD (0.96 and 0.92), between NEF and NEH (0.86 and 0.91), and between MD and NEH (0.90 and 0.82). The results suggested that selection for NEF could improve the maximum duration of fertility, but it could be useful to check the estimates of genetic parameters in a meat-type female duck.

Animals↗

PubMed2001

Selective stimulation of smaller nerve fibers using biphasic rectangular pulses.

Based on the F-H model, a simulation system to study the excitation properties of myelinated nerve fibers was developed. In order to minimize electrochemical damage of nerve tissue, three selective stimulation methods employing biphasic rectangular pulses were studied, which use single, double and triple electrodes, respectively. The simulation results prove that all of the three methods are effective in selective stimulation of smaller nerve fibers in a compound nerve trunk under certain conditions. The feasibility of these methods is also verified by animal experiments on the sciatic nerve trunks of toads. The amplitude and delay of compound action potential and the results of collision experiments proved that the methods are valid. These methods will be very useful in functional neuromuscular stimulation.

Animals↗

PubMed2000

Mice immunized with DNA encoding a modified Pseudomonas aeruginosa exotoxin A develop protective immunity against exotoxin intoxication.

A recombinant plasmid, which contains the Pseudomonas aeruginosa exotoxin A (PE) gene with a C-terminal deletion, was inserted into expression vector pSecTag Xpress. The expression of this bacterial exotoxin in an animal cell was first demonstrated in 3T3 cell by transient transfection and western blot assay. Recombinant plasmid DNA was then injected intramuscularly to BALB/c mice, anti-PE specific antibodies were found in all animals vaccinated with plasmid containing the PE gene and with 'detoxicated' recombinant PE protein. Mice vaccinated with DNA were protected from the intoxication of lethal dosage of P. aeruginosa exotoxin A. Our results indicated that mice vaccinated with DNA encoding the PE gene could express PE protein in vivo, induced specific immune response, and provided sufficient protective immunity that safeguarded mice from the injection of lethal dosage of PE toxin.

ADP Ribose Transferases↗

PubMed2000

Multimicroelectrode stimulation within the cat L6 spinal cord: influences of electrode combinations and stimulus interleave time on knee joint extension torque.

During multimicroelectrode stimulation within the cat L6 spinal cord, the number of electrodes activated, their separation distance, and the stimulus interleave time all influenced isometric knee joint extension torque. The torque evoked by stimulation with a three electrode combination could be enhanced or suppressed when compared with that evoked by single or paired electrode stimulation. A similar difference was noted when comparing two electrode combination versus single electrode stimulation. Relative fatigue was not improved significantly by interleaving the stimuli from two or three microelectrodes. Compared with the extension torque response evoked by noninterleaved stimulation, torque evoked by interleaved stimulation with the two microelectrode combination was decreased when the electrode distance was 2.0 mm or less and increased when the electrode distance was 3.0 mm. Designing an optimal stimulation strategy for multimicroelectrode spinal cord stimulation will be challenging and complex if a suppression effect among these electrodes is to be avoided. To reduce muscle fatigue, an asynchronous, interleaved strategy of stimulation may be required.

Animals↗

PubMed1999

Steroid-responsive pleuropericarditis and livedo reticularis in an unusual case of adult-onset primary hyperoxaluria.

We present a case of a 54-year-old woman with rapidly progressive renal failure of uncertain origin, who developed pleuropericarditis and livedo reticularis 6 weeks after initiation of hemodialysis (HD). The presentation with acute renal failure, the development of serositis, and the dramatic clinical response to empiric steroid therapy initially suggested the diagnosis of a systemic inflammatory disorder or vasculitis. Renal biopsy, performed 3 days after presentation, suggested crystal deposition disease, and subsequent investigations, using both dialysate oxalate concentrations and liver biopsy, led to the diagnosis of primary hyperoxaluria (PH). We discuss this atypical adult presentation of PH and propose a role for the use of steroids in the management of the acute inflammatory symptoms of oxalosis. We also briefly discuss the current medical management of patients with PH, including transplantation.

Age of Onset↗

PubMed1999

Heritabilities and genetic correlations of body weights and feather length in growing Muscovy selected in Taiwan.

1. Heritabilities and genetic correlations in the base population of a closed strain of Muscovy duck, moderately selected for body weight at 10 weeks of age, have been estimated from the data of 9 successive generations for the following traits: male and female body weight at 10 and 18 weeks of age (BW10m, BW18m, BW10f, BW18f) and length of the 8th primary feather at 10 weeks of age (F110m, F110f). 2. Multivariate REML with an animal model was used, pooling data from the 9 generations (3283 and 3289 male and female offspring respectively). The same trait expressed in male and female was considered as 2 different traits. 3. The 8th primary feather was longer in females than in males by 6% to 22% at 10 weeks of age. Body weight was heavier in males than in females by 42% to 58% at 10 weeks of age and by 57% to 75% at 18 weeks of age. 3. The heritability estimates for body weight traits showed moderate values, being a little higher for females than for males at the same age, increasing with age from h2=0.24 at BW10m to h2=0.43 at BW18f. 4. The heritability estimates for feather length showed that a greater response would be obtained in selection for male feather length (h2=0.37) than for female length (h2=0.14). Both have high genetic correlations with body weight so they could be indirectly improved. 5. Heritabilities of the difference in body weights between males and females at 10 weeks (h2=0.07) and 18 weeks of age (h2=0.10) were small, as well as for feather length (h2=0.10). It would probably be difficult to modify sexual dimorphism in body weight through selection. 6. Genetic correlations between BW10m, BW18m and BW10f, BW18f were respectively r(g)=0.77 and r(g)=0.80. They were larger for body weight at the same ages between males and females, r(g)=0.90 (r(g)=0.88 between F110m and F110f). Body weight in males and females at the same age should be better considered as 2 different traits in a selection programme. 7. The cumulated predicted genetic gains expressed per unity of the genetic standard deviation (sigma(g)) over the 8 generations of selection were 1.3 sigma(g) and 1.4 sigma(g) respectively for the BW10m and BW10f. The predicted correlated responses were 1.2 sigma(g) for body weights at 18 weeks of age, 0.9 sigma(g) and 0.7 sigma(g) for F110f and F110m respectively.

Animals↗

PubMed1999

Isometric torque about the knee joint generated by microstimulation of the cat L6 spinal cord.

Isometric torque was generated about the knee joint by microstimulation of the cat L6 spinal cord using a single microelectrode. The torque responses varied with microstimulation location. Appreciable extension torque was generated by microstimulation in ventrolateral locations of the L6 spinal cord. Stimulation parameters (intensity, frequency and pulse-width) also influenced the extension torque. Specific stimulation parameters (100 microA intensity, 40 Hz frequency and 0.20 ms pulse-width) appear best suited for mapping the spinal cord based on knee joint torque responses. Low levels of cocontraction of the extensor and flexor could be achieved when extension torque was produced, but also varied with the stimulation locations. There are locations in the L6 ventral horn where microstimulation could evoke sustained extension for at least 4 min with only a slight change in torque. This study suggests the possibility of restoring lower limb function in patients with spinal cord injury above the lumbar level.

Animals↗

PubMed1999

Knee elasticity influenced by joint angle and perturbation intensity.

The responses of the human knee joint system to small rotational displacements were studied in the horizontal plane to eliminate the effect of gravity. Band-limited noise was used to produce up to +/-3 degrees angular perturbations to the knee joint. Under these restricted conditions, the knee joint system could be described by a linear, second-order model with the assumption that the mechanical properties of the knee were constant over these small displacements. The elasticity about the knee was influenced not only by the static joint angle but also by the perturbation intensity. Realistic models of the knee joint system should be modeled by a position-dependent, nonlinear system to remain valid over a large range of rotation.

Adult↗