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Biomedical subjects

K H Wu

Publications and source records attributed to K H Wu.

At least 19 recordsLinked to original sources
PubMed1998

Integrin-mediated short-term memory in Drosophila.

Volado is a new memory mutant of Drosophila. The locus encodes two isoforms of a new alpha-integrin, a molecule that dynamically mediates cell adhesion and signal transduction. The Volado gene is expressed preferentially in mushroom body cells, which are neurons known to mediate olfactory learning in insects. Volado proteins are concentrated in the mushroom body neuropil, brain areas that contain mushroom body processes in synaptic contact with other neurons. Volado mutants display impaired olfactory memories within 3 min of training, indicating that the integrin is required for short-term memory processes. Conditional expression of a Volado transgene during adulthood rescues the memory impairment. This rescue of memory is reversible, fading over time along with expression of the transgene. Thus the Volado integrin is essential for the physiological processes underlying memory. We propose a model in which integrins act as dynamic regulators of synapse structure or the signalling events underlying short-term memory formation.

Amino Acid Sequence↗
PubMed1998

Age-related changes in blood lymphocyte subsets of Chinese children.

BACKGROUND: Flow cytometric analysis of major lymphocyte populations and their subsets reveals age-related changes in the human cellular immune system. SUBJECTS AND METHODS: Immunophenotypic markers were evaluated in 136 healthy pediatric subjects divided into groups of newborn infants (cord blood), children aged 1 to 2 years, 2 to 5 years, and 6 to 15 years. RESULTS: The percentage of T cells increased gradually with age and the evolution of the percentage of B and NK cells was found to be variable. The percentage of CD4+ cells remains relatively unchanged from infancy to adolescence, but the percentage of CD8+ T cells was lowest at birth and reached maximal levels in the one to two year-old period. The percentage of naive T cells declined with time, but the percentage of memory T cells increased with age. Similar trends were seen in T-cell receptor alphabeta- and gammadelta-bearing T cells. The percentage of CD 11b+CD8+ T cells increased gradually from birth and reached maximal levels from 6 to 15 years old. The expression of the activation markers CD25 and HLA-DR on CD4+ T cells increased with age. The percentage of CD16+CD56- NK cells declined with age, but the evolution of the percentage of CD 16-CD56+ NK cells was variable. The fraction of B cells that expressed CD5 was high at birth (72.9%) and was highest in one to two year olds (73.1%), then declined steadily over time. The CD23 antigen was expressed on 41.9% of B cells at birth and 68.6% during the first to second year, then declined steadily with age. CONCLUSION: These data may serve as a reference range for studies of Chinese pediatric subjects.

Adolescent↗
PubMed1998

The opt1 gene of Drosophila melanogaster encodes a proton-dependent dipeptide transporter.

We have cloned and characterized the opt1 gene of Drosophila melanogaster. This gene encodes a protein with significant similarity to the PTR family of oligopeptide transporters. The OPT1 protein is localized to the apical epithelial membrane domains of the midgut, rectum, and female reproductive tract. The opt1 message is maternally loaded into developing oocytes, and OPT1 is found in the alpha-yolk spheres of the developing embryo. It is also found throughout the neuropil of the central nervous system, with elevated expression within the alpha- and beta-lobes of the mushroom bodies. Transport activity was examined in HeLa cells transiently expressing OPT1. This protein is a high-affinity transporter of alanylalanine; the approximate Km constant is 48.8 microM for this substrate. OPT1 dipeptide transport activity is proton dependent. The ability of selected beta-lactams to inhibit alanylalanine transport suggests that OPT1 has a broad specificity in amino acid side chains and has a substrate requirement for an alpha-amino group. Together these data suggest an important role for OPT1 in regulating amino acid availability.

Amino Acid Sequence↗
PubMed1998

Comparison of local infiltration of tenoxicam and intravenous tenoxicam for postoperative analgesia in herniorrhaphy.

BACKGROUND: The major complaint of herniorrhaphy is postoperative pain which occurs during the first 24 h after operation. Tenoxicam has a long half-life of 60-80 h. Local infiltration of the drug concentrates the pain control effects in the local area. The local infiltration dose can be smaller than the recommended systemic dose needfully to reach the target area to be effective. Therefore we studied the effect of preoperative local infiltration of tenoxicam on postoperative pain. METHODS: Sixty patients, belonging to ASA classes I and II, undergoing unilateral herniorrhaphy, were randomly assigned to 4 groups. General anesthesia was induced with thiamylal 5 mg/kg, fentanyl 2 micrograms/kg, and atracurium 5 mg/kg. Group 1 (G1) patients were preoperatively injected with 10 mg of tenoxicam in 10 ml normal saline or distilled water, in the operative area. Group 2 (G2) and Group 3 (G3) patients were preoperatively given intravenous tenoxicam, 20 mg and 10 mg, respectively. Group 4 (G4) patients were not given preoperative local infiltration or intravenous tenoxicam to serve as control group. The pain score was assessed at 2 h, 9 h, 24 h postoperatively in all groups. We recorded the total amount of acetaminophen used and the form of administration of the analgesic drug. All patients received general anesthesia in uniform technique. RESULTS: Pain score and amount of analgesic drug required in G1 (local infiltration group) patients were significantly decreased compared with the other groups. The postoperative pain score of Visual Analog Scale (VAS) and analgesic requirement in the four groups were ranked as follows: G1 < G2 < G3 < G4. No significant difference was observed between G2, G3 and G4. Only the pain score in G2 patients significantly decreased (p < 0.05) during the late postoperative period (24 h) when compared with G4 patients. CONCLUSIONS: Preoperative local infiltration of tenoxicam can decrease postoperative pain score significantly during the most painful period (24 h) in herniorrhaphy.

Adult↗
PubMed1998

Prevention of coughing induced by endotracheal tube during emergence from general anesthesia--a comparison between three different regimens of lidocaine filled in the endotracheal tube cuff.

BACKGROUND: "Deep" extubation, administration of intravenous (i.v.) narcotics, i.v. lidocaine and forestalling local spray of lidocaine have been used to help diminish coughing during emergence. However, the respective efficacy of these techniques has not been concluded. Sconzo et al. indicated that endotracheal tube (ETT) cuff might serve as a reservoir for local anesthetic. Alkalizing and warming are two techniques frequently used to increase in the proportion of uncharged drugs available. Matias indicated that alkalization could prompt a 63-fold increase of the rate of diffusion of lidocaine across the ETT cuff. Huang et al. also observed that alkalization together with warming could achieve a 118-fold increase further. However, the in vivo effects of ETT-cuff lidocaine have not been studied. METHODS: Eighty patients of ASA Class I-II undergoing elective surgeries were included. They were randomly assigned into four groups. After tracheal intubation, the ETT cuff was filled with one of the following solutions: normal saline 6 ml (Group A), 4% lidocaine 6 ml at room temperature (Group B), 4% lidocaine 5 ml + 7% sodium bicarbonate 1 ml at room temperature (Group C), and 4% lidocaine 5 ml + 7% sodium bicarbonate 1 ml warmed to 38 degrees C (Group D). Changes of vital signs as well as the times of coughing in the course of extubation and post-extubation complications were recorded. One way ANOVA (SPSS for windows) was used for data analysis. RESULTS: The respective number of coughing per patient in the experimental groups (Group B, C and D) was significantly less than the saline or control group (mean = 9.70, 9.15 and 3.95, respectively, p < 0.05). The incidence of sore throat in Group C and Group D was significantly less than the control group (35% and 25%, respectively, p < 0.05). Regarding the hemodynamic changes, systolic arterial pressure (SAP) and mean arterial pressure (MAP) were higher in Group B and C (p < 0.05) before extubation. CONCLUSIONS: Alkalized and warmed lidocaine prestored in the endotracheal tube (ETT) cuff can greatly reduce ETT-induced coughing and thus promote a smoother emergence from general anesthesia with endotracheal intubation.

Adolescent↗
PubMed1998

Views of obstetric patients who refuse regional anesthesia in cesarean section.

BACKGROUND: Regional anesthesia for cesarean section has gained widespread popularity. However, there are still a good few of obstetric patients who refuse it. This study was to investigate the reasons for refusing regional anesthesia in order to gain some insights into the attitudes and concerns of patients. METHODS: Three hundred and twenty-four obstetric patients scheduled for Cesarean section were interviewed just before entering the operating room. They were asked to give one or two reasons for refusing regional anesthesia. RESULTS: Two hundreds of them refused regional anesthesia. The most frequent reasons were apprehension of witnessing the operation (auditory or visional) (45.42%) and fear of backache following regional anesthesia (14.58%). CONCLUSIONS: Anesthesiologists should be aware of patients' feeling or concern and could be capable and willing to discuss with them the relevant problems.

Adolescent↗
PubMed1997

roX1 RNA paints the X chromosome of male Drosophila and is regulated by the dosage compensation system.

The Drosophila roX1 gene is X-linked and produces RNAs that are male-specific, somatic, and preferentially expressed in the central nervous system. These RNAs are retained in the nucleus and lack any significant open reading frame. Although all sexually dimorphic characteristics in Drosophila were thought to be controlled by the sex determination pathway through the gene transformer (tra), the expression of roX1 is independent of tra activity. Instead, the dosage compensation system is necessary and sufficient for the expression of roX1. Consistent with a potential function in dosage compensation, roX1 RNAs localize specifically to the male X chromosome. This localization occurs even when roX1 RNAs are expressed from autosomal locations in X-to-autosome translocations. The novel regulation and subnuclear localization of roX1 RNAs makes them candidates for an RNA component of the dosage compensation machinery.

Animals↗
PubMed1997

Dyspnea resulting from phrenic nerve paralysis after interscalene brachial plexus block in an obese male--a case report.

Phrenic nerve paralysis is a common complication in interscalene brachial plexus block. This complication is often ignored by most anesthesiologists because no clinical symptoms occur in patients who have no underlying lung disease. We present a case of an obese male suffering from dyspnea due to phrenic nerve block after interscalene brachial plexus block. The decreased respiratory reserve and direct compressing effect of the abdominal organs on the diaphragm in the supine position are thought to be the risk factors in this obese patient. Also discussed are the incidence, diagnostic methods, clinical presentation and treatments of phrenic nerve paralysis during interscalene brachial plexus block.

Adult↗
PubMed1995

Mutational analysis of patients with X-linked adrenoleukodystrophy.

Adrenoleukodystrophy (ALD) is an X-linked neurodegenerative disorder characterized by elevated very long chain fatty acid (VLCFA) levels, reduced activity of peroxisomal VLCFA-CoA ligase, and variable phenotypic expression. A putative gene for ALD was recently identified and surprisingly encodes a protein (ALDP) that belongs to a family of transmembrane transporters regulated or activated by ATP (the ABC proteins). We have examined genomic DNA from ALD probands for mutations in the putative ALD gene. We detected large deletions of the carboxyl-terminal portion of the gene in 4 of 112 probands. Twenty-five of the ALD probands whose ALD genes appeared normal by Southern blot analysis were surveyed for mutations by Single Strand Conformation Polymorphism (SSCP) procedures and DNA sequence analysis. SSCP variants were detected in 22 probands and none in 60 X-chromosomes from normal individuals. Mutations were detected in all of the ALD probands. The mutations were distributed throughout the gene and did not correlate with phenotype. Approximately half were non-recurrent missense mutations of which 64% occurred in CpG dinucleotides. There was a cluster of frameshift mutations in a small region of exon 5, including an identical AG deletion in 7 unrelated probands. These data strongly support the supposition that mutations in the putative ALD gene result in ALD.

ATP Binding Cassette Transporter, Subfamily D, Mem↗
PubMed1995

Differential cytotoxicity of cadmium to rat embryonic fibroblasts and human skin fibroblasts.

In order to identify why cadmium is differentially toxic to humans and rats, we compared cadmium-induced cytotoxic responses in rat embryonic fibroblasts (REF) and human skin fibroblasts (HFW). According to the values of the lethal concentration 50% for cadmium, REF were about 13-fold more sensitive than HFW to cadmium acetate (1.5 vs 25 microM). Furthermore, progression of S phase cells was more severely delayed by cadmium in REF than in HFW. At doses that killed 90% of REF or HFW (5 or 50 microM, respectively), 50% of DNA synthesis was inhibited in REF, whereas DNA synthesis was not apparently inhibited in HFW. The differential sensitivity to cadmium could not be simply due to different basal levels of metallothionein, since the cellular metallothionein content in HFW was only 1.6 times that in REF, and metallothionein was apparently induced by cadmium in both cells with similar synthesis rates. Furthermore, elevation of cellular metallothionein levels by zinc sulfate pretreatment decreased cadmium toxicity in both cell types, but did not alter their relative sensitivity to cadmium. The differential sensitivity was also not due to differences in cadmium accumulation, since HFW accumulated more cadmium than REF after a 24-hr exposure to 1 or 5 microM cadmium acetate. Although most of the cadmium remained in the cytoplasm, the nuclei of REF contained 12-fold more cadmium than nuclei of HFW (1.31 vs 0.11 micrograms Cd/mg nuclear protein). Therefore, our results indicate that a high level of cadmium accumulation in nuclei of REF may be responsible for cell killing through breakdown of nuclear functions.

Animals↗
PubMed1995

Prevalence of permanent primary congenital hypothyroidism in Taiwan.

The purpose of this study was to find the prevalence of permanent primary congenital hypothyroidism in Taiwan. From January 1988 to December 1990, there were 991,132 live births in Taiwan. Of these, 329,891 neonates were screened for primary congenital hypothyroidism. Fifty-seven cases of permanent primary congenital hypothyroidism were confirmed. Hence, the prevalence of permanent primary congenital hypothyroidism in that period in Taiwan was 1 in every 5,788 live births. There was a female preponderance with a female to male ratio of 1.7. Of 54 infants who had a thyroid scan, 36 were found to have an ectopic thyroid gland, while 11 were found to have dyshormonogenesis. Among the 57 infants, one case with a delayed rise in the serum thyrotropin level was missed on initial screening. When compared with other studies, these data suggest that the prevalence of permanent primary congenital hypothyroidism varies in different ethnic groups throughout the world.

Congenital Hypothyroidism↗
PubMed1994

[4P- syndrome (Wolf-Hirschhorn syndrome) complicated with delay onset of malignant hyperthermia: a case report].

One 8-month-old female patient, weighted 5 kg, with congenital abnormality (4P- syndrome) underwent elective cheiloplasty for cleft lip and palate. Two hours later, with smooth anesthesia and operation, a life-threatening anesthetic complication of malignant hyperthermia occurred at pediatric intensive care unit. The immediate treatments were initially hyperventilating the patient with 100% O2 and cooling the patient with ice bags. Subsequently, intravenous dantrolene 2.5 mg/kg and symptomatic supportive care were administered successfully to treat the event. Upon reviewing the articles, we found that a congenital chromosome 4P deletion abnormality complicated with a delay onset of malignant hyperthermia has not been described previously.

Chromosome Aberrations↗
PubMed1991

Treatment of malignant trophoblastic tumors. An analysis of 209 cases.

From 1948 to 1985, a total of 630 cases of choriocarcinoma and invasive mole were treated in our hospital. The methods of treatment varied in different periods of time. In the third period (1972-1985), 5 Fu and/or KSM were the main therapeutic agents used in the treatment of 110 cases of choriocarcinoma and 99 cases of invasive mole. Metastases were observed in more than 90% of cases of choriocarcinoma and nearly 1/4 belonged to stage IV. The mortality of choriocarcinoma decreased from 84.3% to 32.7% after treatment and that of invasive mole from 32.4% to 8.1%. 43 of 80 patients treated with chemotherapy alone conceived after recovery, resulting in a total of 50 pregnancies including 31 term deliveries by 28 women. All the children are normal and healthy, the eldest being 11 years old now.

Adult↗
PubMed1991

[Surgical and anesthetic mortality in Mackay Memorial Hospital 1988-1989].

The mortality associated with 52128 anesthetics administered over two years (1988-1989) at Mackay Memorial Hospital, Taipei, was reported. The frequency of death to which anesthesia contributed was 0.4/10000 (2 cases in 52128 anesthetics). The total mortality rate from surgery within one week was 0.2% (105 cases in 52128 anesthetics). Anesthetic deaths were responsible for 1.9% of the total mortality. There were 25 cases of cardiac arrest with 18 fatal cases (7 cases were recovered after cardiopulmonary resuscitation). The causes of cardiac arrest during anesthesia included anesthetic factors (24%), surgical factors (24%) and patients' pathological factors (52%).

Anesthesia↗
PubMed1991

Additive effects of prostaglandin E2 and pulsed electromagnetic fields on fracture healing.

Bone formation of fractured fibulae stimulated by pulsed electromagnetic fields (PEMF), PGE2, and combination of both was assessed with roentgenography and fluorescent labelling compounds, tetracycline, xylenol orange, and calcein. A total of 72 male New Zealand rabbits was osteotomized by creating a 1 mm-gap at fibulae and randomly divided into 8 groups: one control, one treated with PEMF, three treated with PGE2 of various dosages, and three treated with combined treatments of PEMF and PGE2 of specified dosages. PEMF had positive effects on bone formation. Exogenous PGE2 mimicked the effect of PEMF on linear bone growth. The effect of PGE2 on bone formation or bone remodelling was dose-related (5, 15, 50 micrograms/kg), with 5 micrograms/kg body weight as the optimal dosage in this study. Combination of PEMF and PGE2 exhibited a trend of additive effect on bone formation, especially at 15 micrograms/kg of PGE2. It is hypothesized that PEMF may exert its action on bone healing by increasing the endogenous PGE2. We therefore concluded that external stimulation such as PEMF and PGE2 was beneficial and stimulatory towards bone formation and healing in our animal model. However, the effects were somehow specific in electrical waveforms and dosage. Similar to PEMF, PGE2, therefore, may be a potential agent in promoting bone formation in the clinical treatments of fractures or perhaps non-union.

Animals↗
PubMed1990

[Does flumazenil antagonize the anesthetic effect of ketamine, etomidate or thiopental?].

The effect of flumazenil, a benzodiazepine antagonist, was assessed in a random, double-blind clinical study in which each of the four groups of surgical outpatients comprising 20 in each was given either ketamine 100 mg (K), etomidate 20 mg (E), thiopental 300 mg (T) or flunitrazepam 4 mg (F) for induction of anesthesia. On emergence, patients in each group were randomly given 2cc of either 2 coded solutions, one of which contained 0.2 mg flumazenil and the other of which was normal saline. Following injection of coded solution, all patients were assessed at 0, 5, 15, 30, 60 and 120 min for wakefulness. All 10 patients of group F who received flumazenil were alert and able to recall at 5 min, whereas in group T this was noted from 15 to 30 min. Patients of group E and K responded alike in a manner as of those who received normal saline placebo with onset of wakefulness at 30 and 60 min respectively. These results confirm that flumazenil antagonizes flunitrazepam (within 5 min) and also indicate that the antagonizing effect occurs 30 min following injection for thiopental, suggestive of some cross-reactivity between these two drugs.

Adult↗
PubMed1990

[The effect of epidural anesthesia on tourniquet pain: a comparison of 2% lidocaine and 0.5% bupivacaine].

The incidence of tourniquet pain was evaluated in two groups of patients with 20 each undergoing orthopedic surgery of the lower extremities during epidural anesthesia using plain solution of either 2% lidocaine or 0.5% bupivacaine. The drugs were administered in a randomized fashion. Measurement of the levels of sensory loss to pinprick and incidence of tourniquet pain were made by blind-trust. The maximum analgesia level, time between 1st injection and onset of pain, time between tourniquet inflation and onset of pain were recorded similarly in both groups of patients. The incidence of tourniquet pain was significantly greater in patients given 2% lidocaine (40%) than in patients given 0.5% bupivacaine (10%). The incidence of pain was not related to the time of tourniquet inflation, because patients in the bupivacaine group had a significant longer duration of tourniquet inflation than did patients in the lidocaine group. The incidence of pain was also not related to tachyphylaxis, because 7 of 8 patients who complained tourniquet pain in lidocaine group received less than 3 injections for maintenance of analgesia when tourniquet pain started. In summary, it is apparent that tourniquet pain occurs less frequently when bupivacaine is employed for epidural anesthesia as compared to lidocaine.

Adult↗