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Biomedical subjects

C L Wu

Publications and source records attributed to C L Wu.

At least 127 records · Page 7Linked to original sources
PubMed1991

Sphenoidal EEG recording using acupuncture needle electrode in complex partial seizure.

Sphenoidal EEG recording using an uninsulated acupuncture needle electrode were performed in 41 patients with or suspected of complex partial seizures of temporal lobe origin. The anterior temporal spikes were detected by the routine EEG in 17 patients (41%) and by the acupuncture sphenoidal needle in 29 patients (70%). The anterior temporal spikes recorded by the acupuncture needle were almost identical in configuration, amplitude and distribution to those recorded by conventional wire or insulated needle sphenoidal electrodes. The sequence in the frequency of spike detection by these 3 types of sphenoidal electrode were SP1-2, T1-2, F7-8 and A1-2 locations. The spikes of maximal amplitude were most frequently recorded by the SP electrode followed by the T1-2 electrode. The placement of the disposable acupuncture needle was simple and safe. Patients experienced minimal discomfort or pain that lasted at most 0.5 h. No complications occurred. The records were generally free of artifacts. It is concluded that the acupuncture needle can be used as sphenoidal electrode in outpatient EEG recording for the diagnosis of complex partial seizures of anterior temporal-origin.

Action Potentials↗
PubMed1991

The conserved DNA-binding domains encoded by the herpes simplex virus type 1 ICP4, pseudorabies virus IE180, and varicella-zoster virus ORF62 genes recognize similar sites in the corresponding promoters.

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), pseudorabies virus (PRV), varicella-zoster virus (VZV), and equine herpesvirus 1 (EHV-1) are all classified as Alphaherpesvirinae. Each of these five viruses encodes an essential immediate-early (IE) regulatory protein referred to as HSV-1 ICP4, HSV-2 ICP4, PRV IE180, VZV ORF62 protein, and EHV-1 IE1, respectively. These five proteins share extensive homology with each other in domains referred to as regions 2 and 4. The HSV-1 ICP4 region 2 domain contains residues that are required for the DNA-binding capability of ICP4. In this report, we describe the expression of region 2 domains from the ICP4, IE180, and ORF62 genes as fusion proteins in Escherichia coli. DNA-binding assays revealed that each of these region 2 fusion proteins binds to a sequence that overlaps the transcription start site in the promoter for the gene encoding the corresponding protein. Each of the sites with high affinity for one or more of these fusion proteins contains the sequence 5'-ATCGT-3'. This sequence spans the mRNA cap site in the HSV-2 ICP4 gene promoter and is immediately upstream from the transcription start site in the EHV-1 IE1 gene. These results suggest that formation of a specific complex between an IE protein and its own gene promoter may be a common mechanism used by Alphaherpesvirinae to autoregulate transcription of an essential IE gene.

Base Sequence↗
PubMed1991

[Detection of Plasmodium falciparum using the plasmid Pf rep 20 probe (preliminary report)].

A cloned repetitive DNA sequence (rep 20) labeled with 32P was evaluated as diagnostic probe for P. falciparum in 39 blood samples from Hainan and Yunan provinces. Its specificity and sensitivity were studied and compared with total genomic DNA probe isolated from P. f. Hainan Fcc1/HN isolate. The pPF rep 20 probe recognized the DNA of P. f. Hainan, Yunnan and Anhui isolates, but did not hybridize with the DNA of P. vivax, P. cynomolgi, P. knowlesi and P. yoelii. The genomic probe hybridized with the DNA of 3 isolates and cross-hybridized with the DNA of all the other Plasmodium species tested, but did not hybridize with host DNA. The plasmid rep 20 probe was able to detect parasitemia level of 0.001% in 20 microliters blood from culture and 10pg DNA of 3 P. f. isolates after 3 days film exposure. It could hybridize with the blood samples of P. f. patients from Hainan and Yunnan with a sensitivity of 95% (37/39). The genomic probe could detect the same parasitemia and DNA levels as plasmid rep 20 probe for Yunnan and Anhui isolates, and 0.0001% parasitemia and 1 pg DNA for Hainan isolate. It had a sensitivity of 97% (38/39) when used to detect patient samples. The results indicated that plasmid rep 20 probe was specific and rather sensitive to DNA of P. falciparum isolates from China and may be useful in epidemiological studies.

Animals↗
PubMed1990

Codons 262 to 490 from the herpes simplex virus ICP4 gene are sufficient to encode a sequence-specific DNA binding protein.

The HSV-1 immediate early (IE) protein ICP4 (alpha 4, IE175, Vmw175) is an oligomeric molecule which activates transcription of viral early genes, represses transcription of viral IE genes, and binds to specific sequences in certain viral promoters. The extent to which these functions are interrelated has not been fully established. We have expressed truncated portions of the ICP4 gene in E. coli as trpE fusion proteins. DNA-binding studies with these hybrid proteins revealed that ICP4 residues 262 to 490 are sufficient for sequence-specific DNA-binding. DNA-binding was not detected with polypeptides extending from residue 262 to 464 or from residue 306 to 490. Multiple bands of protein-DNA complexes observed in gel mobility shift assays indicate that residues 262 to 490 may also contribute to the oligomerization of ICP4.

Base Sequence↗
PubMed1990

[Experience on the treatment of acute anorectal abscess with primary fistulotomy].

From August 1985 to July 1989, 72 cases with initial attacks of acute cryptoglandular anorectal abscesses were hospitalized and treated in Kuang Tien General Hospital. Among them were 52 cases of the perianal type, 8 of the intersphincteric type, 11 of the ischiorectal type and one case involving the supralevator space. Included were 62 males and 10 females (sex ratio 6:1) with a mean age of 39 years (range, 18 to 63). The mean duration of the follow-up was 24 months. Most anorectal abscesses originate from a cryptoglandular infection and are usually treated initially by incision and drainage. However, a fistula operation may be required if a fistula develops weeks or months later. Several published papers from various hospitals have also pointed out that this disease condition can be successfully treated by a one-stage operation-primary fistulotomy. In order to determine the source of infection, careful examination was carried out in the operating room under adequate anesthesia. A definite or at least a highly suspected offending crypt was found in 57 cases, all of whom were treated by primary fistulotomy. The remaining 15 cases whose offending crypts were undetectable, were treated by incision and drainage. Of the 57 cases treated with primary fistulotomy, four cases developed recurrent abscesses or fistulas. In the incision and drainage group, five cases developed recurrences. Among the nine cases of recurrence, five were of the ischiorectal type. The author surmises that acute anorectal abscess of the ischiorectal type was rarely cured by the one-stage primary fistulotomy operation. However, for the majority of perianal and intersphincteric abscesses, primary fistulotomy should be the first choice of management.

Abscess↗
PubMed1989

Single-step selection of mammalian cell mutants deficient in CTP synthetase.

A single-step selection of Chinese hamster V79 cells deficient in CTP synthetase (CTPS-) is presented. The underlying principle of the direct selection is the differential and efficient killing of synchronized wild-type cells through incorporation of [3H]uridine and [3H]thymidine. The CTPS- mutant cells were recovered by virtue of their not engaging in DNA synthesis, because (1) CTPS- cells are deficient in CTP synthetase and thus are unable to convert [3H]UTP into [3H]CTP, which eventually is converted into [3H]dCTP and incorporated into DNA; (2) the growth of CTPS- mutant cells was arrested as a result of cytidine deprivation, thus escaping the killing by the incorporation of [3H]thymidine. The isolated mutant clones are auxotrophic for cytidine and are stable in phenotype with a reversion frequency of less than 1 x 10(-7). The mutant cells have no or very low CTP synthetase activity when tested by in vitro CTP synthetase assay or by whole-cell [3H]uridine labeling assay. This modified "tritium suicide" method combined with the S-phase cell synchronization could provide a powerful means for the recovery from the cell population of nondividing mutant cells that are auxotrophic for some special nutrient requirement.

Animals↗
PubMed1987

Pesticide clastogenicity in Chinese hamster ovary cells.

Paraquat, alachlor, butachlor, phorate and monocrotophos, several of the most extensively used pesticides in Taiwan, were investigated for their clastogenicity using chromosome aberration (CAb) induction in Chinese hamster ovary (CHO) cells. Significance levels of the binomial trend analysis and binomial mutagenicity data test were two criteria for the summary judgement of the pesticide clastogenicity. Except for phorate, all pesticides tested were clastogenic to CHO cells in the absence of in vitro metabolic activation by S9. 5 microliters/ml rat-liver extract, S9, were used as the source of in vitro metabolic activation. 3 different outcomes were found after the addition of S9. Paraquat: significant decrease in induced CAbs. Monocrotophos: concomitant occurrence of decreased cytotoxicity and increased clastogenicity. Alachlor, butachlor and phorate: increased cytotoxicities with no sign of enhancement in clastogenicity.

Acetamides↗
PubMed1984

Niacin and tryptophan requirements of mule ducklings fed corn and soy-based diets.

Experiments were conducted to determine the dietary niacin and tryptophan requirements of mule ducklings fed a corn-soy basal diet. In niacin requirement experiments, day-old, straight-run mule ducklings were fed diets supplemented with graded levels of niacin for 3 weeks. The results showed that the minimum niacin requirement was 45 mg/kg of the diet. For the determination of the optimal tryptophan in the diet, day-old ducklings of mixed sexes were fed a starter diet for 1 week, and then fed for 12 days experimental diets with graded tryptophan levels and containing 18.0% crude protein and 3013 kcal ME/kg. The minimum tryptophan requirement for maximum growth and feed efficiency was .23% of the diet or 1.28% of the dietary crude protein. Further experiments were performed by using a 3 (niacin 20, 50, and 80 mg/kg) x 4 (total tryptophan .13, .23, .33, and .43% of air-dried diet) factorial design to investigate the relationship between niacin and tryptophan. It was concluded that excess tryptophan could spare the ducklings' need for niacin. Conversely, excess niacin failed to compensate for a deficiency of tryptophan. Maximum growth was obtained and bowed-leg disorder was prevented by the addition of sufficient niacin or tryptophan to the basal diets.

Animals↗
PubMed1983

Non-competitive inhibition of hepatic and intestinal aryl hydrocarbon hydroxylase activities from rats by rifampin.

Rifampin is a semisynthetic antibiotic which is known to alter hepatic cytochrome P-450 mediated drug metabolizing enzymes. Using benzo(a)pyrene as the substrate we have shown that rifampin acts as a non-competitive inhibitor of hepatic microsomal aryl hydrocarbon hydroxylase in vitro at or below 0.10 mM and that it is also a non-competitive inhibitor of intestinal aryl hydrocarbon hydroxylase at or below 0.075 mM. These results suggest that the administration of rifampin with other drugs may result in altered drug biotransformation.

Animals↗
PubMed1983

The optimal age for vaccination against measles in an Asiatic city, Taipei, Taiwan: reduction of vaccine induced titre by residual transplacental antibody.

Children vaccinated when aged between six and thirteen months against measles in Taipei showed a high frequency of response, similar to that reported from Nairobi, Kenya and contrasting with analogous data for the USA. The age for optimal protection against measles mortality by a single dose of vaccine in this group of children is nine months. Maternal antibody exerted a negative effect on measles antibody titre in vaccinees beyond the age at which it blocked the response so that the infants of mothers with the higher titres themselves had lower titres. A separate effect of immunological immaturity on titre of the response could not be demonstrated in children over six months of age.

Adult↗
PubMed1982

Effect of various xenobiotics and steroids on aryl hydrocarbon hydroxylase activity of intestinal and hepatic microsomes from male rats.

The effects of four solvents and 37 xenobiotics and endogenous steroids on intestinal and hepatic microsomal aryl hydrocarbon hydroxylase (AHH) activity were determined. In general, hepatic AHH was more sensitive than intestinal AHH to inhibition by a wide variety of xenobiotics. Acetone, ethanol, dimethyl formamide, triamcinolone acetonide, 17 alpha-propyltestosterone, metronidazole, cimetidine and butylated hydroxyanisole (BHA) activated or stimulated intestinal AHH activity while inhibiting hepatic AHH activity at the same concentrations. Ethoxyquin, progesterone, pregnenolone acetate, deoxycorticosterone acetate, tamoxifen and SKF 525-A exerted markedly different concentration-dependent inhibitions of intestinal and liver AHH activities. The most potent inhibitors of AHH activity were captan, BHA, chlorpromazine, thioridazine, disulfiram and menadione. The ability of steroids to inhibit AHH activity correlated well with lipophilicity.

Animals↗
PubMedDate not supplied

Vitamin D deficiency rickets due to inappropriate feeding: report of one case.

Vitamin D deficiency rickets is rare among infants and children in the industrialized countries. In this paper, we report a 2-year-5-month-old girl with aching and bowed legs. A food allergy with atopic dermatitis was diagnosed since her early infancy. Strict dietary restrictions were done and she was mostly fed soybean juice and rice foods. Fortified soybean formula (Isomil) was introduced one month before admission. Vitamin D deficiency rickets was diagnosed by a history of inappropriate feeding, roentgenographic and laboratory findings. The therapeutic regimen included 1, 25-dihydroxycholecalciferol 0.5 ug/day and calcium carbonate 100 mg/kg/day. Extensive nutritional counseling was also given for correction of aberrant dietary practices. After a one-year follow-up, there was radiological evidence of bone healing, and marked improvement of leg deformities.

Bone and Bones↗