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Biomedical subjects

C Kuo

Publications and source records attributed to C Kuo.

32 records · Page 2Linked to original sources
PubMed1986

Successful treatment of complete left bundle branch block complicating acute viral myocarditis employing Chinese herbs.

A case of complete left bundle branch block complicating acute viral myocarditis successfully treated by Chinese herbal medicine is reported. Complete left bundle branch block may be less commonly encountered in myocarditis. Treatment by Chinese herbal medicine for 49 days was successful in the management of this conduction disturbance. Follow-up studies, up to 3 months, produced normal electrocardiogram with good health.

Acute Disease↗
PubMed1985

Systemic Chlamydia trachomatis infection in mice: a comparison of lymphogranuloma venereum and trachoma biovars.

We developed a murine model of systemic infection with Chlamydia trachomatis biovar lymphogranuloma venereum (LGV). The pathological features of this infection resemble those of human LGV infection since both are characterized by granuloma formation. Mice developed resistance to reinfection with LGV, and this resistance was based on cellular immune mechanisms since it was transferable with immune spleen cells but not with immune serum. Resistance required viable organisms for induction. We compared LGV biovar infection with trachoma biovar infection. Trachoma biovar produced similar but less marked microbiological and pathological features. Cross-immunity was less apparent between serovars from trachoma and LGV biovars than it was between serovars within the same biovar. This model of systemic C. trachomatis infection will be useful in exploring virulence features of LGV.

Animals↗
PubMed1985

Assessment of pentachlorophenol toxicity in newborn calves: clinicopathology and tissue residues.

Newborn Holstein bull calves were fed either analytical pentachlorophenol (aPCP) or technical pentachlorophenol (tPCP) for 6 wk to establish and compare the clinical and pathologic manifestations of toxicity. Four groups of three calves/group were each fed either 1 or 10 mg X (kg body weight)-1 X d-1 of either aPCP or tPCP. A fifth group served as control. Dosages of both PCP preparations were normalized to contain equal concentrations of PCP. Toxic effects were observed only at the 10 mg/kg dose in the tPCP-treated calves. These effects included decreased body weight gain, anorexia, decreased serum protein concentration, elevated serum gamma glutamyl transferase, and decreased triiodothyronine (T3) and thyroxine (T4) concentrations. Histologic lesions included cortical atrophy in the thymus and squamous metaplasia and hyperkeratous changes in the Meibomian gland of the eyelid. Thyroid function, which was assessed in vivo by measuring the rate of T3 and T4 production over 4 h after thyrotropin-releasing hormone (TRH)-challenge, was not impaired suggesting an extrathyroidal site of toxic action. Although serum chemistry indicators were suggestive of hepatic injury there were no discernable lesions. Organ weight analyses were inconclusive but there was a tendency toward enlargement of liver, kidneys and thyroid and decreased weight of lungs, spleen and thymus. A toxic effect clearly related to PCP and not its contaminants was depressed active transport of p-aminohippurate measured in kidney slices in vitro. Steady state concentrations of PCP in serum were about 40 and 90 ppm for the 1 and 10 mg/kg groups, respectively. Concentrations of PCP among the major organs were comparable.

Animals↗
PubMed1984

Antiserum against neurite outgrowth factor in chick gizzard extract and its inhibitory effect on neuritic response in cultured ciliary neurons.

Antiserum against a neurite outgrowth factor (NOF) of gizzard extract that promotes neurite outgrowth from dissociated ciliary ganglionic neurons (CG neurons) of 8-day-old chick embryo was prepared to determine whether or not the antiserum inhibits neurite outgrowth from cultured neurons or explants of chick and murine tissues. When CG neurons were cultured on a polyornithine-coated well exposed to NOF (NOF-bound POR well), marked neurite outgrowth was observed. When NOF-bound POR wells were exposed to antiserum, neurite outgrowth from CG neurons was gradually inhibited with increasing amounts of antiserum, while exposure to preimmune serum did not prevent neurite outgrowth. Antiserum had no effect on neuronal survival during a 48-h incubation. The diluted antiserum, which produced nearly 100% inhibition of the NOF activity, was almost equally active in suppressing the activity of NOFs in conditioned media (CM) of various chick embryo tissues, but showed much less inhibitory effects on NOFs in CM of murine tissues. The appearance of neurites from explants of spinal cord, dorsal root ganglion, or retina of chick embryo was also inhibited by the antiserum. These results indicate that antiserum against NOF from gizzard extract suppressed the activity of NOFs from various sources, and that there are species differences in NOFs, at least between chick and murine.

Animals↗
PubMed1983

Isolation of yeast DNA replication mutants in permeabilized cells.

A random population of temperature-sensitive mutants was screened by assaying for defects in DNA synthesis in a permeabilized yeast DNA replication system. Twenty mutants defective in in vitro DNA synthesis have been isolated. In this paper we describe eight of these mutants. Seven of them fall into three complementation groups--cdc2, cdc8, and cdc16--involved in the control of the cell-division cycle. Because synthesis in vitro represents propagation of replication forks active in vivo at the time of permeabilization, our finding that cdc2 and cdc16 mutants can incorporate dTMP into DNA in such permeabilized cells at 23 degrees C but not at 37 degrees C supports the conclusion that these two mutations directly affect DNA synthesis at replication forks. Such an involvement was previously suggested by in vivo analysis for CDC2 but was less clear for CDC16. Finally, the usefulness of our screening procedure is demonstrated by the isolation of replication mutants in previously undescribed complementation groups. One strain shows a serious defect in in vivo DNA synthesis but normal RNA synthesis.

Cell Cycle↗
PubMed1981

Subchronic administration of technical pentachlorophenol to lactating dairy cattle: performance, general health, and pathologic changes.

Technical grade pentachlorophenol (penta) was fed subchronically to lactating dairy cattle to establish whether exposure approximating farm environments containing substantial penta-treated wood represents a hazard to animal health. Four Holstein cattle in early lactation were fed .2 mg penta/kg body weight per day for 75 to 84 days followed by 2 mg penta/kg body weight per day for 56 to 60 days. Each treated cow was paired with a control cow of equivalent stage of lactation. Milk production, feed intake, and body weight were not affected by either dose except that treated cattle were more efficient converters of feed to milk during the early stage of the 2 mg/kg period. Neither milk fat production nor somatic cell count in milk were affected by exposure to penta. Postmortem examination revealed enlargement of liver, lungs, kidneys, and adrenals and thickening of the urinary bladder wall. Chronic interstitial nephritis and subacute urocystitis were the major pathologic changes in penta-treated cattle. In vitro testing of kidney slices confirmed significant loss of renal function. The relationship of lesions to administration penta is not clear.

Animals↗
PubMed1980

A mouse model of Chlamydia trachomatis pneumonitis.

A mouse model for studying infections due to Chlamydia trachomatis is described. Pneumonitis was produced by intranasal inoculation of four trachoma and one lymphogranuloma venereum strains. The infection was confirmed by cell culture isolation of the organisms from the lung, detection of serum antibody and delayed hypersensitivity, and the observation of inclusions in the interstitial cells of the lung by light and electron microscopy. This study indicates that mice may serve as a useful nonprimate animal model for the study of the pathogenesis and immunology of C. trachomatis infection.

Animals↗
PubMed1980

A mouse model of pneumonitis induced by Chlamydia trachomatis: morphologic, microbiologic, and immunologic studies.

Swiss-Webster white mice were infected with Chlamydia trachomatis organisms through intranasal inoculation. It was found that a typical interstitial pneumonitis could be induced. Histopathologic findings showed that the lung infiltration was predominantly polymorphonuclear cells and was most prominant on Day 2. The cellular infiltrate gradually changed to mononuclear cells after Day 3. Intracytoplasmic inclusions were frequently found in the interstitial cells and occasionally in the bronchial epithelial cells. Typical chlamydial bodies (elementary, intermediate, and reticulate forms) were identified by electron microscopy. The organisms were recovered from mouse lungs on Days 1--7, with the highest yields on Day 2. This correlated with the peak of lung infiltration seen by histologic examination. Antibodies specific to the infecting immunotype began to appear between Day 7 and Day 10 after inoculation and lasted until Day 35 without a decline in titers. A delayed hypersensitivity reaction was observed by footpad test from Day 5 to Day 21, with the peak reaction at Day 7. This study showed that the mouse model could be used to study the immunopathogenesis of C trachomatis infection.

Animals↗
PubMed1972

Replacement of spray nozzle tips based on operational considerations.

In the residual spraying of insecticides, application of the correct dosage is important both to obtain the optimum effectiveness and to avoid wasting insecticide. One of the main factors controlling dosage is the discharge rate of the sprayer, which depends to a great extent on the ability of the nozzle tip to discharge an even spray. However, nozzle tips are subject to erosion and their output increases with use, especially when water-dispersible-power formulations of insecticide are used. To reduce wastage of insecticide, nozzle tips are changed periodically but the tips are expensive and the replacement schedule should be based on the cost of the tip in relation to the cost of the insecticide wasted. A theoretical approach is discussed and a practical method for establishing a replacement schedule on economic considerations is suggested.

Aerosols↗
PubMedDate not supplied

Treatment of concomitant Neisseria gonorrhoeae and Chlamydia trachomatis infections in women: comparison of trimethoprim-sulfamethoxazole with ampicillin-probenecid.

Sixty-nine women with known or suspected uncomplicated gonorrhea were treated randomly either with a single dose of 3.5 g of ampicillin plus 1 g of probenecid or with four doses of trimethoprim-sulfamethoxazole (TMP-SMZ) in two double-strength tablets (160 mg of TMP plus 800 mg of SMZ) twice daily for two days. Overall, 56 (81%) of the women had gonococcal infections, 26 (38%) had chlamydial infections, and 23 (33%) had coexisting Chlamydia trachomatis and Neisseria gonorrhoeae infections. Among the women with genital or anal gonorrhea, two (9%) of 23 treated with TMP-SMZ and three (12%) of 25 treated with ampicillin and probenecid remained infected. TMP-SMZ cured four of four pharyngeal gonococcal infections. C. trachomatis was isolated at the first posttreatment visit significantly more often after treatment with ampicillin and probenecid (10 of 11 times) than after treatment with TMP-SMZ (1 of 10 times; P = 0.003). However, at the second follow-up visit, C. trachomatis was isolated from 30% of the women treated with TMP-SMZ. The area of ectopic columnar epithelium (ectopy) on the ectocervix and edema of this area were highly correlated with the presence of C. trachomatis, and persistence of C. trachomatis was associated with persistent edema of ectopy and with friability. TMP-SMZ is as effective as ampicillin-probenecid for the treatment of uncomplicated genital gonorrhea in women and may be more effective for the treatment of pharyngeal gonorrhea. The optimal dose and duration of TMP-SMZ therapy for C. trachomatis infection requires further study.

Adolescent↗