Biomedical subjects

T Su

Publications and source records attributed to T Su.

At least 37 records · Page 2Linked to original sources

PubMed2000

Induction of mouse CYP2J by pyrazole in the eye, kidney, liver, lung, olfactory mucosa, and small intestine, but not in the heart.

We have recently shown that rat CYP2J4 is inducible by pyrazole in liver, small intestine, and olfactory mucosa. The aim of the present study was to determine whether mouse CYP2Js are also inducible by pyrazole, which was known to induce CYP2A5 in mouse liver and kidney, but not in lung or olfactory mucosa. CYP2J proteins were detected in mouse liver, lung, kidney, heart, eye, olfactory mucosa, and small intestine by immunoblot analysis with an anti-CYP2J4 antibody. The microsomal level of the CYP2J4-related P450s in various mouse tissues ranked in the order of small intestine > olfactory mucosa > liver > kidney > or = heart > lung > eye. Induction of the CYP2J proteins was observed in the eye, liver, lung, kidney, olfactory mucosa, and small intestine, but not in the heart, after daily i.p. injection of pyrazole at 120 or 200 mg/kg for 3 days. CYP2J proteins were induced similarly in C57BL/6 and DBA/2 mice. CYP2A5 was detected in the small intestine in addition to liver and olfactory mucosa; however, treatment with pyrazole induced CYP2A5 in the liver, but not in the olfactory mucosa or the small intestine. Induction of CYP2J mRNAs was also observed by RNA blot analysis with a CYP2J4 cDNA probe. RNA-polymerase chain reaction analysis showed that, in both untreated and pyrazole-treated mice, CYP2J5 was expressed in the kidney and liver, but not in the other tissues examined, whereas CYP2J6 was detected in all tissues examined. The different tissue selectivities in CYP2A5 and CYP2J induction by pyrazole suggest involvement of different regulatory mechanisms.

Animals↗

PubMed2000

[The relationship between GPx activity in gingival fluid and clinical parameters of adult periodontitis].

OBJECTIVE: To study the relationship of glutathione peroxidase (a natural FR scavenger) in gingival cervical fluid (GCF) of patients with periodontitis. METHODS: GCF was collected from 44 sites of 23 patients with adult periodontitis. The volume of GCF was measured with Periotron 8000. GCF-GPx activity was determined by DTNB methods before and after treatment, and the periodontal parameters GI, PD and AL were recorded. RESULTS: GCF-GPx activity was negatively correlated with PD and AL (P < 0.01, P < 0.005), but was not correlated with GI (P > 0.05). After treatment, clinical parameters decreased while GCF-GPx activity increased (P < 0.001), but the increment of GCF-GPx activity showed no correlation with the base level and the changes of clinical parameters. CONCLUSION: The imbalance between FR's production and scavenging might be an important pathological factor of periodontal diseases, and GCF-GPx might be a promising indicator of periodontal status.

Adult↗

PubMed2000

[The effect of intra-articular injection of sodium hyaluronate and prednisolone on rabbits' temporomandibular joints].

OBJECTIVE: To evaluate the different effects of sodium hyaluronate and prednisolone on the surface of rabbits' temporomandibular joints. METHODS: 20 juvenile Japanese large ear rabbits were divided into 5 groups, including one control group and the other 4 experimental groups. In these groups, half of their right inferior cavity of temporomandibular joints were injected with sodium hyaluronate(25 mg/ml, 0.1 ml), while others were injected with prednisolone(1%, 0.1 ml), then the rabbits were killed on the 1st, 3rd, 7th, and 14th days after injection. The specimens were evaluated by scanning electron microscope (SEM) to compare the different effects on the inferior superfacial structure of the articular disc and the surface of the condyle. RESULTS: Prednisolone could change the uniform distribution of the agglutinating substance on the inferior superfacial of the articular disc and the surface of the condyle. In the 1st-day and the 3rd-day groups, the agglutinating substance decreased in some areas and gathered in other areas. In the 7 th-day group, the distribution of the agglutinating substance on the inferior superfacial of the articular disc and the surface of the condyle were more regular than that of the 1st-day and the 3rd-day groups. In the 14th-day group, the distribution of the agglutinating substance were almost as the same as that of the control group. But sodium hyaluronate didn't change the uniform distribution of the agglutinating substance in every group. CONCLUSION: Prednisolone can change the uniform distribution of the agglutinating substance on the inferior superfacial of the articular disc and the surface of the condyle, while sodium hyaluronate don't have this effect.

Animals↗

PubMed1999

Cytochrome P450 and steroid hydroxylase activity in mouse olfactory and vomeronasal mucosa.

The aims of this study are to identify the sex steroid-metabolizing cytochrome P450 enzymes of the vomeronasal organ (VNO) and to determine the activities of VNO microsomes to metabolize estradiol, progesterone, and testosterone. Several P450 isoforms, including CYP1A2, CYP2A, CYP2B, CYP2C, CYP2G1, and CYP3A, NADPH P450-reductase, and microsomal epoxide hydrolase were detected in mouse VNO, although their expression levels were much lower than those in the main olfactory epithelium. VNO microsomes were active toward the three steroid hormones, producing metabolite profiles similar to those seen with olfactory mucosal microsomes. Thus, the mammalian VNO, a steroid hormone target tissue, contains multiple steroid-metabolizing P450 isoforms and is capable of metabolic disposition of the three major sex steroid hormones. These findings support the proposed roles of olfactory mucosal and VNO microsomal P450 enzymes in maintaining cellular hormonal homeostasis and other perireceptor processes associated with olfactory chemosensory function.

Animals↗

PubMed1999

N-glycans are not a universal signal for apical sorting of secretory proteins.

In MDCK cells, N-glycans have been shown to determine the sorting of secretory proteins and membrane proteins to the apical domain in the absence of a dominant basolateral targeting signal. We have examined the sorting of endogenous proteins in ECV304 cells in the presence and absence of tunicamycin, an inhibitor of N-linked glycosylation. A prominent apically secreted protein of 71 kDa was not N-glycosylated and continued to be secreted apically in the presence of tunicamycin. In contrast, other endogenous proteins that were N-glycosylated were secreted preferentially into the basolateral medium or without polarity. When rat growth hormone was expressed in MDCK and ECV304 cells, we observed 65 and 94% of the secretion to the basolateral medium, respectively. Introduction of a single N-glycan caused 83% of the growth hormone to be secreted at the apical surface in MDCK cells but had no significant effect on the polarity of secretion of growth hormone in ECV304 cells. These results indicate that not all cell lines recognise N-glycans as a signal for apical sorting and raises the possibility of using ECV304 cells as a model system for analysis of apical sorting molecules.

Animals↗

PubMed1999

Activity and biological effects of neem products against arthropods of medical and veterinary importance.

Botanical insecticides are relatively safe and degradable, and are readily available sources of biopesticides. The most prominent phytochemical pesticides in recent years are those derived from neem trees, which have been studied extensively in the fields of entomology and phytochemistry, and have uses for medicinal and cosmetic purposes. The neem products have been obtained from several species of neem trees in the family Meliaceae. Six species in this family have been the subject of botanical pesticide research. They are Azadirachta indica A. Juss, Azadirachta excelsa Jack, Azadirachta siamens Valeton, Melia azedarach L., Melia toosendan Sieb. and Zucc., and Melia volkensii Gürke. The Meliaceae, especially A. indica (Indian neem tree), contains at least 35 biologically active principles. Azadirachtin is the predominant insecticidal active ingredient in the seed, leaves, and other parts of the neem tree. Azadirachtin and other compounds in neem products exhibit various modes of action against insects such as antifeedancy, growth regulation, fecundity suppression and sterilization, oviposition repellency or attractancy, changes in biological fitness, and blocking development of vector-borne pathogens. Some of these bioactivity parameters of neem products have been investigated at least in some species of insects of medical and veterinary importance, such as mosquitoes, flies, triatomines, cockroaches, fleas, lice, and others. Here we review, synthesize, and analyze published information on the activity, modes of action, and other biological effects of neem products against arthropods of medical and veterinary importance. The amount of information on the activity, use, and application of neem products for the control of disease vectors and human and animal pests is limited. Additional research is needed to determine the potential usefulness of neem products in vector control programs.

Animals↗

PubMed1999

Efficacy of new formulations of the microbial larvicide Bacillus sphaericus against polluted water mosquitoes in Thailand.

Two new water dispersible granular (WDG) formulations of the microbial control agent Bacillus sphaericus (strain 2362) were extensively evaluated in polluted waters against Culex quinquefasciatus in Thailand. The studies were carried out in stagnant as well as flowing waters during August 1997 to July 1998. The trial period covered both rainy and dry seasons. The two WDG formulations of B. sphaericus tested were low potency (350 ITU/mg) and high potency (630 ITU/mg) products. Both formulations were used at various rates to determine initial efficacy and longevity. The high potency formulations provided excellent control (80 to 90%) of immature mosquitoes at the rates of 50 to 100 mg/ m2, while the less potent formulation yielded similar control at the rates of 89 to 250 mg/m2. Longevity of control was anywhere from one week to four weeks or longer depending on the dosage, habitat, and environmental conditions. Two treatments with low dosages of Bacillus thuringiensis ssp. israelensis WDG provided short-term control lasting for one week. Frequent episodes of heavy rains facilitated long-term suppression of immature mosquitoes in klongs by flushing out the larvae. In the absence of rain, the longevity of treatments in flowing waters was shorter than in the presence of rain. Rain, however, had some but not pronounced effect on longevity in the stagnant water habitats. Operation of floodgates controlling water flow from stagnant water habitats into the Chaophrya River had greater influence on the abundance of mosquito immatures in the ponded polluted waters under dwellings. Precipitation, adding large amounts of water, was probably responsible for diluting the control agents and also resulted in lower counts of immatures per unit volume of water. These variables could influence the efficacy (especially longevity) of treatments employing formulations of microbial agents in operational control programs. The WDG formulations are preferred over other formulations, such as granules, because the former contain larger quantities of toxins per unit mass than the latter and are easily applied as aqueous sprays. Potent formulations with greater content of active ingredients are less costly to ship and transport to distant areas.

Animals↗

PubMed1999

Field evaluation of new water-dispersible granular formulations of Bacillus thuringiensis ssp. israelensis and Bacillus sphaericus against Culex mosquitoes in microcosms.

A variety of formulations of Bacillus thuringiensis var. israelensis de Barjac (B.t.i.) and Bacillus sphaericus Neide (B.s.) have been studied for mosquito control under laboratory and field conditions. High efficacy, specificity, low risk of development of resistance, long shelf-life, and transportability, as well as the safety to nontarget organisms of these 2 microbial agents have been well documented. Some of the currently available formulations of B.t.i. and B.s. have low potency per unit mass. Research and development efforts are focusing on commercializing formulations with high potency and low minimum effective dosage that are suitable for long-distance shipment. To achieve this goal, new water-dispersible granule (WDG) formulations of both microbial agents were prepared and made available by Abbott Laboratories for evaluation. The newly developed WDGs of B.t.i. and B.s. with high potency dispersed readily in water with gentle agitation. These WDGs were evaluated and the minimum effective dosages were determined in microcosms against natural populations of Culex mosquitoes. The minimum effective dosage for B.t.i. WDGs with 4,000 International Toxic Units (ITU)/mg was 0.27-0.53 lb/acre which yielded significant control for up to 7-12 days. The minimum effective dosage for B.s. WDGs with 350-630 ITU/mg was 0.05-0.10 lb/acre, which yielded significant control of immature mosquitoes for up to 14-20 days.

Animals↗

PubMed1999

Mosquito control and bacterial flora in water enriched with organic matter and treated with Bacillus thuringiensis subsp. israelensis and Bacillus sphaericus formulations.

Three tests were conducted during July 17 to October 30, 1998 to study the impact of two mosquitocidal microbial agents on mosquito larvae and their contribution to bacterial flora in aquatic microcosms. Formulations of Bacillus thuringiensis subsp. israelensis (Bti) and Bacillus sphaericus strain 2362 (Bsph) were applied at various rates to outdoor tubs enriched with rabbit pellets and filled with irrigation water from a reservoir. Mosquito larvae were effectively controlled by all treatments; the magnitude of initial and persistent control depended on materials and dosages applied. Bacterial flora were assessed in the irrigation water as well as water in the enriched tubs before and after treatment with the microbial agents. The irrigation water contained 800-1000 total bacterial cells/ml. The populations of total bacteria and spore formers peaked on day 3 after enriching and filling the tubs, then declined progressively to the low levels at the end of the tests. After treatment, the numbers of Bti and Bsph spores in treated tubs prevailed at a dosage-dependent manner, their populations peaked at three hours after treatment, and declined progressively thereafter. The contribution of Bti and Bsph spores to the total bacterial flora was negligible but significant to the counts of spore-forming bacteria. The gram-negative bacteria made up more than 80% of the total bacterial flora during the test periods; and, of these, gram-negative rods constituted the greatest proportion, gradually increasing from the time of flooding to the end of the tests. Gram-negative cocci also occurred in relatively great proportion, but showed a reverse trend as compared with the gram-negative rods, declining gradually from pretreatment to the end of the tests. Gram-positive rods (spore formers), including Bti and Bsph, occurred in low numbers in all the tests but increased slightly in treated tubs due to the addition of Bti and Bsph spores. Gram-positive cocci occurred occasionally in some water samples.

Animals↗

PubMed1999

Bacteria and mosquito abundance in microcosms enriched with organic matter and treated with a Bacillus thuringiensis subsp. israelensis formulation.

Bacteria and mosquito abundance were studied in outdoor tubs unenriched and enriched with 0.04% rabbit pellets during the winter, 1999. The irrigation water used to fill the tubs contained a total bacterial count of 1.15-1.35 x 10(3) cells/ml. Adding rabbit pellets for enrichment yielded a total bacterial count of 5.50-7.63 x 10(5) cells/g. Bacterial densities in unenriched water were significantly lower than in enriched tubs on every sampling day. When bacterial densities in both enriched and unenriched regimens reached peak populations on day 3 post-flooding, their numbers in enriched water were 25-fold higher than the unenriched water. Under cool weather conditions, mosquito oviposition activity was low and larval development was very slow. Egg raft counts and larval densities in enriched water were nevertheless higher than those in unenriched water. After reaching peak populations on day 3 post-flooding, the natural decline in bacterial densities in the top portion of enriched water without mosquito larvae was lower compared with that in water with larvae. In water with larval present, the decline of bacterial levels in top water was greater than in bottom water on day 7 post-flooding. VectoBac G, a granular formulation of Bacillus thuringiensis subsp. israelensis caused a reduction in larval numbers of 80, 93, 73% at the rate of 5.5 lb/ac and a reduction of 94, 93, 86% at the rate of 10.6 lb/ac on days, 1, 3, 7 posttreatment, respectively. After treatment, the reductions of bacterial densities in untreated tubs were greater than treated tubs. These results indicate that mosquito larvae play an important role in the decline of bacterial populations by their feeding activity.

Animals↗

PubMed1999

Effects of neem products containing azadirachtin on blood feeding, fecundity, and survivorship of Culex tarsalis and Culex quinquefasciatus (Diptera: Culicidae).

When late 3rd or early 4th-instar larvae of Culex tarsalis Coquillett and Culex quinquefasciatus Say mosquitoes were treated with sublethal dosages of neem insecticide until pupation, the blood-feeding activity of the resulting adults was essentially the same as that of untreated controls. In contrast, blood-feeding activity was suppressed when newly emerged adults were fed continuously on 10 parts per million (ppm) or 50 ppm azadirachtin (AZ) in 10% sucrose solution for seven days. Fecundity was also reduced by the various neem treatments. When late 3rd or early 4th-instar larvae were treated with 0.010 ppm AZ to pupation, the resultant females had a lower rate of oviposition than did the untreated controls after a full blood meal. When late instar larvae were treated at 0.005 ppm and 0.010 ppm AZ, the resultant females produced smaller egg rafts after a full blood meal, as compared to the controls, but egg viability was not affected. In newly emerged adults feeding continuously on 10 ppm and 50 ppm AZ in 10% sucrose for seven days (before blood feeding), the oviposition rate, size of egg raft, and hatching rate of the eggs after a full blood meal were all reduced. When newly blood-fed adults were fed continuously on 10 ppm and 50 ppm AZ in 10% sucrose for five days, their oviposition rate was lower than controls in most cases, but the egg raft size and viability of eggs were not affected. In freshly blood-fed females topically treated with AZ with 1 or 5 micrograms/female, the oviposition rate and size of egg rafts were generally reduced. The females receiving topical treatment laid eggs and their hatching was not affected. The longevity of adult females feeding continuously on 10 ppm and 50 ppm AZ in 10% sucrose solution after emergence was reduced, whereas, the longevity of males was only affected at the higher concentration.

Animals↗

PubMed1999

[The effects of transforming growth factor alpha and beta 1 on the proliferation of alveolar type II cells in vitro].

OBJECTIVE: To investigate the effect of transforming growth factor alpha and beta(1) (TGFalpha and beta(1)) on the proliferation of alveolar type II cells in vitro and the molecular mechanism related. METHODS: (3)H-TdR incorporation and cell counting for the assay of cell growth; dot blot, in situ hybridization, and immunohistochemical methods for analysing the expression of cyclin D1 and cycle-dependent kinase 4 (CDK4) genes. RESULTS: With increasing of the concentration of TGFalpha and beta(1) (0.01 ng-100 ng/ml), TGFalpha enabled to increase (3)H-TdR incorporation and the number of alveolar type II cells, while the effect of TGFbeta(1) was opposite and both effects were dose-dependent (P < 0.01). TGFalpha-treated cells decreased the expression of CDK4 mRNA, and the relevant in comparing with the control (P < 0.01). On the contrary, TGFbeta(1)-treated cells decreased the expression of CDK4 mRNA), CDK4 as well as the cyclin D1 proteins (P < 0.05). CONCLUSION: Both TGFalpha and beta(1) were considered implicated in the regulation of proliferation of cultured alveolar type II cells isolated from the adult rats and CDK4 might be a common target against TGFalpha and beta(1) signals.

Animals↗

PubMed1998

In vitro reconstitution of human B-cell ontogeny: from CD34(+) multipotent progenitors to Ig-secreting cells.

We describe a long-term, in vitro culture system initiated with CD34(+) or CD34(+)CD38(-) umbilical cord blood hematopoietic progenitors that supports normal human B-lineage development, including the production of mature Ig-secreting B cells. In the first stage (human B-progenitor long-term culture [HB-LTC]), CD34(+) hematopoietic progenitors are cultured on the murine stromal cell line, S17, leading to the sustained production of large numbers of CD10(+), CD19(+) early B progenitors. Reverse transcriptase-polymerase chain reaction (RT-PCR) and three-parameter flow cytometry for VpreB (surrogate light chain), cytoplasmic mu chain, and surface IgM expression were used to characterize the CD19(+) B progenitors present within these cultures. This analysis showed distinct B-lineage subpopulations, including pro-B cells, cycling pre-B cells, and IgM+, IgD-/+ immature B cells. The limited expansion of IgM+ B cells and the immature surface phenotype of this population (IgM+, IgD+, CD10(+), CD38(+)) suggested that HB-LTC conditions were unable to provide appropriate signals for further differentiation. A second culture stage was used to determine if these immature B cells were functionally competent. Purified CD19(+) cells were transferred onto fibroblasts expressing human CD40-ligand in the presence of IL-10 and IL-4. This lead to cell proliferation, modulation of the IgM+ cell surface phenotype to one consistent with an activated mature B cell, secretion of Ig, and isotype switching. Notably, IgM and IgG producing B cells were also generated using two-stage cultures established with highly purified multipotent CD34(+)CD38(-) hematopoietic stem cell progenitors. This culture model should permit detailed in vitro analysis and genetic manipulation of the major transition points in human B ontogeny, beginning with commitment to the B lineage and leading to development and activation of mature B cells.

Animals↗

PubMed1998

Opposite sorting and transcytosis of the polymeric immunoglobulin receptor in transfected endothelial and epithelial cells.

We have transfected a polarised endothelial cell line, ECV 304, and an epithelial cell line, MDCK, with a well characterised epithelial protein, the rat polymeric immunoglobulin receptor (pIgR), in order to study the protein sorting and transcytosis in endothelial cells. The expressed protein was normally processed and the steady state distribution between apical and basolateral surfaces was similar in both cell types. MDCK cells, however, showed a marked polarity in the delivery of newly synthesised pIgR to the cell surface, and in the release of secretory component. 88% of newly synthesised pIgR in MDCK cells was first delivered to the basolateral surface and 99% of secretory component was released from the apical surface. In contrast the basolateral targeting signal of pIgR was only partially recognised in endothelial cells, with 63% of the newly synthesised pIgR being first delivered to the basolateral surface. At steady state only 43% of the pIgR was found on the basolateral membrane. The direction of dimeric IgA transcytosis in endothelial cells was from apical to basolateral surfaces, opposite to that in MDCK cells. These data suggest that endothelial cells poorly recognise the targeting signals of proteins from epithelial cells, and that the direction of transcytosis is linked to the biological role of the cells.

Animals↗

PubMed1998

[Serum type IV collagen and laminin in patients with chronic hepatitis and its clinical significance].

Serum levels of laminin and type IV collagen of 188 patients with different types of viral hepatitis were determined by RIA. Thirty-five blood donors were served as normal control. The results showed that: (1) higher levels of type IV collagen was found in patients with severe chronic hepatitis, post-hepatitis cirrhosis or subfulminant hepatitis; (2) the level of laminin was obviously increased in post-hepatitis cirrhosis and subfulminant hepatitis; (3) there was a positive correlation between the levels of type IV collagen and laminin as well as gamma globulin, and negatively correlated to serum albumin, no correlation with alanine aminotransferase was observed; (4) detecting rate of hepatic fibrosis was increased with combination of serum laminin and type IV collagen examination; (5) serum type IV collagen was more sensitive than that of serum laminin. The results suggest that determination of serum type IV collagen and laminin are useful in diagnosis of hepatic fibrosis, and combination of the two parameters is recommended.

Adolescent↗

PubMed1998

[Cloning and identification of cDNA fragments related to human esophageal cancer].

OBJECTIVE: To search new genes related to human esophageal cancer (EC) for revealing carcinogenesis mechanism and genetic susceptibility of EC. METHODS: Three normal esophageal epithelia (including 1 tumor-adjacent tissue) and two primary squamous cell carcinomas collected from high incidence family in Lin-xian county were studied using technique of mRNA differential display. The differential fragments were sequenced and identified by RT-PCR assay. RESULTS: (1) Eighteen differential fragments were isolated and identified, 13 of which were expressed in normal esophageal epithelia but not in EC(assigned as normal esophageal gene, NEG), while 5 were expressed in EC but not in normal esophageal epithelia(assigned as mutated esophageal gene, MEG). (2) Four NEG fragments were not homologous to the known sequences in the public database of GenBank (of NLM in USA). These 4 fragments were assigned as esophageal cancer related gene (ECRG) 1 to 4. (3)The remaining 14 fragments were homologues to 12 known genes or gene fragment. Their role in EC remains unclear. (4) Using RT-PCR technique, the expression of ECRG between normal epithelia and EC was significantly different. (5) All 4 ECRG genes were expressed in cDNA libraries derived from normal fetal brain, adult brain, liver, kidney, testis, bone marrow and skeletal muscle. (6) In the 20 cancerous and tumor-adjacent tissues obtained from the liver, lung, breast, colo-rectum and endometria, ECRG1 and ECRG2 was not detected by RT-PCR, while ECRG3 was highly expressed. For the ECRG4 the expression was much stronger in tumor-adjacent tissues than in cancerous tissues. CONCLUSION: ECRG 1 and ECRG2 may contribute to the causation and progression of the EC in Lin-xian, and may be candidates of tumor suppressor genes.

Carcinoma, Squamous Cell↗

PubMed1998

Ovicidal activity of neem products (azadirachtin) against Culex tarsalis and Culex quinquefasciatus (Diptera: Culicidae).

Bioactive compounds contained in the seed kernel and other parts of the neem tree (Azadirachta indica A. Juss) have been found to show insecticidal activities and other effects in many species of insects. These activities include antifeedancy, growth regulation, fecundity suppression, male sterility, oviposition repellency, changes in biological fitness such as loss of flying ability, immunodepression, enzyme inhibition, splitting of biological rhythms, and so forth. We investigated the ovicidal effects of various formulations of azadrirachtin (AZ) against the mosquitoes Culex tarsalis Coquillett and Culex quinquefasciatus Say. The formulations tested were wettable powder Azad WP10, emulsifiable concentrate Azad EC4.5, and technically pure AZ. The ovicidal activity of the test neem products was influenced by concentration of AZ, age of the egg rafts, and age of the neem preparations. Other factors such as formulation and mosquito species were also involved in the degree of ovicidal activity. When the egg rafts were deposited directly in fresh neem suspension and left there for 4 h before transfer to untreated water, 1 ppm of AZ produced almost 100% mortality in eggs. When egg rafts aged for 0, 4, 8, 12, and 24 h were exposed to 10 ppm neem suspensions for 36 h, the ovicidal activity was only attained in the egg rafts deposited directly (0 h old) in the neem suspension, not in those with ages of 4-24 h. On aging, depending on the formulations and mosquito species, the neem suspensions at 1 ppm completely lost ovicidal activity within 7-20 days. The egg rafts of Cx. quinquefasciatus were more susceptible to the test neem products than those of Cx. tarsalis. The formulated neem products were more persistent and effective than the technical AZ. The wettable powder (WP) formulation was slightly more persistent and effective than the emulsifiable concentrate (EC). The ovicidal activity of the neem products against mosquitoes from the current research clearly demonstrated the potential of neem products as possible ovicides against Culex mosquitoes.

Animals↗

PubMed1998

Differential xenobiotic induction of CYP2A5 in mouse liver, kidney, lung, and olfactory mucosa.

The effects of pyrazole, which is known to induce hepatic cytochrome P4502A5 (CYP2A5) through posttranscriptional mechanisms, on the level of CYP2A5 in liver and extrahepatic tissues were examined in this study. Intraperitoneal administration of pyrazole at 200 mg/kg for 3 days induced CYP2A4/5 mRNAs and proteins and microsomal coumarin 7-hydroxylation activity in liver and kidney of C57BL/6 mice. A marginal increase (30%) in CYP2A4/5 mRNAs was also observed in the olfactory mucosa but not in the lung, and no increase in CYP2A4/5 proteins or microsomal coumarin 7-hydroxylation activity was observed in either the olfactory mucosa or lung. CYP2A4/5 proteins were not detected on immunoblots in other tissues examined, including breast, bone marrow, testis, prostate, ovary, and uterus from control or pyrazole-treated mice. On the other hand, pyrazole treatment induced CYP2E1 in the olfactory mucosa as well as in liver and kidney, indicating that the olfactory mucosa was exposed to pyrazole. The lack of CYP2A inducibility in the olfactory mucosa was also observed for several other known inducers of hepatic CYP2A5, including cobaltous chloride, stannous chloride, griseofulvin, thioacetamide, and aminotriazole. These results suggest that the mechanisms involved in the induction of hepatic and renal CYP2A5 by pyrazole and other xenobiotic compounds may be tissue-specific.

Amitrole↗