PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Rodent Control”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources

Use of liquid deltamethrin in modified, host-targeted bait tubes for control of fleas on sciurid rodents in northern California.

The efficacy of liquid deltamethrin was evaluated for controlling fleas on golden-mantled ground squirrels, Spermophilus lateralis, and chipmunks, Tamias amoenus and T. senex. A host-targeted bait tube was modified to deliver insecticide to visiting rodents during a seven-week trial conducted in the Southern Cascade Mountains of northern California. A single deltamethrin treatment with one replenishment of bait provided effective flea control on rodents within one week of deployment of bait tubes. A second treatment accompanied by two bait replenishments during the following two-week period maintained effective control throughout the seven-week period, even though all bait tubes were removed from the site after three weeks. Our results suggest that the use of modified bait tubes treated with liquid deltamethrin can provide an effective, economical, and efficient means of controlling vector fleas on the primary disease amplifying rodent hosts in this plague endemic region of California.

Animals↗

The role of dominance and epistasis in the genetic control of blood pressure in rodent models of hypertension.

Genetic analyses of crosses between hypertensive rodent models and their normotensive controls were performed on 43 sets of data published between 1970-1989. In each case, the cross involved F1, F2, and both backcross generations for a "complete genetic cross." Biometrical analysis estimated genetic parameters and their standard errors associated with dominance and epistasis (interaction of alleles that are not at the same locus). The statistical significance of these parameters was determined by comparing the parameter to its standard error. A purely additive inheritance pattern was seldom found. Additive/dominance inheritance was apparent in only two models. The prevailing pattern of inheritance was one with partial dominance for alleles for normal blood pressures and epistatic interactions. Finding epistasis in so many models will have implications for the application of cosegregation and linkage analyses in hypertension research.

Animals↗

In vitro growth control phenotypes of transformed rodent cells prior to and following tumorigenesis.

A number of virus and chemical carcinogen-transformed cell lines were generated in tissue culture and analyzed for growth control phenotypes prior to and following tumorigenesis in appropriate hosts. The cell lines include those of mouse, rat, human, and Syrian hamster, transformed by papovaviruses and adenoviruses (DNA) or murine (RNA) tumor viruses. Cell lines were assayed for: (a) multinucleation or uncontrolled nuclear division (UND+) and uncontrolled DNA synthesis in cytochalasin B (CB) medium; and (b) the continuation of DNA synthesis in media containing reduced (0.5%) amounts of serum. All or nearly all lines of DNA virus transformants exhibited UND+ and high frequencies of DNA-synthetic cells in CB medium. Two lines of SV40-transformed hamster cells also showed UND+ following tumorigenesis in weaning hamsters. In addition, DNA virus transformants showed the ability to continue DNA synthesis unabated in low-serum medium. In contrast, the mouse sarcoma virus (MSV)-transformed lines exhibited varying degrees of controlled nuclear division and reduced DNA synthesis in CB medium, both prior to and following tumorigenesis. However, the reduction in DNA-synthetic cells was often not as great as that found in untransformed cells. Results similar to the RNA virus transformants were observed with hamster cells transformed by chemical carcinogens. Nearly all of the MSV-transformed lines showed significantly reduced levels of DNA synthesis in low-serum medium as was found in untransformed cells. One cell line, KA31, was followed through three consecutive in vivo tumorigenic passages, but these cells did not acquire UND+ or the ability to continue DNA synthesis in low-serum medium. These results suggest that many MSV- and carcinogen-transformed rodent cells exhibit transformation phenotypes at levels barely above those of normal cells and markedly less than those of DNA virus transformants, and yet they are tumorigenic.

Animals↗

Localization of substance P receptors in central neural structures controlling daily rhythms in nocturnal rodents.

Brain areas involved in the genesis and control of daily rhythms receive a prominent neural input that contains the neurotransmitter substance P (SP), a peptide putatively involved in the synchronization of circadian rhythms by environmental light. We investigated the localization of receptors to SP in the suprachiasmatic nucleus of the hypothalamus (SCN) and in the intergeniculate leaflet of the thalamus (IGL) of the rat and hamster using in situ hybridization histochemistry and immunohistochemistry. Consistently with that previously described in the rat, a neuronal population distributed along the lateral margin and at the dorso-latero-caudal aspect of the hamster SCN expresses moderately the mRNA encoding the SP receptor. In both rat and hamster, immunohistochemical data confirm the previous finding and reveal an almost complete absence of SP receptors in the ventral part of the SCN, which receives a direct projection from the retina. In the IGL of both species, numerous neurons prominently express the mRNA encoding the SP receptor. The immunostaining shows a high density of SP receptors on perikarya and dendrites throughout the nucleus. A dense staining is also observed on individual cells and processes bordering the lumen of blood vessels in the SCN and IGL.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effect of chronic feeding of ethanol diet of "average" fat content on rat pancreas.

The present study was done to determine the influence of dietary fat on the effect of ethanol on pancreatic macromolecular content and secretion. Weight-matched groups of Sprague-Dawley rats were divided into controls fed Rodent-Blox ad libitum; American Institute of Nutrition-76 (AIN-76) diet containing 12% calories as fat with 36% of carbohydrate calories replaced with 5% (weight/volume) concentration of ethanol fed ad libitum pair fed with animals given isocaloric amounts of AIN-76 diet for three to six months. Compared with Rodent-Blox fed controls, tissue content of trypsinogen, chymotrypsinogen, amylase, and lipase; specific activity and concentration of trypsinogen, chymotrypsinogen; and concentration of amylase were decreased at six months in AIN-76 fed controls. These changes did not result from diminished food intake, but were due to adaptation to the liquid diet. Animals fed AIN-76 diet plus ethanol did not show significant difference in the total content, specific activity, concentration, and secretion of digestive enzymes compared with those animals pair fed isocaloric amounts of AIN-76 diet. Activation of trypsinogen by exogenous trypsin was lower in rats fed AIN-76 diet and a similar change was observed in animals fed AIN-76 diet with ethanol for six months. These findings are in contrast to increased secretion of proteases and decreased trypsin inhibitor observed previously in animals fed ethanol in a diet containing "high" fat. These data indicate that ethanol effect on the pancreas is modified by dietary intake of fat and/or carbohydrates.

Amylases↗

Effects of bleeding nonanesthetized wild rodents on handling mortality and subsequent recapture.

Handling mortality and recapture rates of wild rodents that were bled from the retroorbital capillary plexus without anesthesia were assessed. In 9,670 captures of seven species of rodents from 1994 through 1998, we found no difference in handling mortality in bled mice compared to those from trapping grids where mice were not bled. Recapture rates of rodents on control (non-bleeding grids) and rodents on bleeding grids was not significantly different for any species. We conclude that bleeding in the absence of anesthesia does not affect immediate mortality or subsequent recapture.

Anesthesia↗

Effect of Glyzophrol on fertility of female black rats (Rattus rattus).

Mild degree of fibrosis, dilatation of blood vessels, haemorrhagic reactions in a few places, granulosa cells in stroma and no effect on maturation process of follicles were observed in ovary of 20 mg/kg of Glyzophrol treated rats. After 60 mg/kg of Glyzophrol treatment, ovary revealed reduction in number of follicles, degenerative changes in existing follicles, frequent proliferation of granulosa cells and fibrosis in stroma along with karyorrhexis, karyolysis and pyknosis in nuclei. Haemorrhage and dilated blood vessels in stroma were well marked, suggesting that ovarian vasculature was affected by glyzophrol. Ovary exhibited increase in activity of acid phosphatase after Glyzophrol treatment. Intense alkaline phosphatase activity was observed in entire ovarian tissue after Glyzophrol treatment.

Acid Phosphatase↗

Use of historical control data in carcinogenicity studies in rodents.

This paper considers the use of historical control data in the evaluation of tumor incidences from carcinogenicity studies in rodents. Although the most appropriate control group for interpretative purposes is always the concurrent control, there are instances in which the use of historical control information can aid an investigator in the overall evaluation of tumor incidence data. One example is rare tumors; another is a tumor that shows a marginally significant result relative to concurrent controls. However, before historical control data can be used in a formal testing framework, a number of important issues must first be considered. The nomenclature conventions and diagnostic criteria for each study should be identical to insure unambiguous identification of all relevant tumors in the historical control database. Criteria should be established that will aid in determining whether a particular study should be included in the database. This will assure a homogeneous set of studies upon which to base statistical comparisons. Since study-to-study variability in tumor rates may exceed what would be expected by chance alone, these sources of variability should be identified and controlled. Finally, statistical procedures should be employed that adjust for extra-binomial variability. This paper also summarizes tumor incidence data from untreated Fischer 344 rats and B6C3F1 mice in the National Toxicology Program (NTP) historical control database. All studies in the database are of two years duration, and all neoplasms occurring with a frequency of 0.5% or more are reported.

Animals↗