PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Shrews”

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 19 recordsLinked to original sources
PubMed2000

A lectin-histochemical study on the seminiferous epithelium of the northern smooth-tailed tree shrew (Dendrogale murina) and the Java tree shrew (Tupaia javanica).

Lectin-binding patterns in the testes of the northern smooth-tailed tree shrew, Dendrogale murina and Java tree shrew, Tupaia javanica were studied by light microscopy and compared the data with those of the common tree shrew. Four lectins (PNA, SBA, BPA and GS-II) were used in this study. Peanut (Arachis hypogaea) agglutinin (PNA), soybean (Glycine max) agglutinin (SBA) and Bauhinia purpurea agglutinin (BPA) showed a strong reaction in the acrosomal region from Golgi to acrosome-phase spermatids in three species of tree shrews. These lectins also showed a granular positive reaction in the cytoplasm from acrosome to maturation-phase spermatids in three species, except that BPA revealed no granular reaction (though it was positive) in the spermatid cytoplasm of the northern smooth-tailed tree shrew and that PNA revealed no reaction in the spermatid cytoplasm of the common tree shrew. While, Griffonia simplicifolia-II agglutinin (GS-II) showed a positive reaction in the acrosomal region of Golgi-phase spermatids in three species of tree shrews. Although GS-II was positive in the spermatocyte cytoplasm of three species, it showed granular in the northern smooth-tailed tree shrew and common tree shrew but not granular in the Java tree shrew. Thus, the lectin-binding patterns in testes were similar among three species belonging to the Order Scandentia. However, slight differences were also detected even among these phylogenetically-close species.

Animals↗
PubMed2004

Organization of the main olfactory bulbs of some mammals: musk shrews, moles, hedgehogs, tree shrews, bats, mice, and rats.

We immunohistochemically examined the organization of the main olfactory bulbs (MOBs) in seven mammalian species, including moles, hedgehogs, tree shrews, bats, and mice as well as laboratory musk shrews and rats. We focused our investigation on two points: 1) whether nidi, particular spheroidal synaptic regions subjacent to glomeruli, which we previously reported for the laboratory musk shrew MOBs, are also present in other animals and 2) whether the compartmental organization of glomeruli and two types of periglomerular cells we proposed for the rat MOBs are general in other animals. The general laminar pattern was similar among these seven species, but discrete nidi and the nidal layer were recognized only in two insectivores, namely, the mole and laboratory musk shrew. Olfactory marker protein-immunoreactive (OMP-IR) axons extended beyond the limits of the glomerular layer (GL) into the superficial region of the external plexiform layer (EPL) or the nidal layer in the laboratory musk shrew, mole, hedgehog, and tree shrew but not in bat, mouse, and rat. We observed, in nidi and the nidal layer in the mole and laboratory musk shrew MOBs, only a few OMP-IR axons. In the hedgehog, another insectivore, OMP-IR processes extending from the glomeruli were scattered and intermingled with calbindin D28k-IR cells at the border between the GL and the EPL. In the superficial region of the EPL of the tree shrew MOBs, there were a small number of tiny glomerulus-like spheroidal structures where OMP-IR axons protruding from glomeruli were intermingled with dendritic branches of surrounding calbindin D28k-IR cells. Furthermore, we recognized the compartmental organization of glomeruli and two types of periglomerular cells in the MOBs of all of the mammals we examined. These structural features are therefore considered to be common and important organizational principles of the MOBs.

Animals↗
PubMed1997

Cardiac-like musculature of the intrapulmonary venous wall of the long-clawed shrew (Sorex unguiculatus), common tree shrew (Tupaia glis) and common marmoset (Callithrix jacchus).

BACKGROUND: The cardiac-like musculature is distributed not only in the heart wall but also in the intrapulmonary venous wall in a few species of insectivores. It has been suggested that the evolutionary origin of venous cardiac-like musculature may be traceable to a basic stock of certain mammalian lines of descent. So, it is important to clarify whether the musculature may be a common structure in lower mammals from insectivores to primates and to examine the functional significance of the structure. METHODS: The distribution of cardiac-like musculature in the intrapulmonary venous wall of the long-clawed shrew (Sorex unguiculatus), common tree shrew (Tupaia glis), and common marmoset (Callithrix jacchus) was observed by light and electron microscopy. The presence of atrial natriuretic polypeptide (ANP) was examined in the musculature by immunohistochemistry. RESULTS: All three species contained cardiac-like myocytes in the tunica media of intrapulmonary venous wall. In the common tree shrew and the common marmoset, cardiac-like musculature was found in the small intrapulmonary vein of 150-200 microns in diameter, while, in the long-clawed shrew, it was distributed even in the intrapulmonary vein of 30 microns in diameter. Ultrastructure of myocytes was fundamentally similar to that of atrial myocytes in the long-clawed shrew and the common tree shrew. The presence of atrial natriuretic polypeptide (ANP) was also demonstrated by immunohistochemistry in the intrapulmonary venous walls of common tree shrews. CONCLUSIONS: The results indicate that the pulmonary venous cardiac-like musculature occurs in the lower eutherian mammals from insectivores to primitive primates. The musculature is thought to act as a regulatory pump in pulmonary circulation and as an endocrine apparatus of ANP.

Animals↗
PubMed1995

Gene mapping in the common shrew (Sorex araneus; Insectivora) by shrew-rodent cell hybrids: chromosome localization of the loci for HPRT, TK, LDHA, MDH1, G6PD, PGD, and ADA.

We selected the common shrew (Sorex araneus) to generate the first insectivore gene map. Shrew-Chinese hamster and shrew- mouse somatic cell hybrid cells were constructed. When the 119 shrew-rodent clones were characterized, only shrew chromosomes were found to have segregated. A panel of hybrid clones was selected for gene assignment. The genes for hypoxanthine phosphoribosyl transferase (HPRT), glucose-6- phosphate dehydrogenase (G6PD), and malate dehydrogenase 1 (MDH1) were assigned to shrew Chromosome (Chr) de [which is the product of a tandem fusion between the 'original' mammalian X Chromosome (Chr) and an autosome], the gene for adenosine deaminase (ADA) and 6-phosphogluconate dehydrogenase se (PGD) to Chromosome jl, the gene for thymidine kinase (TK) to Chromosome hn, and the gene for lactate dehydrogenase (LDHA) to chromosome ik. Further studies in progress.

Adenosine Deaminase↗
PubMed1997

Cryptococcosis in tree shrews (Tupaia tana and Tupaia minor) and elephant shrews (Macroscelides proboscides).

Fungal infections due to Cryptococcus neoformans occurred in seven short-eared elephant shrews (Macroscelides proboscides), six large tree shrews (Tupaia tana), and five lesser tree shrews (Tupaia minor) at the National Zoological Park during a 30-mo period in 1991-1993. Clinical signs were absent or included weight loss, shivering, dyspnea, and/or neurologic disease. Definitive antemortem diagnostic techniques included tracheal lavage and serum cryptococcal antigen latex agglutination titers. Thirteen cases were diagnosed solely by postmortem examination. The source of infection for these animals was uncertain, but C. neoformans is commonly found in soil and other organic material. Two lesser tree shrews and one large tree shrew received antifungal therapy and converted to a negative serum cryptococcal antigen titer.

Animals↗
PubMed2000

Immunohistochemical localization of inhibin and steroidogenic enzymes in the ovary of common tree shrew (Tupaia glis) and northern smooth-tailed tree shrew (Dendrogale murina).

To study the ovarian function of the Order Scandentia, the localization of inhibin and steroidogenic enzymes (3 beta-hydroxysteroid dehydrogenase/isomerase and aromatase) in the ovaries of common tree shrew (Tupaia glis) and northern smooth-tailed tree shrew (Dendrogale murina) was immunohistochemically analysed. As in the results reported for other mammals, inhibin alpha-chain was localized in the follicular epithelium of secondary or Graafian follicles in the two species. The localization of aromatase in the ovary of these two species, however, was different. In the common tree shrew, the aromatase was localized in the thecal cells, whilst in other mammals it is localized in the granulosa cells. These results indicate that in the ovary of the common tree shrew, the oestradiol may be synthesized in the thecal cells.

3-Hydroxysteroid Dehydrogenases↗
PubMed1999

Contraction parameters, myosin composition and metabolic enzymes of the skeletal muscles of the etruscan shrew Suncus etruscus and of the common European white-toothed shrew Crocidura russula (Insectivora: soricidae).

In the Etruscan shrew, the isometric twitch contraction times of extensor digitorum longus (EDL) and soleus muscles are shorter than in any other mammal, allowing these muscles to contract at outstandingly high contraction frequencies. This species has the highest mass-specific metabolic rate of all mammals and requires fast skeletal muscles not only for locomotion but also for effective heat production and for an extremely high ventilation rate. No differences could be detected in the fibre type pattern, the myosin heavy and light chain composition, or in the activity of the metabolic enzymes lactate dehydrogenase and citrate synthase of the two limb muscles, the EDL and the soleus, which in larger mammalian species exhibit distinct differences in contractile proteins and metabolic enzymes. All properties determined in EDL and soleus muscles of Suncus etruscus, as well as in the larger Crocidura russula, are typical for fast-oxidative fibres, and the same holds for several other skeletal muscles including the diaphragm muscle of S. etruscus. Nevertheless, the EDL and soleus muscles showed different mechanical properties in the two shrew species. Relaxation times and, in C. russula, time to peak force are shorter in the EDL than in the soleus muscle. This is in accordance with the time course of the Ca(2+) transients in these muscles. Such a result could be due to different parvalbumin concentrations, to a different volume fraction of the sarcoplasmic reticulum in the two muscles or to different Ca(2+)-ATPase activities. Alternatively, the lower content of cytosolic creatine kinase (CK) in the soleus compared with the EDL muscle could indicate that the observed difference in contraction times between these shrew muscles is due to the CK-controlled activity of their sarcoplasmic reticulum Ca(2+)-ATPase.

Animals↗
PubMed1995

Fatty acids in the triglycerides and phospholipids of the common shrew (Sorex araneus) and the water shrew (Neomys fodiens).

Fatty acid composition of the liver, brown fat, thigh muscle and heart of Sorex araneus and Neomys fodiens was determined by GLC and GLC-MS. In both species of shrew the total amounts of omega 3-PUFAs in the phospholipids were greater than those in the triglycerides. Sorex araneus, which feeds solely on a terrestrial diet, had a larger total amount of omega 6-PUFAs in the triglycerides of the brown fat. The phospholipids of the thigh muscle and heart of Neomys fodiens, however, contained more omega 6-PUFAs than did those of Sorex araneus. These results suggest that the fatty acid composition of the membrane phospholipids of shrews is largely genetically regulated and is affected by diet less than the composition of triglycerides. The main C16-monounsaturated fatty acid of most of the specimens studied was 16:1 omega 5, which is unusual among mammals.

Animals↗
PubMed1998

A new spontaneous animal model of NIDDM without obesity in the musk shrew.

The EDS (early-onset diabetes in suncus) colony has been developed as a new closed breeding colony of the musk shrew (Suncus murinus, Insectivora) exhibiting a high incidence of spontaneous diabetes mellitus. We investigated the characteristic features of diabetic shrews in this colony. All diabetic shrews are characterized by glycosuria (Tes-tape value > or = 3+), hyperglycemia (23.3 +/- 0.8 mmol/l) and polyuria, and they were affected by the age of 3 months. Cumulative incidence (64.1% in males and 27.8% in females) was kept intact after the age of 3 months. The growth pattern of diabetic shrews was similar to that of non-diabetic shrews, and obesity was not consistent in diabetic shrews. The intraperioneal glucose tolerance test revealed both impaired glucose tolerance and impaired insulin secretion in diabetic shrews. Insulin sensitivity of diabetic shrews decreased in the intraperioneal insulin tolerance test. Neither severe hypertrophy nor lymphocytic infiltration was observed in pancreatic islets of diabetic shrews. These facts suggested that diabetic shrews in the EDS colony should be classified as early-onset non-insulin dependent diabetes mellitus (NIDDM) without obesity. Early-onset of severe hyperglycemia with impaired glucose tolerance is a distinctive character compared with other non-obese NIDDM models in rodents. We concluded that the diabetic shrews in the EDS colony are a new animal model of human NIDDM without obesity.

Age of Onset↗
PubMed2003

Novel membrane protein shrew-1 targets to cadherin-mediated junctions in polarized epithelial cells.

While searching for potential candidate molecules relevant for the pathogenesis of endometriosis, we discovered a 2910-base pair cDNA encoding a novel putative 411-amino acid integral membrane protein that we called shrew-1. The putative open-reading frame was confirmed with antibodies against shrew-1 peptides that labeled a protein of approximately 48 kDa in extracts of shrew-1 mRNA-positive tissue and also detected ectopically expressed shrew-1. Expression of epitope-tagged shrew-1 in epithelial cells and analysis by surface biotinylation and immunoblots demonstrated that shrew-1 is indeed a transmembrane protein. Shrew-1 is able to target to E-cadherin-mediated adherens junctions and interact with the E-cadherin-catenin complex in polarized MCF7 and Madin-Darby canine kidney cells, but not with the N-cadherin-catenin complex in nonpolarized epithelial cells. Direct interaction of shrew-1 with beta-catenin in in vitro pull-down assay suggests that beta-catenin might be one of the proteins that targets and/or retains shrew-1 in the adherens junctions. Interestingly, shrew-1 was partially translocated in response to scatter factor (ligand of receptor tyrosine kinase c-met) from the plasma membrane to the cytoplasm where it still colocalized with endogenous E-cadherin. In summary, we introduce shrew-1 as a novel component of adherens junctions, interacting with E-cadherin-beta-catenin complexes in polarized epithelial cells.

Adherens Junctions↗
PubMed2001

[Analysis of cDNA and protein structure of tree shrew cholesterol ester transfer protein].

OBJECTIVE: To obtain the nucleotide sequence and deduced amino acid sequence of cholesteryl ester transfer protein (CETP) cDNA of tree shrew, mammalian insusceptible to atherosclerosis. METHODS: The first strand of cDNA of tree shrew was obtained from its liver. The sequence of tree shrew CETP cDNA was obtained by using techniques of switching mechanism at 5' end of RNA transcript (SMART) and rapid amplification of cDNA end (RACE), The CETP amino acid sequence was deduced from this cDNA and its primary and secondary structures were predicted by using DNAMAN, a software of molecular biology. Results The tree shrew CETP cDNA sequence covers 1636 bp, including a 178 bp fragment at the 3' of untranslated region and a 1458 bp fragment in the coding region, coding the complete sequence of mature tree shrew CETP except the initiator methionine. There are 477 amino acids in its mature protein, one amino acid more than that in human beings, with an extra Gly318. The homology of tree shrew CETP and human CETP and rabbit CETP is 88% and 82% respectively judged by comparing the amino acid sequence of tree shrew CETP and those of human beings and rabbit. The regions concerning the CETP function of binding and transferring neutral lipids in tree shrew CETP amino acid sequence are highly conservative. However, there is a deletion of N-linked glycosylation site at Asn342 in tree shrew protein that may increase the ability of removing peripheral cholesterol and cholesteryl ester. CONCLUSION: The glycosylation in tree shrew CETP may be one of the mechanisms of insusceptibility to atherosis of tree shrew.

Amino Acid Sequence↗
PubMed2004

Delta-9-tetrahydrocannabinol differentially suppresses emesis versus enhanced locomotor activity produced by chemically diverse dopamine D2/D3 receptor agonists in the least shrew (Cryptotis parva).

The principal psychoactive component of marijuana, delta-9-tetrahydrocannabinol (Delta9-THC), suppresses nausea and vomiting in cancer patients caused by chemotherapeutics such as cisplatin. Cisplatin induces vomiting via a number of emetic stimuli, including dopamine. Currently, there is controversy as to whether Delta9-THC can prevent emesis produced by dopaminergic agonists such as apomorphine. The present investigation utilizes the least shrew to evaluate the antiemetic potential and the cannabinoid receptor by which Delta9-THC may prevent emesis produced by four dopamine receptor agonists with differing selectivity for D2 and D3 receptors, i.e., a nonselective dopamine receptor agonist (apomorphine), a D2-preferring receptor agonist (quinpirole), and two D3-preferring receptor agonists (quinelorane and 7-OH DPAT). In addition, relative to its antiemetic doses, the motor suppressive doses of Delta9-THC in dopamine D2/D3-receptor-agonist-treated shrews were also evaluated. Thus, different groups of shrews were injected with either vehicle (V) or varying doses of Delta9-THC [0.5, 1, 2.5, 5, or 10 mg/kg, intraperitoneal (i.p.)] 10 min prior to administration of a 2 mg/kg dose of one of the four cited D2/D3 agonists. Immediately after the last injection, the frequency of vomiting for each shrew was recorded for the next 30 min. To investigate which cannabinoid receptor is involved in the antiemetic action of Delta9-THC, various doses of the CB1 receptor antagonist SR 141716A [0, 5, 10, and 20 mg/kg, subcutaneous (s.c.)] were administered to shrews 10 min prior to an injection of a fully effective antiemetic dose of Delta9-THC (5 mg/kg, i.p.). Ten minutes later, each treated shrew was administered with a 2 mg/kg dose of apomorphine. The emesis frequency was recorded for the next 30 min. For locomotor studies, different groups of shrews received either vehicle or various doses of Delta9-THC (0, 5, 10, 20, or 30 mg/kg) 10 min prior to an injection of vehicle or a 2 mg/kg dose of one of the four D2/D3 receptor agonists. The triad of motor behaviors (spontaneous locomotor activity, total duration of movement, and rearing frequency) were recorded for the next 30 min by a computerized video tracking system. Delta9-THC dose-dependently attenuated the frequency of emesis as well as fully protecting shrews from vomiting produced by each one of the four cited dopamine D2/D3 receptor agonists with ID50s ranging from 1 to 4 mg/kg. SR 141716A reversed the antiemetic activity of Delta9-THC against apomorphine-induced emesis. Delta9-THC also differentially suppressed the triad of motor activities in dopamine D2/D3-receptor-agonist-treated shrews with ID50s ranging from 7 to 21 mg/kg. The results suggest that Delta9-THC prevents emesis via cannabinoid CB1 receptors in a potent and dose-dependent manner in D2/D3-receptor-agonist-treated shrews at doses well below those which cause significant motor depression.

Animals↗
PubMed1998

Toxin-induced IDDM (insulin dependent diabetes mellitus) in the musk shrew.

We administered streptozotocin (STZ) and alloxan (AL) to the musk shrew (Suncus murinus, Insectivora) to determine the effective diabetogenic dose of the two toxins for this species. A single intraperitoneal (i.p.) injection of 75 mg/kgBW or the consecutive 5-day s injection of 25 mg/kgBW of STZ to non-fasted shrews, effectively (100%) induced hyperglycemia (> or = 300 mg/dl) with hypoinsulinaemia (< 30% of control level) in male shrews at 10 days after administration. Morphological studies showed cytological changes of B cells in the pancreatic islets of diabetic shrews. Hyperglycemic shrews induced by STZ were thus in IDDM (insulin dependent diabetes mellitus), and showed high susceptibility to the diabetogenic effect of STZ as compared with rodents. Shrews showed a sex difference in the diabetogenic susceptibility to STZ as do mice (male > female). They also showed a species specific resistance to the diabetogenic effect of AL. Of the eight shrews (with 8-hr fasting) that has been treated with a single injection of 200 mg/kgBW of AL, seven (88%) survived at least 10 days, showing no signs of hyperglycemia. All shrews died within 3 day s after injection of 250 or 300 mg/kgBW. These results indicated that the STZ-induced diabetic shrew is a unique animal model and may be useful for IDDM research. On the other hand, the musk shrew was highly resistant to the diabetogenic effects of AL.

Alloxan↗
PubMed1999

An odontometrical difference in the mandibular molars of two laboratory strains of the musk shrew, Suncus murinus, derived from Bangladesh and Tokunoshima Island of Japan.

We investigated an odontometrical difference in the mandibular molars (M1, M2, and M3) of two laboratory strains of the musk shrew (Suncus murinus) originating in Bangladesh (BAN strain) and Tokunoshima Island of Japan (TKU strain). We used skulls from two strains of shrews that were maintained under identical laboratory conditions. Mesiodistal and buccolingual crown diameters in the trigonid and talonid of the mandibular molars were measured with a measuring microscope, calibrated to 0.001 mm. The crown proportion was expressed by the crown indices calculated from the measurements. Size reduction was analyzed quantitatively according to the reduction index. All crown dimensions were significantly larger in BAN shrews than in TKU shrews (P < 0.01). Sexual differences were noted in the talonid dimensions, while interstrain differences were clearly evident in the trigonid dimensions. The crown indices in M1 showed the least interstrain difference of the three molars. The crown indices showed that TKU shrews had relatively larger buccolingual diameters and talonid diameters than BAN shrews, and the reduction indices showed that TKU shrews had relatively larger M2 and M3 than BAN shrews. To extract the variance components of tooth shape, a principal component analysis was performed after the variables were standardized. After Varimax rotation, each factor was interpreted. The first three factors accounted for 79.9% of all variances. The first component represented the mesiodistal crown proportion of the trigonid-to-talonid crown component. The second and third components represented the relative size of buccolingual diameters in the distal molars for M1. The principal component scores showed that TKU shrews had relatively larger talonids and distal molars than BAN shrews.

Animals↗
PubMedDate not supplied

[Structure and seasonal dynamics of an ectoparasite community on the common shrew (Sorex araneus) in the Il'men'-Volkhov lowland].

Species composition, seasonal dynamics, and a load of ectoparasites per individual and population of the common shrew Sorex araneus have been examined in coniferous and mixed forests of the Ilmen'-Volkhov lowland (a neighbourhood of Oskuy village, Chudovo district, Novgorod Province) during the period 1999-2003. Trapping of mammals was carried monthly, with exception of few accidental gaps. The Gero traps were used for catching micromammalian hosts. The lines of trap were checked 2 times a day, places of lines changed each 3-5 day. Total number of micromammalians collected during the period of study is 3215, including 1115 specimens of the common shrew S. araneus and 246 ones of the pigmy shrew S. minutus. Parasite fauna on the common shrew included 23 ectoparasite species: fleas--12, ixodid ticks--2, gamasid mites--7, and myobiid mites--2 species. Among recorded species, 9 fleas species and some gamasid species are accidental parasites. These accidental ectoparasite species are common to the bank vole Clethrionomys glareolus in the territory investigated. Species composition, occurrence and abundance indices of parasites changed during the year. In total, about 55% shrew specimens are infected with ectoparasites. The infracommunity of ectoparasites on the common shrew usually consists of 6 species or less. Mean number of all ectoparasite individuals per one host specimens varies from 4 to 83. The greatest number of parasites (50 and 83) was recorded on the shrews, which carried 5 and 4 parasites species, respectively. Biodiversity of parasite species in the ectoparasite community on the common shrew and the load of parasites per one host specimen are lower than those in the bank vole. In forest biotopes explored, the most part of temporary ectoparasite species found on the common shrew was also recorded on other small mammals, which could have contacts with this host. It is possible to conclude that among the parasite supracommunity in the explored ecosystem, the temporary ectoparasites represent a "fond" of temporary parasites, which are common for most small mammal species. A role of different shrew and rodent species as main of additional hosts changes depending on a population density of potential mammalian hosts and other environment factors.

Animals↗