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L Martinez

Publications and source records attributed to L Martinez.

At least 19 recordsLinked to original sources
PubMed1992

Protein glycation: effects upon protein recognition by the proximal tubule.

Reabsorption of 125I labeled unmodified and glycated albumin by the proximal tubule was studied using micropuncture technique in wistar rats of different ages. The data show a significant reabsorption of unmodified albumin while the glycated albumin was virtually excluded from reabsorption process. Among different explanations considered, we think molecular charge of the protein seems to be a key factor for the altered recognition of glycated albumin by the proximal tubule.

Animals↗
PubMed1992

Assignment of tyrosine-specific T-cell phosphatase to conserved syntenic groups on human chromosome 18 and mouse chromosome 18.

Phosphorylation of proteins on tyrosine is crucially involved in signal transduction and mitogenesis and is regulated by both kinases and phosphatases. Recently, a number of soluble and transmembrane receptor-linked protein tyrosine phosphatases (PTPase) have been characterized. Among these is a 48.4-kDa PTPase encoded by a cDNA isolated from a T-lymphocyte library by low-stringency screening with probes derived from placental PTPase 1B. A human T-cell PTPase (PTPT) cDNA and somatic cell hybrids were used to assign a PTPT gene to conserved syntentic groups on human chromosome 18 and on mouse chromosome 18. Two unlinked sequences, one on human chromosome 1, were also detected.

Animals↗
PubMed1992

MR imaging of clival and paraclival lesions.

A wide spectrum of diseases involve the clivus and paraclival structures. Primary neoplasms, metastatic tumors, and inflammatory, vascular, and hematopoietic disorders are the most common abnormalities to arise from or directly involve the clivus. MR imaging exquisitely shows and helps characterize the diseases that affect this area. Sagittal and coronal MR imaging allows precise localization and evaluation of the signal characteristics of a mass, enabling a more specific diagnosis. The multiplanar capabilities of MR imaging provide superb visualization of the adjacent cranial nerves and vascular structures, aiding in surgical planning and radiation therapy. In this pictorial essay, the MR imaging, CT, and conventional radiographic findings of various clival and paraclival lesions are illustrated.

Adult↗
PubMed1992

Profile of action of a novel 5-hydroxytryptamine1A receptor ligand E-4424 to inhibit aversive behavior in the mouse, rat and marmoset.

E-4424 (2-(4-[4-(4-chloro-1-pyrazolyl)butyl]-1-piperazinyl)pyrimidine) was shown to be a 5-hydroxytryptamine1A receptor ligand in radioligand binding assays and in an in vitro guinea pig ileum preparation had both 5-hydroxytryptamine1A antagonist and agonist effects. The antagonist/agonist ratio of E-4424 was greater than in the case of buspirone and ipsapirone. E-4424 was compared to diazepam, buspirone and ipsapirone to inhibit the behavioral response to an aversive situation in the mouse black and white test box, the rat social interaction test and a marmoset human threat test. The acute administration of E-4424 (0.0001-0.5 mg/kg, i.p.) to the mouse decreased aversion to the white area of the test box and was as effective as diazepam (0.125-1.0 mg/kg, i.p.) and much more potent than buspirone (0.25-1.0 mg/kg, i.p.) or ipsapirone (0.5-5.0 mg/kg, i.p.). E-4424 was also effective in enhancing rat social interaction and reducing anxiety-related behaviors in the marmoset and was again more potent than diazepam, buspirone or ipsapirone. Withdrawal from a 14-day administration of diazepam, cocaine, nicotine or alcohol exacerbated the response to the aversive situation in the mouse test. This was not observed after withdrawal from a chronic treatment with E-4424, buspirone or ipsapirone. However, E-4424 administered during drug withdrawal prevented the response caused by withdrawal from cocaine, alcohol, nicotine and diazepam: buspirone was ineffective and ipsapirone only attenuated that syndrome after alcohol withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Mouse platelet-derived growth factor receptor alpha gene is deleted in W19H and patch mutations on chromosome 5.

The mouse W19H mutation is an x-ray-induced deletion of more than 2 centimorgans on chromosome 5 encompassing the white spotting mutation W (encoded by the Kit protooncogene), patch (Ph), and recessive lethal (l) loci. The platelet-derived growth factor receptor alpha gene (PDGFRA) like Kit encodes a transmembrane receptor tyrosine kinase. By using mouse-Chinese hamster somatic cell hybrids and haplotype analysis in interspecific backcross mice, mouse Pdgfra was mapped to chromosome 5 in tight linkage with Kit. Hybridization of a PDGFRA probe to DNAs from W19H/ + heterozygous mice and patch heterozygous mice, and their wild-type littermates, demonstrated deletion of Pdgfra. Pulsed-field gel electrophoresis indicated that Kit and Pdgfra are linked on a 630-kilobase Mlu I DNA fragment. Thus the W19H deletion removes at least two receptor tyrosine kinases and the results suggest Pdgfra as a candidate for the Ph locus.

Animals↗
PubMed1991

Müllerian defects in women with normal reproductive outcome.

The incidence of uterine congenital anomalies because of müllerian defects in the normal fertile population is 3.2% (22/679). Twenty (90%) of them are septate uteri, whereas a bicornuate (5%) and a didelphys uterus (5%) have been also found in this population. Based on these findings, we question the usefulness of the septum resection in patients with septate uterus and no previous reproductive failure.

Adult↗
PubMed1991

A pharmacokinetic study of E-4441, a new quinolone, in the rat, mouse and cynomolgus monkey.

The purpose of this present work has been to study the pharmacokinetical profile of E-4441 in the rat, mouse and cynomolgus monkey. Analytical determination of the levels in plasma, urine and organs was affected by two different techniques: a microbiological agar diffusion assay with Bacillus subtilis, and HPLC with preliminary extraction in chloroform (pH 8.5). The kinetic behaviour of the unchanged substance was similar in the three animal species studied. Absorption and excretion took place rapidly (T1/2a = 2-20 min, T1/2el = 25-225 min). In mouse there is a linear relationship between administered dose and the area under the curve (AUC) of plasma levels. The absolute bioavailability of unchanged E-4441 is of 20% and the urinary excretion represents 1 to 2% of the administered oral dose. The organs in which the highest concentrations of substance were found were bile, liver and kidney, while the substance could not be detected in brain, testis, ovary or adipose tissue.

Animals↗
PubMed1990

Gene for parathyroid hormone-like peptide is on mouse chromosome 6.

The single-copy parathyroid hormone-like peptide gene (Pthlh) was assigned to mouse chromosome 6 using a rat PTHLH cDNA as hybridization probe in the Southern blot analysis of DNAs isolated from a panel of mouse x Chinese hamster cell hybrids. The mouse parathyroid hormone gene (Pth) has previously been assigned to mouse chromosome 7 and the PTHLH and PTH genes have also been shown to be on different chromosomes in human and rat. Therefore, despite significant amino-terminal sequence homology between the PTHLH and PTH peptides, as well as similarities in the structural organization of the human PTHLH and PTH genes, the genes encoding these peptides have discrete chromosomal locations in the mouse, rat, and man.

Animals↗
PubMed1990

Localization of mouse melanoma growth stimulatory activity gene (Mgsa) between Afp and Gus on chromosome 5 using interspecific backcross mice.

Melanoma growth stimulatory activity (Mgsa) is a polypeptide mitogen and a possible autocrine growth factor for melanoma and other tumor cells. A restriction fragment length variant of Mgsa was followed in interspecific backcross mic Mgsa was localized between Afp and Gus on mouse chromoson 5, distal to known loci affecting skin pigmentation.

Animals↗
PubMed1989

Mouse melanoma growth stimulatory activity gene (Mgsa) is polymorphic and syntenic with the W, patch, rumpwhite, and recessive spotting loci on chromosome 5.

Melanoma growth stimulatory activity (Mgsa) is a polypeptide growth factor originally detected in culture medium of the human malignant melanoma cell line Hs294T and may have an autocrine role in neoplastic growth. Mgsa is a member of the small inducible gene (SIG) family and shares homology with beta-thromboglobulin and platelet factor 4. Mgsa was localized to chromosome 5 using a cDNA probe for mouse Mgsa and somatic cell hybrids and is thus syntenic with Kit (W), Ph, Rw, and rs loci. The results eliminate Mgsa as the product of the Steel locus on chromosome 10, but raise the possibility that Mgsa might be synonymous with a chromosome 5 locus affecting skin pigmentation.

Animals↗
PubMed1989

Monthly injectable steroid contraceptives and cervical carcinoma.

The World Health Organization Collaborative Study of Neoplasia and Steroid Contraceptives is a large multinational hospital-based case-control study of steroid contraceptives and gynecologic, hepatobiliary, and mammary neoplasms. Monthly injectable steroid contraceptives which contained the long-acting progestogen dihydroxyprogesterone acetofenide plus a shorter-acting estrogen (usually estradiol enanthate) were used by women in two of the countries (Chile and Mexico) from which data were collected. In preliminary analyses of data from Chile (1979-1983), a strong association was observed between use of these products and invasive cervical cancer. Therefore, three additional data sets from these two countries were analyzed in further detail for this report. Analyses of additional data from Chile on invasive cervical cancer (1983-1985) and cervical carcinoma in situ (1979-1986) and of data on invasive cervical cancer from Mexico (1979-1986) failed to confirm the initially observed association. The original finding was probably due to chance, but a causal interpretation cannot be confidently ruled out, and additional studies are warranted.

Algestone Acetophenide↗
PubMed1989

Sigje, a member of the small inducible gene family that includes platelet factor 4 and melanoma growth stimulatory activity, is on mouse chromosome 11.

Stiles and coworkers originally identified a gene they termed JE that is transcriptionally activated in mouse fibroblasts early after treatment with platelet derived growth factor or serum. This gene, now named Sigje, can encode a 148-amino acid secreted, basic polypeptide that belongs to the small inducible gene (SIG) family whose members include, for example, platelet factor 4, melanoma growth stimulatory activity (Mgsa), and interferon inducible protein 10. SIG family members share a conserved array of cysteine and proline residues and a similar predicted secondary structure, and may have evolved from a common ancestral gene. Several members of the SIG family have been assigned to the proximal long arm of human chromosome 4, to a region that has genetic homoeology with a portion of mouse Chromosome 5. We report here that mouse Sigje, in contrast to Mgsa, is on Chromosome 11. Sigje restriction fragment length polymorphisms in Mus spretus DNA were identified with the enzymes TaqI, MspI, BclI, and XbaI, and will be useful in mapping by meiotic recombination.

Animals↗