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Biomedical subjects

D Ray

Publications and source records attributed to D Ray.

At least 19 recordsLinked to original sources

Characterization of Spi-B, a transcription factor related to the putative oncoprotein Spi-1/PU.1.

We have cloned a human cDNA from a new gene, spi-B, on the basis of its homology with the DNA-binding domain of the Spi-1/PU.1 putative oncogene product. spi-B codes for a protein of 262 amino acids presenting 43% overall identity with Spi-1. Its highly basic carboxy-terminal region exhibits 34% sequence identity with the DNA-binding domain of the Ets-1 protein. We showed that the Spi-B protein is able to bind the purine-rich sequence (PU box) recognized by Spi-1/PU.1 and to activate transcription of a reporter plasmid containing PU boxes. Chromosome in situ hybridization allowed us to map spi-B to the 19q13.3-19q13.4 region of the human genome. spi-B, like spi-1, was found to be expressed in various murine and human hematopoietic cell lines except T lymphoid cell lines.

Amino Acid Sequence

Spontaneous clostridial myonecrosis.

Spontaneous, nontraumatic clostridial myonecrosis is a rare infection with an insidious onset and usually fatal outcome. Spontaneous clostridial myonecrosis has a frequent association with colon carcinoma, leukemia, diabetes mellitus, and drug-induced immunosuppression. We present the case of a 73-year-old diabetic man who died of spontaneous Clostridium septicum myonecrosis, who had presented with fulminant gangrene of the right thigh. Clostridium septicum was cultured from the quadriceps muscle postmortem. At autopsy, in addition to the gangrene, there was a Duke's A adenocarcinoma of the cecum, which had not been diagnosed during life. When spontaneous nontraumatic clostridial myonecrosis is diagnosed at autopsy, investigation should include through exam and the obtaining of past medical history in order to elucidate predisposing factors.

Adenocarcinoma

Downstream sequences mediate induction of the mouse cathepsin L promoter by phorbol esters.

The major excreted protein (MEP) of mouse fibroblasts is the precursor to a lysosomal acid protease (cathepsin L) whose synthesis is induced by malignant transformation, growth factors, tumor promoters, and cyclic AMP. We have previously cloned a functional gene for MEP from NIH 3T3 cells. When subcloned into chloramphenicol acetyl transferase (CAT) expression vectors, both 4-kilobase and 300 base pair fragments in the 5'-flanking region of the MEP gene confer CAT activity that is stimulated by cyclic AMP treatment but is not stimulated by phorbol ester treatment of NIH 3T3 cells. These fragments confer constitutive promoter activity that is comparable to that of the SV40 promoter. Primer extension, using RNA from cells transiently transfected with MEP-CAT fusion plasmids, demonstrates that phorbol ester treatment increases the amount of transcript from constructs containing both the promoter and sequences downstream of the transcription initiation site, including the first three introns, but not from constructs containing only the 5'-flanking region of the MEP gene. Nuclear run-off experiments confirm that the increase in endogenous MEP mRNA is mediated by increased transcription and not via relief of transcriptional attenuation. Since both the MEP promoter, which contains three potential binding sites for the AP-2 transcription factor, and the SV40 promoter, which contains both AP-1 and AP-2 binding sites, fail to respond to 12-O-tetradecanoylphorbol-13-acetate in NIH 3T3 cells, these upstream motifs are not sufficient to confer phorbol ester responsiveness in NIH 3T3 cells. These results suggest that the MEP gene is regulated in a complex manner by sequences both upstream and downstream of the transcription initiation site.

Animals

Localization of the human oncogene SPI1 on chromosome 11, region p11.22.

Spi1 is an oncogene specifically activated in acute murine erythroleukemias induced by the Friend spleen focus forming virus (SFFV). Three probes were used for the chromosomal assignment of the human SPI1 oncogene: cDb1 and RaB2 correspond respectively to murine Spi1 and human SPI1 cDNA probes; C45a6B probe is a murine genomic DNA sequence located in the Spi1 5' region and is known as a major SFFV integration site in murine erythroleukemia cells. Somatic hybrid cells enabled cDb1 and RaB2 to be assigned to chromosome 11. The murine C45a6B probe, which is not included in the Spi1 gene, detected a homologous sequence on human chromosome 11. RaB2 was assigned to 11p11.22 by in situ hybridization. Three human genes known between 11p11 and 11p13 (FSHB, CAT, ACP2) were on murine chromosome 2. Therefore, the localization of human SPI1 on 11p11.22 was consistent with the assignment of the Spi1 oncogene to murine chromosome 2.

Animals

Bioaccumulation of nickel and vanadium in tissues of the catfish Clarias batrachus.

Bioaccumulation of nickel and vanadium in the tissues of the liver, kidney, gill, and intestine has been studied following 4 days and 30 days of exposure at sublethal concentrations of nickel and vanadium compounds in the catfish Clarias batrachus. Nickel and vanadium have been found to accumulate in all four tissues observed. High concentrations of nickel and vanadium have been found in the order kidney greater than gill greater than liver greater than intestine during the 4 days and 30 days treatment. A dose-response effect was seen, as the concentration of metals in the tissues increased with concentration and exposure time. The effect on bioaccumulation in the specific tissue provides a better basis for monitoring exposures than whole-body analysis.

Animals

The human homologue of the putative proto-oncogene Spi-1: characterization and expression in tumors.

Spi-1 is a putative proto-oncogene involved in murine virus-induced acute erythroleukemias. We report here the identification of the human homologue of Spi-1 and its expression in normal and tumorigenic human tissues. Characterization of cDNA clones revealed that the human Spi-1 gene encodes a 216 amino acids protein showing 85% identity with the murine counterpart. By sequencing genomic clones, five exons were identified. To investigate the possible role of Spi-1 gene in human cancers, we studied its expression in a panel of human tumors by Northern blot analysis. Spi-1 expression was detected in all the tumors examined. There was no noticeable evidence of messenger RNA alteration as compared to normal tissues.

Adenocarcinoma

Spi-1 oncogene activation in Rauscher and Friend murine virus-induced acute erythroleukemias.

The Friend viruses, like the Rauscher virus, cause murine acute erythroleukemias which evolve in a similar multistep process. In previous studies it has been described that the late malignant proerythroblastic transformation induced by the polycythemia-inducing strain of Friend spleen focus-forming virus (SFFVP) is correlated with Spi-1 oncogene activation by insertional mutagenesis. In this paper we report that Spi-1 genomic rearrangements were also observed in 90% of tumors induced by the anemia-inducing strain of Friend spleen focus-forming virus (SFFVA) and in all Rauscher-induced tumors analyzed. SFFVA and Rauscher proviral insertions occurred in the viral integration cluster previously characterized in SFFVP-induced tumors. The Spi-1 1.4-Kb messenger RNA was found highly expressed in all SFFVA and Rauscher-induced malignant cells as compared to normal tissues. The nucleotide sequence of Spi-1 cDNA isolated from a library constructed from SFFVA-induced tumor cells revealed no difference between the Spi-1 gene transcripts expressed in both SFFVP and SFFVA-induced leukemic cells. These results indicate that Spi-1 gene activation is a general feature in the malignant proerythroblastic transformation which occurs in mice infected with Friend and Rauscher viruses.

Acute Disease

Early fresh frozen plasma prophylaxis of abnormal coagulation parameters in the severely head-injured patient is not effective.

Serious head injury may be complicated by coagulation abnormalities. Fresh frozen plasma (FFP) has been advocated as resuscitation fluid, in patients with head injury, to prevent the development of abnormal coagulation. The efficacy of this practice has never been established. We retrospectively reviewed the records of 149 head-injured patients having a Glasgow Coma Scale of 9 or less. One hundred six received FFP and were without evidence of coagulopathies, while 42 received no FFP or had coagulopathies. Group 1 received FFP within a time from injury (T1) and group 2 received FFP after time (T2) or not at all. Groups were similar in demographics, injuries, presenting Glasgow Coma Scale, and presenting hematologic parameters in serial pretreatment or posttreatment hematologic parameters (P less than .05). There were no differences between patients receiving "early" FFP, as compared with those receiving FFP later or not at all. The time of FFP administration did not appear to be critical for effective prophylaxis against coagulopathy.

Blood Coagulation Disorders

Blood volume restitution after hemorrhage in the newborn lamb.

Blood volume restitution after hemorrhage was investigated in lambs in the first week of life. Two groups of nonsplenectomized lambs were bled 10 and 20% of their blood volume at 2%/min while being suspended horizontally in a sling with their legs dependent, and a third group was bled 20% while lying down. Blood pressure fell 8% in the lambs bled both 10 and 20% while lying down and 44% in those bled 20% while being suspended. Blood volume was completely restored in all three groups by 5 h after the hemorrhage, the rate of restitution being equal among the groups. The initial phase of restitution was slower when the lambs were bled while lying down. Vasopressin levels were increased only in the lambs bled 20% of their blood volume while being suspended. Plasma renin activity increased similarly in all groups. Hemorrhage increased plasma glucose but did not change plasma protein and serum osmolality. We conclude that lambs bled up to 20% of blood volume restitute relatively quickly at a rate independent of the volume shed. The position of the animal affects the degree of hypotension, the levels of vasopressin, and the rate of the initial phase of volume restoration.

Animals

The putative oncogene Spi-1: murine chromosomal localization and transcriptional activation in murine acute erythroleukemias.

We have shown previously that spleen focus forming virus integration near the Spi-1 putative oncogene is observed in 95% of erythroid Friend tumors (Moreau-Gachelin et al., 1988). Here we describe how the proviral insertion in the Spi-1 domain is associated with the enhanced transcription of a 1.4 kb mRNA normally expressed at a low level in normal cells. The gene is localized on murine chromosome 2, band E3. The structure of the Spi-1 gene was determined by sequencing genomic and cDNA clones. The gene has an open reading frame encoding a protein of 218 amino acids, extending over five exons. Proviruses always integrate outside, upstream and in the opposite orientation of the protein-encoding domain. This suggests that SFFV integration activates the expression of Spi-2 gene that may contribute to the erythroleukemic process.

Amino Acid Sequence

Coexistence of a c-myc mRNA initiated in intron 1 with the normal c-myc mRNA and similar regulation of both transcripts in mammalian cells.

We previously described a c-myc mRNA initiated within intron 1 at a major start site designated P3. This mRNA was observed in tumorigenic murine cells with no detectable rearrangement of the c-myc gene. In the present study, we report that P3 mRNA also coexists with the P1/P2 c-myc transcript in non-tumorigenic murine cell lines and that a c-myc mRNA which appears to be an equivalent of the murine P3 transcript is found in various rat and human cells. These data suggest that P3 represents a promoter of the normal, non-rearranged mammalian c-myc gene. Furthermore, both P1/P2 and P3 mRNA levels are similarly regulated by cycloheximide and by dimethylsulfoxide (DMSO) in murine erythroleukemia Friend cells.

Animals

Protooncogene expression in normal, preleukemic, and leukemic murine erythroid cells and its relationship to differentiation and proliferation.

The expression of 18 protooncogenes was examined by Northern blot analysis in preleukemic and leukemic stages of murine erythroleukemias induced by Friend viruses. As controls, erythropoietically stimulated spleens from phenylhydrazine-treated mice were studied. Expression of 10 protooncogenes (c-erb-A, c-erb-B, c-ets, c-sis, c-mos, c-rel, c-src, c-fes, c-fms, N-myc [corrected] was not detectable in Friend erythroleukemias. One protooncogene (c-src) was found expressed in normal erythroid cells but not in erythroleukemias. Four protooncogenes (c-fos, c-abl, N-ras, and c-raf) were expressed at low levels in both steps of erythroleukemia. c-fos and c-abl RNAs were barely detectable in normal erythroid cells. High levels of four protooncogene transcripts (c-H-ras, c-K-ras, c-myc, and c-myb) were detected in preleukemic and leukemic tissues. While c-H-ras RNA was found at similar levels in normal and leukemic erythroid cells, c-myc, c-myb, and c-K-ras were not expressed in normal erythroid cells. To determine whether the elevated levels of c-myc, c-myb, and c-K-ras RNAs in erythroleukemic cells are related to the proliferative state or the undifferentiated state of the cells, the effect of dimethyl sulfoxide-induced differentiation on oncogene expression in two erythroleukemia cell lines was examined. Terminal differentiation was associated with lack of c-myb expression while c-myc and c-K-ras expression was essentially unaffected. These results suggest that the high levels of c-myb transcripts in erythroleukemias may reflect the undifferentiated state of the leukemic cells. In contrast, the elevated expression of c-myc and c-K-ras at both stages of the Friend diseases is probably not related to the stage of differentiation but rather to the uncontrolled proliferation of the cells. Finally among 18 protooncogenes surveyed, only the accumulation of c-myc and c-K-ras RNAs appears to be associated with the Friend erythroleukemic process before the late leukemic phase develops.

Animals

Hydrocephalus in asphyxiating thoracic dystrophy.

We document four patients, including two sibs, with asphyxiating thoracic dystrophy and mild congenital hydrocephalus. All infants were males; three had postaxial polydactyly. The CT scan of brain showed moderate dilatation of the lateral ventricles in all cases. This appears to be the first documentation of apparent hydrocephalus in this condition.

Asphyxia

Endocrine responses of fetal lambs to hemorrhage after alpha 1-adrenergic receptor blockade.

To determine the importance of alpha 1-adrenergic receptors in the endocrine responses of fetal lambs to hemorrhage, eight chronically instrumented fetal lambs were bled of 20% of their measured blood volume after pretreatment with prazosin (24.8 +/- 2.1 days' gestation) or inert vehicle (124.2 +/- 2.2 days' gestation) according to a randomized, crossover protocol. Cortisol levels increased threefold with prazosin injection and remained elevated after hemorrhage but did not change with hemorrhage after vehicle infusion. Plasma renin activity was unaffected by the injection of prazosin but increased in both groups after hemorrhage. Vasopressin levels were unchanged in the control group throughout the experiment but increased tenfold with hemorrhage after pretreatment with prazosin. alpha 1-Adrenergic receptor blockade removes adrenergic inhibition of cortisol secretion and changes the hypotensive threshold for the secretion of vasopressin.

Adrenergic alpha-Antagonists

Effect of dextrose concentration on the intrathecal spread of amethocaine.

Effects of solutions of 0.5% amethocaine, containing different concentrations of dextrose (0%, 1.25%, 2.5% and 5%) were studied after intrathecal injection. The cephalad extent of block was greater with all three dextrose-containing solutions (T6), compared with the isobaric solution which contained no dextrose (T11). The variability of maximum level of block within each group was similar (seven dermatomes), and the rate of onset to maximum extent of block was the same in all groups. The rate of onset to the T12 dermatome was more rapid in the patients who received solutions containing dextrose. The initial onset of effect of the solution containing 1.25% dextrose was more like that of the isobaric solution than of those containing higher concentrations of dextrose.

Adolescent