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At least 19 recordsLinked to original sources
PubMed1992

A conserved regulatory unit implicated in tissue-specific gene expression in Drosophila and man.

The Drosophila melanogaster alcohol dehydrogenase (Adh) gene is expressed in a specific set of tissues during larval development and in adults. Expression in the adult fat body is controlled by the Adh adult enhancer (AAE). Previous studies identified a negative regulatory element in the AAE and a protein that binds specifically to this sequence [adult enhancer factor-1 (AEF-1)]. Here, we show that the AEF-1-binding site in the AAE and in two other Drosophila fat body enhancers overlaps a sequence recognized by the mammalian transcription factor CCAAT/enhancer-binding protein (C/EBP). Remarkably, these two proteins also bind specifically to overlapping sites in a liver-specific regulatory element of the human Adh gene. Cotransfection experiments in mammalian cells reveal that C/EBP stimulates the activity of the AAE by 50-fold, and this activity can be suppressed by AEF-1. In addition, AEF-1 prevents C/EBP binding in vitro, and displaces prebound C/EBP. Thus, a tissue-specific regulatory unit consisting of one positive and one negative regulatory element has been conserved between Drosophila and man.

Alcohol Dehydrogenase↗
PubMedDate not supplied

Pathways of the evolution of hormonal signal realization systems.

The problem of the structural-functional organization, and of the origin and evolution of the chemosignal systems which realize the effect of hormones and hormone-like substances in the higher eukaryotes-lower eukaryotes-prokaryotes series, is reviewed on the basis of an analysis of published information and our own data. The notion that the systems of the conduction and transduction of chemical signals are related to universal and evolutionarily ancient structures is formulated. The roots of these systems take their origin in the single-celled eukaryotes, while individual of their functional units take their origin even in the prokaryotes. The hypothesis is advanced that the progressive evolution of chemosignal systems has traveled common pathways, and has consisted in the linking up and the functional combination of originally general and conservative units in the direction of the ever-increasing specialization of these systems and augmentation of their efficiency.

Animals↗
PubMed2026

Genomic insights into the persistence of Nubian giraffe (Giraffa camelopardalis camelopardalis) in conflict-affected South Sudan.

Armed conflicts can severely disrupt wildlife conservation and management, yet their long-term genomic consequences remain poorly understood. South Sudan has experienced decades of conflict that have limited conservation efforts and prevented genomic assessment of its fauna, including the endangered subspecies of Nubian giraffe (Giraffa camelopardalis camelopardalis). Due to long-standing logistical and political challenges, populations from South Sudan have remained largely unsampled. The Nubian giraffe represents a critical conservation unit and new sampling efforts provide an opportunity to investigate its genomic diversity and potential genetic isolation by the White Nile River, a hypothesized gene flow barrier. Here, we present genomic data from 30 individuals sampled in Boma and Badingilo National Parks in eastern South Sudan. Adding these sequences to existing genomic data reveals genetically distinct groups within the Nubian giraffe according to three regions: Ethiopia-South Sudan, Kenya, Uganda. Despite limited wildlife management due to economic and political constraints in South Sudan, the Nubian giraffe populations have maintained high heterozygosity (He ≈ 0.14%) and minimal evidence of inbreeding (mean FROH ≈ 0.15) compared to Kenya's Nubian giraffe populations. Contrary to expectations, our results reveal measurable gene flow across the White Nile between Nubian giraffe and Kordofan giraffe (G. c. antiquorum). These findings highlight South Sudanese Nubian giraffe as a population that retained genetic diversity and conservation efforts should be enhanced where feasible to ensure this stronghold long-term.

Animals↗
PubMed1987

Clorazepate use may prevent alcohol withdrawal convulsions.

Clorazepate dipotassium was administered orally for the five-day prophylactic treatment of potential, incipient and overt withdrawal signs and symptoms in 226 patients on admission to an inpatient alcohol treatment unit. Conservative estimates based on these patients' histories and on literature reports predicted that between 7 and 40 (3% to 18%) of these persons would be expected to have a withdrawal convulsion. No patients experienced convulsions. This complete absence of seizures suggests that clorazepate is effective in counteracting convulsive and other manifestations of the alcohol withdrawal syndrome.

Administration, Oral↗
PubMed1991

Cooperative binding of Drosophila heat shock factor to arrays of a conserved 5 bp unit.

Drosophila heat shock factor (HSF) exists as a multimer in solution and when bound to its regulatory element (HSE). We have previously reported evidence that subunits of HSF associate to form homotrimers and that each subunit contacts a conserved 5 bp DNA sequence repeated within an HSE. Here we show that HSF binding is highly cooperative at two distinct levels: between subunits of the HSF multimer, and between multimers. The binding of HSF to one of a pair of adjacent trimeric binding sites facilitates HSF binding to the second by over 2000-fold. This cooperativity is particularly important in binding HSF at 37 degrees C, and could account for the requirement for multiple binding sites in vivo and, in part, for the differential expression of heat shock genes.

Allosteric Regulation↗
PubMed1990

The complete cDNA and polypeptide sequences of human erythroid alpha-spectrin.

Overlapping human erythroid alpha-spectrin cDNA clones were isolated from lambda gt11 libraries constructed from cDNAs of human fetal liver and erythroid bone marrow. The composite 8001-base pair (bp) cDNA nucleotide sequence contains 187-bp 5'- and 528-bp 3'-untranslated regions and has a single long open reading frame of 7287 bp that encodes a polypeptide of 2429 residues. As previously described (Speicher, D. W., and Marchesi, V. T. (1984) Nature 311, 177-180), spectrin is composed largely of homologous 106-amino acid repeat units. From the amino acid sequence deduced from the cDNA, alpha-spectrin can be divided into 22 segments. Segments 1-9 and 12-19 are homologous and can therefore be considered repeats; the average number of identical residues in pairwise comparisons of these repeats is 22 out of 106, or 21%. Of these 17 repeats, 11 are exactly 106 amino acids in length, whereas five others differ from this length by a single residue. Segments 11, 20, and 21, although less homologous, appear to be related to the more highly conserved repeat units. The very N-terminal 22 residues, segment 10, which is atypical both in length and sequence, and the C-terminal 150 residues in segment 22 appear to be unrelated to the conserved repeat units. The sequence of the erythroid alpha-spectrin polypeptide chain is compared to that of human alpha-fodrin and chicken alpha-actinin to which it is related. alpha-Spectrin is more distantly related to dystrophin.

Actinin↗
PubMed1990

Conservative segregation of tetrameric units of H3 and H4 histones during nucleosome replication.

We have specifically investigated the behavior of H3 and H4 histones during the replication cycle of MH-134SC cells. Mononucleosomes obtained from cells density-labeled with IdU or dense amino acids in the presence of appropriate radiolabeled precursors were applied to sucrose gradients containing 0.3 M NaCl and 4 M urea for rate zonal centrifugation. This allowed the resolution of dense and normal subnucleosome particles composed of DNA and two molecules each of H3 and H4 without any measurable interparticle histone exchange. On labeling with dense amino acids and radiolabeled lysine, a distinct peak of radiolabeled dense particles was obtained. In contrast, pre-radiolabeled H3 and H4 remained in the normal subnucleosome peak region even after one generation time of culturing with dense amino acids. These data indicate the formation of (H3-H4)2 tetramers composed entirely of new H3 and H4 molecules as well as the conservation of pre-existing tetramers. Density labeling for 1 h with IdU in the presence of radiolabeled lysine yielded a distinct peak of radiolabeled dense particles, indicating the deposition of new tetramers on newly replicated DNA. Similar rate zonal analysis of subnucleosome particles obtained from cells prelabeled for 1 h with radiolabeled lysine followed by various IdU-labeling schedules in nonisotopic media yielded data suggesting that tetramers once deposited do not move about randomly during the replication cycle. A possible mode of nucleosome replication is discussed in the light of the present data.

Animals↗
PubMed1989

Stable binding of Drosophila heat shock factor to head-to-head and tail-to-tail repeats of a conserved 5 bp recognition unit.

The minimal DNA sequence required for the formation of a stable complex with Drosophila heat shock factor (HSF) in vitro is an inverted repeat of a 5 bp recognition unit, -GAA-. Surprisingly, both permutations of this 5 bp unit, head-to-head and tail-to-tail, bind to HSF with similar affinity and with striking 2-fold symmetry. HSF also binds to longer arrays of inverted 5 bp units, and the size of the HSF footprint increases with the addition of each 5 bp unit to these arrays. However, the electrophoretic mobility of the HSF-DNA complexes decreases most distinctly with the addition of every three 5 bp units. Cross-linking of purified HSF in the absence of DNA generates complexes with the sizes expected of HSF trimers. We propose that trimers of HSF bind to DNA and that the number of HSF subunits in direct contact with DNA is determined by the number of correctly positioned 5 bp recognition units.

Animals↗
PubMed1990

A transcribed gene, containing a variable number of tandem repeats, codes for a human epithelial tumor antigen. cDNA cloning, expression of the transfected gene and over-expression in breast cancer tissue.

A monoclonal antibody, H23, that specifically recognizes a breast-tumor-associated antigen, was used to isolate a cDNA insert that codes for the antigenic epitope. Nucleotide sequencing of this cDNA, as well as a longer 850-bp cDNA insert, shows that they are composed of 60-bp (G + C)-rich tandem repeating units. The coding strand was determined and codes for a proline-rich 20-amino-acid repeat motif. A comparison of the highly conserved repeat unit with the deduced flanking amino acid sequences demonstrates conservation of specific subregions of the repeat consensus within the flanking amino acids. Hybridization of the 60-bp cDNA probe with RNAs extracted from a variety of primary and metastatic human tumors yields relatively high levels of hybrid with the breast carcinomas, as compared to lower hybrid levels with RNAs from other epithelial tumors. RNA extracted from breast tissue adjacent to the tumor or from benign breast tumors, demonstrates low or undetectable levels of hybridization. Probing Southern blots with the 60-bp repeat shows that the tumor antigen is highly polymorphic and contains a variable number of tandem repeats (VNTRs). The VNTR nature of the gene was confirmed by probing Southern blots with unique genomic sequences that are physically linked to an isolated gene fragment that also contains the tandem repeat array. Mouse cells transfected with this gene fragment produce tumor antigen that is readily detected by H23 monoclonal antibodies. The allelic forms seen in 10 different primary human tumors demonstrate 100% concordance with the various mRNA species expressed. These studies are extended to the protein forms detected by immunoblot analyses that show both a correlation of the expressed tumor antigen species with the allelic forms as well as significantly increased expression in breast cancer tissue. The above studies unequivocally establish the over-expression of a VNTR gene coding for an epithelial tumor antigen in human breast cancer tissue.

Amino Acid Sequence↗
PubMed1989

A cDNA-based comparison of dehydration-induced proteins (dehydrins) in barley and corn.

Several cDNAs related to an ABA-induced cDNA from barley aleurone were isolated from barley and corn seedlings that were undergoing dehydration. Four different barley polypeptides with sizes of 22.6, 16.2, 14.4 and 14.2 kDa and a single corn polypeptide with a size of 17.0 kDa were predicted from the nucleotide sequences of the cDNAs. These dehydration-induced proteins (dehydrins) are very similar to each other and to a previously identified rice protein induced by ABA and salt, and have at least some similarity to a previously identified cotton embryo protein. Each dehydrin is extremely hydrophilic, glycine-rich, cysteine- and tryptophan-free and contains repeated units in a conserved linear order. A lysine-rich repeating unit occurs twice in each protein, once at the carboxy terminus and once partway through the polypeptide, adjacent to a succession of serines. This repeating unit and the adjacent flanking run of serines are conserved with minimal variation among all dehydrins. Another repeating unit is flanked by the two copies of the lysine-rich unit, and varies in number from one to five copies. This latter repeating unit is less conserved than the former, varying even within a singly dehydrin. The messenger RNAs corresponding to each cDNA are abundant in dehydrating, but not in well-watered seedlings. The amino acid sequence of tryptic peptides from purified dehydration-induced proteins of corn established that the corn cDNAs correspond to a protein that is produced in abundance during the response of corn seedlings to dehydration.

Amino Acid Sequence↗
PubMed2026

Routine transfusion of Rh(D)-positive RBCs to Rh(D)-negative patients designated as do not resuscitate conserves Rh(D)-negative red blood cell inventory.

BACKGROUND: A minority of blood donors are Rh(D)-negative, and Rh(D)-negative red blood cell (RBC) products are often overutilized. As such, Rh(D)-negative RBCs may be difficult to maintain in blood bank inventory. STUDY DESIGN AND METHODS: We changed our blood bank laboratory policy to approve non-alloimmunized Rh(D)-negative patients to receive Rh(D)-positive RBCs for routine transfusion under defined criteria. Those criteria included Rh(D)-negative males (all ages) and females (aged >50 years) who were designated as do not resuscitate (DNR), either with or without intubation, in the electronic medical record. RESULTS: From August 15, 2024 through August 15, 2025, a total of 204 Rh(D)-negative patients met the above criteria and were approved to receive routine Rh(D)-positive RBC transfusions. Within that group, 23 patients received Rh(D)-positive RBCs. The remaining patients either did not require transfusion or were issued Rh(D)-negative RBC units. Since implementing this practice, a total of 68 Rh(D)-negative units were conserved during this time frame. Notably, 28 of the 68 units (41%) were type O, Rh(D)-negative. DISCUSSION: Rh(D)-positive RBCs can be routinely given to non-alloimmunized Rh(D)-negative patients who are not at risk for developing hemolytic disease of the fetus and newborn (HDFN). By creating clear guidelines for the routine administration of Rh(D)-positive RBCs to patients who are not at risk for HDFN, the inventory of Rh(D)-negative RBC units can be directed to those patients who would most benefit from this limited resource.

Erythrocytes↗
PubMed1990

A procaryotic regulatory factor with a histone H1-like carboxy-terminal domain: clonal variation of repeats within algP, a gene involved in regulation of mucoidy in Pseudomonas aeruginosa.

A novel procaryotic transcriptional regulatory element, AlgP, with a histone H1-like carboxy-terminal domain was identified in Pseudomonas aeruginosa. AlgP is required for transcription of the key biosynthetic gene algD, which is necessary for production of the exopolysaccharide alginate causing mucoidy in P. aeruginosa. Mucoidy is a critical virulence determinant of P. aeruginosa invariably associated with the respiratory infections causing high mortality in cystic fibrosis. Here we show that AlgP and histones H1 both have repeated units of the Lys-Pro-Ala-Ala motif (KPAA) and its variations within their long (over 100 amino acids) carboxy-terminal domains. This region of histone H1 tails has been shown to bind to the linker DNA in eucaryotic chromatin fibers. A synthetic 50-mer peptide consisting of repeats from the AlgP carboxy-terminal domain was found to bind DNA in a mobility shift DNA-binding assay. AlgP is encoded by a gene that contains multiple direct repeats organized as tandem, head-to-tail, 12-base-pair (bp) units overlapping with six highly conserved 75-bp units. The repetitive structure of the algP gene appears to participate in the processes underlying the metastable character of mucoidy in P. aeruginosa. Relatively large DNA rearrangements spanning the region with tandem direct repeats encoding the carboxy-terminal histone H1-like structure of AlgP were detected in several strains upon conversion from the mucoid to the nonmucoid phenotype. The frequency of the detectable algP rearrangements associated with the transition into the nonmucoid state varied from strain to strain and ranged from 0 to 50%. The nonmucoid derivatives with the clearly rearranged chromosomal copy of algP were complemented to mucoidy with plasmids containing algP from P. aeruginosa PAO. When a random collection of mucoid strains, isolated from different cystic fibrosis patients, was analyzed by using polymerase chain reaction, an additional level of strain-dependent sequence variation in algP was observed. Variations in the number of the 12-bp repeats were found; however, they did not appear to influence the mucoid status of the strains examined. Thus, the repeated region of algP appears to be a hot spot for DNA rearrangements and strain-dependent variability.

Amino Acid Sequence↗
PubMed1992

The genome size and the structure and content of ribosomal RNA genes in Atlantic cod (Gadus morhua L.).

1. The haploid genome size of the Atlantic cod was estimated to 3.4 x 10(8)kb by reassociation kinetics analysis of cod sperm DNA. 2. The size of the small and large subunit ribosomal RNAs is 1.85 and 4.1 kb, respectively. 3. Restriction enzyme mapping of the rRNA coding unit revealed conservation of an Eco RI site in the coding regions of 18 S and 28 S rRNA and a Bam HI site in the 28 S rRNA coding region compared to other fish species. 4. The length of the repeat unit of the cod rDNA was found to be 30 kb. 5. The rRNA genes are repeated approximately 50 times in the cod genome and constitutes 0.08% of the cod genetic material.

Animals↗
PubMed1990

Alimentary tract cytopathology in human immunodeficiency virus infection: a review of experience in Los Angeles.

In the past decade, over 100,000 cases of the acquired immunodeficiency syndrome (AIDS) have been reported in the United States. Conservative estimates suggest that 1.5 million people are infected with the human immunodeficiency virus (HIV), the etiologic agent of AIDS. Major metropolitan areas, such as Los Angeles, have experienced a rapid increase in the number of AIDS cases. At the Los Angeles County-University of Southern California Medical Center, we have gained significant insight into the cytologic findings associated with HIV infection. Based on our experience, we herein review the technical and morphologic evaluation of alimentary tract cytology specimens from this patient population.

AIDS-Related Complex↗
PubMed2026

Metagenomics Reveals Microbial Community Shifts Associated With Contrasting Anthropogenic Impacts in Freshwater Sources of A Coastal Protected Area in Southeastern Brazil.

This study aimed to characterize freshwater microbial communities, environmental drivers, and anthropogenic impact patterns across three sites on Marambaia Island (southeastern Brazil) using metagenomics. Samples collected from freshwater sources used for human consumption were processed through concentration, nucleic acid extraction, and sequencing on the Illumina NextSeq 2000 platform. A total of 67.2 million reads were assembled into 89,230 bacterial contigs, mostly attributed to Gammaproteobacteria, Alphaproteobacteria, and Betaproteobacteria. Sites under lower anthropogenic influence exhibited higher microbial diversity, whereas impacted sites showed enrichment of opportunistic and fecal-associated genera. A heterogeneous anthropogenic impact profile was observed across sites, corroborated by the proposed Anthropogenic Impact Index (AII). Fourteen antimicrobial resistance genes conferring resistance to beta-lactams, quinolones, sulfonamides, tetracyclines, and macrolides were detected predominantly in sewage-impacted areas, indicating potential diffuse contamination. Redundancy analysis revealed that environmental variables explained 88.1% of microbial community variation, with conductivity, salinity, and turbidity as key drivers. These findings demonstrate the applicability of metagenomics as a powerful tool for assessing microbial diversity, ecological dynamics, and contamination risks in vulnerable freshwater systems.

Brazil↗
PubMed1992

Interlocking intramedullary nailing for the treatment of tibial fractures.

Thirty-seven tibial shaft fractures in 34 patients were treated with the Grosse-Kempf interlocking intramedullary nail over a two year period. Thirty-six tibiae were consolidated at a median of 17 weeks; one had re-fractured following nail removal in a separate injury, but was now uniting on conservative treatment. Using very detailed clinical and radiological analysis, and excluding the patient who had re-fractured, the results were excellent in 19, good in 8, fair in 6 and poor in 3. The most significant complications were haematoma formation and additional comminution during nail insertion. Overall, we found tibial nailing to be a satisfactory procedure, facilitating rapid rehabilitation with early weight bearing and resulting in predictable fracture healing in good alignment.

Adolescent↗