PubMed Health⌕ Search

Biomedical subjects

L Mallet

Publications and source records attributed to L Mallet.

At least 19 recordsLinked to original sources
PubMed1995

A 43.5 kb segment of yeast chromosome XIV, which contains MFA2, MEP2, CAP/SRV2, NAM9, FKB1/FPR1/RBP1, MOM22 and CPT1, predicts an adenosine deaminase gene and 14 new open reading frames.

A 43,481 bp fragment from the left arm of chromosome XIV of Saccharomyces cerevisiae was sequenced. A gene for tRNA(phe) and 23 non-overlapping open reading frames (ORFs) were identified, seven of which correspond to known yeast genes: MFA2, MEP2, CAP/SRV2, NAM9, FKB1/FPR1/RBP1, MOM22 and CPT1. One ORF may correspond to the yet unidentified yeast adenosine deaminase gene. Among the 15 other ORFs, four exhibit known signatures, which include a protein tyrosine phosphatase, a cytoskeleton-associated protein and two ATP-binding proteins, four have similarities with putative proteins of yeast or proteins from other organisms and seven exibit no significant similarity with amino acid sequences described in data banks. One ORF is identical to yeast expressed sequence tags (EST) and therefore corresponds to an expressed gene. Six ORFs present similarities to human dbESTs, thus identifying motifs conserved during evolution. Nine ORFs are putative transmembrane proteins. In addition, one overlapping and three antisense ORFs, which are not likely to be functional, were detected.

Adenosine Deaminase↗
PubMed1995

The mitochondrial receptor complex: Mom22 is essential for cell viability and directly interacts with preproteins.

A multisubunit complex in the mitochondrial outer membrane is responsible for targeting and membrane translocation of nuclear-encoded preproteins. This receptor complex contains two import receptors, a general insertion pore and the protein Mom22. It was unknown if Mom22 directly interacts with preproteins, and two views existed about the possible functions of Mom22: a central role in transfer of preproteins from both receptors to the general insertion pore or a more limited function dependent on the presence of the receptor Mom19. For this report, we identified and cloned Saccharomyces cerevisiae MOM22 and investigated whether it plays a direct role in targeting of preproteins. A preprotein accumulated at the mitochondrial outer membrane was cross-linked to Mom22. The cross-linking depended on the import stage of the preprotein. Overexpression of Mom22 suppressed the respiratory defect of yeast cells lacking Mom19 and increased preprotein import into mom19 delta mitochondria, demonstrating that Mom22 can function independently of Mom19. Overexpression of Mom22 even suppressed the lethal phenotype of a double deletion of the two import receptors known so far (mom19 delta mom72 delta). Deletion of the MOM22 gene was lethal for yeast cells, identifying Mom22 as one of the few mitochondrial membrane proteins essential for fermentative growth. These results suggest that Mom22 plays an essential role in the mitochondrial receptor complex. It directly interacts with preproteins in transit and can perform receptor-like activities.

Amino Acid Sequence↗
PubMed1995

Improved strategy for large-scale DNA sequencing using DNaseI cleavage for generating random subclones.

Large-scale DNA sequencing projects require the use of specific and reliable strategies. Here, we describe an improved strategy using DNaseI cleavage and sequencing strategy using DNaseI cleavage and sequencing from both ends of the plasmid inserts. This strategy yields better results than those obtained using partial digestion with restriction enzymes and cloning in single-stranded vectors.

Bacteriophage M13↗
PubMed1994

Complete DNA sequence of yeast chromosome II.

In the framework of the EU genome-sequencing programmes, the complete DNA sequence of the yeast Saccharomyces cerevisiae chromosome II (807 188 bp) has been determined. At present, this is the largest eukaryotic chromosome entirely sequenced. A total of 410 open reading frames (ORFs) were identified, covering 72% of the sequence. Similarity searches revealed that 124 ORFs (30%) correspond to genes of known function, 51 ORFs (12.5%) appear to be homologues of genes whose functions are known, 52 others (12.5%) have homologues the functions of which are not well defined and another 33 of the novel putative genes (8%) exhibit a degree of similarity which is insufficient to confidently assign function. Of the genes on chromosome II, 37-45% are thus of unpredicted function. Among the novel putative genes, we found several that are related to genes that perform differentiated functions in multicellular organisms of are involved in malignancy. In addition to a compact arrangement of potential protein coding sequences, the analysis of this chromosome confirmed general chromosome patterns but also revealed particular novel features of chromosomal organization. Alternating regional variations in average base composition correlate with variations in local gene density along chromosome II, as observed in chromosomes XI and III. We propose that functional ARS elements are preferably located in the AT-rich regions that have a spacing of approximately 110 kb. Similarly, the 13 tRNA genes and the three Ty elements of chromosome II are found in AT-rich regions. In chromosome II, the distribution of coding sequences between the two strands is biased, with a ratio of 1.3:1. An interesting aspect regarding the evolution of the eukaryotic genome is the finding that chromosome II has a high degree of internal genetic redundancy, amounting to 16% of the coding capacity.

Base Composition↗
PubMed1994

Nucleotide sequence analysis of an 11.7 kb fragment of yeast chromosome II including BEM1, a new gene of the WD-40 repeat family and a new member of the KRE2/MNT1 family.

This paper reports the DNA sequence and analysis of an 11.7 kb segment localized on the right arm of Saccharomyces cerevisiae chromosome II. This fragment contains one incomplete and five long and non-overlapping open reading frames (ORFs) designated from centromere to telomere-proximal side as: YBR1406, 1409, 1410, 1411, 1412 and 1413. YBR1406 corresponds to the 5' end to PG11 encoding phosphoglucoisomerase. YBR1410 encodes a polypeptide of 798 amino acids whose C terminus contains five repeats (WD-40 repeat) similar to those found in the beta-subunits of G proteins and different yeast proteins such as Tup1, Prp4 and Cdc4. The higher similarity score is obtained with dTAFII80, a component of the RNA polymerase II transcriptional complex TFIID. YBR1411 encodes a polypeptide of 464 amino acids which belongs to the family of alpha-mannosyltransferases: KRE2/MNT1, KTR1, KTR2, YUR1 and the product of previously sequenced ORF YBR1445. YBR1412 corresponds to BEM1. The two ORFs, YBR1409 and YBR1413, which do not exhibit significant similarity with any known coding sequences, define new genes.

Adaptor Proteins, Signal Transducing↗
PubMed1994

A 12.5 kb fragment of the yeast chromosome II contains two adjacent genes encoding ribosomal proteins and six putative new genes, one of which encodes a putative transcriptional factor.

The nucleotide sequence of a 12.5 kb fragment localized to the right arm of chromosome II of Saccharomyces cerevisiae has been determined. The sequence contains eight putative genes. Two of them are contiguous and represent two ribosomal protein genes: SUP46 and URP1. SUP46 is implicated in translation fidelity and encodes the ribosomal protein S13. URP1 is homologous to the rat ribosomal protein gene L21. The open reading frame (ORF) YBR1245 is similar in its N-terminal part to transcription factors like SRF and MCM1. The ORF YBR1308 shows homology with proteins of the AAA-family (ATPases Associated with diverse cellular Activities). Two genes are predicted to encode putative membrane proteins.

Amino Acid Sequence↗
PubMed1994

Immunization requirements for pharmacy students.

OBJECTIVE: To identify current immunization requirements for pharmacy students throughout the US. DESIGN: Self-administered questionnaire. SETTING: Seventy-five colleges and schools of pharmacy in the US. MAIN OUTCOME MEASURES: Immunization policies, immunologic requirements, timing of vaccination in relation to the beginning of clerkship experience, payment, mechanism to revise policies. DATA ANALYSIS: Descriptive statistics. RESULTS: Overall, 57 programs (81 percent) have an immunization program in place, but 13 programs (19 percent) have no immunization program. More than 50 percent of the colleges or schools reported requiring that pharmacy students have measles, mumps, rubella, tetanus, and purified protein derivative of tuberculin (PPD) vaccinations upon entry of clerkship. Only 25 college or schools of pharmacy (44 percent) required students to have the hepatitis B vaccine and 8 (14 percent) to have a PPD evaluation upon completion of clerkship experience. Responsibility for the immunization program was shared evenly between the clerkship coordinator and the student health clinic. Approximately 65 percent of programs maintain an immunization record on file for each student. Completion of immunizations was required in 36 schools (64 percent) before entering clerkship activities, 15 (26 percent) before entrance to the professional program, and 3 (5 percent) in the first year of the program. Six schools (11 percent) had a program in place for less than one year, 27 (47 percent) between one and five years, and 24 (42 percent) for more than five years. At the majority of schools, students are responsible for the cost of immunization. CONCLUSIONS: Most schools of pharmacy do not adhere to the specific immunization recommendations described by the Centers for Disease Control and Prevention for healthcare workers. Pharmacy schools need to reexamine their immunization policies and update them to reflect the most current standards. We suggest a policy for immunization of pharmacy students.

Clinical Clerkship↗
PubMed1994

Ticlopidine and fatal aplastic anemia in an elderly woman.

OBJECTIVE: To report a case of aplastic anemia that developed during ticlopidine treatment. CASE SUMMARY: An 84-year-old woman was started on ticlopidine for secondary stroke prevention. Within six weeks of initiating ticlopidine therapy she developed aplastic anemia. She was hospitalized and received empiric antibiotics, antifungal agents, blood transfusions, platelets, and granulocyte colony-stimulating factor. The patient died on day 76 after beginning ticlopidine. DISCUSSION: Hematologic effects such as neutropenia, thrombocytopenia, agranulocytosis, thrombotic thrombocytopenic purpura, and pancytopenia have been described with the use of ticlopidine. Previous case reports have associated ticlopidine with the development of aplastic anemia. CONCLUSIONS: Ticlopidine can produce fatal hematologic adverse effects, and its use should be reserved as second-line therapy.

Aged↗
PubMed1993

RIM2, MSI1 and PGI1 are located within an 8 kb segment of Saccharomyces cerevisiae chromosome II, which also contains the putative ribosomal gene L21 and a new putative essential gene with a leucine zipper motif.

We report the DNA sequence of an 8 kb segment localized on the right arm of chromosome II from Saccharomyces cerevisiae. The sequence reveals the presence of eight open reading frames (ORFs). Three of them, YBR1402, YBR1405 and YBR1406 are previously sequenced genes, respectively the RIM2 (replication in mitochondria), MSI1 (multicopy suppressor of IRA1 gene) and PGI1 (phosphoglucoisomerase) genes. The predicted product of the ORF YBR1401 could be the putative yeast ribosomal protein L21. A new essential gene, YBR1403, has been identified by disruption; it possesses a leucine zipper motif.

Amino Acid Sequence↗
PubMed1993

A 12.8 kb segment, on the right arm of chromosome II from Saccharomyces cerevisiae including part of the DUR1,2 gene, contains five putative new genes.

A 12,820 bp fragment from the right arm of chromosome II of Saccharomyces cerevisiae was sequenced and analysed. This fragment contains six non-overlapping long open reading frames (ORFs) designated from the centromere- to the telomere-proximal ends as: YBR1441, 1443, 1444, 1445, 1446 and 1448. YBR1441 encodes a polypeptide of 845 amino acids which shares a long consensus domain with products of S. cerevisiae MCM2, MCM3, CDC46 and Schizosaccharomyces pombe cdc21+ genes. These genes are involved in DNA replication. YBR1445 encodes a polypeptide of 404 amino acids which has strong similarity with the S. cerevisiae KRE2/MNT1, YUR1, KTR1 gene products. The KRE2/MNT1 protein is an alpha-1,2- mannosyltransferase. The product of YBR1444, which encodes a protein of 375 amino acids, presents a lipase signature sequence and a peroxisomal targeting signal. YBR1448, whose sequence extends further on the telomere-proximal end of the fragment, is identical to the 3' end of the DUR1,2 gene encoding urea amidolyase. The two ORFs, YBR1443 and YBR1446, exhibit no significant similarity with any known gene.

Amino Acid Sequence↗
PubMed1992

Histone H1a subtype presents structural differences compared to other histone H1 subtypes. Evidence for a specific motif in the C-terminal domain.

Following a previous isolation by reverse-phase HPLC of five histone H1 subtypes from adult rat liver, purity of three of them, H1a, H1b and H1d (according to Lennox's nomenclature), was achieved. Structural features of these three subtypes were investigated. Partial cleavage of these subtypes by endoproteinase Glu-C showed a different behavior of the H1a subtype when compared to the H1b and H1d subtypes. Under the conditions used in this work, the H1b and H1d subtypes present three major sites accessible to the endoproteinase Glu-C, while the H1a subtype presents only one major site accessible to the proteinase. Partial N-terminal sequence of the different fragments obtained after proteolysis indicated that the two H1b and H1d subtypes were cleaved inside the globular domain (Glu-54,-75) and between the globular domain and the C-terminal one (Glu-116). The H1a subtype was only cleaved between the globular domain and the C-terminal tail (Glu-116), though Glu-54 and Glu-75 sites were present. These results would suggest some differences in the conformation of these proteins. Furthermore, the partial determined sequences of H1b and H1d showed 85% similarity to each other (the main differences were threonine residues instead of alanine residues in the C-terminal domain) while H1a was only 60% similar to H1b and H1d, for the sequences which aligned. The strongest differences between the H1a subtype and the two other subtypes were observed in the first amino acid residues of the C-terminal domain. The 117-126 amino acid residues (SKASTTKVTV) of H1a were quite different from those of H1b and H1d. This sequence, which showed a number of serine and threonine residues, was not found in any other histone sequence, after consultation with data bases. This H1a subtype was a minor component in adult liver (2.4%). As it was described in testis as a major component, testis histone H1 proteins were fractionated onto reverse-phase HPLC under the same conditions as those used for histone H1 proteins from liver. The pure testis H1a fraction was submitted to the endoproteinase Glu-C digestion. The pattern digestion was the same as that observed for liver H1a. The two 44-76 and 117-126 determined amino acid residues of H1a from testis were strictly identical to those of liver H1a. We demonstrate that H1a is the same protein in liver and testis and we give evidence for a specific motif SKASTTKVTV (117-126 residues) in the sequence of the C-terminal domain.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1992

["Spontaneous" ischemic colitis: infectious or medicamentous colitis? 25 cases].

The diagnosis of non-gangrenous ischaemic colitis is difficult to assert when histological findings are not specific and when no precipitating cardiovascular event can be found. The constant absence of relapse after the initial episode suggests that an extraneous triggering event is involved. We have studied retrospectively 25 cases of spontaneous ischaemic colitis, looking for a non-haemodynamic triggering event. At the onset of colitis 9 patients had been taking non-steroidal anti-inflammatory drugs or antibiotics for 2 weeks or less. In 3 other patients colitis was associated with Escherichia coli O157:H7 infection. Striking clinical, endoscopic and histological similarities exist between ischaemic colitis on the one hand and colitis caused by absorption of non-steroidal anti-inflammatory drugs or ampicillin and the colitis reported in E. coli O157:H7 infection on the other hand. Non-steroidal anti-inflammatory drugs and E. coli O157:H7 intestinal infection, possibly facilitated by an antibiotic treatment with e.g. ampicillin, could be either non-haemodynamic triggering factors for ischaemic colitis, or responsible per se for a transient acute colitis with the same characteristics as ischaemic colitis.

Adult↗
PubMed1992

The CCS1 gene from Saccharomyces cerevisiae which is involved in mitochondrial functions is identified as IRA2 an attenuator of RAS1 and RAS2 gene products.

The ccs1-1 mutation of Saccharomyces cerevisiae, which has been previously described, is associated with an increase in cytochrome content, in respiration, and in ATP synthesis. In addition, this mutation leads to the same phenotype as cells de-regulated in the cAMP pathway. From a yeast genomic library, we have isolated a DNA fragment in a recombinant plasmid pCD1 which complements the ccs1-1 mutation. Homologous integration of this DNA in the genome occurs at the CCS1 locus. An 11 kb of the DNA insert is necessary for complementation. Sequencing part of the fragment identifies CCS1 as the IRA2 gene. The IRA2 gene is known to encode an attenuator of RAS gene product activity which stimulates the GTPase activity of the RAS proteins. This result underlines the involvement of cAMP-dependent phosphorylation in mitochondrial function. We present the sequence of 1 kb DNA upstream of the putative ATG of the IRA2/CCS1 gene product which is devoid of an ORF and could contain several regulatory sites.

Base Sequence↗
PubMed1992

Counseling in special populations: the elderly patient.

This seventh installment in the series on value-added services provides pharmacists with a systematic approach to identifying and meeting the special counseling-related needs of the ambulatory elderly patient. The article describes the physical, mental, and social changes that characteristically accompany the aging process and that create special problems for pharmacists and their elderly patients during the delivery of pharmaceutical care. It also describes a systematic approach that pharmacists can use to evaluate whether their elderly patients need special counseling. Finally, it illustrates how the principles that are discussed can be applied in the practice setting.

Aged↗
PubMed1991

[Endoscopic treatments of digestive hemorrhages of ulcerative origin].

Recently introduced techniques of endoscopic haemostasis for bleeding ulcers offer hopes of improvement in their prognosis. Injections of such haemostatic products as absolute alcohol, adrenaline or polidocanol seem to possess the maximum advantages, including low cost, universal use, technical simplicity and easy application at the patient's bedside. The development for other techniques, such as laser photocoagulation, electrocoagulation and thermocoagulation appear to be limited by their high cost and by the difficulties encountered in their application.

Electrocoagulation↗
PubMed1991

Tuberculosis in the elderly: incidence, manifestations, PPD skin tests, and preventive therapy.

Tuberculosis is a chronic infection caused by Mycobacterium tuberculosis. The incidence of tuberculosis has declined dramatically over the past decades, but it is still highly prevalent in the geriatric population. This report describes the etiology, clinical manifestations, and immunologic changes of tuberculosis in the elderly. The basis for tuberculin skin testing and its interpretation in patients over 65 years of age are discussed, as well as the controversies regarding preventive therapy with isoniazid in the elderly. Guidelines for tuberculosis screening in long-term care facilities are proposed.

Aged↗