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Biomedical subjects

M Suh

Publications and source records attributed to M Suh.

53 records · Page 3Linked to original sources

Direction of synthesis of the message for a 35 000 polypeptide of herpes simplex virus type 2.

A restriction endonuclease map of the coding sequences for the transformation-related 35 000 polypeptide of herpes simplex virus type 2 is reported, using 11 enzymes that cut DNA infrequently. Hybrid-arrested translation with small DNA fragments was used to locate the 5' terminus of these coding sequences. A novel procedure involving translation of the 35 000 mRNA selected with cloned viral DNA that had been digested with exonuclease was employed to confirm that this message is transcribed from left to right. The 35 000 polypeptide can thus be assigned to a 1.2-kilobase mRNA recently reported with the same starting point and direction.

Cell Transformation, Viral↗

Localization of the coding region for a 35000 Dalton polypeptide on the genome of herpes simplex virus type 2.

The cloned BglII N fragment of herpes simplex virus type 2 (HSV-2) DNA has been shown to code for a 35K polypeptide. Subfragments made by cleavage with XhoI, BamHI, SstII and XorII were then cloned and used with RNA extracted from HSV-2-infected cells for mRNA selection and in vitro protein synthesis. We found that the major translation product of such hybrid-selected mRNA has a molecular weight of 35 000. By further mapping, DNA coding sequences for this mRNA were located within the region of BglII N, at approximately 0.585 to 0.596 genome map units. DNA sequences complementary to mRNA encoding a 56K polypeptide were located between 0.607 and 0.612 map units.

Chromosome Mapping↗

Sulphated glycoproteins induced by herpes simplex virus.

BHK cells infected with strain 17 syn+ (HSV-1) or HG52 (HSC-2) incorporated inorganic sulphate into polypeptides which co-migrated on SDS-polyacrylamide gels with virus-induced glycoproteins. The major sulphated glycoprotein was glycoprotein E. In addition, less-intense sulphated bands co-migrated with glycoprotein D and HSV-1 glycoprotein A/B/C. Sulphate label co-migrating with HSV-2 glycoprotein A/B/C was occasionally observed. We have investigated which sulphated polypeptides are excreted from infected cells. Major ones of apparent mol. wt. 32000, 34000 and 35000 were excreted from cells infected with syn+. In addition, polypeptides which migrated in the vicinity of glycoprotein D were often excreted from cells infected with either 17 syn+ or HG52. The 32K, 34K and 35K polypeptides were antigenically related to glycoprotein D and over 95% of the total amount synthesized was excreted. Analysis of intracellular sulphated polypeptides using intertypic recombinants mapped glycoprotein E to between 0.832 and 0.950 units of the HSV genome.

Animals↗

Modifications of the nuclear envelope of BHK cells after infection with herpes simplex virus type 1.

Numerous discrete lesions, which we have termed blebs, appeared in the nucleus of BHK cells 10 to 15 h after infection with herpes simplex virus type 1 (HSV-1). They were formed in the inner portion of the nuclear envelope by the apposition of two thickened lamellae overlying a vacuole. As demonstrated by electron microscopic studies, blebs were regular and associated with the peripheral lamina in the nucleus, averaging 3.5 blebs per micron2. They appeared to be associated with an enrichment of the 155K major capsid protein in the nuclear membrane subfractions as compared with the protein composition of nuclei and plasma membrane fractions. We propose that blebs represent the site of assembly of capsid proteins before DNA insertion and eventual envelopment.

Animals↗

Characterization of a polypeptide present in herpes simplex virus type 2-transformed and -infected hamster embryo cells.

Transformation of hamster embryo cells by herpes simplex virus stimulated the production of a 35-kilodalton (35K) protein that was specifically immunoprecipitated, along with other polypeptides, by rabbit hyperimmune serum. This 35K polypeptide was further analyzed by partial digestion with Staphylococcus aureus V8 protease in parallel with a 35K polypeptide from herpes simplex virus type 2-infected cells. These polypeptides had almost identical partial-proteolytic cleavage maps, indicating that they are probably the same or that they are very similar polypeptides.

Animals↗

Physical disorders among emergency psychiatric patients.

An examination of patients with physical disorders requiring immediate treatment or investigation was undertaken in the Psychiatric Emergency Service of the Royal Ottawa Hospital and found to comprise 7% of the patient population, or one visit per day. Those with physical problems differed from the rest of the emergency patients in that a greater number were over age 60 and were diagnosed as alcoholic or chronic organic brain syndrome. Socio-demographic characteristics were examined as well. The presenting problem was accurate regarding a physical basis in only two-thirds and the disorder could, in some way, be related to a psychiatric diagnosis in 75% of the patients. Emphasis is placed on the fairly high frequency of immediate physical attention required by these patients who come to the psychiatrist. Consequently, psychiatric assessment and management is not the priority for this group and other skills of the psychiatrist are necessary in treating the patient.

Diagnosis, Differential↗

A socio-psychiatric profile of emergency service patients.

A study of patients using the psychiatric emergency services of the Royal Ottawa Hospital was undertaken to determine their demographic and clinical characteristics, correlations between the two and comparisons with other studies. Special clinical forms of every fifth patient seen were analyzed and the data presented. These data are useful in the planning of and establishing and operating a psychiatric emergency service with an attached short-term inpatient unit, as well as assessing the feasibility and value of crisis intervention and brief psychotherapy in treating patients quickly.

Adolescent↗

Analysis of chromosomes, nucleic acids, and polypeptides in hamster cells transformed by herpes simplex virus type 2.

Syrian hamster embryo fibroblasts were oncogenically transformed by UV-inactivated Herpes simplex type 2. Eighteen clones were isolated shortly after transformation occurred. Two clones and their tumor derivatives were studied using several techniques. The karyotype analysis revealed different chromosome patterns in the two clones and a tendency toward hypodiploidy in the tumor derivatives. All of these cell lines were shown by molecular hybridization to contain 40% of the HSV-genome in several copies. The viral DNA sequence complexity was retained in the tumor derivatives, but a decrease in the copy number was observed. Viral RNA's were detected by in situ hybridization in all the lines that were tested. Viral antigens could be observed in these transformed cells by immunofluorescence. Finally, polypeptide analysis showed three differences between normal and transformed cells.

Animals↗

Sequence dependence of benzo[a]pyrene diol epoxide-DNA adduct conformer distribution: a study by laser-induced fluorescence/polyacrylamide gel electrophoresis.

Low-temperature laser-induced fluorescence techniques in combination with polyacrylamide gel electrophoresis (LIF/PAGE) were used to study the binding of (-)-anti- and (+)-anti-benzo[a]pyrene 7,8-dihydrodiol 9,10-epoxide (anti-BPDE) to several sequence-defined duplex oligomers. Two of the oligomers contain central 5'-RAGGAR-3' sequences (R = purine) which appear to be frequently mutated by racemic (+/-)-anti-BPDE in endogenous genes of cells cultured in vitro. Two contain a central 5'-CCGG-3' or 5'-TGGT-3' sequence which are strongly preferred for covalent binding but appear to be not so frequently mutated. Binding of the two enantiomers to the latter two sequences yielded a distribution of BPDE-N2-dG adduct conformations similar to those from binding to highly polymerized, random sequence DNA in vitro which, for (+/-)-anti-BPDE, means that the helix-external conformation of the N2-dG adduct is dominant. Binding of (-)-anti-BPDE to the 5'-RAGGAR-3' sequences yielded more partially base-stacked and less base-stacked (quasi-intercalated) conformer than observed for random sequence DNA. Importantly, the (+)-anti-BPDE in binding to the more mutagenically inclined 5'-RAGGAR-3' sequences yielded little external-type adduct in comparison to the other two sequences and random sequence DNA. Moreover, an unusually high proportion of the (+)-anti-BPDE adducts formed with the 5'-RAGGAR-3' sequences result from cis stereoaddition, which yields a partially base-stacked configuration. Since the (+)-anti-BPDE appears to be the more mutagenic, this result suggests a possible role of internal adduct conformations in mutagenesis.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗

Depurinating and stable benzo[a]pyrene-DNA adducts formed in isolated rat liver nuclei.

Polycyclic aromatic hydrocarbons are bound to DNA by two major pathways, one-electron oxidation and monooxygenation, to form adducts that are stable in DNA under normal conditions of isolation and depurinating adducts that are released from DNA by cleavage of the bond between the purine base and deoxyribose. Isolated rat liver nuclei have been used as an in vitro model for studying covalent binding of aromatic hydrocarbons to DNA, but the depurinating adducts formed by nuclei have not been identified or compared to those formed by the more commonly used rat liver microsomes. To examine the profiles of stable and depurinating adducts, nuclei from the livers of 3-methylcholanthrene-induced male MRC Wistar rats were incubated with [3H]benzo[a]pyrene (BP) and NADPH. Three depurinating adducts, 8-(BP-6-yl)Gua, 7-(BP-6-yl)Gua, and 7-(BP-6-yl)Ade, were obtained from the nuclei, as seen previously with rat liver microsomes or in mouse skin. The profile of stable adducts analyzed by the 32P-postlabeling method was qualitatively similar to that found in the microsomal activation of BP or in mouse skin treated with BP. Low-temperature fluorescence studies of the nuclear DNA revealed the presence of stable BP adducts originating from syn- and anti-BP diol epoxide.

Animals↗