Outbreak of acute hemorrhagic conjunctivitis due to coxsackie A24 variant--Taiwan

Outbreaks of acute hemorrhagic conjunctivitis caused by enterovirus 70 and several serotypes of adenovirus have occurred in Taiwan since 1971. In 1980-1981, there was a pandemic of acute hemorrhagic conjunctivitis in southeast Asia caused by coxsackie A24 variant (CA24v); however, this virus did not affect Taiwan. In October 1985, CA24v was isolated for the first time from patients with acute hemorrhagic conjunctivitis in southern Taiwan. The following summer, a large epidemic of acute hemorrhagic conjunctivitis due to CA24v occurred. An epidemiologic investigation of patients seen at one ophthalmology clinic in Taipei City revealed that school-age children were the most likely group to introduce illness into households (p less than 0.001) and that males were more often household index cases than were females (p less than 0.01). Multiple case households tended to be more crowded (3.0 vs. 2.5 persons per bathroom; p less than 0.05) and had illness introduced by younger family members (median age of index case = 10 vs. 17 years; p less than 0.01). It is unknown whether this outbreak is an isolated occurrence or represents another resurgence of CA24v in the area.

An autopsy-proved case of AIDS in Taiwan

The first case of AIDS positively identified in a non-foreigner in Taiwan was a 25-year-old unmarried male who had practiced homosexuality for ten years. The patient began to have abdominal pain accompanied with loose stools and weight loss in June 1985, followed by fever, cough, headache, dizziness, and loss of memory. Facial hyperpigmentation and extensive oroesophageal candidiasis were noted. Laboratory studies showed severe lymphopenia with a reversed T-helper to T-suppressor ratio, cutaneous anergy and polyclonal gammopathy. Human immunodeficiency virus (HIV) antibodies were positive by ELISA and Western blot, and the virus was isolated from the blood. At autopsy, disseminated cytomegalovirus infection, extensive CNS toxoplasmosis and early lesions of Kaposi's sarcoma were demonstrated. The detection of HIV in the adrenal medulla supports the consensus that the virus is neurotropic.

A unique mechanism regulating gene expression: translational inhibition by a complementary RNA transcript (micRNA)

The expression of the genes for the major outer membrane proteins OmpF and OmpC are osmoregulated. The ompC locus was found to be transcribed bidirectionally under conditions of high osmolarity and a 174-base transcript encoded upstream of ompC was found to inhibit the OmpF production and to substantially reduce the amount of the ompF mRNA. This RNA [mRNA-interfering complementary RNA (micRNA)] has a long sequence that is complementary to the 5' end region of the ompF mRNA. We propose that the micRNA inhibits the translation of the ompF mRNA by hybridizing with it. This RNA interaction may cause premature termination of the transcription of the ompF gene or destabilization of the ompF mRNA or both.

A comparative study on the genes for three porins of the Escherichia coli outer membrane. DNA sequence of the osmoregulated ompC gene

The DNA sequence of the ompC gene which encodes one of the outer membrane porins has been determined. The gene appears to encode a secretory precursor of OmpC protein consisting of a total of 367 amino acid residues with a signal peptide of 21 amino acid residues at its NH2-terminal end. The 5' end noncoding region including the promoter of the ompC gene is extremely [A-T]-rich, and the codon usage in the ompC gene is unusual as are those in genes for other abundant outer membrane proteins. The promoter sequence of the ompC gene was compared with that of the ompF gene, both of which are controlled by the osmoregulatory operon, ompB. The deduced amino acid sequence of the OmpC protein showed extensive homology with that of the other porins (OmpF and PhoE proteins). The homology in the primary amino acid sequences, as well as the coding DNA sequences among the porins, indicates that the structural genes for the three porins evolved from a common ancestral gene. Comparison of the amino acid sequences among the OmpC, OmpF, and PhoE porins will be discussed with regard to structure and function.

Severe pneumococcal infection in patients with neoplastic disease

A study of pneumococcal bacteremia in 56 patients with neoplastic disease from January 1, 1972 to June 30, 1980 is presented and compared to an earlier study between 1955 and 1971. Patients at highest risk were those with Hodgkin's disease who had been splenectomized, multiple myeloma and chronic lymphocytic leukemia showing an attack rate of 15.6/1000, 12.5/1000, and 10.8/1000, respectively. The attack rate was more than three times higher among patients with Hodgkin's disease in the present series compared to the previous series. In 32% of cases there was no identifiable source for the infection. Four splenectomized patients with Hodgkin's disease developed pneumococcal meningitis and two died. The overall mortality rate was 32% versus a rate of 18% for those treated with appropriate antibiotics for more than 24 hours. There was a significant improvement in overall survival when compared with our previous series. As before, almost one fourth (24%) of our isolates were not among those included in the pneumococcal vaccine presently available. Antibiotic prophylaxis should be considered in high risk patients.

DNA sequence of the promoter region of the ompC gene and the amino acid sequence of the signal peptide of pro-OmpC protein of Escherichia coli

The osmoregulated ompC gene of Escherichia coli was cloned and the DNA sequence of a fragment encompassing the promoter region and a portion of the coding region was determined. There were no obvious homologies in the DNA sequences of the promoter regions of the ompC and ompF genes, in contrast to those of the coding regions of the two genes, both of which code for the matrix porins (major outer membrane proteins) and form passive diffusion pores. The amino acid sequence of the signal peptide of pro-OmpC protein was also deduced from the DNA sequence.

Osmoregulation of gene expression. I. DNA sequence of the ompR gene of the ompB operon of Escherichia coli and characterization of its gene product

The ompB region on the Escherichia coli chromosome codes for two genes, ompR and envZ, which are required for the osmolarity sensitive biosynthetic regulation of the outer membrane matrix proteins (porins), OmpF and ompC. A part of the ompB region containing the ompR gene has been cloned (Wurtzel, E. T., Movva, N. R., Ross, F. L., and Inouye, M. (1981) J. Mol. Appl. Genet. 1, 61-69). We have determined the DNA sequence, including the promoter and structural regions encompassed in a 1.3-kilobase pair Ava I-Eco RI subfragment. This fragment codes for the entire ompR gene as well as the 5' end of the envZ gene. The ompR gene codes for a protein of 32,489 daltons, consisting of 284 amino acid residues. This was confirmed by identifying the gene product by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and determining a partial amino acid sequence of the NH2-terminal region of the gene product. A sequence of 57 amino acid residues located in the COOH-terminal region of the protein is extremely basic. It contains 10 arginine plus lysine residues in contrast to 1 glutamic acid residue in this region. In vitro transcription of the DNA from this region indicates that ampR and envZ are co-transcribed as a polycistronic mRNA from a promoter located 5' to the ompR gene. Translation of the am pR gene terminates at two tandem TAS codons and translation of the envZ gene initiates 29 nucleotides downstream. Cloning of the promoter region of ompB at a site 5' to the structural portion of the beta-galactosidase gene indicates that transcription of ompB is under positive control by cAMP.

Template-specific inhibitor for DNA polymerase isolated from cauliflower inflorescence

A novel inhibitory factor which greatly inhibits DNA polymerase activity was isolated from the apical portion of the cauliflower inflorescence during purification of DNA polymerases. It can be adsorbed on a DEAE-cellulose column, but not on CM-Sephadex or DNA-cellulose. The factor exclusively inhibits the incorporation of [3H]dTTP into DNA when poly(rA, dT10) is used as the template primer, but not when activated DNA, heat-denatured DNA or native DNA is used as a template. The concentration of the factor in the reaction medium required for 50% inhibition is approx. 8 microgram/ml. The factor is heat-stable, is inactivated by trypsin, and has a maximum ultraviolet absorption at 278 nm. The molecular weight was estimated as 2500-3000 by Sephadex gel chromatography.