New candidate vaccines against blood-stage Plasmodium falciparum malaria: prime-boost immunization regimens incorporating human and simian adenoviral vectors and poxviral vectors expressing an optimized antigen based on merozoite surface protein 1.

Although merozoite surface protein 1 (MSP-1) is a leading candidate vaccine antigen for blood-stage malaria, its efficacy in clinical trials has been limited in part by antigenic polymorphism and potentially by the inability of protein-in-adjuvant vaccines to induce strong cellular immunity. Here we report the design of novel vectored Plasmodium falciparum vaccines capable of overcoming such limitations. We optimized an antigenic insert comprising the four conserved blocks of MSP-1 fused to tandemly arranged sequences that represent both allelic forms of the dimorphic 42-kDa C-terminal region. Inserts were expressed by adenoviral and poxviral vectors and employed in heterologous prime-boost regimens. Simian adenoviral vectors were used in an effort to circumvent preexisting immunity to human adenoviruses. In preclinical studies these vaccines induced potent cellular immune responses and high-titer antibodies directed against MSP-1. The antibodies induced were found to have growth-inhibitory activity against dimorphic allelic families of P. falciparum. These vectored vaccines should allow assessment in humans of the safety and efficacy of inducing strong cellular as well as cross-strain humoral immunity to P. falciparum MSP-1.

Aberrant regulation of synthesis and degradation of viral proteins in coliphage lambda-infected UV-irradiated cells and in minicells.

The patterns of bacteriophage lambda proteins synthesized in UV-irradiated Escherichia coli cells and in anucleate minicells are significantly different; both systems exhibit aberrations of regulation in lambda gene expression. In unirradiated cells or cells irradiated with low UV doses (less than 600 J/m2), regulation of lambda protein synthesis is controlled by the regulatory proteins CI, N, CII, CIII, Cro, and Q. As the UV dose increases, activation of transcription of the cI, rexA, and int genes by CII and CIII proteins fails to occur and early protein synthesis, normally inhibited by the action of Cro, continues. After high UV doses (greater than 2,000 J/m2), late lambda protein synthesis does not occur. Progression through the sequence of regulatory steps in lambda gene expression is slower in infected minicells. In minicells, there is no detectable cII- and cIII-dependent synthesis of CI, RexA, or Int proteins and inhibition of early protein synthesis by Cro activity is always incomplete. The synthesis of early b region proteins is not subject to control by CI, N, or Cro proteins, and evidence is presented suggesting that, in minicells, transcription of the early b region is initiated at a promoter(s) within the b region. Proteolytic cleavage of the regulatory proteins O and N and of the capsid proteins C, B, and Nu3 is much reduced in infected minicells. Exposure of minicells to very high UV doses before infection does not completely inhibit late lambda protein synthesis.

Fatal diphtheria in an older woman.

A previously healthy 68-year-old woman presented with fever and sore throat. Her condition was initially diagnosed as necrotizing streptococcal tonsillitis and was treated with penicillin G, given intravenously. A swab of her throat taken for culture at the time of admission yielded Corynebacterium diphtheriae 48 hours later. At that time an electrocardiogram showed new T-wave inversion--evidence of diphtheritic myocarditis. She was immediately given 60 000 units of equine diphtheria antitoxin (following a test dose), but later that day she began choking, became apneic and died. The patient had not received any immunizing agents as a child, and no antitoxin was detected in a blood sample obtained prior to administration of the antitoxin. Her death re-emphasizes the seriousness of diphtheria, an infection to which many elderly people are susceptible.

[The significance of Chlamydia trachomatis in chronic infectious urethro-adnexitis in the male]. / Zur Bedeutung von Chlamydia trachomatis bei der chronisch entzündlichen Urethro-Adnexitis des Mannes.

The causative significance of chlamydia trachomatis in chronic urethra-prostatitis can be assumed because of the high incidence in non-gonorrheal and post-gonorrheal urethritis and epididymitis. 158 men with chronic inflammatory urethro-prostatitis were reviewed. In 32.3% the urethral smear and in 29.7% the prostatic fluid were positive for chlamydia trachomatis. Simultaneously leucocyte count and pH of the prostatic fluid as well as the immunoelectrophoresis of the ejaculate were investigated. The correlation of these results with positive chlamydia trachomatis findings demonstrates the significant role of chlamydia trachomatis in chronic inflammatory processes of the urethra and prostate.

[Frequency of virus diseases in a regional hospital]. / Häufigkeit von Viruserkrankungen in einem Landkrankenhaus.

The district hospital Wertingen is nearly 100 km away from the Government-Investigation-Institute für Public Health, South-Bavaria, and there is no direct railway connection to Munich. This is a report how in spite of these insufficient traffic conditions in many cases the etiologic agent of virus diseases could be proved by isolation of virus or by showing specific IgM-antibodies or significant titer-rises in two blood-samples. For a successful investigation of the patient-material the knowledge of clinical symptoms and the anamnesis is most important. Furthermore is important the optimal time for collecting the material, which is for virus isolation always the earliest time after the onset of illness. For demonstration of titer-rises a second blood sample during the recovery has to be sent to the laboratory. During 1981 and 1982 in the district hospital Wertingen the diagnosis of 116 patients with virus diseases could be proved by demonstration of the etiologic agent.

[Epidemiology of tick-borne encephalitis in Southern Germany (author's transl)]. / Frühsommer-Meningoenzephalitis in Süddeutschland.

A recently developed sensitive enzyme immunoassay for the detection of IgM antibodies to tick-borne encephalitis (TBE) virus was used to reinvestigate sera of patients with the clinical diagnosis of meningitis or encephalitis but without conclusive results in the complement fixation assay for TBE virus. 62 cases with sera positive for IgM antibodies to TBE virus collected from 1976 to 1980 were evaluated with regard to clinical and epidemiological aspects of the disease. Of the 62 cases, 37 had apparently been bitten by ticks. The mean age of the patients was 34 years. After a mean incubation period of 12 days (6-21 days) nearly all patients had severe headache and meningitis, in most cases connected with high fever. In 4 patients (6.4%) a serious clinical picture with incomplete recovery was observed. One patient died. Infection peaks occur in July and October. The place of infection or residence was predominantly in southeast Bavaria.

Downstream regulation of int gene expression by the b2 region in phage lambda.

Expression of the int gene after phage lambda infection normally requires the products of genes cII and cIII. However, when the phage carries a deletion in the nonessential b2 region adjacent to int, efficient synthesis of active Int protein does not require cII and cIII function. This inhibition of Int synthesis by nucleotide sequences downstream from the int structural gene behaves in a cis-dominant fashion in mixed infections. It is specific for PL- and not pI-initiated transcripts. Based on these observations, and those of others, a model is proposed in which Int translation from the pL transcript is inhibited by the interaction of downstream b2 nucleotide sequences and nucleotide sequences in the int region. The data imply a novel temporal mechanism regulating prophage lambda induction: circularization of the prophage genome results in the transposition of inhibitory b2 region sequences next to int and blocks further Int protein synthesis beyond the low level required for excision. As a consequence of this process, the control of int expression is transferred from the pL promoter to pI and the cII/cIII system. Such a genetic regulatory mechanism involving the rearrangement of genetic elements downstream from a structural gene may be of general use during development in other systems.

[Virological analyses of irradiated sewer sludge (author's transl)]. / Virologische Untersuchungen an bestrahlten Klärschlämmen.

The virus-inactivating effect of Co60 irradiation was verified by a field test in the sewer sludge irradiation plant at Geiselbullach near Munich. The following samples were tested: 16 waste water inlets 15 waste water outlets 32 fresh sludge samples 62 sewer sludge samples prior to irradiation 52 sewer sludge samples and 9 fresh sludge samples after irradiation. We supplemented these analyses by inoculating sewer sludge samples with polio inoculation virus type 1 before irradiation and by the admixing of virus-pure suspensions in MEM + 2 per cent fetal calf serum and virus sludge mixtures packed in plastic capsules with the material to be irradiated. After irradiation these capsules were picked up again and analyzed for their viral content. As test viruses we selected polio wild virus type 1, echovirus type 6, coxsackie virus B5, coxsackie virus A9 and adeno virus type 1. After the sludge samples had been sufficiently homogenized by an adequately long decaying period and provided they contained 3-per cent solid matter, we managed to obtain the same irradiation results in field tests, as with tests under laboratory conditions. For entero viruses the D-value (decimal reduction) was 300 to 400 krad, for adeno viruses it amounted to 700 krad.