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SUMMARYAn unknown Trypanosoma species was isolated from an axenic culture of intact skin from a domestic dog captured in Rio de Janeiro, Brazil, which was co-infected with Leishmania (Viannia) braziliensis. Giemsa-stained smears of cultures grown in different media revealed the presence of epimastigotes, trypomastigotes, spheromastigotes, transitional stages, and dividing forms (epimastigotes or spheromastigotes). The highest frequency of trypomastigotes was observed in RPMI (15·2%) and DMEM (9·2%) media containing 5% FCS, with a mean length of these forms of 43·0 and 36·0 μm, respectively. Molecular analysis by sequential application of PCR assays indicated that this trypanosome differs from Trypanosoma cruzi and T. rangeli when specific primers were applied. On the other hand, a PCR strategy targeted to the D7 domain of 24sα rDNA, using primers D75/D76, amplified products of about 250 bp in that isolate (stock A-27), different from the amplification products obtained with T. cruzi and T. rangeli. This organism differs from T. cruzi mainly by the size of its trypomastigote forms and kinetoplasts and the absence of infectivity for macrophages and triatomine bugs. It is also morphologically distinct from salivarian trypanosomes reported in Brazil. Isoenzyme analysis at 8 loci demonstrated a very peculiar banding pattern clearly distinct from those of T. rangeli and T. cruzi. We conclude that this isolate is a new Trypanosoma species. The name T. caninum is suggested.

Patients with renal insufficiency have an increased risk of hepatitis B infection and a high probability to develop a chronic course of this disease. After hepatitis B vaccination they are known to show a low rate of seroconversion. In the present study we assessed the efficacy of a new recombinant pre-S1 and pre-S2 containing hepatitis B vaccine in 17 non-responders (anti-HBs titer 0) and 4 low-responders (anti-HBs titeror = 5 IU/ml) with chronic renal insufficiency (16 on chronic hemodialysis therapy and 5 without hemodialysis treatment). Seroconversion rate was 65% after the third and 71% after the fourth vaccination. Only minor side effects were seen. These results encourage to use the new vaccine in a larger number of patients with renal insufficiency.

The antibody response of immunosuppressed heart transplant recipients to vaccination with the hepatitis B (HB) virus vaccine Hepa Gene 3 (HG-3), containing HB virus pre-S1, pre-S2, and S gene products, was examined. Three heart transplant recipients who had been vaccinated preoperatively against HB responded well to the vaccination. Five of 38 patients (13.2%) vaccinated postoperatively before HG-3 vaccination with the second-generation vaccine Gen-H-B-Vax-D (37 without and 1 with detectable anti-HBs response) and 3 of 24 (12.5%) without previous HB vaccination developed protective anti-HBs titers (greater than 10 U/1) after immunization with the HG-3 vaccine. The l low response rate (8/62, 12.9%) found for postoperatively vaccinated patients indicates that heart transplant recipients should be vaccinated against HB before immunosuppressive medication.

Conventional hepatitis B (HB) vaccines, such as the yeast-derived S-vaccine, have some serious drawbacks with regard to efficiency, as shown by the nonresponsiveness rates seen particularly in elderly persons or immunosuppressed patients. We assessed the efficacy of a genetically engineered preS1-containing HB vaccine (HG-3) in nonresponders to the S-vaccine. HG-3 was given to 5 groups of nonresponders: (1) healthy and under 40 years (n = 60); (2) healthy and over 40 (n = 13); (3) hemodialysis patients (n = 40); (4) liver transplant patients (n = 35); and (5) heart transplant patients (n = 84). Seroconversion with HG-3 was observed in 100%, 100%, 92%, 49%, and 40% of the vaccinees in groups 1 to 5, respectively. Both antibody to hepatitis B surface antigen (anti-HBs) and anti-preS antibodies were efficiently induced in these previous nonresponders. These results indicate that HG-3 is remarkably effective in inducing antibodies in S-vaccine nonresponders, even in elderly persons or immunosuppressed patients, and also suggest that the added preS region activates T cells that help produce anti-HBs.

Radioactive copper isotopes were ionized with the resonance ionization laser ion source (RILIS) at the on-line isotope separator ISOLDE (CERN). Using the different hyperfine structure in the 3d10 4s 2 S1/2 – 3d10 4p 2 P01/2 transition the low- and high-spin isomers of 70 Cu were selectively enhanced by tuning the laser wavelength. The light was provided by a narrow-bandwidth dye laser pumped by copper vapor lasers (CVL) and frequency doubled in a BBO crystal. The ground state to isomeric state intensity ratio could be varied by a factor of 30, allowing to assign gamma transitions unambiguously to the decay of the individual isomers. It is shown that the method can also be used to determine magnetic moments. In a first experiment for the 1+ ground state of 70 Cu a magnetic moment of (+)1.8(3) μN and for the high-spin isomer of 70 Cu a magnetic moment of (±)1.2(3) μN could be deduced.