The use of human hematopoietic growth factors (rhGM-CSF and rhEPO) as a supportive therapy for FIV-infected cats

Recombinant human GM-CSF (rhGM-CSF) and erythropoietin (rhEPO) were tested on chronically FIV-infected laboratory cats and uninfected specific-pathogen-free (SPF) cats. In Study 1, a total of eight cats (four cats per group of either infected or uninfected cats) received subcutaneous injection (twice a day) for 2 weeks with 5 microg/kg of rhGM-CSF, while seven cats (three SPF and four FIV-infected cats) served as the placebo-treated control cats. Four of eight rhGM-CSF-treated cats (two cats each from infected and uninfected groups) developed elevated WBC counts which peaked at Days 5-8 of treatment when compared to placebo-treated cats. The elevated WBC counts were attributed to the increase in either neutrophils, lymphocytes, eosinophils, monocytes, or their combinations. The RBC counts, platelet counts, and blood chemistry were not significantly affected by the treatment. Anti-rhGM-CSF antibodies were detected in six of eight rhGM-CSF-treated cats by Day 35 post-first treatment. All rhGM-CSF-treated infected cats but no placebo-treated infected cats had 1-2 log increase in FIV load in the PBMC during the treatment. In vitro studies suggest that rhGM-CSF has an effect on FIV replication in T cells but not in alveolar macrophages. Five of eight rhGM-CSF-treated cats had low-grade fever at 3-6 days of treatment. In Study 2, four cats per group of either infected or uninfected cats were treated (subcutaneously once a day) three times a week for 2 weeks with 100U/kg of rhEPO and monitored as before, while seven cats (three SPF and four FIV-infected cats) served as the placebo-treated control cats. All rhEPO-treated cats had a gradual increase in RBC, Hgb, and PCV counts which peaked at 2-4 weeks post-first rhEPO treatment, whereas none of the placebo-treated cats had significant increase in these parameters. The rhEPO-treated cats also developed elevated WBC counts consisting of either elevated neutrophils, lymphocytes, or their combination by 4 weeks post-first treatment but there was no statistical difference between rhEPO-treated and placebo-treated groups. None of the cats developed anti-rhEPO antibodies and no remarkable changes in blood chemistry, clinical signs, and FIV loads or FIV antibody titers were observed. Overall, rhEPO can be used safely on FIV-infected cats but the use of rhGM-CSF on FIV-infected cats should be performed with discretion.     

Characteristic changes in carbohydrate profile in the kidneys of hereditary nephrotic mice (ICGN strain)

The ICR-derived glomerulonephritis (ICGN) mice consist of heterozygous and homozygous groups and are considered to be a good model for human idiopathic nephrotic syndrome. To reveal changes in cell-surface carbohydrate construction, 24 lectins were applied to kidney sections of 10-, 30- and 50-week-old male heterozygous and homozygous ICGN mice and age-matched male ICR mice. Bandeiraea simplicifolia lectin-I (BSL-I), which specifically binds to alpha-D-galactopyranosyl groups, showed positive staining in the glomeruli of ICGN mice, but not in those of ICR mice. Positive BSL-I staining was observed only in distal tubules of homozygous ICGN mice. Lectin blotting for BSL-I demonstrated characteristic glycoproteins (45, 58 and 64 kD) in ICGN but not in ICR mice, and the levels of these molecules augmented in homozygous ICGN mice with the progression of renal failure. Moreover, succinylated wheat germ agglutinin, Dolichos biflorus agglutinin, Aleuria aurantia lectin and Ulex europaeus agglutinin-I showed positive staining only in the glomeruli of homozygous ICGN mice, but not in those of heterozygous ICGN or ICR mice. The staining intensities of Ricinus communis agglutinin-I, Phaseolus vulgaris agglutinin-E and -L, Lens culinaris agglutinin and Erythrina cristagalli agglutinin (ECL) in the glomeruli of homozygous ICGN mice were stronger than those of heterozygous ICGN and ICR mice. In conclusion, lectin histochemistry provided useful information for the diagnosis and prognosis of nephrotic lesions. Characteristic BSL-I binding glycoproteins may be pathogenic factors which cause renal disease in ICGN mice and are good tools to investigate the molecular mechanism of renal disorders in ICGN mice.     

Heterogeneity of Mycoplasma iowae determined by restriction enzyme analysis

Strains of Mycoplasma iowae were homogeneous in some characteristics and heterogeneous in others. Thus, the biochemical tests, immunofluorescence, and protein profiling by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were group-specific tests. However, some minor differences in protein patterns were seen among strains. The growth inhibition test tended to be strain-specific. Hemagglutination titers were very low and unstable for the majority of strains. One strain (RY-65) with a stable high-titer hemagglutinin failed to react in the hemagglutination-inhibition test against immune sera to the reference strains. Restriction endonuclease DNA analyses was the most useful method to differentiate 1 strain from another.     

Pathological findings of two types of lymphoid malignancy in sheep inoculated with bovine leukemia virus

Different types of lymphoid malignancy were observed in two sheep inoculated with BLV-containing materials. Sheep 1 showed severe leukemic change in the peripheral blood and splenomegaly but lymphosarcoma in the lymph nodes was absent. Sheep 2 had lymphosarcoma in the lymph nodes and various organs. Neoplastic cells had B-cell marker in both cases and a few neoplastic cells contained intracytoplasmic IgM in sheep 2. It was presumed that B-cells might be transformed into neoplastic cells on the way of their differentiation. Some of neoplastic cells might have ability of immunoglobulin-production in sheep 2.     

Studies on closure of the ductus arteriosus in perinatal rats.

Measurements of the inner diameters (calibers) of the ductus arteriosus (DA) and pulmonary artery (PA) were made in late fetal rats and newborn rats, the latter being obtained by spontaneous or caesarean delivery. The fetal and newborn pups were frozen instantly with an acetone-dry ice mixture. The chests of these whole-body frozen pups were shaved with a surgical knife gradually from the back toward the ventral side to expose the DA and PA for measurements of their calibers. As a result, it was revealed that the DA was almost closed 180 min after birth, but that the closure and shrinkage of the DA were accelerated to some extent by caesarean delivery. On the other hand, there was no remarkable change in the PA throughout the postnatal period observed, regardless of the type of delivery, spontaneous or caesarean.     

Latex agglutination test: a simple, rapid and practical method for bovine serum CRP determination.

A semi-quantitative latex agglutination test for bovine serum CRP levels has been established by mixing diluted serum (or diluted standard serum) with a 1% latex suspension containing 0.489 micron latex particles coated with affinity-purified antibody at a ratio of 20 micrograms/mg latex. The agglutination was performed on a glass slide in a moist chamber at room temperature with 45 min. incubation. This test is reliable, reproducible and the results correlate with those of the single radial immunodiffusion (SRID) test. The effect of low temperature storage on CRP concentration revealed a 30% degradation of CRP during 2 years storage at 4 degrees C. The possible role of EDTA addition to prevent a decrease in serum CRP concentration by freezing and thawing is also discussed.