Susumu Makimura

Clindamycin in the Treatment of Babesia gibsoni Infections in Dogs

This report examines the effectiveness of clindamycin for the treatment of babesiosis in dogs (n=10) experimentally infected with Babesia gibsoni (B. gibsoni). Clindamycin (25 mg/kg body weight, per os, q 12 hours for 14 days) gradually reduced parasitemia levels and induced morphological changes that indicated degeneration of parasites (e.g., segmentation; size reduction; localization in the cell limbic and/or torn state of the nucleus; and swelling, decrease, or disappearance of the cytoplasm) in the majority of dogs. Clindamycin treatment reduced the clinical symptoms characteristic of Babesia infection, including anemia, anorexia, and listlessness. Clindamycin might be useful as a medicine for treatment of B. gibsoni infection.

Single administration of enterococcal preparation (FK-23) augments non-specific immune responses in healthy dogs

Influence of a single administration of heat-killed Enterococcus faecalis FK-23 preparation (FK-23) on non-specific immune responses was evaluated in healthy dogs. The dogs received a single administration of FK-23 at a dose of 100 mg/kg perorally and thereafter a complete blood count (CBC), leukocyte differential count, phagocytic activity of peripheral blood neutrophils and a lymphocyte blast transformation (LBT) test were assessed. Although FK-23 had no effect on the CBC or leukocyte differential count, treatment of the drug caused a 1.4-fold increase in neutrophil phagocytosis compared to FK-23 non-treated healthy dogs. LBT activities of phytohemagglutinin (PHA) and pokeweed mitogen (PWM) were also activated to twice the control levels and that of concanavalin A (Con A) was increased to one and a half times by the FK-23 treatment. Thus, a single administration of FK-23 appears to augment host resistance through stimulation of the non-specific immune responses in vivo.

Distribution, Histochemical and Enzyme Histochemical Characterization of Mast Cells in Dogs

This study describes the distribution, proteoglycan properties and protease activity of mast cells from 15 different dog organs. In beagles and mixed breed dogs, staining with Alcian Blue–Safranin O revealed mast cells in all the organs examined. However, their numbers varied and they demonstrated unique localization patterns within some of these organs. Berberine sulphate fluorescence-positive mast cells were observed in the submucosa, muscularis and serosa of the intestines, as well as the tongue and liver (within the connective tissue). Mast cells within the intestinal mucosa were negative for, or demonstrated weak, berberine sulphate staining. Heterogeneity of mast cells in terms of the proteoglycans contained within their granules was further confirmed by determination of critical electrolyte concentrations (CECs). The CECs of mast cells within the connective tissue of several organs, including the intestines (submucosal and muscularis–serosal layers) were all greater than 1.0 M. The results from CEC experiments together with berberine staining indicate that heparin was contained within their granules. Relative to the CECs of mast cells in other organs, mast cells in the intestinal mucosa exhibited lower CECs, suggesting that the proteoglycans within their granules were of lower charge density and/or molecular weight. Although mast cells were classified into two groups by proteoglycans within the granules, enzyme histochemical analysis in beagles revealed three subtypes of mast cells: chymase (MCC), tryptase (MCT) and dual positive (MCTC) cells. There was no correlation between the proteoglycan content and enzyme properties of the mast cell granules.

Distribution and enzyme histochemical characterisation of mast cells in cats.

Mast cells from 15 different cat organs were examined in terms of distribution and protease activity. The number of mast cells in each site was found to vary when visualised by metachromatic staining using Alcian Blue. Enzyme histochemical analysis revealed the existence of two subtypes of mast cells. These were categorised based on protease content, i.e. whether the mast cells contained chymase or tryptase. Tryptase-positive mast cells were clearly identifiable in every organ examined, whereas chymase-containing mast cells were predominantly observed in the ear (skin), tongue, spleen, and submucosa of the stomach and rectum. The chymase-reactive cells were not detected in the heart, or in the muscularis or serosa of the duodenum, jejunum, ileum or rectum. In addition, we suggest the existence of another subtype of mast cell containing both chymase and tryptase and localised within the ear (skin), tongue, spleen and submucosa of the rectum.