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Biomedical subjects

J Spano

Publications and source records attributed to J Spano.

14 recordsLinked to original sources
PubMed2001

Isolation and characterization of canine hematopoietic progenitor cells.

The purpose of this study was to purify and characterize canine hematopoietic progenitor cells for surface antigen phenotype and reconstitution ability. Canine hematopoietic progenitor cells were isolated by density gradient sedimentation, lineage depletion with monoclonal antibodies, and fluorescence-activated cell sorting (FACS) for selection of cells with low-forward and right-angle scatter that were rhodamine 123 (Rh-123)(dull). Isolated cells were characterized for expression of CD34, c-kit, and Flt-3. A canine/murine xenograft model and a mixed-chimerism assay were used to examine the in vivo proliferative potential of isolated cells. The lineage-positive (Lin(+)) cells represented 80 +/- 11% (n = 22) of the input mononuclear cells. Lineage depletion resulted in a fourfold increase in colony-forming unit granulocyte/monocyte (CFU-GM), a 2.5-fold increase in burst-forming unit-erythroid (BFU-E), and a twofold increase in the number of Rh-123(dull) cells over nonlineage-depleted bone marrow mononuclear cells (BMMCs). Lineage depletion led to a 2.7-fold enrichment of CD34 cells, a 10.4-fold enrichment of c-kit cells, and a 10.8-fold enrichment of CD34/c-kit(+1) cells over total BMMCs. Nineteen percent of lineage-negative (Lin(-)) cells were positive for Flt-3. Injection of canine cells into irradiated (400 rads) NOD/SCID mice resulted in the detection of canine CD45(+) cells with BMMCs, Lin(-) cells, or Rh-123(dull) cells. Transplantation of purified Lin(-) cells in dog leukocyte antigen-matched littermates resulted in low-level engraftment for at least 10 weeks. The development of methods for purification and characterization of canine hematopoietic progenitor cells should enhance the utilization of the canine model for a variety of experimental and therapeutic purposes.

Animals↗
PubMed1997

Identification of thrombospondin as a high molecular mass protein released from activated equine platelets.

OBJECTIVE: To establish the existence of platelet-derived proteins in equine plasma, with the future goal of developing an assay for the detection of in vivo platelet activation. ANIMALS: 5 mature healthy horses. PROCEDURE: Platelet-rich plasma and platelet-poor plasma were prepared from anticoagulated blood. Platelets were separated from plasma proteins by gel filtration, then activated with 0.5 microM platelet-activating factor. Protease inhibitors were added, and the released platelet proteins were harvested. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was performed on the released platelet proteins and platelet-poor plasma, and the resultant silver-stained bands were compared. Immunoblot analysis was performed on released platelet proteins, using an antibody to human thrombospondin; human platelet-derived proteins served as the positive control for the antibody. RESULTS: Released platelet proteins in the presence of beta-mercaptoethanol (reduced samples) contained several proteins that were not observed in plasma including (mean +/- SEM) 194 +/- 2, 159 +/- 2, 151 +/- 2, 104 +/- 2, and 95 +/- 1 kd. Immunoblots of released platelet proteins had a prominent 180 +/- 2-kd protein in reduced samples that was recognized by an antibody to human thrombospondin, and with prolonged color development, 2 additional less prominent proteins (166 +/- 1 and 155 +/- 1 kd) were observed. CONCLUSIONS: Several proteins are released from activated equine platelets that are not detectable in normal equine plasma. Thrombospondin is one of the high molecular mass proteins released by activated equine platelets. CLINICAL RELEVANCE: An assay can be developed for detection of thrombospondin in equine plasma and may be useful for detection of in vivo platelet activation in horses.

Animals↗
PubMed1991

Physiological effects of a perfluorochemical blood substitute in beagle dogs.

Perfluorochemical (PFC) emulsions have been examined for use as erythrocyte substitutes in the treatment of various disease states. The physiological changes induced by PFC infusion would be an important determinant of successful clinical therapy. Previous studies have reported PFC induced changes in the disposition of drugs. This report describes some physiological (hematology, cardiovascular, liver enzyme) changes resulting from a 30% blood exchange with a PFC emulsion in Beagle dogs. A 30% blood exchange with hydroxyethylstarch (HES) also was evaluated and compared to the PFC emulsion exchange. The blood pressure was markedly reduced shortly after PFC infusion while HES infusion produced only minor changes. Changes in the heart rate following blood replacement were similar for PFC and HES treated dogs. Hematology profiles also were similar for the PFC and HES treatment groups. The liver enzyme levels in PFC treated dogs showed marked elevations beginning shortly after PFC infusion and remained elevated for months after the initial PFC blood replacement. In contrast, HES treated dogs exhibited no observable changes in liver enzyme levels over the time course of the study.

Animals↗
PubMed1988

Evaluation of Cassia obtusifolia (sicklepod) seed consumption in Holstein calves.

Fifteen Holstein bull calves weighing 135-160 kg (300-350 lb) were randomly assigned to 3 groups of 5 animals each. Each calf was individually fed free choice Bermuda grass hay and 3.63 kg (8 lb) of a commercial 14% crude protein ration/day. Group 1 (control) received no Cassia obtusifolia seed, group 2 (low exposure) received 0.45 kg (1 lb) of C obtusifolia seed (12.5% of ration and approximately 0.27% of body weight) and group 3 (high exposure) received 1.81 kg (4 lb) C obtusifolia seed (50% of ration and approximately 1.19% of body weight) from day 0-9, and then received 1.36 kg (3 lb) (37.5% of ration and 0.89% of body weight) from day 10-24. The effects of low and high C obtusifolia seed contamination were intermittent feed refusal, diarrhea, and decreased weight gain. Average daily weight gains (ADG) for the control, low exposure and high exposure groups, were 0.76, 0.53, 0.31 kg/day, respectively. The ADG of the control calves was significantly greater than the ADG of the high exposure calves (p less than 0.0001) and the low exposure calves (p less than 0.0059). The ADG of the low exposure calves was significantly greater than the ADG of the high exposure calves (p less than 0.0209). No change was observed in serum aspartate aminotransferase, creatine phosphokinase, lactic dehydrogenase activity, and histologic examination showed no evidence of muscle necrosis.

Animals↗
PubMed1988

Platelet function testing in the pony.

Platelet isolation techniques and platelet function were evaluated in 35 adult ponies. Platelet recovery from whole blood was consistent and the preparation of platelet rich plasma was facilitated by an enhanced erythrocyte sedimentation rate. All platelet samples aggregated in response to 10 microM ADP. However, concentrations of ADP as high as 100 microM did not elicit significant 14C-serotonin release. Collagen induced irreversible platelet aggregation and 14C-serotonin release in all samples. The threshold dose for collagen in most ponies was 1.5 micrograms. Arachidonic acid (500 microM) failed to induce irreversible platelet aggregation or 14C-serotonin release in any of the samples evaluated. Pony platelets were nonresponsive to epinephrine (5.5 microM).

Adenosine Diphosphate↗
PubMed1988

Techniques for blood sampling in avian species.

In avian species' common sites for blood sampling include the basilic, jugular, and superficial plantar metatarsal veins, heart and occipital sinus. The lateral thoracic vein is also used in the turkey. The sites with the least trauma to the animal are the basilic, superficial plantar metatarsal, and lateral thoracic veins from which adequate volumes of blood can be obtained. Heart puncture and occipital sinus sampling procedures are expedient and large volumes of blood can be obtained however these sites are the most traumatic. The superficial plantar metatarsal vein was the site for best repeat sampling in the duck and the chicken and the basilic in the turkey.

Animals↗
PubMed1988

A study of erythrocyte changes in white Pekin ducks.

Erythrocyte distribution studies were determined in 5 control (non-stressed) and 5 ducks which were bled 1.6% of their body weight 3 times at 10-day intervals. Erythrocyte distribution studies were performed using a Coulter ZBI with channelizer and Accucomp accessory. The total erythrocyte count (P1 + P2) and the P1 population dropped 10% from the pre-bleeding count; however, test animals exhibited less than a 10% change after the third sampling. There was no apparent effect of the bleeding on the total counts and the P1 count over the 28-day trial period.

Animals↗