Yuji Uzuka

Aloe vera oral administration accelerates acute radiation-delayed wound healing by stimulating transforming growth factor-β and fibroblast growth factor production

BACKGROUND Delayed wound healing is a significant clinical problem in patients who have had previous irradiation. This study investigated the effectiveness of Aloe vera (Av) on acute radiation-delayed wound healing. METHODS The effect of Av was studied in radiation-exposed rats compared with radiation-only and control rats. Skin wounds were excised on the back of rats after 3 days of local radiation. Wound size was measured on days 0, 3, 6, 9, and 12 after wounding. Wound tissues were examined histologically and the expressions of transforming growth factor β-1 (TGF-β-1) and basic fibroblast growth factor (bFGF) were examined by immunohistochemistry and reverse-transcription polymerase chain reaction. RESULTS Wound contraction was accelerated significantly by Av on days 6 and 12 after wounding. Furthermore, the inflammatory cell infiltration, fibroblast proliferation, collagen deposition, angiogenesis, and the expression levels of TGF-β-1 and bFGF were significantly higher in the radiation plus Av group compared with the radiation-only group. CONCLUSIONS These data showed the potential application of Av to improve the acute radiation-delayed wound healing by increasing TGF-β-1 and bFGF production.

Effects of extracellular Ca2+ on phagocytosis and intracellular Ca2+ concentrations in polymorphonuclear leukocytes of postpartum dairy cows

The aim of this study was to determine the effects of extracellular Ca(2+) concentration ([Ca(2+)](e)) on phagocytosis and intracellular Ca(2+) concentration ([Ca(2+)](i)) in bovine polymorphonuclear leukocytes (PMNs). The experiments were performed by using blood samples from parturient paretic and clinically normal parturient cows and manipulating the [Ca(2+)](e) in vitro. Phagocytosis by PMNs (with and without stimulation with phorbol myristate acetate and inhibition with cytochalasin B) and resting [Ca(2+)](i) were significantly lower in parturient paretic cows. Repletion of Ca(2+) in the extracellular media for the samples from these animals increased phagocytosis and resting [Ca(2+)](i). In the blood of clinically normal parturient cows, decreasing the [Ca(2+)](e) decreased phagocytosis and resting [Ca(2+)](i) in PMNs, but increasing the [Ca(2+)](e) did not affect phagocytosis. These results suggest that the hypocalcemic condition of parturient paretic cows in vivo causes decreased phagocytosis and resting [Ca(2+)](i) in PMNs, which may partly contribute to greater susceptibility to infection.

Application of the single blood sample method to estimate feline glomerular filtration rate in a clinically relevant situation

To compare glomerular filtration rate (GFR) estimated by a single blood sample method, the non-ionic contrast medium iodixanol (40 mg I/kg) and the standard GFR tracer inulin (50 mg/kg) were co-administered as a bolus intravenous injection to 12 cats, followed by blood collection 60 and 90 mins later. Serum iodixanol and inulin concentrations were measured separately by high-performance liquid chromatography and colourimetric assay. A correlation (r = 0.90, P <0.01) was noted between GFR values estimated by the single-blood-sample method using iodixanol and inulin, indicating that this procedure can apply to feline GFR estimates, even if different GFR tracers are used. In a feline kidney transplantation study, the GFR was monitored subsequently by this simplified iodixanol method throughout a 750-day observation period with no adverse reactions. The results demonstrate that the simplified method, including the volume of distribution, can be used as an alternative or expedient tool in a clinically relevant situation.

Combination of serum phosphorylated neurofilament heavy subunit and hyperintensity of intramedullary T2W on magnetic resonance imaging provides better prognostic value of canine thoracolumbar intervertebral disc herniation.

The aim of this study was to evaluate the prognostic value of concurrent measurement of serum phosphorylated neurofilament heavy subunit (pNF-H) concentration and intramedullary T2W hyperintensity in paraplegic to paraplegic dogs. Our hypothesis was that concurrent measurement of these would provide a more accurate prediction of functional outcome in dogs with thoracolumbar intervertebral disc herniation (IVDH). A prospective case-control clinical study was designed using 94 dogs with acute onset of thoracolumbar IVDH. The association of serum pNF-H concentration, T2W hyperintensity on sagittal MRI (T2H/L2), deep pain perception and surgical outcome were evaluated with logistic regression analysis after three months for all 94 surgically treated dogs. Sensitivity to predict non-ambulatory outcome was compared among pNF-H and T2H/L2 and combination of both. Logistic regression analysis indicated that serum pNF-H concentration and T2H/L2 were significantly correlated with surgical outcome (P<0.05); however, deep pain perception was not (P=0.41). The results of logistic regression analysis indicated that the odds ratios of unsuccessful long-term outcome were 2.6 for serum pNF-H concentration, 1.9 for T2H/L2 and 2.3 for deep pain sensation. The sensitivity and specificity to predict non-ambulatory outcome for using serum parameter pNF-H>2.6 ng/ml, using T2H/L2 value of>0.84 and using both serum pNF-H and T2H/L2, were 95% and 75.7%, 65% and 86.5%, and 90.0% and 97.5%, respectively. Therefore, combined measurements of serum pNF-H and T2H/L2 might be useful for predicting long-term outcome in dogs with thoracolumbar IVDH.

Performance of a new carbon dioxide absorbent, Yabashi lime ® as compared to conventional carbon dioxide absorbent during sevoflurane anesthesia in dogs

In the present study, we compare a new carbon dioxide (CO2) absorbent, Yabashi lime® with a conventional CO2 absorbent, Sodasorb® as a control CO2 absorbent for Compound A (CA) and Carbon monoxide (CO) productions. Four dogs were anesthetized with sevoflurane. Each dog was anesthetized with four preparations, Yabashi lime® with high or low-flow rate of oxygen and control CO2 absorbent with high or low-flow rate. CA and CO concentrations in the anesthetic circuit, canister temperature and carbooxyhemoglobin (COHb) concentration in the blood were measured. Yabashi lime® did not produce CA. Control CO2 absorbent generated CA, and its concentration was significantly higher in low-flow rate than a high-flow rate. CO was generated only in low-flow rate groups, but there was no significance between Yabashi lime® groups and control CO2 absorbent groups. However, the CO concentration in the circuit could not be detected (≤5ppm), and no change was found in COHb level. Canister temperature was significantly higher in low-flow rate groups than high-flow rate groups. Furthermore, in low-flow rate groups, the lower layer of canister temperature in control CO2 absorbent group was significantly higher than Yabashi lime® group. CA and CO productions are thought to be related to the composition of CO2 absorbent, flow rate and canister temperature. Though CO concentration is equal, it might be safer to use Yabashi lime® with sevoflurane anesthesia in dogs than conventional CO2 absorbent at the point of CA production.

Estimation of glomerular filtration rate in dogs by a single-blood sample method involving iodixanol

OBJECTIVE To establish a simplified single-blood-sample method (SBSM) involving iodixanol to estimate glomerular filtration rate (GFR) in dogs and compare data provided by that procedure with data provided by a conventional multiple-blood-sample method (MBSM) involving inulin. ANIMALS 26 healthy dogs and 36 dogs with naturally occurring renal disease. PROCEDURES Dogs were used in various preliminary experiments to establish protocols for the SBSM and the MBSM of GFR estimation. To evaluate the relationship between GFRs obtained by the SBSM and the MBSM each involving iodixanol, iodixanol (40 mg of I/kg) was administered IV to 26 healthy dogs and 36 dogs with renal disease; blood sample collection was performed before and at 60, 90, and 120 minutes after the injection. To evaluate the relationship between GFRs obtained by the SBSM involving iodixanol and the MBSM involving inulin, iodixanol (40 mg of I/kg) and inulin (50 mg/kg) were coadministered IV to 22 healthy dogs and 3 dogs with renal disease, followed by blood sample collection 30, 60, 90, and 120 minutes later. Serum iodixanol and inulin concentrations were separately determined by reverse-phase high-performance liquid chromatography. RESULTS Findings revealed a correlation (r = 0.99) between GFR estimated by the SBSM and MBSM each involving iodixanol. Likewise, GFR estimated by the SBSM involving iodixanol was correlated (r = 0.89) with that estimated by the MBSM involving inulin. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the SBSM involving iodixanol can be applied to estimate GFR in dogs, instead of use of an MBSM.