Kazuhiro Nakama

Factors associated with patency of the uterine cervix in bitches with pyometra.

This study examined factors involved in the patency of uterine cervices in the bitch with pyometra. The uterine cervices were obtained from the bitches with pyometra at the time of ovariohysterectomy. Cervical patency was measured by inserting the stainless steel rods with different diameter into cervical canals. Collagen concentration and collagenase activity (for type I collagen) in the tissue were determined and the number of neutrophils, which contain the enzymes related to collagen metabolism, and morphological changes in collagenous fibers were studied by histological examination. Levels of mRNA expressions for hormonal factors, estrogen receptor-α (ER-α), progesterone receptor (PR), relaxin (Rlx) and an attractant of neutrophils, interleukin-8 (IL-8), were determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). In the statistical analysis, the cervical patency positively correlated with the collagenase activity, and negative correlation was found between the cervical patency and collagen concentration. Histological examination indicated distinct positive correlation between the cervical patency and the number of neutrophils in the cervical stroma and that the collagenous fiber in the uterine cervix became thinner and degraded with increase of the cervical patency. Although there was no relationship between the cervical patency and the level of mRNA for ER-α, PR or Rlx, IL-8 mRNA level has significant positive correlation with the cervical patency and the number of neutrophils in the cervical stroma. These results suggest that the increased number of neutrophils in the uterine cervix, which could be related to the local expression of IL-8, may be involved in collagen degradation and connective tissue remodeling to increase cervical patency in the bitch with pyometra.

Usefulness of urinary biomarkers for nephrotoxicity in cynomolgus monkeys treated with gentamicin, cisplatin, and puromycin aminonucleoside

The objective of this study was to investigate the availability of novel urinary biomarkers (BMs) such as total protein, albumin, β2-microglobulin, clusterin, cystatin C, neutrophil gelatinase-associated lipocalin (NGAL) for the detection of acute nephrotoxicity in cynomolgus monkeys. Animals (total 9 males/3 groups) were administered gentamicin (GM) subcutaneously at 40 mg/kg for 7 days, cisplatin (CDDP) intravenously at 3 mg/kg once and puromycin aminonucleoside (PAN) intravenously at 20 mg/kg for 7 days. Two-hr urine on Days 0, 3, and 6, and 16-hr urine and blood on Days 1, 4, and 7 were collected. Novel urinary BMs and conventional clinical pathology parameters were evaluated in parallel to histopathological and electron microscopic examinations on the kidneys at termination. Urinary BMs and enzymes increased earlier than serum creatinine and blood urea nitrogen, particularly in 2-hr urine after dosing on Day 0, urinary albumin was increased in all groups and urinary NGAL with the highest magnitude of change rate among urinary BMs was observed in the GM and CDDP groups. Degeneration/necrosis and hyaline droplet of renal tubule, cellular cast and dilatation of renal tubule, and hypertrophy of podocytes were observed in the GEN, CDDP, and PAN groups, respectively. These results showed that the increases of urinary BMs reflected the agent-specific renal damages and these urinary BMs could be useful for the detection of segment-specific nephrotoxicity. Urinary albumin and NGAL are the most useful BMs to estimate glomerular and distal tubular damages, respectively, as well as proximal tubular damage in cynomolgus monkeys.