Colorimetrical rate assay for urinary dipeptidyl peptidase iv (dppiv) activity using a new substrate

We synthesized a new substrate glycyl-L-proline 3,5-dibromo-4-hydroxyanilide (Gly-Pro-DBAP), for dipeptidyl peptidase IV (DPPIV). Its hydrolysis by DPPIV resulted in the formation of a chromophore, 2,6-dibromo-phenol-indo-p-xylenol, and its maximal absorption wavelength (600 nm) was longer than that of p-nitroaniline (415 nm) released from conventional substrate, glycyl-L-proline pnitroanilide (Gly-Pro-pNA). We also established the rate assay for urinary DPPIV activity using Gly-Pro-DBAP. The optimum pH was between 8.5 and 9.0. The apparent Km was 1.1 mmol/1. The detectable range was 2.5–350 U/I. No changes in blank values occured throughout the enzyme reaction in the optimum pH. Its value was also much lower than Gly-Pro-pNA. CVs for within-run and between-run were 1.1% (n=10) and 3.0% (n=10), respectively. Among tested peptidases, only DPPIV could hydrolyze Gly-Pro-DBAP. Among the protease inhibitors, only two, diprotin-A and phenylmethylsulfonyl fluoride (PMSA), could inhibit DPPIV activity. The present method did not interfere with urinary ingredients such as hemoglobin. The correlation between the present (y) and conventional (x) methods is presented by the equation y=1.121×+0.096 (r=0.993). Thus the present method provides practical advantages over the conventional method for routine laboratory use.©1995 wiley-Liss, inc.     

Optimal growth of human blood hematopoietic progenitor cells collected by apheresis for autografts

For safe autografts with peripheral blood hematopoietic cells (PBSCT), better methods for determining the kinetics of stem cell populations and predicting engraftment speed after PBSCT need to be established. Current methods include culture in semi-solid medium and measurement of CD34 cell surface antigen. In this study with only partially purified blood cells obtained from children with cancer in remission, we compared the effects of phytohemagglutinin-stimulated lymphocyte-conditioned medium (PHA-LCM) and recombinant human cytokines on the growth of progenitor cells in a methylcellulose culture system. Interleukin-3 (IL-3) alone supported more progenitor growth than standard PHA-LCM by a factor of 1.54 for colony-forming unit granulocyte/macrophages (CFU-GM) and by a factor of 1.84 for burst-forming unit/erythroids (BFU-E). No significant change, in terms of the number of growing colonies, was observed by adding granulocyte/macrophage colony-stimulating factor (GM-CSF), granulocyte-CSF (G-CSF), or IL-1 to IL-3. However, the addition of G-CSF resulted in increased colony size. A further increase in CFU-GM growth was observed by the addition of IFN-γ to the combination of cytokines. No significant effect was observed when stem cell factor (SCF) was added to the combination of cytokines containing IL-3, G-CSF, and IFN-γ. This analysis suggests that the combination of IL-3, G-CSF, and IFN-γ may provide sufficient stimulation for the growth of human blood cells. The effects of different oxygen tensions on progenitor growth in the presence of IL-3, G-CSF, and IFN-γ were also evaluated. Both CFU-GM and BFU-E formation were increased when the culture was grown at 5% O₂, as compared with an ambient 20% O₂ tension. A small number of infused cells were grown in culture incorporating either IL-3, G-CSF, and IFN-γ at 5% O₂ or PHA-LCM at 20% O₂, and the number of infused cells was correlated to the speed of hematopoietic recovery after PBSCT. Although a significant negative correlation was observed between the number of infused CFU-GM per kilogram of the patient's body weight and the recovery of hematopoiesis under both culture conditions, a better correlation was found when the former method was applied (P lt; .001 vs. P lt; .05). These findings suggest that a culture containing IL-3. G-CSF, and IFN-γ at low O₂ tension provides satisfactory conditions for the proliferation of blood progenitors, and that this mixture of recombinant cytokines may enable a standardized hematopoietic progenitor assay for PBSCT.     

Liver Damage Induced by Bile Duct Ligation Affects CYP Isoenzymes Differently in Rats

Abstract: We examined the influence of liver damage induced by bile ducl ligation on the activity and the expression of hepatic cytochrome P450 (CYP) IA. 2B, 2C6. 2C11. 2E1 and 3A2 in male Sprague-Dawley rats. In the ligation group. testosterone 2α-, 16α-. and 6β-hydroxylase activities were severely decreased, whereas ethoxyresorufin O-deethylase and progesterone 21-hydroxylase activities relatively remained. Pentoxyresorulin O-deethylase and chlorzoxazone 6-hydroxylase activities were reduced to approximately one thirds those of control. The protein contents of these isoenzymes expressed in hepatic microsomes of the ligation group were decreased to 45%. 32%. 79%, 13%, 58%, and 23% of control for CYP1A, 2B, 2C6, 2C11, 2E1 and 3A2. respectively. The rank order of magnitude of the influence of bile duct ligation on CYP isoenzymes, assessed by the reduction in the enzyme activity and the protein content, corresponded with each other except CYP1A. The reduction of the enzyme activities significantly correlated with the reduction in the protein contents of different isoenzymes. These results suggested that bile duct ligation affected CYP isoenzyme activities and contents with different extent.     

HISTOLOGICAL CLASSIFICATION OF EPITHELIAL POLYPOID LESIONS OF THE GALLBLADDER

Thirty epithelial polypoid lesions in 24 surgically resected gallbladders were examined histologically and immunohistochemically and then classified into two types according to the characterstics of the epithelium. One type consisted of proliferation of ordinary gallbladder epithelium without any metaplastic change while the other type was characterized by proliferation of metaplastic epithelium, such as mucous glands, endocrine cells and lysozyme-immuno-reactive cells. Moreover, each lesion was subdivided into non-neoplastic epithelial polyp or neoplastic adenoma. We therefore classified the non-neoplastic epithelial polyps into hyperplastic polyps and metaplastic polyps, and the adenomas into ordinary type and metaplastic type. Moreover, we found that atypical glands within metaplastic-type adenoma were not infrequently observed, and that these lesions also presented metaplastic changes. From these results, the possibility of an adenoma-carcinoma sequence was discussed. ACTA PATHOL JPN 38: 181–192, 1988.     

Abnormal67Ga uptake in a fibrosarcoma of the pericardium with malignant transformation

A 31-year-old woman presented with general malaise, back pain, and edema of the lower extremities. A chest X-ray film showed an enlarged cardiac shadow and clear lung fields. A pericardial lesion with decreased activity on blood pool imaging and increased uptake on gallium citrate imaging displaced the heart upwards and to the left. The pericardial mass showed an inhomogencous signal intensity on MRI and was large enough to obstruct the venous return by compressing the heart. At operation, the mass was found to originate from the pericardium and was histologically identified as a malignant fibrosarcoma. Twelve years previously, the patient had undergone an operation for the removal of a pericardial tumor which was histologically identified as a benign hemangioma. In view of the rarity of pericardial tumors, the present tumor is suspected to have undergone a transformation from benign hemangioma to malignant fibrosarcoma.     

Identification of genes associated with dedifferentiation of hepatocellular carcinoma with expression profiling analysis.

To identify the genes associated with dedifferentiation of hepatocellular carcinoma (HCC), gene expression profiles of HCCs of well-and moderately differentiated grades were compared by means of oligonucleotide arrays. One tumor showed a nodule-in-nodule appearance (NIN), which is occasionally observed in the course of progression of HCC from well to less differentiated grade, when an inner, moderately differentiated tumor (MD) develops sequentially from the outer, well-differentiated tumor (WD). Seventy-six genes were identified to be up-regulated more than 3-fold and 33 genes were down-regulated in the inner nodule in NIN. By statistical analysis of the profiles from 10 individual additional liver tumors, 5 WDs and 5 MDs, we were able to identify 12 genes, LAMA3, PPIB, ADAR, PSMD4, NDUFS8, D9SVA, CCT3, GBAP, ARD1, RDBP, CSRP2, and TLE1, with significantly elevated expression, and 4 genes, CP, IL7R, CD48, and PLGL, with decreased expression in MD. These selected genes were further validated using another 12 tumors, 5 WDs and 7 MDs, with semi-quantitative RT-PCR. We also applied neighborhood analysis to list the genes with high predictability values as most closely correlated with WD-MD distinction. Seven genes, ADAR, PSMD4, D9SVA, CCT3, GBAP, RDBP, and CSRP2, whose expression was elevated and one gene, IL7R, whose expression was decreased, were included among the top 50 predictor genes. These genes are likely to be associated with dedifferentiation of HCC and their identification may help to elucidate the mechanism of liver cancer progression.     

Reductions in bone mass, structure, and strength in axial and appendicular skeletons associated with increased turnover after ovariectomy in mature cynomolgus monkeys and preventive effects of clodronate.

Over 16 months, we evaluated the effects of ovariectomy (OVX) and bisphosphonate clodronate (CLO) on bone in 48 cynomolgus monkeys (9-15 years old) fed a normal calcium diet. We established three OVX groups (oral CLO at 0 [OVX control], 12, or 60 mg/kg per day) and one sham-operated (SHAM) group. At 16 months, the bone mineral density (BMD) values (percentage of group baseline; OVX control vs. SHAM) for lumbar bone (L3-L5), proximal femur, midfemur, radius, and tibia were -2.6% versus 11.2%, -3.5% versus 8.9%, -3.0% versus 9.0%, -5.5% versus 15.7%, and -6.7% versus 13.9%, respectively. In OVX control (i) tibia showed significant loss of bone mineral content (BMC; vs. baseline), (ii) urinary deoxypyridinoline (DPD) and serum osteocalcin (OC) levels increased (peak = 182% and 168%, respectively, of SHAM), (iii) in lumbar bone and midfemur, ultimate load (UL) was reduced (vs. SHAM), (iv) in lumbar bone, trabecular bone-formation rates (BFRs) were not changed significantly, but tibial endocortical and intracortical bone formation rates were significantly raised (vs. SHAM), (v) the volumetric BMD (vBMD) and geometry of the tibial cortex (measured by peripheral quantitative computed tomography [pQCT]) were significantly reduced (vs. SHAM). CLO, 60 mg/kg per day but not 12 mg/kg per day, significantly inhibited OVX-induced changes, age-dependent increases in bone mass, and ability to maintain structure. Thus, in OVX mature cynomolgus monkeys (possibly, a unique model of the cortical bone loss secondary to estrogen deficiency), the post-OVX increases in systemic bone markers were slight, but stimulation of local turnover in the cortical envelope was enough to cause bone loss (more so in tibia than in lumbar trabecular bone). High-dose CLO prevented these changes.