Determination of recombinant human epidermal growth factor (rhEGF) in a pharmaceutical formulation by high performance liquid chromatography with electrochemical detection

A novel HPLC method with electrochemical detection has been developed for the determination of recombinant human epidermal growth factor (rhEGF) in pharmaceutical products. rhEGF was separated from other components in formulation on a reversed-phase C18 column with 24% acetonitrile in 0.1 M phosphate buffer (pH 4.75). The optimum electrochemical oxidation of EGF was obtained at 0.85 V vs. Ag/AgCl in a glassy carbon working electrode due to electroactive tyrosine, tryptophan, methionine, and arginine residues. The quantitation range was from 1.0 to 200 ng of rhEGF with the linear correlation coefficient greater than 0.999. The method was successfully applied for the quantitation of rhEGF in a pharmaceutical preparation.

High glucose induces MCP-1 expression partly via tyrosine kinase-AP-1 pathway in peritoneal mesothelial cells

BACKGROUND

High glucose in peritoneal dialysis solutions has been implicated in the pathogenesis of peritoneal fibrosis in chronic ambulatory peritoneal dialysis (CAPD) patients. However, the mechanisms are not very clear. Peritoneal macrophages seem to participate in the process of peritoneal fibrosis and monocyte chemoattractant protein-1 (MCP-1) plays a key role in the recruitment of monocytes toward the peritoneal cavity. However, little is known about the effect of high glucose on MCP-1 expression and its signal transduction pathway in human peritoneal mesothelial cells.

METHODS

Mesothelial cells were cultured with glucose (5 to 100 mmol/L) or mannitol chronically for up to seven days. MCP-1 expression of mRNA and protein was measured by Northern blot analysis and enzyme-linked immunosorbent assay (ELISA). Chemotactic activity of high-glucose-conditioned culture supernatant was measured by chemotactic assay. To examine the roles of the transcription factors activator protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB), electrophoretic mobility shift assay (EMSA) was performed.

RESULTS

Glucose induced MCP-1 mRNA expression in a time- and dose-dependent manner. MCP-1 protein in cell culture supernant was also increased. Equivalent concentrations of mannitol had no significant effect. High-glucose-conditioned supernatant possessed an increased chemotactic activity for monocytes, which was neutralized by anti-MCP-1 antibody. EMSA revealed that glucose increased the AP-1 binding activity in a time- and dose-dependent manner, but not NF-kappaB. Curcumin, an inhibitor of AP-1, dose-dependently suppressed the induction of MCP-1 mRNA by high glucose. Tyrosine kinase inhibitors such as genistein (12.5 to 50 micromol/L) and herbimycin A (0.1 to 1 micromol/L) inhibited the high-glucose-induced MCP-1 mRNA expression in a dose-dependent manner, and also suppressed the high-glucose-induced AP-1 binding activity.

CONCLUSIONS

: High glucose induced mesothelial MCP-1 expression partly via the tyrosine kinase-AP-1 pathway.

Effect of interleukin-6 deficiency on the formation of periapical lesions after pulp exposure in mice

OBJECTIVE

The multifunctional cytokine interleukin-6 (IL-6) has actions on multiple cell types, including promotion of the development of immune cells and osteoclasts. Periapical inflammation as the result of root canal infection is characterized by the accumulation of inflammatory cells and bone resorption. The effect of IL-6 on periapical lesion formation after pulpal infection is unknown. We sought to determine whether deletion of IL-6 affects periapical lesion formation after pulp exposure.

METHODS

Molar pulps of homozygous IL-6 knock-out mice (IL-6(-/-), strain B6, 129-Il6tm1Koe ) and wild-type mice (IL-6(+/+)) were exposed, and the mice were killed at 1, 2, 3, 5, and 8 weeks after the exposure. Mouse jaws were decalcified and prepared for histologic examination of periapical lesions.

RESULTS

The IL-6(-/-) mice developed larger periapical lesions more rapidly than did the IL-6(+/+) mice.

CONCLUSIONS

IL-6 deletion promoted periapical lesion development.

Uptake of beta-carotene by ovarian and uterine tissues and effects on steroidogenesis during the estrous cycle in cats

OBJECTIVES

To determine uptake of beta-carotene by ovarian and uterine tissues and influence of dietary beta-carotene on steroidogenesis and production of uterine protein during the estrous cycle in cats.

ANIMALS

56 female cats.

PROCEDURE

Cats were fed diets containing 0, 0.4, 2, or 10 mg of beta-carotene daily for 8 weeks prior to detection of estrus. At time of observed estrus, all cats were manually induced to ovulate. Blood samples were obtained at estrus and every 2 days until day 14 after ovulation. On that day, cats underment laparotomy, and the ovaries and uterus were removed. Uterine contents were flushed, and luteal and endometrial tissues were obtained.

RESULTS

Concentrations of beta-carotene in plasma and luteal and endometrial tissues increased in a dose-dependent manner. Concentrations of plasma progesterone were higher between days 6 and 10 after ovulation in cats fed diets containing beta-carotene and continued to increase through day 14 after ovulation in cats fed a diet containing 10 mg of beta-carotene. Plasma concentration of estradiol-17beta also was higher between days 0 and 4 after ovulation in cats fed diets containing beta-carotene. Cats fed a diet containing 10 mg of beta-carotene had the highest plasma estradiol concentration. Total uterine protein concentration was higher in cats fed beta-carotene, compared with values for cats fed an unsupplemented diet.

CONCLUSION AND CLINICAL RELEVANCE

Cats readily absorb beta-carotene. Increased concentrations of progesterone, estradiol, and uterine protein may provide more optimal ovarian function or a better uterine environment for embryonic survival and development.

Influence of oocyte nuclei on demethylation of donor genome in cloned bovine embryos

We recently demonstrated that satellite regions exhibit an aberrant DNA methylation in cloned bovine embryos. Here, we examined, using bisulfite-sequencing technology, whether the inefficient demethylation of cloned donor genomes could be rescued by the presence of oocytic nuclei. Both AciI digestion and sequencing analyses showed that satellite sequence was demethylated more efficiently in cloned tetraploid blastocysts than in diploid clones. When methyl-CpG density (the number of methyl-CpG sites per string) was scored, a significant decrease was observed in tetraploids (P<0.001). These results suggest that unknown mechanisms provided by oocytic nuclei could assist the demethylation of satellite sequences in tetraploid clones.

Early diuresis renogram findings predict success following pyeloplasty

PURPOSE

We sought to determine whether drainage across the ureteropelvic junction, as indicated by diuretic renography 3 months after pyeloplasty, is an adequate predictor of surgical success.

MATERIALS AND METHODS

The medical records of 150 children who underwent pyeloplasty from 1986 to 1995 were reviewed. After excluding nonevaluable cases a total of 127 renal units remained for investigation. Preoperatively each renal unit was examined with a standardized (well-tempered) furosemide stimulated renal scan. Postoperatively 60 renal units were evaluated with standardized diuretic renal scans at 3 and 12 months, 33 renal units at 3 months only and 34 renal units at 12 months only. Surgical success was defined by half-time less than 20 minutes on a standardized diuretic renogram.

RESULTS

Of the 33 renal units with a single postoperative study at 3 months 32 (97%) had halftime less than 20 minutes on diuretic renography. The remaining patient in this group with half-time greater than 20 minutes showed 60% improvement in half-time and did not require reoperation. Excluding those without delayed followup, surgical success was obtained in 93 of the 94 (99%) renal units. Among the 60 renal units evaluated with 2 postoperative renal scans success was noted in 48 (80%) and 59 (98%) at 3 and 12 months, respectively. Stenosis did not recur in 48 renal units with half-time less than 20 minutes 3 months after repair. In 1 case that had been treated for postoperative urinoma half-time was greater than 40 minutes at 3 months and repeat pyeloplasty was required.

CONCLUSIONS

Half-time less than 20 minutes 3 months after pyeloplasty predicts surgical success. Most renal units that improve but still have half-times greater than 20 minutes on an early diuretic renogram will demonstrate continued improvement in drainage patterns at 12 months. Those renal units that show no improvement at 3 months may require reoperation and those with half-time less than 20 minutes at 3 months do not require further evaluation.

Prevalence of arthropod antibodies in Korean patients with allergic rhinitis

Arthropod antigens are main causative agents which induce allergic responses in humans. However, little information is known about the prevalence of specific arthropod allergens in Koreans with allergic diseases. The current study was designed to determine the positive rates of arthropod antibodies by the Korean inhalant panel of MAST-CLA. One hundred sixty patients, who were diagnosed with allergic rhinitis from an out-patient center at the Soonchunhyang University Chunan Hospital, were studied between August 1998 to July 2000. The overall positive rate, at least more than one specific antibody of arthropods such as Dermatophagoides farinae (Df), Dermatophagoides pteronyssinus (Dp), and cockroach mix (Cm), was 46.9%. Each positive rate of Df, Dp, and Cm was 45.0%, 43.1%, and 8.8%, respectively. A significant agreement among arthropod allergens was observed (Df and Dp: 95.6%, Kappa = 0.911, P < 0.001). Our data supported the fact that arthropods were the most common allergens in Korean patients with allergic rhinitis; however, the MAST-CLA should be modified to increase specificity of arthropod allergens.

Early diuresis renogram findings predict success following pyeloplasty

PURPOSE

We sought to determine whether drainage across the ureteropelvic junction, as indicated by diuretic renography 3 months after pyeloplasty, is an adequate predictor of surgical success.

MATERIALS AND METHODS

The medical records of 150 children who underwent pyeloplasty from 1986 to 1995 were reviewed. After excluding nonevaluable cases a total of 127 renal units remained for investigation. Preoperatively each renal unit was examined with a standardized (well-tempered) furosemide stimulated renal scan. Postoperatively 60 renal units were evaluated with standardized diuretic renal scans at 3 and 12 months, 33 renal units at 3 months only and 34 renal units at 12 months only. Surgical success was defined by half-time less than 20 minutes on a standardized diuretic renogram.

RESULTS

Of the 33 renal units with a single postoperative study at 3 months 32 (97%) had halftime less than 20 minutes on diuretic renography. The remaining patient in this group with half-time greater than 20 minutes showed 60% improvement in half-time and did not require reoperation. Excluding those without delayed followup, surgical success was obtained in 93 of the 94 (99%) renal units. Among the 60 renal units evaluated with 2 postoperative renal scans success was noted in 48 (80%) and 59 (98%) at 3 and 12 months, respectively. Stenosis did not recur in 48 renal units with half-time less than 20 minutes 3 months after repair. In 1 case that had been treated for postoperative urinoma half-time was greater than 40 minutes at 3 months and repeat pyeloplasty was required.

CONCLUSIONS

Half-time less than 20 minutes 3 months after pyeloplasty predicts surgical success. Most renal units that improve but still have half-times greater than 20 minutes on an early diuretic renogram will demonstrate continued improvement in drainage patterns at 12 months. Those renal units that show no improvement at 3 months may require reoperation and those with half-time less than 20 minutes at 3 months do not require further evaluation.

Aberrant methylation of donor genome in cloned bovine embryos

Despite recent successes in cloning various animal species, the use of somatic cells as the source of donor nuclei has raised many practically relevant questions such as increased abortion rates, high birth weight and perinatal death. These anomalies may be caused by incomplete epigenetic reprogramming of donor DNA. Genome-wide demethylation occurs during early development, 'erasing' gamete-specific methylation patterns inherited from the parents. This process may be a prerequisite for the formation of pluripotent stem cells that are important for the later development. Here, we provide evidence that cloned bovine embryos may have impaired epigenetic reprogramming capabilities. We found highly aberrant methylation patterns in various genomic regions of cloned embryos. Cloned blastocysts closely resembled donor cells in their overall genomic methylation status, which was very different from that of normal blastocysts produced in vitro or in vivo. We found demethylation of the Bov-B long interspersed nuclear element sequence in normal embryos, but not in cloned embryos, in which the donor-type methylation was simply maintained during preimplantation development. There were also significant variations in the degree of methylation among individual cloned blastocysts. Our findings indicate that the developmental anomalies of cloned embryos could be due to incomplete epigenetic reprogramming of donor genomic DNA.

Effects of pretreatment clinical parameters on bioactive glass implantation in intrabony periodontal defects

BACKGROUND

The various methods for regeneration of periodontal tissue that have been developed can be classified into guided tissue regeneration and bone implantation. Since the implantation materials have shown both deficiencies and merits, dentists have begun exploring the bioactive glass first used in plastic surgery. This paper examines the effectiveness of this new material on periodontal intrabony defects.

METHODS

Clinical effects of bioactive glass implantation in intrabony periodontal defects were evaluated 6 months after surgery in 38 intrabony defects from 38 patients with chronic periodontitis. Twenty-one experimental defects received bioactive glass implantation (test group), while 17 control defects were treated with a flap procedure only (control group). The criteria for comparative observation were preoperative and postoperative probing depth (PD), clinical attachment level (CAL), bone probing depth (BPD), and gingival recession.

RESULTS

Reductions in PD were observed in both groups (P<0.01). The reduction in PD was significantly greater in the test group when preoperative PD exceeded 7 mm (P<0.01). Improvements in CAL were also observed in both groups (P<0.01), with the test group showing significantly greater gains (P<0.05). In those cases where preoperative CAL was less than 7 mm, there was no statistically significant difference between the two groups. Reduction in BPD was observed in both groups, with the test group showing significantly greater reduction (P <0.01). There was no significant difference in BPD change, however, when preoperative BPD was < or =7 mm. Significantly greater reduction of BPD in the test group was observed when intrabony defect depth was >4 mm (P <0.05). Significant improvements in PD, CAL, and BPD were noted in the test group when the crestal involvement exceeded 100 degrees. Correlation test between various clinical parameters indicated that greater changes in PD and CAL in the test group were observed when preoperative CAL was large (P<0.001), and greater changes in PD (P<0.05), CAL (P<0.01), and BPD (P<0.05) were noted when preoperative BPD was large. Correlation between crestal involvement and CAL change was noted only in the control group (P<0.01). High correlations were observed between PD changes and CAL changes and between CAL changes and BPD changes in both groups.

CONCLUSIONS

Use of a bone substitute in a flap operation resulted in significantly greater improvements in CAL and BPD over flap operation alone and seemed to have positive effects in postoperative PD, CAL, and BPD in those cases with more severe preoperative CAL and BPD.

Differential inheritance modes of DNA methylation between euchromatic and heterochromatic DNA sequences in ageing fetal bovine fibroblasts

To elucidate overall changes in DNA methylation occurring by inappropriate epigenetic control during ageing, we compared fetal bovine fibroblasts and their aged neomycin-resistant versions using bisulfite-PCR technology. Reduction in DNA methylation was observed in euchromatic repeats (18S-rRNA/art2) and promoter regions of single-copy genes (the cytokeratin/beta-lactoglobulin/interleukin-13 genes). Contrastingly, a stable maintenance of DNA methylation was revealed in various heterochromatic sequences (satellite I/II/alphoid and Bov-B). The differential inheritance mode of DNA methylation was confirmed through the analysis of individual neomycin-resistant clones. These global, multi-locus analyses provide evidence on the tendency of differential epigenetic modification between genomic DNA regions during ageing.

Prevalence of antibodies to PPD and lipoarabinomannan of Mycobacterium tuberculosis among patients with an indication of fine needle aspiration biopsy

Recent increase in the incidence of lung cancer often makes it difficult to differentiate between lung cancer and tuberculosis (TB), due to their radiologic similarities. Fine needle aspiration biopsy (FNAB) has been widely employed for the diagnosis of lung cancer and TB, but the diagnostic accuracy of TB is not high enough. As a rapid screening test for tuberculosis, we evaluated serological tests using Mycobacterium tuberculosis PPD and lipoarabinomannan (LAM) antigens. A total of 95 patients with indication of FNAB cytology from initial CT findings were enrolled. 25 patients had TB, 76 thoracic malignancy, and six (7.9%) of the lung cancer patients also had TB, indicating much higher prevalence of TB in thoracic tumor patients. Antibodies to PPD were elevated in 18 (72.0%) of 25 TB patients and in 22 (31.4%) of 70 patients with thoracic malignancy. In contrast, only 3 (4.7%) of 64 healthy controls aged 40 or above were seropositive to PPD antigen. The prevalence of anti-PPD antibodies in thoracic tumor patients was therefore significantly greater than that amongst the healthy controls (p<0.001, chi-square test). However, no significant difference in the prevalence of anti-LAM antibodies was found between study subjects and controls. This study demonstrates that thoracic tumor patients have significantly elevated antibodies to PPD; therefore, high anti-PPD seroreactivity in thoracic tumor patients should be cautiously interpreted. A longitudinal investigation on seropositive thoracic tumor patients is required to determine the role of the serological test for TB in lung cancer patients.

Ionizing radiation modulates vascular endothelial growth factor (VEGF) expression through multiple mitogen activated protein kinase dependent pathways

We investigated the role of radiation-induced mitogen activated protein kinase (MAPK) pathway activity in the regulation of proliferation, cell survival and vascular endothelial growth factor (VEGF) production in primary astrocytes and in T9 and RT2 glioblastoma cells derived from Fisher 344 rats. In these cells, ionizing radiation (2 Gy) caused activation of the MAPK pathway which was blocked by specific inhibitor drugs. Blunting of radiation-induced MAPK activity weakly enhanced radiation-induced apoptosis 24 h after exposure in RT2 cells. Furthermore, blunting of MAPK activation weakly enhanced the ability of radiation to reduce RT2 cell growth in clonogenic growth assays. These findings argue that inhibition of MAPK signaling reduces proliferation and enhances cell killing by ionizing radiation in transformed astrocytes. Proliferation and survival of cancer cells has been linked in vivo to enhanced expression of angiogenic growth factors. Recently we demonstrated that the gene product of a novel rodent radiation-responsive gene, progression elevated gene 3 (PEG-3), could enhance vascular endothelial growth factor (VEGF) promoter activity in rodent fibroblasts, leading to increased VEGF protein levels and tumorigenic behavior in vivo. Thus PEG-3 and VEGF expression could be expected to directly correlate with the oncogenic potential of transformed cells. RT2 cells expressed more PEG-3 and VEGF protein than T9 cells, and were more tumorigenic in vivo than T9 cells. Radiation activated the PEG-3 promoter via MAPK signaling and ectopic over-expression of PEG-3 enhanced both basal MAPK activity and basal VEGF promoter activity. Basal MAPK activity partially correlated with basal VEGF promoter activity and VEGF protein levels in primary astrocytes, T9 and RT2 cells. Radiation increased the activity of the VEGF promoter and VEGF protein levels in primary astrocytes, T9 and RT2 cells which were dependent upon MAPK function. Furthermore, inhibition of AP-1 transcription factor signaling by dominant negative c-Jun (TAM67) also significantly reduced basal, and to a lesser extent radiation-induced, VEGF promoter function in RT2 cells. Collectively, our data demonstrate that radiation-induced MAPK signaling can both protect cells from radiation-induced cell death as well as enhance protein levels of pro-angiogenic factors such as VEGF. Enhanced VEGF expression in RT2 cells may be mediated via MAPK and JNK pathway signaling which converges upon the AP-1 transcription factor complex.

Sodium nitroprusside induces apoptosis of H9C2 cardiac muscle cells in a c-Jun N-terminal kinase-dependent manner

Sodium nitroprusside (SNP) induces apoptosis in H9C2 cardiac muscle cells. Treatment with an exogenous NO donor SNP (2 mM) to H9C2 cells resulted in apoptotic morphological changes; a bright blue-fluorescent condensed nuclei and chromatin fragmentation by fluorescence microscope of Hoechst 33258-staining. The activity of caspase-3 like protease was increased during SNP-induced cell death. However, the activity of caspase-1 like protease was not affected by SNP. Pretreatment with Z-VAD-FMK (a pan-caspase inhibitor) or Ac-DEVD-CHO (a specific caspase-3 inhibitor) abrogated the SNP-induced cell death. SNP markedly activated three MAP kinases (JNK/SAPK, ERK and p38 MAP kinase) in the cardiac muscle cells. In this study, selective inhibition of the ERK or p38 MAPK pathway (by PD98059 or SB203580, respectively) had no effect on the extent of SNP-induced apoptosis in cardiac muscle cells. In contrast, inhibition of the JNK pathway by transfection of a dominant negative mutant of JNK markedly reduced the extent of SNP-induced cell death. Taken together, we suggest that JNK/SAPK will be related to SNP-induced apoptosis of H9C2 cardiac muscle cells.

Characterization of nuclear factors binding to AT-rich element in the rat p53 promoter

In this study, we identified AT-rich element located at positions -504 to -516 in the rat p53 promoter by DNase I foot printing assay. This region was previously identified as a positive regulatory element in the murine p53 promoter and designated as PBF1 (p53 binding factor 1) binding site. However, the proteins binding to this AT-rich element have not been identified yet. Therefore, we characterized the binding protein by various biochemical methods. First, we confirmed that by the oligonucleotide competition assay, nuclear factors bound to the AT-rich element in a sequence-specific manner. Two binding proteins were identified in southwestern blotting analysis and the molecular masses of the proteins were 60 and 40 kDa, respectively. The proteins were stable to denaturants or ionic strength. Treatment of chelators showed that the binding proteins did not require divalent cation for DNA-binding activity. In addition, the binding proteins were labile to protease treatment. This study showed that 60 and 40 kDa proteins bound to AT-rich element and the physico-chemical properties provided new insights into the binding proteins.

Microinjection of arginine vasopressin into the central nucleus of amygdala suppressed nociceptive jaw opening reflex in freely moving rats

This study was performed to examine the antinociceptive effect after microinjection of arginine vasopressin (AVP) into the central nucleus of amygdala. We recorded the jaw opening reflex in freely moving rats. After injection of 0.2 or 0.4 nM AVP into the central nucleus of amygdala, digastric electromyogram (dEMG) was suppressed to 55 +/- 5% or 88 +/- 3 of the control. Artificial cerebrospinal fluid had no effects on the basal dEMG activity. V(1) vasopressin receptor antagonist blocked the suppressive effect produced by microinjection of 0.4 nM AVP from 53 +/- 3 to 81 +/- 3% of the control. However, V(2) vasopressin receptor antagonist did not affect changes in dEMG. We observed dEMG activity after intracerebroventricular injection of naloxone, methysergide, or phentolamine. All drugs did not affect the basal dEMG activity at our dose. Naloxone blocked the suppressive effect of 0.4 nM AVP from 42 +/- 4 to 79 +/- 5% of the control. Methysergide also inhibited the suppression of dEMG from 44 +/- 3 to 83 +/- 6% of the control. However, phentolamine, an alpha-adrenergic receptor antagonist, did not affect the suppression of dEMG. These results indicate AVP in the central nucleus of amygdala has potent analgesic effects in the orofacial area. The antinociception of central AVP seems to be mediated by opioid and serotonergic pathways.

Access blood flow as a predictor of early failures of native arteriovenous fistulas in hemodialysis patients

Blood flow imaging using color doppler has proven effective in predicting graft failures in hemodialysis patients, but its effect on native arteriovenous fistulas (AVF) is not well known. This study was performed to investigate whether measurements of the access blood flow can be used as predictors of an early failure of a native AVF in hemodialysis patients. Fifty-three consecutive patients who received native AVF operations were included in this study. Access blood flow was measured at 1 week after operations, and AVF function was followed for 4 months. During the follow-up, access failures developed in 10 patients at 9.8 +/- 3.5 weeks. AVF blood flow was significantly lower in the failure group (n = 10) than in the patent group (n = 43) (450 +/- 214 vs. 814 +/- 348 ml/min, p = 0.003). The incidence of access failures was higher in the patients with a flow <350 ml/min (n = 9) compared to the patients with a flow >350 ml/min (n = 44) (55.5 vs. 11.3%, p = 0.008). The diameters of veins were significantly smaller in the failure group than in the patent group (3.5 +/- 0.5 vs. 4.1 +/- 0.7 mm, p = 0.018). The incidence of diabetes mellitus was higher in the failure group than in the patent group (90 vs. 51%, p = 0.025). However, age, sex, duration from an operation to first cannulation, and different AVF sites did not make a significant difference between the two groups. Our data suggest that access blood flow measurements using color doppler ultrasound during early postoperative periods are useful parameters in predicting an early failure of a native AVF in hemodialysis patients.

Correlation of hematopoietic progenitor cell count determined by the SE-automated hematology analyzer with CD34(+) cell count by flow cytometry in leukapheresis products

The yield of stem cell collection after mobilization is crucial for autologous peripheral blood stem cell (PBSC) transplantation. Quantitative determinations of CD34(+) cells using flow cytometry or stem cell culture have been used, but these methods require much time, technical experience, and expensive reagents. The automated hematology analyzer (Sysmex SE-9000trade mark, TOA, Japan) equipped with the Immature Information (IMI) channel for immature myeloid cells can detect IMI(+) cells within 90 sec. Detection is made possible by the combination of a special reagent system and direct current/radiofrequency biosensors. We studied the relation of IMI(+) cells and variable cell counts with CD34(+) cell yield in autologous stem cell harvest. In a series of 32 patients (median age, 44 years; M:F = 11:21), 184 leukaphereses were performed after mobilization regimens with chemotherapy and G-CSF or G-CSF alone. Full blood cell counts were enumerated on peripheral blood (PB) samples taken prior to each leukapheresis. Mononuclear cell (MNC) and IMI(+) cell counts by automated hematology analyzer and flow cytometry based CD34(+) cell yield were measured on the harvested product. The relationship among PB white blood cells (WBC), PB monocytes, IMI(+) cells, MNC, and CD34(+) cell yield in a single leukapheresis was estimated by Pearson correlation analysis. PB WBC count showed no correlation with CD34(+) cell yield in a single leukapheresis (r = 0.02, P = 0.81). PB monocyte count showed a weak correlation (r = 0.21, P = 0.01) and MNC in harvest also showed a weak correlation (r = 0.36, P = 0.0001) with CD34(+) cell yield. In contrast, CD34(+) cell yield correlated well with IMI(+) cell count (r = 0.68, P = 0.0001), and data could be fitted by a linear regression equation, y = 0.330 + 0.974x. IMI(+) cell assay by the automated hematology analyzer correlated well with the CD34(+) cell yield in a mobilized autologous stem cell harvest. The IMI(+) cell count might be used as a simple and efficient indicator of blood stem cell mobilization and collection.

cDNA sequence and gene expression of storage protein-2--a juvenile hormone-suppressible hexamerin from the fall webworm, Hyphantria cunea Drury

We isolated and sequenced a cDNA clone corresponding to storage protein-2 (SP-2) from the fall webworm, Hyphantria cunea. The cDNA for SP-2 (2572 bp) codes for a 747-residue protein with a predicted molecular mass of 88.5 kDa. The calculated isoelectric point is 7.6. Multiple alignment analysis of amino acid sequence revealed that SP-2 is most similar to BJHSP2 (74.3% identity). According to both the phylogenetic analyses and criteria for amino acid composition, SP-2 belongs to the subfamily of moderately methionine-rich storage proteins (3.2% methionine, 11.8% aromatic amino acid). Topical application of the JH analog, methoprene, after head ligation of larvae, suppressed transcription of the SP-2 gene, indicating hormonal effects at the transcriptional level. The SP-2 transcript was detected by Northern blot analysis in Malpighian tubules, in addition to the fat body where it was most abundant. The local expression of SP-2 in Malpighian tubules suggests that it may have some function in that organ.

Characterization of Cre-loxP interaction in the major groove: hint for structural distortion of mutant Cre and possible strategy for HIV-1 therapy

Although the crystal structure of Cre recombinase complexed with DNA, named loxA, was elucidated a couple of years ago, it has not yet been determined which amino acids of the protein are involved in the specific Cre-loxP interaction. Arg259 and Gln90 interact with DNA substrate in the major groove from which the specificity of protein-DNA interaction comes. In this study, we substituted these residues for other amino acids. Also, two mutated DNA substrates were constructed. In each mutant, one of the bases that interact with Arg259 or Gln90 was changed into another base. In vitro binding assays and recombination assays of variant lox sites with wild-type and mutant-type Cre revealed that Arg259 plays a key role in Cre-loxP binding but Gln90 does not. However, the recombination activity still remained intact, although the binding between Cre and DNA substrate was not ensured.

Attenuation of EGF signaling in senescent cells by caveolin

One of the characteristics of senescent cells is unresponsiveness to external stimuli like EGF. Although they have a normal level of receptors and downstream signaling molecules, EGF cannot induce the activation of Erk kinases and DNA synthesis in senescent cells as much as in young cells. Caveolin proteins directly interact with signaling molecules including EGF receptor and suppress the activation of EGFR upon EGF stimulation. We found that Erk activation after EGF stimulation in senescent human diploid fibroblasts was down-regulated. Those senescent cells showed an increased level of three isoforms of caveolin proteins. This change seems to lie in transcriptional control in senescent cells. We also demonstrated up-regulated caveolin proteins were co-localized with EGFR proteins in detergent-insoluble fractions. From these results, we suggest that the up-regulated expression of caveolin might explain the unresponsiveness of senescent fibroblasts to EGF stimulation.

An engineered lox sequence containing part of a long terminal repeat of HIV-1 permits Cre recombinase-mediated DNA excision

In our previous report, one 34-bp sequence from a long terminal repeat (LTR) of human immunodeficiency virus type 1 (HIV-1) clone, loxLTR-1, was proposed as a target site for site-specific excision by modified Cre recombinase. To support this suggestion, an engineered lox sequence, designated loxIL1, was made. This variant lox has the corresponding sequence of loxLTR-1 at the spacer region and the last two bases of inverted repeat sequence. Through in vitro recombination assay, loxIL1 also allowed the wild-type Cre to specifically recombine the sequence. An in vitro DNA binding experiment with mutants CreK244R and CreK244L revealed that lysine 244 of Cre plays an important role in interaction with the engineered lox. This result suggests that loxLTR-1 would be a candidate for antiviral strategy using site-specific recombinase.