[Chemical stability of salmon calcitonin (sCT) analogues in aqueous solution]

Calcitonin is a peptide hormone with 32 amino acids. Natural calcitonins are presumably quite unstable in solution and numerous analogues of calcitonin had been synthesized to improve the stability. In the present paper, we report the investigation of the chemical stability of salmon calcitonin (sCT) analogues [Val1, Ala7]sCT, [Val1, Ala7, Ala30]sCT and [D-Ala30]sCT in aqueous solutions by reversed phase high-performance liquid chromatography (RP-HPLC) and fast atom bombardment mass spectrometry (FAB-MS) methods. The degradation patterns of the sCT analogues showed a marked dependence on pH and temperature. Most of the degradation products in pH 9.0 solution of sCT and its analogues were identified by FAB-MS analysis. Results showed that the sCT analogues are more stable at pH 3.3 and pH 3.7 than at pH 6.0 and pH 9.0. Analogues without disulfide bridge [Val1, Ala7]sCT and [Val1, Ala7, Ala30]sCT showed higher chemical stability than sCT while [D-Ala30]sCT showed lower chemical stability than the native sCT.

A cytosolic factor is required for mitochondrial cytochrome c efflux during apoptosis

Treatment of HL-60 cells with staurosporine (STS) induced mitochondrial cytochrome c efflux into the cytosol, which was followed by caspase-3 activation and apoptosis. Consistent with these observations, in vitro experiments demonstrated that, except for cytochrome c, the cytosol of HL-60 cells contained sufficient amounts of all factors required for caspase-3 activation. In contrast, treatment of HCW-2 cells (an apoptotic-resistant HL-60 subclone) with STS failed to induce significant amounts of mitochondrial cytochrome c efflux, caspase-3 activation, and apoptosis. In vitro assays strongly suggested that a lack of cytochrome c in the cytosol was the primary limiting factor for caspase-3 activation in HCW-2 cells. To explore the mechanism which regulates mitochondrial cytochrome c efflux, we developed an in vitro assay which showed that cytosolic extracts from STS-treated, but not untreated, HL-60 cells contained an activity, which we designated 'CIF' (cytochrome c-efflux inducing factor), which rapidly induced cytochrome c efflux from HL-60 mitochondria. In contrast, there was no detectable CIF activity in STS-treated HCW-2 cells although the mitochondria from HCW-2 cells were responsive to the CIF activity from STS-treated HL-60 cells. These experiments have identified a novel activity, CIF, which is required for cytochrome c efflux and they indicate that the absence of CIF is the biochemical explanation for the impaired ability of HCW-2 cells to activate caspase-3 and undergo apoptosis.

Effects of electroacupuncture at neiguan on myocardial microcirculation in rabbits with acute myocardial ischemia

This paper reports the effects of electroacupuncture (EA) at Neiguan (P 6) on myocardial microcirculation and electrical activity observed in rabbits with acute myocardial ischemia (AMI) by employing the vascular casting method and taking monophasic action potential (MAP) as an index. It was found that in the ischemic border zone of the heart, the electrical excitability was strengthened, the shortening of the phase repolarization inhibited, and the number of the micrangia increased in some degree following EA. This suggests that EA can relieve arteriolospasm, inhibit extreme dilatation of blood capillaries, modulate imbalance of micro-vasomotion of the coronary artery, improve myocardial blood-supply, and promote normalization of electrical activities of the ischemia myocardium. This fact not only elucidates the recovery mechanism of the ischemic myocardium promoted by EA at Neiguan (P 6), but also provides morphological basis for the theory of relationship between Neiguan of the Pericardium Meridian and the heart.

[Effects of mifepristone on ICE expression and Fas expression in early pregnant chorionic villi]

This study addressed the question whether mifepristone has any effect on apoptosis in early pregnant chorionic villi. Interleukin 1 beta converting enzyme(ICE) expression and Fas expression in early pregnant villi and their changes following mifepristone administration were detected by immunohistochmical method and computer image analysis. During early pregnancy, ICE and Fas were expressed in all component chorionic cells, predominantly syncytiotrophoblasts. ICE stained cytoplasma. Fas stained mainly cytoplasma, and in partial trophoblastic cells, Fas was expressed on membrane and nucleus. In the villi from the pregnant women who received mifepristone for 2 days, expression of Fas increased markely; the ratio of positive nuclear staining cells were significantly raised, but the immunostaining intensity of ICE was slightly increased. These results suggest that mifepristone may terminate early pregnancy via increasing the expression of Fas and promoting apoptosis in the chorionic villi.

The role of keratin filaments during nuclear envelope reassembly in Xenopus egg extracts

We report here a new structure, named 'strings-of-pearls', which are seen to form in Xenopus egg extracts after incubation, as 200 nm membrane vesicles attach to 10 nm filaments. These membrane vesicles fuse together along the filaments to form annulate lamellae (AL) or attach to demembranated sperm chromatin to initiate assembly of a nuclear envelope. Immunoassay with anti-keratin antibodies AE3 showed that the filaments were mainly composed of a 56 kDa keratin-like protein. Addition of AE3 to the extracts resulted in inhibition of AL formation and defective assembly of NE. These results suggest a function of keratins in the assembly of nuclear envelopes during Xenopus development.

[Effects of mifepristone on proliferation and apoptosis in early chorionic villi]

OBJECTIVE

To study the effects of mifepristone on proliferation and apoptosis in early pregnant chorionic villi.

METHODS

Proliferation and apoptosis in early pregnant choionic villi from surgical aspiration and mifepristone induced abortion were studied. Marker for proliferation is proliferating cell nuclear antigen (PCNA) immunohistochemical staining, apoptotic cell death was detected using DNA in situ terminal deoxynucleotidyl transferas-mediated dUTP-biotin nick ending labeling (TUNEL).

RESULTS

In early pregnant chorionic villi, proliferating index of cytotrophoblasts was 53.74% +/- 1.34%, not only nuclear but also cytoplasma were PCNA positive staining, syncytiotrophoblasts were negative. There existed apoptotic cell death in trophoblasts, the apoptotic index were 2.52% +/- 0.86% in syncytiotrophoblasts and 0.52% +/- 0.26% in cytotrophblasts, respectively. After 2 days mifepristone treatment, the proliferating index of cytotrophoblasts decreased slightly and PCNA positive cytoplasmic expression disappeared; while apoptotic cell increased significantly, the apoptotic indices were 22.16% +/- 2.26% in syncytiotrophoblasts and 20.12% +/- 1.74% in cytotrophoblasts, respectively.

CONCLUSION

Mifepristone may inhibit proliferation and promote apoptosis of trophoblasts in early pregnant chorionic villi.

Regulation of aquaporin-4 water channels by phorbol ester-dependent protein phosphorylation

The molecular mechanisms for regulating water balance in many tissues are unknown. Like the kidney, the eye contains multiple water channel proteins (aquaporins) that transport water through membranes, including two (AQP1 and AQP4) in the ciliary body, the site of aqueous humor production. However, because humans with defective AQP1 are phenotypically normal and because the ocular application of phorbol esters reduce intraocular pressure, we postulated that the water channel activity of AQP4 may be regulated by these agents. We now report that protein kinase C activators, phorbol 12,13-dibutyrate, and phorbol 12-myristate 13-acetate strongly stimulate the phosphorylation of AQP4 and inhibit its activity in a dose-dependent manner. Phorbol 12,13-dibutyrate (10 microM) and phorbol 12-myristate 13-acetate (10 nM) reduced the rate of AQP4-expressing oocyte swelling by 87 and 92%, respectively. Further, phorbol 12,13-dibutyrate significantly increased the amount of phosphorylated AQP4. These results demonstrate that protein kinase C can regulate the activity of AQP4 through a mechanism involving protein phosphorylation. Moreover, they suggest important potential roles for AQP4 in several clinical disorders involving rapid water transport such as glaucoma, brain edema, and swelling of premature infant lungs.

[Semiquantitative measurement of progesterone receptors in luteal-phase-defect endometrial cells during secretory phase]

To investigate the changes of endometrial progesterone receptor (PR) of luteal-phase-defect (LPD) patients during the secretory phase, thirteen patients with complaints of infertility or habitual abortion were studied. During the early-mid secretory phase, endometrial tissue was obtained by dilatation and curettage (D & C) for histological and receptor study: meanwhile serum E2, P, FSH, LH and PRL were measured. Based on histologic diagnosis, the patients were divided into two groups: the LPD group (n = 7) and the normal control group(n = 6). PR content was determined by immunohisto-chemical (IHC) assay. The results showed that during the early-mid luteal phase a significantly low PR content on endometrial glandular nucleus was observed in LPD group, compared with normal control(6.75 +/- 2.57 vs 9.50 +/- 1.64 P < 0.05), but no difference in serum progesterone was noted between the two groups. These findings suggest that during early-mid secretory phase, PR content on endometrial glandular nucleus decreases in LPD cases, which results in deficient response of endometrium to proper stimulus of progesterone. This change may cause endometrial secretory deficiency and blockade of embreyo implantation. That is why infertility or habitual abortion happened.

The homeobox-containing gene Wariai regulates anterior-posterior patterning and cell-type homeostasis in Dictyostelium

We have identified a Dictyostelium gene, Wariai (Wri), that encodes a protein with a homeobox and seven ankyrin repeats; both domains are required for function. A null mutation results in a more than doubling of the size of the prestalk O (pstO) compartment, one of the anterior prestalk compartments lying along the anterior-posterior axis of the migrating slug. There is a concomitant decrease in the more posterior prespore domain and no change in the more anterior prestalk A (pstA) and prestalk AB (pstAB) domains. wri null cells also have a morphological defect consistent with an increase in the pstO cell population. Wri itself is preferentially expressed in the pstA but not the pstO compartment, raising the possibility that Wri regulation of pstO compartment size is nonautonomous. Analysis of chimeric organisms is consistent with this model. Development in Dictyostelium is highly regulative, with cells within the prestalk and prespore populations being able to transdifferentiate into other cells to maintain proper cell-type proportioning. Our results suggest that Wri controls cell-type proportioning, possibly by functioning as a negative regulator of a pathway mediating pstO cell differentiation and controlling the mechanism of homeostasis regulating the size of one or more of the cell-type compartments. Our results also suggest that homeobox gene regulation of anterior-posterior axis patterning may have evolved prior to the evolution of metazoans.

Neoplastic transformation of hamster embyro cells by heavy ions

We have studied the induction of morphological transformation of Syrian hamster embryo cells by low doses of heavy ions with different linear energy transfer (LET), ranging from 13 to 400 keV/micrometer. Exponentially growing cells were irradiated with 12C or 28Si ion beams generated by the Heavy Ion Medical Accelerator in Chiba (HIMAC), inoculated to culture dishes, and transformed colonies were identified when the cells were densely stacked and showed a crisscross pattern. Over the LET range examined, the frequency of transformation induced by the heavy ions increased sharply at very low doses no greater than 5 cGy. The relative biological effectiveness (RBE) of the heavy ions relative to 250 kVp X-rays showed an initial increase with LET, reaching a maximum value of about 7 at 100 keV/micrometer, and then decreased with the further increase in LET. Thus, we confirmed that high LET heavy ions are significantly more effective than X-rays for the induction of in vitro cell transformation.

[Relationship between voice spectrum analysis and psychoacoustic evaluation in patients with vocal cords polyps]

The purpose of this paper is to investigate the significance of selected acoustic parameters, to determine their usfulness in monitoring effects of treatments, to correlate them to other clinical voice tests (such as aerodynamic measurements, stroboscopic examination, psychoacoustic evaluation), and to determin if there were correlations among the acoustic parameters. The results showed that pitch perturbation quotient (PPQ), amplitude perturbation quotient (APQ), normalized noise energy a and b (NNEa and NNEb) were positively related to the regularity (REG) in the vocal cord polyp. In the present study, psychoacoustic rough (R), breathy (B) were correlated to the regularity (REG), glottic closure (GLO) and the mean airflow rate. The integrated voice analysis was a simple and effective method for acoustic evaluation of pathologic voice.

[Tailed normal chromatographic peak expressed by plate model]

An equation for describing tailed normal chromatographic peak is derived based on the plate model. In terms of the de Moivre-Laplace theorem, which states that a binomial distribution can be approximated by the Gaussian distribution for large sample size, it is suggested that the concentration distribution along the distance downstream from the inlet of chromatographic column conforms to the Gaussian distribution function, but the concentration distribution with elution volume (or elution time) does not. The equation developed here, which is similar to the Gaussian distribution function, indicates that the normal chromatographic elution curve should be a tailing one. It is also shown that the symmetric Gaussian elution curve is an approximate solution of the plate model and can be obtained by the approximation of the equation here. The equation is proved to be congruent to the results of the diffusion model. Thus, the plate model and diffusion model are equivalent to each other in describing chromatographic process although different mechanism is based on.

Posttranscriptional regulation of collagenase-1 gene expression in synoviocytes by adenosine receptor stimulation

OBJECTIVE

To characterize the transcriptional and posttranscriptional regulation of collagenase-1 by adenosine receptor stimulation in interleukin-1 (IL-1)-stimulated fibroblast-like synoviocytes (FLS).

METHODS

FLS were stimulated with IL-1 and either the nonselective adenosine agonist 5'-N-ethylcarboxamidoadenosine (NECA) or the adenylate cyclase activator forskolin. Electrophoretic mobility shift assays were performed to determine AP-1 and cAMP-responsive element binding protein (CREB) activation. Transcriptional activation was determined by transfecting HS68 dermal fibroblasts with a collagenase-chloramphenicol acetyltransferase construct. Finally, collagenase messenger RNA (mRNA) half-life was determined by activating cells in the presence of IL-1, IL-1 + NECA, or IL-1 + forskolin and culturing cells in the presence of actinomycin D.

RESULTS

NECA and forskolin had no effect on AP-1 activation, c-jun or c-fos gene expression, or CREB phosphorylation. IL-1 markedly increased collagenase promoter activity, and neither NECA nor forskolin blocked this action. Studies of mRNA half-life showed that both NECA and forskolin decreased the half-life of collagenase mRNA in IL-1-stimulated FLS and HS68 cells.

CONCLUSION

The findings of this study demonstrate that NECA and forskolin decrease collagenase gene expression in FLS and dermal fibroblasts due to enhanced mRNA degradation.

Monocytic differentiation of HL-60 promyelocytic leukemia cells correlates with the induction of Bcl-xL

Treatment of human promyelocytic leukemia HL-60 cells with phorbol esters ultimately induces the differentiation of these cells along the monocyte/macrophage lineage, whereas treatment with retinoic acid or DMSO induces granulocytic/neutrophillic differentiation. In this study, we demonstrate the disparate fates of HL-60 cells treated with the phorbol ester 12,13-phorbol dibutyric acid (PDBu) or DMSO. After DMSO treatment, HL-60 cells eventually died via apoptosis, whereas the viability of PDBu-treated cells was not affected during the same interval. The levels of the apoptosis effector proteins Bak and Bad were enhanced, whereas there was a slight down-regulation of the apoptosis suppressor protein Bcl-2 after treatment of the cells with PDBu and DMSO. Treatment with DMSO resulted in the elevation of the apoptosis effector Bax, whereas treatment with PDBu did not significantly alter the levels of this protein. However, treatment of HL-60 cells with PDBu induced the rapid expression of the apoptosis suppressor protein Bcl-xL, whereas the expression of this protein remained unaltered in DMSO-treated cells. The generality of this finding was confirmed by the induction of Bcl-xL in human myeloid U-937 cells, human peripheral blood monocytes exposed to phorbol ester, and mouse thioglycollate-activated and resident peritoneal macrophages. PDBu-treated HL-60 cells remained viable for 7 days and thereafter began to die via apoptosis, with a concomitant down-regulation of Bcl-xL. In conclusion, we propose that Bcl-xL expression is associated with differentiation and survival of hematopoietic cells along the monocyte/macrophage lineage.

Regulation of water channel activity of aquaporin 1 by arginine vasopressin and atrial natriuretic peptide

Aquaporin 1 (AQP1), a six-transmembrane domain protein that functions as a water channel, is present in many fluid secreting and absorbing tissues such as kidney, brain, heart, and eye. It is believed that among the five known mammalian aquaporins, kidney aquaporin (AQP2) is the only water channel that is regulated by arginine vasopressin (AVP). The present data suggest that AQP1 may also be regulated by AVP. The application of AVP to Xenopus oocytes injected with AQP1 cRNA increased the membrane permeability to water. In addition, our data reveal that atrial natriuretic peptide (ANP), a peptide hormone that plays an important role in the regulation of body fluid homeostasis, blocks the AQP1-mediated increase in water permeability. Incubation with 8-bromo-cAMP or direct 8-bromo-cAMP injection into oocytes expressing AQP1 cRNA significantly increased membrane permeability to water, suggesting that stimulation of AQP1 activity by AVP may involve a cAMP-dependent mechanism. Regulation of water permeability by AVP and ANP has potential relevance to active water transport in a variety of tissues that express AQP1 including kidney, brain, and eye.

[Metallothionein expression and its significance in salivary gland tumors]

Expression of metallothionein (MT) in 75 cases of salivary gland tumors was studied by immunohistochemistry. All tumors containing myoepithelial cells were positive for MT immunostaining. In the tumors composed of both adenoepithelial cells and myoepithelial cells, only myoepithelial cells were MT positive. A rather large portion of cells was noted MT positive in myoepithelial carcinoma and myoepithelioma. Compared with S-100 and smooth muscle actin (SMA) antibodies, the effect of staining by MT antibody for myoepithelial cells was more satisfactory. The results indicate that MT may be a better marker for neoplastic myoepithelial cells and useful in the differential diagnosis of salivary gland tumors.

[The relationship between female infertility and genital inflammation of Chlamydia trachomatis]

To address the relationship between female infertility and genital inflammation of chlamydia trachomatis (CT), we took samples from the cervix and fallopian tube of 147 cases of female infertility and investigated the rate of CT infection by using polymerase chain reaction (PCR) assay. 60 cases of normal pregnant women were chosen as controls. The results showed that in the infertile group the CT positive rates for fallopian tubes and cervices were 15.66% and 22.45% respectively, whereas in the control group the tubal positive rate was 3.33%. There was significant difference between the two groups in tubal positive rate (P < 0.05). Youngsters and workers were the high risk population of genital infection of CT. These results indicate that genital infection of CT is an important factor causing infertility; in that disease, the tubal infection of CT is even more important. Besides the damage to tubal mucosa and smooth muscle, CT infection causes tubal adhesion and obstruction. As a result it impairs the function of the fimbriae and leads to infertility.

A sequential two-step mechanism for the production of the mature p17:p12 form of caspase-3 in vitro

The apoptotic cysteine protease, caspase-3, is expressed in cells as an inactive 32-kDa precursor from which 17 kDa (p17) and 12 kDa (p12) subunits of the mature caspase-3 are proteolytically generated during apoptosis. Two amino acid sequences, ESMD downward arrowS (amino acids 25-29) and IETD downward arrowS (amino acids 172-176), in the precursor have been defined as the cleavage sites for the production of the p17 and p12 subunits. Using a cell-free assay system, we demonstrate that the caspase-3 precursor appears to be cleaved first at the IETD downward arrowS site, producing the p12 subunit and a 20-kDa (p20) peptide. Subsequently, the p20 is cleaved at the ESMD downward arrowS site, generating the mature p17 subunit. The cleavage at the IETD downward arrowS site required a protease activity that was selectively inhibited by the peptide, Ac-IETD-CHO (acetyl-IETD-aldehyde), and other protease inhibitors, such as the cowpox viral serine protease inhibitor, CrmA, and N-alpha-tosyl-L-phenylalanine chloromethyl ketone. The protease that catalyzed the cleavage at the ESMD/S site was selectively inhibited by another peptide, Ac-ESMD-CHO (acetyl-ESMD-aldehyde). More interestingly, the caspase-3 inhibitor, Ac-DEVD-CHO, but not the caspase-1 inhibitor, Ac-YVAD-CHO, also selectively inhibited the protease activity that cleaves at the ESMD downward arrowS site. This indicated that the cleavage at the ESMD downward arrowS site was either autocatalytic or that it required a caspase-3-like activity. In summary, we demonstrate that production of the p17:p12 form of caspase-3 is a sequential two-step process and appears to require two distinct enzymatic activities.

[Bioassay of recombinant human platelet factor 4]

OBJECTIVE

To assay the biological activity of recombinant human platelet factor 4 (rhPF4).

METHODS

The bioactivity of rhPF4 was assayed in vitro and in vivo in comparison with native PF4 by using murine and human megakaryocyte culture systems.

RESULTS

rhPF4, like native PF4, had an inhibitory activity on megakaryocytopoiesis in vitro and in vivo in mice. The inhibitory activity could be neutralized by heparin. rhPF4 also had an inhibitory activity on human megakaryocytic leukemia cell line (Meg-01).

CONCLUSION

rhPF4 might be applied to clinical practice.

Estrogen receptor, growth factor receptor and protooncogene protein activities and possible signal transduction crosstalk in estrogen dependent and independent breast cancer cell lines

Binding of estrogen to its receptor (ER) activates early genes that drive responsive cells through the proliferative phase. Earlier studies to evaluate the expression of protooncogenes, growth factors, growth factor receptor and steroid hormone receptor gene activities in the rat uterine system indicated complex pathways that involve significant 'crosstalk' between ER-systems and signal transduction pathways (Bhattacharyya et al., 1994). To analyze the interactions between these factors, we examined two well characterized estrogen dependent (MCF-7) and estrogen independent (MDA-MB-231) human breast cancer cell lines. Antibodies to estrogen receptor, epidermal growth factor receptor, c-Fos, c-Jun, and Ras proteins, protein kinases involved in receptor tyrosine kinase signal transduction pathway, MEK1 and phosphotyrosine were utilized in immunocytochemical localization experiments to evaluate temporal expression of these factors in response to estrogen treatment. ER, which was diminished in MCF-7 cells grown in estrogen-stripped medium, increased 9-fold in estrogen-reconstituted medium by 120 min. Fos and Jun appeared at nuclear and perinuclear cytoplasmic sites within 60 min after estrogen treatment in MCF-7 cells. Fos/Jun proteins were prominent in MDA-MB-231 cells, especially in association with actin filaments. Immunolabeling studies revealed no EGF-r in MCF-7 cells, while MDA-MB-231 cells contained intense EGF-r labeling in the plasma membrane. Ras protein was prominent in the cytoplasm and at the cell surface within 60 min after treatment of MCF-7 cells with estrogen. Ras was intense in MDA cells. Similarly, MCF-7 and MDA cells contained high concentrations of MEK1 and phosphotyrosine (pTyr) containing proteins in their cytoplasm and immunolabeling remained high as long as MCF-7 cells were grown in medium containing estrogen. It is speculated that MEK1 (cytoplasmic) functioning through Fos/Jun or Myc/Max (nuclear) may regulate the activity of AP-1 transcription factor. In all cases however, MEK1 and pTyr protein labeling was more intense in the highly metastatic and hormone independent MDA-MB-231 breast cancer cells. Results revealed signal transduction pathway proteins in ER+ estrogen dependent cells suggesting possible crosstalk between both receptor pathways during the proliferative phase of MCF-7 cells.

[Diagnosis and treatment of iatrogenic ureteral injury]

Diagnosis and treatment of 17 patients who sustained 20 iatrogenic ureteral injuries were analyzed. Primary operations in which ureteral injury occurred are almost gynecologic procedures and general surgery. Injuries were managed by ureteroureterostomy in four, ureteral stent in one, removal suture ligation and ureteral double J-catheter in one, ureteroneocystostomy in ten, psoas-hitch technique and ureteroneocystostomy in one, nephrectomy in two. All patients with appropriate repair were followed-up periods of three to five years. Renal function of these patients had optimal results. When ureteral injury occurs, B-US, IVU, cystoscopy, retrograde ureterography or infusion of dye may be useful. An appropriate repair should be chosen according to length and position of ureteral injuries. Reoperation was optimal in two to three weeks. Immediate recognition of accidental ureteral injury provides optimal results. Patients with unrecognized injuries had suboptimal results.

A JNK signal transduction pathway that mediates morphogenesis and an immune response in Drosophila

The Drosophila MAP kinase DJNK is a homolog of the mammalian c-Jun amino-terminal kinase (JNK). Mutations in the DJNK gene correspond to the complementation group basket. DJNK is phosphorylated and activated by the Drosophila MAP kinase kinase HEP. Substrates of DJNK include the transcription factor DJun. DJNK participates in multiple physiological processes. Exposure to endotoxic lipopolysaccharide initiates an insect immune response and leads to DJNK activation. In addition, embryos lacking DJNK are defective in dorsal closure, a process in which the lateral epithelial cells migrate over the embryo and join at the dorsal midline. These data demonstrate that the DJNK signal transduction pathway mediates an immune response and morphogenesis in vivo.

DNA-dependent protein kinase is a target for a CPP32-like apoptotic protease

We demonstrate that the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs) is specifically, proteolytically cleaved in HL-60 cells treated with staurosporine (STS), a potent inducer of apoptosis. The proteolysis of DNA-PKcs correlated with or preceded apoptotic chromosomal DNA degradation. Cell-free extracts prepared from STS-treated HL-60 cells recapitulated the proteolysis of DNA-PKcs in an in vitro assay using purified DNA-PK as the substrate. Western blot analyses of the apoptotic cell extract showed that the 32-kDa precursor of CPP32 is expressed in HL-60 cells and processed following STS treatment. In addition, whereas the DNA-PKcs protease activity was not inhibitable by many conventional protease inhibitors, it was inhibitable by a highly selective peptide-derived inhibitor of CPP32. These data strongly suggest that CPP32, or a CPP32-like protease, is responsible for DNA-PKcs proteolysis. Finally, our results demonstrated that the cleavage of DNA-PKcs in vitro proceeded in the presence of Bcl-2, indicating that the function provided by Bcl-2 lies upstream the proteolysis of DNA-PKcs.

[Malignant fibrous histiocytoma of kidney]

Malignant fibrous histiocytoma of kidney is one kind of rare tumor. About 20 cases have been reported abroad and 3 in this country. This kind of tumor is characterized by high malignancy and invasive growth. It is difficult to differentiate it from renal cancer by radiology. Fibroblasts stand in line as "storiform pattern" and touton giant cell can be seen under microscopy. The definite diagnosis can be made through immunohistochemistry.

Monocytic differentiation and synthesis of proteins associated with apoptosis in human leukemia U-937 cells acquiring resistance to vincristine

Human leukemia U-937/WT cells were exposed to stepwise increased concentrations of Vincristine so that Vincristine-resistant cell sublines (termed U-937/RV) were developed. Established U-937/RV cell sublines have continuously propagated over a year, both in absence and presence of VCR, and have demonstrated similar features. In contrast to U-937/WT cells, U-937/RV cells have longer doubling time, and are more differentiated as determined by appearance of distinct morphological features and synthesis of mRNA that codes for the monocyte colony-stimulating factor-1 receptor (c-fms). Both apoptosis-suppressing Bcl-2 and Bcl-XL proteins were undectable in U-937/WT cells, whereas Bcl-2 was nearly detectable and Bcl-XL readily detectable in U-937/RV cells. The apoptosis-promoting Bax protein was also absent in U-937/WT cells and readily detected in U-937/RV cells. Vincristine-resistant cells with different levels of resistance synthesize similar levels of c-fms mRNA and Bax protein. Finally, unlike U-937/WT cells, U-937/RV cells have no ability to induce tumors when xenografted in immunodeficient mice. The findings collectively suggest that development of resistance to Vincristine in U-937/WT cells may correlate with cell differentiation and synthesis of proteins that regulate apoptosis.

Characterization of a Ku86 variant protein that results in altered DNA binding and diminished DNA-dependent protein kinase activity

Three proteins known to play a critical role in mammalian DNA double-strand break repair and lymphoid V(D)J recombination are the autoantigens Ku86 and Ku70 and a 465-kDa serine/threonine protein kinase catalytic subunit (DNA-PKcs). These proteins physically associate to form a complex (DNA.PK) with DNA-dependent protein kinase activity. In this study, we demonstrate using electrophoretic mobility shift assays (EMSAs) that the nuclear DNA end-binding activity of Ku is altered in the human promyelocytic leukemic HL-60 cell line. Western blot and EMSA supershift analyses revealed that HL-60 cells expressed both full-length and variant Ku86 proteins. However, a combined EMSA and immunoanalysis revealed that the Ku heterodimers complexed with DNA in HL-60 cells contained only the variant Ku86 proteins. Finally, UV cross-linking experiments and DNA.PK assays demonstrated that the Ku complexes containing variant Ku86 had a greatly reduced ability to interact with DNA-PKcs and that consequently HL-60 cells had severely diminished DNA.K activity. These data provide important insights into the interaction between Ku and DNA-PKcs and into the role of DNA.PK in DNA double-strand break repair.

[The relationship between human chorionic gonadotrophin and lipoprotein metabolism]

We compared human chorionic gonadotrophin (hCG-beta) with lipids, lipoproteins and apolipoproteins in serum between pre- and postmenopausal women, and observed the changes of levels of hCG-beta in animals suffering from hypertriglyceridemia. The results have shown that the concentration of hCG-beta in postmenopausal women is much higher than that in premenopausal women (P < 0.001). Correspondingly, triglyceride (TG) is elevated (P < 0.05). High density lipoprotein cholesterol (HDL-C) and HDL-C/LDL-C ratio are decreased (P < 0.001, P < 0.01). On the other hand, the tendency of highing hCG-beta level has been found in animal study. The concentration of hCG-beta in male rats suffering form hypertriglyceridemia is higher than that in normal animals (P < 0.05).

[Clinical significance of determinations of blood catecholamine, glucose and isulin in burn patients]

Blood catecholamine (CA), glucose and insulin were determined in 30 severe burn patients, of whom 22 were males, and 8 females. Mean burn area was 58.6 percent TBSA. These patients were in hypovolemic shock.

RESULTS

CA release was persistent in severe burn patients showing two peaks in shock period and infection period (P < 0.01). The quantity of epinephrine (E) was normal, while norepinephrine (NE) was presistently high (P < 0.01), and it was over two fold of the normal value. The value seemed to reflect the severity of the injury. When CA did not show a rise in the shock period, or lowered abruptly in the sepsis period, the patients were in high risk. Increasing CA produced increase in gluconeogenesis with insufficiency in SI secretion.

Isolation and characterization of an apoptosis-resistant variant of human leukemia HL-60 cells that has switched expression from Bcl-2 to Bcl-xL

Human promyelocytic leukemia HL-60 cells treated with 8-chloroadenosine-3',5'-cyclic monophosphate (8-Cl-cAMP) undergo growth arrest and subsequently die by apoptosis. We describe here the isolation of a variant of HL-60 cells, HCW-2, which was resistant to the cytotoxic effects of 8-Cl-cAMP, but still underwent growth arrest. Thus, HCW-2 cells appeared to be altered in their ability to undergo apoptosis. HCW-2 cells were also completely refractory to the apoptotic action of cycloheximide and staurosporine, two compounds which were very potent inducers of apoptosis in the parental HL-60 cells, suggesting that the resistance to apoptosis was not unique to 8-Cl-cAMP. Western blot analysis demonstrated that the parental HL-60 cells expressed both Bcl-2 and Bax, two factors known to be intimately involved in the control of apoptosis. Surprisingly, HCW-2 cells no longer expressed Bcl-2 protein and paradoxically contained Bax protein at a level that was approximately 50-fold higher than in HL-60 cells. However, Northern and Western analyses indicated that the apoptotic suppressor gene, bcl-xL, which is not expressed in the parental HL-60 cells, was expressed in HCW-2 cells. Thus, the Bcl-2-independent resistance of HCW-2 cells to apoptotic induction is discussed in terms of the expression of bcl-xL.

Lovastatin induces apoptosis in a metastatic ovarian tumour cell line

Lovastatin is a very specific and potent inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, which regulates a rate-limiting step in the cellular synthesis of isoprenoid and cholesterol. In this study, we demonstrate that treatment of rat ovarian metastatic OV1N cells with lovastatin induces apoptosis. Furthermore, apoptotic death of lovastatin-treated OV1N cells can be prevented by the addition of either mevalonic acid (an immediate metabolite of HMG-CoA) or farnesyl pyrophosphate (one of the downstream products of mevalonic acid metabolism). However, metabolic derivatives of farnesyl pyrophosphate failed to prevent the apoptotic effect of lovastatin on cells. Therefore farnesyl pyrophosphate appears to be important for cell survival and the relationship of this compound to protein farnesylation and apoptosis induction is discussed.

[Monoclonal antibodies to human progesterone receptors: production, indentification and clinical application]

A peptide with 15 amino acid of human progesterone receptor (PR) was synthesized and used as antigen. Five hybridoma cells were obtained by cloning technique. In tests to hybridoma cell H4, the site specificity of the antibody to PR was found. The antibody reacted specifically with PR, but did not cross-react with ER, AR, or GR. Five women who used clomiphene citrate (CC) 100mg/d x 5 days were involved in a study of serum pregesterone (P) and endometrial histology in early luteal phase. There was no difference in serum P level in two groups. Three cases in CC group showed abnormal secretory endometrium. PR concentration in the nuclei of glandular cells of endometrium in CC group was significantly lower than that in the control group. In women with abnormal secretory endometrium, PR concentration in the nuclei of glandular cells was lower than that in women with normal endometrial histology. CC can influence endometrial histology by changing-PR concentration in the nuclei of glandular cells. The endometrium can not respond to the stimulus of P at normal levels and thus results in luteal phase defect.

A simple model for predicting the response of chicks to dietary enzyme supplementation

Two experiments with Leghorn chicks and data from five publications were analyzed to determine whether a simple general equation could be used to predict the relationship between the amount of a crude enzyme added to a diet and chick performance. The maximum improvements in weight gain and feed: gain ratio in Leghorn chicks fed rye diets containing different concentrations of enzymes were as high as 61 and 42%, respectively. Regression analyses demonstrated that there was usually a high linear correlation (r2 > 0.9, P < 0.05) between the concentration of the enzyme when transformed into its logarithmic value and weight gain or the feed:gain ratio. The general prediction equation was Y = A + B(logX), where Y is the performance value (i.e., weight gain, grams), A is the intercept (y-axis), B is the slope of the line (change in performance per units of enzyme in the diet), and X is the amount of enzyme in the diet. The slope of the line provides an index of the overall efficacy of the enzyme treatment. The log-linear model shows that for every ninefold increase in amount of enzyme in the diet (i.e., when the amount was increased to 10 times the starting amount), there was only a doubling of improvement in chick performance. High correlations (r2 values) were also obtained when data from the literature were analyzed. The equation was applicable to different classes and ages of poultry fed diets containing rye, wheat, barley, and lupins. These studies demonstrate that there is a linear relationship between the amount of enzyme added to the diet, when expressed as a logarithmic value, and the corresponding performance of chickens.

A study on oliguric standard in the elderly

Water deprivation test was done in 44 healthy elderly persons, 26 were male, and 18 were female. They were deprived of the intake of water for 25 hours. The results showed that the maximal renal concentration function both in the elderly males and females was 887 +/- 91 mmol/L and 888 +/- 127 mmol/L respectively. The renal excretion of waste products in 24 hours both in the elderly males and females was 815 + 170 mmol/d and 620 + 132 mmol/d respectively. On the basis of point estimation, the minimal essential urine volume per day in the elderly males and females was 926 ml/d and 708 ml/d respectively, if the daily urine volume of the elderly is less than this level, then, the metabolic products generated per day can not be excreted by the kidney, and it would result in disorders of internal environment. Therefore, the oliguric standard in elderly males and females must be less than 926 ml/d and 708 ml per day respectively.

Evidence for a G2 checkpoint in p53-independent apoptosis induction by X-irradiation

The p53 tumor suppressor gene is thought to be required for the induction of programmed cell death (apoptosis) initiated by DNA damage. We show here, however, that the human promyelocytic leukemia cell line HL-60, which is known to be deficient in p53 because of large deletions in the p53 gene, can be induced to undergo apoptosis following X-irradiation. We demonstrate that the decision to undergo apoptosis in this cell line appears to be made at a G2 checkpoint. In addition, we characterize an HL-60 variant, HCW-2, which is radioresistant. HCW-2 cells display DNA damage induction and repair capabilities identical to those of the parental HL-60 cell line. Thus, the difference between the two cell lines appears to be that X-irradiation induces apoptosis in HL-60, but not in HCW-2, cells. Paradoxically, HCW-2 cells display high levels of expression of bax, which enhances apoptosis, and no longer express bcl-2, which blocks apoptosis. HCW-2 cells' resistance to apoptosis may be due to the acquisition of expression of bcl-XL, a bcl-2-related inhibitor of apoptosis. In summary, apoptosis can be induced in X-irradiated HL-60 cells by a p53-independent mechanism at a G2 checkpoint, despite the presence of endogenous bcl-2. The resistance shown by HCW-2 cells suggests that bcl-XL can block this process.

Development of human leukemia U-937 cell sublines resistant to doxorubicin: induction of differentiation and altered sensitivities to topoisomerase-directed drugs

Cell sublines resistant to doxorubicin (DOX) were developed from the human leukemia cell line, U-937/WT, exposed to stepwise DOX increases. In contrast to U-937/WT cells, the DOX-resistant U-937/RD cells have longer doubling time; are more differentiated along the monocytic lineage as determined by the presence of morphological features and mRNA coding for the monocyte colony-stimulating factor-1 receptor; synthesize the apoptosis-associated Bax protein; are less sensitive to apoptosis-inducing topoisomerase II-directed drugs, apparently because of increased synthesis of P-glycoprotein; and are practically non-tumorigenic when xenografted in nude mice. However, U-937/WT and U-937/RD cells exhibit similar sensitivity to the apoptosis-inducing drug 9-nitrocamptothecin. These findings suggest that several mechanisms are involved in the development of DOX-resistance in U-937 cells, and further, 9-nitrocamptothecin can overcome resistance to DOX. These findings may have clinical implications.

[The pathogenetic factors for neurogenic intermittent claudication caused by degenerative lumbar spinal stenosis]

The pathogenetic factors in 89 patients with typical neurogenic intermittent claudication caused by lumbar spinal stenosis were studied retrospectively. 75 patients had degenerative lumbar spinal stenosis, and 67 had unilateral nerve root canal stenosis. In most patients, the stenotic location was found at the entrance zone of nerve root canal (75/89), involving only a single level (60/89) mostly at L4.5. The pathogenetic factors for degenerative lumbar spinal stenosis were degenerative changes of lumbar disc only (55/89), and those for hypertrophy of facet joints (22/89), thickened ligamentum flavum (11/89), and spondylolis thesis (10/89). All patients were operated on: 57 of them had less invasive procedures. The excellent and good early follow-up results were noted in 73% of the patients (65/89). The authors emphasized that the surgical treatment of lumbar spinal stenosis should be as less invasive as possible rather than a tranditional extensive lumbar laminectomy.

Proliferative response of mammary glandular tissue to formononetin

Dietary phytoestrogens have been implicated in infertility among ruminants and may relate to human breast cancer risk. Formononetin is an isoflavonoid phytoestrogen found in animal fodder and in certain human foodstuffs. To investigate a possible mechanism by which phytoestrogens might influence mammary carcinogenesis, this study examined the capacity of formononetin to stimulate mammary gland proliferation. Formononetin was administered to castrated female BALB/c mice by daily subcutaneous injection; then mammary gland proliferation and estrogen receptor expression were quantified, and plasma prolactin levels were measured. A preliminary dose-finding study demonstrated an estrogenic effect on vaginal cytology when formononetin was injected at 40 mg/kg sc. Peak plasma concentrations of 2.5 +/- 0.8 (SD) micrograms/ml at two hours and peak mammary tissue concentrations of 2.0 +/- 0.2 ng/mg tissue at four hours were noted after a single injection at this minimally bioactive dose. Among animals treated with formononetin at 40 mg/kg/day for five days, mammary gland proliferation was enhanced 3.3-fold over saline-treated controls and was comparable to that of animals treated with estradiol-17 beta at 1 microgram/kg/day for five days. Mammary tissue estrogen receptor expression was 2-fold higher among the formononetin-treated animals (P < 0.01 vs. saline-treated controls), and plasma prolactin concentrations were increased 1.7-fold (P < 0.001 vs. saline-treated controls). In subsequent in vitro binding studies, formononetin competitively bound murine mammary estrogen receptors, but with a relative binding affinity 15,000 times less potent than that of estradiol-17 beta. The results demonstrate an ability of formononetin to support mammary gland proliferation. However, the estrogenic potency of formononetin appears extremely weak compared with that of estradiol-17 beta and is roughly proportional to estrogen receptor-binding capacity.

Three chemically distinct types of oxidants formed by iron-mediated Fenton reactions in the presence of DNA

Exposure of Escherichia coli to H2O2 leads to two kinetically distinguishable modes of killing: mode I killing occurs maximally near 2 mM H2O2, whereas mode II killing is essentially independent of H2O2 concentrations up to 20 mM. A major portion of H2O2 toxicity is attributed to DNA damage caused by the iron-mediated Fenton reaction. By studying DNA damage during Fenton reactions in vitro, the same complex kinetics were observed and three types of oxidants were distinguished based upon their reactivities toward H2O2 and alcohols and upon iron-chelator effects. Type I oxidants are sensitive to H2O2 but moderately resistant to ethanol; type II oxidants are resistant to both H2O2 and ethanol; type III oxidants are sensitive to H2O2, ethanol, and t-butanol. To explain these results, we hypothesize that type I oxidants are generated upon Fe2+ associated with DNA only through electrostatic interactions and cause mode I killing of E. coli; type II oxidants arise upon Fe2+, which is at least partially base-associated, and cause mode II killing; type III oxidants arise on Fe2+ free in solution and probably do not cause killing. Therefore, particular interactions of DNA with transition metals should be considered to be an integral part of the chemistry and toxicity of H2O2.

Guanosine induces necrosis of cultured aortic endothelial cells

We have observed that treatment of cultured bovine aortic endothelial (BAE) cells with guanosine can inhibit the proliferation and viability of the cells. The addition of 500 mumol/L guanosine to the medium resulted in approximately 90% inhibition of cell proliferation. It also changed the morphology of BAE cells from having a small cobblestone-like appearance to a giant pancake-like morphology. At a concentration range of 1 to 2.5 mmol/L, guanosine inhibited the viability of quiescent BAE cells. Incubation of the cells with 2 mmol/L guanosine for 24 hours maximally induced the loss of cell viability by approximately 80%. We also compared the effects of different nucleosides on the proliferation and viability of BAE cells and found that at appropriate concentration ranges, only guanosine was able to inhibit the proliferation and viability of the cells. To assess the mechanism that mediates the cytotoxicity of guanosine, we analyzed the degradation pattern of DNA in guanosine-treated cells and found that random DNA degradation occurred in the cells. Thus, we suggest that treatment of BAE cells with guanosine induced cell necrosis.

Analysis of Schizosaccharomyces pombe mitochondrial DNA replication by two dimensional gel electrophoresis

The entire mitochondrial genome of Schizosaccharomyces pombe ura4-294h- was analyzed by the 2D pulsed field gel electrophoresis technique developed by Brewer and Fangman. The genome consists of multimers with an average size of 100 kb and analysis of the overlapping restriction fragments of the complete mitochondrial DNA (mtDNA) genome resulted in simple Y 2D gel patterns. Large single-stranded DNA molecules or double-stranded DNA molecules containing large or numerous single-stranded regions were found in the S. pombe mtDNA preparation. The replication of mtDNA monomers was found to occur in either direction. On the basis of these results, a replication mechanism for S. pombe mtDNA that is most consistent with a rolling circle model is suggested.

Negative and positive regulation of IGF-II mRNA expression in cultured rat cells by chicken serum

We have investigated the possibility that some serum factors might negatively regulate the expression of the insulin-like growth factor-II (IGF-II) gene in 18-54, SF cells. Northern blot analyses indicated that there were three major transcripts (3.8 kb, 1.8 kb, and 1.2 kb) of the IGF-II gene in these cells. We found that incubation of 18-54, SF cells in medium containing very high concentrations (50-100%) of chicken serum greatly inhibited the steady-state level of all three IGF-II mRNA species. In addition, we also found that incubation of 18-54, SF cells in medium containing lower concentrations (10-50%) of chicken serum induced a 3.5 kb IGF-II mRNA. The inhibitory effect of high concentrations of chicken serum on IGF-II mRNA expression was not due to a cytotoxic effect of the serum, because these cells were maintained in 100% chicken serum for up to two weeks without loss of cell viability. The inhibitory effect of chicken serum on IGF-II mRNA was reversible after withdrawal of the serum. Nuclear run-on assays suggested that this negative regulation of IGF-II mRNA in 18-54, SF cells by chicken serum was not the result of transcriptional inhibition. Treatment of 18-54, SF cells that had been previously incubated in 100% chicken serum for 24 h with actinomycin D resulted in a partial restoration of the expression of the 3.8 kb and 1.2 kb IGF-II mRNA in these cells.(ABSTRACT TRUNCATED AT 250 WORDS)

[Anti-implantation action of nylestriol and its effect on endometrium in rabbits]

The anti-implantation action of nylestriol in rabbits was studied. Using the method of arresting mitosis by injection of colchicine, we detected the mitosis frequency of endometrial cells. The activities of carbonic anhydrase (CAH), A1P and PAS reaction were observed under light microscope combined with the histochemical method and microscopic autoexposure control device. The results were as follows: 1. Giving nylestriol orally to rabbits on day 1 of pregnancy produced an obvious anti-implantation effect; 2. The number of mitosis cells in glandular epithelium and stroma of the endometrium in the treatment group was less than that in the control group (P < 0.05); and 3. Compared with the control group, the activities of CAH and A1P, and glycogen content in the endometrium decreased significantly in the treatment group (P < 0.05). The result suggests that nylestriol may prevent the implantation of blastocyst by disturbing decidulization of the endometrium.