Increased expression of osteopontin in patients with triple-negative breast cancer

BACKGROUND

Patients with triple-negative [oestrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER-2/neu) negative] breast cancer, accounting for about 15% of breast cancer cases, are associated with aggressive histology, poor prognosis and shorter survival. Osteopontin is a chemokine-like phosphorylated glycoprotein that plays important role in cancer progression and is found to be a metastasis-associated protein in breast cancer. The goal of the study was to evaluate osteopontin protein expression levels in triple-negative breast carcinomas to determine if they correlated with clinicopathological parameters, thus providing additional support for osteopontin functioning and better understanding of triple-negative breast cancer.

MATERIALS AND METHODS

A database of 239 patients, in whom all three markers (ER, PR, and HER-2/neu) were available, was reviewed. We performed osteopontin protein expression analyses by means of immunohistochemistry on 117 breast carcinoma tissue samples, and then assessed the mean value of osteopontin expression against triple-negative status and clinicopathological parameters.

RESULTS

Of the 239 patients in the study, 47 were classified as triple negative. Of the 117 osteopontin-test patients in this cohort, mean osteopontin levels were significantly higher in the triple-negative breast cancers than in non-triple-negative subtype (P = 0.035). TNM (tumours, nodes, metastases) stage were significantly associated with osteopontin levels (P = 0.038). Univariate analysis showed tumour cell osteopontin positivity above an optimized cut-point to be significantly associated with decreased disease-free survival, but not overall survival. In the multivariate model, osteopontin was an independent prognostic factor for disease-free survival.

CONCLUSIONS

Patients with osteopontin overexpression develop predominantly triple-negative tumours. Osteopontin overexpression is associated with tumour aggressiveness and poor prognosis.

Humoral and cell-mediated immune responses of humans to inactivated influenza vaccine with or without QS21 adjuvant

To evaluate humoral (antibody) and cell mediated immune (CMI) responses, 30 healthy young adults were either given inactivated influenza vaccine with or without QS21 adjuvant. Vaccination site pain and postvaccination myalgias were greater in the QS21 group. Serum antibody increases occurred in 73-93% of subjects for each vaccine and antigen at 2 weeks and 4 weeks but frequencies and mean titers for the two vaccines were not different. No differences in T cell cytotoxicity were detected for either vaccine for influenza A or B infected cells. IFN-gamma for both vaccine groups was increased in supernates after 3 days but not 7 days of stimulation in the cytotoxicity tests; amounts for the two vaccines were similar. To further evaluate CMI, remaining PBMCs were stimulated overnight with cells infected with each vaccine strain; an increase in spot forming cells (sfc) for Granzyme B and IFN-gamma was found for all subjects and in 51 of 54 sfc tests. A slightly higher response in the Gran B test for QS21 subjects was suggested, but no clear immune response advantage was identified among healthy adults for QS21 adjuvanted influenza vaccine.

SEA0400, a novel Na+/Ca2+ exchanger inhibitor, reduces calcium overload induced by ischemia and reperfusion in mouse ventricular myocytes

Given the potential clinical benefit of inhibiting Na+/Ca2+ exchanger (NCX) activity during myocardial ischemia reperfusion (I/R), pharmacological approaches have been pursued to both inhibit and clarify the importance of this exchanger. SEA0400 was reported to have a potent NCX selectivity. Thus, we examined the effect of SEA0400 on NCX currents and I/R induced intracellular Ca2+ overload in mouse ventricular myocytes using patch clamp techniques and fluorescence measurements. Ischemia significantly inhibited inward and outward NCX current (from -0.04+/-0.01 nA to 0 nA at -100 mV; from 0.23+/-0.08 nA to 0.11+/-0.03 nA at +50 mV, n=7), Subsequent reperfusion not only restored the current rapidly but enhanced the current amplitude obviously, especially the outward currents (from 0.23+/-0.08 nA to 0.49+/-0.12 nA at +50 mV, n=7). [Ca2+]i, expressed as the ratio of Fura-2 fluorescence intensity, increased to 138+/-7% (P<0.01) during ischemia and to 210+/-11% (P<0.01) after reperfusion. The change of NCX current and the increase of [Ca2+]i during I/R can be blocked by SEA0400 in a dose-dependent manner with an EC50 value of 31 nM and 28 nM for the inward and outward NCX current, respectively. The results suggested that SEA0400 is a potent NCX inhibitor, which can protect mouse cardiac myocytes from Ca2+ overload during I/R injuries.

T cell activation with systemic agonistic antibody versus local 4-1BB ligand gene delivery combined with interleukin-12 eradicate liver metastases of breast cancer

We have shown that interleukin-12 (IL-12) generated a strong, albeit transient, anti-tumor response, mostly mediated by natural killer (NK) cell. T cell participation, in addition to NK cells, was essential for persistence of the anti-tumor response. Ligation of 4-1BB, a co-stimulatory receptor expressed on activated T cells, is known to amplify T cell-mediated immunity. In this study, we compared the effect of a systemically delivered agonistic anti-4-1BB monoclonal antibody (anti-4-1BB mAb) with intra-tumoral adenoviral-mediated gene transfer of the 4-1BB ligand (ADV/4-1BBL) to liver metastases in a syngeneic animal model of breast cancer. Both treatments induced a dramatic regression of pre-established tumor. When combined with intra-tumoral delivery of the IL-12 gene, both anti-4-1BB mAb and ADV/4-1BBL were synergistic and led to survival rates of 87% and 78%, respectively. The anti-tumor immunity is mainly mediated by CD4+ T cells in IL-12 plus 4-1BB ligand-treated animals, and CD8+ T cells in IL-12 plus anti-4-1BB mAb-treated animals. However, only long-term survivors after treatment with IL-12 and 4-1BBL genes have showed significantly potent, systemic, and tumor-specific T cell-mediated immunity.

[Orthotopic detenia cecal-ascending colon urinary reservoir: report of 18 cases]

OBJECTIVE

To improve the technique of detenia cecal-ascending colon continent urinary reservoir for farther improving the life quality of the patient.

METHODS

Orthotopic detenia cecal-ascending colon urinary reservoir was carried out by complete resection of all the tenia and multiple transverse incision of colonic circular muscular layer for 18 patients with bladder cancer underwent radical cystectomy.

RESULTS

The patients have been followed up for 6-20 months. All were completely continent during the day and 13 patients got complete continence at the night. Only 3 patients had nocturnal incontinence. The capacity of the urine reservoir was 410-520 ml. The maximum intrareservoir pressure was 39-60 cmH2O, while the post-micturition residual volume was 15-46 ml and the maximum flow rate was 12-28 ml/per second. No evidence of ureter reflux and ureteral obstruction was observed and serum electrolytes were normal in all patients.

CONCLUSIONS

Orthotopic detenia cecal-ascending colon urinary reservoir shows good clinical and functional results, and the simple technique, exerts low pressure in the reservoir and produces minimal complications.

Midterm results of complete arterial revascularization in more than 1,000 patients using an internal thoracic artery/radial artery T graft

OBJECTIVE

To report the authors' 7-year experience with the internal thoracic artery/radial artery (ITA/RA) T graft as the only conduits for myocardial revascularization in two- and three-vessel disease.

SUMMARY BACKGROUND DATA

One and two arterial conduits provide increasing survival benefit for coronary grafting and reduce the need for reintervention. Exclusive use of arterial conduits may provide further benefit.

METHODS

From October 1993 to November 2000, 1,020 patients underwent complete arterial revascularization with the ITA/RA T graft. The authors focus on the 909 having initial bypass, with a mean age of 60 and 20% age 70 or older. The incidence of triple-vessel disease was 73%, female gender 28%, diabetes mellitus 27%, peripheral vascular disease 11%, cerebrovascular disease 10%, and chronic obstructive pulmonary disease 6%; ejection fraction was less than 35% in 11%. Perioperative data were collected prospectively. Follow-up information was obtained at a mean of 35.4 months (range 1-88) and was 95% complete.

RESULTS

There were seven (0.08%) deaths within 30 days of surgery. The incidence of perioperative infarction was 3.3%, low cardiac output 2.7%, stroke 2.2%, reoperation for bleeding 3.8%, and deep sternal infection 0.8%. The actuarial survival rate was 90% at 5 years, freedom from infarction was 94%, freedom from catheterization was 83%, and freedom from reintervention (angioplasty or reoperation) was 93%.

CONCLUSION

The ITA/RA T graft for complete arterial revascularization is associated with a low rate of perioperative death and complications and 5-year survival and freedom from reintervention values consistent with other revascularization strategies.

Evidence of a lysosomal pathway for apoptosis induced by the synthetic retinoid CD437 in human leukemia HL-60 cells

The novel synthetic retinoid 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphtalene carboxylic acid (AHPN/CD437) has been proven to be a potent inducer of apoptosis in a variety of tumor cell types. However, the mechanism of its action remains to be elucidated. Recent studies suggest that the lysosomal protease cathepsin D, when released from lysosomes to the cytosol, can initiate apoptosis. In this study, we examined whether cathepsin D and free radicals are involved in the CD437-induced apoptosis. Exposure of human leukemia HL-60 cells to CD437 resulted in rapid induction of apoptosis as indicated by caspase activation, phosphatidylserine exposure, mitochondrial alterations and morphological changes. Addition of the antioxidants alpha-tocopherol acetate effectively inhibited the CD437-induced apoptosis. Measurement of the intracellular free radicals indicated a rise in oxidative stress in CD437-treated cells, which could be attenuated by alpha-tocopherol acetate. Interestingly, pretreatment of cells with the cathepsin D inhibitor pepstatin A blocked the CD437-induced free radical formation and apoptotic effects, suggesting the involvement of cathepsin D. However, Western blotting revealed no difference in cellular quantity of any forms of cathepsin D between control cells and CD437-treated cells, whereas immunofluorescence analysis of the intracellular distribution of cathepsin D showed release of the enzyme from lysosomes to the cytosol. Labeling of lysosomes with lysosomotropic probes confirmed that CD437 could induce lysosomal leakage. The CD437-induced relocation of cathepsin D could not be prevented by alpha-tocopherol acetate, suggesting that the lysosomal leakage precedes free radical formation. Furthermore, a retinoic acid nuclear receptor (RAR) antagonist failed to block these effects of CD437, suggesting that the action of CD437 is RAR-independent. Taken together, these data suggest a novel lysosomal pathway for CD437-induced apoptosis, in which lysosomes are the primary target and cathepsin D and free radicals act as death mediators.

A nonheme iron(II) complex that models the redox cycle of lipoxygenase

The air-stable complex [Fe(6-Me3-TPA) (O2CAr)]+ [1; 6-Me3-TPA = tris(6-methyl-2-pyridylmethyl)amine] has been synthesized as a model for the iron(II) site of lipoxygenase. This iron(II) complex reacts with 0.5 equiv ROOH to form a yellow species, which has been formulated as [FeIII(OH)(6-Me3-TPA) (O2CAr)]+ (2) by electrospray mass spectrometry. Addition of more ROOH converts 2 into a purple species, which is characterized by electrospray ionization mass spectrometry and resonance Raman spectroscopy as [FeIII(OOR)(6-Me3-TPA)(O2CAr)]+. The purple species is metastable and decomposes via Fe-O bond homolysis to regenerate the starting iron(II) complex. These metal-centered transformations parallel the changes observed for lipoxygenase in its reaction with its product hydroperoxide.

[Mathematical models of cardiac myocytes and their applications in simulating electrophysiological activities]

Based on historical developments, the mathematical models of cardiac myocytes and their applications in simulating electrophysiological activities are summed up.

[Analysis of the type, reason for death and cause of non-malpractice tangle]

206 autopsy cases related to the death of non-malpractice medical tangle from 1972 to 1998 were studied retrospectively. 111 (53.88%) were died of natural diseases, 82 (38.81%) inevitable complications and 13 (6.31%) unpredictable medical accidents. For the cause of medical tangles, the diagnosis of 92 cases (44.66%) was questioned. The other disputes focused on the infusion/blood transfusion (31 cases, 15.05%), the injection (20 cases, 9.71%), drug misuse and delay in making diagnosis or giving treatment (18 cases, 8.74% respectively). 13 cases (13.11%) involved complains on medical staff's rudeness and hospital management.

Genotoxicity of two novel pesticides for the earthworm, Eisenia fetida

In this paper, several studies were conducted to evaluate the genotoxicity of two pesticides, Imidacloprid and RH-5849, for earthworm (Eisenia fetida). Earthworms were exposed in different exposure systems to evaluate their acute toxicity and the genotoxicity of the two pesticides was evaluated by using the method of sperm deformity assessment, micronucleus test of root tip cells in Vicia faba, a mouse bone-marrow micronucleus test, and comet assay. LC(50) (interpolated concentration at which 50% mortality of test population occurs) for earthworms varied in different exposure systems. The results indicated that Imidacloprid was consistently more toxic than RH-5849 in all exposure systems. In this study, sperm deformity test was used to detect the potential adverse influences of pesticides on the reproduction of earthworms. The results demonstrated that significant induction of sperm deformity (p<0.01) and a dose-effect relationship displayed at Imidacloprid concentrations higher than 0.5 mg/kg dry soil. However, the sperm deformity frequency of groups exposed to RH-5849 did not show significant difference (p>0.05) from the control until the dose reached 100 mg/kg dry soil. The results of the V. faba micronucleus tests showed that micronuclei frequency of the exposed group did not show significant difference (p>0.05) from the control until the concentration of Imidacloprid and RH-5849 reached 100 mg/ml. The results of the mouse bone-marrow micronuclei test also indicate that two pesticides did not show significant effects (p>0.05) on the micronuclei frequency in mice bone-marrow cells until the dose reached 100 mg/kg for Imidacloprid and 300 mg/kg for RH-5849 (2/3 LD(50)). Although no genotoxicity was detected by using the micronucleus tests, the results of the comet assay showed that the two pesticides induce significant DNA damage (p<0.01) in earthworms and dose-effect relationships were displayed. The 'earthworm comet assay' is a rapid and sensitive way to screen chemicals or terrestrial environments for their DNA-damaging properties.

[Expression of recombinant human stem cell factor in insect cells]

The cDNA of human stem cell factor(hSCF) containing signal sequence was cloned into the transfer vector pVL941 of AcNPV to construct a recombinant transfer vector pVL941-SCF. Sf9 cells were cotransfected with wild type viral DNA and pVL914-SCF to produce the recombinant virus AcNPV-SCF by homologous recombination in cell. Southern-hybridization analysis suggested that the recombinant viral DNA contained hSCF cDNA fragment. The Sf9 cells infected with the recombinant baculovirus AcNPV-SCF expressed biologically active rhSCF which was secreted into the cell culture. The synergistic activities of SCF in conjunction with human interleukin-3(hIL-3) was measured by MTT colorimetric method and TF-1 cell line. The expression level of Sf9 cells reached its highest at about 1970 units/ml in the 3rd day after the infection with AcNPV-SCF. Three SCF bands with molecular masses of 18 x 10(3), 20 x 10(3) and 22 x 10(3) were detected by immunoblotting.

[Surgical treatment in patients with primary bronchogenic carcinoma involving the chest wall.]

BACKGROUND

To sum up experience of surgical treatment for patients with bronchogenic carcinoma involving the chest wall.

METHODS

Thirty-five patients with bronchogenic carcinoma invading chest wall underwent surgical treatment. Extra pleural-pulmonary resection for group one ( n = 16) and en bloc resection of chest wall-pulmonary for group two ( n = 19) were performed.

RESULTS

There was no operative mortality. The 3 and 5 year survival rates in group one were 38. 5 % and 18. 2 % , and 41. 2 % and 35. 7 % in group two respectively. In patients with N(0) disease , 3 and 5 year survival rates were 63. 2 %(12/ 19) and 42. 9 %(6/ 14) respectively , but there was only one patient with N(1-2) disease surviving for over 5 years.

CONCLUSIONS

The operation types and lymph node status play important roles in the prognosis after operation. Reconstruction of chest wall defect could be successful with 2-0 Prolene suture and covering with muscles of chest and back.

EPR properties of mixed-valent mu-oxo and mu-hydroxo dinuclear iron complexes produced by radiolytic reduction at 77 K

Radiolytic reduction at 77 K of oxo/hydroxo-bridged dinuclear iron(III) complexes in frozen solutions forms kinetically stabilized, mixed-valent species in high yields that model the mixed-valent sites of non-heme, diiron proteins. The mixed-valent species trapped at 77 K retain ligation geometry similar to the initial diferric clusters. The shapes of the mixed-valent EPR signals depend strongly on the bridging ligands. Spectra of the Fe(II)OFe(III) species reveal an S = 1/2 ground state with small g-anisotropy as characterized by the uniaxial component (gz-gav/2 < 0.03) observable at temperatures as high as approximately 100 K. In contrast, hydroxo-bridged mixed-valent species are characterized by large g-anisotropy (gz-gav/2 > 0.03) and are observable only below 30 K. Annealing at higher temperatures causes structural relaxation and changes in the EPR characteristics. EPR spectral properties allow the oxo- and hydroxo-bridged, mixed-valent diiron centers to be distinguished from each other and can help characterize the structure of mixed-valent centers in proteins.

Aldosterone biosynthesis in extraadrenal tissues

OBJECTIVE

To determine whether extraadrenal tissues synthesize aldosterone in addition to vascular tissue and brain.

METHODS

Ex vivo kidney perfusion was performed in normal Wistar rats, ACEI pretreated and adrenalectomized rats prior to the perfusion experiment. After equilibration for 30 minutes, 120 ml of perfusate was collected and subjected to reverse-phase HPLC and then aldosterone was measured by RIA. By RT-PCR and Southern blot the expression of aldosterone synthase gene-CYP11B2 mRNA was studied in both kidney tissue and cultured renal tubular epithelial cell, lung and liver tissues. In situ hybridization was used to identify the cell types of liver and lung expressing CYP11B2 mRNA.

RESULTS

Production of aldosterone in the kidney perfusate was not changed in adrenalectomized rats although it was decreased in the group pretreated with ACEI perindopril. By RT-PCR and Southern blot the expression of CYP11B2 mRNA was demonstrated in both kidney tissue and cultured renal tubular epithelial cell. We have also identified CYP11B2 mRNA expression in liver and lung of rats. In situ hybridization showed that CYP11B2 mRNA was localized in the endoplasm of liver fat-storing cell (Ito cells) and type II alveolar cells of lung.

CONCLUSIONS

These studies prove that kidney, liver and lung are able to produce aldosterone.

[Clinical significance of MDR1 and MDRP gene expression in patients with non-small cell lung cancer.]

BACKGROUND

To investigate the clinical significance of MDR1 andMDRP gene expression in patients with non-small cell lung cancer (NSCLC) .

METHODS

Using reverse transcription polymerase chain reaction (RT-PCR) technique , the expression of MDR1 and MDRP gene was determined in cancer and paracancerous tissues from 33 NSCLC patients.

RESULTS

Positive expression of MDR1 gene was 69.7% and 36.4% in lung cancer tissues and paracancerous tissues respectively , and a highly significant difference was observed between the two groups ( P < 0.01) . The expression levels of MDR1 mRNA were much higher than those in paracancerous tissues. The positivity rate of MDRP gene expression in cancer tissues was 63.6% , which was higher than 30.3% in paracancerous tissue. The gene expression levels in cancer tissues were also significantly higher than those in paracancerous tissues. The expression levels of MDR1 and MDRP in cancer tissues of the patients receiving pre-operative chemotherapy were remarkably higher than those of the patients not receiving chemotherapy ( P < 0.05) .

CONCLUSIONS

NSCLC had primary and acquired multidrug resistance. It was of important significance to detect MDR1 and MDRP gene expression in directing chemotherapy of lung carcinoma and in predicting prognosis.

[Primary study on HRV analysis of nonlinear dynamics in animal experiment]

The purpose of this study was to address the relationship between the parameters of nonlinear dynamics and functions of heart. We adopted the methods of nonlinear dynamics in observing the changes of the parameters of nonlinear dynamics under the conditions that sympathetic or parasympathetic nerve of heart exists singly as well as the coronary artery is narrowed. The results showed that in case the sympathetic or parasympathetic nerve was cut off the correlation dimension and entropy were lower than the normals, and in case the coronary artery was seriously narrowed the correlation dimension, entropy and laypunav exponent were also lower than the normals. The conclusion is that the parameters of nolinear dynamics can indicate the changes of the functions of autonomic nerve under the above conditions.

[Clinical study of childhood acute myelogenous leukemia]

OBJECTIVE

To investigate the clinical characteristics, treatment responsiveness and prognostic factors of childhood acute myelogenous leukemia.

METHODS

Two hundred and seventy-four children with acute myelogenous leukemia diagnosed between 1978 and 1995 were retrospectively analyzed.

RESULTS AND CONCLUSIONS

Male:female is 1.6:1. The median age was 7.25 years. M2 and M3 were the commonest subtypes(80%). Twenty cases were hyperleukocytosis and 24 with extramedullary involvement. Thirty two percent of the patients was Auer rods positive. Two hundred and forty-four patients received combination chemotherapy. Complete remission (CR) rates varied from 55.88% to 92.31%. Intensive chemotherapy(including DA, DA + Vm26 or Vp16) was the cornerstone for high CR rate. Other factors influencing CR rate were initial WBC count and hepatosplenomegaly.

Monitoring the genotoxicity of Lake Taihu, using two kinds of micronucleus tests

Mutagenicity of surface water in Lake Taihu was monitored by genotoxicological methods. The goal is to determine the situation concerning the contamination by mutagens, their distribution in the lake, and the potential effect on public health. In this study, the micronucleus test of Vicia faba root tip, a standard monitoring technique now in China, was carried out to make a preliminary screening of environmental mutagens in 39 representative sites of the lake. Highly significant differences in MCN permillage (average number of micronuclei per 1000 cells) and PI (pollution index) values were found among these sites. From the results, a rough distribution of the contamination could be obtained: mainly concentrated in the north-west area of the lake from several tributaries flowing into the lake. In order to provide further evidence, organic extracts from four entrances and one outlet of the five major tributaries were examined by the micronucleus test of human peripheral lymphocytes. The results were in accord with those of the micronucleus tests using Vicia faba. The tests also revealed that the intensity and mechanism of the pollutants were diverse in the different sources.

[The establishment and evaluation of abdominal aorta thrombosis model in rat]

An animal model of abdominal aorta thrombosis based on Virchow's thrombosis principle was induced by endothelium denudation with a polyethylene catheter combining severe stenosis with an aortic constriction in rats. A total of 37 rats were involved in thrombosis induction. Among them thrombus developed in 27 rats. Mean length of thrombus was 8.53 +/- 1.42 mm. The contractibility of vascular wall in the thrombotic group significantly reduced.

[Effects of epidermal growth factor (EGF) on proliferation of human peritoneal mesothelial cells]

In order to study the effects of epidermal growth factor (EGF) on proliferation of human peritoneal mesothelial cells (HMC) and repair repair of damaged human peritoneum, the mesothelial cells from human omentum were seperated and cultured in vitro. The authors assessed the expression of EGF-R on the surface of HMC with ABC immune histochemical method and tested the proliferation extent of HMC treated with EGF at different time and dosage levels with 3H-thymidine incorporation method. The results showed that EGF-R existed on the surface of HMC and EGF could stimulate the proliferation of HMC. The proliferation of HMC growing in the media containing 20 micrograms/L EGF was more significant than that growing in RPMI-1640 alone. The greatest proliferation index (PI = 8.16) of HMC appeared in the media containing 50 micrograms/L EGF. The proliferation of HMC stimulated by EGF was time- and dose-dependent. These studies indicate that the proliferation of HMC stimulated by EGF may play a very important role in the structral and functional recovery of the injured peritoneum.

Effects of tetramethylpyrazine phosphate and sodium ferulate alone or in combination on hemodynamics in anesthetized dog

Hemodynamic actions of intravenous (iv) administration of tetramethylpyrazine phosphate (TMPP) and sodium ferulate (SF) alone or in combination were studied in anesthetized dogs. When given alone, TMPP increased left ventricular systolic pressure (LVSP), peak positive first derivative of left ventricular pressure (+LVdp/dt), coronary blood flow (CBF) and heart rate (HR) while decreasing mean aortic pressure (mAoP). SF alone did not produce any significant hemodynamic changes. When the two were administered in combination, SF antagonized dose-dependently the hemodynamic actions of TMPP. Results of this study did not support the efficacy of combined treatment of Ligusticum wallichi and Angelica root, which contain TMPP and SF respectively.

Expression of human stem cell factor in the baculovirus expression system

A partial cDNA of human Stem Cell Factor (SCF) was isolated and transferred into the genome of Bombyx Mori Nuclear Polyhedrosis Virus adjacent to the polyhedrin promoter. The soluble form of the SCF protein was expressed in Bombyx Mori cells and silkworm larvae and was secreted into the medium in an active state. The recombinant SCF was similar to natural SCF with respect to its interaction with monoclonal antibody and its synergistic biological activity in conjunction with colony-stimulating factor.

[Effects of high concentration glucose on cell growth and matrix biosynthesis in human peritoneal mesothelial cells]

During CAPD, the peritoneal mesothelial monolayer is directly bathed in dialysate containing 1.50%-4.25% glucose. In this study, we separated and cultured mesothelial cells from human omentulum (HMC) to test the effects of glucose on cell growth and matrix biosynthesis. [3H] thymidine incorporation was significantly inhibited in cells grown in > or = 1.00% glucose, compared with cells grown in 0.10% glucose and RPMI-1640 alone. HMC incubated in RPMI-1640 medium released trace fibronectin (FN) as measured by specific enzyme immunoassay, and FN level in supernatants was significantly increased when HMC grew in the media containing glucose more than 0.50%. Glucose induced inhibition of cell proliferation and increase of FN were time-and dose-dependent. Mannitol also achieved the same results, but its inhibitive effect on HMC proliferation is far less than that of isoosmolar glucose. These studies provide evidence for a multitude of direct effects of high concentration ambient glucose level on HMC growth and matrix biosynthesis, and raise the possibility that long-term exposure of HMC to high concentration glucose may induce disturbance in cell repair and metabolism, thus contributing to the formation of sclcerosing peritonitis in CAPD.

Scaling functions for the finite-size effect in fractal aggregates

An exact scaling function for the finite-sized fractal aggregates sharply bounded by a sphere of radius R has been established by using the convolution square of the shape function of aggregates and the inhomogeneity function, which is introduced to take into account the presence of inhomogeneity in fractal aggregates. The scaling function for an inhomogeneous aggregate is mainly determined by the geometric shape of the aggregate but is also dependent upon the degree of inhomogeneity present in the aggregate. The differences between the scaling function reported in this paper and the commonly used ones, exp (−r/ξ) and exp [−(r/ξ)2], are discussed. The simulating calculations have shown that the use of different scaling functions will not only influence the cross-over behavior between the Guinier regime and the fractal regime, but also make the low-q scattering intensity converge to different values.

X-ray absorption studies of the ferrous active site of isopenicillin N synthase and related model complexes

Isopenicillin N synthase (IPNS) from Cephalosporium acremonium (M(r) 38,400) is an iron-containing enzyme that aerobically catalyzes the four-electron oxidative ring closure reactions of delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV), forming the beta-lactam and thiazolidine rings of isopenicillin N. Here, we report Fe K-edge X-ray absorption studies that provide insight into the iron coordination environment and the effect of substrate and nitric oxide binding. Our analysis reveals an iron(II) coordination environment consisting of two N/O-containing ligands at 2.01 +/- 0.02 A, three N/O ligands at 2.15 +/- 0.02 A, and one C/O scatterer at approximately 2.6-2.7 A. Three His ligands are associated with the 2.15-A shell, while an unsymmetrically chelated carboxylate is associated with a scatterer at 2.01 and at 2.6-2.7 A, a combination which is consistent with the ligand environment deduced from 1H NMR studies [Ming, L.-J., Que, L., Jr., Kriauciunas, A., Frolik, C. A., & Chen, V. J. (1991) Biochemistry 30, 11653-11659]. The remaining scatterer at 2.01 A is assigned to a coordinated solvent molecule, most likely hydroxide, which can act as the proton acceptor for the incoming substrate. ACV binding to Fe(II)IPNS evinces an Fe-S interaction at 2.35 +/- 0.02 A, indicative of the coordination of substrate cysteine thiolate to the metal center. Analysis of the Fe(II)IPNS-ACV-NO data reveals one Fe-N at 1.71 +/- 0.02 A, three Fe-(N,O) at 2.04 +/- 0.02 A, one Fe-S at 2.32 +/- 0.02 A, and one Fe-(C,O) at 2.61 +/- 0.02 A, the short Fe-N bond being derived from the binding of NO. Our EXAFS conclusions, supported by corresponding analysis of relevant model complexes, corroborate and refine the working model for the Fe(II) coordination environment developed from previous spectroscopic studies.

Direct measurement of oxygen free radicals following cardiac failure of ischemic dog myocardium with the electron spin resonance technique

OBJECTIVE

To determine whether the involvement of oxygen-derived free radicals in the pathogenesis of ischemic cardiac failure in dogs.

DESIGN

Free radicals were measured in normal and ischemic myocardium from dogs with cardiac failure induced by acute coronary occlusion. The changes in free radical production in ischemic myocardium (compared with normal myocardium with or without polymorphonuclear leukocytes) were studies, with plasma superoxide dismutase and malondialdehyde analyzed concurrently.

MAIN RESULTS

The results showed that the oxygen free radicals in the ischemic myocardium were about 42.5% higher than those in the normal myocardium, about 67.8% higher than those in the normal myocardium washed with normal saline and about 60.5% higher than those in the ischemic myocardium washed with normal saline (P < 0.05). Compared with controls, the concentration of malondialdehyde in ischemic dog myocardium was increased markedly. The activity of plasma superoxide dismutase was not significantly different between control dogs and dogs with ischemic cardiac failure.

CONCLUSIONS

The current results indicate that there was increased production of free radicals and peroxidative damage in ischemic myocardium of dogs with cardiac failure. Polymorphonuclear leukocytes appear to be a main source of free radicals in dog with ischemic cardiac failure.

Electron spin resonance determination and superoxide dismutase activity in polymorphonuclear leukocytes in congestive heart failure

Electron spin resonance spin trapping technique was used to measure the generation of active oxygen free radicals during the respiratory burst of phorbol myristate acetate-stimulated leukocytes, and the superoxide dismutase activity in healthy subjects and in patients with congestive heart failure. The authors also measured the concentration of peroxidation products (primarily malondialdehyde) by the thiobarbituric acid method. Experimental results showed that the electron spin resonance spectra obtained during the respiratory burst of polymorphonuclear leukocytes stimulated with phorbol myristate acetate primarily were those of the spin adduct of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) with the superoxide anion and to a lesser extent those of DMPO with hydroxyl radical. Compared with healthy subjects, the release of oxygen free radicals in the respiratory burst of polymorphonuclear leukocytes stimulated with phorbol myristate acetate and the concentration of thiobarbituric acid reactive product in plasma were significantly increased in patients with congestive heart failure while the activity of superoxide dismutase was markedly lower. The increased production of oxygen free radicals by polymorphonuclear leukocytes and the decreased capability of antioxidative defences might play an important role in the generation and development of cardiac failure.

[A study of rotavirus infections in families]

Using the PAGE method, we detected 194 stool samples collected in 72 families during the epidemic season of rotavirus infection. Rotavirus was found in 29 of the 48 stool specimens of children with diarrhea, and for comparison, it was found in only 1 of the 24 stool specimens of children without diarrhea. Rotavirus infections occurred significantly more often among adults having contacts with children infected by HRV (21.3%) than among adults having no contacts with children infected by HRV (4.5%). Rotavirus infections in most of adults were asymptomatic but some of those with abdominal cramps. The illnesses were generally mild and did not necessitate medical attention. The results suggest that asymptomatic adult contacts may be able to transmit the HRV to other people.