[Detection of HPV in human esophageal cancer in high-incidence area and its correlation with p53 expression]

OBJECTIVE

To investigate the association of HPV with the development of esophageal cancer (EC) in a high-incidence area of EC and to elucidate its correlation with p53 overexpression.

METHODS

Thirty EC specimens were collected from Anyang, Henan. Four pairs of primers were designed to perform in situ hybridization (ISH) and in situ PCR(ISPCR). Immunohistochemical staining was used to detect p53.

RESULTS

HPV L1, HPV-16-E6 and HPV-16-E7 was detected in 10.0%, 60.0% and 63.3% of the EC samples, respectively. The detection rate of HPV-18-E6 was low(6.7%) and no EBV was detected. Overexpression of p53 was identified in 73.3% EC. With ISH or ISPCR, HPV-16-E6 was positive in 53.3% of EC.

CONCLUSION

The low detection rate of HPV L1 and high detection rate of HPV-16-E6 and E7 genes suggest that HPV may be partially lost when integrating into tumor cell genome, while E6 and E7 genes are intact. The results support a role of HPV-16 in the pathogenesis of EC in high incidence area. Although p53 mutation takes an important part in tumor pathogenesis, it is not consistent with the HPV existence in the EC cells.

Important ECG diagnosis-aiding indices of ventricular septal defect children with or without congestive heart failure

In this paper we perform a statistical study of the conventional RR intervals and two newly defined PR' and RT intervals of ECG data. A quadratic classification rule is applied to extract several important ECG diagnosis-aiding indices among normal children and children with ventricular septal defect (VSD) with or without congestive heart failure (CHF). The results show that certain statistics computed from PR', RR and RT intervals are important diagnosis-aiding indices. Best classification vectors are searched for pairwise classification. Two methods, minimum distance criterion and a two-stage classification procedure, are considered for three-way classification. Furthermore, logistic regression models based on transformations of these important diagnosis-aiding indices are proposed. The receiver operating characteristic curves of the proposed models show better performance than those of linear and quadratic logistic models. In order to proceed with this study, a computer algorithm to automatically detect the three intervals is developed and the related ECG data are collected and analysed. The algorithm is also enhanced with an outlier detection procedure for the automatic measurements of the PR' and RT intervals.

Reconstruction of ureteral defects with microvascular vein grafts in a rat model

This study was undertaken to test the performance of an autologous vein graft as a ureteral replacement in the rat model. Twenty-six rats were divided into three groups. In Group 1 (n = 10), the animals had a 3-mm segment of the ipsilateral ureter excised and the ureteral defect repaired, using a superficial epigastric vein graft. In Group 2 (n = 10), the same ureteral defect was created and again repaired, using a superficial epigastric vein graft, with the addition of a Silastic stent. The control, Group 3 (n = 6), had the ureter transected and repaired solely by means of primary anastomosis. Animals from each group underwent urography and were sacrificed for histology at three different postoperative intervals: 1, 4, and 12 weeks. Postoperative urography results showed normal renal function in the animals with ureteral reconstruction using vein grafting aided by a stent, as well as in those with primary ureteral anastomosis. No renal function return was seen in the animals with ureteral reconstruction by vein grafting alone, without stent support. Histologically, a progressive loss of the vascular endothelium, and replacement with the urothelium typical of the ureter, was seen in the stented vein grafts. Severe ureteral obstruction at the proximal site of the graft and hydronephrosis were seen in the vein-graft group without stenting. This study demonstrates that autologous vein grafts can be used successfully to correct a ureteral deficit, contingent on accurate microsurgical technique and immediate stenting.

Active roles of caspase-3 in human gastric carcinoma cell death by apoptosis inducing nucleosides from CD57+HLA-DRbright natural suppressor cell line

The six apoptosis inducing nucleosides (AINs), which were isolated by high performance liquid chromatography from CD57+HLA-DRbright natural suppressor (57.DR-NS) cell cultures, induced apoptosis in human gastric carcinoma (GCIY) cells demonstrating the accumulation of sub-G1 DNA content and morphological changes. By means of DNA unwinding assay, it has been revealed that DNA strand breaks were initially involved in the apoptotic cell death of GCIY cells treated with AINs followed by activation of caspase cascades, especially caspase-3. Actually, the cleavage of fluorogenic substrate for caspase-3 was identified in the reaction. Whereas, the addition of caspase-3 inhibitor into the reaction prevented the cleavage of fluorogenic substrate for caspase-3 and resulted in the blockage of the sub-G1 DNA accumulation and DNA fragmentation as apoptotic signals. Thus, it was definitely elucidated that the activation of caspase-3 displayed a key feature during AIN-induced apoptosis in GCIY cells.

Expression and self-assembly in baculovirus of porcine enteric calicivirus capsids into virus-like particles and their use in an enzyme-linked immunosorbent assay for antibody detection in swine

Porcine enteric calicivirus (PEC) causes diarrhea and intestinal lesions in pigs. PEC strain Cowden grows to low to moderate titers in cell culture but only with the addition of intestinal contents from uninfected gnotobiotic pigs (W. T. Flynn and L. J. Saif, J. Clin. Microbiol. 26:206--212, 1988; A. V. Parwani, W. T. Flynn, K. L. Gadfield, and L. J. Saif, Arch. Virol. 120:115--122, 1991). Cloning and sequence analysis of the PEC Cowden full-length genome revealed that it is most closely related genetically to the human Sapporo-like viruses. In this study, the complete PEC capsid gene was subcloned into the plasmid pBlueBac4.5 and the recombinant baculoviruses were identified by plaque assay and PCR. The PEC capsid protein was expressed in insect (Sf9) cells inoculated with the recombinant baculoviruses, and the recombinant capsid proteins self- assembled into virus-like particles (VLPs) that were released into the cell supernatant and purified by CsCl gradient centrifugation. The PEC VLPs had the same molecular mass (58 kDa) as the native virus capsid and reacted with pig hyperimmune and convalescent-phase sera to PEC Cowden in enzyme-linked immunosorbent assay (ELISA) and Western blotting. The PEC capsid VLPs were morphologically and antigenically similar to the native virus by immune electron microscopy. High titers (1:102,400 to 204,800) of PEC-specific antibodies were induced in guinea pigs inoculated with PEC VLPs, suggesting that the VLPs could be useful for future candidate PEC vaccines. A fixed-cell ELISA and VLP ELISA were developed to detect PEC serum antibodies in pigs. For the fixed-cell ELISA, Sf9 cells were infected with recombinant baculoviruses expressing PEC capsids, followed by cell fixation with formalin. For the VLP ELISA, the VLPs were used for the coating antigen. Our data indicate that both tests were rapid, specific, and reproducible and might be used for large-scale serological investigations of PEC antibodies in swine.

Improvement of skin paddle survival by application of vascular endothelial growth factor in a rat TRAM flap model

The effect of vascular endothelial growth factor (VEGF) on skin flap survival and its ability to induce a pharmacological delay by promoting angiogenesis in a flap was studied in a rat transverse rectus abdominis musculocutaneous flap, using a 3 x 8-cm skin paddle with the inferior epigastric vessels as its main vascular supply. Forty-three Sprague-Dawley rats were divided into four groups. In group 1, VEGF was injected into the femoral vein after the flap was elevated. In group 2, VEGF was injected intra-arterially into the flap through the superior epigastric artery after the flap was elevated. In group 3, VEGF was injected into the subcutaneous fascial layer in the area where the flap would be dissected, and the flap was then raised 7 days after injection. In group 4, the flap was dissected and replaced, using saline injection as the control. On postoperative day 5, the survival area of each skin paddle was measured and the flap was harvested for histological analysis. The results showed that the mean survival area +/- standard deviation for the skin paddle was 6.82 +/- 4.89 cm2 (28.4 +/- 20.4% of the whole skin paddle) in the control group, and 4.2 +/- 3.0 cm2 (17.5 +/- 12.5%) and 6.02 +/- 5.97 cm2 (25.1 +/- 24.9%) in the groups with VEGF systemic and intra-arterial administration respectively. The skin survival area in the group with preoperative subcutaneous administration of VEGF was 17.85 +/- 2.88 cm2 (74.4 +/- 12%), which was significantly higher than the other three groups (p < 0.01). Histological semiquantitative analysis showed increased neovascularization in the flap treated with VEGF preoperatively. The data demonstrate that preoperative treatment with VEGF can induce angiogenesis and enhance skin paddle survival in a musculocutaneous flap.

Eldepryl prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced nigral neuronal apoptosis in mice

OBJECTIVE

To study the apoptotic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on the nigral dopaminergic neurons of mice and 1-methyl-4-phenylpyridium ion (MPP+) on pheochromocytoma (PC12) cells, as well as the antagonism of Eldepryl against MPTP's apoptotic effect.

METHODS

Three groups of C57BL mice were treated with MPTP, Eldepryl plus MPTP and normal saline, respectively, for 7 days before performing TUNEL (terminal deoxyneucleotidyl transferase-mediated dUTP-x nick end labeling) and FACS (fluorescence activated cell sorting) analyses of neuronal apoptosis in the substantia nigra. The same tests were employed in cell culture to examine apoptosis in PC12 cells treated with MPP+, MPTP or PBS.

RESULTS

Intraperitoneal administration of MPTP 30 mg/kg could induce nigral apoptosis, and oral use of Eldepryl prior to MPTP treatment could completely prevent the nigral apoptosis caused by MPTP. MPP+, an intermediate metabolite of MPTP, could lead to the apoptosis of PC12 cells, whereas MPTP itself had no such effect on PC12 cells.

CONCLUSIONS

The experiment indicated that the neurotoxin, MPTP, might cause the death of nigral neurons through a mechanism of apoptosis and this effect might be mediated by its bioactive intermediate metabolite MPP+. Eldepryl could protect the neurotoxicity from MPTP.

Acute respiratory distress syndrome and blastomycosis: presentation of nine cases and review of the literature

Mississippi has the highest prevalence of blastomycosis in the country. In 20 years and 5 months there were 123 patients treated for blastomycosis at the University of Mississippi Medical Center. Among these, 107 patients had lung involvement and nine patients (8.4%) developed acute respiratory distress syndrome. Seven of the nine patients (78%) died of respiratory failure. In six patients, the lungs were the only organs involved. The three other patients had involvement of other organs as well. Average survival after the onset of acute respiratory distress syndrome was 6.9 days (range, 2 to 17 days). Acute respiratory distress syndrome can be triggered by pulmonary infections caused by bacterial diseases and other fungi. Massive proliferation of yeasts in the pulmonary parenchyma is the typical finding of patients with blastomycosis and acute respiratory distress syndrome. Underlying diseases that lead to immunodepression were present in only one patient and probable partial immunodepression was present in two other patients. Data from 19 other cases reported in the literature are discussed. Ann Diagn Pathol 5:1-9, 2001.

[Phosphorus loss potential of soil-water in sites of the main rice-yield area in the Northern Zhejiang]

Phosphorus (P) loss potential and its environmental impact from soil-water were surveyed in Jiashan Yuyao, Deqing and Yuhang, named main rice-yield areas in Northern Zhejiang province China. High P input has resulted in soil P accumulation. Higher soil Olsen-P contributed its bio-available P, water extracted P and increased soil P loss potential. The role of P in paddy soils is of environmental rather than agronomic concern in the process of soil P build-up. During the no-rice time, total P (TP) concentration in the various water including ditch drain inside/outside field, field surface water and pipe drain et al are over the critical values associated with accelerated waters eutrophication. The average proportion of dissolved reactive P (DRP) concentration in TP was 40%, however, these current DRP levels in partly ditch drain outside field and surface or ground water in no-rice time could not caused serious impact to the outside waters nearby rice-yield agriculture area. No significant line correlation between soil P tests and P in field surface water was found in no-rice time due to differences in field tillage among rice-yield areas, while P application increased both soil P and its correspondingly field surface P level after rice was planted at the same time.

Metabolism of 2,4-dichlorophenoxyacetic acid in laying hens and lactating goats

2,4-Dichlorophenoxyacetic acid (2,4-D) labeled with (14)C was found to be rapidly eliminated by laying hens and lactating goats dosed orally for 7 consecutive days at 18 mg/kg of food intake and for 3 consecutive days at 483 mg/kg of food intake, respectively. Excreta of hens and goats contained >90% of the total dose within 24 h after the final dose. Tissue residues were low and accounted for <0.1% of the dose in these animals. For hens, the residues in muscle, liver, and eggs (0.006-0.030 ppm) were lower than those found in fat and kidney (0.028-0.714 ppm), 2,4-D equivalents. The tissue with highest residue in goat was the kidney at 1.44 ppm, 2,4-D equivalents. Milk, liver, composite fat, and composite muscle had significantly lower residue levels of 0.202, 0.224, 0.088, and 0.037 ppm, respectively. The most abundant tissue residue was 2,4-D and acid/base releasable residues of 2,4-D. A minor metabolite was identified as 2,4-dichlorophenol.

Detection and molecular characterization of cultivable caliciviruses from clinically normal mink and enteric caliciviruses associated with diarrhea in mink

Enteric caliciviruses are emerging pathogens responsible for diarrhea or gastroenteritis in their respective hosts. In this report, mink enteric caliciviruses (MEC) were detected in feces from diarrheic mink by both immune electron microscopy (IEM) and RT-PCR using a broadly reactive primer pair (p289/290) targeting the highly conserved RNA polymerase regions of the enteric caliciviruses, Norwalk-like viruses (NLVs) and Sapporo-like viruses (SLVs). The MEC possess classical caliciviral morphology with typical cup-shaped depressions on the viral surface. Sequence analyses based on nucleotide and predicted amino acid (aa) sequences of the RT-PCR products indicated that MEC is most closely related genetically to SLVs of humans and animals. The MEC shared the highest aa identities (64-71%) in the RNA polymerase region with both human SLVs and the porcine enteric calicivirus (PEC) Cowden strain SLV, indicating that MEC may belong to an individual genogroup or subgroup in the SLV genus. The MEC shared only limited aa identities in the RNA polymerase region with vesiviruses (40-51%) and NLVs (29-33%). The RNA polymerase regions of the cultivable, non-enteric mink caliciviruses (MCV) were also amplified by RT-PCR using the primer pair Pol1/Pol3 based on sequences of vesiviruses, and the primer pair p289/290. Sequence analysis indicated that these MCV shared higher aa identities in the RNA polymerase region with vesiviruses (58-81%) than with SLVs (43-51%) including the MEC, lagoviruses (35-37%) and NLVs (27-35%), suggesting that they are most closely related genetically to vesiviruses. The MEC associated with diarrhea in mink are morphologically similar to but are genetically distinct from the cultivable MCV and likely represent a new member of the SLV genus.

Blastomycosis: organ involvement and etiologic diagnosis. A review of 123 patients from Mississippi

Blastomycosis can only be diagnosed through the identification of the yeasts of Blastomyces dermatitidis in body fluids, tissues, or cultured material. The charts from 123 patients treated for blastomycosis at the University of Mississippi Medical Center from January 1980 through May 2000 were reviewed to determine the role of wet preparation, cytology, histology, and culture in diagnosing this fungal disease. Cytology uncovered the etiologic agent in 56.1% of all cases and in 71.8% of pulmonary cases. Cytology also was the first method to disclose the fungus in 57.7% of pulmonary cases. Sputum was the cytology specimen examined in 51% of the patients. In 69 patients with lung involvement, pulmonary cytology was positive in 97% of cases. Wet preparation was the second method to most commonly uncover the fungus in 37.4% of all cases. Histology was the third method with 32.5% of positive cases. Cultures were positive in 64.2% of all cases but they were the first to detect the fungus in only 3.2% of all patients. There was pulmonary involvement in 87% of patients, cutaneous involvement in 20%, osseous involvement in 15%, and central nervous involvement in 3%. In the medical literature the relative proportion of pulmonary versus disseminated disease clearly increased in series reported after 1959. Proportionally to the pattern of patients admitted to the University of Mississippi Medical Center, there is a clear predominance of black males among patients with blastomycosis followed by black females. White females constitute the sex/ethnic group least affected by this fungal disease.

Dysregulation of apoptosis: a possible mechanism leading to chronic progressive renal histological changes in lupus nephritis

OBJECTIVE

To evaluate apoptosis in lupus nephritis and the relationship between the existence of apoptotic cells in renal tissue and histopathological or clinical changes.

METHODS

Apoptosis was detected by in situ nick-end labeling techniques (TUNEL) in renal biopsies from 25 patients with type IV lupus nephritis (LN), 12 patients with IgA nephropathy IgAN, 4 patients with idiopathic mesangioproliferative glomerulonephritis (MsPGN) and 3 patients with acute poststreptococcal glomerulonephritis (APGN). Normal renal tissue obtained at nephrectomy for hypernephroma in 4 adults was used as control. Proliferating cells were identified by proliferating cell nuclear antigen (PCNA) in these patients.

RESULTS

Compared to other proliferative glomerulonephritis and controls, the patients with lupus nephritis had less apoptotic cells, a higher ratio of PCNA + cells/TdT + cells (P/T) in renal tissues; and their P/T ratio in glomeruli and tubulointerstitium correlated with the chronicity index, r = 0.4983 (P = 0.0132), r = 0.8399 (P < 0.001), r = 0.6614 (P = 0.0033), respectively. P/T ratios in the glomerulus and tubule had a positive correlation with 24-hour urinary protein, r = 0.8554 (P < 0.001) and r = 0.7134 (P = 0.001); and a negative correlation with creatinine clearance (Ccr), r = -0.4880 (P = 0.0133) and r = -0.7229 (P = 0.001), which in tubules positively correlated with serum creatinine (Scr), r = 0.4107 (P = 0.0414).

CONCLUSIONS

Apoptosis is reduced in proliferative lupus nephritis. Intense proliferation without a commensurate increase in apoptosis is a possible mechanism that leads to chronic progressive renal histopathological changes.

A randomized controlled clinical trial on etimicin, a new aminoglycoside antibiotic, versus netilmicin in the treatment of bacterial infections

OBJECTIVE

To compare the efficacy and safety of two aminoglycoside antibiotics, etimicin and netilmicin, in the treatment of bacterial infections.

METHODS

A randomized, open label, controlled clinical trial was conducted for the treatment of 65 patients hospitalized with respiratory tract infections, urinary tract infections, and skin and tissue infections. Thirty-four patients received etimicin and thirty-one patients received netilmicin at a dose of 100 mg every 12 hours by intravenous infusion. The duration of treatment was 7-10 days in both groups.

RESULTS

47 patients were enrolled in the etimicin group; 35 patients were assessable for safety and 34 patients were assessable for efficacy, 46 patients were enrolled in the netilmicin group; 32 patients were assessable for safety and 31 patients were assessable for efficacy. The results show that overall efficacy was 85.3% for the etimicin group and 83.9% for the netilmicin group, whereas bacterial clearance rates were 87.5% for the etimicin group and 89.7% for the netilmicin group. The incidence of adverse reactions was 8.6% (3/35) and 9.4% (3/32), respectively.

CONCLUSION

Etimicin and netilmicin were effective and safe for the treatment of respiratory tract infection, urinary tract infection, and skin and tissue infections. The results show there was no statistically significant difference between the two groups (P > 0.05).

The dendritic cell receptor for endocytosis, DEC-205, can recycle and enhance antigen presentation via major histocompatibility complex class II-positive lysosomal compartments

Many receptors for endocytosis recycle into and out of cells through early endosomes. We now find in dendritic cells that the DEC-205 multilectin receptor targets late endosomes or lysosomes rich in major histocompatibility complex class II (MHC II) products, whereas the homologous macrophage mannose receptor (MMR), as expected, is found in more peripheral endosomes. To analyze this finding, the cytosolic tails of DEC-205 and MMR were fused to the external domain of the CD16 Fcgamma receptor and studied in stable L cell transfectants. The two cytosolic domains each mediated rapid uptake of human immunoglobulin (Ig)G followed by recycling of intact CD16 to the cell surface. However, the DEC-205 tail recycled the CD16 through MHC II-positive late endosomal/lysosomal vacuoles and also mediated a 100-fold increase in antigen presentation. The mechanism of late endosomal targeting, which occurred in the absence of human IgG, involved two functional regions: a membrane-proximal region with a coated pit sequence for uptake, and a distal region with an EDE triad for the unusual deeper targeting. Therefore, the DEC-205 cytosolic domain mediates a new pathway of receptor-mediated endocytosis that entails efficient recycling through late endosomes and a greatly enhanced efficiency of antigen presentation to CD4(+) T cells.

[Assessment on application of Chinese herbs in process of corticosterone reduction in nephrotic syndrome]

OBJECTIVE

To evaluate the effect of Chinese herbs in the process of corticosterone (CS) reduction in nephrotic syndrome.

METHODS

One hundred and twenty patients of idiopathic nephrotic syndrome sensitive to prednisone treatment were divided into two groups randomly. The dosage of prednisone used was reduced by routine in both groups but Chinese herbal treatment was added to the treated group in the period of prednisone reduction. The effect of Chinese herbs was estimated by observing the recurrence rate of disease and side-effects of prednisone.

RESULTS

The recurrence rate of disease and the occurrence rate of side-effects of prednisone in the treated group were lesser than that in the control group significantly (P < 0.01).

CONCLUSION

Additional Chinese herbs in the process of CS reduction in the treatment of CS sensitive nephrotic syndrome could extenuate markedly the recurrence rate of disease and the side-effect of CS reduction.

Suppression of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated aryl hydrocarbon receptor transformation and CYP1A1 induction by the phosphatidylinositol 3-kinase inhibitor 2-(4-morpholinyl)-8-phenyl-4H-1- benzopyran-4-one (LY294002)

Numerous flavonoids are ligands of the aryl hydrocarbon receptor (AHR) and function as AHR antagonists and/or agonists. LY294002 [2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one] is a widely used inhibitor of phosphatidylinositol 3-kinase (PI 3-kinase), and is structurally related to members of the flavonoid family. Concentrations of LY294002 >/= 10 microM were cytostatic, but not cytotoxic, to cultures of the immortalized human breast epithelial cell line MCF10A-Neo. Treatment of MCF10A-Neo cultures with the AHR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) stimulated the transcriptional activation of CYP1A1, as monitored by measurements of steady-state CYP1A1 mRNA. Pretreatment of cultures with >/= 10 microM LY294002 suppressed the TCDD activation of CYP1A1 (IC(50) approximately 10 microM). Electrophoretic mobility shift assays employing rat liver cytosol demonstrated that concentrations of LY294002 </= 400 microM did not transform the AHR into a DNA-binding species. However, the addition of LY294002 to cytosol just prior to TCDD addition completely suppressed AHR transformation by TCDD (IC(50) approximately 35 microM). The PI 3-kinase inhibitor Wortmannin was weakly cytostatic, but not cytotoxic to MCF10A-Neo cultures at concentrations </= 500 nM. Exposure of cultures to Wortmannin (10-500 nM) did not suppress TCDD activation of CYP1A1. Analyses of the phosphorylation status of Akt-1, an in vivo substrate of PI 3-kinase, demonstrated that concentrations of LY294002 >/= 50 microM and Wortmannin >/= 10 nM completely suppressed PI 3-kinase activity. Hence, the ability of LY294002 to suppress TCDD-dependent activation of CYP1A1 is unrelated to PI 3-kinase inhibition. Instead, this activity reflects LY294002 functioning as an AHR antagonist. Furthermore, most of the cytostatic activity of LY294002 towards MCF10A-Neo cells is unrelated to the inhibition of PI 3-kinase.

[A report of two Chinese familial Budd-Chiari syndrome]

OBJECTIVE

To investigate the etiology of two Chinese familial Budd-Chiari syndrome (BCS).

METHOD

Four patients with familial BCS (from A and B families), and the other 41 family members were detected by angiography, ultrasound Dopler, etiology analysis and Factor V Leiden (FvL) mutation analysis.

RESULT

Four BCS patients were proved by angiography, 2 by ultra sound Dopler in family A. Ten members in family A were varicosis in low extremeties. FvL mutation was detected in 4 of 6 patients and 2 normal family members. A II(2), A III(7, 11, 15,) B II(10) and B III(5) had FvL mutation. The FvL mutations were compatible with Mendel hereditary law.

CONCLUSION

FvL mutation may be one of main risk factors and varicosis in low extremeties may be another risk factors for familial BCS.

Ti(IV) uptake and release by human serum transferrin and recognition of Ti(IV)-transferrin by cancer cells: understanding the mechanism of action of the anticancer drug titanocene dichloride

The organometallic anticancer agent titanocene dichloride, Cp(2)TiCl(2), is now in phase II clinical trials as an anticancer drug, but its mechanism of action is poorly understood. We show here that the interactions of Cp(2)TiCl(2) with human serum transferrin (hTF) and that of Ti(2)-hTF with adenosine triphosphate (ATP) have characteristics that could allow transferrin to act as a mediator for titanium delivery to tumor cells. Such reactions may therefore be important to the anticancer activity of this new class of drugs. Cp(2)TiCl(2) reacts rapidly with human apo-transferrin under physiological conditions (100 mM NaCl, 25 mM bicarbonate, and 4 mM phosphate, pH 7.4) with carbonate as a synergistic anion. The Cp ligands are released from the drug. Two-dimensional [(1)H, (13)C] NMR studies of epsilon-[(13)C]Met-hTF show that Ti(IV) loads the C-lobe first followed by the N-lobe and binds in the specific Fe(III) sites. The protein conformational changes induced by Ti(IV) appear to be similar to those induced by Fe(III). Carbonate can act as a synergistic anion in Ti(2)-hTF but does not appear to be essential. A specific Ti(IV)-hTF adduct is formed even in the absence of bicarbonate. When the pH of Ti(2)-hTF solutions is lowered, no Ti(IV) is released at the endosomal pH of ca. 5.0-5.5, but one Ti(IV) dissociates between pH 4.5-2.0. In contrast, in the presence of 1 mM ATP, all Ti(IV) is readily released from both lobes when the pH is lowered from 7.0 to 4.5. Moreover, Fe(III) displaces Ti(IV) rapidly from the C-lobe of Ti(2)-hTF (<5 min) but only slowly (days) from the N-lobe. Thus, the species Fe(C)Ti(N)-hTF might also provide a route for Ti(IV) entry into tumor cells via the transferrin receptor. Ti(2)-hTF effectively blocked cell uptake of radiolabeled (59)Fe-hTF into BeWo cells, a human placental choriocarcinoma cell line in culture. These results imply that titanium transferrin might be recognized by the transferrin receptor and be taken up into cancer cells.

Transcripts of immunoglobulin germline mu: an amplified myeloid and B-lymphoid common gene program in various leukemias

To investigate the clinical implications of germline C mu transcription, the splice region between the 3' end of the enhancer and the first exon of immunoglobulin germline mu; was analyzed by RT-PCR in 63 samples from 59 patients with leukemia. Immunophenotypes of 33 samples from patients with acute leukemia were analyzed using a panel of these monoclonal antibodies: anti-immature/stem cell (HLA-DR, CD34); anti-mature myeloid (CD33, CD15); anti-T lymphoid (CD2, CD3, CD5, CD7, CD8), and anti-B lymphoid (CD10, CD19, CD20). Of the 63 samples, 33 (52%) contained germline C mu transcripts: 2/2 patients with chronic lymphocytic leukemia; 17/26 (65.4%) patients with acute myeloblastic leukemia; all 4 patients with chronic myelogenous leukemia in blast crisis and 1 in accelerated phase; 9/12 patients with acute lymphocytic leukemia. A clear correlation between germline transcripts and HLA-DR expression was observed among germline-positive cases (p < 0. 01). C mu expression and response to therapy clearly indicated that germline-mu-positive leukemia patients responded poorly to chemotherapy and had a worse clinical prognosis compared with C mu-negative patients (p < 0.01). After two courses of chemotherapy, 7/9 C mu-negative patients achieved complete remission compared to only 7/29 C mu-positive patients (p < 0.01). We conclude that the gene-regulating immunoglobulin germline C mu may be amplified in myeloid and B-lymphoid cells during leukemogenesis. Such genetic changes may be correlated with cellular terminal differentiation injury, resistance to chemotherapy and uncontrolled malignant cell proliferation.

[The effect of TGF-beta1 on the expression of plasminogen activator inhibitors 1 and matrix metalloproteinases in cultured rat mesangial cells transfected with antisense-TGF-beta1 vector]

OBJECTIVE

To study the plasminogen activator inhibitors 1 (PAI-1) and matrix metalloproteinases (MMPs) expression on the cultured rat mesangial cells (MsC) transfected with antisense-TGF-beta1 vector.

METHODS

Lipofectin method was used to transfect antisense-TGF-beta1 vector into MsC, Western blot and Northern blot analysis for detecting TGF-beta1 peptides and antisense TGF-beta1 RNA level. The expression of PAI-1 and MMPs were determined by Northern blot, Western bolt and zymography assay.

RESULTS

The MsC clone (MAT1) which blocked the expression of TGF-beta1 peptides was successfully established. The MsC clone showed increased expression of MMP-2 mRNA protein and enzyme activity of MMP-2, 3, 7. However, expression of PAI-1 mRNA of MsC clone was suppressed.

CONCLUSION

Blocked expression of TGF-beta1 can upregulate the expression of MMP-2, 3, 7 and downregulate the expression of PAI-1 mRNA in MsC. It is possible that antisense-TGF-beta1 may be used for gene therapy in glomerular diseases.

A monoclonal antibody to the DEC-205 endocytosis receptor on human dendritic cells

DEC-205 is a multilectin receptor for adsorptive endocytosis, expressed in mouse dendritic cells (DC) and some epithelia. DEC-205 is homologous to the macrophage mannose receptor (MMR). A cDNA for murine DEC-205 was used to identify 3 overlapping human DEC-205 clones from a lymphocyte library. The human homologue is a transmembrane protein of 1722 aminoacids with 10 externally disposed C-type lectin domains having 77% identity to the mouse counterpart. The NH(2) terminal cysteine-rich and fibronectin type II domains were expressed and used to immunize mice. A hybridoma, MG38, which specifically recognized the immunogen was obtained from a DEC-205 knockout mouse. The antibody precipitated a 205 kD protein from metabolically labeled, monocyte-derived DCs. MG38 labeled mature monocyte-derived DCs but showed weak or no labeling of other peripheral blood mononuclear cells. In tissue sections, MG38 identified DEC-205 on thymic cortical epithelium and DCs in the thymic medulla and tonsillar T cell areas. In contrast, an anti-MMR antibody stained DEC-205 negative, macrophages in the thymus cortex, the trabeculae of the thymus and tonsil, as well as efferent lymphatics in the tonsil. Therefore, the MG38 anti-DEC-205 antibody is useful for identifying DCs and reveals clear differences in sites where MMR and DEC-205 are expressed in lymphoid tissues.

Characterization of a small round virus associated with the poult enteritis and mortality syndrome

A small round virus (SRV) identified and isolated in our laboratory from intestinal samples of poults affected with the poult enteritis and mortality syndrome was further characterized. The SRV was propagated in turkey embryos and purified by differential and isopycnic ultracentrifugation. The size of the SRV was 30-32 nm in diameter. The buoyant density of the SRV in cesium chloride was between 1.34 and 1.36 g/cm3. It was resistant to chloroform treatment, stable at pH 3.0, and resistant to heat treatment. Attempts to propagate the SRV in turkey embryo kidney, turkey kidney, Caco-2, Vero, and BGM-70 cells were unsuccessful. Analysis of the SRV capsid proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed three polypeptides with molecular weights of 34.5, 31, and 28 kD. Genome analysis of the SRV showed that the SRV had a single-strand RNA genome about 7500 nucleotides in length. Reverse transcription-polymerase chain reactions (RT-PCRs) with primers specific to conserved sequences of enteroviruses yielded products with expected sizes. However, sequence analysis of the RT-PCR products showed that there was no similarity between the sequences and that of enteroviruses. RT-PCR with primers specific to the 3' end of a SRV RNA genome yielded products with expected sizes. These products were sequenced and found to contain 669 nucleotides, excluding the polyadenylated tail. Sequence analysis indicated that the SRV shared 38.18% amino acid identity in the C-terminal capsid precursor protein and 41.26% nucleotide identity of the 3' end of turkey astrovirus RNA genome (Genbank accession no. Y15936). We concluded that the SRV is a member of the astrovirus family.

Phorbol ester-induced production of cytostatic factors by normal and oncogenic Ha-ras-transformed human breast cell lines

The effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on cell cycle progression were examined in the human breast cell line MCF10A-Neo and a derivative line which expresses a Ha-ras oncogene (MCF10A-NeoT cells). Exposure of MCF10A-Neo cultures to TPA induced a G(1) arrest that lasted approximately 16-24 h (IC(50) approximately 0.5 nM). TPA-treated cultures produced a cytostatic conditioned medium. Cytostatic activity was detectable within 1 h of TPA treatment, peaked 3-7 h later and disappeared between 16 and 24 h post-treatment. However, cytostatic conditioned medium could be quickly regenerated by re-feeding previously treated cultures with new medium. Removal of latent transforming growth factor beta (TGF beta) from the culture medium, supplementing the culture medium with anti-TGFbeta or soluble TGF beta(II) receptor, or pre-absorption of conditioned medium with anti-TGF beta all reduced the cytostatic effects of TPA or conditioned medium on MCF10A-Neo proliferation by approximately 50%. Co-treatment with the serine protease inhibitors aprotinin or plasminogen activator inhibitor-1 also suppressed the cytostatic activity of TPA approximately 50%. Conditioned medium isolated from TPA-treated MCF10A-Neo cultures was transiently cytostatic to MCF10A-NeoT cells. The proliferation of MCF10A-NeoT cultures, in contrast to MCF10A-Neo cells, was suppressed at least 72 h following TPA exposure. Conditioned medium isolated from TPA-treated MCF10A-NeoT cultures also suppressed MCF10A-NeoT proliferation for approximately 72 h, but suppressed MCF10A-Neo proliferation for <24 h. These studies suggest that TPA quickly activates proteolytic processes in MCF10A-Neo cells leading to the activation of latent TGF beta supplied by the serum in the culture medium. TPA also stimulates the production of an additional cytostatic factor(s) which signals via a mechanism not involving the TGF beta(II) receptor. Lastly, expression of an activated Ha-ras oncogene alters both the types of cytostatic factors produced following TPA treatment and responsiveness to these factors.