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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Attenuation of EGF signaling in senescent cells by caveolin

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

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

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

Functional inactivation of p73, a homolog of p53 tumor suppressor protein, by human papillomavirus E6 proteins

Human papillomavirus (HPV) is strongly implicated as a causative agent in the etiology of cervical cancer. Of its gene products, E6 binds to and inactivates p53 tumor suppressor protein by ubiquitin/proteasome-dependent degradation. Recently, p73, a novel family of p53, has been identified and demonstrated, like p53, to activate p21(WAF1). Here we show that p73 is also inactivated by HPV-E6, but ubiquitin-mediated proteolysis is not responsive. Yeast two-hybrid and GST pull-down assays indicate a physical interaction between p73 and either HPV-16 or HPV-11 E6 proteins in vivo and in vitro, respectively. The transactivation domain (amino acid residues 1 to 49) is found to be absolutely required for the interaction. Transient co-expression of E6 significantly inhibits the p73-mdiated activation of p21(WAF1) promoter in a p53-defective C33A cell line. Using Gal4-p73 fusion protein, we demonstrate that E6 inhibition of p73 transactivation function is independent of sequence-specific DNA binding, which is confirmed by a direct electrophoretic mobility shift assay. Moreover, E6 inhibits p73 function by interfering with the activity of the amino-terminal activation domain. Co-transfection of E6 mutants reveals that the same portion of E6 appears to be responsible for the inactivation of p53 and p73 function. However, the inactivation mechanism of p73 is clearly different from that of p53, because p73, unlike p53, is inactivated by both high- and low-risk E6s and is not susceptible to E6-dependent proteolysis. These overall results, consequently, suggest that in addition to the inactivation of p53, the functional interference of p73 by HPV-E6 may, at least in part, contribute to E6-mediated transformation and hyperproliferation of cervical cells.

Relationships between dietary intake and cognitive function level in Korean elderly people

We examined the relationship between dietary intake and cognitive performance in Korean elderly people. Data for dietary intake, anthropometric measurements and cognitive function tests were collected and the relationships of the variables were analyzed. A random sample of 210 men and 239 women in Korea, aged 60 and over, was selected. Subjects were free-living elderly people who had not experienced major cognitive function impairment. Main outcome measures, 24 h dietary recall method, food behaviour variables, anthropometrics indices, health variables, and Kwon's Mini-Mental State Examination for Koreans (MMSE-K) for cognitive function test. The prevalence rate of poor cognitive function (MMSE-K score < or = 19) of Korean elderly was 22.3%: women with poor cognitive function had a higher rate (31.0%) than that in men (12.3%). Cognitive ability was related negatively with age and positively with school education level. Female subjects of poor cognitive function had significantly lower intakes of total amount of foods, cereals, vegetables, fruits, milk, spices, and also, energy, protein, fat, carbohydrate, Ca, P, Fe, vitamin A, thiamin, riboflavin, and niacin than those of the normal cognitive score (> or = 24) group (P < 0.05). Male subjects of poor cognitive function had significantly lower intakes of fruits, fiber, and vitamin C than the normal subjects (P < 0.05). The MMSE-K score of female subjects showed a significant positive correlation with total amount of foods, cereals, beans, fruits, milk, oil, spices, and energy, protein, fat, carbohydrate, Ca, Fe, P, riboflavin and niacin intakes. The consumption of adequate nutrients, by taking sufficient amounts and variety of foods, may be important in maintaining adequate cognitive function in elderly Koreans.

Growth inhibition and chemosensitivity of poorly differentiated human thyroid cancer cell line (NPA) transfected with p53 gene

BACKGROUND

We investigated whether retroviral p53 transfection could enhance growth inhibition and chemosensitivity in a p53 mutant papillary thyroid cancer cell line (NPA).

METHODS

NPA cells were transfected with either LXSN/p53 or mock infection in the presence of Adriamycin. Gene expression was confirmed by western blotting. Nude mice were injected subcutaneously with NPA cells after transfection with either LXSN/p53 or mock infection on opposite sides, and the tumor growth was compared.

RESULTS

There was a dose-dependent inhibition of tumor growth with LXSN/p53 transfection. Tumor growth was inhibited more by p53 gene transfection relative to mock transfection in the presence of Adriamycin.

CONCLUSION

These treatment modalities could be beneficial in the treatment of p53 mutant positive thyroid cancers.

Atypical glandular cells of undetermined significance in cervical smears after conization. Cytologic features differentiating them from adenocarcinoma in situ

OBJECTIVE

To evaluate the cytologic features of atypical glandular cells of undetermined significance (AGUS) smears following conization through a comparison with adenocarcinoma in situ (AIS) smears.

STUDY DESIGN

Fifty cervical smears, diagnosed as AGUS based on groups of crowded glandular cells that raised the possibility of AIS, from 38 patients who had conization and 24 AIS smears, histologically confirmed, from 17 patients were reviewed. Subsequent follow-up biopsies or hysterectomies in 38 patients were evaluated.

RESULTS

Nuclear atypia was a more reliable feature than architectural structure in differentiating postcone effect from AIS on cytology. The predominant cytologic features of the postcone smears were crowded glandular cells with a high nuclear/cytoplasmic ratio and relatively small, hyperchromatic nuclei with rather finely granular and uniformly dispersed chromatin, less distinct nuclear membranes, less frequent mitosis and presence of endometrial-type stromal cells in the background. The architecture of the crowded cells in the postcone smears was sometimes similar to that of AIS. No AIS or high grade squamous intraepithelial lesion histology was encountered in follow-up biopsies or hysterectomy specimens.

CONCLUSION

The cytologic features distinguishing AGUS from AIS may be helpful in identifying the postcone effect. Since it is important to avoid miscalling the postcone effect as AIS, it is recommended that one check for a previous history of a cone biopsy.

Primary structures and chain dominance of anti-DNA antibodies

Using several anti-DNA autoantibodies, we analyzed the relative involvement of heavy and light chains in their interactions with DNA. We previously obtained eight hybridomas producing monoclonal anti-DNA autoantibodies by fusing spleen cells from an MRL-lpr/lpr mouse with myeloma cells. The chain dominance was analyzed by UV cross-linking experiments, in which the antibodies were covalently cross-linked with radioisotope-labeled oligonucleotides by short-wavelength UV-light, and the cross-linked H and L chains were analyzed by SDS-PAGE and densitometric scanning. Among these, three were found to be heavy chain dominant antibodies in which heavy chains are dominantly involved in DNA binding. The other five were co-dominant antibodies in which both heavy and light chains are involved in DNA binding. To determine the factor(s) that can explain the chain dominance in DNA binding, we determined the amino acid sequences of the variable regions of both heavy (VH) and light (VL) chains of all eight monoclonal antibodies. By analyzing the data, we were able to draw the following conclusions: (1) The arginine residues are found in the CDR3 regions of both VH and VL of the co-dominant antibodies; whereas, the same residues are found only in the CDR3s of VH, but not in VL, of the heavy chain dominant antibodies. (2) The net charges of the V regions affect the chain dominance. From the results of this study it is suggested that the presence of arginine residue in CDR3 is a critical factor in determining chain-dominance, as well as DNA binding of anti-DNA antibodies in general.

Results on preemptive or prophylactic treatment of lamivudine in HBsAg (+) renal allograft recipients: comparison with salvage treatment after hepatic dysfunction with HBV recurrence

BACKGROUND

Lamivudine has been reported to be able to stabilize liver enzyme and hepatitis B virus (HBV) replication with recurrent hepatitis that has been regarded as a frequent and major risk factor for hepatic dysfunction and chronic liver disease in renal transplant recipients. Because large number of hepatitis antigenemia patients among renal transplant patients experience recurrent hepatic dysfunction with HBV recurrence and permanent histological deterioration, preemptive or primary prophylactic use of lamivudine before transplantation may be more beneficial than a trial for the treatment of advanced hepatic dysfunction.

METHODS

We conducted a double arm study to compare the efficacy of lamivudine between the preemptive (HBV DNA positive) or prophylactic (HBV DNA negative) trial for the maintenance of stable liver function (n=10) and the trial for the salvage of advanced hepatic dysfunction developed after renal transplantation (n=6) in hepatitis B viremia carrier renal transplant recipients.

RESULTS

Hepatic dysfunction with recurrent HBV antigenemia developed in 11 of 36 (30.6%) hepatitis antigenemia patients with a mean duration of 8.4 months (range 5-19.4 months). In six patients treated with lamivudine after hepatic dysfunction from recurrent hepatitis B viremia, serum AST and ALT level normalized within 1 month and HBV-DNA disappeared in all cases. HBV-DNA, however, reappeared in three (50%) without any discontinuation of lamivudine. Liver biopsy revealed recurrent chronic active hepatitis with severe activity of fibrosis in four cases, cholestatic fibrosing hepatitis in one, and permanent cirrhotic change in one. In seven patients who had preemptive lamivudine treatment at 9, 6, 2, 2, 1, 0, 0 month before the transplantation, HBV-DNA had converted to negative with a mean follow up of 1.2 months (range 1-2 month) in all case. Three patients who had prophylactic trials with lamivudine have all remained HBV-DNA negative. The recurrence rate of HBV viremia in the preemptive or prophylactic lamivudine treated group is 10.0% (1/10), which is significantly lower than that (42.3%, 11/25) in the nonlamivudine-treated group. The re-recurrence rate of HBV viremia was significantly higher (3/6, 50.0%) in the reactive lamivudine treated group than in prophylactic or preemptive group (1/10, 10%).

CONCLUSION

Although lamivudine treatment after hepatic dysfunction can be a sound conventional treatment modality, this preliminary study may suggest that preemptive or prophylactic trial of lamivudine before hepatic dysfunction might be a more effective strategy for prevention of permanent histological deterioration and recurrence of hepatitis B viremia.

Effect of BPV1 E2-mediated inhibition of E6/E7 expression in HPV16-positive cervical carcinoma cells

OBJECTIVE

E6 and E7 proteins of high-risk-type human papillomavirus are major etiological agents for cervical carcinomas and are continuously expressed in those cancer cells. They inhibit cell cycle control functions by inactivating p53 and Rb proteins and also immortalize cells through the induction of telomerase activity. Expression of E6 and E7 genes in HeLa, an HPV18-positive cell line, has been shown to be inhibited by the E2 protein of bovine papillomavirus (BPV1), and this resulted in the activation of the p53-mediated growth inhibitory pathway followed by an inhibition of cell proliferation. In this study, the effect of BPV1 E2-mediated inhibition of E6 and E7 expression was examined in HPV16-positive cervical carcinoma cell lines recently established from Korean patients.

METHODS

BPV1 E2 was expressed in the test cells through acute infection of an SV40-BPV1 recombinant virus. Its effect on cell proliferation was assessed through MTT and DNA synthesis assays, and the status of factors involved in cell cycle control was examined through Western blotting and reverse transcription-polymerase chain reaction.

RESULTS

BPV1 E2 expression caused a significant decrease in E6/E7 transcription in all three cell lines. This was accompanied by an increase in the levels of p53 protein and activity and a decrease in the expression of Cdc25A, a Cdk2-activating phosphatase. Concomitantly, E2F1 activity and cellular DNA synthesis capacity were significantly reduced.

CONCLUSIONS

These results indicate that inhibition of E6/E7 gene expression in the HPV16-positive cervical carcinoma cells induces suppression in cell proliferation by activating the growth inhibitory factors, p53 and Rb, and also by downregulating the cell cycle stimulatory factor, Cdc25A.

Brain succinic semialdehyde dehydrogenase: identification of reactive lysyl residues labeled with pyridoxal-5'-phosphate

An NAD+ dependent succinic semialdehyde dehydrogenase from bovine brain was inactivated by pyridoxal-5'- phosphate. Spectral evidence is presented to indicate that the inactivation proceeds through formation of a Schiff's base with amino groups of the enzyme. After NaBH(4) reduction of the pyridoxal-5'-phosphate inactivated enzyme, it was observed that 3.8 mol phosphopyridoxyl residues were incorporated/enzyme tetramer. The coenzyme, NAD+, protected the enzyme against inactivation by pyridoxal-5'-phosphate. The absorption spectrum of the reduced and dialyzed pyridoxal-5'-phosphate-inactivated enzyme showed a characteristic peak at 325 nm, which was absent in the spectrum of the native enzyme. The fluorescence spectrum of the pyridoxyl enzyme differs completely from that of the native enzyme. After tryptic digestion of the enzyme modified with pyridoxal-5'-phosphate followed by [3H]NaBH4 reduction, a radioactive peptide absorbing at 210 nm was isolated by reverse-phase HPLC. The sequences of the peptide containing the phosphopyridoxyllysine were clearly identical to sequences of other mammalian succinic semialdehyde dehydrogenase brain species including human. It is suggested that the catalytic function of succinic semialdehyde dehydrogenase is modulated by binding of pyridoxal-5'-phosphate to specific Lys(347) residue at or near the coenzyme-binding site of the protein.

Effects of fixed low-dose warfarin on hemostatic factors in continuous ambulatory peritoneal dialysis patients

Increased coagulation factors found in dialysis patients may explain in part the high prevalence of thrombotic cardiovascular disease. Several studies showed low-dose warfarin is effective in decreasing coagulation factors and preventing thrombosis without increasing the risk of bleeding. To evaluate the effects of fixed low-dose warfarin therapy on thrombogenesis in continuous ambulatory peritoneal dialysis (CAPD) patients, 76 CAPD patients were assigned randomly to treatment and disease control groups. The treatment group received 2 mg of warfarin daily for 12 months. International normalized ratio (INR) of the prothrombin time and plasma levels of factor VII, D-dimer, von Willebrand factor (vWF), and plasminogen activator inhibitor-1 (PAI-1) were measured before and 3, 6, and 12 months after the start of medication. The same parameters were measured in 30 healthy volunteers at the beginning of the study and in the disease control group during the study period. Of 76 patients, 60 completed the study. Deaths from atherosclerotic cardiovascular disease (cerebral infarction or acute myocardial infarction) occurred in 1 patient in the treatment group (n = 29) and 3 in the disease control group (n = 31), which was not statistically significant. No major bleeding occurred during the study period. With administration of warfarin, there was a small increase in INR in the treatment group. CAPD patients at baseline had significantly higher plasma factor VII, D-dimer, vWF, and PAI-1 levels than normal controls. Warfarin therapy lowered plasma factor VII and D-dimer levels. No change was seen in vWF and PAI-1 levels. In the disease control group, these hemostatic factors showed no change during the study period. There was a negative correlation between serum albumin and INR in the treatment group during the study period. Fixed low-dose warfarin was effective in partially reversing the thrombogenic coagulation profile in CAPD patients without a big increase in the risk of bleeding.

The relationship between oligohydramnios and the onset of preterm labor in preterm premature rupture of membranes

OBJECTIVE

The objective of this study was to determine whether a reduced amniotic fluid volume was associated with the onset of preterm parturition in patients with preterm premature rupture of membranes.

STUDY DESIGN

An amniotic fluid index was determined before transabdominal amniocentesis in 129 patients with preterm premature rupture of membranes (gestational age < or = 35 weeks). Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Survival techniques were used for analysis.

RESULTS

Amniotic fluid index was < or = 5 cm in 29% of patients (38/129). Patients with an amniotic fluid index of < or = 5 cm had a significantly higher rate of positive amniotic fluid culture than those with an amniotic fluid index of >5 cm (42% [16/38] vs 18% [16/91]; P<.01). Spontaneous preterm delivery within 24 hours and 48 hours was more frequent among patients with an amniotic fluid index of < or = 5 cm than those with an amniotic fluid index of >5 cm (for 24 hours, 29% vs 12%; for 48 hours, 42% vs 21%; P<.05 for each). The amniocentesis-to-delivery interval was significantly shorter in patients with an amniotic fluid index of < or = 5 cm than in patients with an amniotic fluid index of >5 cm (median, 38 hours; range, 0.2-1310 hours; vs median, 100 hours; range 0.1-2917 hours; P<.01). Moreover, Cox proportional hazards model analysis indicated that an amniotic fluid index of < or = 5 cm was a significant predictor of the duration of the pregnancy after adjustment for gestational age and the results of amniotic fluid culture (odds ratio, 2.4; 95% confidence interval, 1.4-3.9; P<.001).

CONCLUSION

Patients with preterm premature rupture of membranes and an amniotic fluid index of < or = 5 cm are at increased risk for a shorter interval to delivery.

New cationic liposomes for gene transfer into mammalian cells with high efficiency and low toxicity

Novel cationic amphiphiles, based on hydrophobic cholesterol linked to L-lysinamide or L-ornithinamide, were designed and tested as nonviral gene transfer vectors. Each amide form of amino acid was conjugated to cholesterol by a carbamate ester bond to facilitate efficient degradation in animal cells. Cytotoxicity tests were performed for some cell lines. The transfection efficiency of the amphiphiles on different cell lines was evaluated as a liposomal solution in the presence of the fusogenic helper lipid, dioleoyl phosphatidylethanolamine (DOPE). The efficiency was also compared with other generally used gene carriers, such as lipofectin, 3 beta[N-(N'N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) liposome, and polyethylenimine (PEI).