Synthesis and HIV-1 integrase inhibitory activities of caffeoylglucosides

Caffeoylglucosides, which have a glucose ring as a central linker, were synthesized from methyl D-glucosides, and their anti-HIV-1 activities were tested. Among them, four dicaffeoylglucosides (IC50 = 29.1+/-35.1 microM), 6a, 6b, 9b and 10b, showed HIV-1 integrase inhibitory activity as potent as L-chicoric acid.

Concurrent chemotherapy and radiotherapy in invasive cervical cancer patients with high risk factors

The aim of this study was to evaluate the survival of 395 previously untreated cervical cancer patients with at least one high risk factor following concurrent chemoradiation and to assess the toxicities. Two different chemotherapy regimens were used for concurrent chemoradiation. In the patients with squamous cell carcinoma, 100 mg/m2 of cisplatin was infused intravenously, followed immediately by five consecutive daily administrations of 5-fluorouracil, 1,000 mg/m2/day, each infused intravenously over 24 hr. As for the patients with adenocarcinoma, 70 mg/m2 of cisplatin, 250 mg/m2 of cytoxan and 45 mg/m2 of adriamycin were administered intravenously on days 1, 2, and 3, respectively. The 5-year survival rate was 54.4% with stage III and IV, 62.6% with lymph node metastasis on computed tomogram or MRI, 77.9% with stage I-II disease with lesion size > or =4 cm, and 50.3% with small cell carcinoma or adenocarcinoma. Side effects from concurrent chemoradiation such as nausea, vomiting, and alopecia were present in all 395 cases. Anemia, leukopenia, thrombocytopenia, hepatotoxicity, and nephrotoxicity were observed to varying degrees, but there was no toxic death. This study suggests that cisplatin-based concurrent chemoradiation in treating cervical cancer patients with high risk factors is effective and relatively well tolerated, with acceptable toxicity.

Dual anticancer activity of 8-Cl-cAMP: inhibition of cell proliferation and induction of apoptotic cell death

8-Cl-cAMP induces apoptotic cell death in human cancer cells. To look at this more closely, we examined the changes in the levels of Bcl-2 family proteins during 8-Cl-cAMP-induced apoptosis of SH-SY5Y human neuroblastoma cells. Following the treatment with 8-Cl-cAMP, Bcl-2 was transiently down-regulated and Bad was increased continuously up to day 5. In addition, overexpression of Bcl-2 efficiently blocked the 8-Cl-cAMP-induced apoptosis, suggesting Bcl-2 family proteins may be involved in the 8-Cl-cAMP-induced apoptosis. The contribution of the apoptotic cell death and the inhibition of cell proliferation in the 8-Cl-cAMP-induced growth inhibition was closely monitored in the Bcl-2-overexpressing cells. Though the apoptosis was reduced significantly, no significant difference was observed in the inhibition of cell proliferation up to day 2 of 8-Cl-cAMP treatment. These results suggest that 8-Cl-cAMP exerts anticancer activity by two distinct mechanisms, i.e. , through the inhibition of cell proliferation as well as the induction of apoptosis. Supporting this notion was the observations that (1) suppression of apoptosis by zVAD did not abrogate 8-Cl-cAMP-induced inhibition of cell proliferation, and (2) 8-Cl-cAMP did not show additive inhibition of cell proliferation in RIIbeta-overexpressing cells.

High incidence of multidrug-resistant Streptococcus pneumoniae in South Korea

Streptococcus pneumoniae was isolated from patients with bacteremia, meningitis, pneumonia, and otitis media and used to determine susceptibility to various antibiotics. Of 105 isolates, 51% to 83% were resistant to 6 antibiotics (i.e., the percentages of resistance to penicillin, ampicillin, cephalothin, chloramphenicol, tetracycline, and erythromycin were 78%, 67%, 51%, 56%, 83%, and 58%, respectively). Also, 66 of the 105 isolates were multidrug resistant. Seventy-eight percent of multidrug-resistant strains were highly resistant to tetracycline (minimum inhibitory concentration [MIC] > or = 50 micrograms/ml), and 39% of multidrug-resistant strains were also highly resistant to erythromycin (MIC > or = 128 micrograms/ml). However, only 4% of the 105 isolates were resistant to cefotaxime.

Participation of type II protein kinase A in the retinoic acid-induced growth inhibition of SH-SY5Y human neuroblastoma cells

To examine the role of protein kinase A (EC 2.7.1.37) isozymes in the retinoic acid-induced growth inhibition and neuronal differentiation, we investigated the changes of protein kinase A isozyme patterns in retinoic acid-treated SH-SY5Y human neuroblastoma cells. Retinoic acid induced growth inhibition and neuronal differentiation of SH-SY5Y cells in a dose- and time-dependent manner. Neuronal differentiation was evidenced by extensive neurite outgrowth, decrease of N-Myc oncoprotein, and increase of GAP-43 mRNA. Type II protein kinase A activity increased by 1.5-fold in differentiated SH-SY5Y cells by retinoic acid treatment. The increase of type II protein kinase A was due to the increase of RIIbeta and Calpha subunits. Since type II protein kinase A and RIIbeta have been known to play important role(s) in the growth inhibition and differentiation of cancer cells, we further investigated the role of the increased type II protein kinase A by overexpressing RIIbeta in SH-SY5Y cells. The growth of RIIbeta-overexpressing cells was slower than that of parental cells, being comparable to that of retinoic acid-treated cells. Retinoic acid treatment further increased the RIIbeta level and further inhibited the growth of RIIbeta-overexpressing cells, showing strong correlation between the level of RIIbeta and growth inhibition. However, RIIbeta-overexpressing cells did not show any sign of neuronal differentiation and responded to retinoic acid in the same way as parental cells. These data suggest that protein kinase A participates in the retinoic acid-induced growth inhibition through the up-regulation of RIIbeta/type II protein kinase A.

Characterization of epidermal growth factor receptor function in lysophosphatidic acid signaling in PC12 cells

Lysophosphatidic acid (LPA) is a lipid metabolite that induces the activation of mitogen-activated protein kinase (MAPK) through binding to the G protein-coupled receptor in a number of cell lines and cultures. Recent studies have revealed that LPA is able to rapidly induce the phosphorylation of MAPK through an epidermal growth factor (EGF) receptor-dependent pathway. We investigated the role of the EGF receptor in the signaling pathway initiated by LPA stimulation in nerve growth factor (NGF)-responsive PC12 cells well known to transiently retract their own neurites upon LPA stimulation. LPA-stimulated MAPK signaling was suppressed by the selective EGF receptor inhibitor and in the dominant negative mutant EGF receptor cell line. As in the EGF signaling pathway, the complex of EGF receptor with adapter proteins Shc and Sos was formed in response to LPA stimulation, suggesting there is an intracellular mechanism for transactivation. A neurite retraction assay was also performed to examine the role of the EGF receptor in PC12 cell differentiation, which related to the involvement of LPA-induced neurite retraction. These results suggest that the receptor tyrosine kinase can be activated in a ligand-independent manner through intracellular crosstalk between the signaling pathways.

Limited stress response in Streptococcus pneumoniae

In Streptococcus pneumoniae, heat shock induces the synthesis of 65-, 73-, and 84-kDa proteins, and ethanol shock induces a 104-kDa protein. In this study, the 65-, 84-, and 104-kDa proteins were identified as members of the GroEL, ClpL and alcohol dehydrogenase families, respectively, and the general properties of the stress response of S. pneumoniae to several other stresses were characterized. However, several stresses which are known to induce stress responses in Escherichia coli and Bacillus subtilis failed to induce any high molecular weight heat-shock proteins (HSPs) such as GroEL and DnaK homologues. A minor temperature shift from 30 to 37 C triggered induction of the homologues of DnaK and GroEL of E. coli. These features may provide a foundation for evaluating the role of heat-shock proteins relative to the physiology and pathogenesis of pneumococcus.

Ala99ser mutation in RI alpha regulatory subunit of protein kinase A causes reduced kinase activation by cAMP and arrest of hormone-dependent breast cancer cell growth

Expression of the RIalpha regulatory subunit of protein kinase A type I is increased in human cancer cell lines, in primary tumors, in cells after transformation, and in cells upon stimulation of growth. Ala99 (the pseudophosphorylation site) of human RIalpha was replaced with Ser (RIalpha-p) for the structure-function analysis of RIalpha. MCF-7 hormone-dependent breast cancer cells were transfected with an expression vector for the wild-type RIalpha or mutant RIalpha-p. Overexpression of RIalpha-P resulted in suppression of protein kinase A type II, the isozyme of type I kinase, production of kinase exhibiting reduced cAMP activation, and inhibition of cell growth showing an increase in G0/G1 phase of the cell cycle and apoptosis. The wild-type RIalpha overexpression had no effect on protein kinase A isozyme distribution or cell growth. Overexpression of protein kinase A type II regulatory subunit, RIIbeta, suppressed RIalpha and protein kinase A type I and inhibited cell growth. These results show that the growth of hormone-dependent breast cancer cells is dependent on the functional protein kinase A type I.

Identification of the polyamine induced proteins in Escherichia coli

The polyamine (PA)-induced proteins were identified by SDS-PAGE, and by two dimensional gel analysis in Escherichia coli strains. A large number of the PA-induced proteins were acidic. The molecular weights of the most highly induced proteins were 40 and 82 kDa proteins in the wild type and PA-auxotrophic mutant, respectively. Although a part of the PA-induced proteins were induced both in the wild type and PA auxotrophic mutant, most of them seem to be induced either in the wild type or mutant. These features may provide a foundation for evaluating the role of the PA-induced proteins relative to the physiology and environmental stress of Escherichia coli.

Late development of umbilical metastasis after laparoscopic cholecystectomy for a gallbladder carcinoma

A periumbilical mass developed 47 months after laparoscopic cholecystectomy. Pathologic examination of this mass showed features of moderately differentiated papillary adenocarcinoma, similar to that identified within the previously removed early stage (pT1b) gallbladder carcinoma. The cause of this <late type recurrence> at the laparoscope port is unclear. <Late type recurrence> after laparoscopic cholecystectomy for gallbladder carcinoma has not been reported previously. We reported a case with late periumbilical tumor seeding at the navel trocar insertion site in a 65-year-old female. A review of the preventative information of tumor recurrence and management is discussed. The use of gasless laparoscopy, slow desufflation, trocar site washout, wound protector and specimen bags are recommended.

Effect of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'- dicarboxylate (DDB) on chemical-induced liver injury

The effects of orally administered dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene-dioxybiphenyl-2,2'-d icarboxylate (DDB) on the hepatotoxicity induced by carbon tetrachloride, acetaminophen or ethanol were investigated in rats and mice. Either single or repeated DDB pretreatment (50 or 200 mg/kg) did not alter the hepatotoxicity induced by carbon tetrachloride (0.2 or 1.0 ml/kg, i.p.) in female rats as indicated by increases in the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) in serum. The hepatotoxicity of acetaminophen (350 mg/kg, i.p.) was also unaffected in male mice pretreated with DDB (50 mg/kg/d) for a week. However, DDB administration (50 mg/kg/d for 7 d) decreased the hepatic fatty degeneration induced by repeated ethanol treatment (0.75 g/kg, i.p., x2 times a day for a week) in rats as shown by the accumulation of triglycerides and cholesterol in the liver. Malondialdehyde (MDA) formation in liver homogenates was inhibited by DDB treatment. The significance of the action of DDB on alcoholic fatty liver generation in clinical settings is discussed.

The RIIbeta regulatory subunit of protein kinase A binds to cAMP response element: an alternative cAMP signaling pathway

cAMP, through the activation of cAMP-dependent protein kinase (PKA), is involved in transcriptional regulation. In eukaryotic cells, cAMP is not considered to alter the binding affinity of CREB/ATF to cAMP-responsive element (CRE) but to induce serine phosphorylation and consequent increase in transcriptional activity. In contrast, in prokaryotic cells, cAMP enhances the DNA binding of the catabolite repressor protein to regulate the transcription of several operons. The structural similarity of the cAMP binding sites in catabolite repressor protein and regulatory subunit of PKA type II (RII) suggested the possibility of a similar role for RII in eukaryotic gene regulation. Herein we report that RIIbeta subunit of PKA is a transcription factor capable of interacting physically and functionally with a CRE. In contrast to CREB/ATF, the binding of RIIbeta to a CRE was enhanced by cAMP, and in addition, RIIbeta exhibited transcriptional activity as a Gal4-RIIbeta fusion protein. These experiments identify RIIbeta as a component of an alternative pathway for regulation of CRE-directed transcription in eukaryotic cells.

Molecular cloning, expression, and characterization of dnaK in Streptococcus pneumoniae

DnaK is known to be highly conserved in all species and is a major immunogen in Streptococcus pneumoniae. To elucidate the role of dnaK in S. pneumoniae, dnaK was cloned in Escherichia coli using a homologous dnaK probe generated by PCR. The His-tagged DnaK was overexpressed in soluble form and purified from E. coli. Alignment of the deduced DnaK amino acid sequence from nucleotide sequences of the cloned dnaK revealed high homology with DnaK analogs in E. coli (53%) and Staphylococcus aureus (73%). However, anti-pneumococcal DnaK antiserum did not crossreact with DnaK analogs in E. coli, S. aureus and human cells suggesting that pneumococcal DnaK might be a good candidate as a vaccine.

Interferon-alpha 2a, 13-cis-retinoic acid and radiotherapy for locally advanced carcinoma of the cervix: a pilot study

Standard treatment with radiotherapy for locally advanced cancer of the uterine cervix has a response rate of less than 50%. Recently, concurrent chemotherapy with radiotherapy was introduced into the clinic but is value remains controversial. Interferon and retinoic acid possess antiproliferative, immunomodulatory, and antineoplastic activities. The combination of interferon and retinoic acid has significant activity in patients with squamous cell carcinoma. These compounds may also potentiate radiation cytotoxicity. This pilot study aimed to assess the clinical efficacy and tolerability of the combination of interferon-alpha 2a, 13-cis-retinoic acid and radiotherapy. Patients with locally advanced carcinoma of the cervix were treated at Severance Hospital, Yonsei University College of Medicine. Fifteen patients received the combination of interferon-alpha 2a, 13-cis-retinoic acid and radiotherapy. Twelve patients treated in previous years with comparable radiotherapy and concurrent chemotherapy served as historical controls.

RESULTS

(1) Interferon-alpha 2a, 13-cis-retinoic acid and radiotherapy resulted in a 47% response rate (33% complete remissions) while patients treated with concurrent chemoradiotherapy had a 42% response rate (17% complete remissions) (2). Major toxicity of interferon-alpha 2a, 13-cis-retinoic acid and radiotherapy was fever (60%). There was no grade 3 or 4 toxicity.

CONCLUSION

Systemic interferon-alpha 2a, 13-cis-retinoic acid and radiotherapy is an active and tolerable therapy for locally advanced cervical cancer. Randomized studies are required to define the role of bioradiotherapy in the treatment of advanced cervical cancer.

Potentiation of acetaminophen hepatotoxicity by acute physical exercise in rats

Effects of acute physical exercise on the acetaminophen-induced hepatotoxicity were examined in adult female rats. Rats were forced to move at a speed of 10 m/min for 2 hr in a rotating cage. Immediately following the exercise bout rats were treated with acetaminophen (APAP; 700 mg/kg, i.p.). The physical exercise enhanced the hepatotoxicity of APAP as shown by increases in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities measured 24 hr following the treatment. A significant decrease in hepatic glutathione (GSH) was observed in the rats forced to exercise suggesting that the enhancement of APAP hepatotoxicity was associated with the depression of this endogenous tripeptide. The role of adrenergic stimulation in the exercise-induced hepatic GSH depression was examined by pretreating the animals with a receptor specific adrenergic antagonist, such as prazosin HCl (15 mg/kg, i.p.), propranolol HCl (15 mg/kg, i.p.), and yohimbine HCl (15 mg/kg, i.p.) 15 min prior to the exercise bout, but neither of the antagonists prevented the GSH depression. Administration of alpha-tocopherol acetate (450 mg/kg/day for 3 days and 150 mg/kg on day 4, i.p.) did not affect the exercise-induced GSH depression or lipid peroxidation in liver homogenates as determined by increases in malondialdehyde formation. These results suggest that neither adrenergic stimulation nor oxidative stress plays a significant role in the enhancement of APAP hepatotoxicity and hepatic GSH depression induced by acute physical exercise.

Type II protein kinase A up-regulation is sufficient to induce growth inhibition in SK-N-SH human neuroblastoma cells

We have previously reported that overexpression of RII beta subunit of protein kinase A, which markedly reduces RI alpha protein, induces growth inhibition in SK-N-SH human neuroblastoma cells. To determine whether the reduction of RI alpha or protein kinase A isozyme type I is essential in the growth inhibition of SK-N-SH cells, we overexpressed RI alpha in sense and antisense orientation. Type I protein kinase A activity was increased in the RI alpha-overexpressing cells and was decreased in the RI alpha antisense-expressing cells. However, the changes in type I protein kinase A activities did not affect cell growth. Overexpression of RII beta or C alpha increased type II protein kinase A and inhibited cell growth in both cell lines regardless of the type I protein kinase A level. These results indicate that type II protein kinase A is the main effector in the cAMP-mediated growth regulation of SK-N-SH human neuroblastoma cells.

Analysis of risk factors for postmolar trophoblastic disease: categorization of risk factors and effect of prophylactic chemotherapy

Early identification of high risk molar pregnancy is important in preventing the development of subsequent postmolar trophoblastic disease (PMTD). In the present study, evaluation of risk factors of developing PMTD, and indications for initiating prophylactic chemotherapy, and investigation of the effects of prophylactic chemotherapy were undertaken. One hundred and forty complete molar pregnancies treated at Yonsei University College of Medicine were retrospectively analyzed. Thirty-six cases of PMTD developed in these molar pregnancies during follow-up. Risk factors for PMTD were ranked according to frequency with which they were associated with PMTD. The patients with no risk factors were classified in the low-risk group, with one or two in the medium-risk group, and with three or more in the high-risk group. Prophylactic chemotherapy was administered to 14 of 52 low-risk, to 21 of 46 medium-risk, and to 17 of 42 high-risk patients. Among the high-risk patients, the time required for remission was significantly shorter in the group with prophylactic chemotherapy (13.5 weeks) than in the group without prophylactic chemotherapy (22.4 weeks). There were no differences in the duration until remission among the low- and medium-risk patients. Of the 52 patients who received prophylactic chemotherapy, 8 (15.4%) developed PMTD. Among the high-risk patients the occurrence of PMTD was significantly lower in the prophylactic chemotherapy group. Among the low-risk and medium-risk patients, there were no differences in the occurrence of PMTD between the chemoprophylaxis treated and untreated groups. Our results strongly support the use of prophylactic chemotherapy for patients that were designed under our high risk criteria. Prophylactic chemotherapy helps to prevent or reduce the risk of developing PMTD, and shorten the time required for complete remission in high-risk patients.

Synergistic inhibitory effect of angiotensin-converting enzyme inhibitor and heparin on intimal hyperplasia after rat aorta injury

The respective efficacies of angiotensin-converting enzyme (ACE) inhibitor and standard heparin were investigated with respect to their inhibitory effects on intimal hyperplasia after balloon denudation of rat aorta. Local angiotensin II effects in the artery wall may participate in regulation of the vascular response to arterial injury, apparently independent of the plasma renin and angiotensin system. ACE inhibitors have been shown to block intimal hyperplasia after arterial injury in rats. Increasing evidence points toward an inhibitory effect of heparin on intimal hyperplasia independent of anticoagulation. Balloon catheter aortic denudation was performed in 25 rats pharmacologically treated from six days or one day before to fourteen days after surgery and split into four groups: group A (control group), normal feeding; group B (ramipril group), ramipril 10 mg/kg/day orally; group C (heparin group), heparin 1200 IU/kg/day subcutaneously; group D (combined group), both ramipril and heparin. Animals were killed and aortas were perfused and fixed at physiologic pressure fourteen days after denudation. Cross-sectional intima-to-media area ratios (I-M ratio) were calculated by an image analyze system.

Tick bites in Korea

BACKGROUND

Tick bites are dermatoses not commonly encountered in Korea. Recognizing their clinical signs as well as their histopathologic findings is important in making a diagnosis of tick-related dermatoses. The incidence and causative species are different depending on the geographic areas. The histopathologic findings of tick bites are known to be a variable depending on the species of ticks involved and the duration of their bloodsucking.

METHODS

Five ticks were collected from five patients and three of them were identified as Ixodes (I.) nipponensis.

RESULTS

Histopathologic findings of panniculitis were prominent in four of five cases; septal panniculitis in two cases, and lobular panniculitis in the other cases.

CONCLUSIONS

Ixodes nipponensis was the most common causative species of ticks responsible for tick bites in Korea, and tick bite panniculitis must be considered in the differential diagnosis of panniculitis which is mainly composed of neutrophils.

Neonatal choriocarcinoma of liver

Neonatal choriocarcinoma associated with a seemingly normal gestation is rare. A total of 20 cases of either primary or metastatic choriocarcinoma in infancy have been reported until 1992. We report an additional case of a huge choriocarcinoma of the liver in a 2-month-old boy, who died of tumor hemorrhage. This baby was born to a 19-year-old unmarried mother. The placenta was thought to be normal and was not examined histologically. The liver mass was first noted 2 weeks after birth, and he was admitted because of poor feeding and pallor. Before any therapy was instituted, he died of massive tumor bleeding. Autopsy revealed a huge hemorrhagic tumor mass with massive necrosis in the left lobe of the liver. Several nodular metastases were found only in the lung. The remainder was unremarkable except for bilateral cleft lip and palate. It is presumed that the choriocarcinoma in the liver could be either a primary tumor in the absence of any primary focus in the mother or the infant or a metastatic lesion from an occult choriocarcinoma of the placenta.

Combined chemotherapy and radiation for bulky stages I-II cervical cancer: comparison of concurrent and sequential regimens

Based on analysis of 5-year survival rates among 386 patients with carcinoma of the cervix treated between 1976 and 1984 at Yonsei University College of Medicine, high risk factors have been defined which identify patients with a poor prognosis when treated with radiation alone. Among patients with FIGO Stages I-II disease, lesions > or = 4 cm were indicative of a higher risk of treatment failure. Between 1984 and 1991, 39 patients with Stages I-II large cell squamous cancers > or = 4 cm in diameter were treated with radiation alone. Between 1984 and 1989, 19 comparable patients were treated with sequential chemotherapy consisting of two or three cycles of cisplatin at 100 mg/m2 and a 5-day infusion of 5-fluorouracil at 1000 mg/m2/24 hr. Between 1988 and 1991, 37 comparable patients were treated with concurrent radiation and one to six cycles of chemotherapy employing the same or equivalent drug and dose schedule. The radiation techniques, dose, and fractionation employed were similar in the three groups. The 30-month survival rate was 100, 89.5, and 79.5% (P < 0.05) following concurrent treatment, sequential treatment, and radiation alone, respectively. Response to chemotherapy administered in cycles was evaluated before instituting radiotherapy in the patients treated with sequential chemotherapy and radiation. In conclusion, the combination of radiotherapy and chemotherapy appeared superior to radiation alone, and the toxicity of combined modality therapy is manageable. Also concurrent chemotherapy may be slightly better than sequential chemotherapy and radiation, and given the lesser overall treatment time and expense, this has become the preferred mode of treatment in our institution.