Involvement of ArcA and Fnr in expression of Escherichia coli thiol peroxidase gene

To explore the oxygen response regulators involved in thiol peroxidase gene (tpx) expression in Escherichia coli, we constructed a single-copy tpx-lacZ operon fusion and monitored tpx-lacZ expression in various genetic backgrounds. Expression of the tpx-lacZ fusion was increased 4-fold by aerobic growth. Anaerobic expression of tpx-lacZ in either (delta)arcA or delta(fnr) strains was 2.5-fold depressed compared with that of the wild-type strain. The results of immunoblotting experiments also demonstrated that ArcA and Fnr regulatory proteins repressed thiol peroxidase gene expression during anaerobic growth. Inspection of the tpx promoter region revealed putative binding sites for ArcA and Fnr. It thus appears that ArcA and Fnr function as repressors by blocking the binding of RNA polymerase to the tpx promoter in E. coli under anaerobic growth conditions.

Purification and properties of Thermus filiformis DNA polymerase expressed in Escherichia coli

The gene encoding Thermus filiformis (Tfi) DNA polymerase was expressed under the control of the tac promoter on a high-copy plasmid, pJR, in Escherichia coli. The Tfi DNA polymerase was purified by using heat treatment and DEAE-Sephacel column chromatography. The purified enzyme had a molecular mass of 92 kDa, as estimated by SDS/PAGE. The optimum pH and temperature of the enzyme were 8.4-9.0 and 70-72.5 degrees C respectively. The half-life of the enzyme at 94 degrees C was approx. 40 min. The enzyme was activated by the bivalent cations, Mg(2+) and Mn(2+), and was inhibited by EDTA. The optimal Mg(2+) concentration of the enzyme was 4 mM. The optimal conditions for the PCR reaction were slightly different from those for the enzyme activity except for the optimal Mg(2+) concentration. Low concentrations of KCl had no effect on either the enzymic activity or the PCR amplification. The result of the PCR experiment with the enzyme indicates that Tfi DNA polymerase might be useful in DNA amplification.

The detection of Epstein-Barr virus in the lesions of salivary glands

Epstein-Barr virus (EBV) is known in association with lymphoid and epithelial lesion. Because the salivary gland is an organ close to the oropharynx, it has a higher incidence of EBV infection and is a possible route of EBV infection. Formalin-fixed, paraffin embedded tissue sections of 87 cases of salivary gland diseases were used for the study of EBV with PCR, in situ PCR for EBNA-1 (EBV nuclear antigen-1), and immunohistochemistry for LMP-1 (latent membrane protein-1). EBV was detected in 12 cases (13.8%): 7 of nonspecific chronic sialadenitis (21.2%), 4 of Warthin's tumors (30.8%), and one lymphoepithelial carcinoma. EBNA-1 was negative in all the other lesions. EBV DNA was detected in the nucleus of epithelial cells and the surrounding lymphocytes. LMP-1 positivity was found in the cytoplasm of epithelial cells. The results of the present study showed that EBV is implicated in some of the inflammatory and neoplastic lesions of the salivary gland in which the lymphocytes are abundant. However, the pathogenesis and mechanism of immortalization and tumorigenesis of the epithelial cells in the salivary glands remain to be determined.

Effectiveness of rotor off fraction in allogeneic murine bone marrow transplantation with complete disparity of major histocompatibility

Counterflow centrifugal elutriation (CCE) has been a highly efficient physical method for separating T cells from bone marrow (BM) without impairing cell function and yield. To investigate the usefulness of CCE, the hematopoietic potential as well as the level of T cell contamination in rotor-off (R/O) fraction of BM was studied using a murine bone marrow transplantation (BMT) model [C3H/He (H-2k)-->BALB/C (H-2d)]. The total recovery of cells after CCE procedure was 71.4%. Morphologically, R/O fraction contained abundant mononuclear cells and a few lymphocytes. The numbers of colony forming unit for granulocyte/monocyte (CFU-GM), Sca-1+ cells, and T cells were compared among four fractions of CCE (fractions at flow rate of 17, 25, 28 mL/min, and R/O fraction). The number of CFU-GM per 10(5) nucleated cells in each fraction were significantly higher in R/O fraction (331.3 +/- 34.4) compared to unfractionated marrow (UM) (21.1 +/- 1.3) and fraction of 17 mL/min (FR 17) (23.7 +/- 2.2 ) (chi2 = 0.0044). Neither fraction of 25 mL/min (FR 25) nor fraction of 28 mL/min (FR 28) contained CFU-GM colonies. The concentration of Sca-1+ cells in R/O fraction was significantly higher (1.96-fold) than UM (p < 0.05), and 80.0 +/- 10.1% of Sca-1+ cells in UM were recovered in R/O fraction; 88.1% of Thy-1.2+ T cells were eliminated in R/O fraction (p < 0.05). Mice receiving UM after lethal irradiation (875cGy) suffered from severe graft-versus-host disease (GVHD) and all five died within 7 days after BMT procedure (Group A). Of interest, mice receiving mixture of R/O fraction with lymphocyte-rich fraction (FR 25 plus FR 28) to equalize T cell number as UM, developed severe GVHD and four out of five died (probability of survival; 20%) (Group B). Mice receiving R/O fraction had mild GVHD and four out of five survived for at least 90 days (probability of survival; 80%) (Group C). In group C, probability of survival (p = 0.0006) was higher, and severity of GVHD (p = 0.0043) and progression rate of GVHD (p = 0.02) was lower. In conclusion, the elutriated R/O fraction cells of BM have the advantages of stable engraftment and tolerable GVHD in murine allogeneic BMT with complete major histocompatibility disparity. This could be directly applicable to patients with high risk of GVHD and graft failure in upcoming clinical trials.

Nasal angiocentric lymphoma with hemophagocytic syndrome

OBJECTIVES

Hemophagocytic syndrome (HS) is a fatal complication of nasal angiocentric lymphoma (AL) and difficult to distinguish from malignant histiocyosis. Epstein-Barr virus (EBV)-associated HS is frequently observed in lymphoma of T-cell lineage and EBV is highly associated with nasal AL. Clinicopathologic features of 10 nasal ALs with HS were reviewed to determine the clinical significance and the pathogenetic association with EBV.

METHODS

Ten patients of HS were identified from a retrospective analysis of 42 nasal ALs diagnosed from 1987 to 1996. Immunohistochemical study and in situ hybridization were performed on the paraffin-embedded tumor specimens obtained from 10 patients. Serologic study of EBV-Ab was performed in 3 available patients.

RESULTS

Five patients had HS as initial manifestation, 3 at the time of relapse and 2 during the clinical remission of AL. Four patients were treated by combination chemotherapy (CHOP) and others had only supportive care. The median survival of all patients with HS was 4.1 months (range 2 days-36.5 months) and all had fatal outcome regardless of the treatment-modality. All cases were positive for UCHL1 (CD45RO) and EBV by EBER in situ hybridization. The data of serologic tests indicated the active EBV infection.

CONCLUSIONS

HS is a fatal complication of nasal AL and has a high association with EBV. Reactivation of EBV may contribute to HS and further investigation of predictive factors and effective treatment of HS should be pursued in the future.

Lung metastases manifesting as pulmonary infarction by mucin and tumor embolization: radiographic, high-resolution CT, and pathologic findings

We present a case of lung metastasis manifesting as lung infarction by mucin and tumor embolization. The radiograph and high-resolution CT showed multiple focal consolidations with ground glass attenuation in subpleural areas of both lungs. Diagnosis was made by open lung biopsy, which revealed pulmonary infarction caused by intravascular adenocarcinoma with numerous mucus emboli in pulmonary arteries. Subpleurally located consolidations on high-resolution CT correlated well with the histologic findings of lung infarction by mucin and tumor emboli.

Actinomycin D as a novel SH2 domain ligand inhibits Shc/Grb2 interaction in B104-1-1 (neu*-transformed NIH3T3) and SAA (hEGFR-overexpressed NIH3T3) cells

Actinomycins, a family of bicyclic chromopeptide lactones with strong antineoplastic activity, were screened as inhibitors of Shc/Grb2 interaction in in vitro assay systems. To investigate the effects of actinomycin D on Shc/Grb2 interaction in cell-based experiments, we used SAA (normal hEGFR-overexpressed NIH3T3) cells and B104-1-1 (neu*-transformed NIH3T3) cells, because a large number of the Shc/Grb2 complexes were detected. Associated protein complexes containing Shc were immunoprecipitated from actinomycin D-treated cell lysates with polyclonal anti-Shc antibody. Then the association with Grb2 was assessed by immunoblotting with monoclonal anti-Grb2 antibody. The result of the immunoblotting experiment revealed that actinomycin D inhibited Shc/Grb2 interaction in a dose-dependent manner in both B104-1-1 and EGF-stimulated SAA cells. The inhibition of Shc/Grb2 interaction by actinomycin D in B104-1-1 cells also reduced tyrosine phosphorylation of MAP kinase (Erk1/Erk2), one of the major components in the Ras-MAP kinase signaling pathway. These results suggest that actinomycin D could be a non-phosphorylated natural and cellular membrane-permeable SH2 domain antagonist.

Inhibition of rat adjuvant-induced arthritis by ginkgetin, a biflavone from ginkgo biloba leaves

Ginkgetin, a biflavone isolated from Ginkgo biloba leaves, was previously reported as an inhibitor of group II phospholipase A2. In this study, ginkgetin was evaluated for in vivo antiarthritic and analgesic activities. Ginkgetin (10-20 mg/kg/day) strongly reduced arthritic inflammation in an animal model of rat adjuvant-induced arthritis (86% inhibition at 16 days at a dose of 20 mg/kg/day) via intraperitoneal injection, while prednisolone (5 mg/kg/day) showed 79% reduction. Histological examination of the knee joints confirmed our findings. When analgesic activity was measured, ginkgetin showed a dose-dependent inhibition in an animal model of acetic acid-induced writhing. ED50 values for ginkgetin and indomethacin were 8.9 and 3.8 mg/kg, respectively. All these results indicate that ginkgetin may be a potential antiarthritic agent having analgesic activity.

Bulky, barrel-shaped cervical carcinoma (stages IB, IIA, IIB): the prognostic factors for pelvic control and treatment outcome

The purpose of this study was to assess the prognostic factors for pelvic control and the treatment outcome in bulky, barrel-shaped cervical carcinomas. Between September 1980 and December 1992, 65 patients with stage IB or stage IIA-B carcinoma of the uterine cervix classified as barrel-shaped or concentrically expanded (i.e., at least 5 cm in greatest diameter) were treated with curative intent. Forty patients had stage IB or stage IIA carcinoma (according to the classification of the International Federation of Gynecology and Obstetrics [FIGO]), and 25 patients had FIGO stage IIB carcinoma. Seventy-two percent of the patients were treated with radiotherapy (RT) alone and 28% with radiotherapy followed by extrafascial hysterectomy (RT + S). The median follow-up time of surviving patients was 68 months (range 33-172). Survival and control rates were calculated by the Kaplan-Meier method. The 10-year actuarial pelvic control rate was 75% for all patients. The likelihood of pelvic control was not affected by FIGO stage, tumor size, patient's age, histologic features, or treatment modality (RT vs. RT + S). The extent of tumor regression following external beam radiotherapy correlated with the likelihood of local control (p = 0.02). For patients treated with RT alone, increased brachytherapy dose was associated with an increased likelihood of local control. The 10-year actuarial overall and cause-specific survival rates were 53% and 68%, respectively, and did not differ significantly between treatment groups. It is concluded that for most patients with bulky cervical carcinoma, RT alone provides good local control and survival. However, for patients with tumors that respond poorly to external beam radiotherapy, local control and survival are poor. More aggressive treatment protocols should be considered for these patients. The routine use of adjuvant hysterectomy is not recommended.

Hyperdense enhancement of pancreatic adenocarcinoma on spiral CT: two case reports

We are reporting two cases of pancreatic adenocarcinoma that showed dense contrast enhancement on the early phase spiral CT scan and isodensity on the delayed phase scan. Both lesions were located in the head portion of the pancreas, with diameters of 2 cm and 5 cm, respectively. Despite its extremely rare incidence, adenocarcinoma may be included in the differential diagnosis of enhanced pancreatic tumor on early-phase spiral CT scan.

Difference between active and inactive nucleotide cofactors in the effect on the DNA binding and the helical structure of RecA filament dissociation of RecA--DNA complex by inactive nucleotides

The RecA protein requires ATP or dATP for its coprotease and strand exchange activities. Other natural nucleotides, such as ADP, CTP, GTP, UTP and TTP, have little or no activation effect on RecA for these activities. We have investigated the activation mechanism, and the selectivity for ATP, by studying the effect of various nucleotides on the DNA binding and the helical structure of the RecA filament. The interaction with DNA was investigated via fluorescence measurements with a fluorescent DNA analog and fluorescein-labeled oligonucleotides, assisted by linear dichroism. Filament structure was investigated via small-angle neutron scattering. There is no simple correlation between filament elongation, DNA binding affinity of RecA, and DNA structure in the RecA complex. There may be multiple conformations of RecA. Both coprotease and strand exchange activities require formation of a rigid and well organized complex. The triphosphate nucleotides which do not activate RecA, destabilize the RecA-DNA complex, indicating that the chemical nature of the nucleotide nucleobase is very important for the stability of RecA-DNA complex. Higher stability of the RecA-DNA complex in the presence of adenosine 5'-O-3-thiotriphosphate or guanosine 5'-O-3-thiotriphosphate than ATP or GTP indicates that contact between the protein and the chemical group at the gamma position of the nucleotide also affects the stability of the RecA-DNA complex. This contact appears also important for the rigid organization of DNA because ADP strongly decreases the rigidity of the complex.

Loss of DNA mismatch repair facilitates reactivation of a reporter plasmid damaged by cisplatin

In addition to recognizing and repairing mismatched bases in DNA, the mismatch repair (MMR) system also detects cisplatin DNA adducts and loss of MMR results in resistance to cisplatin. A comparison was made of the ability of MMR-proficient and -deficient cells to remove cisplatin adducts from their genome and to reactivate a transiently transfected plasmid that had previously been inactivated by cisplatin to express the firefly luciferase enzyme. MMR deficiency due to loss of hMLH1 function did not change the extent of platinum (Pt) accumulation or kinetics of removal from total cellular DNA. However, MMR-deficient cells, lacking either hMLH1 or hMSH2, generated twofold more luciferase activity from a cisplatin-damaged reporter plasmid than their MMR-proficient counterparts. Thus, detection of the cisplatin adducts by the MMR system reduced the efficiency of reactivation of the damaged luciferase gene compared to cells lacking this detector. The twofold reduction in reactivation efficiency was of the same order of magnitude as the difference in cisplatin sensitivity between the MMR-proficient and -deficient cells. We conclude that although MMR-proficient and -deficient cells remove Pt from their genome at equal rates, the loss of a functional MMR system facilitates the reactivation of a cisplatin-damaged reporter gene.

Inhibition of human tumor growth by 2'-hydroxy- and 2'-benzoyloxycinnamaldehydes

2'-Hydroxycinnamaldehyde (HCA) was isolated from Cinnamomum cassia Blume (Lauraceae) and 2'-benzoyloxycinnamaldehyde (BCA) was prepared by the reaction of HCA and benzoyl chloride. HCA and BCA strongly inhibited in vitro growth of 29 kinds of human cancer cells and in vivo growth of SW-620 human tumor xenograft without the loss of body weight in nude mice. HCA prevented adherence of SW-620 cells to the culture surface but did not inhibit oncogenic K-Ras processing, implying its antitumor mechanisms at the cellular level.

Incidence and possible reasons for discordant results between positive FDP and negative D-dimer latex assays in clinical specimens

In general, FDP and D-dimer values have a correlation in clinical conditions associated with disseminated intravascular coagulation(DIC) or coagulation activation. However, there are some patients with discordant results who demonstrate elevated FDP and negative D-dimer results by latex agglutination assays. The incidence and possible reasons for the discordance between FDP and D-dimer results were investigated through simultaneous measurements (n = 763) from clinical patients with suspected DIC or coagulation activation. 24.8% (189/763) of samples with elevated FDP were negative for D-dimer assays by the latex agglutination method. Further detailed analysis on randomly-selected discordant samples (n = 41) revealed that the most common reason for the discordance was the lower sensitivity of the semiquantitative latex agglutination method for D-dimer, compared with quantitative enzyme or other latex immunoassay. The other contributing factors to the discordance were accelerated fibrinogenolysis without secondary fibrinolysis, elevated soluble fibrin monomer and rheumatoid factor.

Homocyst(e)ine and atherosclerosis in patients on chronic hemodialysis

Hyperhomocyst(e)inemia is an established risk factor for atherosclerosis. We performed this study to identify the correlating variables and risk factors for atherosclerosis, as measured by the atherosclerotic score (AS), and to determine the relative risk for cardiovascular disease in relation to plasma homocyst(e)ine levels in patients on chronic hemodialysis. We evaluated and measured 61 patients on chronic hemodialysis for clinical and biochemical parameters including atherosclerotic score (AS) and plasma homocyst(e)ine. We divided patients into high and low groups, first, by the mean AS, and second, by the median value of plasma total homocyst(e)ine levels. Then we compared the variables between the two groups. Out of the 61 patients, the median plasma total homocyst(e)ine level was 24.4 micromol/L (mean+/-SD, 27.7+/-17.4; range, 9.8-127.4 micromol/L), and the median AS was 5 (mean+/-SD, 6.2+/-2.8; range, 3-13) out of a possible 20 points. AS was significantly correlated with plasma total homocyst(e)ine levels (r=0.37) and age (r=0.67). Through multivariate analysis, plasma total homocyst(e)ine level and age were determined as significant risk factors for the high-AS group (p<0.05). However, plasma total homocyst(e)ine level did not correlate with age (p>0.05). Eighteen of the 61 patients, presented with cardiovascular disease until the present study, had an AS>6. Cardiovascular disease was found more often in the high-homocyst(e)ine group (>24.4 micromol/L) than in the low-homocyst(e)ine group (odds ratio, 9.3; 95% confidence interval, 2.3-37.4). Regardless of age, hyperhomocyst(e)inemia (especially homocyst(e)ine levels >24.4 micromol/L) is a risk factor that can be modified for the development of cardiovascular disease in patients on chronic hemodialysis.

Risk factors for ovarian metastasis following curative resection of gastric adenocarcinoma

BACKGROUND

Ovarian metastases from gastric carcinoma usually present as large, symptomatic masses and sometimes represent the sole metastatic site. Accordingly, prophylactic oophorectomy may be useful in the overall management of gastric carcinoma. This retrospective study was undertaken to determine the risk factors for ovarian metastasis following curative resection of gastric adenocarcinoma.

METHODS

The clinicopathologic profiles of 690 female patients who underwent curative gastrectomy at Seoul National University Hospital between July 1987 and June 1996 were reviewed, and their first relapse sites were identified. The prognostic factors at the time of gastrectomy influencing ovarian metastasis were analyzed using the Cox proportional hazards model.

RESULTS

The overall 3-year ovarian relapse rate was estimated to be 6.7% (95% confidence interval [CI], 4.2-9.2%). Multiple regression analysis indicated that the number of lymph nodes with metastases and patient age were significant independent risk factors for ovarian metastasis after curative resection of gastric adenocarcinoma. The number of lymph nodes with metastases (>6) was associated with the highest risk of ovarian metastasis, with an adjusted relative risk (aRR) of 38.0 (95% CI, 3.0-480.6). The age of the patient (<50 years) also predicted the risk of ovarian metastasis, with an aRR of 3.1 (95% CI, 1.4-7.0). Lauren diffuse type tended to predict for ovarian metastasis with borderline significance (aRR, 5.9; 95% CI, 0.8-44.3). The 3-year ovarian relapse rate for patients younger than 50 years with more than 6 lymph nodes with metastases was estimated to be 39.5% (95% CI, 23.8-55.7%).

CONCLUSIONS

This study suggests that the risk of ovarian metastasis after curative gastrectomy is strongly associated with the number of metastatic lymph nodes (>6) and patient age (<50 years). Prospective studies are needed to evaluate further the role of prophylactic oophorectomy in young female gastric carcinoma patients who have multiple regional lymph nodes with metastases.

A molecular model of a point mutation (Val297Met) in the serine protease domain of protein C

A heterozygous GTG to ATG (Val297Met) mutation was detected in a patient with inherited protein C deficiency and deep vein thrombosis. Cosegregation of the mutation with protein C deficiency was observed through a family pedigree study. Molecular models of the serine protease domains of wild type and mutant protein C were constructed by standard comparative method. Val 297 was found to be located in the hydrophobic core of the protein. Although the substitution of Met for Val does not greatly alter the hydrophobicity of the protein, it introduces a bulkier side chain, which yields steric hindrance between this residue and adjacent residues, such as Met364, Tyr393, Ile321, Ile323, and Val378. It seems that the Met can not fit into the tight packing into which it is trapped, thereby probably inducing misfolding and/or greater instability of the protein. Such misfolding and/or instability thereby eventually disturbs the catalytic triad, in consistent with the observed type I deficiency state.

Synthesis of N-desmethyl derivatives of 17alpha-acetoxy-11beta-(4-N,N-dimethylaminophenyl)-19-norpregna-4,9-die ne-3,20-dione and mifepristone1: substrates for the synthesis of radioligands

The syntheses of N-desmethyl derivatives of CDB-2914 and the mono-N-desmethyl derivative of Mifepristone are described. We also describe the use of the mono-desmethyl derivatives as substrates for the synthesis of N-tritomethyl derivatives of CDB-2914 and Mifepristone with high specific activity (ca. 80 Ci/mmol), which serve as radioligands for radioimmunoassay.

Arthroscopic posterior cruciate ligament reconstruction using a one-incision technique

Thirty-seven patients with a posterior cruciate ligament injury underwent arthroscopic posterior cruciate ligament reconstruction using a one-incision technique with bone-patellar tendon-bone autograft or allograft. The tibial tunnel was started at the distal end of the graft donor site on the proximal tibia and exited posteriorly at the flat spot 15 mm below the articular margin and just lateral to the midline. The femoral tunnel was made through the lateral anterolateral portal. The 25 mm long proximal bone plug was passed easily through the tibial tunnel using a specially designed suture pusher and guided into the femoral tunnel by pulling the leading suture with the knee flexed 30 degrees. Firm proximal and distal fixations were achieved with interference screws. At a minimum 2 year followup (range, 24-68 months), average knee ligament evaluation scores were 91.1 (range, 67-99) in the Lysholm knee scoring scale and 89.3 (range, 67-99) in the Hospital for Special Surgery knee ligament rating form. The average side to side difference of the posterior translation measured by the KT 2000 arthrometer was 6.08 (range, 5-7 mm) mm preoperatively and 2.2 (range, 0-6 mm) mm postoperatively. There were no significant differences between the acute and the chronic cases. The results of the isolated posterior cruciate ligament injury group were better than the combined ligamentous injury group. The one-incision technique minimizes injury to the extensor mechanism, especially the vastus medialis obliquus muscle, and medial scar. Rigid fixation of the long proximal bone plug allows early rehabilitation.

von Willebrand disease with G4022A mutation (vWd Sungnam): a case report

A 10-year-old male patient affected by type 2 von Willebrand disease (vWD) and his family members were investigated by hemostatic and molecular genetic studies. The propositus, who experienced frequent bleeding episodes, was characterized by a normal level of von Willebrand factor (vWF) antigen (54%), reduced vWF ristocetin cofactor activity (5%), decreased factor VIII clotting activity (25%) and absent high molecular weight multimers in the plasma. An exon 28 fragment coding for the A1 and A2 domains was amplified by polymerase chain reaction and sequenced. We found a heterozygous mutation (G4022A), producing an additional PstI restriction site, which resulted in the substitution of Arg578Gln. Family studies, including the parents and a brother, were negative for this mutation and vWF abnormalities were not observed. We confirmed that G to A mutation in the region of the platelet glycoprotein Ib binding domain of vWF causes the qualitative type 2 defect in von Willebrand disease.

Human immune response to a Pseudomonas aeruginosa outer membrane protein vaccine

In order to evaluate in humans the safety and immunogenicity of a Pseudomonas aeruginosa vaccine composed of outer membrane proteins (OMPs), CFC-101, we carried out a phase I/IIa clinical trial in healthy male volunteers. Groups of six volunteers were immunized either subcutaneously (s.c.) or intramuscularly (i.m.) with three dosages of the vaccine three times at 7-day intervals. The vaccine was well tolerated by volunteers. Local reactions in the injection sites were generally mild and transient. Significant increases in OMP-specific antibody were observed in both route groups after vaccinations but was higher in the i.m.-immunized group, where vaccination with 0.5 or 1.0 mg doses yielded 100% seroconversion. The specificity of the induced antibodies to P. aeruginosa OMP was demonstrated by western blot analysis and immunoprecipitation assay. An increase in Clq-binding capacity and ability to confer mice protection from lethal challenges with P. aeruginosa indicated the protective efficacy of the elicited antibodies. Based on these data, we concluded that the P. aeruginosa OMP vaccine is safe and effective in humans with an optimal dose of 0.5 and 1.0 mg and that i.m. is the better route than s.c. for this vaccine.

Immediate reconstruction of the perineal wound with gracilis muscle flaps following abdominoperineal resection and intraoperative radiation therapy for recurrent carcinoma of the rectum

BACKGROUND

Morbidity associated with a nonhealing perineal wound is the most common complication following proctectomy, particularly in the setting of recurrent carcinoma of the rectum and radiation therapy. Immediate reconstruction using the gracilis myocutaneous and muscle flaps significantly reduces the incidence of major infection associated with perineal wound closure. The purpose of this study was to assess the value of immediate reconstruction of the perineal wound using a gracilis flap in patients undergoing abdominoperineal resection and intraoperative radiation therapy.

METHODS

This study retrospectively reviewed our experience with immediate pelvic reconstruction using gracilis muscle flaps for patients undergoing rectal extirpation and irradiation for recurrent carcinoma of the rectum. From 1990 to 1995, 16 patients underwent abdominoperineal resection (APR) or pelvic exenteration accompanied by immediate wound closure with unilateral or bilateral gracilis muscle flaps. Morbidity and mortality outcomes were compared to those of 24 patients from our institution who, between 1988 and 1992, underwent proctectomy and irradiation for recurrent rectal carcinoma with primary closure of the perineal wound.

RESULTS

Major complications (i.e., major infection requiring hospitalization and/or operation) occurred in 2 (12%) of the patients with gracilis flaps versus 11 (46%) of the patients with primary closure (P = .028 by chi2 analysis for flap vs. primary closure). Minor complications (i.e., persistent sinus and subcutaneous abscess) occurred in 4 (25%) of the patients with gracilis flaps versus 5 (21%) of those with primary closure.

CONCLUSION

Immediate perineal reconstruction using the gracilis myocutaneous flap following proctectomy and irradiation for recurrent rectal carcinoma significantly reduces the incidence of major infection associated with perineal wound closure.

The relationship between cisplatin-induced apoptosis and p53, bcl-2 and bax expression in human lung cancer cells

OBJECTIVES

Given the roles of bcl-2, bax and p53 in apoptosis, we investigated the effect of their expression on the response to cisplatin in order to understand the molecular events of cisplatin-resistance in lung cancers.

METHODS

Three parental human lung cancer cell lines (PC9, PC14 and H69) and their in vitro selected cisplatin-resistant sublines were examined. Cells treated with cisplatin were processed for acridine orange and ethidium bromide staining and DNA gel electrophoresis for the morphologic detection of apoptosis. The endogenous levels of bcl-2, bax and p53 protein expression in lung cancer cells were assessed by Western blot analysis and DNA of polymerase chain reaction-amplified exon 5 to 8 of p53 gene was directly sequenced.

RESULTS

H69, which had bcl-2 expression, p53 mutation and decreased expression of p53 and bax, was relatively resistant to cisplatin and delayed and reduced apoptosis. Although apoptosis was markedly reduced in cisplatin-resistant sublines compared to their parental cells, there were no significant differences in the expression of p53, bcl-2 and bax.

CONCLUSIONS

Cisplatin-resistance was associated with the reduced cellular susceptibility to apoptosis. Cancer cells with the natural expression of bcl-2 and p53 mutation may be more resistant to cisplatin and less susceptible to apoptosis.