[Automated cardiac output measurement by color Doppler echocardiography]

Recently, automated cardiac flow measurement (ACM) has been developed for measuring the volume flow rate of blood flow through the left ventricular outflow tract. Measurements of left ventricular cardiac output by the ACM method were compared with those by the thermal dilution method with a Swan-Ganz catheter in 27 patients (16 men and 11 women; aged 44 +/- 3 years) in whom clear two-dimensional and color Doppler images of the left ventricular outflow tract were obtained. The total time required for left ventricular stroke volume calculation by both ACM and pulsed Doppler methods was measured in 10 patients (six men and four women; aged 41 +/- 2 years). There was an excellent correlation in the measurements of cardiac output between the ACM and thermal dilution methods (y = 0.77x + 0.77, r = 0.84, SEE = 0.4 l/min). The total time required for left ventricular stroke volume calculation by the ACM method was significantly shorter than that by the pulsed Doppler method (92 +/- 10 vs 177 +/- 30 sec, p < 0.01). The ACM method is simple, quick, and accurate for the automated assessment of cardiac output.

Dose-related vestibular and cochlear effects of transtympanic gentamicin

HYPOTHESIS

To test the relative dose-related cochlear and vestibular ototoxicity produced by transtympanically injected gentamicin in the Mongolian gerbil.

BACKGROUND

Transtympanic gentamicin is gaining favor as a relatively noninvasive treatment for Meniere's disease (MD). Few basic science studies exist regarding the vestibular and cochlear toxicities and dosage and administration schedules, however. The absence of standardized procedures and use of different species as animal models may account for the variable outcomes and lack of agreement found in the literature.

METHODS

Histologic evaluation was performed on inner ears from Mongolian gerbils to study vestibular and cochlear damage. Comparisons were made between animals receiving single (1x) and five (5x) daily injections of gentamicin/gelfoam slurry and similarly injected (saline/gelfoam) and noninjected controls.

RESULTS

Two weeks after injection, qualitative and quantitative changes were seen in posterior cristae hair cells in the 1x and 5x gentamicin injected groups. Statistically significant decreases in hair cells were seen when 5x injected ears were compared with 1x injected ears and when 1x injected ears were compared with control ears. When damage was observed in the posterior crista sensory cells, damage was also seen in cochlear hair cells.

CONCLUSIONS

Our results suggest that in the gerbil, gentamicin is ototoxic but not selectively vestibulotoxic. In general, increasing the number of transtympanic injections increases the damage to sensory hair cells in both the posterior crista and the cochlea. A variation in interanimal susceptibility to ototoxic effects exists, but the amount of damage is consistent in both cochlear and vestibular hair cells from the same animal.

[Serial changes in mitral regurgitation after mitral valve repair with artificial chordae tendineae: assessment by transesophageal echocardiography]

Serial changes in mitral regurgitation after anterior mitral valve repair were examined by transesophageal echocardiography (TEE) in 34 of 86 consecutive patients with pure mitral regurgitation who underwent anterior mitral valve repair from 1987 to 1996. The patients were divided into two groups: 15 patients undergoing mitral repair with polytetrafluoroethylene (PTFE; PTFE group) and 19 undergoing conventional mitral repair without PTFE (non-PTFE group). The PTFE group included 11 men and 4 women with a mean age of 52.1 years. They were followed for mean 22.8 +/- 12.0 months. The non-PTFE group included 12 men and 7 women with a mean age of 53.9 years. They were followed for mean 33.9 +/- 20.4 months. Mitral regurgitation jet areas were observed at the time of operation, 1 month after mitral valve repair, and in the late follow-up period. Regurgitation jet areas were 0.7 +/- 0.7, 1.1 +/- 0.9 and 2.5 +/- 2.1 cm2 in the PTFE group, and 1.1 +/- 1.3, 2.4 +/- 1.7, 4.7 +/- 2.9 cm2 in the non-PTFE group. The jet area was significantly smaller in the PTFE group than in the non-PTFE group at 1 month after operation and in the late follow-up period. Moderate to severe regurgitation was observed in two patients (13.3%) in the PTFE group, and eight patients (42.1%) in the non-PTFE group. Mitral valve repair with PTFE showed better results than conventional mitral valve repair without PTFE during the mean follow-up period of 23 months.

Complications after pylorus-preserving pancreatoduodenectomy with gastrointestinal reconstruction by the Imanaga method

BACKGROUND

Pylorus-preserving pancreatoduodenectomies (PPPDs) have been performed for disorders of the pancreatic head and periampullary region. The most commonly used reconstructive technique anastomoses the duodenum end-to-side to the jejunum, with pancreatic and biliary anastomoses placed proximally to the end-to-side duodenojejunostomy. In contrast, we have favored PPPD with gastrointestinal reconstruction by the Imanaga method (PPPD-Imanaga), which consists of end-to-end duodenojejunostomy, end-to-side pancreatojejunostomy, and choledochojejunostomy, performed in that order, because the PPPD-Imanaga provides a physiologic mixture of food, pancreatic juice, and bile in the upper portion of the jejunum.

STUDY DESIGN

To identify their postoperative complications, we retrospectively reviewed the cases of 55 patients who underwent a PPPD-Imanaga between December 1986 and December 1996. In all cases, the right gastric artery was divided and the pancreatic duct was sewn directly to a small opening in the jejunal mucosa. Twenty patients with malignancy received adjuvant radiotherapy.

RESULTS

Five patients died without being discharged, including one who died of cancer progression, for a postoperative mortality rate of 9%. These deaths were limited to patients who had received adjuvant radiotherapy, with only two deaths being procedure related. Delayed gastric emptying, pancreatic leak, and marginal ulcer were observed in 25 (45%), 3 (5%), and 3 (5%) patients, respectively. The delay in gastric emptying was transient and resolved spontaneously, with no patients undergoing reoperation. Only one patient required a reoperation, for the control of intraabdominal bleeding.

CONCLUSIONS

A PPPD-Imanaga can be performed with acceptable morbidity and mortality risks. We conclude that the Imanaga method is a favorable complement to PPPD.

Characteristics of vitamin D3 receptor (VDR) binding to the vitamin D response element (VDRE) in rat bone sialoprotein gene promoter

Bone sialoprotein (BSP) is a mineralised tissue-specific protein that is highly expressed during the initial formation of bone and cementum. Expression of BSP is suppressed by the osteotropic hormone, 1,25-dihydroxyvitamin D3 (vitamin D3), which regulates bone remodelling. In previous studies, we have identified a vitamin D response element (VDRE) that is integrated with a novel inverted TATA box in the rat BSP promoter which mediates the suppression of BSP transcription (1). Although the nucleotide sequences of VDREs in different genes conform to a direct (hexamer) repeat, spaced by three nucleotides, the precise sequences are unique for each VDRE. To determine whether the nucleotide differences in the VDRE influence VDR binding, we have compared interactions of VDR proteins with various VDREs using gel mobility shift analysis. Both natural and recombinant VDRs bound to rat BSP and both mouse and porcine osteopontin (OPN) VDRE oligonucleotides in a concentration-dependent manner with a strong preference for dimer formation, whereas equal amounts of dimer and monomer were bound to the human osteocalcin VDRE. However, whereas a truncated VDR comprising the DNA binding domain alone bound the mouse osteopontin VDRE, it failed to interact with the porcine OPN and rat BSP VDREs. VDR binding to the BSP was sequence specific, as shown by mutagenesis analysis, and could be abolished by heat and VDR antibody. These studies demonstrate that subtle differences in the nucleotide sequence of VDREs affect VDR binding, which mediates the vitamin D3 response.

[Long-term results of mitral valve repair with artificial chordae tendineae]

The long-term results of mitral valve repair using artificial polytetrafluorethylene (PTFE) chordae were assessed in 61 consecutive patients with pure mitral regurgitation who underwent mitral valve repair with replacement of elongated or ruptured chordae tendineae between 1992 and 1996. There were 36 men and 25 women aged from 14 to 73 years (mean 52.1 +/- 13.8 years). The patients were followed up for between 1 to 73 months (mean 29.3 +/- 17.6 months). Fifty-five patients underwent mitral valve repair of the anterior leaflet and 6 repair of the posterior leaflet. There were two hospital and two late deaths. Actual survival rate at 5 years was 93.1%. Freedom from cardiac events at 5 years was 87.8%. Two patients required reoperation due to hemolysis. There were three occurrences of non-fatal thromboembolism. Although further investigation is necessary in a large population, expanded PTFE sutures are excellent for chordal replacement during mitral valve repair.

Pancreatic lymph nodal and plexus micrometastases detected by enriched polymerase chain reaction and nonradioisotopic single-strand conformation polymorphism analysis: a new predictive factor for recurrent pancreatic carcinoma

K-ras point mutations have been observed in approximately 90% of pancreatic carcinomas. We genetically analyzed cases of pancreatic regional lymph nodal and plexus micrometastases in invasive ductal carcinoma of the pancreas who were node negative or had metastases limited histopathologically to pancreaticoduodenal lymph nodes. These cases underwent curative resection in our institute. The utility of genetic analysis was compared with that of histopathological study, in terms of postoperative clinical outcome, as a predictive factor for recurrent pancreatic carcinoma. Samples for DNA extraction were obtained from formalin-fixed, paraffin-embedded specimens. A 0.5-microg quantity of DNA was subjected to enriched PCR and nonradioisotopic single-strand conformation polymorphism analysis. K-ras codon 12 mutations were detected in 83% (10 of 12) of invasive ductal carcinomas. In four cases, the genetic analysis of regional lymph nodal metastases and pancreatic plexus invasion of the pancreatic carcinoma yielded results concordant with those of histopathological analysis. In six cases, however, the metastases detected by genetic analysis were more advanced than was indicated by the histopathological examination. The survival rate of cases with metastases beyond the pancreaticoduodenal lymph nodes was significantly lower than that of cases with metastases limited to the pancreaticoduodenal lymph nodes or with no nodal involvement based on genetic analysis (P < 0.05). Intraoperative analysis of point mutations at K-ras codon 12 in the regional lymph nodes and the pancreatic plexus by enriched PCR/nonradioisotopic single-strand conformation polymorphism analysis is a highly accurate predictive factor for recurrent pancreatic carcinoma.

Heat shock-induced excessive relaxation of DNA in Escherichia coli mutants lacking the histone-like protein HU

Plasmid DNA in exponentially growing Escherichia coli immediately relaxes after heat shock but the relaxed DNA re-supercoils rapidly, the despite continued presence of the heat shock conditions. We have now obtained genetic evidence indicating that the histone-like protein HU of E. coli is required for this re-supercoiling of DNA. Plasmid DNA in a hupA-hupB double gene-disruption mutant relaxed excessively after heat shock, while the relaxation of DNA in a himA-himD double gene-disruption mutant and in an hns insertion mutant was transient, thereby indicating that HU protein, but not IHF or H-NS proteins, is required for the re-supercoiling of DNA. Exposure of the hupA-hupB double mutant to a temperature of 50 degrees C led to both excessive relaxation of DNA and to a decrease in viable cell number but temperatures lower than 46 degrees C did not lead to these events. Based on these results, we propose that HU protein maintains the negative supercoiling of DNA during thermal stress and contributes to cellular thermotolerance in E. coli.

Effect of preoperative 5-fluorouracil on apoptosis of advanced gastric cancer

BACKGROUND

Several studies have reported on apoptosis and the effect of anticancer chemotherapy.

METHODS

We studied apoptosis induced by 5-fluorouracil (5-FU) given preoperatively to 28 patients with advanced gastric cancer and compared the findings with 101 untreated patients. The expression of bcl-2 oncoprotein, cell phase fractions, and histological chemotherapeutic effects were also compared with the apoptotic changes.

RESULTS

The apoptotic and S-phase fractions in 5-FU-treated patients (apoptotic fraction: 10.46 +/- 6.93%, S-phase fraction: 17.49 +/- 11.65%) were significantly greater than those in untreated controls (apoptotic fraction: 6.56 +/- 5.06%, S-phase fraction: 12.17 +/- 6.78%). A positive correlation was observed between 5-FU-induced apoptosis and accumulation of tumor cells in the S-phase fraction. There was an inverse relationship between bcl-2 oncoprotein expression and apoptosis in 5-FU-treated patients, but no significant correlation between histological effect and apoptosis. However, two patients with significant histological effects showed no bcl-2 oncoprotein expression, whereas the histological effects were mild in all the bcl-2-positive patients.

CONCLUSIONS

Apoptosis may be induced by 5-FU administered preoperatively and bcl-2 oncogene expression may suppress 5-FU-induced apoptosis.

[Indication and results of pancreatectomy with combined resection of vessels for adenocarcinoma of the pancreas]

Of 192 patients who received pancreatectomy for invasive adenocarcinoma of the pancreas, 107 (55. 7%) underwent combined resection of vessels at Keio University Hospital and Tochigi Cancer Center, from July 1974 until March 1996. Vascular resections included the portal and/or mesenteric vein in 103, the common hepatic artery in 14, the superior artery in 2 and the celiac axis in 5 cases. The morbidity and mortality rate are 20.2%, 1.2% in the standard resected group and 23.1%, 5.6% in the vessel resected group, respectively. Comparison of the survival rate of curability A and B patients between two groups shows no significant difference. Six patients who underwent resection of the portal and/or mesenteric vein survived more than 5 years. The longest survivor is living 13 years 6 months after surgery. Among the patients who underwent resection of the artery, two patients survived 44 and 22 months after distal pancreatectomy with resection of the celiac axis and the common hepatic artery preserving whole stomach.

Development of neo red cells (NRC) with the enzymatic reduction system of methemoglobin

To assess the oxygen transport capacity and safety of Neo Red Cells (NRC) with the enzymatic reduction system of methemoglobin in vitro and in experimental animals. Stroma free hemoglobin (SFH) prepared without damage of enzymes from outdated human red blood cells, together with inositol hexaphosphate as an allosteric effector, NAD as a coenzyme and glucose, adenine and inosine as a substrate was encapsulated within liposomes composed of hydrogenated soy phosphatidylcholine, cholesterol, myristic acid and alpha-tocopherol in the ratio of 7:7:2:0.28 respectively. NRC thus prepared with a mean diameter of 220 nm, encapsulation efficiency of 1.3 g-Hb:1 g-lipid and P50O2 of 50-60 mmHg were then coated with polyethylene glycol bound to hydrogenated soy phosphatidylethanolamine as a surface modifier to prevent aggregation of NRC in plasma. The methemoglobin formation of the NRC with enzymatic reduction system were evaluated by in-vitro examination and exchange transfusion with rats as in-vivo examination, then the methemoglobin formation was reduced from 1%/hr to 0.4%/hr by the addition of methemoglobin reduction system. The generation of the pyruvate and the lactate were observed within the NRC with enzymatic reduction system, then the activation of the Embden-Meyerhof pathway was confirmed. And we concerned about the availability of the NRC as a perfusate for the cardiopulmonary bypass during moderate or profound hypothermia, then we evaluated the oxygen transporting efficiency and capacity of the NRC under the using of the artificial lung system in vitro examination. The present investigation suggest that the effectiveness of the NRC with enzymatic reduction system, they restrained the formation of methemoglobin and they are efficient oxygen carriers as a perfusate of the artificial lung, and we suggest the new extracorporeal circulation system using of the NRC as a perfusate for the cardiopulmonary bypass.

Transforming growth factor-beta 1 regulation of bone sialoprotein gene transcription: identification of a TGF-beta activation element in the rat BSP gene promoter

Transforming growth factor-beta (TGF-beta) increases steady-state mRNA levels of several extracellular matrix proteins in mineralized connective tissues. Bone sialoprotein (BSP) is a major constituent of the bone matrix, thought to initiate and regulate the formation of mineral crystals. To determine the molecular pathways of TGF-beta 1 regulation of bone proteins, we have analyzed the effects of the TGF-beta 1 on the expression of the BSP in the rat osteosarcoma cell line (ROS 17/2.8). TGF-beta 1 at 1 ng/ml, increased BSP mRNA levels in ROS 17/2.8 cells approximately 8-fold: the stimulation was first evident at 3 hr, reached maximal levels at 12 hr and slowly declined thereafter. Since the stability of the BSP mRNA was not significantly affected by TGF-beta 1, and nuclear "run-on" transcription analyses revealed only a approximately 2-fold increase in the transcription of the BSP gene, most of the increase in BSP mRNA appeared to involve a nuclear post-transcriptional mechanism. Moreover, the effects of TGF-beta 1 were indirect, since the increase in BSP mRNA was abrogated by cycloheximide (28 micrograms/ml). To identify the site of transcriptional regulation by TGF-beta 1, transient transfection analyses were performed using BSP gene promoter constructs linked to a luciferase reporter gene. Constructs that included nt -801 to -426 of the promoter sequence were found to enhance transcriptional activity approximately 1.8-fold in cells treated with TGF-beta 1. Within this sequence, approximately 500 nt upstream of the transcription start site, a putative TGF-beta activation element (TAE) was identified that contained the 5'-portion of the nuclear factor-1 (NF-1) canonical sequence (TTGGC) overlapping a consensus sequence for activator protein-2 (AP-2). The functionality of the TAE was shown by an increased binding of a nuclear protein from TGF-beta 1 stimulated cells in gel mobility shift assays and from the attenuation of TGF-beta 1-induced luciferase activity when cells were co-transfected with a double-stranded TAE oligonucleotide. Competition gel mobility shift analyses revealed that the nuclear protein that binds to the TAE has similar properties to, but is distinct from, NF-1 nuclear protein. These studies have therefore identified a TGF-beta activation element (TAE) in the rat BSP gene promoter that mediates the stimulatory effects of TGF-beta 1 on BSP gene transcription.

Effect of preoperative 5-fluorouracil on apoptosis of advanced gastric cancer

BACKGROUND

Several studies have reported on apoptosis and the effect of anticancer chemotherapy.

METHODS

We studied apoptosis induced by 5-fluorouracil (5-FU) given preoperatively to 28 patients with advanced gastric cancer and compared the findings with 101 untreated patients. The expression of bcl-2 oncoprotein, cell phase fractions, and histological chemotherapeutic effects were also compared with the apoptotic changes.

RESULTS

The apoptotic and S-phase fractions in 5-FU-treated patients (apoptotic fraction: 10.46 +/- 6.93%, S-phase fraction: 17.49 +/- 11.65%) were significantly greater than those in untreated controls (apoptotic fraction: 6.56 +/- 5.06%, S-phase fraction: 12.17 +/- 6.78%). A positive correlation was observed between 5-FU-induced apoptosis and accumulation of tumor cells in the S-phase fraction. There was an inverse relationship between bcl-2 oncoprotein expression and apoptosis in 5-FU-treated patients, but no significant correlation between histological effect and apoptosis. However, two patients with significant histological effects showed no bcl-2 oncoprotein expression, whereas the histological effects were mild in all the bcl-2-positive patients.

CONCLUSIONS

Apoptosis may be induced by 5-FU administered preoperatively and bcl-2 oncogene expression may suppress 5-FU-induced apoptosis.

Bradykinin regulates the histamine-induced Ca2+ mobilization via protein kinase C activation in human gingival fibroblasts

We previously demonstrated that histamine and bradykinin evoke an increase in intracellular Ca2+ ([Ca2+]i) in human gingival fibroblasts by using a fluorescent Ca2+ indicator Fura-2. In this paper, we further demonstrate the regulation of the histamine-induced Ca2+ mobilization by bradykinin. In fibroblasts stimulated with bradykinin (1 microM), subsequent stimulation with histamine (100 microM) failed to mobilize Ca2+, whereas bradykinin induced an increase in [Ca2+]i in the cells pre-stimulated with histamine. The attenuation of the histamine response was dependent on the concentration of bradykinin for the first stimulation. Histamine also failed to induce the formation of inositol 1,4,5-trisphosphate in fibroblasts pretreated with bradykinin. In fibroblasts pretreated with bradykinin (1 microM) for 3 min and then washed with fresh medium, the effect of histamine on [Ca2+]i quickly returned to the control level. The activation of protein kinase C by phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (PMA) elicited a marked decrease in histamine-induced Ca2+ mobilization. When the protein kinase C activity was inhibited with H7, a protein kinase C inhibitor, or was down-regulated by pretreatment with PMA for 20 h, the inhibitory effect of PMA on the histamine response was relieved. In the fibroblasts pretreated with H7 or PMA for 20 h, histamine evoked Ca2+ mobilization even after bradykinin stimulation. These results suggest that the histamine response is regulated by bradykinin receptor activation via the activation of protein kinase C in human gingival fibroblasts.

5-FU-induced apoptosis correlates with efficacy against human gastric and colon cancer xenografts in nude mice

Apoptosis may be an important mechanism by which cancer cells are killed by certain agents. It is reported here that apoptosis is a key event in the killing of human tumor cells by 5-fluorouracil (5-FU) in vivo. Apoptosis induced by 5-FU was determined using two human gastrointestinal tumor xenografts serially transplanted into nude mice: a gastric carcinoma (SC-1-NU) highly sensitive to 5-FU and a colon carcinoma (Co-4) less sensitive to 5-FU. Apoptosis was assayed using the terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-biotin nick end labeling method in paraffin-embedded tissue sections, and by flow-cytometric analysis. Apoptosis-positive cells increased gradually during treatment. 24 hours after the initiation of 5-FU treatment a maximum, of 15.4% of the Co-4 cells were apoptotic. 48 hours after the initiation of 5-FU treatment, apoptosis was found in 34% of the tumor cells in the SC-1-NU strain. Flow-cytometry demonstrated the increase of S-phase fractions in both strains after the administration of 5-FU, and this coincided with the appearance of apoptotic-positive cells. Although the intrinsic. TS activities of two strains differed, TS activities were markedly suppressed in both strains immediately after the administration of 5-FU. Concentration of 5-FU in RNA (F-RNA) increased gradually in both strains, reaching a maximum 24 hours after the administration of 5-FU. These results suggest that apoptosis and inhibition of DNA synthesis induced by 5-FU are closely associated with its antitumor effect.

[The concentration of Tamsulosin hydrochloride in the blood and prostatic tissue of the patients in benign prostatic hyperplasia]

BACKGROUND

The penetration of Tamsulosin hydrochloride into the blood and the prostatic tissue was examined.

METHODS

Fifty-two patients with benign prostatic hyperplasia treated with transurethral resection of the prostate were entered in this study. This drug was administered orally in a dose of 2.0 mg once a day for 7 to 179 days preoperatively. The blood samples were taken simultaneously at the time of the prostatic tissue sampling.

RESULTS

1. The correlation coefficient was hardly significant between aging and concentration of the drug in the blood or in the prostatic tissue. 2. The correlation coefficient was hardly significant between the duration of the drug administration and concentration of the drug in the blood or the prostatic tissue. 3. The correlation coefficient was significant between the concentration of the drug in the blood and the prostatic tissue. 4. The fifty-two patients showed no significant adverse reactions during administration of the drug.

CONCLUSION

These results suggest that the drug can be administered safely to the aged even in a long-term and can be penetrated into the blood and the prostatic tissue with a positive correlation.

[Evaluation of left ventricular ejection fraction using an automated contour tracking method: comparison with equilibrium radionuclide angiography]

A recently developed contour tracking method provides automated edge detection of left ventricular endocardium without a region of interest. The accuracy of this automated contour tracking (ACT) method in the evaluation of left ventricular ejection fraction was assessed in 20 patients (16 males and 4 females, mean age 58 years) using both the ACT method and equilibrium radionuclide angiography. Ejection fractions measured by the ACT method correlated well with those measured by equilibrium radionuclide angiography (y = 0.8x + 11.9, r = 0.91, SEE = 4.0%, p < 0.01). The ACT method provides an accurate estimate of left ventricular ejection fraction.

Cementum, root dentin and bone extracts stimulate chemotactic behavior in cells from periodontal tissue

In this paper, we used the extracts from cementum, bone, dentin and enamel, and compared the chemotactic behavior of human periodontal ligament (HPDL) cells, human gingival fibroblasts (HGF) and human alveolar bone (HAB) cells using modified Boyden chambers. The extracts, obtained using 4 M guanidine HCl ("G" extract), from cementum, root dentin, and bone had greater chemotactic effects than all the 4 M guanidine HCl/0.5 M EDTA extracts ("E" extract). HPDL cells and HGF exhibited higher chemotactic behavior than osteoblast-like HAB cells in response to cementum and root dentin "G" extracts. On the other hand, HAB cells showed the highest migratory activity in response to the bone "G" extract. The chemotactic activities of these extracts were reduced by heat- and trypsin-treatment. These results suggest that proteinaceous chemotactic factors exist in the cementum, root dentin and bone, and they appear to regulate the migration and orientation of HPDL cells, HGF and HAB cells during periodontal wound healing.

Histocompatibility leukocyte antigen-A2402-restricted cytotoxic T lymphocytes recognizing adenocarcinoma in tumor-infiltrating lymphocytes of patients with colon cancer

To cast light on T cell-mediated specific immunity at the tumor site of colon cancer, we investigated whether interleukin-2 (IL-2)-activated tumor-infiltrating lymphocytes (TIL) from colon cancer show histocompatibility leukocyte antigen (HLA)-class I-restricted cytotoxicity against adenocarcinoma. IL 2-activated TIL from all four HLA-A24 patients examined lysed HLA-A2402+ adenocarcinomas, but not HLA-A2402- tumors. Those of two of the four cases also lysed HLA-A2402+ squamous cell carcinomas. CD8+ cytotoxic T lymphocyte (CTL) clones recognizing HLA-A2402+ adenocarcinomas were established from one CTL line. This CTL line produced IFN-gamma upon recognition of an HLA-A2402- adenocarcinoma transfected with HLA-A2402 cDNA. These results suggest the presence of HLA-A2402-restricted CTL recognizing adenocarcinoma at the tumor site of colon cancer. Furthermore, HLA-A31-restricted CTL activity was found in IL-2-activated TIL from one of two HLA-A31+ patients, suggesting the existence of HLA-class I-restricted CTL involving an allele other than A24.

Clonal anergy is a potent mechanism of oral tolerance in the suppression of acute antigen-induced arthritis in rats by oral administration of the inducing antigen

The effects of oral administration of ovalbumin (OVA) on acute OVA-induced arthritis (OIA) in rats, which is mediated by Arthus reaction to the antigen in the joint space, were investigated. The oral administration of OVA before immunization with OVA significantly suppressed the development of acute OIA in a dose-dependent manner, in accordance with decreases in both the in vivo anti-OVA IgG antibody production and in vitro lymphocyte proliferative responses to OVA. These results were shown in both the single high-dose (200 mg x 1) or the multiple low-dose (200 microg x 5) feeding protocols. In vitro study showed that rat IL-2 could reverse the reduced OVA-specific lymphocyte proliferative responses. The spleen cells obtained from OVA-feeding, unprimed rats neither adoptively transferred the suppression to naive recipient rats nor suppressed the in vitro lymphocyte proliferation. These results demonstrate that the acute OIA can be suppressed by the induction of oral tolerance (OT) to OVA, and strongly suggest that the OT was due to clonal anergy of antigen-reactive T lymphocytes, not the active suppression by OVA-specific regulatory cells.

Increase in negative supercoiling of plasmid DNA in Escherichia coli exposed to cold shock

Negative supercoiling of plasmid DNA in Escherichia coli cells can decrease transiently when exposed to heat shock. The effect of cold shock on DNA supercoiling was examined, and analysis by agarose gel electrophoresis in the presence of chloroquine revealed that negative supercoiling of plasmid DNA in cells increased when cells were exposed to cold shock. This increase was transient and was nil when the cells were pretreated with nalidixic acid, an inhibitor of DNA gyrase. In a mutant deficient in expression of HU protein, the increase in negative supercoiling of DNA by cold shock is less apparent than in wild-type cells. It is proposed that DNA gyrase and HU protein have a role in the DNA supercoiling reaction seen with cold shock.