IgA class anti-beta2-glycoprotein I in patients with systemic lupus erythematosus

OBJECTIVE

To search for a possible relationship between the presence of IgA class anti-beta2-glycoprotein I antibody (abeta2-GPI) and clinical manifestations, including thrombotic episodes, in patients with systemic lupus erythematosus (SLE).

METHODS

Serum IgA abeta2-GPI levels in 124 Japanese patients with SLE were measured using a phospholipid independent enzyme immunoassay. Relationships to clinical histories and to various laboratory data including IgG and IgM class abeta2-GPI were examined.

RESULTS

Twenty-five percent of patients with SLE were positive for IgA abeta2-GPI. Patients with a history of thrombosis had significantly higher probabilities for positivity of IgA abeta2-GPI, compared to those without. The presence of IgA abeta2-GPI was correlated with presence of lupus anticoagulant and/or biological false positive result for serological syphilis test. Titer of IgA abeta2-GPI significantly correlated with values of IgG abeta2-GPI, IgM abeta2-GPI, and anti-DNA antibodies.

CONCLUSION

The presence of IgA abeta2-GPI may be related to the occurrence of thrombosis in patients with SLE. Measurements of IgA abeta2-GPI may be of value for evaluating risk of thrombosis in patients with SLE.

Angiomyolipoma: imaging findings in lesions with minimal fat

PURPOSE

To investigate a method of diagnosing angiomyolipoma that contains minimal fat.

MATERIALS AND METHODS

In six cases of angiomyolipoma with minimal fat, the attenuation on contrast material-enhanced and unenhanced computed tomographic (CT) images, the echogenicity on sonograms, the signal intensity on T2-weighted magnetic resonance (MR) images, and the gross configuration of the lesion were retrospectively analyzed. In 100 cases of renal cell carcinoma, the same parameters were analyzed, and results were compared with those of angiomyolipoma.

RESULTS

When compared with the surrounding renal parenchyma, all six angiomyolipomas showed homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, and homogeneous isoechogenicity on sonograms. Of the five angiomyolipomas examined with MR imaging, four were hypointense and one was isointense on T2-weighted images. All six angiomyolipomas protruded from the renal margin. None of the 100 renal cell carcinomas showed homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, or homogeneous isoechogenicity on sonograms.

CONCLUSION

In the kidney, homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, and homogeneous isoechogenicity on sonograms are suggestive of angiomyolipoma that contains abundant muscle and minimal fat.

Recognition of beta-lactam antibiotics by rat peptide transporters, PEPT1 and PEPT2, in LLC-PK1 cells

PEPT1 and PEPT2 are H(+)-coupled peptide transporters expressed preferentially in the intestine and kidney, respectively, which mediate uphill transport of oligopeptides and peptide-like drugs such as beta-lactam antibiotics. In the present study, we have compared the recognition of beta-lactam antibiotics by LLC-PK1 cells stably transfected with PEPT1 or PEPT2 cDNA. Cyclacillin (aminopenicillin) and ceftibuten (anionic cephalosporin without an alpha-amino group) showed potent inhibitory effects on the glycylsarcosine uptake in the PEPT1-expressing cells. Other beta-lactams, such as cephalexin, cefadroxil, and cephradine (aminocephalosporins), inhibited modestly the PEPT1-mediated glycylsarcosine uptake. Except for ceftibuten, these beta-lactams showed much more potent inhibitions on the glycylsarcosine uptake via PEPT2 than via PEPT1. Comparison of the inhibition constant (Ki) values between cefadroxil and cephalexin suggested that the hydroxyl group at the NH2-terminal phenyl ring increased affinity for both PEPT1 and PEPT2. It is concluded that PEPT2 has a much higher affinity for beta-lactam antibiotics having an alpha-amino group than PEPT1 and that substituents at the NH2-terminal side chain of these drugs are involved in the recognition by both peptide transporters.

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.

Malignant fibrous histiocytoma of the cecum: report of a case and review of the literature

Malignant fibrous histiocytoma (MFH) of the gastrointestinal tract is extremely rare. Here we report a case of MFH of the cecum and review other cases of large bowel MFH in the literature. A 64-year-old man had a large tumor mass in the cecum associated with multiple small peritoneal implants. Histologically, most of the lesion showed inflammatory pseudotumor-like appearance; that is, a mixed proliferation of fibroblasts and myofibroblasts loosely arranged in sweeping fascicles or whorled structures and an admixture of chronic inflammatory cell infiltrate. The myofibroblastic nature of the spindle-shaped cells was confirmed by their immunohistochemical and ultrastructural findings. In addition, there was atypical histiocytic cells infiltrate in some areas and marked lymphatic involvement and lymph node metastasis by such histiocytic cells. These features were interpreted as MFH, although it had to be distinguished from inflammatory fibrosarcoma and leiomyosarcoma. The differential diagnosis is discussed here.

Specific inhibition of PCR by non-extendable oligonucleotides using a 5' to 3' exonuclease-deficient DNA polymerase

The Stoffel fragment of Taq DNA polymerase lacks the 5' to 3' exonuclease activity that hydrolyzes potentially blocking DNA strands during primer extension. We there-fore asked whether by using this fragment in the PCR, non-extendable, base-paired oligonucleotides could inhibit amplification in a sequence-dependent manner. Model targets were chosen from the partially conserved ribosomal 16S rDNA of three bacterial species: E. coli, Bacillus subtilis and Neisseria gonorrhoea. A single pair of primers was capable of amplifying a homologous 240-bp region from all three. Two non-extendable "blocking" oligonucleotides were synthesized with sequences complementary to the inter-primer regions of E. coli and B. subtilis, respectively. Both blockers were shown specifically to prevent amplification of their complementary targets, but not of the reciprocal control targets or of the reciprocal control targets or of the non-complementary N. gonorrhea. Specificity was further confirmed by an internal positive control. Similar inhibition was seen with mixtures of targets in a single reaction. With intact Taq DNA polymerase, no blocking was observed. Primers and blockers targeting specific regions of N. gonorrhoea rDNA were used to confirm the requirement that blockers be directed to the inter-primer region. Sequence-dependent amplification inhibition, such as that demonstrated here, would be applicable to PCR-related strategies using primers capable of using multiple targets, where such selective inhibition could be useful.

Plasma adrenomedullin concentrations and cardiac and arterial hypertrophy in hypertension

It has been reported that plasma concentrations of adrenomedullin (AM), a novel vasodilator peptide, are higher in patients with essential hypertension than those in normotensive subjects. To clarify the clinical significance of increased levels of AM in patients with essential hypertension, in this study we examined the relationship between plasma concentrations of AM and the structure of the left ventricle or carotid artery. Plasma AM concentrations; renin activity; and norepinephrine, epinephrine, and creatinine concentrations in 50 patients with untreated essential hypertension without renal dysfunction and heart failure were measured. We also measured the mean wall thickness of the left ventricle and left ventricular mass index by M-mode echocardiography and intimal-medial thickness and arterial distensibility of the carotid artery by ultrasonography. Hypertensive patients were divided into two groups: hypertensives with and those without left ventricular hypertrophy. Plasma AM concentrations in hypertensive patients with left ventricular hypertrophy were significantly higher than in hypertensive patients without left ventricular hypertrophy (7.87+/-2.70 vs 5.74+/-1.65 fmol/mL, P<.01). In all hypertensive patients, plasma AM concentrations were not correlated with blood pressure, plasma renin activity, plasma norepinephrine, plasma epinephrine, or plasma creatinine concentration. Plasma AM concentrations were positively correlated with left ventricular mass index or mean wall thickness (r=.37, P=.009; r=.40, P=.004, respectively) and inversely correlated with carotid artery distensibility (r=-.33, P=.02), whereas plasma AM concentrations were not correlated with intimal-medial thickness. These results suggest that the observed elevation of plasma AM in patients with essential hypertension with normal renal function may be partly related to cardiac hypertrophy and decreased carotid artery distensibility.

Cardiac extension of intravenous leiomyomatosis with successful resection

A case of intravenous leiomyomatosis spreading to the right ventricle is described. A 28-year-old woman had been previously diagnosed as having a smooth muscle tumor of borderline malignancy after hysterectomy for a large uterine tumor, because of its unusual invasive character. Based on the above diagnosis, the patient had been managed clinically as having a uterine sarcoma. One year after her hysterectomy, a local recurrence in the pelvic cavity was detected. Two years later, the tumor appeared as a cardiac tumor causing syncope. The tumor was totally resected in two surgical stages, and the correct diagnosis of an intravenous leiomyomatosis was made. The diagnostic and operative considerations are reviewed and the preferred surgical procedure is discussed.

NG-nitro-L-arginine methyl ester inhibits bone metastasis after modified intracardiac injection of human breast cancer cells in a nude mouse model

We investigated the effects of NG-nitro-L-arginine-methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor, on bone metastasis of human breast cancer, MDA-231 cells. Tumor cells (2 x 10(5) cells in 0.2 ml of phosphate-buffered saline; PBS) were injected through the diaphragm into the left ventricle of the heart of laparotomized nude mice (male 5-week-old ICR-nu/nu). L-NAME (2 mg/mouse/injection in 0.1 ml of PBS) was given intraperitoneally to mice 6 h and 3 h before and immediately, 3 h, 6 h, 18 h and 21 h after the intracardiac injection of tumor cells. As a control, 0.1 ml of PBS was injected instead of L-NAME. The effect of NG-nitro-D-arginine-methyl ester (D-NAME; 2 mg/mouse/injection), an inactive analogue of L-NAME, was also investigated to evaluate the specificity of L-NAME action. Radiographical examination 31 days after the tumor-cell injection showed that the incidence and number of osteolytic bone metastases and the number of bones with metastasis in L-NAME-treated mice were significantly reduced compared with those in PBS-treated mice (P < 0.05). The differences between PBS-treated and D-NAME-treated mice were not significant. Our findings suggest that specific and appropriate NOS inhibitors may represent a new pharmacological approach to therapy for cancer patients at risk of developing osteolytic bone metastases.

Cloning and characterization of a pH-sensing regulatory factor that modulates transport activity of the human H+/peptide cotransporter, PEPT1

We have isolated a cDNA encoding a pH-sensing regulatory factor protein that modulates transport activity of the human H+/peptide cotransporter, hPEPT1, from the human duodenum cDNA library. The cDNA (1,724 bp) for the regulatory factor (hPEPT1-RF) had an open reading frame encoding a 208-amino acid. The 18-195 amino acid residues of hPEPT1-RF were completely consistent with the 8-185 amino acid residues of hPEPT1, whereas the 1-17 and 196-208 residues were unique sequences. Using a reticulocyte lysate, the in vitro synthesized hPEPT1-RF RNA translated a product of approximately 23 kDa. Northern blot analysis and reverse transcription-coupled PCR revealed that both hPEPT1 and hPEPT1-RF mRNA transcripts are expressed in Caco-2 cells. When expressed in Xenopus oocytes, hPEPT1-RF showed no transport activity of glycylsarcosine, but shifted pH profile of the dipeptide transport mediated by the coexpressed hPEPT1. The pH profile of glycylsarcosine uptake in oocytes coexpressing hPEPT1 and hPEPT1-RF was almost similar to that in the Caco-2 cells. This is the first demonstration of cDNA isolation of a regulatory factor which modulates hPEPT1 activity.

Catalytic activities and structural properties of horseradish peroxidase distal His42 --> Glu or Gln mutant

The distal histidine (His) is highly conserved in peroxidases and has been considered to play a major role as a general acid-base catalyst for peroxidase reaction cycle. Recently, however, the X-ray structure of chloroperoxidase from the marine fungus Caldariomyces fumago has revealed that a glutamic acid is located at the position where most of the peroxidase has a histidine residue, suggesting that the carboxyl group in the glutamic acid (Glu) can also assist cleavage of an O-O bond in peroxides [Sundaramoorthy, M., Terner, J., & Poulos, T. L. (1995) Structure 3, 1367-1377]. In order to investigate catalytic roles of the glutamic acid at the distal cavity, two horseradish peroxidase mutants were prepared, in which the distal His42 has been replaced by Glu (H42E) or Gln (H42Q). The formation rate of compound I in the H42E mutant was significantly greater than that for the H42Q mutant, indicating that the distal Glu can play a role as a general acid-base catalyst. However, the peroxidase activity of the H42E mutant was still lower, compared to that for native enzyme. On the basis of the CD, resonance Raman, and EPR spectra, it was suggested that the basicity of the distal Glu is lower than that of the distal His and the position of the distal Glu is not fixed at the optimal position as a catalytic amino acid residue, although no prominent structural changes around heme environment were detected. The less basicity and improper positioning of the distal Glu would destabilize the heme-H2O2-distal Glu ternary intermediate for the peroxidase reaction. Another characteristic feature in the mutants was the enhancement of the peroxygenase activity. Since the peroxygenase activity was remarkably enhanced in the H42E mutant, the distal Glu is also crucial to facilitate the peroxygenase activity as well as the enlarged distal cavity caused by the amino acid substitution. These observations indicate that the distal amino acid residue is essential for function of peroxidases and subtle conformational changes around the distal cavity would control the catalytic reactions in peroxidase.

Neurons and extracellular neurofibrillary tangles in the hippocampal subdivisions in early-onset familial Alzheimer's disease: a case study

We have investigated morphometrically unaffected neurons, intracellular neurofibrillary tangles (I-NFT) and extracellular neurofibrillary tangles (E-NFT) in eight subdivisions of the hippocampal cortex in two cases of early-onset familial Alzheimer's disease (FAD) and six cases of early-onset sporadic Alzheimer's disease (SAD). The hippocampal subdivisions examined included: CA4, CA3, CA2, CA1, prosubiculum, subiculum and presubiculum (PRE), parasubiculum (PARA) and entorhinal cortex (ENT). CA3, CA2 and CA1 in the FAD cases showed more severe neuronal loss and much greater E-NFT formation than in the SAD cases, while ENT in both the FAD cases showed less neuronal loss and less E-NFT formation. These data suggest that the cornu ammonis is affected more severely than the ENT in the FAD cases. These observations indicate that hippocampal pathology in the FAD cases is qualitatively as well as quantitatively different from that in sporadic cases. These results provide further evidence for pathological heterogeneity in AD, although the number of FAD cases examined is very small.

Helicobacter pylori infection and gastric cancer. A nested case-control study in a rural area of Japan

We conducted a seroepidemiological nested case-control study to determine the association of gastric cancer with Helicobacter pylori infection and atrophic gastritis. A cohort of 2858 participants in an annual multiphasic health check-up were followed for eight years. Data for 45 gastric cancer cases and 225 sex-, age-, and address-matched control subjects were analyzed. Helicobacter pylori infection was determined by IgG antibodies, and atrophic gastritis was diagnosed by both serum pepsinogen I level (< or = 70 ng/ml) and the pepsinogen I/II ratio (< or = 3.0). Univariate analysis showed that Helicobacter pylori and atrophic gastritis were significantly associated with gastric cancer. In a multivariate analysis, atrophic gastritis was associated with significantly increased risk of cancer (odds ratio, 3.38; 95% confidence interval, 1.54-7.42); however, Helicobacter pylori was not associated with cancer (odds ratio, 1.84; 95% confidence interval, 0.59-5.72). These results suggest that Helicobacter pylori infection alone is not directly associated with gastric carcinogenesis but has an indirect relation to gastric cancer through the development of atrophic gastritis.

Helicobacter pylori infection and atrophic gastritis. A case-control study in a rural town of Japan

We enrolled five hundred twenty-one patients with atrophic gastritis and 769 controls in a case-control study of atrophic gastritis and Helicobacter pylori infection and lifestyle factors. The participants had no history of upper gastrointestinal surgery. They were selected from 1,395 adult (35 years or older) residents of a rural town in Kyoto prefecture who participated in an annual health examination in 1987. Atrophic gastritis was diagnosed on the basis of serum pepsinogen levels: pepsinogen I levels (< or = 70 ng/ml) and pepsinogen I/pepsinogen II ratios (< or = 3.0). The presence of immunoglobulin G antibodies to H. pylori indicated H. pylori infection. At the time of the health examination, participants were interviewed about daily lifestyle habits such as use of cigarettes and alcoholic beverages and consumption of green-yellow vegetables. Unconditional logistic regression analysis indicated that H. pylori infection was associated with a significantly increased risk for atrophic gastritis for all participants (odds ratio, 8.17; 95% confidence interval, 5.63-11.84); for men (odds ratio, 10.91; 95% CI, 5.25-22.67); and for women (odds ratio, 7.28; 95% CI, 4.72-11.22). We found no statistically significant relations between lifestyle factors and atrophic gastritis.

Liver metastases from colon cancer with intra-bile duct tumor growth: radiologic features

PURPOSE

Our goal was to characterize the radiologic features of liver metastases from colon cancer with intrahepatic bile duct (IHBD) dilatation.

METHOD

Radiologic findings of liver metastases from colon cancer with IHBD dilatation of four patients were compared with pathologic findings.

RESULTS

The cause of bile duct dilatation in all cases was due to papillary tumor growth in the bile duct. In two patients, intra-bile duct tumor growth (IBDTG) was observed on imaging. In the other two patients, IBDTG was not observed, but a nontapered abrupt obstruction of a dilated bile duct was seen, corresponding to the microscopically proven papillary tumor growth in the ductal lumen. In three patients who underwent an extensive hepatic resection, there has been no recurrence. In one patient who had a nonanatomic limited resection, a recurrence was seen 1 year after surgery.

CONCLUSION

When liver tumor with IBDTG is suspected on imaging, liver metastases should be considered in the differential diagnosis besides hepatocellular carcinoma or cholangiocellular carcinoma. Careful preoperative assessment for IBDTG by imaging is essential to determine the extent of surgical resection.

Helicobacter pylori infection and gastric cancer. A nested case-control study in a rural area of Japan

We conducted a seroepidemiological nested case-control study to determine the association of gastric cancer with Helicobacter pylori infection and atrophic gastritis. A cohort of 2858 participants in an annual multiphasic health check-up were followed for eight years. Data for 45 gastric cancer cases and 225 sex-, age-, and address-matched control subjects were analyzed. Helicobacter pylori infection was determined by IgG antibodies, and atrophic gastritis was diagnosed by both serum pepsinogen I level (< or = 70 ng/ml) and the pepsinogen I/II ratio (< or = 3.0). Univariate analysis showed that Helicobacter pylori and atrophic gastritis were significantly associated with gastric cancer. In a multivariate analysis, atrophic gastritis was associated with significantly increased risk of cancer (odds ratio, 3.38; 95% confidence interval, 1.54-7.42); however, Helicobacter pylori was not associated with cancer (odds ratio, 1.84; 95% confidence interval, 0.59-5.72). These results suggest that Helicobacter pylori infection alone is not directly associated with gastric carcinogenesis but has an indirect relation to gastric cancer through the development of atrophic gastritis.

Regulation of thymocyte lineage commitment by the level of classical protein kinase C activity

Thymocyte-positive selection involves signaling through TCR and accessory molecules, and the signaling intensity appears to be critical for this event. The specific inhibitor of classical Ca2+-dependent protein kinase C (cPKC), Gö 6976, inhibited positive selection in fetal thymus organ culture, indicating that cPKC activation is essential for positive selection. The major protein kinase C isoforms in CD4+ CD8+ thymocytes are cPKC-alpha, cPKC-beta, and the novel Ca2+-independent protein kinase C, nPKC-epsilon. To analyze the effect of cPKC activation level on positive selection, we used thymocytes from TCR transgenic mice with nonselecting and RAG-2 -/- backgrounds as they were developmentally arrested at the CD4+ CD8+ stage without positive selection signals. These thymocytes survived and acquired CD4/CD8 lineage commitment in suspension culture upon transient stimulation with limited concentrations of the selective activator of cPKC-alpha and -beta, thymeleatoxin, and the calcium ionophore, ionomycin. However, neither 12-deoxyphorbol 13-phenylacetate 20-acetate, which selectively activates cPKC-beta, nor ingenol 3,20-dibenzoate, which selectively activates nPKC-epsilon, exerted such an effect. The thymeleatoxin/ionomycin concentrations corresponded to those that inhibit glucocorticoid-induced apoptosis in thymocytes and were lower than those that induce proliferation of mature T cells. The CD4 lineage commitment required a higher level of cPKC activity than the CD8 lineage commitment. CD8alpha or CD4 mRNA expression was down-regulated. Functional helper and killer T cells were induced from the CD4 and CD8 lineage-committed cells, respectively, by additional stimulation. These results suggest that thymocyte lineage commitment in positive selection is regulated by the level of cPKC-alpha activity or by the levels of cPKC-alpha and -beta activities.

Regulation of thymocyte lineage commitment by the level of classical protein kinase C activity

Thymocyte-positive selection involves signaling through TCR and accessory molecules, and the signaling intensity appears to be critical for this event. The specific inhibitor of classical Ca2+-dependent protein kinase C (cPKC), Gö 6976, inhibited positive selection in fetal thymus organ culture, indicating that cPKC activation is essential for positive selection. The major protein kinase C isoforms in CD4+ CD8+ thymocytes are cPKC-alpha, cPKC-beta, and the novel Ca2+-independent protein kinase C, nPKC-epsilon. To analyze the effect of cPKC activation level on positive selection, we used thymocytes from TCR transgenic mice with nonselecting and RAG-2 -/- backgrounds as they were developmentally arrested at the CD4+ CD8+ stage without positive selection signals. These thymocytes survived and acquired CD4/CD8 lineage commitment in suspension culture upon transient stimulation with limited concentrations of the selective activator of cPKC-alpha and -beta, thymeleatoxin, and the calcium ionophore, ionomycin. However, neither 12-deoxyphorbol 13-phenylacetate 20-acetate, which selectively activates cPKC-beta, nor ingenol 3,20-dibenzoate, which selectively activates nPKC-epsilon, exerted such an effect. The thymeleatoxin/ionomycin concentrations corresponded to those that inhibit glucocorticoid-induced apoptosis in thymocytes and were lower than those that induce proliferation of mature T cells. The CD4 lineage commitment required a higher level of cPKC activity than the CD8 lineage commitment. CD8alpha or CD4 mRNA expression was down-regulated. Functional helper and killer T cells were induced from the CD4 and CD8 lineage-committed cells, respectively, by additional stimulation. These results suggest that thymocyte lineage commitment in positive selection is regulated by the level of cPKC-alpha activity or by the levels of cPKC-alpha and -beta activities.

A hybrid carcinoma: adenoid cystic carcinoma and salivary duct carcinoma of the salivary gland. An immunohistochemical study

Hybrid tumours of the salivary glands are very rare entities composed of two different tumours, each of which conforms with an exactly defined category. We describe an unusual hybrid carcinoma of the palate; it was comprised of an adenoid cystic carcinoma and a salivary duct carcinoma with a transitional region. These two different compartments showed different characteristics as regards cellular differentiation, proliferative activity, and expression of oncogene and tumour suppressor oncogene proteins, as revealed by using markers for muscle actin, keratin, vimentin, S-100 protein, GFAP, Ki-67, p53, and c-erbB-2 proteins. This case is the first reported with overexpression of p53 and c-erbB-2 proteins in the tumour entities. Salivary gland tumours consist of heterogeneous histological groups, and each has morphological diversity. This case indicates that some of the oncogene and tumour suppressor oncogene proteins may help to produce the histological heterogeneity of the salivary gland tumour.

Increased endothelial cell retraction and tumor cell invasion by soluble factors derived from pancreatic cancer cells

BACKGROUND

Tumor cells induce endothelial cell retraction before invasion. In pancreatic cancer cells, the factors affecting endothelial cell retraction are not well-understood.

METHODS

The activities of the endothelial cell retraction in conditioned media (CM) derived from three human pancreatic cancer cell lines, PSN-1, MiaPaca-2, and Capan-1, were measured for the amount of intercellular junctional transport of FITC dextran through an endothelial cell monolayer in a transwell cell culture system.

RESULTS

The CM derived from the three pancreatic cancer cells induced endothelial cell retraction. The endothelial cell retraction activity in the CM from PSN-1 cells was significantly higher than those from MiaPaca-2 and Capan-1 cells. The CM from PSN-1 cells enhanced both the adhesion and the invasion of MiaPaca-2 and Capan-1 cells. The factors with endothelial cell retraction activity in the CM from PSN-1 cells were characterized as heat-stable, trypsin-sensitive glycoproteins ranging from 10,000 to 50,000 in molecular weight, and were found both in heparin-bound and unbound fractions.

CONCLUSIONS

PSN-1 cells produced and secreted at least two factors inducing the endothelial cell retraction. The factors could play an important role in the establishment of invasion and metastasis of PSN-1 cells.

Characterization of stably transfected kidney epithelial cell line expressing rat H+/peptide cotransporter PEPT1: localization of PEPT1 and transport of beta-lactam antibiotics

We established stably transfected LLC-PK1 cells expressing the rat H+/peptide cotransporter PEPT1 (designated LLC-rPEPT1) and examined membrane localization and uptake by rat PEPT1 of oral beta-lactam antibiotics. The LLC-rPEPT1 cells expressed a novel PEPT1 protein with an apparent molecular mass of 75 kdaltons, which was found in rat intestinal membranes. The cell surface biotinylation of LLC-rPEPT1 cell monolayers grown on membrane filters showed that PEPT1 was localized predominantly on the apical membranes and, to a lesser extent, on the basolateral membranes. The amount of [14C]glycylsarcosine uptake in LLC-rPEPT1 cell monolayers was 3-fold greater from the apical, than from the basolateral side, which suggested that rat PEPT1 expressed on both membranes was functionally active. LLC-rPEPT1 cells grown on plastic dishes transported differently charged oral cephalosporins such as ceftibuten (divalent anion lacking an alpha-amino group) and cephradine (zwitterion with an alpha-amino group) in the presence of an inward H+ gradient, whereas those transfected with the vector alone did not have transport activity. Kinetic analysis revealed that the LLC-rPEPT1 cells had much higher affinity for ceftibuten than for cephradine. Di- and tripeptides and bestatin, a dipeptide-like antineoplastic drug, potently inhibited the uptake of these cephalosporins. These results suggest that the LLC-rPEPT1 cells serve as a useful model with which to analyze the mechanisms involved in membrane targeting and substrate recognition by rat PEPT1.

Surgical management of gastric leiomyosarcoma: evaluation of the propriety of laparoscopic wedge resection

Laparoscopic surgery has been applied to malignant gastric tumors. To evaluate the propriety of laparoscopic wedge resection for gastric leiomyosarcoma it is necessary to question whether lymph node dissection is necessary for the surgical management of gastric leiomyosarcoma. A retrospective study on open surgery cases of gastric leiomyosarcoma was performed to address this issue. The clinical records of 28 patients with gastric leiomyosarcoma who had had surgery were examined. The patients who underwent open surgery were divided into a systematic lymph node dissection (SLND) group (n = 9) and a nondissection (non-D) group (n = 19). No patient had lymph node metastasis at the time of operation or recurrence, and statistical analysis showed no difference between the SLND and non-D groups in terms of survival rates. These data suggest that SLND might not be necessary for the surgical management of gastric leiomyosarcoma and that laparoscopic wedge resection of the stomach can be considered a first-line treatment for gastric leiomyosarcoma.

Detection of human papillomavirus infection in squamous tumours of the conjunctiva and lacrimal sac by immunohistochemistry, in situ hybridisation, and polymerase chain reaction

BACKGROUND

Squamous tumours of the ocular surface, including the lacrimal pathway, range from benign lesions to invasive carcinomas. Some of these tumours are associated with human papillomavirus (HPV) infection, with the types of HPV differing among papillomas and dysplastic or malignant lesions.

METHODS

The relation between squamous tumours of the conjunctiva and lacrimal sac and HPV infection was investigated in 17 individuals with such tumours. Nine of the 17 tumours were benign, four were dysplastic lesions, and four were carcinomas.

RESULTS

Eight specimens showed positive immunohistochemical staining with antibodies to HPV; four of these eight were papillomas, three were dysplastic lesions, and one was a carcinoma. Koilocytosis was detected in seven of these eight tumours. Five of the eight specimens positive for immunohistochemical staining were also positive for HPV DNA by in situ hybridisation, and all eight were positive for HPV DNA by the polymerase chain reaction (PCR) method.

CONCLUSION

Approximately 50% of squamous tumours of the ocular surface and lacrimal sac were associated with HPV infection. This is the first report, to our knowledge, of the detection of HPV in the field of ophthalmology by a combination of immunohistochemistry, in situ hybridisation, and PCR.

[The use of high resolution MR imaging for pre-treatment evaluation of breast cancer: detection of intraductal spread]

Thirty-two patients were examined in order to evaluate the role of high-resolution MRI in the treatment planning of breast cancer. A 1.5T Signa imager (GE Medical Systems) was used with dedicated receive-only breast coil. The pulse sequence based on RARE was used with the fat-suppression technique. After examining both breasts with larger FOV (30 cm), the affected breast alone was examined with smaller FOV (18 cm) and larger matrix (512 x 384) with Gd enhancement. Breast cancer showed more prominent and earlier enhancement compared with normal breast tissue. Linear or spotty continuous enhancement from the main tumor was considered to be suggestive of intraductal spread. Of 32 patients, 20 showed linear or spotty enhancement around the main tumor on MRI, and 15 of these 20 had intraductal spread. On the other hand, 12 out of 32 patients were considered to have little intraductal spread on MRI, and these findings corresponded to the pathological findings. Sensitivity, specificity and accuracy of detecting intraductal spread were 88%, 75% and 78%, respectively. In order to evaluate the extent of intraductal spread, further study using more precise correlation with pathology is necessary. High-resolution MRI was also considered to be useful for evaluating the presence of multifocal or multicentric focies or muscle invasion.