Double-phase helical CT of small renal parenchymal neoplasms: correlation with pathologic findings and tumor angiogenesis

PURPOSE

To correlate the enhancement pattern of double-phase helical computed tomography (CT) of small renal parenchymal neoplasms with pathologic findings and tumor angiogenesis, and evaluate whether the enhancement pattern would be useful in differentiating the histomorphologic types of small renal parenchymal neoplasms.

MATERIALS AND METHODS

Double-phase helical CT (5 mm slice) of the corticomedullary phase (CMP) and late nephrographic phase (NP) was performed in 40 surgically resected renal neoplasms <3.5 cm. The patterns of CT attenuation value and homogeneity were correlated with the subtypes of neoplasms, microvessel density, and the existence of intratumoral necrosis or hemorrhage.

RESULTS

Clear cell renal cell carcinomas (RCC) (n = 29) showed a peak attenuation value in the CMP of >100 HU [Hounsfield units]. Chromophobe cell RCC (n = 2) showed a peak attenuation value in the CMP of <100 HU. Papillary RCC (n = 5) showed a gradual enhancement with the attenuation value in the CMP of <100 HU. However oncocytomas (n = 2) and metanephric adenomas (n = 2) also showed patterns similar to these subtypes of RCC. The degree of enhancement in the CMP correlated with microvessel density (r = 0.87). All tumors with an homogeneous enhancement pattern did not show necrosis or hemorrhage on histologic specimen.

CONCLUSION

The enhancement pattern in double-phase helical CT was different among the subtypes of RCC, and correlated with microvessel density or the existence of intratumoral necrosis or hemorrhage. However it did not differentiate between RCC and other solid tumors.

The role of the sentinel lymph node in gastrointestinal cancer

Evaluation of the clinical significance of the sentinel node concept in GI cancer has just begun. The authors' preliminary data, using intraoperative radiation techniques and the gamma probe, suggest that it is worthwhile to continue the evaluation of this procedure to determine its role in an accurate staging and a minimally invasive approach to GI cancers.

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.

Radio-guided sentinel node detection for gastric cancer

BACKGROUND

Radio-guided detection of sentinel nodes (SNs) has been used to predict regional metastases in patients with malignant melanoma and breast cancer. However, the validity of the SN hypothesis is still controversial for gastrointestinal cancers including gastric cancer. The aim of this study was to test the feasibility and accuracy of radio-guided mapping of SNs for gastric cancer.

METHODS

Some 145 consecutive patients with gastric cancer diagnosed as T1 or T2 and evaluated clinically as N0 were enrolled. Endoscopic injection of technetium-99m-radiolabelled tin colloid was performed before operation and radioactive SNs were identified with a gamma probe. Standard radical gastrectomy with lymphadenectomy was performed in all patients and all resected nodes were evaluated by routine histopathological examination.

RESULTS

Using radio-guided methods, SNs were detected in 138 (95.2 per cent) of 145 patients. The SN was positive in 22 of 24 patients with lymph node metastasis. The incidence of metastasis in the SNs (7.8 per cent) was significantly higher than that in the non-SNs (0.3 per cent) (P < 0.01). The diagnostic accuracy according to SN status was 98.6 per cent (136 of 138).

CONCLUSION

Radio-guided SN mapping is an accurate diagnostic procedure for detecting lymph node metastasis in patients with early-stage gastric cancer.

Requirement for a noncoding RNA in Drosophila polar granules for germ cell establishment

In Drosophila embryos, germ cell formation is induced by specialized cytoplasm at the posterior of the egg, the pole plasm. Pole plasm contains polar granules, organelles in which maternally produced molecules required for germ cell formation are assembled. An untranslatable RNA, called Polar granule component (Pgc), was identified and found to be localized in polar granules. Most pole cells in embryos produced by transgenic females expressing antisense Pgc RNA failed to complete migration and to populate the embryonic gonads, and females that developed from these embryos often had agametic ovaries. These results support an essential role for Pgc RNA in germline development.

Induction of in vitro tumor cell invasion of cellular monolayers by lysophosphatidic acid or phospholipase D

Serum is known to be required for invasion or phagokinesis of certain tumor cells, although the mechanism of its action is not well understood yet. In the in vitro invasion assay system we have developed, MM1 cells exhibiting extensive invasiveness against cultured mesothelial cell monolayers in the presence of 10% fetal calf serum did not invade them without serum. Human small cell lung cancer (OC10) cells also required serum in invasion. Serum could be completely substituted by oleoyl-lysophosphatidic acid (LPA) or bacterial phospholipase D (PLD). Phosphatidic acid also had an invasion-inducing activity, though to a lesser degree. Since human ovarian cancer (RMUG-S) cells require neither serum, LPA nor the PLD for invasion of mesothelial cell monolayers, the production of phospholipid like LPA, a candidate for intracellular second messenger, in tumor cells seems critical for the invasion by MM1 cells or OC10 cells. This result suggests a possible participation of particular signaling cascade, PLD-LPA(PA) system, in the invasion of certain tumor cells.

Antibodies to beta 2-glycoprotein I and clinical manifestations in patients with systemic lupus erythematosus

OBJECTIVE

To investigate whether anticardiolipin antibodies (aCL) in patients with systemic lupus erythematosus (SLE) bind to beta 2-glycoprotein I (beta 2GPI), and to search for a relationship between the presence of IgG and/or IgM anti-beta 2GPI antibody and clinical manifestations in SLE patients.

METHODS

IgG and IgM anti-beta 2GPI in 308 Japanese SLE patients were measured using phospholipid-independent enzyme immunoassays. Relationships to clinical histories and to various laboratory data were examined.

RESULTS

The values of anti-beta 2GPI and aCL, as measured by conventional enzyme immunoassay, showed a strong correlation, but the anti-beta 2GPI assay was more useful in distinguishing beta 2GPI-dependent aCL from beta 2GPI-independent aCL. The presence of IgG anti-beta 2GPI was associated with an increased frequency of a history of thrombosis. Comparisons of various laboratory data suggested that the titer of anti-beta 2GPI may fluctuate with disease activity.

CONCLUSION

The results suggest that pathogenic aCL is directed against structurally altered beta 2GPI and that enzyme immunoassay for anti-beta 2GPI may prove useful in evaluating the risk of thrombosis and monitoring the clinical course in patients with SLE.

Interleukin 1 receptor blockade reduces tumor necrosis factor production, tissue injury, and mortality after hepatic ischemia-reperfusion in the rat

The inflammatory cytokines interleukin (IL) 1 and tumor necrosis factor (TNF) may play an important role in hepatic ischemia-reperfusion (I/R) injury. To study the role of IL-1 in hepatic I-R injury, we investigated the effect of pretreatment with IL-1 receptor antagonist (IL-1ra) on the production of IL-1, TNF, histological findings in the liver, and the survival rate for 7 days. Rats were subjected to 90 min of partial liver warm ischemia by clamping the vessels of the left and middle lobes. In the IL-1ra-treated group, IL-1ra was given 5 min before liver ischemia was induced. IL-1alpha and TNF levels were determined in blood and liver at 0, 30, 90, and 180 min after reperfusion. In a second experiment to determine the effect of IL-1ra pretreatment on survival rate, after 90 min of partial liver ischemia, the right lateral and caudate lobes were excised, leaving only the ischemic lobes. In both groups, IL-1alpha was undetectable in blood, but increased in liver tissue. TNF increased in both blood and liver tissue as reperfusion time increased. Histological evidence of tissue injury was minimal in the IL-1ra-treated group. Furthermore, in the IL-1ra-treated group, the production of TNF decreased in both blood and liver tissue compared with the nontreated group. Survival rates in the IL-1ra-treated and nontreated group were 80% and 30%, respectively. The data demonstrated that the production of IL-1 and TNF increases in hepatic I-R injury and that pretreatment with IL-1ra protects the liver from ischemic insult, indicating an important role for IL-1 in I-R injury.

Sensory mechanism of oxygen sensor FixL from Rhizobium meliloti: crystallographic, mutagenesis and resonance Raman spectroscopic studies

FixL of Rhizobium meliloti (RmFixL) is a sensor histidine kinase of the two-component system, which regulates the expression of the genes related to nitrogen fixation in the root nodule in response to the O(2) levels. The crystal structure of the sensor domain of FixL (RmFixLH), which contains a heme (Fe-porphyrin) as a sensing site, was determined at 1.4 A resolution. Based on the structural and spectroscopic analyses, we propose the O(2) sensing mechanism that differs from the case proposed in BjFixLH as follows; conformational changes in the F/G loop, which are induced by steric repulsion between the bent-bound O(2) and the Ile209 side-chain, would be transmitted to the histidine kinase domain. Interaction between the iron-bound O(2) and Ile209 was also observed in the resonance Raman spectra of RmFixLH as evidenced by the fact that the Fe-O(2) and Fe-CN stretching frequencies were shifted from 575 to 570 cm(-1) (Fe-O(2)), and 504 to 499 cm(-1), respectively, as the result of the replacement of Ile209 with an Ala residue. In the I209A mutant of RmFixL, the O(2) sensing activity was destroyed, thus confirming our proposed mechanism.

Inhibition of in vitro tumor cell invasion by ginsenoside Rg3

The effect of plant glycosides on tumor cell invasion was examined. Among the glycosides tested, ginsenoside Rg3 was found to be a potent inhibitor of invasion by rat ascites hepatoma cells (MM1), B16FE7 melanoma cells, human small cell lung carcinoma (OC10), and human pancreatic adenocarcinoma (PSN-1) cells, when examined in a cell monolayer invasion model. Structurally analogous ginsenosides, Rb2, 20(R)-ginsenoside Rg2 and 20(S)-ginsenoside Rg3 (a stereoisomer of Rg3), showed little inhibitory activity. Neither Rh1, Rh2, 20(R)-ginsenosides Rh1, Rb1, Rc nor Re had any effect. The effective ginsenoside, Rg3, tended to inhibit experimental pulmonary metastasis by highly metastatic mouse melanoma B16FE7 cells as well. Taking account of our previous finding that 1-oleoyl-lysophosphatidic add (LPA) induced invasion by MM1 cells in the monolayer invasion model, the effect of Rg3 on molecular events associated with the invasion induced by LPA was analyzed in order to understand the mechanism of the inhibition. Rg3, which suppressed the invasion induced by LPA, dose-dependently inhibited the LPA-triggered rise of intracellular Ca2+. Protein tyrosine phosphorylation triggered by LPA was not inhibited by Rg3.

Melatonin therapy for REM sleep behavior disorder

Rapid eye movement sleep behavior disorder (RBD) is a parasomnia with clinical symptoms that include punching, kicking, yelling and leaping out of bed in sleep. Polysomnographic (PSG) finding showed REM sleep without muscle atonia. Clonazepam is generally used for treating RBD symptoms but melatonin was reported to be effective so we reconfirmed the effect of melatonin on RBD patients in the present study. We used melatonin (3-9 mg/day) which could ameliorate problem sleep behaviors remarkably, as well as %tonic activity in PSG variables. In the present study, melatonin was reconfirmed to be effective in RBD symptoms, especially for patients with low melatonin secretion, while its mechanism was not clearly known in the present study.

Histopathologic and immunohistochemical study of malignant tumors of peripheral nerve sheath (malignant schwannoma)

Histologic and immunochemical analyses were performed on 38 cases and 33 cases of malignant tumors of the peripheral nerve sheath, respectively. The histologic features consisted of either closely packed or loosely arranged interlacing fascicles of slender spindle cells that showed a wavy pattern. Although no characteristic findings indicative of neurogenic differentiation could be confirmed with anti-S-100-protein, a fair number of positive cells were seen in the area where the tumor cells were loosely arranged and displayed a wavy pattern. When anti-neuron-specific enolase (NSE) and anti-neurofilament antibody (68K, 200K) were applied, they were found to be positive in cells differentiating to ganglion cells and in epithelial cells. Since S-100-protein-positive cells indicate a differentiation to Schwann cells and NSE-positive cells and neurofilament-positive cells to nerve cells, it was concluded that immunohistochemistry can serve as an effective supplementary method for the diagnosis of malignant tumors of the peripheral nerve sheath.

Risk-adapted pre-emptive therapy for cytomegalovirus disease in patients undergoing allogeneic bone marrow transplantation

We prospectively evaluated a risk-adapted pre-emptive treatment with ganciclovir for CMV diseases in patients undergoing allogeneic bone marrow transplantation (BMT). High-level CMV antigenemia (10 or more positive cells on two slides) or CMV antigenemia at any level in patients with grade II-IV acute graft-versus-host disease (aGVHD) were chosen as risk factors. We also retrospectively evaluated virus reactivation in plasma using quantitative real-time polymerase chain reaction (PCR). Fifty patients were evaluable. None of the 27 patients with or without grade I aGVHD developed high-level CMV antigenemia or CMV disease. Among the 23 patients with grade II-IV aGVHD, 12 patients (52%) developed CMV antigenemia and were treated pre-emptively, of whom two developed CMV gastroenteritis or retinitis in spite of therapy. Six of the remaining 11 patients developed CMV gastroenteritis before CMV antigenemia was detectable. All of the eight patients with CMV diseases were successfully treated with ganciclovir and no deaths directly related to CMV disease occurred. In four of the seven evaluable patients with CMV gastroenteritis, real-time PCR was able to detect virus reactivation earlier than CMV antigenemia. Although our risk-adapted pre-emptive therapy effectively reduced CMV-related mortality, further refinements of this approach, particularly in the prevention of CMV gastroenteritis, may be achieved by incorporating real-time PCR.

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.

Flavohemoglobin, a globin with a peroxidase-like catalytic site

Biochemical studies of flavohemoglobin (Hmp) from Escherichia coli suggest that instead of aerobic oxygen delivery, a dioxygenase converts NO to NO3(-) and anaerobically, an NO reductase converts NO to N(2)O. To investigate the structural features underlying the chemical reactivity of Hmp, we have measured the resonance Raman spectra of the ligand-free ferric and ferrous protein and the CO derivatives of the ferrous protein. At neutral pH, the ferric protein has a five-coordinate high-spin heme, similar to peroxidases. In the ferrous protein, a strong iron-histidine stretching mode is present at 244 cm(-1). This frequency is much higher than that of any other globin discovered to date, although it is comparable to those of peroxidases, suggesting that the proximal histidine has imidazolate character. In the CO derivative, an open and a closed conformation were detected. The distal environment of the closed conformation is very polar, where the heme-bound CO strongly interacts with the B10 Tyr and/or the E7 Gln. These data demonstrate that the active site structure of Hmp is very similar to that of peroxidases and is tailored to perform oxygen chemistry.

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.

Small solid renal lesions: usefulness of power Doppler US

PURPOSE

To evaluate whether the vascular pattern at power Doppler ultrasonography (US) improves diagnostic accuracy in small solid renal lesions over that at gray-scale US.

MATERIALS AND METHODS

Gray-scale and power Doppler US were performed prospectively in 64 small (1.5-3.0-cm-diameter) solid renal lesions (26 renal cell carcinomas [RCCs], 34 angiomyolipomas, two oncocytomas, two pseudotumors). At gray-scale US, echogenicity and homogeneity of the lesion, an anechoic rim, intratumoral cysts, shadowing, or a central scar were sought. At power Doppler US, the vascular distribution was divided into four patterns.

RESULTS

Findings at gray-scale US included an anechoic rim or intratumoral cysts in 20 of 26 RCCs (77%) and the two oncocytomas. Shadowing was seen in seven of 34 angiomyolipomas (21%). Echogenicity, homogeneity, and a central scar were not pathognomonic. At power Doppler US, pattern 3 (peripheral) or 4 (mixed penetrating and peripheral) was seen in all RCCs, seven of 34 angiomyolipomas, and the two oncocytomas. Pattern 1 (intratumoral focal) or 2 (penetrating) was seen in 27 angiomyolipomas. Pattern 1 or 2 was characteristic of angiomyolipoma. The rate of correct diagnosis was significantly increased with combined US (78%) as compared to that with gray-scale (42%) or power Doppler (45%) US alone.

CONCLUSION

The vascular distribution at power Doppler US could add important information to gray-scale US findings for differential diagnosis of small solid renal lesions.

Y-27632, an inhibitor of rho-associated protein kinase, suppresses tumor cell invasion via regulation of focal adhesion and focal adhesion kinase

Migration of rat ascites hepatoma (MM1) cells, invasion and phagokinetic movement were induced by the combination of lysophosphatidic acid (LPA) and fibronectin (FN). Induction of migratory activity was tightly correlated with morphological change of MM1 cells from spherical or polygonal-shaped cells to fusiform-shaped ones with pseudopodia. MM1 cells were mobile in a fusiform shape, whereas those of a spherical or polygonal shape were not. A small GTPase Rho and one of its downstream effectors ROCK (Rho-associated coiled-coil forming protein kinase), play essential roles in these processes, as evidenced by suppression of migration and morphological change of MM1 cells by Clostridium botulinum C3 exoenzyme, an inhibitor of Rho, or by Y-27632, an inhibitor of ROCK. Y-27632 also suppressed the formation of fusiform-shaped pseudopodia-carrying MM1 cells that was induced by stimulation with the combination of LPA and FN. LPA and FN also evoked the formation of focal adhesions and actin bundles, and tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin. The inhibitory effect of Y-27632 on LPA-induced migration and morphological change of MM1 cells was considered to be mediated, at least in part, by impaired formation of focal adhesions and actin bundles. Y-27632 suppressed LPA-induced tyrosine phosphorylation of FAK and paxillin, suggesting that ROCK regulates these molecules and Y-27632 inhibits cellular migration and morphological change, at least in part, through this regulation.

Paxillin alpha and Crk-associated substrate exert opposing effects on cell migration and contact inhibition of growth through tyrosine phosphorylation

Protein tyrosine phosphorylation accompanies and is essential for integrin signaling. We have shown that tyrosine phosphorylation of paxillin alpha and Crk-associated substrate (p130(Cas)) is a prominent event on integrin activation in normal murine mammary gland epithelial cells. Tyrosine phosphorylation of p130(Cas) has been demonstrated to facilitate cell migration. We show here that tyrosine phosphorylation of paxillin alpha acts to reduce haptotactic cell migrations as well as transcellular invasive activities in several different experimental cell systems, whereas tyrosine phosphorylation of p130(Cas) exerts opposing effects to those of paxillin alpha. Each of the phosphorylation-null mutants acts as a dominant negative for each phenotype. Moreover, we found that overexpression of paxillin alpha reduced the cell saturation density of normal murine mammary gland cells, whereas overexpression of p130(Cas) increased it. These effects also seemed to depend on tyrosine phosphorylation events. Cell growth rates and morphologies at growing phases were not significantly altered, nor were cells transformed. Addition of epidermal growth factor increased saturation density of the paxillin alpha-overexpressing cells, whereas no further increment was observed in p130(Cas)-overexpressing cells. We propose that tyrosine phosphorylation of paxillin alpha and p130(Cas) exerts opposing effects on several integrin-mediated cellular events, possibly through different signaling pathways.

Identification of the histidine residues involved in substrate recognition by a rat H+/peptide cotransporter, PEPT1

The LLC-PK1 cells stably transfected with a rat PEPT1 cDNA transported ceftibuten (anion) and cephradine (zwitterion), both oral beta-lactam antibiotics, in a H+-gradient-dependent manner. Diethylpyrocarbonate, a histidine residue modifier, abolished ceftibuten uptake. This inhibition was prevented in the presence of glycylsarcosine or cephradine. When expressed in Xenopus oocytes, replacement of either histidine 57 or histidine 121 of the rat PEPT1 with glutamine by site-directed mutagenesis eliminated ceftibuten and [14C]glycylsarcosine transport activities. Immunostaining of oocyte sections indicated that insertion of the mutant transporters in the plasma membranes was not impaired. These findings suggest that both histidine 57 and histidine 121, which are conserved in the rat, rabbit and human PEPT1, are involved in substrate recognition of this molecule.

Inhibition of tumor invasion and metastasis by a novel lysophosphatidic acid (cyclic LPA)

Fetal calf serum (FCS) and 1-oleoyl lysophosphatidic acid (LPA) were previously found to be potent inducers of invasion (transcellular migration) in an in vitro system. A novel LPA, composed of cyclic phosphate and cyclopropane-containing hexadecanoic acid (PHYLPA), first isolated from myxoamoebae of Physarum polycephalum, and its synthetic derivatives (cLPA) were tested for their ability to inhibit tumor cell invasion and metastasis. Amoung these, Pal-cLPA, which has a palmitoyl moiety, was most potent in inhibiting invasion, with 93.8% inhibition at the concentration of 25 microM. Invasion in vitro by mouse melanoma cells (B16), human pancreatic adenocarcinoma cells (PSN-1), human lung cancer cells (OC-10) and human fibrosarcoma cells (HT-1080) was also inhibited by Pal-cLPA. The stimulation of MMI cells with LPA triggered F-actin formation, which was impaired by the addition of Pal-cLPA at invasion-inhibitory concentration. Pal-cLPA induced a rapid increase in adenosine 3',5'-cyclic monophosphate (cAMP) concentration in MMI cells. The addition of dibutyryl cAMP significantly abrogated LPA-induced invasion by MM1 cells and actin polymerization in the cells. The inhibition of MM1 cell invasion by Pal-cLPA may be ascribed to an increased level of cAMP. Pal-cLPA also suppressed invasion in vitro by MM1 cells induced by FCS dose dependently, without affecting proliferation. It also suppressed the pulmonary metastasis of B16 mouse melanoma cells injected into the tail vein of C57BL/6 mice. Thus, Pal-cLPA is effective in inhibiting invasion and metastasis of a variety of tumor cells.

Small renal cell carcinoma: MRI with pathologic correlation

The MRI features of small renal cell carcinomas (RCCs) were retrospectively reviewed and correlated with histology in 24 patients. MRI features on both T1- and T2-weighted images were classified into hypointensity, isointensity, and hyperintensity. Each tumor was pathologically classified into four types: alveolar, papillary, tubular, and cystic. These findings were correlated with MR signal intensities. Alveolar tumors showed hypointensity to isointensity on T1-weighted image and isointensity to hyperintensity on T2-weighted image. In contrast, all papillary tumors showed hypointensity on T2-weighted image. Four of six tumors with hypointensity on T2-weighted image were caused by hemosiderin deposition, hemorrhage, and necrosis. However, there were two papillary RCCs that showed hypointensity on T2-weighted image despite no hemosiderin deposition and no hemorrhage. We conclude that papillary RCC is associated with T2-hypointense appearance as well as hemosiderin deposition, hemorrhage, and necrosis.

Overexpression of p16 INK4a as an indicator for human papillomavirus oncogenic activity in cervical squamous neoplasia

Overexpression of p16(INK4a) has been observed when retinoblastoma protein is inactivated by high-risk human papillomavirus (HPV) oncoprotein E7. We investigated overexpression of p16(INK4a) and HPV infection in cervical squamous neoplasia to evaluate the oncogenic potential among various HPV subtypes. The high-risk HPV was detected by PCR in 69.8% (37/53), 97.5% (39/40), 91.7% (44/48), and 100% (16/16) of cervical intraepithelial neoplasia (CIN)1, CIN2, CIN3, and squamous cell carcinoma (SCC), respectively. The p16(INK4a) overexpression was investigated immunohistochemically using a p16(INK4a)-specific monoclonal antibody (clone E6H4). In high-risk HPV positive cases, 32.4% (12/37) of CIN1, 82.1% (32/39) of CIN2, 93.2% (41/44) of CIN3, and all (16/16) SCC showed p16(INK4a) overexpression. The incidence of p16(INK4a) overexpression was significantly different between CIN1 and CIN2, suggesting that the disorder of cell cycle regulation by HPV frequently occurred from CIN2. As for CIN1 cases, p16(INK4a) overexpression was observed more frequently in HPV16 and HPV52 than in HPV51 and HPV35. Using p16(INK4a) as a bio marker of HPV oncogenic activity, we demonstrate that the level of pRb dysfunction by high-risk HPV varied from subtypes and was getting more frequent from CIN2.

Histogenesis of alveolar soft part sarcoma. An immunohistochemical and biochemical study

In order to clarify the histogenesis of alveolar soft part sarcoma (ASPS), an immunohistochemical and biochemical study was performed on three cases. The immunohistochemical study indicated the presence of actin, desmin, vimentin, and Z-protein in all cases. On the other hand, intermediate filaments other than desmin and vimentin were not detected immunohistochemically. The presence of desmin and Z-protein strongly suggests the myogenic character of this tumor. As to whether ASPS shows striated muscle differentiation or smooth muscle differentiation, the immunohistochemical absence of myoglobin in the three cases suggests that the tumor does not differentiate in the direction of striated muscle. However, biochemical assay of subunits of enolase revealed significantly high amounts of beta-enolase, which is known as a marker for striated muscle, in all three cases. The determined values--735, 426, and 584 ng/mg of protein --are indicative of striated muscle differentiation. In addition, the immunohistochemical study of all cases revealed the presence of beta-enolase in tumor cells. These data definitely show the myogenic character and rhabdomyoblastic differentiation of ASPS.