Biochemical properties of human oral polymorphonuclear leukocytes

Polymorphonuclear leukocytes (PMN) isolated from the oral cavity of healthy human volunteers, spontaneously generated superoxide, nitric oxide (NO) and other reactive oxygen species (ROS) which exhibited strong luminol chemiluminescence (LCL). To understand the physiological roles of oral PMN (OPMN), biochemical properties of the cells were analyzed. Biochemical analysis revealed that OPMN were already primed under physiological conditions. Western blot analysis revealed that they strongly expressed the inducible type of NO synthase (NOS II) and exhibited the activity to catalyze tyrosine phosphorylation of various proteins including a 115 kDa protein (cbl product). OPMN also generated H2O2 and .OH by some superoxide dismutase (SOD)-sensitive mechanism and released myeloperoxidase (MPO). Kinetic analysis using specific inhibitors revealed that OCl- generated by OPMN was predominantly responsible for the enhanced LCL. During the incubation under standard culture conditions, OPMN underwent apoptosis which proceeded more rapidly than that of the circulating PMN (CPMN). Immunochemical analysis revealed that expression of apoptosis-related gene products, such as Bcl-2, Bcl-xL and Bax, was below detectable levels with both cell types. However, caspase-3 but not caspase-1 was markedly activated in OPMN. These results indicate that the primed OPMN spontaneously generate ROS and play an important role in the defense mechanism in the oral cavity and that the generated ROS activate caspase-3 thereby inducing apoptosis of the cells.

Studies of postoperative transarterial infusion chemotherapy for liver metastasis of colorectal carcinoma after hepatectomy

BACKGROUND/AIMS

The aim of this study was to evaluate the efficacy of postoperative transarterial infusion chemotherapy (PTIC) for the prevention of metastatic liver cancer recurrence after hepatectomy following curative surgery for colorectal carcinoma.

METHODOLOGY

Thirty-eight patients who underwent curative hepatectomy for metastatic liver cancer from colorectal carcinoma were studied. Ten out of the 38 patients received PTIC (experimental group) and 28 patients did not receive chemotherapy (control group). PTIC was performed with an intrahepatic indwelling catheter, which was set-up for 3 weeks and repeated 3 times in two monthly intervals.

RESULTS

In the control group, no significant differences were observed in the survival between patients with a single hepatic nodule and those with multiple hepatic nodules. Between patients with hepatic tumors of more than 3 cm in diameter and those with tumors less than 3 cm, and between patients with tumors located at H1 and H2, no significant differences were seen, either. However, the 5-year survival rate of the patients with metachronous liver metastases was 90% which was significantly better than for those patients with synchronous liver tumors (p < 0.05). The 100% of 3- and 100% of 4-year survival rates of the experimental group were significantly better than the 60% and 47% respectively of the control group (p < 0.05). The non-recurrence rate in the remnant liver was also significantly better in the experimental group than that in the control group (p < 0.01). The adverse effect of this protocol was negligible.

CONCLUSION

We conclude that PTIC improved the survival and non-recurrence rate in the remnant liver of the patients with liver metastases from colorectal cancer after hepatectomy, and was considered to be safe and an important protective factor for the prevention of recurrence of liver metastases after hepatectomy.

Relationship between extraosseous accumulation in bone scintigraphy with 99Tcm-HMDP and histopathology

We assessed the relationship between 99Tcm-HMDP extraosseous accumulation (EOA), the histopathology of primary lesions and various laboratory findings. In 155 of 4824 patients, 163 EOA were noted. Of these, 33.7% were in the abdomen, 27.6% in the chest, 22.7% in the extremities, 9.8% in the pelvic area and 6.1% in the head and neck area. We found that 72.4% of EOA were due to malignant processes and 27.6% to benign processes. In the abdomen, 36.6% of the EOA were due to hepatocellular carcinoma and intestinal carcinoma. In the chest, 46.7% of EOA were a result of breast carcinoma. In the extremities, 28.7% of the EOA were due to sarcoma. The mean white blood cell count was elevated (8.0 +/- 6.3 x 10(3)) in patients with malignant processes. The mean serum haemoglobin and haematocrit in benign and malignant processes, for both males and females, were below normal values. All other laboratory findings were within normal limits. Significant differences in serum haemoglobin and haematocrit were noted between male and female patients with benign processes (P = 0.04 and P = 0.04, respectively). No other significant differences between benign and malignant processes were noted. Therefore, EOA is more frequently associated with malignant processes of primary lesions and is often accompanied by leukocytosis and anaemia.

[Evaluation of brain tumor by 99mTc-MIBI: comparison study with 201Tl and predictivity of therapeutic effect]

We compared the detectability of 99mTc-MIBI and 201Tl-chloride for brain tumor in relationship with histopathology. We also evaluated correlation between therapeutic effect using ACNU, Cisplatine and the degree of MIBI tumor uptake. The subjects were 31 brain tumor histologically confirmed by operation or biopsy. Dual-isotope SPECT technique was performed at both 20 min and 180 min after tracer injection. A tumor to normal lung ratio on both early (ER) and delayed image (DR) and retention index (RI) were calculated. The positive rates of 99mTc-MIBI (90.3% and 77.4%) were comparable to that of 201Tl (90.3% and 80.6%). In the relationship with histopathology, both MIBI and Tl accumulated in 100% of glioblastoma (GBM), metastasis (meta), anaplastic astrocytoma and 25% of low grade astrocytoma on both early and delayed images. On semiquantitative analysis, there were no statistical significance among GBM, meta and anaplastic astrocytoma of ER, DR, RI in the both radiopharmaceuticals. However, both ER and DR in GBM tended to be higher than those of anaplastic astrocytoma. In spite of intense MIBI uptake, GBM patients died within six months except one patient. We concluded that MIBI can be helpful in detecting brain tumor as Tl. MIBI also might be useful in estimating the degree of malignancy in glioma. However, intense MIBI uptake did not mean favorable therapeutic effect in patients with GBM treated with ACNU and Cisplatine.

Activation of beta1 integrin signaling stimulates tyrosine phosphorylation of p190RhoGAP and membrane-protrusive activities at invadopodia

The ligation of available alpha6beta1 integrin in adherent LOX melanoma cells by laminin G peptides and integrin stimulatory antibodies induced cell invasiveness, independent of adhesion activity of integrins that were pre-bound to extracellular matrix (Nakahara, H., Nomizu, M., Akiyama, S. K., Yamada, Y., Yeh, Y., and Chen, W.-T. (1996) J. Biol. Chem. 271, 27221-27224). Here, we show that this induced invasion involves an increase in tyrosine phosphorylation of a 190-kDa GTPase-activating protein for Rho family members (p190(RhoGAP); p190) and membrane-protrusive activities at invadopodia. This tyrosine phosphorylation does not occur when the adherent cells are treated with non-activating antibody against beta1 integrin, control laminin peptides, or tyrosine kinase inhibitors genistein and herbimycin A. Although p190 and F-actin co-distribute in all cell cortex extensions, tyrosine-phosphorylated proteins including p190 appear to associate with F-actin specifically in invadopodia. In addition, the localized matrix degradation and membrane-protrusive activities were blocked by treatment of LOX cells with tyrosine kinase inhibitors as well as microinjection of antibodies directed against p190 but not by non-perturbing antibodies or control buffers. We suggest that activation of the alpha6beta1 integrin signaling regulates the tyrosine phosphorylation state of p190 which in turn connects downstream signaling pathways through Rho family GTPases to actin cytoskeleton in invadopodia, thus promoting membrane-protrusive and degradative activities necessary for cell invasion.

Theophylline suppresses the release of interleukin-4 by peripheral blood mononuclear cells

To elucidate the mechanism of the anti-inflammatory effect of theophylline, peripheral blood mononuclear cells (PBMCs) collected from patients with bronchial asthma who had a RAST score for Dermatophagoides farinae (Df) > = 3 were stimulated with Df antigen, and the interleukin-4 (IL-4) production by the stimulated PBMCs was determined in the presence and absence of theophylline. The stimulated IL-4 production in the PBMCs was significantly suppressed by simultaneous treatment with theophylline (8 microg/ml). Furthermore, the intracellular 3',5'-adenosine monophosphate (cAMP) level following stimulation with Df was significantly higher in PBMCs simultaneously treated with theophylline (8 microg/ml) than in nontreated controls. These results suggest that theophylline suppresses the IL-4 production in inflammatory cells by increasing the intracellular cAMP level; this effect may thus provide an additional basis for the benefit of theophylline in antiasthmatic therapy.

Mitochondrial dysfunction in the senescence accelerated mouse (SAM)

Oxidative damage to DNA, proteins, and lipids in mitochondria caused by free radicals may be one factor in aging. Oxidative phosphorylation was estimated in liver mitochondria from senescence accelerated mice (SAMP8) and a senescence resistant substrain (SAMR1). The respiratory control ratio decreased in liver mitochondria of SAMP8 during aging, and it was estimated that at 18 months of age this respiratory control value suggested that it might be insufficient to provide ATP synthesis necessary for normal cell metabolism. In addition, the ADP/O, an index of efficiency of ATP synthesis, was depressed at 18 months of age. Dinitrophenol-dependent uncoupled respiration in liver mitochondria of SAMP8 mice was markedly decreased with aging, suggesting a dysfunctional energy transfer mechanism in mitochondria of aged SAMP8 mice. Active uptake of calcium in liver mitochondria was markedly dysfunctional in SAMP8 mice with aging, and uncoupling of respiration was induced more easily in aged mitochondria. Milder effects on these functional parameters were observed in SAMR1 mice. A similar dysfunction was also observed in heart mitochondria of SAMP8 mice at 12 months of age. The amount of Bcl-x in liver mitochondria was slightly decreased in SAMP8. We suggest that these changes in mitochondrial function may be related to the shorter life span of the senescence accelerated mouse.

Near-saddle-node bifurcation behavior as dynamics in working memory for goal-directed behavior

In consideration of working memory as a means for goal-directed behavior in nonstationary environments, we argue that the dynamics of working memory should satisfy two opposing demands: long-term maintenance and quick transition. These two characteristics are contradictory within the linear domain. We propose the near-saddle-node bifurcation behavior of a sigmoidal unit with a self-connection as a candidate of the dynamical mechanism that satisfies both of these demands. It is shown in evolutionary programming experiments that the near-saddle-node bifurcation behavior can be found in recurrent networks optimized for a task that requires efficient use of working memory. The results suggests that the near-saddle-node bifurcation behavior may be a functional necessity for survival in nonstationary environments.

Monolayer Assemblies and Optical Properties of Europium(III) Complexes with beta-Diketones Containing Various Substituents

Europium(III) complexes with beta-diketones containing various substituents were newly synthesized and their monolayer behaviors on the water surface were studied in situ by a Brewster angle microscopy (BAM) together with surface pressure-area isotherms. Some BAM images look like a thin soap film on the flat surface, consisting of gas and liquid phases. The monolayer assemblies of these complexes could be deposited by both LB and horizontal lifting techniques. The emission probability from the excited singlet state 5D1 increased in the film as compared to the lowest excited state 5D0, and the symmetrically forbidden transition 5D0-->7F0 was enhanced in comparison with those in the solutions and the crystallines. This effect on the fluorescence was observed significantly for the complex with an asymmetrically substituted ligand rather than that with a symmetrically substituted one. These results can be ascribed to the fact that the thermal deactivation of the higher excited state is decreased and also the symmetries of these complexes are slightly distored in the monolayer assemblies. Copyright 1997 Academic Press. Copyright 1997Academic Press

[123I-MIBG lung uptake in patients with diabetes mellitus]

The purpose of this study is to clarify the relationship between 123I-MIBG lung uptake and silent myocardial ischemia (SMI), cardiac autonomic neuropathy (AN) or clinical characteristics. For the quantitative analysis, lung to upper mediastinum uptake ratio (L/M) and heart to upper mediastinum uptake ratio (H/M) were obtained from chest planar image. In addition, both lung washout ratio (%WR-L) and heart washout ratio (%WR-H) were calculated from early and delayed images. Each indices were compared in both diabetic and control groups. Mean values of H/M in diabetes with complication were significantly lower than those of control group. Particularly, AN(+)SMI(+) group showed lowest value. Similarly, mean values of %WR-H in diabetes with complication were significantly higher than those of control group and AN(+)SMI(+) group showed highest value. Although mean value of L/M in each diabetic group was significantly higher than that of control group, there was no statistical significance among each diabetes except AN(+)SMI(-) group on early image. Mean value of %WR-L in AN(+) or SMI(+) group was also significantly higher than that of control group, but there was no statistical significance among each diabetic group. The current study suggested that high pulmonary 123I-MIBG uptake in diabetes was independent of the complication of SMI or AN. Pulmonary endothelial dysfunction related with severity of diabetes mellitus was considered to be the most important factor.

Acetazolamide challenge and technetium-99m-ECD versus iodine-123-IMP SPECT in chronic occlusive cerebrovascular disease

We compared the acetazolamide challenge test using 99mTc-ECD SPECT and 123I-IMP SPECT images in patients with chronic occlusive cerebrovascular disease. We also evaluated the usefulness of linearization correction for acetazolamide challenge test of 99mTc-ECD SPECT.

METHODS

Twenty patients with unilateral chronic occlusive cerebrovascular disease (10 patients had middle cerebral arterial lesion and 10 had internal carotid lesion) were included in the study. Split-dose (a dose fractioning was 1:2), and sequential SPECT technique was used for 99mTc-ECD SPECT studies while only acetazolamide challenge test studies for 123I-IMP SPECT were performed. Permeability surface area product model (PS model) and back-diffusion model (Lassen's correction) were used for linearization correction of acetazolamide challenge with 99mTc-ECD SPECT.

RESULTS

Six of 16 patients with reduced vasodilatory capacity in 123I-IMP SPECT were underestimated by 99mTc-ECD SPECT acetazolamide challenge test. Relative ECD uptake normalized by cerebellar uptake compared with IMP uptake showed a nonlinear relationship, indicating relatively less uptake in high flow range. The underestimations of limited vasodilatory capacity observed in 99mTc-ECD SPECT without linearization correction was modified by linearization algorithm. However, the effect of correction based on PS model was superior than that of Lassen's correction. The corrected 99mTc-ECD uptake ratio, based on PS model, and IMP uptake ratio demonstrated a better linear relationship than that of Lassen's correction.

CONCLUSION

Technetium-99m ECD SPECT corrected based on the PS model is a better method of linearization for evaluating cerebrovascular reserve using acetazolamide challenge.

Behavior of carbonate and magnesium ions in the initial crystallites at the early developmental stages of the rat calvaria

Analysis of the contents of calcium (Ca), magnesium (Mg), phosphate, and carbonate ions in the mineral phase of rat calvaria specimens obtained at different developmental stages indicated that the mineral at the newborn stage contained a negligible amount of carbonate, but a high content of Mg. There was no significant difference in Ca and phosphate (as PO4) contents between the newborn material and that from later stages. A relatively large amount of carbonate was detected in the calvaria from 6-day-old rats, in which only immature crystals were observed, thus indicating the beginning of apatite formation. Furthermore, using laser Raman microprobe analysis we confirmed that the Raman peak at 1120 cm-1 band, indicative of a Mg-CO3 compound, appeared at the 6-day stage. We also observed that the Raman peak at 988 cm-1 found in the samples from the newborn seemed to have shifted to 963-962 cm-1 in the case of those obtained from 6-day-old rats, a shift which suggests the conversion from the non-apatitic to the apatitic form. These results indicate that carbonate ions might facilitate the initiation of crystal development by converting the inhibitory Mg ion into its inactive form (Mg-carbonate compound).

Transmembrane/cytoplasmic domain-mediated membrane type 1-matrix metalloprotease docking to invadopodia is required for cell invasion

The invasion of human malignant melanoma cells into the extracellular matrix (ECM) involves the accumulation of proteases at sites of ECM degradation where activation of matrix metalloproteases (MMP) occurs. Here, we show that when membrane type 1 MMP (MT-MMP) was overexpressed in RPMI7951 human melanoma cells, the cells made contact with the ECM, activated soluble and ECM-bound MMP-2, and degraded and invaded the ECM. Further experiments demonstrated the importance of localization of the MT-MMP to invadopodia. Overexpression of MT-MMP without invadopodial localization caused activation of soluble MMP-2, but did not facilitate ECM degradation or cell invasiveness. Up-regulation of endogenous MT-MMP with concanavalin A caused activation of MMP-2. However, concanavalin A treatment prevented invadopodial localization of MT-MMP and ECM degradation. Neither a truncated MT-MMP mutant lacking transmembrane (TM) and cytoplasmic domains (DeltaTMMT-MMP), nor a chimeric MT-MMP containing the interleukin 2 receptor alpha chain (IL-2R) TM and cytoplasmic domains (DeltaTMMT-MMP/TMIL-2R) were localized to invadopodia or exhibited ECM degradation. Furthermore, a chimera of the TM/cytoplasmic domain of MT-MMP (TMMT-MMP) with tissue inhibitor of MMP 1 (TIMP-1/TMMT-MMP) directed the TIMP-1 molecule to invadopodia. Thus, the MT-MMP TM/cytoplasmic domain mediates the spatial organization of MT-MMP into invadopodia and subsequent degradation of the ECM.

[Evaluation of primary lung cancer and mediastinal lymph node metastasis using 99mTc-MIBI: comparison with 201T1 and relation to chemotherapeutic effect]

We compared the detectability of 99mTc-MIBI and 201T1-chloride for primary lung cancer and mediastinal lymph node metastasis. We also analyzed the relationship between 99mTc-MIBI uptake and effectiveness of chemotherapy in patients with small cell lung cancer. The subjects were fourty-six primary lesions and 8 mediastinal metastatic lymph nodes confirmed by operation, and dual-isotope SPECT technique was performed at both 20 min and 180 min after tracer injection. A tumor to normal lung ratio on both early (ER) and delayed image (DR) and retention index (RI) were calculated. The positive rates of 99mTc-MIBI (early; 82.6%, delayed; 54.3%) were comparable to 201T1 in most primary tumor (87.0% and 84.8%). Whereas tumor smaller than 3 cm diameter was poorly visualized on both 99mTc-MIBI (25% and 0%) and 201T1 (37.5% and 37.5%). Detectabilities of metastatic mediastinal lymph nodes of 99mTc-MIBI (62.5% and 25.0%) was comparable to those of 201T1 (62.5% and 50.0%). Regarding effectiveness of chemotherapy, NC group showed lower uptake of 99mTc-MIBI and significant lower value of RI compared to PR group. We concluded that early image of 99mTc-MIBI SPECT can be helpful in detecting primary lung cancer and metastatic mediastinal lymph node. Additionary, it might be useful for predicting the effects of chemotherapy in small cell lung cancer.

Simple technique for pancreatogastrostomy and the histological findings of pancreatogastric anastomosis

The leakage of pancreatic juice is the most serious complication after pancreatoduodenectomy. In an attempt to lessen the incidence of this complication, we have developed a simple technique for the anastomosis of pancreatogastrostomy. Since March 14, 1995, we have already performed surgical procedures on 8 cases of pancreatogastrostomy using this technique and as yet have never experienced fatal complications. We report the autopsy findings of pancreatogastric anastomosis histologically. The specimen taken from the anastomosis reveals good mucosal continuity. This result suggests the importance of reliable sutures between the pancreatic parenchyma and the full thickness of the gastric wall for the anastomosis of pancreatogastrostomy.

Gadolinium-enhanced MR imaging of thyroid and parathyroid masses

PURPOSE

To evaluate spin-echo and contrast material-enhanced dynamic magnetic resonance (MR) imaging in characterization of thyroid and parathyroid masses.

MATERIALS AND METHODS

Conventional T1- and T2-weighted, gadolinium-enhanced dynamic, and gadolinium-enhanced T1-weighted spin-echo imaging sequences were performed in 85 patients with thyroid and parathyroid tumors. Findings from spin-echo imaging and dynamic curve patterns from mean signal intensity ratios were evaluated for each histologic tumor type.

RESULTS

T1- and T2-weighted imaging did not enable differentiation of benign from malignant tumors. Primary thyroid lymphoma enhanced less than other solid thyroid tumors, and parathyroid adenoma also enhanced less than other tumors (P < .05 compared with papillary carcinoma.

CONCLUSION

Gadolinium-enhanced MR imaging cannot enable prediction of histologic type in thyroid and parathyroid tumors. However, in cases of multiple tumors, the technique may improve the contrast between the different histologic types and sometimes suggest the diagnosis of primary thyroid lymphoma or parathyroid adenoma.

No suppression of respiratory function of mitochondrial isolated from the hearts of anesthetized rats with high-dose pentobarbital sodium

Pentobarbital sodium is a widely used anesthetic for animal experiments. We have already reported that a high dose of pentobarbital sodium (100 mg/kg i.p., twice the usual anesthetic dose) depresses myocardial mechanoenergetics in the canine heart. Furthermore, it has been reported that a high concentration of pentobarbital sodium inhibits myocardial contractility and mitochondrial electron transport and energy transfer. Therefore, we were afraid that the mitochondrial respiratory function would be impaired by pentobarbital anesthesia and that pentobarbital sodium would be an inappropriate anesthetic for cardiac mechanoenergetic studies. In this study, we investigated the respiratory function of mitochondria isolated from the hearts of anesthetized rats with high-dose pentobarbital sodium. We examined the mitochondrial respiratory function by the ADP/O ratio, respiratory control index (RCI), oxygen consumption rate in state III (State III O2) by oximetry, and membrane potential using a fluorescent dye, 3,3'-dipropylthiodicarbocyanine iodide (diS-C3-(5). The ADP/O ratio, RCI, and State III O2 values and changes in membrane potential induced by various respiratory substances were not significantly different between the rats with and without anesthesia. These results indicate that the respiratory function is not suppressed in the isolated myocardial mitochondria of rat hearts after high-dose pentobarbital anesthesia, although the pentobarbital sodium blood concentration was of the same order as that which exerts mitochondrial uncoupling in rat isolated mitochondrial preparation. Therefore, pentobarbital sodium anesthesia up to 100 mg/kg i.p. is applicable for mechanoenergetic studies of excised rat hearts, at least from the energetic aspect.

[Usefulness of rCBF SPECT in patients with encephalitis: comparison study with MRI]

Twenty-nine rCBF SPECT study was done in 17 patients with encephalitis. Five of 6 patients (83.3%) showed regional high uptake in acute phase within a week after onset and 16 of 23 studies (69.6%) showed regional low uptake in subacute and chronic phase. Six of 19 lesions (31.6%) with regional high uptake changed to low uptake and 11 lesions (57.9%) improved to normal uptake on follow up studies. Seventeen of 51 lesions with low uptake (33.3%) improved to normal uptake. On the comparative study with MRI, 8 of 18 (44.4%) high uptake area showed cortical thickness or high intensity on T2 weighted images. Thirty-six of 74 low uptake area (48.6%) showed cortical thickness, brain atrophy or high intensity on T2 weighted images. Forty-eight of 212 regions (22.6%) with normal MRI findings showed abnormal accumulation of cerebral tracer on rCBF SPECT studies. rCBF SPECT was useful tool for diagnosis and follow up management in patients with encephalitis.

[A case of transient tic disorder with abnormal findings on 99mTc-HMPAO SPECT]

We report a case of transient tic disorder with abnormal findings on 99mTc-HMPAO SPECT. The patient was 5-year-old girl with vocal and motor tic. There was no evidence of structural abnormality on magnetic resonance imaging (MRI). Electroencephalogram (EEG) showed spikes and sharp waves on both frontal lobes and parietal lobes (left-side dominant). 99mTc-HMPAO SPECT demonstrated focal regions of hyperperfusion in the both frontal lobes, both parietal lobes and right temporal lobe corresponding to the abnormal findings detected by EEG. It also demonstrated an area of hyperperfusion in the right basal ganglia. It is suggested that 99mTc-HMPAO SPECT is useful for the diagnosis and the understanding of the clinical state of tic disorder.

A mechanism for regulation of melanoma invasion. Ligation of alpha6beta1 integrin by laminin G peptides

Invasion of LOX human melanoma cells involves extracellular matrix (ECM) degradation and formation of cell surface invadopodia. Here we show that the ligation of alpha6beta1 by two peptides derived from the COOH-terminal globular domain of laminin-1 alpha1 chain (laminin G peptides), designated AG-10 (NPWHSIYITRFG) and AG-32 (TWYKIAFQRNRK), and antibodies against alpha6 and beta1 integrins promoted invasiveness. AG-10 and AG-32 inhibited cell adhesion on laminin, and the antibodies blocked cell adhesion on immobilized AG-10 and AG-32, suggesting that the peptides interact primarily with alpha6beta1 integrin. These soluble peptides and integrin antibodies induced invasiveness by causing an 2-3-fold increase in ECM degradation and invadopodial activity independently of adhesion activity of integrins that were prebound to ECM. The induced ECM degradation and invasion was associated with an increased surface expression of the 170-kDa membrane-bound gelatinase, seprase, as well as its intense localization at invadopodia but not at focal adhesions. However, the total expression levels of seprase, gelatinase A and beta1 integrins were not altered. We suggest that laminin G peptides act on the alpha6beta1 integrin signaling of invasion by stimulating invadopodial activities, which is distinct from their direct effects on cell adhesion on immobilized ECM.

The use of 201Tl SPET to predict the response to radiotherapy in patients with head and neck cancer

Thallium-201 (201Tl) is widely used in the diagnosis of malignant tumours. However, its use in predicting the response to radiation therapy for head and neck cancer has not been established. Nineteen patients with histologically proven head and neck cancer were studied. 201Tl single photon emission tomographic (SPET) images were obtained 15 min (early) and 4 h (delayed) post-injection of the radionuclide. For a semi-quantitative assessment, regions of interest were drawn over the lesions and normal soft tissue. Lesion-to-normal tissue uptake ratios of 201Tl activity were measured from mean counts-per-voxel obtained on both the early and delayed scans, representing the early index (EI) and delayed index (DI) respectively. Subsequently, a retention index (RI) was calculated using the formula: RI = (DI - EI) x 100/(EI). The patients were classified into two groups according to the effect of radiotherapy: a partial response or complete response group (PR-CR group) and a no change group (NC group). In the analysis of primary lesions, both the delayed and retention indexes of the PR-CR group were significantly higher than those of the NC group. However, the early index was not significantly different between the two groups. In the metastatic lymph nodes, only the retention index was significantly different between the two groups. Our results demonstrate that 201Tl SPET and a 201Tl index can be used to predict the response to radiotherapy for primary head and neck cancer and lymph node metastases. The retention index is a useful parameter for estimating the effects of radiotherapy.