Formation of PCDDs and PCDFs during the combustion of polyvinylidene chloride

In laboratory-scale combustion of polyvinylidene chloride (PVDC) with a quartz tubular furnace designed and fabricated to provide the desired combustion temperature and mixing state of combustion gas with air, it was found that at 800 degrees C or higher the level of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans [corrected] (PCDDs/PCDFs) resulting from PVDC combustion was no higher than that from heating air alone, and thus far below the levels which resulted from PVDC combustion at 750 degrees C or lower. The results provide the first laboratory confirmation of the relation between PVDC incineration temperature and PCDD/PCDF formation, and of the primary importance of high temperature, turbulence for mixing between air and combustion gas, and sufficient residence time, as governing factors for the minimization of PCDD/PCDF formation in municipal solid waste incinerators.

[Sedative premedication is necessary for infants in anesthetic induction under the presence of mother]

We examined the necessity of sedative premedication for elective operation of childhood when induction was performed beside the mother. One hundred and nine patients (aged from 2 to 8 years) were assigned randomly to two groups; midazolam (0.5 mg.kg-1, orally, n = 56) was administered 45 min before induction in Group M, and vehicle was administered (n = 53) in Group C. The differences between the two groups about their calmness and behavior were investigated using double blind method, and analyzed according to their ages, as infants (2 to 4 years), kindergarteners (5 to 6 years) and school children (7 to 8 years). The significantly higher incidences of agitation or alertness were observed in infants of Group C (P < 0.05) and all other patients were calm and well sedated. We conclude that sedative premedication is necessary in infants even if induction is performed beside patient's mothers.

Inhibition of retinal guanylyl cyclase by the RGS9-1 N-terminus

Cyclic GMP plays a key role in retinal phototransduction and its photoreceptor concentration is precisely controlled by the cooperative action of cGMP phosphodiesterase (PDE) and retinal guanylyl cyclase (retGC). However, studies of the relationship between these two systems have focused only on a Ca(2+)-mediated, indirect connection. Using a retinal "regulator of G-protein signaling" (RGS9-1) and its fragments, we show that the N-terminus of RGS9-1 inhibits retGC activity. We also indicate that the GGL domain and/or the RGS domain function as an internal suppressor against the N-terminus, suggesting that proteins bound to these domains regulate the inhibitory activity of the N-terminus. Direct interaction of retGC with RGS9-1 and its N-terminus is also proved by immunoprecipitation and an overlay technique. Since RGS9-1 also controls the lifetime of transducin-activated PDE through regulating GTPase activity of transducin, this study strongly suggests that RGS9-1 mediates the direct interaction between PDE and retGC systems, and that this ingenious mechanism plays an important role in tuning of cGMP concentration in photoreceptors.

[A case of mediastinal esophago-bronchogenic cyst associated with high serum level of CA 19-9]

We report a case of mediastinal esophago-bronchogenic cyst in a patient with a high serum level of CA 19-9. A 49-year-old man presented with a complaint of dysphagia. Chest X-ray, CT, and MRI showed posterior mediastinal cystic shadow which was diagnosed preoperatively. The serum level of CA 19-9 was 158 U/ml. We underwent extirpation of the cyst through video-assisted thoracoscopic surgery (VATS) and confirmed to be a bronchogenic cyst histologically. The serum level of CA 19-9 returned to normal after the operation.

Localization of caveolin-1 in photoreceptor synaptic ribbons

PURPOSE

The purpose of this study is to determine whether caveolin-1 is a constituent of photoreceptor synaptic ribbons.

METHODS

Immunoblot assay and electron microscopic immunocytochemistry were used to localize caveolin-1 in synaptic ribbons.

RESULTS

Synaptic ribbons were localized close to the active site of presynaptic membranes and surrounded by a halo of synaptic vesicles. Immunosignals of caveolin-1 were clearly detected on the synaptic ribbons in rod and cone photoreceptors. However, the signal was seen neither on synaptic vesicles nor on presynaptic plasma membranes.

CONCLUSIONS

Caveolin-1 is a component protein of synaptic ribbons and may be involved in the regulation of transmitter release.

A simple objective parameter for perfusion study of renal transplant

We proposed a simple parameter, the kidney-to-aorta ratio (KAR), for evaluation of renal transplant perfusion. KAR was calculated from the peak counts of the kidney and the aorta. The calculated values were compared with the visual interpretation of the radionuclide first-pass flow study, percent renal uptake (%RU), and tubular extraction rate (TER) by Bubeck's one point sampling method in 37 studies. KAR correlated well with the visual interpretation of the flow study and the other quantitative parameters. Representative cases, which showed the usefulness of KAR for the objective assessment of the perfusion status of renal transplants, were presented. In conclusion, KAR is a simple and practically useful parameter for objective evaluation and follow-up of renal transplant perfusion.

Pretreatment apoptotic scores do not predict response to radiation therapy in oropharyngeal squamous cell carcinoma

The prognostic value of tumor apoptosis was studied in patients with oropharyngeal squamous cell carcinoma treated with radical radiotherapy. Forty-eight patients with oropharyngeal squamous cell carcinoma who received radical radiotherapy between 1990 and 1995 were enrolled in the study. The radiation treatment for all patients involved the administration of 65 Gy in 26 fractions over a 6.5-week period. The apoptotic index (AI; the apoptotic cell count per 1000 tumor cells ) was distributed from 0 to 10 with a median at 2 and a mode of 1. There was a significant linear correlation between the AI and mitotic index (MI) (r=0.393, 95% confidence interval: 0.129-0.605). The cause-specific 5-year survival for patients with AI greater than the median was 46% and for the counterpart was 41%. There was no difference in cause-specific survival between AI/MI greater than the median (50%) and AI/MI smaller than the median (36%). The number of patients was too small to draw definite conclusions, but the AI and the AI/MI before treatment were not shown to have a prognostic value for oropharyngeal squamous cell carcinoma in our study. The primary sites and treatment methods may influence the prognostic value of AI even for the same histological types.

[A case of primary lung cancer complicated with post-operative intractable pulmonary fistula]

The case was a 76-year-old male. After thoracoscopic left upper lobectomy against primary lung cancer with poor risks such as complication of systemic lupus erythematosus (SLE) and pulmonary emphysema, oral steroid treatment, heavy smoker, decreased renal function, the patient was complicated with intractable pulmonary fistula and MRSA pyothorax. Intracavitary administration of albumin preparation and fibrin glue (Beriplast P) was effective against pulmonary fistula though it was not helpful in the pleurodesis which was conducted 7 times. Teicoplanin (Targosid) was effective against MRSA pyothorax and maintained the renal function.

Early detection of bone marrow involvement in extramedullary plasmacytoma by whole-body F-18 FDG positron emission tomography

The utility of positron emission tomography (PET) with the glucose analog 2-deoxy-2-[F-18] fluoro-D-glucose (F-18 FDG) in plasmacytoma has not been well evaluated. The authors report a case of extramedullary plasmacytoma (EMP) in which whole-body F-18 FDG PET was useful in the early detection of bone marrow involvement. A 34-year-old woman had EMP without histologic or radiologic evidence of bone lesions. However, the early phase of bone marrow involvement was considered because of spotty accumulation shown by F-18 FDG PET. A follow-up F-18 FDG PET study after radiotherapy showed intense multifocal accumulation in the bone marrow, which was confirmed on bone marrow aspiration as abnormal proliferation of plasma cells. Whole-body F-18 FDG PET has the potential to detect the early phase of bone marrow involvement in patients with EMP.

Phosphorylation by cyclin-dependent protein kinase 5 of the regulatory subunit of retinal cGMP phosphodiesterase. II. Its role in the turnoff of phosphodiesterase in vivo

Retinal cGMP phosphodiesterase (PDE) is regulated by Pgamma, the regulatory subunit of PDE, and GTP/Talpha, the GTP-bound alpha subunit of transducin. In the accompanying paper (Matsuura, I., Bondarenko, V. A., Maeda, T., Kachi, S., Yamazaki, M., Usukura, J., Hayashi, F., and Yamazaki, A. (2000) J. Biol. Chem. 275, 32950-32957), we have shown that all known Pgammas contain a specific phosphorylation motif for cyclin-dependent protein kinase 5 (Cdk5) and that the unknown kinase is Cdk5 complexed with its activator. Here, using frog rod photoreceptor outer segments (ROS) isolated by a new method, we show that Cdk5 is involved in light-dependent Pgamma phosphorylation in vivo. Under dark conditions only negligible amounts of Pgamma were phosphorylated. However, under illumination that bleached less than 0.3% of the rhodopsin, approximately 4% of the total Pgamma was phosphorylated in less than 10 s. Pgamma dephosphorylation occurred in less than 1 s after the light was turned off. Analysis of the phosphorylated amino acid, inhibition of Pgamma phosphorylation by Cdk inhibitors in vivo and in vitro, and two-dimensional peptide map analysis of Pgamma phosphorylated in vivo and in vitro indicate that Cdk5 phosphorylates a Pgamma threonine in the same manner in vivo and in vitro. These observations, together with immunological data showing the presence of Cdk5 in ROS, suggest that Cdk5 is involved in light-dependent Pgamma phosphorylation in ROS and that the phosphorylation is significant and reversible. In an homogenate of frog ROS, PDE activated by light/guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) was inhibited by Pgamma alone, but not by Pgamma complexed with GDP/Talpha or GTPgammaS/Talpha. Under these conditions, Pgamma phosphorylated by Cdk5 inhibited the light/GTPgammaS-activated PDE even in the presence of GTPgammaS/Talpha. These observations suggest that phosphorylated Pgamma interacts with and inhibits light/GTPgammaS-activated PDE, but does not interact with GTPgammaS/Talpha in the homogenate. Together, our results strongly suggest that after activation of PDE by light/GTP, Pgamma is phosphorylated by Cdk5 and the phosphorylated Pgamma inhibits GTP/Talpha-activated PDE, even in the presence of GTP/Talpha in ROS.

Phosphorylation by cyclin-dependent protein kinase 5 of the regulatory subunit of retinal cGMP phosphodiesterase. I. Identification of the kinase and its role in the turnoff of phosphodiesterase in vitro

Cyclic GMP phosphodiesterase (PDE) is an essential component in retinal phototransduction. PDE is regulated by Pgamma, the regulatory subunit of PDE, and GTP/Talpha, the GTP-bound alpha subunit of transducin. In previous studies (Tsuboi, S., Matsumoto, H. , Jackson, K. W., Tsujimoto, K., Williamas, T., and Yamazaki, A. (1994) J. Biol. Chem. 269, 15016-15023; Tsuboi, S., Matsumoto, H., and Yamazaki, A. (1994) J. Biol. Chem. 269, 15024-15029), we showed that Pgamma is phosphorylated by a previously unknown kinase (Pgamma kinase) in a GTP-dependent manner in photoreceptor outer segment membranes. We also showed that phosphorylated Pgamma loses its ability to interact with GTP/Talpha, but gains a 10-15 times higher ability to inhibit GTP/Talpha-activated PDE than that of nonphosphorylated Pgamma. Thus, we propose that the Pgamma phosphorylation is probably involved in the recovery phase of phototransduction through shut off of GTP/Talpha-activated PDE. Here we demonstrate that all known Pgammas preserve a consensus motif for cyclin-dependent protein kinase 5 (Cdk5), a protein kinase believed to be involved in neuronal cell development, and that Pgamma kinase is Cdk5 complexed with p35, a neuronal Cdk5 activator. Mutational analysis of Pgamma indicates that all known Pgammas contain a P-X-T-P-R sequence and that this sequence is required for the Pgamma phosphorylation by Pgamma kinase. In three different column chromatographies of a cytosolic fraction of frog photoreceptor outer segments, the Pgamma kinase activity exactly coelutes with Cdk5 and p35. The Pgamma kinase activity ( approximately 85%) is also immunoprecipitated by a Cdk5-specific antibody, and the immunoprecipitate phosphorylates Pgamma. Finally, recombinant Cdk5/p35, which were expressed using clones from a bovine retina cDNA library, phosphorylates Pgamma in frog outer segment membranes in a GTP-dependent manner. These observations suggest that Cdk5 is probably involved in the recovery phase of phototransduction through phosphorylation of Pgamma complexed with GTP/Talpha in mature vertebrate retinal photoreceptors.

High-speed magnetic resonance imaging for four-dimensional treatment planning of conformal radiotherapy of moving body tumors

PURPOSE

High-speed magnetic resonance imaging (MRI) was applied to the determination of the planning target volume (PTV) of moving hepatobiliary tumors.

METHODS AND MATERIALS

Three moving tumors, including two metastatic hepatic tumors and one bile duct tumor, were examined using high-speed MRI and reference fiducial markers before external radiotherapy. Patients were examined for 30 seconds under conditions of normal breathing during the examination. The coordinates of the center of the tumor contours were shown on sagittal and coronal images displayed on the monitor.

RESULTS

The maximum length of movement was 10.6 +/- 7.0 mm in a craniocaudal direction; 5.2 +/- 1.8 mm in a lateral direction; and 4.6 +/- 1.6 mm in a ventrodorsal direction. When the PTV was determined using MRI at exhalation phase with a 10-mm safety margin, clinical target volume (CTV) was not covered in 19% of all images in the 3 patients. With MRI at inhalation phase with a 10-mm safety margin, CTV was not covered in 36% of all images.

CONCLUSION

Four-dimensional treatment planning using high speed MRI, and integrating time and spatial information, has the potential to determine the planning target volume of moving body tumors more precisely than does conventional CT planning.

The Senami Wrist Supporter for patients with rheumatoid arthritis

Abstract One of the wrist orthoses, the Senami Wrist Supporter (SWS), was applied to 203 rheumatoid wrists in 112 patients who had persistent wrist pain and restricted forearm rotation due to synovitis and instability at the distal radioulnar joint (DRUJ). The study was performed by sending out a questionnaire to the patients about the use of the SWS at home, and examining grip strength and forearm rotation with and without the use of the SWS. The average age of the patients was 61 years, and the average follow-up period was 18 months. The rate of compliance of wearing the SWS at home was 73% on average. It was higher in wrists of Larsen-Dale-Eek (LDE) grades 0, I, and II (normal, slight, and definite early abnormality) than in those of grades III, and IV (medium and severe destructive abnormality). Decreased pain was noted in 52% of the wrists at the time of applying the SWS. The SWS was not used in 10% of the wrists because of remission of pain at follow-up. Grip strength increased significantly (P < 0.01) and so did forearm rotation (P < 0.05) by the stabilizing effect of the SWS on the unstable DRUJ. The use of the SWS was confirmed to be an efficient measure to treat painful rheumatoid wrists with early stages of disease at the DRUJ.

Acceleration by KW-5092 of intestinal motility associated with acetylcholine release in vivo

Effect of KW-5092 ([1-[2-[[[5-(piperidinomethyl)-2-furanyl]methyl]amino]ethyl]-2- imidazolidinylidene]propanedinitrile fumarate) on intestinal motility and release of endogenous acetylcholine (ACh) were measured simultaneously in the small intestine of anesthetized dog using the in vivo microdialysis method. Intraarterial and intravenous administrations of KW-5092 accelerated the intestinal motility and increased dialysate ACh concentrations. These KW-5092-induced responses paralleled the increase in blood concentration of KW-5092. Thus, the acceleration of intestinal motility by KW-5092 was found in vivo to be associated with an increase in ACh release from the intestinal cholinergic neurons.

Skull-base invasion of nasopharyngeal carcinoma: magnetic resonance imaging findings and therapeutic implications

PURPOSE

To evaluate the value of skull-base abnormality on MRI for predicting local recurrence in nasopharyngeal carcinoma.

MATERIALS AND METHODS

Between November 1988 and February 1997, 48 patients with NPC were examined with both MRI (1.5 T) and CT prior to radiation therapy. T classification (1987 UICC) based on physical examination and CT findings were T1 in 3 cases, T2 in 22, T3 in 9, and T4 in 14. On MRI, low-intensity tissue with Gd enhancement in the marrow of the skull was considered to be a suspicious finding of skull-base invasion. CT simulation was performed in all patients. The total dose to the primary tumor was 60-75 Gy (mean, 67 Gy). The mean follow-up period was 42 months.

RESULTS

All 14 T4 patients had abnormal tissue in the marrow of the skull base on MRI. Thirty-eight percent (13 of 34) of T1-3 patients were suspected to have skull-base invasion based on MRI (0% for T1, 27% [6 of 22] for T2, and 78% [7 of 9] for T3). The 5-year local control rate was significantly different between T1-3 and T4 tumors (97% vs. 69%, p < 0.025) but was not different by the presence of the MRI abnormality in the skull base.

CONCLUSION

Skull-base invasion suspected solely by MRI does not relate to local recurrence provided that careful treatment planning is performed with the aid of MRI and CT simulator.

Reduction of late complications after irregularly shaped four-field whole pelvic radiotherapy using computed tomographic simulation compared with parallel-opposed whole pelvic radiotherapy

BACKGROUND

Tumor control and late complication rates of irregularly shaped four-field whole pelvic radiotherapy using CT simulation were compared with those of whole pelvic radiotherapy using parallel-opposed fields in a non-randomized study.

METHODS

From 1986 to 1996, 74 patients who underwent surgery for clinical stage I, II or III squamous or adenosquamous cell carcinoma of the uterine cervix were treated with postoperative radiotherapy consisting of 50 Gy in 25 fractions in 6 weeks. Thirty-four patients were treated with an irregularly shaped four-field technique following computed tomography (CT) simulation using beam's eye view and three-dimensional treatment planning and lead blocks. Forty patients received the conventional two-field technique, with CT simulation in 13 patients and X-ray simulation in 27 patients. There was no significant difference in patients' characteristics between the two groups.

RESULTS

There was no statistical difference in survival, relapse-free survival or pelvic control rate between the two-field and irregularly shaped four-field groups with a mean follow-up period of 60 months. The actual 5-year pelvic control rate was 94% for the two-field technique and 100% for the irregularly shaped four-field technique. The incidence of grade II-III bowel complications in the irregularly shaped technique group (2.9%, 1/34) was significantly lower than that in the two-field technique group (17.5%, 7/40) (p < 0.05). The actual 5-year complication rates of grade II leg edema were 28.6 and 3.1% for the two-field technique and irregularly shaped four-field technique groups, respectively (p = 0.0123).

CONCLUSIONS

Irregularly shaped four-field post-operative pelvic radiotherapy using CT simulation appears to be as effective as parallel-opposed whole pelvic radiotherapy with a lower incidence of bowel complication and chronic leg edema.

Structural change of bovine retinal cGMP phosphodiesterase by release of its gamma subunit: direct imaging by improved low angle rotary shadowing

Cyclic GMP phosphodiesterase (PDE), a key enzyme for phototransduction, contains two catalytic subunits, Palpha and Pbeta, and two identical regulatory subunits, Pgammas. Neither the structure of the subunits of PDE nor their changes in structure during PDE regulation have been known. Here, improved low angle rotary shadowing was applied to depict the three-dimensional structure of bovine PDE (Palphabetagammagamma) and its changes by Pgamma release. Palphabetagammagamma and Palphabetagamma were isolated from photoreceptor membranes after treatment with a hydrolysis-resistant GTP analogue, and Palphabeta was prepared from Palphabetagammagamma tryptic digestion. Images of Palphabetagammagamma consisted of two crooked strands. These two strands faced each other to make a ring shape, but this ring structure was bent at the centre line between the two strands. In Palphabetagamma, one of these strands changed its shape toward reducing the central space of the ring structure. This ring appeared to be more bent at the centre line. In Palphabeta, both strands changed their shape such that the ring structure appeared to be a twisted quasi ring shape. These observations suggest that in Palphabetagammagamma each Pgamma is complexed with a catalytic subunit, and that the shapes of Palpha and Pbeta are drastically changed by the Pgamma release. These shape changes are no doubt crucial for various PDE regulations, such as activation of cGMP hydrolysis by Palphabeta, interaction of Palphabeta with GARP2 and a GARP2-like protein and cGMP binding to non-catalytic sites on Palphabeta.

[Application of measuring 99mTc-MAG3 plasma clearance based on one-compartment model (MPC method) to renal transplantation]

Measurement of 99mTc-MAG3 plasma clearance (CLmag) based on one-compartment model (MPC method) was applied to renal transplantation and evaluated for the factors which might affect the calculated results, especially concerning renal depth. Correlation coefficient of CLmag between MPC method using real renal depth and Russell or Bubeck single sampling method was good (r = 0.852 or 0.876, respectively). Regression equation between MPC method and Russell method was y = 1.044x - 3.0 and was more closer to y = x than that between MPC method and Bubeck method. CLmag of MPC method calculated by estimated renal depth from the abdominal thickness was also similar to that by real renal depth. Even if the fixed renal depth, 4 cm, was applied, the coefficient and regression equation between MPC method and Russell method were r = 0.884 and y = 1.004x - 10.2. In conclusion, MPC method is applicable to the evaluation of renal transplants. Though measuring renal depth is best, calculation with fixed renal depth of 4 cm might be practically acceptable.

Modification of liposomes with N-substituted polyacrylamides: identification of proteins adsorbed from plasma

Liposomes prepared from DMPC (80%) and cholesterol (20%) were modified with a series of hydrophobically modified N-substituted polyacrylamides, namely, poly[N-isopropylacrylamide] (PNIPAM), poly[N,N-bis(2-methoxyethyl) acrylamide] (PMEAM), and poly[(3-methoxypropyl)acrylamide] (PMPAM). The hydrophobic group, N-[4-(1-pyrenylbutyl)-N-n-octadecylamine was attached to one end of the polymer chains to serve as an anchor for incorporation into the liposome bilayer. Liposome-polymer interactions were confirmed using fluorescence spectroscopy and chemical analysis. Microscopy revealed differences in aggregation tendency between unmodified and polymer-modified liposomes. Proteins adsorbed to liposome surfaces during exposure to human plasma were identified by immunoblot analysis. It was found that both unmodified and polymer-modified liposomes adsorb a wide variety of plasma proteins. Contact phase coagulation proteins, complement proteins, cell-adhesive proteins, serine protease inhibitors, plasminogen, antithrombin III, prothrombin, transferrin, alpha(2)-microglobulin, hemoglobin, haptoglobin and beta-lipoprotein as well as the major plasma proteins were all detected. Some differences were found between the unmodified and polymer-modified liposomes. The unmodified liposomes adsorbed plasminogen mainly as the intact protein, whereas on the modified liposomes plasminogen was present in degraded form. Also, the liposomes modified with PNIPAM in its extended conformation (below the lower critical solution temperature) appeared to adsorb less protein than those containing the 'collapsed' form of PNIPAM (above the LCST).

[A case of superior mediastinal neurinoma resected from the supra-clavicular area]

We report a case of superior mediastinal neurinoma that was resected from the supra-clavicular area. An abnormal shadow on the chest X-ray film was pointed out in a 53-year-old male. A left supra-clavicular mass was subsequently also discovered. We underwent extirpation of the tumor through supra-clavicular approach and confirmed to be a neurinoma histologically. We consider supra-clavicular approach which allows a good view might be useful.