Nerve stimulating system for peripheral nerve tumor resection under the thoracoscope

The authors report a newly devised nerve stimulator and its clinical application in thoracoscopic surgery. The stimulator is a monopolar system, that has a long extension between the electrodes and the handle. The stimulator is inserted into the chest cavity through a portal, and is used to distinguish motor nerves from the surrounding tissue and to determine whether there is nerve involvement with tumor. The tumor is then safely and rapidly resected by thoracoscopic technique and the major nerves are spared. This method was used in two clinical cases, with excellent results obtained, and with no major complications.

Effect of Varidase (streptokinase) on biofilm formed by Staphylococcus aureus

Staphylococcus aureus forms a fibrin-rich biofilm in the presence of plasma which is highly resistant to attack by the human immune system and to chemotherapy. Varidase, composed mainly of streptokinase, is used for hydrolyzing clots. In this study, we attempted to destroy the biofilm of S. aureus with Varidase and to apply this drug in the treatment of staphylococcal infections. Four clinical isolates were used in the experiments. These organisms formed a several-millimeter-thick biofilm on type IV collagen coated coverslips in trypticase soy broth containing 50% human plasma. The biofilm was composed of bacterial cell which adhered to fibrillar fibers and of sediment derived from plasma. 10,000 U/ml of Varidase, the dose which is used clinically, removed the sediment and reduced the number of live bacteria in biofilms to less than 20% of control. 200 U/ml of Varidase was also effective against biofilms of the organisms. An equal combination of Varidase and ofloxacin had an additive effect on the bacteria. The results of this study demonstrate that Varidase is highly effective in destroying biofilms of S. aureus in vitro and suggest that this drug would be useful for treating staphylococcal infections.

Bond strength of resin to acid-etched dentin studied by 13C NMR: interaction between N-methacryloyl-omega-amino acid primer and dentinal collagen

The application of the hydrophilic methacrylate primer to acid-etched dentin increases the bond strength of the resin to the acid-etched dentin. However, the mechanism for the bonding of the resin to dentinal collagen through the primer remains to be determined. Before a more effective adhesive primer can be developed, we must understand the adsorption behavior of the primer to the dentinal collagen. The purpose of this study was to determine how 5 derivatives of N-methacryloyl-omega-amino acid (NMomegaA) primers enhance the bonding of the resin to acid-etched dentin. The interaction between the NMomegaA primers and dentinal collagen was studied by the 13C NMR technique, including the observation of spin-lattice relaxation times, T1. When the dentinal collagen was dispersed into the NMomegaA solution, the T1 values of the two carbonyl carbons attributed to the amide and the carboxylic acid in the NMomegaA molecule decreased dramatically. This result was due to the interaction between the amide group and the carboxylic acid group in the NMomegaA molecule and the dentinal collagen molecule. The T1 values of these carbonyl carbons decreased when the number of methylene groups in the NMomegaA molecule increased. The interaction became stronger as the number of methylene groups in the NMomegaA molecule was increased. Further, the bond strength of the resin to the acid-etched dentin primed with NMomegaA increased with a decrease in the T1 value of the amide carbonyl carbon. The strength of the interaction of the NMomegaA primer to the dentinal collagen molecule, determined by the 13C NMR technique, showed a direct correlation with the bond strength of the resin to acid-etched dentin that was treated with the NMomegaA primer.

Application of high resolution microfocus X-ray CT for the observation of human tooth

The calcification degree of extracted human teeth was observed by using high resolution microfocus X-ray CT. As samples, upper and lower first premolars extracted from a 21-year-old female were used. The computed tomograms were produced by high resolution microfocus X-ray CT with a open vacuum X-ray source, rotating sample stage, and image sensor. The distinction between enamel and dentin was very clear, and the shape of the pulp cavity was also clearly identified. The secondary dentin was visible in the circumpulpal dentin. The color map displays showed the heterogeneity of the calcification degree not only in the dentin but also in the enamel. The enamel was divided into three layers according to the calcification degree. High resolution microfocus X-ray CT was very useful for the observation of the internal structure of human teeth without destroying the samples.

DNA-dependent protein kinase activity correlates with Ku70 expression and radiation sensitivity in esophageal cancer cell lines

We investigated the relationship between DNA-dependent protein kinase (DNA-PK) activity and radiation sensitivity using 14 esophageal cancer cell lines, TE 1-14. DNA-PK activities differed significantly among the cell lines. The highest DNA-PK activity observed in TE-8 was more than two times higher than the lowest DNA-PK activity observed in TE-5. Significant correlation was observed between DNA-PK activity and D0 (r = 0.766; P = 0.0008). Western blots analysis revealed a significant correlation between DNA-PK activity and Ku70 expression, suggesting that the regulation in DNA-PK activity was associated with Ku70 expression. The data suggest that the measurement of DNA-PK activity and/or Ku70 expression may provide a useful way to predict radiation sensitivity.

Sequential mRNA expression for immediate early genes, cytokines, and neurotrophins in spinal cord injury

In this communication, we demonstrate the sequential expression of endogenous molecules, including immediate early genes (IEGs), cytokines, neurotrophins, and neurotrophin receptors in the injured spinal cord. In the acute phase, expression of IEGs and cytokines mRNAs were rapidly upregulated within 1 h in nonneuronal cells in the lesioned sites and the surrounding spinal white and gray matter. Maximal expression was observed at 1 h for c-fos and TNF-alpha mRNAs, at 3 h for c-jun and IL-6 mRNAs, and at 6 h for IL-1 beta mRNA, and these signals were virtually nondetectable after 6-12 h from the onset of the injury. Some of these genes products may promote the degeneration of damaged cells and tissues, while others may be involved in the subsequent repair processes. In the subacute phase, expression of NGF, BDNF, NT-3, p75LNGFR and Trk B mRNAs began to increase in the nonneuronal cells and neuronal cells from 6 h, and peaked at 24-72 h in the area where expression of mRNAs for IEGs and cytokines overlapped. Signals for IL-6 mRNA were also observed in motoneurons at 24-72 h after the injury, with the suggestion that these molecules may be involved in promoting axonal sprouting in the injured spinal cord. Of further interest was the finding that this upregulation of IL-1 beta, BDNF, and NT-3 mRNAs in injured spinal cord was attenuated by treatment with high dose glucocorticoids, with the suggestion that the downregulation of BDNF and NT-3 might be disadvantageous to survival and axonal sprouting of spinal neurons.

Treatment of superficial esophageal cancer by external radiation therapy alone: results of a multi-institutional experience

PURPOSE

To assess the effectiveness and toxicity of external radiation therapy for superficial esophageal cancer.

METHODS AND MATERIALS

During the period from March 1979 to November 1996, 78 patients with superficial esophageal cancer received radiation therapy without intracavitary irradiation at nine radiotherapy institutions in Japan. All patients had histologically-proven squamous cell carcinoma. Endoscopic ultrasonography was performed in 34 patients to discriminate mucosal from submucosal cancer. Most of the patients had received radiation therapy using conventional fractionation at an average dose of 65.5 Gy.

RESULTS

The survival rates at 1, 2, and 5 years were 88%, 73%, and 45%, respectively. The local control rates at 1, 2, and 5 years were 85%, 79%, and 66%, respectively. Although the difference was not significant, the survival rate of cancer patients with a tumor invading the submucosa was lower than that of the other patients. In 6 mucosal cancer patients, local recurrence was observed in 1 patient with extensive cancer. Regional lymph node recurrence and distant failure were not observed in mucosal cancer patients, while in 28 submucosal cancer patients, the 5-year survival rate and relapse free rate were only 49% and 43%, respectively. Univariate and multivariate analysis identified age as the only significant prognostic factor. Severe late injury, such as esophageal ulcer, perforation, and bleeding, was not observed.

CONCLUSION

External radiation therapy is effective for mucosal cancer. However, further investigation is needed to establish a better standard treatment protocol for submucosal cancer.

Modulation of telomerase activity by zinc in human prostatic and renal cancer cells

Because the up-regulation of telomerase in most cancer tissues is considered to be responsible for the unlimited proliferation of cancer cells, suppression of telomerase activity is an attractive potential target for cancer therapy. The mechanism for the activation of telomerase in cancer cells, however, is still unclear. In the present study, we demonstrated that Zn induces an enhancement of telomerase activity in the human renal cell carcinoma (NRC-12) and prostatic cancer (DU145) cell lines. The maximum elevation of the activity was observed 6 hr after treatment with 100 microM Zn; it was diminished by the addition of either metal chelator or cycloheximide. Other metals such as Cd and Cu also enhanced telomerase activity but to a lesser extent, and no correlation between the activation of telomerase and the induction of metallothionein was observed. Our findings provide the first evidence that metals, especially Zn, can modulate telomerase activity in cancer cells.

[Ineffective and recurrent cases of thoracoscopic sympathectomy for hyperhidrosis and intractable pain]

We reported the cases of thoracoscopic sympathectomy, that is, six cases of hyperhidrosis, three of post herpetic neuralgia, and four of reflex sympathetic dystrophy, including recurrent or incompletely resected or ineffective ones. Recently this procedure for hyperhidrosis had been performed frequently because of its effectiveness, less pain, early discharge and cosmetic aspect. For an ineffective case of hyperhidrosis abdominal respiration which emphasized the exhalation and using an upper abdomen decreased the sweating. The balance of autonomic nerve system, toward parasympathetic dominant, was thought to be improved by conscious respiration. The decrease of sweating right after the operation in a case of incomplete resection indicated that intraoperative maneuver could restrict the sympathetic nerve. This procedure for a pain control could be less effective than that for hyperhidrosis, so an adequate preoperative informed consent was thought to be necessary.

[A case of spontaneous hemopneumothorax associated with uncontrolled massive bleeding after inserting thorathic drain]

A 31-year-old man admitted to our hospital complaining of right chest pain. Chest X-ray on admission revealed a collapsed lung and an air fluid line in the right thorax. A chest tube drainage was carried out, but hemorrhagic pleural fluid was drainaged. Forty minutes later, an anemia developed and chest X-ray showed increased massive right pleural collection. Therefore, emergent surgery was performed. An operation under thoracoscopic guidance was converted into thoracotomy because of massive blood clots and fresh bleeding. A bleeding originating from the branch of 1st intercostal artery and a bulla on upper lobes were noted. The artery was coagulated with electrocoutary and ligated using Endo-loop. This artery is not congenital abnormal one but collateral expanded one of which the elastic lamina is thickened. Spontaneous hemopneumothorax is life-threatening, emergent operation should be undergone.

Effectiveness of the addition of water-soluble photoinitiator into the self-etching primers on the adhesion of a resin composite to polished dentin and enamel

The effectiveness of the addition of a photoinitiator into self-etching primer was investigated by measuring the tensile bond strength between a resin composite and dentin or enamel. The addition of camphorquinone to 5 M (5 wt% MDP -35 wt% HEMA aqueous solution) or 30 M (30 wt% MDP -35 wt% HEMA aqueous solution) did not increase the bond strengths of resin composite to dentin or enamel. On the other hand, the bond strength to dentin was increased by the addition of a water-soluble photoinitiator, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N, N-trimethyl-1- propanaminium chloride (QTX) to 5 M or 30 M. The bond strengths to enamel were not influenced by the addition of QTX to 5 M or 30 M.

Metallothionein modulates the carcinogenicity of N-butyl-N-(4-hydroxybutyl)nitrosamine in mice

We examined the carcinogenicity of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in transgenic mice deficient in the metallothionein (MT) I and II genes and in control (129/Sv) mice. Both strains of mice were given BBN for 8 weeks with or without Zn treatment. All mice were killed at 12 weeks after the cessation of BBN administration. BBN induced bladder tumors in 75% of MT null mice and in 43% of 129/Sv mice. The average number of bladder tumors per mouse was significantly higher in MT null mice (1. 18 +/- 0.27) than in 129/Sv mice (0.43 +/- 0.20). Zn treatment suppressed the carcinogenicity of BBN in 129/Sv mice but not in MT null mice. Histopathological examination of the tumors revealed that the malignant potential of bladder tumors in 129/Sv mice was greater than that in MT null mice. These results indicate that MT is an important modulator of carcinogenicity of BBN in the bladder of mice.

Osteosarcoma metastatic to the kidneys without lung involvement

Symptomatic renal metastasis is very rare in osteosarcoma. A few reported cases had pulmonary metastases before renal involvement. We present a case of metastatic renal osteosarcoma without pulmonary involvement. The patient presented with hematuria 8 years after initial treatment of osteosarcoma of the left distal femur. Computed tomography revealed a bilateral calcified renal mass. The patient died of disease 4 months after detection of the metastases. At autopsy, metastatic osteosarcoma was discovered in the bilateral kidney, both renal veins, inferior vena cava and right atrium. There was no pulmonary involvement. We emphasize the need for renal evaluation for the follow-up of patients with osteosarcoma.

A possible mechanism of TPA-mediated downregulation of neurotrophin-3 gene expression in rat cultured vascular smooth muscle cells

We have previously reported that in cultured rat vascular smooth muscle cells (VSMCs), neurotrophin-3 (NT-3) gene expression was suppressed by TPA (12-O-tetradecanoyl phorbol-13-acetate), which induces an AP-1 transcription factor. In the present study, to clarify the mechanism for TPA-mediated downregulation of NT-3 gene expression, effects of cycloheximide and dexamethasone (Dex) on the TPA-mediated downregulation were examined in VSMCs. Pretreatment with cycloheximide, an inhibitor of protein synthesis, or simultaneous treatment with Dex, an inhibitor of AP-1, suppressed the TPA-mediated downregulation of NT-3 gene expression. Furthermore, co-transfection of c-fos and c-jun expression vectors into VSMCs resulted in decrease in the NT-3 gene expression. The present findings suggest that TPA-induced AP-1 de novo synthesis causes the downregulation of NT-3 gene expression in VSMCs.

Mice with early onset of death (EOD) due to lupus glomerulonephritis

Both MRL-lpr/lpr (lpr) and BXSB mice fall victim to autoimmune disease as a function of age. To combine their properties, brother-sister mating of (female lpr x male BXSB)F1 mice was done. Mice for mating were selected according to indicators of early onset of glomerulonephritis and subsequent early death (i.e., EOD). This mating was continued for more than 16 generations. The EOD mice thus established had homozygous H-2k/k, lpr/lpr, and possible yaa/- (in the case of males). The average life span of males was 83 days while that of females was 126 days. After 12 weeks of age, the majority (> 80%) of male EOD mice were characterized by the abnormality of urine due to glomerulonephritis. We then characterized how glomerulonephritis was evoked, especially in terms of expanding lymphocyte subsets in various immune organs. Similar to the case of parental lpr mice, the major expanding cells were CD4-8-B220+ TCRint cells in the immune organs and kidney. In addition, myeloid cells were found to infiltrate the kidney. This massive infiltration of both TCRint cells and myeloid cells might be responsible for the onset of acute glomerulonephritis. Even after more than 50 generations, these EOD mice still carry both lpr and yaa genes. These results suggest that EOD mice might be a very useful tool for the study of acute lupus glomerulonephritis which is evoked by the genetic abnormalities.

Physiological changes in Pachinko players; beta-endorphin, catecholamines, immune system substances and heart rate

Pachinko is a popular form of recreation in Japan. However, in recent years, along with Pachinko's popularity, "Pachinko dependence" has become topical news. The purpose of this study was to investigate beta-endorphin, catecholamines, immune system responses and heart rate during the playing of Pachinko. The following significant results were observed. (1) Plasma concentration of beta-endorphin increased before playing Pachinko and while in the Pachinko-center (p < 0.05). (2) Beta-endorphin and norepinephrine increased when the player began to win (i.e. at "Fever-start") compared to baseline (p < 0.05). (3) Beta-endorphin, norepinephrine and dopamine increased when the winning streak finished (i.e. at "Fever-end") compared to baseline (p < 0.05-0.01). (4) Norepinephrine increased past 30 minutes after "Fever-end" compared to baseline (p < 0.05). (5) Heart rate increased before "Fever-start" compared to baseline, peaked at "Fever-start" and rapidly decreased to match rates measured at rest. But the increase was observed from 200 seconds after "Fever-start" (p < 0.05-0.001). (6) There was a positive correlation between the number of hours subjects played Pachinko in a week and the differences between beta-endorphin levels at "Fever-start" and those at rest (p < 0.05). (7) The number of T-cells decreased while the number of NK cells increased at "Fever-start" compared to baseline (p < .05). These results suggest that intracerebral substances such as beta-endorphin and dopamine are involved in the habit-forming behavior associated with Pachinko.

Analysis of polymerization behavior of dental dimethacrylate monomers by differential scanning calorimetry

The polymerization and copolymerization activity of dental monomers was investigated using the dynamic differential scanning calorimetry (DSC) method. As aliphatic dimethacrylate monomers, ethyleneglycol dimethacrylates with different lengths of ethyleneglycol and urethane dimethacrylates were used. As aromatic dimethacrylates, Bis-GMA (2,2-bis[4-(3-methacryloxy-2-hydroxypropoxy)phenyl]propane), BMPEPP (2,2-bis(4-methacryloxy poly-ethoxyphenyl)propane), and DMB (1,2-dimethacryloyloxy benzene) were used. Ethyleneglycol dimethacrylates showed sharp exothermic peaks, and the maximum temperatures (Tp) at the exothermic peaks of the DSC curves decreased according to the lengths of ethyleneglycols. Among urethane dimethacrylates, UDMA (dimethacryloxyethyl 2,2,4-trimethylhexamethylene diurethane) and DMPHU (di-(2-methacryloxypropyl) hexamethylene diurethane) showed sharp exothermic peaks, but DMEHU (di-(2-methacryloxyethyl) hexamethylene diurethane) showed an endothermic peak as well as exothermic peaks. This suggests that reactions other than polymerization occurred in the case of DMEHU. The polymerization activity of aromatic dimethacrylates was lower than that of ethyleneglycol dimethacrylates and urethane dimethacrylates. The copolymerization activity of TEGDMA (triethyleneglycol dimethacrylate) and DMB was also investigated using the dynamic DSC method. The DSC curves of the copolymerization between DMB and UDMA or BMPEPP showed broad peaks, but the DSC curves of the copolymerization between TEGDMA and UDMA or BMPEPP showed sharp peaks. The copolymerization activity of TEGDMA was better than that of DMB.

Immunosuppressant deoxyspergualin-induced inhibition of cell proliferation is accompanied with an enhanced reduction of tetrazolium salt

Deoxyspergualin (DSG) has both antitumor and immunosuppressive activities. We explored the mechanism of DSG activities using an aqueous soluble analogue, methyldeoxyspergualin (MeDSG) for in vitro culture studies. It is known that DSG has inhibitory effects on cell proliferation, and we also observed that MeDSG inhibited [3H]-thymidine incorporation by rapidly dividing murine T cell hybridomas. However, when tetrazolium (MTT) colorimetric assay was adopted to evaluate its inhibitory effects on cell proliferation, MeDSG induced an enhanced MTT reduction. When we examined whether these results were applicable to the actively dividing cells of other origins than T cells, similar effects were seen with Raji cells, J774.1 cells and NIH3T3 cells. N-30, another analogue which was capable of suppressing anti-SRBC antibody production in vivo, also induced inhibition of cell growth and an enhanced MTT reduction. In contrast, the analogue which failed to prevent the antibody production, neither enhanced MTT reduction nor inhibited cell proliferation. Our results demonstrated that the ability to generate MTT formazan in dividing cells is a common property among, DSG analogue with the immunosuppressive and antiproliferative activities.

Increased uncoupling protein-2 and -3 gene expressions in skeletal muscle of STZ-induced diabetic rats

Streptozotocin (STZ)-induced diabetic animals are vulnerable to cold stress. Uncoupling proteins (UCPs) play an important role in regulating thermogenesis. We investigated the gene expressions of UCPs in brown adipose tissue (BAT), white adipose tissue (WAT), liver and gastrocnemius muscle of STZ-diabetic rats using Northern blot. UCP-1, -2 and -3 mRNA expressions in BAT were all remarkably lower in STZ-diabetic rats than those in control rats. Both UCP-2 and -3 gene expressions in gastrocnemius muscle were substantially elevated in STZ-diabetic rats and insulin treatment restored UCP gene expressions to normal levels. These results suggest that in STZ-diabetic rats, the overexpression of UCP-2 and UCP-3 in skeletal muscle provides a defense against hypothermogenesis caused by decreased UCPs in BAT.

Parathyroid hormone induces expression of the inducible cAMP early repressor in osteoblastic MC3T3-E1 cells and mouse calvariae

Parathyroid hormone (PTH) regulates gene expression in skeletal osteoblasts mainly through the cAMP-protein kinase A (PKA) pathway. In neuroendocrine cells, activation of the cAMP-PKA signaling pathway leads to induction of the inducible cAMP early repressor (ICER), which is transcribed from an intronic promoter of the CREM gene and acts as a transcriptional repressor. To investigate whether PTH induces ICER expression in osteoblastic cells, RNA from MC3T3-E1 cells was subjected to reverse transcriptase-polymerase chain reaction using primers spanning the ICER sequence. Amplified products were subcloned, sequenced, and used as a probe for Northern blot analysis. In MC3T3-E1 cells, PTH induced ICER mRNA levels, which peaked at 2 h and declined to baseline by 8 h. Cycloheximide caused superinduction of ICER mRNA in response to PTH. In cultured mouse calvariae, PTH also induced ICER mRNA accumulation, which peaked at 2 h and returned almost to baseline by 10 h. Overexpression of ICER IIgamma decreased both baseline and PTH-stimulated prostaglandin G/H synthase 2 promoter activity in MC3T3-E1 cells. The induction of ICER represents a novel mechanism by which PTH regulates gene expression in osteoblastic cells.