DFF45/ICAD restores cisplatin-induced nuclear fragmentation but not DNA cleavage in DFF45-deficient neuroblastoma cells

We have previously defined a homozygously deleted region at chromosome 1p36.2-p36.3 in human neuroblastoma cell lines, NB-1 and NB-C201, and identified six genes including DFF45/ICAD within this region. In this study, we found that NB-C201 cells are much more resistant to various genotoxic stresses such as cisplatin (CDDP) than CHP134 and SH-SY5Y cells that do not have the homozygous deletion. To examine a role(s) of DFF45 in the regulation of apoptosis in response to CDDP, we have established stably DFF45-expressing NB-C201 cell clones (DFF45-1 and DFF45-3) and a control cell clone (NB-C201-C) using a retrovirus-mediated gene transfer. In contrast to NB-C201-C cells, DFF45-3 cells displayed apoptotic nuclear fragmentation in response to CDDP. Although CDDP-induced proteolytic cleavage of procaspase-3 and DFF45 in DFF45-3 cells, we could not detect a typical apoptotic DNA fragmentation. Additionally, deletion analysis revealed that C-terminal region of DFF45 is required for inducing nuclear fragmentation. Unexpectedly, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays demonstrated that DFF45 has undetectable effect on CDDP sensitivity of NB-C201 cells. Taken together, our present results suggest that DFF45/DFF40 system may be sufficient for CDDP-induced nuclear fragmentation but not DNA cleavage.

134 CONCEPTION RATES OF IN VITRO-PRODUCED BOVINE EMBRYOS CRYOPRESERVED IN 6% GLYCEROL AND TRANSFERRED BY THE DIRECT METHOD

Ethylene glycol has been used as the standard cryoprotectant for direct transfer of bovine embryos due to its high permeability. But Merton et al. reported that cryoprotectivity of glycerol for bovine embryos was superior to that of ethylene glycol (2001 Theriogenology 55, 312 abst). We previously reported that nonsurgical transfer of in vivo-derived bovine embryos cryopreserved in a lower concentration (5%) of glycerol and thawed by stepwise method resulted in a 55.4% conception rate, whereas direct transfer without removal of cryoprotectant showed only a 45.1% conception rate (Takada et al. 2005 Jpn. J. Embryo Transfer 27, 59–64). In this experiment, survival and conception rates of in vitro-produced (IVP) bovine embryos cryopreserved in 6% glycerol solution (GLY) were compared to those of embryos cryopreserved in 10% ethylene glycol plus 0.1 M sucrose solution (EG). Cumulus–oocyte complexes were matured and fertilized according to Numabe et al. (2000 Theriogenology 54, 1409–1420). Presumed zygotes were cultured in mSOF supplemented with 5% calf serum (CS) and 0.25% linoleic acid albumin at 38.5�C under 5% CO2, 5% O2, 90% N2 for 7 days. At the expanded blastocyst stage, embryos were placed in GLY or EG in PBS supplemented with 20% CS for 15 min at room temperature and loaded into 0.25-mL straws. Straws were placed directly into an alcohol freezer. When the cryoprotectant was GLY, straws were seeded at -4.0�C, held for 10 min, cooled at 0.5�C min to -30.5�C, and then plunged into liquid nitrogen. When the cryoprotectant was EG, the seeding point was -7.5�C, and the plunging point was -34.0�C, but the rest of the protocol was the same as for GLY. In Exp. 1, thawing in both groups was done in a 30�C water bath, and the contents were directly rehydrated in PBS with 20% CS. Thawed embryos were cultured in mSOF with 5% CS for 24 h to assess embryo survival rate, based on the re-expansion of the blastcoele and on their hatching ability. In Exp. 2, embryos in both groups were thawed and transferred to synchronous recipients without removing the cryoprotectant. Data were analyzed using chi-square analysis. In Exp. 1, the developmental rates of post-thaw embryos were similar in GLY (46/52, 88.5%) and EG (45/52, 86.5%); however, the hatching rate was significantly higher (P < 0.05) in embryos cryopreserved in EG (26/52, 50.0%) than in GLY (15/52, 28.8%). In Exp. 2, the conception rates of embryos were similar in both groups, GLY (7/15, 46.7%) and EG (6/15, 40.0%). In conclusion, after direct rehydration of embryos, the developmental ability of IVP bovine embryos cryopreserved in EG was superior to that of embryos cryopreserved in GLY in vitro. However, conception rates in vivo were similar in both groups. These results suggest that a lower concentration of glycerol might be still useful as a cryoprotectant for direct transfer of IVP bovine embryos.

14 MOTILITY AND FERTILITY OF BULL SPERMATOZOA FROZEN IN EGG YOLK EXTENDER SUPPLEMENTED WITH LACTOFERRIN

Lactoferrin (Lf) is secreted by the prostate, seminal vesicles, and epididymis, and appears to represent a major component of the sperm-coating antigens that protect sperm. The aim of this study was to determine the effects of Lf used in semen extender on motility and fertility of bovine frozen semen. Semen samples were collected from three fertile Japanese Black sires. The semen collected was cooled and extended with egg yolk–Tris extender supplemented with glycerol and Lf (from bovine milk) to give final concentrations of 7% and 0, 10, 100, 500, 1000, or 2000 �g mL-1, respectively. After being extended, the semen was packaged in 0.5-mL straws, frozen, and transferred into liquid nitrogen. At least one week later, the frozen semen was thawed and washed mTALP containing caffeine. Motile sperm were separated by discontinuous 2-step (40 and 80%) Percoll gradient centrifugation. Sperm motility was calculated as the percentage of motile sperm separated by Percoll gradients relative to pre-separated sperm. Sperm motility character (motile sperm, progressive sperm) was analyzed by a CASA system (Hamilton Thorne Biosciences, Beverly, MA, USA). In the following experiment, we examined the effect of Lf added in the extender on improvement of semen fertility. The frozen semen from one sire extended with or without 500 �g mL-1 of Lf was prepared (99 straws with Lf, 99 straws without), distributed to three inseminators, and used to inseminate to 198 cows. The sperm motility and motility character were analyzed by ANOVA and Fisher's exact test. The field trials were evaluated by chi-square test. After selection of motile sperm with the Percoll gradient, examination of sperm motility revealed that addition of Lf in the extender increased sperm motility significantly (P < 0.05) compared to that in the control without Lf: 51.2–53.8% in semen with added Lf (100–2000 �g mL-1) vs. 39.6% in the control. CASA analysis showed that motile sperm and progressive sperm were improved significantly by the addition of Lf; the peak level was 500 �g mL-1 of Lf in the extender. The percentage of motile sperm in semen with added Lf was higher significantly (P < 0.01) than that of the control: with Lf of 100 and 500 �g mL-1, 50.8 and 56.0%, respectively, vs. 39.7% without Lf. The percentage of progressive sperm was also significantly higher (P < 0.05) than that of the control: with Lf of 100 and 500 �g mL-1, 18.8 and 19.0%, respectively, vs. 13.5% without Lf. In the next experiment, we performed field trials to assess the availability of Lf for artificial insemination. In total, the group with Lf showed some but not a significant increase in fertility rate (delivery cow/inseminated cow) compared with the control group without Lf: 56.6% vs. 52.5%, respectively. In conclusion, these results suggest that addition of Lf in sperm extender may be useful for improvement of sperm motility and motility character after freezing and thawing. In the present study, we used fertile bulls, but the concentration of intact Lf in the semen was unknown, which might be the reason why the effect of Lf on the fertility rate was not observed to be significant. In future experiments it would be valuable to demonstrate the effect of Lf in subfertile semen.

The effect of a valine-rich diet on intestinal adaptation to massive small bowel resection in the rat

BACKGROUND/PURPOSE

Recently, valine, which is one of the branched chain amino acids, has been reported to enhance liver regeneration after hepatectomy in the rat. The aim of this study was to investigate the effect of enteral valine supplementation on intestinal adaptation.

MATERIALS/METHODS

Seven-week-old male Lewis rats underwent a 90% small bowel resection. The rats were randomly divided into two groups: group V (valine-rich diet) and group S (standard rat chow), according to the diet. The rats were sacrificed at the operation day and on postoperative days (POD) 7, 14, 30, and 60. The metrics were body weight (BW), blood amino acids, urine organic acids, and morphology of the residual small intestine.

RESULTS

The BW and the intestinal wet weight, jejunal crypt depth, and proliferating cell nuclear antigen-positive cells in group V at POD 7 were significantly higher than those values in group S, while those in group V at POD 30 and 60 were smaller than those in group S. The urine methylmalonic acid (MMA) level in group V at POD 30 and 60 was much higher than in group S.

CONCLUSION

Valine enhanced intestinal adaptation after massive small bowel resection in the acute phase. However, the long-term supplementation disturbed intestinal adaptation, which might be due to the high production of MMA.

Relationship Between Real-Time Monitoring of the Graft Motility and Mucosal Histology in Swine Intestinal Transplantation

We studied the correlation between the motility and the mucosal histology of the small bowel seeking to detect rejection in an early stage by real-time monitoring using a swine model. Intestinal transplantation (ITx) was performed orthotopically using FK506 immunosuppression. The distal about 20 cm segment of the allograft was exteriorized as a Thiry-Vella stoma for biopsies. Strain gauge (SG) force transducers were attached to the graft for real-time monitoring of graft motility. Pigs without ITx were used as controls (group 1). Rejection was classified into four groups by histologic findings: nonrejection (group 2), mild rejection (group 3), moderate rejection (group 4), and severe rejection (group 5). Migrating motor complex (MMC) phase III was analyzed for the following parameters: duration, amplitude, interval, motility index, velocity, and frequency of propagation. In group 2, all parameters were almost the same as those for group 1. In contrast, groups 4 and 5 showed most parameters significantly lower than those in group 1. In group 3, the contractility of the MMC was not significantly altered, but the frequency of the propagation was decreased significantly. In conclusion, graft motility detected by a real-time SG method correlated with the grade of mucosal histology. This method is useful to detect rejection at an early stage by examining the frequency of MMC propagation.

Evaluation of activation treatments for blastocyst production and birth of viable calves following bovine intracytoplasmic sperm injection

The objective of this study was to compare the effectiveness of different methods of bovine oocyte activation following intracytoplasmic sperm injection (ICSI) in terms of oocyte cleavage and blastocyst rates, and calf production. Oocytes were harvested, post mortem, from the ovaries of Japanese Black heifers or cows. ICSI was carried out using a piezo-electric actuator. The injected or sham-injected oocytes that were assigned to three activation treatments, each replicated three times, were studied: (1) exposure to 5 microM ionomycin for 5 min (ionomycin); (2) exposure to 5 microM ionomycin for 5 min followed by culture in TCM199 for 3 h and a further 3h culture in 1.9 mM 6-dimethylaminopurine (DMAP-ionomycin+DMAP); (3) exposure to 7% ethanol in TCM199 for 5 min, 4 h after ICSI (ethanol). One or two blastocysts from the ionomycin+DMAP (8 recipients) and ethanol (17 recipients) oocyte activation treatments were non-surgically transferred into Holsteins for the study of calf production. The highest cleavage and blastocyst production rates were observed in the ionomycin+DMAP treatment (83.9% and 40.1%) by the ICSI. These rates were significantly (P<0.05) higher than those for the ionomycin oocyte activation treatment (57.6% and 18.2%) but did not differ from the ethanol treatment (75.6% and 29.4%). In the sham-injected, the highest blastocyst production rates were observed for the ionomycin+DMAP and ethanol treatments (10.7% and 11.3%). Pregnancy and birth rates for blastocysts derived from the ethanol oocyte activation treatment (58.8% and 47.4%) were significantly higher (P<0.05) than those of the ionomycin+DMAP treatment (12.5% and 9.2%). The results showed that post-ICSI oocyte activation with ethanol is more effective than activation with ionomycin alone or with ionomycin+DMAP for the production of viable blastocysts and calves.

Reconstructive procedure after distal gastrectomy to prevent remnant gastritis

BACKGROUND/AIMS

Gastroduodenostomy (Billroth I) or gastrojejunostomy (Billroth II) after distal gastrectomy is associated with duodenogastric reflux and remnant gastritis. This study sought to determine which reconstructive procedure is least likely to cause remnant gastritis and to determine the correlation between duodenogastric reflux and remnant gastritis.

METHODOLOGY

Sixty patients who underwent curative distal gastrectomy for gastric cancer were classified into three groups by reconstructive procedure: group A, Roux-Y (n=18); group B, Billroth I (n=25); group C, Billroth II (n=17). Intragastric bile reflux was monitored using the Bilitec 2000 14 days after surgery, and endoscopy was performed and a patient questionnaire was completed 12 weeks after surgery.

RESULTS

Bile reflux occurred in 23.9%, 40.4%, and 73.4% of the time (p<0.001), and remnant gastritis developed in 33%, 76%, and 100% of patients (p<0.001), in groups A, B, and C, respectively. Helicobacter pylori infection did not correlate with remnant gastritis (p=0.57). Symptoms following Roux-Y reconstruction were comparable to those following Billroth I and II reconstructions.

CONCLUSIONS

Roux-Y reconstruction following distal gastrectomy is superior to Billroth I and II reconstruction in preventing remnant gastritis because it reduces duodenogastric reflux.

Real-time monitoring for detecting rejection using strain gauge force transducers in porcine small bowel transplantation

PURPOSE

The clinical results of small bowel transplantation (SBT) have not been satisfactory mainly because of the immunological barrier. It is important to detect the presence of and to perform adequate treatment of rejection as early as possible to improve graft survival. Therefore, we have established a pig model to monitor graft motility as a means to detect rejection in real time.

METHODS

Orthotropic SBT was performed in 25 pigs using FK-506 (0.05 to 0.1 mg/kg/d) immunosuppression. The interdigestive motor patterns were evaluated using strain gauge force transducers (SG). Seven pigs without SBT were treated as controls (C). Animals that displayed migrating motor complex (MMC) activity as evidenced by duration, amplitude, and interval in the graft were alive more than 10 days with adequate oral feeding: the functional graft (FG) group. In contrast the rejection (R) group did not show these activities on data recorded within 10 days before death due to rejection.

RESULTS

The FG group showed MMC propagated throughout the graft with all parameters almost the same as the control group except for the duration. In contrast, all parameters in the group R were significantly lower than those in group FG, suggesting that group R motility was obviously impaired by rejection.

CONCLUSIONS

The SG method may afford real-time monitoring of transplanted bowel motility that could be useful to detect rejection after SBT.

Comparison of three-field esophagectomy for esophageal cancer incorporating open or thoracoscopic thoracotomy

BACKGROUND

Thoracoscopic esophagectomy for esophageal cancer has been performed as an alternative to open surgery to reduce surgical trauma. However, its effect on pulmonary function, exercise tolerability, and quality of life is unknown.

METHODS

Fifty-one patients with esophageal cancer underwent thoracic esophagectomy with radical lymphadenectomy by posterolateral thoracotomy (29 cases) or thoracoscopic surgery (22 cases). Patients performed spirometry and exercise tolerance testing and completed a quality-of-life questionnaire before and 3 months after surgery.

RESULTS

Pre-to-postoperative change in vital capacity was 74.3 +/- 10.6% in the thoracotomy group and 84.9 +/- 10.4% in the thoracoscopy group (p = 0.021). Maximum oxygen uptake was similar, but dyspnea was the more common factor limiting exercise tolerance postoperatively in the thoracotomy group. Change in pre-to-postoperative performance status was 1.20 +/- 0.62 in the thoracotomy group and 0.55 +/- 0.51 in the thoracoscopy group (p = 0.0003).

CONCLUSIONS

Thoracoscopic esophagectomy for esophageal cancer has better preservation of pulmonary function and quality-of-life.

A comparison of video-assisted thoracoscopic oesophagectomy and radical lymph node dissection for squamous cell cancer of the oesophagus with open operation

The original article to which this erratum refers was published in British Journal of Surgery 2003; 90: 108–113.

Learning curve of video-assisted thoracoscopic esophagectomy and extensive lymphadenectomy for squamous cell cancer of the thoracic esophagus and results

BACKGROUND

The efficacy of thoracoscopic radical esophagectomy for cancer of the thoracic esophagus and the learning curve required have yet to be clearly established.

METHODS

Eighty treatment-naive patients with esophageal cancer without contiguous spread underwent esophageal mobilization and extensive mediastinal lymphadenectomy through a 5-cm minithoracotomy and four trocar ports. The outcomes in the first 34 patients (group 1) and the last 46 patients (group 2) were compared.

RESULTS

There were no differences in background or clinicopathologic factors between the two groups. The duration of the thoracoscopic procedure and blood loss were less (p <0.0001), the incidence of postoperative pulmonary infection was less (p = 0.0127), and the number of mediastinal nodes retrieved was greater (p = 0.0076) in group 2. Multivariate analysis demonstrated that surgical experience (number of cases performed) predicted the risk of pulmonary infection (p = 0.0331).

CONCLUSION

Video-assisted thoracoscopic radical esophagectomy can be performed with safety and efficacy comparable to those of open esophagectomy. Morbidity decreases with the surgeon's experience.

Immunologic effects of allogeneic versus autologous blood transfusion in patients undergoing radical oesophagectomy

Blood transfusion is often required in patients undergoing radical oesophagectomy, and is associated with immunosuppression that may worsen postoperative and long-term outcomes. However, the immunologic effects of allogeneic versus autologous transfusion have not been studied in this group of patients. We analyzed 103 patients who underwent radical oesophagectomy for oesophageal cancer, including 45 patients who received allogeneic transfusions (Allo), 16 patients who donated autologous blood but were not transfused (Auto-1) and 42 patients who received autologous transfusions (Auto-2). Peripheral blood lymphocyte subsets and natural killer (NK) cell activity were analyzed for 2 weeks postoperatively. Furthermore, the rate of infectious complications such as pneumonia and wound infection was compared. Patients receiving blood transfusion had decreased CD4+ lymphocyte counts and NK cell activity postoperatively, compared to Auto-1 patients. However, these abnormalities were corrected by day 14 in the Auto-2 group, but not in the Allo group. CD8+ lymphocyte counts were decreased in all groups postoperatively, returning to normal by 14 days in the Auto-1 group only. The rate of infectious complications was significantly higher in the Allo than in the Auto group. Blood transfusion is associated with adverse immunologic effects in patients undergoing radical oesophagectomy. However, autologous blood transfusion is favourable compared to allogeneic transfusion. Autologous transfusion programs should be employed when possible in this group of patients.

Transfer of cholesterol and diacylglycerol from lipophorin to Bombyx mori ovarioles in vitro: role of the lipid transfer particle

The objective of this study was to characterize the transfer of diacylglycerol (DAG) and cholesterol from larval Bombyx mori lipophorin to ovarioles. Transfer studies were carried out by incubating pupal ovarioles (5-day) with [(3)H]-cholesterol and [(3)H]-DAG-labeled lipophorin under different conditions. Transfer of both cholesterol and DAG exhibited hyperbolic dependency on lipophorin concentration with apparent Km values of 0.83 +/- 0.17 mg/ml and 0.74 +/- 0.16 mg/ml, respectively. Pretreatment of ovarioles with anti-lipid transfer particle (LTP) IgG significantly inhibited transfer of labeled DAG to ovarioles (75%) and not cholesterol. Injection of B. mori pupae (day 4) with anti-LTP IgG significantly affected the weight (65%), number of eggs (49%), amount of lipid (74%), and protein (65%) of the adult ovaries. Matured eggs had a very faint yellow color and deformed shape compared to controls. The inhibitory effect demonstrates the active role LTP plays in growth of ovaries, development, and oogenesis. The effect on vitellogenin shortage on egg development and maturation was determined by implanting ovaries in male recipients that lack vitellogenin. An 80% decline in egg production was observed. However, the mature eggs were normal in shape, color, and lipid content. Thus, restricting lipid or protein delivery to developing ovaries would dramatically affect choriogenesis.

A comparison of video-assisted thoracoscopic oesophagectomy and radical lymph node dissection for squamous cell cancer of the oesophagus with open operation

BACKGROUND

A direct comparison of open operation and video-assisted thoracoscopic surgery (VATS) for radical oesophagectomy has yet to be published.

METHODS

Medical records of 149 patients with oesophageal squamous cell carcinoma who underwent oesophagectomy and three-field lymphadenectomy were reviewed. Seventy-seven patients had the thoracic procedure performed via a 5-cm minithoracotomy and four ports (VATS group); the others were operated on by conventional posterolateral thoracotomy (open group).

RESULTS

The mean number of retrieved mediastinal nodes, blood loss and morbidity were similar in the VATS and open groups (33.9 versus 32.8 nodes, 284 versus 310 g, and 32 versus 38 per cent respectively). The thoracic procedure took longer in patients having VATS than in the control group (227 versus 186 min; P = 0.031). Vital capacity reduction was less with VATS than in the open group (15 versus 22 per cent; P = 0.016). The 3- and 5-year survival rates were similar: 70 and 55 per cent respectively for VATS compared with 60 and 57 per cent for the open procedure.

CONCLUSION

VATS provides comparable results to open radical oesophagectomy, with less surgical trauma.

Video-assisted thoracoscopic esophagectomy and radical lymph node dissection for esophageal cancer. A series of 75 cases

BACKGROUND

The efficacy of thoracoscopic radical esophagectomy for cancer has yet to be established, mainly because previous reports have not included a sufficient number of cases.

METHODS

Seventy-five treatment-naive patients with esophageal cancer without contiguous spread underwent esophageal mobilization and extensive mediastinal lymphadenectomy through a 5-cm mini-thoracotomy and four trocar ports.

RESULTS

Video-assisted thoracoscopic surgery was performed without major intraoperative complications or emergency conversion to open surgery. We retrieved 34.1+/-13.0 mediastinal nodes, including 11.5+/-3.8 tracheobronchial nodes and 6.2+/-3.0 recurrent laryngeal nodes. Mean time of operation and blood loss were less in the last 39 patients than the first 36 (186.7+/-25.3 min and 165.4+/-101.8 g vs 270. 2+/-96.0 min and 421.5+/-31.2 g, respectively: p <0.0001 and p <0.001). Pulmonary morbidity was 5% in the later 39 patients. Survival was 90%, 80%, and 57% at 1, 2, and 5 years after surgery.

CONCLUSION

Thoracoscopic radical esophagectomy has less morbidity and comparable survival to conventional surgery, after a moderate amount of experience. Mini-thoracotomy is essential to perform the procedure safely and effectively.

Usefulness of self-expandable metallic stent with an antireflux mechanism as a palliation for malignant strictures at the gastroesophageal junction

BACKGROUND

Patients with unresectable malignant gastroesophageal strictures often are troubled with reflux esophagitis after stent placement.

METHODS

A self-expandable metallic stent (SEMS) without an antireflux mechanism was placed in seven patients with unresectable malignant gastroesophageal strictures (group A), and SEMS with an antireflux mechanism was placed in five patients (group B). After we obtained monitoring systems, two patients in group A and all the patients in group B underwent measurement of bilirubin and pH in the esophagus using a 24-h bilirubin and pH monitor.

RESULTS

The mean percentage of total time less than 0.14 for use of the bilirubin absorbance unit was 12.4% in group B and 64.0% in group A. The mean percentage of total time for a pH less than 4 was 2.9% in group B and 37.8% in group A.

CONCLUSION

The placement of SEMS with the antireflux mechanism can be effective not only for palliation of gastroesophageal stricture, but also for prevention of reflux.

Repair of partial patellar ligament avulsion during total knee arthroplasty using the Statak device

Abstract The Statak is a suture anchor device used for attaching soft tissue to bone. This is a report on six knees in which this device was used to repair partial avulsion of the patellar ligament during total knee arthroplasty (TKA). The six patients were all women. The average age of the patients was 69 years. The diagnosis was osteoarthritis in three patients, rheumatoid arthritis in two, and steroid arthropathy in one. Three of the operations were revision arthroplasties. In all six cases, approximately half of the patellar ligaments were accidentally detached from the tibial tubercles during surgery, and were repaired using the Statak devices. The average length of follow-up was 3 years. The Knee Society knee score improved from an average of 15 points preoperatively to 87 points at the latest follow-up. The average total range of motion measured 104° before surgery and 108° at the latest follow-up. Three of the six knees operated on had no extensor lag. The suture anchor simplifies the secure fixation of the ligament to bone. The procedure can be performed easily and quickly. In our opinion, the Statak device has proven itself to be effective for the repair of partial patellar ligament avulsion during TKA.

Ultrastructural features of Borrelia garinii in naturally infected voles, Clethrionomys rufocanus, with special reference to the relationship with peripheral nerves

The ultrastructural features of Borrelia garinii found in the ear tissues of the vole, Clethrionomys rufocanus, are described. The spirochetes were observed in the interstitium of connective tissue or in contact with fibroblasts and were occasionally situated in the endoneurium of the peripheral nerves. The spirochetes did not injure or enter into the fibroblasts or Schwann cells. The cytotoxicity and migration of the spirochetes are also discussed.