Inhibitory effect of liposomal MDP-Lys on lung metastasis of transplantable osteosarcoma in hamster

MDP-Lys (N2-[(N-acetylmuramyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine), a macrophage activator, is a lipophilic derivative of muramyl dipeptide (MDP). Multilamellar liposome incorporated MDP-Lys was prepared using phosphatidylcholine and phosphatidylserine by conventional film method, and its inhibitory effect on lung metastasis was compared with MDP-Lys as a solution in hamster's osteosarcoma. The lung metastatic rates after transplantation of the tumor to a lower extremity, in which the extremity was amputated 3 weeks later, were 50% and 100% 3 and 7 weeks, respectively, after transplantation. The rates after amputation were reduced by the treatment with MDP-Lys proportionally to the logarithmic MDP-Lys dose, and the rates 7 weeks after transplantation were 55% and 60%, respectively, in the MDP-Lys solution (50 microg/day) and liposomal MDP-Lys (20 microg twice/week) groups. Fifty percent of hamsters treated with liposomal MDP-Lys survived for more than 6 months. Considering that hamsters had a lung metastasis rate of 50% before MDP-Lys treatment, liposomal MDP-Lys given at a dose of 20 microg twice/week was effective for inhibiting lung metastasis at a far lower dose of MDP-Lys than that given as a solution (40 microg vs. 350 microg per week). No significant side effect of liposomal MDP-Lys, as evaluated by the comparison of body weight changes among differently treated hamsters, was detected. This greater inhibitory effect of liposomal MDP-Lys can be considered to be due to the longer retention of the liposomal form in the lung.

A histological study of the necrotic area after transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head

We studied nine patients who had had a transtrochanteric anterior rotational osteotomy, as developed by Sugioka, for osteonecrosis of the femoral head. At a mean of 2.5 years after the initial operation we carried out a histological study of the previously necrotic femoral head which had not shown collapse of the new primary weight-bearing site. In seven joints, there was proliferation of fibrous tissue in the dead trabeculae with vascular ingrowth. New bone covering dead trabeculae created the characteristic appearance of 'creeping substitution'. However, these changes were limited and did not extend over the entire necrotic area. Dead bone remained in all the cases. In the other two heads we did not observe proliferation of fibrous tissue or vascular ingrowth, only dead trabeculae and dead bone marrow.

Transtrochanteric rotational osteotomy for osteonecrosis of the femoral head with preoperative superselective angiography

A prospective radiologic and scintigraphic study was made of 15 joints in 12 patients who underwent transtrochanteric rotational osteotomy of the femoral head after identifying by preoperative superselective angiography which arteries should be preserved during surgery. The preoperative superselective angiography revealed that the blood supply to the femoral head was provided by the medial femoral circumflex artery in 12 joints and a branch of the internal iliac artery in 3 joints. These nutrient arteries were preserved during surgery. At the follow-up examination made after at least 2 years, there were no cases of collapse of the new femoral head weight-bearing site, and also there were no cases with a large cold area in the femoral head on the scintigram obtained 2 months postoperatively. For this operative procedure, the nutrient arteries of the femoral head should be confirmed by preoperative superselective angiography, and it is essential that these arteries be preserved during surgery.

[Anesthetic management of a patient with pheochromocytoma and cerebral ischemic attacks]

A 15-year-old girl with history of two cerebral ischemic attacks possibly caused by cerebral vascular spasm was diagnosed as having a pheochromocytoma, and was scheduled for laparoscopic removal of the adrenal tumor. Epidural catheterization was performed at Th 12/L 1. General anesthesia was induced with thiamylal and vecuronium, and maintained with nitrous oxide-oxygen-isoflurane and continuous epidural infusion of 1.5% lidocaine. Phentolamine and thiamylal were continuously administrated into the vein. While operating on the tumor, abnormal hypertension did not occur. Just after removal of the tumor, the systolic blood pressure fell to 50-70 mmHg. The hypotension continued for about 75 min, despite administration of dopamine, norepinephrine and epinephrine. After the emergence from anesthesia, the blood pressure recovered to normal level. No neurocerebral abnormality was found. In patients like this one, we have to prevent cerebral vascular spasm and cerebral infarction caused by excessive secretion of catecholamines.

Rotational acetabular osteotomy for hip dysplasia: spontaneous medial enlargement of the acetabulum

We followed 56 patients (63 joints) who had undergone rotational acetabular osteotomy (RAOs) between 1987 and 1993, mean 7 (5-12) years. The Merle d'Aubigné score increased by 15 points or more in 59 and decreased in 4 hips. The arthrosis progressed in 5 joints. In about 2/3 of the cases, we observed some medial and/or lateral expansion of the subchondral bone in the acetabulum 3 years postoperatively, suggesting enlargement of the load-bearing area.

Targeted systemic chemotherapy using magnetic liposomes with incorporated adriamycin for osteosarcoma in hamsters

To control the growth of primary tumors effectively with systemic chemotherapy, we recently developed intravenously administered small-sized magnetic liposomes as an anticancer drug carrier. We previously reported that intravenously administered magnetic liposomes with incorporated adriamycin (magnetic ADR liposomes) effectively delivered ADR to the target site where a permanent magnet was implanted. In the present study, the therapeutic efficacy of this novel treatment approach, which involves a combination of magnet implantation at the target site and intravenous administration of magnetic liposomes, was further evaluated by comparing tumor growth rates among different administration modalities and by histological examination of treated tumors. Small-sized magnetic ADR liposomes with a mean diameter of 146 nm were prepared by the reverse-phase evaporation method. Syrian male hamsters inoculated with osteosarcoma, Os515, in the right hind limb were studied 7 days after inoculation. One day prior to the animal study, either a permanent magnet (with magnetic force) or non-magnetic alloy (without magnetic force) was implanted in the center of the tumors. Treatment with magnetic ADR liposomes under magnetic force showed significantly greater antitumor activity than intravenous administration of ADR solution or that of magnetic ADR liposomes without magnetic force. ADR administered as magnetic liposomes eliminated weight loss of hamsters, one of the side effects produced by ADR. Interestingly, magnetic liposomes (without incorporated ADR) given under magnetic force also suppressed the tumor growth. The selective accumulation of magnetite particles in the tumor blood vessels was observed by histological examination. These results suggest that this systemic chemotherapy can effectively control the primary tumor without significant side effects, due to the targeting of magnetic ADR liposomes.

Plasma matrix metalloproteinase-9 (gelatinase B) in patients with hepatocellular carcinoma

Increased plasma levels of matrix metalloproteinase (MMP)-9 have been shown in cancerous diseases including hepatocellular carcinoma (HCC). Our present aim was to examine whether the measurement of plasma MMP-9 concentration is clinically useful for assessing or monitoring HCC patients. We measured the plasma MMP-9 concentrations in 47 HCC patients, and compared the results with the clinicopathologic features. The plasma MMP-9 levels in patients with HCC were significantly higher than those in the normal controls. The plasma levels of MMP-9 were not related to the size of HCC tumor, the grade of histological differentiation and the serum alpha-fetoprotein level. The plasma levels of MMP-9 were not significantly changed after the effective treatment of HCC tumors. In conclusion, the plasma MMP-9 test was of little value for assessing or monitoring HCC patients.

A novel human HER2-derived peptide homologous to the mouse K(d)-restricted tumor rejection antigen can induce HLA-A24-restricted cytotoxic T lymphocytes in ovarian cancer patients and healthy individuals

A mouse HER2-derived peptide, HER2p63 (A) (TYLPANASL), can induce K(d)-restricted mouse cytotoxic T lymphocytes (CTL) and also function as a tumor rejection antigen in an in vivo assay. Since the anchor motif of mouse K(d) for peptide binding has much similarity to that of human HLA-A2402, we asked if human HER2p63 (T) (TYLPTNASL) could induce HER2-specific CTL in HLA-A2402-positive individuals. Peripheral blood mononuclear cells (PBMC) of HLA-A2402-positive individuals were sensitized in vitro with HER2p63-pulsed autologous dendritic cells prepared from PBMC. CTL clone derived from these specifically lysed HER2-expressing cell lines bearing HLA-A2402. Cytotoxic activity of the CTL clone against the HER2-expressing cell line bearing HLA-A2402 was blocked by antibodies against CD3, CD8, HLA-A24 or MHC class I, and was also inhibited by the addition of excess HER2p63-pulsed C1R bearing HLA-A2402. Killer cells were generated from PBMC of seven healthy individuals and five ovarian cancer patients, all of HLA-A2402 type, by in vitro sensitization with HER2p63-pulsed autologous antigen presenting cells. These killer cells selectively lysed HER2-expressing SKOV3 transfected with HLA-A2402 cDNA, indicating high immunogenicity of HER2p63 in all 12 individuals examined.

Pathogenesis of retinoic acid-induced abnormal pad patterns on mouse volar skin

BACKGROUND

Abnormal dermatoglyphs on human volar skin have been reported in many syndromes, but little is known about the pathogenesis. Patterns of pads on rodent limb volar skin are homologous to human dermatoglyphs.

METHODS

In previous studies, we showed that transplacental exposure to teratogens induced abnormal pads in mouse fetuses. Moreover, teratogens caused abnormal pad patterns at levels below those that caused skeletal malformations. In this study, we examined morphology and cytokinetics in developing abnormal pads. Pregnant mice were treated with all-trans-retinoic acid at 20 mg/kg orally at embryonal day (E) 12.5 (vaginal plug = E0). The hindlimbs of the embryos were harvested and observed under a light microscope and by scanning electron microscopy. Cell proliferation and cell death were estimated by 5-bromo-2'-deoxyuridine (BrdU) labeling, Nile blue A vital staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL).

RESULTS

Retinoic acid induced aplasia of the fibular tarsal pad and supernumerary interdigital pads on hindlimbs. Cell proliferation was observed in the area of developing pad, but cell death was very rarely seen in either normal or abnormal pads.

CONCLUSIONS

Retinoic acid disturbed pad patterning as a whole rather than individual pad formation.

Pretibial cyst formation after anterior cruciate ligament reconstruction using auto hamstring grafts: two case reports in a prospective study of 89 cases

Eighty-nine cases after anterior cruciate ligaments (ACL) reconstruction were followed prospectively with magnetic resonance imaging (MRI). The patients were examined using axial and sagittal MRI at least twice during the postoperative evaluation of reconstructed ACL. Two cases of pretibial cyst formation were observed. At the time of cyst formation, neither patient had any subjective or objective evidence of knee instability. The cyst of one case communicated with the intra-articular. The minimum follow-up period after the surgical excision was 9 months, with no evidence of recurrence. We might speculate that the critical period for cyst formation in both patients occurred at less than 12 months after their ACL reconstruction. We concluded that the cyst formation was most likely due to incomplete graft tendon incorporation within the osseous tunnel.

Development of a cancer vaccine: peptides, proteins, and DNA

Genetic changes leading to protooncogene activation qualitatively and/or quantitatively alter their gene products and are exclusively or largely restricted to transforming cells and their precursors. The overexpression of HER2 is among those changes and is often detected in adenocarcinomas such as breast, ovarian, lung, and gastric cancer. This provides a rationale for exploring the possibility that HER2 is a target of host immune responses against cancer cells. We have recently demonstrated that HER2 can be a target for tumor-rejecting immune responses against syngeneic murine HER2+ tumor cells. We defined two different peptides, HER2p63-71 and HER2p780-788, with a Kd anchor motif that can induce CD8+ cytotoxic T lymphocytes (CTLs). The growth of HER2+ syngeneic tumors was suppressed in mice immunized with HER2p63-71 or p780-788. Since murine Kd and human HLA-A24 share a similar anchor motif for peptides, HER2p63 71 and HER2p780-788 were examined for induction of CTLs in HLA-A24+ individuals. CD8+ CTL clones specific for these peptides were established and they lysed HER2+ tumor cells in a human leukocyte antigen (HLA)-A24-restricted manner. To elicit specific CD8+ T cell immune responses against cancer, the development of efficient devices to deliver tumor antigen peptides to the major histocompatibility complex (MHC) class I pathway constitutes a central issue. We have developed a novel formula of hydrophobized polysaccharide nanoparticles which can deliver a HER2 oncoprotein containing an epitope peptide to the MHC class I pathway. We designed a simple protein delivery system: cholesteryl group-bearing polysaccharides, mannan or pullulan (CHM or CHP, respectively), complexed with the truncated HER2 protein containing the 147 N-terminal amino acids. These complexes were able to induce CD8+ CTLs against HER2+ tumors. CTLs were MHC class I restricted and specifically recognized HER2p63-71, a part of a truncated HER2 protein used as an immunogen. The complete rejection of tumors also occurred when CHM-HER2 was applied early after tumor implantation. In the effector phase of in vivo tumor rejection, CD8+ T cells played a major role. The results suggest that this unique hydrophobized polysaccharide may help soluble proteins to induce cellular immunity. Such a novel vaccine may be of potential benefit in cancer prevention and cancer therapy.

Trapeziometacarpal joint arthrodesis for the treatment of arthrosis

We undertook a retrospective follow-up study of arthrodesis of 21 trapeziometacarpal joints in 19 patients. Internal fixation was by two or three Kirschner wires and a bone graft. No joint failed to unite. Painless joints and stable grasping were achieved. Subjective estimations of improvement were excellent for 16 joints. However, some patients complained of clumsiness after the procedure. Instability was seen in six metacarpophalangeal (MP) joints of the thumb. The most common indication for trapeziometacarpal joint arthrodesis was painful arthritis in vigorous, young male labourers. However, preoperative evaluation of the function of the MP joint is necessary to determine suitability for surgery.

A HER2/NEU-derived peptide, a K(d)-restricted murine tumor rejection antigen, induces HER2-specific HLA-A2402-restricted CD8(+) cytotoxic T lymphocytes

We have identified an H-2K(d)-binding peptide, HER2p780 (PYVSRLLGI), derived from murine HER2/neu (HER2), that can induce HER2-specific murine cytotoxic T lymphocytes (CTL). Weekly vaccination of BALB/c mice by syngeneic dendritic cells pulsed with HER2p780 peptide, entirely common to murine and human HER2, suppressed growth of pretransplanted HER2-expressing syngeneic tumors. A HER2-expressing human cancer cell line SKOV3 transfected with murine H-2K(d) cDNA could also be lysed by HER2p780-specific murine CTLs, indicating that human HER2-expressing cancer cells can process and present the cognate peptide in the context of H-2K(d). Since H-2K(d) and HLA-A2402 molecules have similar anchor motifs, the possibility of inducing HER2-specific CTL activity with HER2p780 in HLA-A2402 individuals was examined. CD8(+) CTL clones specific for HER2-expressing cancer cell lines were established from peripheral blood lymphocytes with HLA-A2402 by repeatedly sensitizing with peptide-pulsed autologous dendritic cells as well as peripheral blood mononuclear cells. Detailed analysis of their specificity revealed that the cytotoxicity of CTL clones is specific for the cognate peptide with HLA-A2402 restriction. The results suggest that HER2p780 is a unique peptide that may function as a tumor rejection antigen peptide in HLA-A2402 individuals, as it was directly proven here to function in a murine tumor system.

The current perception thresholds vary between horizontal and 70 degrees tilt-up positions

We investigated the influence of posture on current perception threshold (CPT). The subjects consisted of 20 healthy male volunteers (23-31 yr old). At both the horizontal and the 70 degrees tilt-up position (TUP), the CPTs (5, 250, and 2000 Hz) of the middle finger were determined by using the Neurometer CPT/C (Neuropteran, Baltimore, MD). Autonomic nervous activities were evaluated by heart rate variability (HRV) analysis and spontaneous baroreflex sensitivity analysis at the two postures previously mentioned. The three CPTs at the 70 degrees TUP were significantly lower than those at the horizontal posture (5 Hz, P < 0.05; 250 Hz, P < 0.001; 2000 Hz, P < 0.05). The changes in HRV and spontaneous baroreflex sensitivity at the 70 degrees TUP indicated decreasing parasympathetic tone. The CPTs of 5 and 250 Hz were significantly correlated with mean systolic blood pressure at the 70 degrees TUP. The CPT of 2000 Hz was significantly correlated with the 0.15-0.4 Hz component in HRV at both postures. The regression analysis of the difference of 5 Hz CPT with that of the mean systolic blood pressure showed a significant correlation (P < 0.001). To evaluate the clinical course of peripheral nerve disorders, the comparison of CPTs measured during the same posture is important. This suggests that CPTs must be measured at the horizontal posture.

IMPLICATIONS

Current perception thresholds at the 70 degrees tilt-up posture were significantly lower than those at the horizontal posture. When the compensatory mechanism for preserving blood pressure was emphasized, the current perception thresholds would have a relational connection to mean systolic blood pressure, similar to the concept of hypertension-induced hypoalgesia.

Targeted delivery of anticancer drugs with intravenously administered magnetic liposomes in osteosarcoma-bearing hamsters

Although active targeting of anticancer drugs using magnetically responsive carriers is a very attractive treatment approach for solid tumors, successful results are limited. In particular, the therapeutic utility of intravenously administered magnetically responsive carriers has to date not been clearly established. The present study investigates magnetic liposomes designed to act as anticancer drug carriers, which can be effectively delivered to solid tumors via intravenous administration. Magnetic liposomes with incorporated adriamycin (magnetic ADR liposomes) were prepared by the reverse-phase evaporation method, and an in vivo study was carried out to assess the magnetic targeting of these liposomes to hamster osteosarcoma. The average diameter of liposomes thus prepared was 146 nm. Syrian male hamsters inoculated with osteosarcoma, Os515, in the right hind limb were studied 7 days after inoculation. After the hamsters had received an intravenous administration of either magnetic ADR liposomes or ADR solution (corresponding to 5 mg ADR/kg), the ADR concentrations in plasma, tumor, liver, lung, heart, and kidney were determined at designated time intervals. Administration of magnetic ADR liposomes under magnetic force using a permanent magnet (0.4 tesla) implanted in solid tumor produced an approximately 4-fold higher maximum ADR concentration in the tumor than did administration of ADR solution. The former administration modality induced an increase in ADR concentration in the liver and lung and a decrease in the heart compared with concentrations produced by the latter. The present results indicated that intravenously administered magnetic ADR liposomes can be used to effectively deliver ADR to osteosarcoma implanted with a magnet, as well as to the lung, a common site of metastases for osteosarcoma. Our results also suggest that this new treatment approach, which involves a combination of magnet implantation at the target site and intravenous administration of magnetic liposomes, can improve the clinical chemotherapy of solid tumors.

An absorbable pinned-ring device for microvascular anastomosis of vein grafts: experimental studies

In the rabbit, posterior facial vein segments were grafted to the femoral arteries using either conventional suture technique or a mechanical absorbable pinned-ring device. The purpose of this study was to compare patency rates and anastomotic times for the two different methods. The anastomoses were evaluated macroscopically and using light and scanning electron microscopy. The grafts anastomosed with the absorbable rings exhibited 100% patency, while only 83% of the sutured grafts were patent. The mean anastomotic time using the mechanical pinned-ring device was 18.1 min (range 9.8-30 min). The conventionally sutured anastomoses were completed in a mean time of 60 min (range 50-75 min). The experiment has confirmed that the absorbable pinned-ring device provides a safe and fast way to perform microvascular anastomosis.

Double-toe transplantation following temporary insertion of a block of silicone for reconstruction of a traumatic metacarpal defect

The treatment of the mutilated hand with more than one digit missing and a metacarpal defect is challenging. We used double-toe transfer after temporary insertion of a block of silicone to fill the bony defect.

Surgical treatment of the cleft foot

Between 1970 and 1997, we treated a total of 32 cleft feet in 21 patients (11 male and 10 female). We classified cases of cleft foot on the basis of the number of central ray deficiencies. Fourteen patients with 22 cleft feet were followed up for more than 1 year postoperatively (9 feet had no or one central ray deficiency, and 13 feet had two or three central ray deficiencies). The mean follow-up period was 8.8 years. The objective of this study was to evaluate the results of operative treatment of cleft foot. We evaluated the results of three methods: simple closure of the cleft, application of a double-pedicled flap, and insertion of a silicone block. Cosmetic complications, including widening of the foot, hypertrophic scarring, pigmentation of the grafted skin, and overlapping of the toes, were observed in patients with two or three central ray deficiencies. Few functional complications were observed: None of the patients experienced gait disturbances, although one patient complained of pain following walking. Roentgenography showed that the distance between the first and fifth metatarsals was 86 percent of that of the contralateral foot. When treating patients with no or one central ray deficiency, satisfactory results can be expected with simple closure of the cleft. However, in patients with two or three central ray deficiencies, it is difficult to obtain satisfactory results with simple closure of the cleft or application of a double-pedicled flap. Therefore, silicone block insertion to correct the defect is recommended when there is more than one central ray deficiency.

Two Alangium alkaloids from Alangium lamarckii

Two new Alangium alkaloids, 1',2'-dehydrotubulosine (1) and alangine (2), were isolated from the dried fruits of Alangium lamarckii along with tubulosine (3), isotubulosine (4), deoxytubulosine, cephaeline, isocephaeline, psychotrine, neocephaeline, 10-O-demethylcephaeline, 2'-N-(1"-deoxy-1" -beta-D-fructopyranosyl)cephaeline, protoemetine, protoemetinol, salsoline, and alangiside. The structures of the new alkaloids (1 and 2) were determined by spectroscopic and chemical means.

Changes in serum tissue inhibitor of matrix metalloproteinase-1 after interferon alpha treatment in chronic hepatitis C

BACKGROUND/AIMS

The aim of this study was to evaluate the effect of interferon alpha on the metabolism of hepatic fibrosis in chronic hepatitis C, monitoring serum tissue inhibitor of matrix metalloproteinase-1(TIMP-1) and N-terminal propeptide of type III procollagen (PIIINP) reflecting fibrolysis and fibrogenesis, respectively.

METHODS

Serum levels of TIMP-1 and PIIINP were serially measured in 112 treated and 31 untreated patients with chronic hepatitis C during and after interferon alpha treatment. Furthermore, the relationships between these serum markers and the grades of hepatic fibrosis after interferon therapy were also investigated.

RESULTS

Serum pretreatment levels of TIMP-1 and PIIINP in non-responders were significantly higher than those in sustained and transient responders, but these levels were not different in the latter two groups. Serum TIMP-1 levels decreased significantly during and after treatment in sustained responders, and decreased temporarily at the end of treatment in transient responders, although these levels were unchanged during and after treatment in non-responders and untreated patients. In contrast, serum PIIINP levels decreased significantly during and after treatment in all treated groups, but were unchanged in untreated patients. Histological examination 12 months after interferon was completed demonstrated that hepatic fibrosis improved in sustained responders and was unchanged in transient and non-responders, but progressed in untreated patients.

CONCLUSION

These results suggest that interferon alpha treatment of chronic hepatitis C may improve hepatic fibrosis in sustained responders by the acceleration of fibrolysis as well as the inhibition of fibrogenesis, and that it may suppress the progression of hepatic fibrosis in non-sustained responders by the inhibition of fibrogenesis.

Light and electron microscopic study of peripheral nerve damage in patients with lepromatous leprosy (LL) and borderline lepromatous leprosy (BL)

Cutaneous branches of radial nerves in patients with lepromatous leprosy (LL) and borderline lepromatous (BL) were studied by light and electron microscopy. Foamy macrophages were found more or less in the nerve fibers of all leprosy patients and distributed in the epineurial, perineurial and endoneurial areas. In the endoneurium, the foamy macrophages were mainly located in the subperineurial and perivascular spaces. Vacuolated Schwann cells were also found in the nerve fasciculus. In electron microscopy, these foamy macrophages and vacuolated Schwann cells contained numerous small dense materials, irregular in size and shape, considered to be degenerated and fragmented mycobacterium leprae. These dense materials were found also in the cytoplasm of vascular endothelial cells. These findings suggest that mycobacteria enter into the endoneurium via the blood vessels. In our present study, on the other hand, it was very difficult to find the intact mycobacteria in the cytoplasm of the foamy macrophages, Schwann cells or endothelial cells, as well as in the Ziehl-Neelsen staining of paraffin sections. The disappearance of intact bacilli in our present study might have been caused by multi drug therapy. The myelinated nerve fibers were degenerated and disappeared in variable degrees. Degenerative changes of the myelin sheath developed from the outer layer to the inner layer with disarrangement of the lamellar structure. These findings were different from myelin destruction of peripheral nerves in Wallerian degeneration. The degenerative changes of the myelin sheath are caused by degeneration and destruction of Schwann cells in leprosy patients. Fibrosis surrounding myelinated and unmyelinated nerve fibers, i.e., periaxonal fibrosis, was found to a greater or lesser extent in the endoneurium. In the present study, it is still unclear whether the periaxonal fibrosis was due to necrosis of the Schwann cells by infection of mycobacteria or to an autoimmune mechanism such as antiperipheral nerve antibody. However, lamellated concentric fibrosis surrounding regenerative myelinated and unmyelinated nerve fibers with the disappearance of mycobacteria suggests that degenerations and regenerations of nerve axons were repeated during clinical cause. These findings indicated that autoimmune mechanisms play an important role in the pathogenesis of periaxonal fibrosis.

The anatomic relation among the nerve roots, intervertebral foramina, and intervertebral discs of the cervical spine

STUDY DESIGN

An anatomic study of the cervical intervertebral foramina, nerve roots, and intradural rootlets performed using a surgical microscope.

OBJECTIVES

To investigate the anatomy of cervical root compression, and to obtain the anatomic findings related to cervical foraminotomy for the treatment of cervical radiculopathy.

SUMMARY OF BACKGROUND DATA

Cervical foraminotomy is a procedure performed frequently for the management of cervical radiculopathy. However, anatomic studies of cervical foraminotomy have not been fully elucidated.

METHODS

In this study, 18 cadavers were obtained for the study of the cervical spine. All the soft tissues were dissected from the cervical spine. Thereafter, laminectomy and facetectomy were performed on C4 through T1 using a surgical microscope. The nerve roots and surrounding anatomic structures, including intervertebral discs and foramina, were exposed. In addition, the intradural rootlets and their intersegmental connections were observed.

RESULTS

The shape of the intervertebral foramina approximated a funnel, the entrance zone being the most narrow part and the root sleeves conical, with their takeoff points from the central dural sac being the largest part. Therefore, compression of the nerve roots occurred at the entrance zone of the intervertebral foramina. Anteriorly, compression of the nerve roots was caused by protruding discs and osteophytes of the uncovertebral region, whereas the superior articular process, the ligamentum flavum, and the periradicular fibrous tissues affected the nerve posteriorly. The C5 nerve roots were found to exit over the middle aspect of the intervertebral disc, whereas the C6 and C7 nerve roots were found to traverse the proximal part of the disc. The C8 nerve roots had little overlap with the C7-T1 disc in the intervertebral foramen. The C6 and C7 rootlets passed two disc levels in the dural sac. Also, a high incidence of the intradural connections between the dorsal rootlets of C5, C6, and C7 segments was found.

CONCLUSIONS

This study demonstrated the anatomy of the nerve roots, rootlets, and intervertebral foramina, and may aid in understanding the pathology of cervical radiculopathy. The presence of intradural connections between dorsal nerve roots and the relation between the course of the nerve root and the intervertebral disc may explain the clinical variation of symptoms resulting from-nerve root compression in the cervical spine. To perform cervical foraminotomy for cervical radiculopathy, it is necessary to understand the detailed anatomy of the intervertebral foramina thoroughly.