Sodium channel mutations (T929I and F1534S) found in pyrethroid-resistant strains of the cigarette beetle, Lasioderma serricorne (Coleoptera: Anobiidae)

RNA-seq data analysis of cigarette beetle (Lasioderma serricorne) strains having different sensitivities to pyrethroids identified sodium channel mutations in strains showing pyrethroid resistance: the T929I and F1534S mutations. These results suggest that reduced sensitivity of the sodium channel confers the pyrethroid resistance of L. serricorne. Results also showed that the F1534S mutation mostly occurred concurrently with the T929I mutation. The functional relation between both mutations for pyrethroid resistance is discussed.

Molecular monitoring of Neoseiulus californicus released from sheltered slow-release sachets for spider mite control in a Japanese pear greenhouse

A novel system for spider mite control was developed with a slow-release sachet containing Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) protected by a waterproof shelter. Monitoring the efficacy of the predator release system for spider mite control at a Japanese pear greenhouse requires discrimination of N. californicus from other indigenous phytoseiid mite species inhabiting the study site and subsequent identification of the released N. californicus. The report of our earlier study described a PCR-based method for discrimination of N. californicus species. For the present study, we first examined phytoseiid mite species composition in the greenhouse. Subsequently, we developed microsatellite markers to identify the released N. californicus. Finally, we installed the predator release system in the greenhouse and conducted a population survey of phytoseiid and spider mites. Results demonstrated that approximately 1 month is necessary for distribution of the released N. californicus on the leaves.

Pathology of experimental disuse muscular atrophy in rats

The relationship between structural changes and hyaluronic acid (HA) content in muscular atrophy is unknown. The objective of our study was to conduct multifaceted evaluations of the change in muscle extensibility in muscular atrophy, in terms of morphological aspects as well as from a biochemical viewpoint, including changes in intercellular substances. Using a muscular atrophy model of the soleus muscle in the cast-fixed limbs of Wistar rats, we examined changes in HA accompanying muscular atrophy. Compared with controls, the cast-fixed limbs showed histological evidence of muscular atrophy and electron microscopy indicated destruction of the fasciae. Measurement of the HA level in muscle tissue from cast-fixed rats indicated a reduction in concentration per unit of weight. In contrast, serum HA concentrations increased in the cast-fixed group compared with the control group, suggesting that HA present in the fasciae was released into the blood stream during muscular atrophy.

Vascularized nerve grafts for the treatment of large nerve gap after severe trauma to an upper extremity

We reviewed the clinical outcomes of vascularized nerve grafts for the repair of large nerve gaps (longer than 20 cm) after severe trauma to an upper extremity. Six patients who underwent vascularized sural nerve grafting (five to the median nerve and one to the ulnar nerve) with a monitoring skin flap were evaluated. The length of the vascularized sural nerve grafts ranged from 20 to 30 cm, with a mean length of 23.3 cm. All but one of the monitoring skin flap grafts was successful. In those patients for whom the monitoring skin flap graft was successful, the mean static-2PD at the corresponding fingertip was 14.2 mm (range 10-20 mm). Evaluation of these patients with the Semmes-Weinstein test produced the following results: filament 6, two patients; filament 10, three patients. The results of this study show that vascularized sural nerve grafting should be considered as a clinical alternative for nerve reconstruction in patients with nerve defects longer than 20 cm.

Ruptured abdominal aortic aneurysm associated with a psoas abscess

A case of abdominal aortic aneurysm infected by Salmonella dublin is presented. Computed tomography (CT) revealed an abdominal aortic rupture associated with a psoas abscess. An axillo-femoral bypass was performed. The aneurysm and the psoas abscess were resected.

[Anesthetic management of a patient with von Recklinghausen disease complicated with spinal tumor and severe spinal deformity]

We had three occasions of giving anesthesia to a patient with von Recklinghausen disease complicated with spinal tumor and spinal deformity. A 49-year-old male patient who had suffered from von Recklinghausen disease since 35 years of age developed slight low respiratory function due to neurofibroma in the spinal canal and the paravertebral lesion and severe kyphoscoliosis in the lumbar spine which were checked by lumbar X-ray, abdominal ultrasonography and computed tomography during the preoperative period. Transurethral biopsy of the bladder tumor, internal urethrotomy for the urethral stricture and vesical lithotripsy for the bladder stone were performed under general anesthesia. Elevated position of his head and lower extremities and slight right lateral decubitus position were employed during anesthetic induction and semi-Trendelenburg's position during anesthetic maintenance. Convalescence after each operation was uneventful. He was comfortable and had a safe perioperative course. He showed no unward change in neurological symptoms during the post-operative period. This case suggests that we must take the complication such as spinal tumor and spinal deformity into consideration for anesthetic management of patients with von Recklinghausen disease and select the appropriate anesthetic method and patient's position.

[Usefulness of epidural administration of ketamine for relief of postherpetic neuralgia]

Four patients with postherpetic neuralgia had their pain alleviated by epidural administration of ketamine. No oral non-steroidal anti-inflammatory drugs and anti-depressant drugs were effective in all cases. Lidocaine or bupivacaine was administered epidurally to all four patients. When these patients stated that they did not feel pain reduced, they received epidural infusion of ketamine at doses from 5 mg to 20 mg with lidocaine or bupivacaine and their postherpetic neuralgia was controlled. Therefore with these cases, we suspect that epidural administration of ketamine, an antagonist for N-methyl-D-aspartic acid receptor, could be an effective and useful alternative treatment in a patient with refractory postherpetic neuralgia.

[Blood concentrations and side effects of tacrolimus in a living renal transplantation]

In a living renal transplantation, the recipients are administered an immunosuppressive agent preoperatively. The drug exhibits a high incidence of side effects of special note. We examined the side effects of tacrolimus to evaluate the postoperative management of living renal transplantation. Hypertension, hyperglycemia, tachycardia and chest pain were found as the side effects. The blood concentration should be measured frequently to maintain the effective blood concentration and to prevent the side effect.

The effect of age on inflammatory responses and nerve root injuries after lumbar disc herniation: an experimental study in a canine model

STUDY DESIGN

An experimental investigation on the effect of age on pathologic events surrounding the herniated disc and at the adjacent nerve root.

OBJECTIVES

To investigate the role of age on the inflammatory responses and nerve root damage surrounding a sequestered lumbar disc fragment using a dog model.

SUMMARY OF BACKGROUND DATA

Lumbar disc herniation is manifested in patients by variable clinical findings, natural history, and resorption phenomena in which the variability is particularly noted among patients with different ages. There are no previous reports on the effect of age on pathologic events induced by the herniated disc.

METHODS

Six beagle dogs, including two animals of each age group of 6, 12, and 24 months (human equivalent ages of 10, 15, and 24 years), were used in this study. The dogs underwent L4-L5, L5-L6, and L6-L7 laminotomy and discectomy under general anesthesia. An autologous intervertebral disc from the tail was divided into anulus fibrosus and nucleus pulposus fragments. The anulus fibrosus and nucleus pulposus fragments were placed in the anterolateral epidural space of L5-L6 and L6-L7, respectively. The L4-L5 discectomy site served as a control. Dogs were killed at 12 weeks after surgery. The lumbar spine was removed en bloc, and histologic sections were prepared consecutively and examined.

RESULTS

In the nucleus pulposus group at L6-L7, neovascularity, and intensive infiltration of lymphocytes, macrophages, and fibroblasts were observed surrounding the nucleus pulposus fragment in the 24-month-old group only. Degenerative changes of the nerve root fibers were observed in the 24-month-old group only. In the control and anulus fibrosus groups at L4-L5 and L5-L6, there were no marked inflammatory reactions in all age groups. The nerve root fibers around the anulus fibrosus were normal in all age groups.

CONCLUSIONS

There is an effect of age on the inflammatory response and nerve root injury caused by the herniated disc. The apparent neuroprotective mechanism in the young animal, and the apparent inflammatory and resorption changes of the nucleus pulposus fragment in the older animal are quite intriguing.

Characterization of the recombinase activating gene-1 and 2 locus in the Japanese pufferfish, Fugu rubripes

The recombinase activating genes (RAG1 and RAG2) encode nuclear proteins that directly mediate the mechanism V(D)J recombination process that occurs in T- and B-lymphocytes. The expression of RAG1 and RAG2 is required for the proper development of maturing lymphocytes. To identify evolutionary conserved regulatory regions adjacent to both genes we isolated and sequenced a cosmid clone containing 43kb of genomic DNA of the Japanese pufferfish, Fugu rubripes. Fugu has a haploid genome of 400Mb and contains the same number of genes as the genome of higher vertebrates. With low abundance of repetitive DNA, the genome of the pufferfish has shown to be ideal for comparative genomics. We found three complete genes, RAG1, RAG2 and ACS (a possible homologue of the plant 1-aminocyclopropane-carboxylate synthase gene). There is also the 5' exon of a prohormone convertase gene, possibly PACE4. The genetic structure of both RAG1 and RAG2 is identical to that found in other fish, but the size of the intergenic region is smaller in Fugu. Expression analysis by RT-PCR shows the presence of RAG transcripts in kidney of adult Fugu. The human ACS was identified in a cosmid assigned to chromosome 11p11, which is close to the location of the RAGs (11p12). This indicates conservation of linkage between human and pufferfish.

Solitary fibrous tumor of the spinal cord. Report of a case with scrape cytology

BACKGROUND

Solitary fibrous tumor is a rare spindle cell tumor and has been forced at a variety of sites. To the best of our knowledge, only two cases of solitary fibrous tumor arising in the spinal cord have been reported; no cytologic findings were documented.

CASE

A 62-year-old male presented with a spinal cord tumor. A scrape smear of the resected tumor revealed naked, spindle-shaped nuclei. Some nuclei were twisted or had long spindles. In the background, abundant, thin and thick collagen fibers were present. Immunohistochemically, the spindle cells were positive for CD34 and negative for S-100 protein and alpha-smooth muscle actin. Histologic diagnosis of the tumor was benign solitary fibrous tumor.

CONCLUSION

Our case indicates that solitary fibrous tumor can occur in the spinal cord and should be differentiated from other benign spindle cell tumors, such as meningioma and schwannoma. The key cytologic features of solitary fibrous tumor may be the presence of abundant thin and thick collagen fibers in scrape specimens.

Scrape cytology of elastofibroma. Report of a case with diagnostic cytologic features

BACKGROUND

Elastofibroma is a benign, soft tissue tumor that occurs most frequently in the subscapular area in elderly people. To the best of our knowledge, in only two cases has the cytology been reported. The aim of this report is to describe the characteristic cytologic findings of elastofibroma and to discuss the usefulness of elastin stain in scrape smears.

CASE

A 72-year-old female had bilateral masses in the lower subscapular area. Scrape smears from a cut surface of the resected masses revealed abundant, "wormlike" or "braidlike" material with central cores with Papanicolaou stain in an intraoperative consultation. Various-sized, petaloid or crystalloid globules were also present. Those elastic fibers were strongly positive for elastin stain in cytologic preparations.

CONCLUSION

Elastofibroma can be diagnosed cytologically, and elastin-stained, scrape cytologic preparation is especially useful in such a case.

Intraosseous epithelioid malignant peripheral nerve sheath tumor of the phalanx. Case report

We report the first case of intraosseous epithelioid malignant peripheral nerve sheath tumor (MPNST) occurring in the phalanx. The patient was a 50-year-old Japanese man with an intramedullary lytic lesion of the proximal phalanx. Microscopically, the tumor was composed of epithelioid cells or polygonal cells, forming large cell nests with central necrosis. Most tumor cells were diffusely and strongly immunopositive for S-100 protein and vimentin, and negative for cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, alpha-smooth muscle actin, and HMB-45. Laminin-positive material was discontinuously demonstrated between the individual tumor cells. Electron microscopy showed prominent external lamina. Our case indicated that laminin is useful for differentiating epithelioid MPNST from metastatic carcinoma and malignant melanoma.

Ocular activity of topically administered anandamide in the rabbit

Marijuana and its psychoactive constituents, cannabinoids, reduce intraocular pressure (IOP) in humans and animals. Because anandamide, a recently discovered endogenous ligand of cannabinoid receptors, reportedly shows cannabimimetic pharmacological activity, we examined its effect on the eye. Varying amounts of anandamide, in 50 microL of light mineral oil, were topically applied to a rabbit eye and changes in IOP and ocular symptoms were monitored. Anandamide (50 micrograms to 1 mg) induced a significant decrease in IOP within 1 hour after administration; maximum reduction occurred at 2 hours; and there was a return to baseline by 7 hours following administration. A noticeable hyperemia of conjunctival blood vessels was also noted 2 hours after administration. Neither mineral oil alone or with palmitylethanolamide (an analogue of anandamide) caused a significant decrease in IOP or conjunctival hyperemia. This study indicates that anandamide does produce cannabimimetic effect in rabbit eyes.

Organization of the Fugu rubripes Hox clusters: evidence for continuing evolution of vertebrate Hox complexes

The clustered organization of Hox genes provides a powerful opportunity to examine gene gain and loss in evolution because physical linkage is a key diagnostic feature which allows homology to be established unambiguously. Furthermore, Hox genes play a key role in determination of axial and appendicular skeletal morphology and may be a key component of the evolution of diverse metazoan body forms. Despite suggestions that changes in Hox gene number played a role in evolution of metazoan body plans, there has been a general lack of evidence for such variation amongst gnathostomes (or indeed any vertebrate) and it has therefore been widely assumed that differential regulation may be the key element in all vertebrate Hox evolution. We have studied the Hox gene clusters of a teleost fish, Fugu rubripes, to test the possibility that Hox organization may have varied since the origin of jawed vertebrates. We have identified four Hox complexes in Fugu and found an unprecedented degree of variation when compared with tetrapod clusters. Our data show that: Fugu clusters are widely variant with respect to length; at least nine genes have been lost; there is a new group-2 paralogue; and pseudo-gene remnants of group-1 and group-3 paralogues were found in the Hoxc complex, when compared with the present mammalian clusters. We show that gene loss after duplication of the prototypical vertebrate Hox clusters is a key feature of both tetrapod and fish evolution.

Cervical myelo-radiculopathy in athetoid cerebral palsy

Cervical myelopathy complicating athetoid cerebral palsy has not been adequately highlighted in the literature. We report two cases of patients with athetoid cerebral palsy and long histories of involuntary movements who developed cervical myelo-radiculopathy. Dystonic athetoid neck movements may cause excessive axial neck rotation as well as flexion and extension movements of the spine. These repetitive exaggerated movements may result in early degenerative changes of the vertebrae which may enhance the myelo-radiculopathy. The two patients were treated with combined anterior and posterior fusion with satisfactory results. They were bedridden preoperatively but have since started walking with or without a cane. We conclude that combined anterior and posterior fusion is the treatment of choice for severe myelopathy complicating athetoid cerebral palsy.

Cervical spinal cord compression in hereditary multiple exostoses. Report of a case and a review of the literature

Spinal cord compression is an extremely serious complication of hereditary multiple exostoses (HME). A case of HME with compression of the cervical spinal cord is reported. Complete recovery following surgery was achieved. A review of the relevant literature revealed 51 previous cases of HME with cord/cauda equina compression. Most patients were under 30 years of age with more men affected than women. The family history was positive in 60%. The cervical and thoracic areas were predominantly affected, with the symptoms usually developing slowly. Recovery following surgery is to be expected in the majority of cases. In patients with HME and suffering from neurological symptoms, the possibility of spinal cord compression should be considered. Prompt diagnosis and surgical excision provide the best prognosis.

Morphometric analysis of the lumbosacral nerve roots and dorsal root ganglia by magnetic resonance imaging

STUDY DESIGN

Lumbosacral nerve roots and dorsal root ganglia in relation to surrounding bony structures in normal subjects were investigated using magnetic resonance imaging.

OBJECTIVES

This study determined the normal anatomic parameters of the lumbosacral nerve root and dorsal root ganglion, to which degenerative or pathologic changes may be compared.

SUMMARY OF BACKGROUND DATA

In the previous literature, most authors have used various modalities in either cadavers or symptomatic patients to study the anatomic details of the lumbar nerve roots and dorsal root ganglia. The data in the literature are conflicting, mainly because of individual variations and different degrees of degenerative change in the spine.

METHODS

Twenty male volunteers who had no back pain or radiculopathy underwent magnetic resonance imaging. Ages ranged from 22 to 38 years, with a mean of 30.4 years. T1-weighted coronal magnetic resonance images were taken from L1 to S1. Two hundred thirty-three nerve roots were examined, including 36 L1, 40 L2, 40 L3, 39 L4, 40 L5, and 38 S1. nerve roots Measurements were determined using a computer digitizer.

RESULTS

The nerve root origin was at a more cephalad level for the caudad nerve roots, particularly the S1. The take-off angels acutely changed at L1 and S1. The length of the nerve roots increased progressively to a maximum at L5, and decreased at S1. The center of the dorsal root ganglion was positioned more cephalad at S1. The average dimension of the dorsal root ganglion gradually increased from L1 to S1. The most striking difference was in the S1 root, which takes off more cephalad, at a more vertical angle, and has the shortest length of any of the nerve roots. The S1 dorsal root ganglion was also unique in that it was the largest and more frequently located intraspinally.

CONCLUSION

The anatomy of the lumbar nerve roots and dorsal root ganglia and their relations to bony structures have been better defined in this study. Because of its more medial location, S1 radiculopathy may involve both the nerve root and dorsal root ganglion as a result of either disc herniation or degenerative L5-S1 facet changes. The relatively larger dorsal root ganglia and the greater dorsal root ganglion/foramen height ratios in the lower lumbar region may explain the higher incidence of L5 or S1 radiculopathy, particularly given the propensity to disc degeneration and intervertebral foraminal narrowing in the lower lumbar region.

Elastin in the human posterior longitudinal ligament and spinal dura. A histologic and biochemical study

STUDY DESIGN

A histologic and biochemical study of elastin in the posterior longitudinal ligament and spinal dura was performed using autopsy cadavers.

OBJECTIVE

To provide a rationale for resiliency of the PLL and the spinal dura.

SUMMARY OF BACKGROUND DATA

Among the spinal ligaments, the nuchal ligament and the ligamentum flavum have a very high elastin content, and some biochemical and morphologic studies of these ligaments have been published. No reports on the elastin content in the posterior longitudinal ligament or spinal dura have been published.

METHODS

Specimens of the posterior longitudinal ligament and the dura collected from three cadavers were studied histologically. For quantitative analysis of elastin and collagen, the posterior longitudinal ligament specimens were collected from 22 cadavers and the dura specimens from 20 cadavers. Elastin was extracted using the hot alkali method of Lansing et al.

RESULTS

The elastic fibers in the posterior longitudinal ligament generally were arranged parallel in the cephalocaudal direction, whereas the fibers in the spinal dura had a more multidirectional arrangement. The elastin content of the posterior longitudinal ligament averaged 7.3% of the total dry weight and that of the spinal dura was 7.1% for the ventral aspect and 13.8% for the dorsal aspect. The elastin content of the spinal dura was about two times higher in all dorsal specimens than in the corresponding ventral specimens. The elastin content of the lower thoracic region was higher than that of any other region. The amino acid composition of the elastin in the posterior longitudinal ligament and spinal dura was similar to that previously determined in other spinal ligaments.

Cerebellar hemorrhage complicating cervical durotomy and revision C1-C2 fusion

STUDY DESIGN

A case of cerebellar hemorrhage complicating cervical durotomy and revision C1-C2 fusion is reported. There has been only one report on cerebellar hemorrhage after cervical durotomy.

SUMMARY OF BACKGROUND DATA

The patient became comatose approximately 16 hours after surgery. According to a review of the recovery room records, the patient's cerebellar hemorrhage probably occurred some time within the first 10 hours after the procedure and not during the operation.

METHODS

The authors reviewed reports on complicated cerebellar hemorrhage, and the causative factors were studied.

CONCLUSION

Postoperative drainage of cerebrospinal fluid, especially when negative pressure is applied, may play a role in the occurrence of cerebellar hemorrhage.

Hypertrophic spinal pachymeningitis

A patient with idiopathic hypertrophic spinal pachymeningitis (HSP) with predominant involvement of the cervical and thoracic dura is reported. Serial magnetic resonance (MR) images detected isolated thickening and ridges of the dura mater. There has been no report describing the serial changes of MR images in idiopathic HSP. According to a review of the English and Japanese literature on idiopathic HSP, the prognosis of patients with positive inflammatory signs is worse than that of those with no inflammatory signs. Idiopathic HSP is a rarely reported disease that can resemble other disorders associated with dural compression. MR imaging can help to differentiate it from other disorders, and enables the diagnosis of the disease in its early stage. The prognosis of idiopathic HSP with positive inflammatory signs may be worse; the authors stress the significance of early surgical treatment.

Quadriplegia caused by push-up exercises

This paper describes a case of a 52-year-old male patient with spinal cord injury caused by doing push-up exercises in the prone position. To our knowledge, no previous report has been published describing a case of spinal cord injury caused by push-up exercise. These days, sport is recommended not only to the young but also to older persons. However, to the older, who inevitably have some degenerative disease, moderation should be recommended.

Stress fracture of the first rib in a weightlifter

An isolated fracture of the first rib is rare. Stress fractures of the first rib have previously been reported in various sports and the mechanism of fractures of the first rib has been well documented. Stress fractures of the first rib have also been reported in laborers involved in heavy lifting. The course is insidious, and identification of the lesion is usually made on the basis of an incidental roentgenogram. No reported case of stress fracture of the first rib in a weightlifter has hitherto been available. This paper describes such a case for the first time.

Performance of wide-pore silica- and polymer-based packing materials in polypeptide separation: effect of pore size and alkyl chain length

The effects of pore size and alkyl chain length of silica- and polymer-based packing materials in the elution of polypeptides with an acetonitrile gradient in the presence of trifluoroacetic acid were studied. Considerable differences were found in the performance of alkylsilylated phases prepared from various wide-pore silica particles assumed to have 30-50-nm pores. The pore size of such silica gels was found to be the critical factor in determining the efficiency for high-molecular-weight polypeptides. Silica C18 phases having small pore volumes below 20 nm pore diameter showed comparable performances to C4 and C8 phases for polypeptides with molecular weights of up to 80,000, and were more stable. Polymer-based packing materials with adequate pore size provided excellent column efficiencies and recoveries for polypeptides with higher chemical stabilities than silica-based materials.

Hemodialysis-associated amyloidosis of bone of beta-2 microglobulin origin

A case of hemodialysis-associated amyloidosis in a patient who had been on hemodialysis for 10 years is described. Bone lesions were found in the humeral heads, carpal bones, and femoral heads and necks. Specimens obtained from the pathologically fractured left femoral neck revealed amyloid deposits histologically. Immunoperoxidase staining for beta-2 microglobulin was positive in the amyloid at the light-microscopic level. We reconfirmed that bone lesions associated with long-term hemodialysis are manifestations of amyloidosis of beta-2 microglobulin origin. Hemodialysis-associated amyloidosis should be considered in the treatment of long-term hemodialysis patients.

Atlanto-axial subluxation in Down's syndrome

Atlanto-axial subluxation, which was causing symptoms in eight patients with Down's syndrome, was treated by operation. In every case various congenital bony anomalies were found. Marked myelopathy was present in four cases of ossiculum terminale, and mild myelopathy in one with anteroposterior spondyloschisis. Successful posterior arthrodesis was performed from C1 to C2 in six cases, and from the occiput to C2 in the other two patients with anteroposterior spondyloschisis. Excellent bony union and an overall improvement in symptoms was achieved. The follow-up period was from one year to five years and six months. Early surgical stabilization is the treatment of choice in those cases of symptomatic atlanto-axial subluxation in Down's syndrome where there are congenital osseous anomalies and generalised ligamentous laxity, and where the spinal cord is at risk.

Instrumentation surgery for primary tumors of the spine

We performed instrumentation surgery on ten patients with the following rare primary spinal tumors; three solitary plasmacytomas, an aneurysmal bone cyst, a chordoma, a giant-cell tumor, a hemangioma, a solitary bone cyst, a benign osteoblastoma, and a chondrosarcoma. These tumors were found in the cervical spine (one case), thoracic spine (five cases), lumbar spine (two cases), and sacrum (two cases). The patients consisted of five men and five women, and their average age was 43.1 years. Harrington instrumentation was used in six cases, Zielke instrumentation in two, a combination of both in one case, and a Kirshner wire in one. In two cases, iliolumbar fusion was performed with Harrington instrumentation, after total resection of the sacrum. Average duration of the follow-up period was 5 years. This report describes these rare cases and emphasizes the effectiveness of instrumentation surgery in the reconstruction of the spine after extensive surgery.

Stress fracture of the body of pubis in a pregnant woman. Case report

A case with stress fracture of the body of the pubic bone which occurred in a 35-year-old pregnant woman is described. No underlying pathologic process was found and it would seem that the mechanical load acting on the pubic bone to cause stress fracture is brought about by both the muscle imbalance and ligament laxity. In a few weeks after delivery, the fracture showed a complete bony union.

Computer graphic analysis of antigenic sites on the insulin molecule

Antigenic sites on a protein have been predicted by the measurement of hydrophilicity values. We have compared this approach to the use of atomic temp factors to predict the antigenic sites on insulin. These predictions were based upon computer assisted analysis of X-ray crystallography data. The results demonstrate that the hydrophilic sites A6, B19, B23, B24, and B26 are not on the surface of the molecule and therefore are not potential antigenic determinants. Thus, hydrophilicity values alone are not sufficient to predict antigenic sites. In contrast, atomic temp factors were more predictive of antigenicity. These findings may explain why anti-insulin antibodies are less likely to develop against certain hydrophilic sites.

Intraspinal epidermoid and dermoid cysts. Surgical results of seven cases

Seven cases of intraspinal inclusion cysts, surgically treated between 1970 and 1984, are reported in this paper. Four were epidermoid cysts and three dermoid. Two cysts were located in the thoracic spine (one dermoid and one epidermoid) and five in the lumbosacral region (three epidermoid and two dermoid). Associated spinal dysraphia was noted in five cases. Congenital dermal sinus was found in two cases, spina bifida cystica in one, spina bifida occulta in one, and diastematomyelia in one case. The average postoperative follow-up period was 5 years. No neurological symptoms were found in the five patients who received early surgical treatment, but for the two patients whose operations were late, there were some residual neurological deficits. Therefore, early and accurate diagnosis and radical surgical extirpation are emphasized.

Surgical treatment of symptomatic atlantoaxial subluxation in Down's syndrome

Six cases of relatively uncommon symptomatic atlantoaxial subluxation in Down's syndrome were treated surgically. In all cases, various congenital osseous anomalies were found. Marked myelopathy was noted in four cases of ossiculum terminale and mild myelopathy in one case of anteroposterior spondyloschisis. Five cases were treated successfully with posterior arthrodesis of C1 to C2 and one from the occiput to C2. Excellent bony union and overall improvement in the patients' symptoms was achieved, with a follow-up period ranging from 11 months to three years and nine months. In cases of symptomatic atlantoaxial subluxation of Down's syndrome, where the spinal cord is at risk, early surgical stabilization is the treatment of choice.

Spinal deformity and instability after multilevel cervical laminectomy

Sixty-four patients who had undergone multilevel cervical laminectomy were studied for postoperative spinal deformity and instability. Special attention was given to patients with cervical spondylosis (CS), ossification of the posterior longitudinal ligament (OPLL), and spinal cord tumors. Twenty-three (36%) of 64 patients showed postoperative changes in curvature type and 9 (14%) had developed spinal deformity (kyphotic or meandering-type curvature). In two juvenile patients, the deformity developed soon after operation and spinal fusion was required to prevent neurologic complications. In the adult cases, contrary to the hitherto accepted concept, long-term follow-up revealed the tendency of the deformity to develop more frequently in OPLL cases than in CS cases. Mobility of the cervical spine was reduced considerably after laminectomy, both in CS and OPLL cases. There was no adult patient who required further operation for severe deformity or instability after laminectomy. Extensive laminectomy, even including the C2 lamina, seemed to have no adverse effect on the stability of the cervical spine.

An experimental study on prevention of postlaminectomy scar formation by the use of new materials

An experimental study was performed to investigate the prevention of scar formation after lumbar laminectomy, using Elastase and the new polylactic acid (PLA) membrane containing Elastase. The experimental animals consisted of four groups: control group, E group (using intravenous administration of Elastase), P group (covering the laminectomy defect with PLA membrane), and P-E group (covering the laminectomy defect with "PLA" + Elastase" membrane). The animals were killed at varying intervals (2-12 weeks) and changes in the lumbar spines were evaluated histologically. Scar formation was suppressed most significantly in the P-E group, followed in order by the E group, the P group, and the controls.

Elastin in the human intervertebral disk. A histological and biochemical study comparing it with elastin in the human yellow ligament

The elastic fiber and elastin in the human yellow ligament and intervertebral disk were studied histologically and biochemically. The elastic fiber in the human intervertebral disk, which until now had not been clearly identified microscopically, was observed clearly. We found the distribution of the elastic fiber in the intervertebral disk to be very sparse and irregular, and its diameter was small, being about one-tenth of that found in the yellow ligament. The elastin contents of the yellow ligament and intervertebral disk were 46.7% +/- 0.9% and 1.7% +/- 0.2% respectively (mean +/- SE) of the total dry weight. The amino acid composition of elastin in the yellow ligament is similar to that of other tissue, as reported in the literature; however, that found in the intervertebral disk is significantly different. It would appear, therefore, that the elastin in the intervertebral disk is of a different type from that found elsewhere.

Atlanto-axial dislocation in Down's syndrome. Report of two cases requiring surgical correction

Two cases of symptomatic atlanto-axial dislocation in association with Down's syndrome are reported. The first patient showed spinal cord compression and had an ossiculum terminale; the second showed neck pain and had anteriorly inclined facet joint of the axis. Complete reduction was not obtained in either case. Both patients were treated successfully by posterior fusion of C1 and C2 in the maximally obtained position of reduction. In cases of symptomatic atlanto-axial dislocation when the spinal cord is at risk, surgical stabilization is the treatment of choice.

Infrared spectroscopy at high pressures: polarized spectra of single crystals of acetonitrile

Single crystals of three polymorphs of acetonitrile and acetonitrile-d(3) have been grown under pressure in a diamond anvil cell. While still under pressure polarized mid-infrared spectra of these three single crystals have been obtained. In addition, low temperature far-infrared spectra have been recorded for polycrystals of two of the polymorphs. These data have been used to predict likely crystal structures for the three crystalline phases.