Anterior cervical discectomy plus intervertebral polyetheretherketone cage fusion over three and four levels without plating is safe and effective long-term.

Anterior cervical discectomy and fusion (ACDF) is an established treatment for single-level cervical spondylotic myelopathy and radiculopathy, yet its stand-alone use for multi-level disease of the subaxial cervical spine remains controversial. We report a prospectively studied case series of 30 patients receiving polyetheretherketone (PEEK) cage fusion over three and four cervical levels without anterior plating. Seven (23.3%) four-level procedures (all C3 to C7) were performed, the other 23 (76.7%) being three-level, with 19 (64.4%) at C4 to C7 and four (12.3%) at C3 to C6. Long-term follow-up of more than 2 years was available in 67% of patients. This cohort showed statistically significant improvements in visual analogue score for neck pain (p=0.0006), arm pain (p=0.0003) and Japanese Orthopaedic Association myelopathy score (p=0.002). Fused segment heights increased by 0.6-1.1%. Adjacent segment disease requiring ACDF at C3-4 was seen in 6.7% of patients (one after trauma) at a mean follow-up of 62 months. Same segment recurrence requiring posterior decompression with instrumented fusion was found in 10% of patients at a mean follow-up of 49 months, only one of whom had radiological evidence of cage subsidence. The results suggest the procedure is safe and effective with potentially less morbidity than anterior plating, shorter inpatient stays than posterior approaches, acceptable same segment recurrence and lower than predicted adjacent segment disease rates.

Evidence from in vitro and in vivo studies showing that nuclear factor-κB within the pituitary folliculostellate cells and corticotrophs regulates adrenocorticotrophic hormone secretion in experimental endotoxaemia.

The hypothalamic-pituitary-adrenocortical (HPA) responses to bacterial infection are mediated, in part, by the actions of lipopolysaccharide (LPS) on pituitary folliculostellate (FS) cells that release pro-inflammatory cytokines [e.g. interleukin (IL)-6] and thereby facilitate adrenocorticotrophic hormone (ACTH) release from neighbouring corticotrophs. In the present study, two murine pituitary cell lines [TtT/GF (FS cells) and AtT20 D16:16 (corticotrophs)], alone and in co-culture, and an in vivo model of endotoxaemia were used to examine the potential role of nuclear factor-kappa B (NF-κB) in mediating LPS-induced ACTH secretion. Both cell lines expressed mRNAs for the key components of the LPS signalling system. LPS stimulated IL-6 release from TtT/GF cells via a glucocorticoid-sensitive, NF-κB-dependent mechanism; it also activated NF-κB in AtT20 cells, as did corticotrophin-releasing hormone (CRH). IL-6 potentiated (but LPS reduced) the stimulatory effects of CRH on ACTH release from AtT20 cells, whereas blockade of NF-κB (SC-514) increased the ACTH release induced by CRH in the presence or absence of LPS. In co-cultures, CRH and LPS acted synergistically to induce release of both IL-6 and ACTH. However, although SC-514 suppressed the release of IL-6 evoked by CRH and LPS, it potentiated the concomitant increase in ACTH release. In vivo both immunological (LPS) and psychological (restraint) stress increased intrapituitary NF-κB, whereas an NF-κB inhibitor (PHA781535E) attenuated the LPS-induced release of ACTH and abolished the HPA response to restraint stress. The results obtained in the present study support the premise that NF-κB plays an important role in mediating LPS signalling in the anterior pituitary gland, particularly in relation to IL-6 and ACTH secretion, and provide novel evidence that NF-κB blockade in vivo compromises stress-induced ACTH release.

Oblique axis body fracture--pitfalls in management.

BACKGROUND: Transverse fractures through the body of the axis, rather than at the base of the odontoid are uncommon and management with an external orthosis is usually recommended. Oblique fractures through the body of the axis accompanying a hangman's fracture have not been reported and are not described as part of any classification system. Such fractures may be at high risk for treatment failure in an external orthosis. CASE DESCRIPTION: We report on a case of an oblique axis fracture that failed treatment with external orthosis. Posterior instrumented fusion was employed successfully using a C1-C3 and C4 poly axial screw rod construct. Frameless stereotaxy and a biomodel were useful surgical adjuncts. Twelve month follow up revealed bony union in an asymptomatic patient. CONCLUSIONS: Oblique fractures of the body of the axis can displace in a halo-thoracic orthosis. Serial radiological review is required to detect displacement prior to fracture union. Oblique fractures of the body of the axis can be managed surgically with preservation of atlanto-occipital motion, resulting in satisfactory clinical and radiological outcomes.

Formyl peptide receptors and the regulation of ACTH secretion: targets for annexin A1, lipoxins, and bacterial peptides.

The N-formyl peptide receptors (FPRs) are a family of G-protein coupled receptors that respond to proinflammatory N-formylated bacterial peptides (e.g., formyl-Met-Leu-Phe, fMLF) and, thus, contribute to the host response to bacterial infection. Paradoxically, a growing body of evidence suggests that some members of this receptor family may also be targets for certain anti-inflammatory molecules, including annexin A1 (ANXA1), which is an important mediator of glucocorticoid (GC) action. To explore further the potential role of FPRs in mediating ANXA1 actions, we have focused on the pituitary gland, where ANXA1 has a well-defined role as a cell-cell mediator of the inhibitory effects of GCs on the secretion of corticotrophin (ACTH), and used molecular, genetic, and pharmacological approaches to address the question in well-established rodent models. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis identified mRNAs for four FPR family members in the mouse anterior pituitary gland, Fpr-rs1, Fpr-rs2, Fpr-rs6, and Fpr-rs7. Functional studies confirmed that, like dexamethasone, ANXA1 and two ANXA1-derived peptides (ANXA1(1-188) and ANXA1(Ac2-26)) inhibit the evoked release of ACTH from rodent anterior pituitary tissue in vitro. Fpr1 gene deletion failed to modify the pituitary responses to dexamethasone or ANXA1(Ac2-26). However, lipoxin A4 (LXA4, 0.02-2 microM, a lipid mediator with high affinity for Fpr-rs1) mimicked the inhibitory effects of ANXA1 on ACTH release as also did fMLF in high (1-100 microM) but not lower (10-100 nM) concentrations. Additionally, a nonselective FPR antagonist (Boc1, 100 microM) overcame the effects of dexamethasone, ANXA1(1-188), ANXA1(Ac2-26), fMLF, and LXA4 on ACTH release, although at a lower concentration (50 microM), it was without effect. Together, the results suggest that the actions of ANXA1 in the pituitary gland are independent of Fpr1 but may involve other FPR family members, in particular, Fpr-rs1 or a closely related receptor. They thus provide the first evidence for a role of the FPR family in the regulation of neuroendocrine function.

Time-specific effects of perinatal glucocorticoid treatment on anterior pituitary morphology, annexin 1 expression and adrenocorticotrophic hormone secretion in the adult female rat.

Perinatal glucocorticoid (GC) treatment is increasingly associated with long-term disturbances in hypothalamo-pituitary-adrenocortical function. In the male rat, such treatment induces profound molecular, morphological and functional changes in the anterior pituitary gland at adulthood. To determine whether these effects are sex-specific, we have examined the effects of perinatal dexamethasone treatment on the female pituitary gland, focusing on (i) the integrity of the annexin 1 (ANXA1) dependent regulatory effects of GCs on adrenocorticotrophic hormone (ACTH) release and (ii) corticotroph and folliculo-stellate (FS) cell morphology. Dexamethasone was given to pregnant (gestational days 16-19) or lactating (days 1-7 post partum) rats via the drinking water (1 microg/ml); controls received normal drinking water. Pituitary tissue from the female offspring was examined ex vivo at adulthood (60-90 days). Both treatment regimes reduced the intracellular and cell surface ANXA1 expression, as determined by western blot analysis and quantitative immunogold electron microscopic histochemistry. In addition, they compromised the ability of dexamethasone to suppress the evoked release of ACTH from the excised tissue in vitro, a process which requires the translocation of ANXA1 from the cytoplasm to the cell surface of FS cells. Although neither treatment regime affected the number of FS cells or corticotrophs, both altered the subcellular morphology of these cells. Thus, prenatal dexamethasone treatment increased while neonatal treatment decreased FS cell size and cytoplasmic area. By contrast, corticotroph size was unaffected by either treatment, as also was the size of the secretory granules. Corticotroph granule density and margination were, however, increased markedly by the prenatal treatment, while the neonatal treatment had no effect on granule density but decreased granule margination. Thus, perinatal dexamethasone treatment exerts long-term effects on the female pituitary gland, altering gene expression, cell morphology and the ANXA1-dependent GC regulation of ACTH secretion. The changes are similar but not identical to those reported in the male.

The long-term effects of perinatal glucocorticoid exposure on the host defence system of the respiratory tract.

Glucocorticoids are used to mature the fetal lung at times of threatened premature delivery. These drugs modify leukocyte profiles when administered in adulthood, but their effects on the mature host defence system following administration during the perinatal period are incompletely understood. In this study, the long-term effects of perinatal dexamethasone exposure on rodent host defence cells in the pulmonary airspaces, the perivascular compartment of the lung, and the blood were investigated. Rats were treated prenatally (gestational days 16-19) or neonatally (postnatal days 1-7) by inclusion of dexamethasone in the mothers' drinking water (1 microg/ml). The pups were then allowed to develop to adulthood (P60-80), at which time respiratory tissues were collected for light and electron microscopy and bronchoalveolar lavage (BAL), and blood for cell count and fluorescent activated cell-sorting (FACS) analysis. Prenatal treatment had no effect on any parameter examined. Following neonatal dexamethasone exposure, light microscopy of the lung tissue revealed a significant reduction in the number of cells in the perivascular space in both the central and the peripheral regions of the adult lung, but no differences in the number of cells in the airspaces. Neonatal dexamethasone exposure was also characterized by a significant reduction in the total number of white cells in the peripheral blood in adulthood and in particular, the number of lymphocytes relative to neutrophils was significantly reduced at maturity in these animals. The results show that neonatal, but not prenatal, dexamethasone exposure significantly alters the distribution of host defence cells in the blood and lung at maturity compared with control animals. The early neonatal period is characterized by the stress hyporesponsive period in the rat, when endogenous glucocorticoid levels are very low. Therefore, exogenous glucocorticoids administered during this time are likely to have marked "programming" effects on glucocorticoid-sensitive tissues.

Perinatal glucocorticoid treatment disrupts the hypothalamo-lactotroph axis in adult female, but not male, rats.

This study aimed to test the hypothesis that the tuberoinfundibular dopaminergic neurons of the arcuate nucleus and/or the lactotroph cells of the anterior pituitary gland are key targets for the programming effects of perinatal glucocorticoids (GCs). Dexamethasone was administered noninvasively to fetal or neonatal rats via the mothers' drinking water (1 mug/ml) on embryonic d 16-19 or neonatal d 1-7, and control animals received normal drinking water. At 68 d of age, the numbers of tyrosine hydroxylase-positive (TH+) cells in the arcuate nucleus and morphometric parameters of pituitary lactotrophs were analyzed. In control animals, striking sex differences in TH+ cell numbers, lactotroph cell size, and pituitary prolactin content were observed. Both pre- and neonatal GC treatment regimens were without effect in adult male rats, but in females, the overriding effect was to abolish the sex differences by reducing arcuate TH+ cell numbers (pre- and neonatal treatments) and reducing lactotroph cell size and pituitary prolactin content (prenatal treatment only) without changing lactotroph cell numbers. Changes in circulating prolactin levels represented a net effect of hypothalamic and pituitary alterations that exhibited independent critical windows of susceptibility to perinatal GC treatments. The dopaminergic neurons of the hypothalamic periventricular nucleus and the pituitary somatotroph populations were not significantly affected by either treatment regimen in either sex. These data show that the adult female hypothalamo-lactotroph axis is profoundly affected by perinatal exposure to GCs, which disrupts the tonic inhibitory tuberoinfundibular dopaminergic pathway and changes lactotroph morphology and prolactin levels in the pituitary and circulation. These findings provide new evidence for a long-term disruption in prolactin-dependent homeostasis in females, but not males, after inappropriate GC exposure in perinatal life.

Perinatal glucocorticoid treatment produces molecular, functional, and morphological changes in the anterior pituitary gland of the adult male rat.

Stress or glucocorticoid (GC) treatment in perinatal life can induce long-term changes in the sensitivity of the hypothalamo-pituitary-adrenocortical axis to the feedback actions of GCs and, hence, in GC secretion. These changes have been ascribed largely to changes in the sensitivity of the limbic system, and possibly the hypothalamus, to GCs. Surprisingly, the possibility that early life stress/GC treatment may also exert irreversible effects at the pituitary level has scarcely been addressed. Accordingly, we have examined the effects of pre- and neonatal dexamethasone treatment on the adult male pituitary gland, focusing on the following: 1) the integrity of the acute annexin 1 (ANXA1)-dependent inhibitory actions of GCs on ACTH secretion, a process requiring ANXA1 release from folliculostellate (FS) cells; and 2) the morphology of FS cells and corticotrophs. Dexamethasone was given to pregnant (d 16-19) or lactating (d 1-7 postpartum) rats via the drinking water (1 microg/ml); controls received normal drinking water. Pituitary tissue from the offspring was examined ex vivo at d 90. Both treatment regimens reduced ANXA1 expression, as assessed by Western blotting and quantitative immunogold labeling. In particular, the amount of ANXA1 located on the outer surface of the FS cells was reduced. By contrast, IL-6 expression was increased, particularly by the prenatal treatment. Pituitary tissue from untreated control rats responded to dexamethasone with an increase in cell surface ANXA1 and a reduction in forskolin-induced ACTH release. In contrast, pituitary tissue from rats treated prenatally or neonatally with dexamethasone was unresponsive to the steroid, although, like control tissue, it responded readily to ANXA1, which readily inhibited forskolin-driven ACTH release. Prenatal dexamethasone treatment reduced the size but not the number of FS cells. It also caused a marked reduction in corticotroph number and impaired granule margination without affecting other aspects of corticotroph morphology. Similar but less marked effects on pituitary cell morphology and number were evident in tissue from neonatally treated rats. Our study shows that, when administered by a noninvasive process, perinatal GC treatment exerts profound effects on the adult pituitary gland, impairing the ANXA1-dependent GC regulation of ACTH release and altering the cell profile and morphology.

Use of the Solis cage and local autologous bone graft for anterior cervical discectomy and fusion: early technical experience.

OBJECT: The authors prospectively evaluated the clinical and radiological outcomes after anterior cervical discectomy and fusion (ACDF) involving placement of a Solis cage and local autograft in patients who presented with symptomatic cervical spondylosis. METHODS: Twenty-two consecutive patients underwent ACDF for radiculopathy (13 cases), myeloradiculopathy (eight cases), or myelopathy alone (one case) and were assessed at 3, 6, and 12 months. Plain cervical spine radiography demonstrated a significant change in both local (p < 0.05) and regional (p < 0.05) kyphotic angles as well as an increase in segmental height (p < 0.05). At 12 months, plain radiography demonstrated Grades I, II, and III new bone formation in two, three, and 17 patients, respectively. Clinical outcomes were assessed using a visual analog scale for both neck and arm pain and a modified Japanese Orthopaedic Association (JOA) scale for myelopathy. There was a significant improvement in both arm (p < 0.05) and neck pain (p < 0.05). At 12 months, 16 (84%) of 19 and 19 (86%) of 22 patients reported complete resolution of arm pain and neck pain, respectively. There was a significant improvement in JOA scores following surgery (p < 0.05). There were two complications in the series: one case of deep venous thrombosis and one case of postoperative arm pain that resolved after conservative treatment. There were no technical complications. CONCLUSIONS: Early experience with Solis cage-augmented ACDF indicates good clinical and radiological outcomes; additionally, there are the advantages of absent donor site morbidity and anterior plate system-related morbidity.

Kinase-dependent regulation of the secretion of thyrotrophin and luteinizing hormone by glucocorticoids and annexin 1 peptides.

Our previous studies have identified a role for annexin 1 (ANXA1), a protein produced by the pituitary folliculostellate cells, as a paracrine/juxtacrine mediator of the acute regulatory effects of glucocorticoids on the release of adrenocorticotropic hormone and other pituitary hormones. In the present study, we focused on the secretion of thyroid stimulating hormone (TSH) and luteinizing hormone (LH) and used a battery of ANXA1-derived peptides to identify the key domains in the ANXA1 molecule that are critical to the inhibition of peptide release. In addition, as ANXA1 is a substrate for protein kinase C (PKC) and tyrosine kinase, we examined the roles of these kinases in the manifestation of the ANXA1-dependent inhibitory actions of dexamethasone on TSH and LH release. Dexamethasone suppressed the forskolin-induced release of TSH and LH from rat anterior pituitary tissue in vitro. Its effects were mimicked by human recombinant ANXA1 (hrANXA1) and a truncated protein, ANXA1(1-188). ANXA1(Ac2-26), also suppressed stimulated peptide release but it lacked both the potency and the efficacy of the parent protein. Shorter N-terminal ANXA1 sequences were without effect. The PKC inhibitor PKC(19-36) abolished the inhibitory actions of dexamethasone on the forskolin-evoked release of TSH and LH; it also attenuated the inhibitory actions of ANXA1(Ac2-26). Similar effects were produced by annexin 5 (ANXA5) which sequesters PKC in other systems. By contrast, the tyrosine kinase inhibitors, p60v-src (137-157) and genistein, had no effect on the secretion of TSH or LH alone or in the presence of forskolin and/or dexamethasone. Dexamethasone caused the translocation of a tyrosine-phosphorylated species of ANXA1 to the surface of pituitary cells. The total amount of ANXA1 exported from the cells in response to the steroid was unaffected by tyrosine kinase blockade. However, the degree of tyrosine-phosphorylation of the exported protein was markedly reduced by genistein. These results suggest that (i) the ANXA1-dependent inhibitory actions of dexamethasone on the release of TSH and LH require PKC and sequences in the N-terminal domain of ANXA1, but are independent of tyrosine kinase, and (ii) while dexamethasone induces the cellular exportation of a tyrosine-phosphorylated species of ANXA1, tyrosine phosphorylation per se is not critical to the steroid-induced passage of ANXA1 across the membrane.

Opposing influences of glucocorticoids and interleukin-1beta on the secretion of growth hormone and ACTH in the rat in vivo: role of hypothalamic annexin 1.

1. This study exploited established immunoneutralization protocols and an N-terminal annexin 1 peptide (annexin 1(Ac2 - 26)) to advance our knowledge of the role of annexin 1 as a mediator of acute glucocorticoid action in the rat neuroendocrine system in vivo. 2. Rats were treated with corticosterone (500 microg kg(-1), i.p.) or annexin 1(Ac2 - 26) (0.1 - 10 ng rat(-1), i.c.v.) and 75 min later with interleukin 1beta (IL-1beta, 10 ng rat(-1), i.c.v. or 500 microg kg(-1), i.p). Blood was collected 1 h later for hormone immunoassay. Where appropriate, anti-annexin 1 polyclonal antiserum (pAb) was administered subcutaneously or centrally prior to the steroid challenge. 3. Corticosterone did not affect the resting plasma corticotrophin (ACTH) concentration but suppressed the hypersecretion of ACTH induced by IL-1beta (i.p. or i.c.v.). Its actions were quenched by anti-annexin 1 pAb (s.c. or i.c.v) and mimicked by annexin 1(Ac2 - 26). 4. By contrast, corticosterone provoked an increase in serum growth hormone (GH) which was ablated by central but not peripheral administration of anti-annexin 1 pAb. IL-1beta (i.c.v. or i.p.) did not affect basal GH but, when given centrally but not peripherally, it abolished the corticosterone-induced hypersecretion of GH. Annexin 1(Ac2 - 26) (i.c.v.) also produced an increase in serum GH which was prevented by central injection of IL-1beta. 5. The results support the hypothesis that the acute regulatory actions of glucocorticoids on hypothalamo-pituitary-adrenocortical function require annexin 1. They also provide novel evidence that the positive influence of the steroids on GH secretion evident within this timeframe is effected centrally via an annexin 1-dependent mechanism which is antagonized by IL-1beta.

Annexin 1 (lipocortin 1) mediates the glucocorticoid inhibition of cyclic adenosine 3',5'-monophosphate-stimulated prolactin secretion.

Our previous studies have identified a role for annexin 1 (also called lipocortin 1) in the regulatory actions of glucocorticoids (GCs) on the release of PRL from the rat anterior pituitary gland. In the present study we used antisense and immunoneutralization strategies to extend this work. Exposure of rat anterior pituitary tissue to corticosterone (1 nM) or dexamethasone (100 nM) in vitro induced 1) de novo annexin 1 synthesis and 2) translocation of the protein from intracellular to pericellular sites. Both responses were prevented by the inclusion in the medium of an annexin 1 antisense oligodeoxynucleotide (ODN; 50 nM), but not by the corresponding sense and scrambled ODN sequences. Unlike the GCs, 17beta-estradiol, testosterone, and aldosterone (1 nM) had no effect on either the synthesis or the cellular disposition of annexin 1; moreover, none of the steroids or ODNs tested influenced the expression of annexin 5, a protein closely related to annexin 1. The increases in PRL release induced in vitro by drugs that signal via cAMP/protein kinase A [vasoactive intestinal polypeptide (10 nM), forskolin (100 microM), 8-bromo-cAMP (0.1 microM)] or phospholipase C (TRH, 10 nM) were attenuated by preincubation of the pituitary tissue with either corticosterone (1 nM) or dexamethasone (100 nM). The inhibitory actions of the steroids on the secretory responses to vasoactive intestinal polypeptide, forskolin, and 8-bromo-cAMP were specifically quenched by inclusion in the medium of the annexin 1 antisense ODN (50 nM) or a neutralizing antiannexin 1 monoclonal antibody (antiannexin 1 mAb, diluted 1:15,000). By contrast, the ability of the GCs to suppress the TRH-induced increase in PRL release was unaffected by both the annexin 1 antisense ODN and the antiannexin 1 mAb. In vivo, interleukin-1beta (10 ng, intracerebroventricularly) produced a significant increase in the serum PRL concentration (P < 0.01), which was prevented by pretreatment of the rats with corticosterone (100 microg/100 g BW, sc). The inhibitory actions of the steroid were specifically abrogated by peripheral administration of an antiannexin 1 antiserum (200 microl, sc); by contrast, when the antiserum was given centrally (3 microl, intracerebroventricularly), it was without effect. These results support our premise that annexin contributes to the regulatory actions of GCs on PRL secretion and suggest that it acts at point distal to the formation of cAMP.