Abstract P1-12-04: A phase 2 study of eribulin in breast cancer not achieving a pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC)

Background: Residual breast cancer after NAC is associated with a high risk of recurrence. Little evidence supports the use of further chemotherapy in this setting. Eribulin, an inhibitor of microtubule dynamics, demonstrated a survival advantage in patients with metastatic breast cancer who had progressed after previous anthracycline and taxane therapy. This phase 2 trial assessed the efficacy of eribulin (2-yr disease-free survival) administered postoperatively to breast cancer pts not achieving a pCR following standard NAC.

Methods: Women with invasive breast cancer (stage T1-4b, N0-2, M0 at diagnosis) and evidence of residual cancer (>5 mm) in the breast or axillary lymph nodes (LN) following ≥4 cycles of standard anthracycline and/or taxane-containing NAC were eligible. Additional eligibility criteria: age ≥18 yrs, peripheral neuropathy < 1, adequate hematologic, hepatic, and renal function. 3 groups were studied: Cohort A-triple negative (TN), Cohort B-HR+/HER2-, Cohort C-HER2+. After recovery from definitive surgery, all pts received eribulin mesylate 1.4mg/m2 IV on days 1 and 8 every 21 days for 6 cycles. Cohort C pts also received trastuzumab 6mg/kg IV day 1 every 21 days for a total of 1 yr from start of NAC. Adjuvant hormonal therapy and loco-regional radiotherapy were administered per institutional guidelines. We hypothesized post-operative eribulin would result in a 40% increase over the reported 40% 2 yr DFS for TN, and a 15% increase over the reported 80% 2 yr DFS for HR+/HER2- pts who did not achieve pCR following standard NAC.

Results: 127 pts were enrolled (54, Cohort A; 42, Cohort B; 31, Cohort C). Pts on Cohort C continue with study treatment. Here, we present the results of 95 pts treated on Cohorts A and B. Median age-52 yrs (range, 27-74). 87 pts (92%) had invasive ductal adenocarcinoma, 6 (6%) invasive lobular, 1 (1%) mucinous, and 1 (1 %) unknown; 34 pts (36%) had T3 or T4 tumors and 65 (68%) had N1-2 disease at diagnosis. NAC with anthracyclines was administered to 74 pts (78%), taxanes to 88 (93%), and 72 (76%) received both. 71 pts (75%) had mastectomies, 24 (25%) had breast conserving surgery. Median residual tumor was 17.5 mm (range 0.1 to 80); 60 pts (63%) were LN+. 78 pts (81%) completed the planned 6 cycles of eribulin. Adjuvant radiation was administered in 28 pts (30%). 3 pts discontinued treatment due to toxicity (1 each with G3 neutropenia, G3 nausea, and unknown grade neuropathy). The most common treatment-related G3/4 adverse events were neutropenia [29 pts (31%)] and leukopenia [10 pts (11%)]. 3 pts (3%) had G3/4 febrile neutropenia and 2 pts (2%) had G3/4 neuropathy. Growth factors were administered to 22 pts (24%). There were no treatment-related deaths. With a median follow up of 19.2 and 14.9 months for Cohorts A and B respectively, the 2 yr DFS probabilities calculated from date of surgery were 61.1 % (95% CI-41.2-76.0) for Cohort A; 82.2% (95% CI-60.2-92.7) for Cohort B.

Conclusions: The addition of eribulin is safe and feasible in pts who do not achieve pCR following anthracycline and/or taxane based NAC. At a median follow up of 19.2 months, a statistically significant improvement in the estimated 2 yr DFS was evident in the TN (Cohort A) pts.

Citation Format: Yardley DA, Peacock N, Shroff S, Molthrop, Jr DC, Anz B, Daniel BR, Young RR, Weaver R, Harwin W, Webb CD, Ward P, Shastry M, DeBusk LM, Midha R, Hainsworth JD, Burris III HA. A phase 2 study of eribulin in breast cancer not achieving a pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-12-04.

Abstract P5-14-04: A phase 2 study evaluating orteronel, an inhibitor of androgen biosynthesis, in patients with androgen receptor (AR)-expressing metastatic breast cancer: Interim analysis

Background: The frequency of AR expression varies in the different breast cancer subtypes with 88%, 59%, and 32% expression reported in ER+, HER2+, and triple negative tumors, respectively. AR expression is associated with resistance to endocrine therapy in ER+ breast cancer. Androgen levels frequently increase following treatment with aromatase inhibitors suggesting a role for androgen synthesis inhibitors in ER+ breast cancer. AR signaling and expression are seen in triple negative breast cancer (TNBC), and a distinct AR TNBC subtype can be identified by gene expression profiling. AR expression in TNBC offers a potential therapeutic target. Preclinical and clinical studies demonstrated anti-androgen agent activity in breast cancer cell lines; preliminary clinical data suggests activity in TNBC. Orteronel is a novel, oral, selective, nonsteroidal inhibitor of 17, 20-lyase, a key enzyme in androgen biosynthesis that is being evaluated as endocrine therapy in various hormone-sensitive cancers. In this phase 2 study we are evaluating single agent orteronel in AR+ MBC.

Methods: Pts with AR expressing MBC (≥10% staining by central immunohistochemistry) were eligible. Pts were grouped into 2 cohorts for analysis: Cohort 1-TNBC and Cohort 2-ER+ (HER2 could be +/- in this cohort). Pts must have been previously treated with standard therapy for MBC (1-3 chemotherapy regimens for TNBC, 1-3 hormonal therapies + 1 chemotherapy for ER+ patients, ≥2 HER2-targeted regimens for HER2+ patients). A 6 pt lead-in for safety and tolerability of orteronel in AR+ female MBC pts was followed by open enrollment to either cohort. All pts received 300 mg orteronel PO BID over a 4 week cycle and underwent response assessment every 2 cycles. Treatment was continued until disease progression or unacceptable toxicity. The hypothesized response rate for Cohort 1 was 10% and 13% for Cohort 2. We present the results of a protocol-specified interim analysis of the ER+ MBC pts (Cohort 2).

Results: From 3/2014 to 4/2015, a total of 29 pts were enrolled on cohort 2. Median age was 65 years (range, 39-79); 90% ECOG ≤1; 90% HER2-/10% HER2+; median of 7 prior therapies (range 3-11). 93% had prior chemotherapy. Pts received a median of 2 cycles of orteronel treatment (range 1-4) and 3 pts (10%) are still on treatment. Of the 26 pts (90%) pts that have discontinued, 19 (66%) discontinued due to disease progression, 4 (14%) due to pt decision, 2 (7%) due to adverse event (AE), and 1 (3%) due to non-compliance. The most common treatment-related G 3/4 AEs were increased lipase [3 pts (10%)] and hypertension [2 pts (7%)]. There were no treatment-related SAEs or deaths on study. Three pts (10%) had stable disease as their best response. Further response evaluation is underway.

Conclusions: Orteronel monotherapy was well tolerated but appears to have limited single-agent activity in this heavily pre-treated ER+ MBC pt population. The full results from this interim analysis will be presented.

Citation Format: Yardley DA, Peacock N, Young RR, Silber A, Chung G, Webb CD, Jones SF, Shastry M, Midha R, DeBusk LM, Hainsworth JD, Burris HA. A phase 2 study evaluating orteronel, an inhibitor of androgen biosynthesis, in patients with androgen receptor (AR)-expressing metastatic breast cancer: Interim analysis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-14-04.

Supplementation of acellular nerve grafts with skin derived precursor cells promotes peripheral nerve regeneration

Introduction of autologous stem cells into the site of a nerve injury presents a promising therapy to promote axonal regeneration and remyelination following peripheral nerve damage. Given their documented ability to differentiate into Schwann cells (SCs) in vitro, we hypothesized that skin-derived precursor cells (SKPs) could represent a clinically-relevant source of transplantable cells that would enhance nerve regeneration following peripheral nerve injury. In this study, we examined the potential for SKP-derived Schwann cells (SKP-SCs) or nerve-derived SCs to improve nerve regeneration across a 12 mm gap created in the sciatic nerve of Lewis rats bridged by a freeze-thawed nerve graft. Immunohistology after 4 weeks showed survival of both cell types and early regeneration in SKP seeded grafts was comparable to those seeded with SCs. Histomorphometrical and electrophysiological measurements of cell-treated nerve segments after 8 weeks survival all showed significant improvement as compared to diluent controls. A possible mechanistic explanation for the observed results of improved regenerative outcomes lies in SKP-SCs' ability to secrete bioactive neurotrophins. We therefore conclude that SKPs represent an easily accessible, autologous source of stem cells for transplantation therapies which act as functional Schwann cells and show great promise in improving regeneration following nerve injury.

Facilitated sprouting in a peripheral nerve injury

During regeneration of injured peripheral nerves, local conditions may influence how regenerative axon sprouts emerge from parent axons. More extensive lesions might be expected to disrupt such growth. In this work, we discovered instead that long segmental crush injuries facilitate the growth and maturation of substantially more axon sprouts than do classical short crush injuries (20 mm length vs. 2 mm). At identical distances from the proximal site of axon interruption there was a 45% rise in the numbers of neurofilament labeled axons extending through a long segmental crush zone by 1 week. By 2 weeks, there was a 35% greater density of regenerating myelinated axons in long compared with short crush injuries just beyond (5 mm) the proximal injury site. Moreover, despite the larger numbers of axons, their maturity was identical and they were regular, parallel, associated with Schwann cells (SCs) and essentially indistinguishable between the injuries. Backlabeling with Fluorogold indicated that despite these differences, the axons arose from similar numbers of parent motor and sensory neurons. Neither injury was associated with ischemia. Both injuries were associated with rises in GFAP (glial acidic fibrillary protein) and p75 mRNAs, markers of SC plasticity but p75, GFAP and brain-derived neurotrophic factor mRNAs did not differ between the injuries. There was a higher local mRNA level of GAP43/B50 at 7 days following injury and a higher sonic hedgehog protein (Shh) mRNA at 24 h in long crush zones. GAP43/B50 protein and SHH protein both had prominent localization within regenerating axons. Long segmental nerve trunk crush injuries do not impair regeneration but instead generate greater axon plasticity that results in larger numbers of mature myelinated axons. The changes occur without apparent change in SC activation, overall nerve architecture or nerve blood flow. While the mechanism is uncertain, the findings indicate that manipulation of the nerve microenvironment can induce substantial changes in regenerative sprouting.

Undiagnosed dysglycaemia and inflammation in cardiovascular disease

BACKGROUND

Cardiovascular (CV) disease is associated with increased levels of glucose, but the prevalence of dysglycaemia in CV diseases is not fully known. The study examined the prevalence of unknown dysglycaemia and its association with inflammation in Caucasian patients with ischaemic vascular complications, i.e. coronary artery disease (CAD), cerebrovascular disease (CVD) and peripheral artery disease (PAD).

MATERIALS AND METHODS

This case-controlled study involved 149 patients (mean age 68 years) hospitalized for CAD, PAD or CVD and 59 control-subjects (CTR) free from CV-disease. The prevalence of dysglycaemia according to WHO/ADA criteria (impaired fasting glycaemia, impaired glucose tolerance or diabetes mellitus) was assessed by a 75-g oral glucose tolerance test. Inflammatory parameters were analyzed in fasting samples.

RESULTS

Dysglycaemia was found in 49%, 55% and 57% of patients with CAD, CVD and PAD, respectively; all were significantly higher than among the controls (29%). The odds ratio (95% CI) for being dysglycaemic were 1.7 (1.04-2.77), 1.9 (1.19-3.06) and 2.0 (1.25-3.19) for CAD, CVD and PAD, respectively. Inflammatory markers (the total leucocyte count, soluble tumour necrosis factor-receptor type I, C-reactive protein) were elevated in patient groups and tended to increase with increasing blood glucose levels in all groups. The levels of the anti-inflammatory cytokine transforming growth factor-beta1 and insulin-like growth factor binding protein 3 were lowered in patients with CAD and, in patients with PAD, the former was inversely related to the levels of the blood glucose.

CONCLUSIONS

Undiagnosed dysglycaemia was common in patients with ischaemic CV manifestations regardless of vascular bed involved. Inflammation was associated in a dosage-related manner to glucose levels.

Lymphatic cerebrospinal fluid absorption pathways in neonatal sheep revealed by subarachnoid injection of Microfil

There is mounting evidence that a significant portion of cerebrospinal fluid drainage is associated with transport along cranial and spinal nerves with absorption taking place into lymphatic vessels external to the central nervous system. To characterize these pathways further, yellow Microfil was infused into the cisterna magna of 2-7-day-old lambs post mortem to perfuse either the cranial or spinal subarachnoid compartments. In some animals, blue Microfil was perfused into the carotid arteries simultaneously. Microfil was observed in lymphatic networks in the nasal mucosa, covering the hard and soft palate, conchae, nasal septum, the ethmoid labyrinth and the lateral walls of the nasal cavity. Many of these lymphatics drained into vessels located on the lateroposterior wall of the nasopharynx and from this location drained to the retropharyngeal lymph nodes. Additionally, lymphatics containing Microfil penetrated the lateral wall of the nasal cavity and joined with superficial lymphatic ducts travelling towards the submandibular and preauricular lymph nodes. In two cases, lymphatic vessels were observed anastomosing with deep veins in the retropharyngeal area. Microfil was also distributed within the nerve trunks of cranial and spinal nerves. The contrast agent was located in longitudinal channels within the endoneurial space and lymphatics containing Microfil were observed emerging from the mesoneurium. In summary, Microfil distribution patterns in neonatal lambs illustrated the important role that cranial and spinal nerves play in linking the subarachnoid compartment with extracranial lymphatics.

End-Organ reinnervation does not prevent axonal degeneration in nerve allografts following immunosuppression withdrawal

Previous work indicated that appropriate end-organ reinnervation fails to influence axonal degeneration in nerve allografts following immunosuppression withdrawal. In the present study, we examined if differences existed in axonal degeneration when axons regenerated across nerve allografts are allowed or completely denied end-organ reinnervation. Two ACI rat nerve allografts (3 cm long) were sutured into gaps created in both peroneal nerves in Lewis rats. In the right leg, the distal end of the graft was connected to the distal host nerve stump to allow end-organ reinnervation. In the left leg, the distal end was turned back and double ligated (unconnected) to prevent end-organ reinnervation. Rats received Cyclosporin A daily for 12 weeks to allow for regeneration and were sacrificed at 16 (n = 5) or 18 (n = 5) weeks following engraftment to assess axonal degeneration following immunosuppression withdrawal. Five Lewis rats receiving autografts served as control and were sacrificed at 12 weeks. Morphometric analysis was performed. In the control group (autografts) the cross-sectional area of and the number of myelinated fibres in the unconnected grafts was double that of the connected grafts, suggesting a sprouting effect. There was a tenfold reduction in the mean number of fibres at weeks 16 and 18 in the allografts compared to controls, without any significant differences in the connected versus unconnected sides. End-organ reinnervation decreases sprouting of axons within the graft but does not protect axons from degeneration following immunosuppression withdrawal.

Comparison of cerebrospinal fluid transport in fetal and adult sheep

We quantified cerebrospinal fluid (CSF) transport (conductance) and CSF outflow resistance in late-gestation fetal and adult sheep using two methods, a constant pressure infusion method and a bolus injection technique into the lateral ventricles. No significant differences in CSF conductance (fetus 0.013 +/- 0.002, adult 0.014 +/- 0.003 ml x min(-1) x cm H(2)O(-1)) or CSF outflow resistance (fetus 83.7 +/- 9.8, adult 84.7 +/- 19.7 cm H(2)O x ml(-1) x min) were observed. To confirm CSF transport to plasma in fetal animals, (125)I- or (131)I-labeled human serum albumin (HSA) was injected into the lateral ventricles. The tracer entered fetal plasma with an average mass transport rate of 1.91 +/- 0.47% injected/h (n = 9). In two fetuses, we monitored the tracer appearance in plasma and cervical and thoracic duct lymph after injection of radioactive HSA into the ventricular CSF. As was the case in adult animals, fetal tracer concentrations increased in all three compartments over time, with the highest concentrations measured in lymph collected from the cervical lymphatics. These results 1) indicate that global CSF transport parameters in the late-gestation fetus and adult sheep are similar and 2) suggest an important role for extracranial lymphatic vessels in CSF transport before birth.

Prospective analysis of relationships of outcome measures for ulnar neuropathy at the elbow

BACKGROUND

We undertook a prospective study to investigate relationships between outcome measures of ulnar neuropathy at the elbow.

METHODS

Thirty-one patients (mean age 52.6, range 20-80), with clinically and electrically verified ulnar neuropathy at the elbow, were seen independently by a neurosurgeon and a physiotherapist. All tests were administered to all patients on each visit. Data collected included measures of sensory (monofilament, two-point discrimination, vibration) and motor function (grip, key-pinch, muscle atrophy), pain (visual analogue scale (VAS)) and impact on lifestyle (Levine's questionnaires (function status score--FSS, symptom severity score--SSS)), disability of the arm, shoulder and hand module (DASH) and patient-specific measures (PSM). Parametric and non-parametric correlation and factor analysis were done.

RESULTS

Outcome analysis was available for 63 patient visits, with follow-up obtained for 20 patients (mean 8.5 months). Lifestyle and pain instruments (FSS, SSS, DASH, PSM and VAS) all correlated well with each other (r > 0.6, p < .01). DASH was moderately to highly correlated to nine of the 11 measures. Some tests correlated poorly, for example, Semmes-Weinstein monofilament with other sensory measures and muscle atrophy with almost all measures. Factor analysis revealed that there are two principal factors, accounting for 77% of the variance. Factor 1 relates to impact on lifestyle and pain while Factor 2 relates to strength and function.

DISCUSSION/CONCLUSIONS

Intraclass measures, particularly ones assessing lifestyle and pain instruments are strongly correlated. Factor analysis revealed two principal factors that account for the majority of the variance; future studies with a larger sample size are needed to validate this analysis.

Intracranial pressure accommodation is impaired by blocking pathways leading to extracranial lymphatics

Tracer studies indicate that cerebrospinal fluid (CSF) transport can occur through the cribriform plate into the nasal submucosa, where it is absorbed by cervical lymphatics. We tested the hypothesis that sealing the cribriform plate extracranially would impair the ability of the CSF pressure-regulating systems to compensate for volume infusions. Sheep were challenged with constant flow or constant pressure infusions of artificial CSF into the CSF compartment before and after the nasal mucosal side of the cribriform plate was sealed. With both infusion protocols, the intracranial pressure (ICP) vs. flow rate relationships were shifted significantly to the left when the cribriform plate was blocked. This indicated that obstruction of the cribriform plate reduced CSF clearance. Sham surgical procedures had no significant effects. Estimates of the proportional flow through cribriform and noncribriform routes suggested that cranial CSF absorption occurred primarily through the cribriform plate at low ICPs. Additional drainage sites (arachnoid villi or other lymphatic pathways) appeared to be recruited only when intracranial pressures were elevated. These data challenge the conventional view that CSF is absorbed principally via arachnoid villi and provide further support for the existence of several anatomically distinct cranial CSF transport pathways.

Subacute femoral compressive neuropathy from iliacus compartment hematoma

BACKGROUND

Traumatic retroperitoneal hematoma in the iliacus muscle is an unusual but potentially serious cause of femoral compression neuropathy.

CASE REPORT

We describe the clinical, imaging, and management features of a case of traumatic iliacus retroperitoneal hematoma with delayed manifestation of femoral neuropathy.

DISCUSSION

The anatomical substrate for hematoma formation with subacute compression of the femoral nerve is emphasized. A subacute compartment syndrome with progressive edema, swelling and ischemia of iliacus compartment is suggested as the underlying cause. Early fasciotomy with or without hematoma evacuation should be considered in order to provide rapid decompression and to minimize the chance of permanent nerve injury.

Epithelioid hemangioendothelioma of the spine presenting as cervical myelopathy: case report

OBJECTIVE AND IMPORTANCE

We report the first case in the literature of cervical myelopathy caused by progressive cord compression as a result of epithelioid hemangioendothelioma of the cervical vertebra.

CLINICAL PRESENTATION

A 58-year-old man presented with progressive cervical myelopathy. Imaging revealed a vascular, expansile lesion of contiguous cervical vertebrae causing cord compression. The surgical pathology revealed epithelioid hemangioendothelioma, a rare tumor not previously reported to present in such a fashion.

INTERVENTION

Preoperative embolization and a two-stage anterior and posterior surgical decompression and fusion procedure were performed. The high vascularity of this lesion makes surgery a formidable surgical challenge. Adjuvant radiotherapy was administered to the residual tumor because of its potential for low-grade malignancy.

CONCLUSION

The diagnosis relied on accurate histopathological assessment. The general principles of achieving cord decompression and tumor control are important. The literature on epithelioid hemangioendothelioma involving the spine is reviewed, and the tumor biology and the role of adjuvant therapy are discussed.

MR properties of rat sciatic nerve following trauma

T(1) and T(2) relaxation times, magnetization transfer (MT), and diffusion anisotropy of rat sciatic nerve were measured at different time intervals following trauma. The nerve injury was induced by either cutting (irreversible nerve degeneration) or crushing (degeneration followed by regeneration). The MR properties were measured for proximal and distal portions of the injured nerve. The portions of the nerve proximal to the induced injury exhibited MR characteristics similar to those of normal nerves, whereas the distal portions showed significant differences in all MR parameters. These differences diminished in the regenerating nerves within approximately 4 weeks post injury. In the case of irreversible nerve damage, the differences in the distal nerves were slightly larger and did not resolve even 6 weeks after induced trauma. The MR measurements were correlated with histopathology exams. Observed changes in tissue microstructure, such as demyelination, inflammation, and axonal loss, can result in a significant increase in the average T(1) and T(2) relaxation times, reduction in the MT effect, and decrease in diffusion anisotropy. MR parameters, therefore, are very good indicators of nerve damage and may be useful in monitoring therapies that assist nerve regeneration. Magn Reson Med 45:415-420, 2001.

Differential response of sensory and motor axons in nerve allografts after withdrawal of immunosuppressive therapy

OBJECT

Rejection of nerve allografts and loss of regenerated host axons after withdrawal of immunosuppressive therapy poses an ongoing challenge in peripheral nerve repair. The present report is of a blinded prospective controlled study in which an established rat model of nerve allotransplantation is used to examine the effect of fiber type on survival and degeneration of nerve allografts after discontinuation of immunosuppression. The authors hypothesized that sensory axons will selectively resist a rejection response, whereas motor axons will degenerate.

METHODS

Four-centimeter nerve segments from ACI rats were grafted into peroneal and sural (mixed) or saphenous (sensory) nerve gaps in Lewis rats. In some rats, L4-6 dorsal root ganglia were ablated before grafting, creating pure motor sural and peroneal nerves. All rats received 12 weeks of immunosuppressive therapy to support nerve regeneration into allografts. Immunosuppression with cyclosporin was then withdrawn. At planned death (12-18 weeks postsurgery), graft tissue was subjected to histomorphometric analysis for evaluation of axon survival and loss. Graft rejection led to loss of all axons in approximately 60% of the allograft segments. The mixed nerve group was most prone to complete rejection, with significantly lowered axon counts at Weeks 16 and 18 compared with the Week 12 baseline. Axons from the sensory nerve were least likely to degenerate. The pure motor nerve group axons demonstrated intermediate sensitivity, with a selective loss of larger axons at Week 16 and a significant decrease in axon counts from the Week 12 baseline at Week 18.

CONCLUSIONS

Whereas the majority of axons are lost after withdrawal of immunosuppressive therapy from nerve allografts, there is a selective survival of axons from cutaneous sensory nerves and smaller-diameter motor fibers. The biological and molecular mechanisms that make some axons impervious to injury remain to be determined.

Split cord malformation with diastematomyelia presenting as neurogenic claudication in an adult: a case report

STUDY DESIGN

This is a report of a rare presentation of a split cord malformation with diastometamyelia.

OBJECTIVES

This report draws attention to the fact that the only manifestation of diastmetamyelia in the adult patient may be neurogenic claudication.

SUMMARY OF BACKGROUND DATA

Patients with split cord malformations and diastometamyelia rarely have symptomatic onset in adulthood. When present, a traumatic event leading to an acute neurologic change is the usual presentation.

METHODS

An adult patient presented with symptoms of neurogenic claudication in the left leg. Magnetic resonance imaging examination showed a split cord malformation and diastometamylia at L3-L4 with spinal stenosis of the left hemicord. Decompressive laminectomy and subtotal resection of the bony spur were performed.

RESULTS

Two years after decompression, the patient has complete resolution of his leg symptoms and is back to work.

CONCLUSIONS

Neurogenic claudication without any objective neurologic deficit or neurocutaneous stigmas of an underlying spinal cord abnormality may be the only presentation in the adult with diastometamyelia. Decompression to relieve both clinical and radiologic evidence of spinal stenosis obtained excellent outcome.

Detection of host and donor cells in sex-mismatched rat nerve allografts using RT-PCR for a Y chromosome (H-Y) marker

The donor and host source of support cells, such as Schwann cells, in nerve allograft segments have been the subject of debate. The objective of the present study was to assess the utility of a molecular technique that probes for a Y chromosome expressed gene (H-Y) in distinguishing host from donor tissue in sex-mismatched nerve allograft segments. Forty-two Lewis rats received bilateral syngeneic Lewis or allogeneic ACI rat peroneal nerve grafts, with or without cyclosporin A (CsA) treatment. At different times thereafter animals were sacrificed and samples were harvested. We transplanted males and females reciprocally, to study both survival of donor cells (persisting H-Y mRNA in male grafts by transcription polymerase chain reaction (RT-PCR), and graft infiltration by host cells (detectable H-Y mRNA in female grafts). A kinetic analysis revealed a progressive loss of viable donor cells (loss of H-Y mRNA signal) from allografts, beginning 2-3 weeks, and culminating at 4 weeks, with little detectable H-Y in the absence of CsA treatment. CsA treatment led to prolonged survival of allograft cells, confirmed by detectable H-Y mRNA. By studying female grafts in male rats we could confirm that loss of viable donor tissue in allografts was accompanied by infiltration of host (H-Y mRNA positive) cells, whereas no H-Y mRNA signal was seen in males receiving autografts from females or in immunosuppressed allograft segments. These data suggest that reverse RT-PCR analysis for a Y chromosome gene product can be a valuable tool to assess the origin of viable cells in sex-mismatched nerve allotransplantation tissue.

Cyclosporine A inhibits lymphocyte migration into ovine peripheral nerve allografts

Lymphocyte migration into nerve allografts was measured to estimate the cyclosporine A (CsA) dose required to suppress rejection. Twelve outbred sheep received daily subcutaneous CsA at 0, 5, 10, or 15 mg/kg/day for 2 weeks prior to implantation of multiple heterotopic subcutaneous nerve grafts. Lymphocyte migration was determined after 7 days by an intravenous pulse of autologous 111indium-labeled lymphocytes and subsequent quantitation of gamma radioactivity in nerve tissue (CPM/g, mean +/- SEM). Measurement by radioimmunoassay revealed a dose-dependent increase in blood cyclosporine levels. Lymphocyte migration into autografts (404+/-44) was significantly less than migration into allografts (16,554+/-2,049), in control animals (P < 0.01). A dose-dependent inhibition of lymphocyte migration into nerve allografts was observed with counts of 7,662+/-1,692, 4,083+/-1,112, and 1,561+/-232 in sheep receiving 5, 10, or 15 mg/kg/day of CsA, respectively. Daily CsA administration produced effective blood levels and immunosuppression sufficient to inhibit lymphocyte migration into nerve allografts.

Regeneration across cold preserved peripheral nerve allografts

The feasibility of peripheral nerve allograft pretreatment utilizing cold storage (5 degrees C in the University of Wisconsin Cold Storage Solution) or freeze-thawing to prevent rejection was investigated. Regeneration across cold-stored (3 or 5 weeks) or freeze-thawed (FT), 3.0-cm sciatic nerve allografts were compared to fresh auto- and allografts in an inbred rat model. At 16-week post-engraftment, only FT allografts appeared similar to autografts on gross inspection; FT grafts were neither shrunken nor adherent to the surrounding tissue as seen in the other allograft groups. Qualitatively, the pattern of regeneration in the graft segments of the fresh allograft and to a lesser extent of pretreated allografts was inferior to that of autografts as evidenced by a disruption in the perineurium, more extrafascicular axons, smaller and fewer myelinated axons, increased intrafascicular collagen deposition, and the persistence of perineurial cell compartmentation and perivascular infiltrates. Distal to these grafts, the regeneration became more homogenous between groups, although areas of ongoing Wallerian degeneration, new regeneration as well as compartmentation, were more prevalent in fresh and pretreated allografts. Although the number of myelinated fibres was equivalent to autografts, the fibre diameters, the number of large diameter fibres, and the G-ratio were significantly decreased in the allograft groups, which, in part, accounted for the significant decrease in conduction velocity in the 3-week stored and fresh allograft, and the slight decrease in the 5-week stored and FT allograft groups. There was a small return in the Sciatic Function Index towards normal, but no consistent differences between groups were found. Prolonged cold storage and freeze-thawing of nerve allografts resulted in regeneration that was better than fresh allografts, but inferior to autografts. With the concomitant use of host immunosuppression or other immunotherapies, these storage techniques can provide a means of transporting nerve allografts between medical centres and for converting urgent into elective procedures.

Axillary nerve injuries in children

Isolated axillary nerve injury is uncommon, particularly in children. The motor deficit of shoulder abduction may not recover spontaneously and can be a substantial handicap. Detection may be difficult initially, as the injury is masked by trauma such as head injury, and concomitant shoulder injury requiring immobilization. After mobilization, patients learn to partially compensate by using alternate muscles. There are few reports of surgical management of this nerve injury. Most concern predominantly adults, and the results are mixed with on average slightly greater than half having a good recovery (defined as grade 4-5 Medical Research Council muscle power). We present our experience with 4 pediatric patients who had axillary nerve injury. Three patients had an interposition nerve graft, and 1 patient underwent neurolysis. All patients recovered to grade 4-5 deltoid muscle power. Children with an axillary nerve injury which fails to recover spontaneously by 4-6 months should strongly be considered for surgical exploration.

Peripheral nerve repair and grafting techniques: a review

In this review, various conventional nerve repair techniques including direct epineurial repair, grouped fascicular repair, fascicular repair, and nerve grafting are described. The indications for use, as well as the relative advantage and disadvantage, of each technique are discussed. The experimental and clinical evidence from a review of the pertinent literature does not demonstrate a significant difference in outcome of one method over the others. Surgical decisions should be made by a thorough evaluation of all aspects of the nerve injury and surgical methods. All nerve injuries cannot be repaired using only one type of nerve repair method. The surgeon should be familiar with all the techniques described and be prepared to use them under appropriate circumstances.

Long nerve allografts in sheep with Cyclosporin A immunosuppression

Rodent studies of nerve allografts are limited by a relatively short length of graft segment. The authors attempted to establish an outbred sheep model that would allow the study of longer, more clinically relevant nerve gaps. Using outbred ewes, two 8-cm long radial sensory nerves were grafted into gaps (5 cm) in the median nerve. Sheep received an autograft and an allograft. Four sheep were immunosuppressed with Cyclosporin A (CsA) and four were controls. Blood CsA levels greater than 1000 microg/L were obtained. Systemic immunosuppression resulted in severe opportunistic infections, and the sheep were sacrificed between 35 and 47 days following surgery. Histologically, in the autografts and CsA-treated allografts, evidence of nerve regeneration was seen. Non-immunosuppressed allografts were clearly rejected. While clear differences in the histology of experimental and control grafted nerve tissues were seen, the sheep allograft model presents considerable challenges due to immunosuppression-related infectious complications.

Revascularization of peripheral nerve autografts and allografts

The timing and mechanisms of peripheral nerve revascularization were investigated using a 2-cm sciatic nerve graft model in 58 rats. Epineurial perfusion was consistently established by 48 hours and endoneurial perfusion by 72 hours. The pattern of endoneurial perfusion was "all-or-none"--either all or none of the vessels in a fascicle exhibited blood flow. Conventional allografts exhibited similar revascularization dynamics and patterns. Capping the ends of the autograft with Silastic significantly delayed revascularization; no flow was observed at 4 days, and only a peripheral rim of perfused fascicular vessels was observed at 7 days. These patterns suggested that the primary method of revascularization in the conventional graft was longitudinal inosculation; no evidence of peripheral neovascularization or dependence on the graft bed as a source of revascularization was observed. The introduction of a major histocompatibility complex barrier between the grafted tissue and the recipient animal did not alter the timing or the mechanics of blood flow reestablishment.

Peripheral nerve revascularization: histomorphometric study of small- and large-caliber grafts

The revascularization of nerve grafts was investigated using histologic and morphometric techniques. Small-diameter nerve grafts (sciatic in the rat and sural in adult ewes) were studied, as was a large-diameter peroneal nerve graft in the ewe. Ninety-six hours after sciatic nerve engraftment, rats were injected with an intravascular fluorescent tracer. Evans blue albumin (EBA). Specimens were observed for the number of vessels perfused. Analysis showed no difference in vascular pattern between the grafted nerves and their control nerves, suggesting that spontaneous revascularization had occurred to establish a vascular tree essentially identical to the native nerve. Sural and peroneal nerve grafts were evaluated in adult ewes at 7 or 40 days post-nerve grafting. Similar to the rat sciatic nerve, the small-diameter sural nerve grafts were completely revascularized, with an equal number of perfused vessels at both time periods, with respect to control specimens. In contrast, the larger-caliber peroneal nerve grafts were not perfused at 7 days, and very poorly perfused at 40 days. This correlated with scant neural regeneration at 40 days. The finding suggests that small-diameter nerve grafts spontaneously revascularize, and revascularization using microvascular techniques is not necessary. In contrast, the larger-diameter nerve graft did not revascularize well. Such a large-diameter nerve graft would provide a suitable model to investigate the potential merits of a vascularized nerve graft.

Cold preserved nerve allografts: changes in basement membrane, viability, immunogenicity, and regeneration

Rat sciatic nerve graft segments were harvested and pretreated by either placement in the University of Wisconsin Cold Storage Solution at 5 degrees C and storage from 1 to 26 weeks, or repeatedly freezing (-40 degrees C) and thawing (20 degrees C). Following pretreatment, grafts were transplanted as either syngeneic or allogeneic nerve grafts. Storage and freeze-thawing did not affect the Schwann cell basal lamina or laminin distribution of the peripheral nerve. Graft cell viability decreased with increasing time of storage, with some viable cells detectable even after 3 weeks of storage. Freeze-thawed grafts were not viable. Increasing time of storage led to decreasing immune response and graft rejection, but improved regeneration. Freeze-thawed and 26-week stored allografts were nonimmunogenic and rejection was not seen, but regeneration was delayed compared to autografts. Graft storage may become a useful adjunct to clinical nerve allografting to permit elective scheduling of surgery, provide greater time for preoperative tissue testing, and possibly blunt the immune response.

Cervical myelopathy caused by hypoplasia of the atlas: two case reports and review of the literature

OBJECTIVE AND IMPORTANCE

Congenital anomalies of the posterior arch of the atlas (C1) are uncommon. They range from partial clefts to total agenesis of the posterior arch. Developmental cervical canal stenosis is a congenital anomaly that may cause cervical myelopathy. Myelopathy caused by cervical stenosis at the level of the atlas has been reported in only three cases. We present two cases of nontraumatic cervical myelopathy caused by spinal stenosis at the level of the atlas associated with a hypoplastic but complete posterior arch of C1.

CLINICAL PRESENTATION

Two elderly Chinese men developed cervical myelopathy gradually during months to years, without preceding trauma. Imaging revealed a hypoplastic but complete posterior C1 arch associated with changes of spondylosis in both patients, producing severe spinal stenosis and spinal cord compression. Posterior decompression was achieved in both by the removal of the posterior arch of C1 with its surrounding thickened posterior ligaments. Symptoms and clinical findings improved in the two patients during the follow-up period.

CONCLUSION

The anomaly presented in our two cases differs from the established classification of congenital abnormalities of the posterior arch of the atlas, suggesting a different embryological defect. The hypoplastic posterior C1 arch created a congenitally narrowed spinal canal in our patients, rendering the spinal cord more susceptible to compression related to degenerative changes of the spine. Surgical removal of the shortened posterior C1 arch and surrounding degenerative ligaments is an effective treatment for symptomatic patients with this condition.

Lack of association between outcome measures of nerve regeneration

Studies of nerve regeneration in rodents utilize at least one of three classes of outcome measures: electrophysiology, morphometry, and functional tests. The assumption that these measures are correlated was tested utilizing a data set of 16 variables. Significant correlations (Spearman's rho, P < or = 0.05) were found within variable classes; however, none were found between classes. The three commonly utilized outcome measures do not measure the same phenomenon but rather discrete aspects of nerve regeneration.

Management and results of sciatic nerve injuries: a 24-year experience

OBJECT

The purpose of this retrospective clinical study was to present results and provide management guidelines for various types of sciatic injuries.

METHODS

Over a 24-year period, 380 patients with sciatic nerve injuries were managed. In 230 patients (60%), the injury was at the buttock level, with injection injuries comprising more than half of these cases. Thigh-level sciatic injury was evaluated in 150 cases (40%) and was usually secondary to one of four main causes: 1) gunshot wound; 2) femur fracture; 3) laceration; or 4) contusion. Patients with partial deficits uncomplicated by severe pain or with significant spontaneous recovery or late referral were managed medically. Surgical exploration was not indicated in 23% of injuries at the thigh level and almost 50% of those at the buttock level. Most of these patients achieved partial but good spontaneous recovery, especially in the tibial division distribution. Surgical intervention was required for more complete and persistent deficits in either the tibial or peroneal distribution. Divisions of the sciatic nerve were split apart and evaluated independently. Management was guided by nerve action potential (NAP) recordings, which indicated whether neurolysis or resection of the lesion was required. Repair was then made by using sutures or more frequently by graft placement. In most cases in which neurolysis was performed because a positive NAP was recorded distal to the lesion, useful function was found in the peroneal distribution. Unfortunately, significant recovery occurred in only 36% of patients who received suture or graft repairs of the peroneal division. Good-to-excellent outcome was common for the tibial division, even in cases in which repair was proximal and required lengthy grafts. The relatively favorable recovery of tibial as opposed to peroneal divisions of the sciatic nerve occurred regardless of the level or mechanism of injury.

CONCLUSIONS

Surgical exploration and, when necessary, repair of sciatic nerve injuries is worthwhile in selected cases.

Analysis of upper and lower extremity peripheral nerve injuries in a population of patients with multiple injuries

BACKGROUND

The purpose of this study was to determine the prevalence, cause, severity, and patterns of associated injuries of limb peripheral nerve injuries sustained by patients with multiple injuries seen at a regional Level 1 trauma center.

METHODS

Patients sustaining injuries to the radial, median, ulnar, sciatic, femoral, peroneal, or tibial nerves were identified using a prospectively collected computerized database, maintained by Sunnybrook Health Science Centre, and a detailed chart review was undertaken.

RESULTS

From a trauma population of 5,777 patients treated between January 1, 1986, and November 30, 1996, 162 patients were identified as having an injury to at least one of the peripheral nerves of interest, yielding a prevalence of 2.8%. These 162 patients sustained a total of 200 peripheral nerve injuries, 121 of which were in the upper extremity. The mean patient age was 34.6 years (SEM +/- 1.1 year), and 83% of patients were male. The mean injury severity score was 23.1 (+/-0.90), and the mean length of hospital stay was 28 days (+/-1.8).

CONCLUSIONS

Motor vehicles crashes predominated (46%) as the cause of injury. The most frequently injured nerve was the radial nerve (58 injuries), and in the lower limb, the peroneal nerve was most commonly injured (39 injuries). Diagnosis of a peripheral nerve injury was made within 4 days of admission to Sunnybrook Health Science Centre in 78% of the cases. Surgery was required to treat 54% of patients. Head injuries were the most common associated injury, occurring in 60% of patients. Other common associated injuries included fractures and dislocations. The present report aims to aid in identification and treatment of peripheral nerve injuries.

Epidemiology of brachial plexus injuries in a multitrauma population

OBJECTIVE

The purpose was to identify the prevalence, causative factors, injury types, and associated injury patterns in multitrauma patients who sustained brachial plexus injuries.

METHODS

A retrospective review of a prospectively collected and computerized database and a chart review were performed.

RESULTS

Brachial plexus injuries were identified in 54 of 4538 (1.2%) patients presenting to a regional trauma facility. Young male patients predominated. Motor vehicle accidents were the most frequent cause overall, but only 0.67% of such accidents resulted in plexus injuries. Conversely, 4.2% of motorcycle accident victims and 4.8% of snowmobile accident victims suffered brachial plexus injuries. Injuries were supraclavicular for 62% of patients and infraclavicular for 38%. Supraclavicular injuries were more likely to be severe (Sunderland Grade 3 or 4), compared with infraclavicular injuries, which were neurapraxic in 50% of cases (P < 0.01). The former therefore required surgical exploration and reconstruction more often (52 versus 17%; P < 0.05). Associated injuries included closed head injuries with loss of consciousness in 72% of patients (coma in 19%), cervical spine fractures in 13%, and clavicle, scapular, or humeral fractures and shoulder dislocations or sprains in 15 to 22%. Rib fractures were observed in 41% and were complicated by internal thoracic injuries in a similar percentage of cases. The injury severity score ranged from 5 to 59, with a mean of 24, and two patients died.

CONCLUSION

Brachial plexus injuries afflict slightly more than 1% of multitrauma victims. Motorcycle and snowmobile accidents carry especially high risks, with the incidence of injury approaching 5%. Head injuries, thoracic injuries, and fractures and dislocations affecting the shoulder girdle and cervical spine are particularly common associated injuries. Supraclavicular injuries are more common, are of more severe grade, more often require surgery, and are associated with worse prognosis, compared with infraclavicular injuries.

Motor and sensory specificity of host nerve axons influence nerve allograft rejection

Previous studies have shown both survival and loss of regenerated host axons within nerve allograft segments after withdrawal of Cyclosporin A (CsA) immunosuppression. We hypothesized that the nature of end-organ reinnervation may influence the response of the axon, with survival of axons for appropriate innervation vs degeneration for inappropriate innervation. The rat femoral nerve model was chosen, as it has approximately equal sensory (S) and motor (M) divisions. Four ACI rat peroneal nerve allografts were sutured in straight (right leg: MM and SS) or switched (left leg; MS and SM) orientation in each femoral nerve transection gap in each Lewis rat recipient. Rats received CsA for 8 weeks to allow end-organ reinnervation, after which immunosuppression was discontinued. Rats were killed at various times thereafter, and underwent histologic and morphometric analysis of the graft segment axons. The regenerated axon population in the allograft reflected the nerve of origin: significantly more but smaller fibers when the proximal nerve was sensory and fewer but larger fibers when the proximal nerve was motor. After CsA withdrawal, there was a marked decrease of host axons as part of an ensuing rejection episode. The overall proportional decrease of axons was similar across all nerve orientation groups and, therefore, did not appear to be influenced by the nerve of origin or by the end-organ. However, the sensory proximal groups (SS and SM) contained more mature, noninjured fibers, while the motor proximal groups (MM and MS) contained significantly more degeneration and newly regenerating axons. We conclude that the motor or sensory nerve origin of the host axon, rather than the end-organ, influences axon survival after immunosuppression cessation. It is hypothesized that sensory axons may be more resilient while motor axons are selectively vulnerable to this second injury.

Regeneration across preserved peripheral nerve grafts

The potential to store nerve grafts for a prolonged period of time was assessed in a rat sciatic nerve model. Three-centimeter syngeneic nerve grafts were stored in Belzer/University of Wisconsin cold storage solution at different temperatures (5 degrees C, 22 degrees C, or 37 degrees C) for varying time periods (6 h, 24 h, or 3 weeks) prior to transplantation. Functional assessment using serial walking track analyses revealed no difference between storage times and temperatures. At 14 months postengraftment, the conduction velocities and the number of myelinated fibers that had regenerated across all grafts stored at 5 degrees C for all time periods tested were superior to grafts stored at either 22 degrees C or 37 degrees C. Nerve grafts stored for up to 3 weeks at 5 degrees C acted as effective conduits for proximal regenerating fibers and resulted in histologic, electrophysiologic, and functional results equivalent to fresh nerve grafts. Nerve graft storage may be applicable to nerve allografts and potentially provide allograft material that requires reduced or no associated host immunosuppression.

Delayed myelopathy after trivial neck injury in a patient with a cervical neurenteric cyst

BACKGROUND

Neurenteric cysts are rare spinal lesions of congenital origin. They usually present insidiously with a long history of local spinal pain, radiculopathy and myelopathy. We report a 14-year-old male with a high cervical neurenteric cyst who developed a progressive myelopathy after minor neck trauma. Full recovery followed a partial cyst excision and decompressive procedure.

SIGNIFICANCE AND CONCLUSION

The possible pathogenic mechanisms for this unusual presentation include hemorrhage into the cyst, sudden mechanical compression from abnormal spinal movement of a chronically distorted and compressed spinal cord, or an increase in the size of the cyst secondary to accumulation of cyst fluid. In this case a small increase in the cyst size may have resulted in increased mechanical distortion and spinal cord dysfunction on a compressive and ischemic basis.

Evaluation and quality-of-life assessment of amlodipine and enalapril in patients with hypertension

In this multicentre, double-blind trial in 461 patients with essential hypertension, amlodipine (5-10 mg once daily) and enalapril (10-40 mg once daily) were compared in terms of quality of life, efficacy and tolerability after 1 year of treatment (part 1). In part 2, 177 patients successfully treated with amlodipine in part 1 continued in an open evaluation of efficacy and safety of antihypertensive treatment with amlodipine for a further 2 years. In part 1, both drugs were similarly effective in lowering blood pressure (BP) (although significantly more enalapril patients required a diuretic) while maintaining quality of life. Apart from class-typical effects, such as oedema for calcium antagonists and cough for angiotensin-converting enzyme inhibitors, both drugs were equally well tolerated, with few adverse effects of clinical significance. Only a few patients (eight amlodipine (4%), nine enalapril (4%)) were withdrawn from the trial because of drug-related adverse events, demonstrating that the tolerability was good. Neutral to slightly beneficial effects were found in blood lipid concentrations after treatment with amlodipine. The BP reduction seen in the amlodipine patients after part 1 was maintained during part 2. Also, blood lipids and safety variables remained virtually constant. It is concluded that, at similar BP reduction, quality of life is equally well maintained on amlodipine and enalapril therapy. Thus, amlodipine compares favourably with enalapril as an effective and well-tolerated anti-hypertensive agent over the first year. Additionally, amlodipine patients evaluated over a 2-year extension maintained good BP control and the drug was well tolerated.

A long-term, double-blind, comparative study on quality of life during treatment with amlodipine or enalapril in mild or moderate hypertensive patients: a multicentre study

The efficacy, tolerability and impact on quality of life of amlodipine and enalapril were compared in a multicentre, double-blind, general practice study in 461 mild and moderate hypertensives over a 50-week active treatment period. Amlodipine (5-10 mg, once daily) and enalapril (10-40 mg, once daily) were found to be similarly effective in lowering blood pressure while not adversely affecting quality-of-life parameters. However, 20% of the enalapril group compared with 11% of the amlodipine group required the addition of hydrochlorothiazide for blood pressure control (P < 0.01). Diastolic blood pressure was normalised or reduced by 10 mmHg in 204 (90%) patients on amlodipine and in 190 (85%) patients on enalapril. Side-effects were, in general, mild or of little clinical significance. The major side-effects recorded were class-typical of ACE inhibitors and calcium antagonists, namely cough (enalapril) and oedema (amlodipine), respectively. Tolerability was very good, with only 17 patients (8 amlodipine, 4%; 9 enalapril, 4%) being withdrawn from the study due to side-effects definitely related to treatment. Amlodipine monotherapy produced a slightly beneficial effect on blood lipid concentration, and both drugs reduced the calculated 10-year risk of coronary heart disease. It was concluded that the calcium antagonist amlodipine compared favourably with the ACE inhibitor enalapril in terms of antihypertensive efficacy, tolerability and impact on quality of life.

The fate of Schwann cells in peripheral nerve allografts

The phenotype of Schwann cells, whether of host or donor origin, in nerve allografts has been a source of debate. The origin of Schwann cells in peripheral nerve allografts under conditions of no, temporary or continuous immunosuppression was assessed by immunohistochemistry. We hypothesized that host-derived Schwann cells would replace rejected foreign donor Schwann cells after withdrawal of immunosuppression. A murine model of nerve transplantation to normal (wild-type) hosts from donor Shiverer mice, a mutant whose Schwann cells are deficient in myelin basic protein, was used and antibody reactivity against myelin basic protein was employed to ascertain the identity of Schwann cells in the nerve allograft. Without immunosuppression, donor Shiverer Schwann cells were rejected and the nerve graft morphology was restored by host-derived Schwann cells. With continuous immunosuppression, donor Shiverer Schwann cells persisted in the graft segment, associated with a chronic rejection phenomenon. The latter allowed migration of host-derived Schwann cells, over time, into the graft segment in approximately half the cases. After withdrawal of finite (6 weeks) immunosuppression, a rejection response eliminated donor Schwann cells. Replacement by host Schwann cells ensured as was hypothesized.

Effect of cold preservation on lymphocyte migration into peripheral nerve allografts in sheep

Lymphocyte migration into fresh and preserved peripheral nerve allografts was quantitated to assess the effect of cold preservation and freeze-thawing pretreatment on the local immunological response to nerve allografts. Out-bred ewes received multiple 1.5-cm subcutaneous heterotopic peroneal nerve autografts, fresh allografts, and pretreated allografts, implanted within the same recipient. Lymphocyte migration was studied at 7 days by injecting autologous 111indium-labeled lymphocytes intravenously. After 3 hr of recirculation, lymphocyte migration into graft tissue was quantitated by a gamma counter (epm/g, mean +/- SEM). Lymphocyte traffic into fresh nerve allografts (21,623 +/- 3783) increased an average 9.4-fold over the autograft value (2918 +/- 377, P < 0.04). Histologic studies illustrated a marked lymphocytic infiltrate of CD4+ and CD8+ cells and enhanced class I and II MHC expression in fresh allografts, but not in autografts. Short-term cold preservation, for 6 and 12 hr (5 degrees C), enhanced lymphocyte entry into pretreated allograft tissue. Conversely, cold preservation for longer periods (1 and 3 weeks) dramatically reduced lymphocyte migration to values below corresponding autograft levels (783 +/- 100 and 1,252 +/- 120, respectively, P < 0.01). A comparable reduction in lymphocyte migration into nerve allografts was observed after freeze-thawing pretreatment (P < 0.01). Cold preservation of donor allogeneic lymphocytes inhibited their capacity to induce intradermal host lymphocyte migration, implicating passenger lymphocytes as a potential cold-sensitive allogeneic component of the nerve allograft. Assessment of the local response to ovine peripheral nerve allografts, utilizing radiolabeled autologous lymphocytes, demonstrated that cold preservation and freeze-thawing pretreatment significantly reduced lymphocyte migration into nerve allografts. The mechanism(s) of reduced lymphocyte migration may involve inactivation or death of antigen-presenting cells, including passenger lymphocytes.

[Does antihypertensive treatment with amlodipine or enalapril affect quality of life? A multicenter study in general practice]

In this multicentre trial in general practice the effect of one year of therapy with amlodipine or enalapril on quality of life and blood pressure was studied in 461 hypertensive patients. Quality of life was evaluated by means of a questionnaire administered on five occasions during the study. A total of 125 questions were distributed between psychological general well-being, own perception of health, social relations, sexual and cognitive functioning, and a combined index for frequency and intensity of symptoms. Both drugs were equally effective in reducing blood pressure, from 162/106 to 142/91 mm Hg, and had the same effect on quality of life. Neither of the drugs reduced quality of life, and in some of the variables a slight improvement (2-5%) was observed. The two compounds were tolerated equally well. Apart from class-typical effects (coughing for enalapril and edema for amlodipine) no clinically significant side effects were experienced.

Walking track analysis: utilization of individual footprint parameters

Functional assessment of rat sciatic, tibial, and peroneal nerve injuries was performed using walking track analysis. Individual walking print length (PL), toe spread (TS), and intermediate toe spread (ITS) values were measured up to 24 weeks after specific nerve transection, with or without repair. Sciatic and tibial nerve manipulation initially affected all footprint measurements, consistent with loss of intrinsic and extrinsic motor function. After sciatic repair, TS demonstrated partial recovery without any substantial recovery in PL or ITS, compared with sciatic transection values. By contrast, after tibial repair, PL values recovered dramatically, between 16 and 24 weeks, to levels not significantly different from control subjects. This was not observed after tibial transection without repair. TS recovered partially, whereas ITS recovered to control levels by 20 weeks after tibial repair. Peroneal transection resulted in multiple contractures, rendering this group unmeasurable at 4 weeks. After peroneal repair, only the PL reflected significant loss of function at 2 weeks, recovering to control values by 8 weeks. Manual TS measurements in nonwalking rats did not reflect functional nerve regeneration. Thus, individual PL measurements alone can be used to characterize functional recovery after tibial and peroneal nerve injury, whereas TS reflected recovery after sciatic nerve injury.

Double-blind, parallel, comparative study on quality of life during treatment with amlodipine or enalapril in mild or moderate hypertensive patients: a multicentre study

OBJECTIVE

To compare tolerance, antihypertensive efficacy and impact on quality of life of amlodipine and enalapril in patients with mild or moderate hypertension.

DESIGN

Multicentre, double-blind, double-dummy, comparative trial in general practice. Three phases were conducted: 4 weeks on placebo, 12 weeks of dose adjustment (amlodipine or enalapril) and a 38-week maintenance period.

PATIENTS

Four hundred and sixty-one patients of both sexes were enrolled; 451 were available for efficacy evaluation at the end of the trial.

TREATMENT

The patients were allocated to either amlodipine (231) or enalapril (230) treatment. If at the end of dose adjustment (amlodipine 5-10 mg/day, enalapril 10-40 mg/day) diastolic blood pressure was > or = 95 mmHg, hydrochlorothiazide (25-50 mg/day) was added (27 amlodipine patients and 45 enalapril patients).

MAIN OUTCOME MEASURES

Blood pressure changes after 1 year of treatment; between- and within-group changes in quality of life as assessed by psychological general well-being, social and sexual functioning, health-risk perception, alertness, behaviour, and impact of symptom and side effects.

RESULTS

Indices on quality of life were unchanged or increased (2-9%) in both groups. Blood pressure was normalized or reduced by > or = 10 mmHg in 204 (90%) and 190 (85%) patients on amlodipine and enalapril, respectively. Cough was the most frequently reported adverse event in the enalapril group (13%) and oedema in the amlodipine group (22%). Only eight (4%) patients on amlodipine and nine (4%) on enalapril were withdrawn because of drug-related adverse events.

CONCLUSION

At similar blood pressure reduction in mild and moderate hypertension, quality of life is equally well maintained on amlodipine and enalapril therapy.

Comparison of regeneration across nerve allografts with temporary or continuous cyclosporin A immunosuppression

The efficacy of short-term immunosuppression in a nerve allograft model was examined by comparing regeneration across peripheral nerve allografts with either temporary (12 weeks) or continuous (30 weeks) cyclosporin A treatment. One-hundred fifty Lewis rats received 2-cm nerve grafts from allogeneic ACI or syngeneic Lewis rat donors and were allocated to the following groups: allogeneic grafts and continuous cyclosporin A, with 18 weeks (20 rats) or 30 weeks (20 rats) of survival after graft placement; allogeneic grafts and temporary cyclosporin A, with 12 weeks (10 rats), 18 weeks (20 rats), or 30 weeks (20 rats) of survival; and control rats with allogeneic and syngeneic grafts, no cyclosporin A, with 12, 18, or 30 weeks (10 rats each) of survival. Functional regeneration across the nerve grafts was serially assessed with walking-track analysis. Endpoint evaluations included electrophysiological, histological, and morphometric studies. Both walking-track and electrophysiological function reached a plateau at a significantly worse level in nonimmunosuppressed allograft recipients than in syngeneic or treated allograft recipients. The group with temporary therapy experienced significant worsening in both motor and electrophysiological function at Week 18, 6 weeks after cyclosporin A withdrawal, compared to the group with continuous treatment. At Week 30, motor and electrophysiological function in the temporary-treatment group recovered to levels similar to those of the syngeneic and continuous cyclosporin A groups. Histological assessment of the graft segments from the temporary cyclosporin A group at 18 weeks showed evidence of rejection, with mononuclear cell infiltration and demyelination; morphometric evaluation demonstrated significantly decreased numbers of nerve fibers in the distal host segment. These histological and morphometric changes were no longer present in the nerves from the temporarily immunosuppressed rats at Week 30. Withdrawal of immunosuppression after successful regeneration through nerve allografts results in short-term graft rejection. Eventual restoration of graft histological and function parameters is comparable to continuously immunosuppressed rats. Temporary immunosuppression of nerve allograft recipients is feasible.

An assessment of regeneration across peripheral nerve allografts in rats receiving short courses of cyclosporin A immunosuppression

While peripheral nerve reconstruction could benefit from the use of nerve allografts, long term immunosuppression for non-vital organ transplantation is controversial. This study investigated the effectiveness of short course Cyclosporin A immunosuppression. Fourteen Lewis (RT1l) rats were the recipients of 3 cm sciatic nerve grafts from ACI (RT1a) donors, repaired to the transected sciatic nerve of the recipient animal. Animals were treated with Cyclosporin A (5 mg/kg/day) for eight weeks. Neuromuscular function was assessed every two weeks by sciatic function index determinations until 20 weeks. Electrophysiological, histological and morphological evaluations were performed at 14 (n = 6) and 20 weeks (n = 8) postengraftment. Rats had significantly improving functional studies from four to eight weeks (P = 0.01). Function decreased following cessation of Cyclosporin A treatment. Rats evaluated at 14 weeks had histological evidence of graft rejection with inflammatory cell infiltration, extensive demyelination and remyelination, and some Wallerian degeneration. Rats demonstrated improvement in morphological parameters and motor function from 14 to 20 weeks after engraftment. In this sciatic nerve allograft model, short course Cyclosporin A immunosuppression, although resulting in an initial episode of graft rejection, was successful in permitting good long term functional regeneration of neuromuscular function.

Subcutaneous injection of oral cyclosporin A solution

Cyclosporin A (CyA) is the agent of choice for immunosuppression in the majority of rodent organ and tissue allotransplantation experiments. Subcutaneous injection of suitably dissolved pure CyA powder preparation is the acceptable standard of drug administration. We investigated the possibility of using oral CyA solution in an injectable form and compared its availability with that of the standard solution in a rat model. Oral CyA solution diluted in placebo (olive oil) and standard solution prepared from pure compound were injected subcutaneously at a dose of 5 mg/kg/day to two groups of rats. Trough whole blood CyA concentrations were measured on day 10 following initiation of treatment. Blood CyA levels of the standard solution group (1,167 +/- 246 micrograms/liter, mean +/- SD) were virtually identical to those of the oral solution group (1,105 +/- 179 micrograms/liter; P greater than 0.05). In addition, the oral solution was easier to prepare and caused less injection site morbidity than the standard solution. We conclude that placebo-diluted oral CyA solution may be safely injected subcutaneously to rats and results in consistent blood levels, comparable to those achieved with standard solution prepared from pure compound.

Chronic cyclosporin A therapy in rats

We investigated the pharmacokinetics of cyclosporin A (CsA) blood levels and drug toxicity in a chronic rat study in which long-term (30 weeks) CsA was administered. Ninety Lewis rats received subcutaneous CsA at 5 mg/kg/day for 12 weeks, at which time CsA injections were stopped in 50 animals. The remaining 40 rats were maintained on 5 mg/kg CsA daily until week 18 and then switched to an alternate day dosing until week 30. All rats were observed daily and weighed weekly. Whole blood CsA levels were determined by a commercially available radioimmunoassay kit. The daily dosing regimen resulted in greatly elevated trough CsA levels (greater than 1,600 micrograms/liter) and substantial chronic systemic toxicity, with weight loss and death in eight animals. Alternate day dosing reduced trough levels (mean 1,311 micrograms/liter) and decreased toxicity. Chronic administration by the subcutaneous route resulted in a considerable depot effect, with constancy of drug levels over a 48 hr dosing interval and a slow decline of drug levels (15 days) upon cessation of treatment. These results underscore the importance of monitoring both body weight and blood CsA levels in rodent studies when CsA is employed. Investigators should be aware of drug accumulation with chronic therapy and the consequent need to modify dosing to prevent toxicity.

Transsphenoidal management of Rathke's cleft cysts. A clinicopathological review of 10 cases

We report detailed data on 10 patients who underwent transsphenoidal microsurgical management of histopathologically confirmed Rathke's cleft cysts. Preoperatively, pituitary dysfunction was present in 90%, headaches in 80%, hyperprolactinemia in 70%, and visual interference in 40%. Computed tomography and magnetic resonance imaging had 90% and 100% sensitivity, respectively, in disclosing the lesion. The mean follow-up duration was 22 months. There was no mortality. The only morbidity was sustained diabetes insipidus in one case. Resolution or improvement in preoperative dysfunction occurred in the majority of patients: headaches in 100%, visual deficits in 75%, normalization of hyperprolactinemia in 83%, and reversal of panhypopituitarism in 33%. We conclude that Rathke's cleft cysts can be managed safely and effectively with transsphenoidal drainage and partial excision of the wall.

Vernix caseo granulomatous meningitis (vernicomyelia)

An apneic and tetraplegic infant with an open lumbosacral myelomeningocele and an Arnold-Chiari malformation is reviewed. An exuberant chronic aseptic meningitis with foreign body giant cells and immunoreactive keratin was present around the spinal cord and brainstem. This paper discusses the recognition and role of granulomatous meningitis in the clinical course and in the pathogenesis of the unusual cerebellar abnormalities found in this infant.