Flexibility and alignment of the cervical spine after laminoplasty for spondylotic myelopathy

Summary The long term effects of laminoplasty on cervical movement and alignment were investigated by radiography and CT scans in a study of 56 patients with multisegmental myelopathy who had undergone a C3 to C7 open-door laminoplasty. Follow up averaged 5.8 years. Satisfactory neurological improvement occurred in 73%. Cervical flexion decreased by 35% and extension by 57%; the decrease of both movement was statistically significant. Decreased vertebral slip, as well as slightly reduced lordosis, was seen after operation. Increase in measured canal size after operation and at follow up was 48% and 40%; 8% of the expanded canal size was lost at the last follow up. Expansive open-door laminoplasty leads to a better neurological prognosis in this group of patients, while maintaining an increase in canal size and preserving spinal stability.

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Résumé Les effets à long terme de la laminoplastie sur la mobilité et l'alignement du rachis cervical ont été étudiés par radiographie et tomodensitométrie. Le travail a porté sur 56 patients atteints de myélopathie spondylitique multisegmentaire, ayant subi une laminoplastie ouverte C3–C7 avec une greffe osseuse réalisant un espaceur autogène. Le recul est en moyenne de 5.8 ans (de 2 à 10.4) et les résultats ont montré une amélioration neurologique satisfaisante dans 73% des cas. La flexion était diminuée de 35% et l'extension de 57%. Cette diminution de la mobilité était statistiquement significative. On a également observé une réduction du glissement vertébral et une légère réduction de la lordose. L'augmentation de la taille du canal après l'intervention chirurgicale était de 48% et de 40% au dernier examen; à ce moment elle avait disparu dans 8% des cas. Les laminoplasties ouvertes étendues assurent un meilleur pronostic neurologique chez les patients atteints de spondylite multisegmentaire en maintenant la taille du canal et en préservant la stabilité vertébrale.

     

Quantitative analysis of the spinal cord motoneuron under chronic compression: an experimental observation in the mouse

We investigated quantitative changes in spinal cord motoneurons following chronic compression using a mouse model of cervical cord compression. Twenty-five tiptoe-walking Yoshimura (twy) mice with calcified mass lesions compressing the spinal cord posterolaterally at the C1–C2 vertebral levels were compared with five Institute of Cancer Research (ICR) mice that served as controls. Spinal cord motoneurons in the anterior grey horn between the C1 and C3 spinal cord segments were Nissl-stained and counted topographically and then analysed in relation to the extent of spinal cord compression. The number of motoneurons in C1–C3 spinal cord segments decreased significantly with a linear correlation with the transverse area of the spinal cord when the cord was compressed to 50–70% of control values. A significant reduction in the number of motoneurons occurred at the C2–C3 spinal cord segment compressed at the C1–C2 vertebral level. In contrast, at the level rostral to the C1 vertebra, the number of motoneurons increased significantly in proportion to the magnitude of compression. The current study demonstrates that a number of neurons, morphologically consistent with anterior horn cells, were observed at a rostral site absolutely free of external compression where no such cells normally exist.     

Beneficial Effects of Follistatin in Hepatic Ischemia-Reperfusion Injuries in Rats

Background  

Ischemia-reperfusion injury has been demonstrated in a variety of clinical settings. The morbidity associated with liver transplantation and major hepatic resections is partly a result of ischemia-reperfusion injury. Follistatin, an activin-binding protein, binds to activins and subsequently blocks their action. It was reported that blockade of the action of activin with administration of follistatin accelerates recovery from ischemia renal injury. This study was conducted to investigate the involvement of the activin–follistatin system in hepatic ischemia-reperfusion injury.     

Fetal diaphragmatic hernia: prenatal evaluation of lung hypoplasia and effects of immediate operation

The outcome of fetuses with diaphragmatic hernia (CDH) has been reported to be related to the severity of lung hypoplasia. As an index of pulmonary hypoplasia, we attempted to measure the lung-thorax transverse area ratio (L/T) using ultrasonic echography in eight fetuses with left-sided CDH. Two cases with L/T more than 0.28 (controls: 0.52±0.04) were transported postnatally and recovered after early operation without episodes of persistent fetal circulation. Elective surgical repair was performed in six infants immediately after cesarean delivery at 35–37 weeks' gestation. In three cases with L/T between 0.21 and 0.24 who recovered with no complications, surgical reduction of the abdominal organs improved arterial blood gases and high-frequency oscillation ventilation (HFOV) was fully effective for respiratory management. In three with L/T between 0.11 and 0.17, extracorporeal membrane oxygenation (ECMO) was required from the 1st to the 12th postoperative day despite HFOV. Although two infants died of combined cardiovascular anomalies and airway bleeding caused by prolonged HFOV, respectively, one infant with minimal L/T survived. Measurement of L/T may help to predict the outcome of fetuses with CDH and to determine the indications for various treatments including immediate operation after cesarean delivery, HFOV, and ECMO. Offprint requests to: S. Kamata     

Cardiac troponin I in neonates undergoing the arterial switch operation

BACKGROUND: Cardiac troponin I (TnI) is a sensitive and specific marker of myocardial injury, but little is known about its release after complex congenital heart surgery. We investigated whether TnI correlates with early clinical outcome in neonates undergoing the arterial switch operation (ASO) for transposition of the great arteries (TGA). METHODS: Troponin I was measured serially up to 48 hours postoperatively in 31 neonates undergoing the ASO alone (simple TGA) and 9 neonates undergoing the ASO combined with other procedures (complex TGA) (eg, closure of a ventricular septal defect) and correlated with intraoperative and postoperative clinical parameters. RESULTS: There was no mortality. Troponin I peaked at either 4 or 12 hours postoperatively in all patients (median for simple TGA = 3.4 ng/mL, interquartile range 2.4 to 4.6; median for complex TGA = 4.7 ng/mL, interquartile range 3.2 to 6.8, p = 0.20). Peak TnI correlated with the durations of inotropic support (r = 0.54, p < 0.001), ventilation (r = 0.51, p < 0.01), and intensive care unit stay (r = 0.50, p < 0.01). The duration of cardiopulmonary bypass, aortic cross-clamping, and circulatory arrest did not correlate with the peak or total TnI release. The duration of aortic cross-clamping correlated poorly with the duration of inotropic support (r = 0.40, p < 0.05). The complex TGA group had longer aortic cross-clamp times, required more postoperative inotropic support, and had significantly higher total TnI release compared with the simple TGA group. CONCLUSIONS: There are weak but statistically significant correlations between peak TnI and clinical outcome. Complexity of the defect and ischemic times may be as useful to predict outcome in this group of patients.     

Opposing effects of adenosine on the survival of glial cells exposed to chemical ischemia

Extracellular adenosine (Ado) accumulates during brain ischemia. To investigate the pathophysiological role of Ado on glial cells under ischemic conditions, we examined the effect of Ado on the survival of C6 glial cells exposed to chemical ischemia (CI). Treatment with Ado during exposure to CI showed a marked protective effect, that was mediated via intracellular transport and conversion of Ado to inosine (Ino). In contrast, Ado exacerbated CI-mediated cell death when it was added during the recovery time after exposure to CI. Ado cytotoxicity was largely mediated via intracellular transport, but conversion of Ado to Ino abolished its toxicity. Ado-induced cell death was characteristic of apoptosis, and Ado increased the expression of a pro-apoptotic product Bax but decreased that of an anti-apoptotic product Bcl-2. Ado also suppressed the induction of two stress proteins HSC70 and HSP27. Furthermore, Ado induced cytochrome c release and increased caspase-3-like activity. These results indicate the dual opposing effects of Ado on glial cell survival. Intracellular accumulation of Ado can be both cytoprotective and cytotoxic, depending on its metabolic pathway.     

Usefulness of cord-blood harvesting for autologous transfusion in surgical newborns with antenatal diagnosis of congenital anomalies

BACKGROUND/PURPOSE: The risks of homologous transfusion and the effectiveness of predeposit autologous transfusion have been described. The authors examined the clinical usefulness of cord-blood harvesting for autologous transfusion in newborns who had congenital anomalies antenatally diagnosed that would require surgical intervention at or near the time of delivery. METHODS: Of 112 cases of antenatal diagnosis of congenital anomalies, 50 mothers gave informed consent and enrolled in this study. Cord-blood was withdrawn immediately after clamping of the umbilical cord and was used for autologous transfusion in newborns within the first 3 days postpartum. RESULTS: A mean of 72 +/- 54 mL of cord-blood was harvested (27 +/- 18 mL/kg). While preserving cord-blood for 3 days at 4 degrees C, no signs of clot formation or hemolysis were observed. The harvested cord-blood included plasma-free Hb ranging from 1 to 68 (13 +/- 18) mg/dL and thrombin-antithrombin III complex ranging from 2 to 273 (18 +/- 50) ng/mL. Bacteriologic examination of the stored cord-blood showed negative cultures, except for samples from 3 newborns after vaginal delivery. A mean of 46 +/- 34 mL of cord-blood was used in 26 patients for autologous transfusion. No significant complications related to cord-blood transfusion were recognized clinically. CONCLUSIONS: Autologous cord-blood transfusion has the potential to be a useful alternative to homologous transfusion in newborns requiring surgery. Adequate collection and storage techniques for cord-blood must be developed. J Pediatr Surg 36:851-854.     

Different alterations of nuclear triiodothyronine receptor capacity in liver and kidney induced by starvation and triiodothyronine administration

Many studies have shown alterations in the number of nuclear triiodothyronine receptor (NT3R) under pathophysiologic situations. Most of these studies were performed on the rat liver and it is not known whether NT3R in different tissues exhibits an alteration similar to that in the liver. We compared the change of nuclear receptor capacity for T3 in the liver and kidney during starvation and after T3 injection. Fasting for 72 h decreased maximal binding capacity (Cmax) in the rat liver receptor to 67% of the control, while it did not significantly change Cmax in the kidney. These changes in Cmax were parallel to those of nuclear protein concentrations in both tissues. Daily sc injection of T3 (20 micrograms/100 g body weight) for 3 days also caused the different alteration of Cmax in the liver and kidney. After T3, hepatic NT3R increased to 182% of the control, but renal NT3R increased only to 136%. Association constants were the same in all groups. These results show that changes of NT3R capacity under some conditions vary in different tissues.