Experimental study of the efficacy of the endoluminal prosthesis in colonic anastomoses

Colorectal surgery is still associated with a significant morbidity and mortality rate, mostly related to suture failure. We have carried out a randomized experimental study in dogs on colonic anastomoses exposed to a number of anastomotic risk situations. A total of 42 dogs was used. They were divided into three study groups (control, occlusion and diverticulitis), with and without an endoluminal tube. The aim was to assess the efficacy of the endoluminal prosthesis using clinical and radiological assessment of anastomotic healing. Pre- and post-anastomotic intraluminal pressures were also measured to determine whether these might be a factor in suture failure. There were significant differences in suture failure in animals in which the endoluminal tube was used. Mean duration of placement was 10.5 days. In the colon healing study, no significant differences were found between the groups in the pathological examination or in the assay of hydroxyproline content. The presence of the endoluminal tube may increase the maximum pressure applied on the colon wall. No significant differences were found in the intracolonic pressure differentials between the different groups or after the inclusion of the endoluminal prosthesis. The results obtained establish the efficacy of the endoluminal prosthesis in protecting the colonic anastomosis, and could be a valuable technique in colonic anastomoses with a high risk of suture dehiscence.     

Neuroradiological features of intracranial and intraorbital meningeal haemangiopericytomas

The neuroradiological features of six intracranial and one intraorbital haemangiopericytomas (HP) are reviewed. CT was performed before and after IV contrast medium in 5 patients. In 2 patients MRI was performed before and after contrast medium; in another, only unenhanced images were obtained. Five patients were studied by selective external and internal carotid artery angiography. Women constituted 5 of the 7 patients, and the mean age was 50.5 years, thus the sex and age distribution did not differ from that of typical meningiomas. Contrary to previous reports, calcification was present in two of the intracranial HP, and bone erosion was clearly seen in one intracranial HP and the orbital lesion. On MRI the tumours showed no differences from angioblastic meningiomas. All 6 intracranial HP were aggressive; all recurred following treatment and extracerebral metastasis occurred in one case.     

Movement disorders in patients with peripheral facial palsy.

Acute unilateral facial paralysis is usually a benign neurological condition that resolves in a few weeks. However, it can also be the source of a transient or long-lasting severe motor dysfunction, featuring disorders of automatic and voluntary movement. This review is organized according to the two most easily recognizable phases in the evolution of facial paralysis: (1). Just after presentation of facial palsy, patients may exhibit an increase in their spontaneous blinking rate as well as a sustained low-level contraction of the muscles of the nonparalyzed side, occasionally leading to blepharospasm-like muscle activity. This finding may be due to an increase in the excitability of facial motoneurons and brainstem interneurons mediating trigeminofacial reflexes. (2). If axonal damage has occurred, axonal regeneration beginning at approximately 3 months after the lesion leads inevitably to clinically evident or subclinical hyperactivity of the previously paralyzed hemifacial muscles. The full-blown postparalytic facial syndrome consists of synkinesis, myokymia, and unwanted hemifacial mass contractions accompanying normal facial movements. The syndrome has probably multiple pathophysiological mechanisms, including abnormal axonal branching after aberrant axonal regeneration and enhanced facial motoneuronal excitability. Although the syndrome is relieved with local injections of botulinum toxin, fear of such uncomfortable contractions may lead the patients to avoid certain facial movements, with the implications that this behavior might have on their emotional expressions.     

Helical computed tomographic angiography in penetrating neck trauma

The purpose of this study was to evaluate the ability of helical computed tomographic angiography (HCTA) to detect vascular injury in penetrating neck trauma. Thirty-five patients (30 gunshot wounds and 5 stab wounds) were studied prospectively with HCTA. Scans were performed with a 5-mm slice thickness at a 1:1 pitch after injection of 90 ml of nonionic contrast medium (30-second delay) at 3 ml/sec. Results were compared with those for angiography (29), surgery (3), ultrasound (2), and local inspection (1). HCTA correctly revealed 19 normal and 10 abnormal studies. In 8 cases, HCTA revealed irregular vessel margins (3), contrast extravasation (2), lack of vascular enhancement (1), and caliber changes (2). In 2 patients, HCTA revealed indirect signs of injury only. In 6 cases, HCTA findings did not correlate with angiography. HCTA detects both direct and indirect signs of vascular injury. Although indirect findings are more sensitive, the direct evaluation of vessels increases the specificity and has a high negative predictive value.     

Labyrinth Exploration, Emotional Reactivity, and Conditioned Fear in Young Roman/Verh Inbred Rats

An inbreeding program has been carried out with the Swiss sublines of Roman high- and low-avoidance rats since 1993. The present study reports the first experiments conducted with young animals of those inbred strains (RHA-I/Verh and RLA-I/Verh, respectively) from the sixth and seventh inbreeding generations. The results confirmed expected behavioral profiles. Compared to the RHA-I/Verh strain, RLA-I/Verh rats showed decreased entries into the illuminated central arena of an hexagonal tunnel maze, as well as decreased spontaneous locomotor activity and increased defecations, in two independent experiments. Young RLA-I/Verh females explored less than did their RHA-I/Verh counterparts during session 1 of a conditioned-fear experiment preceding shock administration, and in session 2 (conducted 24 h after the application of three footshocks), they showed greater conditioned behavioral inhibition (i.e., reduced amount of rearing), as well as higher defecation scores, than did RHA-I/Verh females.Karl Bättig tragically and unexpectedly died on December 27, 1996     

Cerebrospinal fluid purine metabolites after complex febrile convulsions

Adenosine monophosphate, inosine monophosphate, inosine, adenosine, guanosine, adenine, guanine, hypoxanthine, xanthine and uric acid were determined in cerebrospinal fluid (CSF) of 15 children after complex febrile seizures (CFS) and in 27 after simple febrile seizures (SFS), and compared with those in a control group of 63 children. There was no statistically significant difference between the groups for any of these metabolites, suggesting that CFS and SFS neither significantly disturb the metabolism of nucleotides, nucleosides or bases nor significantly deplete neuron adenosine triphosphate levels.     

Continuous epidural infusion of racemic methadone results in effective postoperative analgesia and low plasma concentrations

PURPOSE: To compare two protocols of epidural administration of racemic methadone for postoperative analgesia (continuous infusion and intermittent bolus), focussing on plasma concentration, analgesic efficacy and side effects. METHODS: Ninety patients undergoing abdominal or lower-limb surgery were randomly assigned to two groups in a prospective double-blind design. The continuous infusion patients (n=60) received initial doses of 3 to 6 mg followed by 6 to 12 mg by continuous infusion over 24 hr. The bolus administration patients (n=30) received repeated boluses of 3 to 6 mg of racemic methadone every eight hours. Pain intensity was assessed on a visual analog scale. Amount of supplementary analgesia was recorded, as was the incidence of side effects. Plasma methadone concentrations were determined by high performance liquid chromatography. Treatment was continued for 72 hr. RESULTS: Pain relief was good and comparable in both groups throughout the three days of treatment. No accumulation of plasma racemic methadone was observed in either group, although the concentrations were significantly higher in the bolus group. Miosis was significantly more frequent in the bolus group. CONCLUSION: Plasma methadone concentrations were significantly lower with continuous infusion. Plasma methadone accumulation, which is considered the main disadvantage for its purported influence on the incidence of side effects, did not occur at the doses used over the three days of treatment that we report.     

Biochemical actions of chronic ethanol exposure in the mesolimbic dopamine system

In previous studies, we have demonstrated that chronic administration of morphine or cocaine produces some common biochemical adaptations in the ventral tegmental area (VTA) and nucleus accumbens (NAc), components of the mesolimbic dopamine system implicated in the reinforcing actions of these and other drugs of abuse. Since this neural pathway is also implicated in the reinforcing actions of ethanol, it was of interest to determine whether chronic ethanol exposure results in similar biochemical adaptations. Indeed, as seen for chronic morphine and cocaine treatments, we show here that chronic ethanol treatment increased levels of tyrosine hydroxylase and glial fibrillary acidic protein immunoreactivity, and decreases levels of neurofilament protein immunoreactivity, in the VTA. Also like morphine and cocaine, ethanol increases levels of cyclic AMP-dependent protein kinase activity in the NAc. These actions of ethanol required long-term exposure to the drug, and were in most cases not seen in the substantia nigra or caudate-putamen, components of the nigrostriatal dopamine system studied for comparison. Altered levels of tyrosine hydroxylase in catecholaminergic cells frequently reflect altered states of activation of the cells. Moreover, increasing evidence indicates that ethanol produces many of its acute effects on the brain by regulating NMDA glutamate and GAB_A receptors. We therefore examined the influence of chronic ethanol treatment on levels of expression of specific glutamate and GABA receptor subunits in the VTA. It was found that long-term, but not short-term, ethanol exposure increased levels of immunoreactivity of the NMDARl subunit, an obligatory component of NMDA glutamate receptors, and of the Glu Rl subunit, a component of many AMPA glutamate receptors; but at the same time, long-term ethanol exposure decreased immunoreactivity levels of the α1 subunit of the GABA_A receptor complex. These changes are consistent with an increased state of activation of VTA neurons inferred from the observed increase intyrosine hydroxylase (TH) expression. These results demonstrate that chronic ethanol exposure results in several biochemical adaptations in the mesolimbic dopamine system, which may underlie prominent changes in the structural and functional properties of this neural pathway related to alcohol abuse and alcoholism. © 1995 Wiley-Liss, Inc.