Spinal cord mensuration--a comparative study on the spinal cord segments and spinal nerves in Zambian goats.

It has been known that the relative length of spinal cord and its segmental volume in domestic animals has established that the dynamics of spinal cord is directly related with the functions of the limbs and in particular to their feeding habits. Bilateral rostrocaudal measurements of spinal nerves involving their root attachment length, root emergence length, interroot length, segment length and cross sectional area were recorded on the dorsal and ventral surfaces of each segment of the spinal cords of five local healthy Zambian goats. We identified that the brachial and lumbar enlargements have involved identical number of spinal cord segments. Brachial and lumbar enlargements extended from C6 to T1 and L4 to L7. The average length of spinal cord was 59.9 cm and it extended up to caudal end of 5th sacral vertebrae. The root emergence length appeared to decrease gradually from C2 segment, which remained less variable in thoracic and lumbar segments and then receded sharply through sacral segments. The dorsal nerves entered spinal cord over a greater area than ventral because of more spinal rootlets. The greatest segment length lied in mid cervical region and then from lumbar segment it decreased sharply up to the end of sacral segments. It is concluded that these goats have a feeding habit similar to that of cattle rather than resting their forelimbs on the shrubs while nibbling the leaves as recorded in Asian goats. It also confirmed that the shrubs were more drooping along with grasses in the Gwembe Valley of Zambia.     

Neuropeptide Y- and vasoactive intestinal polypeptide-containing nerves in the intrinsic external urethral sphincter in the areflexic bladder compared to detrusor-sphincter dyssynergia in patients with spinal cord injury

Specimens of urethra were obtained from patients with cervical and thoracic spinal cord lesion with detrusor-sphincter dyssynergia and from patients with lower motor neurone lesion with detrusor areflexia, undergoing transurethral sphincterotomy. Neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) in nerves associated with both the smooth and striated muscle components of the urethral sphincter were studied immunohistochemically and by immunoassay. In patients with detrusor-sphincter dyssynergia following cervical and thoracic spinal cord injury, NPY- and VIP-immunoreactive varicose nerve fibres were seen in both the smooth and striated muscle components of the urethral sphincter. In the smooth muscle, NPY- and VIP-immunoreactive nerves did not appear to have any particular orientation, but in the striated muscle region they were found to run along the length of individual muscle fibres. In patients with detrusor areflexia following lower motor neurone lesion, while the pattern, density and fluorescence intensity of NPY- and VIP-immunoreactive nerves in the smooth muscle of the sphincter mechanism appeared the same as seen in patients with detrusor-sphincter dyssynergia, there was a marked increase in the density of these nerves in the striated muscle region of the sphincter mechanism. Quantitation of the peptides by immunoassay was consistent with the histochemical findings, with significantly higher levels of both NPY and VIP in the striated muscle of patients with lower motor neurone lesion, compared to those with cervical and thoracic spinal cord lesion, p = 0.04. NPY and VIP levels in urethral smooth muscle were in the same range in lower motor neurone lesion patients and cervical and thoracic spinal cord lesion patients. We conclude that there are increased NPY- and VIP-containing fibres in striated muscle of the intrinsic external urethral sphincter in patients with areflexic bladder compared with those with detrusor-sphincter dyssynergia.     

Is vasoactive intestinal polypeptide the principal transmitter involved in human penile erection?

Previous work from this laboratory reported on the effects of several autacoids and other agents on strips of human corpus cavernosum (cc) muscle. These investigations indicated the presence in the cc muscle of a) atropine-sensitive cholinoceptors, b) alpha- and beta-adrenoceptors and c) a non-adrenergic non-cholinergic mechanism. Several recent publications have presented evidence in support of the possibility that vasoactive intestinal polypeptide (VIP) is an important, or the chief, transmitter in human penile erection. This paper describes the actions of VIP and other compounds on the cc muscle and the effect of intracavernous injection of VIP in volunteers. Among the agents tested, VIP was the most potent relaxant of the cc muscle. This effect, which was seen at a dose as low as 0.03 nM, was suppressed by VIP antiserum. The response of the isolated penile vasculature to VIP was similar. VIP antiserum had no effect on the relaxation of the cc muscle produced by field stimulation. In five of the seven subjects given intracavernous VIP (1.0 micrograms.) some degree of penile enlargement was evident, but none had an erection. It is suggested that local release of VIP, withdrawal of the alpha-adrenoceptor mediated tonic supply to the penis and the activation of the latter's beta-adrenoceptors are all probably involved in penile erection in man.     

Spinal cord lesions in the Ac1uired Immune Deficiency Syndrome (AIDS)

Spinal cord involvement in AIDS is not uncommon. Different types of lesions corresponding to varying pathogenetic mechanisms have been reported.Vacuolar myelopathy is the most frequently found. The symptoms and pathological changes resemble those of subacute combined degeneration; however, cobalamine or folate levels have always been found normal. Its frequent association with the multi-nucleated giant cells characteristic of HIV encephalitis makes it likely that the virus plays a role in its pathogenesis.Cytomegalovirus may be responsible for acute myeloradiculitis involving the spinal roots of the cauda equina and inferior part of the spinal cord. In cases of Herpes simplex virus myelitis has been reported; they are usually associated with cytomegalovirus infection and are due to herpes simplex virus type II.Secondary spread from systemic lymphomas may involve the subarachnoid space of the cord and the spinal roots. Compression of the spinal cord by epidural lymphomatous masses has also been described.Spinal infarcts may be secondary to acute or chronic vasculitis or to less specific vascular processes such as disseminated intravascular coagulation.     

Unsuspected plasticity of single neurons after connection of the corticospinal tract with peripheral nerves in spinal cord lesions

We sought to understand an unsuspected plasticity of single neurons found after connection of the cord with peripheral nerves in paraplegics. Our research aimed at making paraplegics walk again, after 20 years of experimental surgery in animals that, among other things, demonstrated the alteration of the motor end plate receptors from cholinergic to glutamatergic; the same connection was done in humans. The grafts were put in the corticospinal tract of the cord randomly, without possibility of choosing the axons coming from different areas of the brain cortex. As a result, the patient was able to selectively activate the muscles she wanted without cocontractions of the other muscles connected with the same cortical areas. We believe that unlike in nerve or tendon transfers, where the whole cortical area corresponding to the transfer changes its function (a phenomenon that we call "brain plasticity by areas"), in the connection of the lateral bundle of the thoracic cord (the CST) with different peripheral nerves and muscles, the brain plasticity occurs by single neurons; in fact, there are no cocontractions. We propose to call it "brain plasticity by single neurons." We speculate that this phenomenon is due to the simultaneous activation of neurons spread in different cortical areas for a given specific movement while the other neurons of the same areas connected with peripheral nerves of different muscles are not activated. Why different neurons of the same area fire at different times according to different voluntary demands remains to be discovered, and we are committed to solve this enigma.     

Alpha-2A is the predominant alpha-2 adrenergic receptor subtype in human spinal cord.

alpha-2 Adrenergic receptors can be subdivided into four subtypes based on their pharmacologic properties. The subtype of alpha-2 adrenergic receptor present in human spinal cord has not been reported previously. The affinities of nine alpha-2 subtype-selective drugs for the alpha-2 adrenergic receptor in human spinal cord homogenates were determined using [3H]rauwolscine and [3H]RX821002. These drug affinities (pKi values) were highly correlated with those obtained in a tissue or cell line containing only the alpha-2A adrenergic subtype (correlation coefficient of 0.99 and 0.98 for human platelet and HT29 cells, respectively). In contrast, the correlation of pKi values for the human spinal cord with tissues or cell lines containing other adrenergic receptor subtypes was poor. The correlation coefficients for alpha-2B (neonatal rat lung), alpha-2C (OK cell), and alpha-2D (bovine pineal gland) were 0.15, 0.68, and 0.81, respectively. These data suggest that the predominant alpha-2 adrenergic subtype present in human spinal cord is the alpha-2A subtype. Both [3H]rauwolscine and [3H]RX821002 appeared to label a single class of binding sites. The alpha-2 adrenergic receptor density was significantly greater in the sacral region of the cord as compared to either the lumbar or thoracic regions.     

Hyaluronic acid-based agents do not affect anastomotic strength in the rat colon, in either the presence or absence of bacterial peritonitis

BACKGROUND: Hyaluronic acid (HA) agents reduce postsurgical adhesion formation. The effect of their perioperative administration on early anastomotic healing is unknown. This study investigated the influence of two HA-containing agents on the development of strength in colonic anastomosis during the first postoperative week, both in normal rats and in rats with bacterial peritonitis. METHODS: In 90 male Wistar rats a 1-cm segment was resected from the descending colon and an end-to-end anastomosis was constructed. In 108 rats a bacterial peritonitis was induced using caecal ligation and puncture (CLP). Some 24 h after CLP the abdomen was reopened, the caecum was taken out and, after resection of a 1-cm segment, an anastomosis was made. Animals in both groups were randomized to receive either an HA-carboxymethylcellulose (CMC) bioresorbable membrane, 0.4 per cent HA solution or no treatment. One-third of each group was killed at day 1, 3 and 7 after operation. Cultures were taken from the abdominal cavity for microbiological analysis in half of the animals. Subsequently, both bursting pressure and breaking strength were determined as parameters for anastomotic strength. RESULTS: No differences in anastomotic bursting pressure or breaking strength were found between the experimental groups and their controls. In addition, there was no significant difference in the number of bacteria cultured from the abdominal cavity between rats treated with HA and controls. CONCLUSION: Neither HA-CMC bioresorbable membrane nor 0.4 per cent HA solution interferes with the development of early anastomotic strength in the colon, and can therefore be safely used to prevent intra-abdominal adhesion formation after performing bowel anastomosis.     

大鼠脊髓损伤后不同时期移植人脐带间充质干细胞的修复效果观察

目的:观察大鼠脊髓损伤后不同时期局部移植人脐带间充质干细胞(human umbilical cord mesenchy-mal stem cells,hUCMSCs)修复脊髓损伤的效果,探讨hUCMSCs局部移植治疗脊髓损伤(spianl cord injury,SCI)的最佳移植时机。方法:雌性Wistar大鼠80只,随机均分为A、B、C、D组,以Impactor Model-Ⅱ打击器制备脊髓胸10(T10)损伤模型。A组为单纯损伤组,B组损伤后3d移植hUCMSCs,C组损伤后1w移植hUCM-SCs,D组损伤后3w移植hUCMSCs,分别于造模后24h、移植前1d及移植后8w(A组与D组损伤后相应时间点相同)每周对各组大鼠后肢功能进行行为学评分(BBB评分);移植后8周免疫组化染色观察移植细胞的存活、分化和血管再生情况,10周时用生物素葡聚糖胺(biotin dextran amine,BDA)示踪皮质脊髓束(corticospinaltract,CST)观察轴突的再生情况。结果:SCI后24h各组大鼠BBB评分无显著性差异(P0.05),D组在移植前和移植后1周与A组相应时间点的BBB评分无显著性差异(P0.05),移植后2w起各时间点评分均明显高于A组相应时间点,差异有统计学意义(P0.05);A组在SCI后9w时到达平台期,与实验结束时相比差异无统计学意义(P0.05)。移植各组移植后BBB评分逐渐上升,后一个时间点与同组前一时间点比较差异有显著性意义(P0.05),移植后6w开始C组明显高于B、D组(P0.05)。免疫组化染色A组脊髓中未见Brdu阳性细胞,损伤区血管形态欠完整,未见新生血管;损伤周围星形胶质细胞大量增生,细胞肥大、突起增多、排列不规则,形成胶质瘢痕;未见BDA标记的皮质脊髓束通过损伤区。B、C、D组脊髓中均有Brdu阳性标记的细胞存活,C、D组中细胞数量明显多于B组,但三组中均未见到移植细胞向神经元或神经胶质样细胞分化;B、D组损伤周围的星形胶质细胞较A组减少,但排列仍欠规则;C组损伤周围星形胶质细胞形态趋于正常,排列规则,且有大量星形胶质细胞通过损伤区,血管再生数目及通过损伤区的皮质脊髓束神经纤维也明显多于B、D组。结论:大鼠SCI后局部移植的hUCMSCs能长期存活,抑制胶质瘢痕形成,改善后肢运动功能;SCI后1w移植的效果优于SCI后3d和3w时移植的效果。     

Patients with lower motor spinal cord lesion: a decrease of vasoactive intestinal polypeptide, calcitonin gene-related peptide and substance P, but not neuropeptide Y and somatostatin-immunoreactive nerves in the detrusor muscle of the bladder.

Specimens of the detrusor muscle of the bladder from four patients with lower motor neurone lesion and three patients with carcinoma of the bladder used as "controls", were studied immunohistochemically for vasoactive intestinal polypeptide, neuropeptide Y, calcitonin-gene related peptide, substance P and somatostatin. The greatest density of nerves in the bladder from "control" patients contained neuropeptide Y, followed in a decreasing order by vasoactive intestinal polypeptide, calcitonin gene-related peptide, substance P and somatostatin. Neuropeptide Y- and vasoactive intestinal polypeptide-immunoreactive nerves were found throughout the smooth muscle and the base of the mucosa, while calcitonin gene-related peptide-, substance P- and somatostatin-immunoreactive nerves were found predominantly in nerve bundles with a few single fibres at the base of the mucosa. Vasoactive intestinal polypeptide-, neuropeptide Y- and calcitonin gene-related peptide-immunoreactive nerves were also located around blood vessels. In patients with lower motor neurone lesion, there was a decrease in the density of vasoactive intestinal polypeptide-, calcitonin gene-related peptide- and substance P-immunoreactive nerves, but there was little change in neuropeptide Y- or somatostatin-immunoreactive nerves. Urinary retention, bladder areflexia and deficient sensation may be directly linked to neuropeptide neuropathy in patients with lower motor neurone lesion.     

The different characteristics of Dupuytren's disease fibroblasts derived from either nodule or cord: expression of alpha-smooth muscle actin and the response to stimulation by TGF-beta1

Mechanisms behind the onset and progression of Dupuytren's disease are poorly understood. Both myofibroblasts and transforming growth factor beta 1 (TGF-beta(1)) have been implicated. We studied fibroblast cultures derived from nodules or cords of Dupuytren's contracture tissue to determine the proportion of myofibroblasts present in comparison with flexor retinaculum fibroblast cultures. We identified myofibroblasts by immunohistochemical staining for alpha-SMA. We then investigated the effects of TGF-beta(1) stimulation on these fibroblasts. Basal myofibroblast/fibroblast proportions were 9.7% in nodule cell cultures, 2.7% in cord cell cultures and only 1.3% in flexor retinaculum cell cultures. Nodule and cord myofibroblast proportions increased to 25.4% and 24.2%, respectively, in response to TGF-beta(1) treatment. Flexor retinaculum cell cultures showed no response to TGF-beta(1) stimulation. Fibroblasts cultured from specific regions of Dupuytren's tissue retain myofibroblast features in culture. TGF-beta(1) stimulation causes an increased myofibroblast phenotype to similar levels in both nodule and cord, suggesting that previously quiescent cord fibroblasts can be reactivated to become myofibroblasts by TGF-beta(1). This could be an underlying reason for high recurrence rates seen after surgery or progression following injury.     

Multiple extradural arachnoid cysts at the spinal cord and cauda equina levels in the young

STUDY DESIGN: A case report of multiple extradural arachnoid cysts at the spinal cord and cauda equina levels in the young. OBJECTIVE: To report an exceedingly rare case of multiple extradural arachnoid cysts at the spinal cord and cauda equina levels in the young. SETTING: Department of Orthopaedic Surgery, Tokai, Japan. CASE REPORT: An 11-year-old boy was diagnosed with multiple extradural arachnoid cysts at the spinal cord and cauda equina levels extending from the T5 to L5 vertebrae and surgery was performed. At 2 years after surgery, no recurrence was observed and muscle weakness of the lower extremities and sensory disturbance improved. CONCLUSION: Excision of only the arachnoid cysts at the spinal cord level led to a favorable outcome.     

Concentration-effect relationship of cisatracurium at three different dose levels in the anesthetized patient

BACKGROUND: The linearity of cisatracurium elimination and its concentration-effect relation were determined as part of a traditional rich data study with three dose levels in patients receiving balanced anesthesia. METHODS: Forty-eight adults with American Society of Anesthesiologists status I-II were randomized to receive an intravenous bolus dose of 0.075, 0.15, or 0.30 mg/kg cisatracurium. Anesthesia was induced and maintained with nitrous oxide-oxygen, propofol, and fentanyl. The mechanical response of the adductor pollicis muscle was recorded. Arterial blood samples were collected over 8 h. Cisatracurium, laudanosine, and the monoquaternary alcohol concentrations were measured by high-performance liquid chromatography. To assess the relative contribution of the input function, a parametric (assuming elimination from both the central and peripheral compartments) and a nonparametric pharmacokinetic-pharmacodynamic model were both applied to data. RESULTS: Dose proportionality of the body disposition of cisatracurium and its two major metabolites at doses up to 0.30 mg/kg was confirmed. With the parametric approach, the effect compartment concentration at 50% block (EC50) significantly increased with the dose (136 vs. 157 vs. 209 ng/ml), whereas the effect compartment equilibration rate constant decreased (0.0675 vs. 0.0568 vs. 0.0478 min(-1)). A similar dose-dependent effect of the pharmacokinetic-pharmacodynamic relation was observed with the nonparametric approach, but the trend was 50% less pronounced. CONCLUSION: A dose-related change in pharmacokinetic-pharmacodynamic parameters was identified with both modeling approaches. A pharmacokinetic origin was ruled out, although no definite explanation of the underlying mechanism could be provided. These findings suggest that doses relevant to the anesthetic practice be used for estimation of EC50.