Tissue actions of bipolar scissors compared with monopolar devices

OBJECTIVES: To establish whether bipolar scissors offer equivalent cutting performance compared with monopolar scissors and to compare extent of thermal coagulation injury using two electrosurgical generators. DESIGN: Eighteen female rabbits' uterine horns were cut using controlled velocity at several different wattages with either bipolar or monopolar scissors. The specimens were examined microscopically and zones of thermal necrosis were measured using a stage micrometer against a 1 mm standard. RESULTS: Bipolar scissors cut equally well compared with monopolar scissors and showed significantly less thermal injury. When coupled to a constant voltage generator both the bipolar and monopolar scissors performed better. CONCLUSION: Bipolar scissors offer the surgeon significant safety advantages and equivalent or better performance compared with monopolar scissors when used for laparoscopic surgery.     

周围性面神经断裂伤的外科治疗

目的:评估周围性面神经断裂损伤患者手术治疗后的效果,分析影响预后的相关因素.方法:自1999年至2009年因周围性面神经断裂在我院接受手术修复的患者104例,男75例,女29例,年龄2～77岁,中位年龄30岁.单纯面神经吻合术72例,随访至最终恢复的65例(90.2%).自体神经移植术32例,随访至最终恢复的24例(75.0%).面神经功能评价采用了整体及分区House-Brackmann(HB)评价方法,以卡方检验或Fisher确切概率法进行统计分析.结果:单纯面神经吻合术后总体恢复程度为HB Ⅰ级者37例(56.9%),Ⅱ级者11例(16.9%),Ⅲ级者15例(23.1%),Ⅳ级者2例(3.1%);各分区恢复至HB Ⅰ、Ⅱ级的比例分别为:眼部97.6%、面中部97.9%、口角78.6%、额部27.3%(P<0.001).自体神经移植术后总体恢复程度为HB Ⅰ级者4例(16.7%),Ⅱ级者5例(20.8%),Ⅲ级者7例(29.2%),Ⅳ级者8例(33.3%);各分区恢复程度达HB Ⅰ、Ⅱ级的分别为:眼部73.7%、面中部72.7%、口角44.4%、额部37.5%.神经吻合术后面神经功能恢复程度优于自体神经移植术(P=0.002).结论:面神经吻合术和自体神经移植是修复周嗣性面神经断裂损伤的有效方法;面神经受损分支、损伤范围、手术修复距离损伤的时间和患者年龄均对手术预后有所影响.     

The reliability of monopolar and bipolar fine-wire electromyographic measurement of muscle fatigue

This longitudinal study was designed to examine reciprocal relationships between feeding practices and infant growth over the first 6 mo of life. The following three hypotheses were tested: 1) early feeding practices predict later infant growth; 2) early infant growth predicts later feeding practices; and 3) these relationships occur after controlling for related background variables. The sample included 226 healthy, well-nourished infants born at the Queen Elizabeth Hospital, Bridgetown, Barbados. Assessments were made at birth, 7 wk, and 3 and 6 mo of age. Factor analysis of a feeding practices questionnaire for those mothers who attended all three postnatal visits yielded five uncorrelated factors. Three of these factors, preference for breast-feeding, feeding intensity and feeding difficulty, declined with infant age. Two of these factors, father helps and relatives help, increased with infant age. Several background variables, including maternal age, anthropometry and reproductive history, and reliance on outside sources of information were correlated with infant growth. Multivariate analyses confirmed all three hypotheses. The group of feeding practices (particularly the preference for breast-feeding) at 7 wk predicted increases in infant lengths at subsequent ages. Conversely, infant weights at 3 and 6 mo predicted subsequent feeding practices, especially feeding intensity. These reciprocal relationships remained even after statistically controlling for the influence of the background variables. Implications for public policy include the need for comprehensive programs advocating breast-feeding and supporting the general health of mothers and infants.     

Endogenous NGF and CNTF levels in human peripheral nerve injury

Nerve growth factor (NGF) is trophic to sensory and sympathetic fibres, and ciliary neurotrophic factor (CNTF) to motoneurones, in animal models of peripheral nerve injury: NGF excess produces hyperalgesia. In this first study of injured human nerves and sensory ganglia, we quantified and localized endogenous NGF and CNTF in 59 neonate and adult patients with brachial plexus and peripheral nerve injury. NGF levels were generally depleted in injured nerves, but relatively preserved acutely in nerve segments distal to injury. NGF immunostaining was observed in Schwann cells in distal nerve segments with pockets of high levels in some neuromas. CNTF levels and immunostaining in Schwann cells were markedly decreased distally within days of injury. We propose that early local administration of NGF and CNTF-like agents may help prevent degenerative changes in injured nerves, while at later stages local anti-NGF treatment (e.g. of some neuromas) may ameliorate chronic pain.     

The role of focal nerve ischemia and Wallerian degeneration in peripheral nerve injury producing hyperesthesia

BACKGROUND: A new model of pain associated with an experimental peripheral mononeuropathy has stimulated interest in mechanisms of pain and their structural correlates in peripheral nerve, the site of the experimental lesion. METHODS: The pathology of the neuropathy was studied and the results correlated with alterations in nerve blood flow and with the behavioral response to heat applied to the foot. The focal neuropathy was created by loosely tying several ligatures around rat sciatic nerve, which produces hyperesthesia in the ligated limb in 3-5 days. The neuropathology was striking with epineurial and endoneurial vascular stasis, edema, and extensive nerve fiber injury in the ligated segment noted at 1 week after ligation. RESULTS: Nerve blood flow was reduced significantly in the ligated segment during the development of the hyperesthesia response, suggesting that changes in nerve blood flow caused by the ligature compression of the epineurial vessels contributes to the nerve fiber injury and pathophysiology of the model. To further test this hypothesis, the epineurial vasculature was removed from 1-cm lengths of rat sciatic nerve, which reduces nerve blood flow by 58%, and by ligation of the ipsilateral femoral artery, which focally reduces nerve blood flow by 70%, and the behavioral response to heating of the paw was evaluated at 1 week. Crush injury was used as a positive control creating Wallerian degeneration without a substantial reduction in nerve blood flow. CONCLUSIONS: The results suggest that ischemia is an important initial pathogenic mechanism in the hyperesthesia associated with the loose ligature pain model, in so far as it produces Wallerian degeneration and axonal injury. Modest degrees of ischemia producing only demyelination did not produce significant hyperesthesia.     

Diathermy tonsillectomy: comparisons of morbidity following bipolar and monopolar microdissection needle excision

Tonsillectomy is frequently associated with a considerable post-operative morbidity. In some cases reactionary or secondary haemorrhage occurs and all patients suffer a degree of post-operative pain. The use of bipolar diathermy excision has become popular because it reduces intra-operative blood loss, but all diathermy inevitably produces a degree of damage to adjacent normal soft tissues. In turn this inadvertent injury must act to increase the post-operative pain. Monopolar dissection using a fine tungsten diathermy needle (the Colorado needle) allows sharp dissection at low power levels and in previous studies has been shown to produce a reduction in collateral tissue damage. In this prospective study the morbidity associated with tonsillectomy using this needle was compared to that following a standard bipolar dissection. Using the monopolar needle produced no enhanced risk of reactionary or secondary haemorrhage while causing significantly less post-operative pain and a reduction in eschar. We believe that excision using this needle preserves the advantages associated with bipolar dissection while reducing local soft tissue damage.     

NGF involvement in pain induced by chronic constriction injury of the rat sciatic nerve

Chronic constriction injury (CCI) of the rat sciatic nerve, which within 3 days induces thermal and mechanical hyperalgesia and mechanical allodynia, is used as a model for pain resulting from nerve injury. Involvement of nerve growth factor (NGF) in the development of this hyperalgesia is suggested by the increase in the level of mRNA encoding NGF in cells in the injured area and in dorsal root ganglia at the level of the lesion and the greatly increased NGF levels (determined by ELISA) in the ganglia ipsilateral to the CCI. Application of anti-serum to NGF at the site of CCI delayed the appearance of hyperalgesia, whereas pre-immune serum appeared to enhance it. These results are consistent with the view that NGF is an important factor in the appearance of hyperalgesia associated with unilateral mononeuropathy.     

Loss of nerve endings in the spinal dorsal horn after a peripheral nerve injury. An anatomical study in Macaca fascicularis monkeys

In patients, the long-term outcome of injuries to sensory nerves is poor. This is only partly due to mismatching of regenerating axons at the transection site. We found in the macaque monkey that 70% of the transganglionic labelling in the spinal dorsal horn was still significantly reduced 21 months after transection and suturing of the sensory radial nerve. The reduction was evenly distributed throughout the terminal field of nerve endings, which were labelled with a mixture of the intra-axonal nerve tracer wheat germ agglutinin-horseradish peroxidase conjugate and pure horseradish peroxidase.     

Intraoperative extra strong electrical stimulation in the treatment of peripheral nerve injury

OBJECTIVE: To explore the Yinji Capsule (YJC) in improving the left ventricular systolic function of angina pectoris patients with Blood Stasis Syndrome. METHODS: The systolic function of left ventricle (LV) in cardiac cycle of 28 angina pectoris patients with Blood Stasis Syndrome was examined with three-dimensional echocardiograph (3-DE) before and after treatment with YJC. RESULTS: The total symptomatic effective rate was 85.7%. The changes of LV systolic function were those: left ventricle ejection fraction (LVEF) increased from 45.0 +/- 4.9% to 48.2 +/- 3.5% (P < 0.05); EF on early stage and late stage increased from 22.6 +/- 2.1%, 8.3 +/- 1.2% to 28.1 +/- 3.0% and 10.3 +/- 0.9% respectively (P < 0.01, P < 0.05), myocardial region with segment systole (SS) < 5% decreased significantly (P < 0.01). CONCLUSION: YJC could improve LV systolic function on early stage and late stage in cardiac cycles, and mainly improve the systolic function of the region with low SS of LV.     

Heat shock protein 27: developmental regulation and expression after peripheral nerve injury

The heat shock protein (HSP) 27 is constitutively expressed at low levels in medium-sized lumbar dorsal root ganglion (DRG) cells in adult rats. Transection of the sciatic nerve results in a ninefold upregulation of HSP27 mRNA and protein in axotomized neurons in the ipsilateral DRG at 48 hr, without equivalent changes in the mRNAs encoding HSP56, HSP60, HSP70, and HSP90. Dorsal rhizotomy, injuring the central axon of the DRG neuron, does not upregulate HSP27 mRNA levels. After peripheral axotomy, HSP27 mRNA and protein are present in small, medium, and large DRG neurons, and HSP27 protein is transported anterogradely, accumulating in the dorsal horn and dorsal columns of the spinal cord, where it persists for several months. Axotomized motor neurons also upregulate HSP27. Only a minority of cultured adult DRG neurons are HSP27-immunoreactive soon after dissociation, but all express HSP27 after 24 hr in culture with prominent label throughout the neuron, including the growth cone. HSP27 differs from most axonal injury-regulated and growth-associated genes, which are typically present at high levels in early development and downregulated on innervation of their targets, in that its mRNA is first detectable in the DRG late in development and only approaches adult levels by postnatal day 21. In non-neuronal cells, HSP27 has been shown to be involved both in actin filament dynamics and in protection against necrotic and apoptotic cell death. Therefore, its upregulation after adult peripheral nerve injury may both promote survival of the injured neurons and contribute to alterations in the cytoskeleton associated with axonal growth.     

Microvascular injury induced by intravascular platelet aggregation. An experimental study

Microvascular injury due to platelet aggregation was studied in cats for an hour after 1-hour intraaortic infusion of a suspension of collagen fibrils. Haematocrit and numbers of circulating platelets and leukocytes were repeatedly measured in arterial blood and a major cutaneous lymph vessel in the thigh was cannulated for measurement of lymph flow and erythrocyte counts in peripheral lymph. There were seven groups, each of eight cats, viz. normal cats infused with collagen (I) or vehicle (II) and collagen-infused cats which were platelet-depleted--by antiserum (III), or neutrophil-depleted--by anti-serum (IV), or decomplemented--by cobra venom (V), or pretreated with indomethacin--10 mg/kg (VI), or treated with nonimmunized serum (VII). Induced intravascular platelet aggregation reduced the numbers of circulating platelets and leukocytes, and increased haematocrit, lymph flow and numbers of red cells in peripheral lymph. These effects were inhibited by platelet depletion and indomethacin and attenuated by decomplementation and neutrophil depletion. Platelet aggregation was thus shown to induce microvascular injury and increase microvascular permeability, which is partly dependent on complement and neutrophils.     

Regenerative processes in peripheral nerve injury: a new method for their evaluation

The objective of this study was to evaluate a new quantitative electrophysiologic method and instrumentation for assessing the regenerative process in peripheral nerve injuries. The method was based on spectrum analysis of myoelectric signals. Myoelectric data were obtained longitudinally from affected muscles of the upper limb in patients with traumatic brachial plexus injuries, and quantitatively subjected to on-line analysis. Bipolar surface recordings were made during voluntarily mediated motor unit activity at both a low level of activity (nonfatiguing state) and a maximal level (fatiguing state). The results over time for the low-level activity have shown a significant increase in mean frequency of the myoelectric signal in some muscles, a significant decrease in other muscles, and no change in still other muscles. A significant increase in amplitude was observed in every instance. During the maximal level of activity there was a reduction in mean frequency and the amount of reduction was shown to increase over time. The results are useful in indicating the occurrence of peripheral sprouting, axonal regrowth, of central reorganization, and in indicating improved metabolic activity in a muscle. It is concluded that the method is reliable in the study of the regenerative process.     

Anti-hyperalgesic and anti-allodynic effects of intrathecal nociceptin/orphanin FQ in rats after spinal cord injury, peripheral nerve injury and inflammation

OBJECTIVE: To compare the acute and sustained renal hemodynamic effects on hypertensive patients of 100 mg irbesartan and 20 mg enalapril each once daily. PATIENTS: Twenty patients (aged 35-70 years) with uncomplicated, mild-to-moderate essential hypertension and normal serum creatinine levels completed this study. STUDY DESIGN: After random allocation to treatment (n=10 per group), administration schedule (morning or evening) was determined by further random allocation, with crossover of schedules after 6 weeks' therapy. Treatment and administration assignments were double-blind. Twenty-four-hour ambulatory blood pressure was monitored before and after 6 and 12 weeks of therapy. Renal hemodynamics were determined on the first day of drug administration and 12 and 24 h after the last dose during chronic treatment. RESULTS: Administration of each antihypertensive agent induced a renal vasodilatation with no significant change in glomerular filtration rate. However, the time course appeared to differ: irbesartan had no significant acute effect 4 h after the first dose, but during chronic administration a renal vasodilatory response was found 12 and 24 h after the dose; enalapril was effective acutely and 12 h after administration, but no residual effect was found 24 h after the dose. Both antihypertensive agents lowered mean ambulatory blood pressure effectively, with no significant difference between treatments or between administration schedules (morning versus evening). CONCLUSIONS: Irbesartan and enalapril have comparable effects on blood pressure and renal hemodynamics in hypertensive patients with normal renal functioning. However, the time profiles of the renal effects appear to differ, which might be important for long-term renoprotective effects.     

Impairment of peripheral nerve excitability

Functional abnormalities, especially the excitability changes of axon in the peripheral nerve involvement, were reviewed. In GBS and CIDP, the correlation between conduction block and anti-ganglioside antibodies have been discussed. Using anti GM1 antibody positive sera, the suppression of voltage-gated sodium channels (VGSC) has been reported. Although this findings have not been confirmed, the involvement of VGSC may be an important mechanism for eliciting conduction block. In Isaacs' syndrome, voltage-gated potassium channels (VGKC) were suppressed by autoantibodies to VGKC. Furthermore, in generalized myokymia syndrome which shows only myokymia and muscle cramp without grip myotonia, VGKCs are also suppressed in some cases. These findings suggest that some patients with myokymia and neuromyotonia are induced by anti-VGKC antibodies. For evaluating the axonal excitability in vivo, the threshold electrotonus method have been developed and applied for the involvement of peripheral nerves. In ALS, impairment of potassium conductance was shown and was speculated to have the possible rrelation with fasciculation. Thus threshold electrotonus method will be an important method for evaluating axonal excitability in human. The accumulated knowledge about the involvement of axonal ion channels will expand and will be categorized as axonal channelopathies.     

Ultrastructural study on formal pathogenesis of experimentally induced rhabdomyosarcomas (author's transl)

During oncogenesis the rhabdomyosarcomas pass different stages of differentiation. In experimentally induced rhabdomyosarcomas the chronological sequence of cytoplasmatic changes can be analysed. Material and methods: 10 mg 9,10-dimethyl-1,2-benz-anthracene were injected subcutaneously or intramuscularly in the hind-paw of Wistar rats with 100 gms weight. 30, 60, 105, and 150 days later the animals were killed and specimens withdrawn. The soft-tissue was prepared for light- and electron-microscopy. Results: In the soft-tissue tumors, experimentally produced with DMBA, 4 different cell types can be observed, which--depending on exposition time--dominate in the histological picture: (1) The myofibrillar cells. These cells are similar to rhabdomyocytes and contain numerous cytoplasmatic fibrillae with sarcomere-like structure. (2) The myofilamentous cells. These cells contain the fibrillar structure, but without sarcomere-like arrangement. (3) The undifferentiated sarcoma cells. These cells show a pathologically changed ergastoplasm and chondrioma. (4) The matured fibrosarcoma cells are nearly similar to fibrocytes. Under the cytoplasmatic changes especially the hyperplasia of the chondrioma can be observed, in which dystrophic megamitochondriae are found. These possibly reflect the abnormal glycolysis in cancer tissue. Also mitochondrial antibodies are discussed at the form pathogenesis of this change in organelles. Regarding the change of the endoplasmatic reticulu, the annulatae lamellae can be noticed which are typical for tumor cells. Furthermore megacisterns are found, in which protein-containing material is condensed as a consequence of a disturbed synthesis and secretion.