Neuropeptide Y mRNA expression in interneurons in rat spinal cord.

Neuropeptide Y (NPY)-immunoreactive axons are present within the spinal cord. Some of these axons originate from neurons in the brainstem. Other axons arise from within the spinal cord since NPY-immunoreactivity can be detected after complete spinal cord transection. To identify spinal neurons that might express NPY, we localized NPY mRNA in rat spinal cord using in situ hybridization histochemistry. NPY mRNA-containing neurons were localized in the dorsal horn, in medial laminae of the grey matter and in the lateral spinal nucleus in thoracic, lumbar and sacral cord. The location of some of these neurons, and their proximity to sympathetic preganglionic neurons, suggest some NPY-containing interneurons are likely to be involved in spinal as well as supraspinal autonomic reflex pathways.     

Overexpressed nitric oxide synthase in portal-hypertensive stomach of rat: A key to increased susceptibility to damage?

BACKGROUND & AIMS: Portal hypertension predisposes gastric mucosa to increased injury. The aim of this study was to determine whether overexpression of constitutive nitric oxide synthase (cNOS) is responsible for increased susceptibility of portal-hypertensive (PHT) gastric mucosa to damage. METHODS: In gastric specimens from PHT and sham-operated rats, cNOS messenger RNA expression was determined by Northern blotting and cNOS protein expression by Western blotting, immunohistochemistry, and enzyme activity assay. Extent of ethanol- induced gastric mucosal necrosis, mucosal blood flow, and gastric NOS activity in PHT and sham-operated rats was determined after administration of N(omega)-nitro-L-arginine methyl ester (L-NAME) or saline. RESULTS: cNOS messenger RNA level, cNOS enzyme activity, and fluorescence signals for cNOS were increased significantly in PHT rats compared with controls. Inhibition of overexpressed cNOS by L-NAME (5 mg/kg) significantly reduced ethanol-induced mucosal necrosis and normalized blood flow in PHT gastric mucosa, whereas this dose of L- NAME significantly increased mucosal necrosis in sham-operated rats. CONCLUSIONS: Portal hypertension activates the cNOS gene with overexpression of cNOS protein in endothelia of gastric mucosal vessels. Excessive NO production by overexpressed cNOS may play an important role in the increased susceptibility of PHT gastric mucosa to damage. (Gastroenterology 1997 Jun;112(6):1920-30)     

Selective non-operative management of penetrating liver injuries at a UK tertiary referral centre

Introduction

Selective non-operative management (SNOM) of penetrating abdominal injuries has increasingly been applied in North America in the last decade. However, there is less acceptance of SNOM among UK surgeons and there are limited data on UK practice. We aimed to review our management of penetrating liver injuries and, specifically, the application of SNOM.

Methods

A retrospective review was performed of patients presenting with penetrating liver injuries between June 2005 and November 2013.

Results

Thirty-one patients sustained liver injuries due to penetrating trauma. The vast majority (97%) were due to stab wounds. The median injury severity score was 14 and a quarter of patients had concomitant thoracic injuries. Twelve patients (39%) underwent immediate surgery owing to haemodynamic instability, evisceration, retained weapon or diffuse peritonism. Nineteen patients were stable to undergo computed tomography (CT), ten of whom were selected subsequently for SNOM. SNOM was successful in eight cases. Both patients who failed SNOM had arterial phase contrast extravasation evident on their initial CT. Angioembolisation was not employed in either case. All major complications and the only death occurred in the operatively managed group. No significant complications of SNOM were identified and there were no transfusions in the non-operated group. Those undergoing operative management had longer lengths of stay than those undergoing SNOM (median stay 6.5 vs 3.0 days, p<0.05).

Conclusions

SNOM is a safe strategy for patients with penetrating liver injuries in a UK setting. Patient selection is critical and CT is a vital triage tool. Arterial phase contrast extravasation may predict failure of SNOM and adjunctive angioembolisation should be considered for this group.     

腹腔镜在肝局灶性结节性增生诊断及切除中的应用

目的探讨腹腔镜在肝局灶性结节性增生中的诊断及手术切除的应用价值。方法11例肝占位病人均在腹腔镜下行肝肿物切除术,术中肿物送病理学检查,病理诊断为局灶性增生结节。结果本组11例患者均成功实施腹腔镜下肝切除术,标本完整取出,切缘距肿瘤2cm,无中转开腹。术后病人均恢复良好,无并发症,出院后随访均未见复发病例。结论腹腔镜手术对于肝局灶性结节性增生的诊断和治疗有很好的价值。对肝局灶性增生结节位于肝脏边缘,且肿块非巨大的患者,行腹腔镜手术切除应被视为最佳选择。     

The polymorphous light eruption–severity assessment score does not reliably predict the results of phototesting

Background Polymorphous light eruption (PLE) is a very common photodermatosis in which patient history is highly specific. Phototesting is used to confirm the diagnosis and to determine the action spectrum and the severity of this disease. In daily practice and in research studies, it would be convenient to assess disease severity by patient history only. Objectives This study aims to assess PLE disease severity via patient history and compares this with severity assessment via phototesting. Patients and methods Sixty‐one patients with PLE were asked 10 standard questions and all were phototested. The answers to the standard questions were coded with linear scores ranging from 0 to 10. The score of each question was plotted as independent variable in a multiple linear regression model against the score of the phototest (minimal number of irradiations necessary to elicit a positive skin lesion, with a maximum of 6 irradiations) as dependent variable using an enter approach. Furthermore, the scores of the separate questions were added to form a total score, the PLE–severity assessment score (PLE‐SAS). The medians of these PLE‐SASs were compared with the result scores obtained by phototesting. Phototesting was done with ultraviolet A and ultraviolet B irradiation. Results Fifty‐seven of the 61 patients had a positive test result (93%). Using the multiple linear regression model, the severity assessment by patient history (PLE‐SAS) compared with the result of phototesting showed two significant contributing questions (adjusted PLE‐SAS) (P < 0.05) but with a regression coefficient of 0.2. A significant difference in median scores with the severity assessment (PLE‐SAS and adjusted PLE‐SAS) between patients testing positive after 1–3 irradiations compared with those testing positive after 4–6 irradiations was present (P < 0.05). However, the overlap quartile range between both groups was such that the PLE‐SAS and the adjusted PLE‐SAS have little predictive value in individual patients. Conclusions We showed that in PLE, disease severity as determined using the PLE‐SAS or adjusted PLE‐SAS did not reliably predict severity as assessed by phototesting. Two significant contributing questions were not discriminating enough to be used as predicting questions to assess severity. Accurate patient history proved to be a reliable method to diagnose PLE. Phototesting is useful to determine the responsible ultraviolet action spectrum and to exclude differential diagnoses like photosensitive eczema, lupus erythematosus or chronic actinic dermatitis. PLE‐SAS cannot replace phototesting for determining the severity of PLE.     

Ultrastructural localization of nitric oxide synthase immunoreactivity in guinea-pig enteric neurons.

Electron microscopic immunocytochemistry was used to localize immunoreactivity for nitric oxide synthase (NOS) in whole-mount preparations of myenteric plexus and circular muscle from guinea-pig ileum. NOS immunoreactivity was patchily distributed in myenteric neurons and was not specifically associated with any subcellular organelle or with the plasma membrane. This localization leaves unanswered the question of how nitric oxide is stored and released. NOS immunoreactive fibres in the circular muscle were found closer than 100 nm to muscle cells. NOS immunoreactive nerve fibres made synaptic contacts with NOS immunoreactive and non-immunoreactive enteric neurons. These results indicate that nitric oxide may regulate the activity of both myenteric neurons and smooth muscle.     

Serotonin inputs to rabbit sympathetic preganglionic neurons projecting to the superior cervical ganglion or adrenal medulla

The input from serotonin-containing nerve fibres to rabbit sympathetic preganglionic neurons projecting to either the superior cervical ganglion or the adrenal medulla was investigated by combining retrograde tracing with the B subunit of cholera toxin and immunocytochemistry for serotonin. There were pronounced rostrocaudal variations in the density of serotonin fibres in the rabbit intermediolateral cell column from T1 to L4; maximum numbers of fibres were found in T3-6 and L3–4 and minimum numbers in T1 and T10–12. By light microscopy, retrogradely labelled sympathetic preganglionic neurons projecting to the superior cervical ganglion or the adrenal medulla received variable densities of close appositions from serotonin-immunoreactive fibres. Some neurons from each population received many close appositions, whereas others received moderate numbers or few appositions. Appositions occurred on the cell bodies, dendrites, and occasionally axons of sympathetic preganglionic neurons. Rare neurons in both groups of retrogradely labelled cells received no appositions from serotonin-containing nerve fibres. At the ultrastructural level, synapses were found between serotonin-positive boutons and sympathetic preganglionic neurons projecting either to the superior cervical ganglion or to the adrenal medulla. These results indicate that, through direct synaptic contacts, serotonin-immunoreactive, presumably bulbospinal, nerve fibres affect the activity of the vast majority of sympathetic preganglionic neurons that send axons either to the superior cervical ganglion or to the adrenal medulla. This serotonin input may be sympathoexcitatory and could mediate increases in sympathetic nerve activity and in the release of catecholamines from the adrenal medulla. © 1995 Wiley-Liss, Inc.     

Sympathetic preganglionic neurons in rabbit spinal cord that project to the stellate or the superior cervical ganglion

The segmental distribution of symphathetic preganglionic neurons in the rabbit spinal cord that project to the stellate or the superior cervical ganglion was determined using retrograde tracing with cholera toxin B subunit from the stellate ganglion and wheat germ agglutininapo-horseradish peroxidase-gold from the superior cervical ganglion. Sympathetic preganglionic neurons that projected to the stellate ganglion were located in spinal segments T₁ to T₁₀. Sympathetic preganglionic neurons projecting to the superior cervical ganglion were found in segments T₁ to T₈. Both types of neuron had somata that were elongated in the rostrocaudal direction, and dendrites that were mainly confined to the intermediolateral cell column. Almost 95% of the neurons supplying the superior cervical ganglion had axons that passed through the stellate ganglion.