Anaerobic co-digestion of sludge and microalgae grown in municipal wastewater - a feasibility study.

In this study a natural mix of microalgae grown in wastewater of municipal character was co-digested with sewage sludge in mesophilic conditions, in both batch and semi-continuous modes. The semi-continuous experiment was divided into two periods with OLR1 (organic loading rate) of 2.4 kg volatile solids (VS) m-3 d-1 and HRT1 (hydraulic retention time) of 15 days, and OLR2 of 3.5 kg VS m-3 d-1 and HRT2 of 10 days, respectively. Results showed stable conditions during both periods. The methane yield was reduced when adding microalgae (from 200 ± 25 NmL CH4 g VSin-1, to 168 ± 22 NmL CH4 g VSin-1) but VS reduction was also decreased by 51%. This low digestibility was confirmed in the anaerobic batch test. However, adding microalgae improved the dewaterability of the digested sludge. The high heavy metals content in the microalgae resulted in a high heavy metals content in the digestate, making it more difficult to reuse the digestate as fertilizer on arable land. The heavy metals are thought to originate from the flue gas used as a CO2 source during the microalgae cultivation. Therefore the implementation of CO2 mitigation via algal cultivation requires careful consideration regarding the source of the CO2-rich gas.

Quantification and comparison of neurosurgical approaches in the preclinical setting: literature review.

There is a growing awareness of the need for evidence-based surgery and of the issues that are specific to research in surgery. Well-conducted anatomical studies can represent the first, preclinical step for evidence-based surgical innovation and evaluation. In the last two decades, various reports have quantified and compared neurosurgical approaches in the anatomy laboratory using different methods and technology. The aim of this study was to critically review these papers. A PubMed and Scopus search was performed to select articles that quantified and compared different neurosurgical approaches in the preclinical setting. The basic characteristics that anatomically define a surgical approach were defined. Each study was analyzed for measured features and quantification method and technique. Ninety-nine papers, published from 1990 to 2013, were included in this review. A heterogeneous use of terms to define the features of a surgical approach was evident. Different methods to study these features have been reported; they are generally based on quantification of distances, angles, and areas. Measuring tools have evolved from the simple ruler to frameless stereotactic devices. The reported methods have each specific advantages and limits; a common limitation is the lack of 3D visualization and surgical volume quantification. There is a need for a uniform nomenclature in anatomical studies. Frameless stereotactic devices provide a powerful tool for anatomical studies. Volume quantification and 3D visualization of the surgical approach is not provided with most available methods.

"HRCT predictors of GGO surgical resection: Histopathological and molecular correlation in the era of lung sparing surgery".

OBJECTIVES: Ground-glass pulmonary opacities (GGOs) are increasingly encountered in routine clinical practice and an accurate differentiation between benign and malignant lesions is crucial. The aim of this study is to evaluate the relationship between radiological features and the actual biological behavior of these nodules. The secondary endpoint is to identify any radiological predictors able to choose the type of surgical resection and the extent of lymphadenectomy. MATERIALS AND METHODS: This single-center retrospective study included all patients, who underwent high resolution computed tomography (HRCT) and surgical resection for GGOs between 2010 and 2020. Histopathological sampling focused on lesion size, histology, growth pattern, amount of lepidic component, percentage of ground-glass (GG), grade of tumor and proliferation index (Ki67). RESULTS: In 56 patients enrolled, 65 lesions (15 pure GG and 50 part-solid) were resected (44 lobectomies, 9 anatomical segmentectomies, 12 wedge resections). A direct significant correlation was found between: the GG at HRCT and the amount of lepidic component (p < 0.0001; R = 0.305), the tumor grading and the lepidic component at HRCT (p = 0.003), the percentage of GG and the expression of Ki67 (p = 0.016), the lepidic percentage and the expression of Ki67 (p = 0.004; R = 0.223). A total of 609 lymph-nodes were removed (stations N1 and N2) and histopathological analysis was negative for nodal involvement in all cases. CONCLUSION: Pure and part-solid GGOs could benefit from less invasive and lung sparing surgery with just nodal sampling. These would reduce surgical complications and guarantee a better quality of life for the patient. The major limitations are the number of patients and the lack of a longer follow-up.

Correlation between Cranial Nerve Microstructural Characteristics and Vestibular Schwannoma Tumor Volume.

BACKGROUND AND PURPOSE: Vestibular schwannomas are common cerebellopontine angle tumors arising from the vestibulocochlear nerve and can result in cranial nerve dysfunction. Conventional MR imaging does not provide information that could correlate with cranial nerve compression symptoms of hearing loss or imbalance. We used multitensor tractography to evaluate the relationship between the WM microstructural properties of cranial nerves and tumor volume in a cohort of patients with vestibular schwannomas. MATERIALS AND METHODS: A retrospective study was performed in 258 patients with vestibular schwannomas treated at the Gamma Knife clinic at Toronto Western Hospital between 2014 and 2018. 3T MR images were analyzed in 160 surgically naïve patients with unilateral vestibular schwannomas. Multitensor tractography was used to extract DTI-derived metrics (fractional anisotropy and radial, axial, and mean diffusivities of the bilateral facial and vestibulocochlear nerves [cranial nerves VII/VIII]). ROIs were placed in the transition between cisternal and intracanalicular segments, and images were analyzed using the eXtended Streamline Tractography reconstruction method. Diffusion metrics were correlated with 3D tumor volume derived from the Gamma Knife clinic. RESULTS: DTI analyses revealed significantly higher fractional anisotropy values and a reduction in axial diffusivity, radial diffusivity, and mean diffusivity (all P < .001) within the affected cranial nerves VII and VIII compared with unaffected side. All specific diffusivities (axial, radial, and mean diffusivity) demonstrated an inverse correlation with tumor volume (axial, radial, and mean diffusivity, P < .01). CONCLUSIONS: Multitensor tractography allows the quantification of cranial nerve VII and VIII WM microstructural alterations in patients with vestibular schwannomas. Our findings support the hypothesis that tumor volume may cause microstructural alterations of the affected cranial nerves VII and VIII. This type of advanced imaging may represent a possible avenue to correlate diffusivities with cranial nerve function.

Long-term assessment of clinical outcomes and disease progression in patients with corrected Tetralogy of Fallot.

OBJECTIVE: Understanding changes of right ventricular (RV) geometry and function in repaired Tetralogy of Fallot (rToF) patients can improve decision-making for pulmonary valve replacement. Therefore, we aimed to assess the magnitude and clinical correlations of RV changes in rToF patients. PATIENTS AND METHODS: Clinical and MRI data of rToF patients who underwent repeated cardiac magnetic resonance imaging (MRI) at two centers between December 2003 and September 2020 were analyzed together with anatomical factors, including RV outflow tract obstruction, pulmonary artery branch stenosis, and tricuspid regurgitation. Adverse cardiac events and/or NYHA class worsening were documented and correlated with MRI changes. QRS length was reported at each MRI. RESULTS: Two-hundred-and-nineteen rToF patients (53% males, aged 20.2 ± 10.1 years) were enrolled. An increase of ventricular dimensions, except LVEDVi, and worsening of right and left ejection fractions were found over an average period of 5 years of follow-up. These changes were statistically significant but within 10% of the initial value. No significant changes were reported on a year-to-year basis, except in a small group of patients (6%) in whom no predictive factors were identified. Despite similar RV dimensions at the first examination, younger patients had a higher RV ejection fraction and a different annual rate of change of ventricular dimensions compared to older ones. Patients with arrhythmias (20%) were more frequently older and had larger RV dimensions but showed no significant correlations with MRI changes/years. CONCLUSIONS:  Changes in RV dimensions and function occur rarely and very slowly in rToF patients. A small percentage of patients experience a significant worsening in a short time interval without any recognized risk factors. Arrhythmias appear to occur in a small percentage of cases in the late follow-up.

Gastrointestinal stromal tumors (GIST): a proposal of a "CT-based predictive model of Miettinen index" in predicting the risk of malignancy.

PURPOSE: To identify the predictors of malignancy on CT for the evaluation of gastrointestinal stromal tumors (GIST) by correlating CT findings with the mitotic index in order to propose a "CT-based predictive model of Miettinen index." METHODS: One radiologist and one resident in radiology with 14- and 4-year experience in oncological field reviewed the CT findings of 42 patients by consensus, with respect to lesion site, size, contour, tumor growth pattern, enhancing pattern, degree of enhancement of tumor, percentage of tumor necrosis, mesenteric fat infiltration, ulceration, calcification, regional lymphadenopathy, direct invasion to adjacent organs, and distant metastasis. All parameters were correlated with the mitotic index evaluated at histopathological analysis following surgery. Normality of variables was evaluated using Shapiro-Wilk test. Pearson's correlation test was used to assess the interaction between variables. The diagnostic accuracy percentage of tumor necrosis was measured by receiver operating characteristic (ROC) analysis for detecting whether the number of mitosis per 50 high-power fields was > 5. RESULTS: A significant statistical correlation was found between percentage of tumor necrosis and the mitotic index (p < 0.005), dimension, and location of the tumor. CONCLUSION: CT could be an accurate technique in the prediction of malignancy of GIST in a CT risk assessment system, based on the location of the tumor, its size, and the percentage of tumor necrosis.

Nitrogen fixation in mixed Hylocomium splendens moss communities.

The pleurocarpus feather moss, Hylocomium splendens, is one of two co-dominant moss species in boreal forest ecosystems and one of the most common mosses on earth, yet little is known regarding its capacity to host cyanobacterial associates and thus contribute total ecosystem N. In these studies, we evaluated the N-fixation potential of the H. splendens-cyanobacteria association and contrasted the N-fixation activity with that of the putative N-fixing moss-cyanobacteria association of Pleurozium schreberi. Studies were conducted to: quantify N-fixation in H. splendens and P. schreberi in sites ranging from southern to northern Fennoscandia; assess N and P availability as drivers of N-fixation rates; contrast season-long N-fixation rates for both mosses; and characterize the cyanobacteria that colonize shoots of H. splendens. Nitrogen-fixation rates were generally low at southern latitudes and higher at northern latitudes (64-69 degrees N) potentially related to anthropogenic N deposition across this gradient. Nitrogen fixation in H. splendens appeared to be less sensitive to N deposition than P. schreberi. The season-long assessment of N-fixation rates at a mixed feather moss site in northern Sweden showed that H. splendens fixed a substantial quantity of N, but about 50% less total N compared to the contribution from P. schreberi. In total, both species provided 1.6 kg fixed N ha(-1) year(-1). Interestingly, H. splendens demonstrated somewhat higher N-fixation rates at high fertility sites compared to P. schreberi. Nostoc spp. and Stigonema spp. were the primary cyanobacteria found to colonize H. splendens and P. schreberi. These results suggest that H. splendens with associated Nostoc or Stigonema communities contributes a significant quantity of N to boreal forest ecosystems, but the contribution is subordinate to that of P. schreberi at northern latitudes. Epiphytic cyanobacteria are likely a key factor determining the co-dominant presence of these two feather mosses across the boreal biome.

Upper limb motor function in young adults with spina bifida and hydrocephalus.

OBJECTIVE: The objective of the study was to measure upper limb motor function in young adults with spina bifida meningomyelocele (SBM) and typically developing age peers. METHOD: Participants were 26 young adults with SBM, with a Verbal or Performance IQ score of at least 70 on the Wechsler scales, and 27 age- and gender-matched controls. Four upper limb motor function tasks were performed under four different visual and cognitive challenge conditions. Motor independence was assessed by questionnaire. RESULTS: Fewer SBM than control participants obtained perfect posture and rebound scores. The SBM group performed less accurately and was more disrupted by cognitive challenge than controls on limb dysmetria tasks. The SBM group was slower than controls on the diadochokinesis task. Adaptive motor independence was related to one upper limb motor task, arm posture, and upper rather than lower spinal lesions were associated with less motor independence. CONCLUSIONS: Young adults with SBM have significant limitations in upper limb function and are more disrupted by some challenges while performing upper limb motor tasks. Within the group of young adults with SBM, upper spinal lesions compromise motor independence more than lower spinal lesions.

Pleuroparenchymal fibroelastosis (PPFE) associated with giant cell arteritis: A coincidence or a novel phenotype?

Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial lung disease characterized by the fibrotic thickening of subpleural and parenchymal areas of the upper lobes. It may be both idiopathic or secondary to infections, interstitial lung diseases and/or drug exposure. Often PPFE patients report recurrent lower respiratory tract infections, suggesting that repeated inflammatory alterations induced by pulmonary infections may contribute to the development/progression of PPFE. Here, we report for the first time the case of a patient affected by Giant cell Arteritis with histologically proven PPFE. The lung involvement in GCA is rare and interstitial lung diseases are usually reported as an uncommon clinical manifestation of GCA. Our patient is probably the first case presenting PPFE associated with GCA and we wonder if this is a real associative disease or a coincidence perhaps, secondary to drug effects.

Triple therapies plus different probiotics for Helicobacter pylori eradication.

The Helicobacter pylori (H. pylori) cure rate following standard triple therapies is decreasing worldwide. Therefore, further approaches aimed to improve standard triple therapy efficacy should be attempted. This prospective, pilot study aimed to evaluate the therapeutic role of either Lactobacillus reuteri (L. reuteri) or a high concentration of probiotics in addition to standard triple therapies for H. pylori eradication. The study enrolled 65 consecutive dyspeptic patients with H. pylori infection. All patients underwent upper endoscopy with gastric biopsies. Patients were assigned to receive one of the following therapies: (a) standard 7-day triple; (b) the same 7-day triple therapy plus L. reuteri supplementation; (c) the same 7-day triple therapy plus a probiotic mixture; and d) a 14-day standard triple therapy plus a probiotic mixture. H. pylori eradication was checked by using a 13C-urea breath test performed 4-6 weeks after treatment. No therapy regimen achieved > 80% eradication rate at both intention-to-treat (ITT) and per protocol (PP) analyses. Although the 14-day therapy plus a probiotic mixture tended to achieve higher eradication rate (71%), no statistically significant difference emerged among the different therapy regimens tested (range: 53-71%). The lowest incidence of side-effects was observed following the 7-day therapy plus L. reuteri (6%) and highest with the 14-day triple therapy plus probiotic mixture (33%), although the difference failed to reach the statistically significance. In conclusion, our data found that 7-14 days triple therapy with or without probiotic supplementation failed to achieved acceptable H. pylori eradication rates.

Outcomes and quality of life assessment in patients undergoing endoscopic surgery for pituitary adenomas.

The endoscopic technique is increasingly being used for the resection of pituitary adenomas. Its efficacy and safety have been generally accepted, but its impact on the quality of life of the patients treated has not been previously addressed. Most of the studies assessing the quality of life after long-term cure of pituitary adenomas suggest a significantly impaired quality of life (QoL) in all subgroups of pituitary tumours. In our study we analyse QoL data following endoscopic surgery, and attempt comparisons with normative and data from standard approaches. The validated health questionnaire SF-36 was sent to 80 patients who had undergone pure endoscopic resection of a pituitary adenoma. Fifty-four patients returned the completed questionnaire. Outcomes were compared with normative data for the Short Form-36 (SF-36) Heath survey for the general Canadian population. We also compared the results amongst different types of adenomas. We attempted a comparison to previous studies on quality of life for patients who underwent conventional trans-sphenoidal surgery. Our study suggests only minimal impairment of quality of life in patients after successful treatment of pituitary adenomas using the endoscopic approach. There were only very few differences in the perceived quality of life within the different subgroups of adenomas. There was a trend to improved scores in the endoscopic group compared with previous studies in patients treated by conventional approaches. Whilst our data suggest minimal impact on the quality of life for patients after endoscopic removal of pituitary adenomas, further studies with larger number of patients and longer follow-up are required to encourage this finding.

Outcome after liver transplantation in patients with cirrhosis and hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is considered an optimal indication for liver transplantation (LT) because it may eliminate both the tumor and the underlying liver disease. The present study sought to compare cumulative survival, rate of HCC recurrence, and causes of death among patients with cirrhosis and HCC before and after the adoption of more restrictive criteria (Milan selection criteria) at the time of patient listing. Among 226 adult patients who received an elective liver transplantation between 1999 and 2005, 58 (27%) had a diagnosis of HCC at the time. The 38 patients who underwent transplantation for HCC in the period 1989 to 1998 were considered the "historical group." After LT (mean follow-up, 34 + 28 months), the cumulative survival rate was better among HCC versus non-HCC recipients (93% vs 71% at 1 year and 81% vs 67% at 3 years, respectively; P < .046), although the difference tended to attenuate after 5 years (66% vs 67%, respectively). Tumor recurrence (evaluated in patients surviving at least 3 months after LT) was observed in 10/31 in the historical group versus 4/53 among those who underwent transplantation after 1999. Among the causes of death, recurrence represented 50% in the old series and 23% in patients who underwent transplantation after 1999. Cumulative survival significantly improved among HCC patients who underwent transplantation after 1999 (93% vs 66% at 1 year and 81% vs 50% at 3 years; P < .00001). The 58 patients who underwent transplantation with a diagnosis of cirrhosis and concomitant HCC after 1999 showed even better survival than patients who underwent transplantation for end-stage liver disease without malignancy.

Could MRI visualize the invisible? An Italian single center study comparing magnetic resonance lymphography (MRL), super microsurgery and histology in the identification of lymphatic vessels.

OBJECTIVE: Aim of this study is to evaluate the possibility of limb magnetic resonance lymphography (MRL) to differentiate lymphatic vessels from pathological veins, collect a specimen of the identified lymphatic vessel during operations of super microsurgical lymphatic-venular anastomosis (s-LVA) and perform immunohistochemical stainings to confirm the nature of the collected vessels. PATIENTS AND METHODS: Twenty patients presenting lymphedema were enrolled in this study. Five patients reported lower limb lymphedema and 15 patients reported upper limb lymphedema. All patients had the indication for s-LVA and underwent preoperative MRL imaging of the affected limb. A total of 57 lymphatic vessels were identified by MRL and used to guide s-LVA: all these vessels have also been used to perform an intraoperative biopsy for immunohistochemical evaluation. RESULTS: A total of 53/57 vascular structures resulted compatible with lymphatic vessels at the immunohistochemical study performed with D2-40 antibody; 3/57 specimen showed the absence of the D2-40 antibody. A significant association was found between preoperative MRL and immunohistochemical marker D2-40 on collected specimen. CONCLUSIONS: Most of the articles in the international literature report the concomitant presence of both lymphatic and venous vessels at MRL. However, no one in literature describes the possibility to differentiate venous vessels from lymphatic vessels, and this is a crucial issue for the correct evaluation of the lymphatic system in patients with limb lymphedema undergoing a future surgical correction. In the present study, MRL allowed to identify active lymphatic vessels. MRL was predictive to determine preoperatory lymphatic vessels and to perform successful s-LVA in lymphedema patients. This is the first study to prove the nature of the vessels identified at the preoperative MRL with immunohistochemical stainings.

Alpha-SMA expression in hepatic stellate cells and quantitative analysis of hepatic fibrosis in cirrhosis and in recurrent chronic hepatitis after liver transplantation.

BACKGROUND: The alpha isotype of actin expressed by hepatic stellate cells reflects their activation to myofibroblast-like cell and has been directly related to experimental liver fibrogenesis, and indirectly to human fibrosis in chronic liver disease. AIMS: To evaluate the changes in distribution and percentage of alpha-smooth muscle actin-positive hepatic stellate cells and the correlation with the degree of the fibrosis in cirrhotic livers, as well as in patients with recurrent HCV chronic hepatitis after liver transplantation. METHODS: Human liver biopsies were divided in four groups: (1) normal livers obtained from cadaveric liver donors (n=35), (2) cirrhosis post-HBV hepatitis (n=11), (3) cirrhosis post-HCV hepatitis (n=10), and (4) post-transplant recurrent HCV chronic hepatitis (n=13). Samples were stained with anti-alpha-smooth muscle actin antibody by immunoperoxidase method and semi-quantitatively evaluated. Liver fibrosis was assessed from specimens stained with Masson's trichrome and quantified by computer image analysis. RESULTS: The percentage of alpha-smooth muscle actin-positive hepatic stellate cells was significantly higher in the HBV cirrhosis, HCV cirrhosis and post-transplant HCV recurrent hepatitis groups (36.1+/-15.2, 23.8+/-19.7 and 27.8+/-16.4%, respectively) compared to the liver donor group (2.9+/-4.0%). The alpha-smooth muscle actin-positive hepatic stellate cells to fibrous tissue ratio were significantly higher in the post-transplant recurrent HCV hepatitis group (2.36+/-1.12) compared to both the donor livers and the HCV cirrhosis groups (0.74+/-1.09 and 1.03+/-0.91, respectively). The alpha-smooth muscle actin-positive hepatic stellate cell percentage and fibrosis correlated positively in the post-transplant recurrent HCV hepatitis group and negatively in the HCV cirrhosis group. No difference in the immunohistochemical and morphometrical variables was found between the HCV cirrhosis and HBV cirrhosis groups. CONCLUSIONS: These results indirectly confirm that, in vivo, alpha-smooth muscle actin expression is a reliable marker of hepatic stellate cells activation which precedes fibrous tissue deposition even in the setting of recurrent HCV chronic hepatitis after liver transplantation, and it could be useful to identify the earliest stages of hepatic fibrosis and monitoring the efficacy of the therapy. In the presence of advanced cirrhosis other factors, rather than alpha-smooth muscle actin-positive hepatic stellate cells, may sustain fibrosis deposition.

Predictive factors of outcome after liver transplantation in patients with cirrhosis and hepatocellular carcinoma.

Studies to define the optimal upper limits of tumor size and number as predictors of outcome after orthotopic liver transplantation (OLT) have yielded conflicting results. We analyzed 72 patients with cirrhosis and hepatocellular carcinoma (HCC) who underwent OLT over a 12-year period in a single center. Predictive factors for survival and tumor recurrence, according to the Milan criteria, were also examined. Our cohort included 60 men and 12 women of mean age 54 +/- 8 years and mean follow-up of 40 +/- 39 months. Origin of cirrhosis was postviral in 70% and Child class B or C in two thirds of patients. HCC was multifocal in 61%; about one fifth of patients had micro- or macrovascular involvement or positive nodes upon histologic examination. The cumulative size of the lesions was <3 cm in 17 patients; >3 to < or =5 cm in 28 patients; >5 to < or =8 cm in 14 patients; and >8 cm in 13 patients. According to the number and size of tumor nodules, 49 patients met the Milan criteria. During follow-up 25 patients died, 13 due to tumor recurrence. The 1- and 2-year survivals were 90% and 85% for patients who met the Milan criteria versus 57% and 51% for patients exceeding those limits (P = .006). A cumulative tumor size >8 cm was predictive of survival and tumor recurrence upon multivariate analysis. The adoption of Milan criteria for selection of cirrhotic patients has improved survival and reduced the rate of tumor recurrence. The evaluation of cumulative tumor size might further improve patient selection.

Hyperphagic effect of novel compounds with high affinity for imidazoline I(2) binding sites.

Previous studies have suggested that imidazoline I(2) receptors play a role in feeding control in rats. The effect of subcutaneous (s.c.) injections of four novel imidazoline I(2) ligands, 2-naphthalen-2yl-4,5-dihydro-1H-imidazole hydrochloride (benazoline), 2-styryl-4,5-dihydro-1H-imidazole oxalate (tracizoline), o-nitro-tracizoline and o-methyl-tracizoline (metrazoline) on food intake during the light phase was now evaluated in freely feeding male Wistar rats. Their effect was compared to that of idazoxan, a high-affinity ligand at imidazoline I(2) binding sites, but also a potent alpha(2)-adrenoceptor antagonist. Compared to idazoxan, metrazoline exhibits a higher pK(i) for imidazoline I(2) binding sites in rat liver, while the other compounds have a slightly lower pK(i); on the other hand, the novel compounds have much lower affinity than idazoxan at alpha(2)-adrenoceptors. Idazoxan stimulated drinking at a dose as low as 1 mg/kg, and evoked feeding at a higher dose (30 mg/kg). The selective alpha(2)-adrenoceptor antagonist 2-methoxy-idazoxan (RX821002), with negligible affinity at imidazoline I(2) binding sites, significantly increased drinking but failed to stimulate feeding at doses of 10-50 mg/kg. Metrazoline induced hyperphagia and water drinking at doses of 50 mg/kg or higher. Its dipsogenic effect was secondary to the hyperphagic effect, since it was not observed in rats without access to food. Benazoline significantly increased feeding only in response to 30 mg/kg, but its effect was less pronounced than that of metrazoline. Tracizoline and o-nitro-tracizoline were inactive. Following injection into the lateral cerebroventricle at doses up to 100 microgram/rat, and into the third or fourth brain ventricle at doses up to 50 microgram/rat, neither idazoxan nor metrazoline induced hyperphagia. The present results support the idea that imidazoline I(2) ligands influence feeding in rats, and suggest that their site of action is not in the central nervous system. The finding that idazoxan elicits a more potent hyperphagic effect than metrazoline and benazoline, although its affinity for imidazoline I(2) binding sites is lower than that of metrazoline and similar to that of benazoline, raises the question whether its hyperphagic effect might also be due to interaction with other receptors.

Rotational angiography assessment of cerebral aneurysms.

PURPOSE: To compare rotational angiography with conventional digital subtraction angiography in the assessment of cerebral aneurysms. METHODS: Conventional digital subtraction angiography and rotational angiography were compared in 57 patients investigated for the preoperative diagnosis of subarachnoid hemorrhage and in 13 patients after surgery. Images were compared for location, visibility of the aneurysmal neck, vascular branch anatomy, projection, size, presence of spasm, and shape of the aneurysm. RESULTS: Rotational angiography was superior to the digital angiogram in assessing aneurysms and vascular anatomy in the following percentage of cases: 12% for location, 46% for the presence of a neck, 32% in the assessment of branch anatomy, 19% for projection, 12% for size, 3.5% for spasm, and 19% for shape. After surgery, rotational angiography more clearly demonstrated the presence or absence of a neck in 69% of the cases. CONCLUSIONS: Rotational angiography often allows better visualization of vascular anatomy and therefore improves the angiographic assessment of aneurysms when compared with conventional digital subtraction angiography, making it an excellent adjunct in the investigation of subarachnoid hemorrhage. The lack of subtraction artifacts from the surgical clips and multiple angles of view also allow better assessment of the presence or absence of a residual neck in postoperative cases.

Spinal epidural arteriovenous fistulas: arterial and venous approaches to embolization.

The authors describe two patients with multiple spinal arteriovenous fistulas and exclusive epidural venous drainage. Both presented with a myelopathy caused by compression by large epidural veins. Both had arterial embolizations, but one required a venous approach to achieve a stable clinical result.

Quantitative assessment of muscular hypertonia resulting from cortical lesions in primates.

The effects of various cerebral cortical lesions on motor function and in particular on muscle tone have been studied quantitatively in the squirrel monkey (Saimiri sciureus) in an attempt to define the cause of muscular hypertonia and to develop a reliable model for human cerebral spasticity. Unilateral ablation of the primary motor area (MI), either alone or together with the supplementary motor area (MII), produced a contralateral hemiparesis especially marked for fine motor tasks, but did not cause hypertonia. Bilateral ablation of the supplementary motor area alone produced no impairment of motor function or change in muscle tone. Bilateral lesions of the primary motor area, either alone or together with the supplementary motor area, caused a disabling quandriparesis with striking hypertonia affecting chiefly the upper limb flexors and lower limb extensors. Quantitative electromyography revealed augmented stretch responses proportional to the rate of muscle lengthening. This velocity-dependent exaggerated stretch reflex, with a predominantly dynamic component reflecting hyperactivity of the Ia spindle afferents, is similar to that seen in human hemiplegic spasticity. Out results indicate that decorticate hypertonia depends upon the bilateral interruption of fiber tracts originating in motor cortex and distributed both ipsilaterally and contralaterally. Bilateral decortication in the primate seems to be a suitable laboratory model for the objective evaluation of measures proposed for the relief of spasticity in humans.

A persistent median artery causing carpal tunnel syndrome in a patient with chronic renal failure: case report.

A 63-year-old woman presented with carpal tunnel syndrome 6 years after being diagnosed as having chronic renal failure and 1 year after the start of hemodialysis treatment. Symptoms were in the hand contralateral to the side of the arteriovenous fistula used for hemodialysis. During surgery, a large, patent, noncalcified median artery was found pulsating in the carpal tunnel; this pulsation was causing the compression of the median nerve. The flexor retinaculum was decompressed, and the median artery was transposed. This is the first reported case of a persistent median artery in a hemodialysis patient who has symptoms contralateral to the vascular access. The pathophysiology and epidemiology of carpal tunnel syndrome in chronic renal failure patients is reviewed. In addition, the role of the median artery in the vascularization of the hand and the management of a persistent median artery causing carpal tunnel syndrome are reviewed.