[Risk of electromagnetic fields in electric power stations and substations of a petrochemical plant]

Authors evaluate electromagnetic field exposure in the low-frequency range (5-30,000 Hz) in electric power stations and substations of petroleum processing plant. According to the measured values and the reference exposure limits considered, they conclude that operators should be exposed without adverse effects.

Spectrum of SCN1A mutations in severe myoclonic epilepsy of infancy

OBJECTIVES

SCN1A mutations were recently reported in several patients with severe myoclonic epilepsy in infancy (SMEI). The authors analyzed SCN1A mutations in 93 patients with SMEI and made genotype-phenotype correlation to clarify the role of this gene in the etiology of SMEI.

METHODS

All patients fulfilled the criteria for SMEI. The authors analyzed all patients for SCN1A mutations using denaturing high performance liquid chromatography. If a patient's chromatogram was abnormal, the authors sequenced the gene in the patient and both parents.

RESULTS

SCN1A mutations were identified in 33 patients (35%). Most mutations were de novo, but were inherited in three patients. Parents carrying the inherited mutations had either no symptoms or a milder form of epilepsy. A greater frequency of unilateral motor seizures was the only clinical difference between patients with SCN1A mutations and those without. Truncating mutations were more frequently associated with such seizures than were missense mutations. The percentage of cases with family history of epilepsy was significantly higher in patients with SCN1A mutations.

CONCLUSIONS

Unilateral motor seizures may be a specific clinical characteristic of SMEI caused by SCN1A mutations. Ten percent of SCN1A mutations are inherited from an asymptomatic or mildly affected parent, suggesting that SMEI is genetically heterogeneous. The increased frequency of familial epilepsy indicates that other genetic factors may contribute to this disorder.

AQP1 in red blood cells of uremic patients during hemodialytic treatment

Hemodialysis influences the transport of water through the erythrocytic membrane, and induces morphologic and functional modifications. Recently water channels, called aquaporins (AQP), have been identified on the membrane of red blood cells. The aim of the present study was, therefore, to evaluate any relationships between volumetric changes in erythrocytes (MCV), plasma osmolarity and membrane expression of AQP1 in 22 uremic patients during a hemodialysis session, and compare value with those in a control group of 22 healthy volunteers. Membranal AQP1 expression was evaluated using three methods: indirect immunofluorescence under confocal microscopy, immunoenzymatic method after membrane extraction, and immunoblotting. In uremic subjects, at baseline membrane AQP1 expression was significantly lower, whereas plasma osmolality was higher than in controls. At 1 and 2 h of replacement therapy, a progressive increase was observed in erythrocytic AQP1, values similar to those in controls being attained after 3.5 h. During the session osmolality values reduced progressively, becoming significantly lower than basal values. The mean erythrocytic corpuscular volume in patients with ESRD was significantly lower than in cntrols at baseline. This value increased during hemodialysis, attaining statistical significance with respect to the basal value at 3.5 h of dialysis. Close correlations were found between plasma osmolality and AQP1 values (r = -0.930; p < 0.05), and also between MCV and plasma osmolality trend (r = -0.909; p < 0.05). There was a linear correlation (r = 0.63, p < 0.05) between plasma AVP concentrations and plasma osmolality. The variations found in plasma osmolarity during hemodialysis, may induce AQP1 expression on the membrane of intact red blood cells.

[Diverticular disease of the colon in peritoneal dialysis]

Colon diverticular disease is a very common pathology in western countries and represents a risk factor for septic-type complications, especially in peritoneal dialysis patients. We examined both diagnostic procedure and therapeutics options, either pharmacological or surgical. Ultrasonography, which is useful for the diagnosis of diverticulosis and diverticular disease, has been supported in the last few years by new imaging techniques, such as NMR and CT, that also find applications in the treatment of diverticulitis complications like peritoneal abscesses. Our emphasis is on the therapeutic perspective, either dietetic - based on the use of a fibre-rich diet and the infusion of liquids by intravenous injection - or surgical, such as the Hartmann procedure, single anastomosis with stomia conservation and laparoscopic and endoscopic treatment. These therapeutic approaches have reduced both morbidity and mortality rate and have emphasized how the reduction of surgical stress on the mesothelium promotes the recovery of the functional integrity and, consequently, faster resumption of peritoneal dialysis. In conclusion, diverticulosis alone is not a contraindication for peritoneal dialysis, but constitutes a risk factor for the continuation of this alternative treatment.

Prevalence of anti-cardiolipin, anti-beta2 glycoprotein I, and anti-prothrombin antibodies in young patients with epilepsy

PURPOSE

To measure anti-cardiolipin (aCL), anti-beta2 glycoprotein I (anti-beta2GPI), and anti-prothrombin (aPT) antibodies in young patients with epilepsy, and to correlate their presence with demographic data, clinical diagnoses, laboratory and neuroradiologic findings, and antiepileptic drugs (AEDs).

METHODS

Sera from one hundred forty-two consecutive patients with epilepsy with a median age of 10 years were tested for aCL and anti-beta2GPI autoantibodies by solid-phase assays. aPT antibodies also were assayed in sera from 90 patients. Positive results were confirmed after a minimum of 6 weeks. Antinuclear antibodies (ANAs) and antibodies against extractable nuclear antigens (ENAs) also were tested.

RESULTS

An overall positivity of 41 (28.8%) of 142 sera was found. Fifteen patients were positive for aCL, 25 for anti-beta2GPI, and 18 for aPT antibodies. Several patients (12%) displayed more than one specificity in their serum. Only one of these patients had a concurrent positivity for ANAs and ENAs. A predominance of younger patients was found in the antibody-positive group. All types of epilepsy were represented in the positive group. No relation between antibody positivity and AEDs was found. Diffuse ischemic lesions at computed tomography (CT)/magnetic resonance imaging (MRI) scans were present in higher percentages in patients who were antibody positive. No positive patient had a history of previous thrombosis or other features related to systemic lupus erythematosus (SLE), and no patient was born of a mother with SLE.

CONCLUSIONS

Our study suggests a relation between epilepsy and aPL in young patients. A pathogenetic role for these autoantibodies cannot be excluded, and their determination might prove useful even from a therapeutic point of view.

Benign partial epilepsies of adolescence: a report of 37 new cases

PURPOSE

To delineate the electroclinical features of patients with partial seizures in adolescence with a benign outcome.

METHODS

Patients were recruited in five different Italian epilepsy centers. Patients were selected among those with partial seizures between ages 11 and 17 years. We excluded benign childhood epilepsies, those with neurologic or mental deficits, and those with neuroradiologically documented lesions. We also excluded patients with less than 3 years' follow-up or who were still receiving antiepileptic therapy.

RESULTS

There were 37 (22 male, 15 female) patients. Seizures started at the mean age of 14.5 years (range, 11-16.11). Two main electroclinical patterns emerged: 16 of 37 patients had somatomotor seizures frequently associated with focal theta discharges involving the centroparietal regions. Ten of 37 patients showed versive seizures and interictal spiking involving the posterior regions. A third group had clinical characteristics resembling the cases described by Loiseau. All had a favorable outcome.

CONCLUSIONS

This relevant multicenter study further confirms the existence of benign partial epilepsies with onset during adolescence.

[Behaviour of free radicals in Alzheimer's disease]

BACKGROUND

The objective of this study is to evaluate the oxidative stress status in patients affected by Alzheimer's disease, considering the role played by the free radicals in the progression and determination of this disease.

METHODS

We have studied 13 patients aged between 65 and 84 years and diagnosed with Alzheimer's disease on the basis of Brain CT scan or MRI results, PTEA (uditive mapped slow potential waves), EEG analysis, evaluation questionnaire (MMSE, ADAS), free radicals levels.

RESULTS

This study proved the presence of an oxidative stress status in all patients studied, showing an interaction between the disease and oxidative status. A reduction of the free radicals levels after therapy with determinable anti radicals has also been observed.

CONCLUSIONS

The existence between Alzheimer's disease and oxidative stress has already been demonstrated. This study is a contribution to this orientation. Further studies are suggested on the preventive effects, but particularly to demonstrate if the use of antioxidants may be able to decrease or stop the evolution of this disease.

Effects of homocysteine on proliferation, necrosis, and apoptosis of vascular smooth muscle cells in culture and influence of folic acid

BACKGROUND

It is known that hyperhomocysteinemia is associated with an increased risk of vascular disease, yet little is known about the pathogenic mechanisms underlying the action of homocysteine (Hcy) itself.

METHODS

We evaluated the effects of Hcy on cell proliferation, apoptosis, and necrosis in smooth muscle cells (SMCs) cultured for 24 h with different amounts of Hcy. The percentage of apoptotic and necrotic cells from the culture was evaluated using two different techniques: annexin V-FITC and propidium iodide (PI) fluorescence and apoptosis TUNEL assay.

RESULTS

The addition of 10 microM/l of Hcy to the medium was followed by a significant increase in cell proliferation and death, through apoptosis and necrosis, respectively. Notwithstanding this apparent balance, a significant increase was found in the total number of cells present in Hcy-treated culture, thus demonstrating a positive dose-dependent correlation with Hcy concentrations in the culture medium. The addition of folic acid to the culture medium significantly reduced both Hcy concentrations in media and the effects of Hcy on the proliferation/apoptosis/necrosis balance of cells in culture. The percentages for apoptotic cells and for cells with a necrotic morphology continued to increase as Hcy concentrations increased, although the absolute values were lower in the culture treated than in that not treated with folic acid.

CONCLUSIONS

In the presence of folic acid, at increasing concentrations of Hcy, the total number of cells in culture showed increases far less relevant with respect to the control. Also the percentage of apoptotic cells to that of cells with a necrotic morphology, although conserving the tendency to increase to growth of the concentrations of Hcy, have shown absolute values that were lower in the folic acid-treated cultures.

Separation of scattering and absorption contributions in UV/visible spectra of resonant systems

Resonance light scattering (RLS) is a phenomenon due to an enhancement of the scattered light in close proximity to an absorption band. The effect is easily detectable in the case of strongly absorbing chromophores, which are able to interact, thus leading to large aggregates (Pasternack, R. F.; Collings, P. J. Science 1995, 269, 935). The measurement of absorption spectra from solutions containing such resonant systems can lead to misleading results. In this paper, a simple method is described to obtain absorption spectra of aggregated species with a fairly good correction of the scattering component. The RLS spectrum, obtained using a common spectrofluorimeter, is correlated to the extinction spectrum of the same sample, allowing for an estimation of the scattering contribution to the total extinction spectrum. The method has been successfully applied both on real samples containing aggregated chromophores, such as porphyrins, chlorophyll a and gold colloids, and by simulating extinction spectra.

Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus

The purpose of this multicenter study was to analyze the results of shoulder arthroplasty for the treatment of the sequelae of proximal humerus fractures and establish an updated classification system and treatment guidelines for these complex situations. Seventy-one sequelae of proximal humerus fractures were treated with shoulder replacement with the use of the same nonconstrained, modular, and adaptable prosthesis: the Aequalis prosthesis (Tornier Inc, St Ismier, France). The average time between initial fracture and shoulder arthroplasty was 5 years and 5 months. On the basis of anatomic classification schemes, sequelae were divided into 4 types: type 1, humeral head collapse or necrosis with minimal tuberosity malunion (40 cases); type 2, locked dislocations or fracture-dislocations (9 cases); type 3, nonunions of the surgical neck (6 cases); and type 4, severe malunions of the tuberosities (16 cases). The mean postoperative follow-up was 19 months (range, 12 to 48 months). Overall, the postoperative Constant score was excellent in 11 cases (16%), good in 19 cases (26%), fair in 18 cases (25%), and poor in 23 cases (33%). There were 18 complications (27%). Fifty-nine of 70 patients (81%) stated that they were satisfied with the result. The most significant factor affecting functional outcome was greater tuberosity osteotomy (P <.005). Regarding both surgical treatment and postoperative prognosis, we identify 2 categories of proximal humerus fracture sequelae: category 1, intracapsular/impacted fractures sequelae (associated with both cephalic collapse or necrosis [type 1] and chronic dislocation or fracture-dislocation [type 2]), in which an articulating joint can be reconstructed without a greater tuberosity osteotomy; and category 2, extracapsular/disimpacted fractures sequelae (associated with both surgical neck nonunions [type 3] and severe tuberosity malunions [type 4]) where the proximal humerus cannot be reconstructed without a greater tuberosity osteotomy. All of the excellent and good postoperative Constant scores were obtained in type 1 and 2, in which osteotomy of the greater tuberosity was not required. All patients in type 3 and 4, who underwent a greater tuberosity osteotomy, had either fair or poor results and did not regain active elevation above 90 degrees. We conclude that a greater tuberosity osteotomy is the most likely reason for poor and unpredictable results after shoulder replacement arthroplasty for the treatment of the complex sequelae of proximal humerus fractures. Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus should be performed without an osteotomy of the greater tuberosity when possible. If prosthetic replacement is possible without an osteotomy, surgeons should accept the distorted anatomy of the proximal humerus and adapt the prosthesis and their technique to the modified anatomy. A modular and adaptable prosthesis with both adjustable offsets and inclination may allow surgeons to adapt to a large number of malunions and may help to avoid the troublesome greater tuberosity osteotomy in a higher proportion of cases.

A clinical spectrum of the myoclonic manifestations associated with typical absences in childhood absence epilepsy. A video-polygraphic study

We investigated the electroclinical features of 12 patients with childhood absence epilepsy (CAE), presenting with typical absence seizures associated with myoclonic manifestations of the face or neck. All patients underwent repeated and prolonged split-screen video-polygraphic EEG recordings. The polygraphic recordings and clinical correlations of the absence seizures were analysed. All patients presented with multi-quotidian, typical absence seizures. During the absences, the patients could show mild, rhythmic, myoclonic jerks involving facial areas (eyebrows, nostrils, perioral region, chin) or neck muscles (sternocleidomastoideus), with the same frequency as the spike-wave complexes. Polygraphic tracings demonstrated that the myoclonias were correlated to the spike component. Clinically, all patients showed a benign course, with complete seizure control under antiepileptic treatment. In the follow-up, 7 patients withdrew from treatment without relapse. We conclude that all our patients showed an electroclinical picture consistent with CAE. The occurrence of myoclonic manifestations of the face or neck associated with the absences did not influence the benign course of their disease. The electroclinical features observed in our group of patients differentiates our cases both from epilepsy with myoclonic absences and from absences with perioral myoclonia (with Video).

Acquisition of an appetitive behavior reverses the effects of long-term treatment with lithium in rats

Rats exposed to a long-term treatment with lithium chloride develop a deficit of avoidance accompanied by a reduction in the basal levels of extraneuronal dopamine and in dopamine accumulation in the nucleus accumbens shell after acute uptake inhibition. Such a condition is similar to that of an experimental model of depression induced by exposing rats to a chronic stress procedure. Rats exposed to chronic stress are also unable to acquire an appetitive behavior sustained by a highly palatable food. Thus, it was studied whether rats fed a diet containing lithium would develop an appetitive behavior induced by a pure hedonic stimulus. Rats on the lithium diet developed a clear-cut escape deficit condition accompanied by a decreased dopamine output in the nucleus accumbens shell; nevertheless, they learned the appetitive behavior within a similar period to controls. The development of the appetitive behavior coincided with the recovery of the capacity to avoid a noxious stimulus and with the return of the dopaminergic transmission in the nucleus accumbens shell to values similar to those of control rats. It may be concluded that the mechanism of action underlying the behavioral and neurochemical sequelae of a chronic stress is distinct from that of the analogous effects produced by lithium.

Novel mutations of ubiquitin protein ligase 3A gene in Italian patients with Angelman syndrome

Angelman syndrome is a neurobehavioral disorder caused by defects of imprinted gene(s) on chromosome 15q11-13. AS-specific DNA methylation is found in patients carrying 3-4 Mb deletions ( approximately 70%), paternal uniparental disomy (3-5%) or imprinting center mutations (2-9%), while normal methylation pattern with biparental inheritance characterizes the remaining approximately 20-25% AS patients (Stalker et al.,1998; Tsai et al.,1998). Mutations in the Ubiquitin protein ligase 3A gene (UBE3A) have been found in the latter group, but only preliminary figures are available on their frequencies. We selected a sample of 25 AS patients with a clinical diagnosis of AS and a normal methylation pattern in order to search for mutations of the UBE3A gene. Automated sequencing of exons 8, 9, 10, 11 and 12 performed on our 25 patients allowed us to identify three novel mutations: an 897insA in two unrelated familial cases, a 2544insA and an E167X in two sporadic cases. Mutation R482X previously reported in a sporadic patient was identified in a third familial case. Hum Mutat 15:387, 2000.

Effects of lisinopril administration on blood bcl-2 concentrations in patients with immunoglobulin A nephropathy

We evaluated blood concentrations of bcl-2, a proto-oncogene that can inhibit apoptotic phenomena, in a group of patients with immunoglobulin A (IgA) nephropathy. Concentrations of bcl-2 were higher in patients with proteinuria than in those without proteinuria. A 6-month course of 5 mg/day lisinopril given to subjects with proteinuria significantly reduced blood bcl-2 concentrations and caused a reduction in proteinuria. Therefore increased blood bcl-2 concentrations may be considered an index of risk in subjects with IgA nephropathy, and the positive effects of angiotensin-converting enzyme inhibitors on proteinuria in patients with IgA nephropathy may be attributed, at least in part, to their effect on the mechanisms that regulate apoptosis. This is of fundamental importance in resolving glomerular hypercellularity in the course of glomerulonephritis.

Effectiveness of a particular blue lens on photoparoxysmal response in photosensitive epileptic patients

The aim of our work was to test a particular type of lens for photosensitivity control in photosensitive epileptic patients. Previous papers considered color and shade of dark to test lens efficacy. We added a new variable, namely lens material, to these well-known variables. We performed electroencephalography (EEG) and simultaneous video recordings in 83 epileptic patients to evaluate the effectiveness of these experimental blue lenses on photoparoxysmal response (PPR). In addition, we compared the lenses with four other types of commercially available lenses. We found that the experimental lens type was very effective for photosensitivity inhibition in epileptic subjects. Indeed, PPR disappeared in 64 of 83 patients (77%) and diminished in 16 (19%). All the other commercial lenses were less effective. We think that this particular lens type could be useful in managing photosensitive epileptic patients.

Reduced blood bcl-2 protein concentration in patients on hemodialysis

The concentrations of bcl-2 protein that can block programmed cellular death in various cell lines were evaluated in blood samples from 10 uremic patients on hemodialysis, 10 uremics not yet on hemodialysis, and in 10 healthy controls. The bcl-2 protein variations (in uremics on dialysis) were ascertained in patients during the dialysis session. Oxidative stress was evaluated in all groups by assaying the products of intraerythrocytic lipoperoxidation. Dialyzed and nondialyzed uremic patients had higher bcl-2 protein concentrations than healthy subjects. Dialysis causes a significant reduction in the concentrations of bcl-2 protein which becomes statistically significant during the 3rd hour. In both groups of uremic patients a positive correlation was found between bcl-2 protein and products of lipoperoxidation.

Comparison of somatostatin receptor imaging, computed tomography and ultrasound in the clinical management of neuroendocrine gastro-entero-pancreatic tumours

Neuroendocrine tumours displaying somatostatin receptors have been successfully visualised with somatostatin receptor imaging (SRI). However, there may be differences in sensitivity depending on the site of the primary tumour and/or its metastases. We studied 131 patients affected by neuroendocrine tumours of the gastro-entero-pancreatic (GEP) tract. A pathological diagnosis was obtained in 116 patients, while in 15 the diagnosis was based on instrumental results and follow-up. Fifty-one patients were examined for staging purposes, 80 were in follow-up. Images were acquired 24 and 48 h after the injection of 150-220 MBq of indium-111 pentetreotide. Whole-body and SPET images were obtained in all patients. Patients were also studied with computed tomography (CT), ultrasound (US), and other procedures. Tumours were classified according to their site of origin: pancreas n = 39, ileum n = 32, stomach n = 16, appendix n = 9, duodenum n = 5, jejunum n = 5, rectum n = 3, biliary tract n = 2, colon n = 2, caecum n = 1, liver metastases from unknown primary = 15, widespread metastases from unknown primary = 2. Sensitivity for primary tumour localisation was as follows: SRI = 62%; CT = 43%; US = 36%; other procedures = 45%. Sensitivity for liver metastases: SRI = 90%; CT = 78%; US = 88%; other procedures = 71%. Sensitivity for the detection of extrahepatic soft tissue lesions was: SRI = 90%; CT = 66%; US = 47%; other procedures = 61%. Sensitivity for the detection of the primary tumour in patients with metastases from unknown primary sites: SRI 4/17; CT 0/13; US 0/12; other procedures 1/10. In 28% of the patients SRI revealed previously unknown lesions, and in 21% it determined a modification of the scheduled therapy. Our study confirms the important role of SRI in the management of GEP tumours. However, we feel that a critical investigation should address its role in locating primary tumours, in particular in patients with metastases from unknown primary sites.

Transcriptional remodeling and G1 arrest in dioxygen stress in Saccharomyces cerevisiae

Saccharomyces cerevisiae, which lack a functional SOD1 gene, encoding the cytosolic Cu,Zn-superoxide dismutase (SOD1), exhibit a variety of metabolic defects in aerobic but not in anaerobic growth. We test here the hypothesis that some of these defects may be due to specific transcriptional changes programmed for cell survival under dioxygen stress. Analysis of the budding pattern and generation time showed that the slower proliferation of an sod1Delta mutant strain under air was due to an increase from 42 to 89 min spent in the G1 phase of the cell cycle. This delay in G1 was not due to an overall decline in biosynthetic activity since total protein and mRNA synthesis was not reduced even under 100% O2. However, rRNA synthesis was strongly decreased, e.g. by 80% in the mutant under 100% O2 (in comparison to N2). Under these conditions, the mutant permanently arrested in G1; this arrest was due to an inhibition of the Start function that prepares yeast for S phase. This Start arrest was due to an inhibition of transcription of the autoregulated G1 cyclins, CLN1 and CLN2; the transcription of the constitutive G1 cyclin, CLN3, was unaffected by the stress. Expression of a hyperstable Cln3 prevented the G1 arrest, indicating that it was due solely to the inhibition of cell cycle-dependent cyclin expression. This remodeling of transcription in oxidative stress was seen also in the inhibition of glucose derepression of SUC2 expression. In contrast, the signaling and activation of mating pheromone (FUS1) and copper-responsive (CUP1) promoter activity were not affected by dioxygen stress, while genes encoding other anti-oxidant enzymes (SOD2, CTT1 and CTA1) were strongly induced. The UBI loci, encoding ubiquitin, were particularly good examples of this pattern of negative and positive transcriptional response to the stress. UBI1-UBI3 expression was repressed in the mutant under 100% O2, while expression of UBI4 was strongly induced. The data demonstrate that extensive remodeling of transcription occurs in yeast under a strong dioxygen stress. This remodeling results in a pattern of expression of gene products needed for defense and repair, and suppression of activities associated with normal proliferative growth.