Aerosol-Assisted CVD-Grown PdO Nanoparticle-Decorated Tungsten Oxide Nanoneedles Extremely Sensitive and Selective to Hydrogen.

We report for the first time the successful synthesis of palladium (Pd) nanoparticle (NP)-decorated tungsten trioxide (WO3) nanoneedles (NNs) via a two-step aerosol-assisted chemical vapor deposition approach. Morphological, structural, and elemental composition analysis revealed that a Pd(acac)2 precursor was very suitable to decorate WO3 NNs with uniform and well-dispersed PdO NPs. Gas-sensing results revealed that decoration with PdO NPs led to an ultrasensitive and selective hydrogen (H2) gas sensor (sensor response peaks at 1670 at 500 ppm of H2) with low operating temperature (150 °C). The response of decorated NNs is 755 times higher than that of bare WO3 NNs. Additionally, at a temperature near that of the ambient temperature (50 °C), the response of this sensor toward the same concentration of H2 was 23, which is higher than that of some promising sensors reported in the literature. Finally, humidity measurements showed that PdO/WO3 sensors displayed low-cross-sensitivity toward water vapor, compared to bare WO3 sensors. The addition of PdO NPs helps to minimize the effect of ambient humidity on the sensor response.

Clinical characteristics and associated comorbidities in diabetic patients with cranial nerve palsies.

BACKGROUND: Cranial mononeuropathy is one of the not so common forms of diabetic neuropathy that often appears to be a serious problem from a diagnostic and therapeutic point of view. AIM: Objective of this study was to determine the incidence, the clinical characteristics, and risk factors associated with cranial nerve palsies among persons with diabetes. METHODS: We have performed a retrospective study of all diabetic patients with cranial nerve palsies who were hospitalized in a metabolic department over a 12-yr period. RESULTS: During the period of the survey, a total of 8150 diabetic subjects were hospitalized and cranial nerve palsies were identified in 61 patients (0.75%). Isolated III nerve palsies accounted for the majority of patients (0.35%), with VII nerve palsies (0.21%) occurring more frequently than VI (0.15%) and multiple palsies (0.04%). Peripheral neuropathy was present in only 24% of patients. Patients with VII nerve palsies showed a tendency toward a lower coexistence of diabetic complications and cardiovascular risk factors than those with III and VI nerve palsies. CONCLUSIONS: Cranial nerve palsies are a not common problem among patients with diabetes; diagnosis of diabetic mononeuropathy should be considered even in the absence of peripheral neuropathy; the oculomotor nerve was most frequently affected in our case report. The coexistence of diabetic complications and cardiovascular risk factors was slightly lower in patients with VII nerve palsy: this fact is compatible with the hypotesis that this event is less closely related to diabetes and metabolic factors in its pathogenesis.

Micro vs macro electrode DBS stimulation: A dosimetric study.

Deep Brain Stimulation (DBS) is a clinically suitable technique for the treatment of the Parkinson's disease. Recently, also other neurological disorders such as Tourette syndrome, obsessive-compulsive disorder, epilepsy are being to be treated with DBS. However, the debate on its therapeutic mechanisms of action is still open. In order to a better understanding of such mechanisms, in this work the attention is focused on the DBS micro-stimulation. Indeed, a micro electrodes registration and stimulation is a fundamental step, during the surgical phase, to optimize the technique in terms of DBS lead positioning and DBS signal parameters. In this paper a dosimetric analysis with micro electrodes has been carried out, showing a more focused distribution of the electrical potential induced in the neuroanatomical tissues and changes of the excited/inhibited regions, respect to a macro electrodes stimulation.

Severe hypoglycaemia leading to hospital admission in type 2 diabetic patients aged 80 years or older.

AIM: Evidence is mounting that hypoglycaemia among elderly diabetic patients is a very real and costly concern. Objective of this study was to determine the incidence and risk factors for developing severe hypoglycaemia leading to hospital admission, among type 2 diabetic subjects aged 80 years or older. METHODS: Hypoglycaemia was defined as a symptomatic event requiring treatment with i. v. glucose and confirmed by a blood glucose determination <50 mg/dl. RESULTS: During a eight-year period severe hypoglycaemia was identified in 99 subjects. These patients were found to have a reduced cognitive ability, a heavy burden of comorbid disease and a HbA1c values of 5.9%. Of the hypoglycaemic episodes, 76 occurred in patients taking glibenclamide. Diabetes therapy was prescribed by general practitioners in 85 of them. Only 26 patients performed regular home blood glucose self-monitoring. CONCLUSION: Severe hypoglycaemia is a serious and not uncommon metabolic emergency among patients with type 2 diabetes aged 80 years or older; it is more frequent in patients with considerable comorbidity undergoing aggressive diabetes management and in users of a long-acting sulphonylurea. In elderly subject, each patient's risk for hypoglycaemia should be considered and therapy should be individualized accordingly; in our opinion, a great number of episodes may be avoided by teaching the principles of blood glucose monitoring and involving general practitioners in outpatients management of diabetes mellitus.

Channel noise enhances signal detectability in a model of acoustic neuron through the stochastic resonance paradigm.

A number of experimental investigations have evidenced the extraordinary sensitivity of neuronal cells to weak input stimulations, including electromagnetic (EM) fields. Moreover, it has been shown that biological noise, due to random channels gating, acts as a tuning factor in neuronal processing, according to the stochastic resonant (SR) paradigm. In this work the attention is focused on noise arising from the stochastic gating of ionic channels in a model of Ranvier node of acoustic fibers. The small number of channels gives rise to a high noise level, which is able to cause a spike train generation even in the absence of stimulations. A SR behavior has been observed in the model for the detection of sinusoidal signals at frequencies typical of the speech.

Clinical characteristics and associated comorbidities in diabetic patients with restless legs syndrome.

AIM: RLS, despite being a common entity, is often underdiagnosed and appears to be a serious problem from a diagnostic and therapeutic point of view. There have been few studies primarily concerned with the clinical characteristics of RLS in diabetic subjects. Those published have emanated largely from neurological referral centres rather than metabolic departments. The objective of this study was to determine the clinical characteristics and risk factors associated with RLS among persons with diabetes. METHODS: We have performed a retrospective study of all diabetic inpatients with RLS who were seen in the Metabolic Division at "S. Biagio" Hospital, Marsala, over a 18 months period. A detailed history, blood laboratory profile and an electrophysiological evaluation were obtained for each patient. RESULTS: During the period of the survey RLS was identified in 23 patients. These patients were found to have a poorly controlled diabetes and had increased associated comorbidities: they showed an high prevalence of diabetic neuropathy (96%) and metabolic syndrome (74%). Moreover, median duration of RLS symptoms onset was 2.8 years. CONCLUSIONS: RLS is a serious and not uncommon problem among patients with diabetes mellitus. This syndrome is closely related to diabetic neuropathy and probably to metabolic factors in its pathogenesis. Diagnosis of RLS is often delayed and because it can be effectively treated, a better education of the general medical community toward greater awareness of the syndrome is necessary.

Fundamental electrical quantities in deep brain stimulation: influence of domain dimensions and boundary conditions.

Deep Brain Stimulation (DBS) has revealed a convincing clinical efficacy in Parkinson's diseases and essential tremor. Unfortunately, to date no clear understanding of the therapeutic mechanisms has been achieved. Characterization of the distribution of the electrical quantities inside the target areas of the central nervous system is one fundamental step ahead. Starting from the studies that so far addressed this issue, aim of this work is to quantify the role of some parameters, such as dimensions of the conducting domain and of boundary conditions, on the distribution of the fundamental electric quantities inside the brain target area.

Effects of an exogenous noise on a realistic network model: encoding of an EM signal.

Endogenous noise has been shown to play a central role in the detection of an electromagnetic signal in the nervous system. In this work, following a biomedical perspective, an exogenous noise applied to a realistic feedforward network model has been considered. It will be shown that, if the exogenous noise is properly filtered and its level is adjusted, a clear optimization of network encoding of an electromagnetic signal, representative of an external stimulation, is obtained through the stochastic resonance paradigm.

Molecular mechanisms of acute renal failure following ischemia/reperfusion.

Acute renal failure (ARF) necessitating renal replacement therapy is a common problem associated with high morbidity and mortality in the critically ill. Hypotension, followed by resuscitation, is the most common etiologic factor, mimicked by ischemia/reperfusion (I/R) in animal models. Although knowledge of the pathophysiology of ARF in the course of this condition is increasingly detailed, the intracellular and molecular mechanisms leading to ARF are still incompletely understood. This review aims at describing the role of cellular events and signals, including collapse of the cytoskeleton, mitochondrial and nuclear changes, in mediating cell dysfunction, programmed cell death (apoptosis), necrosis and others. Insight into the molecular pathways in the various elements of the kidney, such as vascular endothelium and smooth muscle and tubular epithelium leading to cell damage upon I/R will, hopefully, open new therapeutic modalities, to mitigate the development of ARF after hypotensive episodes and to promote repair and resumption of renal function once ARF has developed.

Concomitant alterations in intragastric pH and ascorbic acid concentration in patients with Helicobacter pylori gastritis and associated iron deficiency anaemia.

BACKGROUND: Seroepidemiological and clinical studies suggest that Helicobacter pylori may cause iron deficiency anaemia (IDA) in the absence of peptic lesions by undefined mechanisms, which still remain to be fully elucidated. Gastric acidity and ascorbic acid (AA) promote iron absorption. AA is lowered in the presence of H pylori infection. H pylori can cause atrophic body gastritis with achlorhydria, decreased iron absorption, and consequent IDA. Whether alterations in intragastric acidity and AA concentrations play a role in IDA developing in patients with H pylori gastritis remains to be determined. AIM: To evaluate gastric juice pH and gastric juice and plasma AA in patients with H pylori infection and unexplained IDA, compared with controls with IDA and a healthy stomach or with controls with H pylori infection and no IDA. RESULTS: Patients with IDA and H pylori gastritis were characterised by concomitant increased intragastric pH (median value 7) and decreased intragastric AA (median value 4.4 micro g/ml) compared with controls with a healthy stomach (median pH 2; median intragastric AA 17.5 micro g/ml) and with H pylori positive controls without IDA (median pH 2.1; median intragastric AA 7.06 micro g/ml). Intragastric AA was inversely related to pH (r=-0.40, p=0.0059) and corporal degree of gastritis (r=-0.53, p=0.0039). Plasma AA concentrations were lower in all infected groups than in healthy controls. CONCLUSIONS: Patients with unexplained IDA and H pylori gastritis present concomitant changes in intragastric pH and AA that may justify impaired alimentary iron absorption and consequent IDA.

ALS-plus: 5 cases of concomitant amyotrophic lateral sclerosis and parkinsonism.

According to El Escorial criteria, amyotrophic lateral sclerosis (ALS), combined with other neurologic disorders, such as dementia and parkinsonism, is defined as ALS-plus. These overlaping syndromes are extremely rare. Here we report 5 cases (3 men, 2 women) of ALS-plus; mean age at the onset of symptoms was 67 years (range, 65-72). In 3 patients, motoneuronal signs preceded the onset of parkinsonian syndrome. In 4 cases, the clinical picture was characterized by the prevalence of motoneuronal signs. Parkinsonism was poorly responsive to L-dopa treatment in all patients. The clinical course did not differ from that expected in patients with only ALS. Our clinical observations and neuropathological reports of nigral neuronal loss in ALS patients suggest a common pathogenic mechanism underlying these disorders.

Ocular lesions associated with systemic hypertension in cats: 69 cases (1985-1998).

OBJECTIVE: To characterize clinical and clinicopathologic findings, response to treatment, and causes of systemic hypertension in cats with hypertensive retinopathy. DESIGN: Retrospective study. ANIMALS: 69 cats with hypertensive retinopathy. PROCEDURE: Medical records from cats with systemic hypertension and hypertensive retinopathy were reviewed. RESULTS: Most cats (68.1%) were referred because of vision loss; retinal detachment, hemorrhage, edema, and degeneration were common findings. Cardiac abnormalities were detected in 37 cats, and neurologic signs were detected in 20 cats. Hypertension was diagnosed concurrently with chronic renal failure (n = 22), hyperthyroidism (5), diabetes mellitus (2), and hyperaldosteronism (1). A clearly identifiable cause for hypertension was not detected in 38 cats; 26 of these cats had mild azotemia, and 12 did not have renal abnormalities. Amlodipine decreased blood pressure in 31 of 32 cats and improved ocular signs in 18 of 26 cats. CONCLUSIONS AND CLINICAL RELEVANCE: Retinal lesions, caused predominantly by choroidal injury, are common in cats with hypertension. Primary hypertension in cats may be more common than currently recognized. Hypertension should be considered in older cats with acute onset of blindness; retinal edema, hemorrhage, or detachment; cardiac disease; or neurologic abnormalities. Cats with hypertension-induced ocular disease should be evaluated for renal failure, hyperthyroidism, diabetes mellitus, and cardiac abnormalities. Blood pressure measurements and funduscopic evaluations should be performed routinely in cats at risk for hypertension (preexisting renal disease, hyperthyroidism, and age > 10 years). Amlodipine is an effective antihypertensive agent in cats.

Blood antioxidant status and urinary levels of catecholamine metabolites in beta-thalassemia.

It has been reported that iron overload in beta-thalassemia leads to an enhanced generation of reactive oxygen species and to oxidative stress. We have studied the oxidant/antioxidant imbalance in the blood of 48 transfusion-dependent beta-thalassemic patients (TLP) (17 males, 31 females, 11-22 year), under chelation therapy, and in 40 sex and age matched healthy controls (CTR). Plasma and lymphocyte levels of vitamin E (Vit E), ubiquinol (CoQ10H2), ubiquinone (CoQ10), plasma concentrations of vitamin A (Vit A), beta-carotene, lycopene, vitamin C (Vit C), total thiols, fatty acid patterns of phospholipids (PL-FA), and plasma and urinary markers of lipoperoxidation (TBA-RM, conjugated dienes, and azelaic acid (AZA), as well as the urinary levels of catecholamine and serotonin metabolites, were evaluated by gas chromatography-mass spectrometry (GC-MS), HPLC and spectrophotometry. Routine laboratory blood analyses were performed on the same samples; 39/48 TLP were HCV positive. Blood samples were collected just before transfusion, the 24 h urine samples the day before. Our results clearly showed that a severe oxidative stress occurs in the plasma of TLP in comparison with CTR. In fact, the levels of lipophilic antioxidants and ascorbate were severely depleted: CoQ10H2 (-62.5%), total CoQ10 (-35.1%), Vit E (-43.8%), beta-carotene (-31.1%), lycopene (-63.7%), Vit A (-35.9%), Vit C (-23.1%). The impairment of the antioxidant status was associated with elevated plasma levels of by-products of lipoperoxidation and urinary concentrations of catecholamine metabolites and of AZA, indicating a high degree of both neurological stress and lipoperoxidation. A significant positive correlation was found between vitamin E and non-transferrin-bound iron (NTBI) (r = -0.81; p < 0.001), while no correlation was found between antioxidant depletion and ferritin serum levels, average blood consumption, or the presence of clinical complications. The administration of selective antioxidants along with an appropriate diet might represent a promising way of counteracting oxidative damage and its deleterious effects on the progression of the disease.

Epidermal oxidative stress in vitiligo.

Epidermal levels of enzymatic and non-enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), vitamin E (Vit E), ubiquinol (CoQ10H2), and reduced glutathione (GSH), as well as polyunsaturated fatty acids of phospholipids (PL-PUFA), were evaluated in the affected epidermis of 15 patients with active vitiligo (AVP) and in the corresponding epidermis of 15 healthy phototype matched controls. The epidermal levels of CoQ10H2, Vit E, GSH, and CAT activity were significantly reduced in AVP and were associated with a marked increase of oxidized glutathione, whereas SODs and GSH-Px activities and ubiquinone concentration remained similar to control values. Antioxidant deficiency, in particular the decline of lipophilic antioxidants, i.e., CoQ10H2 and Vit E, accounts well for PL-PUFA reduction observed in vitiligo epidermis, mainly affecting C18:3 n-3, C20:3 n-6, C20:4 n-6, and C22:6 n-3 fatty acids and suggesting the occurrence of a lipoperoxidative process. In conclusion, both an imbalance of the intracellular redox status and a significant depletion of enzymatic and non-enzymatic antioxidants feature the epidermis of AVP, and represent a fingerprint of an abnormal oxidative stress leading to epidermal cell injury.

[Endoscopic palliative treatment of a neoplastic esophageal fistula: report of a case]. / Palliazione endoscopica di una fistola neoplastica esofagea: caso clinico.

Oesophago-respiratory neoplastic fistulas present serious problems of management, because of the severe status of the patient. Therefore, a palliative treatment, to allow for a gradual respiratory and digestive function recovery with clinical improvements is needed. Surgical palliation has a mortality rate of 40% and a long post-operative hospitalization. Endoscopic palliation, on the other hand, has the same percentage of success of surgical palliation, but has the advantage to be performed in those patients with severe health conditions immediately improving the symptomatology and not excluding a subsequent surgical approach. The Authors present the case of a 70-year-old patient with a neoplastic relapse on the oesophago-gastric anastomosis, associated to an oesophago-respiratory fistula manifesting as severe dysphagia and dyspnoea. An endoscopic palliative treatment of the fistula was performed introducing a metallic coated prosthesis into the oesophagus. Severe clinical conditions regressed immediately and after 3 months they are unchanged. The Authors suggest endoscopic palliation with oesophageal prosthesis as the best therapeutic choice in those cases not amenable to surgery.

[The endoscopic treatment of postoperative stenoses of the upper digestive tract]. / Trattamento endoscopico delle stenosi post-operatorie del tratto digestivo superiore.

The authors compare their experience in dilatation of postoperative benign esophageal strictures. A total of 60 patients (37 males, 23 females: mean age 52), all with severe dysphagia, from January 1985 to September 1995, underwent endoscopic dilatation: 32 of these with Savary dilators and 28 with balloon dilators. Dilatation was effective in 93% in both groups. Two severe complications were recorded (1 heart attack and 1 perforation) in the group that underwent endoscopic dilatation with Savary dilators. During endoscopic management, pain recurred in 43% and 87% of cases after balloon or Savary dilatations, respectively. The authors believe balloon dilators are more effective, better tolerated and with less complications than Savary dilators. They reserve the management with Savary dilators to the extremely severe esophageal strictures.

On coordination modes of adenine in cadmium(II) complexes.

Complexes of cadmium(II) derivatives with adenine from water or by simulation of physiological conditions are obtained. The complexes have been studied by spectroscopic, conductometric, 1H-NMR, and by TG and DSC measurements. Possible coordination modes of the ligand are proposed.

Adenosine deaminase activity in peripheral lymphocytes of patients with gynaecologic malignancies.

Peripheral lymphocyte adenosine deaminase (ADA) activity was assessed in a group of 31 patients with gynaecologic malignancies (19 with carcinoma of the portio, 7 with endometrial adenocarcinoma, 3 with ovarian cancer, 1 with adenocarcinoma of the cervix, 1 with liposarcoma myxoide). 30 female subjects, aged 30 to 70 years, were studied as the control group. Lymphocyte ADA activity in the 31 patients ranged from 0 to 7 U/10(7) cells with a mean of 2.3 U/10(7) cells (normal values: range 2-5 U/10(7) cells; mean 2.8 U/10(7) cells). In cases where the enzyme was absent or far below the controls, a faster evolution of the disease was observed. We would point out that lymphocyte ADA activity in the patients under investigations shows a broad range of variability. Our preliminary observations would suggest that lymphocyte ADA assessment in a larger series of cancer patients may add further prognostic informations.

Fetal tachypnea: prognostic significance and treatment.

We report the case of a pregnant woman with class B diabetes whose fetus, examined in utero by means of real-time ultrasound, showed tachypneic breathing movements. Having considered the clinical course of this case and of those reported in literature, we put forward a hypothesis concerning the pathogenesis and the prognostic significance of fetal tachypnea.