Pd-Doped SSZ-13 for Low-T NOx Adsorption: an Operando FT-IR Spectroscopy Study

In this study, mechanistic aspects of NO adsorption/desorption over a home-made Pd/SSZ-13 passive NOx adsorber (PNA) catalyst are investigated. Operando FT-IR spectroscopy and microreactor experiments are performed to envisage the performance of the catalyst and the pathway involved in NO adsorption, with particular emphasis to the impact of species such as C3H6 and CO. In the absence of C3H6 and CO, NO is observed to adsorb as nitrosyls (anhydrous and hydrated) over both Pd2+ and Pd+ species, and as nitrates. 80 μmolNOx/gcat (NO/Pd molar ratio of 0.8) are adsorbed. The stability of nitrosyls is higher in comparison to the nitrates in that the former initially dehydrate and further decompose at elevated temperatures (> 300 °C) leading to the evolution of NO. The presence of CO and C3H6 negatively affects the amounts of NO adsorbed (53 and 45 μmolNOx/gcat, respectively) due to the reduction of Pd sites. CO admission to the catalyst forms a variety of carbonyl species over Pd2+, Pd+ and Pd0 sites which upon NO admission are readily displaced and NO is adsorbed as hydrated/anhydrous nitrosyls of Pdn+. The nitrosyls so formed exhibit lower thermal stability in comparison to nitrosyls observed in the absence of CO and decompose below 300 °C. The addition of C3H6 leads to the apparent formation of oxidized species like acetone, acrolein and acetates, besides propylene adsorption. The NO adsorption in the presence of C3H6 leads to the formation of Pdn+(NO)(X) complexes; upon heating the decomposition of this complexes is observed at low temperatures along with propylene and water desorption. Formation of organic nitro-compounds is also observed that decompose at higher temperatures.

Diagnostic assessment and outcome of acute pancreatitis in Italy: results of a prospective multicentre study. ProInf-AISP: Progetto informatizzato pancreatite acuta, Associazione Italiana Studio Pancreas, phase II

BACKGROUND AND AIM

Up till now, only one study providing practically complete information on acute pancreatitis in Italy has been published. The aim of this prospective study was to evaluate the clinical characteristics, in terms of diagnostic assessment and outcome, of a large series of patients affected by acute pancreatitis in Italy.

MATERIALS AND METHODS

The study involved 56 Italian centres, homogeneously distributed throughout the entire national territory. Each participating centre was furnished with an ad hoc software including 530 items along with subsequent collection, tabulation and quality control of the data.

RESULTS

One thousand five hundred and forty case report forms of patients affected by acute pancreatitis were collected but 367 of them (24%) were subsequently eliminated from the final analysis. Therefore, 1173 patients (581 females and 592 males) were recruited. Mean age of patients was 62.0+/-18.2 years (95% confidence interval, 60.9-63.0). On the basis of Atlanta classification, 1006 patients (85.8%) were defined as mild and 167 (14.2%) as severe pancreatitis. Biliary forms represented the most frequent aetiological category (813 cases, 69.3%) while alcoholic forms only 6.6% (77 cases); the remaining aetiologies accounted for 7.1% (83 cases) while 200 cases (17.1%) remained without a definite aetiological factor. Complete recovery was achieved in 1016 patients (86.6%) whereas morphological sequelae were found in 121 patients (10.3%) and mortality in 36 patients (3.1%; 0.4% in mild and 19.2% in severe acute pancreatitis). Ultrasonography was largely utilised as a first line diagnostic tool in all patients, with valuable visualisation of the pancreas in 85% of patients. Computer tomography scan was also widely used, with 66.7% of exams in mild and 33.3% in severe pancreatitis. Patients affected by biliary pancreatitis presented more severe (p=0.004) and necrotizing forms (p=0.021). Mortality was significantly related (p<0.001) with the extension of pancreatic necrosis and with an age of over 70 years. Body mass index presented significantly greater values in severe than in mild forms (p<0.001).

CONCLUSIONS

Association of creatinine serum level over 2mg/dl with an abnormal chest X-ray showed a high significant correlation with a more severe outcome in terms of morphological sequelae and mortality (p=0.0001). Acute pancreatitis in Italy more commonly presents biliary aetiology and favourable outcome with low rate of complications and mortality. From a cost-effectiveness standpoint, diagnostic approach to this disease needs to be better standardised.

A prospective multicentre survey on the treatment of acute pancreatitis in Italy

BACKGROUND

The Italian Association for the Study of the Pancreas released a diagnostic and therapeutic algorithm for acute pancreatitis in 1999.

AIM

This study focused on the analysis of the therapeutic approach for the treatment of acute pancreatitis in Italy.

PATIENTS

One thousand, one hundred and seventy-three patients were recruited: 1006 patients (85.8%) had mild acute pancreatitis (MAP) and 167 (14.2%) had the severe acute pancreatitis (SAP); 161 patients showed pancreatic necrosis at computed tomography; 121 patients (10.3%) had sequelae and 36 (3.1%) died.

RESULTS

Non-steroidal anti-inflammatory drugs and tramadol were used more frequently in patients with the MAP whereas opioids and the association schedules were used more frequently in patients with the SAP (P<0.001). Gabexate mesilate was utilised in 831 out of 1173 patients (70.8%); in particular, gabexate mesilate was used in 70.6% patients with MAP and in 73.1% of those with SAP (P=0.521). The duration of the drug administration was significantly shorter in those having MAP than in those having the SAP (P<0.001). The antibiotics most frequently used for the prophylaxis against infection from pancreatic necrosis (43.1%) were carbapenems. Only a small number of patients received enteral nutrition (4.7%). Endoscopic retrograde cholangiopancreatography was carried out in 344 of the 1173 patients (29.3%). Surgery was performed in 48 with SAP (19 had elective biliary surgery and 29 had pancreatic surgery).

CONCLUSIONS

The results of this survey indicate a lack of compliance with the guidelines which regard the indications mainly for interventional endoscopy and surgery.

Prospective multicentre survey on acute pancreatitis in Italy (ProInf-AISP): results on 1005 patients

BACKGROUND AND AIM

Till now, no Italian studies providing information on acute pancreatitis have been published. The aim of this study was to evaluate the epidemiological and clinical characteristics of acute pancreatitis in Italy.

MATERIALS AND METHODS

The study involved 37 Italian centres distributed homogeneously throughout the entire national territory and prospectively collected epidemiological, anamnestic, laboratory, radiological, therapeutic (pharmacological, endoscopic and surgical) data, relevant to each individual case of acute pancreatitis consecutively observed during the period from September 1996 to June 2000.

RESULTS

One thousand two hundred and six case report forms were collected, but 201 patients (16.6%) were subsequently eliminated from the final analysis. We therefore studied 1005 patients, 533 (53%) males and 472 (47%) females, mean age 59.6 +/- 20 years. On the basis of the Atlanta classification of acute pancreatitis, 753 patients of the 1005 cases analysed (75%) were mild and 252 patients (25%) severe. The aetiology was biliary in 60% of the patients, related to alcohol abuse in 8.5%, while in 21% of the cases it could not be identified. Over 80% of the patients (83%) were admitted to hospital within 24 h from the onset of clinical symptoms, while only 6% were admitted after 48 h. In particular, 65% of the patients were admitted to hospital within the first 12 h. Antibiotics were used in 85% of the severe and 75% of mild forms. Endoscopic therapy was carried out in 65% of the severe cases, but only in 40% it was carried out prior to 72 h. Eighty-five patients (8.5% of the total, 34% of the severe forms) underwent surgical intervention: 20% on the first day, 38.5% within the fourth day, and the remaining (41.5% of the cases) later on for infected necrosis. The mean duration of hospitalisation for patients with mild pancreatitis was 13 +/- 8 days, while for the severe disease it was of 30 +/- 14 days. The overall mortality rate was 5%, 17% in severe and 1.5% in mild pancreatitis.

CONCLUSIONS

Acute pancreatitis in Italy is more commonly a mild disease with a biliary aetiology. The treatment of the disease is not optimal and, on the basis of these data, needs to be standardised. Despite this, the overall mortality rate is low (5%).

Neurofibromatosis-1 and ampullary gangliocytic paraganglioma causing biliary and pancreatic obstruction

Gangliocytic paragangliomas (GPs) are exceedingly rare tumors that arise in close proximity of the papilla of Vater. Nevertheless, jaundice is an uncommon presenting symptom, reported in only 3 of 125 cases described in the literature to date, with gastrointestinal bleeding being more common. Association between GPs and neurofibromatosis 1 (NF-1), described in two patients, may be more than casual, being the frequency in normal population 1:3,000. We report an additional case of this association, presenting for the first time with simultaneous obstruction of the common biliary duct, and of the main pancreatic duct. Previous cases of GPs with jaundice and/or NF-1 are reviewed, and updating of the histogenesis presented.

Intraluminal duodenal diverticulum causing acute pancreatitis: CT scan diagnosis and review of the literature

BACKGROUND

Intraluminal duodenal diverticulum is a rare congenital anomaly. First described by Boyd in 1845, no more than 100 cases have been reported up to now: only 17 are associated with acute pancreatitis.

METHODS

A new case of intraluminal duodenal diverticulum with acute pancreatitis is reported and the literature about this association reviewed.

RESULTS

The diagnosis was made by helical CT scan. The pathogenesis of pancreatitis was possibly due to a pure duodenal content reflux through the papilla of Vater. The patient was successfully treated by surgery.

CONCLUSIONS

Intraluminal duodenal diverticulum is a rare but curable cause of pancreatitis, usually affecting young people. We describe, for the first time, its unusual helical CT imaging with two-dimensional reformations.

[Neoplasms of the head and tail of the pancreas]

The majority of cancer of the pancreas-about 70%-arise in the head of the gland and only 20-30% in the body and tail. The latter usually have grown to a large size by the diagnosis is made, due to absence of symptoms. Jaundice is seldom present and pain is the main symptom. We reviewed recent literature, which present homogeneous data. Cancers of the body and tail are rarely resectable, with 30% morbidity and a much lower morbidity-0-10%-in specialized centres. If the lesion is localized and the patient in good physical condition, a laparotomy can be performed, with or without a preliminary laparoscopy to detect distant metastases. Distal pancreatectomy and splenectomy is the treatment of choice. In our experience, only tumors different from ductal adenocarcinoma have a good prognosis. Pain can be managed by surgical or chemical splanchnicectomy and, in selected cases, thoracoscopically.

Effects of six-month administration of recombinant human growth hormone to healthy elderly subjects

In aging, both changes in body composition and a decrease in GH secretion are observed. While recombinant human GH (rhGH) therapy was shown to be effective in GH-deficient adults, its effects on normal aging are controversial. This study addressed the effects of six-month administration of low dosages of rhGH in a group of 5 healthy elderly subjects (age range 71-86 years). All subjects received 2 IU rhGH (Saizen, Serono) x 2/week s.c., which was approximately 0.03 mg/kg/week, and were examined before and 1, 3, and 6 months after the start of the therapy, as well as 3 months after therapy was suspended. Hormonal, metabolic and biochemical parameters, as well as bone density at the forearm level, body composition and muscle strength, assessed by isokinetic exercises, were evaluated at each scheduled visit. After the start of the therapy, there was an average 9 +/- 3% increase (median 8%) in IGF-I levels (IGF-I basal: 145.6 +/- 9 ng/mL, IGF-I peak: 176.0 +/- 10; p < 0.001). An increase in lean body weight, a decrease in fat (p < 0.05), and an improvement in muscle strength (p < 0.01) were recorded. No significant variation was observed in the metabolic parameters. During rhGH therapy, an increase in both bone resorption and formation parameters, and a slightly decreasing trend in bone density were noted. In conclusion, low dosages of rhGH in healthy elderly subjects seem to determine some physiological effects, such as a slight increase in IGF-I levels, which in turn may be responsible for the positive effects on body mass composition and muscle strength, without producing side effects. On the other hand, 6-month subcutaneous rhGH therapy at the dosage employed was unable to improve bone density.

[Potential and limitations of conservative surgery in the treatment of gastric stump cancer]

In the Italian population the risk of gastric stump cancer after surgery for peptic ulcer is increased after 20-30 years. Bearing in mind that further surgery has little curative chances, we examined the series seen at the Institute of General Surgery of the University of Milan (1983-1992) to investigate whether or not patients followed-up endoscopically have a better chance of cure after surgery. Although only 10 patients were available for evaluation, it was evident that patients found at endoscopic screening in stage 0 and I (UICC classification) had a good survival after surgery. Our results support the need of strict endoscopic follow-up of resected patients 20 or more years after surgery and the need of further investigations to establish whether or not resection is useful and safe for early lesions.

Inhibition of inflammatory angiogenesis in rats by loco-regional administration of hydrocortisone and protamine

We have studied the antiangiogenetic effects of hydrocortisone and protamine given intra-arterially. The cornea of male, Sprague-Dawley rats were cauterized with silver nitrate. The following treatments were given: 30 micrograms hydrocortisone topical (t.p.), b.i.d., 50 mg/kg/day intraperitoneally (i.p.) or intra-arterially (i.a.), 10 mg/kg/day protamine i.p. or i.a. Saline was administered to the control groups. In separate experiments we also evaluated the anti-inflammatory effects of hydrocortisone, i.p., on the cauterized corneas. Five days after cauterization, the animals were killed, exsanguinated and India ink was injected to show the network of neovessels. The percentage area of the cornea covered by neovessels was measured morphometrically and evaluated statistically. Hydrocortisone t.p. (-84%), i.a. (-60%) and protamine i.a. (-44%) significantly inhibited angiogenesis in the cauterized cornea. Either drugs, i.p., had any antiangiogenetic effects, but hydrocortisone significantly reduced cell infiltration of the corneas. The results suggest that locoregional administration of antiangiogenetic drugs might be clinically useful.

Effects of ischaemia and reperfusion on liver regeneration in rats

OBJECTIVE

To assess the effects of oxygen free radicals on liver regeneration in rats after 80% hepatectomy.

DESIGN

Open laboratory study.

SETTING

Institute of Biomedical Sciences, University of Milan, Italy.

MATERIAL

Female Sprague-Dawley rats.

INTERVENTIONS

After laparotomy 122 rats had ischaemia induced by clamping of the portal vein and hepatic artery, and 93 rats had manipulation of the vessels only. They were then allowed to recover before 80% hepatectomy was done. Absolute controls (n = 16) did not have a laparotomy. Mortality was recorded, and surviving rats were killed one, three, five, and seven days after operation. A further 10 rats had 80% hepatectomies and then underwent a 10 minute period of ischaemia 24 hours later. These animals were killed after three days. In yet more experiments 38 rats underwent 80% hepatectomies and were then divided into four groups: 8 were given allopurinol 50 mg/kg/day starting three days before operation; 8 were given superoxide dismutase 4.16 mg/kg intraperitoneally 30 minutes before induction of ischaemia; 12 were given verapamil 0.1 mg/kg 30 minutes before induction of ischaemia; and 10 were given saline (controls).

MAIN OUTCOME MEASURES

Incorporation of tritiated thymidine into DNA, differences in liver weights, and lipid peroxide concentrations.

RESULTS

43 rats died after ischaemia/reperfusion and 19 after hepatectomy alone. Ischaemia/reperfusion caused a significant reduction in the incorporation of tritiated thymidine into DNA 24 hours after hepatectomy (p < 0.01), and significant inhibition of recovery of liver weight three (p < 0.01) and five (p < 0.05) days after hepatectomy. These effects were associated with high lipid peroxide concentrations at three days. Allopurinol (p < 0.01, p < 0.05), superoxide dismutase (p < 0.01, p < 0.01) and verapamil (p < 0.01, N.S.) reduced the effects of ischaemia/reperfusion on liver weights or lipid peroxide concentrations three days after hepatectomy.

CONCLUSION

A 10 minute period of ischaemia followed by reperfusion temporarily reduces liver regeneration after 80% hepatectomy in rats.

Effects of intranasal neostigmine on oesophageal motility in man

The effects of intranasally administered neostigmine on oesophageal peristalsis and lower oesophageal sphincter tone were investigated in 21 healthy volunteers. After 30 min of basal recording of oesophageal tracings, neostigmine (3 or 5.4 mg) or the inert vehicle were given. The oesophageal recording was continued for 45-60 min after administration. Neostigmine increased the amplitude and duration of the peristaltic waves without significantly affecting conduction. Lower oesophageal sphincter tone was also increased but post-swallowing relaxation was normal. At the highest dose, the effects of neostigmine lasted 45 min or more. There were no side effects and the heart rate was only slightly slowed. The results suggest that intranasal administration of neostigmine might be clinically useful for stimulation of upper gastrointestinal tract peristalsis.

Effects of autonomic nervous system on gastric damage by ethanol in the rat

To study whether or not the autonomic nervous system influences the defense mechanisms of the gastric mucosa, groups of Sprague-Dawley rats were given stimulants and inhibitors of the different components of the vagus and celiac nerves before administration of absolute or 70% w/v ethanol. The effects of vagotomy and sympathectomy on "adaptive cytoprotection" were studied, as were the effects of blocking the muscarinic receptors and stimulation of beta-adrenergic receptors. We found that: (1) cholinomimetic agents and norepinephrine make the damage caused by 70% ethanol worse; (2) atropine is the only agent that fully protects against absolute ethanol; (3) vagotomy and sympathectomy abolish the effects of atropine and adaptive cytoprotection; and (4) beta-adrenergic stimulation replaces conditions that allow adaptive cytoprotection and the protection by anticholinergics. These results suggest that two different reflexes are triggered by ethanol: when low concentrations are given, the beta-adrenergic-mediated effect is prevalent, with protection of the mucosa; when high concentrations are given, the cholinergic-mediated effect is prevalent with damage of the mucosa.