Computing of temporal information in spiking neural networks with ReRAM synapses

Resistive switching random-access memory (ReRAM) is a two-terminal device based on ion migration to induce resistance switching between a high resistance state (HRS) and a low resistance state (LRS). ReRAM is considered one of the most promising technologies for artificial synapses in brain-inspired neuromorphic computing systems. However, there is still a lack of general understanding about how to develop such a gestalt system to imitate and compete with the brain's functionality and efficiency. Spiking neural networks (SNNs) are well suited to describe the complex spatiotemporal processing inside the brain, where the energy efficiency of computation mostly relies on the spike carrying information about both space (which neuron fires) and time (when a neuron fires). This work addresses the methodology and implementation of a neuromorphic SNN system to compute the temporal information among neural spikes using ReRAM synapses capable of spike-timing dependent plasticity (STDP). The learning and recognition of spatiotemporal spike sequences are experimentally demonstrated. Our simulation study shows that it is possible to construct a multi-layer spatiotemporal computing network. Spatiotemporal computing also enables learning and detection of the trace of moving objects and mimicking of the hierarchy structure of the biological visual cortex adopting temporal-coding for fast recognition.

Memristive neural network for on-line learning and tracking with brain-inspired spike timing dependent plasticity

Brain-inspired computation can revolutionize information technology by introducing machines capable of recognizing patterns (images, speech, video) and interacting with the external world in a cognitive, humanlike way. Achieving this goal requires first to gain a detailed understanding of the brain operation, and second to identify a scalable microelectronic technology capable of reproducing some of the inherent functions of the human brain, such as the high synaptic connectivity (~10⁴) and the peculiar time-dependent synaptic plasticity. Here we demonstrate unsupervised learning and tracking in a spiking neural network with memristive synapses, where synaptic weights are updated via brain-inspired spike timing dependent plasticity (STDP). The synaptic conductance is updated by the local time-dependent superposition of pre- and post-synaptic spikes within a hybrid one-transistor/one-resistor (1T1R) memristive synapse. Only 2 synaptic states, namely the low resistance state (LRS) and the high resistance state (HRS), are sufficient to learn and recognize patterns. Unsupervised learning of a static pattern and tracking of a dynamic pattern of up to 4 × 4 pixels are demonstrated, paving the way for intelligent hardware technology with up-scaled memristive neural networks.

Phlegmasia caerulea dolens of the left leg due to deep vein compression by giant mesenteric cyst: contribution of the immediate drainage of the cyst to the rapid improvement of symptoms and complete recovery

The first description of phlegmasia caerulea dolens of the leg due to deep vein compression by a giant mesenteric cyst is presented. In particular, the authors stress the role of the drainage of the cystic mass, performed as an emergency procedure, in the rapid improvement of symptoms, prevention of complications and achievement of definitive recovery. On the basis of such unusual case, a wide review of the literature on this subject is reported, aiming to stress the most crucial aspects regarding aetiology, clinical features, complications, therapy and prognosis of this disease.

[Laparoscopic incisional hernia repair as first therapeutic choice]

AIM

Incisional hernias are one of the most frequent complications of open abdominal surgery. Historically, the best results have been obtained with the open rives-stoppa approach. This is done by fixing a large piece of prosthetic mesh behind the rectus muscle. Laparoscopic approach allows similar mesh placement with minimal dissection and lower recurrence rate compared to the open mesh repair.

METHODS

Between October 2001 to September 2003, 75 consecutive patients were scheduled to undergo laparoscopic incisional hernia repair with ePTFE mesh (Gore-Tex Dualmesh Plus). Postoperative complications were recorded and analysed.

RESULTS

Most were obese affected by multiple wall defects Conversion to open surgery was required in 1 case Postoperative complications occurred 13.3%. Recurrence occurred in one only case.

CONCLUSIONS

The key to the success of this procedure is avoidance of complications. The laparoscopic approach is safe, effective and relatively complication-free option in the management of patients presenting with a first time or recurrent incisional hernia and recommended as the treatment of choice.

[Surgical treatment of carcinoma of the left colon and rectum as an emergency. A new method for assessing operative risk]

BACKGROUND/AIMS

The surgical treatment of the left colon and rectal cancer emergencies is still controversial. In our opinion the choices to be based on the general health status of the patient.

METHODOLOGY

The authors analysed a series of 63 patients submitted to immediate resection and anastomosis.

RESULTS

Factors significantly related to short term results were chronic heart disease, low albumin serum levels, and colonic perforation. The presence of a diverting colostomy did not provide a protective factor against anastomotic dehiscence. We constructed a Colorectal Tumours Emergencies Score made of the identified four factors in which the score of each factor is the approximated odds ratio (chronic renal failure 7 points, low albumin serum levels 6 points, heart disease 5 points, colon perforation 4 points). Each patient was classified as Low Risk (CTES < 4), Moderate Risk (CTES 4-12), High Risk (CTES > 12), mortality and morbidity being 4% and 20%, 19.3% and 61.3%, 88.9% and 88.9% respectively.

CONCLUSIONS

High risk patients may undergo a staged procedure. Moderate risk patients may be treated by immediate resection of the tumor, without anastomosis. Immediate resection and anastomosis may be reserved to low risk patients.

TIPS (transjugular intrahepatic portosystemic shunt): state of art and personal experience

After a brief historical view, we describe the basic technique currently used to create percutaneous portosystemic shunt. Between September 1992 and March 1995, TIPS was achieved in 50 out of 52 patients; main indications included bleeding from esophageal or gastric varices and refractory ascites. The mean portal pressure reduction was 14.9 mmHg and the mean residual portosystemic gradient was 10.5 mmHg. The average follow-up time was 11.8 months; in this period the overall mortality rate was 28%, while rebleeding occurred in 8 patients and new onsets of encephalopathy occurred in 4 cases. The major problems were due to shunt related complications observed in 46% of the patients; close follow-up and reintervention are required to keep the shunt previous. TIPS, developed ad an alternative to surgery and endoscopic sclerotherapy, is an effective and relatively safe procedure for the treatment of symptomatic portal hypertensive patient.

Transjugular intrahepatic portosystemic shunt versus endoscopic sclerotherapy for the prevention of variceal bleeding in cirrhosis: a randomized multicenter trial. Gruppo Italiano Studio TIPS (G.I.S.T.)

Transjugular intrahepatic portosystemic shunt (TIPS), a new technique for the treatment of portal hypertension, has been successful in preliminary studies to treat acute variceal hemorrhage and to prevent variceal rebleeding. The purpose of this multicenter, randomized controlled trial is to compare the efficacy of TIPS with that of endoscopic sclerotherapy in the prevention of variceal rebleeding in cirrhosis. Eighty-one cirrhotic patients, with endoscopically proven variceal bleeding, were randomized to either TIPS (38 patients) or endoscopic sclerotherapy (43 patients). Randomization was stratified according to the following: if bleeding occurred < 1 week (stratum I); if bleeding occurred 1 to 6 weeks (stratum II); and if bleeding occurred 6 weeks to 6 months (stratum III) before enrollment. Follow-up included clinical, biochemical, Doppler Ultrasound, and endoscopic examinations every 6 months. During a mean follow-up of 17.7 months, 51% of the patients treated with sclerotherapy and 24% of those treated with TIPS rebled (P = .011). Mortality was 19% in sclerotherapy patients and 24% in TIPS patients (P = .50). Hepatic encephalopathy (HE) developed in 26% and 55%, respectively (P = .006). A separate analysis of the three strata showed that TIPS was significantly more effective than sclerotherapy (P = .026) in preventing rebleeding only in stratum I patients. TIPS is significantly better than sclerotherapy in preventing rebleeding only when it is performed shortly after a variceal bleed; however, TIPS does not improve survival and is associated with a significantly higher incidence of HE. The overall performance of TIPS does not seem to justify the adoption of this technique as a first-choice treatment to prevent rebleeding from esophageal varices in cirrhotic patients.

Is the tantalum Strecker stent suitable for TIPS creation? Short- and mid-term results in 20 consecutive patients

PURPOSE

To assess the suitability of tantalum Strecker stents for transjugular intrahepatic portosystemic shunt (TIPS) creation.

METHODS

TIPS was performed with Strecker balloon-expandable stents in the first 20 patients of our series. A total of 26 prostheses were utilized (average 1.3 per patient).

RESULTS

Immediate technical success was achieved in all 20 cases. Nine patients (45%) died during follow-up. The overall average follow-up period was 18.9 months; the 11 survivors were followed for a mean period of 29.8 months. In 4 patients (20%) the stent dislodged towards the hepatic vein during withdrawal of the balloon catheter, and difficulties in recatheterizing the shunt for routine control portal phlebography were frequently encountered. Rebleeding occurred in 5 cases and aggravation of pre-existing encephalopathy occurred in 2 cases. Shunt occlusions or stenosis required further intervention in 4 and 9 patients, respectively.

CONCLUSION

In our opinion the tantalum Strecker stent is not particularly suitable for TIPS. Although it has evident advantages, such as high radiopacity and minimal shortening after deployment, the tendency of the device to dislodge and the difficulty in recatheterization during portal phlebography were important drawbacks. Furthermore, the atraumatic ends of the device did not seem to reduce shunt-related complications, which were comparable to those occurring with other types of stent.

Hepatic encephalopathy after transjugular intrahepatic portosystemic shunt. Incidence and risk factors

Forty-seven consecutive patients were prospectively evaluated to study the incidence of hepatic encephalopathy as well as modifications in the PSE index after TIPS. Various clinical, laboratory, and angiographic parameters were also recorded to identify risk factors for the development of post-TIPS hepatic encephalopathy (HE). Mean follow-up was 17 +/- 7 months. During follow-up, six patients died and one underwent transplantation. All other patients were followed for at least a year. Fifteen patients (32%) experienced 20 acute episodes of precipitated HE (hospitalization was necessary in 10 instances), and five patients (11%) presented a continuous alteration in mental status with frequent spontaneous exacerbation during follow-up. Both precipitated and spontaneous HE occurred more frequently during the first three months of follow-up. Moreover the PSE index was significantly worse than basal values one month after TIPS, thereafter returning to near basal values. HE was successfully treated in all patients but one who required a reduction in the stent/shunt diameter. Increasing age (>65 years) and low portacaval gradient (<10 mm Hg) were predictors of HE after TIPS. A gradual dilation of the stent/shunt should be performed to obtain a portacaval gradient >10 mm Hg to avoid an unacceptable rate of HE after TIPS.

Octreotide versus terlypressin in acute variceal hemorrhage in liver cirrhosis. Emergency control and prevention of early rebleeding

Sixty patients with endoscopically confirmed active variceal bleeding entered a randomized controlled clinical trial aimed at comparing the efficacy of octreotide vs. terlypressin in the control of acute variceal hemorrhage (period I, 24 h) and in the prevention of early rebleeding (period II, 6 days). Of the sixty 30 received octreotide (period I, 100 micrograms bolus followed by continuous intravenous infusion at 25 micrograms/h; period II, 100 micrograms t.i.d. subcutaneously), and 30 received terlypressin (period I, 2 mg intravenous bolus every 4 h; period II, 2nd day, 2 mg every 6 h; from 3th to 7th days, 1 mg every 6 h). Control of bleeding was achieved in 23 (76.6%) patients receiving octreotide and in 16 (53%) treated with terlypressin (NS); none of these patients suffered rebleeding during treatment. No significant difference in mortality was observed between the two groups during the hospitalization period. Complications due to therapy were lower with octreotide than with terlypressin (P < 0.01). Under the same effectiveness conditions the cost/benefit ratio must be taken into account.

Oral isosorbide-5-mononitrate reduces the rebleeding rate during the course of injection sclerotherapy for esophageal varices

A double-blind, multicenter trial was carried out to assess the effectiveness of isosorbide-5-mononitrate in preventing recurrent variceal hemorrhage during the course of endoscopic sclerotherapy. Seventy-six patients with their first bleeding episode from esophageal varices were randomly allocated, after initial control of hemorrhage, to groups receiving either 50 mg/day oral isosorbide-5-mononitrate retard (37 patients) or an identical placebo (39 patients) until variceal eradication. Sclerotherapy was performed at weekly intervals, and varices were intra- and para-variceally injected with 1% polidocanol until eradication. If rebleeding occurred, additional sclerotherapy was performed. Four (10.8%) patients rebled in the isosorbide group, compared with 15 (38.4%) in the placebo group (p = 0.01). The total number of rebleeding episodes was also significantly lower in the isosorbide group (5 versus 19, p = 0.043), whereas comparison between major versus minor rebleedings was not significant. The median transfusion requirement per bleeding episode was not significantly different in the two groups, although the cumulative number of blood units transfused was over threefold greater (22 versus 70) in the placebo group. Two (5.4%) deaths occurred among isosorbide-treated patients and nine (17.9%) among placebo patients (NS). The number of sclerotherapy sessions and the time required to obtain variceal eradication were also comparable in the two groups. Finally, the nitrovasodilator was well tolerated, requiring withdrawal for severe headache in only one patient. In conclusion, isosorbide-5-mononitrate reduces the rebleeding rate and the number of rebleeding episodes before variceal eradication in patients treated with sclerotherapy.

Comparative analysis of torasemide and furosemide in liver cirrhosis

This review concerns studies of the comparative efficacy and safety of torasemide and furosemide in patients with cirrhosis of the liver complicated by ascites and oedema. The short-term trials reviewed indicated that in patients who had failed to respond with adequate diuresis and loss of body weight and ascites to bed rest, restricted salt and water intake and spironolactone, torasemide had a longer duration of action than furosemide and resulted in a greater urinary excretion of salt and water and greater loss of body weight. Torasemide also had less effect than furosemide on urinary potassium excretion and unlike furosemide did not increase the fractional excretion of magnesium or phosphate or the blood ammonia concentration. Two longer term trials in similar patients with decompensated hepatic cirrhosis confirm the results of the shorter term studies. These studies, albeit each in relatively small numbers of patients, confirm the ability of torasemide to enhance diuresis, free water clearance and fractional excretion of sodium and chloride, resulting in loss of body weight and mobilization of ascites in patients with decompensated hepatic cirrhosis. In these patients, the relatively small increase in urinary excretion of potassium, induced by torasemide without any marked effect on renal function or on the plasma neurohormonal profile, enhances its potential safety.

Torasemide versus furosemide in cirrhosis: a long-term, double-blind, randomized clinical study

The effects of long-term therapy (70 days) with torasemide (20 mg/day), a new loop diuretic, were compared with those of furosemide (50 mg/day) in a randomized double-blind trial. Both drugs were administered in association with spironolactone (200 mg/day) in 28 nonazotemic cirrhotic patients with controlled ascites. The treatments did not modify creatinine clearance and exhibited a similar effect on body weight, urinary volume, and fractional excretion of uric acid, sodium, and chloride. The effect of torasemide on fractional potassium excretion was lower than that of furosemide. Torasemide showed higher sparing effect than furosemide on calcium, inorganic phosphate, and magnesium excretion and stronger action on free water clearance. No changes in serum parameters were induced by either treatment. Two episodes of hepatic encephalopathy occurred in the torasemide group. In view of its effects on sodium and water excretion and on other urinary parameters, torasemide can represent an alternative tool for the long-term treatment of ascites.

[The value of ultrasonography in benign breast diseases]

In recent years breast scans have been widely used for the precise diagnosis of breast cancer. However, the value of this diagnostic tool is debatable in comparison to mammography in women of a childbearing age who often present a dense youthful breast. The role of clinical examination as a screening process is also examined. In the light of these findings the Authors evaluated the role played by ultrasonography in breast cancer, and in particular benign breast tumours, in a group of outpatients attending the clinic. The technique used was relatively simple: the scan in the department used for gynecological and obstetrical ultrasonography was fitted with a 5 MHz probe and was used to perform all the scans. In addition, a Kiteco space maintainer was used for ultrasonography of soft tissue. Scans were performed at a distance of 0.5 cm. The Authors examined 107 patients with benign breast tumours using ultrasonography. They evaluated the morphology, dimensions, edges and internal echo-structure of pathological formations and adjacent areas. The value of breast ultrasonography emerges from an analysis of the results both in the study of the glandular structure and in the differentiation between cystic and solid type lesions which are not always diagnosed during clinical examination. A total of 59 fibroadenoma, 44 cysts, 2 lipoma and 2 phylloids were diagnosed. Fibroadenomas had smooth edges in 98.4% of cases and were lobulate in 1.6%. In 100% of cases the fibroadenomas diagnosed presented fine internal homogeneous echoes with a lower echogenicity than that of surrounding glandular tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

[Spontaneous bacterial peritonitis during liver cirrhosis: the clinical findings and therapeutic considerations]

Among 1211 consecutive patients admitted to hospital for liver cirrhosis, 625 (51.6%) had ascites. Forty-four of them (7%) had ascitic infection. Thirty-four cases (5.4%) of spontaneous bacterial peritonitis (SBP) and 10 cases (1.6%) of culture-negative neutrocytic ascites (CNNA) were diagnosed. The infecting organism was most likely Gram-negative of enteric origin (80%), CNNA mortality (30%) was lower than that of SBP (47%). High mortality suggests to treat patients affected by either SBP or CNNA with antibiotics.

[Research on the understanding of the relation between patient, gynecologist and breast disease]

The aim of our work was to identify the most important aspects of the relationship between gynecologist and patient who presents himself during our observation because of breast pathology. In order to evaluate all that said above we asked patients to compile a questionnaire characterized by different questions. The results obtained were very satisfactory and at the same time they lead us to a greater engagement towards the prevention of breast neoplasia, especially for those women predisposed to such disease.

Fine specificity of the human T-cell response to the hepatitis B virus preS1 antigen

The T-cell response to hepatitis B virus envelope antigens was studied in 11 hepatitis B vaccine recipients; 7 were selected to analyze the fine specificity of the T-cell response to the preS1 antigen. Four distinct T-cell epitopes were identified by peripheral blood lymphomononuclear cell stimulation with a panel of short synthetic peptides covering the preS1 sequence. The immunodominance of the preS1 epitopes included within peptides 21-30 and 29-48 was shown by their capacity to restimulate an HLA class II restricted proliferative response of T cells primed with the whole preS1 antigen. Conversely, peptide-specific T cells selected by peripheral blood lymphomononuclear cell stimulation with peptides 21-30 and 29-48 were able to recognize the native preS1 molecule, confirming that these epitopes are actually generated by the intracellular processing of preS1. Finally, amino acid residues essential for T-cell activation by peptide 21-30 were identified using 10 analogues of the stimulatory peptide containing single alanine substitutions. These results may be relevant to the design of efficient synthetic vaccines against hepatitis B virus infection.

Short-term oral zinc supplementation does not improve chronic hepatic encephalopathy. Results of a double-blind crossover trial

The effect of short-term oral zinc supplementation (zinc sulfate 600 mg/day) on hepatic encephalopathy, was assessed in a double-blind, crossover trial. Fifteen cirrhotic patients with stable, chronic hepatic encephalopathy were randomized to receive either oral zinc or a placebo for 10 days. Following a two-week washout period, these were crossed over to the alternate treatment. Conn's index, which comprises the evaluation of the mental state, asterixis, number connection test, EEG record, and plasma ammonia, was used to score the degree of hepatic encephalopathy, both at the beginning and end of each treatment period. Serum zinc was significantly raised after oral zinc administration and reached the levels observed in cirrhotics without hepatic encephalopathy. Despite this, however, no modification in the parameters included in Conn's index were observed. In conclusion, this study failed to confirm that short-term oral zinc supplementation improves chronic hepatic encephalopathy.

Insulin and glucagon levels in fulminant hepatic failure in man

The behavior of insulin and glucagon and related metabolic substrates was assayed in plasma of patients with fulminant hepatic failure. All 12 subjects were provided the same nutritional support. High levels of insulin and glucagon were present at all times and no difference was observed between surviving patients (four) and those who died (8). Elevated values for branched-chain and aromatic amino acids as well as alanine were present. Statistically significant lower levels of aromatic amino acids and consequently a greater branched chain-aromatic amino acid ratio was found in surviving vs nonsurviving patients. A significantly greater level of alpha-fetoprotein was found in patients who survived as compared to those who died.

Rifaximin versus neomycin on hyperammoniemia in chronic portal systemic encephalopathy of cirrhotics. A double-blind, randomized trial

Preliminary data suggest that rifaximin a new non-absorbable rifamycin-derivate, has beneficial effects on chronic portal systemic encephalopathy (PSE). To compare the efficacy and safety of rifaximin vs neomycin in the treatment of the hyperammoniemic state of PSE, 30 cirrhotic patients with grade I to III of PSE were randomly allocated to one of two groups: group A (15 patients) receiving rifaximin (400 mg/8h) and group B (15 patients) neomycin (1gr/8h). The duration of treatment was 21 consecutive days. Age, sex, hepatic and renal function, level of PSE, EEG and number connection test were similar in both groups. A significant decrease in blood ammonia levels was observed at the end of the treatment period in both groups; moreover rifaximin produced an earlier reduction of blood ammonia levels. The neuropsychic syndrome related to the PSE improved in both groups without significant difference. No side effects attributable to therapy were observed in the rifaximin group. These results indicate that, rifaximin is at least as effective as neomycin in the achievement and maintenance of low blood ammonia levels in cirrhotics with chronic PSE.

Hepatic encephalopathy: lack of changes of gamma-aminobutyric acid content in plasma and cerebrospinal fluid

The aim of the study was to verify the role of gamma-aminobutyric acid in the pathogenesis of hepatic encephalopathy occurring in cirrhotic patients by attempting to correlate plasma and cerebrospinal fluid content of authentic gamma-aminobutyric acid with the neurological manifestations of hepatic encephalopathy. For this purpose, plasma and cerebrospinal fluid gamma-aminobutyric acid levels were measured by means of mass fragmentography in 17 cirrhotic patients with hepatic encephalopathy and in 6 cirrhotics without neurological symptoms. Moreover, in all patients, a second sample was obtained during the clinical course of hepatic encephalopathy. The mean plasma and cerebrospinal fluid gamma-aminobutyric acid levels were not different in patients with or without hepatic encephalopathy and did not change during the evolution of the neurological symptoms. The lack of changes in the gamma-aminobutyric acid content in plasma and cerebrospinal fluid during hepatic encephalopathy is in contrast with the hypothesized importance of increased entry into the brain of gamma-aminobutyric acid in the pathogenesis of hepatic encephalopathy.

Cholinergic mediation of growth hormone secretion induced by thyrotropin-releasing hormone in cirrhotic patients

In order to evaluate the possible involvement of muscarinic cholinergic receptors in the GH response to TRH in patients with liver cirrhosis, 8 males with post-hepatitic cirrhosis and 11 males with post-alcoholic cirrhosis were primed with the anticholinergic agent pirenzepine and tested with TRH. In addition, 10 male patients affected by piecemeal necrosis were tested in a similar manner. High basal concentrations of GH were found in all groups. None of the patients with piecemeal necrosis responded to TRH, whereas in patients with post-hepatitic and in post-alcoholic cirrhosis, TRH induced a significant rise in GH levels. The priming with pirenzepine (40 mg given iv 10 min before TRH) completely blocked the TRH-induced GH increase, but did not affect the TRH-induced TSH release. These data suggest that a muscarinic cholinergic pathway is involved in the anomalous response of GH to TRH in patients with liver cirrhosis. The lack of effect of pirenzepine on the TRH-stimulated TSH release suggests that the muscarinic cholinergic mediation is peculiar for the effect of TRH on GH secretion.

Vasoactive factors in the mechanism of renal sodium handling in cirrhotics: the effect of acute plasma expansion

Twenty cirrhotic patients with ascites, divided into two groups of 10 each, according to their daily urinary sodium excretion (sodium retainers and sodium excretors) and given a diet of 75 mEq of sodium daily, underwent acute plasma volume expansion with 1,000 ml of 10% dextran in saline, infused through a catheter located in the right atrium. Even if a significant increase in sodium excretion was observed in both groups (p less than 0.001 in sodium excretors and p less than 0.05 in sodium retainers), plasma expansion did not reverse sodium retention in sodium retainers. A significant increase in creatinine clearance was found only in sodium retainers (p less than 0.02). Basal plasma renin activity and plasma aldosterone were elevated only in a few patients of both groups. The renin-angiotensin-aldosterone system was highly responsive to plasma expansion. Sodium retainers, who showed an ineffective natriuretic response after expansion, were able to suppress both plasma renin activity and plasma aldosterone in an analogous manner to the sodium-excreting group. This result lends strong support to the concept that the elevated aldosterone level in cirrhosis is not the major determinant of sodium retention. The kallikrein-kinin system was responsive to volume stimulus, since a decrease in kallikrein excretion was noted. It was significant in sodium retainers (p less than 0.05). Plasma PGE1,2 levels were significantly higher in sodium retainers than in controls. This may suggest that there is an activation of the intrarenal prostaglandin system, which could play a protective role against renal ischaemia. After volume expansion, PGE1,2 increased, but not significantly. Octopamine appeared unrelated to sodium excretion and unresponsive to volume stimulus. Endotoxins did not seem to be involved in renal sodium handling. Plasma volume expansion seemed effective in inducing a reduction of vasoconstrictor and sodium-retaining factors, such as the renin-angiotensin-aldosterone system. It is possible to suggest that volume expansion could increase PGE1,2. Plasma volume expansion produced different rates of sodium excretion in the two groups of patients and this suggests that impaired sodium handling in cirrhosis could, to some extent, be independent of effective plasma volume.

Negative nitrogen balance in cirrhotics. (A correct therapeutic approach)

The aims of this study were: 1. the assessment of the nitrogen balance (NB) in both compensated and encephalopathic cirrhotics, 2. the evaluation of the efficacy of a new therapeutic approach: amino acid solutions enriched with branched chain (BCAA) but poor in aromatic (AAA) amino acids. Solutions containing only BCAA were also employed: 42 cirrhotics were divided into the following groups: 1st group (26 cases), cirrhosis without hepatic encephalopathy (HE); 2nd group (16 cases), cirrhosis with HE. Six patients (23%) in the 1st group showed a positive NB at the beginning; 20 (77%) were negative; 18 of them were fed an oral diet (0.8 g protein/kg/day; 35 cal/kg/day) as a result of which they were brought into a positive NB within 5 days (from - 7.38 +/- 0.95 to + 3.67 +/- 0.46 g N/24 h). In two cases the diet failed to give a positive NB, so it was replaced by a BCAA enriched solution infusion (NB raised from - 1.0 +/- 5.4 g N/24 h). Patients in the 2nd group were put on total parenteral nutrition (TPN); two cases receiving glucose alone achieved a positive NB only when BCAA enriched solutions were added (from - 4.0 to + 3.0 g N/24 h). Four patients treated for 3 days with BCAA alone did not achieve a positive NB; in these cases likewise, BCAA enriched solutions were added in order to achieve a positive NB (from - 0.8 to + 4.2 g N/24 h); all 14 cases treated from the beginning with glucose + BCAA enriched solutions became positive, on average, within 5 days (from - 4.82 +/- 0.89 to + 3.15 +/- 0.61 g N/24 h). In addition to the NB, other parameters (blood ammonia, BCAA/AAA ratio, blood urea, electroencephalograms) and clinical symptoms were beneficially influenced by these solutions.

[Non-A, non-B hepatitis. Seroimmunological, epidemiological and clinical findings]

The characteristics of a third type of viral hepatitis, defined as non-A, non-B are analysed on the basis of the most recent reported findings. The problems of identification of the aetiological agent, its transmisibility in animals, the carrier condition, its possible evolution into chronic and fulminating forms, the effectiveness of immune globulin prophylaxis and epidemiological and clinical aspects are discussed. Reference is then made to the results of an epidemiological study of 293 patients with acute viral hepatitis, admitted to the Infectious Diseases Division of Parma Hospital. Diagnosis of non-A, non-B hepatitis was formulated, by exclusion, in 64 cases (21.8%). Intragroup studies pointed to an intermediate period of incubation and clinico-biochemical picture between A and B hepatitis the possible non-parenteral contagion route and possibilities of recurrence and development into chronic forms. Further information on hepatitis or on non-A, non-B hepatitis, can be provided by screenings based on antigen C demonstration (AgHC).