New Insights into Oxidative Stress and Inflammatory Response in Neurodegenerative Diseases

Oxidative stress (OS) and inflammation are two important and well-studied pathological hallmarks of neurodegenerative diseases (NDDs). Due to elevated oxygen consumption, the high presence of easily oxidizable polyunsaturated fatty acids and the weak antioxidant defenses, the brain is particularly vulnerable to oxidative injury. Uncertainty exists over whether these deficits contribute to the development of NDDs or are solely a consequence of neuronal degeneration. Furthermore, these two pathological hallmarks are linked, and it is known that OS can affect the inflammatory response. In this review, we will overview the last findings about these two pathways in the principal NDDs. Moreover, we will focus more in depth on amyotrophic lateral sclerosis (ALS) to understand how anti-inflammatory and antioxidants drugs have been used for the treatment of this still incurable motor neuron (MN) disease. Finally, we will analyze the principal past and actual clinical trials and the future perspectives in the study of these two pathological mechanisms.

[Mycobacterium bovis tuberculosis in a female patient with AIDS]

M. bovis, the agent of bovine tuberculosis, was in other times, the main ethiological agent of tuberculosis (TBC) in industrialized countries. At the moment, the human cases have become not very frequent, except in those countries where the illness is even endemic. In patients with immunodeficiency syndrome, it usually presents as a systemic illness. We present the case of a woman with AIDS and disseminated TBC caused by M. bovis. The isolated micobacteria turned out to be resistant to rifampin and pyrazinamide. She was treated with isoniazid, ethambutol and ofloxacin with good clinical evolution. This case turned out to be the first isolation of M. bovis in a patient with AIDS, in Muñiz hospital.

Serotonin inhibition of the NMDA receptor/nitric oxide/cyclic GMP pathway in human neocortex slices: involvement of 5-HT(2C) and 5-HT(1A) receptors

The NMDA receptor/nitric oxide (NO)/cyclic GMP pathway and its modulation by 5-hydroxytryptamine (5-HT) was studied in slices of neocortical samples obtained from patients undergoing neurosurgery. The cyclic GMP elevation produced by 100 microM NMDA was blocked by 100 microM of the NO synthase inhibitor N(G)-nitro-L-arginine (L-NOARG) or by 10 microM of the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3,-alpha] quinoxaline-1-one (ODQ). The NMDA effect was prevented by 5-HT or by the 5-HT(2) agonist (+/-)-1-(2, 5-dimethoxy-4-iodophenyl)-2-aminopropane ((+/-)-DOI; EC(50)=22 nM). The (+/-)-DOI inhibition was insensitive to the 5-HT(2A) receptor antagonist MDL 100907 or the 5-HT(2B) antagonist rauwolscine; it was largely prevented by 1 microM of the non-selective 5-HT(2C) antagonists mesulergine (5-HT(2A,B,C)), ketanserin (5-HT(2A,C)) or SB 200646A (5-HT(2B,C)); it was completely abolished by 0.1 microM of the selective 5-HT(2C) receptor antagonist SB 242084. The NMDA-induced cyclic GMP elevation also was potently inhibited by the selective 5-HT(2C) agonist RO 60-0175 and by the antidepressant trazodone, both added at 1 microM, in an SB 242084-sensitive manner. Finally, the 5-HT(1A) agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT; 1 microM) inhibited the NMDA-evoked cyclic GMP response, an effect blocked by the selective 5-HT(1A) receptor antagonist WAY 100635. In conclusion, the NMDA receptor/NO/cyclic GMP pathway in human neocortex slices can be potently inhibited by activation of 5-HT(2C) or 5-HT(1A) receptors.

[Hepatolithiasis and Caroli's disease in Argentina: results of a multicenter study]

The goal of this study was to determine the prevalence, epidemiology and clinical-therapeutical evolution of hepatolithiasis (HL) in Argentina. With this purpose a survey was conducted sending a questionnaire to ten referencial and interventional radiology centers in the country. Seven centers answered on time. In the last five years a total of 8,736 consecutive patients were examined for cholangiography (endoscopic retrograde cholangiography, PTC). A total of 5,920 (68%) were biliary lithiasis and 53 (0.9%, range 0.5-2.6%) of these were HL. In case of HL the diagnostic procedure was the ERCP in 68% of the cases, and the PTC in the remainder 32%. The patients with HL (53% females, mean age 52, range 23-85) clinically presented cholangitis (79%); pancreatitis (6%) and five (9.4%) showed evolution to a biliary cirrhosis. Associated diseases or abnormalities of the biliary tree were: biliary postsurgical strictures (BPS), 28%; Caroli's Syndrome, 20%; and choledocholithiasis, 28%. While a 9.4% presented a "biliary history" (that was defined as two or more episodes of biliary surgery) and a 5.7% lacked associated or predisposing diseases. Follow-up was lost in 23% of the cases and in 77% a follow up of 38 months (range 8-60) was observed with 4.8% mortality rate. The treatment was hepatobiliary surgery in 58% of the cases; endoscopic papillotomy in 17% and combined treatments that included extracorporeal shock wave lithotripsy and ursodeoxycholic acid (UDCA) in 15%. Four out of 53 cases (7.5%) received UDCA as the only successful therapy. HL is an entity with high biliary morbidity in 85% of the cases and development in to cirrhosis in 9.4%. When the diagnosis is made in the western world both BPS and Caroli must be discarded first. Combined treatments or only UDCA are new therapeutical alternative in the western world.

Activity of putative cognition enhancers in kynurenate test performed with human neocortex slices

Some cognition enhancers were previously shown to potently prevent antagonism of the N-methyl-D-aspartate (NMDA)-evoked release of norepinephrine (NE) brought about in slices of rat hippocampus by kynurenic acid, an endogenous NMDA receptor blocker. We have examined the impact of putative nootropic agents in the kynurenate test performed with slices of human cerebral cortex from patients undergoing neurosurgery. In slices of human neocortex, local application of NMDA evoked release of [3H]NE; the effect of NMDA was antagonized by several NMDA receptor antagonists, including kynurenic acid. The antagonism of the NMDA-evoked [3H]NE release produced by 300 microM kynurenate was potently (EC50 <10 microM) prevented by most of the nootropics tested, including aniracetam, oxiracetam, D-cycloserine, and the glutamate analog CR 2249 (but not its enantiomer CR 2361). Nicotine or tacrine (up to 10 microM) did not show any effect in the kynurenate test. Nicotine (30-100 microM) itself increased the release of [3H]NE; interestingly, the nicotine-evoked overflow was blocked not only by the nicotin receptor antagonist mecamylamine but also by NMDA receptor antagonists, suggesting an indirect mechanism mediated by glutamate/aspartate release. To conclude, the similarities between the data obtained here with human neocortex slices and those previously obtained in the rat indicate that the kynurenate test performed with rat brain slices may represent a useful biochemical assay to study cognition-enhancing drugs.

Removal of tumours of the orbital apex via a postero-lateral orbitotomy

BACKGROUND

The surgical management of pure apical tumours of the orbit may be problematic with traditional approaches. A postero-lateral approach, specifically designed for apical growths, provides a more favourable angle of vision through a relatively small bone opening.

METHODS

A series of 103 consecutive cases of intraorbital tumours, operated on in a community-based institution, was retrospectively reviewed. Out of this series, 8 patients, harbouring lesions located in the posterior intraconal space, underwent a postero-lateral orbitotomy. This approach, through a small opening on the orbital and temporal portions of the greater wing of the sphenoid, with the lesser sphenoidal wing, the orbital plate of the frontal bone, the lateral rim of the orbit being maintained intact, allowed adequate exposure of the orbital apex and successful extirpation of the tumours. In four patients the histological examination disclosed a cavernoma; the other patients had, respectively, a dermoid cyst, a lymphoma, a hemangiopericytoma and a metastatic melanoma.

RESULTS

No recurrences were observed in a follow-up period ranging from 1 to 7 years postoperatively (the patient with melanoma died 16 months after operation for systemic complications of her illness). One patient showed transient weakness of lateral rectus muscle due to surgical manipulation, which subsided in few months.

CONCLUSIONS

The postero-lateral orbitotomy represents a reliable alternative to other traditional surgical approaches when dealing with tumours of the orbital apex, providing excellent exposure of this region with a low rate of operative morbidity.

Longitudinal study of cerebral blood flow following early or delayed surgery for ruptured intracranial aneurysms

Out of a series of 43 cases operated on for ruptured intracranial aneurysms over a 12-month-period, 32 patients were followed up to 12 months postoperatively with repeated evaluations of cerebral blood flow, using the Xenon133 inhalation technique. No statistically significant differences in cerebral perfusion were detected between the subgroups of good-grade patients, who were submitted respectively to early, or delayed surgery. Depression of flow in the affected hemisphere of poor-grade patients was principally related to the preoperative occurrence of an intracerebral haematoma. The overall results were not consistent with the hypothesis that early surgical intervention results in long-lasting effects on the cerebral circulation.

[Reproducibility of the nyctohemeral cycle of blood pressure in patients with severe Parkinson disease]

Nineteen hospitalised, severe and treated parkinsonians (9 males, 10 females), stage IV and V of Hoehn and Yahr's classification, underwent 2 days running ambulatory blood pressure monitoring (ABPM) by ABPM 630 Nippon-Colin device, during a period of therapeutic stability. Hospitalisation allowed reproducibility of daily activity. Diurnal, nocturnal and 24 hours systolic blood pressure (SBP), as well as nocturnal and 24 hours diastolic blood pressure (DBP) were reproducible with a good correlation for each patient. Diurnal diastolic BP was the lone not reproducible value but had a good day 1-day 2 correlation. [table: see text]

CONCLUSION

Parkinsonian ABPM data, except diurnal DBP, are reproducible.

Subsequent bleeding from ruptured intracranial aneurysms treated by wrapping or coating: a review of the long-term results in 47 cases

Forty-seven patients, who underwent surgery over a 34-year period by the wrapping or coating of ruptured intracranial aneurysms, have been retrospectively evaluated. The following materials were used in the surgical procedures: muscle with gelatin sponge (7 cases), gauze (2 cases), oxidized cellulose with Biobond (28 cases), Histoacryl with gauze or fascia (10 cases). The patients were monitored for up to 37 years (mean, 13.7 +/- 8.2 yr). One or more subsequent bleedings occurred in eight patients (17%). Three patients had additional bleeding and died in the early postoperative phase (within 1 mo after surgery). In five patients, the subsequent bleeding occurred between 1 and 15 years postoperatively, with two fatalities. One patient experienced two recurrences. Therefore, the mortality rate for postoperative bleedings was 10.6% (five patients) in the whole series, and the incidence of early (within 1 mo after surgery) fatal bleedings was 6.4%. After the first month from the initial hemorrhage, the global risk of subsequent bleeding was 0.93%/yr. Among the nine patients whose aneurysms were wrapped with muscle, gelatin sponge, or gauze, four additional bleedings occurred, whereas four relapses were observed among the 38 cases treated by employing bioadhesive agents (P < 0.04; Fisher's exact test). The rate of further bleeding was higher (25%) in patients undergoing surgery in the premicrosurgical era compared with that (8.7%) recorded in patients treated by microsurgery (difference statistically not significant).

Toxic neuropathy after adenine arabinoside treatment in chronic HBsAg-positive liver disease

A 62-year-old woman with hepatitis-B-surface-antigen-positive hepatic cirrhosis presented with weakness and paresthesias over the distal part of the limbs in the course of adenine arabinoside 5'-monophosphate (ARA-AMP) treatment, and recovered spontaneously after several weeks of drug withdrawal. Electrophysiological and histological studies demonstrated axonal neuropathy. Although the patient received a relatively low total dose (120 mg/kg), her age and advanced liver disease may have played a role in the ARA-AMP neurotoxicity.

Diagnosis of pancreatic allograft rejection by measurement of urinary radioimmunoreactive insulin

The accurate, early, and sensitive diagnosis of pancreatic allograft rejection is one of the major problems in clinical pancreas transplantation today. Pancreaticocystotomy is a popular technique for pancreas transplantation that permits simple and frequent urinary chemistry examinations. In this experiment, 20 mongrel dogs with a bladder-drained pancreatic transplant had serial monitoring of urinary amylase (UA) and urinary insulin (UI). The mean UI in the nonrejection state was 9.6 +/- 12 mIU/L. In eight dogs varying degrees of rejection were documented by histopathology. All three animals having severe acute rejection had high levels of IU (all greater than 300-800 mIU/L). Of the five animals with mild-to-moderate rejection, all had significant UI elevations to greater than 100 mIU/L but none had elevations above 200 mIU/L (P less than 0.05 for all groups). Ten animals were treated with prednisone, Imuran, and cyclosporine (CsA), and five of these dogs had good graft function for greater than 14 days, during which the mean UI was extremely low (11 +/- 6.4 mIU/L, P less than 0.05). These values were not significantly different from the 0-14-day values for three pancreas autotransplants with bladder drainage (8.9 +/- 7.2 mIU/L, P less than 0.05). All rejections were preceded by significant rises of UI occurring two to five days prior to rejection. In seven animals, early graft dysfunction (1-4 days) developed, with total graft necrosis by five days. This graft injury was presumably caused by preservation damage or early vascular thrombosis and was associated with early (1-4 days) marked elevations of the UI (greater than 300 mIU/L). None of the animals with grafts surviving to rejection at seven days or more had these early severe elevations, and thus these early UI rises are pathognomonic of graft damage. In contrast, UA and lipase showed inconsistent association with rejection or early damage, although falls in UA generally occurred at or following the time of rejection. Marked daily variations in UA measurements were the most difficult aspect of UA monitoring. Serial electromagnetic flow probe studies of blood flow to the pancreas graft showed a good correlation between loss of blood flow and rises in UI associated with early graft injury. These results suggested that the UI assay gives a sensitive, early, accurate, and specific differential prediction of pancreas graft dysfunction. Specifically, the UI assay appears to be of value not only in the early differential diagnosis of graft injury and graft rejection, but also in the assessment of the severity of rejection.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of alpha-adrenergic stimulation and beta-adrenergic blockade on azygos blood flow and splanchnic haemodynamics in patients with cirrhosis

The effects of beta-blockade with propranolol and of alpha-adrenergic stimulation with methoxamine, a powerful alpha-agonist, on azygos blood flow and on systemic and hepatic haemodynamics were investigated in 26 cirrhotic patients with portal hypertension. Beta-adrenergic blockade with propranolol (n = 12), evidenced by a significant reduction of heart rate (-17 +/- 1%, P less than 0.001) and cardiac index (-17 +/- 2%, P less than 0.001), caused a mild but significant decrease of hepatic venous pressure gradient (-10 +/- 2%, P less than 0.05) and a marked fall of azygos venous blood flow (-31 +/- 5%, P less than 0.05). Alpha-adrenergic stimulation with methoxamine (n = 14), manifested by a significant increase of mean arterial pressure (19 +/- 2%, P less than 0.001), mimicked the effects of propranolol on hepatic venous pressure gradient (-10 +/- 4%, P less than 0.05) and cardiac index (-11 +/- 2%, P less than 0.001). However, azygos blood flow was not significantly reduced by methoxamine (0.7 +/- 0.1 vs 0.6 +/- 0.1 l/min). On the contrary, hepatic blood flow was significantly reduced by methoxamine (-19 +/- 4%, P less than 0.01) but not by propranolol (-7 +/- 7%, ns). Similarly, in 8 patients who received methoxamine after being beta-blocked by propranolol, azygos blood flow, that was markedly reduced by beta-blockade, did not experience a further reduction but increased slightly by alpha-adrenergic stimulation, while hepatic blood flow, that was not reduced by propranolol, decreased significantly during the subsequent methoxamine infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive measurement of the pressure of esophageal varices using an endoscopic gauge: comparison with measurements by variceal puncture in patients undergoing endoscopic sclerotherapy

Measurements of variceal pressure with a noninvasive endoscopic pressure gauge and by direct variceal puncture were performed in 20 cirrhotic patients with portal hypertension in the course of the first session of therapeutic sclerotherapy following an episode of variceal bleeding. Endoscopic gauge measurements of the pressure of esophageal varices gave similar values (15.5 +/- 2.7 mm Hg) than measurements by variceal puncture (15.4 +/- 2.4 mm Hg; not statistically significant), and there was a highly significant linear correlation between both measurements (r = 0.9, p less than 0.001). Azygos blood flow, that was markedly increased in these patients (852 +/- 399 ml per min), was directly related to variceal pressure (r = 0.73, p less than 0.01). Variceal pressure was significantly lower than portal pressure (18.8 +/- 5.0 mm Hg) (p less than 0.05), indicating that measurements of variceal pressure cannot substitute measurements of portal pressure. The study demonstrates that the noninvasive endoscopic gauge technique allows an accurate estimation of variceal pressure in patients with portal hypertension. This technique may provide additional useful information in the evaluation of portal hypertension as well as on the mechanism of variceal bleeding.

Pentoxifylline, albumin excretion rate and proteinuria in type I and type II diabetic patients with microproteinuria. Results of a short-term randomized study

An association between renal microvascular complications and hemorheological alterations has been suggested in diabetes mellitus. Therefore, a hemorheologic approach in the treatment of diabetic microproteinuria has been proposed. Eighty-two type I and type II diabetic patients with microproteinuria were randomized and assigned to two different protocols: protocol A, patients treated with pentoxifylline (Trental 400); protocol B, patients without hemorheologic treatment, in whom hypoglycemic therapy was just more strictly enforced. A significant improvement of the hemorheologic pattern and a significant marked reduction of albumin excretion rate and proteinuria was found in diabetic patients treated with pentoxifylline, independently of the degree of metabolic control. These results were readily achieved and were confirmed throughout the study. Moreover, these results were comparable to those obtained in diabetic patients of protocol B. Pentoxifylline might therefore be considered as the first useful therapeutic agent in the treatment of diabetic microproteinuria.

Plasma fibronectin, von Willebrand factor antigen, and blood rheology. Association with diabetic microvascular disease

Plasma fibronectin might play a role in the pathogenesis and progression of diabetic microvascular disease. To test this hypothesis we measured plasma fibronectin, von Willebrand factor antigen, fibrinogen, erythrocyte filtrability, whole-blood viscosity, proteinuria and albuminuria in 25 control subjects and 29 diabetic patients with and without microvascular complications. Plasma fibronectin was significantly higher in the diabetic patients, especially in those with retinopathy and nephropathy. A significant correlation between fibronectin and von Willebrand factor antigen was found in both patients with and without microangiopathy (p less than 0.001). In diabetic patients with and without microvascular complications, several significant correlations were found between increased fibronectin levels and reduced erythrocyte filtrability (p less than 0.001) and between the increase of fibronectin and whole-blood viscosity (p less than 0.001). Furthermore, a significant correlation was found between plasma fibronectin levels, proteinuria (p less than 0.001) and albuminuria (p less than 0.001). The relationship between plasma fibronectin and changes of blood rheology may be important for the occurrence and progression of diabetic microangiopathy.

Exudative ascites in the course of acute type B hepatitis

Two patients who presented with an exudative ascites in the course of typical acute type B hepatitis are reported. In one of them, ascites was associated with an exudative pleural effusion. In both patients, the clinical course of the hepatitis was uneventful, and ascites and pleural effusion disappeared spontaneously. Portal hypertension and common causes of exudative ascites were excluded. It is suggested that the development of exudative ascites in these patients represent a hitherto unrecognized manifestation of the hepatitis itself.