Single (B or C), dual (BC or BD) and triple (BCD) viral hepatitis in HIV-infected patients in Madrid, Spain

INTRODUCTION

There are very limited data about the prevalence of multiple hepatitis virus infections in HIV infected individuals. In HIV uninfected individuals with triple BCD hepatitis, hepatitis D virus (HDV) appears to be the dominant virus. However, in HIV infected patients with triple hepatitis it is not known if HDV replication inhibits hepatitis B virus (HBV) and/or hepatitis C virus (HCV) replication.

METHODS

We calculated the prevalence of single (B or C), dual (BC) and triple (BCD) hepatitis in 423 HIV-infected patients with positive HCV serum antibodies and/or positive serum HBsAg. In patients with multiple infections we performed an evaluation of serum markers of HBV, HCV and HDV replication.

RESULTS

The prevalence of multiple hepatitis was 4.7% (95% confidence interval, 2.7-6.7%). Multiple hepatitis occurred only among patients who acquired HIV through injection drug use. The most common multiple hepatitis was triple BCD. Patients with hepatitis BC and past or chronic hepatitis D were significantly more likely to have cirrhosis and a negative serum HBeAg and HCV PCR than patients with single hepatitis B or hepatitis C. Patients with chronic hepatitis D showed uniform suppression of HBV and HCV replication markers.

CONCLUSIONS

In our geographic area approximately 5% of HIV infected patients with hepatitis suffer multiple hepatitis virus infection. In patients with triple hepatitis BCD virus infection, HDV appears to be the dominant virus causing inhibition of both HBV and HCV replication.

Spinal anesthesia for emergency abdominal surgery in uncontrolled hyperthyroidism

Patients with uncontrolled hyperthyroidism presenting as an emergency are at considerable risk. The anesthetic management of a thyrotoxic patient undergoing incidental emergency surgery is discussed. We focus on the intraoperative problems and, above all, postoperative pain management with regional anesthesia.

Phase II study of a fixed dose-rate infusion of gemcitabine associated with docetaxel in advanced non-small-cell lung carcinoma

PURPOSE

To evaluate the efficacy and toxicity profile of the combination of docetaxel and prolonged gemcitabine infusion in front-line chemonaive patients with advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A total of 50 chemonaive patients diagnosed with advanced NSCLC according to the AJCC/TNM classification system were included in the present study. Treatment consisted of 1000 mg/m(2) gemcitabine given as a 100-min continuous infusion (10 mg/m(2) per min) on days 1 and 8 of each course and 75 mg/m(2) docetaxel as a 60-min infusion on day 8, repeating each course every 21 days.

RESULTS

The ECOG performance status of the patients were as follows: 0 (10%), 1 (60%), and 2 (30%). All patients had two-dimensionally measurable disease. Their median age was 63 years (range 41-75 years). Of the 50 patients, 28 (56%) had squamous cell carcinoma, 14 adenocarcinoma (28%), and 8 (16%) large-cell carcinoma, and 40% and 60% of patients presented with stage IIIB and IV disease, respectively. Of those with stage IV disease, 33% had more than one metastatic site. A total of 220 courses were administered with a median of five courses per patient. Of 46 patients assessed for response, 12 (26%) had a partial remission (95% CI 13-39%). In 19 patients (41%) the disease remained stable, while disease progression was observed in 15 (33%). The median time to disease progression was 4 months, and median survival time was 7 months. At 1 year, 25% of patients remained alive, and the main grade 3/4 toxicity (according to the WHO scale) consisted of neutropenia ( n=6, 12%), asthenia ( n=4, 8%), peripheral edema ( n=3, 6%), dyspnea ( n=3, 6%), and diarrhea ( n=2, 4%).

CONCLUSIONS

Prolonged gemcitabine infusion combined with docetaxel is well tolerated and its efficacy is similar to that of other chemotherapeutic schemes used for NSCLC treatment. However, the prolonged infusion of gemcitabine did not appear to result in any improvement in outcome or toxicity versus the standard dose rate.

[Study of cancer-associated asthenia: foundation of the ASTHENOS group]

Asthenia in cancer patients is a highly controversial subject. A distinct definition of asthenia in medical literature is lacking as well as its prevalence and incidence. Also, no simple tools for its diagnosis are available. Moreover its etiopathogenesis is complex and multifactorial, thereby making therapeutic approaches difficult. Recently, a Spanish group has been set up for the study and treatment of asthenia in cancer patients. This paper reports on its establishment, objectives and first conclusions.

Clips for the prevention and treatment of postpolypectomy bleeding (hemoclips in polypectomy)

INTRODUCTION

The most accurate method for the prevention and treatment of complications after polypectomy has not been well defined. The prophylactic use of hemoclips may reduce the risk of bleeding, mainly in pedunculated big polyps.

OBJECTIVE

To evaluate the accuracy of hemoclips in the prophylaxis and treatment of bleeding after endoscopic polypectomy.

MATERIAL AND METHODS

Retrospective study of 223 consecutive endoscopic polypectomies performed in our Endoscopy Unit between january and october 2001. Hemoclips were routinely used only for large polyps (15 to 40 mm); all of them were located in the colon except one, a gastric polyp.

RESULTS

From a total of 223 polypectomies (215 patients), hemoclips were used for 34 (15.2%), in 30 of them just before and in 4 just after polypectomy. When used prophylactically no complication was observed, except one mild bleeding episode (3.3%) that stopped with the placing of a second hemoclip. The therapeutic clipping (4 polypectomies) induced immediate haemostasis in all cases.

CONCLUSIONS

The prophylactic use of hemoclips is associated with a very low risk of bleeding after endoscopic resection of big polyps. Therapeutic clipping is an effective measure for polypectomy-related bleeding.

[Changes in carbohydrate metabolism in the HIV/AIDS patient]

Over the last few years, there has been a considerable reduction in the mortality and morbidity associated with HIV patients, due to the use of protease inhibitors which have led to a true revolution in the treatment of this infection. A new problem has arisen with the increased life expectancy: the onset of a plurimetabolic syndrome characterized by hypertriglyceridaemia, hypercholesterolaemia and hyperglycaemia; in addition to anomalies in composition and distribution of body fat (central obesity and loss of peripheral fat) due to the associated lipodystrophy. As a result of the metabolic alterations, there is an increase in the risk of cardiovascular disease. Hyperglycaemia is the result of insulin resistance and is detected in between 13.6% and 46% of patients, possibly leading to type 2 diabetes (diagnosed in between 2.4% and 7% of the patients). These alterations have been documented as potentially related with the use of protease inhibitors and other drugs used in the handling of HIV patients. The appropriate treatment of altered metabolism of carbohydrate requires: 1) a customized dietary approach depending on individual BMI and lipid alterations; 2) a physical exercise programme; 3) the use of insulin sensitization drugs: metformin and thiazolidinediones and, where the therapeutic goals are not achieved or there is a contraindication for oral hypoglycaemic drugs; 4) insulin therapy with regimens similar to other diabetic patients.

Tubularized incised-plate urethroplasty for hypospadias reoperation

OBJECTIVE

To review our preliminary results of tubularized incised-plate (TIP) urethroplasty for reoperative hypospadias repair.

PATIENTS AND METHODS

The study comprised 15 patients, of whom eight had undergone a previous repair by techniques that included incision into the midline of the urethral plate, while in the remaining seven the midline of the plate had been left undisturbed. The meatus at reoperation was subcoronal or on the distal shaft in all but one boy, who had a midshaft hypospadias. All had previously undergone one attempt at hypospadias repair, except for one patient presenting after two failed 'meatal advancement and glanuloplasty incorporated' procedures. The TIP repair was undertaken as described for primary surgery, except that the dorsal dartos flaps for interposition between the neourethra and skin closure were available less often.

RESULTS

TIP resulted in a functional neourethra and a cosmetically normal meatus in 13 of the 15 patients. One boy healed with a slightly rounded meatus and the other had wound dehiscence; fistulae developed in another two boys, giving three patients with complications. The fistulae occurred in boys whose original surgery did not include urethral plate incision, while the dehiscence was in a patient with partial excision of the plate during previous tubularized preputial flap repair.

CONCLUSIONS

TIP urethroplasty can potentially be used for hypospadias reoperation. Previous incision of the urethral plate was not a contraindication in these selected cases in which the plate appeared supple. However, TIP repair should be avoided in repeat hypospadias surgery if the plate has been resected or is obviously scarred.

Tubularized incised-plate urethroplasty for proximal hypospadias

OBJECTIVE

To report the experience of one surgeon using tubularized incised-plate (TIP) urethroplasty to repair proximal hypospadias in a consecutive series of boys.

PATIENTS AND METHODS

The records of 33 consecutive patients with midshaft to scrotal hypospadias undergoing TIP repair by one surgeon were reviewed. Dorsal plication was used as necessary for penile straightening, to preserve the urethral plate. Standard TIP urethroplasty was undertaken, and the follow-up included the selective use of neourethral calibration and urethroscopy.

RESULTS

Plication was necessary in 18 (55%) patients. The incised plate had a supple appearance in all but two boys. The mean (range) follow-up was 9 (1-48) months and included calibration in 16 (48%) and urethroscopy in 13 (39%) patients. Complications were noted in 11 (33%) boys, of whom seven (21%) developed small fistulae. The two patients in whom the incised plate appeared unhealthy had dehiscence of the repair and contracture of the neourethra with recurrent penile curvature, respectively. There was one meatal stenosis and one short neourethral stricture.

CONCLUSIONS

TIP urethroplasty can be used to repair proximal hypospadias in the absence of severe penile curvature, and if the incised urethral plate has a supple appearance. As with distal hypospadias repair, the procedure creates a normal-appearing penis with a slit-like meatus.

[CT diagnosis of appendicitis. Report of a case and review of the literature]

Diagnosis of appendicitis has been historically supported in clinical findings. Imaging studies such as US and CT have been used mainly in cases where clinical diagnosis of appendicitis is uncertain. CT techniques have ranged between full abdominopelvic examinations after administration of oral and intravenous contrast media and unhenhanced scanning limited to the right bowel quadrant. We present the case report of an 18-year-old male patient with recurrent abdominal pain, with clinical suspicion of appendicitis; an abdominopelvic CT examination was performed that showed a suggestive image of appendicitis. This diagnosis was confirmed with the results of surgery and pathologic examination of the appendix.

Solid-phase synthesis and inhibitory effects of some pyrido[1,2-c]pyrimidine derivatives on leukocyte formations and experimental inflammation

A number of pyrido[1,2-c]pyrimidines bearing a nitrogen, oxygen, or sulfur functionality at C-1 were synthesized on solid-phase using the iminophosphorane methodology and tested for their effects on leukocyte functions in vitro and antiinflammatory activity. Compound 5c was found to be a strong scavenger of superoxide anion and an inhibitor of chemiluminescence induced by 12-O-tetradecanoylphorbol 13-acetate in human neutrophils. These pyrido[1,2-c]pyrimidines inhibited the generation of PGE(2) by COX-2 in RAW 264.7 macrophages stimulated with lipopolysaccharide. Compounds 7, 5f, 6, and 8 inhibited enzyme activity, whereas the remaining compounds also acted on the induction phase. In addition, 5a-f, 6, and 7 administered p.o. at a dose of 20 mg/kg showed antiinflammatory activity in the carrageenan mouse paw edema model, where they inhibited PGE(2) levels in inflamed paws without affecting the content of this eicosanoid in stomachs. Inhibition of PGE(2) production and superoxide scavenging may participate in the mechanism of the antiinflammatory action of these pyrido[1,2-c]pyrimidine derivatives.

Electrogenic Na(+)-dependent L-alanine transport in the lizard duodenum. Involvement of systems A and ASC

L-Alanine transport across the isolated duodenal mucosa of the lizard Gallotia galloti has been studied in Ussing chambers under short-circuit conditions. Net L-alanine fluxes, transepithelial potential difference (PD), and short-circuit current (Isc) showed concentration-dependent relationships. Na(+)-dependent L-alanine transport was substantially inhibited by the analog alpha-methyl aminoisobutyric acid (MeAIB). Likewise, MeAIB fluxes were completely inhibited by L-alanine, indicating the presence of system A for neutral amino acid transport. System A transport activity was electrogenic and exhibited hyperbolic relationships for net MeAIB fluxes, PD, and Isc, which displayed similar apparent K(m) values. Na(+)-dependent L-alanine transport, but not MeAIB transport, was partially inhibited by L-serine and L-cysteine, indicating the participation of system ASC. This transport activity represents the major pathway for L-alanine absorption and seemed to operate in an electroneutral mode with a negligible contribution to the L-alanine-induced electrogenicity. It is concluded from the present study that the active Na(+)-dependent L-alanine transport across the isolated duodenal mucosa of Gallotia galloti results from the independent activity of systems A and ASC for neutral amino acid transport.

Synchronus renal cell carcinoma and Bellini duct carcinoma: a case report on a rare coincidence

Bellini duct carcinoma or collecting duct carcinoma (CDC) is a rare but aggressive primary renal neoplasm. The coexistence of two synchronous neoplasms in the same kidney is highly infrequent. As a result, it is hardly surprising that there are no references to renal cell carcinoma (RCC) combined with CDC of the same kidney in the literature. Histology and immunohistochemistry are important tools for differentiating between the two types of tumors involved. We present the first case of a synchronous occurrence of RCC and CDC of the same kidney.

Membrane mechanisms for electrogenic Na(+)-independent L-alanine transport in the lizard duodenal mucosa

The active Na(+)-independent transport of L-alanine across the duodenal mucosa of the lizard Gallotia galloti was studied in Ussing-type chambers using a computer-controlled voltage clamp. Addition of L-alanine to the Na(+)-free bathing solutions resulted in a significant L-alanine absorption (J(net)) that was paralleled by an increase in transepithelial short-circuit current (I(sc)) and potential difference (PD) without apparent changes in the tissue conductance. The concentration dependence of J(net), PD, and I(sc) displayed Michaelis-Menten kinetics. L-alanine-induced electrical changes were completely inhibited by external alkaline pH or by the H(+)-ionophore carbonyl cyanide m-chlorophenyl-hydrazone in the bathing solution. The alanine-induced electrogenicity was dependent on the presence of extracellular K(+) and could be blocked by serosal Ba(2+) or mucosal orthovanadate. These results suggest the existence of an H(+)-coupled L-alanine cotransport at the apical membrane of enterocytes. The favorable H(+) driving force is likely to be maintained by an apical vanadate-sensitive H(+)-K(+)-ATPase, allowing the extrusion of H(+) in an exchange with K(+). Potassium exit through a basolateral barium-sensitive conductance provides the key step for the electrogenicity of L-alanine absorption.

The right radial approach for stenting of lesions in the right coronary artery with anomalous take-off from the left sinus of valsalva

Angioplasty and stenting of lesions located in anomalous right coronary arteries arising from the left sinus of Valsalva is technically challenging. We suggest that the right radial artery provides a more direct approach that is particularly advantageous in such cases and include illustrative case reports.

[Simultaneous assessment of myocardial perfusion and ventricular function using thallium-201 at rest/Tc-99m tetrofosmin at effort with single-photon emission computerized tomography, synchronized with electrocardiogram (synchronized SPECT). Initial experience in Latin America]

Gated SPECT is a useful technique to evaluate myocardial perfusion, wall motion abnormalities and wall thickening. There is not published experience in Latin-America using dual isotope rest Thallium-201/stress Tc-99m Tetrofosmin Gated SPECT.

METHOD

We studied 27 patients with coronary artery disease. Coronary angiography was performed in all the patients. We used an injection at rest of 3 mCi of Thallium-201 followed by stress and the administration of 15 mCi of Tetrofosmin and Gated SPECT acquisition. Five days after, the patients were injected with 20 mCi of Sestamibi at stress, with a second Gated SPECT acquisition. Perfusion data were analyzed using 20 SPECT segment analysis. To study the wall motion, we divided the heart in 29 segments and every segment was scored using a 4 points scale (3 = normal, 2 = mild hipokinesia, 1 = severe hipokinesia, 0 = akinesia).

RESULTS

The perfusion and wall motion segmental score agreement between stress Tc-99m tetrofosmin and stress Tc-99m sestamibi were 97% and 84% respectively.

CONCLUSIONS

Rest Thailium-201/stress Tc-99m Tetrofosmin Dual isotope Gated SPECT technique is a good protocol to assess simultaneous myocardial perfusion and wall motion. There is a good agreement of the results with the use of rest Thallium-201/stress Tc-99m Sestamibi Dual isotope Gated SPECT study.

Recovery of minimal change nephrotic syndrome and acute renal failure in a patient withRenal cell carcinoma

We describe a 78-year-old patient with nephrotic syndrome due to minimal-change glomerulopathy, associated with a renal adenocarcinoma. Oliguric acute renal failure requiring hemodialysis was also observed. Surgical removal of the tumor and corticosteroid therapy resulted in resolution of the nephrotic state and improvement of the renal function. Nephrotic syndrome is an unusual complication of renal cell carcinomas, and the association of minimal-change glomerulopathy (MCG) and solid tumors is particularly uncommon. In spite of this, MCG should be considered in the nephropathies causing nephrotic syndrome and acute renal failure in patients with renal malignancies.

[Myocardial perfusion evaluated with a 2-isotope technique. Experience with the first 1600 cases in Mexico]

SPECT has a high sensitivity for the diagnosis of coronary artery disease. Dual isotope protocol using rest thallium and stress MIBI was introduced in Mexico 4 years ago. This protocol reunite the advantages of both radiotracers for the study of myocardial perfusion. We present our experience of the first three years. One thousand six hundred patients were studied with suspected myocardial ischemia; 288 were excluded because of an absence of a proper follow up. In 895 of the 1312 patients a coronariography was performed. Images were evaluated by dividing the heart in 20 segments using a 5 points scale (0 = normal to 4 = absence of perfusion). It was considered a perfusion defect when a segment had a score greater or equal to 2 and the SPECT study was considered abnormal if two or more segments had a MIBI stress score equal or greater than 2. The global sensitivity for diagnosis of ischemia was 96.28%. Dual isotope method is appropriate for the diagnosis of ischemic heart disease. It has a high sensitivity and specificity for the recognition of global coronary disease and for specific coronary territories. This work constitutes the greatest series in Latin America that uses this diagnosis method.

Amyloid beta interacts with the amyloid precursor protein: a potential toxic mechanism in Alzheimer's disease

Amyloid beta protein (Abeta) deposition in the brain is a hallmark of Alzheimer's disease (AD). The fibrillar form of Abeta is neurotoxic, although the mechanism of its toxicity is unknown. We showed that conversion of Abeta to the fibrillar form markedly increased binding to specific neuronal membrane proteins, including amyloid precursor protein (APP). Nanomolar concentrations of fibrillar Abeta bound cell-surface holo-APP in cortical neurons. Reduced vulnerability of cultured APP-null neurons to Abeta neurotoxicity suggested that Abeta neurotoxicity involves APP. Thus Abeta toxicity may be mediated by the interaction of fibrillar Abeta with neuronal membrane proteins, notably APP. An Abeta-APP interaction reminiscent of the pathogenic mechanism of prions may thus contribute to neuronal degeneration in AD.

Genetic polymorphism of alcohol dehydrogenase in europeans: the ADH2*2 allele decreases the risk for alcoholism and is associated with ADH3*1

Polymorphism at the ADH2 and ADH3 loci of alcohol dehydrogenase (ADH) has been shown to have an effect on the predisposition to alcoholism in Asian individuals. However, the results are not conclusive for white individuals. We have analyzed the ADH genotype of 876 white individuals from Spain (n = 251), France (n = 160), Germany (n = 184), Sweden (n = 88), and Poland (n = 193). Peripheral blood samples from healthy controls and groups of patients with viral cirrhosis and alcohol-induced cirrhosis, as well as alcoholics with no liver disease, were collected on filter paper. Genotyping of the ADH2 and ADH3 loci was performed using polymerase chain reaction-restriction fragment length polymorphism methods on white cell DNA. In healthy controls, ADH2*2 frequencies ranged from 0% (France) to 5.4% (Spain), whereas ADH3*1 frequencies ranged from 47. 6% (Germany) to 62.5% (Sweden). Statistically significant differences were not found, however, between controls from different countries, nor between patients with alcoholism and/or liver disease. When all individuals were grouped in nonalcoholics (n = 451) and alcoholics (n = 425), ADH2*2 frequency was higher in nonalcoholics (3.8%) than in alcoholics (1.3%) (P =.0016), whereas the ADH3 alleles did not show differences. Linkage disequilibrium was found between ADH2 and ADH3, resulting in an association of the alleles ADH2*2 and ADH3*1, both coding for the most active enzymatic forms. In conclusion, the ADH2*2 allele decreases the risk for alcoholism, whereas the ADH2*2 and ADH3*1 alleles are found to be associated in the European population.

[Quality of antihypertensive drug prescription in a health area]

OBJECTIVE

To find the compliance with previously established criteria on the quality of prescription of medication for hypertension.

DESIGN

Retrospective and concurrent evaluation study of scientific and technical quality, with processing data, using as data source the clinical history.

SETTING

Primary care teams in a Madrid Health Area.

PARTICIPANTS

873 clinical histories of hyper-intense patients in treatment with diuretics, beta-blockers, ACE inhibitors and/or calcium antagonists were chosen through systematic probabilistic sampling with a randomised start.

MEASUREMENTS AND MAIN RESULTS

Data on age, sex, recording of treatment, linked pathologies and situations conditioning the choice of medicine were gathered. Information on the defined use criteria of the various pharmacological groups was also collected. 1145 drugs were used on 873 patients. Most common were the thiazide diuretics (36%), followed by ACE inhibitors (34.4%), calcium antagonists (21%) and beta-blockers (8.6%). 72% of the patients were undergoing one single therapy. 89.7% of the cases (95% CI, 87.43-91.59) had the treatment correctly recorded in the clinical record. Of the 721 hyperintense patients over 59 years old, 70.3% (95% CI, 66.81-73.60) fitted the defined criterion for use of diuretics. 48.7% fitted the ACE inhibitor criteria defined (CI, 43.71-53.78); 85.7% the beta-blocker criteria (CI, 76.85-91.69); and 58.7% the calcium antagonist criteria (95% CI, 52.17-64.9).

CONCLUSIONS

The fit of the use of diuretics with the defined quality criterion is acceptable, while in the cases of ACE inhibitors and calcium antagonists the quality of prescription could be improved, while the use of beta-blockers is minimal.

[Intraoperative control of mean arterial pressure and heart rate with alfentanyl with fuzzy logic]

OBJECTIVES

To describe a fuzzy logic controller that adjust alfentanil infusion during surgery based on changes in mean arterial pressure (MAP) and heart rate (HR).

MATERIAL AND METHODS

We designed a fuzzy logic controller using if ... then ... conditions written in C language, to be executed by a 486 PC with a 66 Mhz CPU. The controller was used with eight ASA I-II patients undergoing gynecological surgery under anesthesia with propofol, alfentanil and ventilated with oxygen/air. MAP and HR were input every three minutes, after which the controller generated an infusion based on those figures. We performed a statistical study of alfentanil consumption time until extubation and time of hemodynamic stability. Relative error of MAP was calculated.

RESULTS

The controller was used for a total of 373 min with the eight patients. MAP was 15% below the desired level for 2.14% (18 min) of that time and was 15% over the desired level for 5.6% (21 min) of the time. MAP held steady within the range of stability for the remaining 92.26% (334 min) of the time the controller was used. The relative error of MAP was 7.8 +/- 1.5%. Mean time until extubation was 7 min and 2 s.

CONCLUSIONS

We believe the controller can be used to automate taks executed by experts. The controller was useful for stabilizing HR and MAP.

[Simultaneous analysis of myocardial perfusion and ventricular function. Normal values in the Mexican population]

Myocardial perfusion imaging is an useful procedure in the evaluation of patients with coronary artery disease, Gated SPECT technique evaluates simultaneously perfusion and ventricular function, left ventricular ejection fraction (LVEF), ventricular volumes and the transient ischemic dilatation of the left ventricle.

OBJECTIVE

To evaluate the normal ventricle volumes and the ejection fraction of the LV obtained automatically with the Gated SPECT in Mexican population.

METHODS

100 patients were studied with low likelihood for CAD. All of them were studied with Tc-99m Sestamibi Gated SPECT. We obtained automatically the LVEF, and the end diastolic and systolic left ventricular volumes.

RESULTS

Myocardial perfusion, regional motion and systolic thickening were normal in all patients. We obtained the mean values of EF and end diastolic and systolic volumes. These values were lower in female.

CONCLUSION

Tc-99m Sestamibi myocardial perfusion SPECT is an useful procedure, with high accuracy for the simultaneous evaluation of myocardial perfusion and ventricular function.

Aging renders the brain vulnerable to amyloid beta-protein neurotoxicity

The formation of fibrillar deposits of amyloid beta protein (Abeta) in the brain is a pathological hallmark of Alzheimer's disease (AD). A central question is whether Abeta plays a direct role in the neurodegenerative process in AD. The involvement of Abeta in the neurodegenerative process is suggested by the neurotoxicity of the fibrillar form of Abeta in vitro. However, mice transgenic for the Abeta precursor protein that develop amyloid deposits in the brain do not show the degree of neuronal loss or tau phosphorylation found in AD. Here we show that microinjection of plaque-equivalent concentrations of fibrillar, but not soluble, Abeta in the aged rhesus monkey cerebral cortex results in profound neuronal loss, tau phosphorylation and microglial proliferation. Fibrillar Abeta at plaque-equivalent concentrations is not toxic in the young adult rhesus brain. Abeta toxicity in vivo is also highly species-specific; toxicity is greater in aged rhesus monkeys than in aged marmoset monkeys, and is not significant in aged rats. These results suggest that Abeta neurotoxicity in vivo is a pathological response of the aging brain, which is most pronounced in higher order primates. Thus, longevity may contribute to the unique susceptibility of humans to Alzheimer's disease by rendering the brain vulnerable to Abeta neurotoxicity.

Neuronal apoptosis induced by HIV-1 Tat protein and TNF-alpha: potentiation of neurotoxicity mediated by oxidative stress and implications for HIV-1 dementia

Apoptosis of neurons and non-neuronal cells has been demonstrated in the brain of AIDS patients with dementia. Previous studies suggest that the apoptotic stimuli are likely to be soluble factors. Several candidates for the soluble factors that lead to neuronal apoptosis in HIV-1 infection have been proposed, including the HIV-1 Tat protein and TNF-alpha. The mechanisms that lead to neuronal apoptosis in the brain of AIDS patients in vivo, may involve the combined effects of more than one pro-apoptotic factor. In this study, we examine whether exposure of primary human neurons to the combination of HIV-1 Tat and TNF-alpha can potentiate the induction of neuronal apoptosis compared with exposure to either factor alone. TNF-alpha was shown to potentiate the induction of neuronal apoptosis by HIV-1 Tat via a mechanism that involves increased oxidative stress. Antioxidants inhibited, but did not completely abolish the induction of neuronal apoptosis by Tat, suggesting that other mechanisms are also likely to be involved. These findings suggest that soluble HIV-1 Tat and TNF-alpha may play a role in neuronal apoptosis induced by HIV-1 infection of the CNS, particularly when present in combination. Our findings further suggest that one mechanism whereby combinations of pro-apoptotic factors may potentiate the induction of neuronal apoptosis in the brain of AIDS patients is by increasing oxidative stress. Understanding the role of oxidative stress and other mechanisms that lead to apoptosis in HIV-1 infection of the CNS may advance the development of new therapeutic strategies to prevent neuronal cell death and improve neurologic function in AIDS patients.

Influence of chronic alcohol abuse and liver disease on hepatic aldehyde dehydrogenase activity

Alcohol metabolism results in the production of acetaldehyde, a compound that is much more toxic than ethanol itself. Hepatic aldehyde dehydrogenase (ALDH) is the main enzymatic system responsible for acetaldehyde clearance from the hepatocyte. The objective of this study was to determine the modifications in ALDH activity due to chronic alcohol abuse and liver disease. ALDH activity was determined in samples of liver tissue from 69 alcoholic and 82 nonalcoholic subjects, with and without liver disease. According to the results of liver pathology examination, alcoholic patients were classified into the following groups: controls, with no liver disease (group 1), noncirrhotic liver disease patients (group 2), and cirrhotics (group 3). Nonalcoholic subjects were categorized, using the same criteria, into groups 4, 5, and 6, respectively. ALDH activity was determined spectrophotometrically at two substrate concentrations: 18 mM for total activity and 180 microM for low Km activity. High Km activity was calculated by subtracting the low Km activity value from that of total ALDH activity. Results obtained in each group were expressed as the mean +/- SD of mU of g of wet weight. There were no significant differences when the total ALDH activity from the alcoholic and the nonalcoholic patients with a similar degree of liver pathology were compared: group 1, 1257 +/- 587 vs. group 4, 1328.1 +/- 546.2 (p: NS); group 2, 919.1 +/- 452.4 vs. group 5, 753.5 +/- 412 (p: NS); and group 3, 430.2 +/- 162.4 vs. group 6, 473.2 +/- 225.3 (p: NS). On the other hand, total ALDH activity was significantly lower in cirrhotics than in controls, both among alcoholics (p < 0.01) and among nondrinkers (p < 0.05). The low Km activity was severely reduced in cirrhotics, both alcoholics and nonalcoholics (p < 0.01). High Km activities in cirrhotic patients were low, compared to controls, both in alcoholics and nonalcoholics, although the difference was nonsignificant. The results of the present study suggests that chronic alcohol abuse does not depress ALDH activity. A reduction in the ALDH activity detected in patients with severe liver disease (cirrhotics) was clearly a consequence of liver damage. This reduction was due mainly to a decrease of the low Km ALDH activity, but a trend to a decrease in the high Km ALDH activity was also detected.

Neuronal localization of presenilin-1 and association with amyloid plaques and neurofibrillary tangles in Alzheimer's disease

Mutations in the presenilin-1 (PS1) gene is a cause of early- onset familial Alzheimer's disease (AD). Endogenous PS1 is associated with the endoplasmic reticulum in the cell body of undifferentiated SH-SY5Y neuroblastoma cells. At early stages of neuronal differentiation in rat hippocampal culture, PS1 appears in all neuritic processes and in growth cones. In mature differentiated neurons, PS1 is concentrated in the somatodendritic compartment but is also present at lower levels in axons. A similar localization of PS1 is observed in vivo in neurons of the adult human cerebral cortex. In sporadic AD, PS1 appears in the dystrophic neurites of mature amyloid plaques and co-localizes with a subset of intraneuronal neurofibrillary tangles (NFTs). About 30% of hippocampal NFTs are labeled with a highly specific antibody to the PS1 C-terminal loop domain but not with an antibody to the PS1 N terminus. This observation is consistent with a potential association of the PS1 C-terminal fragment with NFTs, because PS1 is constitutively cleaved to N- and C-terminal fragments in neurons. These results suggest that PS1 is highly expressed and broadly distributed during early stages of neuronal differentiation, consistent with a role for PS1 in neuronal differentiation. Furthermore, the co-localization of PS1 with NFTs and plaque dystrophic neurites implicates a role for PS1 in the diverse pathological manifestations of AD.

[Fuzzy logic and postoperative pain]

OBJECTIVE

To apply a fuzzy logic expert control system for the treatment of postoperative pain in a clinical setting.

MATERIAL AND METHODS

A system was designed consisting of a perfusion pump guided by a fuzzy logic computer interface to regulate the perfusion of alfentanil in accordance with the patient's pain response. The system was also equipped with a safety device that halted perfusion in case of desaturation, bradypnea or heart rate or blood pressure variations greater than 25%. The system was used in the first 90 minutes after surgery in a patient who underwent bilateral saphenectomy.

RESULTS

All system functions worked properly, maintaining the target analgesic values (visual analog scale < or = 2) 77% of the time.

CONCLUSION

It is possible to use fuzzy logic to obtain adequate treatment of postoperative pain.

Apoptosis induced by HIV-1 infection of the central nervous system

Apoptosis plays a role in AIDS pathogenesis in the immune system, but its role in HIV-1-induced neurological disease is unknown. In this study, we examine apoptosis induced by HIV-1 infection of the central nervous system (CNS) in an in vitro model and in brain tissue from AIDS patients. HIV-1 infection of primary brain cultures induced apoptosis in neurons and astrocytes in vitro as determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and propidium iodide staining and by electron microscopy. Apoptosis was not significantly induced until 1-2 wk after the time of peak virus production, suggesting induction by soluble factors rather than by direct viral infection. Apoptosis of neurons and astrocytes was also detected in brain tissue from 10/11 AIDS patients, including 5/5 patients with HIV-1 dementia and 4/5 nondemented patients. In addition, endothelial cell apoptosis was frequently detected in the brain of AIDS patients and was confirmed by electron microscopy. Most of the apoptotic cells were not localized adjacent to HIV-1-infected cells, providing further evidence for induction by soluble factors. In six non-AIDS control patients with normal brain, apoptotic cells were absent or limited to rare astrocytes. However, TUNEL-positive neurons and astrocytes were frequently detected in seven patients with Alzheimer's disease or abundant senile plaques. These studies suggest that apoptosis is a mechanism of CNS injury in AIDS which is likely to be induced by soluble factors. The apoptosis of endothelial cells in the CNS raises the possibility that some of these factors may be blood-derived.

Amyloid fibril toxicity in Alzheimer's disease and diabetes

Several lines of evidence suggest that amyloid deposition in the brain contributes to neuronal degeneration in Alzheimer's disease (AD). In the AD brain, diffuse plaques composed mostly of amorphous beta amyloid (Am-beta A) are inert, whereas compact plaques composed of beta amyloid fibrils (Fib-beta A) are associated with neurodegenerative changes. The effects of these two types of amyloid were tested on primary rat hippocampal neurons. Fib-beta A induced the formation of dystrophic neurites and caused neuronal cell death, whereas Am-beta A was not toxic. In addition, Fib-beta A caused synapse loss in the remaining viable neurons, whereas Am-beta A did not significantly affect synapse number. We also examined the effects of amylin, the primary constituent of the amyloid fibrils that form in the pancreas in adult-onset diabetes. Amylin was toxic to rat and human insulin-producing islet cells in the concentration range of fibril formation. The relative toxic potencies of amylin peptides of different species correlated with their fibril-forming capacity. Soluble amylin was not toxic. The amyloid fibril-binding dye Congo red inhibited the toxicity of both beta A and amylin. Congo red afforded protection against toxicity by a dual mechanism. When present during the phase of fibril polymerization, Congo red could inhibit fibril formation from some peptides. When added to preformed fibrils, Congo red bound to fibrils rendering them nontoxic. These results suggest that fibril formation is necessary for both beta A and amylin toxicity. Congo red appears to be a general inhibitor of amyloid fibril toxicity and may therefore be a useful prototype for drugs targeted to the amyloid pathology of AD and adult-onset diabetes.

[Jejuno-ileal volvulus, a rare cause of intestinal obstruction]

Volvulus of the small bowel without predisposing anatomical defects is a rare cause of acute intestinal obstruction in the Western world, and its incidence is decreasing in Europe and America, although it is common in others parts of the world. The causes of primary volvulus of the small bowel and the mechanism of rotation of the entire root of the mesentery remain unexplained. Several anatomical and dietary factors have been implicated. This theory requires strong peristalsis, tense, firm abdominal muscles and feeding pattern of very bulky meals taken at long intervals. In the present case, a large quantity of bulky poorly digested food consumed previously, and strong abdominal muscles are in keeping with the above theory.

[Esophageal intramural pseudodiverticulosis]

Esophageal intramural pseudodiverticulosis is an uncommon and benign primary disease of the esophagus. Less than 150 cases have been reported. We report a new case diagnosed by endoscopy during the investigation of an upper gastrointestinal bleeding, in a 48-year-old man who was assymptomatic from the esophageal point of view. We discuss the clinical, pathogenic, diagnostic and therapeutic aspects of this disease.

beta-amyloid fibrils induce tau phosphorylation and loss of microtubule binding

A central issue in the pathogenesis of Alzheimer's disease (AD) is the relationship between amyloid deposition and neurofibrillary tangle formation. To determine whether amyloid fibril formation affects the phosphorylation state of tau, primary cultures of fetal rat hippocampal and human cortical neurons were treated with beta-amyloid (beta A) in a soluble, amorphous-aggregated, or fibrillar form. Fibrillar beta A, but not soluble or amorphous-aggregated beta A, markedly induces the phosphorylation of tau at Ser-202 and Ser-396/Ser-404, resulting in a shift in the tau M(r) in human cortical neurons. Hyperphosphorylated tau accumulates in the somatodendritic compartment of fibrillar beta A-treated neurons in a soluble form that is not associated with microtubules and is incapable of binding to microtubules in vitro. Dephosphorylation of beta A-induced tau restores its capacity to bind to microtubules. Thus, amyloid fibril formation alters the phosphorylation state of tau, resulting in the loss of microtubule binding capacity and somatodendritic accumulation, properties also exhibited by tau in the AD brain. Amyloid fibril formation may therefore be a cause of abnormal tau phosphorylation in AD.