Alirocumab reduces total coronary plaque burden in patients with familial hypercholesterolaemia and no previous clinical atherosclerotic disease

Background

It is well known that statins, ezetimibe and other lipid lowering treatments such as Evolocumab (PCSK9-Inhibitor) reduce cardiovascular events by decreasing LDL-cholesterol (LDL-C) levels and slowing the progression of coronary atherosclerosis. Nevertheless, cardiovascular (CV) risk remains. Alirocumab, a PCSK9 inhibitor has demonstrated a reduction in cardiovascular events but its relationship with coronary atherosclerosis reduction has not been adequately demonstrated.

Purpose

The ARCHITECT trial sought to determine whether Alirocumab 150 mg/2 weeks is able to stop or reverse coronary atherosclerosis progression, by assessing coronary plaque burden (CPB) by serial multidetector computed tomography (MDCT).

Methods

A total of 104 patients with molecularly characterized heterozygous familial hypercholesterolaemia (FH) without clinical cardiovascular disease were enrolled in this trial. Patients had to have CPB >30% as documented by MDCT, be on maximum tolerated statin therapy with or without ezetimibe and LDL-C >100 mg/dL. Patients underwent a MDCT at enrollment and after 18-month treatment with alirocumab and they were analyzed by means of QAngio CT (Medis medical imaging system, the Netherlans). The pre-specified primary endpoint was change in CPB.

Results

Median age was 53.3 (46.2–59.4) years (54, 51.9% woman). Median LDL-cholesterol was 138.9 mg/dL. There was a significant reduction in the primary endpoint as Alirocumab reduced CPB from 34.6 (32.9–36.8)% to 30.4 (27.4–33.4)%. Significant reductions in LDL-C (67%) and atherosclerotic plaque volume were also found. Plaque regression as estimated by CPB was found in 91 (87.5%) patients. Main resuts may be found in figure 1.

Conclusions

Alirocumab demonstrated significant regression of CPB on MDCT over 18 months. ARCHITECT provides crucial mechanistic clues on coronary plaque behavior under the use of Alirocumab and its results could link and explain ODYSSEY-OUTCOMES results.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi

Persistence to long-term PCSK9 inhibitors treatment and its effectiveness in familial hypercholesterolemia: data from the SAFEHEART study

Background

Most patients with heterozygous familial hypercholesterolemia (FH) do not achieve current LDL-C goals proposed by European guidelines with conventional lipid-lowering therapy (LLT). Chronic use of PCSK9 inhibitors (PCSK9i) have shown to reduce LDL-C levels up to 61% on top of statins. Persistence to chronic LLT is important to reduce the burden of atherosclerotic cardiovascular disease (ASCVD).

Purpose

To analyze persistence and effectiveness of PCSK9i in clinical practice setting in FH patients from the SAFEHEART register with long-term follow-up.

Methods

SAFEHEART is an open, long-term prospective study of a cohort of subjects with molecular diagnosis of FH. Follow-up is carried out every year through a standardized phone-call to collect clinical conditions, persistence to medications, lipid profile, and cardiovascular events. This study analyses subjects ≥18 years of age on stable LLT who have received PCSK9i.

Results

696 individuals (46% females), median age 56.4 years (IQR 49–66) started with PCSK9i (49% alirocumab and 51% evolocumab). Out of them 38% had history of ASCVD, and 89% were on maximum LLT. Median LDL-C at the moment of starting PCSK9i was 145 mg/dL (IQR, 123–177), representing a poor 2016 & 2019 ESC/EAS guidelines achievement (3% and 0.1% respectively). After a median follow-up of 3.7 years (IQR, 2.3–4.8), 669 patients (96%) remained on PCSK9i treatment during entire follow-up. Only 27 patients (4%) discontinued, 5 temporarily (0.7%) and 22 permanently (3.2%). Most common reasons for PCSK9i treatment interruption were medical decision (n=6), adverse event (AE) (n=5), patient decision not related with AE (n=5) and comorbidity (n=5). Median time to permanent discontinuation was 15 months (IQR, 4–33).

Median LDL-C levels observed and % of LDL-C reduction obtained after 1 year of treatment and in the last follow-up visit were: 63 mg/dL (IQR, 43–88), 61 mg/dL (IQR, 44–82), 57.6% (IQR, 39.5–69) and 58% (IQR, 44–68), respectively. 2016 ESC/EAS guidelines LDL-C goals was achieved by 70% of patients at year 1 and 77% in the last follow-up visit after the introduction of PCSK9i (p<0.001). 2019 ESC/EAS goals were achieved by 44.5% and 48% (p=0.1).

Conclusion

Long-term persistence to PCSK9i treatment in FH patients is very high (96%) and reasons for discontinuation are diverse. This study shows that COVID-19 pandemic did not affected persistence to treatment. Effectiveness in LDL-C reduction and LDL-C goal achievement improved significantly with introduction of PCSK9i in clinical practice setting.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): AMGEN

Oxidative species increase arginase activity in endothelial cells through the RhoA/Rho kinase pathway

BACKGROUND AND PURPOSE

NO produced by endothelial NOS is needed for normal vascular function. During diabetes, aging and hypertension, elevated levels of arginase can compete with NOS for available l-arginine, reducing NO and increasing superoxide (O(2) (.-)) production via NOS uncoupling. Elevated O(2) (.-) combines with NO to form peroxynitrite (ONOO(-)), further reducing NO. Oxidative species increase arginase activity, but the mechanism(s) involved are not known. Our study determined the mechanism involved in peroxynitrite and hydrogen peroxide-induced enhancement in endothelial arginase activity. We hypothesized that oxidative species increase arginase activity through PKC-activated RhoA/Rho kinase (ROCK) pathway.

EXPERIMENTAL APPROACH

Arginase activity/expression was analysed in bovine aortic endothelial cells (BAEC) treated with an ONOO(-) generator (SIN-1) or H(2) O(2). Pretreatment with inhibitors of Rho kinase (Y-27632) or PKC (Gö6976) was used to investigate the mechanism involved in arginase activation.

KEY RESULTS

Exposure to SIN-1 (25 µM, 24 h) or H(2) O(2) (25 µM, 8 h) increased arginase I expression and arginase activity (35% and 50%, respectively), which was prevented by ROCK inhibitor, Y-27632, PKC inhibitor, Gö6976 or siRNA to p115-Rho GEF. There was an early activation of p115-Rho GEF (SIN-1, 2 h; H(2) O(2), 1 h) and Rho A (SIN-1, 4 h; H(2) O(2), 1 h) that was prevented by using the PKC inhibitor. Exposure to SIN-1 and H(2) O(2 ) also reduced NOS activity, which was blocked by pretreatment with p115-RhoGEF siRNA.

CONCLUSIONS AND IMPLICATIONS

Our data indicate that the oxidative species ONOO(-) and H(2) O(2) increase arginase activity/expression through PKC-mediated activation of RhoA/Rho kinase pathway.

Normal values in ambulatory oesophageal pH monitoring at two levels in Spain

AIM

Upper oesophageal pH monitoring may play a significant role in the study of extra-oesophageal GERD, but limited normal data are available to date. Our aim was to develop a large series of normal values of proximal oesophageal acidification.

METHODS

155 healthy volunteers (74 male) participated in a multi-centre national study including oesophageal manometry and 24 hours oesophageal pH monitoring using two electrodes individually located 5 cm above the LOS and 3 cm below the UOS.

RESULTS

130 participants with normal manometry completed all the study. Twelve of them were excluded for inadequate pH tests. Twenty-seven subjects had abnormal conventional pH. The remaining 91 subjects (37 M; 18-72 yrs age range) formed the reference group for normality. At the level of the upper oesophagus, the 95th percentile of the total number of reflux events was 30, after eliminating the meal periods 22, and after eliminating also the pseudo-reflux events 18. Duration of the longest episodes was 5, 4 and 4 min, respectively (3.5 min in upright and 0.5 min in supine). The upper limit for the percentage of acid exposure time was 1.35, 1.05 and 0.95%, respectively. No reflux events were recorded in the upper oesophagus in 8 cases.

CONCLUSION

This is the largest series of normal values of proximal oesophageal reflux that confirm the existence of acid reflux at that level in healthy subjects, in small quantity and unrelated to age or gender. Our data support the convenience of excluding pseudo-reflux events and meal periods from analysis.

Proteolytic activity in salivary gland products of sheep bot fly (Oestrus ovis) larvae

This study identified and characterized hydrolytic enzymes in salivary gland products of Oestrus ovis larvae. Third instars were collected from the heads of slaughtered goats. Salivary glands were extracted, their products obtained by centrifugation and the enzymatic profile determined. Optimum pH, temperature of maximum proteolytic activity, thermal stability, and resistance of salivary gland products were determined on collagen and subclasses of proteases were identified using protease inhibitors. Zymograms were used to determine the molecular weight of proteases. Antigenic protein bands were revealed by immunoblotting using sera obtained from experimentally infested goats. Seven positive enzymatic activities were detected in salivary gland products: acid phosphatase, naphthol-AS-BI-phosphohydrolase, esterase (C4), esterase lipase (C8), leucine arylamidase, alpha-glucosidase and N-acetyl-beta-glucosaminidase. Optimum pH for proteolytic activity was 8.0; proteolytic activity increased with temperature (10-50 degrees C) then drastically decreased at 60 degrees C. Proteases in O. ovis salivary gland products belong to the serine subclass. In Zymograms, bands of proteolytic activity were detected in the 20-63 kDa range; the immunoblot showed three antigenic bands, one of them related to a protease band (63 kDa). Serine proteases in O. ovis salivary gland products are most likely involved in larval nutrition and host immuno-modulation.

Adhesive properties of a LamB-like outer-membrane protein and its contribution to Aeromonas veronii adhesion

AIMS

To identify and characterize nonfimbrial proteins from Aeromonas veronii involved in the attachment to epithelial cells in vitro.

METHODS AND RESULTS

Two Aer. veronii mucin- and lactoferrin-binding proteins with molecular masses of 37 and 48 kDa were identified by Western blot analysis. According to its N-terminal amino acid sequence, the 48-kDa protein was identified as Omp48, an outer-membrane protein similar to LamB of Escherichia coli. LamB is a well-known porin involved in maltose transport across the outer membrane in E. coli. In a microtitre plate assay, Omp48 bound to the immobilized extracellular matrix proteins collagen and fibronectin, and the mucin- and lactoferrin-binding activity was confirmed. Adhesion of Omp48 to mucin, lactoferrin and collagen was diminished by preincubation with homologous glycoproteins or other carbohydrates, suggesting a putative Omp48 lectin-like binding domain. Anti-Omp48 antiserum significantly inhibited the Aer. veronii adhesion to confluent HeLa cell monolayers and pretreatment of cells with purified Omp48 elicited competitive inhibition of adhesion. Similarly, cross-inhibition of Aer. hydrophila and Aer. caviae adhesion was achieved with the same treatments, indicating the existence of a conserved surface protein among these species.

CONCLUSIONS

Taken together, these data indicate that Omp48 is involved in Aer. veronii adhesion to epithelial cells and might be an alternative adhesion factor of this micro-organism.

SIGNIFICANCE AND IMPACT OF THE STUDY

The adhesive potential of Aeromonas spp. is correlated with pathogenicity; however, the adhesion mechanism is complex and not well understood. This study provides evidence of a putative adhesion factor that might be contributing to pathogenicity of Aer. veronii and could be used for vaccine development.

Restoration of peristalsis in the esophagus of a patient diagnosed of achalasia

We report the case of a patient with dysphagia in whom a clinical and manometric follow-up was carried out. We initially observed a motor disorder of the esophageal spasm type. During manometric follow-up a progression to vigorous achalasia was observed. The patient was treated with pneumatic dilation, which obtained a good response to treatment. In manometries performed after treatment we observed a return of peristalsis in the distal esophageal body. Early treatment and short evolution of disease may allow peristalsis to recover in these cases. Peristalsis recovery casts new doubts on achalasia etiology.

Streptococcal erythrogenic toxin B induces apoptosis and proliferation in human leukocytes

BACKGROUND

Previous reports have shown the presence of erythrogenic toxin type B (ETB), apoptosis, proliferation, and leukocyte infiltration in biopsies from patients with acute poststreptococcal glomerulonephritis (APSGN).

METHODS

Attempting to correlate the apoptotic and proliferative events with the interaction of ETB or its precursor (ETBP) with leukocytes, mononuclear leukocytes from 12 healthy subjects were cultured with ETB or ETBP to analyze the levels of apoptosis, proliferation, expression of modulatory apoptosis gene products, and oxidative metabolism. After four days of incubation, cells were assessed for apoptosis by morphological criteria, annexin V assay, and terminal deoxy transferase uridine triphosphate nick end-labeling (TUNEL) assay. The expression of regulatory apoptosis genes was assessed by relevant monoclonal antibodies; proliferation was by incorporation of radioactive thymidine; and oxidative metabolism was by oxidation of 2',7'-dichlorofuorescein diacetate to 2',7'-dichlorofuorescein. Neutralization of Fas-L and cysteine protease activity of ETB were performed by incubation of ETB-treated leukocyte cultures with anti-human Fas-L mAb or with E64, respectively.

RESULTS

Elevated levels of apoptosis in ETBP/ETB-treated leukocytes were found when compared with controls: morphological criteria (P < 0.01), Annexin V (control, 5.01 +/- 0.61; ETBP, 10.60 +/- 1.98%, P = 0.0005), and TUNEL (control, 12.5 +/- 2.6; ETBP, 20.56 +/- 3.06%, P = 0.001; ETB, 30.69 +/- 5.05%, P = 0.001). Increased expression of apoptosis was accompanied by increased expression of Fas (control, 20.15 +/- 5.28; ETBP, 43.51 +/- 5.6%, P = 0.03; ETB, 47.16 +/- 5.54%, P = 0.01), Fas ligand (control, 5.64 +/- 2.38; ETBP, 11.66 +/- 3.65%, P = 0.04; ETB, 16.39 +/- 5.05%, P = 0.02) and p53 products (control, 9.22 +/- 3.44; ETBP, 22.82 +/- 5.72%, P = 0.01; ETB, 24.60 +/- 5.20%, P = 0.01). Treatment of ETB-leukocyte cultures with anti-human Fas-L exhibited 2.2-fold lower apoptosis expression. Treatment with E64 significantly abrogated the apoptotic effect of ETB. There was no increment on leukocyte oxidative metabolism. Mononuclear leukocytes also showed elevated levels of proliferation when treated with different concentrations (from 50 to 6.2 microg/mL) of streptococcal proteins (Stimulation index ranging: ETBP, 5.6 +/- 1.9 to 6.4 +/- 1.9; ETB, 9.9 +/- 2.8 to 13.9 +/- 3.8).

CONCLUSIONS

These results delineate an additional pathway for the pathogenesis of APSGN related to the role of cationic streptococcal ETB or ETBP on the induction of apoptosis and proliferation during the course of the disease.

Mucosal immune response of spotted sand bass Paralabrax maculatofasciatus (Steindachner, 1868) orally immunised with an extracellular lectin of Aeromonas veronii

To assess the immunogenic and immunoprotective role of the extracellular lectin from Aeromonas veronii (MCBP), which has affinity for mucosal constituents such as mucin, lactoferrin, immunoglobulins and collagen, spotted sand bass (Paralabrax maculatofasciatus) were orally immunised either with soluble MCBP, adjuvant-conjugated MCBP or immobilised MCBP on latex microspheres. The results suggest that the MCBP is capable of eliciting protective immunity against A. veronii infections when administered orally. The highest mucosal immune response was elicited in fish immunised with MCBP covalently linked to cholera toxin B subunit (CTB) or to Escherichia coli heat-labile toxin (hLT). MCBP-CTB was found to elicit immunoprotection against a challenge with live Aeromonas cells with a relative percent survival of almost 70% and without the expression of the severe histopathological alterations induced by A. veronii.

[Mucinous adenocarcinoma of the appendix associated with ovarian tumors and pseudomyxoma peritonei. The difficulty in differential diagnosis]

Mucinous adenocarcinoma of the appendix is rare. If there is a concomitant ovarian tumor to determine the primary might be difficult. Histological features are not always determinant, but there are some macroscopic findings that may suggest an origin in the appendix. We report a case of synchronous tumors in appendix and ovaries with pseudomyxoma peritonei. The patient presented with mass sensation in the right lower quadrant, asthenia, anorexia and weight loss. Abdominal ultrasound and CT scan showed a tumor involving cecum, appendix, terminal ileum and pelvis. Findings on colonoscopy and biopsies were inconclusive. At laparotomy, the tumor compressed appendix, cecum and ascendant colon, terminal ileum, ovaries and peritoneum. Histopathological analysis demonstrated a well-differentiated mucinous adenocarcinoma of appendiceal origin with metastasis in ovaries and peritoneum (pseudomyxoma peritonei).

What predictive parameters best indicate the need for emergent gastrointestinal endoscopy after foreign body ingestion?

Our aim was to determine what parameters may be used to indicate an emergent endoscopy after foreign body (FB) ingestion and to ascertain how often FBs are found endoscopically. Demographic data, gastroesophageal antecedents, clinical and endoscopic data, and complications were obtained. We examined 122 patients endoscopically. The onset of symptoms was immediate after FB ingestion in 93% of patients. Dysphagia was the most frequent symptom (66%), with the pharynx the most frequent location of impaction (71%). Endoscopy confirmed the presence of FBs in 52% of patients. Extraction was performed in 78%. The immediate onset of symptoms, dysphagia, and the absence of pharynx localization of impaction were predictive indicators of a positive FB finding (p < 0.05), with diagnostic sensitivity of 86% and specificity of 63%. Upper endoscopy should be performed in all patients with FB ingestion, even though no FB was found in 48%.

Protection of BALB/c mice against experimental Helicobacter pylori infection by oral immunisation with H pylori heparan sulphate-binding proteins coupled to cholera toxin beta-subunit

The presence of Helicobacter pylori in the gastroduodenal mucosae is associated with chronic active gastritis, peptic ulcers and gastric cancers such as adenocarcinoma and low-grade gastric B-cell lymphoma. In response to the presence of antibiotic-resistant strains, the use of vaccines to combat this infection has become an attractive alternative. The present study used a murine model of infection by a mouse-adapted H. pylori strain to determine whether infection in BALB/c mice can be successfully eradicated by intragastric vaccination with H. pylori heparan sulphate-binding proteins (HSBP) covalently coupled to the beta-subunit of cholera toxin (CTB). It was shown that vaccination confers protection against exposure of BALB/c mice to the pathogen, as revealed by microbiological, histopathological and molecular methods.

Five-year analysis of endoscopic retrograde cholangiopancreatography in the Hospital del Bierzo

OBJECTIVES

endoscopic retrograde cholangiopancreatography (ERCP) is a widely available endoscopic modality, that is not without risks, but is no longer limited to tertiary referral centers. We evaluated the procedure in terms of imaging success, overall therapeutic failure, complications and mortality.

METHODS

this retrospective study ran from January 1992 to December 1997. The following data were collected: 1) cannulation rate, 2) failure to obtain images of the duct, 3) type of ERCP, 4) overall therapeutic failure rate and stone extraction, 5) overall complication rate, 6) immediate complications, 7) late complications (within the first 30 days), and 8) mortality.

RESULTS

of 425 ERCP procedures performed, all data for 393 were obtained and included in the analysis. The cannulation success was 94%. Failure to obtain a suitable image occurred in 10%. ERCP was diagnostic in 60% and therapeutic in 40%. Sphincterotomy was performed in 83% of the patients. The therapeutic failure rate was 15%. Stone extraction was successful in 69%. The overall complication rate was 8.6%; 2.2% of these complications were severe or fatal. Immediate complications occurred in 4% and late complications in 5.9%. Immediate complications were less frequent in diagnostic ERCP (p < 0.01). Late complications were: pancreatitis (3. 5%), bleeding (1.4%), perforation (0.3%) and cholangitis (0.8%). There was no difference in the frequency of severe pancreatitis between the types of ERCP procedure. Bleeding occurred more frequently in sphincterotomy (p < 0.05). The overall mortality rate was 1.6%.

CONCLUSIONS

a continuous audit in each endoscopy unit should be performed to improve ERCP procedures. Diagnostic and therapeutic ERCP carry a similar risk of severe pancreatitis. The bleeding rate was higher in therapeutic ERCP and sphincterotomy.

[Critical vision in the treatment of invasive vesical cancer with ionizing radiation]

OBJECTIVE

To review the treatment of invasive bladder cancer with ionizing radiation.

METHODS

Patient selection criteria, prognostic factors, treatment of different tumor types with radiation using different strategies alone or in combination with chemotherapy are analyzed in the literature.

RESULTS/CONCLUSIONS

The role of radiotherapy in the treatment of invasive carcinoma of the bladder is crucial: 1) preoperative radiotherapy in combination with radical surgery achieves results comparable with those of cystectomy in terms of survival and a higher local control rate; 2) used in combination with cisplatin post-TUR, irradiation is highly effective for local control of the tumor and bladder preservation, with complete remission rates ranging from 60-70%, which are higher than those of radical cystectomy; 3) in this latter therapeutic modality the effect of radiotherapy is dose-related and is influenced by factors such as tumor size, presence or absence of urinary obstruction, presence of multiple lesions on the bladder wall and extravesical spread. Over the last few years, a number of therapeutic procedures have been developed, which can improve the previously mentioned results when used appropriately. Among these are hyperfractionation, accelerated irradiation and concomitant radio and chemotherapy. Studies to determine tumor radiosensitivity (Fs2/a) and the use of gene therapy could enhance the tumor control rate in the future, although a system for the selection on patients for conservative or multilating treatment based on clinical, clinicopathological and scientific criteria will have to be developed. Finally, the use of special techniques, particularly brachytherapy and intraoperative irradiation, in combination with external radiotherapy has achieved excellent results (high local control and survival rates) in certain situations, basically in single/small-sized tumours.

[Amebic liver abscesses with bacterial superinfection in a nonendemic area]

A 26-year-old man was admitted to hospital with asthenia, weight loss, right upper quadrant abdominal pain, diarrhea without blood, and fever. Abdominal ultrasonography showed multiple hypoechoic areas in the left hepatic lobe. On abdominal CT, multiple hypodense areas without contrast capture were consistent with hepatic abscesses. Cultures were obtained and the patient was placed empirically on metronidazole, gentamicin and ampicillin, without improvement in the first 72 hours, and a drain was placed in the largest lesion collecting a purulent material. The abscess culture was positive for group C beta-hemolytic Streptococcus. Entamoeba histolytica serology was positive and colon biopsies revealed trophozoites. Multiple left hepatic lobe abscesses secondary to E. histolytica, with bacterial superinfection, is an unusual presentation of amoebic infection, considering that Spain is not an endemic area.

Serum malondialdehyde: possible use for the clinical management of chronic hepatitis C patients

Serum lipid peroxidation products are increased in inflammatory liver disease and, as we previously reported, also in chronic hepatitis C. We have performed a specific assay of malondialdehyde, the reported most abundant product of lipid peroxidation, in serum of twenty four chronic hepatitis C patients, before, during, and after interferon treatment. Liver biopsies were performed in each patient before and after interferon treatment. The results show higher serum malondialdehyde values in chronic hepatitis C patients than healthy subjects (n = 68) before interferon treatment (p < .001). Mean value of serum malondialdehyde levels after interferon treatment was significantly lower than before it (p < .002). Associating the histopathological findings in each of the 48 biopsies performed, with serum malondialdehyde and alanine aminotransferase activity levels, of the sample obtained the same day of biopsy, a much better correspondence with the histopathological severity was observed for malondialdehyde concentration than for alanine aminotransferase activity. These levels decreased significantly after interferon treatment. However, when the patients were grouped in responding (group I; n = 9) and non-responding (group II; n = 15) to interferon treatment, according to the histopathological findings before and after interferon, the values of group I before interferon treatment were significantly higher than group II (p < .03). Thus, a potential predictive value could be ascribed to the serum malondialdehyde levels before interferon treatment in these patients. We propose the utility of the specific assay of malondialdehyde for the clinical management of chronic hepatitis C patients.

Lipid peroxidation products and antioxidants in human disease

Lipid peroxidation (LPO) is a free radical-related process that in biologic systems may occur under enzymatic control, e.g., for the generation of lipid-derived inflammatory mediators, or nonenzymatically. This latter form is associated mostly with cellular damage as a result of oxidative stress, which also involves cellular antioxidants in this process. This article focuses on the relevance of two LPO products, malondialdehyde (MDA) and 4-hydroxynonenal (HNE), to the pathophysiology of human disease. The former has been studied in human serum samples of hepatitis C virus-infected adults and human immunodeficiency virus-infected children. In these two cases it is shown that the specific assay of serum MDA is useful for the clinical management of these patients. The presence of MDA in subretinal fluid of patients with retinal detachment suggests the involvement of oxidative stress in this process. Moreover, we were able to report the dependence of this involvement on the degree of myopia in these patients. The assay of MDA contents in the peripheral nerves of rats fed a chronic alcohol-containing diet or diabetic mice also confirms the pathophysiologic role of oxidative stress in these experimental models. In these two cases, associated with an increase in tissue LPO products content, we detected a decrease of glutathione peroxidase (GSHPx) activity in peripheral nerve, among other modifications. We have demonstrated that in vitro HNE is able to inhibit GSHPx activity in an apparent competitive manner, and that glutathione may partially protect and/or prevent this inactivation. The accumulation of LPO products in the brain of patients with Alzheimer's disease has also been described, and it is on the basis of this observation that we have tried to elucidate the role of oxidative stress and cellular antioxidants in beta-amyloid-induced apoptotic cell death of rat embryo neurons. Finally, we discuss the possible role of the observed vascular effects of HNE on human arteries.

Analysis of the interaction of Aeromonas caviae, A. hydrophila and A. sobria with mucins

Aeromonas species are known to be involved in human gastrointestinal diseases. These organisms colonize the gastrointestinal tract. Aeromonas hydrophila, A. caviae, and A. sobria have been demonstrated microscopically to adhere to animal cell lines that express mucous receptors, but quantitative studies of adherence to mucosal components such as mucin have not been published to date. Purified bovine submaxillary gland, hog gastric mucin, and fish skin mucin were used as a model to study mucin-binding activity among A. caviae, A. hydrophila, and A. sobria strains. Our findings revealed that binding of radiolabeled and enzyme-conjugated mucins to Aeromonas cells varied depending on the labeling procedure. The highest binding was observed when the three mucin preparations were labeled with horseradish peroxidase. Binding of the various horseradish peroxidase-labeled mucins by A. caviae, A. hydrophila, and A. sobria cells is a common property among Aeromonas species isolated from human infections, diseased fish, and from environmental sources. The proportion of Aeromonas strains which bind the various horseradish peroxidase-labeled mucins was significantly higher for A. hydrophila than for A. caviae and A. sobria. Bacterial cell-surface extracts containing active mucin-binding components recognized the horseradish peroxidase-labeled mucins. The molecular masses of the mucin-binding proteins were estimated by SDS-PAGE and Western blot as follows: A. caviae strain A4812 (95 and 44 kDa); A. hydrophila strain 48748 (97, 45, 33 and 22 kDa); and A. sobria strain 48739 (95 and 43 kDa). Mucin interaction with Aeromonas cells was also studied in terms of growth in mucin-rich media. The culture conditions greatly influence the expression of A. hydrophila mucin-binding activity.

Response to fluconazole and itraconazole of Candida spp. in denture stomatitis

The significance of Candida albicans in the development of denture stomatitis (DS), as well as the clinical and microbiological efficacy of treatment with fluconazole and itraconazole was studied in 115 patients affected with DS and 200 controls (100 healthy patients with dental prosthesis and 100 healthy patients without prosthesis). Specimens were taken from all patients; subsequently all patients with positive culture of the DS group were treated with fluconazole. A second specimen was taken after 15 days of treatment with fluconazole, and if the results were positive again, treatment with itraconazole was instituted and the patients were given appointments for taking a third specimen. The incidence of C. albicans was 92% in the group of patients with DS. After treatment with fluconazole, a clinical cure of 97% and a microbiological cure of 78% was obtained in the patients with DS. In 3.2% of the cases strains resistant to fluconazole were found. The cases of microbiological resistance to fluconazole were treated with itraconazole resulting in a clinical cure of 100% and a microbiological cure of 77%. The results show the poor correlation of the clinico-microbiological response after treatment with these antifungal agents in denture stomatitis.

4-hydroxynonenal-induced relaxation of human mesenteric arteries

The effect of 4-hydroxynonenal (4-HNE), a circulating lipid peroxidation product, on the vascular tone of human mesenteric arteries is studied. 4-HNE promotes relaxation of human mesenteric arterial rings in a concentration-dependent manner. Removal of the endothelium or treatment with N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME; 10(-4) M) partially prevented 4-HNE-induced relaxation, thus suggesting the intervention of nitric oxide from endothelial origin in the vascular effects of 4-HNE.

Cryptic domains of a 60 kDa heat shock protein of Helicobacter pylori bound to bovine lactoferrin

Bovine lactoferrin binds to a 60 kDa heat shock protein of Helicobacter pylori. Binding ability was related to human immunoglobulin G because bovine lactoferrin binding proteins were isolated by extraction of cell surface associated proteins with distilled water, applied on IgG-Sepharose and nickel sulphate chelate affinity chromatography. Binding was demonstrated by Western blot after purified protein was digested with alpha-chymotrypsin and incubated with peroxidase-labeled bovine lactoferrin. Binding was inhibited by bovine lactoferrin, lactose, rhamnose, galactose, and two iron-containing proteins, ferritin and haptoglobin. Helicobacter pylori binds ferritin and haptoglobin via charge or hydrophobic interactions because this binding was not inhibited by specific and various glycoproteins or carbohydrates. Carbohydrate moieties of bovine lactoferrin molecules seem to be involved in binding because glycoproteins with similar carbohydrate structures strongly inhibited binding. Scatchard plot analysis of the binding of peroxidase-labeled bovine lactoferrin to H. pylori cells yielded a kd 2.88 x 10(-6) M. In addition, binding of H. pylori cells to bovine lactoferrin was enhanced when bacteria treated with pepsin or alpha-chymotrypsin after isolation from iron-restricted and iron-containing media.

Construction of an Actinobacillus pleuropneumoniae-Escherichia coli cosmid cloning vector [Gene 160 (1995) 81-86]

We constructed a cosmid vector, pSW206, which should be useful for the construction of genomic libraries of Actinobacillus pleuropneumoniae (Apl) DNA. pSW206 is based on the broad-host-range plasmid RK2 and can be introduced into Apl by conjugation.

Construction of Actinobacillus pleuropneumoniae-Escherichia coli shuttle vectors: expression of antibiotic-resistance genes

We constructed several cloning vectors, designated pGZRS-18/19 and pGZRS-38/39, which were based on an endogenous Actinobacillus pleuropneumoniae (Apl) 4.3-kb plasmid. They carry the lacZ alpha-complementation fragment and MCS from pUC18/19, and either the bla gene under the control of a putative Apl promoter or the KmR gene from Tn903. These vectors replicate in representative strains of Apl serotypes 1 and 7, Escherichia coli, Pasteurella haemolytica (Ph) and Haemophilus (Actinobacillus) actinomycetemcomitans. We also found that Apl and Ph did not express genes under the control of the lacZ or bla promoters, suggesting that their RNA polymerases may not utilize these promoters.

[Frequency of molecular alterations in heterozygous beta-thalassemia in southern Spain and their relation to the hematologic phenotype]

INTRODUCTION

Heterozygous beta-thalassemia manifests hematologically with microcytosis, reduced red blood cell hemoglobin concentration and high hemoglobin A2 levels. Almost all molecular alterations are due to point mutations. We attempt to determinate the frequency of that mutations in the Oriental Andalusia Area, and its relationship with the hematological phenotype.

PATIENTS AND METHODS

We have studied 45 heterozygous patients. DNA samples were amplified by PCR, using the printers CD7 and HI1. A 16 Kb fragment corresponding to beta globin gene was obtained and analyzed by Dot Blot assay and hybridized with allelic specific oligonucleotide (ASO) probes to detect the 6 more frequent mutations found in the South of Spain.

RESULTS

Codon 39 nonsense mutation (31.1%) was the most frequent finding followed by IVS-1 NT 110 (26.7%). The relationship between hematological parameters and molecular mutations concluded that IVS-I NT 6 mutation developed a minimal anemia.

DISCUSSION

From the practical point of view, this study indicates that we were able to detect more than 90% of heterozygous beta-tal. with 5 out of 6 ASO probes used in this work. Thus, our data also provides a further implication in prenatal diagnosis.

The evaluation of Escherichia coli as a model for oxidant stress in mammalian hepatocytes: role of glutathione

Among bacteria, Escherichia coli are unique because they contain an amount of glutathione (GSH) comparable to that of mammalian cells. Thus, this bacterium has been suggested as a model for oxidant stress in mammalian systems. Two common strains of E. coli, ATCC 29682, a B strain, and AB 1157, a K-12 strain, were exposed to paraquat (PQ) or t-butyl hydroperoxide (TBH) and the effect on GSH, growth, and lethality was assessed. Exposure of both strains to 5 mM PQ resulted in an 80% decrease in GSH. Exposure to 5 mM TBH resulted in a 31% decrease in GSH in the K-12 strain and an 80% decrease in the B strain. No correlation was found between the GSH decrease in either strain and the PQ or TBH growth inhibitory effects. TBH exposures increased oxidized GSH (GSSG) export. However, no increase in intracellular GSSG or protein-mixed disulfides was found after exposure to either oxidant nor was GSSG secreted following PQ. After failing to inhibit GSH synthesis with buthionine sulfoximine, a B strain GSH-deficient mutant [RCI-1] was constructed. There was no difference in the growth and lethality responses to the oxidants between GSH-deficient and -sufficient strains. GSH supplementation with N-acetylcysteine or L-2-oxothiazolidine decreased the sensitivity of the E. coli B strain to the growth inhibitory but not the lethality effects of TBH. The lack of a correlation of changes in GSH with either oxidant-induced growth inhibitory or lethality effects, the presence of catalase in the cytoplasm not peroxisomes, and the absence of glutathione peroxidase are limitations to the value of this bacterium as a model for mammalian oxidant stress.