Alnespirone (S 20499), an agonist of 5-HT1A receptors, and imipramine have similar activity in a chronic mild stress model of depression

A chronic mild stress (CMS) model of depression was used to study an antidepressant-like activity of alnespirone (S 20499), a selective agonist of 5-HT1A receptors. In this model, a substantial decrease in consumption of a palatable sucrose solution over time is observed in rats subjected to a variety of mild stressors. This effect can be reversed by chronic administration of various classes of antidepressant drugs. Chronic (5 weeks) treatment with alnespirone, in a dose range between 1-5 mg/kg/day, gradually and dose dependently reversed the CMS-induced reductions in sucrose consumption without any significant effects in the non-stressed control animals. The onset of action of the most active doses (2.5 and 5 mg/kg/day) and the overall efficacy of alnespirone in the CMS model were comparable to those observed following similar administration of imipramine (10 mg/kg/ day). At the lower (0.5 mg/kg/day) and higher (10 and 20 mg/kg/day) doses, alnespirone was ineffective against the CMS-induced deficit in sucrose consumption. These data provide further support for previous suggestions, based on both the clinical observations and animal data, that agonism at 5-HT1A receptors may result in antidepressant action.

Rotavirus-specific cytotoxic T lymphocytes recognize overlapping epitopes in the amino-terminal region of the VP7 glycoprotein

Rotavirus-specific cytotoxic T lymphocytes (CTL) play an important role in the resolution of rotavirus infection. The outer capsid glycoprotein, VP7, elicits a class I MHC-restricted CTL response. Vaccinia virus recombinants expressing the VP7 genes from simian rotavirus SA11 (serotype G3) and from the RF strain of bovine rotavirus (serotype G6) were used to analyze the CTL activity to this antigen in BALB/c (H-2(d)) and C57BL/6 (H-2(b)) mice neonatally infected with homologous and heterologous rotaviruses. A vaccinia virus recombinant expressing the first amino-terminal 88 amino acids of VP7 was constructed and used to search for cross-reactive CTL against this region of the protein. By using synthetic Kb, Db, and Kd motif-fitting peptides two overlapping CTL epitopes have been identified located in the first hydrophobic domain (H1) of VP7. Splenocytes obtained from rotavirus SA11-infected C57BL/6 mice induced the strongest CTL response against target cells sensitized with a peptide containing a Kb-restricted CTL epitope (amino acids 8-16). A second Kd-restricted epitope (residues 5-13) was recognized by splenocytes derived from rotavirus-infected BALB/c mice. These findings reveal the existence of CTL epitopes in the H1 signal sequence of the VP7 glycoprotein that coexist with a CTL epitope (residues 31-40) previously described within the H2 region.

Treadmill training enhances glucose tolerance more in pregnant than in virgin rats

To determine whether aerobic training throughout gestation modifies glucose tolerance, female Wistar rats were mated or kept nonpregnant and run or not on a 10 degrees slope treadmill for 5 days/week at 20 m/min, starting with a 20-min run, and with a progressive daily increase of 5 min, reaching a 75-min run on the 20th day of protocol or gestation. The exercise protocol did not modify food intake, maternal and fetal weights, litter size or blood lactic acid levels. The rise in blood glucose after an oral glucose load (2 g/kg body weight) did not differ between trained and untrained nonpregnant rats but was lower in trained than in untrained pregnant rats. In the untrained rats the rise in plasma insulin levels after the glucose load was much greater in pregnant than in nonpregnant rats; in trained rats this difference between groups was attenuated by the greater effect of exercise decreasing the plasma insulin response to the glucose load in pregnant than in nonpregnant rats. Thus, an aerobic exercise protocol that does not modify the outcome of pregnancy does significantly reduce the altered oral glucose tolerance in pregnant rats and only has a minor effect in nonpregnant rats.

Local and systemic liberation of proinflammatory cytokines in ulcerative colitis

Determination of plasma and tissue cytokine levels in inflammatory bowel disease have frequently resulted in conflicting data. In the present study we determined in patients with ulcerative colitis (UC), the levels of the proinflammatory cytokines interleukin (IL)-1beta, IL-6, interferon (IFN)-gamma, and tumor-necrosis factor (TNF)-alpha liberated by peripheral blood mononuclear cells (PBMC) and lamina propria mononuclear cells (LPMC) after 48-hr culture with pokeweed mitogen (PWM). IL-1beta, IL-6, IFN-gamma and TNF-alpha in the supernatant were detected by ELISA. Results show low basal levels of IL-1beta secretion by PBMC and LPMC, and a considerable increase after mitogen stimulation. Basal IL-6 production by PBMC was higher in UC patients than in controls [2029 pg/ml, CI95(-165 to 4223) vs 572 pg/ml (-383 to 1527) respectively, P = 0.05] and also after PWM activation [14,995 pg/ml (7759-22,230) vs 6598 pg/ml (3240-9956), respectively, P = 0.05]. In LPMC, no differences in IL-6 secretion were observed. TNF-alpha in activated PBMC of patients with UC was not significantly increased in relation to control (P = 0.09). No constitutive secretion of IFN-gamma was observed in mononuclear cells. IFN-gamma levels secreted by activated LPMC were lower in patients with UC than in controls [1571 pg/ml (-108 to 3251) vs 7953 pg/ml (3851-12,055), respectively, P = 0.03]. These results suggest that IL-6, IL-1beta, and TNF-alpha participate as mediators in the inflammatory phenomena observed in UC. Further studies are necessary to evaluate the role of IFN-gamma in this condition.

[Evaluation of a simple rapid polymerase chain reaction (PCR) technique for the diagnosis of Helicobacter pylori infection in childhood]

BACKGROUND

The purpose of this study was to evaluate the use of polymerase chain reaction (PCR) applied to the diagnosis Helicobacter pylori infection in the pediatric population, by means of a rapid and simple method of extraction and posterior detection by a colorimetric hybridation of amplified H. pylori DNA.

METHODS

Fifty three gastric biopsies, obtained through upper gastrointestinal endoscopy from 53 patients with gastric pathology (45 recidivant abdominal pain and eight hematemesis), were processed from october 1995 to july 1996. Three non invasive tests were performed: detection of IgG by (Cobas) Core Anti-H. pylori EIA (Roche), breath test with 13C-urea and PCR of dental plaque, as well as four invasive ones: histologic study, culture into selective (Pylori Agar, bioMérieux) and non selective media (Columbia Agar with 5% sheep blood, bioMérieux), test of rapid urease and PCR of gastric biopsies. A 20% solution of Chelex 100 resin (DNA Extraction Reagen, Perkin Elmer) was used for DNA extraction, amplification was performed from gen ureA (Clayton, 1992) and amplified DNA was detected by colorimetric hybridation (PCR ELISA, Boehringer, Mannheim). Duration of the PCR process was: extraction 25 min, amplification two hours and detection three hours.

RESULTS

Results of culture and PCR from gastric biopsies agreed in 84.3% of cases (27 positives, 16 negatives and two not determined). Two samples were positive by culture and negative by PCR, and were considered as PCR false negatives due to positivity of three or more other tests. Six samples were negative by culture and positive by PCR, being considered as culture false negatives due to positivity of three or more other tests. Sensitivity of PCR and culture was 94.2 and 82.8%. Specificity was 100% for both tests. None of the dental plaque samples was positive.

CONCLUSIONS

When invasive techniques are to be done for microbiologic diagnose of H. pylori, PCR increases the confirmation rate of infection; the present procedure enables daily routine work due to its simplicity and its short turnaround time.

Rapid detection of toxigenic Clostridium difficile from stool samples by a nested PCR of toxin B gene

Toxigenic Clostridium difficile is the aetiologic agent of most cases of antibiotic-associated diarrhoea and pseudomembranous colitis. The present standard method for C. difficile diagnosis is a cytotoxicity assay, performed on human fibroblast cultures. It is time consuming and requires special facilities. A nested-PCR assay detecting toxin B gene within a few hours was designed. One hundred and two stool samples were collected during four months. All samples were processed for toxin B-PCR, cultured for C. difficile and tested for cytotoxicity. This approach achieved 99% concordance with the cytotoxic assay. The sensitivity and specificity for the new PCR assay were 96.3% and 100% respectively. The procedure described is easy to perform, does not require special equipment and has produced excellent results. It deserves serious consideration for routine clinical microbiology laboratory use.

Pregnancy modifies the alpha2-beta-adrenergic receptor functional balance in rabbit fat cells

The sympathetic nervous system controls lipolysis in fat by activation of four adrenergic receptors: beta1, beta2, beta3, and alpha2. During pregnancy, maternal metabolism presents anabolic and catabolic phases, characterized by modifications of fat responsiveness to catecholamines. The contributions of the four adrenergic receptors to adipocyte responsiveness during pregnancy have never been studied. Our aim was to evaluate the influence of pregnancy on adrenergic receptor-mediated lipolysis in rabbit white adipocytes. Functional studies were performed using subtype-selective and non-selective adrenergic receptor agonists. Overall adrenergic responsiveness was measured with the physiological agonist epinephrine. Non-adrenergic agents were used to evaluate different steps of the lipolytic cascade. The alpha2- and beta1/beta2-adrenergic receptor numbers were determined with selective radioligands. Non-adrenergic agents revealed that pregnancy induced an intracytoplasmic modification of the lipolytic cascade in inguinal but not in retroperitoneal adipocytes. Pregnancy induced an increase in beta1- and specially beta3-mediated lipolysis. The amounts of adipocyte beta1/beta2- and alpha2-adrenergic receptors were increased in pregnant rabbits. Epinephrine effects revealed an increased contribution of alpha2-adrenergic receptor-mediated antilipolysis in adipocytes from pregnant rabbits. These results indicate that pregnancy regulates adipocyte responsiveness to catecholamines mainly via the alpha2- and beta3-adrenergic pathways. Pregnancy induces an intracytoplasmic modification of the lipolytic cascade, probably via hormone-sensitive lipase, with differences according to fat location.-Bousquet-Mélou, A., C. Muñoz, J. Galitzky, M. Berlan, and M. Lafontan. Pregnancy modifies the alpha2-beta-adrenergic receptor functional balance in rabbit fat cells.

[Haemophilus influenzae type b invasive disease in Catalonia (1996)]

BACKGROUND

The purpose of this study was to find out the incidence and characteristics of H. influenzae type b invasive disease (HibID) in Catalonia, Spain.

MATERIAL AND METHODS

An active surveillance of H. influenzae isolated from normally sterile sites was carried out during 1996. Microbiology laboratories of hospitals of Catalonia were periodically contacted by telephone. The serotype of all the strains was studied.

RESULTS

The incidence of H. influenzae invasive disease (HIID) was 7.1 per 100,000 in children under 5 years and 1.0 per 100,000 in those over 5 years. The incidence of serotype b was 6.4 per 100,000 children under 5 years and 0.2 above this age. Only three strains belonged to types other than b (d, e and f).

CONCLUSIONS

The incidence of HIbID is uncommon in Catalonia, lower than that registered in the prevaccine era in other countries and regions of the same geographical area.

[Common variable immunodeficiency associated with autoimmune thrombocytopenia: anesthetic management]

A 44-year-old man diagnosed of common variable immunodeficiency associated with thrombopenia due to autoimmunity required anesthesia for anal fissure repair and hemorrhoidectomy. Hemostatic complications developed after surgery, with extreme thrombopenia (1,000 platelets/pl) and analytical changes that necessitated administration of six units of platelets from apheresis, as well as immunoglobulins, antifibrinolytic agents (e-aminocaproic acid) and granulocytic colony stimulating factors. Anesthesia for such patients is reviewed, with emphasis on careful management of the airways, preparation of sufficient material for surgery (rapid transfusion equipment, large caliber intravenous catheters, sterile material) and orientation of anesthetic technique toward general anesthesia through a laryngeal mask.

[Study of the viral etiology of lower respiratory tract infections in a neonatal unit]

OBJECTIVE

To study the possible viral etiology in 139 infants with lower respiratory tract infection who required hospitalization in the Infant Unit of our hospital, from October 1994 to June 1995.

PATIENTS AND METHODS

139 patients were admitted, aged from 13 days to 14 months, during this period. The etiological agent was detected by direct immunofluorescence from nasopharyngeal secretions. Monoclonal antibodies were used against Respiratory Syncitial Virus, Influenza A Virus, Influenza B Virus, Adenovirus and Parainfluenza 3 Virus. Antibody detection against these viruses by Complement Fixation Test was done on 29 of these patients, with paired sera (acute and convalescent phase).

RESULTS

In 82 patients (59%) we found at least one viral agents from the nasopharyngeal specimens, but in 64 of these only one was detected, in the remaining 18, there were more than one. Significant levels of antibodies were detected in only six of the 29 patients tested. Serology was negative in the remaining 23 patients.

CONCLUSIONS

Syncitial Respiratory Virus is the first virus responsible for the lower respiratory tract infection in this age group (49%). There was no correlation between serological diagnosis and antigen detection.

[Congenital anomalies of the mitral valve in the adult: presentation of 3 cases]

Congenital mitral valve anomalies are uncommon and their incidence in adults is very unusual. Transthoracic echocardiography is essential for their diagnosis. In this study two adult patients with parachute mitral valve and one with isolated cleft of mitral valve are described. An echocardiographic exam was decisive in obtaining the diagnosis for each of these patients. Clinical aspects, typical echocardiographic findings and therapeutical approaches of these entities are discussed.

[Cronkhite-Canada syndrome]

The case of a 76-year-old patient with the Cronkhite-Canada syndrome admitted for diarrhea is presented. Although the clinical, endoscopical and histological data suggested the diagnosis, confirmation was achieved following necropsy, as well the evolution and the different treatment schedules carried out.

Aerobic exercise during pregnancy reverts maternal insulin resistance in rats

PURPOSE AND METHODS

To determine whether pregnancy modifies the effect of aerobic exercise on insulin responsiveness, female rats were mated or kept nonpregnant and exercised or not on a treadmill (10 degrees slope, 20 m.min-1) 5 d.wk-1 during a 20-min period that was increased progressively up to 70 min on the 19th d. On day 20, a hyperinsulinemic euglycemic clamp was performed with 0.8 IU insulin.h-1.kg-1 under conscious conditions.

RESULTS

Food intake and body weight, circulating lactic acid, glucose, and insulin as well as fetal body weight and number were unaffected by the exercise protocol. The rate of glucose infusion required to maintain basal glucose levels during the clamp was similar in exercised and nonexercised virgin rats and significantly lower in pregnant than in virgin nonexercised rats. However, in exercised pregnant rats the glucose infusion rate was almost as high as in the exercised virgin rats.

CONCLUSIONS

The results show that although our aerobic exercise protocol does not affect insulin responsiveness in nonpregnant rats, it completely reverts the insulin resistance present in late pregnant rats.

Interference of nonsteroidal antiinflammatory drugs with very late activation antigen 4/vascular cells adhesion molecule 1-mediated lymphocyte-endothelial cell adhesion

OBJECTIVE

To study the effect of nonsteroidal antiinflammatory drugs (NSAIDs) on the adhesion of peripheral blood lymphocytes (PBL) to activated human umbilical vein endothelial cells (HUVEC) under conditions that resemble blood flow.

METHODS

Assays of adhesion of PBL to HUVEC or recombinant vascular cell adhesion molecule 1 (rVCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin were performed under continuous rotation at 37 degrees C. The phenotype of PBL subpopulations attached was characterized by flow cytometry. Lymphocytes were pretreated with different doses (5-100 microg/ml) of aceclofenac, diclofenac, indomethacin, or piroxicam or with inhibitory monoclonal antibodies (MAb) prior to the adhesion assays. The effect of NSAIDs on lymphocyte adhesion molecules was assessed by flow cytometry. To determine whether NSAIDs interfere with the affinity state of very late activation antigen 4 (VLA-4) integrin, we studied the effect of these drugs on the appearance of a beta1 activation-dependent epitope recognized by the HUTS21 MAb both on human T lymphoblasts and on synovial fluid lymphocytes (SFL).

RESULTS

In the flow-resembling model, PBL-HUVEC adhesion was mainly mediated by the VLA-4/ VCAM-1 adhesion pathway. The major PBL subset attached was the CD3+, CD45RO+ memory T cell, with CD49d(high) expression. Aceclofenac, diclofenac, and indomethacin, but not piroxicam, were able to inhibit PBL adhesion to HUVEC or rVCAM-1. However, the quantitative expression of VLA-4 was not affected by treatment of PBL with any of the NSAIDs studied. On T lymphoblasts and SFL, mostly CD45RO+ cells, the expression of the beta1 activation-dependent epitope detected by HUTS21 MAb was significantly decreased by aceclofenac, diclofenac, and indomethacin.

CONCLUSION

Some NSAIDs are able to inhibit the adhesion of PBL to HUVEC under conditions that resemble blood flow by interfering with the conformational change in VLA-4 that increases its affinity for VCAM-1.

[Analysis of telomeric length in epithelial carcinoma of the ovary]

BACKGROUND

As a consequence of the high cell division rate, telomeric repeat reduction in human tumor cells, giving rise to genetic instability, has recently been described. The aim of this study was to analyze by Southern blot telomeric length alterations in a retrospective group of patients with ovarian epithelial carcinoma.

PATIENTS AND METHODS

Tumor and corresponding normal DNA were isolated from paraffin-embedded tissue of 16 patients with ovarian epithelial carcinoma. Telomeric Restriction Fragments (TRF) were studied by Southern blot and densitometric analysis.

RESULTS

No telomere alterations were detected in 37.5% of patients (6/16). Of the remaining ten, 5 were found to have telomere reduction and five telomere elongation. No significant correlation was found between clinicopathological variables, response to chemotherapy, survival rate or time to progression, and telomere length alterations.

CONCLUSIONS

In ovarian epithelial carcinoma telomere elongation may be a marker of the presence of immortal cells within the tumor, but telomere or the absence of telomeric alterations do not rule out the presence of these cells. Although TRF analysis can be performed in paraffin-embedded tissues, it is not the best indicator of telomerase activity and thus of tumor aggressiveness in early stages of this carcinoma.

In vitro encystation of Blastocystis hominis: a kinetics and cytochemistry study

The kinetics of in vitro encystation of Blastocystis hominis was studied over 9 days. The differentiation between trophic (TF) and cyst forms (CF) was determined by differential counts before and after treatment with distilled water. A cytochemistry study using acridine orange and Calcofluor white wet-mount preparations of CF was carried out. The growth curves of TF and CF were related because the decrease in TF was followed by an increase in CF, and vice versa. The maximum of CF counts was obtained on the 6th or 7th day. Using the differential acridine orange stain, two subpopulations of CF, yellow-orange fluorescent cells or precysts and green fluorescent cells or cysts, were detected and their curves were also related. CF was stained by Calcofluor white, which suggested the existence of beta-(1-4)-glycosyl residues in the wall cysts of B. hominis.

Expression of the leukocyte early activation antigen CD69 is regulated by the transcription factor AP-1

The leukocyte Ag CD69, one of the earliest cell surface activation Ags, is up-regulated at the transcriptional level by proinflammatory stimuli involving the NF-kappaB/Rel family of transcription factors. However, promoter fragments lacking a critical kappaB motif respond to other stimuli such as phorbol esters and triggering Abs against TCR/CD3. Since the 5' promoter flanking region of the CD69 gene contains several putative binding sequences for transcription factor activating protein-1 (AP-1), we explored its role in the inducible expression of CD69. Stimuli that induce AP-1, but not NF-kappaB, such as pyrrolidine dithiocarbamate, augmented the cell surface expression of CD69 as well as its mRNA levels, and the promoter activity of the CD69 gene. This up-regulation is accompanied by an increased binding of jun and fos family members to a consensus AP-1 binding site of the proximal (-16) CD69 promoter region, which seems to be functionally responsive to different activation signals and is trans activated by c-jun expression vectors. Furthermore, cotransfection of a dominant negative version of c-jun, but not IkappaB, abolished the inducible transcriptional activity of the CD69 promoter. In conclusion, the inducible expression of the CD69 gene by mitogenic signals is regulated by the transcription factor AP-1.

Expression of the leukocyte early activation antigen CD69 is regulated by the transcription factor AP-1

The leukocyte Ag CD69, one of the earliest cell surface activation Ags, is up-regulated at the transcriptional level by proinflammatory stimuli involving the NF-kappaB/Rel family of transcription factors. However, promoter fragments lacking a critical kappaB motif respond to other stimuli such as phorbol esters and triggering Abs against TCR/CD3. Since the 5' promoter flanking region of the CD69 gene contains several putative binding sequences for transcription factor activating protein-1 (AP-1), we explored its role in the inducible expression of CD69. Stimuli that induce AP-1, but not NF-kappaB, such as pyrrolidine dithiocarbamate, augmented the cell surface expression of CD69 as well as its mRNA levels, and the promoter activity of the CD69 gene. This up-regulation is accompanied by an increased binding of jun and fos family members to a consensus AP-1 binding site of the proximal (-16) CD69 promoter region, which seems to be functionally responsive to different activation signals and is trans activated by c-jun expression vectors. Furthermore, cotransfection of a dominant negative version of c-jun, but not IkappaB, abolished the inducible transcriptional activity of the CD69 promoter. In conclusion, the inducible expression of the CD69 gene by mitogenic signals is regulated by the transcription factor AP-1.

Unusual invasive bronchial aspergillosis in a patient with acute lymphoblastic leukemia

Invasive tracheobronchial aspergillosis is an uncommon form of Aspergillus lung infection observed in immunocompromised patients. A 43-year-old patient diagnosed with acute lymphoblastic leukemia presented prolonged fever and hemoptysis during remission induction chemotherapy. The bronchoscopic examination showed pale mucosa with multiple raised white-colored nodules of 3 to 5 millimeters in diameter in all the bronchi. Hyphae of Aspergillus sp were observed in the biopsy of one of the nodules and in the examination of the bronchoalveolar lavage. Despite amphotericin B therapy, the patient developed bilateral necrotizing pneumonia and multiple abscesses in the brain and in the thyroid gland, and died. From a review of the literature in the Medline database, four similar cases (two in AIDS patients, one in lymphoma and the remaining case in an acute myeloid leukemia patient) have been reported.

[Diagnosis of tuberculosis in children. Evaluation of the PCR technique]

OBJECTIVE

The purpose of this study was to evaluate the usefulness of the technique of polymerase chain reaction (PCR) for the diagnosis of tuberculosis in the pediatric population.

PATIENTS AND METHODS

All patients seen at the University Hospital Sant Joan de Déu in Barcelona during the year of 1995 in which there was a clinical suspicion of or an interest in discarding tuberculosis were studied. Two types of diagnoses were considered: 1) Diagnosis from clinical evidence without microbiological confirmation, 2) A certain diagnosis including microbiological confirmation. All samples received at the microbiology laboratory were processed by baciloscopy, culture and PCR, Amplicor PCR M. tuberculosis was used as the PCR method.

RESULTS

Sixty-four samples (most of them gastric juices) from 41 children were processed during the study period. Fourteen patients, between 8 months and 17 years of age, were diagnosed of tuberculosis, Microbiological confirmation by culture and/or PCR was obtained in four patients (31%). PCR was the only positive technique in one child (staining and culture negative) with clinical evidence of tuberculosis. All samples from the other three patients that had positive cultures also had positive PCR results. False positives were not detected.

CONCLUSIONS

PCR improves the diagnosis of pediatric tuberculosis. It stands out because of its quickness (possibility of a 9 hour turn-around time), sensitivity (slightly higher than cultures in our series) and specificity.

[Etiology of enteritis in a university general hospital in Barcelona (1992-1995)]

BACKGROUND

The aim of the study was to describe the etiology of enteropathogenic agents over a four-year period (1992-1995) in a University Hospital in Barcelona.

METHODS

We studied 12,793 stool samples, 4519 were obtained from patients under 15 years and 8274 were obtained from patients over 14 years. The specimens were examined for bacteriological, parasitological and virological enteropathogens.

RESULTS

In 3380 specimens of 12,793 stool samples studied were identified an enteropathogen (26.4%). Polymicrobial associations were observed in the 6.8% of the cases. Pathogens were identified in 45% of children samples and 16.3% of adults samples. The etiological enteritis agents more frequently detected in the paediatric patients were Campylobacter (13.5%), rotavirus (11.3%) and Salmonella (10.2%); and Salmonella (4.9%), Campylobacter (3.1%) and Giardia intestinalis (2.1%) in adults. Cryptosporidium (13.5%) was the most frequent cause of gastrointestinal tract infections in HIV-infected subjects. In the children with stools positives, the presence of red and white blood cells were more frequent than the adults with stools positives (73% versus 26.6%).

CONCLUSIONS

The enteropathogenic agents such as Campylobacter, Salmonella, and Giardia were the most frequent cause of gastroenteritis in our environment. In the children, rotavirus infections predominated during the cold months. The most frequent cause of gastroenteritis in HIV-infected patients was Cryptosporidium followed by Campylobacter.

Internucleosomal breakdown of the DNA of brain cortex in human spongiform encephalopathy

The analysis of chromatin structure in cases of human spongiform encephalopathies could show the possible involvement of apoptosis in neuronal cell death. Genomic DNA was purified from peripheral blood lymphocytes and from a biopsy of the brain cortex in a case of Creutzfeldt-Jakob disease. Restriction fragment polymorphism with AspI, PvuII, Del and NspI showed the pattern of wild type PrP gene. The DNA purified from the brain consisted of partially degraded DNA in internucleosomal-sized fragments, whereas the DNA from peripheral blood lymphocytes showed the high molecular weight of unbroken DNA. These results are consistent with the possible activation in vivo of the apoptotic endonuclease and the internucleosomal fragmentation of DNA of the brain cortex in the patient affected by Creutzfeldt-Jakob disease, suggesting the involvement of apoptosis in neuronal cell death in human spongiform encephalopathy.

Laccase isoenzymes of Pleurotus eryngii: characterization, catalytic properties, and participation in activation of molecular oxygen and Mn2+ oxidation

Two laccase isoenzymes produced by Pleurotus eryngii were purified to electrophoretic homogeneity (42- and 43-fold) with an overall yield of 56.3%. Laccases I and II from this fungus are monomeric glycoproteins with 7 and 1% carbohydrate content, molecular masses (by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) of 65 and 61 kDa, and pIs of 4.1 and 4.2, respectively. The highest rate of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) oxidation for laccase I was reached at 65 degrees C and pH 4, and that for laccase II was reached at 55 degrees C and pH 3.5. Both isoenzymes are stable at high pH, retaining 60 to 70% activity after 24 h from pH 8 to 12. Their amino acid compositions and N-terminal sequences were determined, the latter strongly differing from those of laccases of other basidiomycetes. Antibodies against laccase I reacted with laccase II, as well as with laccases from Pleurotus ostreatus, Pleurotus pulmonarius, and Pleurotus floridanus. Different hydroxy- and methoxy-substituted phenols and aromatic amines were oxidized by the two laccase isoenzymes from P. eryngii, and the influence of the nature, number, and disposition of aromatic-ring substituents on kinetic constants is discussed. Although both isoenzymes presented similar substrate affinities, the maximum rates of reactions catalyzed by laccase I were higher than those of laccase II. In reactions with hydroquinones, semiquinones produced by laccase isoenzymes were in part converted into quinones via autoxidation. The superoxide anion radical produced in the latter reaction dismutated, producing hydrogen peroxide. In the presence of manganous ion, the superoxide union was reduced to hydrogen peroxide with the concomitant production of manganic ion. These results confirmed that laccase in the presence of hydroquinones can participate in the production of both reduced oxygen species and manganic ions.

[Clinical significance of Blastocystis hominis infection: epidemiologic study]

BACKGROUND

To evaluate the frequency of Blastocystis hominis parasitation and to ascertain its role as an intestinal a prospective study during 18 months pathogen has been carried out.

SUBJECTS AND METHODS

The study included 2,039 patients, which were classified in three groups (asymptomatic [group A], with suspicion of parasitosis [group B], with diarrhoea [group C]). In all cases a coproparasitological study was performed. In the group C the presence of non-parasitic enteropathogens was also investigated. In patients with B. hominis in the absence of other pathogens clinical and epidemiological characteristics were evaluated. Also, its was determined the morphology and quantification of parasites.

RESULTS

Parasites were identified in 26.2% of population. B. hominis was identified in 336 patients (16.5%). The frequency of parasitation was superior in adults (p < 0.0001), with a slight predominance in the female sex. The rate of asymptomatic carriers was 3.3%. In 21 patients B. hominis (group C) was observed in absence of other enteropathogens. Statistical significant association was found between B. hominis, in absence of other pathogens and the presence of clinical manifestations (p < 0.0001), the most common of which were diarrhoea and abdominal pain. We did not find a statistically significant association between the number of B. hominis present and stool characteristics. The vacuolar form was the predominant morphological type. The ameboid form was observed only in diarrhoeal stools.

CONCLUSIONS

B. hominis is the most frequent parasite found in faecal parasitological investigation. In absence of other causes, B. hominis must be considered as a pathogen.

[Myocardial revascularization with one and two mammary arteries: clinical results and long-term follow-up]

BACKGROUND

Coronary bypass grafts made with internal mammary artery have better long-term results than those made with saphenous vein. It is possible that the use of both mammary arteries would lead to even better results.

AIM

To compare the long-term survival and the incidence of new coronary events of patients, in whom one or two mammary arteries were used as coronary bypass grafts.

PATIENTS AND METHODS

One hundred and eight randomly selected patients who received one mammary artery for myocardial revascularization and 108 patients, matched for prognostic factors, who received two mammary arteries were studied. These patients were followed for a mean of 4 years (range 1 to 12 years). Operative complications, hospital mortality and long-term probability of being free of disease were compared in both groups.

RESULTS

Operative mortality was similar in both groups (0.9%). Patients that received two mammary arteries had a higher frequency of operative wound complications. Long-term survival was 84% in patients who received one and 83% in patients who received two mammary arteries. The probabilities of being free of myocardial infarction (92 and 82% respectively) and angina (94 and 86% respectively) were lower in the later group.

CONCLUSIONS

Patients who received two mammary arteries had a higher probability of a long term disease free survival than patients who received one mammary artery.

Iron, anemia, and infection

The data on the relationship between iron deficiency and infection are conflicting. Some researchers conclude that mild iron deficiency is beneficial for immunity, whereas others contend that any deficit is not good for immunity. Additionally, infection or inflammation generate anemia and profound changes in iron metabolism mediated by cytokines. These changes are important confounders to consider in assessments of iron status.

Quinone redox cycling in the ligninolytic fungus Pleurotus eryngii leading to extracellular production of superoxide anion radical

Quinone redox cycling is generally known as an intracellular process that implies the reduction of quinones (Q) into semiquinones (Q-.) or hydroquinones (QH2), which autoxidize reducing oxygen to superoxide anion radical (O-.2). We demonstrate here for the first time the existence of quinone redox cycling in a ligninolytic fungus, Pleurotus eryngii, showing two particularities: extracellular production of O-.2 and involvement of ligninolytic enzymes. Experiments were performed with P. eryngii cultures, showing laccase activity, and four quinones: 1,4-benzoquinone (BQ), 2-methyl-1,4-benzoquinone (MeBQ), 2,3,5,6-tetramethyl-1,4-benzoquinone (duroquinone, DQ), and 2-methyl-1,4-naphthoquinone (menadione, MD). The overall process consisted of cell-bound divalent reduction of quinones, followed by extracellular laccase-mediated oxidation of hydroquinones into semiquinones, which autoxidized to a certain extent producing O-.2 (at the pH values of natural degradation of lignin, some autoxidation of hydroquinones was observed only with DQH2 and MDH2). The existence of a redox cyclic system involving quinones was evidenced by determining the chemical state of quinones along incubation under several conditions (either different O2 concentrations and pH values or laccase amounts). Thus, QH2/Q ratios at system equilibrium decreased as either pH values and oxygen concentration (allowing hydroquinones autoxidation) or the amount of laccase increased. Once the cyclic nature of the system was demonstrated, special attention was paid to the production of O-.2 during hydroquinone oxidation. Except in the case of BQH2, production of O-.2 was found in samples containing hydroquinones and laccase. By the use of agents promoting the autoxidation of semiquinones (superoxide dismutase and Mn2+), production of O-.2 during oxidation of BQH2 could finally be demonstrated.

Highly informative single-stranded conformation polymorphism (SSCP) of short tandem repeats in DNA identification

The analysis of short tandem repeats (STR) by PCR is a useful technique widely used in DNA identification. Some loci have alleles differing in the number of complete repeat units, whereas others are polymorphic with alleles differing even to the level of a single base. Minor differences in the sequence of STR can confuse the analysis when the PCR product are poorly resolved in denaturing PAGE. The study by SSCP of STR in loci CSF1PO, TPOX, and THO1 and the alleles of locus DIS80 is shown in a representative case of paternity dispute. The analysis of short tandem repeats (STR) by the conformation polymorphisms of single-stranded DNA (SSCP) clearly enhanced the degree of resolution. The high resolution of SSCP of the STR may be the result of the arrangement of very prominent secondary structure and conformation due to the primary repetitive sequence. The method may be of particular interest to distinguish STR with similar PAGE mobility under denaturing conditions and to distinguish tandem repeats of the same size but different sequence.

Pyrrolidine dithiocarbamate inhibits the production of interleukin-6, interleukin-8, and granulocyte-macrophage colony-stimulating factor by human endothelial cells in response to inflammatory mediators: modulation of NF-kappa B and AP-1 transcription factors activity

Endothelial cells (EC) play a key role in the inflammatory response, both by the production of proinflammatory cytokines and by their interaction with leukocytes. Molecular genetic analysis has demonstrated that functional NF-kappa B sites are involved in the transcription of interleukin-6 (IL-6), IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) genes in response to inflammatory mediators. Thus, we have explored the effect of two inhibitors of the NF-kappa B activation, pyrrolidine dithiocarbamate (PDTC) and N-acetylcysteine (NAC), on the production of these cytokines by EC. Both PDTC and NAC inhibited, in a dose-dependent manner, the synthesis of IL-6, IL-8, and GM-CSF induced by tumor necrosis factor (TNF)-alpha or bacterial lipopolysaccharides (LPS) in human umbilical vein endothelial cells (HUVEC). PDTC appeared to prevent IL-6, IL-8, and GM-CSF gene transcription, as it blocked the induction of specific mRNA by TNF-alpha or LPS. The TNF-alpha mediated transcriptional activation of a chloramphenicol acetyltransferase (CAT) plasmid containing three copies of the -72 kappa B binding site from the IL-6 promoter was abrogated by PDTC. According to transfection experiments, electrophoretic mobility shift assays (EMSA) demonstrated that the antioxidant prevented the induction of NF-kappa B DNA-binding activity by TNF-alpha. Under the same conditions, PDTC by itself or in combination with TNF-alpha, enhanced the DNA-binding activity of AP-1, as well as c-fos and c-jun mRNA levels. Altogether, these results indicate that the antioxidant PDTC specifically inhibits the transcription of IL-6, IL-8, and GM-CSF genes through the inhibition of the NF-kappa B activation, while increasing the expression of AP-1. Our data make evident the antiinflammatory and immunoregulatory potential of the pharmacological inhibition of the NF-kappa B activation. In addition, PDTC and related molecules may be a useful tool to explore the expression of genes involved in the inflammatory response.

Transcriptional up-regulation of intracellular adhesion molecule-1 in human endothelial cells by the antioxidant pyrrolidine dithiocarbamate involves the activation of activating protein-1

The redox status of the cell plays an essential role in regulating signal transduction, transcription factor activity, and expression of cell surface molecules. In this study, we show that pyrrolidine dithiocarbamate (PDTC), a potent antioxidant agent, upregulated the cell surface expression of intercellular adhesion molecule-1 (ICAM-1) in human endothelial cells (EC). Further analysis of PDTC-mediated ICAM-1 up-regulation revealed that PDTC increased ICAM-1 mRNA levels and augmented its gene promoter activity. Transfection experiments in EC with reporter constructs harboring nested deletion fragments of the ICAM-1 promoter indicated the presence of a functional PDTC-responsive region located between positions -136 to -353 of the promoter. Gel retardation assays together with supershift analysis revealed that PDTC induced the binding of c-fos and c-jun to a consensus activating protein-1 (AP-1) binding site located at position -284. PDTC alone or in combination with TNF-alpha enhanced AP-1-dependent transactivation in HUVEC, as determined by DNA binding assays. The functional implication of AP-1 in the transcription of the ICAM-1 gene was further demonstrated by cotransfection experiments in which a c-jun expression vector induced the promoter activity of the PDTC-responsive element of the ICAM-1 promoter. Taken together, these results indicate that the antioxidant PDTC induces transcriptional activation of ICAM-1 and that this induction is mediated at least in part by the transcription factor AP-1. This mechanism might be operative in pathologic conditions in which a redox imbalance plays a key role, such as ischemia/reperfusion injury or arteriosclerosis.

Transcriptional up-regulation of intracellular adhesion molecule-1 in human endothelial cells by the antioxidant pyrrolidine dithiocarbamate involves the activation of activating protein-1

The redox status of the cell plays an essential role in regulating signal transduction, transcription factor activity, and expression of cell surface molecules. In this study, we show that pyrrolidine dithiocarbamate (PDTC), a potent antioxidant agent, upregulated the cell surface expression of intercellular adhesion molecule-1 (ICAM-1) in human endothelial cells (EC). Further analysis of PDTC-mediated ICAM-1 up-regulation revealed that PDTC increased ICAM-1 mRNA levels and augmented its gene promoter activity. Transfection experiments in EC with reporter constructs harboring nested deletion fragments of the ICAM-1 promoter indicated the presence of a functional PDTC-responsive region located between positions -136 to -353 of the promoter. Gel retardation assays together with supershift analysis revealed that PDTC induced the binding of c-fos and c-jun to a consensus activating protein-1 (AP-1) binding site located at position -284. PDTC alone or in combination with TNF-alpha enhanced AP-1-dependent transactivation in HUVEC, as determined by DNA binding assays. The functional implication of AP-1 in the transcription of the ICAM-1 gene was further demonstrated by cotransfection experiments in which a c-jun expression vector induced the promoter activity of the PDTC-responsive element of the ICAM-1 promoter. Taken together, these results indicate that the antioxidant PDTC induces transcriptional activation of ICAM-1 and that this induction is mediated at least in part by the transcription factor AP-1. This mechanism might be operative in pathologic conditions in which a redox imbalance plays a key role, such as ischemia/reperfusion injury or arteriosclerosis.

Pentosan polysulfate-induced thrombocytopenia: a case diagnosed with an ELISA test used for heparin-induced thrombocytopenia

We report a patient who developed severe thrombocytopenia and ischemic stroke following pentosan polysulfate treatment. An ELISA test employed in type-II heparin-induced thrombocytopenia was highly positive. To our knowledge, this is the first case in which this test has been performed in a pentosan polysulfate-induced thrombocytopenia (PIT). Our data suggest that the antibody against pentosan polysulfate-platelet complex also cross-reacts with heparin-platelet factor 4 complex. Due to its greater sensitivity and wider availability, this ELISA test should be used in cases where PIT is suspected.

Expression of CD15 in normal and metaplastic Paneth cells of the digestive tract

AIMS

To substantiate that incubation with monoclonal antibody CD15 (C3D-1) elicits a distinctive immunoreaction in normal small intestinal Paneth cells, normal and metaplastic Paneth cells along the digestive tract were assessed to determine whether they are also immunoreactive to CD15.

METHODS

Paneth cells in paraffin wax embedded specimens of normal small intestine, appendix and proximal ascending colon, and from cases of chronic gastritis and ulcerative colitis were investigated immunohistochemically for lysozyme and CD15 antigen expression by means of the avidin-biotin peroxidase complex method.

RESULTS

CD15 antibody reacted with a high proportion of both normal and metaplastic Paneth cells. Paneth cell immunoreactivity to CD15, however, was less intense and less extensive than to antilysozyme antibody, though the latter also stained many other cell types and was more commonly associated with nonspecific background staining.

CONCLUSIONS

CD15 seems to be a valuable adjuvant for the study of Paneth cells in the normal and diseased digestive tract. Furthermore, as CD15 has been shown to be involved in activation of phagocytes, its expression in Paneth cells reinforces their proposed role as antimicrobial agents and regulators of the intestinal flora.

Cluster headache syndrome associated with middle cerebral artery arteriovenous malformation

Cluster headache (CH) is an idiopathic cephalalgic syndrome, although several pathological processes have been described in association with this syndrome. We report two cases of cluster headache in hospitalized patients with middle cerebral artery dependent arteriovenous malformation (AVM). After surgical removal of the AVM the headache completely resolved, suggesting that complementary studies and treatment of the underlying aetiology may be indicated for secondary forms of cluster headache.

Interleukin 1 and tumor necrosis factor in obese alcoholics compared with normal-weight patients

We performed a liver biopsy and measured plasma concentrations of interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha), and spontaneous and lipopolysaccharide-stimulated in vitro monocyte production of IL-1 beta and TNF-alpha in 19 obese and 17 age-matched, normal-weight alcoholics admitted for treatment of their alcoholism. Nine healthy normal-weight alcoholics had cirrhosis in their liver biopsy (Fisher's exact test: P=0.031). A histologic score (derived from the sum of fat, necrosis, fibrosis, and inflammation in the biopsy) correlated with body mass index and the percentage body fat, calculated by using the sum of four skinfold-thickness measures. Plasma concentrations and spontaneous in vitro monocyte production of IL-1 beta and TNF-alpha were below detection limits. No significant differences were observed between normal-weight and obese alcoholics with or without cirrhosis and normal control subjects in lipopolysaccharide-stimulated monocyte production of IL-1 beta (6.5 +/- 0.8, 10.1 +/- 2.7, 7.9 +/- 1.6, and 5.28 +/- 4.24 micrograms/L, respectively) or TNF-alpha (2.8 +/- 0.4, 3.7 +/- 1.0, 3.0 +/- 0.44, and 1.97 +/- 1.01 micrograms/L, respectively). However, a positive correlation was found between IL-1 beta production and body mass index (r=0.333, P=0.047), percentage body fat (r=0.412, p=0.013), abdominal circumference (r=0.416, P=0.012), and total histologic score (r=0.331, P=0.049). A multiple-regression model accepted abdominal circumference as the only independent predictor of IL-1 beta production. TNF-alpha did not correlate with any of the above-mentioned indexes. We conclude that obese alcoholics have a higher frequency of histologic liver damage and that IL- 1 beta production by stimulated monocytes is related to abdominal fat accumulation.

[Microbiological study of the respiratory tract in children with cystic fibrosis]

PURPOSE

Pulmonary infections is a main cause of morbimortality in patients suffering from cystic fibrosis. The objective of this study was to know the flora implicated in respiratory pathology of all mucoviscidotic children attending Hospital Sant Joan de Déu of Barcelona.

METHODS

Quantitative cultures from respiratory samples (most of them: sputum) of 26 patients were performed from January 91 to June 93. There were 13 girls and 13 boys, aged 1 to 13 years (mean: 7 years).

RESULTS

282 microorganisms were isolated from 203 positive samples. Cultures of 88.4% of patients yielded in some moment Haemophilus influenzae, 82.6% of them Haemophilus parainfluenzae, 65.3% Pseudomonas aeruginosa, 50% Streptococcus pneumoniae, 38.4% Staphylococcus aureus. The most prevalent microorganism was P. aeruginosa (66%) followed by H. influenzae (29%) and S. aureus (26.6%). 59% of P. aeruginosa strains showed a mucoid phenotype.

CONCLUSIONS

Haemophilus sp. causes short term infections that affect children of all ages, whereas infections due to P. aeruginosa persist in spite of correct antimicrobial therapy.

[Cerebral toxoplasmosis in patients with human immunodeficiency virus (HIV) infection. Clinico-radiological and therapeutic aspects in 63 patients]

We have retrospectively reviewed 63 cases of encephalic toxoplasmosis (ET) in HIV-infected patients in order to determine clinical and radiological characteristics, the diagnostic value of serologic determinations, and the response to antioxoplasmic therapy. ET was the AIDS-defining condition in 44% of the patients. Eighty of the patients had a CD4 cell count < 100/microliters when ET was diagnosed. Only 4.8% of the patients had been taking anti-Pneumocytis carinii prophylaxis with cotrimoxazol. The most frequent clinical presentation was focal neurologic signs in 80.9% of the patients, with headache and fever in 53.3% and 42.4%, respectively. The most frequent cerebral CT finding was hipodense lesions (92%) with ring enhancement (68.9%). They were most frequently had a hemisferic location. Seroconversion was detected in two patients (6%), whereas 55 patients had serologic evidence of latent infection by Toxoplasma gondii (87.3%). Ninety eight percent of the patients were treated with sulphadiazine plus pyrimethamine. However, such therapy should be discontinued in 22% of them and switched to clindamycin plus pyrimethamine. The overall mortality rate during the acute phase of the disease was 7.9%, but 41.4% of the survivors exhibited neurologic sequelae. Relapsing ET was detected in 33.3% of the patients, and it was usually due to discontinuation of treatment. The mean survival time after the diagnosis of ET was 11.5 months. ET is the most common opportunistic infection of the central nervous system among our AIDS patients. Primary prophylaxis for toxoplasmic infection seems advisable in our epidemiologic environment, when CD4 cell count is less than 200/microliters and there is serologic evidence of latent infection. Acute ET usually has a good response to therapy, and the acute mortality rate is low. However, most of the survivors will remain with neurologic sequelae. The high frequency of adverse effects to sulphamide therapy with clindamycin make the need of alternative treatment strategies urgent.