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Biomedical subjects

A Papa

Publications and source records attributed to A Papa.

At least 19 recordsLinked to original sources
PubMed2000

Genetic heterogeneity of HIV-1 in Greece.

The aim of this study was to detect and determine the genetic variation of HIV-1 in Greece and to analyze the phylogenetic relationships and transmission dynamics of identified variants. Eighty-six blood samples from HIV-1 seroconverted patients of different risk groups were collected from the AIDS clinic, AHEPA Hospital, Thessaloniki, Greece. Retroviral DNA was extracted from uncultured peripheral blood mononuclear cells. HIV-1 DNA sequences encoding a 500-bp fragment of the gp120 C2-C3 region were amplified from each study subject, and they were genetically subtyped by heteroduplex mobility assay and DNA sequencing. Genetic distances and phylogenetic relationships of DNA sequences were estimated using PHYLIP software. Our results revealed that 82 out of 86 (95.3%) subjects carried subtype B sequences, while four (4.7%) carried subtype A sequences. Subtype A in Greek individuals not having traveled abroad was documented. An average of intrasubtype B genetic divergence of 15% was noted. Our findings demonstrate the presence of at least two genetic subtypes of HIV-1 in northern Greece--subtype B and subtype A. The predominant subtype is subtype B, which was transmitted into Greece by multiple sources. Our observations lend support to the argument that the distribution of HIV-1 subtypes is determined by founder effects or other processes rather than any tropism for particular cell types or mode of transmission.

Adult↗
PubMed2000

Review article: potential therapeutic applications and mechanisms of action of heparin in inflammatory bowel disease.

Unfractioned heparin was recently reported to be beneficial in the treatment of inflammatory bowel disease. The available uncontrolled data show that it may be effective in steroid-resistant ulcerative colitis with a percentage of complete clinical remission of over 70% after an average of 4-6 weeks of therapy. The administration of unfractioned heparin is not currently justified by the very limited available data. The worsening of rectal bleeding is infrequent in treated ulcerative colitis patients and only rarely does it require blood transfusion or a colectomy. Low molecular weight heparin was used in a single trial in patients with steroid-refractory ulcerative colitis, with results similar to those observed with unfractioned heparin. Since a prothrombotic state has been described in inflammatory bowel disease, and microvascular intestinal occlusion seems to play a role in the pathogenesis of inflammatory bowel disease, it is reasonable that part of the beneficial effects of unfractioned heparin in inflammatory bowel disease may result from its anticoagulant properties. However, beyond its well-known anticoagulant activity, unfractioned heparin also exhibits a broad spectrum of immunomodulating and anti-inflammatory properties, by inhibiting the recruitment of neutrophils and reducing pro-inflammatory cytokines. Moreover, it can restore the high-affinity receptor binding of basic fibroblast growth factor and this would aid healing of the ulcerated mucosa. In conclusion, unfractioned heparin may represent a safe therapeutic option for severe, steroid-resistant ulcerative colitis, although randomized, controlled trials are needed to confirm these data.

Anticoagulants↗
PubMed2000

"Warm-up" phenomenon in adult and elderly patients with coronary artery disease: further evidence of the loss of "ischemic preconditioning" in the aging heart.

BACKGROUND: A reduction of exercise-induced ischemia in patients with coronary artery disease by means of brief period of exercise followed by resting is called the "warm-up" phenomenon. This phenomenon may represent a clinical counterpart of "ischemic preconditioning." We studied the warm-up phenomenon in both adult and elderly patients with similar angiographic evidence of coronary artery disease, using three exercise tests after excluding the "training effect." METHODS: In order to verify the presence of "training effect," three exercise tests were performed in days 1, 2, and 3 ("training" tests). The third test was used as baseline for a successive test, performed after a recovery period of 10 minutes to reestablish baseline electrocardiographic conditions. A third exercise test was performed 30 minutes later ("warm-up" tests). RESULTS: "Training" tests did not differ in all parameters in both adult and elderly patients. "Warm-up" tests showed that time to onset 1-mm ST depression was significantly higher (p < .001). whereas ST depression and time to recovery was significantly lower in the second and third test in adult but not in elderly patients (p < .001 ). Difference (in seconds) in the time at which 1-mm ST depression occurred on first warm-up exercise compared with the second was inversely correlated with age (p < .001 ). CONCLUSIONS: Previous exercise followed by resting is able to reduce the successive exercise-induced ischemia ("warm-up" phenomenon) in adult but not in elderly patients with coronary artery disease. This is independent of a greater age-related severity of coronary disease and of "training effect." These results confirm the hypothetical age-related reduction of "ischemic preconditioning" in aging heart.

Adaptation, Physiological↗
PubMed2000

Pheromone responses and high-level aminoglycoside resistance of conjugative plasmids of Enterococcus faecalis from Greece.

Fifteen of 22 clinical isolates of Enterococcus faecalis with high-level aminoglycoside resistance isolated in Greece, which were tested for mating ability, co-transferred pheromone response genes together with aminoglycoside resistance determinants to a sensitive recipient strain. Nine of them belonged to the same pulsotype, while the remaining six isolates were genetically unrelated. The prgB gene, which encodes aggregation substance, was detected in all the clinical isolates and transconjugants by both PCR and DNA hybridization but prgA, which encodes the surface exclusion protein, was only detected in two isolates, whereas it is present in most pheromone response plasmids from other sources.

Aminoglycosides↗
PubMed2000

Prevalence of factor V Leiden and the G20210A prothrombin-gene mutation in inflammatory bowel disease.

A hypercoagulable state has been hypothesized as a contributing factor in the pathogenesis of inflammatory bowel disease (IBD); moreover, such patients have an increased risk of thrombotic complications. The aim of the present paper was to study the prevalence of the two most important causes of inherited thrombophilia: factor V Leiden and the G20210A prothrombin-gene mutation in patients with Crohn's disease (CD) and ulcerative colitis (UC). Fifty-two patients affected by IBD (33 UC and 19 CD, 16 female and 36 male; mean age, 42 years) and 156 healthy controls (48 female and 108 male; mean age, 37 years) were studied. Seven out of 52 patients (13%) had previous thrombotic events. High molecular weight DNA was analysed for the presence of factor V Leiden and the G20210A prothrombin-gene mutation. One out of 52 IBD patients (1.9%) and three out of 156 control subjects (1.9%) were heterozygous for factor V Leiden. One IBD patient (1.9%) and four healthy controls (2.6%) were heterozygous for the prothrombin-gene mutation. The prevalence of the two mutations was similar in patients and controls. In the subgroup of IBD patients with previous thrombotic events, only one patient was heterozygous for the prothrombin-gene mutation. Factor V Leiden and the G20210A prothrombin-gene mutation do not seem to play a major role in the pathogenesis of IBD or be associated with an increased incidence of thrombotic complications, but with limited data.

Adult↗
PubMed2000

Helicobacter pylori eradication and remission of low-grade gastric mucosa-associated lymphoid tissue lymphoma: a long-term follow-up study.

Helicobacter pylori infection plays a crucial role not only in the pathogenesis but also in the treatment of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The aim of the present study was to evaluate whether H. pylori eradication provides a definite cure in the early stage of this neoplasia by means of a prolonged follow-up. All patients affected by low-grade gastric MALT lymphoma in stage IE that were referred to our department from January 1995 to June 1999 were enrolled in a prospective study. Diagnosis was histologically proved and H. pylori status was evaluated. Staging was performed according to a modified Ann Arbor classification. All patients who proved positive for H. pylori infection were treated with eradicating therapy, and a prolonged clinical and histologic follow-up was carried out. Until June 1999, seven low-grade gastric MALT lymphomas in stage IE were diagnosed (four men and three women; mean age, 56 years). All patients were H. pylori-positive and eradication was obtained in all of them after the first cycle of antibiotic therapy. Complete histologic regression of lymphoma was observed in all cases in a period variable between 3 and 6 months. The mean follow-up period was 42 months (range, 20-54). Only one patient showed a recurrence of lymphoma 22 months after treatment associated with H. pylori reinfection. Our results show the high efficacy of H. pylori eradication in determining a prolonged remission of low-grade gastric MALT lymphomas in stage IE. Thus, this therapeutic approach may avoid or delay the indication for more aggressive therapies, such as surgical resection.

Adult↗
PubMed2000

HIV-1 co-receptor CCR5 and CCR2 mutations among Greeks.

The frequency of CCR5 and CCR2 alleles in human immunodeficiency virus (HIV)-positive and HIV-negative populations of Northern Greece was investigated. The frequency of the CCR5Delta32 allele among the HIV-negative subjects was 0.052, while it was approximately two-fold lower among the seropositives, suggesting that the heterozygous genotype confers a partial resistance to the HIV infection. No significant difference in CCR2 allele frequency between the two groups was observed.

Alleles↗
PubMed1999

Six-day or seven-day regimens with ranitidine bismuth citrate plus high-dose clarithromycin and tinidazole are both effective against Helicobacter pylori infection.

We compared the efficacy of two therapies to eradicate H. pylori infection including ranitidine bismuth citrate (400 mg twice daily), clarithromycin (500 mg twice daily), and tinidazole (500 mg twice daily), administered for six or seven days. Eighty H. pylori-positive patients were consecutively recruited and randomly subdivided into groups A and B, receiving one of the two treatment regimens. The H. pylori status was evaluated by means of histology and rapid urease test at entry, and by [13C]urea breath test alone eight weeks after treatment. All 40 patients in group A and 39/40 in group B completed the study. Thirty-six of 40 patients in the group A (90%) and 36 of 39 in the group B (92%) became H. pylori-negative. Slight or mild side-effects occurred in 4/40 patients (10%) of group A and in 5/39 (13%) of group B. In conclusion, both regimens we tested yielded high eradication rates with modest side effects. This is the first trial investigating a triple-drug RBC-based regimen administered for only six days.

Adolescent↗
PubMed1999

Three-day antibiotic therapy with azithromycin and tinidazole plus lansoprazole or pantoprazole to cure Helicobacter pylori infection: a pilot study.

OBJECTIVE: The aim of the present study was to investigate and compare the effects of two proton-pump inhibitors, lansoprazole (Limpidex 30 mg, Sigmatau) vs pantoprazole (Peptazol 40 mg, Boehringer Mannheim), included in a three-day antibiotic therapy regimen with azithromycin (Zitromax 500 mg, Pfizer) and tinidazole (Fasigin 500 mg, Pfizer). DESIGN: Seventy consecutive, H. pylori-positive patients were randomly pre-treated with lansoprazole 30 mg o.d. (once daily) or pantoprazole 40 mg o.d. for two days, and subsequently respectively assigned to one of the two following treatment regimens, given for only three days: regimen A (LAT) comprising lansoprazole 30 mg o.d. plus azithromycin 500 mg o.d. and tinidazole 500 mg b.i.d. (bis in die), or regimen B (PAT) comprising pantoprazole 40 mg o.d. plus azithromycin 500 mg o.d. and tinidazole 500 mg b.i.d. H. pylori status was evaluated by means of histology and rapid urease test at entry, and by 13C-urea breath test alone 8 weeks after treatment. MAIN OUTCOME MEASURES: Sixty-nine of the enrolled patients completed the study: 34 in the LAT group and 35 in the PAT group. One patient in the LAT group was lost to follow-up. In the LAT group, after the end of treatment, 28/34 patients were H. pylori-negative (per protocol: 82%; intention-to-treat: 80%). In the PAT group, after treatment, 29/35 patients were H. pylori-negative (per protocol and intention-to-treat: 83%). Mild or slight side-effects occurred in only one patient in the LAT group and in one in the PAT group. CONCLUSIONS: From this study there is no evidence that either of the two proton-pump inhibitors used is preferable in a three-day antibiotic regimen with azithromycin and tinidazole. The excellent side-effect and tolerability profiles, associated with acceptable eradication rates, make the two treatment regimens we tested particularly useful when patient compliance is difficult to achieve.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1999

Prevalence and early diagnosis of coeliac disease in autoimmune thyroid disorders.

BACKGROUND AND AIMS: Coeliac disease is associated with several autoimmune disorders such as insulin-dependent diabetes, Sjogren's syndrome, Addison's disease and thyroid diseases. The aim of our study was to evaluate the prevalence of coeliac disease in patients affected by autoimmune thyroid diseases by means of anti-gliadin and anti-endomysial antibodies. PATIENTS: We studied 92 patients affected by autoimmune thyroid diseases (47 chronic autoimmune thyroiditis, 22 Hashimoto's thyroiditis and 23 Graves' disease). Ninety patients with non autoimmune thyroid disorders (51 multifollicular goitre, 28 solitary nodule and 11 papillary carcinoma) and 236 blood donors also took part in the study as control groups. METHODS: Total serum IgA were measured in all subjects to exclude selective IgA deficiency; then we measured anti-gliadin antibodies and anti-endomysial antibodies. In patients with anti-gliadin/anti-endomysial antibody positivity and/or with haematinic and laboratory signs of malabsorption we carried out gastrointestinal endoscopy with duodenal histological examination. RESULTS: Among the 92 patients with autoimmune thyroid disease, 4 (4.3%) showed anti-gliadin and anti-endomysial positivity and had coeliac disease; among the 90 patients with non autoimmune thyroid diseases, 1 (1.1%) had coeliac disease; finally, among the blood donors, 1 subject (0.4%) was anti-gliadin-anti-endomysium antibody positive and had coeliac disease. Those subjects presenting with only anti-gliadin antibody positivity did not have coeliac disease. CONCLUSIONS: These results show that the prevalence of coeliac disease in patients with autoimmune thyroid diseases is significantly increased when compared with the general population (p = 0.009) but not with patients affected by non autoimmune thyroid disorders (p = 0.18). We suggest a serological screening for coeliac disease in all patients with autoimmune thyroid disease measuring anti-endomysial antibodies, considering that early detection and treatment of coeliac disease are effective in preventing its complications.

Adult↗
PubMed1998

Retrospective serological and genetic study of the distribution of hantaviruses in Greece.

A retrospective serological and genetic study of hantaviruses responsible for hemorrhagic fever with renal syndrome (HFRS) in Greece during the last 17 years is presented. Fifty-one serum samples taken from 30 HFRS cases previously diagnosed by immunofluorescence assay were tested by ELISA for IgG (Hantaan, Dobrava, and Puumala) and IgM antibodies (Hantaan and Puumala). Results were compatible with the majority of infections being related to hantaviruses carried by rodents of the subfamily Murinae. RNA was extracted from 26 selected samples and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using primers specifically designed for the detection of hanta-viruses associated with murine (MS-N-specific, MM-G1-specific primers) or arvicoline rodents (PPT-N-specific primers). In addition, primers previously designed for the detection of the G2 coding region of the Murine-associated hanta-viruses were also used. Sequencing of the PCR products was then performed, followed by phylogenetic analysis of nucleotide sequence differences. Eleven out of the 26 serum samples tested were found to be positive by PCR with the MS-N primers, whereas four were positive with the MM-G1 primers, and only two with the G2 primers. None of the samples was found positive with the PPT primers. The sequence analysis showed that the virus that was responsible for these 11 HFRS cases was the Dobrava virus, which is endemic throughout the Balkans.

Adult↗