Biomedical subjects

M Rossi

Publications and source records attributed to M Rossi.

At least 217 records · Page 12Linked to original sources

PubMed1999

The alcohol dehydrogenase gene: distribution among Sulfolobales and regulation in Sulfolobus solfataricus.

The distribution of the alcohol dehydrogenase gene (adh) among different Archaea was investigated by Southern blot analysis revealing the potentiality of the adh gene as a specific marker for the genus Sulfolobus. Moreover, the in vivo expression of the adh gene from a new isolate of Sulfolobus solfataricus, G theta, was studied to investigate gene regulation in Archaea. Primer extension analysis allowed the identification of a single initiation site and the TATA box element. Comparison of the G theta adh promoter with the corresponding Ssadh (adh from S. solfataricus) and RC3adh (adh from Sulfolobus RC3) also revealed the presence of two putative regulatory inverted repeats at the 5' of the TATA element. Northern blot analysis and enzymatic assays demonstrated that the transcription and expression of the G theta adh gene is regulated by different carbon and energy sources or by the natural substrate of the ADH enzyme.

Alcohol Dehydrogenase↗

PubMed1999

The role of antithrombin III in the perioperative management of the patient with unstable angina.

BACKGROUND: To evaluate the effectiveness of intraoperative administration of antithrombin III (AT III) to improve anticoagulation and preserve the hemostatic mechanisms during cardiopulmonary bypass (CPB) in patients with unstable angina under heparin treatment. METHODS: We divided 22 patients, scheduled for coronary artery bypass grafting, into two groups. Group A (11 patients) received 3000 International Units (IU) of AT III concentrates plus heparin before aortic cannulation. Group B (11 patients) received only heparin. Blood drainage, allogeneic blood transfusions, and intraoperative activated coagulation time were recorded. Also, AT III, thrombin-antithrombin complex (TAT), fragment 1.2 (F 1.2), and D-dimers were measured during the operation and the first postoperative day. RESULTS: Group A patients had fewer transfusions and had less chest-tube drainage. In group A, AT III levels increased after AT III concentrates administration and were always higher than in group B. In group B, F 1.2 and TAT increased significantly more after CPB and at the end of operation. Differences in D-dimers between the groups were not significant. CONCLUSIONS: Intraoperative administration of AT III concentrates allowed adequate anticoagulation during CPB and attenuated the coagulative cascade activation and the consequent consumptive coagulopathy.

Angina, Unstable↗

PubMed1999

Human papillomavirus with co-existing vulvar vestibulitis syndrome and vestibular papillomatosis.

OBJECTIVE: The role of HPV infection in cases of vulvar papillomatosis and vulvar vestibulitis syndrome is still unclear and data from the literature is controversial. In this study we intended to investigate the prevalence of viral infection, with a multidisciplinary approach, in cases with a co-existence of the two patterns. METHOD: Sixteen consecutive cases with diagnosis of vulvar vestibulitis syndrome and co-existence of vestibular papillomatosis were enrolled in the study and investigated by the means of vulvar cytology, vulvoscopy, histology, ViraPap and Polymerase Chain Reaction. RESULT: Cytology, vulvoscopy and histology did not demonstrate suitable accuracy for the diagnosis. Viral DNA identification revealed two (12.50%) positive cases using PCR and one (6.25%) positive case with ViraPap. CONCLUSION: The results of the present investigation indicate that even in cases of co-existing vulvar papillomatosis and severe vulvar vestibulitis syndrome, the prevalence of HPV infection is too low to be considered causal.

Adult↗

PubMed1999

IgA antibodies to tissue transglutaminase: An effective diagnostic test for celiac disease.

OBJECTIVE: Tissue transglutaminase (tTG) is the main autoantigen recognized by endomysial antibodies. The aim of this study was to assess sensitivity, specificity, and predictive value of IgA and IgG antibodies to tTG in the diagnosis of celiac disease compared with endomysial antibodies. STUDY DESIGN: We established enzyme-linked immunosorbent assay procedures to measure IgA and IgG antibodies to tTG in sera from 48 untreated and 33 treated patients with celiac disease and from 63 patients with gastrointestinal disease who were in a control group. Sera from 10 patients with celiac disease were examined at various times after gluten was reintroduced into the patients' diet. RESULTS: Both IgA and IgG to tTG were significantly (P <.001) higher in serum of untreated patients with celiac disease versus those in the control group; IgA but not IgG was significantly (P <.001) higher in untreated versus treated patients with celiac disease. IgA and IgG antitissue tTG had a diagnostic sensitivity, specificity, and positive predictive value of 92% and 21%, 98% and 97%, and 98% and 83%, respectively. The concordance rate of IgA anti-tTG with IgA antiendomysial antibodies was 95%. In 5 of the 10 patients undergoing gluten challenge, IgA antiendomysium antibodies were detected earlier than IgA anti-tTG antibodies. CONCLUSIONS: tTG-based enzyme-linked immunosorbent assay is an effective diagnostic test, although immunofluorescent-based assays are more sensitive, particularly during gluten challenge.

Adolescent↗

PubMed1999

Outcome after distal vascular reconstruction in women.

Although women are less likely to develop symptomatic atherosclerosis, little data exists on the long-term outcome of women undergoing infrainguinal arterial reconstructions. This study analyzes the operative mortality rate, complications, and the short-term and long-term results after these procedures in both men and women who had symptomatic vascular disease. From 1984 to 1997, 3956 infrainguinal arterial reconstructions were performed at Albany Medical Center. A total of 2474 (62.54%) reconstructions were performed in men and 1482 (37.46%) in women. The mean ages were 67 years for men and 71 years for women. Forty-three percent of the men were smokers compared with 26% of the women. Diabetes was present in 51% of the men and 55% of the women. Claudication was the indication for bypass in 298 (12.05%) men and 110 (7.42%) women. Limb salvage occurred in 2176 (87.95%) men and 1372 (92.58%) women. Perioperative 30-day patency rates were 96.66% in men and 96.50% in women. Primary patency rates at 1, 3, 5, and 10 years were compared; no significant difference existed between men and women. Secondary patency also was similar in both men and women. These results indicate that women requiring arterial reconstruction for infrainguinal occlusive disease had short-term and long-term graft patency results that were comparable with the results of men.

Aged↗

PubMed1999

Smith-Lemli-Opitz syndrome: evidence of T93M as a common mutation of delta7-sterol reductase in Italy and report of three novel mutations.

The Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis characterised by facial dysmorphisms, mental retardation and multiple congenital anomalies. SLOS is caused by mutations of the human Delta7-sterol reductase (DHCR7) gene and, so far, 19 different mutations have been described. Among these, mutations impairing the activity of the C-terminus appear to be the most severe. Here we report the mutational analysis of the DHCR7 gene in nine Italian SLOS patients. The T93M mutation, previously reported in one patient, results the most frequent one (7/18 alleles) in our survey. Furthermore, we identified three novel mutations, two missense mutations (N407Y and E448K), and a 33 bp deletion spanning part of exon 5 and the donor splice site of intron 5.

Adolescent↗

PubMed1999

Reduction in caregiver-identified problem behaviors in patients with Alzheimer disease post-hearing-aid fitting.

Studies and clinical procedures related to patients with Alzheimer disease (AD) largely have ignored the hearing ability of either the patient or caregiver. Yet the majority of treatment and investigation depends on or presupposes communication ability. Further, caregiver complaints often center around communication-based issues. Hearing deficits may be the most frequently unrecognized condition in patients with AD because patients either communicate adequately in quiet or the impairment is masked by other behavioral symptoms of AD. The current investigation identified individuals with AD with perceived and measured hearing impairment, provided amplification management, and evaluated the impact of treatment on caregiver-identified problem behaviors believed to be related to hearing status. Specifically, treatment compliance (hearing-aid use) and treatment efficacy (reduction in perceived hearing handicap and problem behaviors) were measured in the current investigation. A multiple-baseline design across individuals with multiple dependent variables was used to evaluate the reduction of problem behaviors post-hearing-aid treatment. Eight participants were included and 1 to 4 problem behaviors were significantly reduced for each patient after hearing-aid treatment. All participants were able to complete the necessary evaluation for hearing-aid fitting and wore their hearing aids between 5 and 15 hours per day by the end of the study. This investigation employed novel methodology in the areas of on-site hearing evaluation and hearing-aid selection, advanced hearing-aid technology, and primary data recording of caregiver-identified problem behaviors by caregivers.

Aged↗

PubMed1999

Antibiotic combination therapy in patients with chronic, treatment-resistant pouchitis.

BACKGROUND: Pouchitis is the major long-term complication after ileal pouch-anal anastomosis for ulcerative colitis. About 15% of patients have a chronic, treatment-resistant disease. AIMS: To evaluate the efficacy of an antibiotic combination for chronic active, treatment-resistant pouchitis. PATIENTS AND METHODS: Eighteen patients were treated orally with rifaximin 1 g b.d. + ciprofloxacin 500 mg b.d. for 15 days. Symptoms assessment, endoscopic and histological evaluations were performed at screening and after 15 days using the Pouchitis Disease Activity Index (PDAI). Improvement was defined as a decrease of at least 3 points in PDAI score, and remission as a PDAI score of 0. Systemic absorption of rifaximin was determined by high performance liquid chromatography. Faecal samples were collected before and after antibiotic treatment for stool culture. RESULTS: Sixteen out of 18 patients (88.8%) either improved (n=10) or went into remission (n=6); the median PDAI scores before and after therapy were 11 (range 9-17) and 4 (range 0-16), respectively (P < 0.002). No side-effects were reported. Rifaximin plasma levels and urinary excretion were negligible, confirming its mainly topical activity. A significant decrease in total anaerobes and aerobes, enterococci, lactobacilli, bifidobacteria and bacteroides in faecal samples was observed, while the reduction in number of coliforms and Clostridium perfringens did not reach a statistical significance. CONCLUSIONS: A combination of rifaximin and ciprofloxacin was effective in patients with active chronic, treatment-resistant pouchitis, suggesting the need, in these patients, for treatment using antibiotic agents with wide antibacterial spectrum of activity.

Adult↗

PubMed1999

Intravenous or intranasal administration of gliadin is able to down-regulate the specific immune response in mice.

The mucosal lesion in coeliac disease (CD) represents an immunologically mediated injury triggered by gliadin and is restricted by a particular assortment of major histocompatibility complex (MHC) class II genes. Therefore, immunomodulatory strategies to tolerize gliadin-specific, class II-restricted T-cell responses could represent an alternative to current treatments of CD, which are based on a gluten-free diet. In this study, BALB/c mice derived from a gluten-free diet colony were tolerized by either intranasal (i.n.) or intravenous (i.v.) administration of single or multiple doses of gliadin. While a single dose failed to induce tolerance, a significant decrease in gliadin-specific T-cell proliferation was detected (P < 0.001) after multiple i.n. or i.v. administrations. No significant difference in antibody titre was detected for antigen-specific immunoglobulin G (IgG) or the IgG1 subclass, but a lower IgG2a-specific titre was observed. Both interferon-gamma (IFN-gamma) and interleukin (IL)-2 expression, measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR), were reduced on antigen administration, both i.v. and i.n. Neither regimen showed a regulatory effect on IL-4 production. As T helper 1 (Th1) cytokines seem to be important in the pathogenesis of CD, our data therefore highlight the potential of i.n. and i.v. routes for the design of useful immunomodulatory strategies for CD.

Administration, Intranasal↗

PubMed1999

beta-glycosidase from the hyperthermophilic archaeon Sulfolobus solfataricus: structure and activity in the presence of alcohols.

beta-Glycosidase from the extreme thermophilic archaeon Sulfolobus solfataricus is a tetrameric protein with a molecular mass of 240 kDa, stable in the presence of detergents, and with a maximal activity at temperatures above 95 degrees C. Understanding the structure-activity relationships of the enzyme under different conditions is of fundamental importance for both theoretical and applicative purposes. In this paper we report the effect of methanol, ethanol, 1-propanol, and 1-butanol on the activity of S. solfataricus beta-glycosidase expressed in Escherichia coli. The alcohols stimulated the enzyme activity, with 1-butanol producing its maximum effect at a lower concentration than the other alcohols. The structure of the enzyme was studied in the presence of 1-butanol by circular dichroism, and Fourier-transform infrared and fluorescence spectroscopies. Circular dichroism and steady-state fluorescence measurements revealed that at low temperatures the presence of the alcohol produced no significant changes in the tertiary structure of the enzyme. However, time-resolved fluorescence data showed that the alcohol modifies the protein microenvironment, leading to a more flexible enzyme structure, which is probably responsible for the enhanced enzymatic activity.

1-Butanol↗

PubMed1999

Basophil releasability in young highly trained and older athletes.

PURPOSE: Exercise-induced hypoxemia in highly trained athletes is associated with an increase in histamine release during exercise. The cells most implicated in blood histamine release are basophils. The aim of this study was to determine whether high-level endurance training induces modifications in histamine releasability from human basophils. METHODS: Seven young highly trained athletes (YA) [aged 26.1+/-1.3 yr (mean +/- SEM)] and seven master athletes (MA) (64.4+/-4.1 yr), all known to develop exercise-induced hypoxemia, were respectively compared with seven young untrained men (YC) (23.0+/-1.5 yr) and seven older untrained men (OC) (61.6+/-1.3 yr). During an incremental exhaustive exercise, blood samples for measurement of anti-IgE-induced histamine release from leukocytes were drawn at rest, VO2max, and recovery. RESULTS: Basophils from "leukocyte-rich" supernatant in YA and MA showed significantly higher histamine release induced by anti-IgE (1 microg x mL(-1) than, respectively, YC (P<0.01) and OC (P<0.05) at rest, VO2ax (P<0.01), and recovery (P<0.01). Basophils in YA and MA also showed a histamine release induced by anti-IgE that was higher at VO2max than at rest (respectively. P<0.01 and P<0.05), but this change was not found in the control groups. CONCLUSION: In conclusion, the basophils in highly trained endurance athletes, both young and older, showed higher anti-IgE-induced histamine release than those of untrained men. This effect of high-level training seemed to be potentiated by exercise.

Adult↗

PubMed1999

Crystallization and preliminary X-ray diffraction studies of the carboxylesterase EST2 from Alicyclobacillus acidocaldarius.

EST2, a thermophilic carboxylesterase from Alicyclobacillus acidocaldarius, belonging to the HSL group of the esterase/lipase superfamily, has been crystallized for the first time. Ammonium sulfate was used as a precipitant and the crystallization proceeded at pH 7.8. The crystals belong to space group P41212 or its enantiomorph P43212, with unit-cell parameters a = b = 78.8, c = 106. 4 A. A complete data set has been collected at the synchrotron source Elettra in Trieste to 2.4 A resolution, using a single frozen crystal.

Bacillaceae↗

PubMed1999

Homology modeling and active-site residues probing of the thermophilic Alicyclobacillus acidocaldarius esterase 2.

The moderate thermophilic eubacterium Alicyclobacillus (formerly Bacillus) acidocaldarius expresses a thermostable carboxylesterase (esterase 2) belonging to the hormone-sensitive lipase (HSL)-like group of the esterase/lipase family. Based on secondary structures predictions and a secondary structure-driven multiple sequence alignment with remote homologous protein of known three-dimensional (3D) structure, we previously hypothesized for this enzyme the alpha/beta-hydrolase fold typical of several lipases and esterases and identified Ser155, Asp252, and His282 as the putative members of the catalytic triad. In this paper we report the construction of a 3D model for this enzyme based on the structure of mouse acetylcholinesterase complexed with fasciculin. The model reveals the topological organization of the fold corroborating our predictions. As regarding the active-site residues, Ser155, Asp252, and His282 are located close to each other at hydrogen bond distances. Their catalytic role was here probed by biochemical and mutagenic studies. Moreover, on the basis of the secondary structure-driven multiple sequence alignment and the 3D structural model, a residue supposed important for catalysis, Gly84, was mutated to Ser. The activity of the mutated enzyme was drastically reduced. We propose that Gly84 is part of a putative "oxyanion hole" involved in the stabilization of the transition state similar to the C group of the esterase/lipase family.

Amino Acid Sequence↗

PubMed1999

A conventional beagle dog model for acute and chronic infection with Helicobacter pylori.

Helicobacter pylori has been widely recognized as an important human pathogen responsible for chronic gastritis, peptic ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Little is known about the natural history of this infection since patients are usually recognized as having the infection only after years or decades of chronic disease. Several animal models of H. pylori infection, including those with different species of rodents, nonhuman primates, and germ-free animals, have been developed. Here we describe a new animal model in which the clinical, pathological, microbiological, and immunological aspects of human acute and chronic infection are mimicked and which allows us to monitor these aspects of infection within the same individuals. Conventional Beagle dogs were infected orally with a mouse-adapted strain of H. pylori and monitored for up to 24 weeks. Acute infection caused vomiting and diarrhea. The acute phase was followed by polymorphonuclear cell infiltration, interleukin 8 induction, mononuclear cell recruitment, and the appearance of a specific antibody response against H. pylori. The chronic phase was characterized by gastritis, epithelial alterations, superficial erosions, and the appearance of the typical macroscopic follicles that in humans are considered possible precursors of MALT lymphoma. In conclusion, infection in this model mimics closely human infection and allows us to study those phases that cannot be studied in humans. This new model can be a unique tool for learning more about the disease and for developing strategies for treatment and prevention.

Acute Disease↗

PubMed1999

An Lrp-like protein of the hyperthermophilic archaeon Sulfolobus solfataricus which binds to its own promoter.

Regulation of gene expression in the domain Archaea, and specifically hyperthermophiles, has been poorly investigated so far. Biochemical experiments and genome sequencing have shown that, despite the prokaryotic cell and genome organization, basal transcriptional elements of members of the domain Archaea (i.e., TATA box-like sequences, RNA polymerase, and transcription factors TBP, TFIIB, and TFIIS) are of the eukaryotic type. However, open reading frames potentially coding for bacterium-type transcription regulation factors have been recognized in different archaeal strains. This finding raises the question of how bacterial and eukaryotic elements interact in regulating gene expression in Archaea. We have identified a gene coding for a bacterium-type transcription factor in the hyperthermophilic archaeon Sulfolobus solfataricus. The protein, named Lrs14, contains a potential helix-turn-helix motif and is related to the Lrp-AsnC family of regulators of gene expression in the class Bacteria. We show that Lrs14, expressed in Escherichia coli, is a highly thermostable DNA-binding protein. Bandshift and DNase I footprint analyses show that Lrs14 specifically binds to multiple sequences in its own promoter and that the region of binding overlaps the TATA box, suggesting that, like the E. coli Lrp, Lrs14 is autoregulated. We also show that the lrs14 transcript is accumulated in the late growth stages of S. solfataricus.

Amino Acid Sequence↗

PubMed1999

Diagnostic value of anti-hepatitis C virus (HCV) core immunoglobulin M in recurrence of HCV infection after orthotopic liver transplantation.

The significance of anti-hepatitis C virus (HCV) core immunoglobulin M (IgM) and its relationship with genotypes, alanine aminotransferase abnormality, and histological data were studied for 18 patients who had undergone orthotopic liver transplantation due to HCV-related end-stage disease. During follow-up, IgM response seemed to be associated with the recurrence of HCV infection but did not correlate with abnormal alanine aminotransferase levels and histological data. In addition, the results of this study indicated that the detection of HCV RNA is critical for diagnosis of reinfection in liver transplantation.

Hepacivirus↗

PubMed1999

Sleep apnoea in ischaemic heart disease: differences between acute and chronic coronary syndromes.

OBJECTIVE: To evaluate the incidence of sleep apnoea in acute and chronic coronary syndromes. DESIGN: Analysis of sleep and breathing characteristics in a polysomnographic study. SETTING: Cardiology department in tertiary referral centre. PATIENTS: 23 patients were studied soon after acute myocardial infarction (group 1), 22 after clinical stabilisation of unstable angina (group 2), and 22 who had stable angina (group 3). Conditions liable to cause sleep apnoea, such as obesity, chronic obstructive pulmonary disease, neurological disorders, or the use of benzodiazepines, were exclusion criteria. MAIN OUTCOME MEASURES: Sleep apnoea and hypopnoea, oxygen saturation, and sleep indices evaluated soon after clinical stabilisation in groups 1 and 2 and also in group 3. RESULTS: Sleep apnoea, mainly of the central type, was equally present in groups 1 and 2 (mean (SD) apnoea-hypopnoea index: 11.10 (19.42) and 14.79 (20.52), respectively) and more severe than in group 3 (2.82 (6.43), p < 0. 01). Total time spent at SaO(2) < 90%, although significantly greater in group 1 and 2 (0.89 (2.4), 1.42 (3.23) min) than in group 3 (0.01 (0.05) min, p < 0.05), was clinically irrelevant. More arousals per hour of sleep (p < 0.05) were detected in group 1 (5.15 (3.71)) and group 2 (5.31 (2.14)) than in group 3 (2.83 (1.51)). CONCLUSIONS: Sleep apnoea, chiefly of the central type, not only characterises acute myocardial infarction, as found by others, but also unstable angina studied after recent stabilisation. Patient selection by exclusion of other causes of breathing disorders shows that coronary disease related apnoea is absent in the chronic coronary syndrome. In acute syndromes the lack of clinically significant apnoea related oxygen desaturation, together with the low associated incidence of major ischaemic and arrhythmic events, suggests that sleep apnoea is benign in these circumstances, despite a worsening of sleep quality.

Adult↗

PubMed1999

Repeated intracerebroventricular administration of glucagon-like peptide-1-(7-36) amide or exendin-(9-39) alters body weight in the rat.

Central nervous system glucagon-like peptide-1-(7-36) amide (GLP-1) administration has been reported to acutely reduce food intake in the rat. We here report that repeated intracerebroventricular (i.c.v.) injection of GLP-1 or the GLP-1 receptor antagonist, exendin-(9-39), affects food intake and body weight. Daily i.c.v. injection of 3 nmol GLP-1 to schedule-fed rats for 6 days caused a reduction in food intake and a decrease in body weight of 16 +/- 5 g (P < 0.02 compared with saline-injected controls). Daily i.c.v. administration of 30 nmol exendin-(9-39) to schedule-fed rats for 3 days caused an increase in food intake and increased body weight by 7 +/- 2 g (P < 0.02 compared with saline-injected controls). Twice daily i.c.v. injections of 30 nmol exendin-(9-39) with 2.4 nmol neuropeptide Y to ad libitum-fed rats for 8 days increased food intake and increased body weight by 28 +/- 4 g compared with 14 +/- 3 g in neuropeptide Y-injected controls (P < 0.02). There was no evidence of tachyphylaxis in response to i.c.v. GLP-1 or exendin-(9-39). GLP-1 may thus be involved in the regulation of body weight in the rat.

Animals↗