Lamivudine: a new strategy to suppress HBV replication in the pretransplant setting.
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Adult↗
Biomedical subjects
A Gomes
Publications and source records attributed to A Gomes.
Hepatitis C virus infection and liver transplantation.
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Adult↗
Wilson's disease: challenging diagnosis, management, and liver transplantation timing.
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Adult↗
Purification and characterization of a trypsin-like enzyme with fibrinolytic activity present in the abdomen of horn fly, Haematobia irritans irritans (Diptera: Muscidae).
This work describes the purification and characterization of a trypsin-like enzyme with fibrinolytic activity present in the abdomen of Haematobia irritans irritans (Diptera: Muscidae). The enzyme was purified using a one-step process, consisting of affinity chromatography on SBTI-Sepharose. The purified protease showed one major active proteinase band on reverse zymography with 0.15% gelatin, corresponding to a molecular mass of 25.5 kDa, with maximum activity at pH 9.0. The purified trypsin-like enzyme preferentially hydrolyzed synthetic substrates with arginine residue at the P1 position. The Km values determined for three different substrates were 1.88 x 10(-4), 1.28 x 10(-4), and 1.40 x 10(-4) M for H-alpha-benzoyl-Ile-Glu-Gly-Arg-p-nitroanilide (S2222), DL-Ile-Pro-Arg-p-nitroanilide (S2288), and DL-Phe-Pip-Arg-p-nitroanilide (S2238), respectively. The enzyme was strongly inhibited by typical serine proteinase inhibitors such as SB
Animals↗
Molecular typing of methicillin-resistant Staphylococcus aureus by pulsed-field gel electrophoresis: comparison of results obtained in a multilaboratory effort using identical protocols and MRSA strains.
Pulsed-field gel electrophoresis (PFGE) has become the gold standard of molecular methods in epidemiological investigations. In spite of its high resolving power, use of the method has been hampered by inadequate laboratory-to-laboratory reproducibility. In the project described here we have addressed this problem by organizing a multilaboratory effort in which the same bacterial strains (subtype variants of the Iberian and Brazilian methicillin-resistant Staphylococcus aureus--MRSA--clones) were analyzed by twenty investigators in thirteen different laboratories according to an indentical protocol, which is reproduced here in detail. PFGE patterns obtained were analyzed at a central laboratory in order to identify specific technical problems that produced substandard macrorestriction patterns. The results including the specific technical problems and their most likely causes are described in this communication. Also listed are seven major epidemic clones of MRSA which have been characterized by molecular fingerprinting techniques and the prototypes of which have been deposited at the American Type Culture Collection, from where they will be available for interested investigators for the purpose of typing MRSA isolates. It is hoped that this communication will contribute to the improvement of the reproducibility and technical/aesthetic quality of PFGE analysis.
Bacterial Typing Techniques↗
Sinus tissue pharmacokinetics after oral administration of amoxicillin/clavulanic acid.
OBJECTIVES: The in vitro synergy of the amoxicillin/clavulanic acid combination has not always translated in vivo into clinical superiority compared with amoxicillin alone. Specifically, conflicting reports have disputed the superiority of the combination in the treatment of both acute otitis media and acute sinusitis. One possible reason for this may have to do with inadequate target tissue pharmacokinetics. To explore this possibility in the sinuses, we undertook the present investigation. STUDY DESIGN: A randomized, open, single-dose, sinus tissue pharmacokinetic study with oral amoxicillin/clavulanic acid. METHODS: Twenty-three adult patients with chronic rhinosinusitis who had been selected for surgery were randomly allocated to receive a tablet of 875/125 mg amoxicillin/clavulanate 2 to 4 hours before surgery began. During the operation tissue samples were collected at specific sinonasal sites for determination of both amoxicillin and clavulanic acid concentration levels. RESULTS: Amoxicillin displayed adequate tissue levels throughout the sinuses, high enough to cover common susceptible pathogens. However, the presence of clavulanate was detected in only half of the sinonasal tissue samples. CONCLUSIONS: The kinetics of oral clavulanic acid apparently fails to provide a widespread anti-beta-lactamase activity capable of enhancing the activity of amoxicillin in all parts of the sinuses. Despite this, amoxicillin/clavulanic acid maintains a central role in the treatment of acute rhinosinusitis, because amoxicillin is still the most effective oral beta-lactam against Streptococcus pneumoniae, a particularly virulent and increasingly resistant upper respiratory tract pathogen. Also, as our data show, a concomitant anti-beta-lactamase activity can be expected to occur, although in an unpredictable fashion.
Adult↗
Snoring in Portuguese primary school children.
OBJECTIVE: To determine the prevalence of snoring and its potential associations with sleep problems, such as daytime symptoms, medical conditions, school performance, and behavioral disturbances in Portuguese children attending primary school. METHODS: A previously validated questionnaire was sent to the parents of 1381 children attending primary schools in a parish of Coimbra, Portugal. To assess behavioral disturbances, the Portuguese version of Rutter's Children's Behavior Questionnaire for completion by teachers was used. RESULTS: Of the 988 questionnaires returned (71.5%), complete information concerning snoring was obtained for 976 children (496 girls and 480 boys; mean age: 8.1 +/- 1.5 years). Loud snoring during sleep was reported as frequent or constantly present (LSn) in 84 children (8.6%), as occasionally present in 299 children (30.6%), and as never present (NSn) by 593 children (60.8%). The LSn and NSn groups did not differ with respect to age, gender, sleep duration, time to fall asleep, frequency of night wakings, bedwetting, daytime tiredness, and school achievement. However, LSn was significantly associated with increased bedtime problems (fears and struggles), increased need for comforting activities to fall asleep, behaviors suggestive of parasomnias (sleep talking, teeth grinding, and night terrors), increased daytime sleepiness and irritability, and behavioral disturbances. Children in the LSn group were also more likely to report recurrent medical problems particularly those involving infections of the respiratory tract. CONCLUSIONS: Snoring is a common symptom in Portuguese children that is associated with behavioral daytime and sleep time disturbances. Children with loud snoring may benefit from early evaluation and intervention.
Achievement↗
Bidder's organ extract induced anaphylaxis in experimental animals.
Bidder's organ (BO, a vestigeal organ), present in toad Bufo melanostictus (Schenider), is a characteristic feature of all male bufo. Its possible anaphylactic properties are investigated on experimental animals. BO extract produced both in vivo and in vitro anaphylactic reaction in guineapig. Dyspnoea and bronchoconstriction was a major cause of anaphylactic death. Blood histamine level was significantly increased in the anaphylactic animals. BO extract significantly released histamine from chopped lung preparation, an action antagonised by disodium chromoglycate. BO extract degranulated peritoneal mast cell in vitro. Passive cutaneous anaphylactic reactions were enhanced by BO extract and were significantly inhibited by disodium chromoglycate. Anaphylotoxin (identity not known) present in bidder's organ is probably involved in toad defence.
Anaphylatoxins↗
Hannahpep: A novel fibrinolytic peptide from the Indian King Cobra (Ophiophagus hannah) venom.
A novel fibrinolytic peptide (Hannahpep) was isolated and purified from the venom of the Indian King Cobra (Ophiophagus hannah) by thin-layer chromatography followed by reverse-phase high-performance liquid chromatography. The MW of the peptide was found to be 610 Da and the amino acid sequence of Hannahpep was determined to be Arg, His, Ala, Arg, His, Asp. Hannahpep produced defibrinogenating activity in male albino mice. It exhibited significant fibrinolytic and fibrinogenolytic activity in vitro. Hannahpep showed plasma-anticlotting activity. However, it lacked hemolytic, hemorrhagic, or phospholipase activity. This peptide may have possible therapeutic application in the management of thrombosis or occlusion of a blood vessel.
Animals↗
Feasibility of external beam radiation for prevention of restenosis following balloon angioplasty.
PURPOSE: Brachytherapy has been shown to inhibit neointima formation after vascular balloon injury. This study was done to test the feasibility of low dose external radiation for prevention of restenosis in a non-stented balloon injury model. MATERIALS AND METHODS: Twelve red Duroc swine underwent balloon overdilation injury of both iliac arteries. Twelve Gy was delivered to one side using a Theratron T-1000 Cobalt unit with the other side used as the control. Twelve weeks post injury arteriograms were performed. The animals were then sacrificed and iliac arteries explanted. Histomorphometric analysis of arterial cross sections was performed. RESULTS: Neointima formation was observed in all arteries. Unilateral thrombosis was noted in two animals. The mean neointimal thickness in the radiated and control arteries was 0.63 +/- 0.17 mm and 0.72 +/- 0.31 mm, respectively. The differences in minimal luminal diameter and the neointimal thickness between the two groups were not statistically significant. Complications included superficial hair loss in the radiation port in 4 animals, and 2 deaths prior to the completion date (1 of hemorrhagic enteritis possibly related to the radiation, and 1 of iliac rupture). CONCLUSION: External radiation at this low dose is not effective in preventing vascular restenosis following balloon injury in this animal model.
Angioplasty, Balloon↗
Cystic fibrosis patients with the 3272-26A-->G mutation have mild disease, leaky alternative mRNA splicing, and CFTR protein at the cell membrane.
We characterized the 3272-26A-->G mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, creating an alternative acceptor splice site in intron 17a, that competes with the normal one, although we predict from consensus values, with lower efficiency. We analyzed five Cystic Fibrosis (CF) Portuguese patients with the 3272-26A-->G/F508del genotype. Besides clinical and haplotype characterization of those patients, we report here results from CFTR transcript analysis in nasal brushings from all five patients. RT-PCR analysis supports alternative splicing in all patients and carriers, but not in controls. By sequencing, we determined that the alternative transcript includes 25 nucleotides from intron 17a, which predictively cause frameshift and a premature stop codon. The use of this alternative splice site causes a reduction in the levels of normal transcripts from the allele with this mutation and, most probably, of normal protein as well. By immunocytochemistry of both epithelial primary cell cultures and slices from CF polyps, CFTR protein is detected at the cell membrane, with three different antibodies. Ussing chamber analysis of one nasal polyp shows a high sodium absorption, characteristic of CF. Altogether, the results suggest that the main defect caused by the 3272-26A-->G mutation is a reduction in normal CFTR transcripts and protein and therefore this mutation should be included in class V, according to Zielenski and Tsui.
Adolescent↗
Proconvulsive effect of tea (Camellia sinensis) in mice.
Investigations were carried out to evaluate the effect of acute and chronic administration of both black and green tea on three models of experimentally induced convulsions in mice. Tea extract (both black and green) significantly accelerated the onset of convulsion, increased the duration of convulsion and mortality in mice. Since both the extracts failed to alter the GABA level in brain, based on the earlier report that both black and green tea might act on Ca(2+) channels, it can be suggested that the observed proconvulsive effect of tea is not mediated through GABA but through Ca(2+) channels.
Animals↗
A double headed serine proteinase inhibitor--human plasma kallikrein and elastase inhibitor--from Boophilus microplus larvae.
Preying on cattle, the hard tick Boophilus microplus causes heavy economical losses to Brazil. Tick proteins are a good target to be used as tools for tick control. Serine protease inhibitors from B. microplus larvae (BmTI) were preliminarily characterized. One-week-old larvae were the source of a 2% protein solution in 5 mM Tris-HCl, 20 mM NaCl, pH 7.4. The inhibitors were purified by affinity chromatography on trypsin-Sepharose, and ion-exchange chromatography on Resource Q column, and they separated in two major active peaks, corresponding to 10-kDa and 18-kDa proteins (BmTI-B and BmTI-A, respectively). Both purified proteins inhibited trypsin with Ki of 0.3 and 3.0 nM, respectively, but only the 18-kDa protein inhibited elastase (Ki 1.4 nM) and plasma kallikrein (Ki 120 nM). BmTI-A did not change prothrombin time (PT) and thrombin time (TT), but it increased activated partial thromboplastin time (APTT) was dose-dependent. The partial amino acid sequence indicated that BmTI-A belongs to the bovine pancreatic trypsin inhibitor (BPTI)-Kunitz type inhibitor family. These inhibitors (by their properties) play a role in the feeding process of the tick. Development of antibodies against these proteins may be used to impair the normal feeding and consequently, the parasite would be no longer viable.
Amino Acid Sequence↗
A randomized, double-blind, placebo-controlled clinical trial of vitamin A in Mozambican children hospitalized with nonmeasles acute lower respiratory tract infections.
OBJECTIVE: The objective of this study was to test the potential of routine vitamin A supplementation at admission to speed up recovery during hospitalization for acute lower respiratory tract infections (ALRI) and to decrease the levels of morbidity at 6 weeks after discharge. The study was conducted in the Central Hospital of Maputo (CHM), Mozambique, from 1995 to 1997. METHODS: Children aged 6-72 months with ALRI admitted to the paediatric wards of the CHM were assigned to a supplementation group (n = 71, receiving 200000 IU of vitamin A) or a control group (n = 93, receiving a placebo). RESULTS: The prevalence of vitamin A deficiency was very high and similar between the two groups. The median number of inpatient days for the supplementation group was 3, for the placebo group 4 days. On day 5 the rate of clinical discharge was 88.4% (n = 61/69) in the experimental intervention group and 73.9% (n = 65/88) in the placebo group (P = 0.023). CONCLUSION We found a statistically significant reduction in duration of admission among vitamin A-supplemented children with ALRI. This effect is in line with what is known about the role of vitamin A in human defence and immune mechanisms and with the serological evidence of the extent of vitamin A deficiency among the children in this trial.
Breast Feeding↗
The role of transjugular liver biopsy in a liver transplant center.
Transjugular liver biopsy is a particularly useful procedure in overcoming the classic limitations of percutaneous biopsy, such as hemorrhagic diathesis or tense ascites. The authors evaluated the impact that this technique had in their liver transplant program, considering performance and safety in 160 procedures. Histologic characterization was accomplished in 75% of cirrhotic patients and in 96% of patients with acute liver disease. Confirmation of a presumptive diagnosis was made in 76% of patients and a previously unsuspected diagnosis was raised in 11%. Hemochromatosis, Wilson's disease, and acute alcoholic hepatitis were the most challenging diagnoses and, together with patients with liver failure, had the most relevant implications in transplant decisions. The availability of transjugular liver biopsy provided decisive information regarding patient selection and the best timing to proceed with transplantation.
Adolescent↗
Penetration of cefuroxime into chronically inflamed sinus mucosa.
OBJECTIVES: Despite its seeming relevance, limited information exists about antibiotic sinus tissue penetration and how it is affected by inflammation. Thus the reason for the present investigation. STUDY DESIGN: A randomized, open, multiple-dose, pharmacological study, employing cefuroxime axetil, an approved oral antimicrobial for the treatment of acute bacterial rhinosinusitis, was developed. METHODS: Twenty subjects, selected for surgery because of chronic rhinosinusitis, were randomly allocated to receive either a short (3-8 d) or a long (9-14 d) preoperative treatment regime with 500 mg cefuroxime axetil BID, the last dosage being taken 3 to 4 hours before surgery. At the operation, tissue samples were collected at specific sinonasal sites for both pharmacological determination of antibiotic levels and histopathological assessment of the degree of inflammation. The blood levels of the drug were simultaneously assayed. RESULTS: Cefuroxime kinetic behavior on chronically inflamed mucosa was shown to be, for the most part, dependent on the blood levels, regardless of the inflammatory state. Distribution was even throughout the different sinus cavities, and the tissue levels were still, 3 to 4 hours after dosing, above the reported minimum inhibitory concentration (MIC) values for some of the most prevalent sinus pathogens. The extended treatment course did not seem to add any extra histopathological or pharmacological benefit. CONCLUSIONS: Cefuroxime penetrates adequately and uniformly into chronically inflamed sinus mucosa, apparently unaffected by the degree of inflammation, in a way not dissimilar to its pharmacokinetic behavior in the normal state. Persistent MIC levels for common pathogens still warrant antimicrobial efficacy for a significant period of time after dosing.
Adult↗
Drink for thought: a Mediterranean experience pro-liver transplantation in alcoholic cirrhosis.
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Alcohol Drinking↗
Viper venom-induced inflammation and inhibition of free radical formation by pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from anantamul (Hemidesmus indicus R. BR) root extract.
The present investigation explored the possible venom neutralizing effect of a pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from the methanolic root extract of Hemidesmus indicus R.Rr. 2-OH-4-MeO benzoic acid possessed potent anti-inflammatory, antipyretic and antioxidant properties. The compound effectively neutralized inflammation induced by Vipera russelli venom in male albino mice and reduced cotton pellet-induced granuloma in rats. The compound produced a significant fall in body temperature in yeast-induced pyrexia in rats but did not change the normothermic body temperature. The compound effectively neutralized viper venom-induced changes in serum phosphatase and transaminase activity in male albino rats. It also neutralized free radical formation as estimated by TBAPS and superoxide dismutase activities. The antisnake venom activity of the pure compound is partly mediated through the above physiological process.
Acid Phosphatase↗