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Biomedical subjects

C Fontana

Publications and source records attributed to C Fontana.

At least 19 recordsLinked to original sources

Levobupivacaine 0.75% vs. lidocaine 4% for topical anaesthesia: a clinical comparison in cataract surgery.

BACKGROUND: The aim of this study was to compare the efficacy of topical levobupivacaine drops 0.75% vs. lidocaine drops 4% in cataract surgery. METHODS: We examined 203 patients undergoing cataract surgery by phacoemulsification. They were randomized into two groups: one received four drops of lidocaine 4% and the other received four drops of levobupivacaine 0.75%. The onset and offset times of sensory block were evaluated. Application, intraoperative and postoperative subjective pain was quantified by the patients using a verbal pain score. Complications, rates of supplemental anaesthesia, and the satisfaction of surgeon and patients were also recorded. RESULTS: The mean sensory onset and offset times were significantly higher for the levobupivacaine group (P < 0.01). Pain score was lower in the levobupivacaine group than in the lidocaine one and the difference was statistically significant at all stages (P < 0.01). The mean satisfaction scores of patients and surgeon were also statistically higher for levobupivacaine (P < 0.01). No significant differences for complications and rates of supplemental anaesthesia were found. CONCLUSIONS: Topical levobupivacaine 0.75% shows the same efficacy and safety as lidocaine 4% in cataract surgery by phacoemulsification. There was an adequate block with a good level of satisfaction of surgeon and patients. Levobupivacaine 0.75% offers a new and acceptable choice for topical anaesthesia in cataract surgery.

Administration, Topical↗

Efficacy and comparison of 0.5% levobupivacaine with 0.75% ropivacaine for peribulbar anaesthesia in cataract surgery.

BACKGROUND AND OBJECTIVE: The low cardiovascular and neurological toxicity of levobupivacaine has led to its application as a local anaesthetic in a wide variety of specialist applications including peribulbar block for cataract surgery. The aim of this study was to evaluate the efficacy of levobupivacaine 0.5% and to compare block quality vs. ropivacaine 0.75% in peribulbar anaesthesia. METHODS: We examined 208 patients subjected to cataract surgery by phacoemulsification who were randomized into two groups according to the anaesthetic used for peribulbar block, namely levobupivacaine 0.5% or ropivacaine 0.75%, both with the addition of hyaluronidase. Nerve block was carried out by injection of 6 mL of the anaesthetic mixture equally distributed between the inferotemporal and superonasal areas. The success of the block was evaluated by determining the time of motor and sensory onset, akinesia score, times of motor and sensory offset and satisfaction of the patient and surgeon after 24 h. Pre-block, post-block and postoperative intraocular pressure as well as the duration of surgical intervention was also determined. RESULTS: With respect to ropivacaine, levobupivacaine showed a significant reduction (P < 0.001) in the average motor and sensory onset. Both the akinesia score (P < 0.01) and mean motor and sensory offset times were also higher (P < 0.001). Neither the average intervention times nor the satisfaction of the patient/surgeon showed any significant differences between the two groups. CONCLUSIONS: Levobupivacaine (0.5%) has better anaesthetic properties with respect to 0.75% ropivacaine and is well-suited for peribulbar block in cataract surgery.

Aged↗

Linezolid as rescue drug: a clinical case of soft tissue infection caused by a Staphylococcus aureus strain resistant in vivo to teicoplanin.

The authors report and discuss a patient admitted to intensive care unit (ICU) for acute respiratory failure due to upper airway obstruction caused by face and neck soft tissue infection. An oxacillin-resistant Staphyloccoccus aureus was isolated from necrotic skin lesions and from skin biopsy. The strain was susceptible in vitro to teicoplanin, but it showed resistance in vivo, despite appropriate dosage. After 6 days of full dose therapy, since the clinical course worsened, teicoplanin was interrupted and linezolid was started. In 48 hours signs of infection regressed, and the patient was discharged from the ICU after 10 days of linezolid treatment. Linezolid resulted as a rescue drug for a life-threatening infection.

Acetamides↗

Are surgical scrubbing and pre-operative disinfection of the skin in orthopaedic surgery reliable?

This study attempts to establish the actual effectiveness of pre-surgical disinfection of the patient and surgeon's hands. We evaluated bacterial density and composition on the skin of 15 patients undergoing knee arthroscopy and the left hand of two surgeons after standard disinfection with povidone-iodine. Three samples were taken after the first 6-min scrub in the first surgical operation from the periungual space of the 1 degrees finger, from the interdigital space between the 2 degrees and 3 degrees fingers and from the transverse palmar crest of the left hand of two surgeons for seven consecutive surgical sessions, for a total of 42 samples, and two samples from the pre-patellar skin and from the popliteal skin of 15 patients undergoing knee arthroscopy, for a total of 30 samples. Pre-surgical handwashing and disinfection procedures were identical in each case. Pre-surgical disinfection of the patient's skin with povidone-iodine was shown to be completely effective, with 100% of samples negative. Samples taken from the interdigital space and the palmar crest (100% of samples negative) demonstrated the efficacy of disinfection of the surgeon's hands with povidone-iodine, while the periungual space was contaminated in 50% of the samples. The bacterial strains isolated belong to the staphylococcus genus in 100% of the cases, with pathogenic strains in 29.6% of the cases. Standard pre-surgical disinfection of skin in areas easily accessible to the disinfectant is sufficient in itself to guarantee thorough sanitization. Standard scrubbing of the surgeon's hands is insufficient in eliminating bacterial contamination, including pathogenic germs, in the periungual space, where it is probably difficult for the disinfectant to come into contact with the skin.

Anti-Infective Agents, Local↗

Infections in a burn intensive care unit: experience of seven years.

The objective of this study is to describe infections in a specialized burns intensive care unit from 1993 to 1999. The criteria for admission to the unit are: children with burns involving at least 10% or adults with burns involving at least 20% of total body surface; burns affecting face, perineum or feet; suspected or proven airway injury; electric or chemical burns; age less than one year or above 50; or pre-existing disease with any extent of burns. Surveillance of hospital-acquired infection was prospective. Hospital-acquired infection criteria used were those modified from the Centers for Disease Control and Prevention. Diagnosis of infection using skin biopsy was not done. Over the study period, 320 patients were admitted to our burns intensive care unit. One hundred and seventy-five (55%) developed 388 hospital-acquired infections. The rate for vascular catheter-associated bloodstream infections was 34 per 1,000 central line-days. The rate of ventilator associated pneumonia was 26 infections per 1,000 ventilator-days. Primary bloodstream was the most common infection with 189 episodes (49%); followed by 83 burn wound infections (21%) and 56 pneumonias (14%). In 76% of these infections and in 97% of the primary bloodstream infections, aetiological agents were identified. The micro-organisms causing infections were S taphylococcus aureus (24%), Pseudomonas aeruginosa (18%), Acinetobacter spp. (14%) and coagulase-negative staphylococci (12%). Candida spp. caused 8% of infections. Gram-positive and Gram-negative organisms exhibited resistance to most antimicrobial agents used for therapy. During the first three days of hospitalization in the burns intensive care unit there were eight infections caused by S. aureus and three of these were resistant to oxacillin. These data provide background information regarding extensive burn patients on which decisions for control and prevention of hospital-acquired infections can be made.

Adolescent↗

C-reactive protein is increased in patients with degenerative aortic valvular stenosis.

OBJECTIVES: The goal of this study was to assess the presence of systemic inflammation in degenerative aortic valvular stenosis. BACKGROUND: Local inflammatory changes, resembling those observed in atherosclerosis, have been recently reported in degenerative aortic valvular stenosis. It is presently unknown whether systemic signs of inflammation, similar to those observed in atherosclerosis, may be present in this disorder. METHODS: C-reactive protein (CRP) was measured by enzyme immunoassay in 141 subjects: 62 with trileaflet degenerative valvular aortic stenosis and 79 volunteers with similar demographic and clinical characteristics. IgG antibodies against Helicobacter pylori (enzyme-linked immunosorbant assay) and Chlamydia pneumoniae (microimmunofluorescence assay) were also measured. RESULTS: C-reactive protein levels (mg/dl, mean +/- SD) were 0.848 +/- 1.42 in patients and 0.394 +/- 0.50 in controls (p = 0.0001, Mann-Whitney U test). Seroprevalence of H. pylori was 68.7% in patients and 79.7% in controls (p = NS), whereas seroprevalence of C. pneumoniae infection was higher in patients than it was in controls (59.7% vs. 33%, p = 0.003; chi-square test). After adjustment for various covariates in multiple logistic regression, the odds ratio for degenerative aortic stenosis was 3.41 for C. pneumoniae infection (95% confidence intervals [CI]: 1.60 to 7.30) and 2.76 for CRP (95% CI: 1.08 to 7.05). There was no significant difference in patients or controls in CRP levels according to the serostatus for C. pneumoniae. CONCLUSIONS: Systemic signs of inflammation, similar to those found in atherosclerosis, are present in patients with degenerative aortic valve stenosis. They do not seem to be linked to C. pneumoniae or H. pylori infection.

Aged↗

Infection with Helicobacter pylori and leukocyte response in patients with myocardial infarction.

To test whether Helicobacter pylori may contribute to the inflammatory response following myocardial infarction, the levels of IgG antibodies to Helicobacter pylori and some parameters of leukocyte activity were measured in 63 patients and 61 comparable controls. Helicobacter pylori-positive patients showed a significantly higher expression of the adhesion molecule LFA-1 on neutrophils than Helicobacter pylori-negative patients (433+/-29.0 vs. 398.8+/-38.9 mean fluorescence channels; P<0.0001), whereas no significant difference for any parameters tested was found in control subjects. These data suggest a role of Helicobacter pylori in inducing a leukocyte response following myocardial infarction.

Aged↗

Isolation and characterization of a DNA probe for Staphylococcus aureus subspecies aureus biovar.

The gene encoding for polynucleotide phosphorylase (pnp) of a new biovar of Staphylococcus aureus subsp. aureus (NBSA) has been isolated from a genomic library of strain M280(0). The coding region consisted of a 1094-bp HindIII-HindIII DNA fragment encoding for a protein of 277 amino acids with a calculated molecular mass of 29.5 kDa. The nucleotide sequence of the structural gene, contained a continuous open reading frame of 836 bp, showed significant homology with the genes of bacterial polynucleotide phosphorylase from Bacillus subtilis (67.7% identity), from Haemophilus influenzae (62.4% identity), from Pseudomonas luminescens (61.6% identity), and from Escherichia coli (59.7% identity). DNA-DNA and DNA-colony slot-blot hybridizations demonstrated that the pnp gene, employed as a molecular probe, is specific for the identification of NBSA strains.

Base Sequence↗

Identification of nuclei from apoptotic, necrotic, and viable lymphoid cells by using multiparameter flow cytometry.

BACKGROUND: Methods widely used to detect apoptosis do not allow us to easily distinguish between nuclei from viable or necrotic cells. Even if apoptosis and necrosis seem to occur as alternatives at the single cell level, they could be present simultaneously in a cell population much more frequently than expected. For this reason, attention was focused on attempting to recognize, by multiparameter flow cytometry, the characteristics of viable cells and of apoptotic or necrotic dead cells. METHODS: Apoptosis and necrosis were induced in vitro in murine thymocytes and lymphocytes from adult peripheral blood by using dexamethasone or prostaglandin E2 treatment and heat shock at 60 degrees C or hydrogen peroxide, respectively. Traditional methods, such as DNA gel electrophoresis and propidium iodide staining followed by single-fluorescence analysis or annexin-V-fluorescein isothiocyanate plus propidium iodide staining by using flow cytometry, were compared with a new method. This method consisted of combined light-scatter and red fluorescence analysis by flow cytometry after isolation of nuclei by hypotonic solution as well as high-dose detergent treatment and DNA staining with propidium iodide. RESULTS: Results showed that, although traditional methods such as DNA-gel electrophoresis and single-parameter fluorescence flow cytometry analysis were unable, as expected, to discriminate among viability, apoptosis, and necrosis, our new method has enabled us to easily identify nuclei from viable, apoptotic, and necrotic cells. Results obtained by using our method were comparable to those obtained by using two-color analysis of cells after propidium iodide/annexin V staining. CONCLUSIONS: A highly reproducible, inexpensive, rapid, and easily accessible method of analysis has been developed for simultaneously detecting apoptosis and necro sis.

Animals↗

Simple enzymatic method for rapid identification of a Staphylococcus aureus subspecies aureus biovar.

In order to correctly identify a new biovar of Staphylococcus aureus subsp, aureus, (NBSA) a simple, rapid, and reliable enzymatic assay was developed. The assay was based on the detection of the production of three enzymes: alpha-glucosidase, beta-glucosidase and beta-N-acetyl-glucosaminidase. Of a total of 46 isolates of Staphylococcus aureus subsp. aureus from clinical specimens, the new assay correctly identified 19 as NBSA and 27 as typical Staphylococcus aureus subsp. aureus. Among the 19 NBSA isolates, 15 (79%) showed a clear biochemical profile while only four isolates (21%) showed a less well-defined enzymatic combination, due to a phenotypic alteration caused by subculturing. Since this assay is both simple to perform and inexpensive, it is potentially applicable in the laboratory.

Acetylglucosaminidase↗

Iodine, thyroid function, and very low birth weight infants.

OBJECTIVE: Research was undertaken to test two hypotheses. First, during the early neonatal period, thyroid function of very low birth weight (VLBW) infants is suppressed by exposure to iodine-containing antiseptic solutions and/or iodized contrast media. Second, this suppression is more pronounced in small for gestational age (SGA) infants. METHODS: Urinary iodine concentration and thyroid function measurements were obtained prospectively from 44 VLBW infants with gestational ages at birth of 30 +/- 2.3 weeks and weights of 1223 +/- 231 g. Eleven of these infants were SGA. The infants were grouped according to iodine exposure: 18 infants had no increased exposure and served as control infants; 9 infants were exposed to an iodine-containing antiseptic (povidone iodine); 12 infants were exposed to an iodized contrast medium (iopamidol); and 5 infants were exposed to both agents. Urinary iodine and serum free triiodothyronine, free thyroxine, and thyrotropin were measured on days 1, 7, 14, 21, and 28 of life. RESULTS: During the period of maximum exposure (days 1 to 7), the concentration of iodine in the urine of study infants was 2 to 4 orders of magnitude greater than that in the urine of control infants (123 +/- 141 micrograms/L). During the subsequent 3 weeks, levels of urinary iodine in study infants returned to levels that were not significantly different from controls. On day 7 of life, iodine-exposed infants had a significantly higher mean thyrotropin level than control infants, whereas on day 28, free triiodothyronine and thyroxine levels were lower. Of the 26 iodine-exposed infants, 6 had transient hyperthyrotropinemia and 2 had transient hypothyroidism. When exposed to iodine, SGA infants had more labile thyroid function than normally grown iodine-exposed or control infants. These SGA infants had significantly lower levels of thyroid hormones in umbilical cord blood, increased production of thyroid hormones on day 14 of life, and lower levels again at 1 month. CONCLUSION: In VLBW infants, the use of iodine-containing antiseptic solutions and iodized contrast media results in massive uptake of iodine that is associated with alterations in thyroid function. It is reasonable to suggest that, whenever possible, iodized products should be avoided in VLBW infants, because their routine use results in exposure to excessive loads of iodine, which can be associated with hyperthyrotropinemia and hypothyroidism.

Anti-Infective Agents, Local↗

Differentiation of Clostridium difficile, Clostridium bifermentans, Clostridium sordellii, and Clostridium perfringens from diarrheal stool by API ZYM and API LRA oxidase test.

A simple, rapid and reliable outline for identification of clostridia isolates from human infections was developed. It consists of a combination of API ZYM and API LRA Oxidase tests. The enzymatic activities were performed with strains sub-cultured onto carbohydrate-free medium (Columbia blood agar). Fifty-five strains of Clostridium difficile, C. bifermentans, C. sordellii, and C. perfringens from clinical specimens and eight reference standard strains representing different species of the same genus were analyzed. The accuracy of the new method was evaluated by comparison with the results obtained by DNA/DNA analysis.

Bacterial Typing Techniques↗

[Electrical burns of the upper limbs].

During a period of 27 months, between 1991 and 1993, 15 patients with upper limb lesions caused by electrical hazards were admitted in the Burn Emergency Service of the Hospital das Clinicas-FMUSP. This lesion is usually a dramatic condition and requires a sound physiopathologic knowledge by the surgeon. These accidents may have permanent incapacitating sequelae, and due to long periods of treatment (2 months), social-economic costs are very high. Based on our experience, we suggest a less aggressive approach (no amputation at emergency), and a close continuous surveillance.

Adolescent↗

Transdermal scopolamine for reduction of drooling in developmentally delayed children.

Ten developmentally delayed children with excessive drooling were randomized in a double-blind, placebo-controlled study to assess the efficacy and safety of transdermal scopolamine. Over half of the patients had a statistically significant reduction in drooling, and one-third had cessation of drooling, while wearing the scopolamine patch. This short-term study supports earlier reports of the safety and efficacy of transdermal scopolamine for reducing excessive drooling in developmentally disabled children.

Administration, Cutaneous↗

Twelve aberrant strains of Staphylococcus aureus subsp. aureus from clinical specimens.

A new biovar of Staphylococcus aureus subsp. aureus was isolated from human clinical specimens and described on the basis of studies of 12 isolates that were compared with 11 standard reference strains. Both DNA hybridization experiments and numerical taxonomy analysis demonstrated that these strains were strictly related to S. aureus subsp. aureus; however, they were significantly different from the latter. The atypical strains belonging to the new biovar can be distinguished from typical S. aureus subsp. aureus strains by their alpha-chymotrypsin, alpha-glucosidase, beta-N-acetylglucosaminidase, lipase (C-14), and leucine arylamidase enzymatic activities and novobiocin resistance. Thus, the combination of alpha-glucosidase and beta-N-acetyl-glucosaminidase is more useful for distinguishing these S. aureus strains from the other, typical ones.

DNA, Bacterial↗

Double sugar-tyrosine medium improves O-1 phage Salmonella screening.

A modification of the procedure for O-1 phage Salmonella screening is presented. The novel method is based on the use of two media, i.e., a new medium (double sugar-tyrosine [DST]), which permits the combination of adonitol and sucrose fermentation and tyrosine clearing tests, and the previously described o-nitrophenyl-beta-D-galactopyranoside urease indole medium. In comparative trials, the new procedure and the conventional one were used to screen for Salmonella isolates from 553 lactose-negative strains of members of the family Enterobacteriaceae. The O-1 phage test, performed on DST medium, recognized the same number of phage-susceptible Salmonella strains as did the standardized method; however, it permitted the correct identification of a greater number of phage-resistant strains for discard (95.6 versus 85.3%). In particular, DST medium presented a higher efficacy than triple sugar iron agar (which is the corresponding medium in the reference procedure) in correctly identifying phage-negative cultures for discard (69.1 versus 28.5%).

Culture Media↗