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At least 1,117 records · Page 62Linked to original sources

PubMed1998

Wiropress SL: a multipurpose dental pressure vessel with transparent chamber.

Pneumatic vessels used in dentistry provide a pressurized environment to enhance the outcome of many laboratory procedures. A pressurized environment directs volume loss associated with polymerization shrinkage, minimizes air inclusions in powder/liquid mixtures, raises the boiling point of liquids, and facilitates flow of impression and replication materials, improving surface detail. The following report illustrates the usefulness of a reliable pneumatic vessel during denture base repair resin processing and replication of pattern details.

Acrylic Resins↗

PubMed2006

Assessment of cord blood unit characteristics on the day of transplant: comparison with data issued by cord blood banks.

BACKGROUND: Selection of a cord blood (CB) unit for allogeneic transplantation relies on graft characterization results provided by cord blood banks (CBBs). The goal was to compare the graft characterization results obtained upon thawing and washing to those provided by CBBs at selection. STUDY DESIGN AND METHODS: With tests that assess CB graft characteristics known to impact engraftment, CB units have been analyzed after thaw and before infusion. Our results were compared to data provided by CBBs to determine the impact on engraftment and assess how CBB-supplied information can affect future CB unit selection. RESULTS: Variability was noted as to the type of information provided by the different CBBs. Also, variability was found between the information provided by CBBs and the graft characterization results obtained upon thawing and washing. In some cases, CB measures known to be predictive of engraftment were found much lower than reported by CBBs. Only the total nucleated cell count, which is the main CB graft selection criterion besides HLA matching, correlated favorably. CONCLUSIONS: Our data reveal a high degree of variability in graft characteristics provided by CBBs and often poor correlation with results obtained on thawed and washed CB units. We suggest that standardized laboratory procedures aimed at graft characterization should be used by both CBBs and transplant centers to avoid unacceptable discrepancies.

Blood Banking↗

PubMed2005

The impact of catecholamines in patients with or without beta-blockers on the ventricular fibrillation cycle length and ventricular fibrillation cycle length variability.

OBJECTIVES: To evaluate the impact of epinephrine, norepinephrine, or placebo on the ventricular fibrillation cycle length (VFCL) and the variability of VFCL (cvVFCL) measurements in implantable cardioverter defibrillator (ICD) patients with or without beta-blockers. METHODS: Forty-three patients scheduled for their 6-week post-ICD placement noninvasive electrophysiologic study were included in the study at the Arrhythmia Procedure Laboratory at Hartford Hospital, Hartford, CT. This randomized, double-blind, placebo-controlled evaluation was approved by the Hartford Hospital Institutional Review Board. RESULTS: After 2 seconds of continuous VF, 7 consecutive VFCLs were measured from the ICD device recording printout using a 0.5 mm scale ruler under magnification at baseline and after the infusion of catecholamines (epinephrine or norepinephrine at 2 mcg/min) or matching placebo at steady state. The average VFCL and the cvVFCL were determined for each study phase. Subgroup analysis based on chronic beta-blocker use was performed. No between-group differences were noted for epinephrine, norepinephrine, or placebo group for baseline (P=0.538) or postinfusion VFCL (P=0.749) or for baseline (P=0.561) or postinfusion cvVFCL (P=0.623) Regardless of catecholamine group randomization, longer pre- and postinfusion VFCL were noted in those receiving beta-blockers (P=0.157, P=0.019) but no differences in cvVFCL were noted (P=0.216, P=0.474) versus those without beta-blockers, respectively. CONCLUSION: Moderately dosed epinephrine or norepinephrine does not affect either VFCL or the variability of VFCL after short duration of ventricular fibrillation. Chronic cardioselective beta-blockade prolongs VFCL without any impact on coefficient of variation of VFCL.

Adrenergic alpha-Agonists↗

PubMed2004

Clinical significance of hepatic iron deposition and serum iron values in patients with chronic hepatitis C infection.

OBJECTIVES: To assess the potential association between hepatic iron deposition or serum iron values and hepatic fibrosis and inflammatory activity in patients with chronic hepatitis C virus infection. METHODS: In 100 consecutive patients with hepatitis C virus infection, tissue iron deposition was assessed by quantifying iron stain on liver biopsy specimens. Serum iron, ferritin, and transferrin saturation were determined by standard laboratory procedures. Statistical analyses incorporated potential confounders associated with hepatic fibrosis. RESULTS: Twenty-one patients had no fibrosis (stage 0), 13 had portal fibrosis (stage 1), 31 had periportal fibrosis (stage II), 10 had bridging fibrosis (stage III), and 25 had cirrhosis (stage IV). Positive iron stain found in liver biopsy specimens of 19 patients was associated with stage III or IV fibrosis (p = 0.004). No significant difference was found between the iron concentration or the hepatic iron index in patients with stage III or IV fibrosis compared with patients with stage I or II fibrosis. At least 1 of 3 serum iron values assessed was abnormal in 55 patients. In univariate analysis, elevated serum iron (p = 0.01), serum ferritin (p < 0.001), and transferrin saturation (p = 0.002) were associated with stage III or IV fibrosis. In multivariate analysis, the only independent predictive factor of severe hepatic fibrosis was serum ferritin (p < 0.02; odds ratio = 11.35). The serum ferritin value and tissue iron stain had a significant positive correlation (p < 0.001). CONCLUSIONS: Increased hepatic iron deposition may be associated with more advanced hepatic fibrosis in patients with chronic hepatitis C virus infection. The serum ferritin value, an independent predictor of severe hepatic fibrosis in patients with chronic hepatitis C virus infection, may predict hepatic iron deposition and severity of fibrosis.

Adult↗

PubMed1998

Animal models sensitive to anti-anxiety agents.

Animal models of anxiety serve two primary purposes in psychopharmacological research. (i) The pharmacological profile observed in the model provides a basis which, depending on its predictive validity, permits an estimation of clinical activity. (ii) Insofar as the 'anxiety' occurring in the animal model is homologous to human anxiety disorders, it is possible to investigate the underlying cellular and molecular mechanisms. The most commonly used laboratory procedures for the identification of anxiolytic effects of drugs are described in this paper.

Animals↗

PubMed1998

The millennium criteria for the diagnosis of atopic dermatitis.

Atopic dermatitis forms an active area of basic and clinical research, where important new knowledge about genetics and immunopathogenesis has surfaced over the past years, and where simultaneous development of new and innovative therapies is under way. However, the inclusion of any patient in an atopic dermatitis study, whether it is on its genetics, pathogenesis or therapy, requires a diagnosis which is irrefutable. Since there is no simple and also no complicated laboratory procedure to reach a diagnosis of atopic dermatitis, different sets of clinical criteria have been developed for the purpose of making the diagnosis uniformly in different studies as well as in different study centers. The most commonly used are Hanifin and Rajka's set of diagnostic features, which have major and minor clinical criteria to be fulfilled in order to establish a diagnosis of atopic dermatitis. Recent developments in the immunology of atopy have clearly established the major abnormality in this syndrome, the preferential production of allergen-specific IgE. In this contribution, it is suggested that the presence of such antibodies in a given patient should be a mandatory criterium for the diagnosis of atopic dermatitis. Such a diagnostic test however establishes a diagnosis of atopic syndrome, not atopic dermatitis. Thus, for atopic dermatitis we have to rely, for the time being, on additional clinical criteria. The clinical features described in the literature are critically evaluated, and it is suggested that in addition to the mandatory presence of allergen-specific IgE, 2 of 3 principal criteria (pruritus, typical morphology and distribution, chronic or chronically relapsing) should be present for such a diagnosis. Finally, the minor features originally described by Hanifin and Rajka and later evaluated by others are revised and divided over 4 subcategories; a) related to subclinical eczema; b) related to dry skin; c) extra skin folds; and d) ophthalmological pathology. They are suggested to be used as additional criteria only, needed when clinical suspicion is high but the new mandatory and principal diagnostic criteria described here are inconclusive. For study purposes, we suggest that the mandatory and principal criteria are sufficient. They are now evaluated and validated in ongoing atopic dermatitis treatment studies.

Animals↗

PubMed1991

An automated microassay for enzyme inhibitory effects of M2 antibodies in primary biliary cirrhosis.

In primary biliary cirrhosis (PBC), autoantibodies are produced to the M2 group of mitochondrial antigens, of which a major constituent is the E2 subunit of the pyruvate dehydrogenase complex (PDC). These antibodies, in addition to conventional reactivities with PDC, characteristically inhibit the catalytic function of PDC in vitro, as judged by a macroinhibition assay based on spectrophotometry. We describe a microinhibition assay adapted for microtitre plates and for an automated readout of results by an ELISA plate reader. We show that this microassay has a sensitivity similar to that of the macroassay. In a study of 83 sera, from PBC and other diseases, the inhibitory microassay proved specific for PBC. This automated inhibitory microassay for PBC-sera could become a primary laboratory procedure for the diagnosis of PBC, particularly because it may identify antibodies to the actual autoepitope on the PDC-E2.

Animals↗

PubMed1987

Recurrent herpes labialis in a military brass band.

80-90% of the adult population is known to have neutralizing antibodies to herpes simplex virus type 1 (HSV1), of these 18-32% suffer from occasional recurrent herpes labialis (RHL). It is thought that local trigger factors as external traumata, UV-light and chemical stimuli, or systemic factors like fever or common cold, may induce RHL. The aim of the present study was to investigate the frequency of RHL in a military brass band and compare this with the frequency of the disease in a control population of soldiers from the same unit. Both populations were national servicemen aged 19-22 yr. The diagnosis of RHL was based on the presence of herpetic vesicles in the labial region. Of the diagnosed cases, 10% were confirmed by laboratory procedures according to standard methods. The incidence of RHL over a period of 8 months was twice as frequent in the group of brass and woodwind players as in the control group of soldiers from the same military unit. This may indicate that the mechanical trauma to the labial tissue which occurs during playing may cause the increased frequency of RHL in musicians.

Adult↗

PubMed1989

Periodontal tissue reactions following root canal obturation with an injection-thermoplasticized gutta-percha technique.

The thermoplasticized gutta-percha obturation technique is a relatively recent development in endodontics. In this study we evaluated the possible effects of heat transmitted to the periodontal tissues when the Obtura root canal filling device was used in dog teeth. Two 8-month-old beagle dogs were used; 56 root canals of 36 teeth (maxillary incisors and first, second and third premolars of both jaws) were divided into two groups. In Group A 26 root canals were obturated with the lateral condensation technique, while in Group B 30 root canals were obturated using the Obtura device, without sealer. Observation periods were 1, 3, 7, 28 and 56 days. After routine laboratory procedures, hematoxylin-eosin stained sections were examined under a light microscope. In this experimental model the thermoplasticized gutta-percha obturation technique caused a periapical inflammatory reaction at all observation periods. Inflammatory reaction and destruction of collagen fibers were localized in the area around the apical delta, while the alveolar founding bone, the roots of the teeth and the periodontal ligament at the side of the root surfaces remained normal.

Animals↗

PubMedDate not supplied

Diagnostic validity of three swab techniques for identifying chronic wound infection.

This study examined the diagnostic validity of three different swab techniques in identifying chronic wound infection. Concurrent swab specimens of chronic wounds were obtained using wound exudate, the Z-technique, and the Levine technique, along with a specimen of viable wound tissue. Swab and tissue specimens were cultured using quantitative and qualitative laboratory procedures. Infected wounds were defined as those containing 1 x 10(6) or more organisms per gram of tissue. Accuracy was determined by associating the quantitative cultures of swab specimens with the cultures from tissue specimens using receiver operating characteristic curves. Of the 83 study wounds, 30 (36%) were infected. Accuracy was the highest for swab specimens obtained using Levine's technique at 0.80. Based on Levine's technique, a critical threshold of 37,000 organisms per swab provided a sensitivity of 90% and a specificity of 57%. The mean concordance between swab specimens obtained using Levine's technique and tissue specimens was 78%. The findings suggest that swab specimens collected using Levine's technique provide a reasonably accurate measure of wound bioburden, given that they are more widely applicable than tissue cultures. The diagnostic validity of Levine's technique needs further study using an alternative reference standard, such as the development of infection-related complications.

Bacterial Typing Techniques↗

PubMed1981

Comparison of several laboratory tests for quantifying azotaemia in dogs.

Fifty blood samples collected from 14 normal dogs and 11 dogs with renal disease and azotaemia were assayed in various ways for urea and creatinine. Urea concentrations measured by Azostix, Urastrat and Unitest correlated well with a reference urea assay method, and there was good correlation between creatinine concentrations determined by Unitest and a reference method. The performance of the four simpler laboratory procedures examined was considered satisfactory for clinical purposes.

Animals↗

PubMed1999

Epidemic of blindness in kangaroos--evidence of a viral aetiology.

OBJECTIVE: To determine the cause of an epidemic of blindness in kangaroos. DESIGN AND PROCEDURES: Laboratory examinations were made of eyes and brains of a large number of kangaroos using serological, virological, histopathological, electron microscopical, immunohistochemical methods, and PCR with cDNA sequencing. In addition, potential insect viral vectors identified during the disease outbreak were examined for specific viral genomic sequences. SAMPLE POPULATION: For histopathological analysis, 55 apparently blind and 18 apparently normal wild kangaroos and wallabies were obtained from New South Wales, Victoria, South Australia, and Western Australia. A total of 437 wild kangaroos and wallabies (including 23 animals with apparent blindness) were examined serologically. RESULTS: Orbiviruses of the Wallal and Warrego serogroups were isolated from kangaroos affected with blindness in a major epidemic in south-eastern Australia in 1994 and 1995 and extending to Western Australia in 1995/96. Histopathological examinations showed severe degeneration and inflammation in the eyes, and mild inflammation in the brains. In affected retinas, Wallal virus antigen was detected by immunohistochemical analysis and orbiviruses were seen in electron microscopy. There was serological variation in the newly isolated Wallal virus from archival Wallal virus that had been isolated in northern Australia. There were also variations of up to 20% in genotype sequence from the reference archival virus. Polymerase chain reactions showed that Wallal virus was present during the epidemic in three species of midges, Culicoides austropalpalis, C dycei and C marksi. Wallal virus nucleic acid was also detected by PCR in a paraffin-embedded retina taken from a blind kangaroo in 1975. CONCLUSION: Wallal virus and perhaps also Warrego virus are the cause of the outbreak of blindness in kangaroos. Other viruses may also be involved, but the evidence in this paper indicates a variant of Wallal virus, an orbivirus transmitted by midges, has the strongest aetiological association, and immunohistochemical analysis implicates it as the most damaging factor in the affected eyes.

Animals↗

PubMed2005

Rapid identification of virulence genes in enterotoxigenic Escherichia coli isolates associated with diarrhoea in Queensland piggeries.

OBJECTIVE: To identify virulence genes in enterotoxigenic E coli (ETEC) isolates associated with diarrhoea in neonatal, 1 to 3 week-old and weaned pigs in southeast Queensland. DESIGN: Multiplex PCR and serotyping were applied to E coli isolates obtained over a 5-year period (1998-2002) from cases diagnosed at Toowoomba Veterinary Laboratory. PROCEDURE: A total of 126 isolates from 25 different Queensland piggeries were tested for haemolytic activity on 5% sheep blood agar and by multiplex PCR for the presence of five commonly recognised fimbrial (F4, F5, F6, F41 and F18) and three enterotoxin genes (STa, STb, LT). A subset of 62 representative isolates were serotyped by slide agglutination. For comparative purposes, multiplex PCR was also performed on the DNA of 31 ETEC isolates from 9 serotypes originating from piggeries in southern New South Wales. RESULTS: A total of 113 (89.7%) of the isolates from Queensland possessed ETEC virulence genes, including 14 of 15 isolates from neonatal pigs (93.3%), 18 of 23 isolates from 1 to 3 week old pigs (78.3%) and 81 of 88 isolates from weaned pigs (92.1%). F4:STa:STb:LT (serotype O149) was the most prevalent pathotype in neonatal and 1-3 week old pigs and F4:STa:STb:LT (serotype O149) and F18:STa:STb:LT (serotype O141) were most prevalent in weaned pigs. In comparison, isolates obtained from neonatal pigs from New South Wales belonged to a more diverse range of pathotypes and serotypes. CONCLUSION: Multiplex PCR was a rapid and specific method for detecting the presence of ETEC virulence genes in porcine E coli isolates. For isolates obtained from cases of suspected colibacillosis in Queensland, growth of a heavy pure culture of haemolytic E coli was a sensitive prognostic indicator of the presence of ETEC virulence genes in the isolate. ETEC pathotypes and serotypes remained stable in Queensland piggeries over the five-year study period and appear to have changed little over the last three decades.

Animals↗

PubMed1994

The effect of investment type on the fit of cast titanium crowns.

In order to determine the best laboratory procedure for titanium crown casting, a set of thermal expansion measurements and casting experiments were carried out using a casting machine (argon arc, pressure difference type) and three different investments, two conventional SiO2 based investments and a new Al2O3/MgO based investment. The thermal expansion measurements involved a cycle of heating and cooling. The relatively low mould temperatures recommended (200 degrees C) or chosen (350 degrees C) for the conventional investments provided zero or negative mould expansion for the compensation of metal shrinkage. Crowns made from these investments exhibited heavy reaction with the mould, and the common cleaning method of sand blasting appeared to be essential. This cleaning process, however, was not adequate for the assessment of casting accuracy as the short sand blasting time (15 s) rapidly altered the fit of the crowns. The metal reacted little with the new investment and the best compensation (0.15 mm discrepancy) for the metal shrinkage, as assessed 'as cast', was achieved when the investment was heated to 950 degrees C and then cooled to the recommended mould temperature (600 degrees C).

Chemical Phenomena↗

PubMed1980

Production of aseptic spores of vesicular-arbuscular endophytes and their viability after chemical and physical stress.

The survival of germinating spores of vesicular-arbuscular endophytes after treatments with oxidizing agents, antibiotics, moist heat, ultrasonic radiation, and ultraviolet radiation was compared with that of their contaminating microbes. Spores of three species were rapidly decontaminated by treatment with 0.42% (wt/vol) chlorine available from 5.0% (wt/vol) chloramine-T at 30 degrees C for 20 to 40 min depending on the species and the soil from which they were extracted. This treatment did not change spore viability. The survival of spores was reduced by exposure for 20 min to 1.11% chlorine at 30 degrees C for Glomus caledonius or at 35 degrees C for Acaulospora laevis. Growth of any bacteria surviving treatment with oxidizing agents was inhibited by 100 mug of chloramphenicol per ml in agar; however, spore germination and germ tube growth were reduced only by concentrations greater than 200 mug/ml in agar. Spore germination was decreased by concentration of pimaracin, which controlled fungal growth. The spores survived moist heat at 40 degrees C for 80 min, 55 degrees C for 10 min, and 60 degrees C for less than 1 min. The viability of spores was unaffected by ultrasonic irradiation for up to 4 min. Spores of G. caledonius and A. laevis were extremely resistant to ultraviolet radiation. Their viability was unaffected by exposure to 5 x 10 ergs cm from an ultraviolet source of 253.7nm. The spores had very thick, pigmented walls, and the possibility that these provided some protection against the physical and chemical treatments is discussed. The degree of physiological damage to the spores caused by the treatments demonstrated some adverse effects of basic laboratory procedures. This information, together with that on the comparative sensitivity of contaminating microbes to the treatments, was used in the development of protocol for producing large numbers of uncontaminated spores.

Journal Article↗

PubMed1967

Quantitative bacteriological analysis of sputum as a test of antibiotic efficacy.

After 5 days of treatment, sputa were analyzed from 40 patients treated with sodium fusidate and 20 patients treated with naficillin. There was a significant decrease in the number of staphylococci, but no significant change in the other flora. The quantitative bacteriological analysis of sputum specimens proved to be a useful laboratory procedure for providing information on the in vivo effectiveness of specific antibacterial therapy in respiratory infections.

Bacteria↗

PubMed1971

Evaluation of methods used to purify acid-extracted group A streptococcal M protein.

The literature includes descriptions of both acid-soluble and acid-insoluble M protein in the preparation of "hot acid-extracted group A streptococcal M protein." We present evidence for the contamination of crude type 1 acid-insoluble M protein. The purification of preparations of crude and partially purified acid-soluble type 1 and type 12 M protein is described. Our quantitative criteria for purification were recovery of M precipitin activity, improvement in specific activity, and removal of carbohydrate. Exclusion of nucleic acid is also discussed. Greater purification in a single passage was found with a carboxymethylcellulose column (with acidic elution) than with hydroxyapatite, diethylaminoethyl-Sephadex, or carboxymethyl-cellulose (with neutral elution) columns or with ammonium sulfate fractional precipitation. Carboxymethylcellulose with acidic elution was found to be a satisfactory standard laboratory procedure for the preparation of purified acid-extracted (acid-soluble) group A streptococcal M protein.

Chemical Precipitation↗

PubMed2002

Ability of the borreliacidal antibody test to confirm lyme disease in clinical practice.

Highly specific borreliacidal antibodies are induced by infection with Borrelia burgdorferi, and a borreliacidal antibody test (BAT) may be an accurate laboratory procedure for confirming Lyme disease in clinical practice. To investigate this, 34 Lyme disease sera and 34 sera from patients with other illnesses who had presented to a primary-care facility located in an area of borreliosis endemicity were tested by the BAT and Western blotting (WB). The BAT was more sensitive (79% versus 65%; P = 0.090), especially in cases in which patients had a single erythema migrans lesion (P = 0.021). In addition, the potentially cross-reactive sera were negative by the BAT but WB yielded three (9%) false-positive results. The results from 104 sera from possible Lyme disease patients demonstrated the clinical usefulness of the more sensitive and specific BAT. The BAT was positive for 40 (38%) sera from patients with Lyme disease-related symptoms and appropriate clinical and epidemiological findings. WB confirmed Lyme disease in 30 (75%) of the 40 BAT-positive patients but failed to detect B. burgdorferi infection in 10 BAT-positive patients. WB was also positive for 11 BAT-negative sera, but six (55%) patients had case histories which suggested that the results were false positives. Collectively, the results confirm that the BAT is a sensitive and highly specific test and suggest that widespread use would increase the accuracy of serodiagnostic confirmation of Lyme disease.

Blotting, Western↗