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Biomedical subjects

B Sener

Publications and source records attributed to B Sener.

At least 55 records · Page 3Linked to original sources
PubMed1998

Rate of carriage, serotype distribution and penicillin resistance of Streptococcus pneumoniae in healthy children.

This study was aimed to define the carriage rates for Streptococcus pneumoniae in a given population in Ankara and also to determine the serotypes and penicillin resistance of these strains. Oropharyngeal swabs were taken from a total of 661 children aged between 0-11 years and living in a province of Ankara between January 1995-January 1997. Serotyping was performed by detection of the Quellung reaction. The isolates were screened for penicillin susceptibility by the agar dilution method according to the guidelines of NCCLS. The total rate of pneumococcal carriage in the study population was 23.90% and the isolation rate was found to be statistically associated with age, being higher in small children. Among the 158 S. pneumoniae isolates, the most prevalent serotypes (in order of frequency) were 6, 19, 9, 23, 3 and 14. Penicillin susceptibility was examined in 120 of the isolates. 55 of them (45.83%) were susceptible, 53 (44.17%) were intermediately and 12 (10.0%) were highly resistant to penicillin. Evaluation of the results showed that serotypes 6, 14 and 23 were those most often associated with penicillin resistance. The significant rate of isolation of penicillin-resistant pneumococci in healthy carriers points to the importance of active immunization in risk groups and also the importance of the rational use of antibiotics to limit the spread of resistant strains.

Carrier State↗
PubMed1998

Effects of sodium hypochlorite on nickel-titanium Lightspeed instruments.

Sodium hypochlorite is a major irrigant in endodontics, and nickel-titanium instruments are gaining in popularity. This paper investigated the corrosion of nickel-titanium Lightspeed instruments in 1% and 5% NaOCl solutions. The instruments were immersed in ultrasonicated NaOCl solutions for varying times up to 1 h. Corrosion was determined by electrothermal absorption spectrometry in 100 microL aliquots of NaOCl. Background contamination of nickel in the 1% and 5% NaOCl solutions used was low, but high enough to interfere in detecting any increases in nickel after immersing the instruments. The amounts of titanium recorded in the 1% NaOCl solutions were insignificant. However, a statistically significant amount of titanium was detected from the Lightspeed instruments after immersion times of 30 and 60 min in 5% NaOCl. Clinically such instruments do not have an 'in situ' time of 30 min, and this corrosion may be considered irrelevant clinically.

Analysis of Variance↗
PubMed1998

Evaluating the sizes of Lightspeed instruments.

The diameters of six different sized Lightspeed cutting heads were measured using a modified optical micrometer. Six specimens of instrument sizes 20, 22.5, 27.7, 30, 32.5 and 45 were examined. Except for one cutting head of size 30, all the recorded diameters were oversized compared to the expected diameter and the permitted tolerance (+/- 0.005 mm). Perfectly machined instruments would increase by 12.5%, 9.09% and 8.3% from instrument sizes 20-22.5, 27.5-30 and 30-32.5, respectively. Under the conditions of this study, the corresponding increases were 7.1%, 6.75% and 8.54%. Instrument size 20 had the widest range and is the smallest instrument in the Lightspeed set. The largest differences between the recorded and expected means were registered for the size 45 group. An earlier study using a different measuring method reported that Lightspeed instruments were mostly undersized.

Dental Instruments↗
PubMed1998

Structure-activity relationships of imperialine derivatives and their anticholinergic activity.

In order to check the structure-activity relationship and prepare more potent derivatives of imperialine with anticholinergic activity, imperialinol (2), 3 beta-acetoxyimperialine (3), 3 beta-propionoxyimperialine (4), and 3 beta-butyroxyimperialine (5) were prepared. Compounds 4 and 5 displayed better anticholinergic activity against muscarinic receptors of the heart and brain than imperialine (1). The decrease in activity in 2 showed the importance of the 6-keto functionality in imparting the anticholinergic activity.

Alkaloids↗
PubMed1998

Trends in antimicrobial resistance of Streptococcus pneumoniae in children in a Turkish hospital.

The antimicrobial susceptibilities of 143 isolates of Streptococcus pneumoniae recovered from the sputa of children with lower respiratory tract infections in a Turkish university hospital were determined. Five isolates (3.5%) were resistant and 57 isolates (39.9%) intermediately resistant to penicillin. The most common serotype among these resistant isolates was serotype 23, followed by serotypes 19 and 14. The overall resistance rates were 31% for tetracycline, 11% for erythromycin and cefaclor, 4% for chloramphenicol, 2% for cefotaxime and 0% for vancomycin. The data highlight the need for surveillance of resistance and serotype distribution of S. pneumoniae in our geographical area.

Child↗
PubMed1998

Two-year results of photorefractive keratectomy with scanning spot ablation for myopia of less than -6.0 diopters.

BACKGROUND AND OBJECTIVE: To investigate the efficacy, predictability, stability, and safety of photorefractive keratectomy (PRK) with scanning spot ablation for the treatment of myopia of less than -6.0 D. PATIENTS AND METHODS: Twenty eyes of 20 patients (11 men, 9 women) were enrolled into the study. The mean age was 26.2 +/- 5.4 years. Mean spherical equivalent myopia was -3.53 +/- 1.13 D, ranging from -2.25 to -6.00 D. Patients underwent excimer laser PRK for the treatment of myopia. Follow-up time was at least 24 months in all patients. RESULTS: Mean spherical equivalent refraction was +0.84 +/- 0.99 D at 1 month, +0.19 +/- 0.54 at 3 months, -0.01 +/- 0.53 at 12 months, and -0.13 +/- 0.50 at 24 months. There was a mean regression of 0.65 D between 1 and 3 months. At 24 months, 16 (80%) of the eyes remained within +0.50 D of emmetropia and 18 (90%) of the eyes remained within +/- 1.0 D of emmetropia. Nineteen (95%) of the eyes had uncorrected visual acuity of 20/40 or better. The mean corneal haze score was maximum at 3 months (0.88 +/- 0.22). There was no clinically significant corneal haze (greater than 2+). One eye (5%) lost 2 or more lines of best-corrected visual acuity. CONCLUSION: Excimer laser PRK with the scanning spot ablation technique is effective, predictable, stable, and safe for the treatment of myopia of less than -6.0 D.

Adult↗
PubMed1997

New steroidal alkaloids from Buxus longifolia.

Four new steroidal alkaloids, (+)-cyclovirobuxeine F (1), N-benzoyl-O-acetylbuxalongifoline (2), buxasamarine (3), and (+)-cyclobuxamidine (4), along with two known steroidal bases, 16 alpha-acetoxybuxabenzamidienine (5) and trans-cyclosuffrobuxinine (6), were isolated from the leaves of Buxus longifolia. The alkaloids 1-4 showed significant antibacterial activity.

Alkaloids↗
PubMed1997

Antinociceptive effect of some amaryllidaceae plants in mice.

The antinociceptive effects of ethanolic extracts of Pancratium maritimum L., Narcissus tazetta subspecies tazetta and Leucojum aestivum L. bulbs have been investigated in mice using the p-benzoquinone-induced abdominal constriction and hot-plate tests. In the p-benzoquinone-induced abdominal constriction test the ethanolic extracts of P. maritimum (300, 600 or 1200 mg kg-1, s.c.) and N. tazetta subsp. tazetta (5, 50, 100 or 200 mg kg-1, s.c.) caused dose-dependent inhibition of abdominal constrictions whereas a fluctuating response was obtained from ethanolic extracts of L aestivum (2.5-500 mg kg-1, s.c.). In the hot-plate test P. maritimum and L. aestivum caused a significant increase of latency only at the highest concentrations used (1200 mg kg-1 and 500 mg kg-1, i.p., respectively). However, at these concentrations they also caused significant toxic effects. In contrast with P. maritimum and L. aestivum, N. tazetta subsp. tazetta (5-500 mg kg-1, i.p.) extracts had no antinociceptive effect in this test. These findings indicate that the antinociceptive effect of Amaryllidaceae plants differs depending on the model of nociception investigated.

Abdomen↗
PubMed1996

Evaluation of the microbiology of chronic sinusitis.

Chronic sinusitis is one of the most common diseases treated in outpatient centres. In this prospective study, 49 patients with the diagnosis of chronic maxillary sinusitis were evaluated microbiologically by using sinus swab, irrigation fluid and sinus mucosal tissue specimens obtained during endoscopic sinus surgery. There was no bacterial growth in seven cases. In the remaining 42 cases a total of 89 bacteria were isolated, 28 of them being classical pathogens and 61 being non-classical pathogens. Among the classical pathogens Staphylococcus aureus was the most common one. The correlation between the isolates obtained from maxillary sinus and isolates obtained from throat, nose and nasopharynx did not have a predictive value. Since the overall rate of classical pathogen isolation from patients with chronic sinusitis was not significantly high, the possible role of factors other than bacterial growth should be identified in the pathogenesis of chronic sinusitis.

Adolescent↗
PubMed1995

The effect of tonsillectomy on neutrophil chemotaxis in adults with chronic tonsillitis.

Neutrophil random motility and chemotactic responsiveness were determined in 17 healthy adults and 19 adult patients with chronic tonsillitis before and 10 days after tonsillectomy, using a modified Boyden chamber method. The mean chemotactic index values of the healthy controls were significantly higher when compared with the chronic tonsillitis patients before tonsillectomy. The postoperative mean chemotactic values were increased, and there was a statistically significant difference between the mean chemotactic index of neutrophils in preoperative and postoperative patients. The authors conclude that this change in host defense mechanism may be the reason for frequent attacks of acute tonsillitis in these patients.

Adult↗
PubMed1995

A bidesmosidic hederagenin hexasaccharide from the roots of Symphytum officinale.

A new bidesmosidic triterpenoidal saponin 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-alpha-L - arabinopyranosyl]-hederagenin-28-O-[alpha-L-rhamnopyranosyl- (1-->4)-beta-D- glucopyranosyl-(1-->6)-beta-D-glucopyranosyl] ester, was isolated from the roots of Symphytum officinale. The structure was assigned by chemical methods and spectral analysis (1H, 13C, DEPT, NMR, EI-MS and FAB-MS) including 1H-1H COSY, 1H-13C COSY and HOHAHA. The prosapogenin of this saponin is also a new compound.

Carbohydrate Conformation↗
PubMed1995

[Grinding precision and accuracy of the fit of Cerec-2 CAD/CIM inlays].

The grinding precision of one Cerec-1 (C1) and one Cerec-2 (C2) CAD/CIM unit each was evaluated using standardized inlay-like (mod) samples (n = 40) of Vita Cerec Mk II porcelain and Dicor MGC glass ceramic. Typical dimensions (B, E, F, H) of the sampleS were measured and the standard deviations (SD) analysed statistically using the F-test. SD of C2-machined sample dimensions were significantly lower using both Vita, B: p < 0.05; E: p < 0.001; F: p < 0.001; H: p < 0.001, and Dicor MGC, B: p < 0.05; E: p < 0.001; F: p < 0.001; H: p < 0.01, than those machined with C1, indicating a strong improvement of grinding precision of C2 compared to C1. Accuracy of fit to human molar cavities of mod inlays machined with C1 (n = 6) and C2 (n = 6) was evaluated using a scanning electron microscope with 100x magnification. The width of the interfacial luting gap was generally lower in C2 inlays (56 +/- 27 microns) than with C1 (84 +/- 38 microns). Significant differences (t-test) were seen in margin sections "cervical line angles above CEJ" (C1 = 124 +/- 44/C2 = 59 +/- 30 microns, p < 0.05), "cervical line angles at CEJ" (C1 = 109 +/- 55/C2 = 67 +/- 27 microns, p < 0.05) and "gingival margin above CEJ" (C1 = 81 +/- 32 microns/C2 = 31 +/- 18 microns, p < 0.05).

Ceramics↗
PubMed1994

Hypoglycaemic effect of Momordica charantia extracts in normoglycaemic or cyproheptadine-induced hyperglycaemic mice.

The hypoglycaemic effect of orally administered extracts of Momordica charantia L. fruits was examined in normoglycaemic or cyproheptadine-induced hyperglycaemic mice. The aqueous extract reduced the fasting glucose levels of hyperglycaemic or normoglycaemic mice. However, the ethanol extract did not affect the fasting or nonfasting glucose levels significantly in both groups of mice. There was no significant difference between the glucose-loaded and glucose-loaded plus aqueous extract given group. On the other hand, oral glucose-loading of the cyproheptadine-induced hyperglycaemic animals reduced the fasting glucose levels significantly. These results showed that aqueous extract of M. charantia fruits has a hypoglycaemic activity without improving the tolerance to glucose in cyproheptadine-induced diabetic mice.

Animals↗
PubMed1994

A bidesmosidic triterpene glycoside from the roots of Symphytum officinale.

A new bidesmosidic triterpenoidal saponin of hederagenin was isolated from the ethanolic extract of the roots of Symphytum officinale L. Its structure was elucidated by using 1H NMR, 1H-1H COSY NMR, heteronuclear 1H-13C correlated spectroscopy (heteroCOSY), 13C NMR, DEPT, FAB mass spectrometry and chemical evidence as 3-O-alpha-L-arabinopyranosyl]-hederagenin-28-O-[beta-D-gluco pyranosyl- (-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]ester.

Carbohydrate Sequence↗