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1.
Int J STD AIDS ; 17(4): 237-46, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16595046

ABSTRACT

We evaluated a study setting for assessment of the long-term vaccine efficacy (VE) of human papillomavirus (HPV) virus-like-particle (VLP) vaccine against cervical carcinoma. A total of 22,412 16- to 17-year old adolescent women from seven cities in Finland were invited by letter to participate in a phase III study of a quadrivalent HPV (types 6, 11, 16, 18) VLP vaccine, between September 2002 and March 2003. A total of 30,947 18-year old women were invited to participate as unvaccinated controls. These women were asked about their willingness to participate in an HPV vaccination trial and to fill a health questionnaire. These three population-based cohorts of adolescent women, including women vaccinated with HPV vaccine or placebo vaccine and unvaccinated control women, are systematically followed over time. The study cohort database will be linked with the Finnish Cancer Registry using cervical carcinoma in situ (CIS) and invasive cervical carcinoma (ICC) as endpoints. Assuming that the cumulative incidence of CIS and ICC over 15 years is 0.45%, and that there is no loss to follow-up, and power of 80%, the determination of 70% total VE will require 3357 HPV vaccine recipients, 3357 placebo vaccine recipients, and 6714 unvaccinated controls. At the baseline, 2632 (12%) of the invited adolescents volunteered to the phase III vaccination trial, and 6790 (22%) responded to the questionnaire study. During a recruitment period of 10 months, 874 HPV vaccine recipients, 875 placebo recipients and 1919 unvaccinated controls were enrolled. Population-based enrollment of large cohorts of vaccinated and unvaccinated adolescents for passive registry-based follow-up with cervical carcinoma as the end-point is feasible and currently going on in Finland.


Subject(s)
Adolescent Health Services , Papillomaviridae/immunology , Papillomavirus Infections/prevention & control , Papillomavirus Vaccines , Patient Selection , Sexually Transmitted Diseases/prevention & control , Viral Vaccines/therapeutic use , Adolescent , Clinical Trials, Phase III as Topic , Cohort Studies , Female , Finland/epidemiology , Follow-Up Studies , Humans , Longitudinal Studies , Male , Multicenter Studies as Topic , Papillomavirus Infections/epidemiology , Population Surveillance/methods , Registries , Sexually Transmitted Diseases/epidemiology , Surveys and Questionnaires
2.
Gynecol Endocrinol ; 18(5): 278-90, 2004 May.
Article in English | MEDLINE | ID: mdl-15346664

ABSTRACT

Despite improvements in both diagnostic assessment and treatment of infertile couples, many couples still have no explanation for their infertility. Unexplained infertility (the failure to conceive of a couple in whom no definitive cause for infertility can be found) has an incidence of 10-20% in all infertile couples. The incidence varies with the population studied and with the criteria used. Unexplained infertility is not an absolute condition but rather a relative inability to conceive, and many of these couples may conceive without treatment. The treatment options for unexplained infertility are several and the treatment results are promising. Expectant management can be recommended if the woman is under 28-30 years of age and the infertility duration is less than 2-3 years. In vitro fertilization (IVF) has revolutionized the treatment of infertile couples, as well as profoundly increasing the basic understanding of human reproduction. IVF can be used as both a diagnostic and a therapeutic tool in couples with unexplained infertility. The pregnancy rates with IVF are good, at 40% per treatment cycle. In addition, the outcome of pregnancies among women with unexplained infertility is generally comparable to that of spontaneous and other pregnancies using assisted reproductive technologies.


Subject(s)
Infertility, Female/etiology , Infertility, Male/etiology , Adult , Female , Humans , Infant, Newborn , Infertility, Female/therapy , Infertility, Male/therapy , Male , Pregnancy , Pregnancy Outcome , Reproductive Techniques, Assisted
3.
Ultrasound Obstet Gynecol ; 21(2): 174-80, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12601842

ABSTRACT

OBJECTIVE: To evaluate the possible difference in uterine and spiral artery impedance to blood flow among women with unexplained and tubal infertility during spontaneous and gonadotropin-stimulated cycles. METHODS: We prospectively compared uterine and spiral artery pulsatility index and peak systolic velocity in a longitudinal study in women with either unexplained infertility (n = 20) or tubal infertility (n = 18). Measurements of uterine and spiral artery impedance were taken on days 11-12, 16-17 and 21-23 of the spontaneous cycle and on days 1, 5 and 10 during gonadotropin stimulation. In addition, measurements were taken on the days of oocyte pick-up and embryo transfer. RESULTS: A clinical pregnancy was achieved in 8/20 (40%) women with unexplained and 6/18 (33.3%) women with tubal infertility with in-vitro fertilization treatment. There were no differences in the uterine artery pulsatility index or peak systolic velocity during the spontaneous or the in-vitro fertilization cycle between the two groups. The impedance to blood flow in the uterine or spiral artery did not differ between women conceiving with in-vitro fertilization-embryo transfer and those who did not. However, the spiral artery pulsatility index on the 5th day of gonadotropin stimulation was significantly lower among women with unexplained infertility (0.96 +/- 0.25) compared to women with tubal infertility (1.24 +/- 0.30; P < 0.05), but on the other days of gonadotropin stimulation the spiral artery pulsatility index and peak systolic velocity were similar. CONCLUSIONS: Impaired uterine or spiral artery blood flow is not an important factor in unexplained infertility.


Subject(s)
Fallopian Tube Diseases/diagnosis , Infertility, Female/diagnosis , Uterus/blood supply , Adult , Arteries/physiopathology , Blood Flow Velocity/physiology , Fallopian Tube Diseases/physiopathology , Female , Humans , Infertility, Female/physiopathology , Longitudinal Studies , Pregnancy , Prospective Studies , Pulsatile Flow
4.
J Chromatogr A ; 918(1): 211-20, 2001 May 18.
Article in English | MEDLINE | ID: mdl-11403450

ABSTRACT

Four cation-exchange materials, possessing propanesulfonic acid ligands, for use in capillary electrochromatography were prepared from different commercially available 5-microm bare-silica particles ranging from 80 to 800 A in pore size. The performance of the materials was investigated at different compositions of the mobile phase (pH, ionic strength, and acetonitrile content) using tricyclic antidepressants and related quaternary ammonium analogues as test analytes. The wide-pore materials promoted pore flow, but this had no positive influence on the performance. The small-pore (highest surface area) particles gave, as could be expected, the best selectivity.


Subject(s)
Antidepressive Agents, Tricyclic/analysis , Cation Exchange Resins/chemistry , Chromatography, Micellar Electrokinetic Capillary/methods , Hydrogen-Ion Concentration , Osmolar Concentration
5.
J Mol Biol ; 305(1): 79-93, 2001 Jan 05.
Article in English | MEDLINE | ID: mdl-11114249

ABSTRACT

Cellobiohydrolase Cel7A (previously called CBH 1), the major cellulase produced by the mould fungus Trichoderma reesei, has been successfully exploited as a chiral selector for separation of stereo-isomers of some important pharmaceutical compounds, e.g. adrenergic beta-blockers. Previous investigations, including experiments with catalytically deficient mutants of Cel7A, point unanimously to the active site as being responsible for discrimination of enantiomers. In this work the structural basis for enantioselectivity of basic drugs by Cel7A has been studied by X-ray crystallography. The catalytic domain of Cel7A was co-crystallised with the (S)-enantiomer of a common beta-blocker, propranolol, at pH 7, and the structure of the complex was determined and refined at 1. 9 A resolution. Indeed, (S)-propranolol binds at the active site, in glucosyl-binding subsites -1/+1. The catalytic residues Glu212 and Glu217 make tight salt links with the secondary amino group of (S)-propranolol. The oxygen atom attached to the chiral centre of (S)-propranolol forms hydrogen bonds to the nucleophile Glu212 O(epsilon1) and to Gln175 N(epsilon2), whereas the aromatic naphthyl moiety stacks with the indole ring of Trp376 in site +1. The bidentate charge interaction with the catalytic glutamate residues is apparently crucial, since no enantioselectivity has been obtained with the catalytically deficient mutants E212Q and E217Q. Activity inhibition experiments with wild-type Cel7A were performed in conditions close to those used for crystallisation. Competitive inhibition constants for (R)- and (S)-propranolol were determined at 220 microM and 44 microM, respectively, corresponding to binding free energies of 20 kJ/mol and 24 kJ/mol, respectively. The K(i) value for (R)-propranolol was 57-fold lower than the highest concentration, 12.5 mM, used in co-crystallisation experiments. Still several attempts to obtain a complex with the (R)-enantiomer have failed. By using cellobiose as a selective competing ligand, the retention of the enantiomers of propranolol on the chiral stationary phase (CSP) based on Cel7A mutant D214N were resolved into enantioselective and non- selective binding. The enantioselective binding was weaker for both enantiomers on D214N-CSP than on wild-type-CSP.


Subject(s)
Adrenergic beta-Antagonists/metabolism , Cellulase/chemistry , Cellulase/metabolism , Propranolol/chemistry , Propranolol/metabolism , Trichoderma/enzymology , Adrenergic beta-Antagonists/chemistry , Binding Sites , Catalysis , Catalytic Domain , Cellulase/genetics , Cellulose 1,4-beta-Cellobiosidase , Chromatography, High Pressure Liquid , Crystallography, X-Ray , Drug Design , Hydrogen-Ion Concentration , Models, Molecular , Mutation/genetics , Protein Binding , Protein Structure, Tertiary , Stereoisomerism , Substrate Specificity
6.
Swed Dent J ; 24(3): 105-16, 2000.
Article in English | MEDLINE | ID: mdl-11061208

ABSTRACT

The aim of this study was to compare the estimation ability of a dental hygienist to that of a dentist when, independently, recording the oral health status and treatment need in a population of elderly, receiving home nursing. Seventy-three persons, enrolled in a home nursing long-time care programme, were recruited. For the oral examination a newly developed protocol with comparatively blunt measurement variables was used. The oral examination protocol was tested for construct validity and for internal consistency reliability. Statistical analyses were performed using Wilcoxon matched pairs signed rank sum test for testing differences, while inter-examiner agreement was estimated by calculating the kappa-values. Comparing the two examiners, good agreement was demonstrated for all mucosal recordings, colour, form, wounds, blisters, mucosal index, and for the palatal but not the lingual mucosa. For the latter, the dental hygienist recorded significantly more changes. The dental hygienist also recorded significantly higher plaque index values. Also regarding treatment intention and treatment need, the dental hygienist's estimation was somewhat higher. In conclusion, when comparing the dental hygienist's and the dentist's ability to estimate oral health status, treatment intention, and treatment need, some differences were observed, the dental hygienist tending to register "on the safe side", calling attention to the importance of inter-examiner calibration. However, for practical purpose the inter-examiner agreement was acceptable, constituting a promising basis for future out-reach activities.


Subject(s)
Dental Care for Aged/methods , Dental Hygienists , Dentists , Health Services Needs and Demand , Home Care Services , Oral Health , Aged , Dental Care for Aged/statistics & numerical data , Dental Hygienists/statistics & numerical data , Dentists/statistics & numerical data , Diagnosis, Oral/methods , Diagnosis, Oral/statistics & numerical data , Health Services Needs and Demand/statistics & numerical data , Home Care Services/statistics & numerical data , Humans , Observer Variation , Statistics, Nonparametric , Sweden
7.
Ultrasound Obstet Gynecol ; 15(6): 527-30, 2000 Jun.
Article in English | MEDLINE | ID: mdl-11005123

ABSTRACT

OBJECTIVE: To evaluate the influence of uterine artery impedance to blood flow on the day of embryo transfer for prediction of early pregnancy loss and obstetric outcome. METHODS: The uterine artery pulsatility index (PI) and resistance index (RI) were evaluated prospectively by transvaginal Doppler in 102 infertile women, who conceived as the result of fresh or frozen embryo transfer. Uterine artery impedance to blood flow was compared to the obstetric outcome. RESULTS: The 111 treatment cycles studied resulted in 31 spontaneous abortions, four ectopic pregnancies, and 76 deliveries. There were no differences in uterine artery PI and RI (mean +/- SD) between cycles resulting in normal delivery (2.69 +/- 0.71 and 0.88 +/- 0.06) and those resulting in spontaneous abortion (2.71 +/- 0.67 and 0.88 +/- 0.05) or ectopic pregnancy (2.36 +/- 0.54 and 0.85 +/- 0.06). There were no differences in PI and RI between uncomplicated singleton pregnancies (2.74 +/- 0.78 and 0.88 +/- 0.06) and those developing intra-uterine growth restriction (IUGR), pregnancy-induced hypertension (PIH), or preterm birth (2.54 +/- 0.47 and 0.87 +/- 0.04, pooled data). CONCLUSIONS: Uterine artery PI and RI on the day of embryo transfer were unrelated to the risk of the pregnancy ending in spontaneous abortion or ectopic pregnancy. These values were of no value in the prediction of IUGR, PIH or preterm birth.


Subject(s)
Embryo Transfer , Pregnancy Outcome , Uterus/blood supply , Vascular Resistance , Adult , Arteries/diagnostic imaging , Chorionic Gonadotropin/blood , Embryo Transfer/methods , Female , Humans , Pregnancy , Prognosis , Prospective Studies , Pulsatile Flow , Regional Blood Flow , Ultrasonography, Doppler , Uterus/diagnostic imaging
8.
Electrophoresis ; 21(8): 1587-96, 2000 May.
Article in English | MEDLINE | ID: mdl-10832892

ABSTRACT

The cellulases CBH 58 from the fungus Phanerochaete chrysosporium and CBH I from the fungus Trichoderma reesei were compared as chiral selectors in capillary electrophoresis (CE) applying the partial filling technique. Amines, e.g., norephedrine, two bambuterol analogs, as well as acids, e.g., di-p-toluoyl tartaric acid and dibenzoyl tartaric acid, which could not be enantioseparated in the liquid chromatographic use of the selectors, could be separated in the corresponding CE experiments. Due to the very high enantioselectivities, terbutaline, alprenolol and propranolol could be completely enantioresolved with selector plugs shorter than the sample plugs. The affinity of propranolol to CBH 58 was so high at pH 7.0 that neither of the enantiomers reached the detector; therefore, a plug of the displacing disaccharide cellobiose was injected after the sample to elute the propranolol enantiomers. The enantiomers could also be made to leave the capillary at opposite ends, thereby causing an infinite enantioresolution. A new preconcentration technique was introduced, which takes advantage of the very high affinity of propranolol to CBH 58 and the eluting ability of cellobiose. A 12.5 cm long plug of rac-propranolol could be preconcentrated and enantioseparated in a single procedure.


Subject(s)
Cellulase/analysis , Phanerochaete/enzymology , Trichoderma/enzymology , Electrophoresis, Capillary/methods , Molecular Structure , Reproducibility of Results
9.
J Chromatogr A ; 898(1): 63-74, 2000 Nov 10.
Article in English | MEDLINE | ID: mdl-11185624

ABSTRACT

Cellobiohydrolase 58 (EC 3.2.1.91, P.c. Cel 7D) from Phanerochaete chrysosporium was immobilized on silica and the resulting material, CBH 58-silica, was then used as a chiral stationary phase (CSP) in liquid chromatographic separations of enantiomers. The enantioselectivities obtained on CBH 58-silica were compared with those on CBH I-silica (a phase based on a corresponding cellulase from Trichoderma reesei). CBH 58-silica displayed higher selectivity than CBH I-silica for the more hydrophilic compounds, such as atenolol and metoprolol, although great similarities in chiral separation of beta-adrenergic antagonists were found between the two phases. None of the acidic compounds tested could be resolved on the CBH 58 phase. Moreover, the solutes were retained more on the CBH 58 phase in general, indicating an improved application potential in bioanalysis. Addition of cellobiose or lactose, both of which are inhibitors of cellulases, to the mobile phase impaired the enantioselectivity, indicating an overlap of the enantioselective and catalytic sites. The chiral analytes also functioned as competitive inhibitors and their inhibition constants were determined.


Subject(s)
Cellulase/chemistry , Cellulase/metabolism , Cellulose 1,4-beta-Cellobiosidase , Chromatography, High Pressure Liquid , Hydrogen-Ion Concentration , Kinetics , Osmolar Concentration , Phanerochaete/enzymology , Stereoisomerism
10.
Spec Care Dentist ; 20(3): 109-13, 2000.
Article in English | MEDLINE | ID: mdl-11203883

ABSTRACT

In Sweden, efforts are being made to create strategies for evaluating realistic dental treatment needs among the elderly, who are retaining more natural teeth. These strategies focus on the importance of maintaining adequate oral hygiene. Elderly in long-term-care facilities often depend on nursing personnel for carrying out daily oral hygiene procedures. Therefore, the nursing personnel's knowledge about and attitudes toward oral health make oral health education for health care professionals an important concern. The purpose of this study was to evaluate the clinical oral health outcome in residents after their caregivers had undergone a one-session, four-hour oral health education program. The study consisted of an intervention with a pre- and a post-test and was carried out in three municipalities in the southwestern part of Sweden. A newly developed oral health screening protocol was carried out for 170 subjects living in long-term-care facilities both before and 3-4 months after nursing personnel had attended an oral health education program. Following the intervention, a statistically significant improvement was recorded for changes in oral mucosal color, a modified plaque index which measured oral hygiene status, and a mucosal index which recorded mucosal inflammation. This study indicated that a limited, one-session, four-hour oral health education, offered to caregivers within long-term-care facilities, had a positive impact on the oral health status of residents.


Subject(s)
Health Education, Dental , Homes for the Aged , Nursing Staff , Oral Health , Aged , Aged, 80 and over , Attitude of Health Personnel , Dental Care for Aged , Dental Plaque Index , Education, Nursing , Female , Health Services Needs and Demand , Health Status , Humans , Long-Term Care , Male , Mass Screening , Middle Aged , Mouth Mucosa/anatomy & histology , Oral Hygiene , Outcome Assessment, Health Care , Statistics, Nonparametric , Stomatitis/classification , Sweden , Workforce
11.
Acta Obstet Gynecol Scand ; 77(8): 849-53, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9776600

ABSTRACT

BACKGROUND: The aim of this study was to determine the long-term prognosis of fecundity among couples with unexplained infertility and to compare pregnancy course and outcome in spontaneous versus treatment-related pregnancies. METHODS: A prospective follow-up study of 70 couples with a diagnosis of unexplained infertility. All couples had participated in a study at the Helsinki University Central Hospital where the effectiveness was compared with intrauterine insemination, direct intraperitoneal insemination or timed intercourse, each combined with superovulation. The follow-up was carried out by collecting all available information on treatment-related and spontaneous pregnancies from hospital records and questionnaires mailed to these same women 6 years later. RESULTS: Of 70 couples, 45 (64.3%), conceived during the follow-up period. Of all 83 pregnancies, 50 (60.2%) began spontaneously and 33 (39.8%) with infertility treatment. Rate of multiple deliveries was 25% in treatment-related pregnancies, but only 2.8% in spontaneous pregnancies (p<0.05). Mean birthweight among singleton pregnancies was 3 120 grams in treatment-related, and 3387 grams in spontaneous pregnancies (p<0.05). The rate of small-for-gestational-age (<-2 s.d.) and preterm births (before 37 completed weeks) in both groups was equal. CONCLUSIONS: The long-term prognosis of couples with unexplained infertility was good, and many of the pregnancies began spontaneously. The birthweight of singleton neonates in treatment-related pregnancies was lower than in spontaneously conceived pregnancies, but otherwise perinatal outcome was similar.


Subject(s)
Infertility, Female/therapy , Infertility, Male/therapy , Pregnancy Outcome , Female , Forecasting , Humans , Insemination, Artificial/methods , Male , Pregnancy , Prognosis , Superovulation
12.
Chirality ; 10(6): 513-8, 1998.
Article in English | MEDLINE | ID: mdl-9725010

ABSTRACT

An increase in both retention and enantioselectivity for some beta-blocking agents was observed when exchanging potassium to sodium ion in the buffer used as mobile phase. A large effect of ionic strength on retention was observed, while the enantioselectivity was constant.


Subject(s)
Cellulase/chemistry , Potassium/chemistry , Sodium/chemistry , Adrenergic beta-Antagonists/chemistry , Buffers , Metoprolol/chemistry , Oxprenolol/chemistry , Silicon Dioxide , Spectrophotometry, Ultraviolet , Stereoisomerism , Temperature
13.
Acta Obstet Gynecol Scand ; 76(6): 550-4, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9246961

ABSTRACT

BACKGROUND: To compare intrauterine insemination (IUI), direct intraperitoneal insemination (DIPI), and timed-intercourse (TI), each combined with superovulation, in the treatment of couples with unexplained infertility, including couples with minimal endometriosis. METHODS: A retrospective analysis of 233 superovulation cycles in 70 couples with unexplained infertility or minimal endometriosis. Stimulation protocol, pregnancy rate, pregnancy outcome, and complications of treatment were analyzed. RESULTS: The pregnancy rare was 8.6% per cycle and 28.5% per couple. A majority of all treatment pregnancies (85%) occurred during the first four cycles of treatment. The duration of infertility did not influence the pregnancy rate. The pregnancy rate in patients with unexplained infertility was higher, but not significantly, than in patients with minimal endometriosis (27.7% versus 18.4%). No predictive marker for successful stimulation was found, except for the higher luteal progesterone level in cycles resulting in pregnancy. The multiple pregnancy rate was high: 30% of all pregnancies and 40% of all deliveries were multiple. CONCLUSIONS: Superovulation in combination with insemination or intercourse is effective and is still recommended in the treatment of couples with unexplained infertility.


Subject(s)
Infertility, Female/etiology , Insemination, Artificial, Homologous/methods , Ovarian Hyperstimulation Syndrome/complications , Adult , Chorionic Gonadotropin/administration & dosage , Clomiphene/administration & dosage , Endometriosis/complications , Female , Humans , Infertility, Female/therapy , Infertility, Male , Male , Pregnancy , Sperm Count , Sperm Motility
14.
Community Dent Oral Epidemiol ; 25(3): 211-6, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9192149

ABSTRACT

The aim of the study was to evaluate the prevalence of subjective perception of dry mouth in an adult population and to determine the prevalence of pharmacotherapy in this population. An additional aim was to assess a possible co-morbidity between symptoms of dry mouth and continuing pharmacotherapy. Four-thousand-two-hundred persons were selected at random from the national census register of the adult population of the southern part of the province of Halland, Sweden. The sample was stratified according to age and sex, and 300 men and an equal number of women aged 20, 30, 40, 50, 60, 70 and 80, were included. A newly developed questionnaire was mailed to each individual. In addition to questions about subjective perception of dry mouth, the subjects were asked to report on present diseases and continuing pharmacotherapy. Three-thousand-three-hundred and thirteen (80.5%) evaluable questionnaires were returned. The estimated prevalence of xerostomia in the population was 21.3% and 27.3% for men and women, respectively. This difference between the sexes was statistically significant. In non-medicated subjects, women tended to report a higher prevalence of xerostomia compared with men, 18.8% vs. 14.6%, and also among medicated subjects the estimated prevalence of dry mouth was higher for women than for men, 32.5% vs. 28.4%. There was a strong association between xerostomia and increasing age and also between xerostomia and continuing pharmacotherapy. The average prevalence of dry mouth among medicated and non-medicated subjects was 32.1% and 16.9%, respectively, the difference being statistically significant. There was also a strong association between xerostomia and the number of medications. In a logistic regression, the probability of reporting mouth dryness was significantly greater in older subjects and in women, and the probability increased with the number of medications taken. In conclusion, this epidemiological survey of an adult population has demonstrated that women, independent of age, do report a higher prevalence of xerostomia than men and that the symptom of dry mouth is strongly associated with age and pharmacotherapy. It is, however, not possible to discriminate between disease and pharmacotherapy as causal factors.


Subject(s)
Attitude to Health , Xerostomia/epidemiology , Xerostomia/psychology , Adult , Age Factors , Aged , Aged, 80 and over , Chi-Square Distribution , Drug-Related Side Effects and Adverse Reactions , Female , Humans , Logistic Models , Male , Middle Aged , Odds Ratio , Polypharmacy , Prevalence , Sex Factors , Sweden/epidemiology , Xerostomia/chemically induced
15.
FEBS Lett ; 390(3): 339-44, 1996 Jul 29.
Article in English | MEDLINE | ID: mdl-8706890

ABSTRACT

The cellulases cellobiohydrolase 1 (CBH 1) and endoglucanase 1 (EG 1) from the fungus Trichoderma reesei are closely related with 40% sequence identity and very similar in structure. In CBH 1 the active site is enclosed by long loops and some antiparallel beta-strands forming a 40 A long tunnel, whereas in EG 1 part of those loops are missing so that the enzyme has a more common active site groove. Both enzymes were immobilized on silica and these materials were used as chiral stationary phases for chromatographic separation of the enantiomers of two chiral drugs, propranolol and alprenolol. The CBH 1 phase showed much better resolution than did the EG 1 phase, suggesting that the tunnel structure of the protein may play an important role in the chiral separation. The chiral compounds were found to be competitive inhibitors of both enzymes when p-nitrophenyl lactoside (pNPL) was used as substrate. (S)-enantiomers showed stronger inhibitory effects and also longer retention time on the stationary phases than the (R)-enantiomers. The consistency between kinetic data and retention on the stationary phases clearly shows that the enzymatically active sites of CBH 1 and EG 1 are involved in chiral recognition.


Subject(s)
Cellulase/chemistry , Cellulase/metabolism , Trichoderma/enzymology , Alprenolol/pharmacology , Binding Sites , Binding, Competitive , Cellulase/antagonists & inhibitors , Cellulose 1,4-beta-Cellobiosidase , Chromatography , Enzyme Inhibitors/pharmacology , Glycosides/metabolism , Hydrogen-Ion Concentration , Kinetics , Models, Molecular , Molecular Structure , Propranolol/pharmacology , Protein Conformation
16.
Electrophoresis ; 16(4): 557-63, 1995 Apr.
Article in English | MEDLINE | ID: mdl-7588526

ABSTRACT

Enkephalin-related peptides were separated at low pH in a capillary with covalently bonded aminopropyl groups. The peptides are electrostatically repelled from the capillary surface and much higher efficiencies and faster separations were achieved compared to separations using uncoated capillaries. At low pH the amino groups are protonated, which results in reversed electroosmosis. The influence of voltage and ionic strength on the mobility and the separation efficiency was studied. The repeatability of migration times within one day was very good with relative standard deviations of 0.3-0.7%. Increasing the pH decreased the electroosmosis, eventually turning towards the cathode in the pH range 5-6; the separation performance, however, was lower at higher pH. Neutral and anionic micellar agents were added to the background electrolyte at different concentrations; the enkephalins had weak association with the neutral micellar agents but were distributed to the anionic taurodeoxycholic acid (TDC) micelles, giving rise to changes in separation selectivities. Very high efficiencies were obtained for peptides with a low distribution to the TDC micelles, while the efficiencies were impaired for those with a strong association with the micelles, which may indicate a slow mass transfer in the association process.


Subject(s)
Chromatography/methods , Electrophoresis/methods , Enkephalins/analysis , Amino Acid Sequence , Electric Conductivity , Enkephalins/chemistry , Hydrogen-Ion Concentration , Molecular Sequence Data , Osmolar Concentration , Peptides/analysis , Propylamines , Reproducibility of Results , Silanes/chemistry , Silicon Dioxide
17.
Chirality ; 6(7): 596-604, 1994.
Article in English | MEDLINE | ID: mdl-7986673

ABSTRACT

In order to obtain milligram amounts of the enantiomers of a series of compounds to be tested for binding to the melatonin binding site, a system for semipreparative enantiomeric separation was set up using tri-acetylcellulose as the chiral stationary phase. Interactions of this class of compounds with tri-acetylcellulose were examined on an analytical scale with a series of 20 compounds. Apparently, both steric and electrostatic interactions determine retention behavior on tri-acetylcellulose. Semipreparative separations were carried out for a subset of seven compounds. The purity of the first eluting enantiomer usually was around 99%, whereas the purity of the second eluting enantiomer was slightly less. The system described is easy to use and has the major advantage that a series of compounds can be separated with one technique. The purities obtained are sufficient for a first screen of their affinity.


Subject(s)
Cellulose/analogs & derivatives , Melatonin/analogs & derivatives , Melatonin/metabolism , Receptors, Cell Surface/metabolism , Binding Sites , Chromatography, High Pressure Liquid/methods , Indicators and Reagents , Melatonin/isolation & purification , Receptors, Melatonin , Stereoisomerism , Structure-Activity Relationship
19.
J Chromatogr ; 532(2): 305-19, 1990 Nov 16.
Article in English | MEDLINE | ID: mdl-2084128

ABSTRACT

The enantiomers of omeprazole and some of its analogues have been separated on a chiral stationary phase comprising trisphenylcarbamoylcellulose coated on 3-aminopropyl silica. The nature of the supporting silica has a crucial effect on the separations obtained. The racemisation half-life of omeprazole was estimated to be 1.3.10(2) h at 37 degrees C. In vitro tests on isolated gastric glands from rabbits showed that both enantiomers of omeprazole had an inhibitory effect on acid formation.


Subject(s)
Cellulose/analogs & derivatives , Chromatography, High Pressure Liquid/methods , Gastric Acid/metabolism , Gastric Mucosa/drug effects , Omeprazole/isolation & purification , Animals , Gastric Mucosa/metabolism , Half-Life , Omeprazole/chemistry , Omeprazole/pharmacology , Particle Size , Polysaccharides/chemistry , Rabbits , Stereoisomerism
20.
J Chem Ecol ; 16(2): 429-41, 1990 Feb.
Article in English | MEDLINE | ID: mdl-24263500

ABSTRACT

Diastereomers of the spiroacetal, 2,8-dimethyl-1,7-dioxaspiro [5.5]undecane, represent main components of the cephalic secretion from males of the solitary bee,Andrena wilkella. The major compound proved to be of high enantiomeric purity, showing (2S,6R,8S) configuration. Only the naturally occurring enantiomer attracted patrolling males in the field; its antipode was behaviorally inactive and in a racemic mixture did not inhibit response. The (E,Z) diastereomers were also found to be almost inactive. EAG studies gave the same result as the behavioral tests. The biological function of the spiroacetal is discussed in view of the evolution of the mating behavior inA. wilkella.

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