ABSTRACT
Mycobacteriophage L5 integrates into the genome of Mycobacterium smegmatis via site-specific recombination between the phage attP site and the bacterial attB site. These two sites have a 43-bp common core sequence within which strand exchange occurs and which overlaps a tRNAGly gene at attB. We show here that a 29-bp segment of DNA is necessary and sufficient for attB function and identify the positions of strand exchange.
Subject(s)
DNA, Bacterial/genetics , Mycobacteriophages/genetics , Recombination, Genetic , Virus Integration/genetics , Anticodon , Base Sequence , Molecular Sequence Data , RNA, Transfer/geneticsABSTRACT
The effect of a two minute cold pressor test on transmitral velocities measured by pulsed Doppler was studied in 11 healthy volunteers. Blood pressure increased significantly during cold immersion but peak atrial and peak early diastolic transmitral velocities and their ratio (A:E) were unchanged. There was no correlation between changes in Doppler variables and changes in calculated mean arterial blood pressure during the test. Heart rate changes were variable and not related to changes in blood pressure. In individual people the change in pulse interval during cold immersion was significantly and inversely correlated with the change in the A:E ratio. The large acute increase in arterial pressure seen during the cold pressor test in normal volunteers had no consistent effect on the transmitral velocity profile although small changes in heart rate were associated with large changes in A:E ratio. The effect of small changes in heart rate may be of considerable importance in determining transmitral velocity profiles. Thus in clinical and experimental studies in which the heart rate is not controlled, Doppler data on transmitral flow should be interpreted with caution.
Subject(s)
Coronary Circulation , Hemodynamics , Mitral Valve/physiology , Ultrasonography , Adult , Blood Pressure , Female , Heart Function Tests , Heart Rate , Humans , MaleABSTRACT
A sample of 1,003 children, aged 15 years, were examined for prevalence of gingival recession. It was found that 17% had pseudo gingival recession and 1% had true recession. The highest degree of association with local etiological factors was that between recession and the width of keratinized gingiva; frenal pull was the second most highly associated factor followed by tooth arch relationship and the least association existed between plaque and gingival recession. There was no association between calculus and recession.
Subject(s)
Gingival Diseases/pathology , Adolescent , Dental Calculus/pathology , Dental Plaque/pathology , Female , Gingiva/pathology , Gingival Diseases/etiology , Humans , Incisor , Labial Frenum/pathology , Male , Malocclusion/pathology , MandibleABSTRACT
An investigation was conducted to determine the appropriate dental services for a university using one university dental service as a model. After examination of the aims, population, demands and needs, possible alternative strategies were considered by comparing the organizational structure of three different types of university dental service.
Subject(s)
Dental Health Services , Student Health Services , Dental Care , Dental Health Services/organization & administration , Fees, Dental , Health Services Needs and Demand , State Medicine , Student Health Services/organization & administration , Students , United KingdomABSTRACT
The oral health of sixty-two dental students was examined over an interval of two or three years. The results were recorded and certain conclusions reached.
