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R Lamont

Publications and source records attributed to R Lamont.

6 recordsLinked to original sources
PubMed1997

Organized Structure of Lithium Perfluorooctanesulfonate at the Graphite-Solution Interface

The structure of aggregates of lithium perfluorooctanesulfonate (LiFOS) adsorbed to the interface between graphite and aqueous solution have been measured. This fluorocarbon surfactant produces aggregates which are long ( approximately 100 nm) and thin ( approximately 5 nm), and about one molecule ( approximately 1.3 nm) deep. The aggregates lie in straight, parallel arrays on the surface with a characteristic repeat distance, or period, perpendicular to the long axis. As the bulk concentration of LiCl is increased, the period decreases, but as the bulk concentration of LiFOS is increased, the period increases. The decrease in period on addition of salt is similar to that observed for sodium dodecyl sulfate (SDS) and is explicable in terms of electrostatic forces. The increase in period on addition of surfactant is in sharp contrast to the behavior of SDS and may be due to a higher surfactant packing-parameter for LiFOS.

Journal Article↗
PubMed1997

Isolated choroid plexus cysts and association with fetal aneuploidy in an unselected population.

We sought to determine the relationship between an isolated choroid plexus cyst diagnosed antenatally and fetal aneuploidy in an unselected population at a district general hospital. Over a 5-year period all women attending for a detailed anomaly scan at 18-20 weeks' gestation were screened for evidence of a fetal choroid plexus cyst. All cases of choroid plexus cyst were recorded prospectively. The size, position and number of the cysts were noted and associated abnormalities seen on ultrasound were also recorded. Cases of choroid plexus cyst associated with fetal aneuploidy were noted. A total of 13,690 women were screened, and 84 cases of choroid plexus cyst were identified (0.6%). Of these, 41% underwent prenatal karyotyping by amniocentesis; 78 of 84 cases (93%) were isolated. Six had other markers for aneuploidy, and three of these fetuses had trisomy 18. All cases of isolated choroid plexus cyst resulted in chromosomally normal neonates. This was confirmed by either normal antenatal karyotype or postnatal examination by the pediatricians. The size, position and number of cysts did not appear to influence the risk of aneuploidy. We conclude that the risk of aneuploidy for a case of isolated choroid plexus cyst in an unselected population appears to be very low, and in this series was 0%. In this setting, we suggest detailed ultrasound examination is essential, rather than routine karyotyping.

Adolescent↗
PubMed1996

Bacterial vaginosis.

Bacterial vaginosis is the most common cause of vaginal infectious morbidity, including vaginal discharge. The condition is easily diagnosed and treated. If undiagnosed or left untreated, the condition is associated with serious adverse sequelae in both obstetrics and gynaecology. If bacterial vaginosis is detected in early pregnancy, the woman has a five-fold increased risk of late miscarriage or preterm delivery compared with women without the condition. Further research is necessary to establish whether adverse sequelae such as premature labour, preterm prelabour rupture of the membranes, late miscarriage or postpartum endometritis can be reduced by treating the condition in early pregnancy.

Female↗
PubMed1993

Serum antibody opsonic activity against Actinobacillus actinomycetemcomitans in human periodontal diseases.

Actinobacillus actinomycetemcomitans is frequently associated with severe periodontitis. Many periodontitis patients have elevated levels of serum IgG antibodies to A. actinomycetemcomitans, but the role of these antibodies is unknown. This study evaluated the functional capacity of anti-A. actinomycetemcomitans IgG antibody to enhance phagocytosis of A. actinomycetemcomitans by polymorphonuclear leukocytes. Chemoluminescence assays were done using sera from 64 subjects, 61 of whom had severe periodontitis; results were compared with the subject's anti-A. actinomycetemcomitans IgG titer and avidity. There was a strong correlation between chemoluminescence and antibody log titer (P < .00001) and a weak correlation between chemoluminescence and antibody avidity (P < .05). The results support the hypothesis that anti-A. actinomycetemcomitans IgG antibodies are important in promoting phagocytosis and killing of A. actinomycetemcomitans. Subjects who develop high levels of highly avid antibodies against A. actinomycetemcomitans may have greater resistance to continued or repeated infection by this pathogen.

Actinobacillus Infections↗