P31 The relationship between the relative amount of Porphyromonas gingivalis in saliva and halitosis

Objectives  Porphyromonas gingivalis is one of the microorganisms that most actively produce CH₃SH and we have reported that subjects with P . gingivalis have higher CH₃SH levels than subjects without P .  gingivalis . However, little is known about the relationship between P . gingivalis levels in saliva and the condition of oral malodor. In this study, we evaluated the association between the relative amount of P . gingivalis in saliva and halitosis in mouth air.
Methods  All of the subjects were patients at the Preventive Dentistry and Breath Odor Clinic of Kyushu Dental College, where they received a periodontal examination. Volatile sulfur compounds (VSC: hydrogen sulfide and methyl mercaptan) were measured using gas chromatography. Saliva samples were collected in a sterile plastic tube over a period of 5 min while the subject chewed on paraffin wax, and were then immediately stored at –80°C until use. Template DNA was obtained from the stored saliva using an Easy-DNA Kit (Invitrogen, CA, USA) according to the manufacturer's instructions. Conventional PCR assays were used to confirm the presence of P . gingivalis . A 5' nuclease TaqMan PCR was used to quantify P . gingivalis in saliva. The relative numbers of bacteria were measured using the comparative threshold cycle method.
Results  We found a quantitative relationship between the P . gingivalis levels in saliva and the condition of halitosis in mouth air.
Conclusion  We analyzed the relationship between the relative amount of P . gingivalis in saliva and oral malodor.     

Demographic variables of gestational trophoblastic disease in KwaZulu-Natal, South Africa.

The aim of the study was to map out the pattern of referral of patients with gestational trophoblastic disease (GTD) presenting to a large tertiary referral centre, from the health districts of KwaZulu Natal province, South Africa, and to determine the demographic variables in the presentation of the disease. This retrospective study reviewed the clinical charts of 98 patients managed at the combined gynaecology/oncology clinic over a 5-year period. The types of GTD included molar pregnancy 50 (51%), choriocarcinoma 46 (46%) and placental site trophoblastic tumour 2 (2%). The majority of patients were referred by the district or regional hospitals (63.3%), followed by self-referrals (23.5%). There were 51 (52%) patients from eThekwini health district and only 25 patients (25.4%) from the Northern health districts. With regard to previous pregnancy state, 63.3% (n = 62) had term pregnancy, 13.3% (n = 13) had previous miscarriage and 2% (n = 2) had previous ectopic pregnancy. Five patients (5.1%) had previous molar pregnancy. We did not find a trend of referral of patients being predominantly from the Northern regions of KwaZulu Natal.     

The Fagerström Test for Nicotine Dependence: a revision of the Fagerstrom Tolerance Questionnaire

We examine and refine the Fagerström Tolerance Questionnaire (FTQ; Fagerström, 1978). The relation between each FTQ item and biochemical measures of heaviness of smoking was examined in 254 smokers. We found that the nicotine rating item and the inhalation item were unrelated to any of our biochemical measures and these two items were primary contributors to psychometric deficiencies in the FTQ. We also found that a revised scoring of time to the first cigarette of the day (TTF) and number of cigarettes smoked per day (CPD) improved the scale. We present a revision of the FTQ: the Fagerström Test for Nicotine Dependence (FTND).     

Peripheral mechanisms of fatigue in muscles of normal and dystrophic mice.

We evaluated the contribution of different processes to fatigue of normal and dystrophic mouse muscles using an in vitro electromyography chamber. Fatigue was induced by repetitive nerve stimulation at 30 Hz for 0.5 s, every 2.5 s until tension decreased by about 50%. We monitored the compound nerve action potential (AP), compound muscle AP, and isometric tension responses to nerve stimulation, and compound muscle AP and tension responses to direct muscle stimulation. In normal mice, about 50% reduction in nerve-evoked tension occurred by 2.4 min in extensor digitorum longus (EDL), 4.8 min in diaphragm, and 9 min in soleus. Analysis of the responses revealed that the fatigue was caused by failure of more than one process in all muscles, and failure of nerve conduction did not contribute to fatigue in any muscle. Failure of neuromuscular transmission, muscle membrane excitation, and excitation-contraction (E-C) coupling and contractility accounted for 55, 45, and 0%, respectively, of the fatigue in EDL, for 21, 74, and 5% of the fatigue in diaphragm, and for 2, 54, and 44% of the fatigue in soleus. In dystrophic mice, while about 50% reduction in nerve-evoked tension occurred by 8.1 min in EDL and 5.6 min in diaphragm, only 29% reduction in tension occurred by 80 min in soleus. Failure of neuromuscular transmission, muscle membrane excitation, E-C coupling and contractility accounted for 22, 63 and 15% of the fatigue in EDL, for 21, 79, and 0% of the fatigue in diaphragm, and for 15, 59, and 26% of the fatigue in soleus. The proportion of slow-twitch oxidative fibers was more than normal in dystrophic EDL, but the same as normal in dystrophic diaphragm and soleus. The slower onset of fatigue was attributable to lesser failure of neuromuscular transmission in dystrophic EDL, and to lesser failure of E-C coupling and contractility in dystrophic soleus.     

Lans lecture. Lamellar refractive surgery: where have we been and where are we going?

In summary, the greatest challenge for lamellar refractive surgery is in the treatment of myopia. There are and always will be patients who are satisfied with a partial correction of myopia. Many of these patients can be served quite adequately by currently available refractive techniques, but a technique in which level of accuracy is adequate for the treatment of myopia in general is not yet available. Lamellar refractive surgery--where have we been and where are we going? We have seen the evolution of the epikeratoplasty procedure for almost a decade and continue to see procedural changes which may increase the accuracy and stability of the procedure, such as alternative modalities for tissue preservation and alternative methods for surgical attachment. It remains potentially useful in several areas of refractive surgery, but its inaccuracy in the treatment of myopia remains a significant problem. Will the epithelial healing problems and postoperative care be too cumbersome for the general ophthalmologist? Will the excimer laser fill the needs of myopic refractive surgery? Personally, I do not feel that any biological lens, be it a cornea which has had incisions as with radial keratotomy, or a cornea which is remolded in one way or another as with the excimer laser, will produce predictable refractive results to the extent that is required to satisfy the general needs of the myopic population. Hydrogel keratophakia is in its infancy, but it holds the potential of being a far more accurate procedure because of the ability to interchange lenses to further refine the refractive result. Refractive surgery will in the next decade achieve a level of sophistication far greater than what we have seen to date. Lans could not have dreamed of the remarkable evolution in refractive surgical innovation in the past century. It is hoped that we will not have to wait that long to create a readily available solution to the problem of refractive surgery for myopia.