facility. At the Royal Postgraduate Medical School in Hammersmith we discussed the projects of senior registrars doing full-time research. At the new medical sciences building of the University of Sheffield we noted some interesting research in progress, some being done by senior registrars paid by the university. In association with the wage and price controls outlined by the federal government, funds for medical research have been frozen in Canada. I am not aware that the insuring agencies of the provincial governments make any funds available for research, as does the NHS in Britain. The financial support for full-time teachers in Ontario medical schools is designated as support for teaching and administration but not for research. Funds are not made available in university departments of anesthesia to attract and hold outstanding research anesthetists. There are few research positions available in university departments of anesthesia, so there is little incentive for Canadians to train for research in anesthesia and stay in this country. A national health service that has a solid background in investigation is not all bad. The consultants in anesthesia making major contributions in teaching and research are paid for their work, so that the difference between their income and that of clinicians is not great. To be sure, there seems to be much frustration with government in the planning of future facilities. But in the financing of research in anesthesia, the British system seems ahead of the Canadian system. G.R. SELLERY, MD, FRCP[C]
Associate professor University of Western Ontario Chief, department of anesthesia Victoria Hospital London, ON
Dental caries vaccination
To the editor: The principal factor in the initiation of dental caries is the action on tooth surfaces of acid produced in the dental plaque as a result of microbial breakdown of dietary carbohydrates, especially sucrose.1 Although efficient and frequent tooth brushing should be beneficial, plaque remains untouched in inaccessible sites.2 Nevertheless, fluoride, either provided in the drinking water or applied to the tooth surface, increases the resistance of enamel to caries.3 Restriction of dietary sugar intake also diminishes the incidence of caries.4 Although there are many microorganisms in dental plaque, if one were the predominant etiologic factor in cariogenesis, then a feasible preventive measure might be vaccination. Indeed, monkeys can be actively immunized
against dental caries.5 There is now evidence that Streptococcus mutans may be such an organism,6 and there have been encouraging long-term results of vaccination of monkeys with material derived from whole bacteria given intravenously or disrupted bacteria given by submucous injection.7 The oral cavity of these monkeys, however, was colonized with the same serotype of S. mutans as was in the vaccine, whereas seven serotypes have been found to occur naturally in man.6 Probably only two of the serotypes are common in the oral flora, so that a vaccine may need to include only these two or possibly only one serotype if one antigen proves to be common to all strains. Under natural conditions, however, vaccination might fail if other bacterial species replaced S. mutans as a cause of caries in immunized people. Furthermore, the mechanism of protection has yet to be established. Nevertheless, since antibody, complement and leukocytes have been detected in the crevicular fluid, and because secretory antibody is present in saliva,9 there is sufficient evidence that vaccination could affect the oral flora. S. mutans vaccination would generally be safe in man, although there is always a possibility of autoimmune complications with administration of any streptococcal vaccine.10 However, neither nephritis nor rheumatic fever has been linked with S. mutans.5 Vaccines administered submucosally might be unpleasant, although no more so than a local anesthetic solution. It is conceivable, therefore, that unless simpler measures, such as antiseptic mouthwashes, are found to be equally effective, patients may soon demand vaccination against dental caries. C.L.B. LAVELLE, PH D, MDS Department of oral biology University of Manitoba Winnipeg, MB
References 1. HARTLES RL, LEACH SA: Effect of diet on dental caries. Br Med Bull 31: 137, 1975 DAM, JENKINS GN: The normal microbial flora of man. Society for Applied Bacteriology symposium series, vol 3, London,
2. GEDDES
Acad Pr, 1974, p 85 3. JENKINS GN: Recent advances in work on fluoride and the teeth. Br Med Bull 31: 142,
1975 4. GUSTAFSSON BE, QUENSEL CE, LANKE LS, et al: The effect of different levels of carbohydrate intake on caries activity in 436 individuals observed for five years. Acta Odontol Scand 11: 232, 1954 5. BOWEN V/H: A vaccine against dental caries. A pilot experiment in monkeys (Macaca irus). Br Dent J 126: 159, 1969
6. HARDIE JM, BOWDEN GH: Bacterial flora of dental plaque. Br Med Bull 31: 131, 1975 7. BOWEN V/H, COHEN B, COLMAN G: Immun-
ization against dental caries. Br Dent J 139: 45, 1975
8. PERCH B, KJEMUS E, RAvN T: Biochemical and serological properties of Streptococcus mutans from various human and animal
sources. Acta Pathol Microbiol Scand [B] 82: 357, 1974 9. LENNER T, CHALLACOMBE 55, CALDWELL 5: An immunological investigation into the prevention of caries in deciduous teeth of rhesus monkeys. Arch Oral Blol 20: 305, 1975
10. MAsSELL BF, HONIKMAN LH, AMEZENA 3: Rheumatic fever following streptococcal vac-
cination. JAMA 207: 1115, 1969
304 CMA JOURNAL/FEBRUARY 21, 1976/VOL 114
Locasalen® for the treatment of chronic eczema Indications
LOCASALEN is intendedfor the treatment of subacute to hyperchronic inflammatory and/ordysplastic skin diseases, sawell as hyperkeratotic conditions in particular. The indications for LOCASALEN thus include chronic constitutional eczema orneurodermatitis; chronic exogenouseczema irrespective of origin, (e.g.: skin disorders dueto attrition, occupational eczema); chronic eczema of microbial or mycotic origin; tytotic eczema; hyperkeratosis asencountered in ichthyosis or chronic dyshidrosis; pustulceisof the palms and soles; lichen planus; chronic cutaneous lupus erythematosus; psoriasis.
Dosage and Administration
Ass rule LOCASALEN should be applied once or twice dailywhen dressings are not used and once dailywhen employed under occlusivedressing. It is not usually necessaryto coverthe treated area. Thethickness of the layer should vary depending on the nature andseverity of the skin disorder, since in this way, it is possible to regulate moisture retention. In cases in which transitoryexudative must be anticipated, LOCASALEN should be applied in a verythin layer, thereby allowing larger quantitiesof moistureto be released through the filmof ointment. LOCASALEN can alsoexert an occlusive effect but only if applied in athick layer. It panetrateswell into the skin and when rubbed in thoroughly, leavesonthe skins transparent, oily film that can be removed with soapand water or askin cleanser. Excess filmcan be removed relatively well with papertissue, scarcely leaving any perceptible sheen.
Adverse Reactions
The local tolerabilityof LOCASALEN proved to be very goodGases in which local irritation made it advissbleto discontinuethe medication accounted for less than 2% of thetotal number of patientstreated. Adverse reactions consists mainly of local reddeninoof theskin, desquamation, pruritis and smarting. LOCASALEN contains nopreservatives, odour correcting agents, emulsifiers, stabilizers or antibiotic supplements which have been recognized as potential sensitizers. Hypersensitivityto salicylic acid can occur; however, the incidence in the population asa whole is approximately 0.2%. Systemic side effectsattributable tothe transcutaneous abeorption of salicylic acid or flumethasone pivalate have not been reported. Absorption of sslicylic acid does occur; however, investigations haveshown that irrespective of theamount of LOCASALEN employed, and even applied underocclusive dressings, plasma concentrations of salicylic acid did not exceed ordinary therapeutic levels ss a result of transcutaneous absorption. Investigations have shownthat under extreme conditions-where 40 to6O grams of ointmant were applied daily to80-90% of the bodysurface under occlusive dressings-plasma cortisol and urinary steroids have been obeerved to decrease below normal levels. This decrease proved transitoryand was not accompanied by any clinical symptoms.
Warnings
LOCASALEN is not indicated inacute weepingor subacute exudative stages. Astranscutaneous absorption of thesalicylic acid component may give rise to systemic effects, LOCASALEN should not beapplied toextensive areasof the skin in small children or pregnant women. Likewise corticosteroidsare known to be abeorbed percutaneously, therefore in patients requiring applications of LOCASALEN to extensive areas or for prolonged periods, adrenal function should be carefully monitored. All contact of the drug with theeyes, mouth, mucous membranesahould beavoided.
Precautions
If sensitivity or idiosyncratic reactions occu.LOCASALEN should be discontinued and appropriate measures taken. Thessfety of the use of topical corticosteroids in pregnant females has not been established. Therefore theyshould not be used extensively on pregnant patients in large amountsor for prolonged periodsof time. Patients should beadvised toinform subeequent physicians of the prior use of corticosteroids. In the presence of an infection, the use of an appropriate antifungal or antibacterial agent should be instituted. If a favourable response does not occurpromptly, LOCASALEN should be discontinued unttl the infection has been adequately controlled.
Contraindications
Tuberculosis of the skin, syphilitic skin affections, viral and acute fungal infectionsof the skin. Systemic fungal infections. This preparation is not for ophthalmic use. LOCASALEN is contraindicated in individualawith a history of hypersensitivityto itacomponents.
Supplied
Flumethasone Pivalate 0.02% and salicylic acid 3.0% ointmont in tubesof 15gm and 50gm.
CIBA
Dorval, P.Q.
Associate professor University of Western Ontario Chief, department of anesthesia Victoria Hospital London, ON
Dental caries vaccination
To the editor: The principal factor in the initiation of dental caries is the action on tooth surfaces of acid produced in the dental plaque as a result of microbial breakdown of dietary carbohydrates, especially sucrose.1 Although efficient and frequent tooth brushing should be beneficial, plaque remains untouched in inaccessible sites.2 Nevertheless, fluoride, either provided in the drinking water or applied to the tooth surface, increases the resistance of enamel to caries.3 Restriction of dietary sugar intake also diminishes the incidence of caries.4 Although there are many microorganisms in dental plaque, if one were the predominant etiologic factor in cariogenesis, then a feasible preventive measure might be vaccination. Indeed, monkeys can be actively immunized
against dental caries.5 There is now evidence that Streptococcus mutans may be such an organism,6 and there have been encouraging long-term results of vaccination of monkeys with material derived from whole bacteria given intravenously or disrupted bacteria given by submucous injection.7 The oral cavity of these monkeys, however, was colonized with the same serotype of S. mutans as was in the vaccine, whereas seven serotypes have been found to occur naturally in man.6 Probably only two of the serotypes are common in the oral flora, so that a vaccine may need to include only these two or possibly only one serotype if one antigen proves to be common to all strains. Under natural conditions, however, vaccination might fail if other bacterial species replaced S. mutans as a cause of caries in immunized people. Furthermore, the mechanism of protection has yet to be established. Nevertheless, since antibody, complement and leukocytes have been detected in the crevicular fluid, and because secretory antibody is present in saliva,9 there is sufficient evidence that vaccination could affect the oral flora. S. mutans vaccination would generally be safe in man, although there is always a possibility of autoimmune complications with administration of any streptococcal vaccine.10 However, neither nephritis nor rheumatic fever has been linked with S. mutans.5 Vaccines administered submucosally might be unpleasant, although no more so than a local anesthetic solution. It is conceivable, therefore, that unless simpler measures, such as antiseptic mouthwashes, are found to be equally effective, patients may soon demand vaccination against dental caries. C.L.B. LAVELLE, PH D, MDS Department of oral biology University of Manitoba Winnipeg, MB
References 1. HARTLES RL, LEACH SA: Effect of diet on dental caries. Br Med Bull 31: 137, 1975 DAM, JENKINS GN: The normal microbial flora of man. Society for Applied Bacteriology symposium series, vol 3, London,
2. GEDDES
Acad Pr, 1974, p 85 3. JENKINS GN: Recent advances in work on fluoride and the teeth. Br Med Bull 31: 142,
1975 4. GUSTAFSSON BE, QUENSEL CE, LANKE LS, et al: The effect of different levels of carbohydrate intake on caries activity in 436 individuals observed for five years. Acta Odontol Scand 11: 232, 1954 5. BOWEN V/H: A vaccine against dental caries. A pilot experiment in monkeys (Macaca irus). Br Dent J 126: 159, 1969
6. HARDIE JM, BOWDEN GH: Bacterial flora of dental plaque. Br Med Bull 31: 131, 1975 7. BOWEN V/H, COHEN B, COLMAN G: Immun-
ization against dental caries. Br Dent J 139: 45, 1975
8. PERCH B, KJEMUS E, RAvN T: Biochemical and serological properties of Streptococcus mutans from various human and animal
sources. Acta Pathol Microbiol Scand [B] 82: 357, 1974 9. LENNER T, CHALLACOMBE 55, CALDWELL 5: An immunological investigation into the prevention of caries in deciduous teeth of rhesus monkeys. Arch Oral Blol 20: 305, 1975
10. MAsSELL BF, HONIKMAN LH, AMEZENA 3: Rheumatic fever following streptococcal vac-
cination. JAMA 207: 1115, 1969
304 CMA JOURNAL/FEBRUARY 21, 1976/VOL 114
Locasalen® for the treatment of chronic eczema Indications
LOCASALEN is intendedfor the treatment of subacute to hyperchronic inflammatory and/ordysplastic skin diseases, sawell as hyperkeratotic conditions in particular. The indications for LOCASALEN thus include chronic constitutional eczema orneurodermatitis; chronic exogenouseczema irrespective of origin, (e.g.: skin disorders dueto attrition, occupational eczema); chronic eczema of microbial or mycotic origin; tytotic eczema; hyperkeratosis asencountered in ichthyosis or chronic dyshidrosis; pustulceisof the palms and soles; lichen planus; chronic cutaneous lupus erythematosus; psoriasis.
Dosage and Administration
Ass rule LOCASALEN should be applied once or twice dailywhen dressings are not used and once dailywhen employed under occlusivedressing. It is not usually necessaryto coverthe treated area. Thethickness of the layer should vary depending on the nature andseverity of the skin disorder, since in this way, it is possible to regulate moisture retention. In cases in which transitoryexudative must be anticipated, LOCASALEN should be applied in a verythin layer, thereby allowing larger quantitiesof moistureto be released through the filmof ointment. LOCASALEN can alsoexert an occlusive effect but only if applied in athick layer. It panetrateswell into the skin and when rubbed in thoroughly, leavesonthe skins transparent, oily film that can be removed with soapand water or askin cleanser. Excess filmcan be removed relatively well with papertissue, scarcely leaving any perceptible sheen.
Adverse Reactions
The local tolerabilityof LOCASALEN proved to be very goodGases in which local irritation made it advissbleto discontinuethe medication accounted for less than 2% of thetotal number of patientstreated. Adverse reactions consists mainly of local reddeninoof theskin, desquamation, pruritis and smarting. LOCASALEN contains nopreservatives, odour correcting agents, emulsifiers, stabilizers or antibiotic supplements which have been recognized as potential sensitizers. Hypersensitivityto salicylic acid can occur; however, the incidence in the population asa whole is approximately 0.2%. Systemic side effectsattributable tothe transcutaneous abeorption of salicylic acid or flumethasone pivalate have not been reported. Absorption of sslicylic acid does occur; however, investigations haveshown that irrespective of theamount of LOCASALEN employed, and even applied underocclusive dressings, plasma concentrations of salicylic acid did not exceed ordinary therapeutic levels ss a result of transcutaneous absorption. Investigations have shownthat under extreme conditions-where 40 to6O grams of ointmant were applied daily to80-90% of the bodysurface under occlusive dressings-plasma cortisol and urinary steroids have been obeerved to decrease below normal levels. This decrease proved transitoryand was not accompanied by any clinical symptoms.
Warnings
LOCASALEN is not indicated inacute weepingor subacute exudative stages. Astranscutaneous absorption of thesalicylic acid component may give rise to systemic effects, LOCASALEN should not beapplied toextensive areasof the skin in small children or pregnant women. Likewise corticosteroidsare known to be abeorbed percutaneously, therefore in patients requiring applications of LOCASALEN to extensive areas or for prolonged periods, adrenal function should be carefully monitored. All contact of the drug with theeyes, mouth, mucous membranesahould beavoided.
Precautions
If sensitivity or idiosyncratic reactions occu.LOCASALEN should be discontinued and appropriate measures taken. Thessfety of the use of topical corticosteroids in pregnant females has not been established. Therefore theyshould not be used extensively on pregnant patients in large amountsor for prolonged periodsof time. Patients should beadvised toinform subeequent physicians of the prior use of corticosteroids. In the presence of an infection, the use of an appropriate antifungal or antibacterial agent should be instituted. If a favourable response does not occurpromptly, LOCASALEN should be discontinued unttl the infection has been adequately controlled.
Contraindications
Tuberculosis of the skin, syphilitic skin affections, viral and acute fungal infectionsof the skin. Systemic fungal infections. This preparation is not for ophthalmic use. LOCASALEN is contraindicated in individualawith a history of hypersensitivityto itacomponents.
Supplied
Flumethasone Pivalate 0.02% and salicylic acid 3.0% ointmont in tubesof 15gm and 50gm.
CIBA
Dorval, P.Q.
