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Biomedical subjects

J Suhonen

Publications and source records attributed to J Suhonen.

At least 37 records · Page 2Linked to original sources
PubMed1994

Release of preventive agents from pacifiers in vitro. An introduction to a novel preventive measure.

Clinical data show that the later primary teeth are colonized by mutans streptococci (MS), the less caries will develop, if at all. Since up to 90% of teething children develop a sucking habit, pacifiers were designed to release preventive agents into the mouth. Simultaneous use of sodium fluoride and xylitol increases the enamel fluoride content. Xylitol affects specifically growth and metabolism of mutans streptococci. The aim of this study was to determine the release of fluoride, xylitol and sorbitol from pacifiers in vitro. A disintegration apparatus was designed to test the dissolution of tablets containing NaF resp. 0.25 mg F, 160 mg xylitol and 150 mg sorbitol from the pacifiers. Six pacifiers were agitated simultaneously with a standardised pump movement, 30 strokes/min, in 15 ml normal saline at +37 degrees C for 2, 5, 10, 20, 40, 60 and 90 min. The released fluoride was determined in 1 ml samples of saline to which 1 ml Tisab was added using a combined F-ion electrode. Xylitol and sorbitol were analyzed by using an ion chromatograph with a pulsed-amperometric detector. A linear slow release of fluoride, xylitol and sorbitol from the pacifiers could be observed up to 90 min. After 2700 strokes the residual saline in the suction chambers (vol. approximately 0.4 ml) was equally analyzed, where all 3 ingredients could still be detected.

Cariostatic Agents↗
PubMed1992

Mutans streptococci and their specific oral target. New implications to prevent dental caries?

Over the past 25 years collection and analysis of clinical, dietary and microbiological data have led to the conclusion that caries is a bacterial infection, initiated by mutans streptococci which can be transmitted within a family by saliva. Bacteria attach themselves selectively to various oral surfaces. In order to inhabit the mouth mutans streptococci require the presence of teeth. The targets of the odontopathogens (tooth hard substances and gingival sulcus) appear into the oral cavity on a "peculiar" way: these surfaces and tissues are not exposed to bacterial colonization from birth as skin and mucosa. Teething starts 8 +/- 2 months after birth at which age the infant's antibody-dependent defence system is physiologically weak. Teeth erupt slowly during the night, at a period of least intraoral activity. Theoretically, streptococcal colonization can begin as soon as a few mm2 of incisal edges of primary teeth become visible. The earlier the establishment of mutans streptococci in the plaque of the primary teeth, the earlier and more extensive is the caries development. These aspects might open new possibilities for the prevention of the dental diseases, provided that means are found by which the primary colonization can be hindered or postponed.

Dental Caries↗
PubMed1991

Histochemistry of sympathetic neurons allotransplanted from young and aged mice to the submandibular gland.

Sympathetic ganglion tissue of young (3 months) and aged (24 months) NMRI mice was allotransplanted into the submandibular gland to study the influence of aging on the survival of grafted neurons. The submandibular gland (SMG) was chosen as a host tissue because of its high concentration of NGF and good blood supply. Four weeks postgrafting the viability of transplants was evaluated using the formaldehyde-induced fluorescence technique, tyrosine hydroxylase (TH) immunohistochemistry, and morphometry. The density of neurons, catecholamine fluorescence and TH immunoreactivity (TH-IR) appeared to be almost unchanged when the transplant was completely surrounded by the SMG tissue, whereas transplants located within the interlobular septum and capsule, or even outside the capsule, showed significantly reduced neuronal survival. The shape of most of the transplanted neurons was not different from those in the intact ganglia. The average diameter of the transplanted young neurons was significantly decreased; this was not the case with the aged neurons. The histograms of grouped diameter values showed a shift to smaller cells in ganglion transplants in both age groups. The transplants in mice treated with 6-OH-dopamine showed considerable regrowth of adrenergic nerve fibers. There seemed to be no marked difference in the survival of transplanted neurons between aged and young animals. The results indicate that the sympathetic neurons from both young adult and aged animals survive the allotransplantation procedure. The neurotrophic factors together with dense vascularization present in the mouse submandibular gland may be beneficial for the restoration of the integrity of mature and aged adrenergic neurons.

Aging↗
PubMed1991

Combination chemotherapy of dental plaque infections.

Chemotherapy against dental plague micro-organisms has proved effective in combatting both caries and periodontal disease. Chlorhexidine is the drug of choice when a broad-spectrum antiplaque agent is called for. However, because its mechanism of action is unspecific and the high concentrations needed for maximum effect may cause side effects, combination chemotherapy has been suggested. Chlorhexidine has been successfully combined with fluoride and, more recently, with xylitol. The combination allows the use of less concentrated solutions than if the agents were administered alone. Further, the mode of bactericidal action of chlorhexidine, fluoride and xylitol appears to be additive. A new aspect in the prevention is to control the primary bacterial colonization at the very moment when teeth erupt. To achieve this, new ways of delivering chemotherapeutic and other preventive agents are called for.

Anti-Infective Agents↗
PubMed1990

Viability of adrenal chromaffin cells in the superior cervical ganglion of young adult and aged rats.

Adrenal medullary tissue was autotransplanted to the superior cervical ganglion (SCG) of aged (26 months old) and young adult (3 months old) rats. Four and 20 weeks after operation, the viability of the transplants was evaluated using the formaldehyde-induced fluorescence (FIF) technique and tyrosine hydroxylase (TH) immunocytochemistry. Four weeks postgrafting, the transplant consisted of a densely-packed group of intensively fluorescent chromaffin cells in both age groups. The cells showed strong TH immunoreactivity and some of them were elongated, but only a few displayed short processes. At 20 weeks, most of the cells were spindle shaped and sent out fluorescent processes and a few of them were transformed toward ganglion-like cells. The results suggest that both young and old adrenal chromaffin cells are able to survive, produce neuronal processes and transform toward a neuronal phenotype in the rat superior cervical ganglion.

Adrenal Medulla↗
PubMed1990

Survival of both young and aged sympathetic neurons in the adrenal cortex after autotransplantation.

Sympathetic ganglion tissue of 3-months- and 18-months-old Fischer-344 rats was autotransplanted into the adrenal gland in order to determine the effect of aging on the survival of grafted neurons. Adrenal cortex was chosen as the host tissue because it is well vascularized and has a high concentration of glucocorticoids, which stimulate the synthesis of catecholamines. At 4 weeks following the transplantation, the density of neurons was decreased in all transplants, but approximately the same proportion of remaining neurons showed tyrosine hydroxylase immunoreactivity as in intact ganglia. At 8 weeks, a subpopulation of large neurons showed an increased accumulation of age pigment. The heavily pigmented neurons were usually devoid of catecholamines, whereas small non-pigmented neurons frequently showed strong catecholamine histofluorescence and tyrosine hydroxylase immunoreactivity. There was no marked difference between old and young animals in the survival of transplanted neurons. The results show that the sympathetic neurons from both 3-months-and 18-months-old animals survived the autotransplantation procedure. The humoral environment of the adrenal cortex may be beneficial for the restoration of the integrity of sympathetic neurons.

Adrenal Cortex↗
PubMed1989

Spray dispensing of antiseptics is effective for hand disinfection.

The effectiveness of three hand antiseptics administered using a spray dispenser (Nebucid 840) was studied together with that of conventional hand disinfection. The tests were carried out by a group of 20 dental students. To obtain baseline samples, the subjects washed their hands with unmedicated Sterisol liquid soap under running water for 30s and dried them on sterile-packed paper towels. Microbiologic samples were taken from fingerprints pressed gently onto blood agar plates, which were then incubated aerobically and analyzed. The hand disinfection efficacy of 3 ml Isosept solution rubbed onto the hands for 30 s, followed by air drying for 60 s, was studied as a conventional control method. Dermocol, HD 410, and Hibisol antiseptics were sprayed onto the subjects' hands for 3 s using the automatic dispenser, after which the hands were gently rubbed for 30 s and air-dried for 60 s, before fingerprint contact sampling. All the tests were performed three times, with a minimum of 3 days between the series. The results showed Hibisol applied with the spray dispenser to be significantly more effective in reducing bacterial growth than the other methods. No growth was observed on 51 plates out of 60, while bacterial growth was observed in 29 cases out of 60 in the Isosept series. In most cases the spray-dispensed antiseptics proved to be more efficient than the conventional hand antiseptic. All the antiseptics were significantly more effective than the liquid soap.

Adult↗