Bone formation in rabbit cancellous bone defects filled with bioactive glass granules

We examined new bone formation after filling cancellous bone defects with bioactive glass (BG) in granular form. Cylindrical defects in the trochanter area of 18 rabbit femora were filled with BG granules (diameter 600-830 μm) and compared with similar defects filled with morcellized autogenous bone. New bone formation and surface reaction of BG particles were evaluated by light microscopy, histomorphometry, and scanning electron microscopy. The chemical profile at the bone- material interface was studied by energy dispersive x-ray analysis (EDXA). In the BG group, 41, 32, and 38 percent of the defects were filled with new bone after 3, 6, and 12 weeks, respectively. The corresponding figures for the autogenous bone group were 36, 29, and 34 percent. The thickness of the reaction layer on the glass surface increased from 82 to 163 μm during the observation periods. An intimate contact without intervening soft tissue between new bone lamellae and BG granules was a constant finding. EDXA showed a chemical continuum between the granules and the new bone. No adverse reactions related to BG were observed. BG is a promising material for filling cancellous bone defects.     

Stimulatory Effect of Prostaglandin F2α on Gastric Acid Secretion in Rats

Abstract: The effect of intravenously administered prostaglandin F_2α on gastric acid secretion was investigated in anaesthetized rats. Doses of 0.03–0.3 mg/kg PGF_2α stimulated gastric acid output in rats with intact vagi, whereas an inhibitory effect was observed in vagotomized animals. Treatment with 5 mg/kg of Na-meclofenamate intravenously attenuated the secretory response to PGF_2α, while 10 mg/kg of indomethacin intravenously and 3 mg/kg of 8-phenyltheophylline intraperitonelly were without any effect. The results indicate that intravenously administered PGF_2α stimulates gastric acid secretion in anaesthetized rats via activation of the vagus nerve. The effects of Na-meclofenamate and indomethacin suggest that PGF_2α may exert its secretagogue action via specific receptors. The lack of the effect of 8-phenyltheophylline indicates that adenosine which reportedly had a similar effect on gastric secretion after intravenous injection seems not to be involved here.     

Age-related expression of juvenile periodontitis

To test the hypothesis that localized and generalized juvenile periodontitis is one disease entity, the localization of bone loss was measured from orthopantomograms of 88 patients with untreated juvenile periodontitis. Linear regression analysis showed a significant correlation between the age of the patient and the number of teeth with bone loss. Similarly, a correlation was found between the Gingival Bleeding Index scores, the age of the patient, and the number of affected teeth. It is concluded that juvenile periodontitis, known to be genetically controlled, is a disease entity which starts as a localized form with affected first molars and/or incisors and develops, if not treated, gradually to the generalized form of the same disease, which resembles the adult periodontitis.     

Sodium load increases renal angiotensin type 1 receptors and decreases bradykinin type 2 receptors.

The regulation of both angiotensin receptors and bradykinin receptors during sodium intake is poorly understood. We hypothesized that an altered balance between renal angiotensin type 1 (AT1) receptors and bradykinin type 2 (B2) receptors might contribute to an increase in blood pressure during periods of high-sodium intake. We studied the effects of high-sodium intake on renal AT1 receptors and B2 receptors in 5-6-week-old spontaneously hypertensive rats (SHR) receiving high-sodium chloride (6% NaCl) or mineral salts (10.5%, composition: 57% NaCl, 28% KCl, 12% MgSO4) compared to those receiving a low-sodium (NaCl 0.125%) diet for 10 weeks. Mineral salt intake was included due to its beneficial effects on blood pressure and cardiac hypertrophy. Receptor densities were measured by quantitative autoradiography. AT1 receptors were quantified using incubation with 125I-Sar1-Ile8-angiotensin II and displacement was measured with PD123319 (10 micromol/l), whereas B2 receptors were quantified using 125I-HPP-icatibant and displacement was measured with icatibant (3 micromol/l). Compared to the SHR controls, a further increase in blood pressure occurred after 2 weeks in the 6% NaCl group and after 6 weeks in the mineral salt group. AT1 receptor density increased in the renal cortex by 41% (p<0.01) in the 6% NaCl group and by 26% (p<0.05) in the mineral salt group. B2 receptor density decreased in the renal medulla by 26% (p<0.01) in the 6% NaCl group, and decreased even more i.e., by 45% (p<0.001), in the mineral salt group. It was shown that a 6% NaCl or a 10.5% mineral salt loading was capable of increasing renal AT1 receptor density and decreasing renal B2 receptor density. An altered balance between these receptors might be associated with hypertension under conditions of sodium loading.     

Trends in toothbrushing and utilization of dental services in Finland

Abstract Prevention and control of common dental diseases highly depends on individual behavior, and during the last decades, individuals have increasingly been required to take responsibility for their own oral health. In Finland the rate of toothbrushing and dental visits were first surveyed nationwide in 1971 by interviews with a sample of 1063 individuals, drawn to represent the total population aged 15 yr and over. At the time, 68% of the 829 dentulous interviewees claimed to brush at least once a day. Using another sample of 1006 interviewees, drawn in the same manner, in 1990 the brushing rate was found to have increased to 91% 853 dentulous subjects. Daily brushing was more frequent among women (98%) than men (83%). The most distinct positive change regarding brushing frequency was found among men and those with only elementary education. In 1971 the interval between the two most recent dental visits was 1 yr or less for 44% of all the interviewees and for 25% it was more than 5 yr. In 1990, 53% of the interviewees had visited a dentist within a year and the visiting interval was more than 5 yr for 16%. The youngest subjects were the most frequent visitors: 60% of them in 1971 and 74% in 1990. The results indicate a clear trend toward more frequent brushing in Finland. However, this trend regarding dental visits does not seem to be equally remarkable.     

Does hormone-replacement therapy prevent fractures in early postmenopausal women?

The purpose of this population-based prospective cohort study was to examine the effect of hormone-replacement therapy (HRT) on the risk of fractures. The study population consisted of 7217 postmenopausal women aged 47-56 years (mean, 53.3 years) at baseline from data taken from the Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) in Finland. We compared fracture incidences between HRT users and nonusers. A total of 679 (9.4%) women recorded validated fractures during the 5-year follow-up. Of these, 268 (39%) women had a distal forearm fracture. Two thousand six hundred seventy women (37%) had used HRT >6 months during the follow-up--one-half of them continuously. The relative risk, estimated as hazard ratio with Cox regression, was 0.69 (95% CI, 0.58-0.82) for any fracture and 0.49 (0.36-0.66) for distal forearm fracture among HRT users as compared with never-users. After adjusting for age, body mass index (BMI), number of chronic health disorders, fracture history, and time since menopause (independent risk factors) the corresponding risks were 0.67 (0.55-0.81) and 0.53 (0.37-0.74), respectively. The respective adjusted risks for continuous HRT users were 0.62 (0.48-0.79) and 0.41 (0.26-0.67). The adjusted risk of other than distal forearm fracture was 0.74 (0.55-0.98). The results suggest that HRT has a beneficial effect on prevention of fractures in general and on that of distal forearm fracture in particular in early postmenopausal women.     

Dental knowledge, attitudes towards oral health care and utilization of dental services among male industrial workers with or without an employer-provided dental benefit scheme

Abstract In industrialized countries various dental benefit schemes have been implemented to improve the utilization of dental services, though few studies have demonstrated that effect. Prior to a comprehensive clinical study in southern Finland, a postal questionnaire survey of male industrial workers (age 38–65 yrs) was conducted to investigate knowledge and attitudes concerning oral health care and whether access to an employer-provided dental benefit scheme was associated with the utilization of dental services. The response rate was 81% (n=325) in the subsidized group and 69% (n=174) in the control group. In both groups, 60% of the subjects had had their last dental visit within a year but 91% of the subsidized workers compared to 79% of the controls had visited a dentist in the past two years (p<0.001). The subjects had similar attitudes towards the importance of regular dental care and its implications for dental and general health. Subsidization explained the disparity in the current dental visiting pattern between the groups better than the possibility of using working hours for dental visits. Backward stepwise logistic regression revealed that the probability of a dental visit within the past two years was positively associated with access to an employer-provided dental benefit scheme, tooth brushing to maintain dental health, and number of teeth, and negatively associated with number of carious teeth. Our results demonstrate a positive impact of subsidization on the utilization of dental services.