Putative factors associated with molar incisor hypomineralisation: an epidemiological study

AIM

The aim of the study was to examine the aetiological factors involved in the development of molar incisor hypomineralisation (MIH).

METHODS

The study population comprised 4,049 children (2,029 girls, 2020 boys) aged 7-12 years. Children were examined for MIH in the school environment. Putative aetiological factors were evaluated using a questionnaire sent to children's families. The questionnaire included questions on prenatal, perinatal, and postnatal systemic conditions. Multivariate analysis was performed using multiple logistic regression, and Pearson's Chi-square test was used to evaluate nominal or ordinal variables with Fisher's exact test used in cases of small sample sizes. A level of p < 0.05 was considered statistically significant.

RESULTS

MIH was observed in 7.7 % of the study population. A total of 3,827 completed questionnaires were returned, yielding a response rate of 95.3 %. MIH was found to be associated with prematurity (7 %), gastrointestinal problems (3.9 %), pneumonia (6.3 %), frequent fever (26.1 %), measles (14.7 %), and chickenpox (29.3 %) before age 4 years.

STATISTICS

Prevalence did not vary significantly between girls and boys (p > 0.05). Prematurity, gastrointestinal problems, pneumonia, frequent high fever, measles, and chickenpox before age 4 years were found to be significantly related with MIH (p < 0.05).

CONCLUSIONS

The aetiology of MIH is not clear yet, and the results of this study support the results of previous studies regarding the putative causal effect of several factors.

Significance of vitronectin and PAI-1 activity levels in carotid artery disease: comparison of symptomatic and asymptomatic patients

AIM

Carotid atherosclerosis one of the main risk factors for ischemic stroke. Acute thrombosis after atherosclerotic plaque disruption is a major complication of primary atherosclerosis, leading to acute ischemic syndromes and atherosclerotic progression. PAI-1 is the most important and most rapidly acting physiological inhibitor of tissue-type (t-PA) and urokinase type (u-PA) plasminogen activators. Active PAI-1 form spontaneously converts to the latent with a half-life of ~1 h. Complex formation with vitronectin increases half life of PAI-1 by two- to four-folds. Thus, this inhibitor function of PAI-1 facilitated by Vn that binds the inhibitor and may regulate its activity by the stabilizing the active PAI-1 conformation. In addition, PAI-1/VN complexes may effect vascular structure and function. However, the exact role of these complexes in vascular remodelling are not completely clear. The aim of the present study was determining, correlating and comparing the plasma vitronectin, t-PA and PAI-1 activity levels in asymptomatic and symptomatic patients with carotid artery plaque.

METHODS

A total of 37 carotid artery disease patients were included in this study. Blood samples were obtained from Cerrahpasa Medical School, Department of Heart and Vessel Surgery, University of Istanbul. Plasma vitronectin, tPA and PAI-1 activity levels were determined by ELISA.

RESULTS

We found plasma PAI-1 activity levels were elevated in the asymptomatic group as compared with symptomatic group (P=0.038). We have also found a positive correlation between PAI-1 activity and vitronectin levels in symptomatic group (r=0.399, P=0.039).

CONCLUSION

Decreased PAI-1 activity levels correlate with vitronectin in the symptomatic group; a) may be the consequence a compensatory mechanisms (due to possibilty in increased fibrinolytic activity and decreased vascular remodelling) against disease progression. b) or may be also cause progression of disease by increase of vascular remodelling.

TBARS, carnitine, and reduced glutathione levels in human bladder carcinoma

In this study, we investigated tissue levels of reduced glutathione (GSH) and carnitine as well as thiobarbituric acid reactive substances (TBARS, as a marker of lipid peroxidation) levels in bladder carcinoma and control group of patients. The average GSH, carnitine and TBARS levels for tumor group were respectively 7.11 +/- 3.3 micro g/mg protein, 1.81 +/- 0.39 nmol/mg protein, and 4.29 +/- 3.2 micro mol/mg protein, versus 14.45 +/- 4.11 micro g/mg protein, 2.14 +/- 0.66 nmol/mg protein, and 2.3 +/- 0.6 micro mol/mg protein for normal bladder tissues. Thus, tissue reduced glutathione levels (GSH) were significantly lower in patients as compared with the control group (p < 0.001) whereas average TBARS levels in the tumor group were found to be higher than those in control group. The average tissue carnitine levels in the patient group were found to be lower compared with the control group but the difference was not statistically significant (p > 0.05).

Prevalence of temporomandibular dysfunction in Turkish children with mixed and permanent dentition

This study was carried out to determine the prevalence of temporomandibular joint (TMJ) dysfunction in mixed and permanent dentition and to evaluate the sex distribution in Turkish children. One hundred and eighty-two children with mixed dentition and 212 with permanent dentition were selected for the study, which used a questionnaire and clinical examination. Children with one or more signs (TMJ sounds, TMJ tenderness, muscle tenderness, restricted mouth opening) and/or symptoms (TMJ pain during mastication and mouth opening, restriction of the jaw opening and TMJ sounds) met the criterion of TMJ dysfunction. The total prevalence of signs and symptoms of TMJ dysfunction in the studied population was 68% (68% in girls and 68% in boys) in mixed dentition and 58% (61% in girls and 56% in boys) in permanent dentition. The Z-test and analysis of variance (ANOVA) were used for statistical analysis of the difference between the results. The total prevalence of signs and symptoms of TMJ dysfunction in mixed dentition was found to be higher than in permanent dentition (P < 0.05). No statistically significant difference was found in the total prevalence of TMJ dysfunction between girls and boys.

Diffuse cavernous hemangioma of the rectum and sigmoid colon

We present an 18-year-old man with painless rectal bleeding, hematuria and diffuse cavernous hemangioma of the rectum and sigmoid colon. Thirty units of blood were transfused during the interval preceding definitive surgery. Low anterior resection and partial cystectomy were performed. During the postoperative period no rectal bleeding occurred, but he died of massive intracerebral bleeding 10 months after the operation.

Carbohydrate-deficient transferrin and sialidase levels in coronary heart disease

Transferrin is a N-glycosylated glycoprotein and plays an important role in iron transport from sites of absorption and storage to sites of utilization. The main component of normal serum transferrin contains two biantennary glycans, each consisting of 2 mol of sialic acid (Tetrasialo transferrin). Normal serum also contains small amounts of tri- and disialotransferrin. We have undertaken this study to investigate the levels of serum carbohydrate-deficient transferrin (Desialotransferrin) and sialidase levels in patients with coronary heart disease. In patient group, serum desialotransferrin and sialidase levels were found to be significantly higher than control group (p < 0.01 and p < 0.001, respectively). We conclude that increased activity of sialidase may be responsible for increased desialotransferrin in patients with coronary heart disease. Serum desialotransferrin levels may be useful critaria to diagnosis and pathogenesis of coronary heart disease.

Tissue and serum sialidase levels in breast cancer

Breast cancer is both one of the most common and one of the most treatable of all human malignancies. It has been suggested by various investigators that sialic acid increases in the sera of cancerous patients. In cancer patients, an increase in the levels of serum sialic acid may also be due to an increase in the activity of serum or tissue sialidase. The purpose of the present investigation was to determine whether the concentration of sialidase in serum and breast tissue could be used as a tumor marker in breast cancer. In this study; serum sialidase levels in 26 patient with breast cancer and 31 controls were found to be 77.04+/-25.07 U/l and 55.56+/-7.50 U/l, respectively. The mean tissue sialidase levels in 26 breast cancer patients and 13 controls were 39.76+/-17.03 U/g protein and 14.30+/-7.09 U/g protein, respectively. Serum and tissue sialidase levels in breast cancer were significantly higher than those found in the control group (P < 0.001). The mean serum and tissue sialidase levels in 14 Grade I-II and 12 Grade III breast cancer patients were found to be 67.73+/-11.87 U/l and 33.41+/-12.17 U/g protein and 87.89+/-31.94 U/l and 47.17+/-19.30 U/g protein, respectively. Also we found a significant difference between the levels of serum and tissue sialidase in Grade I-II and III (P < 0.05).

Profiles of the fatty acids in the plasma membrane of human brain tumors

Several studies demonstrated that certain fatty acids have specific effects on tumor cells. n-3 series fatty acids (alpha-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid) may suppress the carcinogenesis, whereas n-6 series fatty acids (arachidonic acid, linoleic acid) may exert tumor promoting effects. In this study, 19 patients with various brain tumors and 12 control brain tissues were studied. n-3, n-6, n-9 unsaturated fatty acids and certain saturated fatty acids levels were measured in the plasma membrane of tumor or control brain tissues by capillary gas chromatography. We found that the level of docosahexaenoic acid from n-3 series fatty acids was significantly lower in gliomas and meningiomas than controls (p = 0.000). Total n-3 fatty acids level was also significantly lower in tumors than controls (p = 0.000). The levels of linoleic acid, arachidonic acid and dihomogamma linolenic acid from n-6 series were significantly higher in gliomas and meningiomas compared with controls (p = 0.000). Total n-6 fatty acids level was also significantly higher in tumors than controls (p = 0.000). Furthermore, in total n-9 fatty acids, total unsaturated fatty acids and total saturated fatty acids levels, there were no significant differences in gliomas and meningiomas compared with controls (p = 0.6840, p = 0.4388 and p = 0.4343, respectively). This findings suggest that n-6 fatty acids can act as a tumor-promoting agent in human brain tumors.

Prostaglandin E2 levels in human brain tumor tissues and arachidonic acid levels in the plasma membrane of human brain tumors

Arachidonic acid is stored in the cell membrane and released when the cell is activated by appropriate stimuli. It is the substrate for prostaglandins. Both experimental and human tumors often synthesize high levels of prostaglandins, most notably prostaglandin E2 (PGE2). Some experiments suggest that these compounds increase tumor growth through their actions on host immunocytes. In this study, 22 patients with various brain tumors and 12 control brain tissues were studied. PGE2 levels in tissue samples were measured by ELISA. Arachidonic acid levels in the plasma membrane of tissue samples were analyzed by capillary gas chromatography. The levels of PGE2 were significantly higher in gliomas (n = 10) and meningiomas (n = 7) compared with control tissues (P = 0.000 and P = 0.000, respectively). Also, PGE2 levels in meningiomas were significantly higher than in gliomas (P = 0.000). Arachidonic acid levels in the plasma membrane of gliomas (n = 9) and meningiomas (n = 6) were significantly higher than in the control tissues (P = 0.000 and P = 0.000, respectively). These results suggest that the increased production of PGE2 may suppress the immune system and play an important role in tumor growth.

The distribution of tissue fibronectin and sialic acid in human breast cancer

Our findings indicate that sialic acid and fibronectin levels in breast tumors are higher than those in normal tissues. The mean tissue fibronectin and sialic acid concentrations for patients with breast cancer were 30.90 +/- 9.68 microg/mg protein and 21.60 +/- 9.35 microg/mg protein, respectively, and for normal controls were 12.47 +/- 5.69 microg/mg protein, respectively. Tissue fibronectin and sialic acid can be important markers for human breast cancer.

The molecular markers of hemostatic activation on coronary artery disease

Endothelial cells, circulating platelets, and proteins of the coagulation and fibrinolytic systems are known to contribute to the hemostatic processes. Various molecular markers of hemostatic alteration are found in increased amounts in the circulation during the activation of this process. In this study, we investigated serum lipoprotein (a) and plasma platelet factor 4, beta-thromboglobulin, thrombin-anthithrombin complex, fibrinopeptid A, D-dimer, tissue plasminogen activator, tissue plasminogen activator inhibitor, and fibronectin levels in patients with coronary artery disease. The levels of all these markers were found to be significantly higher as compared to the control group. Our findings suggest that patients with coronary artery disease have greater blood coagulability than controls, and the use of molecular markers has become greatly important in clinical practice.

The importance of Lp(a)-fibronectin interaction in atherogenesis

An elevated concentration of lipoprotein (a) (Lp(a)) in serum has been considered a risk factor for coronary heart disease by various investigators. The apo(a) portion of Lp(a) binds to the carboxyterminal heparin binding domain of fibronectin. Lp(a) bound to fibronectin is internalized through the fibronectin receptor pathway and thereby causes increased accumulation of lipid and foam cell formation. In the present study, fibronectin and Lp(a) concentrations have been assayed in patients with coronary heart disease (CHD) and healthy subjects. Serum total cholesterol, triglyceride, LDL, VLDL and HDL cholesterol levels in patients with coronary heart disease were significantly different from the control group (p < 0.001). Plasma fibronectin (p < 0.05) and serum Lp(a) (p < 0.001) levels were found to be significantly elevated when compared with the control group.

Plasma Lp(a) and t-PA-PAI-1 complex levels in coronary heart disease

In this study we investigated serum Lp(a) and plasma t-PA-PAI-1 complex levels in patients with coronary heart disease (CHD). Serum total cholesterol, triglyceride, LDL and VDL cholesterol levels (p < 0.001) and HDL cholesterol levels (p < 0.01) in patients group were found to be significantly different from those in control group. The mean Lp(a) and t-PA-PAI-1 complex levels in patients with coronary heart disease were significantly higher as compared to control group (p < 0.001). This data indicate that the elevated levels of serum Lp(a) and plasma t-PA-PAI-1 complex may play an important role in the pathogenesis of coronary atherosclerosis.

The prognostic importance of fibronectin and sialic acid levels in human pituitary adenomas

In this study, fibronectin and sialic acid levels were determined in human pituitary adenomas. The mean fibronectin and sialic acid levels for human pituitary adenomas were found to be 31.64 +/- 15.82 microgram/mg protein and 21.90 +/- 9.82 microgram/mg protein, respectively, versus 6.30 +/- 2.96 microgram/mg protein and 9.88 +/- 2.81 microgram/mg protein for the normal brain tissues. Fibronectin and sialic acid levels were significantly higher (P < 0.001) in human pituitary adenomas than the normal brain tissues. In human infiltrative and non-infiltrative pituitary adenomas, the mean fibronectin and sialic acid levels were found to be 40.87 +/- 15.90 microgram/mg protein, 27.59 +/- 11.10 microgram/mg protein and 22.40 +/- 9.51 microgram/mg protein, 16.21 +/- 3.20 microgram/mg protein, respectively. Fibronectin and sialic acid levels were slightly elevated (P < 0.05) in human infiltrative pituitary adenomas compared with non-infiltrative adenomas.

Tissue sialic acid and fibronectin levels in human prostatic cancer

We investigated the tissue concentration of sialic acid and fibronectin in patients with prostatic cancer. The mean sialic acid and fibronectin levels in patients with prostatic cancer were 19.02 +/- 6.30 micrograms/mg protein, respectively versus 13.01 +/- 4.53 micrograms/mg protein and 11.77 +/- 6.74 micrograms/mg protein for normal prostatic tissues. Sialic acid and fibronectin levels in cancerous patients were significantly higher than in the control group (P < 0.05).

The relationship between the electrophoretic mobility of lipoproteins and coronary heart disease

Low density lipoproteins (LDL) in patients with coronary atherosclerosis have a substantially lower content of sialic acid when compared with the LDL from healthy subjects. Desialylated LDL have smaller sizes and greater electrophoretic mobilities than sialylated ones. Desialylated LDL may be responsible for the accelerated development of foam cells in atherosclerosis. In the present study, we investigated a relationship between the electrophoretic mobility of lipoproteins and the number of significantly obstructed vessels in patients with coronary heart disease (CHD). Our findings indicate that when the number of significantly obstructed vessels is increased, the electrophoretic mobility of lipoproteins is high. We also investigated the possible role of serum sialidase activity on lipoprotein desialylation in patients with coronary heart disease. In patients with single vessel disease (p < 0.01) and double-triple vessel disease (p < 0.001) the mean serum sialidase activity was significantly higher than in the control group.

Microleakage of direct and indirect inlay/onlay systems

The purpose of this in vitro study was to evaluate the microleakage of direct and indirect inlay/onlay systems. Two of the groups investigated have indirect applications only and consist of microfine composites. The other two groups of inlay/onlay systems have both direct and indirect applications and are hybrid composites. Standardized MOD preparations were cut in 60 extracted human premolars. One gingival margin was placed in enamel above the cementoenamel junction (CEJ) and the other was placed in dentine below the CEJ. The inlays were made and luted according to each manufacturer's recommendation. The restored teeth were thermocycled and immersed in a basic fuchsin solution for 24 h. Following the mesiodistal sectioning of the specimens, extent of dye penetration at the restoration-glass ionomer cement and tooth-glass ionomer cement interfaces were scored using a stereomicroscope. Both direct and indirect inlays showed substantial leakage at gingival-dentine margins. However, there was only superficial leakage at enamel margins. Comparing the overall indirect inlay systems, EOS inlay leaked the most (P < 0.05). Indirect Brilliant Dentin inlays showed a significantly smaller amount of leakage than the other inlay systems. SR-Isosit and Estilux Posterior C VS inlays provided a favourable marginal seal. In the case of Brilliant Dentin and Estilux Posterior C VS, indirect inlays leaked more than direct inlays. Generally, no significant difference was observed between the interfaces evaluated in microleakage performance.

Tissue fibronectin levels of human prostatic cancer, as a tumor marker

In this study, tissue fibronectin levels have been assayed in human prostatic cancer, benign prostatic hyperplasia and normal prostatic tissue. The mean tissue fibronectin levels for prostatic cancer, benign prostatic hyperplasia and normal groups were found to be 20.22 +/- 8.66 micrograms/mg protein and 11.77 +/- 6.74 micrograms/mg protein, respectively. In the malignant group, the mean fibronectin concentrations, appeared to be significantly higher than normal, (p < 0.05). On the other hand, fibronectin levels of benign prostatic hyperplasia were found to be statistically insignificant in comparison to the normal group (p > 0.05).

Plasma fibronectin and sialic acid levels in various types of human brain tumors

In this study, fibronectin and sialic acid concentrations were determined in plasma from patients with pituitary adenoma, meningioma and glioma, and, from controls. The mean plasma fibronectin levels in patients with pituitary adenoma, meningioma and glioma (p < 0.001) appeared to be significantly lower than controls. On the contrary, the mean plasma sialic acid values in patients with pituitary adenoma (p < 0.01), and glioma (p < 0.001) were significantly higher as compared to normal plasmas. The mean plasma sialic acid values in patients with meningioma were not different from those in controls. Also, the mean fibronectin levels in patients with glioma were found to be significantly higher than those in patients with meningioma (p < 0.05).

Fibronectin and sialic acid levels in human meningiomas and gliomas

In this study, fibronectin and sialic acid levels have been assayed in human meningiomas and gliomas. The mean fibronectin and sialic acid levels for human meningiomas were 22.01 +/- 9.70 micrograms/mg protein and 19.58 +/- 4.89 micrograms/mg protein, respectively, and for human gliomas were 27.30 +/- 13.70 micrograms/mg protein and 25.67 +/- 11.60 micrograms/mg protein, respectively, versus 9.23 +/- 5.40 micrograms/mg protein and 13.50 +/- 4.30 micrograms/mg protein for normal brain tissues. Fibronectin and sialic acid levels were significantly higher in human meningiomas (P < 0.01 and P < 0.05) and gliomas (P < 0.001 and P < 0.01) than control group. Also the mean fibronectin and sialic acid levels were found to be 18.27 +/- 7.08 micrograms/mg protein and 17.04 +/- 6.25 micrograms/mg protein in Grade I-II and 32.60 +/- 15.00 micrograms/mg protein and 29.50 +/- 11.60 micrograms/mg protein in Grade III-IV gliomas, respectively. Fibronectin and sialic acid levels were significantly higher in Grade III-IV gliomas than Grade I-II gliomas (P < 0.05).

Sialic acid levels in various types of cancer

Serum or plasma total sialic acid (TSA) and lipid bound sialic acid (LSA) are useful markers for human cancer. In this study, sialic acid levels have been demonstrated in various types of human cancer including brain, thyroid and Hodgkin's. TSA was found to be significantly elevated in various human brain tumors, especially in the microsomal fraction. Also serum and tissue LSA levels indicated significant increases when compared to the normals in various brain and thyroid tumors. TSA levels were significantly higher in the plasma and leucocyte in patients with Hodgkin's. The results show that sialic acid can be advisable as a beneficial marker for detecting malignancies. But it can not be used as a criteria for identifying tumor types.

Tissue lipid composition of human gliomas and meningiomas

This study is a comparative analysis of some lipid fractions in human brain tumors and normal brain tissue. Gliomas and meningiomas were studied and in these tumors while total lipid, total and free cholesterol and total phosphoglyceride levels were found to be significantly lower than in normal controls, the difference in esterified cholesterol levels was found to be insignificant. No significant differences in lipid fractions existed between gliomas and meningiomas except total and esterified cholesterol values.

[SEM investigation of the effects of various fluoride preparations on dentin surface]

Fluor preparations are effective agents to remove dentinal hypersensitivity. In this study the effects of %4 NaF, Bifluoride 12 and diamine silver fluoride (Saphoride) on dentin surface is evaluated with SEM. Prepared dentin surface was covered with smear layer and different crystal forms were observed on the dentin surface.

Subcellular localization of sialic acid in human brain tumors

The subcellular localization of sialic acid has been investigated in various types of human brain tumors, such as astrocytoma, meningioma and primary malignant lymphoma. High levels of sialic acid were observed in the microsomal fraction of all types of tumors. However, there was no significant difference between values obtained in meningioma, primary malignant lymphoma, and normal tissue, in the fractions examining nucleus, mitochondria and supernatant.

[Escherichia coli, coliform bacteria, Pseudomonas aeruginosa, Proteus and Staphylococcus aureus carriers among children 5-15 years old]

The throat swap cultures of 250 children between 5-15 years ages examined for the microorganisms, E. coli, Coliform, Protus, Ps. aeruginosa and S. aureus. 66 (26.4%) E. coli, 64 (25.6%) S. aureus, 9 (3.6%) Coliform, 3 (1.2%) Ps. aeruginosa, 2 (0.2%) Proteus organisms were isolated from throat swaps cultures of 144 (57.6%) children. 106 (42.4%) children had contained normal oral flora. S. aureus and E. coli strains were tested using disk method for the sensitivity of some antibiotics. S. aureus strains were resistant 12.5% to gentamycin, 9.4% to cefoperazone and (1% to cefazolin, 48.4% to lincomycin and 87.5% to ampicillin. E. coli strains were resistant 42% to gentamycin, 37% to cefoperazone and 74% to cefazolin.