Effects of formalin fixation on tissue optical polarization properties.

Formalin fixation is a preparation method widely used in handling tissue specimens, such as biopsies, specifically in optical studies such as microscopy. In this note, we examine how formalin fixation affects the polarization properties of porcine myocardium and liver as assessed by optical polarimetry. Spatial maps of linear retardance and depolarization were derived from four myocardial and four liver samples before and after formalin fixation. Overall, linear retardance and depolarization increased after fixation for both myocardium (15% and 23% increase, respectively) and liver (38% and 51%, respectively). The relative increase in retardance was greater in liver compared to myocardium, although the absolute increase in retardance was comparable for both. The effect of fixation on bulk optical properties was also investigated for myocardium where the scattering coefficient increased from 92 to 132 cm(-1) and the absorption coefficient remained constant at 1.1 cm(-1).

Serum lipid and lipoprotein profile in children with iron deficiency anemia.

BACKGROUND: A close association has been found between serum lipoprotein abnormalities and the risk of atherosclerosis. In adults, high stored body iron, high serum iron concentrations and low iron binding capacity were found to be risk factors for coronary heart disease. Iron-deficient diets have caused contradictory lipid changes in rats. This report investigates the relationships between iron deficiency, macronutrient intake and the serum lipid and lipoprotein profiles in children with iron deficiency anemia (IDA). METHODS AND RESULTS: Fifty-six children with IDA, aged 3.0 +/- 1.3 years and 60 healthy age- and sex-matched controls were evaluated. The mean total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C), lipoprotein (a) levels and LDL-C/high density lipoprotein cholesterol (HDL-C) and TC/HDL-C ratios of the IDA group were significantly lower than those of controls. While there were no differences in triglycerides and apolipoprotein B (apoB) values between patients and controls, apolipoprotein A-1 (apoA-1) and HDL-C levels were higher in the IDA group. Dietary energy, carbohydrates, total fat and protein intakes of the IDA group were lower than those of controls. After oral iron supplementation, the lipoprotein profile of patients with IDA became similar to controls. In the multivariate analysis, while energy was taken as a covariate, there was no difference in the lipid profile of patients and controls. CONCLUSIONS: Patients with IDA are also deficient in macronutrients. The low atherogenic serum lipid profile of IDA is not a direct result of iron deficiency itself, but related to decreased energy and protein intakes.

Prevalence of nocturnal enuresis and accompanying factors in children aged 7-11 years in Turkey.

There has been limited epidemiological research about nocturnal enuresis in Turkey. The objectives of this study were to ascertain the prevalence of nocturnal enuresis and the epidemiological factors associated with this in Turkish children aged 7-11 y, living in Manisa. Included in the study were 2000 children from various primary schools in Manisa. Parents were asked to fill out our specially designed questionnaire. In all, questionnaires for 1703 children were completed and returned to the department (871F, 51.1%; 832M, 48.9%). The prevalence of nocturnal enuresis for females was 10.6%, for males it was 16.9% and the overall prevalence was 13.7%. The prevalence of nocturnal enuresis decreased with age. Enuresis nocturna was found to be more common in children with a family history of bedwetting (76.5%). Deep sleeping, poor toilet habits and low educational level of the family were associated with enuresis. Consanguineous marriage did not influence the incidence of enuresis nocturna. There was no difference between enuretics and nonenuretics with reference to breastfeeding, being firstborn or being right- or left-handed. In our opinion, enuresis is an important problem for both families and children in Turkey for which specific guidelines should be developed. Various methods have been tried in the treatment of enuresis because of its multi-factorial aetiology. Child, family and physician co-operating together achieve the best help to both child and family.

Low levels of high density lipoprotein cholesterol in Turkish children: an important risk factor.

In Turkish adults, the incidence of coronary artery disease (CAD) has been found to be high. However, no detailed lipid, or lipoprotein data of children are available from Turkey. The present study was designed to define the borderline lipid and lipoprotein levels of sera in 397 healthy children (aged 5-14 years; 206 boys and 191 girls). Mean levels of total cholesterol (TC), triglyceride (TG), high- and low-density lipoprotein cholesterol (HDL-C and LDL-C, respectively) were found to be 150, 79, 46.7, and 87.6 mg/dL, respectively, for boys, and 152, 77.5, 46.3 and 90.5 mg/dL, respectively, for girls. Lipids and lipoproteins did not show any significant correlation with age and body mass index (BMI), except for TG in boys in whom TG levels were positively correlated with age and BMI. There were no significant differences in lipid and lipoprotein levels between boys and girls. As in the Turkish adult population, serum HDL-C levels of Turkish children were profoundly low on international comparison. Twenty-three (53%) of 43 children with low HDL-C level (< or = 35 mg/dL) had abnormal ratios of TC/HDL-C (> or = 5) and/or LDL-C/HDL-C (> or = 4.5), whereas only 13 (3.7%) of the remaining 354 children with a HDL-C level less than 35 mg/dL had abnormal ratios of TC/HDL-C (> or = 5) and/or LDL-C/HDL-C (> or = 4.5). The low levels of HDL-C in Turkish children may be associated with the high incidence of CAD in the Turkish adult population.

Should children with infection be tested for lipid, lipoprotein and apolipoprotein?

The lipid profile is known to alter in patients with infection, but there has not been a study of the apolipoprotein levels in serum of otherwise healthy children during infection. Lipids, lipoproteins, apolipoproteins A-1 and B and lipoprotein (a) were evaluated prospectively in 31 consecutive children, aged 4-15 years, who were admitted to the hospital with bacterial pharyngitis. The degree of dyslipidemia associated with bacterial pharyngitis was assessed using each child as his/her own control and by comparison with 79 healthy children who had not had an infection during the past 3 months. Serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A-1 and apolipoprotein B levels were significantly decreased during the symptomatic phase of the disease, whereas the serum triglyceride level was slightly elevated. Serum lipoprotein (a) concentration did not change significantly. In conclusion, it is suggested that serum lipids, lipoproteins and apolipoproteins should not be assessed during infection because of the possible transient changes of these parameters during infection or inflammation.

Hypernatriuria and kaliuresis in enuretic children and the diurnal variation.

PURPOSE: We investigate the underlying pathophysiological cause of primary nocturnal enuresis by comparing electrolyte alterations in urine samples of enuretics during the daytime and nighttime compared with those of nonenuretic subjects. MATERIALS AND METHODS: Urine output, urine specific gravity and urinary electrolytes in 15 enuretic and 12 nonenuretic children were measured. We collected daytime serum and urine samples of children fed a similar diet between 7 a.m. and 7 p.m., and nighttime between samples 7 p.m. and 7 a.m. Urinary calcium/creatinine ratio, tubular reabsorption of phosphorus and excretions of fractional sodium and potassium were calculated. RESULTS: There was no significant difference between the calcium/creatinine ratio ratios. There was a significant increase in fractional sodium and fractional potassium values in enuretics compared to nonenuretics during the day and at night. Daytime and nighttime fractional sodium and fractional potassium values in enuretics were similar. In contrast to nonenuretics, enuretic patients had no diurnal variation of fractional sodium. There was significant positive correlation between bedwetting status, and fractional sodium and fractional potassium. CONCLUSIONS: Since sodium and potassium excretions were higher in enuretic patients than nonenuretic children, and no significant diurnal variation in urinary excretion of these ions there might be a difference in the mechanism of reabsorption of sodium and potassium between enuretic and nonenuretic children.

Renal functions of enuretic and nonenuretic children: hypernatriuria and kaliuresis as causes of nocturnal enuresis.

OBJECTIVE: The aim of this study was to investigate the pathophysiologic cause(s) of primary nocturnal enuresis. Therefore, electrolyte concentrations of urine specimens were evaluated in the morning, and alterations compared between enuretics and nonenuretics. METHODS AND PATIENTS: First morning urine specimens of 27 enuretics and 21 nonenuretic subjects fed the same diet were collected, and urinary electrolytes were measured. The urinary Ca/Cr ratio, tubular reabsorption of phosphorus (TRP) and fractional sodium (FE Na%) and potassium excretions (FE K%) were determined for patients and controls. RESULTS: There was no significant difference in the Ca/Cr ratio and TRP between patients and controls, but enuretic patients had significantly higher FE Na% and FE K% values than controls (p < 0.001). There were significant positive correlations between FE Na% and (r = 0.81, p < 0.001) FE K% and the frequency of bedwetting, respectively, among enuretic patients (r = 0.54, p < 0.001). CONCLUSION: Since Na and K excretion of enuretic patients was higher than in nonenuretics, it can be concluded that there may be a benign hereditary and/or postural renal tubular handling disorder of Na and K in enuretic children.

Effects of passive exposure to tobacco, socioeconomic status and a family history of essential hypertension on lipid profiles in children.

There is abundant evidence that the atherosclerotic process begins in childhood. Dyslipidemia is a major risk factor for atherosclerosis in adults and children. In the present study, we measured serum lipoprotein concentrations in 194 healthy children aged between 4 to 14 years. Children were grouped according to the socioeconomic status of the families, family history of essential hypertension and passive tobacco exposure. The values of total cholesterol, low density lipoprotein cholesterol and the ratio of total cholesterol/high density lipoprotein cholesterol in the low socioeconomic group were found to be significantly higher than the values obtained for the middle-high socioeconomic group. The values of total cholesterol, low density lipoprotein cholesterol, the ratio of total cholesterol/high density lipoprotein cholesterol and low density lipoprotein cholesterol/high density lipoprotein cholesterol in the passive smoker group were found to be significantly higher than those of the nonsmoker group. But, the socioeconomic level in the passive smoker group was found to be significantly lower than that of the nonsmoker group, and therefore, the impact of passive smoking on the serum lipids in children was related to socioeconomic status. A significant difference in terms of blood lipid fractions between the groups with and that without a family history of essential hypertension was not found. These results suggest that passive smoking and lower socioeconomic status are important risk factors for cardiovascular heart disease, while a positive family history of essential hypertension is not an important risk factor.