Eleven children, each having one or two pairs of premolars to be extracted for orthodontic purposes, participated in the study. The model involved placement of a special orthodontic band that allowed the accumulation of plaque in a defined area between the band and the buccal enamel. Examination of enamel changes was carried out in experimental teeth that had been exposed to local plaque accumulation for one, two, four, eight, or 14 days. The specimens were examined under the light (LM) and the scanning electron microscope (SEM). All teeth had signs of very mild dental fluorosis. No indications of demineralization were noted after one day. SEM examination showed signs of crystal dissolution in some of the two-day specimens. Six of eight four-day specimens exhibited surface dissolution. All eight- and 14-day specimens showed signs of surface demineralization in the LM as well as in the SEM. These observations documented that undisturbed bacterial deposits are capable of initiating enamel demineralization within short time periods, even in children living in a water-fluoridated area.
Thirty-four caries-free teeth destined for orthodontic extraction were banded to provide a protected area for the accumulation of plaque. The teeth were extracted at one, two, four, eight, and 14 days after being banded, and samples of the flora below the band were analyzed for the presence of Streptococcus sanguis, Streptococcus 'mitior', 'mutans streptococci', Actinomyces viscosus, Actinomyces naeslundii, Actinomyces odontolyticus, Lactobacillus species, and Veillonella. After plaque sampling, the teeth were sent to the Royal Dental College (Copenhagen) for histological analysis. The results showed that S. mutans could colonize the area below the band after one day, but that colonization was only 100% at 14 days. Lactobacillus was only isolated from 2/8 samples at four days and from 4/8 samples at 14 days. S. sanguis and 'S. mitior' were regularly isolated at all banding times, and Veillonella was isolated from all samples. A. viscosus was the most commonly isolated Actinomyces. The numbers of Streptococcus and Veillonella were significantly higher at day 1 than at day 14 (p < 0.05). S. mutans and A. viscosus were isolated more frequently at day 14 than at day 1 (p < 0.01). Histological examination revealed that dissolution of the enamel below a band could occur after two days, but that even after 14 days dissolution could be questionable. Dissolution was detected in areas where S. mutans was not isolated (8/34), but S. mutans was also present in samples showing dissolution (12/34). There was no relationship between dissolution and the numbers of S. mutans; however, the isolation frequency of S. mutans was associated with dissolution (p < 0.05). The results also suggested that there were subject-associated factors that influenced the composition of the bacterial community, as evidenced by Lactobacillus being isolated from all samples from one subject after 14 days, while the other subject was negative for Lactobacillus.
Radiographically diagnosed incipient approximal carious lesions in deciduous molar teeth and control sites were sampled microbiologically at 6- or 12-week intervals for at least 12 months. Microbiological findings were related to radiographically diagnosed progression or non-progression of the lesions. Lactobacillus appeared at the site of 85% of progressive lesions before clinical diagnosis of progression was made and was never isolated from non-progressive lesions or control sites. Significant positive associations were detected between Streptococcus mutans, Lactobacillus, Veillonella and Actinomyces odontolyticus and progressive lesions. Singificant negative associations were detected with Streptococcus mitior, Actinomyces naeslundii and Actinomyces viscosus. Comparison of the data from control surfaces in subjects with and without progressive lesions suggested that the former were more highly colonized with S. mutans. The data emphasizes the significance of S. mutans and Lactobacillus in lesion progression and draws attention to a role of A. odontolyticus. The negative association suggests a shift in the flora with a reduction in S. mitior and A. viscosus and A. naeslundii in progressive lesions.
A freshly isolated oral strain, Lactobacillus casei RB1014, was grown in continuous culture to compare the effects of pH and fluoride on growth and metabolism. The cells were grown at pH 7.0 to 3.2 in the absence of fluoride and from pH 7.0 to 5.4 with 20 mM NaF. Cell numbers varied from 3 X 10(9) to 30 X 10(9)/ml on blood agar during alterations in the growth pH from 7.0 to 4.27. Only when the culture was stressed by lowering the pH to 3.2 were cell numbers drastically reduced. Cells growing at pH 7.0 without fluoride were unable to grow when plated on fluoride agar (10.5 mM) at pH 5.5; however, when the growth pH was allowed to decrease to 4.94, cells grew on the fluoride plates in numbers equal to those growing on blood agar. This fluoride tolerance trait appeared rapidly once pH control was removed and was lost when the culture was returned to pH 7.0. The addition of 20 mM NaF to the culture medium did not adversely affect growth, provided that the pH was maintained at 6.0 or above; cells tolerant to 10.5 and 16 mM NaF appeared on pH 5.5 plates during this phase. In cells removed from the chemostat throughout the experiment and incubated at the pH of growth in a pH stat, glycolytic activity was optimum at pH 5.5 in the absence of NaF. Fluoride stimulated glycolytic activity by cells incubated at pH 7.0 and by cells growing with 20 mM NaF, provided that the pH of growth remained at or above 6.0. A more detailed examination of the adaptation to fluoride tolerance during shifts to acidic pH values revealed that cells capable of growth on acidic fluoride agar plates appeared within 2 h of the start of the fall in pH of the chemostat culture. Estimation of the intracellular pH during the period of the initial pH fall revealed that the intracellular pH was identical to the extracellular pH (i.e., no pH gradient [delta pH]), indicating that fluoride would not be transported into the cells to inhibit metabolism. However, once the pH of the medium was stabilized, delta pHs were generated, with the delta pH increasing as the pH declined. The inhibition of glycolysis by fluoride increased in proportion to the delta pH. Cells grown at pH 5.5 generated larger delta pHs than did cells grown at pH 7.0, although the values were normally small (approximately 0.9 U). The data suggest that the inherent fluoride tolerance of L. casei RB1014 was associated with relatively small delta pHs.
Although the sperm counts of 5 of 8 adult male-to-female transsexuals were low, other aspects of testicular function were normal. Plasma production rates of testosterone averaged 6.4 mg/24 hours, a value similar to the 5.7 mg/24 hours produced by heterosexual adult men. Production rates of 17β-estradiol and estrone, 55µg/24 hours and 52 µg/24 hours, were also normal. Observed abnormalities of pituitary function and pituitary response to LHRH cannot be explained by abnormal testicular steroidogenesis.
The hypothesis that gold therapy enhances endogenous cortisol secretion was tested in juvenile rheumatoid arthritis patients. The secretion of cortisol, dehydroepiandrosterone-sulfate (DHEA-S) and several peptide hormones was determined from plasma samples collected every 20 min for 24 hours. In random patients cortisol secretion was significantly greater in gold treated patients than in similar patients not receiving gold. However, when untreated patients were restudied after initiation of gold therapy, there was no significant change in cortisol secretion. Gold therapy also did not significantly alter secretion of the peptide hormones or DHEA-S. Thus, gold does not appear to influence endogenous hormone secretion.
Augmented gonadotropin secretion associated with sleep is a major biological correlate of puberty. This study compared urinary and plasma gonadotropin values in 131 subjects (66% of whom were 11–19 yr of age). The comparison was made from plasma and urine samples collected during a 24-h period, a 3-h period after the iv infusion of LRH, and during the wake/sleep hours of the 24-h study. Twenty-four-hour mean plasma gonadotropins derived from samples drawn at 20-minintervals correlated closely with the 24-h urinary gonadotropins [r = 0.786 for LH (n = 128; P < 0.001) and r = 0.887 for FSH (n = 131; P < 0.001)]. After an iv bolus of LRH, the peak plasma LH and FSH responses also correlated closely with the simultaneous 3-h urinary LH and FSH values [r = 0.911 for LH (n = 35; P < 0.001) and 0.933 for FSH (n = 30; P < 0.001)] Comparison of the percent changes in urinary and plasma gonadotropins during sleep/wake periods was also made for children, adolescents, and adults. The mean observed sleep time (±SD) was 10.1 ± 1.5 h. The correlation for changes in urinary and plasma gonadotropins during sleep was not as strong [r = 0.308 for LH (n = 69; P < 0.01) and r = 0.50 for FSH (n = 29; P < 0.01)] as the 24-h comparisons. Of the 20 pubertal subjects (Tanner Stages II-IV), 7 had either discordant changes between urinary and plasma values or significant increases of sleep, plasma LH not reflected in sleep, urinary LH. The results demonstrate that sleep/wake differences in urinary gonadotropins are qualitatively similar to plasma changes but are quantitatively unreliable as a screening test for the presence of pubertal hypothalamic-pituitary maturation. Of the multiple factors that may account for this discrepancy between plasma and urinary values, a major cause is the fact that the sleep-augmented surge in LH is often small in magnitude compared to basal LH secretion. Consequently, frequent plasma gonadotropin measurements remain the only means of consistently demonstrating augmented gonadotropin secretion associated with sleep during puberty. (J Clin Endocrinol Metab52: 225, 1981)
Endocrinologic evaluation of 39 patients with trisomy 2 and associated hypogonadism demonstrated elevations of follicle-stimulating hormone and luteinizing hormone; consequently, it can be concluded that both germinal and Leydig cell function are affected. A negative correlation between testicular size and plasma follicle-stimulating hormone was documented. Plasma testosterone levels were found to be normal in male patients as were estradiol levels in female patients with trisomy 21. On the basis of these findings, the simplest and most practical diagnostic approach to evaluate germinal cell function appears to be a single plasma follicle-stimulating hormone determination supplemented by an accurate measurement of testicular volume in males.
To assess the potential of antihypertensive drugs for interference with somatic growth and sexual development in hypertensive children, the effect of clonidine therapy on various endocrine, cardiovascular, and neuromuscular functions has been examined in five male adolescents with idiopathic hypertension. In studies done before and at the end of 4 weeks of twice-daily clonidine therapy, in an average daily dose of 0.31 mg, no significant effects were noted in the secretory patterns of growth hormone, luteinizing hormone, follicle-stimulating hormone, prolactin, cortisol, aldosterone, or testosterone, measured in blood obtained every 20 minutes for 24 hours. In blood obtained while the patients were supine and then erect, plasma renin activity and norepinephrine levels were significantly lowered after clonidine therapy. Cardiovascular responses to dynamic exercise were little altered beyond a 17% decrease in maximal oxygen consumption. The performance of fine motor skills was minimally altered. These data provide preliminary evidence that clonidine, an antihypertensive drug that affects the adrenergic nervous system, may not interfere with normal growth and maturation in adolescent males.
Plasma cortisol was measured at 20-min intervals for 24 h in eight patients with Cushing's disease and ACTH-secreting pituitary tumors. The 24-h mean (+/- SD) cortisol level was 25.6 +/- 11.3 microgram/dl (range, 15.5--40.6), which was significantly higher than the level of normal control subjects (P less than 0.01). The 24-h mean ACTH level varied between 22--107 pg/ml, with a mean +/- SD of 63.4 +/- 27.2. The mean ACTH level was higher than that of the control subjects but the difference was not statistically significant. The 24-h cortisol secretory pattern was characterized by an absence of the normal circadian variation and a failure of the plasma cortisol level to fall to less than 2 microgram/dl between 2300--0300 h. The coefficient of variation, an expression of the amplitude of cortisol secretory episodes, was significantly decreased in patients with Cushing's disease compared to normal control subjects; there was no significant difference in the number of cortisol secretory episodes in the patients vs. control subjects. Three of the patients were restudied after successful resection of their ACTH-secreting pituitary tumors. Two showed normalization of their 24-h circadian cortisol patterns and normal metyrapone responses. In the third, the 24-h mean cortisol level was normal, but the circadian cortisol rhythm remained abnormal. This patient had diminished ACTH reserve, demonstrated by a subnormal response to metyrapone. Additional studies will be required to determine if normalization of the circadian cortisol rhythm occurs in all patients with Cushing's disease who are cured after transsphenoidal microsurgery and who also show normal ACTH reserve.
Plasma melatonin and LH were measured at 20 minute intervals for 24 hours in four normal pubertal boys. All four subjects showed a significant augmentation of LH and melatonin during noctural sleep. There was also a significant correlation between the LH and melatonin levels (p less than 0.001). There were periods of episodic secretion of melanin during the diurnal waking period which seemed related to "stress". These data indicate that the peripheral concentrations of melatonin which occur during sleep are insufficient to prevent spontaneous LH secretion during puberty.
Testicular development in a patient with deletion of the distal (fluorescent) segment of the Y chromosome is described. The presence of a normal dose of H-Y antigen was demonstrated by Goldberg's cytotoxicity test. It is concluded that the distal fluorescent segment of the Y chromosome is void of genes regulating H-Y antigen activity.
In previous studies we had established that emaciated women with active primary anorexia nervosa (AN) had immature 24-hr luteinizing hormone (LH) secretory patterns. In this study, we have examined the circadian LH patterns of eight women with AN who had partially or fully recovered their ideal weights. Three of the women were studied before and after weight gain and five women were studied only after the appearance of binge-eating and consequent weight gain (by history). Our findings are: (1) The adult (mature) circadian LH secretory pattern was not present in women who had partially or totally achieved ideal weight but who otherwise remained symptomatic; (2) those women who showed both weight gain and normalization of LH pattern were also symptomatically improved in other respects; (3) the degree of immaturity of pattern did not correlate reliably with the duration of illness, the degree of fatness, or the extent of deficit from ideal weight; (4) the mode of illness onset and the type of secretory pattern were not related; and (5) the return of menses did not show a simple relationship to weight, fatness, or maturity of LH pattern.
To determine the role of body fat in regulating secretion of luteinizing hormone and follicle-stimulating hormone, we measured both at 20-minute intervals for 24 hours in eight children with Turner's syndrome. The 24-hour mean luteinizing hormone levels varied from 20.2 to 70.5 mlU per milliliter. Total body weight, total body fat and percentage of body fat showed a significant negative correlation with the 24-hour mean luteinizing hormone concentrations (P less than 0.01). The 24-hour mean follicle-stimulating hormone concentrations ranged from 60.4 to 229 mlU per milliliter, with a significant negative correlation between total body fat and percentage body fat and the 24-hour mean concentrations (P less than 0.05). These negative correlations were not mediated by estrogens or androgens.
Plasma PRL was measured at 20-min intervals in six patients with Parkinson's disease under various treatment protocols. In addition, 24-h mean GH levels were measured. The results of these studies showed that two untreated patients with Parkinson's disease had normal 24-h mean PRL levels with the normal increase during sleep. During chronic treatment with L-dopa-carbidopa (Sinemet), the 24-h PRL level was 12.8 +/- 4.9 ng/ml (mean +/- SD) and there was persistence of augmented PRL secretion during sleep. The 24-h mean GH level ranged from 1.5-4.4 ng/ml, with a mean of 2.5 ng/ml. The addition of a dopamine agonist (Lergotrile mesylate) resulted in a significant (P less than 0.01) suppression of the 24-h mean PRL levels and abolition of the normal sleep augmentation after 2 weeks of therapy. This suppression was maintained in one patient who was restudied 4 months after the addition of dopamine agonist therapy to L-dopa-carbidopa. The 24-h mean GH levels did not change significantly after the addition of the dopamine agonist when compared to L-dopa-carbidopa alone. These results suggest a dichotomy between the PRL and GH responses to combined L-dopa-carbidopa and dopamine agonist therapy. In addition, the preservation of normal PRL regulation in the two untreated patients with Parkinson's disease suggests that dopaminergic neurons are not universally affected in this disorder.
The concentration of PRL was measured every 20 min for 24 h in six prepubertal and three adolescent boys. In both groups, PRL secretory episodes occurred throughout the 24-h period. In all subjects, the mean concentration of PRL was significantly higher during sleep than during wakefulness; the mean concentration during the entire 24-h period, during sleep or during wakefulness, was not different between the prepubertal subjects and the adolescents. These data suggest the absence of an ontogenetic change for PRL secretion in boys. During acute sleep-wake reversal, two of three pubertal boys showed significantly higher PRL during daytime sleep than during nocturnal wakefulness. This suggest that PRL release in adolescent boys is linked with sleep, rather than with clock time.