Factors related to grade retention in children with short stature

A recent study by Holmes et al. (1982) revealed a high degree (23%) of grade retention in a group of children with significant short stature secondary to growth hormone deficiency (GHD), constitutional delay (CD); or Turner's Syndrome (TS). Parents indicated in a free response format that 'immaturity' and 'small size' were the reasons for retention. The present follow-up study obtained academic achievement data on 47 of the 56 short children from the Holmes et al. (1982) study to assess what role academic factors, not spontaneously mentioned by parents, may have had in the retention decision. Results indicated that despite repeating a year in the primary grades, the group of retained children were still functioning 6 months below grade expectation, compared to grade appropriate achievement in the never-retained group. Parents and teachers were both accurate in their perceptions of children's academic achievement. Behavioural ratings by teachers indicated more adjustment difficulties for retained children, while parent ratings of behaviour showed a similar high level of problems for short children regardless of retention status. Although both groups of children possessed average intellectual abilities, the retained children obtained lower IQ scores than the never retained children. In summary, a majority of short children were achieving appropriate grade levels, but a substantial minority were experiencing under-achievement, behaviour problems, and grade retention, despite average intelligence.

Ultrasonic Acoustic Emissions from the Sapwood of Thuja occidentalis Measured inside a Pressure Bomb

An improved method of counting acoustic emission (AE) events from water-stressed stems of cedar (Thuja occidentalis L.) is presented. Amplified AEs are analyzed on a real time basis by a microcomputer. The instrumentation counts AE events in a fashion nearly analogous to scintillation counting of radioactive materials.The technique was applied to measuring ultrasonic AEs from the stems of cedar inside a pressure bomb. The shoots were originally fully hydrated. When the shoots are dehydrated in the bomb by application of an overpressure very few AEs were detected. When the bomb pressure is reduced after dehydration of the shoot, AE events could be detected. We conclude that ultrasonic AEs are caused by cavitation events (= structural breakdown of water columns in the tracheids of cedar) and not by the breaking of cellulose fibers in the wood.

Isolation of Chlamydia using McCoy cells and Buffalo green monkey cells

Unselected eye and genital specimens from 233 patients were cultured for Chlamydia. The isolation rates were compared using McCoy cells and Buffalo green monkey cells, both procedures being performed with and without the addition of cycloheximide and centrifugation. No significant difference was found in the isolation rates using the four methods. The characteristics of the two cell lines and the advantages of omitting cycloheximide treatment and centrifugation are discussed.

56K fibroblast protein not specific for Duchenne muscular dystrophy but for skin biopsy site

Recently, we reported the detection by two-dimensional gel electrophoresis of a 56,000 (56K)-molecular weight polypeptide that was present in cultured skin fibroblasts from normal males but was not detectable in fibroblasts from Duchenne muscular dystrophy (DMD) patients. Since then we have established that the 56K polypeptide is not present in skin fibroblasts from normal females, DMD carrier females, or in normal male fibroblasts obtained from sources other than the Repository for Mutant Human Cell Strains, Montreal. Further inquiry has led to the discovery that all the normal male fibroblast cultures obtained from the Montreal repository had been established from preputial skin. Fibroblast cultures from DMD patients, DMD carriers, as well as other normal individuals, had been derived from non-genital skin biopsies. Thus, the absence of the 56K polypeptide is not specific for DMD, but rather is related to the site of skin biopsy.

Validity of urine glucose measurements for estimating plasma glucose concentration

Both physicians and diabetic patients have traditionally relied on measurement of glycosuria as an indirect method of estimating plasma glucose concentration to guide adjustment of insulin and diet therapy. Our observations on the correlation between mean plasma glucose concentration with simultaneous urine glucose concentration or excretion rate re-emphasize the limitations of this approach. Although our observations show a significant correlation (P less than 0.0001) between plasma glucose concentration and urine glucose concentration or urine glucose excretion rate, the wide confidence limits [95% confidence limits (minimum) +/- 150 mg/dl] on plasma glucose concentration estimated from urine glucose measurements limit the clinical applicability of such estimates. Differences among subjects in the renal resorption of glucose contribute to the wide variance of estimates. However, significant variability in renal glucose resorption within individuals is documented, further reinforcing the limitations of urine glucose determinations for reliable estimates of plasma glucose concentrations. Diabetologists need to reconsider the applicability of urine glucose measurements in evaluation of adequacy of therapy and in adjustment of insulin dosage.

Hypokalemia after resuscitation from out-of-hospital ventricular fibrillation

We studied serum electrolyte levels, blood gas values, and diuretic history in 115 patients immediately after resuscitation from out-of-hospital ventricular fibrillation. Comparisons were made with 84 patients admitted for acute myocardial infarction and with 88 ambulatory patients with coronary heart disease. Admission serum potassium values of 3.60 mEq/L or lower were found in 56 (49%) of the resuscitated patients, compared with 16 (19%) and eight (9%) of the comparison groups, respectively. In the resuscitated patients, the mean serum potassium level was 3.70 +/- 0.72 (SD) mEq/L, compared with 4.09 +/- 0.66 and 4.17 +/- 0.35 mEq/L in the respective comparison groups. Reduced serum potassium concentration was not related to simple extracellular alkalosis. However, the absence of a causative relationship to diuretic use suggested that it occurred during cardiac arrest and resuscitation. Rapid correction of extracellular acidosis by bicarbonate therapy and ventilation may have produced a shift of extracellular potassium into the intracellular compartment even in the absence of extracellular alkalosis.

Methylphenidate treatment of hyperactive children: effects on the hypothalamic-pituitary-somatomedin axis

To further define the influence of methylphenidate on the growth hormone-somatomedin axis and prolactin secretion, serum growth hormone and prolactin concentrations were assessed over 24 hours and in response to provocative stimuli. The nine hyperactive subjects were all studied during methylphenidate therapy and after drug discontinuation, Diurnal patterns of growth hormone and prolactin concentrations were assessed using an ambulatory, continuous blood withdrawal procedure to ensure that activity, caloric intake, and sleep patterns mimicked normal schedules. No significant difference in integrated concentration of growth hormone, fasting somatomedin concentration, or prolactin integrated concentration was detected between subjects receiving or not receiving methylphenidate. There was a significant increase in peak growth hormone response to arginine stimulation among subjects receiving methylphenidate therapy; however, this appeared to correlate with acute methylphenidate administration. These data do not support the hypothesis that growth defects in hyperactive children treated with methylphenidate are caused by alteration in the hypothalamic-pituitary-somatomedin axis.

Proline incorporation by cultured skin fibroblasts from patients with duchenne muscular dystrophy

The incorporation of proline by cultured skin fibroblasts derived from normal individuals and patients with Duchenne muscular dystrophy (DMD) was analyzed by SDS-gel electrophoresis combined with a double-labeling procedure [Pediatr. Res., 12: 887 (1978)]. DMD fibroblasts showed increased proline incorporation into protein of approximately 130 000 daltons which could be degraded partially by collagenase. This difference was observed only at 7 days after seeding, and may be due to slight differences in growth rate as comparison of cells harvested at 2 and 7 days indicated that increased proline incorporation into high molecular weight protein was associated with day 7 cells, whether normal or DMD. During 14 days in culture normal and DMD strains did not differ in protein content, doubling time or incorporation of [3H]leucine and [14C]proline into cellular protein, although the ratio of [14C]proline to [3H]leucine incorporated was greater for DMD fibroblasts at 7 days. Incorporation of [14C]proline and [3H]leucine into extracellular proteins was greater in DMD fibroblast cultures. These subtle differences support the hypothesis that the DMD gene is expressed in fibroblasts.

Analysis of fibroblast proteins from patients with Duchenne muscular dystrophy by two-dimensional gel electrophoresis

Duchenne muscular dystrophy (DMD), the most common and severe form of the muscular dystrophies, is an X-linked inborn error of metabolism with multiple tissue involvement. Although the major pathological changes are observed in skeletal muscle, abnormalities have also been detected in the heart, nervous system, red blood cells, lymphocytes and cultured skin fibroblasts. For many reasons, such as readily available tissue material, fewer secondary changes and the potential for prenatal diagnosis, cultured skin fibroblasts should be the tissue of choice to search for the primary defect. Several abnormalities have been reported in DMD fibroblasts, suggesting that the genetic abnormality is expressed in these cells. To search for potentially mutant protein(s) we have compared the protein composition of normal and DMD fibroblasts by two-dimensional gel electrophoresis and have now found one protein spot consistently missing in DMD cells. The nature of this protein and its relation to the DMD gene are unknown.

Anorectal sepsis: microbiology in relation to fistula-in-ano

One hundred and sixty-five patients presented in a 4-year period: 68 (41.2 per cent) had had previous anorectal sepsis and in 56 of these patients (82.3 per cent) the presenting sepsis was at the site of the previous abscess. The abscesses were drained and pus was sent for culture; any fistula, if found, was laid open. A second examination under anaesthesia was performed within 7--10 days if no fistula had been found. The pus from 114 patients grew bowel-derived organisms; 62 (54.4 per cent) fistulas were found. The pus from 34 patients grew skin-derived organisms but no fistula was demonstrated in this group. It is suggested that a second examination need only be performed if culture of the pus grows bowel-derived organisms: anorectal abscesses which grow skin-derived organisms are not associated with a fistula.

Free and total insulin integrated concentrations in insulin dependent diabetes

Studies of the 24 hr insulin concentration profiles in diabetic subjects on chronic exogenous insulin have been hampered by the presence of endogenous anti-insulin antibody, which gives spurious estimates of radioimmunoassayable insulin concentrations. The introduction of polyethylene glycol precipitation of endogenous antibody has allowed development of reliable assays for determination of free and total insulin concentration in subjects on insulin therapy. This article reports our observations of plasma free and total insulin concentration in 50 Type I and Type II ambulatory insulin dependent diabetics, utilizing a continuous 24 hr blood withdrawal technique. In response to exogenous insulin, study subjects had marked elevations in insulin concentrations compared to controls. Mean free insulin integrated concentration was 3.5-fold higher in diabetics than nondiabetics. Mean total insulin integrated concentration was 868 microunits/ml, more than 20 times in excess of total insulin concentration in nondiabetics. There was a wide range among diabetics in the percentage of total insulin in the free insulin fraction. Neither free nor total insulin integrated concentration correlated with dose of exogenous insulin. Free and total insulin concentration profiles showed a limited range of variation in insulin concentration during the 24 hr of study, no subject having a profile that mimicked that observed in nondiabetic subjects. Glucose integrated concentration showed no correlation with free insulin integrated concentration, however, it did correlate inversely with the percentage of total insulin in the free insulin fraction. These data emphasize the difficulty in establishing normal patterns of insulin among diabetic subjects on conventional subcutaneous insulin therapy.

Biochemical specificity of septal hyperreactivity: a behavioral discrimination

Intra-septal injections of specific monoamine and cell body neurotoxins were used to determine the anatomical and biochemical elements critical to both short and longer term changes in reactivity normally seen after septal lesions. A multivariate discrimination performed on the basis of tactile, foot-shock and heat responsiveness revealed that septal lesions have a unique effect not accounted for by specific monoamine induced degeneration. Injections of 6-hydroxydopa and monosodium glutamate had slight effects on heat and shock responsiveness not at all comparable in degree or kind to septal lesion effects. Decreased hippocampal, but not hypothalamic, levels of norepinephrine may be associated with the longer term increased responsiveness to shock and heat in animals with septal lesions.

Differential distribution of norepinephrine and serotonin along the dorsal-ventral axis of the hippocampal formation

Norepinephrine (NE) and Serotonin (5-HT) are differentially distributed along the dorsal-ventral axis of the Hippocampal Formation (HF). A kinetic analysis of the uptake of labeled NE and 5-HT was performed to assess the relative density of nerve terminals which accumulate NE and 5-HT (Vmax) and the apparent affinity for uptake (Km). The results reveal a greater density of NE and 5-HT terminals in the ventral HF and a higher Km for 5-HT uptake in the dorsal HF. The results are discussed in terms of potential explanation of reported differences following independent manipulation of the dorsal and ventral hippocampal formation.

Cardiac function in primary hypothyroidism

Cardiac chamber dimensions and myocardial function were studied in 15 children with primary hypothyroidism prior to and after thyroxine therapy. Small pericardial effusions were detected in 11 of 15 subjects before therapy, which resolved in nine of 11 subjects after initiation of thyroxine replacement. There was no association between the severity of the thyroid failure and the presence of effusion, and no evidence of cardiac compromise due to effusions. No significant abnormality in cardiac chamber or myocardial dimensions, systolic time intervals, or indices of myocardial contractility was detected among the hypothyroid children as compared with a normal population. Neither myocardial dimensions nor contractility indices changed significantly on reestablishment of normal thyroxine concentrations with exogenous hormone. These data refute the existence of a myocardiopathy associated with hypothyroidism in children.

Integrated concentration of growth hormone in juvenile-onset diabetes

Twenty-four-hour patterns of plasma growth hormone concentrations were evaluated during 50 studies of 42 subjects with juvenile-onset diabetes mellitus. Blood was sampled continuously over 24 h using a portable peristaltic pump under conditions in which subjects remained ambulatory and maintained their daily dietary and insulin regimens. All diabetics showed diurnal patterns characterized by frequent episodes of secretion of growth hormone. The mean 24-h concentration of growth hormone, designated the integrated concentration, was significantly higher among juvenile-onset diabetics (P less than 0.001) than it was in age- and sex-matched nondiabetic populations. Juvenile-onset diabetics younger than 20 yr had significantly higher (P less than 0.005) growth hormone integrated concentrations than did older juvenile-onset diabetics. There was no statistically significant correlation between the integrated concentrations of glucose and growth hormone; thus, the study failed to provide us with support for the hypothesis that elevated growth hormone concentrations in diabetics are a consequence of hyperglycemia. Variability of diurnal glucose concentrations was positively correlated (P less than 0.015) with the growth hormone integrated concentration among juvenile-onset diabetics. Our observations indicate that rapid declines in plasma glucose concentration or episodes of absolute hypoglycemia were significant factors, contributing to both the elevated integrated concentration and the secretory spiking of growth hormone observed in the diabetic population.

Morphine injections into the periaqueductal-periventricular gray attenuate septal hyperreactivity

Animals with septal lesion-induced reactivity were injected with 2 dose levels of morphine in the periaqueductal-periventricular gray. Both doses of morphine transiently attenuated the reactivity. Naloxone injected IP significantly antagonized the morphine attenuation of the septal-lesion induced reactivity.

Serum cholesterol and triglycerides in children with growth hormone deficiency

To test the hypothesis that hyperlipidemia is characteristic of growth hormone deficiency in childhood, we have measured serum cholesterol and triglyceride concentrations in 24 euthyroid children with growth hormone deficiency. Although modest elevations of cholesterol and/or triglyceride above the 95th percentile for age, race, and sex were present in 46% of the children studied, the mean (+/- 1 SD) cholesterol of 173 +/- 36 mg/dl and the mean triglyceride of 80 +/- 42 mg/dl were not significantly different from published normal mean values. Administration of human growth hormone for 4 mo to 15 of these subjects did not alter these mean cholesterol and triglyceride values, but did result in a marked improvement in the growth rate. Some individuals (n = 6) with a subnormal growth response to therapy and/or a low serum thyroxine and high serum cholesterol were treated for an additional 4 mo with growth hormone and thyroid hormone together. There was a statistically significant decrement in serum cholesterol in this group. We conclude that modest hyperlipidemia does exist in some children with growth hormone deficiency. Subclinical hypothyroidism may play a role in the hypercholesterolemia of some children, as may growth hormone deficiency itself. Any association of growth hormone and lipid metabolism remains to be clarified.

Triglyceride concentrations: the disaccharide effect

The mean 24-hour or integrated concentration of triglyceride is significantly higher when dietary sucrose is provided rather than an equivalent amount of its component monosaccharides, glucose and fructose. In contrast, the plasma triglyceride concentration after a 12-hour fast is not significantly different.