Avoidance of Cow's Milk-Based Formula for At-Risk Infants Does Not Reduce Development of Celiac Disease: A Randomized Controlled Trial

BACKGROUND & AIMS

Feeding during the first months of life might affect risk for celiac disease. Individuals with celiac disease or type 1 diabetes have been reported to have high titers of antibodies against cow's milk proteins. Avoidance of cow's milk-based formula for infants with genetic susceptibility for type 1 diabetes reduced the cumulative incidence of diabetes-associated autoantibodies. We performed a randomized controlled trial in the same population to study whether weaning to an extensively hydrolyzed formula reduced the risk of celiac disease autoimmunity or celiac disease.

METHODS

We performed a double-blind controlled trial of 230 infants with HLA-defined predisposition to type 1 diabetes and at least 1 family member with type 1 diabetes. The infants were randomly assigned to groups fed a casein hydrolysate formula (n = 113) or a conventional formula (control, n = 117) whenever breast milk was not available during the first 6-8 months of life. Serum samples were collected over a median time period of 10 years and analyzed for antibodies to tissue transglutaminase (anti-TG2A) using a radiobinding assay, to endomysium using an immunofluorescence assay, and antibodies to a deamidated gliadine peptide using an immunofluorometry assay. Duodenal biopsies were collected if levels of anti-TG2A exceeded 20 relative units. Cow's milk antibodies were measured during the first 2 years of life.

RESULTS

Of the 189 participants analyzed for anti-TG2A, 25 (13.2%) tested positive. Of the 230 study participants observed, 10 (4.3%) were diagnosed with celiac disease. We did not find any significant differences at the cumulative incidence of anti-TG2A positivity (hazard ratio, 1.14; 95% confidence interval, 0.51-2.54) or celiac disease (hazard ratio, 4.13; 95% confidence interval, 0.81-21.02) between the casein hydrolysate and cow's milk groups. Children who developed celiac disease had increased titers of cow's milk antibodies before the appearance of anti-TG2A or celiac disease.

CONCLUSIONS

In a randomized controlled trial of 230 infants with genetic risk factors for celiac disease, we did not find evidence that weaning to a diet of extensively hydrolyzed formula compared with cow's milk-based formula would decrease the risk for celiac disease later in life. Increased titers of cow's milk antibody before anti-TG2A and celiac disease indicates that subjects with celiac disease might have increased intestinal permeability in early life. ClinicalTrials.gov Number: NCT00570102.

Molecular mechanisms controlling the rate and specificity of catechol O-methylation by human soluble catechol O-methyltransferase

Molecular mechanisms determining the turn-over rate and specificity of catechol O-methylation were studied by combining enzyme kinetic measurements, computational modeling of substrate properties and fitting ligands in a 3D model of the active site of the enzyme. Enzyme kinetic measurements were carried out for 46 compounds, including most clinically used catechol drugs, by using recombinant human soluble catechol O-methyltransferase (COMT). The most important mechanism decreasing the turnover rate and increasing affinity was the electron withdrawing effect of substituents. Several other mechanisms by which substituents affected reactivity and affinity were identified. Highest turnover rates were determined for unsubstituted catechol and pyrogallol. Pyrogallol derivatives generally seemed to be more specific substrates than catechols. Catecholestrogens were the most specific endogenous substrates, whereas catecholamines were rather poor substrates. Among the catechol drugs used in the L-DOPA treatment of Parkinson's disease, the COMT inhibitors entacapone and tolcapone were not methylated, whereas the DOPA decarboxylase inhibitor benserazide was 15 times more specific substrate than L-DOPA, the target of COMT inhibition. The structure-activity relationships found allow the prediction of reactivity, affinity, and specificity with useful accuracy for catechols with a wide range of structures and properties. The knowledge can be used in the evaluation of metabolic interactions of endogenous catechols, drugs and dietary catechols, and in the designing of drugs with the catechol pharmacophore.

The specificity of glucuronidation of entacapone and tolcapone by recombinant human UDP-glucuronosyltransferases

The COMT inhibitors entacapone and tolcapone are rapidly metabolized in vivo, mainly by glucuronidation. In this work, the main UGT isoforms responsible for their glucuronidation in vitro were characterized by using a subset of representative cloned and expressed human UGT isoforms. Entacapone in particular was seen to be an exceptionally good substrate for UGT1A9 with an even higher reaction velocity value at 500 microM substrate concentration compared with that of the commonly used substrate, propofol (1.3 and 0.78 nmol min(-1) mg(-1), respectively). Neither entacapone nor tolcapone was glucuronidated by UGT1A6. Tolcapone was not detectably glucuronidated by UGT1A1, and the rate of glucuronidation of entacapone was also low by this isoform. However, UGT1A1 was the only UGT capable of catalyzing the formation of two glucuronides of the catecholic entacapone. Both COMT inhibitors were glucuronidated at low rates by the representative members of the UGT2B family, UGT2B7 and UGT2B15. Michaelis-Menten parameters were determined for entacapone and tolcapone using recombinant human UGT isoforms and human liver microsomes to compare the kinetic properties of the two COMT inhibitors. The kinetic data illustrates that UGT1A9 exhibited a much greater rate of glucuronidation and a far lower K(m) value for both entacapone and tolcapone than UGT2B15 and UGT2B7 whose contribution is minor by comparison. Entacapone showed a 3 to 4 times higher V(max) value and a 4 to 6 times lower K(m) value compared with those of tolcapone both in UGT1A9 cell lysates and in human liver microsomes.

Production of human UDP-glucuronosyltransferases 1A6 and 1A9 using the Semliki Forest virus expression system

Human UDP-glucuronosyltransferases (UGTs) 1A6 and 1A9 were expressed using Semliki Forest virus (SFV) vectors. Infection of chinese hamster lung fibroblast V79 cells with recombinant SFV-UGT viruses resulted in efficient protein expression as detected by metabolic labeling, Western blot analyses and immunofluorescence microscopy. The expression of UGT 1A6 and UGT1A9 in the SFV-infected cells was approximately two fold higher than in a stable V79 cell line. No UGT signal was detected in noninfected cells. In addition, SFV-UGT viruses also efficiently infected other mammalian cells, such as baby hamster kidney (BHK), chinese hamster ovary (CHO) and human lung (WI-26 VA4) cells leading to high production of recombinant enzyme. The measurement of enzyme activities and kinetic parameters using p-nitrophenol and nitrocatechol (entacapone) as substrates for UGT1A6 and UGT1A9, respectively, showed that the overall kinetic properties of the enzymes produced by the two systems were similar. We conclude that the SFV expression system represents an efficient, fast and versatile method for production of metabolic enzymes for in vitro assays.

Nephrectomy in severe hypertension

We describe a 12-year-old girl who died due to hypertensive encephalopathy and a 7-year-old boy with a favorable outcome after bilateral nephrectomy. Both had end-stage renal disease. Nephrectomy should be considered as a possible treatment of severe hypertension even without end-stage renal disease, if the patient has symptoms of hypertensive encephalopathy.

Radiochemical high-performance liquid chromatographic assay for the determination of catechol O-methyltransferase activity towards various substrates

A new chromatographic catechol O-methyltransferase (COMT) assay based on S-adenosyl-L-[methyl-14C]methionine and on-line radioactivity detection was developed. With minor modifications in the mobile phase composition the methylation velocities for 30 structurally diverse compounds including simple catechols, neurotransmitters, catecholestrogens and catecholic drugs could be measured using human and rat recombinant soluble COMT. The enzymes showed very similar substrate selectivities. The radiochemical method was validated using 3,4-dihydroxybenzoic acid as a model substrate and it was shown that accurate and reproducible methylation velocity values could be achieved for both of the catecholic hydroxyls. The method proved to be suited for determining the enzyme kinetic parameters and can probably be further used for gathering enzyme kinetic data on differentially substituted catechols in order to construct proper structure-activity relationships for COMT.

Glucuronidation of entacapone, nitecapone, tolcapone, and some other nitrocatechols by rat liver microsomes

PURPOSE

Nitrocatechol COMT inhibitors are a new class of bioactive compounds, for which glucuronidation is the most important metabolic pathway. The objective was to characterize the enzyme kinetics of nitrocatechol glucuronidation to improve the understanding and predicting of the pharmacokinetic behavior of this class of compounds.

METHODS

The glucuronidation kinetics of seven nitrocatechols and 4-nitrophenol, the reference substrate for phenol UDP-glucuronosyltransferase activity, was measured in liver microsomes from creosote-treated rats and determined by non-linear fitting of the experimental data to the Michaelis-Menten equation. A new method that combined densitometric and radioactivity measurement of the glucuronides separated by HPTLC was developed for the quantification.

RESULTS

Apparent K(m) values for the nitrocatechols varied greatly depending on substitution pattern being comparable with 4-nitrophenol (0.11 mM) only in the case of 4-nitrocatechol (0.19 mM). Simple nitrocatechols showed two-fold Vmax values compared with 4-nitrophenol (68.6 nmol min-1 mg-1), while all disubstituted catechols exhibited much lower glucuronidation rate. Vmax/K(m) values were about 10 times higher for monosubstituted catechols compared to disubstituted ones. The kinetic parameters for COMT inhibitors were in the following order: K(m) nitecapone > > entacapone > tolcapone; Vmax nitecapone > entacapone > tolcapone; Vmax/K(m) tolcapone > nitecapone > entacapone.

CONCLUSIONS

Nitrocatechols can in principle be good substrates of UGTs. However, substituents may have a remarkable effect on the enzyme kinetic parameters. The different behaviour of nitecapone compared to the other COMT inhibitors may be due to its hydrophilic 5-substituent. The longer elimination half-life of tolcapone in vivo compared to entacapone could not be explained by glucuronidation kinetics in vitro.

The state of young adults with juvenile onset diabetes

Childhood diabetes is most common in Nordic countries and its incidence is rising. In order to evaluate the efficacy of health care follow-up units we investigated physical and psychosocial health status, mode of coping with adult health care and medical treatment in 82 young adults (46 males, 36 females, average age 20.9 yr. and average disease duration 12.7 yr.) who had had diabetes since childhood. All but three of them made regular visits to a health care facility but only 27% monitored blood glucose reasonably well. Only eight percent had a HbA1 concentration within the optimal range, and half had a inappropriate level. Half of the subjects with high HbA1 in adolescence had managed to improve it since leaving the paediatric unit. The most common clinical findings were lipohypertrophy and depressed patellar and achillar reflexes. Up to 70% had background retinopathy and 10% proliferative retinopathy, while two thirds (62%) had depressed conduction velocity of the peroneal nerve. Clinically significant psychiatric problems were found in 17% of the patients, depression being the most prominent feature. Among the social characteristics, delayed social maturation and lack of vocational education were found to be more common than in age-matched controls. One in three exhibited a major overt physical problem and one in five a major psychosocial problem. In conclusion, whatever the health care follow-up unit attended by young adults with diabetes since childhood, the teams face health problems that differ totally from one individual to another. It is important at this transitional age to focus attention in a broad-minded manner on the many factors complicating diabetes or affecting good compliance with treatment.

Characterization of 1-hydroxypyrene as a novel marker substrate of 3-methylcholanthrene-inducible phenol UDP-glucuronosyltransferase(s)

Rats were treated with acetone, pyrazole, phenobarbital, 4,4'-methylenebis-(2-chloroaniline) (MOCA), 3-methylcholanthrene, creosote oil, or a mixture of polychlorinated biphenyls (Aroclor 1254) to study the inducibility and enzyme kinetics of UDP-glucuronosyltransferases towards 1-hydroxypyrene, which is a human metabolite and a urinary biomarker of exposure to pyrene. The rate of 1-hydroxypyrene glucuronidation was analyzed in rat liver microsomes by a fluorometric HPLC assay of the formed glucuronide. The apparent K(m) and Vmax values in untreated controls (K(m) = 0.27 mM; Vmax = 31 nmol/min./mg protein) did not differ markedly from those in rats treated with acetone, pyrazole or phenobarbital, whereas the significantly decreased K(m) and increased Vmax values of the rats treated with the carcinogenic chemicals, MOCA (0.11; 51), creosote (0.06; 137), 3-methylcholanthrene (0.07; 141) or the Aroclor-1254 polychlorinated biphenyl (PCB) mixture (0.08; 226), implicated major changes in the hepatic expression of UDP-glucuronosyltransferases. 1-Hydroxypyrene proved to be a high affinity substrate and a sensitive marker of the polycyclic aromatic hydrocarbon (PAH) metabolizing UDP-glucuronosyltransferase(s). Catalytically, the most efficient isoforms were induced in creosote, 3-methylcholanthrene and PCB-treated rats showing Vmax/K(m) ratios which were 22-27 times greater than in untreated controls. Our findings suggest the existence of a 3-methylcholanthrene type inducible and a functionally efficient low-K(m)/ high-Vmax form(s) of UDP-glucuronosyltransferase(s) that detoxify 1-hydroxypyrene and probably other polycyclic aromatic hydrocarbons as well.

Medical student abuse: an international phenomenon

OBJECTIVE

To evaluate the prevalence of physical and psychological mistreatment of medical students at two medical schools in Finland.

STUDY DESIGN AND SETTING

To enable comparison between Finnish and American students, we used the American Medical Association's Office of Education Research questionnaire.

RESULTS

Three of every four students surveyed reported experiencing some kind of mistreatment during their medical education. Students most commonly reported sexual mistreatment, usually as slurs and sexual discrimination, from classmates, preclinical teachers, clinical teachers, clinicians, nurses, and patients. Other forms of verbal abuse, psychological mistreatment, and physical threats were also reported.

CONCLUSIONS

All forms of mistreatment were reported occurring less frequently than in the United States; still, the level of such behavior was high. The results suggest the need for more international awareness and debate regarding the habits and behavior of teaching staff in medical schools.

Association of recurrent acute otitis media with nasopharynx dimensions in children

The purpose of this study was to evaluate the hypothesis that the nasopharyngeal anatomy has influence in the risk of recurrent acute otitis media (AOM) attacks. We analysed the occurrence of acute otitis media in 238 healthy schoolchildren who were X-rayed for orthodontic purposes. Six measurements reflecting the size and shape of the bony nasopharynx were recorded from lateral cephalograms. The means for almost all the dimensions of the bony nasopharynx measured were smaller in the children with two or more attacks of AOM in their history than in those with no attack or only one attack. Logistic multivariate modelling showed the distance from the posterior nasal spine to the sella-basion line to be a significant risk factor for recurrent otitis media in girls (difference 1.0 mm; 95 per cent confidence interval 0.1-2.0 mm; p = 0.04) and the shape of the nasopharynx (roundness) in boys (difference 1.9 mm; 95 per cent confidence interval 0.1-4.0 mm; p = 0.01). Measuring the nasopharyngeal bony dimensions may help to identify those children with a risk of recurrent otitis media, at whom prophylactic therapies should be targeted.

Ocular complications in young adults with insulin-dependent diabetes mellitus since childhood

A cross-sectional study in 80 insulin-dependent diabetic patients born 1963-1968 who experienced the onset of diabetes before 15 years of age showed that at a mean age of 21.6 (range 17-25) years and after a mean duration of diabetes of 13.3 (range 6-24) years, 80% of the patients had retinopathy: 70% had background and 10% proliferative changes. Retinopathy correlated with the duration of the diabetes and poor glucose control at 15 years of age but not with the actual level of glycated haemoglobin. The severity of retinopathy was worse in women than in men. One patient (1.2%) was blind. Two patients had had cataract operations and 66% had myopic refraction in one or both eyes. In 61 patients a further period of ophthalmological follow-up of 3-4 years was included. After 20 years of diabetes, all had retinopathy and 29% had proliferative changes: 33% had received laser treatment after 8-27 (mean 16.1) years of diabetes. Altogether, 2 patients (2.5% of the original series) were blind. For prevention of diabetic retinopathy and blindness, good glucose control from puberty and careful ophthalmological follow-up after transfer of the patient from paediatric to adult diabetes care play major roles.

Social maturation in juvenile onset diabetes

We re-examined a group of 82 (36F, 46M) patients with juvenile onset diabetes at the age of 19-25 years and compared their social outcome in early adulthood with that of a group of 211 randomly selected controls. Their basic school achievements and vocational or higher education were covered in detail in an interview which also included data on their employment status. Various descriptors of social situation and social maturation assessed in a separate interview formed a social maturation index. Relations between factors probably affecting social maturation and this index were analysed. The average marks scored by the diabetics in Finnish comprehensive schools were significantly lower than those of the controls. High school, vocational and commercial schools were discontinued more often by the patient group. Diabetics (27%) and controls (35%) continued their studies equally often in various vocational high schools or universities. Presently, 17% of the diabetics and 11% of the controls had no vocational education or were not on their way to gaining it. Working experience, employment status and unemployment were similar in both groups, but diabetics were more often employed in public service and commerce. At the time of the study the diabetics were significantly more often unmarried and living in the same household as their parents compared with the controls. Other parameters also indicated difficulties in the diabetic group in separating from parents. The overall social maturation index showed poor social maturation in diabetics more often than in the controls. Neither social background, education nor sex were related to poor social maturation. It is concluded that having diabetes delays social maturation.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemic nephropathy in children

Epidemic nephropathy, a form of hemorrhagic fever with renal syndrome, caused by the Puumala serotype of hantaviruses and occurring endemically in northern Scandinavia, was studied in 13 children. The clinical symptoms and signs were somewhat different from those reported in adults; none of our patients had hemorrhagic manifestations despite low thrombocyte counts. The most common presenting symptoms were fever, abdominal pain, and renal tenderness with oliguria followed by polyuria. The predominant laboratory findings were proteinuria and/or hematuria and elevated serum creatinine levels. Thrombocytopenia was a constant finding in the children in whom thrombocyte count was obtained. Most children had a decreased serum sodium concentration during the oliguric phase of the disease. All the children recovered, with no long-term renal disease. Epidemic nephropathy is an important alternative for differential diagnosis in children with findings suggesting nephritis, especially in endemic areas. An awareness and knowledge of this syndrome and an ability to diagnose it by means of a specific antibody measurement will probably improve our understanding of its epidemiologic features in children.

Serum insulin and other cardiovascular risk indicators in children, adolescents and young adults

We wanted to determine the levels of fasting serum insulin during growth, the tracking of serum insulin, and the correlation of serum insulin with other coronary heart disease risk indicators in children and young adults. In 1986 2433 subjects, aged nine to 24 were studied, and insulin data were available from the same population in 1980 and 1983. Serum insulin levels showed a peak during puberty in both sexes and the decline in insulin continued after the age of 21. Tracking of serum insulin was only moderate, especially in females and young boys. Serum insulin correlated positively with body mass index, concentrations of serum triglycerides, and blood pressure, and inversely with the concentration of high density lipoprotein cholesterol. High triglycerides, high systolic blood pressure, and low level of high density lipoprotein cholesterol clustered among subjects within the highest insulin quartile. Our results suggest that the insulin resistance phenomenon, caused mainly by obesity and leading to unfavourable levels of other coronary heart disease risk indicators, is already developing in children and young adults. This suggests that preventing obesity in early life is important.

Effect of once-a-week training program on physical fitness and metabolic control in children with IDDM

To examine whether a physical activity program could improve physical fitness and glycemic control, 32 children and adolescents with insulin-dependent diabetes mellitus (IDDM) were examined before the program and 3 mo later. Fifty percent of the subjects (n = 16) participated in the training for 1 h/wk (exercise group), whereas the remaining subjects were engaged in nonphysical activities for an equal amount of time (nonexercise group). Age of the subjects ranged from 8.2 to 16.9 yr, (mean 11.9 yr), with mean duration of diabetes 0.6-13.1 yr (5.2 yr). During the 3-mo program peak oxygen consumption (VO2) rose from 40.0 to 43.8 ml.min-1.m-2 (P less than .01) in the exercise group but only by 1.3 ml.min-1.m-2 in the nonexercise group (NS). Metabolic control did not improve in either group, with glycosylated hemoglobin level rising from 9.8 to 10.5% (P less than .01) in the exercise group and from 9.4 to 9.7% (NS) in the control group. When subjects were stratified according to their participation, metabolic control was significantly better among diabetic subjects participating frequently (greater than or equal to 11 of 13 sessions) than among those participating infrequently (less than 11 of 13 sessions), regardless of the type of activity. It was concluded that a training program of 1 h/wk for 3 mo does improve physical fitness but not the metabolic control of diabetes. On the other hand, glycemic control appears to be best among diabetic subjects who are motivated to participate in any kind of program related to the treatment of their disease.

Nocturnal release of immunoreactive growth hormone-releasing hormone and growth hormone in normal children

To evaluate the role of growth hormone-releasing hormone (GHRH) in the physiologic release of growth hormone (GH) we studied the nocturnal secretion of immunoreactive GHRH (ir-GHRH) and its relationship to GH release and various stages of sleep in six prepubertal (three boys) and six pubertal children (two boys) with normal stature. Their ages ranged from 8.1 to 14.9 yr and their bone ages from 6.8 to 14.8 yr. Blood was withdrawn continuously between 2200-0600 h at a constant rate of 5 mL/20 min. The EEG was simultaneously registered. The ir-GHRH and GH data were analyzed by a discrete-pulse detection algorithm (Pulsar). The number of nocturnal ir-GHRH pulses varied from 0-8 (median 7) and the number of GH peaks from 2-6 (median 3). Pubertal children had significantly more (p less than 0.05) ir-GHRH pulses and the pulse amplitude was higher (p less than 0.05) than in the prepubertal children. There were no significant differences in the GH parameters between the two groups. The ir-GHRH peaks were not significantly related to any specific sleep stage. The majority of the GH pulses (71%) were associated with slow wave sleep (p less than 0.001). Two-thirds (69%) of the GHRH peaks preceded closely or coincided with GH pulses (p less than 0.02). Pubertal subjects had more isolated ir-GHRH peaks than prepubertal children (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular risk in young Finns, results from the second follow-up study

A comprehensive study of coronary heart disease (CHD) risk factors and their determinants in children and adolescents in Finland was initiated in the late 1970's. The main cross-sectional study was undertaken in 1980, with 3596 subjects aged from 3 to 18 years participating. The first follow-up study was carried out in 1983, and the second in 1986. The present report describes briefly some findings in 2746 children and young adults, aged 9, 12, 15, 18, 21 and 24 years, participating in 1986. Serum total cholesterol concentrations, mean (SD), ranged between 4.31 (0.73) and 4.91 (0.81) mmol/l in boys, and between 4.73 (0.85) and 5.09 (0.82) mmol/l in girls, respectively. Mean serum cholesterol values had fallen from 1980 to 1986 by 5.4% in such age cohorts, which had been included in all three studies. Fat content in the diet remained unchanged (38 E %), whereas the mean P/S ratio increased from 0.24 in 1980 to 0.31 in 1986. Young Finns from East Finland had a higher somatic risk index than those from West Finland (P greater than 0.001). The clustering of somatic risk factors was stable between 1980 and 1986. Further follow-up of the cohorts will, we hope, provide the tools for implementing primary prevention of CHD in Finland.

Reduced insulin removal and erythrocyte insulin binding in obese children

To study the relationship between childhood obesity, weight loss, hyperinsulinaemia and the erythrocyte insulin receptor, we measured the plasma concentrations of immunoreactive insulin (IRI) and C-peptide and the binding of 125I-insulin to erythrocytes in 12 obese children with a mean age +/- SD of 11.4 +/- 2.5 years and a mean relative weight score +/- SD of 4.8 +/- 1.4 and 12 age-matched normal-weight children. Eight obese children were re-evaluated after 1 year's participation in a weight reduction programme. The obese children had higher fasting plasma concentrations of IRI (P less than 0.01) and C-peptide (P less than 0.05) and a lower C-peptide to IRI molar ratio (P less than 0.01) than the normal-weight children. The obese children had in addition a reduced erythrocyte insulin binding (P less than 0.05 or less) over the physiological range of circulating insulin concentration. There was a negative correlation (r = -0.60; P less than 0.01) between the insulin tracer binding and the relative weight. The weight reduction programme resulted in a decrease of 1.0 SD (P less than 0.05) in the mean relative weight score. At the end of the therapy the obese children had lower fasting blood glucose levels (P less than 0.05) and lower plasma IRI concentrations at 90 min (P less than 0.05) after an oral glucose load than at the onset of therapy. There were no significant differences between the insulin binding characteristics at the commencement and at the end of the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Variable plasma growth hormone (GH)-releasing hormone and GH responses to clonidine, L-dopa, and insulin in normal men

The effects of synthetic GHRH-(1-44) (1 microgram/kg, iv), clonidine (0.15 mg/m2, orally), L-dopa (0.5 g, orally), and insulin (0.1 IU/kg, iv) on plasma immunoreactive (ir) GHRH and GH levels were determined in normal men, aged 31-46 yr (n = 4-8). In addition, plasma ir-GHRH and GH concentrations were determined before and after the administration of clonidine in six younger men, aged 19-25 yr. GHRH was extracted from plasma using Sep-Pak C18 cartridges and measured with a mid-portion-specific GHRH antiserum. The mean plasma ir-GHRH and GH levels ranged from 9-11 ng/L and 0.5-1.5 microgram/L, respectively, in the older men during a 2-h control study. After GHRH administration, the mean plasma ir-GHRH concentration increased to a peak of 512.5 ng/L at 3 min and GH to a peak of 9.2 micrograms/L at 10 min. Clonidine resulted in a significant increase in mean plasma GH levels (P less than 0.05) in the younger men, but not in the older men. Plasma ir-GHRH concentrations did not change after clonidine. L-Dopa increased plasma ir-GHRH at 60 min (P less than 0.05) and GH at 60-120 min (P less than 0.05). Insulin-induced hypoglycemia increased plasma GH levels (to a mean of 23.8 micrograms/L at 60 min; P less than 0.001), whereas plasma ir-GHRH levels did not change. We conclude that the mechanisms of the various GH stimulation tests differ. Some GH responses, including those induced by insulin, do not appear to be mediated by GHRH.

Postnatal decrease in insulin binding to erythrocytes in infants of diabetic mothers

To clarify the role of insulin receptors in the macrosomia and the tendency to hypoglycemia in infants of mothers with insulin-treated diabetes mellitus (IDM) we studied insulin binding in erythrocytes from mixed umbilical blood and from peripheral venous blood collected when the infants were 3-14 days old. Normal infants were matched for gestational and postnatal age. The IDM infants were macrosomic, with significantly higher birth weights relative to gestational age than the control infants. Plasma free insulin concentrations in cord blood were 15-fold higher in the IDM than in the normal infants and more than 3-fold higher in the peripheral venous blood at the median age of 4 days. Hypoglycemia occurred in 12 of the 17 IDM and in none of the normal infants. In umbilical blood insulin binding to erythrocytes was similar in the IDM and normal infants. In both groups insulin binding decreased during the first postnatal weeks, but the decrease was significantly greater in the IDM than in the normal infants. The decrease in insulin binding to erythrocytes was a consequence of decreased receptor affinity as well as decreased receptor concentration in the IDM infants, but was mainly due to decreased receptor concentration in the normal infants. We conclude that insulin binding to its erythrocyte receptor in cord blood in IDM infants is similar to that in normal infants in spite of the simultaneous gross hyperinsulinemia in the IDM infants. The resulting increase in insulin action would then contribute to the tendency toward hypoglycemia and may be partly responsible for the macrosomia in IDM infants. The marked postnatal decrease in insulin binding in IDM infants is a possible explanation for their diminishing risk of hypoglycemia after the first few days of life in spite of persisting hyperinsulinemia.

Serum insulin-releasing activity and the Prader-Willi syndrome

Pathogenesis and etiology of the various clinical features of the Prader-Willi syndrome (PWS) are not completely understood. There is evidence suggesting a hypothalamic abnormality leading to hypogonadism in this syndrome. To test the possible hypothalamic involvement in the pathogenesis of obesity in these patients we studied the sera of 5 patients with PWS for insulin-releasing activity of possible hypothalamic origin. In addition 4 patients with a PWS-like syndrome and 6 obese patients with signs of central nervous system damage were studied. All five patients with PWS showed significant insulin-releasing activity in their sera. Of the four patients with PWS-like symptoms three showed similar activity while three of the obese patients with central nervous system damage had this activity in their sera. Serum insulin-releasing activity has been shown earlier to be associated with childhood obesity and it could play a role in the pathogenesis of obesity in PWS.

Insulinotropic activity in the serum of obese and nonobese infants and children

The ability of a serum fraction, mol wt 1000-5000, to stimulate insulin release in vitro was studied in 123 obese and normal weight children aged 0-17 yr. The sera were fractionated by serial molecular filtration after treatment with urea. Stimulation of insulin release was determined with a bioassay using isolated rat islets in perifusion. The islet-stimulating activity was found in all obese children less than the age of 10 yr and in the majority of the obese children older than 10 yr of age. In normal weight children the activity was also found in the majority of infants, but was infrequent in older children. The serum islet-stimulating activity was positively correlated with the duration and degree of obesity and with linear growth rate. The molecular structure and origin of the insulinogenic activity in the serum is still unknown. In high-performance liquid chromatography it has the same elution characteristics as the hypothalamic insulin-glucagon liberin. The present results suggest a role for the serum islet-stimulating activity in the pathogenesis of obesity.

Erythrocyte insulin binding in preterm newborn infants

To characterize the erythrocyte insulin receptor in newborn infants we studied the binding of 125I-insulin to the erythrocytes from 42 preterm infants (14 at birth, 14 aged 2-7 days, and 14 aged 8-16 days) with a mean gestational age of 34.1 wk, and from 32 term infants (16 at birth and 16 aged 2-7 days). The insulin binding to cord blood erythrocytes from preterm infants was significantly higher than that of cord blood cells from term infants and to postnatal cells from preterm as well as term infants. The erythrocytes from preterm infants aged 2-7 days bound more insulin than cells from preterm infants aged 8-16 days. The maximum insulin binding (specific insulin binding at tracer concentration of insulin) correlated negatively with the gestational age both at birth and over the 1st postnatal wk. In the preterm infants there was a strong negative correlation between the maximum insulin binding and postnatal age. The enhanced insulin binding to cord blood erythrocytes from preterm infants was due to both an increased receptor concentration and a high affinity for insulin. The increased affinity persisted over the 1st wk of life. In preterm infants older than 1 wk the insulin binding characteristics were basically similar to those in term newborn infants. In all infants studied the receptor concentration seemed to be postnatal age dependent while the receptor affinity was gestational age dependent. No correlation was found between the insulin binding data and the plasma concentrations of immunoreactive insulin or C-peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Atherosclerosis precursors in Finnish children and adolescents. VII. Serum immunoreactive insulin

In the Finnish Multicentre Study of the risk factors of coronary heart disease serum immunoreactive insulin (IRI) was measured in 3,486 children and adolescents aged 3-18 years. Serum IRI increased with age till the age of 15 years in both sexes. The increase in serum IRI levelled off with the progression of pubertal development. Serum IRI levels were higher in girls than in boys from the age of 6 years onwards. Comparison of serum IRI gave identical results from eastern and western parts of the country. Serum IRI correlated positively with skinfold thickness, weight, relative weight and body mass index in all age groups except the 3-year-old children.

Partial purification of an insulin-releasing activity in human serum

An activity that enhances insulin release from perifused rat pancreatic islets has recently been isolated from human serum fractions (molecular weight 1,000-5,000 daltons). To characterize this activity we have studied the insulin-releasing effect of serum subfractions from obese and non-obese children obtained by reversed-phase high-performance liquid chromatography (HPLC). The serum insulin-releasing activity eluted in the HPLC system at 12-13 minutes, which corresponded to the retention time of the tridecapeptide insulin-glucagon liberin isolated from bovine hypothalamus. Insulin-releasing activity was found in serum subfractions from both obese and normal-weight children. The relative insulin-releasing potency of the active subfractions was higher than that of the original total serum fractions, indicating the presence of some substance(s) which inhibit insulin secretion in the total serum fractions. Oral glucose loading increased the relative insulin-releasing activity in the HPLC subfractions from obese children. This study suggests that the insulin secretagogue in human serum might be identical to hypothalamic insulin-glucagon liberin as these substances behave similarly on reversed-phase HPLC and have parallel insulin-releasing properties.

Relation of enteroinsular hormones at birth to macrosomia and neonatal hypoglycemia in infants of diabetic mothers

To study the role of enteroinsular hormones in fetal macrosomia and neonatal hypoglycemia in infants of diabetic mothers, we measured plasma concentrations of free and total immunoreactive insulin, C-peptide, pancreatic glucagon, enteroglucagon, and gastric inhibitory polypeptide at birth in 35 IDMs and 35 infants of normal mothers. Twenty fasting adults of normal weight were also studied. Sixteen IDMs were macrosomic at birth; 17 developed neonatal hypoglycemia over the first postnatal hours. The IDMs had ten times higher concentrations of free IRI than the normal infants in cord blood. Free IRI concentrations were related to the severity of maternal diabetes, with the infants of white class D to F mothers having the highest levels. The IDMs with macrosomia had a twofold increase in the concentrations of free IRI when compared with IDMs of normal weight. There was a significant correlation between the birth weight ratio and the concentrations of free IRI. The IDMs who developed neonatal hypoglycemia had considerably higher concentrations of free IRI than did normoglycemic IDMs. The decrease of blood glucose over the first postnatal hours correlated strongly with the free IRI concentrations in the cord blood. The IDMs had a threefold increase of the C-peptide concentrations over those in normal infants. Six IDMs had a molar ratio of C-peptide to free IRI of less than 1. Both the IDMs and normal infants had substantially higher concentrations of enteroglucagon and lower concentrations of GIP than did the fasting adults. Our data provide direct evidence that IDMs are markedly hyperinsulinemic at birth and that ambient hyperinsulinemia plays a crucial role in the development of fetal macrosomia and neonatal hypoglycemia. Moreover, the observed discrepancy in the relative increase of free IRI and C-peptide, combined with the low molar ratio of C-peptide to IRI, suggests a decreased metabolic clearance of insulin or transplacental passage of insulin from the maternal circulation in infants of mothers with insulin-treated diabetes.

Ceftazidime in the treatment of chronic suppurative otitis media in children

Seventeen children aged 5 months to 3 years with recurrent or chronic otitis media complicated by Pseudomonas aeruginosa were treated with ceftazidime. All patients had been previously treated with several antibiotics. All strains of Pseudomonas were initially sensitive to ceftazidime. In four of the six cases which failed bacteriologically, the Pseudomonas was found to be of intermediate sensitivity after treatment. In 11 patients the Pseudomonas was eradicated during treatment but reappeared in 4 during the follow-up period. All 11 patients were clinically cured or improved. Three of the six children whose Pseudomonas was not eliminated from aural discharge showed some clinical improvement whereas the remaining three showed no clinical response to treatment. The range of MIC values of ceftazidime, gentamicin and carbenicillin for the Pseudomonas isolated were respectively 0.5 to 4.0, 0.25 to 2.0 and 4.0 to 125 mg/l. The mean ceftazidime serum level at 1 h after the first injection of 50 mg/kg was 74.12 (S.D. 12.84) mg/l and at 12 h post injection 1.93 (S.D. 4.14) mg/l.

Basal insulin secretion and erythrocyte insulin binding in preterm and term newborn infants

To study the ontogeny of the insulin secretion and the erythrocyte insulin receptor we measured plasma immunoreactive insulin and C-peptide concentrations and the binding of [125I]-insulin to the erythrocytes in cord blood from 16 preterm and 16 term infants. 20 normal-weight adults were also studied. The C-peptide concentrations and the molar ratio of C-peptide to insulin were lower in the newborn infants than in the adults. The immunoreactive insulin correlated positively with birth weight in the term infants. The insulin binding to erythrocytes from the newborn infants was increased when compared to the adults. Erythrocytes from the preterm infants bound more insulin than the cells from the term infants. There was a strong negative correlation between insulin binding and gestational age. In the term infants, plasma C-peptide correlated negatively with the insulin binding. The increased binding to erythrocytes from the term infants was due to an increase in the receptor concentration. The high insulin binding in the preterm infants was a result of both an increased receptor concentration and affinity. These data suggest that the basal insulin secretion is similar in preterm and term infants and that the clearance of insulin is decreased in newborn infants. The increased insulin binding in newborn infants may be a mechanism by which the growth stimulatory effect of insulin in fetal life is mediated.

Erythrocyte insulin binding in normal infants, children and adults

To establish normal insulin binding criteria, we studied the binding of insulin to erythrocytes from normal subjects of different ages. Insulin binding to cord erythrocytes and to erythrocytes from infants aged 2-7 days was significantly higher at tracer and physiological insulin concentrations than was binding to cells from children aged 1-15 years and adults. In infants aged 1-12 months the maximum insulin binding to erythrocytes was significantly higher than that to erythrocytes from children, and in addition, it correlated negatively with age. An increase in receptor concentration was found in cord erythrocytes whereas an increased receptor affinity for insulin was found in erythrocytes from infants. Insulin binding characteristics in erythrocytes from prepubertal and pubertal children were basically similar to those in women. Erythrocytes from men bound significantly higher amounts of insulin than did those from women. This difference was associated with changes in receptor affinity for insulin. There was no correlation between the insulin binding characteristics and the circulating concentration of insulin or C-peptide. The increased erythrocyte insulin binding at birth persisted over the neonatal period. There was an overall negative correlation between the maximum insulin binding and age in the subjects studied, but the major decrease in erythrocytes insulin binding occurred during the first year of life past the neonatal period. These observations stress the importance of using age-matched controls in studies on erythrocyte insulin binding in disease states.

Serum calcium and 25-OH-D3 in mothers of newborns with craniotabes

Serum calcium and 25-OH-D3 in mothers of newborns with craniotabes. The aim of this study was to investigate whether calcium or vitamin D balance during late pregnancy have influence on the outcome of newborn craniotabes. 27 mothers and their fullterm newborns with craniotabes in two series were studied for clinical findings, course of pregnancy and calcium and vitamin D metabolism after the pregnancy. Calcium and phosphorus balance were studied in the first 16 mother-newborn pairs and were studied in the first 16 mother-newborn pairs and compared to a control group. Serum 25-OH-D3 concentrations were determined in the next 11 pairs and compared to a control group delivering in the same season and also to unpregnant women. The course of pregnancy did not show retrospectively any significant alterations and the clinical findings except craniotabes of the newborns were normal. In four cases the fetal head was engaged before 33th of gestation. In mothers serum calcium level was lower (p less than 0.05) and the excretion of phosphorus decreased (p less than 0.05) after the pregnancy as compared to controls. The values of serum 25-OH-D3 were at the same level in mothers and newborns with craniotabes as compared to controls but the values of mothers were lower (p less than 0.001) as compared to unpregnant controls In conclusion, craniotabes of the newborns seems to have no unique etiologic factor. The changes of calcium and vitamin D metabolism during pregnancy may be considered as predisposing factors in some cases and early engagement in some other. Perhaps also other reasons can be found.

Glucose metabolism in rat hypothalamus

In vitro glucose oxidation and glucose transport in the rat medial (MH) and lateral (LH) hypothalamic areas was measured. Glucose oxidation was calculated from the conversion of [U-14C]glucose to 14CO2 and glucose transport from 14CO2 produced from [1-14C]glucose in the presence of phenazine and methosulphate and NaF. Increasing glucose in the medium from 1 mM to 20 mM enhanced glucose oxidation two-fold in MH and 40% in LH. Addition of insulin, 100 microU/ml, to the medium decreased glucose oxidation 30% both in MH and LH at both 4 mM and 20 mM glucose. Fasting did not affect glucose oxidation in either of these hypothalamic areas. Glucose transport was not affected by insulin, but was increased significantly when glucose was raised from 0.25 mM to 1.0 mM. Fasting also increased glucose transport in both hypothalamic areas. In conclusion, extracellular glucose concentration seems to be the major regulator of glucose utilization by the rat hypothalamus. Insulin, rather than increasing, seems to decrease glucose oxidation while having no effect on glucose transport.

Hyperplasia of islets of Langerhans and low serum insulin in cot deaths

Of the fifty-seven cases of cot death studied two-thirds were younger than 3 months, which is also the peak age of infantile hypoglycaemia. Findings from routine necropsy and histology were scarce; in eleven cases they could be regarded as potentially fatal. About half of the infants had had a mild virus-type infection approximately one week before death. Special attention was paid to endocrine pancreas. Insulitis or lymphocytes in the septa were discovered in twelve cases. Hyperplasia of the islets of Langerhans was a common observation; the hyperplasia being either nesidioblastosis-like with clusters of islets around ducti, or diffuse. The average proportion of islet tissue in the whole pancreas parenchyma was around 5% in infants aged 1--6 months, the percentage being significantly greater than in age-matched controls (4.3%). The pancreatic insulin content was also higher in the cot death cases. Serum insulin values were low (mean 4.8 +/- 1.2 microU/ml) in cot deaths; in the controls they were twice as high (mean 11.6 +/- 1.6 microU/ml) (p less than 0.005). The cause of death in this group of cot deaths could thus be (congenital?) hyperplasia of the islets, possibly combined with a lesion in the B-cells caused by a virus. The mechanism of death would be hypoglycaemia.