Increased neonatal thyrotropin in Down syndrome

AIM

Down syndrome (DS) is frequently associated with thyroid dysfunction. The aim of this study was to investigate the blood concentration of thyrotropin (TSH) observed at neonatal screening of infants with DS and its possible association with development of hypothyroidism during childhood.

METHODS

TSH levels from neonatal screening of 73 children (34 F) with DS born in 1986-1996 were studied retrospectively and compared with those of controls. The DS children were followed up regarding thyroid function to the age of 10 years in this descriptive study.

RESULTS

The DS infants had a higher mean TSH level and a higher TSH standard deviation score (SDS) than controls (7.0 +/- 7.45 mU/L vs. 3.9 +/- 2.43 mU/L and 1.1 +/- 2.67 vs. 0, respectively). The differences were mainly attributable to higher values in the male DS children. The TSH level at screening did not predict thyroid dysfunction during childhood.

CONCLUSION

Infants with DS, especially boys, showed elevated levels of TSH at neonatal screening, indicating the occurrence of mild hypothyroidism already in early life. The TSH levels could not predict development of manifest thyroid disease later in childhood.

Prolonged induction of germfree bile acid pattern in conventional rats by antibiotics

Male conventional rats have been treated for five days with benzylpenicillin, neomycin, kanamycin, erythromycin, bacitracintneomycin, succihylsulfathiazole or metronidazole. Total fecal bile acids were analyzed in samples collected during periods of three days during the pretreatment period and during the eight weeks following drug treatment. Metronidazole or succinylsulfathiazole had no or minor effects on the conventional bile acid pattern and the "bile acid index" (ratio beta-muricholic acid/deoxycholic acid) remained low. Benzylpenicillin, neomycin or kanamycin induced a germfree bile acid pattern, i.e. increased the relative amounts of alpha-and beta-muricholic acid in feces and eliminated deoxycholic acid and hyodeoxycholic acid from feces. The high bile acid index was normalized within three weeks after termination of drug treatment but the excretion of alpha- and beta-muricholic acid was not normalized until a normal flora had been established by giving an enema with intestinal contents from intact, oncentional rats. Treatment with eythromycin or bacitracintineomycin also produced a germfree bile acid pattern. In these cases, the bile acid index was not back to normal until after five to eight weeks and the excretion of the muricholic acids was not normalized until an enema with intestinal bacteria had been given. It is suggested that these long-lasting effects of antibiotics on the metabolism of bile acids in the intestinal tract should be considered after short-term antibiotic therapy in humans.

A simple screening assay for the most common JK*0 alleles revealed compound heterozygosity in Jk(a-b-) probands from Guam

The Jk(a-b-) phenotype results from alterations in the JK gene and is characterized by absence of the RBC urea transporter in the cell membrane. The frequency of Jk(a-b-) varies among populations,but this phenotype is most commonly found in people of Polynesian and Finnish descent. Although rare, Jk(a-b-) individuals present a clinical challenge because anti-Jk3 is produced readily in response to transfusion and pregnancy, and Jk(a-b-) blood is not routinely available. Identification of Jk(a-b-) patients and donors is most often performed serologically. However, ten JK*0 alleles have been identified, and this information can be used in DNA-based typing. We selected five JK*0 alleles that had been encountered by our reference laboratory in two or more samples from unrelated individuals and designed an allele-specific primer PCR assay for use as an initial screening tool. After in-house validation,we tested genomic DNA from a family: a mother and her two sons referred to us for genetic investigation of their Jk(a-b-)phenotypes. Two different nucleotide substitutions, -1g>a in intron 5 (IVS5) and 956C>T in exon 10, originally associated with Polynesian and Indian/African populations respectively, were identified in the family. The mother and one son were compound heterozygotes, and the second son was homozygous for IVS5-1g>a. We conclude that the effort to design and validate such a screening assay was cost-efficient when compared with DNA sequencing costs. Furthermore, selection of the more common JK*0 mutations was a practical approach that resulted in rapid identification of the genetic bases behind the Jk(a-b-) phenotypes in this unusual family. Although an obvious target for eventual inclusion into high-throughput genotyping platforms for clinical diagnostic services, current systems are very limited. Our approach provides a simple and inexpensive method for the identification of these rare alleles.

Lipopolysaccharide administration to the allergic nose contributes to lower airway inflammation

BACKGROUND

Allergic rhinitis (AR) is an inflammatory reaction not confined to a single local compartment, but rather involving the whole airway system. Allergens known to induce AR are not always the sole trigger of the inflammatory reaction as infections and organic dust might also cause exacerbations of rhinitis and associated conditions.

OBJECTIVE

To examine the effects of intranasal lipopolysaccharide (LPS) exposure, as a surrogate for upper airway bacterial infections, in patients with symptomatic AR.

METHODS

Fourteen patients with a history of moderate to severe pollen-induced AR were challenged intranasally with LPS. After 3-6 weeks, the same patients were challenged again, first with allergen and 24 h later with LPS. Nasal symptom scores, nasal lavage leucocyte counts and nasal airway resistance were assessed at 6-24 h after each provocation along with measurements of nitric oxide (NO) levels in the nose and lung.

RESULTS

Six hours after the LPS challenge, an increased level of leucocytes could be obtained in the lavage fluid, but no symptoms were experienced and no increase in nasal resistance could be recorded. The NO production in the upper and lower airways was similar before and 6 h after the provocation. In contrast, in patients exposed to pollen before the LPS challenge, both the nasal and the pulmonary NO levels were enhanced. This was accompanied by an increase in leucocytes.

CONCLUSION

The present study demonstrates a priming effect of allergen on the nasal response to LPS as well as the presence of a systemic link between airway mucosal sites in the upper and lower airways. This suggests that exogenously derived signals, like upper airway infections, can interfere with the initiation, maintenance and progression of asthma.

Tissue repair using allogeneic mesenchymal stem cells for hemorrhagic cystitis, pneumomediastinum and perforated colon

Mesenchymal stem cells (MSC) possess anti-inflammatory properties and participate in tissue repair. We used MSC to heal therapy-induced tissue toxicity. Ten consecutive patients, treated with MSC due to tissue toxicity following allogeneic hematopoietic stem cell transplantation, (ASCT) were included. Their median age was 48 (13-64) years. Seven had hemorrhagic cystitis grades 2-5, two had pneumomediastinum and one had perforated colon and peritonitis. MSC donors were mainly third-party, HLA-mismatched (n=11), HLA-haploidentical (n=3) and, in two cases, the HLA-identical ASCT sibling donors. MSC were given intravenously, the median cell dose was 1.0 (range 0.7-2)x10(6)/kg. In five patients, the severe hemorrhagic cystitis cleared after MSC infusion. Gross hematuria disappeared after median 3 (1-14) days. Two patients had reduced transfusion requirements after MSC infusion, but died of multiorgan failure. In one of them, MSC donor DNA was demonstrated in the urinary bladder. In two patients, pneumomediastinum disappeared after MSC infusions. A patient with steroid-resistant graft-versus-host disease of the gut experienced perforated diverticulitis and peritonitis that was reversed twice by MSC. MSC is a novel treatment for therapy-induced tissue toxicity.

Glucose metabolism in human adipose tissue studied by 13C-glucose and microdialysis

OBJECTIVE

Microdialysis can be used to monitor carbohydrate metabolism and lipolysis in adipose tissue. This method, however, does not discriminate between local metabolite production and delivery from other tissues. Our aim was to study glucose metabolism by direct delivery of 13C-labelled glucose into adipose tissue by microdialysis.

MATERIAL AND METHODS

Seven healthy adults were studied after an overnight fast. In three of them the effect of physical activity on glucose metabolism was tested. Microdialysis catheters were introduced into abdominal adipose tissue and 25 mM 13C-labelled glucose was added to the perfusion fluid. An extraction procedure for separating lactic acid from glucose and glycerol in the microdialysate samples was developed. After derivatization, the 13C enrichment of the compounds was analysed by gas chromatography-mass spectrometry.

RESULTS

13C-labelled lactate was detected in the first 15-min eluate fraction following that in which 13C-glucose had reached the microdialysis probe. In the different subjects, 22-35 % of adipose tissue lactate was produced locally. During exercise there was an increase in the lactate concentration and a decrease in 13C enrichment of lactate. Although lactate production in the adipose tissue increased during exercise, most adipose tissue lactate resulted from inflow. The administered 13C-labelled glucose also rapidly converted to 13C-glycerol. The 13C enrichment of glycerol was lower than that of lactate. During exercise the 13C enrichment of glycerol increased, indicating that newly synthesized depot fat was preferentially hydrolysed during physical activity.

CONCLUSIONS

Metabolism of glucose to lactate and glycerol in subcutaneous adipose tissue is a rapid process that can be monitored in vivo by administration of stable isotope labelled glucose into the microdialysis probe. In adults at rest about one-fourth of adipose tissue lactate is produced locally.

Females born large for gestational age have a doubled risk of giving birth to large for gestational age infants

AIM

To analyse if females born large for gestational age (LGA) have an increased risk to give birth to LGA infants and to study anthropometric characteristics in macrosomic infants of females born LGA.

METHODS

The investigation was performed as an intergenerational retrospective study of women born between 1973 and 1983, who delivered their first infant between 1989 and 1999. Birth characteristics of 47,783 females, included in the Swedish Birth Register both as newborns and mothers were analysed. LGA was defined as >2 SD in either birth weight or length for gestational age. The infants were divided into three subgroups: born tall only, born heavy only and born both tall and heavy for gestational age. Multiple logistic and linear regression analyses were performed.

RESULTS

Females, born LGA with regard to length or weight, had a two-fold (adjusted OR 1.96, 95% Cl 1.54-2.48) increased risk to give birth to an LGA infant. Females, born LGA concerning weight only, had a 2.6 (adjusted OR 2.63, 95%, 1.85-3.75) fold increased risk of having an LGA offspring heavy only and no elevated risk of giving birth to an offspring that was tall only, compared to females born not LGA. In addition, maternal obesity was associated with a 2.5 (adjusted OR 2.56, 95%, 2.20-2.98) fold increased risk of having an LGA newborn, compared to mothers with normal weight.

CONCLUSION

Females, born LGA, have an increased risk to give birth to LGA infants, compared to mothers born not LGA. Maternal overweight increases this risk even further.

Increased lipolysis in LCHAD deficiency

An increasing number of fatty acid oxidation defects are being detected owing to diagnostic improvements and a greater awareness among clinicians. The metabolic block leads to energy disruption, fatty infiltration, and toxic effects on organ functions exerted by beta-oxidation metabolites. This investigation was undertaken to assess the influence of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency on lipolysis and energy turnover. We addressed the question whether the lipolysis and glucose production rates would be altered in the fasting state in a child with this disease. Lipolysis, glucose production and resting energy expenditure (REE) were studied in a 17-month-old girl with LCHAD deficiency and her healthy twin sister. Lipolysis and glucose production were determined after a 4-6 h fast by constant-rate infusion of [1,1,2,3,3-(2)H(5)]glycerol and [6,6-(2)H(2)]glucose and analysis by gas chromatography-mass spectrometry. REE was estimated by indirect calorimetry. The affected girl showed 50% higher lipolysis than did her sister, whereas the glucose production rates were similar. Plasma levels of dicarboxylic acids of 6-12 carbon atoms chain length, 3-hydroxy fatty acids of 6-18 carbon atoms chain length, total free fatty acids, and acylcarnitines were increased in the patient, as was REE. Since glucose production rates and plasma glucose levels were similar in the two girls, the increased lipolysis observed in the patient probably represents a compensatory mechanism for energy generation. This is achieved at the price of an augmented risk for fatty acid infiltration and toxic effects of beta-oxidation intermediates. This highlights the importance of avoiding fasting in these patients.

Estrogen receptor β represses breast tumor growth and angiogenesis in vivo

10101

Background: Estrogens are well known stimulators of breast cancer cell growth in vitro as well as in vivo. Two different estrogen receptors exist, namely estrogen receptor (ER) α and β. ERα mediates the proliferative effect of estrogen in breast cancer cells and we have earlier shown that ERβ inhibits cell-cycle progression in vitro. Estrogens are well known stimulators of in vivo breast cancer cell growth as well as angiogenesis, and the effect is mediated through ERα. The function of ERβ in this context is not well understood. Methods: We have used ERα-positive T47D breast cancer cells stably transfected with a Tet/Off regulated ERβ expression vector system. The ERβ-inducible tumor cells are studied in vitro as well as in vivo. Results: By transplanting ERβ-inducible breast cancer cells into SCID-mice, we show that ERβ inhibits tumor growth and reduces the volume of established tumors. Furthermore, we show by immunohistochemistry, that the number of blood microvessels in the tumor periphery is decreased by ERβ expression, counteracting the well-known pro-angiogenic effect of ERα. By Western blot analysis on tumor extracts, we show that the concentration of the important pro-angiogenic growth factors VEGF and bFGF, normally expressed by breast tumor cells, is decreased in the ERβ-expressing tumors compared to the normal tumors. To exclude that the observed anti-angiogenic effect is just a result of reduced tumor growth, we incubated Tet/Off regulated ERβ expressing cells in vitro, during non-hypoxic conditions. We found that the expression of ERβ leads to decreased expression of VEGF and PDGFβ at the mRNA and protein-levels. In transient transfection assays, we found estrogen-ERα mediated up regulation of VEGF, PDGFβ and bFGF-promoter activities in T47D cells, and these activities were all suppressed following co-transfection with an ERβ-expression vector. Conclusions: We conclude that ERβ inhibits growth factor expression at transcriptional level in breast cancer cells; taken together, our data indicates that ERβ inhibits growth and angiogenesis of tumors formed by T47D breast cancer cells. This makes ERβ an interesting therapeutic target in breast cancer and perhaps treatment with the newly designed ERβ-selective ligands might work as a new anti-proliferative and anti-angiogenic therapy.

No significant financial relationships to disclose.

Decreased maternal lipolysis in intrauterine growth restriction in the third trimester

OBJECTIVE

Intrauterine growth restriction (IUGR) is a common complication of pregnancy. There are many possible aetiologic factors of maternal, placental and/or fetal origin. Often there is no known explanation. The aim of this study was to investigate whether a reduction in maternal energy substrate production could be one of the factors involved in IUGR.

DESIGN

Measurement of maternal energy substrate production and glucoregulatory hormones in women with growth-restricted fetuses.

SETTINGS

University Hospital, Uppsala, Sweden.

POPULATION

Ten healthy pregnant women with IUGR were compared with eight recently reported healthy women with normal pregnancies. The women were studied at 35.4+/-1.6 weeks of gestation after an overnight fast.

METHODS

Rates of glycerol and glucose production were analysed by gas chromatography/mass spectrometry following constant-rate infusion of [1,1,2,3,3-(2)H5]glycerol and [6,6-(2)H2]glucose.

MAIN OUTCOME MEASURE

Third trimester glycerol and glucose production.

RESULTS

Glycerol production, reflecting lipolysis, was lower in the women with IUGR than in those with normal pregnancies, 2.36+/-0.58 versus 3.06+/-0.66 micromol kg-1 minute-1 (P=0.033), whereas there was no difference in rate of glucose production (glucose production rate [GPR]), 12.1+/-1.5 versus 13.2+/-1.5 micromol kg-1 minute-1 (P=0.23). Plasma glycerol levels were increased in the women with IUGR (P=0.008).

CONCLUSIONS

Lipolysis is lower in pregnancies complicated by IUGR as compared with normal pregnancies. Increased lipolysis during pregnancy provides substrate for maternal energy metabolism, which spares glucose for the fetus. A reduced maternal production of energy substrate could be one of several factors underlying IUGR. A lack of relationship between insulin levels and either lipolysis or GPR suggests defective regulation of energy substrate production in this group of pregnant women.

Final height after combined growth hormone and GnRH analogue treatment in adopted girls with early puberty

BACKGROUND

Girls adopted from developing countries often have early or precocious puberty, requiring treatment with gonadotrophin-releasing hormone (GnRH) analogues. During such treatment, decreased growth velocity is frequent.

AIM

To study whether the addition of growth hormone (GH) to GnRH analogue treatment improves final height in girls with early or precocious puberty.

METHODS

Forty-six girls with early or precocious puberty (age < or =9.5 y) adopted from developing countries were randomized for treatment for 2-4 y with GnRH analogue, or with a combination of GH and GnRH analogue.

RESULTS

During treatment, the mean growth velocity in the GH/GnRH analogue group was significantly higher compared to the control group. Combined GH/GnRH analogue treatment resulted in a higher final height: 158.9 cm compared to 155.8 cm in the GnRH analogue-treated group. Three out of 24 girls (13%) in the combined group and nine of the 22 girls (41%) treated with GnRH analogue alone attained a final height below -2 standard deviation scores (SDS).

CONCLUSION

The difference between the two groups is statistically significant, and possibly of clinical importance. A future challenge is to identify a subgroup with clinically significant advantage of GH addition to GnRH analogue treatment. Being very short on arrival in Sweden and being short and young at start of treatment are possible indicators.

Endogenous glucose production and lipolysis in anorexia nervosa--a study using stable isotope-labelled compounds

Glucose production and lipolysis were investigated in teenage girls with anorexia nervosa using glucose and glycerol labelled with stable isotopes. The production of energy substrates were also maintained in the very underweight patients who showed higher relative rates of substrate mobilization compared to those who had gained some weight.

CONCLUSION

The investigation shows that glucose production, necessary to provide fuel for the central nervous system, is also maintained in starving patients with anorexia nervosa.

A novel nonsense mutation of the mineralocorticoid receptor gene in a Swedish family with pseudohypoaldosteronism type I (PHA1)

Pseudohypoaldosteronism type I (PHA1) is a condition associated with salt wasting leading to dehydration, hypotension, hyperkalemia, and metabolic acidosis. Sporadic cases and two familial forms, one autosomal dominant and one autosomal recessive form, have been described. The autosomal dominant or sporadic form manifests milder salt wasting that remits with age. Mutations in the gene encoding the mineralocorticoid receptor (MR) have been identified in patients with the autosomal dominant inheritance. However, recent studies suggest that the autosomal dominant and sporadic forms are genetically heterogeneous and that additional genes might be involved. We report on the study of 15 members of a Swedish five-generation family with the autosomal dominant form of PHA1. Interestingly, neuropathy was found in two of five affected individuals. A novel heterozygous nonsense mutation C436X in exon 2 was identified in the index patient by linkage analysis, PCR, and direct sequencing of the MR gene. Analysis of the family demonstrated that the mutation segregated with PHA1 in the family. It is unclear whether the neuropathy is associated with the mutation found. Our results together with previously published data suggest that loss-of-function mutations of the MR gene located at 4q31.1, commonly are associated with the autosomal dominant form of PHA1.

Pubertal development and final height after autologous bone marrow transplantation for acute lymphoblastic leukemia

We describe pubertal development and growth in 17 children who underwent bone marrow transplantation (BMT), including total body irradiation (TBI) for ALL. Seven children also received cranial irradiation (CI) and five boys testicular irradiation. All underwent transplantation before (n=15) or at the beginning of (n=2) puberty and reached a final height (FH). Puberty started spontaneously in all boys not given testicular irradiation. All boys who received testicular irradiation developed hypergonadotrophic hypogonadism. Puberty started spontaneously in two girls and was induced with increasing doses of ethinylestradiol in two girls. In two girls, a low dose of ethinylestradiol was given until menarche. In one girl with early onset of puberty and short stature, puberty was blocked with a GnRH analogue. The standard deviation score for height decreased significantly from BMT to FH, both in the children who received TBI only (-1.1, P=0.005) as well as in those given additional CI (-1.7, P=0.027). Most of the loss occurred during puberty. In all, 10 children received growth hormone (GH) treatment. CI, young age at BMT, and short duration of GH treatment were predictors of height loss after BMT. Although limited by the small and heterogeneous sample, our study supports the use of early GH treatment in children with decelerating growth rate and low GH levels.

Insulin sensitivity and lipolysis in adolescent girls with poorly controlled type 1 diabetes: effect of anticholinergic treatment

OBJECTIVES

Increased GH secretion could be one factor behind the impaired glycaemic control often seen in adolescent girls with type 1 diabetes. Because GH induces insulin resistance, treatment with anticholinergic agents, such as pirenzepine (PZP), has been used to reduce GH secretion. However, in a previous study of adolescent girls with type 1 diabetes, we observed an improvement in glycaemic control during 12 weeks of PZP therapy despite unchanged excretion of GH in urine. Considering the complex mechanisms behind urinary GH excretion, the effects of PZP on pituitary GH secretion or secretory pattern cannot be excluded. Thus, to assess the effect of anticholinergic treatment on metabolic control in adolescent girls with diabetes, we have investigated GH secretion, insulin sensitivity and lipolysis before and during treatment with PZP.

PATIENTS

Eleven adolescent girls with type 1 diabetes and poor metabolic control were investigated before and after treatment with PZP, 100 mg orally, twice a day for 3 weeks.

DESIGN

Serum samples for analysis of haemoglobin A1c and IGF-I were obtained in addition to serum profiles of GH, insulin and IGFBP-1 before and after 3 weeks of PZP treatment. Effects on insulin sensitivity and lipolysis were also assessed.

MEASUREMENTS

IGFBP-1 was measured every hour, whereas serum GH and insulin were measured every 20 min for 24 h. Insulin sensitivity was analysed with the hyperinsulinaemic euglycaemic clamp technique. The rate of lipolysis was assessed under basal conditions following a constant rate infusion of [1,1,2,3,3-2H5]-glycerol. In five girls, lipolysis was also estimated during the hyperinsulinaemic euglycaemic clamp.

RESULTS

There was a significant reduction in haemoglobin A1c levels (9.9 +/- 0.2%vs. 9.1 +/- 0.2; P < 0.0001) during 3 weeks of PZP treatment. In additional, the glucose requirement during the euglycaemic hyperinsulinaemic clamp increased by more than 30% (72.5 +/- 4.9 vs. 96.8 +/- 8.5 mg/m2/min; P = 0.003). However, we could not demonstrate any significant changes in GH secretion (area under the curve, basal levels or peak amplitude) or in the GH secretory pattern (peak height, peak length or interpeak interval). Concordantly, the IGF-I levels were statistically unchanged, as were IGFBP-1 concentrations. The rate of lipolysis did not change under basal conditions (3.40 +/- 0.53 vs. 3.04 +/- 0.54 micro mol/kg/min, n = 11, P = 0.54) or during the hyperinsulinaemic euglycaemic clamp (1.58 +/- 0.21 vs. 2.08 +/- 0.26 micro mol/kg/min; n = 5, P = 0.32).

CONCLUSIONS

Our observations of an increased glucose requirement during the clamp as well as a decrease in haemoglobin A1c demonstrate improved insulin sensitivity in the adolescent girls with diabetes following pirenzepine therapy. The mechanism behind the improvement is not clear, as neither secretion nor the secretory pattern of GH changed significantly. The persistently high levels of GH might explain the unaltered rate of lipolysis despite the improved insulin sensitivity. The observed improvement in glycaemic control in adolescent girls with type 1 diabetes following pirenzepine therapy is promising, although more studies on this topic are needed.

Growth charts for Down's syndrome from birth to 18 years of age

BACKGROUND

Growth in children with Down's syndrome (DS) differs markedly from that of normal children. The use of DS specific growth charts is important for diagnosis of associated diseases, such as coeliac disease and hypothyroidism, which may further impair growth.

AIMS

To present Swedish DS specific growth charts.

METHODS

The growth charts are based on a combination of longitudinal and cross sectional data from 4832 examinations of 354 individuals with DS (203 males, 151 females), born in 1970-97.

RESULTS

Mean birth length was 48 cm in both sexes. Final height, 161.5 cm for males and 147.5 cm for females, was reached at relatively young ages, 16 and 15 years, respectively. Mean birth weight was 3.0 kg for boys and 2.9 kg for girls. A body mass index (BMI) >25 kg/m(2) at 18 years of age was observed in 31% of the males and 36% of the females. Head growth was impaired, resulting in a SDS for head circumference of -0.5 (Swedish standard) at birth decreasing to -2.0 at 4 years of age.

CONCLUSION

Despite growth retardation the difference in height between the sexes is the same as that found in healthy individuals. Even though puberty appears somewhat early, the charts show that DS individuals have a decreased pubertal growth rate. Our growth charts show that European boys with DS are taller than corresponding American boys, whereas European girls with DS, although being lighter, have similar height to corresponding American girls.

Errors in estimating neonatal production of glucose with stable isotopes during "approximate steady state"

In studies of glucose metabolism in neonates, a commonly used approach is based on constant rate infusion of glucose labelled with a stable isotope in order to reach an approximate steady state with regard to isotopic enrichment in plasma. Under presumed conditions of a glucose steady state, the rates of appearance and disappearance of glucose can, in principle, be calculated with use of a simple steady-state formula. However, in the neonate, steady-state conditions do not generally prevail and results derived on such assumptions are questionable. In the present study, we have taken a pragmatic approach and compared estimates obtained from the conventional formula with values calculated with Steele's non-steady-state method. The results show that the estimated glucose appearance and disappearance rates change more or less over the observed time period in all the typical cases studied, and that "steady-state estimates" may differ from the corresponding non-steady-state values by up to 37%. In a sensitivity analysis, the value of the distribution volume factor was found to be non-critical, a circumstance that supports the use of Steele's method. Thus, even though the classical Steele pool-fraction method for computation of rates of appearance and disappearance under non-steady-state conditions has been criticized, it is still the most realistic alternative to the frequently used simple steady-state formula in applications to newborns.

Diabetes control deteriorates in girls at cessation of growth: relationship with body mass index

AIM

Diabetic patients, particularly girls, often experience poor metabolic control during puberty and adolescence. The aim of this study was to investigate metabolic control during adolescence, especially in relation to pubertal stages, growth, insulin treatment and body mass index (BMI).

METHODS

We studied the records of 38 (consecutive) girls with prepubertal onset of Type 1 diabetes mellitus. Data from the age of 10 to 18-20 years were obtained with regard to glycaemic control, growth, age at menarche, final height and BMI, and analysed in relation to both chronological age and age at menarche.

RESULTS

HbA1c was lowest 3 years before menarche; mean (+/- sd) 7.6 (+/- 1.2). After the pubertal growth spurt, there was a marked impairment of metabolic control, the highest level of HbA1c occurring 3 years after menarche. Mean age at menarche was 13.3 (+/- 1.1) years and mean linear growth after menarche only 4.7 cm, giving a final height of 164.9 (+/- 5.3) cm which is 2.7 cm below the Swedish mean. During adolescence the degree of correlation between BMI and HbA1c continuously increased, pointing out the effect of body fat on metabolic control in this age group. The level of HbA1c at 10 years of age could not predict the metabolic control after cessation of puberty, but prepubertal BMI appears to be a risk factor for both obesity and poor glycaemic control in late adolescence.

CONCLUSIONS

The highest HbA1c was found after cessation of growth. Prepubertal BMI is a possible predictor of metabolic control in adolescent diabetic girls.

The transcription factors SOX9 and SOX10 are vitiligo autoantigens in autoimmune polyendocrine syndrome type I

Vitiligo is common in the hereditary disorder autoimmune polyendocrine syndrome type I (APS I). Patients with APS I are known to have high titer autoantibodies directed against various tissue-specific antigens. Using sera from APS I patients for immunoscreening of a cDNA library from human scalp, we identified the transcription factors SOX9 and SOX10 as novel autoantigens related to this syndrome. Immunoreactivity against SOX9 was found in 14 (15%) and against SOX10 in 20 (22%) of the 91 APS I sera studied. All patients reacting with SOX9 displayed reactivity against SOX10, suggesting shared epitopes. Among the 19 patients with vitiligo, 12 (63%) were positive for SOX10 (p < 0.0001). Furthermore, three of 93 sera from patients with vitiligo unrelated to APS I showed strong reactivity against SOX10, which may indicate a more general role of SOX10 as an autoantigen in vitiligo.

Peripheral astigmatism in emmetropic eyes

The long-term aim of the work introduced here is to investigate the influence of off-axis aberrations on human vision, especially for subjects with a large central scotoma. The latter use their peripheral vision in spite of its poor off-axis optical quality, and a correction of the off-axis aberrations might be of great assistance. The eccentric fixation angles used by these subjects can be up to 20-30 degrees. In this initial study we have measured oblique astigmatism, the major off-axis aberration, in 20 emmetropic eyes in 10 degrees steps out to 60 degrees nasally and temporally using a 'double pass' setup. The results show very large individual differences and the oblique astigmatism also varies from nasal to temporal side. In an off-axis measurement angle of 30 degrees the astigmatism varied between subjects from 1 to 7-D, with a mean astigmatism of about 4-D on the nasal side and about 1.5-D lower on the temporal side. At 60 degrees temporally, the mean astigmatism was 7-D. At 60 degrees nasally, all subjects had astigmatism larger than 8-D and the mean astigmatism was 11-D. The results indicate that any attempt to correct the off axis astigmatism in an eye with central scotoma cannot be based on central refraction; instead, individual measurements are necessary.

Immunocytochemical demonstration of oestrogen receptor beta in blood vessels of the female rat

The role of oestrogen receptor (ER) beta in vascular function remains unclear. With the use of a specific ERbeta antibody we have now, using immunocytochemistry, visualized ERbeta in different parts of the vascular tree. In about 70% of medial smooth muscle cells of female rat aorta, tail artery and uterine artery, nuclear immunoreactivity to ERbeta was observed. In these vessels endothelial cells also expressed ERbeta. Vascular expression of the ERalpha subtype was lower than that of ERbeta. In aorta and tail artery, no immunoreactivity towards ERalpha was observed, while in uterine vessels occasional medial smooth muscle and endothelial cells expressed this ER subtype. ERbeta and alpha expression in uterine vessels was independent of the stage of the oestrous cycle, suggesting that variations in uterine blood flow occurring during the cycle are independent of ER density. The regional distribution of ERalpha, as determined by immunocytochemistry, was supported by measurements of ERalpha levels by enzyme immunoassay. In the uterine artery, the level of ERalpha was several times higher (P<0.001) than that of aorta and tail artery (10.1+/-1.7 fmol/mg protein in the uterine artery vs 3.3+/-1.0 and 0.5+/-0.5 fmol/mg protein in aorta and tail artery respectively). Thus, a prominent nuclear expression of ERbeta was observed in the vascular wall of several parts of the vascular tree, while ERalpha predominantly was expressed in uterine vessels, suggesting that ERbeta and alpha may have different roles in vascular function.