Observation of a correlated free four-neutron system.

A long-standing question in nuclear physics is whether chargeless nuclear systems can exist. To our knowledge, only neutron stars represent near-pure neutron systems, where neutrons are squeezed together by the gravitational force to very high densities. The experimental search for isolated multi-neutron systems has been an ongoing quest for several decades1, with a particular focus on the four-neutron system called the tetraneutron, resulting in only a few indications of its existence so far2-4, leaving the tetraneutron an elusive nuclear system for six decades. Here we report on the observation of a resonance-like structure near threshold in the four-neutron system that is consistent with a quasi-bound tetraneutron state existing for a very short time. The measured energy and width of this state provide a key benchmark for our understanding of the nuclear force. The use of an experimental approach based on a knockout reaction at large momentum transfer with a radioactive high-energy 8He beam was key.

Half-life measurement of 65Ga with γ-spectroscopy.

The literature half-life value of 65Ga is based on only one experiment carried out more than 60 years ago and it has a relatively large uncertainty. In the present work this half-life is determined based on the counting of the γ-rays following the ß-decay of 65Ga. Our new recommended half-life is t1/2 = (15.133 ±â€¯0.028) min which is in agreement with the literature value but almost one order of magnitude more precise.

Half-life measurement of 66Ga with γ-spectroscopy.

The half-life of (66)Ga, an isotope very important for high-energy efficiency calibration of γ-detectors, has been measured using γ-spectroscopy. In order to reduce systematic uncertainties, different source production methods and γ-counting conditions have been applied. A half-life value of t(1/2)=(9.312±0.032)h has been obtained in agreement with a recent measurement but in contradiction with some of the earlier results.

Y-chromosome markers in Turner syndrome: Screening of 130 patients.

BACKGROUND: The presence of Y-chromosome material in patients with Turner syndrome (TS) is a risk factor for the development of gonadoblastoma. Cytogenetic analysis detects Y-chromosome mosaicism in about 5% of Turner patients. However, if Y-chromosome sequences are present in only a few cells, they may be missed by routine analysis. The use of molecular techniques to detect the presence of Y-chromosome fragments in such patients is becoming increasingly important. AIM: The objective of our study was to analyze cryptic Y-chromosome derivatives in Hungarian TS patient population by real-time PCR (RT-PCR). SUBJECTS AND METHODS: Cytogenetic and RT-PCR methods were used to examine peripheral blood DNA of 130 Hungarian patients with TS for the presence of Y-chromosome. With RT-PCR, 4 regions throughout the Y-chromosome were analyzed. RESULTS: Initial cytogenetic karyotyping assessing 10-50 metaphases revealed 3 patients with Y-chromosome positivity. RT-PCR revealed further 6 patients with Y-chromosome, who were initially considered as Y-negatives by standard kayotyping. The consecutive cytogenetic analysis of a large number (about 100) of metaphases (in 5 patients) and/or FISH (in 6 patients) however, also confirmed the presence of the Y-chromosome in these patients. Prophylactic gonadectomy was carried out in all 9 patients and 1 of them was diagnosed as having bilateral gonadoblastoma without clinical symptoms. CONCLUSIONS: We recommend a routine molecular screening for hidden Y-chromosome sequences in Turner patients, who are negative for Y-chromosome by conventional cytogenetic analysis, in order to calculate the future risk of developing gonadoblastoma.

Laterality disturbance and hypopituitarism. A case report of co-existing situs inversus totalis and combined pituitary hormone deficiency.

The authors present the case history of a 52-yr-old male patient with a unique association of combined pituitary hormone deficiency (CPHD) and situs inversus totalis. Except for signs and symptoms of pituitary hormone deficiency, the patient had no dysmorphic features, and hearing impairment, primary mental or neurological defects were also absent. Pituitary magnetic resonance imaging (MRI) scan showed hypoplasia of the anterior lobe of the pituitary gland and an ectopic posterior pituitary lobe. Despite the presence of situs inversus totalis, the patient was right-handed and functional MRI demonstrated left-hemisphere activation during language tests. Kartagener syndrome was considered, but immunofluorescence analysis showed normal localization of the outer dynein arm protein in respiratory epithelial cells obtained from the nasal mucosa. Direct DNA sequencing of all coding exons of the pituitary transcription factor 1 (PIT1) and prophet of PIT1 (PROP1) genes failed to detect disease-causing mutations, suggesting that these genes were not involved in the development of CPHD in our patient. More interestingly, the potential role of the paired like homeodomain transcription factor 2 (PITX2) gene, which has been implicated not only in CPHD, but also in left-right patterning in animal models, was also excluded, as sequencing showed the absence of mutations in coding exons of this gene. To our knowledge, PITX2 gene mutations have not been investigated in CPHD patients who had situs inversus totalis. We conclude that in contrast to animal models, the PITX2 gene is not involved in the development of situs inversus totalis, at least not in our CPHD patient.

Limited value of serum steroid measurements in identification of mild form of 21-hydroxylase deficiency.

BACKGROUND: ACTH stimulation test is widely used as a basic diagnostic method for non-classical congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD). However, the interpretation of this test has not been definitely established. To determine the cut-off values of basal and post-ACTH serum 17-OHP concentrations, data of patients with suspected 21-OHD has been analysed. PATIENTS AND METHODS: Two hundred and eighty-seven patients with postnatal/peripubertal virilization were investigated. Serum steroid concentrations were measured by RIA, urinary steroid profile was determined by capillary gas chromatography and mutation analysis of CYP21 gene was performed by allele specific PCR. 21-OHD was diagnosed by elevated serum 17-OHP concentrations, high level of the urinary 17-OHP metabolites and/or homozygosity for CYP21 mutations. RESULTS: Twenty-one patients of the total of 287 subjects (7.3 %) were identified as having 21-OHD. The numbers of 21-OHD patients compared to total numbers of patients with different ranges of serum 17-OHP were as follows: basal values below 3.5 ng/ml (mean + 1 SD) 0/225; between 3.5 - 6.6 ng/ml 3/41; above 6.6 ng/ml (mean + 2 SD) 18/21. Post-ACTH values below 6.4 ng/ml (mean + 1 SD) 0/226, between 6.4 - 10.3 ng/ml 0/35, above 10.3 ng/ml (mean + 2 SD) 21/26. CONCLUSION: There are patients with inappropriate peripubertal virilization who have slightly elevated 17-OHP concentrations. In this subgroup of patients more sensitive and specific methods are needed to establish the diagnosis of 21-OHD. Therefore we suggest performing an ACTH stimulation test in patients with a morning 17-OHP level above 3.5 ng/ml. Furthermore, urinary steroid profile and/or CYP21 gene analysis are needed in patients with a stimulated 17-OHP value between 10 and 30 ng/ml. These tests will distinguish between patients with non-classical 21-OHD and patients with other disorders.

Novel AIRE mutations and P450 cytochrome autoantibodies in Central and Eastern European patients with APECED.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare recessive disorder that results in several autoimmune diseases due to the mutations in the AIRE (autoimmune regulator) gene. APECED patients develop several autoimmune endocrine disorders and are characterized by the high titer autoantibodies to organ-specific antigens such as the steroidogenic P450 cytochromes. So far, 38 mutations have been identified in the AIRE gene. We report here the genetic and autoantibody analysis of 27 APECED patients of Eastern and Central European origins and one Egyptian patient. From 54 analyzed APECED chromosomes, eight mutations were detected, four of which (T16M, W78R, IVS1_IVS4, 30-53dup23bp) are novel. The most prevalent reason for APECED in these populations was the occurrence of R257X (36 chromosomes) that has been described earlier as a common and recurrent mutation in several other populations. The analysis of humoral immunity to steroidogenic P450 cytochromes by the immunoblotting of E. coli expressed antigens in the 18 APECED patients showed that 67%, 44%, and 61% of the Eastern and Central European APECED patients had autoantibodies to P450c17, P450c21, and P450scc, respectively.

Serum osteocalcin and insulin-like growth factor I levels in children with congenital adrenal hyperplasia.

Patients with the virilizing forms of congenital adrenal hyperplasia (CAH) need a life-long glucocorticoid replacement therapy and also an additional mineralocorticoid replacement in cases with the salt-wasting form of the disease. Glucocorticoids are reported to decrease the serum osteocalcin levels and to inhibit the effects of insulin-like growth factor I (IGF-I). To collect data on the age related patterns of osteocalcin and IGF-I production in patients with CAH, measurements of these compounds have been carried out in a considerably large sample of treated CAH patients and control subjects in childhood and adolescence. Data of 62 patients between 0. 3-19 years of age were compared to the data of 188 control children. Osteocalcin and IGF-I were determined by radioimmunoassay. A lower than normal level of serum osteocalcin was found in both male and female patients at chronological ages above 11.6 and 9.6 years, respectively. Furthermore, no pubertal osteocalcin peak could be seen when data were evaluated according to the bone age. Serum IGF-I levels were higher in male CAH patients at the chronological age of 0.3-15.5 years and in female patients at the chronological age of 4. 6-9.5 years. In pubertal years serum IGF-I concentrations were lower in CAH patients when data were evaluated according to the bone age. We conclude that serum osteocalcin is decreased during and after puberty in CAH patients on replacement doses of glucocorticoids. Normal to elevated serum levels of IGF-I in treated CAH cases suggest that the shorter final height of these patients may not be due to the decreased activity in the growth hormoneIGF-I axis, but rather to the advanced bone maturation and the premature epiphyseal fusion.

Serum and urinary steroids in girls with precocious pubarche and/or hirsutism due to mild 3-beta-hydroxysteroid dehydrogenase deficiency.

To obtain data on the correlation of serum and urinary steroids in nonclassical 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) deficiency, 9 girls with precocious pubarche and 33 adolescent girls with mild to severe hirsutism were studied. Urinary steroid profiles were analyzed by capillary gas chromatography. Serum 17-OH-pregnenolone (17-OHPreg) and 17-OH-progesterone (17-OHP) were determined by RIA after column-chromatographic separation. One out of 9 girls with precocious pubarche and 4/33 girls with hirsutism had elevated ratios of 17-OHPreg to 17-OHP after ACTH stimulation in serum and elevated urinary excretion of 5-ene steroids under basal conditions. These patients were defined to have decreased adrenal 3 beta-HSD activity. Basal and ACTH-stimulated serum 17-OHPreg levels in patients with mild 3 beta-HSD deficiency overlapped those of healthy controls and peripubertally virilized female patients without enzyme deficiency. Post-ACTH 17-OHPreg/17-OHP ratios in serum discriminated patients with and without 3 beta-HSD deficiency using a cutoff value of 13 instead of mean + 2 SD for age-related control values (6.7 and 11.6 for girls with Tanner stage II-III and IV-V, respectively). Sums of urinary 5-ene steroids in patients with 3 beta-HSD deficiency overlapped those in patients without enzyme deficiency. Results showed that an abnormal post-ACTH serum 17-OHPreg/17-OHP ratio may not be associated with elevated urinary 5-ene steroid excretion, and vica versa. In conclusion, patients with simultaneous elevation of post-ACTH serum 17-OHPreg/17-OHP ratio and basal urinary 5-ene steroid excretion are supposed to have mild 3 beta-HSD deficiency.

Two families with hereditary diabetes insipidus not due to osmoreceptor failure.

Two families with hereditary central diabetes insipidus (CDI) are reported. The pedigree in both families shows an autosomal dominant trait. The plasma arginine-8-vasopressin (AVP) determined by radioimmunoassay was markedly lower in these CDI patients than in healthy controls; the difference being even more pronounced after a hyperosmotic challenge. Since in the present study histamine also failed to increase the plasma AVP concentration, the authors consider it unlikely that an osmoreceptor failure would be implicated in the pathogenesis of CDI in these cases. The AVP concentration of the lumbar cerebrospinal fluid was also measured in two members of one of the families: the level found at the lower normal range indicates that some AVP secretion has been maintained in the extrahypothalamic vasopressinergic system of these patients.

[Insulin metabolism in obese children tested by oral and intravenous glucose loading]. / Elhízott gyermekek inzulin anyagcseréjének vizsgálata per os és i.v. glukóz-terhelés során.

Authors performed 0.5 g/kg intravenous and 1.75 g/kg p.os glucose tolerance tests in 25 alimentary obese children. C-peptide and Immunoreactive Insulin determinations were performed in every case. The average ratio of the two peptide during i.v. loads was calculated, too. Results were compared with the data of 6 children with ideal body weight respectively, whose results were obtained in similar circumstances. They find that i.v. glucose load produces different degrees in detected by C-peptide insulin secretion in normal as well as in obese children and the secretion rate is practically permanent till the end of the test in both groups. The low C-peptide/insulin ratio during i.v. glucose tolerance test in obese children indicates insulin resistance and explains decreased glucose tolerance. The "early-phase insulin release" detected in insulin curves of i.v. glucose load is resulted not only by the insulin reservoir capacity of beta-cells, but also by the insulin excretion capacity of the liver and the receptor activity of target cells. There is no connection between maximum glucose level responses to i.v. load and maximum C-peptide and insulin responses, whereas increases in maximum C-peptide response are parallel with those of in weight. C-peptide responses, being different in degree and experienced during the two types of tolerance test, support the "incretin" phenomenon. This mechanism may be important in the development of beta-cell hyperfunction which has been proved in obesity.