A translocation breakpoint cluster disrupts the newly defined 3' end of the SNURF-SNRPN transcription unit on chromosome 15

Balanced translocations affecting the paternal copy of 15q11--q13 are a rare cause of Prader-Willi syndrome (PWS) or PWS-like features. Here we report on the cytogenetic and molecular characterization of a de novo balanced reciprocal translocation t(X;15)(q28;q12) in a female patient with atypical PWS. The translocation breakpoints in this patient and two previously reported patients map 70-80 kb distal to the SNURF-SNRPN gene and define a breakpoint cluster region. The breakpoints disrupt one of several hitherto unknown 3' exons of this gene. Using RT--PCR we demonstrate that sequences distal to the breakpoint, including the recently identified C/D box small nucleolar RNA (snoRNA) gene cluster HBII-85 as well as IPW and PAR1, are not expressed in the patient. Our data suggest that lack of expression of these sequences contributes to the PWS phenotype.

Localization of GTP cyclohydrolase in monoaminergic but not nitric oxide-producing cells

The first and rate-limiting enzyme in tetrahydrobiopterin (BH4) biosynthesis is GTP cyclohydrolase (GTPCH). BH4 serves as the essential cofactor for aromatic L-amino acid hydroxylases, such as tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH), as well as for nitric oxide synthase (NOS). We hypothesized that to provide access to the cofactor, a close association exists between BH4-synthesizing and BH4-dependent enzymes, and we determined the relationship among GTPCH, neuronal NOS (nNOS), and TH in rat brain and adrenal gland using immunohistochemistry and in situ hybridization. Analyses of adjacent sections revealed specific localization of GTPCH in TH-containing cells of the substantia nigra, ventral tegmental area, hypothalamus, locus ceruleus, and adrenal medulla, and also in TPH-containing cells of the dorsal raphe nucleus and pineal gland. Thus, BH4 can be synthesized in all monoaminergic cells and is readily available for the enzymes requiring it. In contrast, analysis of adjacent sections showed that nNOS was not colocalized with GTPCH. Scattered nNOS-positive cells were found in the cortex, striatum, cerebellum, and olfactory bulb, all areas that receive monoaminergic innervation. The absence of GTPCH in nNOS cells suggests that nitric oxide-producing cells may either obtain biopterin from monoamine-containing processes which terminate in close proximity, or take up biopterin released into the blood. Double labelling of the same section for TH and nNOS revealed the TH nerve terminals connecting with the nNOS-positive cell bodies, suggesting the possibility that the BH4-containing nerve terminals may directly donate this cofactor to the nNOS-containing cells.

Different mechanisms and recurrence risks of imprinting defects in Angelman syndrome

Angelman syndrome (AS) is a neurogenetic disorder that appears to be caused by the loss of function of an imprinted gene expressed from maternal chromosome 15 only. Approximately 6% of patients have a paternal imprint on the maternal chromosome. In the few cases, this is due to an inherited microdeletion, in the 15q11-q13 imprinting center (IC), that blocks the paternal-->maternal imprint switch in the maternal germ line. We have determined the segregation of 15q11-q13 haplotypes in nine families with AS and with an imprinting defect. One family, with two affected siblings, has a microdeletion affecting the IC transcript. In the other eight patients, no mutation was found at this locus. In two families, the patient and a healthy sibling share the same maternal alleles. In one of these families and in two others, grandparental DNA samples were available, and the chromosomes with the imprinting defect were found to be of grandmaternal origin. These findings suggest that germ-line mosaicism or de novo mutations account for a significant fraction of imprinting defects, among patients who have an as-yet-undetected mutation in a cis-acting element. Alternatively, these data may indicate that some imprinting defects are caused by a failure to maintain or to reestablish the maternal imprint in the maternal germ line or by a failure to replicate the imprint postzygotically. Depending on the underlying cause of the imprinting defect, different recurrence risks need to be considered.

C15orf2 and a novel noncoding transcript from the Prader-Willi/Angelman syndrome region show monoallelic expression in fetal brain

The Prader-Willi syndrome (PWS) region contains several genes transcribed from the paternal chromosome only. We have previously identified a testis-specific gene, C15orf2, which maps between NDN and SNURF-SNRPN and is expressed from both alleles. Here we report on two novel genes (prader-willi region non-protein-coding RNA 1 and 2) located between NDN and C15orf2. By database search we found five partially duplicated copies, of which only one of each appears to be active. PWRN2 is expressed only in testis and is biallelic. PWRN1 is biallelically expressed in testis and kidney, but monoallelically in fetal brain. Methylation analysis of a CpG island 15 kb upstream of exon 1 showed absence of methylation in spermatozoa, but methylated and unmethylated alleles in fetal brain. Reinvestigation of C15orf2 revealed that this gene is also expressed in fetal brain and that expression in this tissue is monoallelic. We conclude that PWRN1 and C15orf2 may play a role in PWS.

New York State universal newborn hearing screening demonstration project: inpatient outcome measures

OBJECTIVE

To evaluate the feasibility of universal newborn hearing screening by examining inpatient outcome measures from 8 hospitals located in geographically diverse areas of New York State over a 3-yr period.

DESIGN

Funding was provided by the New York State Department of Health to implement predischarge hearing screening programs in the neonatal intensive care units (NICUs) and well-baby nurseries (WBNs) of eight hospitals. Various screening protocols including transient evoked otoacoustic emissions alone or in combination with conventional auditory brain stem response or screening auditory brain stem response were implemented by each site. Measured outcomes included rate of misses, refusals, and fails. Results were analyzed as a function of year of operation, nursery type, and geographic location.

RESULTS

Six out of eight hospitals successfully implemented universal hearing screening during the first year, and the remaining 2 hospitals implemented programs during the second year of the project. Over a period of 3 yr, 69,761 newborns were screened at the eight hospitals representing 96.9% of all live births. The overall fail rate (4.04%) combined with the miss rate (2.61%) resulted in 6.63% of infants referred for outpatient follow-up. Mean data indicated that inpatient outcome measures improved with year of operation, with most individual hospitals also showing improvements. Both fail and miss rates were higher in the NICU than in the WBN and for hospitals located in New York City than in other regions of the state.

CONCLUSIONS

Inpatient outcome measures of a universal newborn hearing screening project, which involved multiple centers across geographically diverse regions of New York State, were acceptable in terms of successfully screening a high percentage of live births and attaining low refer rates for outpatient screening. This study adds to the growing body of literature supporting the feasibility of screening all newborns before hospital discharge.

Receptor for advanced glycation end products (RAGE) polymorphisms are associated with systemic lupus erythematosus and disease severity in lupus nephritis

OBJECTIVE

Interaction of advanced glycation end products (AGEs) with their receptors (RAGE) plays an important role in inflammation in auto-immune diseases. Several functional polymorphisms of RAGE have been described. In this study we analysed the role of RAGE polymorphisms in disease susceptibility for systemic lupus erythematosus (SLE). In addition, we investigated whether these polymorphisms in SLE are associated with serum levels of soluble RAGE (sRAGE), renal involvement (lupus nephritis (LN)) and its outcome.

METHODS

For this cross-sectional study DNA samples of 97 SLE patients, 114 LN patients and 429 healthy controls (HC) were genotyped for four RAGE polymorphisms: -429 T/C, -374 T/A, 2184 A/G and Gly82Ser. Differences in genotype frequencies and allele frequencies were tested between patients and HCs. In SLE patients, sRAGE was measured by enzyme-linked immunosorbent assay (ELISA). In addition, association of genotypes with sRAGE and disease severity in LN was analysed.

RESULTS

The C allele of -429 T/C, the T allele of -374 T/A and the G allele of 2184 A/G were significantly more prevalent in SLE and LN compared with HC. In LN, the C allele of RAGE -429 T/C, the A allele of -374 T/A and the G allele of RAGE 2184 A/G polymorphism were significantly associated with more proteinuria and worse renal function during the first two years of treatment. No association of genotype with sRAGE was found.

CONCLUSION

RAGE polymorphisms are associated with susceptibility to SLE and LN. In addition, some of these polymorphisms are likely to be associated with disease severity and initial response to treatment in LN.

New York State universal newborn hearing screening demonstration project: effects of screening protocol on inpatient outcome measures

OBJECTIVE

To examine differences among various test protocols on the fail rate at hospital discharge for infants in the well-baby nursery (WBN) and neonatal intensive care unit (NICU) who received hearing screening through a universal newborn hearing screening demonstration project.

DESIGN

The outcomes of several screening protocols were examined. Two technologies were used: transient evoked otoacoustic emissions (TEOAEs) alone or in combination with the auditory brain stem response (ABR). The performance of test protocols in both nurseries within eight hospitals was examined over a 2- to 3-yr period. In the WBN, six hospitals used a screening protocol of TEOAE technology first followed by an ABR (automated or conventional) technology screening for newborns who referred on TEOAE screening. Two hospitals used TEOAE only in the WBN. Seven hospitals used screening protocols in the NICU that used a combination of TEOAE and ABR technologies (TEOAE technology administered first or second, before or after TEOAE, or TEOAE and ABR tests on all infants). Only one hospital used TEOAE technology exclusively for hearing screening.

RESULTS

Significant differences among screening protocols were found across hospitals in the first, second, and third years of the program. The combination of TEOAE technology and ABR technology (a two-technology screening protocol) resulted in a significantly lower fail rate at hospital discharge than the use of a single-technology (TEOAE). Fail rates at discharge were twice as high using the one-technology protocol versus two-technology protocol, even when the best outcomes from program year 3 were considered exclusively. Results of two-technology versus one-technology protocols were similar in the NICU. Use of a second technology for screening TEOAE fails significantly reduced every hospital that used the protocol's fail rate at discharge.

CONCLUSIONS

A two-technology screening protocol resulted in significantly lower fail rates at hospital discharge in both the WBN and NICU nurseries than use of a single-technology (TEOAE) hearing screening protocol.

High-risk Ewing's sarcoma: end-intensification using autologous bone marrow transplantation

Because of retrospective analysis showing survival to be related to primary tumor size, in February 1982 a study to test this hypothesis prospectively was begun at the University of Florida. Patients with primary tumors 8 cm or less in maximum diameter and no metastases received adjuvant chemotherapy consisting of vincristine, cyclophosphamide, doxorubicin, and dactinomycin plus radiotherapy or surgery (standard-risk protocol). All others received a similar regimen followed by end-intensification with high-dose melphalan and autologous bone marrow transplantation (Protocol HR-2). Because of poor results of HR-2, another high-risk protocol (HR-3) was initiated in January 1985. Patients on HR-3 received 2 cycles of chemotherapy containing vincristine, cyclophosphamide, and doxorubicin followed by local radiation therapy and maintenance chemotherapy. At the end of this therapy, autologous bone marrow transplantation (ABMT) was performed, using a preparatory regimen of total body irradiation and intensive chemotherapy. The 2-year disease-free survival rate was 70% for the standard-risk protocol, 20% for HR-2, and 80% for HR-3. The follow-up on HR-3 is still short, but the results are promising enough to warrant further clinical trials.

High-dose chemotherapy with marrow reinfusion and hyperfractionated irradiation for children with high-risk brain tumors

Between November 1990 and March 1993, nine pediatric patients with newly diagnosed brain tumors having a high risk of failure with standard treatment received high-dose thiotepa/cyclophosphamide chemotherapy followed by autologous bone marrow infusion and involved-field hyperfractionated radiation therapy. The presenting diagnoses were brainstem glioma (BSG) [6], parietal mixed high-grade oligodendroglioma-astrocytoma [1], thalamic anaplastic astrocytoma [1], and high-grade parietal glioma [1]. Following chemotherapy there were two partial responses, one minor response, three with stable disease, and one with progressive disease. Responses were not evaluated in two patients who had toxic deaths. Following radiation two patients, one with brainstem glioma and one with anaplastic mixed glioma, achieved complete remission. The overall survival is no better than conventional therapy.

Protein phosphatase 1beta is required for the maintenance of muscle attachments

Type 1 serine/threonine protein phosphatases (PP1) are important regulators of many cellular and developmental processes, including glycogen metabolism, muscle contraction, and the cell cycle [1] [2] [3] [4] [5]. Drosophila and humans both have multiple genes encoding PP1 isoforms [3] [6] [7]; each has one beta and several alpha isoform genes (alpha(1), alpha(2), alpha(3) in flies, alpha and gamma in humans; mammalian PP1beta is also known as PP1delta). The alpha/beta subtype differences are highly conserved between flies and mammals [6]. Though all these proteins are >85% identical to each other and have indistinguishable activities in vitro, we show here that the Drosophila beta isoform has a distinct biological role. We show that PP1beta9C corresponds to flapwing (flw), previously identified mutants of which are viable but flightless because of defects in indirect flight muscles (IFMs) [8]. We have isolated a new, semi-lethal flw allele that shows a range of defects, especially in muscles, which break away from their attachment sites and degenerate.

Protein-A-mediated targeting of bacteriochlorophyll-IgG to Staphylococcus aureus: a model for enhanced site-specific photocytotoxicity

A model for studying the efficiency of photodynamic action with a photosensitizer placed exclusively on the bacterial cell wall has been used. Bacteriochlorophyllide molecules, conjugated to rabbit immunoglobulin G (IgG), were synthesized. The conjugated pigment bacteriochlorophyll (Bchl)-IgG bound with high specificity to protein-A residues naturally exposed on the cell wall of the bacterium Staphylococcus aureus Cowan I. In bacterial suspensions the phototoxicity of the targeted conjugates (0.5-2.5 pigment per IgG molecule) was dose dependent (LD50 = 1.7 microM) in the presence of light (lambda > 550 nm) and inhibited by native IgG but not by ovalbumin, suggesting selective interaction with protein-A on the bacterial cell wall. No dark toxicity was noticed even with the highest conjugate concentration tested. In contrast, the photocytotoxicity of bacteriochlorophyll-serine (Bchl-Ser, LD50 = 0.07 microM) used as a nontargeted control was not inhibited by IgG. In spite of its lower apparent potency, Bchl-IgG was found to be 30 times more efficacious than Bchl-Ser: At LD50, only 66,000 Bchl-IgG molecules were bound per bacterium compared to 1,900,000 molecules of Bchl-Ser. The higher efficacy of Bchl-IgG is explained by its exclusive position on the bacterial cell wall. Consequently, photogeneration of oxidative species is confined to the cell wall and its vicinity, a seemingly highly susceptible domain for photodynamic action. In considering the design of cell-specific sensitizers for bacterial and cancer therapies, it would be beneficial to identify the more discretely sensitive subcellular domains as targets.

Inhibition of KSP by ARRY-520 induces cell cycle block and cell death via the mitochondrial pathway in AML cells

Kinesin spindle protein (KSP), a microtubule-associated motor protein essential for cell cycle progression, is overexpressed in many cancers and is a potential anti-tumor target. We found that inhibition of KSP by a selective inhibitor, ARRY-520, blocked cell cycle progression, leading to apoptosis in acute myeloid leukemia cell lines that express high levels of KSP. Knockdown of p53, overexpression of XIAP and mutation in caspase-8 did not significantly affect sensitivity to ARRY-520, suggesting that the response is independent of p53, XIAP and the extrinsic apoptotic pathway. Although ARRY-520 induced mitotic arrest in both HL-60 and Bcl-2-overexpressing HL-60Bcl-2 cells, cell death was blunted in HL-60Bcl-2 cells, suggesting that the apoptotic program is executed through the mitochondrial pathway. Accordingly, inhibition of Bcl-2 by ABT-737 was synergistic with ARRY-520 in HL-60Bcl-2 cells. Furthermore, ARRY-520 increased Bim protein levels prior to caspase activation in HL-60 cells. ARRY-520 significantly inhibited tumor growth of xenografts in SCID mice and inhibited AML blast but not normal colony formation, supporting a critical role for KSP in proliferation of leukemic progenitor cells. These results demonstrate that ARRY-520 potently induces cell cycle block and subsequent death in leukemic cells via the mitochondrial pathway and has the potential to eradicate AML progenitor cells.

A multicenter long-term safety and efficacy trial of preterm formula supplemented with long-chain polyunsaturated fatty acids

BACKGROUND

The tissue accretion of long-chain polyunsaturated fatty acids is compromised in infants born prematurely. Human milk contains long-chain polyunsaturated fatty acids, but most preterm infant formulas do not. The long-term effects of preterm formula supplemented with arachidonic acid and docosahexaenoic acid, in proportions typical of those in human milk, were therefore investigated.

METHODS

In this double-blind, randomized study, 288 preterm infants received experimental formula (n = 77), unsupplemented (control) formula (n = 78), or human milk (n = 133) until 48 weeks postconceptional age (PCA). Term formula, without supplemental long-chain polyunsaturated fatty acids, was administered from 48 to 92 weeks PCA to formula-fed infants and to infants weaned from human milk. Anthropometric and fatty acid data were assessed by using analysis of variance.

RESULTS

At 92 weeks PCA, no statistically significant anthropometric measurement differences were found except for midarm circumference, which was smaller in human milk-fed infants than in those fed formula. Phospholipid concentrations were similar in the experimental and human milk-fed groups, and docosahexaenoic acid levels were significantly greater than in the control group. The types and incidences of adverse events were similar among the feeding groups.

CONCLUSIONS

The results of this study demonstrate the efficacy and long-term safety of preterm formula supplemented with long-chain polyunsaturated fatty acids.

Infections with highly pathogenic avian influenza A virus (HPAIV) H5N8 in harbor seals at the German North Sea coast, 2021

In brain tissue of three harbor seals of the German North Sea coast, high virus loads of highly pathogenic avian influenza virus (HPAIV) H5N8 were detected. Identification of different virus variants indicates high exposure to HPAIV circulating in wild birds, but there is no evidence for H5 specific antibodies in healthy seals. Replication of avian viruses in seals may allow HPAIV to acquire mutations needed to adapt to mammalian hosts as shown by PB2 627K variants detected in these cases.