[Role of anti-Müllerian hormone in follicle recruitment and maturation]

Anti-Müllerian hormone (AMH), a member of the TGF-beta family, plays a crucial role during male sexual differentiation. This paper reviews the role of anti-Müllerian hormone in the ovary. In vivo and in vitro studies showed that AMH has an inhibitory effect on primordial follicle recruitment and it decreases the sensitivity of follicles for the FSH-dependent selection for dominance. Besides its functional role in the ovary, the AMH serum level serves as an excellent candidate marker of ovarian reserve.

Comparative quantification of umbilical cord blood CD34+ and CD34+ bright cells using the ProCount™-BD and ISHAGE protocols

The total number of CD34+ cells is the most relevant clinical parameter when selecting human umbilical cord blood (HUCB) for transplantation. The objective of the present study was to compare the two most commonly used CD34+ cell quantification methods (ISHAGE protocol and ProCount - BD) and analyze the CD34+ bright cells whose 7-amino actinomycin D (7AAD) analysis suggests are apoptotic or dead cells. Twenty-six HUCB samples obtained at the Placental Blood Program of New York Blood Center were evaluated. The absolute numbers of CD34+ cells evaluated by the ISHAGE (with exclusion of 7AAD+ cells) and ProCount (with exclusion of CD34+ bright cells) were determined. Using the ISHAGE protocol we found 35.6 +/- 19.4 CD34+ cells/microL and with the ProCount method we found 36.6 +/- 23.2 CD34+ cells/microL. With the ProCount method, CD34+ bright cell counts were 9.3 +/- 8.2 cells/microL. CD34+ bright and regular cells were individually analyzed by the ISHAGE protocol. Only about 1.8% of the bright CD34+ cells are alive, whereas a small part (19.0%) is undergoing apoptosis and most of them (79.2%) are dead cells. Our study showed that the two methods produced similar results and that 7AAD is important to exclude CD34 bright cells. These results will be of value to assist in the correct counting of CD34+ cells and to choose the best HUCB unit for transplantation, i.e., the unit with the greatest number of potentially viable stem cells for the reconstitution of bone marrow. This increases the likelihood of success of the transplant and, therefore, the survival of the patient.

Angular spectrum of quantized light beams

We introduce a generalized angular spectrum representation for quantized light beams. By using our formalism, we are able to derive simple expressions for the electromagnetic vector potential operator in the case of (a) time-independent paraxial fields, (b) time-dependent paraxial fields, and (c) nonparaxial fields. For the first case the well-known paraxial results are fully recovered.

Immunophenotype of hematopoietic stem cells from placental/umbilical cord blood after culture

Identification and enumeration of human hematopoietic stem cells remain problematic, since in vitro and in vivo stem cell assays have different outcomes. We determined if the altered expression of adhesion molecules during stem cell expansion could be a reason for the discrepancy. CD34+CD38- and CD34+CD38+ cells from umbilical cord blood were analyzed before and after culture with thrombopoietin (TPO), FLT-3 ligand (FL) and kit ligand (KL; or stem cell factor) in different combinations: TPO + FL + KL, TPO + FL and TPO, at concentrations of 50 ng/mL each. Cells were immunophenotyped by four-color fluorescence using antibodies against CD11c, CD31, CD49e, CD61, CD62L, CD117, and HLA-DR. Low-density cord blood contained 1.4 +/- 0.9% CD34+ cells, 2.6 +/- 2.1% of which were CD38-negative. CD34+ cells were isolated using immuno-magnetic beads and cultured for up to 7 days. The TPO + FL + KL combination presented the best condition for maintenance of stem cells. The total cell number increased 4.3 +/- 1.8-fold, but the number of viable CD34+ cells decreased by 46 +/- 25%. On the other hand, the fraction of CD34+CD38- cells became 52.0 +/- 29% of all CD34+ cells. The absolute number of CD34+CD38- cells was expanded on average 15 +/- 12-fold when CD34+ cells were cultured with TPO + FL + KL for 7 days. The expression of CD62L, HLA-DR and CD117 was modulated after culture, particularly with TPO + FL + KL, explaining differences between the adhesion and engraftment of primary and cultured candidate stem cells. We conclude that culture of CD34+ cells with TPO + FL + KL results in a significant increase in the number of candidate stem cells with the CD34+CD38- phenotype.

Neonatal oral administration of DiaPep277, combined with hydrolysed casein diet, protects against Type 1 diabetes in BB-DP rats. An experimental study

AIMS/HYPOTHESIS

Environmental factors such as diet and bacterial antigens play an important role in the onset of Type 1 diabetes. Different self-antigens are suggested to play a role in the development of diabetes. Antibodies against the 60-kDa heat shock protein 60, which have a high homology to bacterial heat shock protein 65, have been found in the circulation at the onset of diabetes in humans and in pre-diabetic NOD-mice. One of the immunodominant epitopes in autoimmune diabetes is p277, a specific peptide of human heat shock protein 60 corresponding to positions 437-460. In this study we investigated whether neonatal oral administration of DiaPep277 (a synthetic peptide analogue of p277) affected the development of diabetes in the BioBreeding-Diabetes Prone (BB-DP) rat, and whether this could potentiate the effect of a protective hydrolysed casein-diet.

METHODS

BB-DP rats were orally inoculated once per day with placebo or DiaPep277 at days 4, 5, 6 and 7 of life. At the age of 21 days rats were weaned on to a conventional, cereal-based diet or on to the hydrolysed casein-diet.

RESULTS

The development of diabetes in animals receiving DiaPep277 in combination with the hydrolysed casein-diet was delayed by 17 days, and a relative reduction of the incidence by 64% was seen. Non-diabetic animals did not show any sign of insulitis.

CONCLUSIONS/INTERPRETATION

Short-term neonatal feeding with p277 in early life, combined with diet adaptation, appears to provide a procedure to significantly reduce the development of Type 1 diabetes in later life.

Flavor decomposition of the sea-quark helicity distributions in the nucleon from semiinclusive deep inelastic scattering

Double-spin asymmetries of semiinclusive cross sections for the production of identified pions and kaons have been measured in deep inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with reanalyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.

Developmental coordination disorder: a review of research on subtypes and comorbidities

The interest in Developmental Coordination Disorder (DCD) has grown considerably over the last decade. Nevertheless, its etiology and prognosis are still poorly understood. The idea is growing that DCD may not be a uniform disorder. This review summarizes research on DCD, with a particular focus on subtype and comorbidity studies. The main message of the paper is that, in order to understand the etiology and prognosis of DCD, we need to have a better understanding of its nature. This requires an awareness of the existence of subtypes and comorbidities. Current theories on comorbidity phenomena are discussed in terms of their possible merit for the development of the field. Particular attention is given to the Automatization Deficit Hypothesis, a theory based on research on dyslexia.

The spectrum of lower motor neuron syndromes

This review discusses the most important lower motor neuron syndromes. This relatively rare group of syndromes has not been well described clinically. Two subgroups can be distinguished: patients in whom motor neurons (lower motor neuron disease (LMND)) are primarily affected or motor axons and their surrounding myelin (multifocal motor neuropathy (MMN)), both leading to muscle atrophy and weakness. Both hereditary and sporadic forms of LMND have been described. The discussion of recent advances in the genetic knowledge of several hereditary forms of LMND may lead to a better understanding of the pathophysiology and the development of therapeutic strategies. By contrast, the pathogenesis of sporadic LMND is largely unknown. It is, therefore, difficult to consider the various sporadic forms of LMND, discussed in this review, as separate diseases. Because the diagnostic and therapeutic options may differ, it would seem rational to consider sporadic LMND as a spectrum of syndromes which can be distinguished from each other on the basis of clinical presentation.MMN is a lower motor neuron syndrome with presumed immunemediated pathogenesis. Evidence of motor conduction block on nerve conduction studies and a positive response to treatment with intravenous immunoglobulins (IVIg) are considered the most relevant criteria for the diagnosis of MMN. As it is treatable, it is important to distinguish MMN from LMND. Careful electrophysiological analysis in the search for conduction block is, therefore, required in all adult patients with pure lower motor neuron syndromes. For the individual patient, distinction between the various lower motor neuron syndromes is important as it enables the physician to provide adequate information over the disease course in LMND and to facilitate early treatment in MMN.

Comparison of maximal voluntary isometric contraction and hand-held dynamometry in measuring muscle strength of patients with progressive lower motor neuron syndrome

Context. Maximal voluntary isometric contraction, a method quantitatively assessing muscle strength, has proven to be reliable, accurate and sensitive in amyotrophic lateral sclerosis. Hand-held dynamometry is less expensive and more quickly applicable than maximal voluntary isometric contraction. Objective. To investigate if hand-held dynamometry is as reliable and valid as maximal voluntary isometric contraction in measuring muscle strength in patients with an adult-onset, non-hereditary progressive lower motor neuron syndrome. Design. Two testers performed maximal voluntary isometric contraction and hand-held dynamometry measurements in six muscle groups bilaterally in patients with progressive lower motor neuron syndrome to assess reliability and validity of both the methods. Setting. Outpatient units of an academic medical center. Patients. A consecutive sample of 19 patients with non-hereditary progressive lower motor neuron syndrome (median disease duration 32.5 months, range 10-84) was tested. Outcome measures. Comparison between maximal voluntary strength contractions as measured by hand-held dynamometry and maximal voluntary isometric contraction. Results. Low intra- and interrater variation in all muscle groups were found, intraclass correlation coefficients vary between 0.86 and 0.99 for both methods. Both methods correlated well in all muscle groups with Pearson's correlation coefficients ranged between 0.78 and 0.98. Scatter plots indicated a trend to under-estimate muscle strength above 250 N by hand-held dynamometry as compared with maximal voluntary isometric contraction. Conclusions. For longitudinal evaluation of muscle strength in patients with progressive lower motor neuron syndrome (i.e. between 0 and 250 N), muscle strength can be accurate quantified with both hand-held dynamometry and maximal voluntary isometric contraction. Hand-held dynamometry has the advantage of being cheap and quickly applicable. However, our results indicate that hand-held dynamometry is less sensitive than maximal voluntary isometric contraction in detecting subnormal muscle strength in strong muscle groups (i.e. >250 N), due to limited strength of the tester.

Long-term prophylactic insulin treatment can prevent spontaneous diabetes and thyroiditis development in the diabetes-prone bio-breeding rat, while short-term treatment is ineffective

OBJECTIVE

Prophylactic insulin treatment has been demonstrated to reduce diabetes development in the diabetes-prone bio-breeding (DP-BB) rat. These prophylactic insulin treatments were given from 50 to 150 days of age. However, several data indicate that the diabetogenic process in DP-BB rats starts well before day 50.

DESIGN AND METHODS

DP-BB rats were given bovine insulin pellets from 21 to 60 days of age, from 21 to 100 days of age and from 60 to 100 days of age. At 160 days of age a glucose tolerance test was performed to establish beta-cell function and pancreata collected for histological analysis.

RESULTS

Prophylactic insulin treatment from 21 to 100 days of age gave a 42% reduction of diabetes incidence. The other treatment protocols had no effect. Non-diabetic rats treated with insulin from day 21 to 100 showed normal glucose tolerance and no sign of insulitis at 160 days of age. Non-diabetic rats of the control group and the other treatment groups showed normal glucose tolerance, but a slight increase of insulitis. Interestingly, the 21-100 day treated rats showed reduced serum levels of anti-colloid antibodies as compared with the control group.

CONCLUSIONS

These results show that short-term prophylactic insulin treatment cannot prevent diabetes and thyroiditis development in DP-BB rats. The prophylactic treatment must start well before 60 days of age and be prolonged into the phase when the rats normally become diabetic to reduce diabetes incidence. These findings imply that in the human situation prophylactic insulin treatment must be prolonged over the normal range of diabetes onset.

Validation of a volumic reconstruction in 4-d echocardiography and gated SPECT using a dynamic cardiac phantom

A dynamic cardiac phantom was used as a reference to compare the volumes reconstructed with 4-D echocardiography and gated single-photon emission computed tomography (SPECT). 4-D echocardiography used a new prototype of rotating scan head to acquire ultrasound (US) images during a cardiac cycle, associated with a new protocol (left ventricular 4-D or LV 4-D) to reconstruct the volume deformations of the heart as a function of time. Gated SPECT data were acquired with a standard single-head gamma camera, and the reconstructions were carried out using the Mirage software released by Segami. The influences of different LV 4-D parameters were tested and analyzed. End-diastolic volume, end-systolic volume, and ejection fraction were measured using both LV 4-D and gated SPECT. Results obtained showed a straight correlation between the two examinations. The agreement confirmed the relevance of the comparisons. This study is an initial step before conducting clinical trials to exhaustively compare the two modalities.

Sporadic lower motor neuron disease with adult onset: classification of subtypes

The discovery of the genetic basis of hereditary lower motor neuron disease (LMND) and the recognition of multifocal motor neuropathy as a distinct clinical entity necessitate a new classification of LMND. To this end, we studied the clinical and electrophysiological features of 49 patients with sporadic adult-onset LMND in a cross-sectional study. Disease duration was more than 4 years to exclude the majority of patients with amyotrophic lateral sclerosis. Based on the pattern of weakness, we identified three groups: 13 patients with generalized weakness (group 1); eight patients with symmetrical, distal muscle weakness (group 2); and 28 patients with non-generalized asymmetrical weakness of the arms in most patients (group 3). Group 3 could be subdivided into patients with weakness in predominantly the distal (group 3a) or the proximal (group 3b) muscle groups, both with disease progression to adjacent spinal cord segments. Distinctive features of group 1 were an older age at onset, more severe weakness and muscle atrophy, lower reflexes, greater functional impairment, more widespread abnormalities on concentric needle EMG, respiratory insufficiency and serum M-protein. In groups 2 and 3, concentric needle EMG findings also suggested a more widespread disease process. Retrospectively, the prognosis of sporadic adult-onset LMND appears to be favourable, because clinical abnormalities were still confined to one limb in most patients after a median disease duration of 12 years. We propose to classify the patients in the different subgroups as slowly progressive spinal muscular atrophy (group 1), distal spinal muscular atrophy (group 2), segmental distal spinal muscular atrophy (group 3a) and segmental proximal spinal muscular atrophy (group 3b). The described clinical phenotypes may help to distinguish between different LMND forms.

Evidence for quark-hadron duality in the proton spin asymmetry A1

Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A1. Longitudinally polarized positrons were scattered off a longitudinally polarized hydrogen target for values of Q2 between 1.2 and 12 GeV2 and values of W2 between 1 and 4 GeV2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable x. This finding implies that the description of A1 in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q2 above 1.6 GeV2.

Q2 dependence of nuclear transparency for exclusive rho0 production

Exclusive coherent and incoherent electroproduction of the rho(0) meson from 1H and 14N targets has been studied at the HERMES experiment as a function of coherence length (l(c)), corresponding to the lifetime of hadronic fluctuations of the virtual photon, and squared four-momentum of the virtual photon (-Q2). The ratio of 14N to 1H cross sections per nucleon, called nuclear transparency, was found to increase (decrease) with increasing l(c) for coherent (incoherent) rho(0) electroproduction. For fixed l(c), a rise of nuclear transparency with Q2 is observed for both coherent and incoherent rho(0) production, which is in agreement with theoretical calculations of color transparency.

Heterologous expression of the Aspergillus nidulans alcR-alcA system in Aspergillus niger

The inducible and strongly expressed alcA gene encoding alcohol dehydrogenase I from Aspergillus nidulans was transferred together with the activator gene alcR, in the industrial fungus Aspergillus niger. This latter organism does not possess an inducible alc system but has an endogenously constitutive lowly expressed alcohol dehydrogenase activity. The overall induced expression of the alcA gene was of the same order in both fungi, as monitored by alcA transcription, alcohol dehydrogenase activity and heterologous expression of the reporter enzyme, beta-glucuronidase. However, important differences in the pattern of alcA regulation were observed between the two fungi. A high basal level of alcA transcription was observed in A. niger resulting in a lower ratio of alcA inducibility. This may be due to higher levels of the physiological inducer of the alc regulon, acetaldehyde, from general metabolism in A. niger which differs from that of A. nidulans.

Regulation of the α-glucuronidase-encoding gene (aguA) from Aspergillus niger

The alpha-glucuronidase gene aguA from Aspergillus niger was cloned and characterised. Analysis of the promoter region of aguA revealed the presence of four putative binding sites for the major carbon catabolite repressor protein CREA and one putative binding site for the transcriptional activator XLNR. In addition, a sequence motif was detected which differed only in the last nucleotide from the XLNR consensus site. A construct in which part of the aguA coding region was deleted still resulted in production of a stable mRNA upon transformation of A. niger. The putative XLNR binding sites and two of the putative CREA binding sites were mutated individually in this construct and the effects on expression were examined in A. niger transformants. Northern analysis of the transformants revealed that the consensus XLNR site is not actually functional in the aguA promoter, whereas the sequence that diverges from the consensus at a single position is functional. This indicates that XLNR is also able to bind to the sequence GGCTAG, and the XLNR binding site consensus should therefore be changed to GGCTAR. Both CREA sites are functional, indicating that CREA has a strong influence on aguA expression. A detailed expression analysis of aguA in four genetic backgrounds revealed a second regulatory system involved in activation of aguA gene expression. This system responds to the presence of glucuronic and galacturonic acids, and is not dependent on XLNR.

Mimic syndromes in sporadic cases of progressive spinal muscular atrophy

Described are patients initially diagnosed with progressive spinal muscular atrophy (PSMA), in whom further evaluation established another diagnosis. The authors prospectively investigated incident and prevalent cases of PSMA. Seventeen of 89 patients, after initial registration, were later excluded because reassessment revealed a diagnosis other than PSMA. In 11 of the 17 patients with a revised diagnosis, a potential treatment was available: multifocal motor neuropathy (7), chronic inflammatory demyelinating polyneuropathy (2), inflammatory myopathy (1), and MG (1). Other misdiagnoses included myopathy, syringomyelia, ALS, idiopathic chronic axonal polyneuropathy, and idiopathic brachial plexus neuropathy. One patient with a possible herniated lumbar disk recovered spontaneously.

Cloning of a prolidase gene from Aspergillus nidulans and characterisation of its product

Using EST sequence information available from the filamentous fungus Aspergillus nidulans as a starting point, we have cloned the prolidase-encoding gene, designated pepP. Introduction of multiple copies of this gene into the A. nidulansgenome leads to overexpression of an intracellular prolidase activity. Prolidase was subsequently purified and characterised from an overexpressing strain. The enzyme activity is dependent on manganese as a cofactor, is specific for dipeptides and hydrolyses only dipeptides with a C-terminal proline residue. Although these proline dipeptides are released both intracellularly and extracellularly, prolidase activity was detected only intracellularly.