Molecular cloning and expression of an anti-idiotype antibody mimicking a protective oligosaccharide of the parasite Schistosoma mansoni

Genes encoding the heavy and light chains of an anti-idiotype antibody (AB2) mimicking a protective oligosaccharide of Schistosoma mansoni were cloned and expressed as a single-chain Fv fragment. The expression in a functional state was tested using the AB1. A specific binding between sFv and AB1 was observed. Immunization with the recombinant AB2 indicates its capacity to elicit anti-S. mansoni antibodies. Received: 28 April 1997 / Accepted: 24 June 1997     

Metabolic Response of the Cerebral Cortex Following Gentle Sleep Deprivation and Modafinil Administration

Study Objectives:

The main energy reserve of the brain is glycogen, which is almost exclusively localized in astrocytes. We previously reported that cerebral expression of certain genes related to glycogen metabolism changed following instrumental sleep deprivation in mice. Here, we extended our investigations to another set of genes related to glycogen and glucose metabolism. We also compared the effect of instrumentally and pharmacologically induced prolonged wakefulness, followed (or not) by 3 hours of sleep recovery, on the expression of genes related to brain energy metabolism.

Design:

Sleep deprivation for 6–7 hours.

Setting:

Animal sleep research laboratory.

Participants:

Adults OF1 mice.

Interventions:

Wakefulness was maintained by “gentle sleep deprivation” method (GSD) or by administration of the wakefulness-promoting drug modafinil (MOD) (200 mg/kg i.p.).

Measurements and Results:

Levels of mRNAs encoding proteins related to energy metabolism were measured by quantitative real-time PCR in the cerebral cortex. The mRNAs encoding protein targeting to glycogen (PTG) and the glial glucose transporter were significantly increased following both procedures used to prolong wakefulness. Glycogenin mRNA levels were increased only after GSD, while neuronal glucose transporter mRNA only after MOD. These effects were reversed after sleep recovery. A significant enhancement of glycogen synthase activity without any changes in glycogen levels was observed in both conditions.

Conclusions:

These results indicate the existence of a metabolic adaptation of astrocytes aimed at maintaining brain energy homeostasis during the sleep-wake cycle.

Citation:

Petit, JM; Tobler I; Kopp C; Morgenthaler F; Borbély AA; Magistretti PJ. Metabolic response of the cerebral cortex following gentle sleep deprivation and modafinil administration. SLEEP 2010;33(7):901–908.     

Complex constitutional subtelomeric 1p36.3 deletion/duplication in a mentally retarded child with neonatal neuroblastoma

Monosomy 1p36 is one of the most frequent subtelomeric microdeletion syndromes characterized by distinct craniofacial features and developmental delay/mental retardation. Other common symptoms include hypotonia, seizures, brain abnormalities, visual, auditory and heart defects. Neuroblastoma is a rare feature since to our knowledge only two patients with “pure” 1p36 deletion have been described. We report on a child with developmental delay and facial dysmorphy who developed neuroblastoma at 1 month of age. No primary site outside of the liver could be demonstrated and the tumour regressed spontaneously. Standard karyotyping was normal while subtelomeric screening using Multiplex Ligation-dependent Probe Amplification (MLPA) method revealed a constitutional de novo subtelomeric 1p36 deletion. Subsequent Agilent 244K oligonucleotide array-based comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) analysis showed a complex 1p36.3 deletion/duplication rearrangement. Among the best candidate genes predisposing to the development of neuroblastoma located in 1p36, the AJAP1 gene is the only gene present in the duplication while CHD5, TNFRSF25 and CAMTA1 are located outside of the rearrangement. Therefore, a gene-dosage effect involving a gene located in the duplication including AJAP1 might explain the neuroblastoma observed in our patient. The rearrangement might equally interfere with the expression of a gene located outside of it (including CHD5 located 1 Mb away from the rearrangement) playing a role in the tumorigenesis. In conclusion, this study illustrates the complexity of such rearrangement characterized by array CGH and strengthens that constitutional 1p36.3 rearrangement predisposes to the development of neuroblastoma.     

Deletion 18q21.2q21.32 involving TCF4 in a boy diagnosed by CGH-array

We report on a 12 year-old boy presenting with severe developmental delay, dysmorphic features, limb anomalies, growth retardation, hypoplastic vermis and corpus callosum. Conventional and high-resolution cytogenetic analyses were normal. CGH-array allowed characterisation of a de novo 6.2 Mb 18q21.2q21.32 interstitial deletion involving TCF4, the recently identified gene responsible for Pitt-Hopkins syndrome (PHS). No tachypnoea-apnoea paroxysms were observed. We discuss the dysmorphic features particularly involving the ears, which might be helpful towards PHS and 18q21 deletion diagnosis.     

46,XY gonadal dysgenesis: evidence for autosomal dominant transmission in a large kindred

46,XY gonadal dysgenesis is characterized by abnormal testicular determination. We describe a large kindred in which various disorders of sexual development were observed, ranging from completely female phenotype without ambiguities of the external genitalia (five cases) to men with isolated penile or perineal hypospadias (four cases), including two cases with moderate virilization and one case with ambiguity of the external genitalia. Histologic examination of gonadal tissue was performed on seven subjects. These findings were suggestive of complete gonadal dysgenesis in one patient, partial gonadal dysgenesis in three patients, and mixed gonadal dysgenesis in three patients. Four patients developed gonadal tumors (two gonadoblastoma, two dysgerminoma, and one immature teratoma, i.e., one patient had a dysgerminoma with some areas of gonadoblastoma). All affected subjects had no other congenital anomalies or dysmorphic features. Analysis of families with several affected individuals with 46,XY gonadal dysgenesis implied an X-linked mode of inheritance because of the apparent absence of male-to-male transmission. However, a sex-limited autosomal dominant mode of inheritance affecting only XY individuals could not be ruled out. Analysis of the pedigree we report indicated an autosomal dominant mode of inheritance because of male-to-male transmission. This kindred supports the involvement of at least one autosomal gene in non-syndromic 46,XY gonadal dysgenesis.     

Humanization by variable domain resurfacing and grafting on a human IgG4, using a new approach for determination of non-human like surface accessible framework residues based on homology modelling of variable domains

Many antithrombotic agents have only a small therapeutic window, frequently leading to bleeding problems. However, interfering with platelet adhesion through the collagen-VWF-GPIbalpha axis is expected to cause less bleeding problems. Our group developed a monoclonal antibody, 82D6A3, directed against the von Willebrand factor (VWF) A3-domain, which inhibits the VWF-interaction to fibrillar collagen. 82D6A3 has antithrombotic effects in vivo without bleeding time prolongation. To further investigate the promising features of 82D6A3, we have humanized it by variable domain resurfacing and grafting on the constant regions of a human IgG4. First, the sequence of the variable domains was determined and the murine scFv was constructed. The expressed scFv had a comparable activity as the IgG of 82D6A3, and its DNA was thus used in subsequent humanization procedures. For this, a new approach was introduced to identify non-human like framework surface residues, since the general distribution of accessible residues described for human and murine heavy and light chain variable domains showed several discrepancies with the homology modelled Fv of 82D6A3. Identification of non-human like framework residues and evaluation of their surface accessibility within the context of the homology modelled Fv of 82D6A3, revealed 10 residues that need to be humanized without influencing the conformation of the CDR loops. Indeed, the humanized scFv of 82D6A3, obtained by mutating all 10 residues to their human counterpart, was still binding with high affinity to VWF and retained the inhibitory properties of the murine scFv. Next, in order to increase its half life and to decrease its immunogenicity, the humanized variable domains were grafted on the constant regions of a human IgG4, resulting in h82D6A3 with an in vitro activity comparable to that of the murine IgG.     

Human leukocyte antigen DR15 is associated with reduced relapse rate and improved survival after human leukocyte antigen-identical sibling hematopoietic stem cell transplantation.

Human leukocyte antigen (HLA) DR15 is associated with autoimmune cytopenia in patients with aplastic anemia, myelodysplastic syndrome, and paroxysmal nocturnal hemoglobinuria. Presence of this antigen also predicts response to immunosuppressive treatment. If DR15 expression on hematopoietic cells also favors induction of immune responses in an allogeneic setting, a lower relapse rate after hematopoietic stem cell transplantation (HSCT) might result through an enhanced graft-versus-leukemia effect. We retrospectively analyzed outcome of HLA-identical sibling HSCT in 192 consecutive patients with acute or chronic leukemia or non-Hodgkin lymphoma. Patients carrying the DR15 antigen had a higher estimated 5-year overall survival (76%) than did DR15-negative patients (55%; P = .04). Improved survival for DR15 patients was due to a significant decrease in death from relapse (5% for DR15(+) versus 24% for DR15(-); P = .02), whereas no difference was seen for rates of transplant-related mortality (19% and 21%, respectively; P = .76). Findings were confirmed by multivariate analyses. Our results show an association of DR15 with a decreased risk of disease relapse and improved survival after HSCT for leukemia or non-Hodgkin lymphoma. This adds to the growing list of links between DR15 and immune reactions in hematopoiesis.     

Skin tolerability associated with transdermal drug delivery systems: an overview

As transdermal patches become more widely prescribed, it is important that clinicians understand: (a) the common causes of skin reactions with these medications; (b) how to minimize these reactions; and (c) how to manage the signs and symptoms. Here we review published data for skin reactions with patch medications approved within the past decade. Overall, the most common application site signs and symptoms appear to be localized redness (erythema) or itching, sometimes accompanied by swelling (edema). Typically, these are mild to moderate in severity, transient in nature, and occur in 20% to 50% of patients. Most are localized to the area of application, and resolve spontaneously within several days following patch removal. Discontinuations due to these types of event are infrequent, ranging from 1.7% to 6.8% in the 6-month trials reviewed here. Based on expert opinion, the majority of these skin reactions would be a form of irritant contact dermatitis, with infrequent cases of allergic contact dermatitis. These types of reactions usually cause minimal pain or discomfort to the patient, and are unlikely to be of medical concern. Signs and symptoms of irritant contact dermatitis may be minimized by rotation of the application site, careful removal of the patch, and appropriate use of moisturizers and topical corticosteroids. In conclusion, the potential advantages of transdermal patches usually outweigh any additional skin issues; however, further research into treatment and management strategies is required.