Is there a future for spermatid injections?

Microinjection of spermatids into oocytes has proven to be a successful assisted reproduction procedure in the animal model. In the human, low fertilization and cleavage to the 4-cell stage were reported after intracytoplasmic sperm injection (ICSI) with round spermatids. In comparison with a conventional ICSI-testicular sperm extraction (TESE) programme, the implantation rate after round spermatid injection is dramatically low. Different problems have been encountered during the development of the spermatid injection technique and they could be partially responsible for the lower outcome when using round spermatids. Compared with the round spermatid cells, spermatids in the elongation phase are easy to isolate and identify from other round cells present in a wet preparation. The morphological identification does not reveal anything about the viability or the genetic normality of the round spermatids. Severe testicular dysfunction may have consequences on the quality of the few spermatogenic cells present. Others factors, such as the pathology of the patient, play an important role in the successful treatment. Even if the results are extremely low, spermatid injection seems more favourable for men who have already proven their capacity to produce some spermatozoa. A spermatogenic block at the round spermatid level has led to early abortions, increasing the suspicion of the role of a genetic factor. In order for this technique to be safe for use in clinics, more intensive work is needed to improve the selection and handling of cells and to ascertain the genomic imprinting and gene expression necessary for embryonic development. Hence, when using immature cells for conception, the screening of the patient and the follow-up of the pregnancies and babies should be mandatory.     

Is there a future for vaccination as a treatment for Alzheimer's disease?

Vaccination of APP transgenic mice with Abeta has been shown to prevent amyloid deposits. A clinical trial of Abeta vaccination in Alzheimer's disease (AD) was halted due to serious neurological complications developing in some patients. Such complications were not observed in transgenic mice. Since human APP is not a mouse self-protein, vaccination of mice with Abeta should not produce an autoimmune reaction although this would be anticipated in AD. Moreover, mouse C1q poorly recognizes human Abeta so complement activation is much weaker in transgenic mice than in AD. Vaccination will increase complement activation through formation of antigen-antibody complexes. In mice this will enhance phagocytosis. But in AD, where complement is already overactivated, and where the senile plaques are relatively insoluble, this stimulation should increase production of the membrane attack complex, adding to the autodestruction of neurons. The future of vaccination as a therapy for AD will require surmounting the problems of autoimmune reactions generally and autotoxic complement activation specifically.     

Is HCMV a tumor promoter?

Human cytomegalovirus (HCMV) is a beta-herpesvirus that causes persistent infection in humans and can cause severe disease in fetuses and immunocompromised individuals. Although HCMV is not currently causally implicated in human cancer, emerging evidence suggests that HCMV infection and expression may be specifically associated with human malignancies including malignant glioma, colon, and prostate cancer. In addition, multiple investigators have demonstrated that HCMV can dysregulate signaling pathways involved in initiation and promotion of malignancy, including tumor suppressor, mitogenic signaling, inflammatory, immune regulation, angiogenesis and invasion, and epigenetic mechanisms. This review highlights some of the recent evidence that HCMV might play a role in modulating the tumor microenvironment as well as in the initiation and promotion of tumor cells themselves.     

Is there a future for ovulation induction in the current era of assisted reproduction?

The clinical use of medical induction of ovulation in normogonadotrophic anovulatory women (WHO II), including polycystic ovary syndrome, is increasingly questioned. However, we believe that this treatment modality still represents a highly effective means of fertility treatment in women with low pregnancy chances without intervention. A conventional treatment algorithm involving clomiphene citrate (CC) followed by FSH induction of ovulation may result in a 71% cumulative singleton live birth rate. In attempts to improve treatment outcome further and reduce complication rates, new compounds such as insulin-sensitizing agents or aromatase inhibitors are currently used increasingly. Approaches such as patient selection for different treatment modalities on the basis of initial screening characteristics and alternative protocols for FSH ovulation induction may also be proposed to render treatment algorithms more patient tailored and therefore improve overall outcomes. More research is needed in this area, rather than referring these patients to assisted reproduction prematurely. This may lead to a more individually tailored approach for ovulation induction in a given patient, resulting in a further improvement of the balance between chances for success versus complications.     

Is there a common molecular pathway for addiction?

Drugs of abuse have very different acute mechanisms of action but converge on the brain's reward pathways by producing a series of common functional effects after both acute and chronic administration. Some similar actions occur for natural rewards as well. Researchers are making progress in understanding the molecular and cellular basis of these common effects. A major goal for future research is to determine whether such common underpinnings of addiction can be exploited for the development of more effective treatments for a wide range of addictive disorders.     

Is immunosuppression a future therapeutic strategy for multiple sclerosis?

Although in previous studies no clear demonstration was found of the efficacy of azathioprine, cyclophosphamide and methotrexate as immunoprophylactic agents in cases of multiple sclerosis (MS), over the past five years a number of well-designed clinical trials utilizing immunosuppressive and immunomodulatory agents have shown partial efficacy regarding the drugs involved, but they have not been able to determine in what way these drugs can modify the natural course of this disease. Among the immunosuppressors, mitoxantrone is of particular interest as during the past two years three controlled trials have taken place in Europe and have demonstrated its efficacy both as regards clinical (frequency of symptoms, progression of the disease) and magnetic resonance imaging (MRI) criteria. Due to its potentially severe cardiotoxicity related to total cumulative dose, mitoxantrone is only prescribed for a limited period, and its use is limited to selected patients with a high relapse rate and incomplete remission, or to those who do not respond to beta-interferon treatment. The immunomodulatory agents have less immediate efficacy, but because they are well tolerated they can be used early in the course of the disease and over a prolonged period of time. The beta-interferons (1a or 1b) have been given market approval for use in the treatment of MS: three large, randomized, double-blind studies have demonstrated their capacity to reduce by 30% the frequency of symptoms and the appearance of disabilities associated with relapse and with the progression of the disease. Glatirameracetate or copolymer 1, which is available in France (ATU), has been found to reduce the frequency of relapse by 30%. It constitutes an alternative immunomodulatory treatment for relapsing-remitting patients without major functional disabilities and who suffer from severe side effects with beta-interferon treatment. In the future, the early use of immunomodulatory agents and therapeutic drug combinations may be introduced. Therapeutic trials are currently in progress to determine the viability of this approach.     

Is there a common genetic basis for autoimmune diseases?

Autoimmune diseases (ADs) represent a diverse collection of diseases in terms of their demographic profile and primary clinical manifestations. The commonality between them however, is the damage to tissues and organs that arises from the response to self-antigens. The presence of shared pathophysiological mechanisms within ADs has stimulated searches for common genetic roots to these diseases. Two approaches have been undertaken to sustain the "common genetic origin" theory of ADs. Firstly, a clinical genetic analysis showed that autoimmunity aggregates within families of probands diagnosed with primary Sj?gren's (pSS) syndrome or type 1 diabetes mellitus (T1D). A literature review supported the establishment of a familiar cluster of ADs depending upon the proband's disease phenotype. Secondly, in a same and well-defined population, a large genetic association study indicated that a number of polymorphic genes (i.e. HLA-DRB1, TNF and PTPN22) influence the susceptibility for acquiring different ADs. Likewise, association and linkage studies in different populations have revealed that several susceptibility loci overlap in ADs, and clinical studies have shown that frequent clustering of several ADs occurs. Thus, the genetic factors for ADs consist of two types: those which are common to many ADs (acting in epistatic pleitropy) and those that are specific to a given disorder. Their identification and functional characterization will allow us to predict their effect as well as to indicate potential new therapeutic interventions. Both autoimmunity family history and the co-occurrence of ADs in affected probands should be considered when performing genetic association and linkage studies.     

Is there a role for viruses in triggering autoimmune hepatitis?

A role for viruses in autoimmune hepatitis (AH) has been repeatedly proposed but convincing evidence links only two viruses, hepatitis A and Epstein-Barr virus, to the type 1 form of the disease, and only in those rare cases where a genetic predisposition exists and the viral infection occurs at the right time, i.e. when other unknown factors are cooperating. In spite of an impressive amount of information conclusively showing molecular mimicry between cytochrome P450IID6 (the target autoantigen of autoantibodies characteristic of AH type 2) sequences and viral (hepatitis C virus, herpes simplex virus 1, cytomegalovirus, human T lymphotropic viruses 1 and 2) or bacterial (Salmonella typhimurium) antigens, no infectious agent is clearly able to induce this second form of the disease. In conclusion, the molecular mimicry theory has so far found little clinical evidence in its support and many more clinical observations are needed in order to unreveal possible links between viruses and AH.     

Is there a place and role for endocytic TCR signaling?

T‐lymphocyte activation relies on the cognate recognition by the TCR of the MHC‐associated peptide ligand (pMHC) presented at the surface of an antigen‐presenting cell (APC). This leads to the dynamic formation of a cognate contact between the T lymphocyte and the APC: the immune synapse (IS). Engagement of the TCR by the pMHC in the synaptic zone induces a cascade of signaling events leading to phosphorylation and dephosphorylation of proteins and lipids, which ultimately shapes the response of T lymphocytes. Although the engagement of the T‐cell receptor (TCR) takes place at the plasma membrane, the TCR/CD3 complexes and the signaling molecules involved in transduction of the TCR signal are also present in intracellular membrane pools. These pools, which are both endocytic and exocytic, have tentatively been characterized by several groups including ours. We will herein summarize what is known on the intracellular pools of TCR signaling components. We will discuss their origin and the mechanisms involved in their mobility at the IS. Finally, we will propose several hypotheses concerning the functional role(s) that these intracellular pools might play in T‐cell activation. We will also discuss the tools that could be used to test these hypotheses.     

Is there a role for immunotherapy in controlling HIV infection?

Although HAART restores immune function in patients with HIV infection, restoration is incomplete. Functional restoration is seen primarily in responses to antigens that are prevalent in HIV-infected persons. Immunization is required to restore responses to antigens that are not predictably present. As an exception, HIV-specific responses are also generally not restored despite the prevalence of these antigens. This may be because HIV replication specifically targets and either destroys or renders nonfunctional HIV-reactive CD4+ T cells. Perhaps because HIV selectively targets HIV-reactive immune cells, therapeutic immunization strategies are particularly important areas of investigation in the treatment of HIV disease. Strategies designed to restore HIV-specific CD4+ T-cell function must also enhance the activity of HIV-specific cytolytic T cells, since these are the likely key mediators of defense against HIV replication. Both active immunization strategies and treatment interruption strategies may enhance HIV-specific immune responses. Treatment interruption, by increasing exposure to HIV antigens through heightened HIV replication, also runs the risk of permitting sufficient HIV replication to damage HIV-responsive CD4+ cells as well as enhancing the losses of other CD4+ cell populations that may protect against opportunistic complications of HIV disease. Thus, treatment interruption strategies require careful and sophisticated monitoring and should not be tried at home.     

Is there a role for telemedicine in adult allergy services?

Telemedicine refers to the application of telecommunication and information technology (IT) in the delivery of health and clinical care at a distance or remotely and can be broadly considered in two modalities: store‐and‐forward and real‐time interactive services. Preliminary studies have shown promising results in radiology, dermatology, intensive care, diabetes, rheumatology and primary care. However, the evidence is limited and hampered by small sample sizes, paucity of randomized control studies and lack of data relating to cost‐effectiveness, health‐related quality of life and patient and clinician satisfaction. This review appraises the evidence from studies that have employed telemedicine tools in other disciplines and makes suggestions for its potential applications in specific clinical scenarios in adult allergy services. Possible examples include: triaging patients to determine the need for allergy tests; pre‐assessment for specialized treatments such as allergen immunotherapy, follow‐up to assess treatment response and side effects; and education in self‐management plan including training updates for self‐injectable adrenaline and nasal spray use. This approach might improve access for those with limited mobility or living far away from regional centres, as well as bringing convenience and cost savings for the patient and service provider. These potential benefits need to be carefully weighed against evidence of service safety and quality. Keys to success include delineation of appropriate clinical scenarios, patient selection, training, IT support and robust information governance framework. Well‐designed prospective studies are needed to evaluate its role.     

Is there evidence for a latent class called 'hypomanic temperament'?

BACKGROUND: Affective disorders belong to the most common psychiatric disorders. Several risk factors have been postulated and empirically investigated. Researchers like Akiskal [Interpersonal Factors in the Origin and Course of Affective Disorders, Gaskell, London, 1996] have pointed out the associations between sub-affective temperaments and affective disorders. However, no study has dealt with the issue whether there is a latent class of such sub-affective temperaments or if such temperaments are best conceptualized as fully dimensional. We investigated whether the Hypomanic Personality Scale [J. Abnorm. Psychol. 121 (1986) 214-222] as an indicator of hyperthymia is taxonic in structure. METHODS: We chose two different samples to address this issue: A sample of young adults (n = 1,966) and another sample of adolescents (n = 4,045). We ran MAXCOV-HITMAX analyses based on identical subsets of items in both samples. RESULTS: Neither in the sample of young adults nor in the sample of adolescents there was evidence for a latent class called 'hypomanic temperament'. LIMITATION: Only one indicator for vulnerability and one procedure to test for latent classes was used. Furthermore, we do not know how many of our sample had a life-time history or current affective disorders. CONCLUSIONS: The hypomanic-hyperthymic temperament is best conceptualized as a dimension in the general population. However, before drawing final conclusions about the taxonicity of the risk for affective disorders, more research is needed using different measures, samples and methods to resolve this question of the dimensionality of vulnerability. Additionally, the question remains open how to conceptualize mania itself.