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Transgenic tomato plants expressing an Arabidopsis thionin (Thi2.1) driven by fruit-inactive promoter battle against phytopathogenic attack.

Tomato is one of the most important crop plants; however, attacks by pathogens can cause serious losses in production. In this report, we explore the potential of using the Arabidopsis thionin (Thi2.1) gene to genetically engineer enhanced resistance to multiple diseases in tomato. Potential thionin toxicity in fruits was negated by the use of a fruit-inactive promoter to drive the Thi2.1 gene. In transgenic lines containing RB7/Thi2.1, constitutive Thi2.1 expression was detected in roots and incidentally in leaves, but not in fruits. Disease assays revealed that the transgenic lines that were tested conferred significant levels of enhanced resistance to bacterial wilt (BW) and Fusarium wilt (FW). Further studies indicated that BW disease progression in transgenic lines was delayed by a systemic suppression of bacterial multiplication. By adopting a safe genetic engineering strategy, the present investigation is another step forward demonstrating thionin practicality in crop protection.

Antimicrobial Cationic Peptides↗

Repair-resistant mutation in Neurospora.

Chronic UV treatment produces severalfold fewer mutations in Neurospora conidia than does the same total dose of acute UV. Experiments were designed to determine the conditions required for chronic UV mutagenesis. Measurement of the coincidence frequency for two independent mutations revealed the existence of a subset of cells which are mutable by chronic UV. Analysis of forward mutation at the mtr locus showed that the genetic alterations produced by chronic UV were virtually all point mutants, even though the assay system could detect alterations or deletions extending into neighboring genes. A significant fraction of the mutants produced by acute UV were multigenic deletions. The size of the dose-rate effect (acute UV mutation frequency divided by chronic UV mutation frequency) was compared for several different mutation assay systems. Forward mutations (recessive lethals and mtr) gave values ranging from four to nine. For events which were restricted to specific molecular sites (specific reversions and nonsense suppressor mutations), there was a wider range of dose-rate ratios. This suggests that chronic UV mutation may be restricted to certain molecular sequences or configurations.

Chromosome Deletion↗

Genetic effects induced in Saccharomyces cerevisiae by cyclophosphamide in vitro without liver enzyme preparations.

Cyclophosphamide induced forward mutation in Saccharomyces cerevisiae strain S288C and mitotic recombination in strains D3 and D5 but not in strain D4. The yeast cells were treated with the compound in phosphate buffer without recourse to metabolic activation protocols. Elevation of the treatment temperature increased the genetic activity of cyclophosphamide. Respiration-deficient isolates of strains S288C and D3 were more sensitive than the respiratory competent parent strains were for inducing forward mutation and mitotic recombination, respectively. Cyclophosphamide was incubated in phosphate buffer alone for increasing time intervals; strain D3 cells were added to aliquots for each time interval and incubated for an additional 30 min. The frequency of induced recombination increased as the time of compound incubation increased, showing that spontaneous degradation of cyclophosphamide to genetically active breakdown products was responsible for the genetic damage induced in the yeast cells.

Cyclophosphamide↗

[Ageing, genetics and the somatotropic axis].

Research on ageing made a big leap forward when genes regulating lifespan were discovered about a decade ago. First isolated by screening the genome of the nematode Caenorhabditis elegans, most of these genes belong to an essential signalling pathway that is highly conserved during animal evolution. Orthologous genes in vertebrate species are the families of genes coding for insulin, insulin-like growth factors (IGF) and related proteins. Intensively studied and well-known for their pivotal roles in proliferation, differentiation, survival and metabolism of most cells, we now discover their multiples functions with respect to the control of longevity and their ability to modulate the cell's responses to oxidative stress, a major cause of cellular and organismal ageing. The activity of IGF signalling in mammals depends on a complex interplay of endocrine signals that together constitute the somatotropic axis. Accordingly, several components of this hormone axis, like growth hormone or growth hormone releasing hormone receptors, regulate efficiently animal longevity, which has been elegantly demonstrated by studies performed in genetically modified mouse models. From this and other work, it becomes increasingly clear that the control of ageing is a question of hormonal regulations. We here present several of these models and discuss the respective contributions of insulin and IGF signalling to the regulation of lifespan. We review data on the Klotho gene that acts on lifespan via surprising and not yet fully understood molecular mechanisms, connecting this new, hormone-like substance to IGF and insulin signalling. We further report recent evidence showing that human lifespan might be controlled in similar ways. Finally, we shed some light on clinical GH treatment in humans, from an endocrinologist's point of view.

Aging↗

Third International Conference on Systemic Lupus Erythematosus.

A Fourth International Conference on Systemic Lupus Erythematosus will be held in Jerusalem in March 1995. We look forward to a better understanding of the molecular, genetic, immunologic, and clinical aspects of the disease and trust that this knowledge will result in improved treatment.

Animals↗

Cavernous angioma associated with oligo-astrocytoma-like proliferation. Report of two cases and review of the literature with a reappraisal of the term "angioglioma".

Reporting two cases of cavernous angioma closely associated with oligo-astrocytoma we were stimulated to revise the proper use of the term "angioglioma", introduced by Councilman 80 years ago7. In the past this term was often used in a merely descriptive sense i.e. either to give a name to an exceptional coincidence of AVM and glioma or simply to describe a hypervascularized glioma. Today, according to the majority of authors, such a use of this term has to be rejected as inappropriate. Occasionally however the term angioglioma has been used to designate a true mixed composite neoplasm developed after the transformation of both glial and angiogenic elements determined by simultaneously or consecutively acting (even possibly intermingled) oncogenic factors. Among reported cases claimed to be examples of "true" angioglioma, the association cavernomaoligodendroglioma/astrocytoma seems the most intriguing besides being also the most frequent one. Opinions about this topic however did continue to be unequivocal. While some authors regarded the oligodendroglial proliferation associated with AVM as merely reactive or malformative, others considered it as truly neoplastic putting forward the hypothesis of a common viral or genetic aetiology for both AVM and glioma.

Adult↗

QSAR for non-nucleoside inhibitors of HIV-1 reverse transcriptase.

By means of QSAR algorithms we model the potency pIC(90) [mM] of 154 non-nucleoside reverse transcriptase inhibitors (NNRTI) of the wild-type HIV-1 virus, considered as the second generation analogues of Efavirenz. In addition, 56 inhibitors of the K-103N viral mutant form are also investigated. A pool of 1494 theoretical molecular descriptors provided mainly by the Dragon 5 software is explored by several methods of variable selection: forward stepwise regression, the replacement method, and the genetic algorithm approach. The optimal models found include up to seven parameters: R = 0.7991, R(l-20%-o) = 0.7233 for the case of wild-type, and R = 0.9261, R(l-5%-o) = 0.8802 for the K-103N mutation.

Alkynes↗

ACE2: A novel therapeutic target for cardiovascular diseases.

Hypertension afflicts over 65 million Americans and poses an increased risk for cardiovascular morbidity such as stroke, myocardial infarction and end-stage renal disease resulting in significant mortality. Overactivity of the renin-angiotensin system (RAS) has been identified as an important determinant that is implicated in the etiology of these diseases and therefore represents a major target for therapy. In spite of the successes of drugs inhibiting various elements of the RAS, the incidence of hypertension and cardiovascular diseases remain steadily on the rise. This has lead many investigators to seek novel and innovative approaches, taking advantage of new pathways and technologies, for the control and possibly the cure of hypertension and related pathologies. The main objective of this review is to forward the concept that gene therapy and the genetic targeting of the RAS is the future avenue for the successful control and treatment of hypertension and cardiovascular diseases. We will present argument that genetic targeting of angiotensin-converting enzyme 2 (ACE2), a newly discovered member of the RAS, is ideally poised for this purpose. This will be accomplished by discussion of the following: (i) summary of our current understanding of the RAS with a focus on the systemic versus tissue counterparts as they relate to hypertension and other cardiovascular pathologies; (ii) the newly discovered ACE2 enzyme with its physiological and pathophysiological implications; (iii) summary of the current antihypertensive pharmacotherapy and its limitations; (iv) the discovery and design of ACE inhibitors; (v) the emerging concepts for ACE2 drug design; (vi) the current status of genetic targeting of the RAS; (vii) the potential of ACE2 as a therapeutic target for hypertension and cardiovascular disease treatment; and (viii) future perspectives for the treatment of cardiovascular diseases.

Angiotensin-Converting Enzyme 2↗

Gestational carcinoma of the female breast.

Few neoplastic diseases can equal the amazing complexity and sheer perversity of carcinoma of the breast. No doubt as many decades of research lie ahead in its study as already have passed. Clinicians have long appreciated the special relationship of the disease to gestation. Diagnosis and treatment of breast cancer during pregnancy represent only a small part of this fascinating relationship. Although indispensable as research tools, animal models pertain to the human disease only in limited, ill-defined ways. The etiology of human breast cancer remains unclear; chemical, viral, hormonal, genetic, and immunologic theories have all been put forward as possibilities. Although gestation clearly alters both the initiation and growth of mammary tumors, its exact role in the various theoretical considerations remains a mystery. The obstetrician-gynecologist holds an important front-line position in the war against breast cancer, as does any provider of primary care to women, and, indeed, as do women themselves. Rather than decrease vigilance during pregnancy, the physician should pursue with extra vigor any breast mass discovered in the gravid patient, when the clinical examination is even less reliable than usual. The finding of a breast mass usually necessitates biopsy. Except for the inclusion of specific pregnancy-related problems, such as galactocele, the diagnostic spectrum of breast masses removed during pregnancy does not differ from that in nonpregnant women. The discovery of a highly suspicious breast mass, or the confirmed biopsy diagnosis of malignancy, in a pregnant patient should indicate the need for referral to a surgical oncologist versed in this unusual problem. The best approach to gestational breast cancer continues to be the team approach, with consultation from specialists in obstetrics, surgical oncology, anesthesiology, nuclear medicine, radiology, radiation oncology, pathology, and medical oncology. The age and general condition of the patient, the extent of the tumor, the stage of gestation, and the informed opinions of the patient and her spouse help to determine the therapeutic strategy. Careful staging not only guides present therapy but also the therapy of future victims through continued investigation. Most surgeons favor operation without delay if cure seems within reach. Mastectomy, with or without cesarean section, can be accomplished without detriment in the hands of a knowledgeable surgeon-anesthesiologist team. By following certain guidelines, the search for metastasis can be conducted safely and appropriately. The clinical situation occasionally may require the initiation of adjuvant radiotherapy or chemotherapy during pregnancy, by experienced consultants. Ongoing studies of tissue hormone receptors and cell kinetics will continue to give insight into the effects of gestational hormones on breast cancer and can aid in the selection of treatment options for the individual patient...

Abortion, Therapeutic↗

Can we justify spermatid microinjection for severe male factor infertility?

During 1995 and 1996 the first spermatid pregnancies were announced with both round spermatid (ROSI) and elongated spermatid (ELSI) injections. These publications were flanked by live births from ROSI in a number of animal species, with resulting offspring appearing normal, healthy and fertile. However, the live births in humans heralded a scientific and ethical debate on the clinical use of this technology; and in a number of countries nationwide moratoria prohibiting spermatid microinjection were enjoined. Concerns surrounded the biological condition of spermatids and clinical implications of utilizing an immature spermatozoon for conception. Nevertheless, case reports and a few scientific studies on human spermatid conception have been published in recent years, and further polemic on testicular histopathology and prognosis has ensued. This paper reviews the current arguments on the clinical use of ROSI and ELSI, and evaluates the biology of the main contributory components of a spermatozoon to the subsequent embryo, namely the genetic material, the microtubular organizing complex and the putative oocyte activating factor. We also consider the relevant testicular histopathology and likely outcome in the context of the current birth rate from ROSI and ICSI. We conclude by considering the way forward for infertile men who require this technology to become genetic fathers, and whether the time is now appropriate to consider clinical trials.

Clinical Trials as Topic↗

Malignant melanoma: genetics and therapeutics in the genomic era.

Cell for cell, probably no human cancer is as aggressive as melanoma. It is among a handful of cancers whose dimensions are reported in millimeters. Tumor thickness approaching 4 mm presents a high risk of metastasis, and a diagnosis of metastatic melanoma carries with it an abysmal median survival of 6-9 mo. What features of this malignancy account for such aggressive behavior? Is it the migratory history of its cell of origin or the programmed adaptation of its differentiated progeny to environmental stress, particularly ultraviolet radiation? While the answers to these questions are far from complete, major strides have been made in our understanding of the cellular, molecular, and genetic underpinnings of melanoma. More importantly, these discoveries carry profound implications for the development of therapies focused directly at the molecular engines driving melanoma, suggesting that we may have reached the brink of an unprecedented opportunity to translate basic science into clinical advances. In this review, we attempt to summarize our current understanding of the genetics and biology of this disease, drawing from expanding genomic information and lessons from development and genetically engineered mouse models. In addition, we look forward toward how these new insights will impact on therapeutic options for metastatic melanoma in the near future.

Animals↗

Molecular signals for late Tertiary/early Quaternary range splits of an Eurasian steppe plant: Clausia aprica (Brassicaceae).

Several vegetation belts stretch continuously from Europe to Asia, taiga and steppe being most prominent. Numerous plant species within these belts share a conspicuous distribution area, which is longitudinally contracted or disrupted approximately along longitude 70 degrees E. To date no hypothesis for this intriguing distribution pattern has been put forward. We detected molecular footprints in the contemporary genetic composition in nuclear DNA (ITS1, ITS2) and chloroplast DNA (trnL-trnF spacer region) of the steppe element Clausia aprica (Brassicaceae) providing evidence for a severe longitudinal range split and genetic differentiation east of the Ural Mountains about 1 million years ago caused by Quaternary climatic oscillations. Clausia aprica provides the first phylogeographical analysis on the intraspecific evolution of an Eurasian steppe plant.

Asia↗

The amyloid precursor protein: beyond amyloid.

The amyloid precursor protein (APP) takes a central position in Alzheimer's disease (AD) pathogenesis: APP processing generates the beta-amyloid (Abeta) peptides, which are deposited as the amyloid plaques in brains of AD individuals; Point mutations and duplications of APP are causal for a subset of early onset of familial Alzheimer's disease (FAD). Not surprisingly, the production and pathogenic effect of Abeta has been the central focus in AD field. Nevertheless, the biological properties of APP have also been the subject of intense investigation since its identification nearly 20 years ago as it demonstrates a number of interesting putative physiological roles. Several attractive models of APP function have been put forward recently based on in vitro biochemical studies. Genetic analyses of gain- and loss-of-function mutants in Drosophila and mouse have also revealed important insights into its biological activities in vivo. This article will review the current understanding of APP physiological functions.

Journal Article↗

[Brooke-Spiegler syndrome].

BACKGROUND: Brooke-Spiegler syndrome is an association of multiple trichoepitheliomas and cylindromas, sometimes accompanied by other adnexal tumors. CASE REPORT: A 44-year-old woman with trichoepitheliomas involving the naso-genal and mental areas associated with cylindromas and spiradenomas on the forehead and pretragal regions creating a turban effect. Other complete or diassociated syndromes were found in family members. No neoplastic tumor was identified. DISCUSSION: Brooke-Spiegler syndrome is an hereditary disease with autosomal dominant transmission. Both benign and malignant neoplasias can be associated. The concomitant existence of different tumors could be helpful in understanding the pathophysiology. There is some debate about the exact origin of the trichoepitheliomas, cylindromas and spiradenomas. Several single-cause theories have been put forward but remain to be confirmed as the genetic anomalies identified for trichoepitheliomas and cylindromas map to different sites. Patients with Brooke-Spiegler syndrome should be explored for malignant neoplasia. A family study is indicated.

Adenoma, Sweat Gland↗

Severe acute respiratory syndrome-associated coronavirus genotype and its characterization.

OBJECTIVE: To study the severe acute respiratory syndrome (SARS)-associated coronavirus genotype and its characteristics. METHODS: A SARS-associated coronavirus isolate named ZJ01 was obtained from throat swab samples taken from a patient in Hangzhou, Zhejing province. The complete genome sequence of ZJ01 consisted of 29,715 bp (GenBank accession: AY297028, version: gi: 30910859). Seventeen SARS-associated coronavirus genome sequences in GenBank were compared to analyze the common sequence variations and the probability of co-occurrence of multiple polymorphisms or mutations. Phylogenetic analysis of those sequences was done. RESULTS: By bioinformatics processing and analysis, the 5 loci nucleotides at ZJ01 genome were found being T, T, G, T and T, respectively. Compared with other SARS-associated coronavirus genomes in the GenBank database, an A/G mutation was detected besides the other 4 mutation loci (C:G:C:C/T:T:T:T) involved in this genetic signature. Therefore a new definition was put forward according to the 5 mutation loci. SARS-associated coronavirus strains would be grouped into two genotypes (C:G:A:C:C/T:T:G:T:T), and abbreviated as SARS coronavirus C genotype and T genotype. On the basis of this new definition, the ZJ01 isolate belongs to SARS-associated coronavirus T genotype, first discovered and reported in mainland China. Phylogenetic analysis of the spike protein gene fragments of these SARS-associated coronavirus strains showed that the GZ01 isolate was phylogenetically distinct from other isolates, and compared with groups F1 and F2 of the T genotype, the isolates of BJ01 and CUHK-W1 were more closely related to the GZ01 isolate. It was interesting to find that two (A/G and C/T) of the five mutation loci occurred in the spike protein gene, which caused changes of Asp to Gly and Thr to Ile in the protein, respectively. CONCLUSION: Attention should be paid to whether these genotype and mutation patterns are related to the virus's biological activities,epidemic characteristics and host clinical symptoms.

Genotype↗

[Alzheimer's type dementia: recent data].

Dementia of the Alzheimer type (DTA) is the most common form of adult-onset dementia. The clinical features of the disease include progressive memory defect, intellectual impairment and behavioral disturbances. The number of patients suffering from DTA is increasing dramatically, due to the growing proportion of old people. DTA therefore is a major public health problem. Brain lesions include several histopathological changes (mostly in the cerebral cortex and hippocampus): neurofibrillary tangles, senile plaques, granulo-vacuolar degeneration, Hirano bodies, angiopathy, loss of nerve cells. Postmortem brain examination reveals characteristic neurochemical deficits. The most consistent reduction in neurotransmitter-synthesizing enzyme observed so far is a reduction in choline acetyltransferase activity, suggesting a cholinergic deficit. However, other deficits involving noradrenaline and somatostatin have also been reported. Several hypotheses (genetic, viral, toxic, immunologic, metabolic) have been put forward in order to explain DTA. The relationship between these hypotheses and the neurochemical deficits is still unclear, but the existence of characteristic neurotransmitter-related deficits allows specific therapeutic trials.

Aged↗

New diagnostic findings in coeliac disease.

Coeliac disease, a life-long gluten-sensitive disorder, characterized by malabsorption, villous atrophy and crypt hyperplasia, is well recognized. However, the disease is evidently underdiagnosed, and the classic forms constitute only the tip of the 'coeliac iceberg'. Patients with coeliac disease can have subtle symptoms, if any. Diagnostic difficulties may further emerge when minor mucosal changes are found. In coeliac screening and case-finding a novel test, the antitissue transglutaminase test, has proven promising with a sensitivity and specificity of over 95 %. Genetic and immunohistological research has taken a great leap forward. Coeliac disease is strongly associated with HLA-DQ2, coded by the DQA1*0501 and DQB1*02 alleles, or the DQ8 (DQA1*03, DQB1*0302 alleles). The disease is rare in patients who do not share these alleles, a circumstance which can be utilized in diagnostics. An increase in small bowel intraepithelial lymphocytes especially gammadelta+ T-cell receptor-bearing cells is typical, albeit not pathognomonic, for coeliac disease. Combining new symptoms, humoral immunity, genetics and immunohistological staining can today offer a greater diagnostic scope for coeliac disease, especially in cases where clinical presentation and small bowel biopsy findings remain doubtful.

Alleles↗

[Cardiomyopathies].

Cardiomyopathies, and more specifically hypertrophic cardiomyopathy, have opened the route to what is now called genetic cardiology. Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left and/or right ventricular hypertrophy, and disorganisation of tissular architecture. Approximately 60% of HCM are transmitted as an autosomal dominant trait. The clinical aspects of HCM vary markedly, and several morphological variants were described, depending on the localization of hypertrophy. This pathology is often complicated by cardiac failure, but the major risk is sudden death, and the predictive factors are presently very unrefined. Several pathogenic hypotheses were forwarded in the past, and one surprising result of genetic analyses is that none of these hypotheses was confirmed. Four disease genes were identified, and they encode sarcomeric proteins, cardiac myosin heavy chain, troponin T, tropomyosin and cardiac myosin binding protein C. To this high intergenic heterogeneity is associated a high intragenic heterogeneity. A major fall out of these genetic findings is the recent discovery of adult healthy carriers, around 30% in our experience. Genetype/phenotype relationships are being performed, and this is the first approach to a prognostic evaluation based on genetic localisation. The work on hypertrophic cardiomyopathy is currently being used as a model to analyse dilated cardiomyopathies, characterized by dilatation and impaired contraction of the left or both ventricles. The mode of inheritance of these forms of cardiomyopathies is complex. Five families with an autosomal inheritance were analyzed since two years, the loci were found, but the disease genes are not identified yet. Identification of patients at high risk and early treatment or prevention are the current goals.

Cardiomyopathies↗