The transcriptional activator Opaque-2 controls the expression of a cytosolic form of pyruvate orthophosphate dikinase-1 in maize endosperms.

The maize Opaque-2 (O2) protein is a transcription factor of the basic/leucine-zipper class, involved in the regulation of endosperm proteins including the 22kDa alpha-zein storage proteins and b32 protein. In this study we have focussed our attention on the relationship between O2 and the cyPPDK1 gene, which encodes a cytoplasmic pyruvate orthophosphate dikinase (PPDK) isoform. The results of this study showed that PPDK activity is detectable in wild-type maize endosperms, while in o2 mutant endosperms, the levels of PPDK protein, mRNA and enzymatic activity are reduced, indicating that O2 is involved in the regulation of cyPPDK1 in this tissue. By employing transient expression experiments in tobacco mesophyll protoplasts, we have demonstrated that the O2 protein can activate expression of a chloramphenicol acetyl transferase reporter gene placed under the control of the cyPPDK1 promoter. An in vitro binding assay and DNaseI footprint analysis demonstrated that a specific sequence in the cyPPDK1 promoter can be recognized and protected by maize O2 protein. The regulation by the O2 locus of cyPPDK1 reported here, and control of alpha-zein synthesis by O2 suggest that the O2 protein may play a more general role in maize endosperm development than previously thought.

Use and misuse of antidepressant drugs in a random sample of the population of Rome, Italy.

Prescribing patterns of antidepressant drugs were studied, over a period of 30 months, in a random sample of 8743 residents of the area of Rome, Italy. Data from the regional outpatient drug monitoring system were used. The proportion of subjects receiving, during the study period, at least one prescription of antidepressant drugs, was 5.4%; the female-to-male ratio was 2.1. Consumption prevalence increased with age. The single most prescribed drug was fluoxetine followed by amitriptyline and ademetionine. For a surprisingly high proportion of subjects, the observed length of treatment was shorter than expected on the basis of current knowledge in clinical pharmacology. Inappropriate diagnostic and therapeutic procedures are likely explanations.

Genetic variation of foot-and-mouth disease virus from field outbreaks to laboratory isolation.

Foot-and-mouth disease virus (FMDV), by nature of its RNA genome, possesses a high rate of mutation during replication. This results in extensive genetic polymorphism of virus populations in nature. The emergence of FMDV variants during replication has been reported. Genetic changes in the viral capsid protein (VP1) gene can result in amino acid changes affecting the immunodominant epitopes of FMDV. The genetic heterogeneity of FMDV in the field and the antigenic variants observed after cell culture isolation has been investigated by PCR sequencing and reactivity with monoclonal antibodies. These methods were applied to viruses causing two different outbreaks of FMD before and after replication in cell culture and in the animal host. The VP1 region of the genome was amplified by PCR and sequenced to reveal variant sequences identified after passage and to determine their presence in the original field tissue. In one case, reactivity with monoclonal antibodies was lost after passage as a result of an amino acid change in the subpopulation. These findings suggest that host cells can select specific virus genetic and antigenic subpopulations during virus isolation and propagation.

The search for improved methods for diagnosing leptospirosis: the approach of a laboratory in Brescia, Italy.

The authors describe work in progress at the laboratory in Brescia, Italy, on the application of molecular methods to the diagnosis of leptospirosis. This work includes the following: a) Development of polymerase chain reaction (PCR) assays capable of amplifying specific deoxyribonucleic acid fragments from most Leptospira interrogans strains. b) Development of a microtitre-based assay for rapid detection of PCR-positive samples. c) Characterisation of Leptospira strains through restriction endonuclease analysis of PCR products and amplified fragment length polymorphism.

[Severe arterial spasm and secondary thromboses of the limbs in chronic ergotism]. / Grave arteriospasmo e trombosi secondarie agli arti da ergotismo cronico.

A 40 year old woman who took a daily dose of 2-4 mg of Ergotamine Tartrate (Cafergot) regularly for 6 years to combat persistent migraine, was treated for a non-atherosclerotic arterial disease, severe arteriospasm of the great limb arteries, hyperplasia of the intima and segmental thrombosis. Binding of adrenergic alpha and beta receptors was investigated. Surprisingly it was found that the number of adrenergic beta receptors was significantly lower thant that of a healthy woman of the same age used as a control while the number of alpha receptors was not significantly different. This action of ergotamine on beta receptors could be explained by a dopamine-mimetic stimulation, due to the central nervous system, that could lead to the preferential regulation of beta receptors rather than alpha receptors, almost as a protective mechanism of alpha receptors.

Late sequelae of Perthe's disease (long-term follow-up of 34 hips).

The long-term results were studied in 31 patients (34 hips) with Perthe's disease. The patients were divided into two groups (above and below 25 years of age) in order to study the time at which the late complications become clinically and radiologically evident. The incidence of painful hip and radiological arthrosis is reported in each group in relation to age and initial grade of the disease. The significant prognostic factors were the initial severity of the disease (Types 1-3), the age at which it appeared, and the shape of the femoral head as assessed by the method of Mose. Treatment had been so varied that it was excluded as a factor in our analysis. The development of painful hip and radiological arthrosis (not always painful) only appeared to a significant extent in patients over the age of 25 at follow-up, and both were directly related to the initial grade of the disease.