Characterisation of SMN hybrid genes in Spanish SMA patients: de novo, homozygous and compound heterozygous cases

Autosomal recessive spinal muscular atrophy (SMA) is classified, by age of onset and maximal motor milestones achieved, into type I (severe form), type II (intermediate form) and type III (mild/moderate form). SMA is caused by mutations in the survival motor neuron telomeric gene (SMN1) and a centromeric functional copy of this gene (SMN2) exists, both genes being located at 5q13. Homozygous deletion of exons 7 and 8 of SMN1 has been detected in approx 85% of Spanish SMA patients regardless of their phenotype. Nineteen cases with the sole deletion of exon 7 but not exon 8 (2 cases of type I, 13 cases of type II, four cases of type III) were further analysed for the presence of SMN2-SMN1 hybrid genes. We detected four different hybrid structures. Most of the patients were carriers of a hybrid structure: centromeric intron 6- centromeric exon 7- telomeric exon 8 (CCT), with or without neuronal apoptosis-inhibitor protein (NAIP). In two patients, a different hybrid structure, viz. telomeric intron 6- centromeric exon 7- telomeric exon 8 (TCT), was detected with or without NAIP. A phenotype-genotype correlation comparing the different structures of the hybrid alleles was delineated. Type I cases in our series are attributable to intrachromosomal deletion with a smaller number of SMN2 copies. Most cases with hybrid genes are type II occurring by a combination of a classical deletion in one chromosome and a hybrid gene in the other. Type III cases are closely associated with homozygozity or compound heterozygozity for hybrid genes resulting from two conversion events and have more copies of hybrid genes and SMN2 than type I or II cases.

Neonatal spinal muscular atrophy with multiple contractures, bone fractures, respiratory insufficiency and 5q13 deletion

We present the case of a floppy neonate with marked and generalized weakness, respiratory insufficiency and fetal akinesia deformation sequence. The infant showed multiple joint contractures, two bone fractures and needed mechanical ventilation from birth to death at 16 days of age. Electrophysiological assessment showed electrically unexcitable motor and sensory nerves. Muscle biopsy showed diffuse atrophy of type I and type II fibers. Necropsy confirmed the diagnosis of infantile spinal muscular atrophy (SMA) with severe loss of motor neurons in anterior horns and motor nuclei of brainstem. There were also neuronal loss, gliosis, chromatolysis, ballooned cells, empty cell beds and neuronophagia figures in other brainstem and brain nuclei. Genetic analysis of the patient revealed homozygous deletions of survival motor neuron gene 1 (SMN1) and a single copy of SMN2 in region 5q13. This case confirms that the loss of spinal motor neurons underlies the muscular atrophy in severe cases of 5q SMA. This case also shows that the presence of multiple joint contractures, bone fractures and respiratory insufficiency in SMA in the neonatal period does not necessarily exclude the occurrence of classical deletions in the SMA 5q13 region. Rather, these atypical clinical findings show the extreme severity and prenatal onset of the disease in these SMA cases, which may be related with the occurrence of a single copy of SMN2 gene. More reports of clinically, pathologically and genetically well-documented cases are essential to define the different types of this disease.

[Standards for the appropriate use of percutaneous transluminal coronary angioplasty and aortocoronary surgery]

INTRODUCTION AND OBJECTIVES

The large differences in rates of use of clinical procedures among regions, hospitals and physicians raise questions as to whether some population groups are receiving inappropriate procedures or others are not receiving necessary ones. The objective of this study is to develop criteria for the appropriate use of coronary revascularization procedures in Spain.

METHODS

Following the RAND appropriateness method, criteria were developed for the appropriate use of coronary revascularization (percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery) in Spain. A literature review was produced as well as a comprehensive and mutually exclusive list of 1,826 indications for coronary revascularization. A panel of 12 experts (4 interventional cardiologists, 4 non-interventional cardiologists and 4 cardiovascular surgeons) rated the appropriateness of each indication on a scale from 1 (highly inappropriate) to 9 (highly appropriate). The ratings were made twice; anonymously in the first round, and during a 2-day meeting in the second round. In accordance with the panelists' mean rating and level of agreement, each indication was classified as appropriate, uncertain or inappropriate for revascularization, angioplasty and bypass surgery.

RESULTS

Criteria have been developed for the appropriate use of angioplasty and bypass surgery which can be applied to patients with coronary artery disease. The combination of clinical characteristics makes it possible to classify patients with a high degree of specificity.

CONCLUSIONS

These criteria can be used retrospectively, to measure the proportions of appropriate use, or prospectively, as an aid to decision making in order to promote the appropriate use of coronary revascularization.

Di-(2-ethylhexyl)phthalate in sewage sludge and post-treated sludge: quantitative determination by HRGC-MS and mass spectral characterization

DEHP was quantified into sewage sludge, thermally dried sludge and compost samples from different areas of Catalonia (North East Spain) using high-resolution gas chromatography (HRGC) coupled to a mass spectrometry (MS). The aim of the work was to determine the evolution of this ubiquitous environmental contaminant along some post-treatment sludge processes, such as composting and thermally drying. DEHP concentration detected in some sludges are above the maximum limit suggested by the EC (100 ppm d.m.) for agricultural use. However, the composting and thermally drying reduce the amount of DEHP in sewage sludge to acceptable level for safe land application. The study was completed with the characterization and long-term observation of DEHP in sewage sludge, composted sludge and thermally dried sludge mixed with two types of soils. In all cases, the percentage of DEHP degraded was higher than 50% after 9 months of incubation.

Determination of three anabolic compounds in calf urine by liquid chromatography with photodiode-array detection

A method for the determination of three anabolic hormones (diethylstilbestrol, dienestrol and trenbolone) in calf urine is described. After enzymatic hydrolysis, the samples were cleaned up by C18 solid-phase extraction. Drugs were extracted with hexane and analyzed by isocratic elution on a Discovery RP-Amide C16 5 microns column with photodiode-array detection at 240 and 347 nm. Both retention time and UV spectra were used for identification. Detection limits for the HPLC system were calculated to be 0.3 ng injected for all analytes in the standard mixture. However, for urine samples these limits increased because of the presence of unidentified matrix components. After extraction from urine, the limits of detection for the whole analytical procedure were 5 and 10 ng injected for trenbolone and stilbenes, respectively. The average recoveries of the hormones from spiked samples were in the range 53.1-56.7% with RSD between 11.3 and 14.5% for the whole procedure in the concentration range 25-2.5 ng ml-1.

Benzimidazo[1,2-c]quinazolines: a new class of antitumor compounds

A series of substituted benzimidazo[1,2-c]quinazolines have been synthesized. This class of compound has been designed by structural comparison with other intercalator patterns. The determination of in vitro activities has shown high inhibitory values.

[The follow-up of the cancer patient: how and when?]

The medical resources devoted to cancer patient follow-up are growing. However, intensive follow-up is not translated to any significant improvement survival in a majority of patients. A few neoplasias have an effective salvage therapy, and are worth having strict follow-up to diagnose earlier the recurrence. In many tumours, as breast cancer, an early diagnosis of recurrence does not imply an improvement on survival. Tumoral markers are able to detect the presence of tumour cells even before being clinically apparent and are routinely used in the follow-up of tumours; however, they do not seem to improve survival. The cost-benefit relation of multiple revision in cancer patients apparently cured is debated. No general consensus is achieved to define the best tests to follow-up cancer patients. The trend is to minimize the diagnostic tests and to recommend a clinical follow-up with anamnesis and physical exploration.

[Incidence of anti-HCV and ALT in blood donors]

A study was carried out in 2,000 blood donors aimed to assess the incidence of anti-C hepatitis virus antibodies. Of the total number of samples, 10 cases were found positive (0.5%), a figure lower than the national average. Of these 10 cases, ALT levels were high in 5 (0.2%). The potential risk of post-transfusion C hepatitis increases in accordance with the number of blood units transfused. This incidence of anti-C hepatitis virus antibodies is discussed with regard to previous findings in other countries, the incidence of positive donors being also very low.