PubMed · 11634838
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C R Landa. 1987. [Not Available].. https://pubmed.ncbi.nlm.nih.gov/11634838/
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Introduction. Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease caused by the loss of the SMN1 gene, with a variable clinical spectrum determined primarily by the number of copies of the SMN2 gene. The development of new therapies underscores the importance of early molecular diagnosis and genotype-phenotype characterization. Objective. To describe 27 years of experience in the molecular diagnosis of SMA at a pediatric referral hospital in Argentina and to evaluate the correlation between SMN2 copy number and the SMA types.Population and methods. A retrospective descriptive study was conducted on 1060 pediatric patients with clinically suspected SMA who were evaluated between 1997 and 2024. Molecular diagnosis was performed using PCR-RFLP and, since 2012, MLPA to determine SMN1 and SMN2 copy number. Genotype-phenotype correlation was evaluated in 260 patients with complete clinical characterization. Results. The diagnosis was confirmed in 513 patients. A homozygous deletion of the SMN1 gene was detected in 99.6% of unrelated cases. The positivity rate increased over time. A significant correlation was observed between the number of SMN2 copies and the type of SMA, with milder phenotypes associated with a higher number of copies. Conclusion. Molecular diagnosis of SMA enabled accurate and timely characterization of patients, avoiding invasive procedures and optimizing therapeutic decision-making. Genotype-phenotype correlation is a fundamental tool for prognosis and clinical management, highlighting the importance of an interdisciplinary approach.
BACKGROUND: Human cytomegalovirus (CMV) is one of the most commonly found agents of congenital infections. Primary maternal infection is associated with risk of symptomatic congenital diseases, and high morbidity is frequently associated with very low birth weight. Neonates with asymptomatic infection develop various sequelae during infancy. This is the first Argentine study performed in neonates with congenital and postnatal HCMV infection. The purpose of this study was to evaluate the performance of the polymerase chain reaction (PCR) technique with different pairs of primers, to detect cytomegalovirus isolated in tissue cultures and directly in urine and dried blood spot (DBS) specimens. Results were compared with IgM detection. METHODS: The study was performed between 1999 and 2001 on routine samples in the Laboratory. A total of 61 urine and 56 serum samples were selected from 61 newborns/infants, 33 patients whose samples were analyzed during the first two to three weeks of life were considered congenital infections; the remaining 28 patients whose samples were taken later than the third week were grouped as perinatal infections, although only in 4 the perinatal transmission of infection was determined unequivocally. Cytomegalovirus diagnosis was made by isolating the virus from urine samples in human foreskin fibroblast cells. Three different primer pairs directed to IE, LA and gB genes were used for the HCMV PCR assay in viral isolates. Subsequently, PCR and nested PCR (nPCR) assays with gB primers were performed directly in urine and in 11 samples of dried blood spot (DBS) on Guthrie Card, these results were then compared with serology. RESULTS: The main clinical manifestations of the 33 patients with congenital infection were purpura, jaundice, hepatomegaly and anaemia. Three patients presented low birth weight as single symptom, 10, intracranial calcifications, and 2, kidney failure. In the 28 patients grouped as with perinatal infection, anaemia, hepatosplenomegaly and enzymatic alteration were predominant, and 4 patients were HIV positive. The primers used to amplify the gB region had a PCR positivity rate of 100%, whereas those that amplified IE and LA regions had a PCR positivity rate of 54% and 61% respectively, in CMV isolates. Amplification by PCR of urine samples (with no previous DNA extraction), using primers for the gB region, detected 34/61 positive samples. Out of the 33 samples from patients with congenital infection, 24 (73%) were positive. When nPCR was used in these samples, all were positive, whereas in the remaining 28 patients, two negative cases were found. Cytomegalovirus DNA detection in 11 samples was also carried out in DBS: 7 DBS samples were positive and 4 were negative. CONCLUSIONS: Primers directed to the gB fragment region were the best choice for the detection of CMV DNA in positive isolates. In congenital infections, direct PCR in urine was positive in a high percentage (73%) of samples; however, in patients grouped as with perinatal infection only 36% of the cases were positive. With n-PCR, total sample positivity reached 97%. PCR technique performed in DBS allowed identifying congenital infection in four patients and to be confirmed in 3. These results show the value of nPCR for the detection of all cases of CMV infection. The assay offers the advantage that it may be performed within the normal working day and provides reliable results in a much shorter time frame than that required for either traditional tissue culture or the shell-viral assay.
CONTEXT: The success of measures to restrict smoking in indoor environments and the intensity of enforcement vary among countries around the world. In 2001, the Pan American Health Organization (PAHO) launched the Smoke-Free Americas Initiative to build capacity to achieve smoke-free environments in Latin America and the Caribbean. OBJECTIVE: To assess secondhand smoke concentrations in public places in the capital cities of Argentina, Brazil, Chile, Costa Rica, Paraguay, Peru, and Uruguay in conjunction with the Smoke-Free Americas Initiative. DESIGN AND SETTING: Multicountry assessment of vapor-phase nicotine concentrations using a common protocol in all 7 Latin American countries. A total of 633 sampling devices were placed for 7 to 14 days in 1 hospital, 2 secondary schools, 1 city government building, 1 airport (2 in Argentina), and restaurants and bars in each country. MAIN OUTCOME MEASURE: Concentrations of airborne nicotine. RESULTS: Airborne nicotine was detected in most (94%) of the locations surveyed. By country, Argentina and Uruguay had the highest median concentrations in most environments (eg, in hospitals: 1.33 [interquartile range [IQR], 0.51-3.12] microg/m3 and 0.8 [IQR, 0.30-1.69] microg/m3, respectively). Overall, bars and restaurants had the highest median concentrations (3.65 [IQR, 1.55-5.12] microg/m3 and 1.24 [IQR, 0.41-2.48] microg/m3, respectively). Nicotine concentrations were also found in a number of key, sentinel buildings, including 95% (155/163) of hospital samples (in the physicians' and nurses' stations the median was 0.27 [IQR, 0.02-1.94] microg/m3), schools, government buildings, and/or airports in most countries. CONCLUSIONS: The finding of airborne nicotine in critical locations in Latin America provides a basis for enforcing smoke-free initiatives and for strengthening the protection of the public from unwanted exposure to secondhand smoke.