Systematic genetic study of Alzheimer disease in Latin America: mutation frequencies of the amyloid beta precursor protein and presenilin genes in Colombia

Nearly all mutations in the presenilin 1 (PSEN1), presenilin 2 (PSEN2), and amyloid beta precursor protein (APP) genes lead to early-onset Alzheimer disease (EOAD, onset age at or before 65 years). In order to assess the genetic contribution of these genes in a series of Colombian AD cases, we performed a systematic mutation analysis in 11 autosomal dominant, 23 familial, and 42 sporadic AD patients (34% with age of onset < or = 65 years). No APP missense mutations were identified. In three autosomal dominant cases (27.2%), two different PSEN1 missense mutations were identified. Both PSEN1 mutations are missense mutations that occurred in early-onset autosomal AD cases: an I143T mutation in one case (onset age 30 years) and an E280A mutation in two other cases (onset ages 35 and 42 years). In addition, a novel PSEN1 V94M mutation was present in one early-onset AD case without known family history (onset age 53 years) and absent in 53 controls. The E318G polymorphism was present in five AD cases and absent in controls. In PSEN2, two different silent mutations were detected, including one not reported elsewhere (P129). The majority of the Colombian AD cases, predominantly late-onset, were negative for PSEN and APP mutations.

Human and dogs Toxocara canis infection in a poor neighborhood in Bogota

Prevalence of Toxocara canis antibodies was studied in a poor community of Bogotá, Colombia. Two-hundred-seven patients, from both sexes and all age groups, were studied. Positive ELISA titers were found in 47.5% of the population, a high prevalence compared with reports from developed countries. T. canis ova were positive in 43.6% of fecal samples from dog puppies. An endemic pattern of the disease is described: socioeconomic status, weather, pollution, poor hygiene and a significant population of infected dogs. Neither the physical examination nor ELISA titers could detect any case of T. canis disease.

APOE epsilon4 and Alzheimer's disease: positive association in a Colombian clinical series and review of the Latin-American studies

OBJECTIVE

As the strength of the association between the APOE epsilon4 allele and Alzheimer's disease (AD) varies across ethnic groups, we studied if there was such an association in Colombian patients.

METHOD

We performed apolipoprotein E (APOE) genotyping in a clinical sample of 83 unrelated AD patients, predominantly late-onset (>65 yrs) including familial ( n =30) and sporadic AD cases (n= 53) diagnosed according to NINCDS-ADRDA criteria and assessed by a multi-disciplinary team. Control subjects (n = 44) had no significant cognitive impairment by medical interview and neuro-psychological testing.

RESULTS

We found a high association (OR= 5.1 95%CI 1.9 -13.6) between APOE epsilon4 and AD, in this series with predominantly late-onset cases with familial aggregation in 24 cases (28.9%). A significant negative association was found between epsilon2 and AD (OR= 0.2 95% CI 0.05-0.75).

CONCLUSION

Further population-based surveys in Colombia are warranted to precise a possible dose effect of APOE epsilon4.

Assisted Salvage of Ischemic Fasciocutaneous Flap Using Adipose-Derived Mesenchymal Stem Cells: In-Situ Revascularization

Adipose-derived mesenchymal stem cells (ASCs) have been shown to produce vascular endothelial growth factor (VEGF) and can increase perfusion in patients with critical limb ischemia. We will show that this concept can be applied to augment blood flow in zones of flap ischemia. We presented a case study of a 26-year-old man with a complex hand injury covered by a reverse radial perforator fasciocutaneous flap, which developed ischemic necrosis and was treated by debridement, transplantation of ASCs to enhance vascular support, and saline dressings. ASCs are found in the stromal vascular fraction (SVF), a heterogeneous collection of cells, including pericytes and endothelial cells, that is prepared from lipoaspirate using collagenase digestion followed by centrifugation. These were injected into the flap, the palmar tissues both subjacent and peripheral to the flap, and the skin-grafted donor site. The case was documented with photography, measurements at hand therapy, and follow-up angiography MRI. At 72 hours, new vessels appeared diffusely; at 1 week, the remaining tissues of flap were bleeding. The wound, 11 cm × 4 cm, contracted spontaneously and was healed at 21 days. The skin graft over the donor site demonstrated unusual suppleness and elasticity. 3D CT angiography disclosed a new layer of vascularity in the superficial tissues of the palm when compared with the normal side. The patient regained full composite flexion, pinch, opposition, and wrist extension. Application of ASCs into the supporting tissues surrounding the ischemic flap, and into the flap itself, constituted a form of in-situ revascularization (ISR) that was subjectively and objectively effective for this patient.

LEVEL OF EVIDENCE

5.

Bone response to zinalco implants

The evolution of dog femur bone implanted in vivo with either steel or with a metal alloy (zinalco), was compared at different time-periods inverted exclamation markU9 months. Bone behavior was studied by radiology, scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) and it was shown that zinalco corroded whereas the steel remained unaltered in the presence of body fluids. Small amounts of metal ions were released continuously, promoting disordered bone growth enriched with organic tissue. After 9 months, the organism managed to compensate for this effect and the proportion of mineral to organic tissue resulted in being normal, although it was unable to correct the shape and the direction of the growth.

Development of hepatic microsomal activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase and cholesterol 7 alpha-hydroxylase in the young chick

1. The 3-hydroxy-3-methylglutaryl-CoA reductase activity increased from 1 to 4 weeks of age, but decreased from 4 to 8 weeks of age. 2. Cholesterol 7 alpha-hydroxylase activity increased from 1 to 4 weeks, decreased from 4 to 6 weeks, and increased again from 6 to 8 weeks of age. 3. Serum total and free cholesterol concentrations decreased from 1 to 6 weeks of age, but increased from 6 to 8 weeks of age.