Biomedical subjects

B Berenfeld

Publications and source records attributed to B Berenfeld.

4 recordsLinked to original sources

PubMed1999

Sequence requirements for formation of conformational variants of tau similar to those found in Alzheimer's disease.

Alz-50 and MC-1 monoclonal antibody reactivity is dependent on both the extreme N-terminus of tau (residues 7-9) and a 30-amino acid sequence of tau (amino acids 312-342) in the third microtubule binding domain, suggesting that the specificity of the Alz-50 and MC-1 antibodies for Alzheimer's disease (AD) pathological tau lies in their ability to recognize a specific conformation of the tau molecule in AD. The present study uses deletional and site-directed mutants of tau to further refine the C-terminal (third microtubule binding domain) epitope requirements for Alz-50, MC-1, and several new antibodies that recognize similar epitopes in tau to amino acids 313-322 of tau, and to demonstrate that intervening portions of the tau molecule are not required for the formation of conformational variants of tau similar to those seen in AD. Further analysis of deletional and site-directed mutations of tau demonstrate subtle variations in the epitope requirements for Alz-50, MC-1, CP-1, CP-2, and CP-28, suggesting that these antibodies, albeit different, all recognize a similar pathological conformation of tau. Additional experiments using synthetic peptides demonstrate that the NH2-terminal (amino acids 1-18) and COOH-terminal (amino acids 309-326) portions of the Alz-50, MC-1, CP-1, CP-2, and CP-28 epitopes can interact with high affinity under near physiological conditions.

Alzheimer Disease↗

PubMed1999

Altered conformation of recombinant frontotemporal dementia-17 mutant tau proteins.

Recently, a series of both non-coding (intronic) and coding (exonic) mutations in the tau gene have been linked to a family of autosomal dominant dementias referred to as frontotemporal dementia-17. While linkage analysis has demonstrated that these mutations segregate with disease in affected families, it is unclear how mutant tau proteins could lead to the degenerative cascade seen in frontotemporal dementia-17. The present study demonstrates that coding mutations of tau seen in frontotemporal dementia-17 exhibit altered physical and structural characteristics as determined by reverse phase high performance liquid chromatography and circular dichroism spectroscopy. These data suggest that the previously identified mutations in the tau gene seen in frontotemporal dementia-17 are not merely benign polymorphisms, but may have functional consequences for microtubule binding, microtubule polymerization, and the abnormal aggregation of tau seen in a variety of neurodegenerative diseases.

Chromatography, High Pressure Liquid↗

PubMed1996

[Total knee replacement].

The medical records of 319 patients who underwent 350 primary total knee replacements were analyzed retrospectively. The age range was 44-89 years (average 66). In all we used a Biomet ACG prosthesis and preserved the posterior cruciate ligament. Results, measured objectively with Knee Society scores, were satisfactory for all ages, especially the younger. However, even in older age groups subjective results were promising. We emphasize the importance of preserving the posterior cruciate ligament and its advantages for all age groups.

Adult↗

PubMed1994

[Adamantinoma of the tibia].

Adamantinoma of the tibia is a rare, malignant growth originating in epithelial fetal cells. We present a 17-year-old girl who had prolonged pain in her right calf for 6 years. X-ray showed a growing malignant lesion whose nature was confirmed by biopsy. After planning the anatomical and functional aspects, the tibia was excised in its diaphyseal part, which included the growth with wide margins. Iliac bone was implanted in place of excised tibial bone. After 1 year the implant showed complete healing and had grown to impressive size, ensuring safe carrying of body weight, and the length and function of the limb were completely normal. 4 years postoperatively no pathologic lesion was noted on clinical examination, in X-rays nor in another biopsy of the implanted bone and the surrounding soft tissues.

Adolescent↗