Versatile and Tunable Poly(Ethylene Glycol)-Based Hydrogels Crosslinked through the Ugi Reaction.

The four-component Ugi condensation reaction has been investigated to assemble chemically crosslinked hydrogels using multivalent star-shaped poly(ethylene glycol) components. The resulting biocompatible hydrogels are highly versatile in composition and function. It is shown that acid, aldehyde, and cyanide components can be varied yielding materials with precise structure and tunable stiffness. Additionally, the resulting hydrogels were proven extremely robust to consecutive drying-swelling cycles. This property was explored to develop a reversible humidity colorimetric sensor gel. Overall, this work demonstrates the application of the four-component Ugi reaction as a powerful tool to quickly generate crosslinked gels with precise control in chemical composition.

Affinity-Triggered Assemblies Based on a Designed Peptide-Peptide Affinity Pair.

Affinity-triggered assemblies rely on affinity interactions as the driving force to assemble physically crosslinked networks. WW domains are small hydrophobic proteins binding to proline-rich peptides that are typically produced in the insoluble form. Previous works attempted the biological production of the full WW domain in tandem to generate multivalent components for affinity-triggered hydrogels. In this work, an alternative approach is followed by engineering a 13-mer minimal version of the WW domain that retains the ability to bind to target proline-rich peptides. Both ligand and target peptides are produced chemically and conjugated to multivalent polyethylene glycol, yielding two components. Upon mixing together, they form soft biocompatible affinity-triggered assemblies, stable in stem cell culture media, and display mechanical properties in the same order of magnitude as for those hydrogels formed with the full WW protein in tandem.

Microglandular hyperplasia of the cervix: frequency in cone specimens, histological patterns, clinical aspects and immunohistochemical markers for differential diagnosis with adenocarcinoma

Although endocervical microglandular hyperplasia (MGH) is a common diagnosis, it can be confused with adenocarcinoma (ACa), mainly of the clear cell type. OBJECTIVES: Evaluate the frequency of MGH diagnosis in conization specimens, their histological patterns and characterize the differential diagnosis between MGH and ACa through immunohistochemical markers, as well as some clinical aspects. METHODS: We reviewed 223 cervical cones and 50 ACa in cervical biopsies in order to: 1) assess the frequency of MGH in cones; 2) verify immunohistochemical expression of p53, carcinoembryonic antigen (CEA) and Ki67 in both lesions; 3) correlate the findings to age, parity and hormonal status. RESULTS: We found 35 cases of MGH (15.7 percent), of the following patterns: 21 glandular (60 percent); 7 reticular (20 percent); 6 trabecular (17.1 percent) and one solid (2.8 percent). Average age was 36 years and mean parity was three children. Of the MGH patients, 51.42 percent were pregnant or made use of some hormonal therapy. ACa occurred in older patients (mean: 53 years), multiparous and with no hormonal history. CEA was negative in MGH and positive in 62 percent of ACa. Ki67 was weakly positive (5 percent-10 percent stained nuclei) in 8.6 percent of MGH and strong (> 40 percent stained nuclei) in 80 percent of ACa. p53 expression was negative in MGH and only present in 10 percent of ACa. CONCLUSIONS: MGH was common in cones, mainly in young women. Half of the cases were associated with hormonal therapy or pregnancy. CEA and Ki67 were useful but p53 expression was not important for the differential diagnosis with adenocarcinoma.

Embora a hiperplasia microglandular da endocérvice (MGH) seja um diagnóstico freqüente, algumas vezes pode ser confundida com adenocarcinoma (ACa), principalmente de células claras. OBJETIVOS: Avaliar a freqüência da MGH em cones de colo uterino, seus padrões histológicos e o diagnóstico diferencial entre MGH e ACa, através de marcadores imuno-histoquímicos e de alguns aspectos clínicos. MÉTODOS: Foram revisados 223 cones, bem como 50 biópsias cervicais com o diagnóstico de adenocarcioma para: 1) verificar a freqüência de MGH nos cones; 2) avaliar a expressão de p53, antígeno carcinoembrionário (CEA) e Ki67 nas lesões; 3) correlacionar as lesões com idade, paridade e estado hormonal. RESULTADOS: MGH ocorreu em 35 cones (15,7 por cento), com os padrões glandular (21 [60 por cento]); reticular (7 [20 por cento]); trabecular (6 [17,1 por cento]) e sólido (um [2,8 por cento]). A média de idade foi 36 anos e de paridade, três filhos; 51,42 por cento estavam grávidas ou usavam terapia hormonal. O ACa ocorreu em pacientes mais velhas (média: 53 anos), multíparas e sem história hormonal. CEA foi negativo em todas MGH e positivo em 62 por cento dos ACa. Ki67 apresentou reatividade baixa (5 por cento a 10 por cento dos núcleos corados) em 8,6 por cento das MGH e alta (> 40 por cento dos núcleos corados) em 80 por cento dos ACa. p53 foi negativo na MGH e positivo em apenas 10 por cento dos ACa. CONCLUSÃO: MGH foi freqüentemente encontrada em cones, principalmente em jovens, sendo metade dos casos associada a terapia hormonal ou gravidez. As expressões do CEA e do Ki67 foram importantes no diagnóstico de ACa, porém o p53 não contribuiu para diferenciar as lesões.