1,218 research outputs found
Case Report: Fourth Branchial Cleft Cyst: A Case of Acute Suppurative Thyroiditis
This case report presents a 4 year-old-female patient with a neck mass who was diagnosed with an infected fourth branchial cleft cyst with left thyroid lobe involvement through fistulation. The case emphasizes the importance of considering uncommon etiologies, such as congenital anomalies, as a differential diagnosis when evaluating pediatric neck masses. The patient was prescribed broad-spectrum antibiotics, which led to the regression of the mass and inflammatory signs. Close follow-up in endocrinology and otorhinolaryngology appointments was maintained, and after 7 months, hypoplasia of the left lobe was observed. Thyroid function was reevaluated, and after two years, no recurrences were noted. The case highlights the significance of a comprehensive examination and assessment of corresponding clinical features, which can significantly reduce the rate of misdiagnoses and achieve an individualized diagnosis.info:eu-repo/semantics/publishedVersio
A platform for efficient, thiol-stable conjugation to albumin's native single accessible cysteine
Herein we report the use of bromomaleimides for the construction of stable albumin conjugates via conjugation to its native, single accessible, cysteine followed by hydrolysis. Advantages over the classical maleimide approach are highlighted in terms of quantitative hydrolysis and absence of undesirable retro-Michael deconjugation
The course of specialization in public health in Rio de Janeiro, Brazil, from 1926 to 2006: lessons and challenges
<p>Abstract</p> <p>Background</p> <p>Public health, as a field of knowledge, depends on its professionals. Their education and training, therefore, is considered to be an important factor for the quality of health services. In Brazil, the Course of Specialization in Public Health of the National School of Public Health is one of the oldest in the country. The course has existed for over 80 years, during which it has had an eventful history, with modifications in its organization, interruptions in its delivery, threats to its survival and changes in the institutions hosting it, reflecting the wider transformation in Brazilian society and public life over that period.</p> <p>Methods</p> <p>In this article we analyse this course via its history, disciplines, organization and characteristics of the student body.</p> <p>Results</p> <p>Insights were gained into the advancement of public health in Brazil and the progress of education for professionals in this field was highlighted. The course has formed nearly 2000 specialists in public health.</p> <p>Conclusions</p> <p>An analysis of the course's history provides valuable lessons for other schools of public health trying to train professionals in developing countries.</p
HIPK2 and extrachromosomal histone H2B are separately recruited by Aurora-B for cytokinesis
Cytokinesis, the final phase of cell division, is necessary to form two distinct daughter cells with correct distribution of genomic and cytoplasmic materials. Its failure provokes genetically unstable states, such as tetraploidization and polyploidization, which can contribute to tumorigenesis. Aurora-B kinase controls multiple cytokinetic events, from chromosome condensation to abscission when the midbody is severed. We have previously shown that HIPK2, a kinase involved in DNA damage response and development, localizes at the midbody and contributes to abscission by phosphorylating extrachromosomal histone H2B at Ser14. Of relevance, HIPK2-defective cells do not phosphorylate H2B and do not successfully complete cytokinesis leading to accumulation of binucleated cells, chromosomal instability, and increased tumorigenicity. However, how HIPK2 and H2B are recruited to the midbody during cytokinesis is still unknown. Here, we show that regardless of their direct (H2B) and indirect (HIPK2) binding of chromosomal DNA, both H2B and HIPK2 localize at the midbody independently of nucleic acids. Instead, by using mitotic kinase-specific inhibitors in a spatio-temporal regulated manner, we found that Aurora-B kinase activity is required to recruit both HIPK2 and H2B to the midbody. Molecular characterization showed that Aurora-B directly binds and phosphorylates H2B at Ser32 while indirectly recruits HIPK2 through the central spindle components MgcRacGAP and PRC1. Thus, among different cytokinetic functions, Aurora-B separately recruits HIPK2 and H2B to the midbody and these activities contribute to faithful cytokinesis
Next generation maleimides enable the controlled assembly of antibody-drug conjugates via native disulfide bond bridging
The advent of Adcetrisâą and Kadcylaâą, two recently FDA-approved antibody-drug conjugates (ADCs), in the clinic has had a major impact on the treatment of lymphoma and breast cancer patients, respectively, worldwide. Despite these successes many new ADCs fail at various stages of development, often due to shortcomings in the methods used for their assembly. To address this problem we have developed next generation maleimides (NGMs), which specifically re-bridge reduced interchain disulfide bonds and allow the efficient conjugation of small molecules to antibodies, without the need for engineering of the target antibody. The method is site-specific and generates near homogeneous products in good yields. Moreover, adjustment of the reaction conditions allows control of the conjugation in terms of stoichiometry (drug-loading) and site selectivity. Using this method we prepared a series of ADCs from trastuzumab and doxorubicin (DOX) with a controlled drug-to-antibody ratio (DAR) of 1, 2, 3 and 4. All of these constructs were fully active by ELISA and had more than 90% of re-bridged disulfide bonds by CE-SDS when compared to clinical grade antibody. Furthermore, digest experiments of the DAR 2 material revealed that almost all of the drug had been targeted to the Fab arms of the antibody. Thus, NGMs offer a flexible and simple platform for the controlled assembly of ADCs from an antibody
A HER2 selective theranostic agent for surgical resection guidance and photodynamic therapy
In many cancers early intervention involves surgical resection of small localised tumour masses. Inadequate resection leads to recurrence whereas overzealous treatment can lead to organ damage. This work describes production of a HER2 targeting antibody Fab fragment dual conjugated to achieve both real time near-infrared fluorescent imaging and photodynamic therapy. The use of fluorescence emission from a NIR-dye could be used to guide resection of tumour bulk, for example during endoscopic diagnosis for oesophago-gastric adenocarcinoma, this would then be followed by activation of the photodynamic therapeutic agent to destroy untreated localised areas of cancer infiltration and tumour infiltrated lymph nodes. This theranostic agent was prepared from the Fab fragment of trastuzumab initially by functional disulfide re-bridging and site-specific click reaction of a NIR-dye. This was followed by further reaction with a novel pre-activated form of the photosensitiser chlorin e6 with the exposed fragments' lysine residues. Specific binding of the theranostic agent was observed in vitro with a HER2 positive cell line and cellular near-infrared fluorescence was observed with flow cytometry. Specific photo-activity of the conjugates when exposed to laser light was observed with HER2 positive but not HER2 negative cell lines in vitro, this selectivity was not seen with the unconjugated drug. This theranostic agent demonstrates that two different photo-active functions can be coupled to the same antibody fragment with little interference to their independent activities
Prime movers : mechanochemistry of mitotic kinesins
Mitotic spindles are self-organizing protein machines that harness teams of multiple force generators to drive chromosome segregation. Kinesins are key members of these force-generating teams. Different kinesins walk directionally along dynamic microtubules, anchor, crosslink, align and sort microtubules into polarized bundles, and influence microtubule dynamics by interacting with microtubule tips. The mechanochemical mechanisms of these kinesins are specialized to enable each type to make a specific contribution to spindle self-organization and chromosome segregation
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