217 research outputs found

    A 10-Year Experience in Intraoperative Parathyroid Hormone Measurements for Primary Hyperparathyroidism: A Prospective Study of 91 Previous Unexplored Patients

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    Introduction. Primary hyperparathyroidism (PHP) is characteristically determined by high levels of calcium and high or inappropriate levels of parathyroid hormone (PTH). Technological advances have dramatically changed the surgical technique over the years once intraoperative parathyroid hormone (IOPTH) assay had allowed for focused approaches. Objective. To evaluate our 10-year experience in employing a rapid intraoperative PTH assay for PHP. Methods. A prospective cohort of 91 PHP-operated patients in a tertiary institution in São Paulo, Brazil, from June 2000 to April 2011. Results. We had 85 (93.4%) successful parathyroidectomies, 6 (6.6%) failed parathyroidectomies in 91 previous unexplored patients, and 5 (100%) successful remedial surgeries. The IOPTH was true-positive in 88.5%, true-negative in 7.3%, false-positive in 2.1%, and false-negative in 2.1% of the procedures. IOPTH was able to obviate additional exploration or to ask for additional exploration in 92 (95.8%) procedures. Conclusion. The IOPTH revealed to be an important technological adjunct in the current parathyroid surgery for PHP

    Total Parathyroidectomy with Presternal Intramuscular Autotransplantation in Renal Patients: A Prospective Study of 66 Patients

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    Surgical treatment of secondary (SHPT) and tertiary hyperparathyroidism (THPT) may involve various surgical approaches. The aim of this paper was to evaluate presternal intramuscular autotransplantation of parathyroid tissue as a surgical option in SHPT and THPT treatment. 66 patients with renal chronic disease underwent surgery from April 2000 to April 2005 at Universidade Federal São Paulo, Brazil. There were 38 SHPT patients (24 women/14 men), mean age of 39.yrs (range: 14–58), and 28 THPT patients (14 women/14 men), mean age of 43.4 yrs (range: 24–62). Postoperative average followup was 42.9 months (range: 12–96). Postoperative intact PTH increased throughout followup from 73.5 pg/mL to 133 pg/mL on average from 1st to the 5th year, respectively, in SHPT and from 54.9 pg/mL to 94.7 pg/mL on average from 1st to 5th year, respectively, in THPT group. Definitive hypoparathyroidism was observed in 4 (6.06%) patients and graft-dependent recurrence in 6 (9.09%). Presternal intramuscular autotransplantation of parathyroid tissue is a feasible and safe surgical option in SHPT and THPT treatment

    Diagnóstico precoce de neoplasia endócrina múltipla tipo 2B: um desafio para os médicos

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    BACKGROUND: The hereditary form of medullary thyroid carcinoma may occur isolated as a familial medullary thyroid carcinoma (FMTC) or as part of Multiple Endocrine Neoplasia 2A (MEN2A) and 2B (MEN2B). MEN2B is a rare syndrome, its phenotype may usually, but not always, be noted by the physician. In the infant none of the MEN2B characteristics are present, except by early gastrointestinal dysfunction caused by intestinal neuromas. When available, genetic analysis confirms the diagnosis and guides pre-operative evaluation and extent of surgery. Here we report four cases of MEN2B in which the late diagnosis had a significant impact in clinical evolution and, potentially, in overall survival. CASE REPORT: We report four cases, 2 men and 2 women, with differences in their phenotypes and with a late diagnosis. The first case has a history of severe gastrointestinal obstruction requiring a surgery intervention two days after his birth. The second told had nodules in the oral mucosa and constipation since childhood. The third case referred a history of constipation from birth until 5 months of life. The fourth has had a history of chronic constipation since childhood. DISCUSSION: New concepts have emerged since the RET oncogene was identified in 1993 as the responsible gene for hereditary medullary thyroid carcinoma. The majority of MEN2B individuals have M918T mutation in the exon 16 of RET, with a few cases having a mutation A883F or the association of V804M with E805K, Y806C or S904C mutations. The consensus classifies the RET mutation in codon 918 as of highest risk and recommends total thyroidectomy and central lymph node dissection until 6 months after birth. A fast and precise diagnosis is essential to reach these goals. The identification of early manifestations such as intestinal ganglioneuromatosis and oral mucosal neuromas should prompt the physician to initiate an investigation for multiple endocrine neoplasia type 2B. CONCLUSION: The diagnosis of MEN2B is very important to allow appropriate investigation of associated diseases and to allow counseling and appropriate screening of relatives for a RET mutation. Even patients with MEN2B, which often have typical physical features, may not be properly recognized and be followed as a sporadic case. Based on this, all suspicious cases of multiple endocrine neoplasia should undergo a molecular genetic test.A forma hereditária do carcinoma medular da tiróide pode ocorrer de modo isolado, o carcinoma medular da tiróide familiar (FMTC), ou como parte das neoplasias endócrinas múltiplas tipo 2A (MEN2A) e 2B (MEN2B). MEN2B é uma síndrome rara e seu fenótipo é usualmente, mas nem sempre, notado pelo médico. Na infância, nenhuma das características de MEN2B estão presentes, exceto pela disfunção gastrintestinal precoce, causada pelos neuromas intestinais. Quando disponível, a análise genética confirma o diagnóstico e orienta a avaliação pré-operatória e extensão da cirurgia. Neste artigo, apresentamos quatro casos de MEN2B, nos quais o diagnóstico tardio teve impacto significativo na evolução clínica e, potencialmente, na mortalidade em geral. APRESENTAÇÃO DOS CASOS: Apresentamos quatro casos, dois homens e duas mulheres, com diferenças em seus fenotipos e com diagnóstico tardio. O primeiro caso tem história de obstrução gastrintestinal importante em que foi necessária cirurgia dois dias após o nascimento. O segundo paciente apresentava nódulos na mucosa oral e constipação desde a infância. O terceiro referia história de constipação desde o nascimento até 5 meses de idade. O quarto tinha história de constipação intestinal desde a infância. DISCUSSÃO: Novos conceitos emergiram desde que o oncogene RET foi identificado, em 1993, como o gene responsável pelo carcinoma medular da tiróide hereditário. A maioria dos indivíduos apresenta a mutação M918T no éxon 16 do RET, enquanto poucos casos apresentam a mutação A883F ou a associação de V804M com E805K, Y806C ou S904C. O consenso recomenda a tiroidectomia total com dissecção dos linfonodos no compartimento central até os 6 meses após o nascimento. O diagnóstico rápido e preciso é essencial para o atingir os objetivos. CONCLUSÃO: O diagnóstico precoce de MEN2B é muito importante para propiciar a investigação apropriada de doenças associadas e para permitir aconselhamento e rastreamento dos parentes para uma mutação do RET. Pacientes com MEN2B, que apresentam frequentemente achados típicos ao exame físico, podem não ser reconhecidos e seguidos como casos esporádicos. Por causa disso, todos os casos de neoplasia endócrina múltipla devem ser avaliados pelo teste genético para mutações do RET.Federal University of São Paulo Department of Medicine Division of EndocrinologyFleury-Medicina e SaúdeUNIFESP, Department of Medicine Division of EndocrinologySciEL

    Patterns and Collective Behavior in Granular Media: Theoretical Concepts

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    Granular materials are ubiquitous in our daily lives. While they have been a subject of intensive engineering research for centuries, in the last decade granular matter attracted significant attention of physicists. Yet despite a major efforts by many groups, the theoretical description of granular systems remains largely a plethora of different, often contradicting concepts and approaches. Authors give an overview of various theoretical models emerged in the physics of granular matter, with the focus on the onset of collective behavior and pattern formation. Their aim is two-fold: to identify general principles common for granular systems and other complex non-equilibrium systems, and to elucidate important distinctions between collective behavior in granular and continuum pattern-forming systems.Comment: Submitted to Reviews of Modern Physics. Full text with figures (2Mb pdf) avaliable at http://mti.msd.anl.gov/AransonTsimringReview/aranson_tsimring.pdf Community responce is appreciated. Comments/suggestions send to [email protected]

    A quantitative risk assessment of waterborne infectious disease in the inundation area of a tropical monsoon region

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    Flooding and inundation are annual events that occur during the rainy season in Cambodia, and inundation has a strong relationship with human health. This study simulated the coliform bacteria distribution using a hydraulic model and estimated the impact of inundation on public health using a dose–response model. The model parameters were calibrated using field survey data from Cambodia and obtained good agreement with the coliform group count distribution. The results suggest that the impact of inundation on human health is most noticeable in residential areas. The annual average risk of infection during medium-sized flood events is 0.21. The risk due to groundwater use ranges from 0.12 to 0.17 in inundation areas and reaches as high as 0.23 outside the inundation areas. The risk attributed to groundwater use is therefore higher than that for surface water use (0.02–0.06), except in densely populated areas at the city center. There is a high risk for infection with waterborne disease in residential areas, and the annual average risk during small flood events is 0.94. An assessment of possible countermeasures to reduce the risk shows that the control of inundation may bring more risk to public health in Cambodia. Shallower inundation water (<0.3 m) leads to a higher risk of infection, but if the depth is greater than 2 m, the risk is low in residential areas.The simulated results explain the spatial distributions of infection risk, which are vitally important for determining the highest priority places with relatively high risk and will be helpful for decision makers when considering the implementation of countermeasures

    Resonant magnetic exciton mode in the heavy-fermion antiferromagnet CeB6

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    Resonant magnetic excitations are widely recognized as hallmarks of unconventional superconductivity in copper oxides, iron pnictides, and heavy-fermion compounds. Numerous model calculations have related these modes to the microscopic properties of the pair wave function, but the mechanisms underlying their formation are still debated. Here we report the discovery of a similar resonant mode in the non-superconducting, antiferromagnetically ordered heavy-fermion metal CeB6. Unlike conventional magnons, the mode is non-dispersive, and its intensity is sharply concentrated around a wave vector separate from those characterizing the antiferromagnetic order. The magnetic intensity distribution rather suggests that the mode is associated with a coexisting order parameter of the unusual antiferro-quadrupolar phase of CeB6, which has long remained "hidden" to the neutron-scattering probes. The mode energy increases continuously below the onset temperature for antiferromagnetism, in parallel to the opening of a nearly isotropic spin gap throughout the Brillouin zone. These attributes bear strong similarity to those of the resonant modes observed in unconventional superconductors below their critical temperatures. This unexpected commonality between the two disparate ground states indicates the dominance of itinerant spin dynamics in the ordered low-temperature phases of CeB6 and throws new light on the interplay between antiferromagnetism, superconductivity, and "hidden" order parameters in correlated-electron materials
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