Use of cell-based assays in myasthenia gravis and other antibody-mediated diseases.

The increasing demand on diagnostic assays that are sensitive and specific for pathogenic antibodies, and the interest in identifying new antigens, prompted the development of cell-based assays for the detection of autoantibodies in myasthenia gravis and other autoimmune disorders. Cell-based assays were initially used to show that clustering the AChR improved the positivity in myasthenia gravis, and similar assays have now been applied to detection of antibodies to neuromuscular junction candidate proteins such as LRP4 and agrin. In addition cell-based assays have been used in the routine detection of antibodies to proteins expressed on the surface of neurons (NMDAR, LGI1, CASPR2, AMPAR, GABA-A/B, GlyR, and DPPX) and glia (AQP4, MOG). Here, we summarize the findings in myasthenia and discuss the advantages, disadvantages and controversial issues of using cell-based assays in the detection of these antibodies, and their relevance to the testing of preclinical models of disease.

Prostate anatomy in motheaten viable (me(v)) mice with mutations in the protein tyrosine phosphatase SHP-1.

OBJECTIVE: To study prostate and seminal vesicle anatomy in viable motheaten (mev) with mutations in PTPN6 gene leading to a severe reduction in the activity of protein tyrosine phosphatase SHP-1. Homozygous mev mice exhibit multiple anomalies that include immunodeficiencies, increased proliferation of macrophage, neutrophil, and erythrocyte progenitors, decreased bone density and sterility. MATERIAL AND METHOD: We analyzed macro- and microscopic anatomy of the seminal vesicle and prostate macro- and microscopic anatomy of 5 mev/mev and 8 wt/wt adult 7 week old mice. Computerized morphometric analysis was performed to measure the relative changes appearing in the epithelial volume of the different prostatic lobes. RESULTS: All mice studied revealed normal genital organs (penis, testis, epididymis, vas deferens) and bladder. The seminal vesicle was absent in all mev/mev individuals analyzed, being normal and very noticeable in wt/wt mice. The different glands that compose the prostatic complex (anterior, ventral and dorso-lateral prostate) were atrophied in mev/mev mice: anterior prostate 0.4 times, ventral 0.19 times, dorsal 0.35 times and lateral 0.28 times those of the respective regions in wt/wt mice. Microscopically, mev/mev mice revealed scarce and large prostatic ducts, acini severely atrophic with empty lumen and scarce loose epithelial component forming tufts and infoldings, and hyperplastic changes in fibromuscular stroma. CONCLUSIONS: The prostate of mev/mev mice exhibits signs of aberrant differentiation and the resulting phenotype may be related to the loss of function of SHP-1. Prostatic anomalies in these mice affect, together with defects in sperm maduration, for their sterility. These data suggest SHP-1 plays an important role in prostate epithelial morphogenesis.

Conservative approach versus urgent appendectomy in surgical management of acute appendicitis with abscess or phlegmon.

BACKGROUND: Surgical management of acute appendicitis with appendiceal abscess or phlegmon remains controversial. We studied the results of initial conservative treatment (antibiotics and percutaneous drainage if necessary, with or without interval appendectomy) compared with immediate surgery. METHODS: We undertook an observational, retrospective cohort study of patients with a clinical and radiological diagnosis of acute appendicitis with an abscess or phlegmon, treated in our hospital between January 1997 and March 2009. Patients younger than 14, with severe sepsis or with diffuse peritonitis were excluded. A study group of 15 patients with acute appendicitis complicated with an abscess or phlegmon underwent conservative treatment. A control group was composed of the other patients, who all underwent urgent appendectomy, matched for age and later randomized 1:1. The infectious risk stratification was established with the National Nosocomial Infections Surveillance System (NNIS) index. Dependent variables were hospital stay and surgical site infection. Analysis was with SPSS, with p < 0.05 considered significant. RESULTS: Interval appendectomy was performed in 7 study group patients. Surgical site infection episodes were more frequent in the control group (6 vs. 0, p < 0.001). A greater percentage of high risk patients (NNIS ≥ 2) was identified in the control group (80 vs. 28.7%, p < 0.03), mostly related with contaminated or dirty procedures in this group (p < 0.001). No significant difference between groups was found in hospital stay. CONCLUSION: Initial conservative treatment should be considered the best therapeutic choice for acute appendicitis with abscess or phlegmon.

Knockdown of protein tyrosine phosphatase SHP-1 inhibits G1/S progression in prostate cancer cells through the regulation of components of the cell-cycle machinery.

SHP-1, a haematopoietic cell-specific tyrosine phosphatase, is also expressed in human prostate. In this study, we report that SHP-1 depletion in PC-3 cells induced by small interfering RNAs causes G1 phase cell-cycle arrest accompanied by changes in some components of the cell-cycle machinery. SHP-1 knockdown increases p27(Kip1) (p27) protein stability, its nuclear localization and p27 gene transcription. These effects could be mediated by PI3K-AKT pathway as SHP-1 interacts with PI3K regulating its activity and p110 catalytic subunit phosphorylation. The increase in p27 protein stability could also because of reduced cyclin-dependent kinase (CDK2) activity. SHP-1 knockdown decreases the CDK6 levels, inducing retinoblastoma protein hypophosphorylation, downregulation of cyclin E and thereby a decrease in the CDK2 activity. However, the codepletion of SHP-1 and p27 does not produce re-entry into the cycle, implying that p27 is not required to maintain cell-cycle arrest induced by SHP-1 depletion. The maintenance of the PC-3 cell anti-proliferative response after p27 loss could be because of mislocalization of CDK2 induced by SHP-1 knockdown. This study shows that SHP-1 depletion promotes cell-cycle arrest by modulating the activity of cell-cycle regulators and suggests that SHP-1 may be required for the proper functioning of events governing cell-cycle progression.

[Intrathoracic lipoblastoma with costal involvement]. / Lipoblastoma intratorácico con afectación costal.

We report the case of a two-year-old girl with a lipoblastoma arising from the chest wall with intrathoracic extension and costal involvement. The diagnosis was confirmed histologically after surgery. Plain-film chest x-rays showed an extrapleural mass; computed tomography (CT) and magnetic resonance imaging (MRI) suggested fatty contents. The differential diagnosis is mainly versus liposarcoma, which is extremely rare in children.

[Phosphotyrosine phosphatase SHP-1, somatostatin and prostate cancer]. / Fosfotirosina fosfatasa SHP-1, somatostatina y cáncer de próstata.

We review the mechanisms involved in prostatic growth based on androgens and product of neuroendocrine secretion, with special reference to the role of somatostatin (SS) in the inhibition of neoplastic growth. Our contributions in the field confirm the antiproliferative effect of SS on the prostate is mediated by phosphotyrosine phosphatase SHP-1, that is present in human prostate. This enzyme plays a role in the control of prostatic cell proliferation and in the progression of prostate cancer. Besides, we consider its presence may determine the therapeutic potential of SS in the control of prostate cancer.

[Kearns-Sayre syndrome: pediatric neuroradiologic findings in computed tomography and magnetic resonance imaging]. / Síndrome de Kearns-Sayre: hallazgos en tomografía computarizada y resonancia magnética del sistema nervioso central.

Clinical presentation of mitochondrial disorders is heterogeneous because the affected organs are those depending on a high rate of aerobic metabolism. They can appear at any age and evolution is progressive. Signs that guide diagnostic suspicion, especially in the pediatric age group, are heterogeneous clinical presentation and multisystem involvement. Within the spectrum of diseases caused by mitochondrial myopathy, there are clearly defined syndromes such as Kearns-Sayre syndrome. Muscle biopsy shows ragged red fibers and approximately 80 % of patients present sporadic deletions in mitochondrial DNA. Imaging studies reveal areas of hypointensity in basal ganglia and midbrain that are not visible after administration of contrast enhancement in computed tomography, and symmetric T2 hyperintensity lesions in these areas in magnetic resonance imaging. We present a patient with Kearns-Sayre syndrome, in whom radiological alterations were helpful in reaching the diagnosis.

Identification of a protein-tyrosine phosphatase (SHP1) different from that associated with acid phosphatase in rat prostate.

Using [32P]poly(Glu,Tyr) as substrate, we have identified, for the first time, in the rat prostatic gland a protein-tyrosine phosphatase activity different from that associated with prostatic acid phosphatase. Concanavalin A-Sepharose 4B was used to separate the two protein-tyrosyl phosphatases activities. The activity retained by the lectin had characteristics of the prostatic acid phosphatase. It was sensitive to inhibition by PNPP and the optimum pH shifted towards physiological values when [32P]poly(Glu,Tyr) was used as substrate. However, the major protein-tyrosine phosphatase activity was not retained by the lectin, and corresponded, at least in part, to SHP1 as probed by the presence of the protein, its mRNA and the loss of PTPase activity after immunodepletion of SHP1. This enzyme is localized within the epithelial cells. Thus, the coexistence of two protein-tyrosine phosphatase activities in rat prostate, one associated with the acid phosphatase and the other related to SHP1, makes it necessary to analyze the importance of both activities in vivo and their possible function regarding prostatic cell growth and its regulation.

Ureteral triplication and duplicated opposite kidney with refluxing ureterocele.

A case is reported of ureteral triplication with ectopia of two of the ureters and contralateral duplication with a ureterocele. This patient is the youngest that we have found reported with this type of anomaly and the only one presenting with abdominal distention and an intact but refluxing ureterocele.

[Simple renal cyst open into the urinary tract]. / Quiste renal simple abierto a vias excretoras.

The authors present the case of a three-year old girl in whose left kidney, they observed a cystic image communicating with a calyx. The authors class the said lesion as a simple, renal cyst open to ducts. They make a differential diagnosis with other entities (calicial diverticulum, hydrocalicosis, hydatidic cyst and kidney tumour) on the basis of histological, radiological and clinical findings. To reach the same, they assess the structure of the cyst epithelium which is at all times simple cuboid; the radiographic image and the intravenous urography by filling the cyst cavity retrogressively with contrast and the record of macroscopic hematuria which would correspond to the rupture of the cyst in the excretory duct. The suggest a traumatic origin in the mechanism which opened the cyst into the excretory duct.

[Respiratory distress syndrome and pulmonary congenital malformations (author's transl)]. / "Distress respiratorio y malformaciones broncopulmonares.

The present report is based on three infants with respiratory distress syndrome due to congenital lobar emphysema in two and cystic adenomatoid malformation of the lung in the third. The serious worsening of the respiratory distress in two children prompted a partial pulmonary resection within the first 24 hours of life. A brief description of the clinical, radiological and pathological characteristics of this anomalies is included. Our three patients remain asymptomatic showing a normal development, after a follow-up period of five months in one child and just over two years for the other two. Any neonate showing progressive respiratory distress should have a chest X-ray taken to rule out a lobar emphysema or a severe malformation of the lung leading to abnormal ventilation. The management in this cases should be the immediate resection of the affected pulmonary lobes.