Glucocorticoids as a risk factor for infection and adverse outcomes in non-HIV and non-transplant patients with cryptococcal meningitis

BACKGROUND

Cryptococcal meningitis (CM), an opportunistic fungal infection affecting immunocompromised hosts, leads to high mortality. The role of previous exposure to glucocorticoids as a risk factor and as an outcome modulator has been observed, but systematic studies are lacking.

OBJECTIVE

The primary aim of this study is to evaluate the impact of glucocorticoid use on the clinical outcomes, specifically mortality, of non-HIV and non-transplant (NHNT) patients diagnosed with CM.

METHODS

We queried a global research network to identify adult NHNT patients with CM based on ICD codes or recorded specific Cryptococcus CSF lab results with or without glucocorticoid exposure the year before diagnosis. We performed a propensity score-matched analysis to reduce the risk of confounding and analysed outcomes by glucocorticoid exposure. We used a Cox proportional hazards model for survival analysis.

RESULTS

We identified 764 patients with a history of glucocorticoid exposure and 1267 patients without who developed CM within 1 year. After propensity score matching of covariates, we obtained 627 patients in each cohort. The mortality risk in 1 year was greater in patients exposed to prior glucocorticoids (OR: 1.3, CI: 1.2-2.0, p = 0.002). We found an excess of 45 deaths among CM patients with previous glucocorticoid use (7.4% increased absolute risk of dying within 1 year of diagnosis) compared to CM controls without glucocorticoid exposure. Hospitalisation, intensive care unit admission, emergency department visits, stroke and cognitive dysfunction also showed significant, unfavourable outcomes in patients with glucocorticoid-exposed CM compared to glucocorticoid-unexposed CM patients.

CONCLUSIONS

Previous glucocorticoid administration in NHNT patients seems to associate with 1-year mortality after CM adjusted for possible confounders related to demographics, comorbidities and additional immunosuppressive medications. Serial CrAg screening might be appropriate for higher-risk patients on glucocorticoids after further cost-benefit analyses.

Molecular testing for thyroid nodules: Where are we now?

Approximately 25% of the fine needle aspiration samples (FNAB) of thyroid nodules are classified as "indeterminate samples", that means, Bethesda III and IV categories. Until the last decade, most of these cases underwent diagnostic surgery, although only a minority (13-34%) confirmed malignancy postoperatively. In view of this, with the objective of improving the preoperative diagnosis in these cases, the molecular tests emerged, which are validated from the diagnostic point of view, presenting good performance, with good diagnostic accuracy, being able to avoid diagnostic surgeries. With the advancement of knowledge of the role of each of the mutations and gene rearrangements in thyroid oncogenesis, molecular markers have left to play only a diagnostic role and have been gaining more and more space both in defining the prognostic role of the tumor, as well as in the indication of target therapy. Thus, the objective of this review is to show how to use the tool of molecular tests, now commercially available in the world, in the management of indeterminate cytological nodules, assessing the pre-test malignancy risk of the nodule, through clinical, ultrasonographic and cytological characteristics, and decide on the benefit of molecular testing for each patient. In addition, to discuss its new and promising prognostic and therapeutic role in thyroid cancer.

Clinical Characteristics and Outcomes of Chagas Disease in the United States: A Multicenter Retrospective Analysis

Chagas disease affects approximately 300,000 patients in the United States. We evaluated a multicenter U.S.-based network to obtain clinical characteristics and outcomes of chronic Chagas disease by disease forms. This was a U.S.-based, multicenter, population-based, retrospective cohort study. We queried TriNetX, a global research network, to identify patients with dual-positive IgG serology for Trypanosoma cruzi. We captured outcomes of interest for up to 5 years. We found 429 patients with evidence of dual-positive T. cruzi IgG out of 19,831 patients with an available test result from 31 U.S. medical centers. The positive proportion for those tested was 2.2%, up to 4.6% among Hispanics. We found a prevalence of a positive Chagas serology of 0.02% among Hispanics. Cardiomyopathy risk reached an annual rate of 1.3% during the initial 5 years of follow-up among patients with the indeterminate form. We found no new events for pulmonary embolism, sudden death, or left ventricular aneurysms at 5 years. Annual risks for arrhythmias and stroke for chronic Chagas cardiomyopathy (CCC) were 1.6% and 0.8%, respectively. The yearly mortality and hospitalization rates for CCC were 2.7% and 17.1%, respectively. Only 13 patients had a documented antitrypanosomal therapy course within 6 months after diagnosis. Of those receiving treatment, 10 patients received benznidazole and three nifurtimox. Chagas disease screening in patients from endemic areas living in the United States remains crucial. Chronic Chagas cardiomyopathy carries a considerable disease burden, translating into increased morbidity and mortality and an enlarging medical health service utilization.

Diabetes Mellitus Type 2 as a Risk Factor and Outcome Modifier for Cryptococcosis in HIV Negative, Non-transplant Patients, a Propensity Score Match Analysis

Cryptococcosis is an opportunistic fungal infection of worldwide distribution with significant associated morbidity and mortality. HIV, organ transplantation, malignancy, cirrhosis, sarcoidosis, and immunosuppressive medications are established risk factors for cryptococcosis. Type 2 diabetes mellitus (DM2) has been hypothesized as a risk factor and an outcome modifier for cryptococcosis. We aimed to compare outcomes among HIV-negative, non-transplant (NHNT) patients with and without DM2. We queried a global research network to identify NHNT patients (n = 3280). We performed a propensity score-matched (PSM) analysis comparing clinical outcomes among cryptococcosis patients by DM status. We also characterize adults with cryptococcosis and DM2 as the only risk factor. After PSM, NHNT patients with DM2 were more likely to develop cognitive dysfunction [9% vs. 6%, OR 1.6; 95% CI (1.1-2.3); P = 0.01] but had similar mortality, hospitalization, ICU, and stroke risk after acquiring cryptococcosis when compared to NHNT patients without DM2. Pulmonary cryptococcosis was the most common site of infection. Among 44 cryptococcosis patients with DM2 as the only identifiable risk factor for disease, the annual incidence of cryptococcosis was 0.001%, with a prevalence of 0.002%. DM2 is associated with increased cognitive dysfunction risk in NHNT patients with cryptococcosis. It is rare for DM2 to be the only identified risk factor for developing cryptococcosis. Kidney disease, hyperglycemia, and immune dysfunction can increase the risk of cryptococcosis in patients with DM2.

Feasibility of a snowball sampling survey to study active surveillance for thyroid microcarcinoma treatment among endocrinologists and surgeons of Brazil

OBJECTIVES

This study aims to investigate if a sampling method using virtual networks is feasible to survey AS adoption among this "hard-to-reach" population of Brazilian doctors.

METHODS

An online piloted 11-point structured survey questionnaire (designed using Googleforms®) probed the actual treatment patterns for adult patients with PTMCs, including treatment decision-making nonoperative options, was undertaken between 10 November and 30 November 2020. Participants were reached by the mobile phone Application (APP) and a snowball sampling strategy was used to recruit a total of 4783 members (maximum number of potential reach), which is the total of doctors of the all 21 social media WhatsApp® groups.

RESULTS

From a total of 4783 members (maximum number of potential reach), there were 657 (13.7%) doctors (actual reach) who clicked the web link of the questionnaire, out of whom 512 (10.7%) fully completed the online survey. Among the survey respondents, 361 were endocrinologists (70.5%) and 151 were surgeons (29.5%). Overall, for low-risk PTMCs in an elderly patient, 118 responders (23%) recommend AS, while 390 (76%) recommend immediate surgery as the management, including lobectomy (18.5%) and Total Thyroidectomy (58.2%). The present responders tended to recommend surgery for PTMCs that were located adjacent to the dorsal surface of the thyroid, were multiple, or raised the size during the follow-up.

CONCLUSION

Using snowball sampling strategy as an innovative route to conduct surveys was feasible and applicable but the rate of response was still very low. Our data also suggests the need to investigate if AS is embraced by Brazilian doctors.

Treatment strategies for low-risk papillary thyroid carcinoma: a position statement from the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism (SBEM)

Increasingly sensitive diagnostic methods, better understanding of molecular pathophysiology, and well-conducted prospective studies have changed the current approach to patients with thyroid cancer, requiring the implementation of individualized management. Most patients with papillary thyroid carcinoma (PTC) are currently considered to have a low risk of mortality and disease persistence/recurrence. Consequently, current treatment recommendations for these patients include less invasive or intensive therapies. We used the most recent evidence to prepare a position statement providing guidance for decisions regarding the management of patients with low-risk PTC (LRPTC). This document summarizes the criteria defining LRPTC (including considerations regarding changes in the TNM staging system), indications and contraindications for active surveillance, and recommendations for follow-up and surgery. Active surveillance may be an appropriate initial choice in selected patients, and the criteria to recommend this approach are detailed. A section is dedicated to the current evidence regarding lobectomy versus total thyroidectomy and the potential pitfalls of each approach, considering the challenges during long-term follow-up. Indications for radioiodine (RAI) therapy are also addressed, along with the benefits and risks associated with this treatment, patient preparation, and dosage. Finally, this statement presents the best follow-up strategies for LRPTC after lobectomy and total thyroidectomy with or without RAI.

Prognostic factors for incomplete response in thyroid microcarcinoma: an analysis of initial response to therapy in 517 patients

OBJECTIVE

Although thyroid microcarcinoma (TMC) usually has a favorable prognosis, some patients present a higher risk of disease recurrence or persistence. Thus, we aimed at identifying possible risk factors associated with an incomplete response to therapy in TMC.

METHODS

This was a retrospective study of 517 patients with TMC treated with total thyroidectomy, with or without radioactive iodine (RAI) therapy, reclassified after 1.1 ± 0.4 years according to the response to treatment into "favourable" (excellent/indeterminate) or "unfavorable" (biochemical/structural incomplete) responses. We evaluated participants' age, sex, tumor size, histological variants, multifocality, presence of vascular/lymphatic/perineural invasion, extrathyroidal extension, metastatic lymph nodes (LN), and distant metastasis. The effect of RAI therapy on the response range was analyzed in a given subgroup.

RESULTS

The mean age observed was 46.4 ± 12.0 years, and 89.7% were female. We noted 97.5% with papillary carcinoma, 27.8% with multifocality and 11.2% with LN metastasis. Although the majority of patients had a low risk of recurrence/persistence (78%), 75% were submitted to RAI therapy. Incomplete response (20.7%) was associated with multifocality (p=0.041; OR=1.619) and metastatic LN (p=0.041; OR=1.868). These variables were strongly correlated (p=0.000; OR=3.283). No cut-off of tumor size was identified as a predictor of incomplete response by the receiver operating curve analysis. RAI treatment did not influence the response of patients with multifocality or LN metastasis.

CONCLUSION

Multifocality and LN metastasis are independent risk factors for incomplete response in TMC patients and are strongly correlated. Additional RAI therapy was not associated with a more favorable response in these subgroups.

Analysis of the status of treatment of benign thyroid diseases - a public health problem aggravated in the COVID-19 pandemic era

OBJECTIVE

Goiters and benign nodules detected in the thyroid are growing lesions and the COVID-19 pandemic have negatively impacted on their surgical treatment. The appropriate selection of patients to treatment will improve the overall health status. This article review will focus on the impact of the COVID-19 pandemic on treatment of benign conditions of the thyroid gland and their implications.

METHODS

This review pointed out the status of the health system in developing country and the problems to treat benign surgical diseases of thyroid. Aspects of epidemiology, incidence, clinical presentation and surgical treatment of goiters, economic and health status impact were cited.

RESULTS

All surgical treatment of goiter and other benign conditions were postponed, forced to redirect, and reschedule all benign surgeries, situation aggravated by poor public management and closure of hospital beds. These conditions have caused deterioration in patients' physical (decompensated thyroid disease) and mental health status, increasing work disabilities and burdening society by increasing the social and health cost. The overall situation could be catastrophic in emergent countries where this increased disease-related social expenditure on surgical treatment may increase the risk of national impoverishment as increase the treatment cost. Brazilian Society Head and Neck Surgery related some recommendations and new suggestions were made to safely treat these high potential hazard surgical conditions.

CONCLUSIONS

Surgeries for goiter and benign thyroid conditions can be performed during the COVID-19 pandemic, following strict safety protocols for the patient and the medical team, reducing the negative economic and on patient health impact.

Intermediate-risk thyroid carcinoma: indicators of a poor prognosis

OBJECTIVE

The intermediate-risk (IR) category includes tumors with different degrees of aggression. We aimed to identify the risk factors associated with unfavorable response to initial treatment and compare the effect of low/high radioactive iodine (RAI) therapy.

METHODS

A total of 614 IR patients were selected from a database, during 1972-2015. All patients underwent total thyroidectomy and RAI therapy and were reclassified after 12-18 months into the favorable (complete/indeterminate) response group and the unfavorable (biochemical/incomplete structural) response group. A total of 92 patients were assessed for late response (mean: 9.19 ± 5.73 years). Age, gender, tumor size, histology, multifocality, vascular invasion, extrathyroidal extension, presence and number of lymph node metastasis, and stimulated thyroglobulin at ablation (sTg) were evaluated.

RESULTS

Mean age at diagnosis was 41.47 ± 15.81 years, and 83.6% of the patients were female. Within 12-18 months after initial therapy, unfavorable response was detected in 41.2% of the patients and was associated, in multivariate analysis, with lymph node metastasis (p = 0.041; odds ratio [OR] = 1.9), presence of more than five metastatic lymph nodes (p = 0,017; OR = 2.6), and sTg > 10 ng/mL (p = 0.005; OR = 10.0). For patients with a longer follow-up, sTg >10 ng/mL was associated with unfavorable response (p = 0.002; OR = 6.8). A higher RAI dose was not related to better prognosis at the end of the follow-up.

CONCLUSION

A sTg level of >10 ng/mL and lymph node metastasis were associated with an unfavorable response 12-18 months after initial treatment. A RAI dose below 150 mCi was proven sufficient to treat IR patients.

Plasmapheresis as an Effective Treatment for Thyroid Storm in Critical Patients: Case Reports and Systematic Literature Review

Background: Thyrotoxic crisis is a rare, multisystemic and lethal condition, especially when its reversal is delayed. The Burch Wartofsky score establishes severity and predicts the indication of plasmapheresis, but once there is organ dysfunction this therapy should be considered despite of the score. When it is added to conventional treatments it is really effective because of the quick clinical compensation of critically ill patients regardless of the main trigger factor of this emergency. Clinical Cases: 5 patients with thyrotoxic crisis, 1 man and 4 women that had Graves’disease (4 cases) or TSH-secreting tumor (1 case). The precipitating factors were: 1 case due to orchitis, 2 due to poor adhesion, 1 due to antithyroid drugs hepatoxicity and 1 due to ketoacidosis. All them had elevated free T4 ranging from 3.38 to >7.77 ng/dL. All them had high Burch Wartofsky scores (55 to 70) and severe organ dysfunctions: 4 cases with hepatopathy (hepatosplenomegaly, jaundice and coagulopathy) and cardiopathy (diastolic dysfunction and pulmonary hypertension) and 1 case with severe diabetic ketoacidosis. Plasmapheresis (2 to 3 sessions were performed) were indicated for clinical compensation and so subsequent definitive treatment: 3 cases received radioiodine therapy and 1 case had total thyroidectomy. All of them progressed well. The patient who died had already severe prior comorbidities. We performed a systematic survey on PubMed of English articles (case reports and reviews) in humans and we analyzed our 5 cases along with the 108 articles about the use of plasmapheresis in thyroid storm from 1970 to 2020 and we compare them to 394 ones of conventional treatments in past 10 years. Our objective was to evidence plasmapheresis is not related to a higher mortality of patients who underwent to it. We found 7% of mortality in both groups. The chi square test showed an Odds Ratio of (CI 95%) = 1,091 reinforcing there is no relation between number of deaths and treatment type. Conclusion: Plasmapheresis is a therapeutic option with few reports in the literature and without clear guidelines about indication criteria or better timing to initiate it. The statistical analysis showed that 3 or more organ dysfunctions in thyroid storm are related to higher death rates. Its early employment within 24 hours of the initial symptoms and the prompt normalization of free T4 are related to lower mortality. It is a safe and effective therapy that allows thyroid storm patients to be compensated to receive definitive treatment with lower chances of death. Reference: Ono Y, Ono S, Yasunaga H, Matsui H, Fushimi K, Tanaka Y. Factors Associated With Mortality of Thyroid Storm: Analysis Using a National Inpatient Database in Japan. Medicine (Baltimore). 2016;95(7):e2848.

A cutoff thyroglobulin value suggestive of distant metastases in differentiated thyroid cancer patients

Serum thyroglobulin is used as part of the early postoperative assessment of differentiated thyroid cancer (DTC) since there is a clear relationship between an increased risk of recurrence and persistent disease after initial treatment and high postoperative stimulated thyroglobulin (ps-Tg) values. Thus, although ps-Tg above 10-30 ng/mL is considered an independent predictor of worse prognosis, the value that is associated with distant metastases is not defined. Thus, this was our objective. We selected 655 DTC patients from a nuclear medicine department database (Irmandade Santa Casa de Misericórdia de São Paulo, Brazil). All patients had received total thyroidectomy and radioactive iodine (RAI) therapy and had ps-Tg values higher than 10 ng/mL with negative anti-thyroglobulin antibodies. Then, we selected patients who presented post-therapy whole-body scan with pulmonary and/or bone uptake but with no mediastinum or cervical uptake. Patients with negative findings on functional imaging or any doubt on lung/bone uptake were submitted to additional exams to exclude another non-thyroid tumor. Of the 655 patients, 14.3% had pulmonary and 4.4% bone metastases. There was a significant difference in ps-Tg levels between patients with and without metastases (P<0.001). The cutoff value of ps-Tg was 117.5 ng/mL (sensitivity: 70.2%; specificity: 71.7%) for those with lung metastasis, and 150.5 ng/mL (sensitivity: 79.3%; specificity: 85%) for those with bone metastasis. The cutoff value for patients with eitherpulmonary or bone metastasis was 117.5 ng/mL (sensitivity: 70.2%; specificity: 83.7%). Our findings demonstrated that ps-Tg could predict distant metastasis in DTC patients. We identified a cutoff of 117.5 ng/mL with a high negative predictive value of 93.7%.

The impact of minimal extrathyroidal extension in the recurrence of papillary thyroid cancer patients

OBJECTIVE

We aimed to evaluate the impact of minimal extrathyroidal extension (mETE) alone on the risk of recurrence of papillary thyroid carcinoma (PTC). The impact of other factors, including multifocality, age, tumor size, and stimulated thyroglobulin (sTg) values was also assessed.

SUBJECTS AND METHODS

We retrospectively analyzed 1,108 PTC patients from a medical institution, who presented tumors ≤ 4 cm without any adverse characteristics other than mETE. Patients were classified according to their response to initial treatment 12 to 24 months after surgery as proposed by the 2015 American Thyroid Association (ATA) guideline. Statistical analysis was performed using multivariate logistic regression and receiver operating characteristic (ROC) curve.

RESULTS

In the multivariate logistic regression analysis, mETE did not have an impact on the response to initial treatment (p = 0.44), similar to multifocality, age, and tumor size. Initial Tg value was the only variable associated with a poor response (p < 0.01, odds ratio = 1.303, 95% confidence interval 1.25-1.36). The ROC analysis revealed that Tg was significant (area under curve = 0.8750); the cutoff value of sTg as a predictor of poor response was 10 ng/mL (sensitivity = 72.2%, specificity = 98.5%).

CONCLUSION

For low-risk PTC presenting mETE as the only aggressive feature, the initial sTg value is essential to identify patients who may have a poor response after initial treatment and benefit from further treatment. Arch Endocrinol Metab. 2020;64(3):251-6.

Can current molecular tests help in the diagnosis of indeterminate thyroid nodule FNAB?

Approximately 15-30% of all thyroid nodules evaluated with fine-needle aspiration biopsy (FNAB) are classified as cytologically indeterminate. The stepwise unraveling of the molecular etiology of thyroid nodules has provided the basis for a better understanding of indeterminate samples and an opportunity to decrease diagnostic surgery in this group of patients. Over the last 15 years, several studies have tested different methodologies to detect somatic mutations (by polymerase chain reaction and next-generation sequencing, for example), and to identify differentially expressed genes or microRNA, aiming at developing molecular tests to improve the presurgical diagnosis of cytologically indeterminate nodules. In this review, we will provide an overview of the currently available molecular tests and the impact of mutation testing on the diagnosis of thyroid cancer. We will also review current published data and future perspectives in molecular testing of thyroid nodule FNAB and describe the current Brazilian experience with this diagnostic approach. Based on currently available data, especially for countries outside the US-Europe axis, a rational use of these tests must be made to avoid errors with regard to test indication and interpretation of test outcomes. In addition to clinical, radiological, and cytological features, we still need to determine local malignancy rates and conduct more independent validation and comparative performance studies of these tests before including them into our routine approach to indeterminate FNAB.

Thyroglobulin levels before radioactive iodine therapy and dynamic risk stratification after 1 year in patients with differentiated thyroid cancer

OBJECTIVES

We sought to assess the relationship between stimulated thyroglobulin (sTg) before radioactive iodine therapy (RIT), and the dynamic risk stratification 1 year after treatment, and to establish the utility of the sTg as a predictor of response to therapy in these patients. A retrospective chart review of patients with differentiated thyroid cancer (DTC) who underwent RIT after surgery and were followed for at least 1 year, was carried out.

SUBJECTS AND METHODS

Patients were classified according to the dynamic risk stratification 1 year after initial treatment. The sTg values before RIT were compared among the groups. ROC curve analysis was performed.

RESULTS

Fifty-six patients were enrolled (mean age 44.7 ± 14.4 years, 80.7% had papillary carcinoma). Patients with excellent response had sTg = 2.1 ± 3.3 ng/mL, those with indeterminate response had sTg = 8.2 ± 9.2 ng/mL and those with incomplete response had sTg = 22.4 ± 28.3 ng/mL before RIT (p = 0.01). There was a difference in sTg between excellent and incomplete response groups (p = 0.009) while no difference was found between indeterminate and either excellent or incomplete groups. The ROC curve showed an area under the curve of 0.779 assuming a sTg value of 3.75 ng/mL.

CONCLUSION

Our study results suggest that the higher the sTg before RIT, the greater the likelihood of an incomplete response to initial treatment. A sTg cut-off of 3.75 ng/mL was found to be a good predictor of response to initial treatment in patients with DTC.

Inheritable and sporadic non-autoimmune hyperthyroidism

Hyperthyroidism is a clinical state that results from high thyroid hormone levels which has multiple etiologies, manifestations, and potential therapies. Excluding the autoimmune Graves disease, autonomic adenomas account for the most import cause of non-autoimmune hyperthyroidism. Activating germline mutations of the TSH receptor are rare etiologies for hyperthyroidism. They can be inherited in an autosomal dominant manner (familial or hereditary, FNAH), or may occur sporadically as a de novo condition, also called: persistent sporadic congenital non-autoimmune hyperthyroidism (PSNAH). These three conditions: autonomic adenoma, FNAH and PSNAH constitute the inheritable and sporadic non-autoimmune hyperthyroidism. Particularities in epidemiology, etiology, molecular and clinical aspects of these three entities will be discussed in this review in order to guide to an accurate diagnosis allowing among others genetic counseling and presymptomatic diagnosis for the affected families. The optimal treatment based on the right diagnosis will avoid consequences of a persistent or relapsing hyperthyroidism.

Talking to the dead: using Post-mortem data in the assessment of stress in tiger sharks (Galeocerdo cuvier) (Péron and Lesueur, 1822)

Sharks are very sensitive to stress and prone to a high mortality rate after capture. Since approximately 50 million of sharks are caught as bycatch every year, and current recommendations to reduce the impact of commercial fishing strongly support immediate release, it is imperative to better understand post-release mortality caused by the stress of capture and handling. Blood samples allow the assessment of stress levels which are valuable tools to reduce mortality in commercial, recreational and scientific fishing, being essential for the improvement in those conservation measures. Biochemical analyses are widely used for sharks as stress indicators, with secondary plasma parameters (lactate, glucose and ions) being the most often employed assays. However, it is virtually impossible to determine baseline plasma parameters in free-ranging sharks, since blood withdrawal involves animal capture and restrain, which are stressful procedures. This study aims at analyzing secondary parameters of five healthy tiger sharks captured with circular hooks and handlines in Fernando de Noronha (Northeastern Brazil) and comparing them with secondary parameters of three dead tiger sharks caught off Recife (also Northeastern Brazil). The results showed that the analysis of some plasma constituents in dead animals may be an efficient tool to assess stress and lethality. However, traditional parameters such as glucose and calcium, need to be used with caution. The results also demonstrated the extreme importance of urea and phosphorus for assessing stress response and mortality in tiger sharks, both parameters frequently neglected and of utmost importance for shark's homeostasis.

Thoracoscopy in the management of pediatric empyemas

INTRODUCTION

Thoracoscopy is increasingly being used in the treatment of empyema. This study assesses feasibility, efficacy and safety in children.

MATERIAL AND METHODS

Clinical files of patients who underwent primary thoracoscopy for empyema between 2006 and 2014 were reviewed. Demographic, clinical and surgical data were analyzed and a comparison between the period before (period1) and after (period2) the learning curve was performed.

RESULTS

Ninety-one patients (53 males, 58%) were submitted to thoracoscopy at a median age of 4 years. There were 19 conversions to thoracotomy with a steady decrease of conversion rate until 2009 (period1) and no conversions thereafter (period2). There was no difference in any of the analyzed parameters between patients submitted to thoracoscopy alone and those requiring conversion in period1. Six cases (6.6%) needed redo-operation (five in period2) and thoracotomy was the elected approach in four. Necrotizing pneumonia was present in 60% of the reoperated cases; in other words, in period2 3 out of 9 cases with necrotizing pneumonia required reintervention (p=0.07). Thoracotomy was avoided in sixty-eight (75%) patients (62% in period1 versus 92% in period2, p=0.001).

DISCUSSION AND CONCLUSIONS

Thoracoscopic approach for empyema is feasible and safe avoiding a significant number of thoracotomies after a short learning curve. An increase of reintervention rate should be expected, but throracoscopy alone is effective in the great majority of the cases. Necrotizing pneumonia may be associated with a higher risk of reintervention, as it is a contra-indication to thoracoscopy and probably surgery.

Asthma prevalence and risk factors in early childhood at Northern Portugal

Asthma is the commonest and most important chronic non-infectious disease in childhood and it has become more prevalent in recent years. There is a shortage of studies in relation to early childhood and so, as part of the INAIRCHILD project, this cross-sectional study aimed to assess the prevalence of asthma and its associated risk factors, namely demographic, environmental, psychosocial and clinical factors for infants and preschoolers living in Northern Portugal. Data concerning asthma prevalence were collected through questionnaires based on those from the International Study of Asthma and Allergies in Childhood (ISAAC-derived), the questionnaires were distributed to 1042 children attending the 17 nurseries involved in the INAIRCHILD project (10 in urban and suburban context, and 7 in rural context). The response rate was 48%. Prevalence of asthma based on symptomatology and odds ratio was calculated. Around 52% of the studied children presented at least one of the respiratory symptoms investigated (wheeze, dyspnea and cough) in the absence of upper respiratory infections. The prevalence of asthma was 10.7%, comparable to the figures for Portuguese schoolchildren (6-7 years old) reported by the national Directorate-General of Health, thus showing that an early diagnosis might be possible and helpful for the mitigation of childhood asthma. Environmental context (urban, suburban or rural), gender and family asthma history showed clear associations with asthma prevalence, namely non-rural location, male gender, and having an asthmatic parent were found to be risk factors.

Effectiveness of Different Mechanical Methods on Dentin Caries Removal: Micro-CT and Digital Image Evaluation

PURPOSE

To determine the caries removal effectiveness (CRE) and minimal invasive potential (MIP) of caries excavation methods using digital imaging and microtomography analyses.

METHODS

Twelve human molars with occlusal caries lesions in dentin were randomly divided into three groups (carbide bur, exacavator, and polymer bur). They were sectioned mesiodistally, and standardized digital and computed microtomography x-ray (micro-CT) images were taken from each section before and after caries excavation. On each image, initial carious dentin (IC), prepared cavity (PC), and residual caries (RC) were defined according to visual criteria using ImageJ software. CRE was determined based on the RC/IC ratio, whereas MIP was determined by the PC/IC ratio. Data were analyzed using one-way analysis of variance and Student t-test or with Kruskal-Wallis and Student-Newman-Keuls test. The level of significance was set at 0.05.

RESULTS

For both digital image and micro-CT analysis, the carbide bur showed higher CRE values than the excavator (p=0.0063 and p=0.0263, respectively) and the polymer bur (p=0.0028 and p=0.0005, respectively). The latter two presented similar results (p>0.05). Regarding MIP, for the digital image analysis, the polymer bur was different from the carbide bur (p=0.0030) but was not different from that of the excavator (p=0.1240). For micro-CT analysis, the MIP values of all the groups were significantly different, and the polymer bur was the most conservative method (p<0.05).

CONCLUSIONS

The carbide bur was the most effective method for caries removal but was not completely conservative. The polymer bur and excavator presented low invasive potential but were not able to remove all of the carious dentin.

Differential miRNA expression defines migration and reduced apoptosis in follicular thyroid carcinomas

The objective of the study was to identify microRNAs (miRs) characteristic for follicular thyroid carcinoma (FTC) and to define their role in tumorigenesis. A miR-microarray study was conducted to identify miRs differentially expressed between FTCs and their surrounding tissues. Selection was further reinforced by a literature review. Four miRs were selected and confirmed by RT-qPCR: miR-146b, -183, -221 were up-regulated, whereas miR-199b down-regulated in FTCs. The influence of these miRs on cell proliferation, cell cycle, apoptosis and migration was studied in HTori and FTC-133 cells. Functional characterization suggests an impact of miR-183 and miR-146b in FTC development. Overexpression of both miRs significantly induces migration. Moreover, overexpression of miR-183 significantly represses apoptosis. MiR-199b and -221 do not have significant effects on proliferation, cell cycle, apoptosis or migration in HTori and FTC-133 cells. Our data suggest that miR-146b and miR-183 may influence FTC development through the induction of migration and apoptosis inhibition.

Impact of molecular screening for point mutations and rearrangements in routine air-dried fine-needle aspiration samples of thyroid nodules

BACKGROUND

The diagnostic limitations of thyroid fine-needle aspiration (FNA), such as the indeterminate category, can be partially overcome by molecular analyses. However, until now, rearrangements have only been detected in fresh FNA material and the number of follicular thyroid carcinomas (FTCs) was rather low in previous studies. We aimed at investigating the impact of point mutations and rearrangement detection in a set of routine air-dried FNA smears with a higher percentage of FTCs.

METHODS

RNA and DNA was extracted from 310 FNAs (164 indeterminate, 57 malignant, 89 benign) and corresponding formalin-fixed paraffin-embedded tissue (156 follicular adenomas [FAs], 32 FTCs, 44 papillary thyroid carcinomas [PTCs], 9 follicular variant PTCs, and 69 goiters). PAX8/PPARG and RET/PTC rearrangements were detected by qPCR, BRAF and RAS mutations by high-resolution melting PCR and by pyrosequencing.

RESULTS

Forty-seven mutations were detected in the FNAs: 22 BRAF, 13 NRAS, and 3 HRAS mutations, 8 PAX8/PPARG, and one RET/PTC-rearrangement. While the presence of a BRAF and RET/PTC mutation was associated with cancer in 100% of samples each, the presence of a RAS and PAX8/PPARG mutation was associated with cancer in only 12% and 50% of samples, respectively. In the indeterminate group 4 of 25 carcinomas were identified by molecular FNA screening, which increased the sensitivity from 67% (cytology alone) to 75% (cytology plus molecular screening).

CONCLUSION

Molecular screening for point mutations and rearrangements is feasible in air-dried FNAs. Although the impact of detecting point mutations and rearrangements in FNAs has most likely been overestimated in previous studies, molecular FNA analyses improve presurgical diagnostics. The detection of BRAF mutations in FNA may improve the choice of surgery and postsurgical treatment. Further data are necessary to elucidate the true impact of detecting RAS and PAX8/PPARG mutations in FNAs. The inclusion of additional rare somatic mutations and miRNA markers might further improve the impact of molecular FNA diagnostics.

Impact of different methodologies on the detection of point mutations in routine air-dried fine needle aspiration (FNA) smears

Currently the best method to select suspicious thyroid nodules for surgery is fine needle aspiration (FNA) cytology. However, FNA cytology has some inherent limitations, which can partly be overcome by molecular analysis. Therefore, molecular testing for somatic mutations has emerged as the most promising approach for molecular FNA diagnostics. The objective of this methodological study was to evaluate the feasibility of detecting BRAF, NRAS, HRAS, and KRAS mutations from routine air-dried thyroid FNA smears, and to find an optimal method for detecting these mutations in FNA samples. DNA was extracted from 110 routine air-dried FNA smears and the corresponding surgically obtained formalin-fixed paraffin-embedded tissues. The presence of BRAF, NRAS, HRAS, and KRAS mutations was assessed by real-time PCRs and high resolution melting analysis, and/or pyrosequencing in comparison to real-time PCRs using hybridization probes and fluorescence melting curve analysis. The high-resolution melting-PCRs revealed a significantly lower number of PCR failures and questionable results, and detected more mutations than the PCRs using hybridization probes. The number of PCR failures ranging from 14-16% by high-resolution melting-PCRs could be further reduced to 5-14% by adding pyrosequencing assays. Moreover, pyrosequencing increased the specificity of the assays, up to 98-100%, while the sensitivity ranged between 32-63%. In summary, the mutation detection, especially in air-dried FNA samples, improves when using PCR assays in combination with high resolution melting analysis. Additional improvement can be obtained by subsequent pyrosequencing in comparison to previously described real-time PCRs using hybridization probes and fluorescence melting curve analysis.

Inverse correlation of miRNA and cell cycle-associated genes suggests influence of miRNA on benign thyroid nodule tumorigenesis

CONTEXT

The molecular etiology of cold and benign thyroid nodules (CBTNs) is largely unknown. Increased thyroid epithelial cell proliferation is a hallmark of CBTNs. MicroRNAs (miRNAs) are prominent regulators of cell proliferation.

OBJECTIVE

Our objective was to assess the influence of miRNAs on the increased proliferation and thus the molecular etiology of CBTNs.

DESIGN

By using microarrays, we defined the molecular pattern of increased proliferation of CBTNs as a differential expression of cell-cycle-associated genes and miRNAs. In silico integration of differentially expressed miRNAs and mRNAs showed an inverse correlation between the expression of 59 miRNAs and 133 mRNAs. Inverse correlations between cell-cycle-associated genes such as CDKN1C and miR-221, CCND1 and miR-31, GADD45A and miR-130b, or CDKN1A and let-7f suggest a modulation of proliferation in CBTNs by miRNAs. Their expression was validated using quantitative RT-PCR and functionally characterized in cell line models.

RESULTS

Comparative quantitative RT-PCR of 20 samples of CBTNs and their surrounding tissue revealed an 11-fold down-regulation of miR-31 with a 2.6-fold up-regulation of CCND1, and a 2.6-fold up-regulation of miR-130b with a 2.3-fold down-regulation of its target GADD45A. Using HTori and FTC-133 cell lines, we analyzed proliferation, cell cycle, and apoptosis after transfection of miRNA-31 and miRNA-130b mimic and inhibitors. Overexpression of miR-31 and the resultant down-regulation of CCND1 led to an arrest in the cell cycle phase G1. Overexpression of miR-130b led to an increase of apoptosis and necrosis within 72 h.

CONCLUSION

miR-31 and miR-130b may have an effect on tumorigenesis of CBTNs by regulating proliferation and apoptosis and the cell cycle through cyclin D1.

Detection of PAX8/PPARG and RET/PTC rearrangements is feasible in routine air-dried fine needle aspiration smears

BACKGROUND

The diagnostic limitations of fine needle aspiration (FNA), like the indeterminate category, can be partially overcome by molecular analysis. As PAX8/PPARG and RET/PTC rearrangements have been detected in follicular thyroid carcinomas (FTCs) and papillary thyroid carcinomas (PTCs), their detection in FNA smears could improve the FNA diagnosis. To date, these rearrangements have never been analyzed in routine air-dried FNA smears, but only in frozen tissue, formalin-fixed paraffin-embedded (FFPE) tissue, and in fresh FNA material. Fixed routine air-dried FNA samples have hitherto been judged as generally not suitable for testing these rearrangements in a clinical setting. Therefore, the objective of the present study was to investigate the feasibility of extracting RNA from routine air-dried FNA smears for the detection of these rearrangements with real-time polymerase chain reaction (RT-PCR).

METHODS

A new method for RNA extraction from routine air-dried FNA smears was established, which allowed analysis for the presence of four variants of PAX8/PPARG and RET/PTC 1 and RET/PTC 3, which were analyzed in 106 routine FNA smears and the corresponding surgically obtained FFPE tissues using real-time quantitative PCR (RT-qPCR). To assess RNA quality, an intron-spanning PAX8 cDNA was amplified.

RESULTS

Acceptable RNA quality was obtained from 95% of the FNA samples and 92% of the FFPE samples. PAX8/PPARG was detected in 4 of 96 FFPEs and in 6 of 96 FNAs. PAX8/PPARG was present in 4 of 10 FTCs and in 3 of 42 follicular adenomas (FAs). Similarly, RET/PTC was found in 3 of 96 FFPEs and in 4 of 96 FNAs. Two of 21 PTC samples and 3 of 42 FA samples carried this rearrangement.

CONCLUSION

These data are the first to show the feasibility of extracting RNA from routine air-dried FNA smears for the detection of PAX8/PPARG and RET/PTC rearrangements with RT-qPCR. These promising methodological advances, if confirmed in larger series of FNA and FFPE samples, may lead to the introduction of molecular analysis of routine air-dried FNA smears in everyday practice.

Current state and future perspective of molecular diagnosis of fine-needle aspiration biopsy of thyroid nodules

CONTEXT

Fine-needle aspiration biopsy (FNAB) is the most sensitive and specific tool for the differential diagnosis of thyroid malignancy. Some limitations of FNAB can be overcome by the molecular analysis of FNAB. This review analyzes the current state and problems of the molecular analysis of FNAB as well as possible goals for increasing the diagnostic rate, especially in the indeterminate/follicular lesion cytological group.

EVIDENCE ACQUISITION

Twenty publications were evaluated for the diagnostic material and assay systems used, the type, and the number of mutations screened. Sensitivity, specificity, and false-negative and false-positive rates were calculated for all publications.

EVIDENCE SYNTHESIS

Testing for a panel of somatic mutations is most promising to reduce the number of indeterminate FNAB. A mean sensitivity of 63.7% was achieved for indeterminate lesions. However, there is a broad sensitivity range for the investigation of mutations in the indeterminate lesions. Therefore, additional molecular markers should be defined by mRNA and microRNA expression studies and evaluated in FNAB samples of thyroid carcinomas without known somatic mutations, and especially for the many benign nodules in the indeterminate/follicular lesion fine-needle aspiration cytology category. This approach should improve the differential diagnosis of indeterminate/follicular lesion FNAB samples.

CONCLUSION

Testing for a panel of somatic mutations has led to an improvement of sensitivity/specificity for indeterminate/follicular proliferation FNAB samples. Further methodological improvements, standardizations, and further molecular markers should soon lead to a broader application of molecular FNAB cytology for the differential diagnosis of thyroid nodules and to a substantial reduction of diagnostic surgeries.

Spirometric tests to assess the prevalence of childhood asthma at Portuguese rural areas: influence of exposure to high ozone levels

The study here reported aimed to: i) evaluate the prevalence of childhood asthma at a Portuguese rural area with high ozone concentrations through lung function tests, validating the previously estimated one assessed through questionnaires (similar to those of the ISAAC); ii) compare the achieved prevalence with the one reported at an unexposed area (with low ozone concentrations), aiming to evaluate the influence of exposure to high ozone levels; and iii) determine potential risk factors. Ninety-five of the original 478 children that completed the questionnaires, mentioned to have at least one of asthma symptoms (wheeze, dyspnea or cough) and were therefore evaluated by spirometry. FEV(1) was in average 89.7% for asthmatics and 102.8% for non-asthmatics. For the studied sample the risk was higher for girls with a tendency to be higher from 8 to 10 years old. Lifetime prevalence of childhood asthma at the exposed area was 9.2%. Children living at the exposed area had 3 times higher risk of having asthma than those living at the unexposed area. Considering that ozone concentrations were the main difference between both areas, it can be suggested that ozone pollution increased asthma prevalence. Nevertheless, it should be remarked that further studies should be done to confirm these results.

Fat-soluble vitamins in human lactation

Lactation has three distinct phases: colostrum, transition, and mature, with the quantity of fat-soluble vitamins and carotenoids tending to decline while the total fat content increases. The number of deliveries seems to be directly related to higher concentrations of beta-carotene and vitamin E in colostrum. Little is known about vitamin quantities during the other phases. In the present study, vitamin A and E concentrations during different phases of lactation were measured in primiparous and multiparous mothers to analyze the variation and suitability for the diet of a breastfed child. Phase of lactation and number of deliveries were highly significant for log mean vitamin A while only one phase showed significance for log mean vitamin E. There was a sharp decline in the levels of vitamin A and E in the course of the initial phase of lactation. The variability between measurements declined as colostrum transitioned to mature milk. There were significant measurable inter-group differences in retinol levels in milk obtained during early lactation. Vitamin A and E content can reach 2.5 and 1.4 times of levels recommended intake, respectively.

Role of viruses and atypical bacteria in asthma exacerbations among children in Oporto (Portugal)

BACKGROUND

Upper respiratory tract infections are known to be a significant precipitant of acute asthma exacerbations. The aim of this study was to evaluate seasonal trends and the role of these pathogens in asthma exacerbations in school-aged children from Oporto (Portugal).

METHODS

Nasal aspirates were collected from children aged 6 to 12 years old with asthma exacerbations attended in the Pediatric Emergency Department one day per week from January 1 to December 31, 2003. Demographic data, severity of asthma and asthma exacerbations, and current treatment were recorded. Samples were obtained through nasal wash with 1 ml saline and were processed by immunofluorescence assays (respiratory syncytial virus, adenovirus, parainfluenza and influenza virus), retrotranscription polymerase chain reaction (rhinovirus) and polymerase chain reaction (enterovirus, Chlamydia pneumoniae and Mycoplasma pneumoniae).

RESULTS

In 54 eligible children, 37 nasal samples were obtained. Infectious agents were detected in 78 % of the patients. Rhinovirus was detected in 70.3 %, Mycoplasma pneumoniae in 16.2 %, enterovirus in 10.8 %, and Chlamydia pneumoniae in 2.7 %. Coinfection was identified in 21.6 % of the samples. There was no significant correlation between current treatment status, severity of asthma or exacerbations and the isolated agents. Two distinct peaks of asthma exacerbation were found, 40.5 % in spring and 32.4 % in autumn [corrected] The highest number of cases was recorded in March and the lowest in August and January. Rhinoviruses was detected in 27 % of the cases in autumn and in 24.3 % in spring [corrected]

CONCLUSIONS

These results confirm the previously reported high frequency of rhinovirus detection in asthma exacerbations in children and provide evidence that asthma exacerbations and rhinovirus infections follow a seasonal pattern, occurring mostly in spring and autumn. The findings also underscore the frequency of Mycoplasma pneumoniae detection, and emphasize the importance of this agent as a possible trigger of asthma exacerbations.

[Hypoglycaemia without ketosis. A case report]

INTRODUCTION

Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a rare disease, inherited as autosomal-recessive trait, with variable clinical presentation including severe hypoglycaemia, cardiomyopathy, sudden infant death, progressive liver failure, 'Reye like' syndrome, neuromyopathy, muscle weakness and rhabdomyolysis.

CASE REPORT

We report a 3 years old male patient admitted to our emergency department with vomiting, hypotonia and prostration, after a common respiratory infection. The presence of hypoketotic hypoglycaemia and elevated liver enzymes in the admission motivated a metabolic study. We found an abnormal low lactate/pyruvate ratio, decreased serum carnitine and dicarboxylic aciduria leading to the diagnosis of a fatty acid oxidation disorder (LCHADD). The molecular study of HADHA gene revealed homozygosity for the G1528C mutation in the patient DNA, and heterozygosity in both parents.

CONCLUSIONS

The diagnosis of a fatty acid oxidation disorder must be considered in the presence of vomiting associated with excessive prostration specially if there is hypoketotic hypoglycaemia or familiar sudden infant death history. Physicians should be aware about these conditions and for the importance of measuring both glycaemia and ketone bodies during the evaluation of high risk situations.

[Multifocal phakic intraocular lens implant to correct presbyopia]

INTRODUCTION

Presbyopic surgery is considered as the new frontier in refractive surgery. Different solutions are proposed: myopization of one eye, insertion of an accommodative crystalline lens, scleral surgery, the effects of which are still unknown, and finally multifocal phakic implants. We therefore decided to undertake a prospective study under the Huriet law to determine its efficacy and specify the conditions required for an anterior chamber multifocal phakic implant.

MATERIAL AND METHOD

Fifty-five eyes of 33 patients received an anterior chamber foldable multifocal phakic implant. Twenty-one females and 12 males underwent surgery. Initial refraction was between -5D and +5D. The implant's single addition was +2.50. Recuperating a distant uncorrected visual acuity of 0.6 or better and near uncorrected vision of Parinaud 3 or better can be considered a very good postoperative result.

RESULTS

Average follow-up was 42.6+/-18 weeks. Mean postoperative refraction was -0.12+/-0.51 D. Mean postoperative uncorrected visual acuity was 0.78+/-0.20. Postoperative uncorrected visual acuity was Parinaud 2.3+/-0.6. Eighty-four percent of eyes operated on recuperated 0.6 or better without correction and Parinaud 3 or better without correction. Lenses in four eyes were explanted for different reasons, essentially optical, and no severe anatomical complications were observed.

CONCLUSIONS

Placing an anterior chamber multifocal phakic implant to correct presbyopia is an effective technique with good predictability and has the advantage of being reversible in case of intolerance, optical parasite effects or undesired complications. Considering the particularity of this surgery, it is imperative to respect very strict inclusion criteria: anterior chamber depth equal to or above 3.1 mm, open angle, endothelial cell count equal to or above 2000 cells/mm2, absence of an incipient cataract or the slightest evidence of macular alteration.

Étude in vivo de l’accommodation naturelle chez un sujet albinos

Modifications of the anterior segment during accommodation of the eye under examination cannot be studied in a simple and direct way with anterior segment imaging techniques such as Scheimpflug photography, A Scan, B Scan, and UBM. With this equipment, it is necessary to stimulate the fellow eye in order to observe the variations of the analyzed eye. The techniques using ultrasound equipment can only be used with contact systems or with water baths that will modify the anatomical dimensions or the pressure of the anterior segment. With the Scheimpflug photographic technique, geometrical reconstructions are necessary and cannot be used in certain axes. Optical coherence tomography provides the advantage of producing non-contact images of the anterior segment in static and dynamic conditions that are then easy to use. The target of the optical system can be focused and unfocused with negative or positive lenses, thus reproducing the conditions of natural accommodation. With a normal subject, the morphological modifications of the crystalline lens behind the iris screen cannot be studied because the infrared light source used is blocked by the pigment epithelium. The absence of this pigment in an albino subject allowed us to study the modifications of the crystalline lens and the ciliary body during accommodation. In this study, we were able to definitely confirm all the modifications of the anterior segment as described by von Helmholtz in 1855, who, at the time, used very rudimentary optical procedures based on the reflections of a flame on the surface of the crystalline lens.

Analyse du segment antérieur de l’œil avec un tomographe à cohérence optique

PURPOSE

To study the biometric modifications of the anterior segment depending on accommodation and age. To try and define their possible applications in certain fields of anterior segment surgery, in particular in refractive implants.

MATERIAL AND METHOD

Anterior chamber biometry can be very easily studied with 1310-nm wavelength optical coherence tomography. The equipment has a fixation target that can be focused and defocused with negative lenses in order to stimulate natural accommodation. The human anterior chamber was therefore studied during accommodation. We studied 104 eyes of 56 patients aged between 7 and 82 years. Refraction was between +5D and - 5D. A single operator carried out all the measurements. The anterior chamber's horizontal diameter, the anterior chamber's depth, the horizontal pupil diameter and the horizontal radius of curvature of the crystalline lens' anterior pole were measured unaccommodated or after stimulating accommodation.

RESULTS

The different static or dynamic measurements were compared to ametropia, age and accommodation. At rest, the average AC diameter was 12.33 mm, the average AC depth was 3.11 mm and the average pupil diameter was 4.26 mm. On average, for 1 D of accommodation, the crystalline lens anterior pole moved forward by 30 microm. There was a 0.3-mm reduction in its radius of curvature and a 0.15-mm reduction in pupil diameter. Several other measurements are illustrated on graphs.

CONCLUSIONS

The AC OCT is a user-friendly instrument to evaluate the anterior segment and explore the anterior chamber (cornea, iris, crystalline lens, irido-corneal angle). The 1310-nm light wavelength is blocked by pigments preventing exploration behind the iris. However, the AC OCT is capable of providing good-quality images and a better visualization of the anatomical relationships of the anterior segment, even behind an opaque cornea.

Contact entre le cristallin naturel et différents modèles d’implants réfractifs phakes. Étude avec l’OCT de chambre antérieure

Three patients received three different models of phakic implants. With the usual slit-lamp examination method, we were not able to establish whether there was contact between the implants and the natural crystalline lens. Using the anterior chamber optical coherence tomography scanner (AC-OCT), we were able to demonstrate that there was direct contact between the natural crystalline lens and the three different phakic implants. A dynamic study of these contacts was carried out during accommodation. These observations show that examination of the anterior segment with the optical coherence tomography scanner is essential in refractive surgery.

The first green lineage cdc25 dual-specificity phosphatase

The Cdc25 protein phosphatase is a key enzyme involved in the regulation of the G(2)/M transition in metazoans and yeast. However, no Cdc25 ortholog has so far been identified in plants, although functional studies have shown that an activating dephosphorylation of the CDK-cyclin complex regulates the G(2)/M transition. In this paper, the first green lineage Cdc25 ortholog is described in the unicellular alga Ostreococcus tauri. It encodes a protein which is able to rescue the yeast S. pombe cdc25-22 conditional mutant. Furthermore, microinjection of GST-tagged O. tauri Cdc25 specifically activates prophase-arrested starfish oocytes. In vitro histone H1 kinase assays and anti-phosphotyrosine Western Blotting confirmed the in vivo activating dephosphorylation of starfish CDK1-cyclinB by recombinant O. tauri Cdc25. We propose that there has been coevolution of the regulatory proteins involved in the control of M-phase entry in the metazoan, yeast and green lineages.

Comparative genomics of the SOX9 region in human and Fugu rubripes: conservation of short regulatory sequence elements within large intergenic regions

Campomelic dysplasia (CD), a human skeletal malformation syndrome with XY sex reversal, is caused by heterozygous mutations in and around the gene SOX9. SOX9 has an extended 5' control region, as indicated by CD translocation breakpoints scattered over 1 Mb proximal to SOX9 and by expression data from mice transgenic for human SOX9-spanning yeast artificial chromosomes. To identify long-range regulatory elements within the SOX9 5' control region, we compared approximately 3.7 Mb and 195 kb of sequence around human and Fugu rubripes SOX9, respectively. We identified only seven and five protein-coding genes in the human and F. rubripes sequences, respectively. Four of the F. rubripes genes have been mapped in humans; all reside on chromosome 17 but show extensive intrachromosomal gene shuffling compared with the gene order in F. rubripes. In both species, very large intergenic distances separate SOX9 from its directly flanking genes: 2 Mb and 500 kb on either side of SOX9 in humans, and 68 and 97 kb on either side of SOX9 in F. rubripes. Comparative sequence analysis of the intergenic regions revealed five conserved elements, E1-E5, up to 290 kb 5' to human SOX9 and up to 18 kb 5' to F. rubripes SOX9, and three such elements, E6-E8, 3' to SOX9. Where available, mouse sequences confirm conservation of the elements. From the yeast artificial chromosome transgenic data, elements E3-E5 are candidate enhancers for SOX9 expression in limb and vertebral column, and 8 of 10 CD translocation breakpoints separate these elements from SOX9.

The myosin light chain kinase gene is not duplicated in mouse: partial structure and chromosomal localization of Mylk

The gene encoding myosin light chain kinase (MYLK) is duplicated on human chromosome 3 (HSA3; 3p13;3q21) and on a chromosome with conserved synteny to HSA3 in most non-human primate species. In human, the functional copy resides on 3q21, whereas the 3p13 site contains a pseudogene. To trace the origin of the duplication, we characterized the mouse gene Mylk. A single sequence corresponding to the functional Mylk was detected. We sequenced a 180-kb bacterial artificial chromosome clone containing the 24 first exons of Mylk; the complete mouse gene is expected to span >200 kb. Comparisons with the draft of the human genome revealed that the sequence and structure of MYLK are conserved in mammals. Fluorescence in situ hybridization (FISH) analysis indicated that the mouse gene localizes to a single site on chromosome 16B4-B5, a region with conserved synteny with HSA3q. Our study provides information on both the structure and the evolution of MYLK in mammals and suggests that it was duplicated after the divergence of rodents and primates.

Expression of the genes encoding the vasopressin-activated calcium-mobilizing receptor and the dual angiotensin II/vasopressin receptor in the rat central nervous system

The distributions of two newly discovered receptors, the vasopressin-activated calcium-mobilizing receptor (VACM-1) and the dual angiotensin II/vasopressin receptor (AII/AVP), in the central nervous system (CNS) of the rat were determined using reverse transcriptase-polymerase chain reaction and in situ hybridization. The sequence of the rat VACM-1 cDNA was determined and found very homologous to the rabbit and human sequences. Both VACM-1 and AII/AVP receptor genes were widely expressed in the brain, but differed according to the cell type studied. Glial cells were very faintly labelled. The epithelial cells of the choroid plexuses, the ependymal cells and the pia mater were all labelled. Both genes were most active in neurones throughout the CNS. VACM-1 and AII/AVP receptors were detected in neurones previously shown to possess V1a and V1b vasopressin receptors, and/or the AT1 and AT2 angiotensin II receptors in many brain areas. This was the case for the magnocellular neurones of the supraoptic and paraventricular nuclei of the hypothalamus. We suggest that the VACM-1 and AII/AVP receptors may account for the V2-like responses to vasopressin by these neurones which lack a genuine V2 vasopressin receptor.

Evolution of the Gypsy endogenous retrovirus in the Drosophila melanogaster subgroup

We conducted a phylogenetic survey of the endogenous retrovirus Gypsy in the eight species of the Drosophila melanogaster subgroup. A 362-bp fragment from the integrase gene (int) was amplified, cloned, and sequenced. Phylogenetic relationships of the elements isolated from independent clones were compared with the host phylogeny. Our results indicate that two main lineages of Gypsy exist in the melanogaster subgroup and that vertical and horizontal transmission have played a crucial role in the evolution of this insect endogenous retrovirus.