AZOOR with unilateral disc edema: An atypical case report

Acute zonal occult outer retinopathy (AZOOR) diagnosis is challenging and frequently delayed. Atypical findings were described, nevertheless optic disc edema has not been consistently reported. In this study we pretend to describe a challenging diagnosis of AZOOR. In our case, a 19-year-old female presented painless vision loss in her right eye for 2 weeks. Fundus examination revealed optic disc hyperaemic edema and the visual field (VF) an enlarged blind spot. Non-infectious optic neuritis was assumed and intravenous corticotherapy administered. Four months later, VA had improved, but a VF defect persisted. Funduscopic examination showed mild peripapillary atrophy and autofluorescence zonal hyperautofluorescence around optic disc. Optical coherence tomography demonstrated diffuse loss of outer retinal layers and electroretinogram weakened signal at the corresponding region. In conclusion, unilateral optic disc edema, generally not associated with AZOOR typical presentation, hamper an early diagnosis and expresses this case relevance.

No evidence of resistance to itraconazole in a prospective real-world trial of dermatomycosis in India

BACKGROUND

The prevalence of superficial fungal infections in India is believed to have increased substantially in the past decade. We evaluated the treatment outcomes and risk factors associated with clinical response to a treatment course of itraconazole for the management of dermatomycosis in India.

METHODS

In this real-world, prospective pilot study (August 2019 to March 2020), adult participants (18-60 years), diagnosed with T. cruris or T. corporis, received itraconazole 200 mg/day (any formulation) orally for 7 days, and were followed for an additional 7 days.

RESULTS

The study was terminated early due to the COVID-19 pandemic. Of 40 enrolled participants (mean [SD] age, 35.5 [12.73] years; {62.5%}] male; 37 received itraconazole and 20 (50%) completed the study. The median (range) Clinical Evaluation Tool Signs and Symptoms total score at baseline was 5.5 (2-10). Clinical response of "healed" or "markedly improved" based on the Investigator Global Evaluation Tool at day 7 (primary objective) was 42.9% (12/28; 95% CI: 24.53%, 61.19%). Itraconazole minimum inhibitory concentration for identified microorganisms, T. mentagrophytes species complex (91.7%) and T. rubrum (8.3%), was within the susceptibility range (0.015-0.25 mcg/mL). At day 14, 8/13 (61.5%) participants achieved a mycological response, 2/13 participants (15.4%) had a mycological failure and 90% showed a clinical response.

CONCLUSION

COVID-19 pandemic affected patient recruitment and follow-up, so the findings call for a careful interpretation. Nevertheless, this real-world study reconfirmed the clinical efficacy and microbial susceptibility to itraconazole for the fungi causing dermatophytosis in India.

TRIAL REGISTRATION

Trial registration number: Clinicaltrials.gov NCT03923010.

Cognitive conversion disorder (functional cognitive disorder) – what’s new?

Introduction

Some patients present with significant subjective cognitive symptoms, sometimes interfering with day-to-day live, that are not compatible with any recognizable psychiatric, neurodegenerative or systemic condition. Recent studies have proposed that these patients can be diagnosed with Conversion Disorder (Subtype Cognitive), also known as Functional Cognitive Disorder (FCD). This is a relatively recent concept, that still lacks consensus.

Objectives

Review the current state of knowledge regarding prevalence, diagnosis criteria, core clinical features and proposed treatment of Functional Cognitive Disorder.

Methods

Bibliographic review of the literature published in English in the last 5 years, in the databases Pubmed, PsycINFO and Cochrane. The keywords used were: Functional Cognitive Disorder; Cognition; Conversion Disorder. A review of the titles and abstracts of the resulting articles was made, and selected according to their relevance to the study.

Results

Ten articles related to prevalence, diagnosis, clinical associations and treatment of Functional Cognitive Disorder were selected, of which two were systematic reviews, three descriptive studies, three cross sectional clinical studies of memory clinics attendants, one cohort prospective study and one article was a case series report.

Conclusions

The prevalence of FCD is estimated between 11.6% and 56% of patients presenting to memory clinics. However, the prevalence of FCD is hindered by the lack of consensus regarding its definition. Recently, Ball et al proposed a definition in line with the DSM-5 definition of Conversion Disorder with emphasis on positive criteria with the identification of positive evidence of internal inconsistency. Treatment discussion is still limited, and the approach is similar to other conversion disorders.

Bleuler’s a or autism spectrum disorder in adults?

Introduction

Nowadays we know that autism spectrum disorders (ASD) and Schizophrenic spectrum (SS) are different types of disorders in their etiology, symptoms and prognosis, but the clinical distinction is often difficult to make due to comorbidity and similar symptoms.

Objectives

With this project, the authors intend to explore the differential diagnosis between ASD and SS specially when we talk about critical ages of onset.

Methods

An analysis of articles searched on Pubmed (articles between 2010-2020) with the key words “adult autism”, “childhood onset schizophrenia”, “childhood psychosis”.

Results

Early-onset schizophrenia (EOS) is defined as occurring before age 18 years. The condition share key diagnostic symptoms with adult-onset schizophrenia (AOS) but his prognoses and comorbidities differ. Autism spectrum disorder (ASD) is a common neurodevelopmental disorder characterized by difficulties since early childhood across reciprocal social communication and restricted interests and behaviors. ASD is a lifelong neurodevelopmental disorder, however there is a lack of answers and research for adults with ASD. There are shared aspects of odd thinking, rigid behaviors and impaired socialization in schizophrenia and ASD and COS seems to have a strong relationship with ASD, being comorbid in up to 50% of cases.

Conclusions

Usually the evaluation of the developmental history of the person, prodrome and onset, its course and the presence of positive symptoms of schizophrenia is enough to help us find a diagnosis. Unfortunately, in some ages the conclusion is not so easy to find. However is essential to determine whether the clinical manifestations belong to the autistic spectrum, the schizophrenic or result from comorbidity.

Transcranial magnetic stimulation and eating disorders, any efficacy?

Introduction

Eating Disorders (ED) tend to evolve chronically, with resistance to different therapeutic strategies. Chronicity is associated with high mortality rates, so it is necessary to study new therapeutic strategies. Transcranial Magnetic Stimulation (TMS) is a non-invasive, safe treatment method, whose application has been studied in several pathologies.

Objectives

Determine the therapeutic potential of Transcranial Magnetic Stimulation in the treatment of Eating Disorders.

Methods

Bibliographic review of the literature published in English in the last 10 years, in the databases Pubmed, PsycINFO and Cochrane. The keywords used were: TMS, Transcranial Magnetic Stimulation, Eating Disorder, Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder. A review of the titles and abstracts of the resulting articles was made, and selected according to their relevance to the study.

Results

Eighteen articles related to the treatment of ED with TMS were selected, either as primary or secondary outcome, of which six were review articles, ten were randomized controlled trials (RCT), one article was an oral communication and another article was a case report. Three RCTs showed improvement in bulimia nervosa, specifically in symptoms of “food craving”. Four RCT and one case report showed improvement in the symptoms of anorexia nervosa, one RCT showed no improvement in anorexia nervosa.

Conclusions

TMS appears to have some therapeutic potential for the treatment of ED, particularly in reducing food craving, despite some contradictory results. This work reinforces the need for more robust studies to evaluate the effectiveness of TMS, preferably randomized, with a longer follow-up and a cost-benefit analysis.

Comparative clinical prognosis of massive and non-massive pulmonary embolism: A registry-based cohort study

AIMS

Little is known about the prognosis of patients with massive pulmonary embolism (PE) and its risk of recurrent venous thromboembolism (VTE) compared with non-massive PE, which may inform clinical decisions. Our aim was to compare the risk of recurrent VTE, bleeding, and mortality after massive and non-massive PE during anticoagulation and after its discontinuation.

METHODS AND RESULTS

We included all participants in the RIETE registry who suffered a symptomatic, objectively confirmed segmental or more central PE. Massive PE was defined by a systolic hypotension at clinical presentation (<90 mm Hg). We compared the risks of recurrent VTE, major bleeding, and mortality using time-to-event multivariable competing risk modeling. There were 3.5% of massive PE among 38 996 patients with PE. During the anticoagulation period, massive PE was associated with a greater risk of major bleeding (subhazard ratio [sHR] 1.72, 95% confidence interval [CI] 1.28-2.32), but not of recurrent VTE (sHR 1.15, 95% CI 0.75-1.74) than non-massive PE. An increased risk of mortality was only observed in the first month after PE. After discontinuation of anticoagulation, among 11 579 patients, massive PE and non-massive PE had similar risks of mortality, bleeding, and recurrent VTE (sHR 0.85, 95% CI 0.51-1.40), but with different case fatality of recurrent PE (11.1% versus 2.4%, P = .03) and possibly different risk of recurrent fatal PE (sHR 3.65, 95% CI 0.82-16.24).

CONCLUSION

In this large prospective registry, the baseline hemodynamic status of the incident PE did not influence the risk of recurrent VTE, during and after the anticoagulation periods, but was possibly associated with recurrent PE of greater severity.

Seroprevalence of Trypanosoma cruzi in pregnant women in Midwest Brazil: an evaluation of congenital transmission

Chagas disease (CD) is caused by the protozoan Trypanosoma cruzi and it is mainly acquired through the vector route, however, blood transfusion and congenital transmission are implicated in the spread of the illness worldwide. The congenital route can occur at any stage of pregnancy and its frequency varies. In the Federal District, in Brazil, the frequency of T. cruzi infection in pregnant women and their offspring has not been updated. Thus, the aim of this study was to estimate the prevalence of T. cruzi infection in pregnant women and the rate of congenital transmission in the Federal District. A cross-sectional study was conducted to estimate the seroprevalence of T. cruzi from 2014 to 2016 in the population of pregnant women attended by the public health service throughout the Federal District and a descriptive cohort for the evaluation of congenital transmission. During the study, prenatal data of 98,895 women were consulted and pregnant women registered in 2016, presenting with positive T. cruzi serology, were part of the descriptive cohort. The estimated prevalence of T. cruzi infection in the three years was 0.19% and the congenital transmission rate was 1/40 (2.5%). Our results have shown that, although the main routes of transmission of CD have been interrupted, there is still a risk of congenital transmission in the Federal District. This present study highlights the need for the continuous implementation of a screening program for pregnant women and timely treatment of infected newborns and children.

Unsafe abortion in Brazil: a systematic review

Background

In Brazil, abortion is legally allowed in cases of risk to the woman's life, pregnancy resulting from rape and cases of fetal anencephaly. Despite the restrictive legislation, studies estimated that around 1 million abortions took place in the country in 2005. Abortions occurred regardless of womeńs socioeconomic position, race, age and religion, but unsafe practices were more common among young women, with low educational levels, single, students or domestic workers. This study sought to update knowledge on unsafe abortion in Brazil.

Methods

We carried out a systematic review with study search on Medline and LILACS, with no language restriction, from 2008 to 2018. We evaluated article quality using the Joanna Briggs Institute instruments. We evaluated 50 articles.

Results

There was a decrease in the ratio of induced abortions by 1,000 women of reproductive age reaching 16 per 1,000 in 2013. However, direct estimates do not indicate a decrease in the prevalence of induced abortion, estimated to be 13% in 2016. Higher prevalences were observed in more socially vulnerable populations. Half of all women reported using medications for terminating pregnancies and the number of hospital admissions due to complications from abortion decreased from 1992 to 2009. Maternal morbimortality from abortion had a reduced frequency but it is likely that maternal deaths from abortion are under-reported.

Conclusions

Abortion is frequently used in Brazil, especially in less-developed regions and by more socially-vulnerable women. Access to safer methods probably contributed to the reduction of complications, hospitalizations and morbimortality from abortion. However, half of all women still used other unsafe methods and the number of admissions due to complications from abortion is still high. The small scientific production and lack of methodological adequacy led to the development of a special issue on Abortion in Brazil in the jornal Reports in Public Health.

Key messages

Restrictive legislation does not prevent abortion, but limits access to safe abortion and makes it diffiult to prevent morbidity and mortaliity from abortion. Restrictive legislation and the stigma associated with abortion make studies difficult to estimate the rates, complications and factors associated with abortion.

Hearing Screening in Preschool Children of a Rural Community in Portugal - A 10-year Experience

Introduction Preschool hearing screening programmes would identify later onset or progressive hearing losses and conductive hearing loss, due to the high prevalence of otitis media with effusion in childhood. Hearing loss associated with otitis media with effusion can have a great impact on reading, writing, central auditory processing and balance.

Objectives The present study aims at characterising the audiological alterations found in preschool children screened in a rural community in Portugal, and the correlation between audiological findings and otoscopy.

Methodology This is an observational study using the results obtained in a ten year audiological and otological screening of preschool children. Otoscopy, Tympanometry and Audiometry (1, 2 and 4 KHz presented at 40 and 20 dB intensity) were performed at the first stage of the screening and the results were classified as “pass” or “refer”. Every non-normal result of any category would imply a second stage consisting of observation by an ENT specialist at the site and the establishing of a follow-up plan. Written Informed Consent was obtained from the parents prior to initiating the study.

Results 595 children aged 5 and 6 years were screened between 2007 and 2017, of whom 192 (32.3%) required referral to the second stage. The most frequent alteration was found in the tympanogram. The tympanograms showed a significant correlation with the otoscopy performed by the ENT doctor, mainly type B tympanograms. The pass/refer audiometry also showed a statistically significant correlation with the medical otoscopy, although weak in all frequencies studied.

Conclusion It’s extremely important to perform a hearing screening in the age range of 5-6 years (with a high predisposition to middle ear problems), with the main objective of identifying and referring for treatment children who present alterations in order to reduce the consequences of the hearing impairment.

A rectal metastasis of an unknown lobular breast carcinoma and its management

Breast cancer is the most common cancer in women but gastro- intestinal metastases of breast cancer are rare. They can occur years after the diagnosis or at the diagnosis of breast cancer. We report the case of a patient complaining of dyschesia, tenesmus and anal incontinence leading to the discovery of a rectal metastasis of an unknown breast neoplasia. Given the oligo-metastatic condition, multidisciplinary and aggressive management was the chosen therapy.

P1313 A curious case of endocarditis

INTRODUCTION

Nonbacterial thrombotic endocarditis (NBTE) is a rare form ofnoninfectious endocarditis in which a small sterile vegetations deposited on the heart valves (mostly aortic and mitral).It has been reported in every age group, most commonly affecting patients between the fourth and eighth decades of life with no sex predilection. Patients with advanced malignancy and those with systemic lupus erythematosus are the most common populations affected by NBTE, and they are typically asymptomatic until embolization occurs. Here, we report a case of a female patient with rheumatoid arthritis whose diagnosis was made prior to any thromboembolic event.

CASE REPORT DESCRIPTION

An 83-year-old female patient with a 10-year history of rheumatoid arthritis, was admitted for urinary tract infection with exacerbation of chronic renal disease and decompensated heart failure of unknown etiology. On physical examination, she was febrile (38,3ºC) with a blood pressure of 130/70 and pulse rate of 90 beats/min. Cardiac auscultation revealed a sistolic murmur of grade 1/4 in the fifth left intercostal space. A joint deformities in the hands were noted, such as interosseous atrophy and ulnar deviation. To evaluate this new sistolic murmur,the transthoracic echocardiogramwas performed and showed a vegetation in the mitral valve. Then, a transesophageal echocardiogram(TEE) was requested to better characterize this vegetation, showing a vegetation of 19x4mm involving the posterior cusp of the mitral valve leaflet, with moderate mitral regurgitation,being the hypothesis of infective endocarditis (IE) proposed. There were no other significant abnormalities in the remaining echocardiogram. Empirical antibiotic therapy to IE was initiated. The TEE was repeated after 4 weeks of antibiotic therapy with maintenance of the referred vegetation and mention of a smaller one (10x2mm). Clinical investigation didn’t show any infectious process. Hence, the hypothesis of NBTE was established. Anti-coagulation therapy was started immediately. The NBTE lesion disappeared in the follow-up echocardiography three months post anti-coagulation treatment.

CONCLUSION

Although NBTE is an uncommon and difficult diagnosis that requires a high degree of suspicion, its timely diagnosis is essential since it allows the prevention of thromboembolic events, resulting in a positive impact on patients" quality of life. In addition, the existence of this clinical condition may allow the diagnosis of another underlying disease, such as a hidden neoplasia. Thus, the authors believe that the sharing of this clinical case will allow a reflection on this entity emphasizing the importance in the hypotheses of vegetation diagnosis. From the authors" knowledge, from the available medical literature, the clinical case presented is one of the few NBTEs described in patients with rheumatoid arthritis, with mitral valve involvement and whose diagnosis was made before any thromboembolic event.

Abstract P1313 Figure. A vegetation of mitral valve

Choroid thickness profile in patients with lupus nephritis

BACKGROUND

Choroidopathy is a rare manifestation of systemic lupus erythematosus (SLE). This entity is associated with active phases of severe SLE and it is frequently accompanied by acute kidney failure, central nervous system involvement and coagulopathy.

PURPOSE

To evaluate the choroid thickness of patients with lupus nephritis (LN) without choroidopathy, and to compare this with that of age-matched SLE patients without LN and healthy control subjects.

STUDY DESIGN

Cross-sectional case control study.

MATERIAL AND METHODS

Fifteen women with LN in remission phase (study group), 15 women with SLE in remission without LN (SLE control group), and 15 healthy women (healthy control group), without ocular diseases or significant refractive error, were recruited. Full ophthalmological examination and a macular optical coherence tomography in enhanced depth imaging mode were performed. The choroid thickness was measured at nine macular points and six lines of mean choroidal thickness were determined. A comparative analysis between the three groups was performed using the one-way ANOVA test and the paired t-test. The choroid thickness of patients under corticotherapy was also compared to that of patients without corticotherapy. Additionally, the correlation between choroid thickness and disease duration was evaluated using the Pearson analysis.

RESULTS

The mean macular choroidal thickness was 295.73 ± 67.62 μm in the study group, 233.34 ± 41.01 µm in the SLE control group, and 240.98 ± 37.93 μm in the control group ( p = 0.00006 and p = 0.0003, respectively). Additionally, the choroid thickness was significantly thicker than in the SLE and healthy control groups at the foveal ( p = 0.004 and p < 0.000), nasal ( p < 0.000 and p = 0.001), superior ( p = 0.002 and p < 0.000) and inferior ( p < 0.000 and p = 0.001) mean lines. The choroidal thickness in this group was not associated with the duration of the disease. The subgroup of patients with LN under corticotherapy did not reveal a significantly different choroidal thickness.

CONCLUSION

This study suggests a relationship between LN and choroidal changes, which may represent an increased risk for choroidopathy in these patients. Choroid thickening was not related with the duration of the disease. This thickening may be correlated with histopathological changes similar to those occurring in kidney glomeruli.

Epidural catheter anchored in the posterior lateral epidural space: How to manage it

We describe a case of an epidural catheter entrapment without knotting, kinking, shearing or breakage confirmed by CT scan and how to manage it. A patient was admitted for tibial fracture repair under general anesthesia with an epidural. At discharge day, multiple attempts to retrieve the catheter were made. Contrast CT scan showed the catheter anchored in the left posterior-lateral epidural space. Despite the absence of guidelines regarding epidural catheter entrapment, all the methods described in the literature were used. This is a rare complication and it may be associated with neurological and infectious complications. Radiologic imaging should be obtained to better characterize the catheters' position and plan removal. In this case, tension in the paraspinal muscles or in the supraspinous and intraspinous ligaments could explain the entrapment. General anesthesia with the non-depolarising muscle relaxant allowed muscles and ligaments to relax and we were able to retrieve the catheter intact.

Behavioral manifestations post hemispherectomy due to Sturge–Weber syndrome–A case of success

Introduction

Sturge-Weber syndrome or encephalotrigeminal angiomatosis is an uncommon neurocutaneous syndrome that manifests with vascular malformations involving the brain, eye and skin; Severe cases present with refractory seizures, sometimes requiring major surgery such as hemispherectomy. Most of the times, some degree of mental retardation and behavioral problems are associated, requiring use of psychotropic medication and other contention strategies. This report describes the case of a 19-year-old boy who was submitted to a left hemispherectomy by the age of one, and was still able to successfully complete basic education. He started presenting severe behavioral problems, with aggressive outbursts, by the beginning of adulthood, having been committed to psychiatry ward. By the age of 22, the patient finds himself calm and functional considering his limitations, with no need for hospital admission for 2 years.

Objectives/aims

To describe a clinical case whilst reviewing literature concerning this matter.

Methods

Case report with complete clinical history and medical data. Non-systematic review of PubMed database under the terms “Sturge-Weber disease”, “Hemisferectomy”, “behavioral disorder due to organic causes”, “post hemisferectomy out-comes”.

Results/discussion

Although presenting with severe arteriovenous malformation, refractory epilepsy and left hemispherectomy, the patient was able to conclude basic instruction; He has lived with his family until the age of 19, when he started displaying disruptive behaviour; after 3 hospital admissions and perfecting psychotropic drugs treatment, the patient was admitted to an institution for rare diseases patients Since then he has experienced a calm and functional life, with trained professionals who can offer the non-pharmacological approaches he needs.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The Psychiatry consultation in primary health care setting at an Oporto Area: Sociodemographic and clinical data

Introduction

The Psychiatry consultation is a collaborative approach between primary health care services and community mental health teams. Our clinic provides support to three Oporto areas (Bonfim/Paranhos, Campanhã and Maia/Valongo) corresponding to a population of 350,000 inhabitants.

Objectives

To analyze and collect Psychiatry consultation data of the first semester of 2015 in Maia/Valongo region. We aim to describe our population's sociodemographic characteristics, the most common referral motive, diagnosis and therapeutics, and orientation.

Methods

Psychiatry consultation data of the first semester of 2015 were collected and analyzed using SPSS software (version 20).

Results

One hundred and sixty-one patients were evaluated. A total of 26.09% were male and 73.91% were female. The mean age was 51.61 years old. The most frequent referral motives were depressive (47.82%) and anxiety (23.60%) symptoms. The two most common diagnostic groups according to the International Classification of Diseases (version 10) were F30-F39–Mood affective disorders (57.76%) and F40-F48–Neurotic, stress-related and somatoform disorders (18.63%). 22.36% of the patients were referred without medication, but only four were discharged drug-free, corresponding to bereavement situations. 34.16% of our population were previously prescribed two or more psychotropic drugs, increasing to 63.98% after assessment. Only 18.63% met criteria to hospital referral.

Conclusions

The Psychiatry consultation selects the most severe patients and allows a faster evaluation of mentally ill patients awaiting hospital consultation, thus preventing unnecessary access to the emergency room. Authors consider that all the patients referred to a hospital consultation should be previously evaluated by a consultant psychiatrist on a primary health care setting.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Using the soil and water assessment tool to estimate dissolved inorganic nitrogen water pollution abatement cost functions in central portugal

Coastal aquatic ecosystems are increasingly affected by diffuse source nutrient water pollution from agricultural activities in coastal catchments, even though these ecosystems are important from a social, environmental and economic perspective. To warrant sustainable economic development of coastal regions, we need to balance marginal costs from coastal catchment water pollution abatement and associated marginal benefits from coastal resource appreciation. Diffuse-source water pollution abatement costs across agricultural sectors are not easily determined given the spatial heterogeneity in biophysical and agro-ecological conditions as well as the available range of best agricultural practices (BAPs) for water quality improvement. We demonstrate how the Soil and Water Assessment Tool (SWAT) can be used to estimate diffuse-source water pollution abatement cost functions across agricultural land use categories based on a stepwise adoption of identified BAPs for water quality improvement and corresponding SWAT-based estimates for agricultural production, agricultural incomes, and water pollution deliveries. Results for the case of dissolved inorganic nitrogen (DIN) surface water pollution by the key agricultural land use categories ("annual crops," "vineyards," and "mixed annual crops & vineyards") in the Vouga catchment in central Portugal show that no win-win agricultural practices are available within the assessed BAPs for DIN water quality improvement. Estimated abatement costs increase quadratically in the rate of water pollution abatement, with largest abatement costs for the "mixed annual crops & vineyards" land use category (between 41,900 and 51,900 € tDIN yr) and fairly similar abatement costs across the "vineyards" and "annual crops" land use categories (between 7300 and 15,200 € tDIN yr).

Characterization of heavy-metal contamination in surface sediments of the Minho river estuary by way of factor analysis

Surface sediments were collected in August 2009 from 49 sites along the Minho estuary (between Tui and Caminha) and analyzed for grain size, organic carbon (Corg) and total nitrogen (Ntot) contents, and major (silicon [Si], aluminum [Al], iron [Fe], calcium [Ca], magnesium [Mg], sodium [Na], potassium [K], titanium [Ti], and mangesese [Mn]) and trace element (arsenic [As], chromium [Cr], copper [Cu], mercury [Hg], lithium [Li], lead [Pb], rubidium [Rb], tin [Sn], and zinc [Zn]) concentrations. Factor analysis was used to decrease 22 selected variables into 4 factors accounting for 85.9 % of the total variance explained, suggesting distinct elemental sources or sediment components affecting their spatial distributions. Although factors 1 (detrital component; elements strongly associated with fine- [Na, Mg, Ti, Li, Cr, Cu, Fe, Al, Zn, Ca, and As] and coarse-grained sediments [Si, K, Rb; mean grain-size [MGS]) and 3 (Fe-Mn oxyhydroxide sediment component; Fe, Mn, As, fine fraction) are interpreted as reflecting predominance of natural contributions, factors 2 (urban and industrial contamination: sediment components [Pb, Hg, organic carbon [Corg], total nitrogen [Ntot] and 4 (components associated with contamination by nautical activities; the association of tin [Sn] and calcium [Ca]) seem to indicate anthropogenic contributions). Nevertheless, the influence of elemental contributions derived from tungsten (W)-Sn mineralizations and those resulting from mining activities can also contribute to the obtained geochemical associations and should be considered. Spatial distribution of dominant factor scores shows the dominance of factors 2 and 4 between Tui and Vila Nova de Cerveira, whereas samples dominated by factors 3 and 1 are found between Ilha da Boega and Seixas and in the Caminha areas, respectively. Despite the dominance of factor score 1 in the Caminha area, the distribution pattern of dominant factor scores shows samples dominated by other factor scores that can be explained by dredging activities in this river sector that restore ancient sedimentary characteristics or expose contaminated sediments. Through the identification of sample locations dominated by factors associated with contamination, it will be possible to select them as priority areas where new environmental (e.g., toxicity tests, organic Sn compounds, tracers of sewage contamination) studies should be implemented in the future.

[Predictive near-infrared SLO signs for tears of the retinal pigment epithelium due to age-related macular degeneration]

PURPOSE

The aim of this study was to identify potential predictive markers in confocal scanning laser ophthalmoscopy (cSLO)-based imaging for tears of the retinal pigment epithelium (RPE) in the presence of pigment epithelial detachments (PED) due to age-related macular degeneration (AMD).

METHODS

Fifteen eyes of 15 patients (mean age 77 years, SD ± 6) with RPE tears and pre-existing PEDs were retrospectively analysed for the presence of increased signals on near-infrared imaging (NIR) using confocal scanning laser ophthalmoscopy (cSLO).

RESULTS

In 87 % of the cases increased reflectance signals on NIR in the area of the PED were noted prior to the development of an RPE tear. On average, these signals were recorded 58 days (SD ± 40) before the rip was diagnosed. In 62 % of the patients these signals were localised opposite to the rip location at the rim of the PED.

CONCLUSION

Increased reflectance signals on NIR imaging may serve as a predictive marker for RPE tears in patients with PED in AMD. These signals recordable with a non-invasive imaging method should be prospectively validated in a larger cohort of patients with PEDs. It may be useful in the management of patients exhibiting this manifestation of exudative AMD.

Rhabdomyolysis: risk factors and incidence in polytrauma patients in the absence of major disasters

PURPOSE

Rhabdomyolysis is a syndrome caused by musculoskeletal tissue damage that leads to the release of large amounts of intracellular elements, which particularly affect renal function. The most common causes are severe trauma, ischemia, surgical procedures, and drug abuse. We aimed to determine the incidence of rhabdomyolysis by measuring muscle injury markers (CK, myoglobin), to identify pre/post-admission as well as iatrogenic risk factors for rhabdomyolysis in severe polytrauma, to clarify the relevance of orthopedic injuries and surgical treatment in the onset/worsening of rhabdomyolysis, and to correlate risk factors with its main complication-acute renal failure (ARF).

METHODS

Prospective study of severe polytrauma patients (Injury Severity Score (ISS) >15), with CK and myoglobin values measured at admission and after 24, 48, and 72 h. Peak values, variations between admission and peak, and variations between admission and day 3 were all determined. The correlations of those values with the onset of ARF and other negative outcomes were assessed.

RESULTS

A total of 57 consecutive patients with a median ISS of 29 were included. ARF was present in 20 patients (38 %). CK-0 level was correlated with male gender (p < 0.027) and ISS (0.014); Mb-0 level was correlated with hypovolemic shock (0.003) and skeletal fracture (p < 0.043). CK-max was correlated with surgery (p < 0.038) and surgery duration (p < 0.014); Mb-max was correlated with surgery (p < 0.002) and anesthesia duration (p < 0.005). Δ-CK was correlated with surgery (p < 0.01) and surgery duration (p < 0.017), and Δ0-3-CK was correlated with surgery (p < 0.042). Logistic regression analysis found relationships between Δ0-3-CK and both ICU admission (p < 0.003) and MODS (p < 0.012), and between Mb-max and ARF (p < 0.034).

CONCLUSION

We found that a large number of factors are implicated in CK and Mb variations. Rhabdomyolysis is a very frequent complication, but increase in CK marker alone does not seem to be correlated with the incidence of ARF. Therefore, Mb level should be considered in this group of patients.

Determination of eight selected organophosphorus insecticides in postmortem blood samples using solid-phase extraction and gas chromatography/mass spectrometry

A simple, rapid and sensitive method is described for the determination of omethoate, dimethoate, diazinon, chlorpyrifos, parathion-ethyl, chlorfenvinphos, quinalphos and azinphos-ethyl in postmortem whole blood samples. The analytes and internal standard (ethion) were isolated from the matrix by solid-phase extraction, and were analysed by gas chromatography/mass spectrometry in the selected ion monitoring mode. The method has shown to be selective after analysis of postmortem samples of 40 different origins. Calibration curves were established between 0.05 (0.1 for omethoate) and 25 µg/mL, and the values obtained for intra- and interday precision and accuracy were within the criteria usually accepted for bioanalytical method validation. Lower limits of quantitation were 50 ng/mL for all compounds, except for omethoate (100 ng/mL); the limits of identification of the method were 25 ng/mL for all analytes, except for omethoate, for which 50 ng/mL was obtained. Absolute recovery was determined at three concentration levels, and ranged from 31 to 108%. The proposed method is simple and fast, and can be routinely applied in the determination of these compounds in postmortem whole blood samples within the scope of forensic toxicology. In addition, mass spectrometry has demonstrated to be a powerful and indispensable tool for the unequivocal identification of the analytes, since the acceptance criteria were accomplished even at very low levels, thus allowing obtaining forensically valid and sound results.

1alpha,25(OH)2D3 and its 3-epimer promote rat lung alveolar epithelial-mesenchymal interactions and inhibit lipofibroblast apoptosis

Although alveolar wall thinning has been attributed to apoptosis of interstitial lung lipofibroblasts (LFs), the underlying molecular mechanism(s) remains unknown. Although the physiological vitamin D steroid hormone 1alpha,25(OH)(2)D(3) (1,25D) has been suggested as a local paracrine/autocrine effector of fetal lung maturation and is known to affect fibroblast apoptosis, its effects on LF apoptosis are unknown. We determined the role of 1,25D and its metabolite, C-3-epimer (3-epi-1,25D), on LF and alveolar type II (ATII) cell differentiation, proliferation, and apoptosis. Embryonic day 19 Sprague-Dawley fetal rat lung LFs and ATII cells were treated with 1,25D or 3-epi-1,25D (1 x 10(-10) to 1 x 10(-8) M) for 24 h, and cell proliferation, apoptosis, and differentiation were assessed. Both 1,25D and 3-epi-1,25D exhibited dose-dependent increases in expression of the key homeostatic epithelial-mesenchymal differentiation markers, increased LF and ATII cell proliferation, and decreased apoptosis. Furthermore, rat pups administered 1,25D from postnatal days 0 to 14 showed increased expressions of key LF and ATII cell differentiation markers, increased Bcl-2-to-Bax ratio as an index of decreased spontaneous alveolar LF and ATII cell apoptosis, increased alveolar count, and a paradoxical increase in septal thickness. We conclude that spatial- and temporal-specific actions of vitamin D play a critical role in perinatal lung maturation by stimulating key alveolar epithelial-mesenchymal interactions and by modulating LF proliferation/apoptosis. These data not only provide the biological rationale for the presence of an alveolar vitamin D paracrine system, but also provide the first integrated molecular mechanism for increased surfactant synthesis and alveolar septal thinning during perinatal lung maturation.

Selective mutism: a consensus based care pathway of good practice

BACKGROUND

Selective mutism (SM) now acknowledged as an anxiety condition, tends to be a poorly understood, highly complex and vastly under-recognised clinical entity. Children with SM are a vulnerable group as the condition is not the remit of any one professional group. This inevitably leads to delay in formal diagnosis and management. There is a lack of systematic research on which to base guidelines for management.

AIM

To develop, agree and validate key principles underlying the management of SM through a consensus process involving international experts, in order to create a local care pathway.

METHODS

A local multi-agency consultation process developed 11 statements, which were felt to be the key principles underpinning a potential care pathway for managing SM. Thirteen recognised experts from North America, Europe and Australia participated in a modified Delphi process involving two rounds using a Likert-scale and free commentary. Both quantitative and qualitative analyses were used in the validation or revision of the statements at each stage.

RESULTS

Response rates were 100% for Round 1 and 84.6% for Round 2. Despite the differing professional backgrounds and service contexts, by successive revision and/or revalidation of statements, it was possible to arrive at a consensus about key principles relating to early recognition, assessment and intervention. The agreed key principles are presented together with the resulting local care pathway.

CONCLUSION

Through a Delphi process, agreement was reached by a multidisciplinary group of professionals, on key principles that underpin the timely identification, assessment and management of children with SM. These include the potential for staff in school/preschool settings to identify SM and that intervention programmes should generally be based in these settings. Children with SM should receive assessment for possible coexisting disorders, whether developmental, emotional or behavioural and additional specific intervention given for these. Agreement was reached as to what constitutes clinical progress, intervals for monitoring progress, criteria for referral onwards for multidisciplinary specialist assessment and the role of selective serotonin reuptake inhibitor (SSRI) medication. A consensus methodology has been successfully used to compensate for the lack of evidence base and harness the expertise of a relatively small number of experienced professionals in order to provide a basis for the future development of services.

United Kingdom school-entry hearing screening: current practice

OBJECTIVE

To determine if the school-entry hearing screening (SEHS) programme continues to make a useful contribution to the identification of childhood hearing impairment in the light of the recent implementation of universal newborn hearing screening, and thereby to inform future policy development.

DESIGN

Postal questionnaire survey to determine current implementation and effectiveness of SEHS SETTING: 244 school health services managed within primary care and acute trusts throughout the UK.

PARTICIPANTS

229 SEHS service leads approached; 195 responded.

MAIN OUTCOME MEASURE

Details of implementation; positive predictive value of the screening test and its referral criteria.

RESULTS

Implementation of the SEHS is variable, and there is no national approach to data collection, audit and quality assurance. Less than 10% of services had available robust data. The yield from screening ranges from 0.05% to 0.59% for permanent sensorineural hearing impairment and from 0.07% to 0.44% for permanent conductive hearing impairment. The positive predictive values from screen referral vary from 0.62% to 12.16% for permanent sensorineural hearing impairment and 1.24% to 17.56% for permanent conductive hearing impairment.

CONCLUSION

This comprehensive survey provides a previously unavailable national examination of the SEHS. The few available data on yield indicate that the SEHS may have a small but important role to play in identification of childhood hearing impairment, but the overwhelming conclusion is the urgent need for national guidelines on implementation of this screening programme to determine its value since the implementation nationally of universal newborn hearing screening.

Cost-effectiveness of implementing automated grading within the national screening programme for diabetic retinopathy in Scotland

AIMS

National screening programmes for diabetic retinopathy using digital photography and multi-level manual grading systems are currently being implemented in the UK. Here, we assess the cost-effectiveness of replacing first level manual grading in the National Screening Programme in Scotland with an automated system developed to assess image quality and detect the presence of any retinopathy.

METHODS

A decision tree model was developed and populated using sensitivity/specificity and cost data based on a study of 6722 patients in the Grampian region. Costs to the NHS, and the number of appropriate screening outcomes and true referable cases detected in 1 year were assessed.

RESULTS

For the diabetic population of Scotland (approximately 160,000), with prevalence of referable retinopathy at 4% (6400 true cases), the automated strategy would be expected to identify 5560 cases (86.9%) and the manual strategy 5610 cases (87.7%). However, the automated system led to savings in grading and quality assurance costs to the NHS of 201,600 pounds per year. The additional cost per additional referable case detected (manual vs automated) totalled 4088 pounds and the additional cost per additional appropriate screening outcome (manual vs automated) was 1990 pounds.

CONCLUSIONS

Given that automated grading is less costly and of similar effectiveness, it is likely to be considered a cost-effective alternative to manual grading.

Current practice, accuracy, effectiveness and cost-effectiveness of the school entry hearing screen

OBJECTIVES

To describe and analyse in detail current practice of school entry hearing screening (SES) in the UK.

DATA SOURCES

Main electronic databases were searched up to May 2005.

REVIEW METHODS

A national postal questionnaire survey was addressed to all leads for SES in the UK, considering current practice in terms of implementation, protocols, target population and performance data. Primary data from cohort studies in one area of London were examined. A systematic review of alternative SES tests, test performance and impact on outcomes was carried out. Finally, a review of published studies on costs, plus economic modelling of current and alternative programmes was prepared.

RESULTS

The survey suggested that SES is used in most of England, Wales and Scotland; just over 10% of respondents have abandoned the screen; others are awaiting national guidance. Coverage of SES is variable, but is often over 90% for children in state schools. Referral rates are variable, with a median of about 8%. The test used for the screen is the pure tone sweep test but with wide variation in implementation, with differing frequencies, pass criteria and retest protocols; written examples of protocols were often poor and ambiguous. There is no national approach to data collection, audit and quality assurance, and there are variable approaches at local level. The screen is performed in less than ideal test conditions and resources are often limited, which has an impact on the quality of the screen. The primary cohort studies show that the prevalence of permanent childhood hearing loss continues to increase through infancy. Of the 3.47 in 1000 children with a permanent hearing loss at school screen age, 1.89 in 1000 required identification after the newborn screen. Newborn hearing screening is likely to reduce significantly the yield of SES for permanent bilateral and unilateral hearing impairments; yield had fallen from about 1.11 in 1000 before newborn screening to about 0.34 in 1000 for cohorts that had had newborn screening, of which only 0.07 in 1000 were unilateral impairments. Just under 20% of permanent moderate or greater bilateral, mild bilateral and unilateral impairments, known to services as 6-year-olds or older, remained to be identified around the time of school entry. No good-quality published comparative trials of alternative screens or tests for SES were identified and studies concerned with the relative accuracy of alternative tests are difficult to compare and often flawed by differing referral criteria and case definitions; with full pure tone audiometry as the reference test, the pure tone sweep test appears to have high sensitivity and high specificity for minimal, mild and greater hearing impairments, better than alternative tests for which evidence was identified. There is insufficient evidence regarding possible harm of the screen. There were no published studies identified that examined the possible effects of SES on longer term outcomes. No good-quality published economic evaluations of SES were identified and a universal SES based on pure tone sweep tests was associated with higher costs and slightly higher quality-adjusted life-years (QALYs) compared with no screen and other screen alternatives; the incremental cost-effectiveness ratio for such a screen is around 2500 pounds per QALY gained; the range of expected costs, QALYs and net benefits was broad, indicating a considerable degree of uncertainty. Targeted screening could be more cost-effective than universal school entry screening; however, the lack of primary data and the wide limits for variables in the modelling mean that any conclusions must be considered indicative and exploratory only. A national screening programme for permanent hearing impairment at school entry meets all but three of the criteria for a screening programme, but at least six criteria are not met for screening for temporary hearing impairment.

CONCLUSIONS

The lack of good-quality evidence in this area remains a serious problem. Services should improve quality and audit screen performance for identification of previously unknown permanent hearing impairment, pending evidence-based policy decisions based on the research recommendations. Further research is needed into a number of important areas including the evaluation of an agreed national protocol for services delivering SES to make future studies and audits of screen performance more directly comparable.

The JAZ family of repressors is the missing link in jasmonate signalling

Jasmonates are essential phytohormones for plant development and survival. However, the molecular details of their signalling pathway remain largely unknown. The identification more than a decade ago of COI1 as an F-box protein suggested the existence of a repressor of jasmonate responses that is targeted by the SCF(COI1) complex for proteasome degradation in response to jasmonate. Here we report the identification of JASMONATE-INSENSITIVE 3 (JAI3) and a family of related proteins named JAZ (jasmonate ZIM-domain), in Arabidopsis thaliana. Our results demonstrate that JAI3 and other JAZs are direct targets of the SCF(COI1) E3 ubiquitin ligase and jasmonate treatment induces their proteasome degradation. Moreover, JAI3 negatively regulates the key transcriptional activator of jasmonate responses, MYC2. The JAZ family therefore represents the molecular link between the two previously known steps in the jasmonate pathway. Furthermore, we demonstrate the existence of a regulatory feed-back loop involving MYC2 and JAZ proteins, which provides a mechanistic explanation for the pulsed response to jasmonate and the subsequent desensitization of the cell.

The efficacy of automated "disease/no disease" grading for diabetic retinopathy in a systematic screening programme

AIM

To assess the efficacy of automated "disease/no disease" grading for diabetic retinopathy within a systematic screening programme.

METHODS

Anonymised images were obtained from consecutive patients attending a regional primary care based diabetic retinopathy screening programme. A training set of 1067 images was used to develop automated grading algorithms. The final software was tested using a separate set of 14 406 images from 6722 patients. The sensitivity and specificity of manual and automated systems operating as "disease/no disease" graders (detecting poor quality images and any diabetic retinopathy) were determined relative to a clinical reference standard.

RESULTS

The reference standard classified 8.2% of the patients as having ungradeable images (technical failures) and 62.5% as having no retinopathy. Detection of technical failures or any retinopathy was achieved by manual grading with 86.5% sensitivity (95% confidence interval 85.1 to 87.8) and 95.3% specificity (94.6 to 95.9) and by automated grading with 90.5% sensitivity (89.3 to 91.6) and 67.4% specificity (66.0 to 68.8). Manual and automated grading detected 99.1% and 97.9%, respectively, of patients with referable or observable retinopathy/maculopathy. Manual and automated grading detected 95.7% and 99.8%, respectively, of technical failures.

CONCLUSION

Automated "disease/no disease" grading of diabetic retinopathy could safely reduce the burden of grading in diabetic retinopathy screening programmes.

Audiological issues in children with cleft lip and palate in one area of the U.K

OBJECTIVE

The purpose of this study was to determine the extent of multidisciplinary care and audiological services rendered to children with CL/P who underwent surgical repair of the cleft in 1998 and 1999. This followed proposals to radically reorganize cleft lip and palate services in the U.K. after unsatisfactory findings in a national review.

METHOD

Information was obtained from questionnaires sent to clinicians (audiologists; ear, nose, and throat surgeons; and community pediatricians) from audiology teams, and parents were asked to retrieve information from their Personal Child Health Record. Standards chosen were based on the Clinical Standards Advisory Group, the South Thames Audiology Audit Group, and the National Deaf Children's Society.

RESULTS

None of the agreed standards were achieved at an acceptable level.

CONCLUSIONS

This demonstrates the need for better communication systems between teams, including better use by parents and professionals of the Personal Child Health Record. A clinical care pathway is suggested here with other recommendations.

[Pediatric Guillain-Barré syndrome. Experience in the Neuropediatrics Unit of a Portuguese hospital]

INTRODUCTION

Guillain-Barré syndrome (GBS) is an acute inflammatory ascending polyradiculoneuropathy. Autoimmune mechanisms play a role in the demyelinating process. Clinically, progressive symmetric loss of motor strength, areflexia, sensitive and autonomic manifestations are observed. Albuminocytological dissociation and electrophysiological signs of demyelination are frequently found. It is the most common cause of acute flaccid paralysis in children.

PATIENTS AND METHODS

Retrospective review of all children with GBS admitted to Garcia de Orta Hospital in a 10 year period (1994-2003).

RESULTS

17 children (18 months to 14 years) were admitted during this period. Respiratory or gastrointestinal prodrome was identified in 15 children, with positive serologic studies in six. The main clinical manifestations were disturbances of gait, progressive muscular weakness, sensitive manifestations (pain, paresthesias) and osteotendinous areflexia. 13 children had albuminocytological dissociation and acute demyelinating neuropathy was identified in 12.64% of children were treated with immunoglobulins (2 g/kg). Clinical evolution was favourable in 16 cases, with a death secondary to autonomic dysfunction.

CONCLUSIONS

Clinical presentation may be unspecific, particularly in young patients, with pain as a primary complaint, preceding muscular weakness and areflexia. Increased cerebrospinal protein and abnormal electrodiagnostic studies may be absent in the early course of GBS. Immunoglobulin therapy was efficacious and well-tolerated.

School hearing screening programme in the UK: practice and performance

BACKGROUND

Paediatric audiology services and screening programmes are currently under review.

AIMS AND METHODS

To investigate current practice and performance of the school hearing screening programme (SHSP) by means of a questionnaire.

RESULTS

SHSP was found to detect previously unrecognised hearing loss at low cost. Wide variation in practice was shown, and the majority of services had no computerised system for data collection.

CONCLUSION

There is a need for nationally agreed protocols and quality assurance procedures.

Impact of positive legionella urinary antigen test on patient management and improvement of antibiotic use

AIM

To assess the incidence of legionella infection over a 27 month period at a large university hospital.

MATERIAL AND METHODS

The present retrospective cohort study enrolled patients with legionellosis, defined as those presenting a positive urinary antigen for legionella together with a medical history, clinical findings, and radiological findings consistent with pneumonia. These patients were evaluated to determine the relation between their test results and changes in treatment modalities. A control group of patients with pneumonia but a negative urinary antigen test for legionella were also analysed.

RESULTS

Twenty seven of 792 assessed patients tested positive for legionella. In 22 of these patients, legionella active antibiotics were administered empirically. In seven patients, the test results prompted a legionella specific treatment, whereas in 12 cases, non-specific antibiotics were stopped within 24 hours. Overall, treatment was altered in more than half of the patients as a result of the test results.

CONCLUSIONS

The urinary antigen may have a direct impact on clinical management of pulmonary legionellosis. However, patient comorbidities and individual clinical judgment are still important for determining the best treatment to be given in each individual case.

Effect of telmisartan 80 mg once daily on 24-h blood pressure profile in patients with mild-to-moderate hypertension failing to respond to prior antihypertensive therapy

Blood pressure is not adequately controlled in almost 50% of patients with hypertension who are in receipt of antihypertensive therapy. This multicentre, prospective, open-label trial was designed to determine whether or not once-daily telmisartan 80 mg reduced blood pressure during the last 6 h of the 24-h dosing interval in patients with mild-to-moderate hypertension who were unresponsive to previous antihypertensive therapy. The study comprised 100 patients (47 males, 53 females) who had failed to respond satisfactorily to prior treatment given for a minimum of 3 months. At screening, 24-h ambulatory blood pressure monitoring (ABPM) was conducted after the patient had been treated with the currently prescribed antihypertensive medication. Following 5 weeks of telmisartan 80 mg treatment, ABPM was repeated. Telmisartan significantly reduced mean systolic blood pressure, diastolic blood pressure (DBP) and pulse pressure compared with previous antihypertensive therapy over each time interval (24-h, morning, night-time and the last 6 h of the dosing interval [2.00 a.m.-8.00 a.m.]) analysed. In addition, more than 90% of patients responded successfully (clinic DBP <90 mmHg or a >10 mmHg reduction in clinic DBP) at the end of telmisartan treatment. In conclusion, telmisartan provides effective blood pressure control throughout the 24-h dosing interval in patients with mild-to-moderate hypertension who were unresponsive to previous antihypertensive medication.

Reactive phenotypes after acute and chronic NK-cell activation

Several phenotypic changes have been shown to occur after NK-cell stimulation, involving molecules that have been proved to regulate NK-cell migration into tissues and NK-cell activation and proliferation as well as target cell recognition and killing. Here, we review the reactive phenotypes observed in vivo after acute and chronic NK-cell activation.

Slow fiber cluster pattern in pig longissimus thoracis muscle: implications for myogenesis

Recent evidence implicates fiber type proportions as playing a role in meat eating quality, and in pigs it has been suggested that the slow oxidative fibers contribute to both juiciness and tenderness. The fiber distribution in pigs is different from that found in most other species, in which the various types of skeletal muscle fiber are distributed in a "checkerboard" pattern, because in pigs the slow oxidative fibers have a clustered distribution. The initial processes leading to fiber clustering are likely to occur during myogenesis, but the precise mechanistic aetiology of this patterning and whether the slow oxidative fiber clusters occur in a random or ordered fashion is unknown. In the present study longissimus thoracis muscle from Large White crossbred pigs was sampled at the 10th rib, 48 h postmortem. Transverse cryo-sections were cut and histochemically stained to allow the identification of the main muscle fiber types: slow oxidative, fast glycolytic, and fast oxidative glycolytic. Images of the sections were captured and analyzed using point processes and Voronoi Tesselations to examine the randomness and spatial distribution of the clusters of slow oxidative fibers found in pig longissimus thoracis muscle. The results showed that an assumption of complete spatial randomness can be rejected and that a mathematical model incorporating a minimum distance of 1.7 to 2.0 microm between cluster centers produced fiber patterns similar to those observed in the original transverse sections of the muscle. In addition, if it assumed that the central fiber in each cluster is derived from primary myoblast progenitors, these results suggest that there may be some degree of repulsion between the primary fibers during the initial stages of cluster formation. The mechanistic basis of such repulsion is not clear, but it is speculated that secreted factors, such as sonic hedgehog or myostatin may play a role.