Automated lung cancer assessment on 18F-PET/CT using Retina U-Net and anatomical region segmentation

OBJECTIVES

To develop and test a Retina U-Net algorithm for the detection of primary lung tumors and associated metastases of all stages on FDG-PET/CT.

METHODS

A data set consisting of 364 FDG-PET/CTs of patients with histologically confirmed lung cancer was used for algorithm development and internal testing. The data set comprised tumors of all stages. All lung tumors (T), lymphatic metastases (N), and distant metastases (M) were manually segmented as 3D volumes using whole-body PET/CT series. The data set was split into a training (n = 216), validation (n = 74), and internal test data set (n = 74). Detection performance for all lesion types at multiple classifier thresholds was evaluated and false-positive-findings-per-case (FP/c) calculated. Next, detected lesions were assigned to categories T, N, or M using an automated anatomical region segmentation. Furthermore, reasons for FPs were visually assessed and analyzed. Finally, performance was tested on 20 PET/CTs from another institution.

RESULTS

Sensitivity for T lesions was 86.2% (95% CI: 77.2-92.7) at a FP/c of 2.0 on the internal test set. The anatomical correlate to most FPs was the physiological activity of bone marrow (16.8%). TNM categorization based on the anatomical region approach was correct in 94.3% of lesions. Performance on the external test set confirmed the good performance of the algorithm (overall detection rate = 88.8% (95% CI: 82.5-93.5%) and FP/c = 2.7).

CONCLUSIONS

Retina U-Nets are a valuable tool for tumor detection tasks on PET/CT and can form the backbone of reading assistance tools in this field. FPs have anatomical correlates that can lead the way to further algorithm improvements. The code is publicly available.

KEY POINTS

• Detection of malignant lesions in PET/CT with Retina U-Net is feasible. • All false-positive findings had anatomical correlates, physiological bone marrow activity being the most prevalent. • Retina U-Nets can build the backbone for tools assisting imaging professionals in lung tumor staging.

Which animal-to-feeding-place ratio at time-controlled hay racks is animal appropriate? Preliminary analysis of stress responses of horses

Introduction

Automated feeding systems offer numerous advantages for animals and humans, but the associated benefits and risks can often only be seen under practical conditions. The space allowance (~80 cm per horse) at time-controlled hay racks for horses in group housing, unlike at partitioned feeding stands or transponder-controlled feed stations, currently falls below the required individual distance between the horses, which can result in a high level of aggression between the horses due to the lack of partitions between them. Hence, a feed-through at a time-controlled hay rack cannot be equated with a feeding place. In this preliminary study, we therefore aimed to determine the minimum animal-to-feeding-place ratio (AFR) at time-controlled hay racks that would provide adequate individual distances between the horses.

Methods

To do so, we assessed behavioral and physiological parameters (via video behavioral observations and salivary cortisol measurements) of up to 28 horses in a loose housing system. Over 2 observation days per treatment, four AFRs were investigated in a balanced sequence: 1:1.2, 1:2, 1:3, and C (single feeding in familiar surroundings as a control).

Results

We found that the horses expressed less aggressive behavior, especially those behaviors with a high risk of injury such as biting and kicking, when there were three times as many openings as there were horses at time-controlled hay racks, as compared with only 20% more openings or twice as many openings as there were horses [lineal mixed model: F (3, 4) = 7.411; adjusted R 2 = 0.733; p (AFR_1:2) = 0.06, p (AFR_1:3) = 0.02, p (AFR_C) = 0.01]. The salivary cortisol levels during feeding decreased more strongly with more generous AFRs [p (AFR_metric) = 0.02]. The factors hierarchy and individual showed no influence. In contrast, the day of the experiment and the associated weather conditions, despite randomized selection, influenced both the behavioral and the physiological parameters.

Discussion

The results of this preliminary study indicate that the investigated time-controlled hay racks must provide at least three times as many feeding places as there are horses to ensure that neighboring horses can keep their individual distance and stress-free feeding is possible. Further studies on more farms and different types as well as arrangement of hay racks are proposed.

3D printing of resilient biogels for omnidirectional and exteroceptive soft actuators

Soft robotics greatly benefits from nature as a source of inspiration, introducing innate means of safe interaction between robotic appliances and living organisms. In contrast, the materials involved are often nonbiodegradable or stem from nonrenewable resources, contributing to an ever-growing environmental footprint. Furthermore, conventional manufacturing methods, such as mold casting, are not suitable for replicating or imitating the complexity of nature's creations. Consequently, the inclusion of sustainability concepts alongside the development of new fabrication procedures is required. We report a customized 3D-printing process based on fused deposition modeling, printing a fully biodegradable gelatin-based hydrogel (biogel) ink into dimensionally stable, complex objects. This process enables fast and cost-effective prototyping of resilient, soft robotic applications from gels that stretch to six times their original length, as well as an accessible recycling procedure with zero waste. We present printed pneumatic actuators performing omnidirectional movement at fast response times (less than a second), featuring integrated 3D-printed stretchable waveguides, capable of both proprio- and exteroception. These soft devices are endowed with dynamic real-time control capable of automated search-and-wipe routines to detect and remove obstacles. They can be reprinted several times or disposed of hazard-free at the end of their lifetime, potentially unlocking a sustainable future for soft robotics.

[200 years of the animal hospital Zurich: A cross-section through the lectures of the exam year 1864]

INTRODUCTION

The current study analyzed eleven lecture transcripts from the Zurich Veterinary School of the years -1861-1864. The work presents the staff and organizational situation of the school at that time. Lectures concerned mostly clinical subjects, especially special pathology and therapy. The texts were transcribed, summarized and analyzed according to the criteria species, diagnosis and therapy. The drugs were listed. Therapy concepts follow the principles of humoral pathology, but transition to cellular pathology was imminent. The pathogens of infectious diseases are not identified yet, but are suspected to be called «contagions».

Investigation of gamma secretase gene complex mutations in German population with Hidradenitis suppurativa designate a complex polygenic heritage

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory disease affecting apocrine gland-bearing skin in the axilla, groin and under the breasts. Mutations of the gamma secretase gene complex, which is essential in the activation of Notch signalling pathways, were shown in some families with HS and in a few sporadic cases. Although an imbalance in Notch signalling is implicated in the pathogenesis, the exact mechanism of HS development is yet unknown.

OBJECTIVES

We aim to investigate the genetic basis of HS by determining the presence of mutations of gamma secretase gene complex in a cohort of HS patients and by searching for a disease-causing pathogenic variant in a multi-generational HS family using parametric linkage analysis.

METHODS

Thirty-eight patients clinically diagnosed with HS were included in this study. All exons and exon-intron boundaries of the genes encoding gamma secretase complex consisting of six genes: APH1A, APH1B, PSENEN, NCSTN, PSEN1 and PSEN2 were sequenced by Sanger technique. Genetic mapping with parametric linkage analysis for the patients in the family was performed with eight affected and four healthy individuals. The logarithm of odds was calculated.

RESULTS

In a sporadic patient with early-onset, severe lesions in axilla and groin, a novel single-nucleotide deletion causing frameshift in exon 1 of the NCSTN gene was identified ((NM_015331.3): c.38delG, p.(Gly13Glufs*15)). The LOD score of 1.5 was never exceeded in any region of the genome, pointing towards intricate multi-genic inheritance pattern within the affected family.

CONCLUSIONS

The gamma secretase gene complex mutations were rare in our cohort (3.2%). Besides, our analysis indicates a possible complex multi-genic inheritance in a seemingly autosomal dominantly inherited large HS family. Genetics of both familial and sporadic HS may be complicated in most cases, and the role of other potential genes such as autoinflammatory and modifier genes as well as environmental factors may influence the pathogenesis.

Hair cortisol concentration in clinically healthy slaughter calves with and -without chronic bronchopneumonic -lesions

INTRODUCTION

The hypothesis of this study was that healthy calves undergo less stress and thus have lower hair cortisol concentrations than calves with chronic bronchopneumonic lesions. Fifty healthy calves (group 1) and 50 calves with chronic bronchopneumonic lesions (group 2) were used immediately after slaughter, at which time hair samples and both adrenal glands were collected. The hair samples and the left adrenal gland were used for cortisol measurement and the right adrenal gland was used for histological and morphometrical examinations. The median hair cortisol concentrations of calves in groups 1 and 2 were 1.6 and 1.9 pg/mg hair, respectively, and did not differ significantly. The same was true for the mean cortisol concentration of the adrenal gland (1.1 and 1.4 µg/g tissue) and for the adrenal cortisol content (3.7 and 4.6 µg). The weights of the cortex (3.3, mean, and 3.5 g, median) and medulla (1.7 and 1.8 g, both median) did not differ significantly between the groups. This study did not detect differences in hair and adrenal cortisol concentrations between clinically healthy slaughter calves with and without chronic bronchopneumonic lesions. In further studies, calves with clinical signs should be taken into account.

Synthesis of M-UiO-66 (M = Zr, Ce or Hf) employing 2,5-pyridinedicarboxylic acid as a linker: defect chemistry, framework hydrophilisation and sorption properties

MOFs of general composition [M₆(OH)₄(O)₄(PDC)_6−x(Cl)_2x(H₂O)_2x] with M = Zr, Ce, Hf; and 0 ≤ x ≤ 2 were obtained and characterised in detail.

Protistan predation interferes with bacterial long-term adaptation to substrate restriction by selecting for defence morphotypes

Bacteria that are introduced into aquatic habitats face a low substrate environment interspersed with rare productive 'hotspots', as well as high protistan grazing. Whereas the former condition should select for growth performance, the latter should favour traits that reduce predation mortality, such as the formation of large cell aggregates. However, protected morphotypes often convey a growth disadvantage, and bacteria thus face a trade-off between investing in growth or defence traits. We set up an evolutionary experiment with the freshwater isolate Sphingobium sp. strain Z007 that conditionally increases aggregate formation in supernatants from a predator-prey coculture. We hypothesized that low substrate levels would favour growth performance and reduce the aggregated subpopulation, but that the concomitant presence of a flagellate predator might conserve the defence trait. After 26 (1-week) growth cycles either with (P+) or without (P-) predators, bacteria had evolved into strikingly different phenotypes. Strains from P- had low numbers of aggregates and increased growth yield, both at the original rich growth conditions and on various single carbon sources. By contrast, isolates from the P+ treatment formed elevated proportions of defence morphotypes, but exhibited lower growth yield and metabolic versatility. Moreover, the evolved strains from both treatments had lost phenotypic plasticity of aggregate formation. In summary, the (transient) residence of bacteria at oligotrophic conditions may promote a facultative oligotrophic life style, which is advantageous for survival in aquatic habitats. However, the investment in defence against predation mortality may constrain microbial adaptation to the abiotic environment.

Risk factors causing postweaning multisystemic wasting syndrome (PMWS) onset in Swiss pig farms

Postweaning multisystemic wasting syndrome (PMWS) was epizoozic between 2003 and 2008 in Switzerland. Nevertheless, infectious risk factors including porcine reproductive and respiratory syndrome virus (PRRSV) were missing at all or were seen only sporadically (enzootic pneumonia and actinobazillosis). In a case-control study, 30 farms with PMWS affected pigs were compared to 30 inconspicious farms ("matched pairs"). The case-control allocation was verified by PCV2 DNA measurements of 5 healthy weaned pigs in each control farm, 5 healthy and 5 PMWS affected weaners in each PMWS affected farm. Diseased pigs showed in average 1.8x10(8) DNA templates per ml serum significantly higher than healthy pigs from control farms with 1x10(6) DNA templates per ml serum. Virus load in healthy pigs did not differ between control- and PMWS affected farms. PMWS mainly emerged among affected pigs in the 5th to 8th week of age. In a logistic regression model risk factors were identified such as high occupancy in weaning pens (p = 0.002), large groups in gestation facilities (p = 0.03) as well as reduced birth weight < 1.3 kg (p = 0.04). We suggest these factors might have lead to chronic stress e.g. through influencing negatively social interaction in pigs or disturbances of the maturing immune system. Heavy fly and rodent infestation might not only be viewed as a vector for disease transmission, but, also as a stress factor.

Constituents of Euphorbiaceae, 13. Comm. [1] Isolation and Structure Elucidation of Five Cerebrosides from Euphorbia characias L

Five cerebrosides B-1−B-4 were isolated from the fraction B, obtained from the latex of Euphorbia characias L. On the basis of spectral evidences and chemical reactions they were characterized as (2S, 3S, 4R, 8Z)-1-O-(β-D-glucopyranosyl)-2N-[(2'R)-2'-hydroxytetracosenoyl]-8 (Z)-octadecene-1,3,4-triol-2-amino (B-1), (2S, 3S, 4R, 8Z)-1-O-(β-D-glucopyranosyl)-2 N-[(2'R)-2'-hydroxyhexacosenoyl]-8(Z)-octadecene-1,3,4-triol-2-amino(B-2), (2 S, 3 S,4 R, 8 Z)-1-O-(β-D-glucopyranosyl)-2N-[(2'R)-2'-hydroxyoctacosenoyl]-8 (Z)-octa-decene-1,3,4-triol-2-amino (B-3), (2 S, 3 S, 4R, 8Z)-1-O-(β-D-glucopyranosyl)-2N-[(2'R)-2'-hydroxyhexacosanoyl]-8 (Z)-octadecene-1,3,4-triol-2-amino (B-3a), (2S, 3S, 4R, 8Z)-1-O-(β-D-glucopyranosyl)-2 N-[(2'R)-2'-hydroxyheptacosanoyl]-8 (Z)-octadecene-1,3,4-triol-2-amino (B-4).

Reversed phase column flash chromatography was effective for the isolation of the cerebrosides. FAB-MS spectrometry, 1H NMR, 13C NMR analyses and DQF-COSY and 1H-detected HMQC (single bond and multiple bond) experiments and chemical reactions were useful in providing informations for the structure elucidation.

Improvement of anaerobic digestion performance by continuous nitrogen removal with a membrane contactor treating a substrate rich in ammonia and sulfide

The effect of reduced ammonia levels on anaerobic digestion was investigated. Two reactors were fed with slaughterhouse waste, one with a hollow fiber membrane contractor for ammonia removal and one without. Different organic loading rates (OLR) and free ammonia and sulfide concentrations were investigated. In the reactor with the membrane contactor, the NH4-N concentration was reduced threefold. At a moderate OLR (3.1 kg chemical oxygen demand - COD/m(3)/d), this reactor performed significantly better than the reference reactor. At high OLR (4.2 kg COD/m(3)/d), the reference reactor almost stopped producing methane (0.01 Nl/gCOD). The membrane reactor also showed a stable process with a methane yield of 0.23 Nl/g COD was achieved. Both reactors had predominantly a hydrogenotrophic microbial consortium, however in the membrane reactor the genus Methanosaeta (acetoclastic) was also detected. In general, all relevant parameters and the methanogenic consortium indicated improved anaerobic digestion of the reactor with the membrane.

Epigenetic silencing of miRNA-9 is associated with HES1 oncogenic activity and poor prognosis of medulloblastoma

BACKGROUND

microRNA-9 is a key regulator of neuronal development aberrantly expressed in brain malignancies, including medulloblastoma. The mechanisms by which microRNA-9 contributes to medulloblastoma pathogenesis remain unclear, and factors that regulate this process have not been delineated.

METHODS

Expression and methylation status of microRNA-9 in medulloblastoma cell lines and primary samples were analysed. The association of microRNA-9 expression with medulloblastoma patients' clinical outcome was assessed, and the impact of microRNA-9 restoration was functionally validated in medulloblastoma cells.

RESULTS

microRNA-9 expression is repressed in a large subset of MB samples compared with normal fetal cerebellum. Low microRNA-9 expression correlates significantly with the diagnosis of unfavourable histopathological variants and with poor clinical outcome. microRNA-9 silencing occurs via cancer-specific CpG island hypermethylation. HES1 was identified as a direct target of microRNA-9 in medulloblastoma, and restoration of microRNA-9 was shown to trigger cell cycle arrest, to inhibit clonal growth and to promote medulloblastoma cell differentiation.

CONCLUSIONS

microRNA-9 is a methylation-silenced tumour suppressor that could be a potential candidate predictive marker for poor prognosis of medulloblastoma. Loss of microRNA-9 may confer a proliferative advantage to tumour cells, and it could possibly contribute to disease pathogenesis. Thus, re-expression of microRNA-9 may constitute a novel epigenetic regulation strategy against medulloblastoma.

Proteomic analysis of the Theileria annulata schizont

The apicomplexan parasite, Theileria annulata, is the causative agent of tropical theileriosis, a devastating lymphoproliferative disease of cattle. The schizont stage transforms bovine leukocytes and provides an intriguing model to study host/pathogen interactions. The genome of T. annulata has been sequenced and transcriptomic data are rapidly accumulating. In contrast, little is known about the proteome of the schizont, the pathogenic, transforming life cycle stage of the parasite. Using one-dimensional (1-D) gel LC-MS/MS, a proteomic analysis of purified T. annulata schizonts was carried out. In whole parasite lysates, 645 proteins were identified. Proteins with transmembrane domains (TMDs) were under-represented and no proteins with more than four TMDs could be detected. To tackle this problem, Triton X-114 treatment was applied, which facilitates the extraction of membrane proteins, followed by 1-D gel LC-MS/MS. This resulted in the identification of an additional 153 proteins. Half of those had one or more TMD and 30 proteins with more than four TMDs were identified. This demonstrates that Triton X-114 treatment can provide a valuable additional tool for the identification of new membrane proteins in proteomic studies. With two exceptions, all proteins involved in glycolysis and the citric acid cycle were identified. For at least 29% of identified proteins, the corresponding transcripts were not present in the existing expressed sequence tag databases. The proteomics data were integrated into the publicly accessible database resource at EuPathDB (www.eupathdb.org) so that mass spectrometry-based protein expression evidence for T. annulata can be queried alongside transcriptional and other genomics data available for these parasites.

Human cell-conditioned media produced under embryonic-like conditions result in improved healing time after laser resurfacing

BACKGROUND

Laser resurfacing procedures are continuing to grow in popularity as patients select less invasive procedures for rejuvenation of photo-damaged and aging skin. However, although physicians have begun exploring options to aid in postlaser healing, currently available treatments have little clinical evidence to support their use for wounded skin.

METHODS

When grown under conditions of very low oxygen and suspension, a simulation of the embryonic environment, neonatal cells have been found to produce proteins and growth factors in types and quantities similar to those of fetal cells. The human cell-conditioned media (hCCM) produced by the cells was extracted and formulated into a gel to evaluate its efficacy in the healing of postlaser wounds.

RESULTS

A split-face clinical evaluation of the material was performed, with 42 subjects undergoing combination ablative and nonablative laser procedures. Three concentrations of the hCCM were tested (× 0.1, × 1.0, × 10.0), and a dose-response trend was seen in the blinded physician evaluation, particularly in the assessment of crusting. In addition, transepidermal water loss readings showed a significant difference (p ≤ 0.05), indicating a more rapid return to normal skin barrier function with the active treatment. Histopathologic evaluation of subject biopsies showed reduced inflammation and a more normal epidermal appearance in the active treatment sites.

CONCLUSIONS

The results of this clinical evaluation support the use of the soluble hCCM produced under embryonic-like conditions to accelerate wound healing after laser resurfacing procedures. The utility of the × 10 concentration appears to promote more rapid, scarless wound healing after resurfacing procedures and more normal skin recovery.

High mobility, low voltage operating C(60) based n-type organic field effect transistors

We report on C(60) based organic field effect transistors (OFETs) that are well optimized for low voltage operation. By replacing commonly used dielectric layers by thin parylene films or by utilizing different organic materials like divinyltetramethyldisiloxane-bis(benzocyclo-butene) (BCB), low density polyethylene (PE) or adenine in combination with aluminum oxide (AlOx) to form a bilayer gate dielectric, it was possible to significantly increase the capacitance per unit area (up to two orders of magnitude). The assembly of metal-oxide and organic passivation layer combines the properties of the high dielectric constant of the metal oxide and the good organic-organic interface between semiconductor and insulator provided by a thin capping layer on top of the AlOx film. This results in OFETs that operate with voltages lower than 500 mV, while exhibiting field effect mobilities exceeding 3 cm(2) V(-1) s(-1).

Re-irradiation of head and neck cancer-impact of total dose on outcome

AIM

To evaluate the outcome of re-irradiation and to define favourable pre-treatment characteristics.

PATIENTS AND METHODS

seventy-five patients with locally recurrent head and neck cancer were treated with re-irradiation, either postoperatively or as definitive treatment, with and without chemotherapy. Mean time period between first and second series of irradiation was 19 months. Mean overall dose of re-irradiation was 46 Gy. Median follow-up was 8.7 months.

RESULTS

Overall survival, loco-regional disease-free survival and metastasis-free survival after two years were 23%, 24% and 77%, respectively. Higher overall doses of re-irradiation gave a statistically significant better outcome with regard to overall survival (p=0.018).

CONCLUSION

For patients with locally recurrent head and neck cancer, re-irradiation is a feasible therapeutic option. The total dose at re-irradiation improves overall survival. Therefore, re-irradiation with curative intent should only be applied if a sufficient total dose of ≥46 Gy can be given.

In-patient suicide--a 13-year assessment

OBJECTIVE

To describe the suicide rates of psychiatric in-patients in the canton of Zurich for the period 1992-2004, and to determine putative risk factors.

METHOD

The data were derived from the psychiatric case register of the canton Zurich. The analyses were based on person-years calculations and standardised mortality ratios. Additional information was assessed via case records.

RESULTS

During the 13-year period the standardised mortality ratio was 48.9. The risk of suicide was particularly high in patients with personality and affective disorders. Most suicides occurred during regular leave periods, despite the fact that clinical assessment had indicated there was no suicide risk for the patient.

CONCLUSION

The suicide risk of in-patients is distinctly higher than in the general population. A better assessment of suicide risk before regular leave periods could lead to a decrease of suicides in in-patient settings, as well as a more rigorous treatment of borderline cases, and of affective and psychotic symptoms.

["Arnold Näf: an extract from notes of the entire veterinary medicine of 1864"]

Arnold Näf studied Veterinary Medicine at the Tierarzneischule in Zürich from 1861 to 1864. During the lectures in clinical medicine he made several notes, which were published in the book: "Arnold Näf: Notes from the entire veterinary medicine 1864". In the present work the person of prosector Meyer together with his lectures about obstetrics, horse shoeing, specific pathology and therapy as well as prescription science are described in more detail. Hans Jakob Meyer was born in Schlieren, January 10, 1831 and died May 8, 1895. He was teaching Veterinary Medicine from 1855 to 1895 at the Tierarzneischule in Zürich. The therapy about glanders, mange and strangles in the horse was compared with the contemporary literature. Partial agreement with the application of substances used at that time has been found.

Potential renal protective benefits of intra-operative BNP infusion during cardiac transplantation

BACKGROUND

Recombinant BNP (nesiritide) is known to reduce endothelin levels, cause afferent arteriole vasodilation, and increase natriuresis and diuresis. We hypothesized that intraoperative infusion of BNP may benefit renal function in cardiac transplant patients.

METHODS

From June 2003 to September 2005, 22 consecutive heart transplant patients received BNP at a dose of 0.01 microg/kg/min before initiation of cardiopulmonary bypass (group A). BNP infusion was continued for a mean of 3.3 +/- 1.9 days. Hemodynamics, urine output, and serum creatinine levels were prospectively collected and compared with 22 consecutive patients who underwent heart transplantation between May 2002 and June 2003 following the identical transplant protocol, but without BNP infusion (group B).

RESULTS

At 24 hours postoperatively, mean blood pressure was comparable between groups (87 +/- 11 mm Hg vs 89 +/- 17 mm Hg, P = .7), but pulmonary artery pressure (18 +/- 5 mm Hg vs 24 +/- 5 mm Hg, P = .001) and central venous pressure (12 +/- 5 mm Hg vs 16 +/- 4 mm Hg, P = .01) were lower with BNP infusion, whereas cardiac index was augmented (2.8 +/- 0.5 vs 2.4 +/- 0.6, P = .03). Requirement of low-dose inotropic and vasopressor support was equally distributed between groups (P > or = .72). Postoperative urine output for the initial 24 hours was higher in group A (84 +/- 15 vs 55 +/- 36 mL/h, P = .01). None of the patients with BNP infusion required additional diuretics or renal replacement therapy during the first week after transplantation. Mean postoperative serum creatinine levels as compared with preoperative values remained unchanged within group A (P = .12), but increased significantly in group B (P < .001).

CONCLUSIONS

Intraoperative BNP infusion in heart transplant recipients was associated with favorable postoperative hemodynamics, significantly improved urine output, and stable serum creatinine levels. A prospective, randomized, multicenter trial is warranted to evaluate the potential renal protective benefits of intraoperative BNP infusion in this patient population.

Pipecolic acid as a diagnostic marker of pyridoxine-dependent epilepsy

Pyridoxine-dependent epilepsy, although described some decades ago, may still be an underdiagnosed disorder. We have recently described isolated pipecolic acid elevations in the plasma and/or CSF of three patients with pyridoxine-dependent epilepsy with an intriguing inverse correlation to the oral intake of pyridoxine. We have now confirmed these findings in a further 6 unrelated patients with pyridoxine-dependent epilepsy. Pipecolic acid in plasma was 4.3- to 15.3 fold elevated compared to the upper normal range before pyridoxine and remained in the mildly elevated range while on pyridoxine. Pipecolic acid was even more markedly elevated in CSF. The extent of pipecolic acid elevation in CSF exceeded that of plasma by a factor of 2.2 to 4.8. This clearly discriminates pyridoxine-dependent epilepsy from other possible defects with elevated pipecolic acid. Determination of pipecolic acid in plasma and/or CSF should be included in the diagnostic work-up of patients with therapy-resistant seizures. It will in addition prevent patients with pyridoxine-dependent epilepsy from experiencing potentially dangerous pyridoxine-withdrawal, which until now has been necessary to prove the diagnosis.

Effects of usual nutrient intake and vitamin D status on markers of bone turnover in Swiss adolescents

OBJECTIVE

To evaluate the effects of nutrient intake and vitamin D status on markers of type I collagen formation and degradation in adolescent boys and girls.

DESIGN

Cross-sectional study.

SETTING

Canton of Vaud, West Switzerland.

SUBJECTS

A total of 92 boys and 104 girls, aged 11-16 y. Data were collected on height, weight, pubertal status (self-assessment of Tanner stage), nutrient intake (3-day dietary record) and fasting serum concentration of 25-hydroxyvitamin D (25OHD), and markers of collagen formation (P1NP) and degradation (serum C-terminal telopeptides: S-CTX).

RESULTS

Tanner stage was a significant determinant of P1NP in boys and girls and S-CTX in girls. Of the nutrients examined, only the ratio of calcium to phosphorus (Ca/P) was positively associated with P1NP in boys, after adjustment for pubertal status. 25OHD decreased significantly at each Tanner stage in boys. Overall, 15% of boys and 17% of girls were identified as being vitamin D insufficient (serum 25OHD <30 nmol/l), with the highest proportion of insufficiency at Tanner stage 4-5 (29%) in boys and at Tanner stage 3 (24%) in girls. A significant association was not found between 25OHD and either bone turnover marker, nor was 25OHD insufficiency associated with higher concentrations of the bone turnover markers.

CONCLUSIONS

The marked effects of puberty on bone metabolism may have obscured any possible effects of diet and vitamin D status on markers of bone metabolism. The mechanistic basis for the positive association between dietary Ca/P ratio and P1NP in boys is not clear and may be attributable to a higher Ca intake per se, a critical balance between Ca and P intake or higher dairy product consumption. A higher incidence of vitamin D insufficiency in older adolescents may reflect a more sedentary lifestyle or increased utilisation of 25OHD, and suggests that further research is needed to define their requirements.

SPONSORSHIP

Nestec Ltd and The Swiss Foundation for Research in Osteoporosis.

Methylcrotonyl-CoA carboxylase (MCC) deficiency associated with severe muscle pain and physical disability in an adult

We present a patient with methylcrotonyl-CoA carboxylase (MCC) deficiency (McKusick 210200) who suffered from severe muscle pain and physical disability, and propose that this disorder be considered in the differential diagnosis of adult patients presenting with muscle pain and weakness.

[Irreversible bilateral amaurosis in a 36-year-old immigrant]

We report on a 36-year-old man with a history of mild head trauma. The initial clinical findings and the CT-scan of the brain revealed no pathological result, although the patient suffered from weakness of the right arm and bilateral blindness. Those findings were interpreted as psychogenic disorder. Nine days later he developed an instable gait, a child like attitude, amnesia and enuresis. The CT-scan revealed a subacute bilateral occipital stroke in the region of the arteriae cerebri posteriors. No cause for the stroke was found. In spite of the rareness of cortical blindness in young people as a cause of stroke, a detailed medical history and clinical examination should always be performed, and by unclearness additional investigations should be considered.