Linking transformations of organic carbon to post-treatment performance in a biological water recycling system

Ozone, electrolysis and granular activated carbon (GAC) were examined as potential post-treatments to follow a household-scale biologically activated membrane bioreactor (BAMBi), treating a wash water containing trace urine and feces contamination. Each post-treatment was evaluated for abilities and reaction preferences to remove or transform dissolved organic carbon (DOC), chemical structures that contribute color, and assimilable organic carbon (AOC), which can support bacterial regrowth. Batch treatment with each technology demonstrated an ability to remove ≥95% DOC. Ozone demonstrated a reaction selectivity through increased reaction rates with larger compounds and color-contributing compounds. Electrolysis and GAC demonstrated generally less-selective reactivity. Adding post-treatments to full-scale systems reduced DOC (55-91%), AOC (34-62%), and color (75-98%), without significant reaction selectivity. These reductions in DOC and AOC were not linked to reduction of bacterial concentrations in treated water. Reductions in bacterial concentrations were observed with ozone and electrolysis, but this is credited to oxidation chemicals produced in these systems and not the removal or transformations of organic materials.

Comparing the anti-bacterial performance of chlorination and electrolysis post-treatments in a hand washing water recycling system

Innovative solutions are necessary to enable the decentralized recycling of greywater for applications requiring high-quality water, such as hand washing. While physical barriers such as ultrafiltration membranes effectively prevent the passage of bacteria, and chemical and biological treatments can effectively reduce the carbon content of the treated water, there exists a knowledge gap regarding the application of anti-bacterial strategies to prevent the growth of harmful bacteria following treatment. In this study, the effluent water from a household-scale greywater treatment system was fed to seven parallel experimental post-treatment tanks: three receiving direct chlorination with free chlorine residuals of 0.2, 1 or 5 mg Cl2/L, three with chlorine produced through electrolysis at the same residual concentrations, and one control with no chlorine added. For increasing concentrations of direct chlorination, the median total cell count (TCC) values were 9 × 104, 2.9 × 104 and 1.8 × 103 cells/mL, respectively. Electrolysis treatment produced very similar TCC concentrations, 8.8 × 104, 1.1 × 104 and 2.3 × 103 cells/mL. The TCC concentrations were lower than the concentration of the water entering each tank (∼3 × 105 cells/mL). Intact cell count (ICC) measurements indicated that the viable cell concentrations, were less than 10% of the TCC values. Though electrolysis treatment can produce powerful oxidants, such as hydroxyl radical, there was no evidence that electrolysis in this system provided additional benefits beyond chlorine production for control of total or intact cell counts. Oxidation of bacteria by chlorine was the dominant anti-bacterial mechanism in our system. Monitoring of dissolved organic carbon (DOC) and assimilable organic carbon (AOC) did not suggest that carbon-limitation significantly impacted cell counts when chlorination or electrolysis treatment was applied. This work demonstrates that either direct chlorination or electrolysis treatment are able to reduce bacteria concentrations over long-term operation of a hand washing water treatment system. We recommend selecting chlorine residual targets such that a chlorine residual is maintained during periods of challenging operating conditions. We observed that a target residual of 1 mg Cl2/L, in our system, maintained the TCC below the concentration found in Zurich drinking water.

Real-world multicentre experience of the pathological features of colonic ischaemia and their relationship to symptom duration, disease distribution and clinical outcome

AIM

To determine the pathological features of colonic ischaemia (CI) and their relationship to symptom duration, disease distribution and clinical outcome in a real-world, clinical setting.

METHOD

A retrospective, multicentre chart review was performed in patients diagnosed with CI at Montefiore Medical Center (January 2005 to July 2015), and Yale-New Haven Hospital (January 2005 to June 2010). Patients were included if clinical presentation, colonoscopic findings and colonic pathology were all consistent with CI.

RESULTS

Six hundred and sixteen patients with pathologically proven CI were included. Common pathological findings included inflammation (51.1%), ulceration (38.2%), fibrosis (26.0%) and necrosis (20.4%). Infarction and ghost cells were seen in 1.6% and 0.2% of cases, respectively. There was a significant relationship between symptom duration and hyalinization of the lamina propria (P = 0.05) and cryptitis/crypt abscesses (P = 0.01). Patients with isolated right CI (IRCI) were more likely than patients with isolated left CI (ILCI) to exhibit necrosis (P < 0.01), cryptitis/crypt abscess (P < 0.01) and inflammation (P = 0.03). Patients with poor outcomes were more likely to exhibit necrosis (P < 0.01) and capillary fibrin thrombi (P < 0.01) and less likely to exhibit fibrosis (P < 0.01) and epithelial changes (P < 0.01).

CONCLUSION

CI is accompanied by a broad spectrum of pathological findings. The traditional pathognomonic findings of CI are rare and cannot be relied upon to exclude the diagnosis. Patients with IRCI and/or poor outcomes were more likely to have pathological findings of necrosis than patients who had ILCI and/or nonpoor outcomes.

Physical fitness in adolescents with normal weight and overweight

We studied the associations of overweight (OW, BMI > or =85th percentile) and physical activity (PA) with physical fitness in adolescents. The nationally representative sample was 1120 boys and 1146 girls, aged 15-16 years. Height and weight were self-reported. The level of PA was based on self-reported frequency and duration of sweating during organized and non-organized activity. Fitness was measured by sit-ups, sit-and-reach, five-jump, back-and-forth jumping, ball skills, coordination and endurance shuttle run tests. The fitness index was calculated as the mean of z-scores for individual tests. The prevalence of OW was 17.3% in boys and 11.8% in girls. The main effect of PA (in analysis of variance) on all fitness tests was significant (P< or =0.005). The main effect of OW was significant (P<0.002) for all tests, except for sit-and-reach. According to linear regression models, the association between PA and fitness was stronger than that between OW and fitness. Sit-ups, endurance shuttle-run and fitness index showed the strongest association with PA (standardized beta coefficients 0.31-0.49). OW was not associated with sit-and-reach test (coefficient 0.04) and only weakly with the ball skills test (coefficients -0.10 to -0.12). In conclusion, OW had the most negative association with cardiorespiratory and muscle endurance, and explosive power tests.

[MRI in spinal injuries]

The improvement of preclinical emergency medicine has increased the long-term survival of patients which sustained severe injuries of the spinal cord. However, the incidence of late complications has been increased due to the long-term survival. With the increasing use of magnetic resonance imaging (MRI) in this patient group the diagnosis of typical late complications of the spinal cord has improved. In this article we suggest the following terms to describe late complications of the spinal cord: syrinx, atrophy, cyst, malacia, disruption, and thethering.

Effect of pentobarbital on visual processing in man

To investigate the effect of sedative agents on visual processing in humans, we analysed the BOLD contrast signal response to a visual stimulation paradigm in 15 healthy, adult volunteers using functional magnetic resonance imaging. The subjects were tested during alert state and under sedation following intravenous administration of pentobarbital. The injection of pentobarbital not only significantly reduced the response signal strength but the reduction in BOLD contrast signal was related to the ratio of amount of sedative administered and the subject's body weight. The three subjects with the highest relative sedative dosage even displayed an inverted (negative) BOLD contrast signal. A significant reduction in the number of positively correlating pixels was found 15 min after administration of pentobarbital. All measured parameters returned to near pre-sedative levels by the end of the experimental session. The relative dosage dependence of the strength of the BOLD signal the negative BOLD signal in the three subjects with the highest relative sedative dosage indicates that pentobarbital had a more pronounced effect on cerebral blood flow than on cerebral oxidative metabolism.

Effect of pentobarbital on visual processing in man

To investigate the effect of sedative agents on visual processing in humans, we analysed the BOLD contrast signal response to a visual stimulation paradigm in 15 healthy, adult volunteers using functional magnetic resonance imaging. The subjects were tested during alert state and under sedation following intravenous administration of pentobarbital. The injection of pentobarbital not only significantly reduced the response signal strength but the reduction in BOLD contrast signal was related to the ratio of amount of sedative administered and the subject's body weight. The three subjects with the highest relative sedative dosage even displayed an inverted (negative) BOLD contrast signal. A significant reduction in the number of positively correlating pixels was found 15 min after administration of pentobarbital. All measured parameters returned to near pre-sedative levels by the end of the experimental session. The relative dosage dependence of the strength of the BOLD signal the negative BOLD signal in the three subjects with the highest relative sedative dosage indicates that pentobarbital had a more pronounced effect on cerebral blood flow than on cerebral oxidative metabolism.

Accuracy of MRI-guided stereotactic thalamic functional neurosurgery

Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy.

[Characteristics of pedigree cat breeding in the Netherlands: breeds, population increase and litter size]

A survey of the Dutch Cat Fancy was carried out to determine reproductive, patterns of pedigree cats. The data of the present study were obtained by questioning the pedigree registers of the cat clubs participating in the foundation 'Overleg Platform van de Nederlandse Cat Fancy'. The Dutch Cat Fancy registers 34 different cat breeds. From 1992 up to 1996 a total of 25.985 litters were registered. Over this period the number of litters increased from 4989 to 5313. Litters from Longhair and Exotic Shorthair cats comprised the biggest group and accounted for 55% of the total number of litters. However, over this period, the number of Longhair and Exotic Shorthair litters decreased by 9%. Litters from British Shorthair, Birman, Maine Coon and Norwegian Forrest Cat increased in number as did litters from small breeds such as Ragdoll, Bengal and Sphynx. Litters from Abyssinian, Siamese, Oriental Shorthair cats remained relatively the same. The average litter size of the total cat population, based on pedigree certificates, was calculated at 3.3 kittens per litter. For different breeds litter size varied from 2.7 (Longhair and Exotic Shorthair) to 4.3 (Burmese and Maine Coon). Taking into account an average age of 14 years, the total Dutch pedigree cat population was estimated at 240,000 viz. about 10% of the total cat population.

Severe tick-borne encephalitis following passive immunization

We report on a 5-year-old girl with an unusually severe course of tick-borne encephalitis following passive immunization with specific hyperimmune globulin after a tick bite in an endemic area. Serial investigations of the CSF revealed intrathecal production of specific antibodies paralleled by increasing numbers of B-cells after initial T-cell pleocytosis. Focal central lesions were evident on MRI.

CONCLUSION

The severity of the presented case questions the benefit of passive immunization and rather justifies consideration of vaccine recommendation to residents and travellers to areas endemic for tick-borne encephalitis virus.

[Back pain in children: symptoms which should be taken seriously]

Back pain in children is a rare but serious problem. The varied etiologies and the necessary diagnostic workup are illustrated in 8 children. Infectious processes were found in 3 children, spondylodiscitis twice and epidural abscess once. Tumours (one eosinophilic granuloma and one spinal ependymoma) were present in 2 boys. One girl had a herniated lumbar disc. Malformations (spondylolysis and diastematomyelia) were the cause of symptoms in 2 children. Leading symptom in all 8 children was back pain lasting from 3 days to 2 years. Careful clinical neurological examination, parameters of inflammation in the blood and conventional radiography of the spine were helpful in guiding further investigations. Scintigraphy was useful for localization of infectious and tumorous diseases. MRI was superior to CT in evaluating tumours and malformations of the spinal cord. In most cases CT was sufficient in workup of infectious and osseous processes.

A novel point mutation in the translation initiation codon of the pre-pro-vasopressin-neurophysin II gene: cosegregation with morphological abnormalities and clinical symptoms in autosomal dominant neurohypophyseal diabetes insipidus

Autosomal dominant neurohypophyseal diabetes insipidus (ADNDI) is a rare variant of idiopathic central diabetes insipidus. Several different mutations in the human vasopressin-neurophysin II (AVP-NP II) gene have been described. We studied nine family members from three generations of an ADNDI pedigree at the clinical, morphological, and molecular levels. AVP concentrations were measured during diagnostic fluid restriction tests. Coronal and sagittal high resolution T1-weighted images of the pituitary were obtained from affected and healthy family members. PCR was used to amplify the AVP-NP II precursor gene, and PCR products were directly sequenced. Under maximal osmotic stimulation, AVP serum levels were close to or below the detection limit in affected individuals. Magnetic resonance imaging studies revealed the characteristic hyperintense ("bright spot") appearance of the posterior pituitary in two healthy family members. This signal was absent in all four ADNDI patients examined. The coding sequences of AVP and its carrier protein, neurophysin II, were normal in all family members examined. Affected individuals showed a novel single base deletion (G 227) in the translation initiation codon of the AVP-NP II signal peptide on one allele. The mutation in the AVP-NP II leader sequence appears to be responsible for the disease in this kindred, possibly by interfering with protein translocation. The absence of the hyperintense posterior pituitary signal in affected individuals could reflect deficient posterior pituitary function.

Follow-up of optic pathway gliomas in children with neurofibromatosis type 1

Optic pathway gliomas (OPG) are found in about 15% of patients with neurofibromatosis Type 1 (NF-1). The natural history of OPG is not yet well documented. Treatment in cases with growing tumors is still controversial. Twenty-one patients with NF-1 and OPG, diagnosed over a 20-year period, and followed neuroradiologically and ophthalmologically for at least two years, were reevaluated. The diagnosis of OPG was made at a mean age of 7.1 years (range 0-14.5 years); six children were asymptomatic, 15 were symptomatic. The mean follow-up was 9.0 years (2.0-18.5 (years). In eight initially operated or biopsied patients (three optic nerve and five chiasmal gliomas) tumor regrowth was found in one patient without progression on subsequent follow-up. Improvement of visual acuity occurred in one child after operation of a large suprasellar tumor and deterioration in one patient after biopsy of a chiasmal glioma. The neuroradiological follow-up of the 13 not-operated and not-radiated patients (four optic nerve and nine chiasmal gliomas) was stable in 10, progressive in three, resulting in visual loss in one patient. In 11 children (52%) a second tumor outside the optic pathway was found at a mean age of 4.0 years after the diagnosis of an OPG. Until now they are mostly asymptomatic. Second site tumors were operated in two children because of rapid tumor growth, one child died of a brainstem tumor. OPG are a frequent complication in children with NF-1, appearing within the first decade.(ABSTRACT TRUNCATED AT 250 WORDS)

[Magnetic resonance imaging in neuroradiology. Indications and applications]

On the basis of own experience with 250 MR-Angiographies and with reference to the literature the authors report on the role MR-Angiography is assuming in neuroradiological diagnostic procedures. As a noninvasive method MR-Angiography contributes to the evaluation of vessel stenosis and occlusion, venous sinus thrombosis and neurovascular compression syndromes. It supports the work-up of space-occupying lesions, as well as arteriovenous malformations and aneurysms. In addition to the diagnosis, follow-up examinations serve as a noninvasive means of therapy control particularly after interventional endovascular procedures. Knowledge of the diagnostic capabilities and limitations, the choice of the correct examination technique and modification of technical variables contribute to establish MR-Angiography as a valuable adjunct to MR imaging.