Neuroprotection is improved by watertightness of fetal spina bifida repair in the sheep model.

OBJECTIVES: A contributing factor to unsuccessful prenatal spina bifida aperta (SBA) repair via an open approach may be incomplete neurosurgical repair causing persistent in-utero leakage of cerebrospinal fluid (CSF) and exposure of the fetal spinal cord to amniotic fluid. We aimed to investigate the neurostructural and neurofunctional efficacy of watertight prenatal SBA repair in a validated SBA fetal lamb model. METHODS: A well-powered superiority study was conducted in the validated SBA fetal lamb model (n = 7 per group). The outcomes of lambs which underwent watertight or non-watertight multilayer repair through an open approach were compared to those of unrepaired SBA lambs (historical controls) at delivery (term = 145 days). At ∼75 days, fetal lambs underwent standardized induction of lumbar SBA. At ∼100 days, they were assigned to an either watertight or non-watertight layered repair group based on an intraoperative watertightness test using subcutaneous fluorescein injection. At 1-2 days postnatally, as primary outcome, we assessed reversal of hindbrain herniation using magnetic resonance imaging (MRI). Secondary proxies of neuroprotection were: absence of CSF leakage at the repair site; hindlimb motor function based on joint-movement score, locomotor grade and Motor Evoked Potential (MEP); four-score neuroprotection scale, encompassing live birth, complete hindbrain herniation reversal, absence of CSF leakage and joint-movement score ≥ 9/15; and brain and spinal cord histology and immunohistochemistry. As the watertightness test cannot be used clinically due to its invasiveness, we developed a potential surrogate intraoperative three-score skin-repair-quality scale based on visual assessment of the quality of the skin repair (suture inter-run distance ≤ 3 mm, absence of tear and absence of ischemia), with high quality defined by a score ≥ 2/3 and low quality by a score < 2/3, and assessed its relationship with improved outcome. RESULTS: Compared with unrepaired lambs, lambs with watertight repair achieved a high level of neuroprotection (neuroprotection score of 4/4 in 5/7 vs 0/7 lambs) as evidenced by: a significant 100% (vs 14%) reversal of hindbrain herniation on MRI; low CSF leakage (14% vs 100%); better hindlimb motor function, with higher joint-movement score, locomotor grade and MEP area under the curve and peak-to-peak amplitude; higher neuronal density in the hippocampus and corpus callosum; and higher reactive astrogliosis at the SBA lesion epicenter. Conversely, lambs with non-watertight SBA repair did not achieve the same level of neuroprotection (score of 4/4 in 1/7 lambs) compared with unrepaired lambs, with: a non-significant 86% (vs 14%) reversal of hindbrain herniation; high CSF leakage (43% vs 100%); no improvement in motor function; low brain neuron count in both the hippocampus and corpus callosum; and small spinal astroglial cell area at the epicenter. Both watertight layered repair and high (≥ 2/3) intraoperative skin-repair-quality score were associated with improved outcome, but the watertightness test and skin-repair-quality scale could not be used interchangeably due to result discrepancies. CONCLUSIONS: Watertight layered fetal SBA repair is neuroprotective since it improves brain and spinal-cord structure and function in the fetal lamb model. This translational research has important clinical implications. A neurosurgical technique that achieves watertightness should be adopted in all fetal centers to improve neuroprotection. Future clinical studies could assess whether a high skin-repair-quality score (≥ 2/3) correlates with neuroprotection. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Management of Fibro-adipose Vascular Anomalies (FAVA) in Paediatric Practice.

Fibro-adipose vascular anomaly (FAVA) is a discrete type of vascular anomaly. We describe our experience managing FAVA at a tertiary level paediatric hospital and offer a treatment algorithm. METHODS: A retrospective review of 27 patients with proven FAVA was undertaken. All patients had undergone MRI and USS evaluation. Patient demographics, presenting concerns, treatment methods, and outcomes were recorded and evaluation with the paediatric outcomes data collection instrument (PODCI) completed a minimum of 12 months after definitive treatment. RESULTS: Mean age at presentation was 8.9 years (range: 9 m-17.4 y) and mean post-treatment follow-up was 7.4 y (range: 2 y-11.6 y). Twenty of 27 lesions affected the lower limb. Severe neurogenic-type pain was present in 23 cases and contractures across joints in 11 cases. Sclerotherapy with sodium tetradecyl sulphate was used in 11 cases, with no improvement in symptoms. Cryoablation provided pain relief in 3/4 cases, but contracture subsequently increased in one patient and pain recurred in another.Fourteen cases underwent surgery (four surgical excisions alone, 10 in combination with other procedures). Three patients required four further surgical procedures that include one amputation for intractable pain and poor function.PODCI evaluations suggest overall good function, with surgical management and interventional radiology that provide comparable results. Surgery did correct deformity. CONCLUSION: If conservative measures or cryoablation fail to achieve symptomatic control, surgical excision should be considered, combined with adjunctive procedures, to correct contractures and balance muscle forces.Relief of pain may compensate for the loss of muscle mass and overall improves function. Multidisciplinary team working is essential.

Is hypertensive left ventricular hypertrophy a cause of sustained ventricular arrhythmias in humans?

Sudden cardiac death (SCD) is most commonly secondary to sustained ventricular arrhythmias (VAs). This review aimed to evaluate if left ventricular hypertrophy (LVH) secondary to systemic hypertension in humans is an isolated risk factor for ventricular arrhythmogenesis. Animal models of hypertensive LVH have shown changes in ion channel function and distribution, gap junction re-distribution and fibrotic deposition. Clinical data has consistently exhibited an increase in prevalence and complexity of non-sustained VAs on electrocardiographic monitoring. However, there is a dearth of trials suggesting progression to sustained VAs and SCD, with extrapolations being confounded by presence of co-existent asymptomatic coronary artery disease (CAD). Putatively, this lack of data may be due to the presence of more homogenous distribution of pathophysiological changes seen in those with hypertensive LVH versus known pro-arrhythmic conditions such as HCM and myocardial infarction. The overall impression is that sustained VAs in the context of hypertensive LVH are most likely to be precipitated by other causes such as CAD or electrolyte disturbance.

Haploinsufficiency of X-linked intellectual disability gene CASK induces post-transcriptional changes in synaptic and cellular metabolic pathways.

Heterozygous mutations in the X-linked gene CASK are associated with intellectual disability, microcephaly, pontocerebellar hypoplasia, optic nerve hypoplasia and partially penetrant seizures in girls. The Cask+/- heterozygous knockout female mouse phenocopies the human disorder and exhibits postnatal microencephaly, cerebellar hypoplasia and optic nerve hypoplasia. It is not known if Cask+/- mice also display seizures, nor is known the molecular mechanism by which CASK haploinsufficiency produces the numerous documented phenotypes. 24-h video electroencephalography demonstrates that despite sporadic seizure activity, the overall electrographic patterns remain unaltered in Cask+/- mice. Additionally, seizure threshold to the commonly used kindling agent, pentylenetetrazol, remains unaltered in Cask+/- mice, indicating that even in mice the seizure phenotype is only partially penetrant and may have an indirect mechanism. RNA sequencing experiments on Cask+/- mouse brain uncovers a very limited number of changes, with most differences arising in the transcripts of extracellular matrix proteins and the transcripts of a group of nuclear proteins. In contrast to limited changes at the transcript level, quantitative whole-brain proteomics using iTRAQ quantitative mass-spectrometry reveals major changes in synaptic, metabolic/mitochondrial, cytoskeletal, and protein metabolic pathways. Unbiased protein-protein interaction mapping using affinity chromatography demonstrates that CASK may form complexes with proteins belonging to the same functional groups in which altered protein levels are observed. We discuss the mechanism of the observed changes in the context of known molecular function/s of CASK. Overall, our data indicate that the phenotypic spectrum of female Cask+/- mice includes sporadic seizures and thus closely parallels that of CASK haploinsufficient girls; the Cask+/- mouse is thus a face-validated model for CASK-related pathologies. We therefore surmise that CASK haploinsufficiency is likely to affect brain structure and function due to dysregulation of several cellular pathways including synaptic signaling and cellular metabolism.

Determinants of Radiation Dose in Selective Ophthalmic Artery Chemosurgery for Retinoblastoma.

BACKGROUND AND PURPOSE: Retinoblastoma is the most common pediatric ocular neoplasm. Multimodality treatment approaches are commonplace, and selective ophthalmic artery chemosurgery has emerged as a safe and effective treatment in selected patients. Minimizing radiation dose in this highly radiosensitive patient cohort is critical. We explore which procedural factors affect the radiation dose in a single-center cohort of children managed in the UK National Retinoblastoma Service. MATERIALS AND METHODS: A retrospective review was performed of 177 selective ophthalmic artery chemosurgery procedures in 48 patients with retinoblastoma (2013-2017). Medical records, angiographic imaging, and radiation dosimetry data (including total fluoroscopic screening time, skin dose, and dose-area product) were reviewed. RESULTS: The mean fluoroscopic time was 13.5 ± 13 minutes, the mean dose-area product was 11.7 ± 9.7 Gy.cm2, and the mean total skin dose was 260.9 ± 211.6 mGy. One hundred sixty-three of 177 procedures (92.1%) were technically successful. In 14 (7.9%), the initial attempt was unsuccessful (successful in 13/14 re-attempts). Screening time and radiation dose were associated with drug-delivery microcatheter location and patient age; screening time was associated with treatment cycle. CONCLUSIONS: In selective ophthalmic artery chemosurgery, a microcatheter tip position in the proximal or ostial ophthalmic artery and patient age 2 years or younger were associated with reduced fluoroscopic screening time and radiation dose; treatment beyond the first cycle was associated with reduced fluoroscopic screening time.

Draft Genome Sequence of Petroleum Hydrocarbon-Degrading Pseudomonas aeruginosa Strain PK6, Isolated from the Saurashtra Region of Gujarat, India.

Pseudomonas aeruginosa strain PK6, a potential petroleum hydrocarbon-degrading soil bacterium, was isolated from a site contaminated by a petroleum hydrocarbon spill from an automobile service station in Junagadh, Gujarat, India. Here, we provide the 6.04-Mb draft genome sequence of strain PK6, which has genes encoding enzymes for potential and related metabolic pathways of the strain.

Draft Genome Sequence of Textile Azo Dye-Decolorizing and -Degrading Pseudomonas aeruginosa Strain PFK10, Isolated from the Common Effluent Treatment Plant of the Ankleshwar Industrial Area of Gujarat, India.

Here, we report the draft genome sequence of Pseudomonas aeruginosa strain PFK10, isolated from the common effluent treatment plant (CETP) of the Ankleshwar industrial area of Gujarat, India. The 6.04-Mb draft genome sequence of strain PFK10 provides information about the genes encoding enzymes that enable the strain to decolorize and degrade textile azo dye.

Clinician referrals for stress echocardiography: are we compliant with the NICE guidelines?

Accurate diagnosis of stable angina is of paramount importance, and where possible, this should be based on clinical history. In cases of uncertainty, the National Institute for Health and Care Excellence (NICE) provides a framework for assisting diagnosis based on pre-test likelihood (PTL) of coronary artery disease. Functional testing such as stress echocardiography (SE) is recommended as a first-line investigation in patients with PTL of 30-60%. This study evaluated hospital clinicians' adherence to this recommendation. A prospective analysis of patients referred for SE at a district general hospital between March and May 2013 was performed. Data were extracted from an electronic database of SE reports and medical notes. A total of 193 patients were assessed. The most common PTL was 61-90%, accounting for 40% of the cohort. Of them, 14% had a PTL of 30-60%. Of these, 15% had positive SE; 57% described non-anginal pain, as defined by NICE, of whom only nine cases had SE positivity. None of these patients required revascularisation. Findings suggest that SE is being used in a much broader selection group than advocated by NICE. This may often be for its exclusion value rather than to stratify risk. Although utility may be justified in high-risk patients to avoid proceeding directly to invasive angiography, SE appears to add little in those with non-anginal pain and with low PTL. Greater focus should be directed towards characterisation of symptoms, which may negate the need for subsequent investigation.

The effect of smoking on bone healing: A systematic review.

OBJECTIVES: To review the systemic impact of smoking on bone healing as evidenced within the orthopaedic literature. METHODS: A protocol was established and studies were sourced from five electronic databases. Screening, data abstraction and quality assessment was conducted by two review authors. Prospective and retrospective clinical studies were included. The primary outcome measures were based on clinical and/or radiological indicators of bone healing. This review specifically focused on non-spinal orthopaedic studies. RESULTS: Nine tibia studies and eight other orthopaedic studies were considered for systematic review. Of these 17 studies, 13 concluded that smoking negatively influenced bone healing. CONCLUSIONS: Smoking has a negative effect on bone healing, in terms of delayed union, nonunion and more complications.

What is the effect of penicillin dosing interval on outcomes in streptococcal infective endocarditis?

OBJECTIVES: Penicillin is an important treatment option for streptococcal infective endocarditis (IE), but its short half-life requires frequent re-dosing (4- or 6-hourly). There is a variation between the dosing regimens in different guidelines and consequent differences in the dosing interval. The objective of this study was to examine the relationship between the penicillin dosing interval and outcomes in streptococcal IE. METHODS: A retrospective study of cases of streptococcal IE was undertaken using the Leeds Endocarditis Service database. Cases were included if the first-line therapy had been penicillin and excluded if patients had received less than 72 h of therapy. Details of antimicrobial therapy and outcomes were collated using strict definitions. Various parameters were considered as independent variables in a multivariate logistic regression analysis. Univariate analysis of categorical data was carried out using a χ(2) test, and analysis of continuous data using an unpaired t-test. RESULTS: Two hundred and twelve cases were included in the final analysis. Of the parameters considered, a 4-hourly dosing interval [unadjusted OR = 2.79 (95% CI 1.43-5.62)] and initial echocardiographic evidence of abscess or severe valve regurgitation [unadjusted OR = 0.30 (95% CI 0.13-0.66)] were the only statistically significant factors associated with the success or failure of penicillin therapy. The odds of a successful outcome were almost three times greater with a 4-hourly regimen than with a 6-hourly regimen. Failure of penicillin therapy had no correlation with the MIC of penicillin or the concurrent administration of gentamicin. CONCLUSIONS: Penicillin continues to be an effective therapy for IE. This study suggests that a 4-hourly dosing interval may be relevant in predicting the success of initial medical therapy. Further prospective studies are warranted to evaluate relationships in more detail.

Treatment outcomes for keloid scar management in the pediatric burn population.

INTRODUCTION: Keloids scars are challenging problems facing many reconstructive surgeons and have proven to be resistant to many treatments. This is evident by the broad range of treatments available and implemented with inconsistent results. We reviewed our experience to better define the disorder and to evaluate the impact of specific treatment options as related to our patient population. METHODS: After obtaining Institutional Review Board approval, we examined the medical records of pediatric patients who were evaluated at our pediatric burn center between 2000 to 2008. All study subjects were identified as having keloid scars confirmed by clinical evaluation (raised scar extending beyond the margins of the original wound [1,2]). Treatments included excision and grafting [split thickness autograft (STAG) or full thickness autograft (FTAG)], excision and grafting with steroid injection, excision and primary closure, or excision and primary closure with steroid injection. Patients were included only if there was follow-up of 12 months or greater. RESULTS: One hundred and ten subjects with a diagnosis of a keloid scar were identified. Twenty-six were treated with excision and skin grafting and 8 were treated with a steroid and surgery regimen. Of the patients treated with surgery and steroids, the treatment varied from an intra-operative injection to post-operative injections at 6-week intervals. The number of injections was determined by the administering surgeon and varied from one to three. Clinical end points were determined by the administering surgeon and included: (1) no further improvement in scar maturation or (2) absence of improvement. Recurrence was defined as return of a raised scar consistent with a keloid scar. The recurrence rate was 87.5% for patients treated with surgery and steroids and 80.0% for surgery only. This difference was not statistically significant. CONCLUSIONS: Our data demonstrate that steroids do not significantly decrease recurrence in pediatric burn related keloids as compared to previously published series involving non-burn related keloids [3,5]. This further emphasizes that burn related keloids respond differently to conventional treatments that have proven successful in keloid scars from other mechanisms of injury. A consistent and effective treatment algorithm should be implemented in treating keloid scars from burn wounds.

Polypeptide-catalyzed biosilicification of dentin surfaces.

In situ formation of mineral particles by biocatalysis would be advantageous for occluding dentin tubules to reduce permeability or for sealing of material-tooth interfaces. One approach would require that the peptide-catalyst remain functional on the dentin surface. Based on recent observations of retained activity on other surfaces, we hypothesized that poly(L-lysine) (PLL), an analog of the protein catalyst responsible for silica formation in primitive marine species, would remain functional on dentin. PLL was applied to dentin discs along with a pre-hydrolyzed silica precursor, tetramethyl orthosilicate (TMOS). Discs were analyzed microscopically (scanning electron microscopy, SEM) and chemically (x-ray photoelectron spectroscopy, XPS). The treated discs, but not the negative controls, exhibited partial distinct coating whose XPS survey was consistent with that of silica, demonstrating that the polypeptide was required and retained its mediating activity. Peptide-catalysts that mediate mineral formation can retain functionality on dentin, suggesting a wide range of preventive and treatment strategies.

Evidence for an intrinsic mechanism of antinociceptive tolerance within the ventrolateral periaqueductal gray of rats.

Repeated microinjections of morphine into the ventrolateral periaqueductal gray produce antinociceptive tolerance. This tolerance may be a direct effect of morphine on cells within the ventrolateral periaqueductal gray or may require activation of downstream structures such as the rostral ventromedial medulla or spinal cord. Experiment 1 examined whether tolerance develops when opioid receptors in the ventrolateral periaqueductal gray are blocked prior to repeated systemic morphine administration. Microinjections of naltrexone hydrochloride (1microg/0.4microl) into the ventrolateral periaqueductal gray blocked antinociception and significantly attenuated the development of antinociceptive tolerance produced from systemic morphine administration. Experiment 2 examined whether tolerance develops when the effects of morphine are isolated to the ventrolateral periaqueductal gray. This was accomplished by microinjecting morphine (5microg/0.4microl) into the ventrolateral periaqueductal gray while simultaneously blocking the descending output through the rostral ventromedial medulla. Inhibition of neurons within the rostral ventromedial medulla by microinjecting the GABA(A) agonist muscimol (10ng/0.5microl) blocked the antinociception produced by microinjection of morphine into the ventrolateral periaqueductal gray but did not block the development of tolerance. These data demonstrate that the ventrolateral periaqueductal gray is both necessary and sufficient to produce tolerance to the antinociceptive effect of morphine. The ventrolateral periaqueductal gray is necessary in that tolerance does not develop if opiate action within the ventrolateral periaqueductal gray is blocked (experiment 1). The ventrolateral periaqueductal gray is sufficient in that tolerance occurs even when morphine's effects are restricted to the ventrolateral periaqueductal gray (experiment 2).

Application of mortality prediction systems to individual intensive care units.

OBJECTIVE: To evaluate the predictive accuracy of the severity of illness scoring systems in a single institution. DESIGN: A prospective study conducted by collecting data on consecutive patients admitted to the medical intensive care unit over 20 months. Surgical and coronary care admissions were excluded. SETTING: Veterans Affairs Medical Center at Buffalo, New York. PATIENTS AND PARTICIPANTS: Data collected on 302 unique, consecutive patients admitted to the medical intensive care unit. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Data required to calculate the patients' predicted mortality by the Mortality Probability Model (MPM) II, Acute Physiology and Chronic Health Evaluation (APACHE) II and Simplified Acute Physiology Score (SAPS) II scoring systems were collected. The probability of mortality for the cohort of patients was analyzed using confidence interval analyses, receiver operator characteristic (ROC) curves, two by two contingency tables and the Lemeshow-Hosmer chi-square statistic. Predicted mortality for all three scoring systems lay within the 95 % confidence interval for actual mortality. For the MPM II, SAPS II and APACHE II, the c-index (equivalent to the area under the ROC curve) was 0.695 +/- 0.0307 SE, 0.702 +/- 0.063 SE and 0.672 +/- 0.0306 SE, respectively, which were not statistically different from each other but were lower than values obtained in previous studies. CONCLUSION: Although the overall mortality was consistent with the predicted mortality, the poor fit of the data to the model impairs the validity of the result. The observed outcome could be due to erratic quality of care, or differences between the study population and the patient population in the original studies. The data cannot be used to distinguish between these possibilities. To increase predictive accuracy when studying individual intensive care units and enhance quality of care assessments it may be necessary to adapt the model to the patient population.

A self-heated thermistor technique to measure effective thermal properties from the tissue surface.

A microcomputer based instrument to measure effective thermal conductivity and diffusivity at the surface of a tissue has been developed. Self-heated spherical thermistors, partially embedded in an insulator, are used to simultaneously heat tissue and measure the resulting temperature rise. The temperature increase of the thermistor for a given applied power is a function of the combined thermal properties of the insulator, the thermistor, and the tissue. Once the probe is calibrated, the instrument accurately measures the thermal properties of tissue. Conductivity measurements are accurate to 2 percent and diffusivity measurements are accurate to 4 percent. A simplified bioheat equation is used which assumes the effective tissue thermal conductivity is a linear function of perfusion. Since tissue blood flow strongly affects heat transfer, the surface thermistor probe is quite sensitive to perfusion.

Cell-mediated immunity to varicella-zoster virus infection in subjects with lymphoma or leukemia.

Normal subjects and patients with lymphoma or leukemia were tested for the levels of lymphocytes, E-rosette--forming T-cells, serum and vesicle fluid interferon, and specific in vitro proliferative response to varicella-zoster antigen after clinical varicella or herpes zoster illness. The effect of polyinosinic acid/polycytidilic acid on the immune response was also evaluated. The development of VZ specific cell-mediated response in normal subjects was characterized by intense proliferative activity eight to ten days after the onset of illness, with significant decline 70 to 80 days later. The responses in subjects with lymphoma or leukemia were much lower. Few subjects with chickenpox or zoster with lymphoma or leukemia died during the infection. Death was associated with significant depletion of E-rosette--forming T-cells, and grossly deficient specific cellular response to VZ antigen. Treatment with Poly IC frequently induced elevations in serum as well as vesicle fluid interferon levels, and increased the proliferative activity of lymphocytes against VZ antigen.