Exploring the utility of whole‐exome sequencing as a diagnostic tool in a child with atypical episodic muscle weakness

The advent of whole‐exome next‐generation sequencing (WES) has been pivotal for the molecular characterization of Mendelian disease; however, the clinical applicability of WES has remained relatively unexplored. We describe our exploration of WES as a diagnostic tool in a 3½‐year old female patient with a 2‐year history of episodic muscle weakness and paroxysmal dystonia who presented following a previous extensive but unrevealing diagnostic work‐up. WES was performed on the proband and her two parents. Parental exome data was used to filter potential de novo genomic events in the proband and suspected variants were confirmed using di‐deoxy sequencing. WES revealed a de novo non‐synonymous mutation in exon 21 of the calcium channel gene CACNA1S that has been previously reported in a single patient as a rare cause of atypical hypokalemic periodic paralysis. This was unexpected, as the proband's original differential diagnosis had included hypokalemic periodic paralysis, but clinical and laboratory features were equivocal, and standard clinical molecular testing for hypokalemic periodic paralysis and related disorders was negative. This report highlights the potential diagnostic utility of WES in clinical practice, with implications for the approach to similar diagnostic dilemmas in the future.     

Sustained attention in children and adolescents after traumatic brain injury: relation to severity of injury, adaptive functioning, ADHD and social background

Primary objective: To examine the relationship of child and family psychosocial variables and traumatic brain injury (TBI) severity as it relates to sustained attention (the Paediatric Assessment of Cognitive Efficiency, PACE).

Research design: Forty-two children and adolescents were recruited and participated in a 2 year longitudinal study to evaluate sustained attention using the computerized testing metric, PACE. More specifically, errors of omission (inattention) and commission (impulsiveness) were measured.

Main outcomes and results: Significant improvement on inattention and impulsiveness were observed over time. High pre-injury psychosocial adversity and low pre-injury adaptive functioning significantly predicted a greater number of inattention errors. Severity of injury predicted the reduction of impulsiveness. Moreover, omission errors immediately after TBI predicted later secondary attention-deficit/hyperactivity disorder (SADHD, ADHD that emerges after TBI).

Conclusions: Based on these findings, it is important to consider pre-injury child and family psychosocial characteristics in addition to severity of injury when predicting outcome of TBI in children.     

Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting

Elastic recoil of the vessel wall is a common cause of failure of percutaneous transluminal angioplasty in renal arteries. To oppose such recoil, balloon-expandable metal stents were implanted in artificially stenotic renal arteries in pigs and normal renal arteries in dogs and pigs. The stents were then examined angiographically and histologically at regular intervals. All stents were completely covered with endothelialized neointima in 3 weeks. There was no difference in intimal thickness between the stenotic and nonstenotic renal arteries. A large stent diameter and a large open or nonmetal surface may cause less intimal hyperplasia, but nonturbulent, fast arterial flow is probably the most important factor in ensuring long-term patency of the vessel.     

Cytomegalovirus-seronegative blood components for the prevention of primary cytomegalovirus infection after marrow transplantation. Considerations for blood banks

The authors report 2.5 years' experience with the use of cytomegalovirus (CMV)-seronegative blood components for the prevention of primary CMV infection after allogeneic marrow transplantation from seronegative marrow donors to 104 CMV-seronegative patients. Patients and blood donors were screened for CMV-seronegativity by a combination of passive latex agglutination, complement fixation, and indirect hemagglutination CMV antibody screening methods. Changes in blood banking procedures necessary to provide CMV-seronegative components are detailed. Providing CMV-seronegative components was a considerable undertaking; a mean, per patient, of 19 units of red cells and 105 units of platelets was required. Twenty percent of the platelet support was provided by family members and 80 percent by volunteer donors. CMV-infection was eliminated in all but one patient not considered infected at the time of transplantation. The capability to provide CMV-seronegative components depends on an adequate supply of seronegative donors, a sensitive and practical screening method for CMV antibody, a major commitment by the blood bank, and close communication between the blood bank and the patients' physicians.     

Outpatient metrizamide myelography: prospective evaluation of safety and cost effectiveness

A group of 228 consecutive patients undergoing metrizamide myelography was prospectively evaluated for postprocedure symptoms. The observed prevalence of these symptoms concurs with previously reported inpatient studies, with the most common sequelae being exacerbation or onset of spine or extremity pain, headache, nausea, and paresthesia. Limitation of administered dose of metrizamide in lumbar myelography may slightly reduce the occurrence of common symptoms, but withdrawal of contrast medium at the completion of examination had no impact on their occurrence. There was a higher occurrence of paresthesia in cervical myelography, but otherwise there was no significant difference in symptoms between cervical and lumbar studies. Outpatient metrizamide myelography can be performed with relative safety with the potential for significant cost savings.     

The effect of PGI2 and theophylline on the response of platelets subjected to shear stress

A specially designed rotational viscometer was used to investigate the effects of the antiplatelet agent PGI2 in combination with theophylline on the response of human platelets subjected to shear stress. Samples of citrated platelet-rich plasma (PRP) were exposed to shear stress in the viscometer for a period of 5 min at 23 degrees C. The levels of stress studied ranged from 50 to 300 dynes/sq cm. Pretreatment of the platelets with 0.01 microM PGI2 and 500 microM theophylline before exposure to shear stress caused a large reduction in shear-induced platelet aggregation. However, it was also observed that the PGI2-- theophylline pretreatment concomitantly caused a large increase in shear-induced platelet lysis and serotonin release at stress levels equal to or greater than 150 dynes/sq cm. This observed increase in platelet fragility may have important implications for clinical applications of PGI2. The results are discussed and compared to those obtained in prior work in which platelets were pretreated with acetylsalicylic acid or with PGE1.     

Membrane fluidity changes accompanying phagocytosis in normal and in chronic granulomatous disease polymorphonuclear leukocytes

We have studied membrane fluidity changes in polymorphonuclear leukocytes (PMN) during phagocytosis. Membrane fluidity was assessed by electron spin resonance (ESR) using a nitroxide-substituted stearic acid analog (5DS) as a spin probe. PMN from normal subjects and from 3 CGD patients (2 males, 1 female) were incubated in Kreb's Ringers phosphate with or without opsonized zymosan. ESR spectra were obtained and the order parameter (S), which is inversely related to membrane fluidity, was calculated. Without zymosan addition, S for normal (0.638) and for CGD (0.635) were not significantly different (p less than 0.35). The S values indicate that under resting conditions the molecular environment of the CGD membrane is similar to that of normal PMN membranes. However, with addition of opsonized zymosan, the normal, but not the CGD, PMN showed a significant increase (CGD, S = 0.638; normal, S = 0.647; p less than 0.001). This change in S for the normals is consistent with a more restricted movement of 5DS. Treatment of normal PMN with a mixture of scavengers specific for H2O2 (catalase, 1600 U/ml), O2-.(superoxide dismutase, 100 micrograms/ml), and for HO., (sodium benzoate, 1mM) during zymosan stimulation gave S values similar to those of resting cells. Catalase alone also lowered S value, suggesting that H2O2 was instrumental in causing the initial S value increase. This idea was supported by studies in which CGD cells were incubated with zymosan in the presence of glucose oxidase, an enzyme that catalyzes glucose oxidation resulting in the direct reduction of molecular oxygen to H2O2. Our results indicate that reduced O2 by- products, particularly H2O2, can cause altered biophysical properties of PMN membrane during phagocytosis.     

Correlation between follicular fluid content and the results of in vitro fertilization and embryo transfer. II. Inhibin and aromatase inhibitor activity

The inhibin content and aromatase inhibitor activity (AIA) of 72 follicular fluids (FF) obtained from 42 women undergoing in vitro fertilization (IVF) and embryo transfer (ET) were studied as a function of IVF ET outcome. Inhibin levels were determined by bioassay (BA) and RIA; AIA was measured by BA. The inhibin content of follicles characterized as immature by their estradiol (E2) levels and E2/progesterone (P) ratios was significantly lower (P less than 0.05) than that of mature follicles (i.e. leading to pregnancy). The mean AIA for mature follicles were significantly lower than AIA in groups where pregnancy was not obtained. AIA for follicles from which a pregnancy was obtained for each ET was also significantly lower than that in FF characterized as immature of hypermature. The highest E2/AIA and inhibin BA/AIA ratios were associated with the highest incidence of successful IVF ET outcome. No correlation was found between AIA and inhibin, on the one hand, and E2, delta 4-androstenedione, E2/P, and PRL, on the other. However, a positive correlation was found between inhibin (RIA and BA) and P, reflecting the production of inhibin by granulosa cells during luteinization. These studies allowed us to conclude that FF inhibin levels do not differ according to IVF ET outcome, but are an index of follicular maturation. AIA not only constitutes an index of follicular maturation and granulosa cell luteinization, but is of predictive value for IVF ET outcome as E2/AIA and inhibin BA/AIA ratios.