Algorithms for sleep–wake identification using actigraphy: a comparative study and new results

The aim of this study was to investigate two new scoring algorithms employing artificial neural networks and decision trees for distinguishing sleep and wake states in infants using actigraphy and to validate and compare the performance of the proposed algorithms with known actigraphy scoring algorithms. The study employed previously recorded longitudinal physiological infant data set from the Collaborative Home Infant Monitoring Evaluation (CHIME) study conducted between 1994 and 1998 [ http://dccwww.bumc.bu.edu/ChimeNisp/Main_Chime.asp ; Sleep 26 (1997) 553 ] at five clinical sites around the USA. The original CHIME data set contains recordings of 1079 infants <1 year old. In our study, we used the overnight polysomnography scored data and ankle actimeter (Alice 3) raw data for 354 infants from this data set. The participants were heterogeneous and grouped into four categories: healthy term, preterm, siblings of SIDS and infants with apparent life‐threatening events (apnea of infancy). The selection of the most discriminant actigraphy features was carried out using Fisher’s discriminant analysis. Approximately 80% of all the epochs were used to train the artificial neural network and decision tree models. The models were then validated on the remaining 20% of the epochs. The use of artificial neural networks and decision trees was able to capture potentially nonlinear classification characteristics, when compared to the previously reported linear combination methods and hence showed improved performance. The quality of sleep–wake scoring was further improved by including more wake epochs in the training phase and by employing rescoring rules to remove artifacts. The large size of the database (approximately 337 000 epochs for 354 patients) provided a solid basis for determining the efficacy of actigraphy in sleep scoring. The study also suggested that artificial neural networks and decision trees could be much more routinely utilized in the context of clinical sleep search.     

Trainee impact on advanced diagnostic bronchoscopy: An analysis of 607 consecutive procedures in an interventional pulmonary practice

Background and objective: Complications during advanced diagnostic bronchoscopy are rare and include: pneumothorax, bleeding, mediastinitis and lymphadenitis. Increased complications have been demonstrated in patients undergoing routine bronchoscopy procedures performed by trainees. This study aimed to determine the impact of trainees during advanced diagnostic bronchoscopy on procedure time, sedation use and complications. Methods: A retrospective review of a quality improvement database including consecutive pulmonary procedures performed by an interventional pulmonologist (D.R.S.) at the University of Calgary, from 1 July 2007 to 1 April 2011. Results: Six hundred seven (55.2%) of the 1100 procedures involved an advanced diagnostic procedure defined as: endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA), electromagnetic navigation bronchoscopy (ENB) and/or peripheral EBUS. A trainee participated in 512 (84.3%) procedures. A complication occurred in 25 patients (4.1%), with a trend towards increased complication rates in the trainee group (4.7% vs 1.1%, difference 3.6%, P = 0.076). Significant differences were seen when a trainee participated versus when no trainee participated for procedure length (58.32 min vs 37.69 min, difference 20.63 min (95% confidence interval: 19.07–22.19), P = 0.001) and for the dose of propofol (178.3 mg vs 137.1 mg, difference 41.2 mg (95% confidence interval: 19.81–63.38), P = 0.002). Conclusions: In an academic interventional pulmonology practice utilizing the apprenticeship model, trainee participation in advanced diagnostic bronchoscopy increased procedure time, increased the amount of sedation used and resulted in a trend to increased complications. Attempts to modify trainee procedural training to reduce the burden of procedural learning for patients are warranted.     

Heart Transplantation for Corrected Transposition of the Great Vessels

Orthotopic heart transplantation was performed in a patient with corrected transposition of the great vessels. Technical modifications were necessary to be able to transplant a normal heart in this patient. The surgical technique is illustrated.     

Hepatic GVHD after HLA-haploidentical bone marrow transplantation in children with severe combined immunodeficiency: the effect of ursodeoxycholic acid

We describe two children with a severe combined immune deficiency (SCID) with B cells. Following a T-cell-depleted haploidentical bone marrow transplantation (BMT), they both developed a chronic graft-versus-host disease (GVHD) of the skin and a severe persisting hyperbilirubinaemia and elevated liver enzymes. The diagnosis of a vanishing bile duct syndrome was confirmed by liver biopsies. Because corticosteroids and cyclosporin A induced only a partial response, ursodeoxycholic acid (UDCA) was added to their treatment schedule. Serum bilirubin and liver enzymes returned to normal within months. A control liver biopsy showed normal and proliferating bile ducts without cholestatic damage. We conclude that UDCA was well tolerated and may be of value as an additional treatment for hepatic GVHD in SCID.     

Mastication after surgical reconstruction of the mandibular residual ridge

A group of thirty-one female denture patients who underwent surgical reconstruction of their deficient residual ridges with ridge extension and skin graft or ridge augmentation with bone graft were evaluated with regard to their masticatory function before surgery, then at 8 months and 12 months post-operative with their new dentures. Two objectives tests of masticatory efficiency were used. The masticatory efficiency index (MEI), based on the size of chewed almond particles, determined the potential capacity of patients to masticate while the masticatory performance (MP) based on the time required to masticate food before swallowing assessed the individual ability of each patient to chew food. A subjective index of difficulty (SD) provided information on the patient's own assessment of chewing difficulty of certain foods selected for their hard texture. The evolution of each index and their interrelationship were statistically evaluated. It was shown that the masticatory performance (MP) and the subjective index of difficulty (SD) both improved significantly during the rehabilitation period and even more rapidly than the masticatory efficiency index (MEI). The discrepancy between the objective and the subjective tests and the overestimation from the patients indicate that the real benefit of the rehabilitation is not limited to improved chewing, but also to an acquired self-confidence in mastication.     

Destruxin analogs: variations of the α-hydroxy acid side chain

This work describes the synthesis of three destruxin E cyclodepsipeptidic analogs. These compounds have an identical amino acid sequence but differ by the nature of the hydroxy acid residue which is 2-hydroxy-3-phenylpropionic (Hpp), 2-hydroxy-5-trimethylsilyl-4-pentynoic (Hpy-TMS) and 2-hydroxy-4-pentynoic (Hpy) acid, respectively. The insecticidal properties on the Galleria mellonella larvae (paralysis and lethal effect) of these analogs are presented in comparison with the natural destruxin E. All these compounds have toxic effects, the most potent being Hpy that induces the same effect as destruxin E.     

PARATHYROID SUPPRESSIBILITY IN HYPERPARATHYROIDISM DUE TO CHRONIC RENAL FAILURE: STUDIES WITH AUTOTRANSPLANTED PARATHYROID TISSUE

Suppressibility of parathyroid hormone (PTH) secretion by calcium was evaluated in six patients with chronic renal failure and parathyroid tissue autotransplanted into the forearm. One patient was reinvestigated after renal transplantation. Plasma PTH levels were measured in the venous effluent of transplanted parathyroid tissue (VE) and in peripheral blood (PB) with two radioimmunoassays (RIA). One of these detected predominantly the intact human parathyroid hormone-(1–84) [PTH-(1–84)] (N-assay) and another in addition carboxyl (COOH)-terminal fragments (C-assay). At 5 min after the start of 12-min calcium infusions, resulting in a mean increase of plasma calcium levels of 0±6 mmol/l (P < 0±01), PTH was lowered to 44±10% (mean ± SE) (P < 0±01) of preinfusion levels in the VE and to 88±4% (P < 0±05) in PB, when measured in the N-assay; subsequently the plasma calcium level remained raised and PTH level lowered. When estimated in the C-assay, PTH was significantly lowered to 82± 6% (P < 0–05) in the VE at 120 min, and to between 91 ± 2% and 96 ± 2% (P < 0±01- < 0±05) in the PB at 20 to 120 min after the start of the calcium infusions. The results were extended with gel permeation chromatography of representative plasma samples. After renal transplantation and restoration of renal function gel filtration analysis indicated that the levels of intact PTH-(1–84) were 49±6 and of its COOH-terminal fragments 3±5 higher in the VE than in PB. In response to i.v. calcium administration intact PTH and its COOH-terminal fragments were lowered to 25% and 62% in the VE, and to 29% and 86% in PB, respectively. These findings demonstrate that the secretion of intact PTH-(1–84) is suppressed within minutes in response to i.v. calcium administration; a slower fall of the secretion of COOH-terminal PTH fragments was demonstrated only after restoration of near-normal renal function.     

Reduction of Energy Required for Defibrillation by Delivering Shocks in Orthogonal Directions in the Dog

Reduction of energy required to defibrillate (ERD) seems to represent a necessary condition for intensive development of implantable defibrillator, so as for minimization of cardiac and pulmonary damages provoked by high energy transthoracic defibrillation electric shocks. The present work describes a defibrillation method using shocks delivered in orthogonal directions and separated by a 100 ms delay. Defibrillation threshold measured with classical unidirectional shocks on 30 dogs has been found to be 286.8 ± 22.2 joules. In the same animals, defibrillation threshold measured by use of orthogonal shocks has been found to be 101.4 ± 14.9 joules. We conclude that this crossed shocks method leads to a substantial reduction of ERD (64%).     

ARTIFICIAL URETERAL REPLACEMENT FOR URETERAL NECROSIS AFTER RENAL TRANSPLANTATION: REPORT OF 3 CASES

Purpose

We applied a new minimally invasive technique of artificial ureteral replacement for renal transplant ureteral necrosis.

Materials and Methods

Artificial ureteral replacement was performed in 3 renal transplant recipients with ureteral necrosis (complete in 1 and distal in 2) after failure of primary endoscopic treatment. Under fluoroscopic guidance a percutaneous tract is created and progressively dilated. The ureteral silicone polytetrafluoroethylene bonded tube is introduced into the pyelocaliceal renal graft cavities, tracked subcutaneously down to the suprapubic area and introduced into the bladder via a short incision.

Results

There were no immediate postoperative complications except for transient postoperative acute prostatitis in 1 patient. No secondary complications were observed with a mean followup of 2.5 years. All grafts have good late function and all tubes are patent with no evidence of encrustation or obstruction. The tubes are well tolerated underneath the skin. Reflux was present in all 3 cases with no clinical manifestation. An asymptomatic episode of lower urinary tract infection was observed in the female patient.

Conclusions

In select cases of ureteral necrosis after renal transplantation artificial ureteral replacement by subcutaneous pyelovesical bypass offers a possible alternative to open ureteral reconstruction.