Ventricular function and ventriculo-arterial coupling after palliation of hypoplastic left heart syndrome: A comparative study with Fontan patients with LV morphology.

BACKGROUND: Conceptually the right ventricle (RV) is less suitable to support the Fontan circulation than the left (LV). After palliation of hypoplastic left heart syndrome (HLHS) involving aortic reconstruction during the Norwood procedure the RV is exposed to abnormal afterload. We studied ventricular function and ventriculo-arterial coupling in HLHS patients (RV) and Fontan patients with single LV morphology that did (LV+N) and did not (LV-N) undergo Norwood-type aortic reconstruction. METHODS: Eighty patients (55 RV, 8 LV+N, 17 LV- N) were simultaneously studied with the conductance-catheter and echocardiography 4.8 (0.9-22.9)years after Fontan completion. RESULTS: Ejection fraction (EF) was lowest in the HLHS group (RV 60.9±11.0 vs. LV+N 68.4±10.5 vs. LV-N 69.7±8.0, P=0.003) whereas end systolic elastance (Ees), i.e. ventricular contractility, and end diastolic stiffness (Eed) were highest (Ees: RV 3.38±2.2 vs. LV+N 2.3.±13.8 vs. LV-N 1.92±1.37mmHg/ml, P=0.02; Eed: RV 0.59±0.36 vs. LV+N 0.48±0.29 vs. LV-N 0.32±0.17mmHg/ml, P<0.02). Arterial elastance, a measure of afterload, was highest in HLHS patients and correlated positively with Ees and Eed and inversely with EF in the study cohort. Only long axis function analysis suggested superior ventricular function in HLHS patients whereas all other echocardiographic measures did not reveal any group differences. CONCLUSION: Ventricular contractility of the RV of HLHS patients is higher than that of the ventricle of Fontan patients with LV morphology. This likely reflects a physiological response to higher arterial elastance resulting from aortic arch reconstruction. Increased arterial elastance negatively impacts diastolic stiffness, which is higher in the systemic RV than LV.

Effects of organic plant oils and role of oxidation on nutrient utilization in juvenile rainbow trout (Oncorhynchus mykiss).

Producing organic fish diets requires that the use of both fishmeal and fish oil (FO) be minimized and replaced by sustainable, organic sources. The purpose of the present study was to replace FO with organic oils and evaluate the effects on feed intake, feed conversion ratio (FCR), daily specific growth rate (SGR) and nutrient digestibility in diets in which fishmeal protein was partly substituted by organic plant protein concentrates. It is prohibited to add antioxidants to organic oils, and therefore the effects of force-oxidizing the oils (including FO) on feed intake and nutrient digestibility was furthermore examined. Four organic oils with either a relatively high or low content of polyunsaturated fatty acids were considered: linseed oil, rapeseed oil, sunflower oil and grapeseed oil. Substituting FO with organic oils did not affect feed intake (P > 0.05), FCR or SGR (P > 0.05) despite very different dietary fatty acid profiles. All organic plant oils had a positive effect on apparent lipid digestibility compared with the FO diet (P < 0.05), whereas there were no effects on the apparent digestibility of other macronutrients when compared with the FO diet (P > 0.05). Organic vegetable oils did not undergo auto-oxidation as opposed to the FO, and the FO diet consequently had a significantly negative effect on the apparent lipid digestibility. Feed intake was not affected by oxidation of any oils. In conclusion, the study demonstrated that it is possible to fully substitute FO with plant-based organic oils without negatively affecting nutrient digestibility and growth performance. Furthermore, plant-based organic oils are less likely to oxidize than FOs, prolonging the shelf life of such organic diets.

MicroRNA identity and abundance in porcine skeletal muscles determined by deep sequencing.

MicroRNAs (miRNA) are short single-stranded RNA molecules that regulate gene expression post-transcriptionally by binding to complementary sequences in the 3' untranslated region (3' UTR) of target mRNAs. MiRNAs participate in the regulation of myogenesis, and identification of the complete set of miRNAs expressed in muscles is likely to significantly increase our understanding of muscle growth and development. To determine the identity and abundance of miRNA in porcine skeletal muscle, we applied a deep sequencing approach. This allowed us to identify the sequences and relative expression levels of 212 annotated miRNA genes, thereby providing a thorough account of the miRNA transcriptome in porcine muscle tissue. The expression levels displayed a very large range, as reflected by the number of sequence reads, which varied from single counts for rare miRNAs to several million reads for the most abundant miRNAs. Moreover, we identified numerous examples of mature miRNAs that were derived from opposite sides of the same predicted precursor stem-loop structures, and also observed length and sequence heterogeneity at the 5' and 3' ends. Furthermore, KEGG pathway analysis suggested that highly expressed miRNAs are involved in skeletal muscle development and regeneration, signal transduction, cell-cell and cell-extracellular matrix communication and neural development and function.

A nonlinear operator-based speech feature analysis method with application to vocal fold pathology assessment.

Traditional speech processing methods for laryngeal pathology assessment assume linear speech production with measures derived from an estimated glottal flow waveform. They normally require the speaker to achieve complete glottal closure, which for many vocal fold pathologies cannot be accomplished. To address this issue, a nonlinear signal processing approach is proposed which does not require direct glottal flow waveform estimation. This technique is motivated by earlier studies of airflow characterization for human speech production. The proposed nonlinear approach employs a differential Teager energy operator and the energy separation algorithm to obtain formant AM and FM modulations from filtered speech recordings. A new speech measure is proposed based on parameterization of the autocorrelation envelope of the AM response. This approach is shown to achieve impressive detection performance for a set of muscular tension dysphonias. Unlike flow characterization using numerical solutions of Navier-Stokes equations, this method is extremely computationally attractive, requiring only a small time window of speech samples. The new noninvasive method shows that a fast, effective digital speech processing technique can be developed for vocal fold pathology assessment without the need for direct glottal flow estimation or complete glottal closure by the speaker. The proposed method also confirms that alternative nonlinear methods can begin to address the limitations of previous linear approaches for speech pathology assessment.

Direct speech feature estimation using an iterative EM algorithm for vocal fold pathology detection.

The focus of this study is to formulate a speech parameter estimation algorithm for analysis/detection of vocal fold pathology. The speech processing algorithm proposed estimates features necessary to formulate a stochastic model to characterize healthy and pathology conditions from speech recordings. The general idea is to separate speech components under healthy and assumed pathology conditions. This problem is addressed using an iterative maximum-likelihood (ML) estimation procedure, based on the estimation-maximization (EM) algorithm. A new feature for characterizing pathology, termed enhanced-spectral-pathology component (ESPC), is estimated and shown to vary consistently between healthy and pathology conditions. It is also shown that the mean-area-peak-value (MAPV) and the weighted-slope (WSLOPE) indexes, which are obtained from the ESPC estimate, are meaningful measures of speech pathology conditions. For classification purposes, a five-state hidden-Markov-model (HMM) recognizer was formulated, based on the MAPV, WSLOPE, and ESPC spectral features. A set of log Mel-frequency filter bank coefficients were used to parameterize the ESPC feature. An evaluation of the HMM-based classifier was performed using speech recordings from healthy and vocal fold cancer patients of sustained vowel sounds. It is shown that while both MAPV and WSLOPE are useful features for vocal fold pathology detection, superior performance was achieved using a finer spectral representation of ESPC (e.g., a detection rate of 88.7% for pathology and 92.8% for healthy condition). One main advantage of the proposed method is that it does not require direct estimation of the glottal flow waveform. Therefore, the limitation of the inability to characterize vocal fold pathology, due to incomplete glottal closure, is no longer an issue. The results suggest that general analysis of the ESPC feature can provide a quantitative, noninvasive approach for analysis, detection, and characterization of speech production under vocal fold pathology.

A noninvasive technique for detecting hypernasal speech using a nonlinear operator.

Speakers with a defective velopharyngeal mechanism produce speech with inappropriate nasal resonance (hypernasal speech). It is of clinical interest to detect hypernasality as it is indicative of an anatomical, neurological, or peripheral nervous system problem. There are various clinical techniques used to determine hypernasality. The current techniques are physically invasive or intrusive to some extent. A preferred approach for detecting hypernasality, would be noninvasive to maximize patient comfort and naturalness of speaking. In this study, a noninvasive technique based on the Teager Energy operator is proposed. Utilizing a property of the Teager Energy operator and a model for normal and nasalized speech, a significant difference between the Teager Energy profile for lowpass and bandpass filtered nasalized speech is shown. This difference is shown to be nonexistent for normal speech. A classification algorithm is formulated that detects the presence of hypernasality using a measure of the difference in the Teager Energy profiles. The classification algorithm was evaluated using a native English speaker population producing front (/i/) and mid (/A/) vowels. Results show that the presence of hypernasality in speech can be reliably detected using the proposed classification algorithm.

Robust estimation of speech in noisy backgrounds based on aspects of the auditory process.

A new approach to speech enhancement is proposed where constraints based on aspects of the auditory process augment an iterative enhancement framework. The basic enhancement framework is based on a previously developed dual-channel scenario using a two-step iterative Wiener filtering algorithm. Constraints across broad speech sections and over iterations are then experimentally developed on a novel auditory representation derived by transforming the speech magnitude spectrum. The spectral transformations are based on modeling aspects of the human auditory process which include critical band filtering, intensity-to-loudness conversion, and lateral inhibition. The auditory transformations and perceptual based constraints are shown to result in a new set of auditory constrained and enhanced linear prediction (ACE-LP) parameters. The ACE-LP based speech spectrum is then incorporated into the iterative Wiener filtering framework. The improvements due to auditory constraints are demonstrated in several areas. The proposed auditory representation is shown to result in improved spectral characterization in background noise. The auditory constrained iterative enhancement (ACE-II) algorithm is shown to result in improved quality over all sections of enhanced speech. Adaptation of auditory based constraints to changing spectral characteristics over broad classes of speech is another novel aspect of the proposed algorithm. The consistency of speech quality improvement for the ACE-II algorithm is illustrated over time and across all phonemes classified over a large set of phonetically balanced sentences from the TIMIT database. This study demonstrates the application of auditory based perceptual properties of a human listener to speech enhancement in noise, resulting in improved and consistent speech quality over all regions of speech.

Objective speech quality assessment and the RPE-LTP coding algorithm in different noise and language conditions.

The formulation of reliable signal processing algorithms for speech coding and synthesis require the selection of a prior criterion of performance. Though coding efficiency (bits/second) or computational requirements can be used, a final performance measure must always include speech quality. In this paper, three objective speech quality measures are considered with respect to quality assessment for American English, noisy American English, and noise-free versions of seven languages. The purpose is to determine whether objective quality measures can be used to quantify changes in quality for a given voice coding method, with a known subjective performance level, as background noise or language conditions are changed. The speech coding algorithm chosen is regular-pulse excitation with long-term prediction (RPE-LTP), which has been chosen as the standard voice compression algorithm for the European Digital Mobile Radio system. Three areas are considered for objective quality assessment which include: (i) vocoder performance for American English in a noise-free environment, (ii) speech quality variation for three additive background noise sources, and (iii) noise-free performance for seven languages which include English, Japanese, Finnish, German, Hindi, Spanish, and French. It is suggested that although existing objective quality measures will never replace subjective testing, they can be a useful means of assessing changes in performance, identifying areas for improvement in algorithm design, and augmenting subjective quality tests for voice coding/compression algorithms in noise-free, noisy, and/or non-English applications.

Postoperative computed tomography three months after lumbar disc surgery. A prospective single-blind study.

In a prospective single-blind study, 60 patients surgically treated for lumbar disc herniation underwent clinical examination and computed tomography preoperatively and 3 months after surgery. At follow-up (58 patients; median, 31 months; range, 21-37 months), 29 patients had an excellent outcome (51%), 20 improved (33%), and 9 were unchanged or worse (16%). Dural or radicular scar tissue was present by computed tomography in 88% of the patients, but the findings could not be correlated with the clinical outcome. Recurrent or persistent disc herniation was found in 9% of the patients. The clinical outcome of patients with abnormal computed tomography did not differ significantly from patients without this finding. A relation between facet joint degeneration and less successful clinical outcome was demonstrated. Computed tomography (without contrast) 3 months after surgery gave little information which could be correlated with the clinical outcome. Patients with an excellent outcome had all degrees of intraspinal scar tissue.

[Symptomatic pelvic girdle relaxation. Clinical aspects]. / Symptomgivende bekkenløsning. Klinikk.

In pregnancy a relaxation of the sacroiliac joints and the symphysis is a physiologic phenomenon which usually occurs without symptoms. In some cases, however, these changes cause characteristic symptoms, with pain and difficulty in walking: the symptomatic pelvic girdle relaxation. The condition may be confirmed by tenderness of the joints and provocation of pain by the sacroiliac joints tests. Usually the symptoms disappear shortly after giving birth, but some women suffer for several months, and a few suffer persistent symptoms, the pelvic joint syndrome.

Sleep cystometries in children with nocturnal enuresis.

A combined analysis was done of sleep and bladder filling during sleep. Cystometry did not specifically affect sleep, since most of the cystometry studies in cases of enuresis did not lead to sleep stage changes on electroencephalography. Bladder instability was not accompanied by lighter sleep. Increasing patient age did not appear to have any influence on sleep or bladder behavior. We conclude that it is possible to provoke enuresis at any sleep stage and that sleep is unaffected by bladder filling in enuretic patients.

Electroencephalographic changes in patients with herpes zoster.

EEGs of 42 patients with herpes zoster and 6 with herpes zoster-associated encephalitis were studied to characterize the nature and prevalence of EEG abnormalities in apparently uncomplicated herpes zoster. Thirty-one percent of herpes zoster patients had EEG changes with reduced rhythm frequency ranging from 7 to 2 Hz activity. Frontotemporal localization was observed in 54% of the abnormal EEGs. When compared to EEG in herpes zoster associated encephalitis, the findings were qualitatively the same, but tended to be more severe in the encephalitis cases. No effect of acyclovir on the EEG could be demonstrated.

Nocturnal studies in enuretics. A polygraphic study of sleep-EEG and bladder activity.

In patients with monosymptomatic enuresis we investigated bladder activity together with electroencephalography during sleep on two consecutive nights. Thirty-one patients were investigated. Enuretic episodes were found to be normal micturitions not related to any specific sleep stage. Except for a very few bladder contractions outside the enuresis episode we did not observe any bladder activity. In the few instances where bladder activity was seen it was not associated with changes in EEG activity. The bladder contractions were all eliminated by pelvic floor activity, and this could be seen without any disturbances of the sleep indicating that voiding can be inhibited without the child waking up.

Acupuncture treatment of chronic tension headache--a controlled cross-over trial.

In a controlled trial the effect of traditional Chinese acupuncture v. placebo acupuncture was evaluated in 18 patients with chronic tension headache (mean disease duration 15 years). All patients suffered from daily or frequently recurring headache, the intensity of which was recorded by the patient over a period of 15 weeks. Each patient was treated by traditional Chinese acupuncture as well as by placebo acupuncture in a cross-over design following randomization. Each period of treatment comprised six treatments. Traditional Chinese acupuncture was found to be significantly more pain-relieving than placebo acupuncture, according to the pain registration of the patients themselves. The pain reduction was 31%. Acupuncture is therefore found to be a reasonable treatment for chronic tension headache.

Simultaneous registration of sleep-stages and bladder activity in enuresis.

A combined monitoring of sleep stages and bladder activity for the evaluation of enuresis is on trial. Polygraphic recordings in 7 patients, comprising the preliminary material, have shown single-event bladder contractions without forewarning or changes in sleep stages. A volume dependency of the enuresis episodes seems so far to be a major mechanism.

Acute urinary retention in first trimester of pregnancy.

A 34-year old pregnant women with retroverted uterus and suffering from acute attacks of urinary retention in the first trimester of pregnancy is described. The attacks of retention were caused by the enlarged retroverted uterus associated with a 1x1 cm, well differentiated papilliferous carcinoma in the right side of the trigone. The urinary symptom disappeared after resection of the tumor.