Development of Improved Software Intelligent System for Audiological Solutions.

Of late, there has been an increase in hearing impairment cases and to provide the most advantageous solutions to them is an uphill task for audiologists. Significant difficulty faced by the audiologists is in effective programming of hearing aids to provide enhanced satisfaction to the users. The main aim of our study was to develop a software intelligent system (SIS): (i) to perform the required audiological investigations for finding the degree and type of hearing loss, and (ii) to suggest appropriate values of hearing aid parameters for enhancing the speech intelligibility and the satisfaction level among the hearing aid users. In this paper, we present a Neuro-Fuzzy based SIS to automatically predict and suggest the hearing-aid parameters such as gain values, compression ratio and threshold knee point, which are needed to be fixed for different octave frequencies of sound inputs during the hearing-aid trial. The test signals for audiological investigations are generated through the standard hardware present in a personal computer system and with the aid of a software algorithm. The proposed system was validated with 243 subjects' data collected at the Government General Hospital, Chennai, India. The calculated sensitivity, specificity and accuracy of the proposed audiometer incorporated in the SIS were 98.6%, 96.4 and 98.2%, respectively, by comparing its interpretations with those of the 'gold standard' audiometers. Furthermore, 91% (221 of 243) of the hearing impaired subjects attained satisfaction in the first hearing aid trials itself with the gain values as recommended by the improved SIS. The proposed system reduced around 75% of the 'trial and error' time spent by audiologists for enhancing satisfactory usage of the hearing aid. Hence, the proposed SIS could be used to find the degree and type of hearing loss and to recommend hearing aid parameters to provide optimal solutions to the hearing aid users.

Speech Outcome in Oral Cancer Patients - Pre- and Post-operative Evaluation: A Cross-sectional Study.

AIM: The tongue plays a major role in articulation. Speech outcome depends on the site of lesion, extent of resection, and flexibility of the remaining structures. The aim of this study is to evaluate the speech outcome measures such as sounds that are misarticulated and speech intelligibility and its connection to tumor site before and after surgery. METHODOLOGY: Totally, 24 (12 pre- and 12 post-operative patients) patients who had buccal and tongue cancer underwent speech intelligibility rating and articulation screening. RESULT: The results show that the speech outcome is worse in postoperative patients when compared to preoperative patients. The articulation errors produced by tongue cancer patients were more than the errors produced in buccal cancer patients. The type of reconstruction also affects the speech outcome. CONCLUSION: The perceptual analysis of oral cancer patients showed specific articulation issues and reduced intelligibility of speech in regards to site of lesion and type of reconstruction surgery. To reduce the speech errors, effective rehabilitation is recommended. A comprehensive speech evaluation and analysis of error patterns would help us in planning the rehabilitative measures of speech which is the most important factor in re-establishing interpersonal communication and well-being of the individual.

Comparing the posture and comfort of anaesthesiologists during laryngoscopy and tracheal intubation in the head-elevated laryngoscopy position in supine position and with a 25° backup: A randomised clinical crossover trial.

Background and Aims: The head-elevated laryngoscopy position (HELP) and a 25° backup have been proposed to enhance glottic visualisation, yet concerns about ergonomic discomfort hinder their widespread adoption. This study compares the comfort and posture adopted by anaesthesiologists while performing laryngoscopy and tracheal intubation with patients in HELP while in a supine position or with 25° backup. Methods: The study included 48 patients aged 18-60 years with normal airways and 12 experienced anaesthesiologists. Patients were randomised into two groups using permuted block randomisation. Anaesthesiologists performed laryngoscopy and intubation in supine HELP and 25° backup HELP positions. Anaesthesiologist's posture was determined by measuring the angles of neck, wrist, elbow, back and knee joints, which were compared using Student's t-test, and subjective comfort assessed on a Likert scale was compared using the Chi-square test. As mentioned by the anaesthesiologist, Cormack- Lehane grading was also noted and compared using a Chi-square test between groups, taking a P value <0.05 as significant. Results: Both positions demonstrated comparable anaesthesiologist posture (P = 0.919) and comfort (P = 0.644). However, the 25° backup HELP positions significantly improved Cormack-Lehane grades, with 68% achieving grade 1 compared to 31% in the supine HELP group (P = 0.012). Haemodynamic stability and tracheal intubation time showed no significant differences between the groups (P = 0.475 and 0.117, respectively), and no complications were reported in either group. Conclusion: Anaesthesiologists' posture and comfort during laryngoscopy and tracheal intubation are similar between supine and 25° backup in patients with easy airways.

Spondylodiscitis: A Diagnostic and Management Dilemma.

Aims Spondylodiscitis (SpD), a debilitating infective condition of the spine, mandates early diagnosis and institution of appropriate therapy, for which accurate microbiology and histological evaluation of the affected tissue is vital. The objectives of the study were to assess the correlation between clinical and magnetic resonance imaging (MRI) findings with histopathology (HPE) and microbiology (MB) in clinically diagnosed spondylodiscitis. Settings and design This was a prospective study of 34 consecutive patients reporting at the outpatient department of a tertiary hospital with clinical and imaging features of SpD, who underwent image-guided/surgical biopsy of lesions. Methods and material The provisional diagnosis of SpD in all patients was made on the combined basis of clinical profile and MRI Spine findings. Tissue samples in all patients, obtained by either open surgery or CT-guided biopsy, were subjected to HPE and MB analysis.  Results SpD has a bimodal age distribution with the majority of patients being males in the fourth to fifth decades. Only raised erythrocyte sedimentation rate (ESR) was consistently seen amongst laboratory parameters, with leucocytosis being added pointer towards pyogenic etiology. MRI remained the imaging modality of choice for SpD but was not dependable for etiologic differentiation. On HPE and MB evaluations, 24 patients (71%) had findings consistent with infective SpD, while combined results augmented etiologic confirmation for 28 patients (82.4%). HPE was more sensitive than traditional MB methods to determine etiology in SpD, but the addition of the GeneXpert (Cepheid, Sunnyvale, California, United States) technique improved the MB positivity rate, especially in patients with tubercular SpD. Six patients (17.6%) with both negative HPE and MB results were categorized as 'Non-specific' SpD. Conclusions SpD poses a challenge to determine the etiology for the administration of specific antimicrobial therapy. A stratified standard institutional approach needs adoption to systematically evaluate SpD patients by having a high index of clinical suspicion, early imaging, followed by tissue biopsy for HPE and MB. Despite efforts to reach a diagnosis, a subset of patients without conclusive etiologic agent identification would remain as 'Non-specific', needing empiric antibiotic treatment based on clinico-radiologic profile.

Prevalence and Auditory Characteristics of Auditory Neuropathy Spectrum Disorder in Adult Population with Sensory Neural Hearing Loss: A Hospital Based Study in South India.

Auditory neuropathy spectrum disorder (ANSD) is a heterogenous group of disorder characterized by abnormalities in auditory brainstem responses (ABR) with preserved otoacoustic emissions and/or cochlear microphonics. The aim of the study is to estimate the prevalence and evaluate the audiological characteristics of ANSD in adult population with sensory neural hearing loss. A prospective study was conducted on the adult population (≥ 18 years) attending ENT outpatients clinic at Rajiv Gandhi Government General Hospital, Chennai. All patients reported to the department with auditory and vestibular symptoms underwent case history, otoscopic examination, and routine audiological evaluation (pure tone audiometry, speech audiometry and immittance audiometry). Patients with indications of ANSD in case history and routine audiological evaluation were further evaluated using distortion product otoacoustic emissions and ABR. A total of 8682 adult population was evaluated during the period of 2017 to 2018. Out of 8682 patients, 1343 (15.46%) of them had sensory neural hearing loss of varying degrees. Out of 1343 adults with sensory neural hearing loss, 24 (1.78%) adults were diagnosed as ANSD. The prevalence of ANSD in adult population with sensory neural hearing loss in our study is 1.32% per 1000 adults. The clinical characteristics of ANSD shows impairment in speech perception irrespective of degree of hearing loss, preserved cochlear functions and abnormal ABR. Hence ANSD is not a rare clinical finding in adults with sensory neural hearing loss, but its prevalence was estimated to be lower in Indian population. Often young females are affected causing significant impairment in speech perception and disability.

Functional Outcome of Varus Derotation Osteotomy in Legg-Calve-Perthes Disease: Can It Be Justified in Late-Presenting Disease?

BACKGROUND: Legg-Calve-Perthes disease (LCPD) in children older than seven years has often been associated with accelerated progress and poor outcome. The results of varus derotation osteotomy (VDRO) of the proximal femur in this cohort are not consistently predictable. This study was aimed at assessing the functional outcome of VDRO for hip containment in children with late-presenting LCPD. MATERIALS AND METHODS: A quasi-prospective observational study was conducted to determine the functional outcomes of children with late-presenting unilateral LCPD who underwent VDRO between 2016 and 2021, with a minimum follow-up of two years. A retrospective chart review followed by a patient/parent-reported outcome measure using the Paediatric Outcome Data Collection Instrument (PODCI) was utilised. RESULTS: Thirteen children were included in this study, with a mean age of 8.30 years (range: 7-12 years; SD: -1.493). Three children were in the early stages of the disease, modified Elizabethtown I and IIA (1 and 2, respectively). The majority of the children were in Stage IIB of the modified Elizabethtown staging (n=6), followed by Stage IIIA (n=4). The two children presenting in Stage IV of the disease were excluded from the analysis. The mean standardised and normative PODCI scores for transfer and mobility were 98.23 and 48.03, respectively. The mean standardised and normative PODCI scores for sports and physical were 93.15 and 49.76, respectively. Neither of the scores showed a statistically significant difference between the late and early stages of the disease (Transfer and Basic Mobility Scale: Standardised (p=0.273), Normative (p=0.268); Sports and Physical Functioning Scale: Standardised (p=0.618), Normative (p=0.631)). However, a higher mean PODCI score was noted for the early stages. There was no statistically significant difference between the median score and the duration since surgery. However, there was a moderate negative correlation between the time scores and the times since surgery for the late stages of the disease, viz. Stage IIB and IIIA (Transfer and Basic Mobility Scale: Standardised (-0.445), Normative (-0.450); Sports and Physical Functioning Scale: Standardised (-0.228), Normative (-0.228)). This correlation, however, did not reach a statistical significance. CONCLUSION: VDRO can be regarded as a functionally rewarding option for femoral head containment in late-presenting LCPD across the evolutionary stages of the disease.

Clinical Experience on Hearing Screening in Twins and Triplets: A Retrospective Study.

Twin or multiple pregnancies often have neonatal complications. Common complications include low birth weight, respiratory distress, neonatal intensive care unit (NICU) admission (>5 days) and low APGAR score especially on second twin. (1) To compare referral rates of newborn hearing screening in twins and triplets between risk and non-risk babies for hearing loss, (2) to determine the effects of birth order on referral rates in twins and triplets. A retrospective study was carried out from the case records of the neonates enrolled in the referral based NICU hearing screening program during April 2013 to December 2014 at Institute of Obstetrics and Gynecology, Chennai. 1405 neonates (723 males and 682 females) in the age range of 3-28 days were screened during this period among which 76 were twins (38 pairs) and 9 were triplets (3 sets). We classified them further into non risk and risk babies among twins according to the Joint Committee for Infant Hearing (JCIH) recommendations. A dual step hearing screening protocol was used to screen the neonates. They were initially tested with distortion product otoacoustic emission (DPOAE) then with automated auditory brainstem response (AABR) before discharged from the hospital. Out of 76 (100%) twin babies 43 (56.58%) babies had one or more risk factors for hearing loss. Most common risk factors were low birth weight, premature birth, mechanical ventilation >5 days, hyperbilirubinemia, infections, ototoxic medications and family history of hearing loss. Each risk factor was observed in equal proportion in 1st born and 2nd born twins. 12 (15.76%) risk babies and 11 (14.47%) non risk babies failed in DPOAE testing. Out of 9 triplets babies (3 set) 3 babies had risk factors for hearing loss. One baby in 2nd born babies group failed AABR screening. Referral rates were slightly higher in 2nd born twins when compared to 1st born twins in DPOAE testing. Chi square test did not reveal any significant association between referral rates with risk factors and birth order (p > 0.05). The referral rates in twins are higher than the total population screened. There is some influence of birth order on the referral rates in twins. It needs to be further investigated on larger population.

Vestibular Evoked Myogenic Potentials After Epleys Manoeuvre Among Individuals with Benign Paroxysmal Positional Vertigo.

VEMP abnormalities in individuals with BPPV are often reported to be associated with utricle and saccule degeneration. The aim of the present study is to assess the frequency of VEMP abnormalities using vestibular evoked myogenic potentials in individuals with Posterior canal Benign Paroxysmal Positional Vertigo (BPPV) after Epley's manoeuvre. 36 individuals (36 ears) with definite posterior canal BPPV and 36 healthy controls were considered for the present study. All the them underwent otoscopic examination, Dix-Hallpike manoeuvre to diagnose posterior canal BPPV. Further Audiological Evaluation including pure tone audiometry was carried out to rule out vestibular disorders associated with hearing loss. Epley's manoeuvre was performed on all individuals with BPPV by an experienced otorhinolaryngologist. Cervical and Ocular Vestibular Evoked Myogenic Potentials (VEMP) were used to investigate the saccule and utricle functions following Epley's manoeuvre. Cervical VEMP and ocular VEMP abnormalities were observed in 8/36 (22.22%) and 18/36 (50%) affected ears with BPPV respectively. Cervical VEMP responses were reduced in amplitude among 1/36 (2.77%) and absent in 7/36 (19.44%) of affected ears with BPPV. Ocular VEMP responses were reduced in amplitude on 11/36 (30.55%), followed by absent responses in 5/36 (13.88%) ears with BPPV. Two patients with posterior canal BPPV i.e., 4/64 (5.55%) ears had bilateral absence of ocular VEMP responses. Two ears with BPPV 2/36 (5.55%) had absence of both cervical and ocular VEMP responses in BPPV affected ear. T test showed significant difference (p < 0.01) in the amplitude of ocular VEMP among posterior canal BPPV individuals when compared to cervical VEMP. The present study highlights individuals with Posterior canal BPPV may have otoconia dislodgement or macular degeneration of utricle, saccule, both utricle and saccule unilaterally, or bilaterally. VEMP may be useful in evaluating degeneration of both otolith organs associated with BPPV.

Constituents with independence from growth temperature for bacteria using pyrolysis-gas chromatography/differential mobility spectrometry with analysis of variance and principal component analysis.

Four bacteria, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus warneri, and Micrococcus luteus, were grown at temperatures of 23, 30, and 37 degrees C and were characterized by pyrolysis-gas chromatography/differential mobility spectrometry (Py-GC/DMS) providing, with replicates, 120 data sets of retention time, compensation voltage, and ion intensity, each for negative and positive polarity. Principal component analysis (PCA) for 96 of these data sets exhibited clusters by temperature of culture growth and not by genus. Analysis of variance was used to isolate the constituents with dependences on growth temperature. When these were subtracted from the data sets, Fisher ratios with PCA resulted in four clusters according to genus at all temperatures for ions in each polarity. Comparable results were obtained from unsupervised PCA with 24 of the original data sets. The ions with taxonomic features were reconstructed into 3D plots of retention time, compensation voltage, and Fisher ratio and were matched, through GC-mass spectrometry (MS), with chemical standards attributed to the thermal decomposition of proteins and lipid A. Results for negative ions provided simpler data sets than from positive ions, as anticipated from selectivity of gas phase ion-molecule reactions in air at ambient pressure.

Prevalence and Audiological Characteristics of Auditory Neuropathy Spectrum Disorder in Pediatric Population: A Retrospective Study.

Auditory neuropathy spectrum disorder (ANSD) is a type of hearing disorder which is challenging for assessment and rehabilitation. This disorder has been studied over a decade and prevalence of the disorder is variable. The study aimed at estimating the prevalence and audiological characteristics of ANSD in children. A retrospective study was conducted from the medical records of pediatric patients evaluated at Rajiv Gandhi Government General Hospital and Madras Medical College, Chennai to estimate the prevalence of ANSD. Medical records of 2,624 children evaluated during the period of November 2010 to October 2012 within the age range of 6 months to 12 years were analyzed. Out of 2,624 pediatric population assessed 217 (8.26 %) of them had unilateral or bilateral sensory neural hearing loss with varying degrees. Out of 217 children with sensory neural hearing loss 5.06 % (N = 11) had ANSD. Audiological characteristics varied among the group. Children with ANSD had varied degree of hearing thresholds from normal to profound hearing impairment. All of them had 'A' type tympanogram with absent stapedial reflexes. DPOAEs or TEOAEs were observed in 54 % of population with ANSD. All of them had abnormal auditory brainstem responses (ABR). Replicable cochlear microphonics was observed in 46 % of children with ANSD. These results indicate that ANSD is not a rare condition among children and we emphasize the use of objective tests like tympanometry, Stapedial Reflex test, otoacoustic emissions and ABR in routine hearing assessment procedure for all children to identify ANSD.

Assessment of suitability of i-gel and laryngeal mask airway-supreme for controlled ventilation in anesthetized paralyzed patients: A prospective randomized trial.

CONTEXT: Laryngeal mask airway supreme (LMA-S) has an inflatable cuff while i-gel has a noninflatable cuff made of thermoplastic elastomer. AIMS: To study the efficacy of ventilation and the laryngeal seal pressures (LSPs) with either device. Our secondary objectives were to compare the ease of insertion, adequacy of positioning the device, hemodynamic response to device insertion, and any postoperative oropharyngeal morbidity. SETTINGS AND DESIGN: A prospective, randomized, single-blinded study at Teaching Medical School in South India. MATERIALS AND METHODS: Forty-two patients posted for surgery under general anesthesia were randomly divided into two groups - LMA-S and i-gel. After a standardized premedication and anesthesia induction sequence, the supra-glottic devices were introduced. Ease of insertion was assessed from the number of attempts taken to insert, insertion time, and any maneuvers required to insert the device. Position of the device was assessed by the ease of gastric catheter placement and the fibreoptic grading of laryngeal visualization. Efficacy of ventilation was determined from the LSP, peak inspiratory pressure (PIP), and end-tidal carbon dioxide (EtCO2)values. Any postoperative oropharyngeal morbidity was also recorded. STATISTICAL ANALYSIS: Descriptive analysis was reported as a mean and standard deviation, median, and range of continuous variables. Demographics were analyzed using a unpaired t-test for parametric data and Chi-square test for nonparametric data. Respiratory and hemodynamic data was analyzed using one-way ANOVA to find statistical difference within and between the two groups. RESULTS: LMA-S was successfully inserted in 95% of patients and i-gel in 85.5% of patients. There was a significant difference (P = 0.021) in the LSPs between the two groups (18.15 cmH2O in LMA-S and 21.28 cmH2O in the i-gel group). There was no significant difference in the PIPs, leak fraction, and the EtCO2values. CONCLUSION: Both devices are suitable for positive pressure ventilation (PPV) in anesthetized paralyzed patients. However, i-gel gives a better laryngeal seal when compared to LMA-S and may be chosen preferentially for PPV.

Identifying Early Onset of Hearing Loss in Young Adults With Diabetes Mellitus Type 2 Using High Frequency Audiometry.

Diabetes mellitus (DM) is a metabolic disorder caused by hyperglycemia which leads to dysfunction of various organs. Hearing acuity is equally hindered by this disorder. Among individuals with DM audiological characteristics of DM type 1 are of great concern in the literature. This study aims at establishing high frequency audiometry (HFA) as a useful tool in identifying early onset of hearing loss in individuals with DM type 2. 20 non-diabetic participants and 20 individuals with DM type 2 in the age range of 20-40 years were considered for the study. Subjects in both groups underwent otoscopic examination, PTA at 0.25, 0.5, 1, 2, 4 and 8 kHz and HFA at 9, 10, 11.2, 12.5, 14 and 16 kHz. Results revealed statistically significant difference in thresholds of both PTA and HFA at all frequencies across the group, but the mean threshold difference between the diabetic and non-diabetic group was marked in HFA than in PTA. In the diabetic subjects the thresholds of PTA was within 25 dBHL at all frequencies when compared to the thresholds of HFA. Individuals with DM type 2 showed bilateral symmetrical mild hearing loss in HFA and the hearing loss increased with ascending test frequencies from 9,000 to 16,000 Hz. Mild hearing loss in HFA is an indicator for early onset of hearing loss in DM type 2. Hence this present study emphasis the clinical utility of HFA in young adults with DM type 2.

Prevalence and referral rates in neonatal hearing screening program using two step hearing screening protocol in Chennai - A prospective study.

OBJECTIVE: To estimate the prevalence and referral rates in well born and high risk babies using two step hearing screening protocol with Distortion Product Otoacoustic Emissions (DPOAE) and Automated Auditory Brainstem Response (AABR). METHOD: A prospective study was carried out on 1405 neonates (983 well born babies and 422 high risk babies) who were screened during May 2013 to January 2015 at Institute of Obstetrics and Gynecology, Madras Medical College, Chennai. All neonates were screened using two step screening protocol. They were initially tested with DPOAE. Referred babies in DPOAE were screened with AABR subsequently. RESULTS: Among 1405 (100%) neonates 983 (69.96%) were well born babies and 422 (30.03%) were high risk babies. Total referral rate in DPOAE was found to be 311 (22.13%) among which 195 (13.87%) were well born babies and 116 (8.25%) were high risk babies. Out of 311 babies 31 (2.20%) babies were referred in AABR screening. In 31 babies referred in AABR 11(0.78%) were from well born group and 20 (1.42%) were from the high risk group. Further diagnostic evaluation of these babies, 2 (0.14%) were confirmed to have hearing loss. This study reveals, the prevalence of congenital hearing loss in our population is 1.42 per 1000 babies. CONCLUSION: Using two step protocol especially AABR along with DPOAE at the initial level of testing significantly reduces referral rates in new born screening programs. Also AABR decreases the false positive responses hence increasing the efficiency of screening program.

Randomized Comparison of Extrafascial Versus Subfascial Injection of Local Anesthetic During Ultrasound-Guided Supraclavicular Brachial Plexus Block.

BACKGROUND AND OBJECTIVES: The optimal site for local anesthetic injection during an ultrasound-guided supraclavicular brachial plexus block (BPB) is not known. We tested the hypothesis that local anesthetic injected deep to the "brachial plexus sheath" during supraclavicular BPB would produce faster onset of surgical anesthesia than an injection superficial to the sheath. METHODS: After research ethics approval and informed consent, 32 patients undergoing upper-extremity surgery under an ultrasound-guided supraclavicular BPB were randomly assigned to receive 25 mL of a 1:1 mixture of 2% lidocaine with 1:200,000 epinephrine and 0.5% bupivacaine, deep to (subfascial, Gp SF) or superficial to (extrafascial, Gp EF) the brachial plexus sheath. Sensory-motor blockade of the ipsilateral musculocutaneous, median, radial, and ulnar nerves and time to "readiness for surgery" (defined as a sensory and motor block scale of 1 in all the 4 nerves tested) were assessed by a blinded observer, using a 3-point qualitative scale (2 to 0), every 5 minutes for 40 minutes and at 2, 4, 6, 8, 10, 12, and 24 hours after surgery. RESULTS: The time to "readiness for surgery" was significantly shorter (Gp SF: 7 ± 3 minutes vs Gp EF: 20 ± 10 minutes; P < 0.001), and the duration of postoperative analgesia was longer (Gp SF: 9.3 ± 1.4 hours vs Gp EF: 6.1 ± 1.4 hours; P < 0.001) in the subfascial group than in the extrafascial group. There were no complications directly related to the technique or the local anesthetic injection. CONCLUSIONS: Injection of local anesthetic deep to the brachial plexus sheath at the supraclavicular fossa, under ultrasound-guidance, results in faster onset of surgical anesthesia and prolonged duration of postoperative analgesia than an injection superficial to the sheath.

A pulmonary syndrome in patients with acute myelomonocytic leukemia and inversion of chromosome 16.

Different subtypes of acute myelogenous leukemia have distinct clinical presentations and courses. The specific clinical and molecular aspects of these leukemias have helped modify and create specific strategies for their management. We observed an increased incidence of pulmonary complications in patients with acute myelomonocytic leukemias (AMML) with inversion of chromosome 16 [inv(16)] irrespective of the presence of hyperleukocytosis. We reviewed patient records available over a period of 12 years at The Cleveland Clinic Foundation of patients with AMML with inv(16) and compared the incidence of pulmonary complications to a matched control group of patients with AMML but without inv(16). We found an increased incidence of pulmonary complications in the AMML with inv(16)group when compared to the control group. Two of these patients demonstrated brochiolitis obliterans with organizing pneumonia (BOOP) on lung biopsy. No specific etiology for the pulmonary complications was identified. These findings represent the first observation of an association between WHO-AMML with inv(16) [FAB-AML M4 with inv(16)] with a pulmonary syndrome at presentation. BOOP should be suspected in these cases. A larger prospective study to evaluate this association is warranted.

Novel monosaccharide fermentation products in Caldicellulosiruptor saccharolyticus identified using NMR spectroscopy.

BACKGROUND: Caldicellulosiruptor saccharolyticus is a thermophilic, Gram-positive, non-spore forming, strictly anaerobic bacterium of interest in potential industrial applications, including the production of biofuels such as hydrogen or ethanol from lignocellulosic biomass through fermentation. High-resolution, solution-state nuclear magnetic resonance (NMR) spectroscopy is a useful method for the identification and quantification of metabolites that result from growth on different substrates. NMR allows facile resolution of isomeric (identical mass) constituents and does not destroy the sample. RESULTS: Profiles of metabolites produced by the thermophilic cellulose-degrading bacterium Caldicellulosiruptor saccharolyticus DSM 8903 strain following growth on different monosaccharides (D-glucose, D-mannose, L-arabinose, D-arabinose, D-xylose, L-fucose, and D-fucose) as carbon sources revealed several unexpected fermentation products, suggesting novel metabolic capacities and unexplored metabolic pathways in this organism. Both 1H and 13C nuclear magnetic resonance (NMR) spectroscopy were used to determine intracellular and extracellular metabolite profiles. One dimensional 1H NMR spectral analysis was performed by curve fitting against spectral libraries provided in the Chenomx software; 2-D homonuclear and heteronuclear NMR experiments were conducted to further reduce uncertainties due to unassigned, overlapping, or poorly-resolved peaks. In addition to expected metabolites such as acetate, lactate, glycerol, and ethanol, several novel fermentation products were identified: ethylene glycol (from growth on D-arabinose), acetoin and 2,3-butanediol (from growth on D-glucose, L-arabinose, and D-xylose), and hydroxyacetone (from growth on D-mannose, L-arabinose, and D-xylose). Production of ethylene glycol from D-arabinose was particularly notable, with around 10% of the substrate carbon converted into this uncommon fermentation product. CONCLUSIONS: The present research shows that C. saccharolyticus, already of substantial interest due to its capability for biological ethanol and hydrogen production, has further metabolic potential for production of higher molecular weight compounds, such as acetoin and 2,3-butanediol, as well as hydroxyacetone and the uncommon fermentation product ethylene glycol. In addition, application of nuclear magnetic resonance (NMR) spectroscopy facilitates identification of novel metabolites, which is instrumental for production of desirable bioproducts from biomass through microbial fermentation.

Analysis of bacteria by pyrolysis gas chromatography-differential mobility spectrometry and isolation of chemical components with a dependence on growth temperature.

Pyrolysis gas chromatography-differential mobility spectrometry (py-GC-DMS) analysis of E. coli, P. aeruginosa, S. warneri and M. luteus, grown at temperatures of 23, 30, and 37 degrees C, provided data sets of ion intensity, retention time, and compensation voltage for principal component analysis. Misaligned chromatographic axes were treated using piecewise alignment, the impact on the degree of class separation (DCS) of clusters was minor. The DCS, however, was improved between 21 to 527% by analysis of variance with Fisher ratios to remove chemical components independent of growth temperature. The temperature dependent components comprised 84% of all peaks in the py-GC-DMS analysis of E. coli and were attributed to the pyrolytic decomposition of proteins rather than lipids, as anticipated. Components were also isolated in other bacteria at differing amounts: 41% for M. luteus, 14% for P. aeruginosa, and 4% for S. warneri, and differing patterns suggested characteristic dependence on temperature of growth for these bacteria. These components are anticipated to have masses from 100 to 200 Da by inference from differential mobility spectra.

Analysis of bacterial strains with pyrolysis-gas chromatography/differential mobility spectrometry.

Eight vegetative bacterial strains and two spores were characterized by pyrolysis-gas chromatography with differential mobility spectrometry (py-GC/DMS) yielding topographic plots of ion intensity, retention time, and compensation voltage simultaneously for ions in positive and negative polarity. Biomarkers were found in the pyrolysate at characteristic retention times and compensation voltages and were confirmed by standard addition with GC/MS analyses providing discrimination between Gram negative and Gram positive bacterial types, but no recognition of individual strains within the Gram negative bacteria. Principal component analysis was applied using two dimensional data sets of ion intensity versus retention time at five compensation voltages including the reactant ion peaks all in positive and negative ion polarity. Clustering was observed with compensation voltage (CV) chromatograms associated with ion separation in the DMS detector and little or no clustering was observed with the reactant ion peaks or CV chromatograms where ion separation is poor. Consistent clustering of Gram positive B. odysseyi and Gram negative E. coli in both positive and negative polarities with the reactant ion peak chromatograms and key CV chromatograms suggests common but unknown common chemical compositions in the pyrolysate.

Coil embolization of a solitary congenital intrahepatic hepatoportal fistula.

Congenital hepatic artery-to-portal vein fistula, a rare type of arteriovenous malformation that may be intrahepatic or extrahepatic, is an uncommon cause of severe infantile portal hypertension. Many researchers believe that acquired intrahepatic arterioportal fistulas are best treated by embolization and that extrahepatic arterioportal fistulas require surgical intervention. The experience with congenital intrahepatic arterioportal fistulas is very limited and has required both embolization and surgical intervention. We report a case of solitary congenital arterioportal fistula successfully treated with coil embolization.