Uncovering the neural control of laryngeal activity and subglottic pressure in anaesthetized rats: insights from mesencephalic regions.

To assess the possible interactions between the dorsolateral periaqueductal gray matter (dlPAG) and the different domains of the nucleus ambiguus (nA), we have examined the pattern of double-staining c-Fos/FoxP2 protein immunoreactivity (c-Fos-ir/FoxP2-ir) and tyrosine hydroxylase (TH) throughout the rostrocaudal extent of nA in spontaneously breathing anaesthetised male Sprague-Dawley rats during dlPAG electrical stimulation. Activation of the dlPAG elicited a selective increase in c-Fos-ir with an ipsilateral predominance in the somatas of the loose (p < 0.05) and compact formation (p < 0.01) within the nA and confirmed the expression of FoxP2 bilaterally in all the domains within the nA. A second group of experiments was made to examine the importance of the dlPAG in modulating the laryngeal response evoked after electrical or chemical (glutamate) dlPAG stimulations. Both electrical and chemical stimulations evoked a significant decrease in laryngeal resistance (subglottal pressure) (p < 0.001) accompanied with an increase in respiratory rate together with a pressor and tachycardic response. The results of our study contribute to new data on the role of the mesencephalic neuronal circuits in the control mechanisms of subglottic pressure and laryngeal activity.

Impact of the glutamatergic neurotransmission within the A5 region on the cardiorespiratory response evoked from the midbrain dlPAG.

Stimulation of the dorsolateral periaqueductal grey matter (dlPAG) in rats evokes an active defensive behaviour together with a cardiorespiratory response characterised by tachypnoea, tachycardia and hypertension. The dlPAG neurons involved in these responses are excitatory, presumably glutamatergic, due to the presence of vesicular glutamate transporter VGLUT2 within their axon terminals. Previously, our group described a functional interaction between dlPAG and the pontine A5 region. Accordingly, in the present work, in order to characterize the role of glutamate within this interaction, experiments were carried out in spontaneously breathing anaesthetized rats (sodium pentobarbitone 60 mg/kg i.p., suplemented with 20 mg/kg i.p.). The cardiorespiratory response evoked by electrical stimulation of the dlPAG (1 ms pulses, 20-50 µA, given at 100 Hz, during 5 s) was analysed before and after the microinjection, within the A5 region, of either kynurenic acid (non-specific glutamate receptor antagonist; 5-10 nmol), DAP-5 (NMDA antagonist; 1 pmol), CNQX (non-NMDA antagonist; 1 pmol) or MCPG (metabotropic antagonist; 0,1 nmol). Kynurenic acid decreased the intensity of both the tachypnoea (p < 0,001) and tachycardia (p < 0,001) induced by dl-PAG stimulation. Blockade of no-NMDA receptors reduced the increase of respiratory frequency, heart rate and pressor response to dl-PAG stimulation (p < 0,01, p < 0,001, p < 0,05 respectively). Blockade of either NMDA or metabotropic receptors reduced the dlPAG-evoked tachycardia and pressor response (p < 0,01; p < 0,05 respectively). These results suggest a neuromodulatory role for A5 region via glutamate neurotransmission of the dlPAG-evoked cardiorespiratory response, confirming the role of the ventrolateral pons in the neuronal circuits involved in respiratory and heart rate control.

Apophysomyces variabilis: draft genome sequence and comparison of predictive virulence determinants with other medically important Mucorales.

BACKGROUND: Apophysomyces species are prevalent in tropical countries and A. variabilis is the second most frequent agent causing mucormycosis in India. Among Apophysomyces species, A. elegans, A. trapeziformis and A. variabilis are commonly incriminated in human infections. The genome sequences of A. elegans and A. trapeziformis are available in public database, but not A. variabilis. We, therefore, performed the whole genome sequence of A. variabilis to explore its genomic structure and possible genes determining the virulence of the organism. RESULTS: The whole genome of A. variabilis NCCPF 102052 was sequenced and the genomic structure of A. variabilis was compared with already available genome structures of A. elegans, A. trapeziformis and other medically important Mucorales. The total size of genome assembly of A. variabilis was 39.38 Mb with 12,764 protein-coding genes. The transposable elements (TEs) were low in Apophysomyces genome and the retrotransposon Ty3-gypsy was the common TE. Phylogenetically, Apophysomyces species were grouped closely with Phycomyces blakesleeanus. OrthoMCL analysis revealed 3025 orthologues proteins, which were common in those three pathogenic Apophysomyces species. Expansion of multiple gene families/duplication was observed in Apophysomyces genomes. Approximately 6% of Apophysomyces genes were predicted to be associated with virulence on PHIbase analysis. The virulence determinants included the protein families of CotH proteins (invasins), proteases, iron utilisation pathways, siderophores and signal transduction pathways. Serine proteases were the major group of proteases found in all Apophysomyces genomes. The carbohydrate active enzymes (CAZymes) constitute the majority of the secretory proteins. CONCLUSION: The present study is the maiden attempt to sequence and analyze the genomic structure of A. variabilis. Together with available genome sequence of A. elegans and A. trapeziformis, the study helped to indicate the possible virulence determinants of pathogenic Apophysomyces species. The presence of unique CAZymes in cell wall might be exploited in future for antifungal drug development.

Brainstem and Autonomic Nervous System Dysfunction: A Neurosurgical Point of View.

Central autonomic control nuclei and pathways are mainly integrated within the brainstem, especially in the medulla oblongata. Lesions within these structures can lead to central dysautonomia.Central autonomic control structures can be damaged by tumors, during surgery, or by other neurosurgical pathologies. These may elicit clinical or subclinical autonomic complications that can constitute a serious clinical problem.The authors present a broad review of the central autonomic nervous system, its possible dysfunctions, and the relation between neurosurgery and this "not-well-known system". Preliminary results of an autonomic study of brainstem lesions that is currently being carried out by the authors are also shown.

Neurons of the A5 region are required for the tachycardia evoked by electrical stimulation of the hypothalamic defence area in anaesthetized rats.

In order to assess the possible interactions between the pontine A5 region and the hypothalamic defence area (HDA), we have examined the pattern of double staining for c-Fos protein immunoreactivity (c-Fos-ir) and tyrosine hydroxylase, throughout the rostrocaudal extent of the A5 region in spontaneously breathing anaesthetized male Sprague-Dawley rats during electrical stimulation of the HDA. Activation of the HDA elicited a selective increase in c-Fos-ir with an ipsilateral predominance in catecholaminergic and non-catecholaminergic A5 somata (P < 0.001 in both cases). A second group of experiments was done to examine the importance of the A5 region in modulating the cardiorespiratory response evoked from the HDA. Cardiorespiratory changes were analysed in response to electrical stimulation of the HDA before and after ipsilateral microinjection of muscimol within the A5 region. Stimulation of the HDA evoked an inspiratory facilitatory response, consisting of an increase in respiratory rate (P < 0.001) due to a decrease in expiratory time (P < 0.01). The respiratory response was accompanied by a pressor response (P < 0.001) and tachycardia (P < 0.001). After muscimol microinjection within the A5 region, pressor and heart rate responses to HDA stimulation were reduced (P < 0.01 and P < 0.001, respectively). The respiratory response persisted unchanged. Finally, to confirm functional interactions between the HDA and the A5 region, extracellular recordings of putative A5 neurones were obtained during HDA stimulation. Seventy-five A5 cells were recorded, 35 of which were affected by the HDA (47%). These results indicate that neurones of the A5 region participate in the cardiovascular response evoked from the HDA. The possible mechanisms involved in these interactions are discussed.

BaroWavelet: An R-based tool for dynamic baroreflex evaluation through wavelet analysis techniques.

BACKGROUND AND OBJECTIVE: Baroreflex sensitivity constitutes an indicator of the function of the baroreceptor control mechanism of blood pressure levels. It can be computed after estimating heart rate and blood pressure variability. We propose a novel tool for the evaluation of baroreflex sensitivity using wavelet analysis methods. This tool, known as BaroWavelet, incorporates an algorithm proposal based on the analysis methodology of the RHRV software package, as well as other conventional techniques. Our objectives are to develop and evaluate the tool, by testing its ability to detect changes in baroreflex sensitivity in humans. METHODS: The code for this tool was designed in the R programming environment and was organized into two analysis routines and a graphical interface. Simulated recordings of blood pressure and inter-beat intervals were employed for an initial evaluation of the tool in a controlled environment. Finally, similar recordings obtained during supine and orthostatic postural evaluations, from patients that belonged to the open-access EUROBAVAR data set, were analyzed. RESULTS: BaroWavelet identified the scripted changes of the baroreflex sensitivity in the simulated data. The algorithm proposal was also able to better retain additional information regarding the dynamics of the baroreflex. In the EUROBAVAR subjects, baroreflex sensitivity components were significantly smaller during orthostatism when compared with the supine position. CONCLUSIONS: BaroWavelet managed to characterize baroreflex dynamics from the recordings, which were consistent with the findings reported in the literature. This demonstrates its effectiveness to perform these analyses. We suggest that this tool may be of use in research and for the evaluation of baroreflex sensitivity with clinical and therapeutic purposes. The new tool is available at the official GitHub repository of the Autonomic Nervous System Unit of the University of Málaga (https://github.com/CIMES-USNA-UMA/BaroWavelet).

Impact of a peer-to-peer escape room activity in the learning of Human Physiology of medical students from the university of Málaga.

Escape room's popularity has raised over the past years among young adults. It creates a distended competitive environment, where participants collaborate to achieve a common objective through teamwork. We decided to apply this format as a teaching method for medical students at the University of Malaga, Spain. A peer-to-peer physiological cardiorespiratory escape room was designed by intern undergraduate students, collaborating within the Department of Human Physiology. This activity integrated the contents of the Human Physiology syllabus, which were organized into four stages that culminated in a final medical case. Intern students oversaw the design, promotion, preparation and execution of the activity, and were in charge of conducting the evaluation and follow up. The escape room was done in mid-December, after all theoretical and practical contents had been delivered, for four consecutive years, improving from each year's experience. The target group for this activity were second year medical students, who were asked to team up freely in groups of four to six students before the start of the activity. The students in each group cooperated with each other while trying to solve the different puzzles and questions in each stage of the escape room. After the activity, the results of the final evaluation exam of these participants were compared against non-participants, who served as a control group. Qualitative feedback was also received from the participants via a special survey that was designed for this task. Results between 2020 and 2023 (three last activities) show that the final mark of the participants was significantly higher than in non-participants (6.39 ± 0.14 vs. 5.04 ± 0.2; p < 0.0007). The global exam mark also increased in the participants (5.43 ± 0.10 vs. 4.44 ± 0.15; p < 0.0007). A significant difference was observed in the performance in cardiovascular (p < 0.0007) and respiratory-related questions (p < 0.0007), which was substantial in the participants. The qualitative feedback received from the participants was mainly positive, indicating an overall acceptance of the format by the students. We conclude that escape room format with a peer-to-peer structure is an efficient teaching tool for medical students performed by medical students in the field of Human Physiology.

Validation of a basic neurosonology laboratory for detecting cervical carotid artery stenosis. / Validación de un laboratorio básico de neurosonología para la detección de estenosis carotídea cervical.

INTRODUCTION: Most of the cases of ischaemic stroke in our setting are of atherothrombotic origin. Detecting intracranial and cervical carotid artery stenosis in patients with ischaemic stroke is therefore essential. Ultrasonography has become the tool of choice for diagnosing carotid artery stenosis because it is both readily accessibility and reliable. However, use of this technique must be validated in each laboratory. The purpose of this study is to validate Doppler ultrasound in our laboratory as a means of detecting severe carotid artery stenosis. PATIENTS AND METHODS: We conducted an observational descriptive study to evaluate diagnostic tests. The results from transcranial and cervical carotid Doppler ultrasound scans conducted by neurologists were compared to those from carotid duplex scans performed by radiologists in patients diagnosed with stroke. Arteriography was considered the gold standard (MR angiography, CT angiography, or conventional arteriography). RESULTS: Our sample included 228 patients. Transcranial and cervical carotid Doppler ultrasound showed a sensitivity of 95% and specificity of 100% for detection of carotid artery stenosis > 70%, whereas carotid duplex displayed a sensitivity of 87% and a specificity of 94%. Transcranial carotid Doppler ultrasound achieved a sensitivity of 78% and a specificity of 98% for detection of intracranial stenosis. CONCLUSIONS: Doppler ultrasound in our neurosonology laboratory was found to be a useful diagnostic tool for detecting cervical carotid artery stenosis and demonstrated superiority to carotid duplex despite the lack of B-mode. Furthermore, this technique was found to be useful for detecting intracranial stenosis.

MiDRMpol: A High-Throughput Multiplexed Amplicon Sequencing Workflow to Quantify HIV-1 Drug Resistance Mutations against Protease, Reverse Transcriptase, and Integrase Inhibitors.

The detection of drug resistance mutations (DRMs) in minor viral populations is of potential clinical importance. However, sophisticated computational infrastructure and competence for analysis of high-throughput sequencing (HTS) data lack at most diagnostic laboratories. Thus, we have proposed a new pipeline, MiDRMpol, to quantify DRM from the HIV-1 pol region. The gag-vpu region of 87 plasma samples from HIV-infected individuals from three cohorts was amplified and sequenced by Illumina HiSeq2500. The sequence reads were adapter-trimmed, followed by analysis using in-house scripts. Samples from Swedish and Ethiopian cohorts were also sequenced by Sanger sequencing. The pipeline was validated against the online tool PASeq (Polymorphism Analysis by Sequencing). Based on an error rate of <1%, a value of >1% was set as reliable to consider a minor variant. Both pipelines detected the mutations in the dominant viral populations, while discrepancies were observed in minor viral populations. In five HIV-1 subtype C samples, minor mutations were detected at the <5% level by MiDRMpol but not by PASeq. MiDRMpol is a computationally as well as labor efficient bioinformatics pipeline for the detection of DRM from HTS data. It identifies minor viral populations (<20%) of DRMs. Our method can be incorporated into large-scale surveillance of HIV-1 DRM.

Presence and activity of ammonia-oxidising bacteria detected amongst the overall bacterial diversity along a physico-chemical gradient of a nitrifying wastewater treatment plant.

We wished to discover if we could gain greater insights into how biological treatment plants function by contrasting the presence and activity of the most abundant Bacteria in plug flow and completely mixed activated sludge plants. Presence was assessed by amplifying 16S rRNA gene fragments (using PCR) and activity by amplifying native 16S rRNA, using reverse-transcriptase PCR (RT-PCR), using Bacteria-specific primers. The amplified sequences were compared using denaturing gradient gel electrophoresis (DGGE). The plug flow plant exhibited a strong physico-chemical gradient with an initial anoxic zone, whilst the two completely mixed reactors did not. Similarities were observed between the profile of the banding pattern for presence and activity. However, in the plug flow reactor one prominent band was detected in the active population (16S rRNA) but was absent from the corresponding profile of the 16S rRNA gene. Sequencing of this band revealed its identity as a Nitrosomonas-like sequence. The intensity of the 16S rRNA sequenced varied along the physico-chemical gradient of the plug-flow reactor in a manner that coincided with the growth of ammonia-oxidising bacteria (AOB) and the loss of ammonia. This band was also absent from the completely mixed reactors, although significant numbers of AOB were detected in all systems ( approximately 10(6)-10(8)cells ml(-1)) by fluorescence in situ hybridisation (FISH). An abundant and highly active AOB population was present in the anoxic zone of the plug-flow reactor where up to 60% of the total ammonia was removed. An examination of nitrogen removal/production rates, together with the above data, reveal that complex nitrogen removal processes occur in this system. These data also enabled the calculation of a specific in situ growth rate for the AOB as 0.12h(-1).

Dexmedetomidine, high-flow nasal oxygen and sugammadex-reversal of rocuronium: overcoming anaesthetic challenges in a parturient with congenital muscular dystrophy presenting for caesarean section.

Congenital muscular dystrophies are characterised by progressive skeletal muscle weakness from birth or early infancy. Maternal respiratory compromise, joint contractures and presence of spinal instrumentation or fusion are some of the anaesthetic challenges that may be encountered in the obstetric setting. The choice of anaesthetic technique for surgical delivery needs to be considered on an individual basis. Multidisciplinary involvement is paramount to optimise peripartum care and outcomes. In this case report, we present the use of dexmedetomidine, humidified high-flow nasal oxygen, rocuronium and sugammadex in the anaesthetic management of a wheelchair-bound, non-invasive bilevel positive airway pressure ventilation-dependent parturient with congenital muscular dystrophy, who was presenting for caesarean section.

Glutamate receptors of the A5 region modulate cardiovascular responses evoked from the dorsomedial hypothalamic nucleus and perifornical area.

To assess the possible function of glutamate in the interaction between the dorsomedial hypothalamic nucleus-perifornical area (DMH-PeF) and the A5 pontine region (A5), cardiovascular and respiratory changes were studied in response to electrical stimulation of the DMH-PeF (1 ms pulses, 30-50 µA given at 100 Hz for 5 s) before and after the microinjection of kynurenic acid (non-specific glutamate receptor antagonist; 50 nl, 5 nmol), MK-801 (NMDA receptor antagonist; 50 nl, 50 nmol), CNQX (non-NMDA receptor antagonist; 50 nl, 50 nmol) or MCPG (metabotropic glutamate receptor antagonist; 50 nl, 5 nmol) within the A5 region. DMH-PeF electrical stimulation elicited a pressor (p < 0.001) and tachycardic response (p < 0.001) which was accompanied by an inspiratory facilitation characterised by an increase in respiratory rate (p < 0.001) due to a decrease in expiratory time (p < 0.01). Kynurenic acid within the A5 region decreased the tachycardia (p < 0.001) and the intensity of the blood pressure response (p < 0.001) to DMH-PeF stimulation. After the microinjection of MK-801 and CNQX into the A5 region, the magnitude of the tachycardia and the pressor response were decreased (p < 0.05 and p < 0.01; p < 0.001 and p < 0.05, respectively). After MCPG microinjection into the A5 region, a decrease in the tachycardia (p < 0.001) with no changes in the pressor response was observed during DMH-PeF stimulation. The respiratory response elicited by DMH-PeF stimulation was not changed after the microinjection of kynurenic acid, MK-801, CNQX or MCPG within the A5 region. These results suggest that A5 region glutamate receptors play a role in the cardiovascular response elicited from the DMH-PeF. The possible mechanisms involved in these interactions are discussed.

Skeletal muscle membrane lipid composition is related to adiposity and insulin action.

The cellular basis of insulin resistance is still unknown; however, relationships have been demonstrated between insulin action in muscle and the fatty acid profile of the major membrane structural lipid (phospholipid). The present study aimed to further investigate the hypothesis that insulin action and adiposity are associated with changes in the structural lipid composition of the cell. In 52 adult male Pima Indians, insulin action (euglycemic clamp), percentage body fat (pFAT; underwater weighing), and muscle phospholipid fatty acid composition (percutaneous biopsy of vastus lateralis) were determined. Insulin action (high-dose clamp; MZ) correlated with composite measures of membrane unsaturation (% C20-22 polyunsaturated fatty acids [r= 0.463, P < 0.001], unsaturation index [r= -0.369, P < 0.01]), a number of individual fatty acids and with delta5 desaturase activity (r= 0.451, P < 0.001). pFAT (range 14-53%) correlated with a number of individual fatty acids and delta5 desaturase activity (r= -0.610, P < 0.0001). Indices of elongase activity (r= -0.467, P < 0.001), and delta9 desaturase activity (r= 0.332, P < 0.05) were also related to pFAT but not insulin action. The results demonstrate that delta5 desaturase activity is independently related to both insulin resistance and obesity. While determining the mechanisms underlying this relationship is important for future investigations, strategies aimed at restoring "normal" enzyme activities, and membrane unsaturation, may have therapeutic importance in the "syndromes of insulin resistance."

Variability of automated carotid intima-media thickness measurements by novice operators.

Carotid intima-media thickness (C-IMT) measurements provide a non-invasive assessment of subclinical atherosclerosis. The aim of the study was to assess the inter- and intra-observer variability of automated C-IMT measurements undertaken by two novice operators using the Panasonic CardioHealth Station. Participants were free from cardio-metabolic disease, and each underwent serial bilateral C-IMT ultrasound measurements. Immediate interoperator measurement variability was calculated by comparing initial measurements taken by two operators. Immediate retest variability was calculated from two consecutive measurements and longer term variability was assessed by conducting a further scan 1 week later. Fifty apparently healthy participants (n = 20 females), aged 26·2 ± 5·0 years, were recruited. Operator 1 recorded a median (interquartile range) right and left-sided C-IMT of 0·471 mm (0·072 mm) and 0·462 mm (0·047 mm). Female's right and left C-IMT were 0·442 mm (0·049 mm) and 0·451 mm (0·063 mm), respectively. The limits of agreement (LoA) for immediate interoperator variability were -0·063 to 0·056 mm (mean bias -0·003 mm). Operator 1's immediate retest intra-operator LoA were -0·057 to 0·046 mm (mean bias was -0·005 mm). One-week LoA were -0·057 to 0·050 mm (mean bias -0·003 mm). Operator 2 recorded median right and left-sided C-IMT of 0·467 mm (0·089 mm) and 0·458 mm (0·046 mm) for males, respectively, whilst female measurements were 0·441 mm (0·052 mm) and 0·444 mm (0·054 mm), respectively. Operator 2's intra-operator immediate retest LoA were -0·056 to 0·056 (mean bias <-0·001 mm). Intra-operator LoA at 1 week were -0·052 to 0·068 mm (mean bias 0·008 mm). Novice operators produce acceptable short-term and 1-week inter- and intra-operator C-IMT measurement variability in healthy, young to middle-aged adults using the Panasonic CardioHealth Station.

Autonomic dysfunction elicited by a medulla oblongata injury after fourth ventricle tumor surgery in a pediatric patient.

We report the case of a 9-year-old male patient with a recurrent fourth ventricle anaplastic ependymoma who developed severe arterial hypertension and blood pressure lability during and after surgery. A punctual bilateral lesion located within mid dorsal medulla oblongata caused by both infiltration and surgical resection was observed in postoperative MRI. Three years later, the patient remained neurologically stable but the family referred the presence of a chronic tachycardia as well as palpitations and sweating with flushing episodes related to environmental stress. On autonomic evaluation, an increase in sympathetic outflow with tachycardia together with orthostatic hypotension caused by baroreceptor reflex dysfunction was observed. We postulate that a bilateral injury to both nuclei of the solitary tract may have caused central dysautonomia.

Multiplexed next-generation sequencing and de novo assembly to obtain near full-length HIV-1 genome from plasma virus.

Analysing the HIV-1 near full-length genome (HIV-NFLG) facilitates new understanding into the diversity of virus population dynamics at individual or population level. In this study we developed a simple but high-throughput next generation sequencing (NGS) protocol for HIV-NFLG using clinical specimens and validated the method against an external quality control (EQC) panel. Clinical specimens (n=105) were obtained from three cohorts from two highly conserved HIV-1C epidemics (India and Ethiopia) and one diverse epidemic (Sweden). Additionally an EQC panel (n=10) was used to validate the protocol. HIV-NFLG was performed amplifying the HIV-genome (Gag-to-nef) in two fragments. NGS was performed using the Illumina HiSeq2500 after multiplexing 24 samples, followed by de novo assembly in Iterative Virus Assembler or VICUNA. Subtyping was carried out using several bioinformatics tools. Amplification of HIV-NFLG has 90% (95/105) success-rate in clinical specimens. NGS was successful in all clinical specimens (n=45) and EQA samples (n=10) attempted. The mean error for mutations for the EQC panel viruses were <1%. Subtyping identified two as A1C recombinant. Our results demonstrate the feasibility of a simple NGS-based HIV-NFLG that can potentially be used in the molecular surveillance for effective identification of subtypes and transmission clusters for operational public health intervention.

Skeletal muscle triglyceride levels are inversely related to insulin action.

In animal studies, increased amounts of triglyceride associated with skeletal muscle (mTG) correlate with reduced skeletal muscle and whole body insulin action. The aim of this study was to test this relationship in humans. Subjects were 38 nondiabetic male Pima Indians (mean age 28 +/- 1 years). Insulin sensitivity at physiological (M) and supraphysiological (MZ) insulin levels was assessed by the euglycemic clamp. Lipid and carbohydrate oxidation were determined by indirect calorimetry before and during insulin administration. mTG was determined in vastus lateralis muscles obtained by percutaneous biopsy. Percentage of body fat (mean 29 +/- 1%, range 14-44%) was measured by underwater weighing. In simple regressions, negative relationships were found between mTG (mean 5.4 +/- 0.3 micromol/g, range 1.3-1.9 micromol/g) and log10M (r = -0.53, P < or = 0.001), MZ (r = -0.44, P = 0.006), and nonoxidative glucose disposal (r = -0.48 and -0.47 at physiological and supraphysiological insulin levels, respectively, both P = 0.005) but not glucose or lipid oxidation. mTG was not related to any measure of adiposity. In multiple regressions, measures of insulin resistance (log10M, MZ, log10[fasting insulin]) were significantly related to mTG independent of all measures of obesity (percentage of body fat, BMI, waist-to-thigh ratio). In turn, all measures of obesity were related to the insulin resistance measures independent of mTG. The obesity measures and mTG accounted for similar proportions of the variance in insulin resistance in these relationships. The results suggest that in this human population, as in animal models, skeletal muscle insulin sensitivity is strongly influenced by local supplies of triglycerides, as well as by remote depots and circulating lipids. The mechanism(s) underlying the relationship between mTG and insulin action on skeletal muscle glycogen synthesis may be central to an understanding of insulin resistance.

A new noninvasive index to predict sustained ventricular tachycardia and sudden death in the first year after myocardial infarction: based on signal-averaged electrocardiogram, radionuclide ejection fraction and Holter monitoring.

A prospective study of the prognostic significance of the signal-averaged electrocardiogram (ECG), left ventricular function and 24 hour Holter ECG monitoring was performed in 102 patients (age 63 +/- 11 years) after myocardial infarction. The signal-averaged ECG (40 Hz high pass bidirectional filtering) was obtained 10 +/- 6 days after the acute myocardial infarction and all three tests were performed within 72 hours of each other. Ejection fraction was determined by radionuclide ventriculography. An abnormal signal-averaged ECG was seen in 44% of patients; abnormal ejection fraction (less than 40%) in 52% and high grade ectopic activity (greater than or equal to 10 ventricular premature depolarizations/h or couplets, or nonsustained ventricular tachycardia, or a combination of these) in 62%. During a 12 +/- 6 month follow-up period, 15 patients (14.7%) had an arrhythmic event defined as sustained ventricular tachycardia or sudden cardiac death, or both. The event rates were higher in patients with an abnormal versus a normal signal-averaged ECG (29 versus 3.5%, p = 0.003), an abnormal versus a normal ejection fraction (24 versus 6%, p = 0.001) and the presence versus the absence of high grade ectopic activity (23 versus 9%, p = 0.09). Patients with an abnormal signal-averaged ECG and an abnormal ejection fraction had a significantly higher (p = 0.0007) event rate than did patients in whom both the tests were normal (36 versus 0%; odds ratio 30.1).(ABSTRACT TRUNCATED AT 250 WORDS)