Increased sensitivity of the arterial chemoreceptor drive in young men with mild hypertension

Objective. To examine the clinical signiﬁ cance of polyfunctional 24-hour Holter monitoring with simultaneous recording of electrocardiogram, blood pressure (BP) and respiratory efforts by respiratory inductance plethysmography (Incart, Russia) and functional features of young men with prehypertension or mild arterial hypertension with different proﬁ le of night arterial blood pressure (BP) decline («dippers», «non-dippers», «over-dippers»).Design and methods. We examined 43 adolescents and young men aged 16–26 years (mean age 19,4 ± 0,5 years). All of them underwent echocardiography («Vivid 7», GE); 48,8 % of patients were overweight or obese (body mass index, BMI > 24,9 kg/m2), and BMI was comparable in all groups. Results. Breathing disturbances (apnea/hypopnea episodes) were found in 86 % patients and were positively related with high frequency (HF) spectrum power of heart rate variability (HRV) at night-time and were not related with BMI, BP or type of night BP decline. The analysis of echocardiography revealed that in «non-dippers» (n = 18) left ventricular myocardial mass index (LVMMI) was higher (94,3 ± 16,6 g/m2) than in «over-dippers» (n = 15; 77,8 ± 10,3 g/m2, р < 0,001). In daytime «non-dippers» had lower HRV (total power spectrum and power in all three groups) and power spectrum of VLF and LF spectrum at night. The frequency of repolarization instability (transient T-wave inversion) and early repolarization syndrome was higher in «over-dippers» (66,7 %, р < 0,01). Circadian index of HR was also higher (150 %) in «over-dippers». The number of sleep apnea in «non-dippers» and «dippers» was higher (39,7 ± 29,7 and 37,1 ± 18,1 episodes per hour of sleep) than in «over-dippers» (22,3 ± 12,0 episodes per hour of sleep, р < 0,05), but the last group had more hypopneas.Conclusion. Breathing disturbances were a frequent, and, probably, physiological, ﬁ nding at polyfunctional 24-hour Holter monitoring in young overweight men with pre- or mild hypertension. There is a relationship between LVMMI and nocturnal BP dipping even in young men. Young «non-dippers» demonstrate the same clinical pattern as the older ones. «Over-dipper» type is characterized predominantly by lower HR at night and ECG repolarization abnormalities.

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Elevated Blood Pressures in Obese Young Men With Mild Hypertension Are Sustained During the Day and Night

American Journal of Hypertension ◽

10.1093/ajh/7.7.609 ◽

1994 ◽

Vol 7 (7_Pt_1) ◽

pp. 609-614 ◽

Cited By ~ 2

Author(s):

Pietro Nazzaro ◽

Konrad Stepniakowski ◽

Irene M. O'Shaughnessy ◽

Ahmed H. Kissebah ◽

Brent M. Egan

Keyword(s):

Mild Hypertension ◽

Young Men ◽

Elevated Blood ◽

Blood Pressures

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The physiological correlates of adaptive responses by l.h. Garkavi in adolescents and young people with overweight and mild hypertension

Journal of New Medical Technologies eJournal ◽

10.12737/10334 ◽

2015 ◽

Vol 9 (1) ◽

pp. 0-0

Author(s):

Казидаева ◽

E. Kazidaeva

Keyword(s):

Blood Pressure ◽

Young People ◽

Diastolic Blood Pressure ◽

Mild Hypertension ◽

Spectral Power ◽

Young Patients ◽

Young Men ◽

Training Group ◽

Blood Parameters ◽

Overweight And Obesity

Purpose of this research is to study the physiological correlates of adaptive reactions of the organism on leukocyte formula blood using the algorithm of L.H. Garkavi in young patients with mild arterial hypertension and overweight. Materials and methods. The study included the data of comprehensive survey of 56 young men (16-26 years, mean 18.6+/-0.6 years) with mild hypertension, with overweight and obesity (BMI from 25.0 to 34.8 kg/m²). In addition to laboratory studies, multifunctional monitoring of ECG+AD (Incart, SPb) in outpa-tients was carried out for all young men. Results. There are all types of adaptive reaction in the studied group, excepting a “stress reaction”. 8 ado-lescents (14,3%) had a leukocyte distribution corresponding to a “training reaction”, 39,3% young men demon-strated a “reaction of quiet activation”, 25,0% – a “reaction of increased activation” and 21,4% of adolescents had an “over activation”. Average diastolic blood pressure in the “quiet activation” and “over activation” groups a night was higher (62,4±1,8 mm Hg, t=2,0; df=17, P=0,04 and 63,3±2,2 mm Hg, t=2,1; df=15, P=0,04) than in the “training” group (57,3±1,4 mm Hg). Night diastolic blood pressure decline in “training”, “quiet activation” and “increased activation” groups was 22,8%, 20,3% и 21,0% to be due to a tendency to excessive night decrease of diastolic blood pressure («over-dippers»).Young men with reaction of the increased activation had lower spectral power of very low, low and high frequency band in the day-time than in the “training” group. Significant correlations were obtained between systolic blood pressure value a day and night, spectral analysis of heart rate variability results and white blood parameters. Conclusion. The revealed physiological correlates allow to recommend the method of adap-tive reactions by L.H. Garkavi to assess the functional capacity of young people with mild hypertension and overweight.

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Detection of viruses by electron microscopy: Increased sensitivity by direct micro-ultracentrifugation of samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128821 ◽

1987 ◽

Vol 45 ◽

pp. 908-909

Author(s):

Alain R. Trudel ◽

M. Trudel

Keyword(s):

Electron Microscopy ◽

Fold Increase ◽

Observation Time ◽

Clinical Samples ◽

Maximum Speed ◽

Viral Particles ◽

Structural Details ◽

Latex Spheres ◽

Increased Sensitivity ◽

Size Of Particles

AirfugeR (Beckman) direct ultracentrifugation of viral samples on electron microscopy grids offers a rapid way to concentrate viral particles or subunits and facilitate their detection and study. Using the A-100 fixed angle rotor (30°) with a K factor of 19 at maximum speed (95 000 rpm), samples up to 240 μl can be prepared for electron microscopy observation in a few minutes: observation time is decreased and structural details are highlighted. Using latex spheres to calculate the increase in sensitivity compared to the inverted drop procedure, we obtained a 10 to 40 fold increase in sensitivity depending on the size of particles. This technique also permits quantification of viral particles in samples if an aliquot is mixed with latex spheres of known concentration.Direct ultracentrifugation for electron microscopy can be performed on laboratory samples such as gradient or column fractions, infected cell supernatant, or on clinical samples such as urine, tears, cephalo-rachidian liquid, etc..

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Preplate neurons in embryonic mouse cortex: Ultrastructural observations using photoconversion of the fluorescent lipophilic dye dil

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124938 ◽

1992 ◽

Vol 50 (1) ◽

pp. 906-907

Author(s):

Linda C. Hassinger ◽

James E. Crandall

Keyword(s):

Mouse Embryos ◽

Embryonic Mouse ◽

Cortical Afferents ◽

Mouse Cortex ◽

Carbocyanine Dye ◽

Increased Sensitivity

We have begun to look directly at small numbers of afferent axons to early generated neurons that form the preplate in the developing mouse cortex. The carbocyanine dye Dil (1’1, dioctadecyl-3,3,3’3’-tetramethyl-indocarbocyanine) has proved especially useful for this goal. DiI labels axons and their terminals with greater sensitivity and without some of the disadvantages of axon filling with HRP. The increased sensitivity provided by labeling embryonic axons with DiI has given us new insights into the development of cortical afferents. For instance, we reported originally that afferents from the thalamus were present below the cortex as early as embryonic day 15 (E15) based on HRP injections into mouse embryos. By using DiI placements into the thalamus in aldehyde-fixed brains, we now know that thalamic fibers reach the cortex 24 hrs earlier.

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Bayesian removal of noise for increased sensitivity in vector pattern recognition lattice imaging of interfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150800 ◽

1993 ◽

Vol 51 ◽

pp. 994-995

Author(s):

L. Fei ◽

P. Fraundorf

Keyword(s):

Pattern Recognition ◽

Perfect Crystal ◽

Unit Cell ◽

Ion Milling ◽

Beam Radiation ◽

Major Interest ◽

Unit Cells ◽

Mapping Process ◽

Increased Sensitivity ◽

Electron Microscopes

Interface structure is of major interest in microscopy. With high resolution transmission electron microscopes (TEMs) and scanning probe microscopes, it is possible to reveal structure of interfaces in unit cells, in some cases with atomic resolution. A. Ourmazd et al. proposed quantifying such observations by using vector pattern recognition to map chemical composition changes across the interface in TEM images with unit cell resolution. The sensitivity of the mapping process, however, is limited by the repeatability of unit cell images of perfect crystal, and hence by the amount of delocalized noise, e.g. due to ion milling or beam radiation damage. Bayesian removal of noise, based on statistical inference, can be used to reduce the amount of non-periodic noise in images after acquisition. The basic principle of Bayesian phase-model background subtraction, according to our previous study, is that the optimum (rms error minimizing strategy) Fourier phases of the noise can be obtained provided the amplitudes of the noise is given, while the noise amplitude can often be estimated from the image itself.

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The Effect of Stapedectomy on the Loudness of One’s Own Voice

Journal of Speech and Hearing Research ◽

10.1044/jshr.0803.223 ◽

1965 ◽

Vol 8 (3) ◽

pp. 223-234 ◽

Cited By ~ 1

Author(s):

William Melnick

Keyword(s):

Middle Ear ◽

Normal Subjects ◽

Sound Energy ◽

Loudness Function ◽

Before And After ◽

Increased Sensitivity

Five subjects with normal middle ear mechanisms, and otosclerotic patients, before and after stapedectomy, matched the loudness of their voices to the loudness of a 125-cps-sawtooth noise. The results showed loudness matching functions with gradual slopes, less than 1.00, for the normal subjects and the patients prior to stapedectomy. Post-surgically, the loudness function for the patients increased in steepness to considerably more than 1.00. These results are explained, most logically, in terms of increased sensitivity of the altered middle ear to sound energy generated by the listener’s own voice.

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Modified Earpieces and CROS for High Frequency Hearing Losses

Journal of Speech and Hearing Research ◽

10.1044/jshr.1101.204 ◽

1968 ◽

Vol 11 (1) ◽

pp. 204-218 ◽

Cited By ~ 9

Author(s):

Elizabeth Dodds ◽

Earl Harford

Keyword(s):

Hearing Loss ◽

Hearing Aids ◽

High Frequency ◽

Hearing Aid ◽

Sound Field ◽

Intensity Level ◽

Test Results ◽

High Frequency Hearing Loss ◽

Increased Sensitivity ◽

Difficult Cases

Persons with a high frequency hearing loss are difficult cases for whom to find suitable amplification. We have experienced some success with this problem in our Hearing Clinics using a specially designed earmold with a hearing aid. Thirty-five cases with high frequency hearing losses were selected from our clinical files for analysis of test results using standard, vented, and open earpieces. A statistical analysis of test results revealed that PB scores in sound field, using an average conversational intensity level (70 dB SPL), were enhanced when utilizing any one of the three earmolds. This result was due undoubtedly to increased sensitivity provided by the hearing aid. Only the open earmold used with a CROS hearing aid resulted in a significant improvement in discrimination when compared with the group’s unaided PB score under earphones or when comparing inter-earmold scores. These findings suggest that the inclusion of the open earmold with a CROS aid in the audiologist’s armamentarium should increase his flexibility in selecting hearing aids for persons with a high frequency hearing loss.

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