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Biomedical subjects

R Hauser

Publications and source records attributed to R Hauser.

At least 199 records · Page 11Linked to original sources
PubMed1974

Resolution of three distinct populations of nerve endings from rat brain homogenates by zonal isopycnic centrifugation.

Conditions have been established for the fractionation of subcellular components of rat forebrain homogenates by zonal isopycnic equilibration in continuous sucrose density gradients using a B-XIV rotor. The fractions were analyzed biochemically and by ultra-structural morphometry. Starting from postnuclear supernates of forebrain homogenates, it has been possible to resolve three distinct populations of nerve endings from one another, as well as from free mitochondria and myelin fragments. The three types of nerve endings differ in their apparent specific gravity, their biochemical properties, and their ability selectively to accumulate exogenous transmitter substances in vitro. These three particle populations are likely to represent, in order of increasing modal equilibrium density, (a) cholinergic nerve endings, characterized by their high content of acetylcholine, (b) gamma-amino butyric acid (GABA)-containing nerve endings with high glutamate decarboxylase activity and the ability to accumulate exogenous GABA, (c) adrenergic nerve endings that accumulate exogenous dopamine and noradrenaline and exhibit high monoamine oxidase activity.

Acetylcholine↗
PubMedDate not supplied

Distortion product otoacoustic emissions in normal and hearing-impaired ears.

Otoacoustic emissions of distortion products (DPOAE's) were recorded in normal and hearing-impaired human ears using relatively straightforward methods. Two pure-tone stimuli at fixed frequency levels of 73 dB HL for f1 and of 67 dB HL for f2 were used. The frequencies of the two primaries were chosen so that their geometric mean represented standard audiometric frequencies. Measurements of the emission amplitudes at 2f1-f2 and the adjacent noise floor were achieved by spectral averaging. A total of 101 subjects (199 ears) were tested. Seventy-seven ears in 46 subjects had normal hearing (hearing levels less than or equal to 20 dB at standard audiometric frequencies; average hearing levels, less than or equal to 10 dB). Thirty-six ears in 25 subjects had near-normal hearing (no hearing complaints, hearing levels less than or equal to 40 dB; average hearing levels, less than or equal to 20 dB). No significant differences in mean DPOAE values were apparent between these two groups of ears. All but two of these 113 ears (98%) showed emissions at three or more of the six frequencies tested between 1 and 6 kHz. Emissions were detected in more than 75% at each frequency between 1 and 6 kHz and in more than 85% between 1 and 4 kHz. A further 86 ears in 44 subjects exhibited varying degrees of sensorineural hearing loss caused by different pathologies. In general, emission amplitudes approximated the shapes of the audiograms, and a highly significant correlation between hearing thresholds and emission amplitudes was demonstrated in the frequency range of 1 to 4 kHz.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation↗
PubMedDate not supplied

[The Balgrist hip cup--a 4-to-10-year survival analysis of cement-free hip cups].

The results of 715 cement-free acetabular sockets used in primary total hip arthroplasties are shown according to a survivorship analysis after Kaplan-Meier. The survival probability of the examined cement-free polyethylene sockets after 5 years lies between 88.1% and 93.6% (Endler screw socket of polyethylene: 93.6%; Balgrist socket of polyethylene: 88.1%; Balgrist socket of polyethylene with titanium coating: 90.6%). The survival probability of the Endler socket after ten years is only 44.2%. No statistically significant difference in the survival curves of the polyethylene socket models could be found (p logrank 0.797). The Balgrist sockets with the outer split ring made of titanium show a far better survival rate (98.8% after 4 years) than those made of polyethylene. This result justified the further development of a Modular Revision socket made of titanium so that the original idea could be extended to revision interventions where large acetabular defects have to be coped with.

Acetabulum↗
PubMedDate not supplied

[The Balgrist acetabulum with uncemented endoprosthesis of dysplastic coxarthrosis and other acetabulum defects].

The Balgrist socket, one of the first cementless and non-threaded press-fit acetabular replacements, ensures primary stable fixation. Tapered design and self-locking fixation of the Balgrist socket achieve initial stability not only in osteoarthritis secondary to congenital subluxation but also in acetabular bone stock damage due to other etiologies. The non-threaded design of the socket permits easier femoral head bone grafting for reconstruction of the acetabular rim.

Acetabulum↗
PubMedDate not supplied

Ultrafine particles in human lung macrophages.

As knowledge about size dependency of particle toxicity continues to grow, attention has been focused on ultrafine particles (i.e., < 0.1 microm in diameter). In recent studies with rats, investigators learned that ultrafine particles likely have greater pulmonary toxicity than larger particles, and it is possible that exposure to, and accumulation of, these particles in the human lung may be associated with adverse respiratory health effects. As part of an ongoing study, the authors performed bronchoalveolar lavage in 14 healthy current nonsmokers to investigate the extent to which ultrafine particles were present in lung macrophages. In addition, 10 of the 14 subjects performed pulmonary function tests. Eleven of the 14 subjects were utility workers, and 3 were nonmaintenance employees of a university. The authors used a Zeiss CEM902 electron microscope to study macrophages isolated from bronchoalveolar lavage fluid. Morphometric quantification revealed ultrafine particles in lung macrophages of all 14 volunteers; the average number of ultrafine particles/microm3 cytoplasm per cell (UFavg) ranged from 34 to 231 (mean = 95, standard deviation = 54). Regression analysis showed that the UFavg was associated inversely with percent predicted forced expiratory volume in 1 second (FEV1.0) (beta = -1.2 percent predicted FEV1.0/10 ultrafine particles x microm3 cytoplasm per cell [standard error = 0.45, p = .031). The demonstration of ultrafine particles in all 14 subjects, independent of occupational exposure, suggests that there is environmental exposure to ultrafine particles. The negative association between the number of ultrafine particles and ventilatory function demonstrates a need for further investigation into the pulmonary health effects of ultrafine particles.

Adult↗
PubMedDate not supplied

Variability of nasal lavage polymorphonuclear leukocyte counts in unexposed subjects: its potential utility for epidemiology.

Recent studies have utilized nasal lavage to study the inflammatory cells of the nasal epithelium. In unexposed subjects, investigators have reported wide interindividual variability in lavage cell counts. The intraindividual variability of cell counts in sequential lavages has been less well described. Investigators have also reported that nasal lavage may washout cells, resulting in lower cell counts on subsequent lavages. The present study was designed to characterize both the variability in cell counts in unexposed volunteers and the kinetics of cell washout. Twenty-one subjects participated in two nasal lavage trials. In Trial 1, a baseline lavage was followed by a lavage 72 h later; in Trial 2, the baseline lavage was followed by a lavage 48 h later. Intraclass correlation coefficients of reliability (R) were calculated for each trial. In Trial 1, the R was 0.88, with a one-sided confidence interval > or = 0.75, whereas in Trial 2 R was 0.67, with a confidence interval > or = 0.40. The smaller R in Trial 2 may suggest that washout was more evident at 48 h than at 72 h after the baseline lavage. Furthermore, these R values suggest that within-subject variability is smaller than between-subject variability, supporting the utility of nasal lavage as a reliable technique for investigating the nasal cavity response to air pollutants.

Adult↗
PubMedDate not supplied

Temporal trends in human semen parameters in New England in the United States, 1989-2000.

The current study explores trends in semen parameters in New England in the United States. A retrospective review was performed of 551 semen analysis records from 1989 to 2000 at Vincent Memorial Andrology Laboratory of Massachusetts General Hospital. After age adjustment, semen pH and motility significantly increased 0.05 units/year and 2.33%/year, respectively, while sperm with normal morphology decreased 0.33%/year. Sperm concentration showed a small upward trend. The year of birth in the present study ranged from 1932 to 1981; 2% were born between 1932 and 1941, 13% between 1942 and 1951, 48% between 1952 and 1961, 36% between 1962 and 1971, and 1% were born between 1972 and 1981. There were significant positive relationships between year of birth and semen volume (0.04 mL/1-year interval increase in year of birth) and motility (0.61 percent/1-year interval increase in year of birth), as well as with sperm concentration and morphology. Overall, there were temporal and year of birth trends in several human semen parameters.

Adult↗
PubMedDate not supplied

Probability of sperm detection in nonobstructive azoospermic men undergoing testicular sperm extraction procedures unrelated to clinical parameters.

The study was conducted to evaluate the significance of preoperative clinical parameters for detection of mature testicular sperm cells in nonobstructive azoospermic men. Sixty-five consecutive men with nonobstructive azoospermia underwent testicular sperm extraction procedures. Testicular samples were analyzed histologically with patterns classified as mature spermatogenesis (normal or partial), arrest of spermatogenesis, and Sertoli cell only. Testicular sperm cells were isolated for use in an IVF/ICSI program. Histologic patterns and detection rate of sperm cells were correlated to clinical characteristics. Mature sperm cells were found in all levels of serum FSH. The men were divided into 3 groups based on their clinical characteristics (serum FSH level and testicular size). The distribution of the different testicular histologic patterns, as well as detection rate of sperm cells, was similar in all groups. No correlation was found between serum levels of FSH, LH, prolactin, or testosterone and sperm presence. None of these parameters, nor the testicular size and consistency, can serve as predictive variables of the histological pattern or the presence of mature sperm cells in the testicular biopsies in cases of nonobstructive azoospermia. Until an effective predictive tool is available, a trial of sperm retrieval is recommended for all azoospermic men independent of their clinical characteristics.

Adult↗
PubMedDate not supplied

The expression of mannose-ligand receptor is correlated with sperm morphology.

The objective of the present study was to evaluate the association between the expression of sperm mannose-ligand receptors and sperm morphology. Sperm samples were obtained from 45 men, 30 fertile sperm donors and 15 infertile men. Sperm concentration, motility and morphology were evaluated and then incubated with control medium (Ham's F-10 + 1% HSA) for 4 h. Expression of mannose-ligand receptors was evaluated by mannosylated-BSA-FITC (subdivided into 3 patterns: I, for uncapacitated sperm; II, for capacitated; and III, for acrosome-reacted sperm). The mean (+/- SE) frequencies of sperm cells of the total sperm population that expressed patterns I, II, and III were 88 +/- 2.1%, 7 +/- 1.6%, and 5 +/- 0.8%, respectively, for fertile men, and 90 +/- 2.1%, 7 +/- 1.3%, and 3 +/- 0.5%, respectively, for infertile men. The rate of pattern III expression of mannose-ligand receptors was significantly higher in the fertile group compared to the infertile patients (p <.01). A poor but significant correlation was observed between the rate of pattern III and the percentage of normal-forms sperm cell in the ejaculate (r =.35, p =.018). Fertile sperm samples express more advanced patterns of mannose-ligand receptors compared to infertile men. This phenomenon is related to the morphology of human sperm cell in the ejaculate more than to any other basic sperm characteristics.

Humans↗
PubMedDate not supplied

Improvement in the cervical mucus penetration test by using standard sperm control.

The objective of the present experiments was to establish an acceptable standard for the cervical mucus penetration test (CMPT) by determining the minimal progressive motile spermatozoa concentration (PMSC) that will yield the highest score for proven fertile donor sperm specimens. For this purpose, fresh and frozen-thawed samples were used. Semen was obtained from 29 fertile donors and different PMSC (8, 10, and 14 x 10(6)/mL) were prepared for each sample. The same mucus specimen was used for testing each sperm sample in the three different dilutions. No difference in the scoring of the CMPT between the fresh vs. frozen-thawed groups was found. When PMSC of 14 x 10(6)/mL was used, almost all specimens scored the highest rank. The present study revealed that only semen samples with a minimal PMSC of 14 x 10(6)/mL cells can be used in the CMPT. The information that the freeze-thaw process does not affect the CMPT results supports the concept of cryopreservation of pooled fertile donor specimens in aliquots with adequate concentration of progressive motile spermatozoa for later use as a CMPT control.

Cervix Mucus↗