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Biomedical subjects

R Hauser

Publications and source records attributed to R Hauser.

At least 91 records · Page 5Linked to original sources
PubMed1996

[3-year follow-up after endonasal microscopic paranasal sinus surgery in migraine and cluster headache].

BACKGROUND: Migraine and cluster headache can both be triggered by sensitive intranasal areas. METHODS: Endoscopic nasal surgery was performed in 20 patients with chronic migraine without aura or cluster headaches that were refractory to other forms of treatment for a mean period of 18 years (range of 1-45 years). The selected patients showed clinical and radiographic evidence of contact between the middle turbinate and the nasal septum. All patients experienced immediate relief of pain following topical application of cocaine to the presumable triggering area. Five patients with cluster headache and 15 patients with migraine were treated. RESULTS: All patients with cluster headache were free of symptoms after surgical intervention and for a mean follow-up period of three years. Six of the 15 patients with migraine were completely free of symptoms after a mean follow-up period of three years; five had improved more than 50% in the duration and frequency of their attacks. Treatment was unsuccessful in four patients. CONCLUSION: This trial established a likely relationship between nasal trigger areas and cluster headache through the trigeminovascular system and a possible relationship to some type of migraine without aura.

Adult↗
PubMed1996

An Airway Wallstent for the treatment of tracheobronchial malignancies.

BACKGROUND: The palliative effect of a new Airway Wallstent with a polyurethane covering was tested in patients with inoperable malignant lesions of the central airways. METHODS: Thirty six stents were inserted in 27 patients with obstruction (n = 24) or fistulae (n = 3), 15 of whom later received radiotherapy. The degree of symptom relief was assessed 1, 30, and 90 days after stent insertion. RESULTS: Stent deployment was successful in all patients. Significant improvements were observed one day after placement compared with before placement, with no change at 30 and 90 days, in dyspnoea index (mean (SD) 3.2 (0.7) before stent insertion compared with 1.8 (0.7) one day after insertion); Karnofsky index (32 (18) before insertion compared with 55 (15) one day after insertion); and obstruction of airway diameter (85 (11)% before insertion compared with 10 (12)% on day 1 after stent insertion). Stent-related complications needing later interventions included retained secretions (five patients), granuloma formation at ends of the stent (four patients), and stent migration (four patients). Over a median observation period of two months (range two days to 8.5 months) all stent coverings remained intact without delamination or tumour ingrowth. CONCLUSIONS: The Airway Wallstent provided excellent palliation for malignant obstructions and fistulae of the central airways. Retention of secretions and granuloma formation at the ends of the stent warrant minor technical improvements.

Adult↗
PubMed1996

A regression approach to the analysis of serial peak flow among fuel oil ash exposed workers.

We investigated the association between exposure to fuel oil ash and acute airway obstruction in 31 boilermakers and 31 utility workers during the overhaul of a large oil-fired boiler. Air flow was assessed with self-recorded serial peak expiratory flow rate measurements (PEFR) using a mini-Wright meter. Exposure to thoracic particulates with an aerodynamic diameter of 10 gm or smaller (PM10) was assessed using personal sampling devices and detailed work diaries. All subjects were male, with an average age of 43 yr, and an average of 18 yr at their current trade. Average PM10 exposure on work days was 2.75 mg/m3 for boilermakers and 0.57 mg/m3 for utility workers. Three daily PEFR measurements (start-of-shift, end-of-shift, and bed-time) were analyzed simultaneously, using Huber linear regression. After adjustment for job title, welder status, age, height, smoking, and weld-years, for each mg/m3 increase in PM10, the estimated decline in PEFR was 13.2 L/min (p = 0.008) for end-of-shift, 9.9 L/min (p = 0.045) for bed-time, and 6.6 L/min (p = 0.26) for start-of-shift of the following day. This decline of the exposure effect over the 24-h period that follows was statistically significant (p = 0.004). No other factors were found to significantly modify the effect of exposure. Our results suggest that occupational exposure to fuel oil ash is associated with significant acute decrements in peak flow.

Adult↗
PubMed1996

In vitro import of proteins into mitochondria of Trypanosoma brucei and Leishmania tarentolae.

In eukaryotic evolution, the earliest branch of organisms to have mitochondria are the trypanosomatids. Their mitochondrial biogenesis not only includes import of most proteins, but also, unlike in other organisms, import of the whole set of tRNAs. In order to investigate these processes, we devised novel procedures for the isolation of mitochondria from two trypanosomatid species: Trypanosoma brucei and Leishmania tarentolae. Isotonic cell lysis followed by equilibrium density centrifugation in Nycodenz gradients yielded mitochondrial fractions exhibiting a membrane potential. Furthermore, we have used these fractions to reconstitute import of mitochondrial matrix proteins in vitro. Energy-dependent uptake of an artificial precursor protein, containing a trypanosomal presequence attached to mouse dihydrofolate reductase and of yeast mitochondrial alcohol dehydrogenase could be demonstrated. The presequences of both proteins were processed in T. brucei whereas only the trypanosomal one was cleaved in L. tarentolae. Trypsin pretreatment abolished the ability of the mitochondria to import proteins, indicating the involvement of proteinaceous components at the surface of mitochondria.

Aldehyde Oxidoreductases↗
PubMed1996

[Transitory evoked otoacoustic emissions and distortion product emissions in disorders of middle ear ventilation].

Both the amplitude and power spectra of otoacoustic emissions are affected by the transfer properties of the middle ear. This prospective study examined the influence of eustachian tube dysfunction on transiently evoked otoacoustic emissions (TEOAEs) and distortion-product otoacoustic emissions (DPOAEs). In all, 18 ears were studied that exhibited negative middle ear pressures with or without middle ear fluid. Measurements were performed at the time of diagnosis during the recovery stage, and after the middle ear became normally ventilated. Findings showed that TEOAE and DPOAE levels increased while airbone gaps were reduced by an average of 8 dB after negative middle ear pressures returned from -400 daPa to a normal state. There was a tendency for negative middle ear pressure to affect DPOAEs more in the 1-kHz region than in higher frequencies. By contrast, TEOAEs and airbone gaps were more uniformly affected across the entire frequency range. These results for ears with eustachian tube dysfunction were somewhat different from those results of studies obtained in healthy ears tested during experimental changes in middle ear pressure.

Adolescent↗
PubMed1996

Incidence of deep sepsis in uncemented total hip arthroplasty using clean air facility as a function of antibiotic prophylaxis.

Eight hundred and twenty two uncemented primary total hip arthroplasties (THAs) were performed between September 1980 and December 1992. The population that underwent uncemented THA can be divided into two groups based on the perioperative antibiotic prophylaxis: group 1 contains 439 primary THAs from September 1980 to September 1987 without antibiotic prophylaxis; group 2 contains 383 primary THAs who received short-term cefamandole prophylaxis from October 1987 to December 1992. Laminar air-flow and whole-body exhaust suits were used during the whole period of this study. Both groups consisted of relatively young patients with a mean age of 53.8 years in group 1, and 54.3 years in group 2. Using Kaplan-Meier survivorship analysis, the estimated survival rate of sepsis-free hips in group 1 was 97.9% at one year, 97.6% at two years, and 97.4% at three and up to eleven years. In group 2 with antibiotic prophylaxis no deep infection occurred; the rate of sepsis-free hips at five years is 100%. Under clean air conditions, antibiotic prophylaxis significantly decreased the incidence of deep sepsis (p log-rank 0.004).

Adolescent↗
PubMed1996

The Balgrist hip socket for fixation without cement: analysis of 387 primary total hip replacements.

The results of 387 primary hip arthroplasties in which an uncemented Balgrist hip socket had been used in 346 patients were reviewed after a maximum of six years. The mean age of the patients at the time of operation was 54.3 years. Acetabular deficiency according to the AAOS classification was found in 21% of these primary arthroplasties. Three acetabular components (0.77%) had been revised. Using Kaplan-Meier survivorship analysis, with the use of prosthesis revision as the endpoint of failure, the survival rate at five years was found to be 99%. Four acetabular components (1%) had migrated and lysis of bone around the component in zone III occurred in one patient (0.26%). The data suggest that the unique socket design of the Balgrist hip socket (consisting of two tapered parts: an expansive outer titanium-alloy split ring and an insert of polyethylene) provides very satisfactory clinical results with various acetabular defects.

Adolescent↗
PubMed1996

[Reliability of the rapid Streptococcus A test].

The results of three second-generation immune assays for direct detection of group A streptococcus were compared in 65 patients with acute pharyngitis. The assays included Strep A Plus, (Abbott), Concise Strep A (Hybritech) and Cards Plus (Pacific Biotech). A standard culture was used as reference. Additionally a nucleic acid hybridization assay (Gen-Probe) was applied after enhanced broth culturing. The sensitivities and specificities of the three immunoassays were similar and showed that Strep A Plus had an 84.2% sensitivity and 88.9% specificity, Concise Strep A an 82.4% sensitivity and 92.3% specificity, and Cards Plus an 84.2% specificity and 90.7% sensitivity. The Concise Strep A had significantly more doubtful results in comparison with the two other rapid immune assays (9.7% versus 2.3%, P = 0.034. The standard culture and the DNA probe test gave the same results in 94% of cases. Clinical parameters were found to be unreliable for the diagnosis of group A streptococcal pharyngitis. However, findings show that when the rapid immune assay is positive, it is reasonable to start antibiotic treatment without performing a bacterial culture. In cases with a negative assay, management is best tailored to clinical symptoms and laboratory examinations.

Adolescent↗
PubMed1995

tRNAs are imported into mitochondria of Trypanosoma brucei independently of their genomic context and genetic origin.

The mitochondrial genome of Trypanosoma brucei does not encode any identifiable tRNAs. Instead, mitochondrial tRNAs are synthesized in the nucleus and subsequently imported into mitochondria. In order to analyse the signals which target the tRNAs into the mitochondria, an in vivo import system has been developed: tRNA variants were expressed episomally and their import into mitochondria assessed by purification and nuclease treatment of the mitochondrial fraction. Three tRNA genes were tested in this system: (i) a mutated version of the trypanosomal tRNA(Tyr); (ii) a cytosolic tRNA(His) of yeast; and (iii) a human cytosolic tRNA(Lys). The tRNAs were expressed in their own genomic context, or containing various lengths of the 5'-flanking sequence of the trypanosomal tRNA(Tyr) gene. In all cases efficient import of each of the tRNAs was observed. We independently confirmed the mitochondrial import of the yeast tRNA(His), since in organello [alpha-32P]ATP-labelling of the 3'-end of the tRNA was inhibited by carboxyatractyloside, a highly specific inhibitor of the mitochondrial adenine nucleotide translocator. Import of heterologous tRNAs in their own genomic contexts supports the conclusion that no specific targeting signals are necessary to import tRNAs into mitochondria of T. brucei, but rather that the tRNA structure itself is sufficient to specify import.

Animals↗
PubMed1995

Fertility in cases of hypergonadotropic azoospermia.

OBJECTIVE: To review the outcome of reconstructive microsurgery in men with hypergonadotropic azoospermia. DESIGN: A retrospective study on patients with hypergonadotropic azoospermia who underwent scrotal exploration and bypass microsurgery. SETTING: Male infertility microsurgery clinic affiliated with a tertiary university hospital. PATIENTS: Thirty-one hypergonadotropic azoospermic men with evidence of spermatogenesis on testicular biopsy. INTERVENTIONS: Microsurgical exploration of the testes, operative sperm aspiration, and bypass procedures: vasoepididymostomy or vasovasostomy. MAIN OUTCOME MEASURES: Intraoperative aspirated sperm, postoperative ejaculated sperm, proof of fertilizing ability (fertilizations), and pregnancies. RESULTS: Sperm were aspirated intraoperatively in all cases and were detected in postoperative ejaculations in 87%. Of the 14 patients with long-term follow-up data, 6 achieved pregnancies (8 children), and 3 more demonstrated the capacity for fertilization at IVF. CONCLUSIONS: The observation of a high serum FSH in men with azoospermia does not rule out the possibility of obstruction and the capacity for fertility. Caution should be exercised particularly if unilateral testicular atrophy is present. A testicular biopsy should be performed to detect possible spermatogenesis and, if present, then a microsurgical bypass can lead to a successful pregnancy.

Adult↗
PubMed1995

Le(a) and Le(b) tissue glycosphingolipids.

BACKGROUND: The Le(a) and Le(b) antigens are synthesized by cells making exocrine secretions, but it is not well-defined where plasma and red cell Le(a) and Le(b) antigens are made. STUDY DESIGN AND METHODS: This study uses chromatographic and immunochemical methods to extract Le(a) and Le(b) glycolipids from human tissues. RESULTS: Le(a) and Le(b) antigens may be synthesized by both epithelial and mesodermal tissues. Expression of Lewis transferase activity was demonstrated in various tissues, confirming the epistatic interaction by Le and H genes to form the Leb antigen. CONCLUSION: The Le(a) and Le(b) substances found in plasma might originate from the epithelial cells of the digestive tract.

Epithelium↗
PubMed1995

[Effect of contralateral noise exposure on otoacoustic distortion product emissions in man].

The influence of contralateral white noise with levels of 50 and 60 dBnHL on the amplitude of distortion-product otoacoustic emissions (DPOAE) was measured. Thirty ears of normally hearing adults (17 women, 13 men, mean age 26.5 +/- 5.3 years) were examined. Two representative DPOAE frequencies 2f1-f2 = 1342 Hz and 6341 Hz were compared. The lower DPOAE frequency was placed in the frequency region where middle-ear pressure has a strong influence on DPOAE amplitudes, the higher DPOAE frequency respectively in the region where lesser influence is exerted by middle-ear pressure. During the application of contralateral white noise a statistically significant total of 85% of DPOAE amplitudes was reduced, although there was some variation in the individual behaviour of DPOAE amplitudes. In general the higher DPOAE frequency (6341 Hz) was reduced distinctly less than the lower DPOAE frequency (1342 Hz). The reaction of DPOAE amplitude depended closely on the time course of the contralateral stimulus and amplitude reductions were present over 10 minutes without adaptation or fatigue. It is not possible to differentiate between middle-ear or inner-ear mediate effects but the middle ear is at least involved. Based on the presence of those DPOAE amplitude reductions over ten minutes without adaptation or fatigue and the fact that lower frequencies are influenced much more than higher frequencies a synergistic effect--middle-ear and efferent mediated--is suggested.

Adult↗
PubMed1995

Pregnancies after microsurgical correction of partial epididymal and vasal obstruction.

A group of 16 infertile patients suspected of having a partial epididymal obstruction on the basis of severe oligozoospermia, normal-sized testes and a normal serum follicle-stimulating hormone, underwent scrotal exploration. Evidence of partial obstruction of the epididymis was found in 13 cases and of the vas deferens in one case, and was supported by finding normal spermatogenesis on testicular biopsy. Vasoepididymostomy or vasovasostomy were performed, resulting in a significant improvement of semen analysis in 50% of cases and in six pregnancies in two patients. The diagnosis of partial epididymal obstruction should be considered when the above criteria are met. If pregnancies do not result when intracytoplasmic sperm injection (ICSI) is used with the ejaculated spermatozoa, a testicular biopsy followed by a microsurgical by-pass procedure should be considered whenever normal spermatogenesis is diagnosed. In all cases, the epididymal spermatozoa should be aspirated during the operation and either used immediately for insemination or stored frozen. The remarkable results of the new artificial reproduction technologies and in particular ICSI, question the indication for microsurgical correction in cases of partial epididymal obstruction.

Adult↗
PubMed1995

Pheochromocytoma in pregnancy: case report and review of the literature.

Pheochromocytoma is a rare disease that may occur during pregnancy. Only a few hundred cases have been published in the literature. Manifestations include hypertension with various clinical presentations, possibly resembling those of pregnancy-induced hypertension, or pre-eclamptic toxemia. Differentiation of these conditions is not always feasible, thus creating a serious risk, because fetal and maternal morbidity and mortality are far higher with pheochromocytoma. Biochemical measurements of catecholamines and their metabolites are apparently a convenient way to establish diagnosis during pregnancy, inasmuch as interpretation of radiological evaluation is complicated by the gravid uterus, and might even be potentially dangerous due to the use of ionizing radiation. More sophisticated methods for evaluation are not always practical during pregnancy. Medical treatment aims at controlling symptoms, mandating the use of alpha- and beta-receptors blockade medication. Surgical intervention is the only possible curative method available, but the critical issue is probably to identify the exact timing during the course of pregnancy for such intervention, or the ability to control symptoms until delivery. Although malignant transformation of pheochromocytoma have been reported, it is extremely uncommon. The overall prognosis is mainly affected by early diagnosis, and multidisciplinarian management.

Adrenal Gland Neoplasms↗
PubMed1995

Upper airway response in workers exposed to fuel oil ash: nasal lavage analysis.

OBJECTIVES: Among other constituents, fuel oil ash contains vanadium pentoxide, a known respiratory irritant. Exposure to ambient vanadium pentoxide dust has been shown to produce irritation of the eyes, nose, and throat. The usefulness of nasal lavage in detecting an inflammatory response to exposure to fuel oil ash among 37 boilermakers and utility workers was investigated. METHODS: A baseline lavage was performed on the morning of the first day back to work after an average of 114 days away from work (range 36 hours to 1737 days). A lavage was performed after exposure on the morning three days after the baseline lavage. Exposure to respirable particulate matter of diameter < or = 10 microns (PM10) and respirable vanadium dust were estimated with daily work diaries and a personal sampling device for respirable particulates. These estimates were made for each subject on each workday during the three days between lavages. For each subject, the adjusted change in polymorphonuclear cells was calculated by dividing the change in polymorphonuclear cell counts by the average of the counts before and after exposure. The association between the adjusted polymorphonuclear cell counts and exposure was assessed with multiple linear regression, adjusted for age and current smoking. RESULTS: Personal sampling (one to 10 hour time weighted average) showed a range of PM10 concentrations of 50 to 4510 micrograms/m3, and respirable vanadium dust concentration of 0.10 to 139 micrograms/m3. In smokers the adjusted polymorphonuclear cell count was not significantly different from zero (-0.1%, P > 0.5), but in nonsmokers it was significantly greater than zero (+50%, P < 0.05). In both non-smokers and smokers, there was considerable variability in adjusted polymorphonuclear cell counts and a dose-response relation between these adjusted cell counts and either PM10 or respirable vanadium dust exposure could not be found. CONCLUSION: A significant increase in polymorphonuclear cells in non-smokers but not smokers was found. This suggests that in non-smokers, exposure to fuel oil ash is associated with upper airway inflammation manifested as increased polymorphonuclear cell counts. The lack of an increase in polymorphonuclear cells in smokers may reflect either a diminished inflammatory response or may indicate that smoking masks the effect of exposure to fuel oil ash.

Adult↗