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Biomedical subjects

R Hauser

Publications and source records attributed to R Hauser.

At least 37 records · Page 2Linked to original sources
PubMed2000

Varicocele and the testicular-renal venous route: hemodynamic Doppler sonographic investigation.

The aim of this study was to quantify the anatomic and hemodynamic components of the testicular venous drainage for the purpose of understanding their mechanisms of interacting in producing mutual effects, such as "nutcracker" phenomenon, reflux, and varicoceles. Seventy-five male subjects were studied at rest and during Valsalva maneuver. Aortomesenteric distance and angle, flow velocity in different segments of the renal veins, testicular vein diameter, and flow inversion were evaluated using standard ultrasound equipment with spectral and color Doppler capabilities. The velocity of flow in the proximal segment of the left renal vein (17.5 cm/s) was found to be significantly lower than that in both the distal left renal vein (121 cm/s) and the right renal vein (37 cm/s). The flow velocity in the proximal left renal vein decreased with decrease in the aortomesenteric distance and angle. Testicular vein diameters greater than 3 mm were statistically associated with decreased superior mesenteric artery angle. A significant association also was found between the left testicular vein diameter (in Valsalva maneuver) and inversion of flow. The decrease in flow velocity in the left renal vein proximal to the bifurcation of the superior mesenteric artery from the aorta supports the "nutcracker" theory. An association was found between the decrease of superior mesenteric artery angle and the increase in testicular vein diameter. Another association exists between the presence of reflux during Valsalva maneuver and increased testicular vein diameter. These finding were significant only for testicular vein diameter values greater than 3 mm.

Adolescent↗
PubMed2000

[Immunohistochemical identification of testicular germ cells--preliminary report].

The use of testicular spermatozoa for intracytoplasmic sperm injection introduced a new treatment modality for management of male infertility. Since testicular biopsies of non-obstructive azoospermic men are not homogenous in their histological patterns, identification with certainty of focal spermatogenesis might be difficult, particularly in those with small foci of spermatogenesis. We used an immunohistochemical marker of the male germ line, an antibody generated against RBM (RNA-binding-motif), to recognize with high precision the presence of germ cells in the biopsy. Biopsies of 30 men with azoospermia, most with non-obstructive azoospermia and a few with obstruction of the vas deferens, were evaluated. Immunohistochemical staining for RBM protein contributed to the detection and accuracy of the identification of germ cells. Furthermore, this immunohistochemical technique aided the histopathologist to focus on even small foci of spermatogenesis. Absence of the protein expression confirmed the diagnosis of Sertoli-cell-only syndrome. The results indicate that expression of RBM can be a diagnostic marker for identifying the germ cells of small concentrations of spermatogenesis. This method can enhance the accuracy of histopathological evaluation of testicular biopsies that had formerly relied mainly on hematoxylin-and-eosin staining.

Biopsy↗
PubMed2000

[Fatal ethanol poisoning of the alcohol abusers].

The examined cohort consisted of 137 alcohol abusers, who died suddenly because of the acute ethanol poisoning. Among them there were 109 men and 28 women from 25 to 73 (mean 46.3 +/- 9.22) years old. Autopsy examinations performed in Department of the Forensic Medicine revealed no traumas or diseases explaining the sudden death, but showed the increased blood ethanol concentration from 3.6 to 8.8 (mean 4.67 +/- 0.74) g/l and urine ethanol concentration from 2.0 to 7.3 (mean 4.88 +/- 0.87) g/l. In the period 1996-1999 in Gdańsk Province there was twofold decrease in the number of sudden death caused by the acute ethanol poisoning in the alcohol abusers.

Acute Disease↗
PubMed1999

[Acute toxoplasmosis in coexistent non-Hodgkin lymphoma].

There are many reasons for cervical lymph node enlargement. In particular, the large group of infectious diseases must be considered along with malignant diseases. The coexistence of an uncommon infectious disease with malignant disease is a rare event. We report the case of an otherwise healthy 69-year-old man with marked enlargement of his cervical lymph nodes. A diagnosis of a recent toxoplasmosis infection was made based on positive IgG and IgM toxoplasma titers and the results of fine-needle aspiration from a lymph node. Since the enlarged lymph nodes persisted for more than weeks, the lymph node was excised. Histological examination revealed a non-Hodgkin's lymphoma. IgM titers in toxoplasmosis can persist up to 1 year. In cases with rare infectious diseases like toxoplasmosis in immunocompromised patients, swollen lymph nodes that persist or grow should lead to the suspicion of additional disease. A diagnosis can be confirmed by removing a lymph node for histology.

Aged↗
PubMed1999

The concentration of glutamate in cerebral tissue as a factor for the assessment of the emotional state before death. A preliminary report.

In this paper the concentration of glutamate in the hemispheres of the brain, the cerebellum and the brain stems of rats exposed to sensory stimulation before death and of control rats are presented. Statistically significant differences in the concentration of this neurotransmitter were found in the hemispheres of the brain in the cases of stress lasting 10 min and 1 min and in the cerebellum after a stress of 10 min. This suggests that it may be possible to diagnose the post-mortem state of emotional tension related to sensoric aversive input which takes place directly before death.

Acoustic Stimulation↗
PubMed1999

Pre-freezing sperm preparation does not impair thawed spermatozoa binding to the zona pellucida.

The present study was conducted to assess the fertilizing potential of frozen-thawed spermatozoa, which were cryopreserved after separation on a Percoll gradient, or washed out of seminal plasma. For this purpose, binding to the zona pellucida and other characteristics of the treated sperm cells were compared with those of cryopreserved spermatozoa from the same original sample which were not manipulated before freezing. Semen specimens were obtained from 80 candidates for sperm donation. Percoll-treated sperm samples compared with the sibling, unprocessed controls had significantly higher values of sperm motility characteristics and per cent of cells with normal morphology after freezing and thawing. Sperm binding ability to the zona pellucida was not statistically different (109 +/- 8.1% and 94 +/- 6.7% in unprocessed and Percoll-treated samples respectively). Sperm specimens processed by washing had significantly higher values for motility characteristics than untreated sibling samples, but no differences were found between the treated and untreated samples for morphology and binding to the zona pellucida (hemizona index of 75 +/- 7.0% and 76 +/- 6.7% in unprocessed and washed samples respectively). These findings suggest that, judged by the binding assay, the aforementioned pre-freezing separation processes have no adverse effect upon the fertilizing potential of the thawed sperm cells. These procedures make it possible to optimize the progressive motile sperm cell concentration of the frozen specimen, which facilitates the storage of samples with good quality, even when the features of the original semen are sub-optimal.

Cell Separation↗
PubMed1999

Genetic evaluation of infertile men.

Recently, microdeletions in the azoospermic factor region of the Y chromosome, in addition to chromosomal anomalies, have been detected in men with azoospermia or severe oligozoospermia. In this study we evaluated the molecular and cytogenetic defects of infertile men. The frequency of Y microdeletions among 105 azoospermic, 28 oligozoospermic and 32 fertile men was tested on lymphocyte DNA using a series of 20 sequence-tagged sites. In addition, microdeletions were evaluated on testicular-derived DNA among 26 azoospermic patients who underwent testicular biopsy and in whom no sperm cells could be identified. Karyotype analysis was performed on 72 of the infertile patients. Deletions were detected in 6.7% azoospermic and 3.6% oligozoospermic men. No deletions were identified among the fertile men. Identical results were obtained with DNA derived either from lymphocytes or testicular tissue. The frequency of chromosomal aberrations in the 72 infertile patients tested (62 azoospermic, 10 oligozoospermic) was 16.6%, with a high percentage of gonosome anomalies. Additional andrological parameters (hormone values, cryptorchidism) failed to identify men at risk for having microdeletions before the test. Our findings support the recommendation to perform genetic defect screening among infertile men before their enrollment in an intracytoplasmic injection/in-vitro fertilization programme.

Adult↗
PubMed1999

Testicular sperm retrieval and cryopreservation prior to initiating ovarian stimulation as the first line approach in patients with non-obstructive azoospermia.

The potency for fertilization and successful implantation was compared between fresh and cryopreserved testicular spermatozoa obtained from the same patient with non-obstructive azoospermia. Spermatozoa cryopreserved at the outset were also evaluated. Non-obstructive azoospermic men (n = 55) underwent testicular sperm extraction (TESE); mature spermatozoa were found in 33 (60%) of them. Of 57 intracytoplasmic sperm injection (ICSI) cycles in 25 patients, 15 used fresh spermatozoa (14 patients, group 1), 24 used the excess spermatozoa cryopreserved after 'fresh' ICSI (11 couples who did not conceive in the 'fresh' cycle, group 2) and 18 cycles used cryopreserved spermatozoa at the outset (11 other patients, group 3). Fertilization, cleavage, embryo quality, implantation and take home baby rates were not significantly different in groups 1 and 2, and 6/14 couples ultimately had healthy babies (42.8% cumulative take home baby rate per TESE). In group 3, neither the fertilization rate, embryo development, pregnancy nor implantation rates per embryo transfer were significantly different from groups 1 and 2. The cumulative delivery and ongoing pregnancy rate in this group was 36. 4%. Cryopreservation did not impair the availability of motile spermatozoa for ICSI. When immotile spermatozoa were injected, however, fertilization rate decreased dramatically. Since criteria for predicting the presence of spermatozoa in the testicular tissue of patients with non-obstructive azoospermia are inadequate, it is suggested that TESE be performed prior to initiating ovarian stimulation.

Adult↗
PubMed1999

Pulmonary function in workers exposed to low levels of fuel-oil ash.

Previously, we reported significant lung function changes after exposure to fuel-oil ash during a boiler overhaul in which median PM10 and vanadium concentrations were 2.9 mg/m3 and 11.9 micrograms/m3, respectively. In this study, we examined prospectively 18 boilermakers involved in the short-term, partial overhaul of a large, oil-fired boiler where occupational exposures to PM10 and metals were relatively low. Vanadium and PM10 exposure levels were measured before and during boiler work. For PM10, median exposure before and during boiler work was 0.5 and 0.6 mg/m3, respectively. For vanadium, median exposure before and during boiler work was 1.0 and 12.7 micrograms/m3, respectively, comparable with the results of our previous study. Spirometric (PFT) testing was done three times: first day on the job (PFT1), end of overhaul (PFT2), and 2 weeks post-overhaul (PFT3). Spirometry results were analyzed using repeated measures analysis of variance. No significant differences were found. Boilermakers working on a short-term overhaul of an oil-fired boiler exhibited no significant change in any lung function parameter comparing pre-, during, and 2 weeks post-exposure. The comparatively low levels of exposure to PM10 and vanadium observed during boiler work, the short duration of the overhaul, and the healthy worker effect are possible explanations for these results.

Adult↗
PubMed1999

Optical tracking of a microscope for image-guided intranasal sinus surgery.

The objective of this study was to examine the effects of optical and tracking properties on the accuracy of an optically locatable operating microscope. The intraoperative arrangement was based on experimental results obtained from a skull model. Measurements were taken from 24 patients undergoing intranasal microscopic sinus surgery for various disorders. Two major groups of influencing factors were determined from measurements on the model: 1) optical properties of the microscope, such as the method of focal point adjustment, focal length, and magnification of the lens; and 2) tracking properties of the microscope, such as the distance of the digitizer to the tracked object, the number of reference infrared light-emitting diodes (IR-LEDs), and the area circumscribed by these IR-LEDs. Patient measurements showed an overall spatial error of 2.39+/-1.15 mm with a laser-supported adjustment of the focal point of the microscope. Although the associated 95th percentile was at 4.36 mm, such a value is encouraging for further development of microscopically navigable systems. It must be noted that the noninvasive patient-to-image registration was performed on the basis of a computed tomographic image with a slice distance of 2 mm.

Electronic Data Processing↗
PubMed1999

Evaluation of a new self-expandable silicone stent in an experimental tracheal stenosis.

STUDY OBJECTIVES: To assess the usefulness of an animal model for testing new tracheobronchial stents. SETTING: Animal laboratory of a university hospital. ANIMALS AND INTERVENTIONS: In a series with 12 mini-pigs, we induced a stable fibromalacic tracheal stenosis that was 50% to 70% of the normal tracheal diameter. After dilation we inserted a 16 x 40-mm self-expandable silicone stent into the stenotic part of the trachea in 10 of the mini-pigs. Five of the stents had a smooth outer surface, and five had additional silicone retaining spikes. Because of a long stenosis in two of the mini-pigs, two overlapping stents (one smooth and one with spikes) were inserted. MEASUREMENTS AND RESULTS: Stent deployment was successful and resulted in the disappearance of the slight to moderate stridor in all of the mini-pigs. Over a mean (+/- SD) observation period of 24 days (range, 10 to 41 days), all of the mini-pigs redeveloped stridor. Three of them died unexpectedly of suffocation: in all three a smooth stent had migrated, leading to total obstruction of the stenosis. In total, five of the six smooth stents migrated, and only one of the six spiked stents migrated. There was considerable granulation tissue formation at the ends of all of the stents. In the two control mini-pigs, a 12 x 35-mm Dumon stent was inserted. Both Dumon stents migrated, and one of them had considerable granuloma formation at its ends. At the end of the observation period, all stents were removed endoscopically and were found not to have deteriorated over time. CONCLUSIONS: Our model proved to be suitable for the evaluation of the technical aspects of the Polyflex stent. Spikes on the outer stent surface are more effective in preventing migration than smooth-surface stents. Long-term compatibility, however, seems to be difficult to test with our model because both the Polyflex and the Dumon stents had excessive granulation tissue formation at both ends, a factor which--in the case of the Dumon stent--does not occur to such a degree in benign human airway stenoses. Our results indicate a need for prospective long-term studies in benign human airway stenoses.

Animals↗
PubMed1998

In vivo import of unspliced tRNATyr containing synthetic introns of variable length into mitochondria of Leishmania tarentolae.

The mitochondrial genomes of trypanosomatids lack tRNA genes. Instead, mitochondrial tRNAs are encoded and synthesized in the nucleus and are then imported into mitochondria. This also applies for tRNATyr, which in trypanosomatids contains an 11 nt intron. Previous work has defined an exon mutation which leads to accumulation of unspliced precursor tRNATyr. In this study we have used the splicing-deficient tRNATyr as a vehicle to introduce foreign sequences into the mitochondrion of Leishmania tarentolae. The naturally occurring intron was replaced by synthetic sequences of increasing length and the resulting tRNATyr precursors were expressed in transgenic cell lines. Whereas stable expression of precursor tRNAsTyr was obtained for introns up to a length of 76 nt, only precursors having introns up to 38 nt were imported into mitochondria. These results demonstrate that splicing-deficient tRNATyr can be used to introduce short synthetic sequences into mitochondria in vivo. In addition, our results show that one factor which limits the efficiency of import is the length of the molecule.

Animals↗
PubMed1998

Urine vanadium concentrations in workers overhauling an oil-fired boiler.

Since fuel oil ash contains vanadium (V), the measurement of urinary levels of V may provide a biological marker in workers exposed to fuel oil ash. The usefulness of urine V samples as a biological monitoring tool ultimately depends on determining the appropriate time of sampling relative to when exposure occurs. Twenty boilermakers were studied during the overhaul of a large oil-fired boiler. A total of 117 urine samples were collected, 65 start-of-shift (S-O-S) and 52 end-of-shift (E-O-S) samples. Air V exposures were estimated with personal sampling devices and work history diaries. Air V concentrations ranged from 0.36 to 32.19 micrograms V/m3, with a mean +/- SD of 19.1 +/- 10.7, and a median of 18.5. On the first day of work on the overhaul, the V urine levels at the E-O-S (mean +/- SD were 1.53 +/- 0.53, median was 1.52 mg V/g creatinine) were significantly higher than those at the S-O-S (0.87 +/- 0.32, median was 0.83), P = 0.004. However, the V concentrations of the S-O-S urine samples on the last Monday of the study were not significantly different from the S-O-S urine levels on the previous Saturday, a time interval of about 38 hr between the end of exposure and sample collection. The Spearman correlation coefficient (r) between the S-O-S urine V and the workplace concentration of V dust during the previous day was r = 0.35. In summary, the results suggest a rapid initial clearance of V (elevating the E-O-S V concentration on the first day of work relative to the S-O-S concentration), followed by a slow clearance that is not complete 38 hr after the end of exposure, as evidenced by the Monday morning urine V concentrations. The Spearman correlations suggest that the S-O-S urine is preferred to the E-O-S urine for across-shift biological monitoring of V exposure.

Adult↗
PubMed1998

Pulmonary responses to oil fly ash particles in the rat differ by virtue of their specific soluble metals.

Occupational exposure to residual oil fly ash (ROFA) particulate has been associated with adverse respiratory health effects in humans. We hypothesized that ROFA collected at different sites within an oil burning power plant, by virtue of its differing metal and sulfate composition, will induce differential lung injury. Ten ROFA samples collected at various sites within a power plant were analyzed for water- and 1.0 M HCl-leachable arsenic (As), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), zinc (Zn), and sulfur by inductively coupled plasma-atomic emission spectroscopy. All ROFA samples contained variable amounts of leachable (water-extractable) and 1.0 M HCl-extractable Fe, V, and/or Ni. All other metals, except Zn (ROFA No. 1 contained 3.43 and No. 3, 6.35 micrograms/mg Zn), were present in negligible quantities (< 1.0 microgram/mg) in the water extract. In vivo pulmonary injury from exposure to whole saline suspensions of these ROFA was evaluated. Male, SD rats (60 days old) were intratracheally instilled with either saline or saline suspension of whole ROFA (< 3.0 mass median aerodynamic diameter) at three concentrations (0.833, 3.33, or 8.33 mg/kg). After 24 h, lungs were lavaged and bronchoalveolar lavage fluid (BALF) was analyzed for cellular influx and protein content as well as lactate dehydrogenase (LDH) and N-acetyl glucosaminidase (NAG) activity and total hemoglobin as indicators of lung injury. ROFA-induced increases in BALF protein and LDH, but not neutrophilic inflammation, were associated with its water-leachable total metal, Ni, Fe, and sulfate content. However, the neutrophilic response following ROFA exposure was positively correlated with its water-leachable V content. Modest lung injury was observed with the ROFA samples which contained the smallest amounts of water-leachable metals. The ability of ROFA to induce oxidative burst in alveolar macrophage (AM) was determined in vitro using a chemiluminescence (CL) assay. AM CL signals in vitro were greatest with ROFA containing primarily soluble V and were less with ROFA containing Ni plus V. In summary, ROFA-induced in vivo acute pulmonary inflammation appears to be associated with its water-leachable V content; however, protein leakage appears to be associated with its water-leachable Ni content. ROFA-induced in vitro activation of AM was highest with ROFA containing leachable V but not with Ni plus V, suggesting that the potency and the mechanism of pulmonary injury will differ between emissions containing V and Ni.

Animals↗
PubMed1998

Expression of mannose-ligand receptors on human spermatozoa: effect of lecithin and association with sperm binding to the zona pellucida.

OBJECTIVE: To evaluate the change in the expression of mannose-ligand receptors and sperm binding capacity after the incubation of sperm cells with lecithin liposomes. DESIGN: A randomized, blinded-controlled experiment. SETTING: Andrology laboratory at the Lis Maternity Hospital. PATIENT(S): Fifteen fertile sperm donors and 10 subfertile men. INTERVENTION(S): Incubation of sperm samples with either control medium or 1 mg/mL of liposomal lecithin for 2 hours. MAIN OUTCOME MEASURE(S): Expression of mannose-ligand receptors as evaluated by mannosylated bovine serum albumin-fluorescein isothiocyanate and sperm binding to the zona pellucida as evaluated by the hemizona assay. RESULT(S): The mean +/- SE percentages of spermatozoa with patterns I, II, and III were 86% +/- 4.8%, 11% +/- 3.4%, and 3% +/- 1.6%, respectively, after treatment with control medium and 71% +/- 5.7%, 22% +/- 3.5%, and 7% +/- 2.5%, respectively, after treatment with lecithin. The same effect of lecithin was observed in the 10 sperm samples from subfertile men. The mean +/- SE numbers of sperm that bound to hemizonae after treatment with control medium or lecithin were 116 +/- 32.4 and 176 +/- 29.6, respectively. Statistically significant correlations were observed between the shift in patterns II and III and the enhancement of sperm binding after lecithin treatment (r = 0.44 and 0.6, respectively). CONCLUSION(S): Lecithin shifts the expression of mannose-ligand receptors to the capacitated and acrosoine-reacted patterns and enhances the binding capacity of the sperm cells.

Adult↗