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Biomedical subjects

H G Schiefer

Publications and source records attributed to H G Schiefer.

At least 19 recordsLinked to original sources

Influence of autogenous leucocytes and Escherichia coli on sperm motility parameters in vitro.

Urogenital infections are considered important factors in male infertility. In this in vitro study we have evaluated the impact of leucocytes in association with an artificial infection with Escherichia coli on the motility of human spermatozoa. Ejaculates and blood samples were obtained from healthy donors with normal semen parameters. Ejaculates were prepared by swim-up technique and five fractions were isolated for incubation. Leucocyte subtypes were separated from blood samples by gradient centrifugation. Purified sperm suspensions were adjusted to a concentration of 20 x 106 ml-1 and incubated with lymphocytes/ monocytes, polymorphonuclear granulocytes (PMN), and E. coli. Samples were incubated for up to 6 h at 37 degrees C. Motility analysis was performed using a computer-assisted sperm analyzer (CASA). Spermatozoa incubated with 3 x 106 PMN ml-1 revealed a significant (P=0.003) decrease in progressive motility after 2 h. This decrease remained weakly significant (P=0.024) after 4 and 6 h. Lymphocytes and monocytes had no effect on sperm motility. Spermatozoa incubated with granulocytes and E. coli demonstrated highly significant alterations in motility after 4 and 6 h of incubation (P < 0.001). The PMN indicate an effect on motility of spermatozoa under experimental conditions. However, the results suggest that bacteria are the primary agents that interfere with sperm motility.

Ejaculation↗

Experimental Escherichia coli epididymitis in rats: a model to assess the outcome of antibiotic treatment.

OBJECTIVE: To assess the effect of initial antimicrobial therapy with a new highly potent quinolone (sparfloxacin) on the outcome of infection, especially acute and chronic inflammation, in a rat model of unilateral Escherichia coli epididymitis. MATERIALS AND METHODS: The study included 60 Sprague-Dawley rats, each of which received 0.1 mL of an E. coli (0:6 strain) suspension (106 colony forming units/mL) injected into the right ductus deferens. At 24 h after infection an oral antimicrobial treatment with sparfloxacin was initiated in half of the animals. The rats were killed 14 days, 3 and 6 months after infection, and both epididymes and the prostate gland cultured to re-isolate E. coli. To evaluate the grade of inflammation in both epididymes, histological variables, including acute and chronic inflammation and scar formation, were evaluated and a total inflammatory score, representing the sum of all variables, computed. RESULTS: Whereas antimicrobial therapy eradicated the pathogen, in untreated animals the pathogen was detectable for up to 6 months after infection in the infected epididymis and/or the prostate gland, while the contralateral epididymis was sterile. The inflammatory reaction in the infected epididymis was significantly less in treated animals (P < 0.001). Subclinical nonbacterial inflammation was present in the contralateral epididymis. CONCLUSIONS: Although adequate antimicrobial treatment eradicated the pathogen and reduced the grade of epididymal damage, inflammation was not avoided. Subclinical inflammation of the contralateral epididymis may contribute to impaired fertility. These results indicate that an inflammatory reaction initiated by bacteria might persist as a nonbacterial process despite early therapy, or by bacteria undetectable by conventional culture techniques, and may compromise male fertility.

Animals↗

Escherichia coli-induced alterations of human spermatozoa. An electron microscopy analysis.

This study evaluated if the negative influence of Escherichia coli on the motility of human spermatozoa is a consequence of E. coli-induced ultrastructural alterations. Suspensions of spermatozoa were artificially infected with E. coli from a serotyped, pathogenic strain and incubated at 37 degrees C for 6 h. After incubation, spermatozoa were fixed in glutaraldehyde, stained with osmium tetroxide and ruthenium red and embedded in Spurr(R)-resin followed by ultramicrotomy. The sections were analysed subsequently by use of transmission electron microscopy. Uninfected suspensions of spermatozoa in medium and bacterial suspensions served as controls. Negative contrast technique was performed to facilitate visualization of ultrastructural details of the bacterial capsule after experimental exposure to spermatozoa. Electron microscopic evaluation revealed multiple and profound alterations in the ultrastructure of spermatozoa such as membrane defects and cytoplasmic vacuoles exclusively in spermatozoa of infected samples (> 90%). Morphological alterations involved all superficial structures of spermatozoa, in particular the plasma membrane of the mid-piece and neck as well as the inner and outer acrosomal membrane of the acrosome, indicating that morphological defects account for the immobilization of spermatozoa by E. coli. The results suggest that E. coli infection of ejaculates results in immobilization and impaired acrosomal function in human spermatozoa, findings that support the indication for antimicrobial chemotherapy in symptomatic and silent infections that affect the ejaculate.

Escherichia coli↗

Diagnosis and therapeutic management of 18 patients with prostatic abscess.

OBJECTIVES: Our retrospective study aimed to analyze the findings and therapeutic strategies in 18 men who were admitted to our department as outpatient emergency cases with prostatic abscess. METHODS: During the period 1985 to 1997, prostatic abscess was diagnosed in 18 patients (mean age 48 years, range 20 to 68) on the basis of evidence of fluctuation at digital rectal examination and transrectal ultrasound (TRUS) findings. Diagnostic workup included analysis of midstream urine and abscess fluid for leukocytes and pathogens. Therapeutic options were conservative treatment and/or draining procedures. RESULTS: Predisposing diseases were found in 13 men. Fluctuation at digitorectal palpation was present in 15 patients. In 3 patients, diagnosis was based on TRUS. All men demonstrated leukocytes in their midstream urine. Causative pathogens in midstream urine were found in 11 patients. In 3 men, additional microbiologic evaluation of abscess fluid revealed uncommon pathogens. All patients received antibiotic treatment. Nine men with monofocal abscess less than 1 cm in diameter were treated with antibiotic therapy and a suprapubic catheter. Surgical drainage (transperineal or transrectal puncture, partly guided by TRUS, or transurethral unroofing) was performed in 12 patients and included 3 patients in whom conservative treatment failed. CONCLUSIONS: Our data confirm the importance of predisposing factors in the pathogenesis of prostatic abscess. Medical history and analysis of midstream urine indicated a diagnosis that was confirmed by digital palpation. In some cases, TRUS may improve diagnosis and treatment. Although both operative and conservative therapy strategies appear feasible, prostatic abscess chiefly requires individually selected drainage procedures.

Abscess↗

Alterations of bacterial clearance induced by propofol.

BACKGROUND: The purpose of the study was to investigate the potential influence of the anaesthetic agent propofol on immune function in terms of systemic clearance and organ distribution of injected Escherichia coli in a rabbit model. METHODS: Defined numbers of E. coli (1.3 x 10(8) colony-forming units, CFU) were injected intravenously 1 h after starting a 4-h infusion of the anaesthetic propofol (2 ml.kg-1.h-1, Disoprivan 1%; n = 6)) or after saline application (n = 6). As propofol is formulated in a 10% lipid emulsion, the lipid vehicle Intralipid (2 ml.kg-1.h-1; n = 6) alone was investigated in a separate group. Parameters monitored were arterial pressure and rates of bacterial elimination from the blood. Three hours after bacterial injection, the animals were killed, and tissue samples of liver, spleen, lung, and kidney were collected for microbiological examinations. RESULTS: Compared to saline-treated animals, infusion of propofol induced increased accumulation of E. coli in lung and spleen, thus reflecting reticuloendothelial system dysfunction. CONCLUSION: As the lipid emulsion by itself induced the same effects, the impaired immune function due to propofol is thought to be attributed to its solvent Intralipid.

Anesthetics, Intravenous↗

Outcome of antibiotic therapy with ciprofloxacin in chronic bacterial prostatitis.

Chronic bacterial prostatitis (CBP) is a rare infection of the prostate with Escherichia coli being the predominant causative pathogen. Appropriate antimicrobial therapy is mandatory for cure. We report on our experience with a 4-week regimen of ciprofloxacin in 40 men suffering from CBP due to E. coli. Follow-up was conducted over a period of 12 to 24 months. The microbiological work-up included an analysis of expressed prostatic secretions (EPS) and semen. Eradication of the pathogen in EPS was achieved in 92% of patients 3 months after therapy and in about 70 to 80% of patients evaluated 12 and 24 months after treatment, respectively. Treatment failure was not associated with the presence of prostatic calculi, as assessed by transrectal ultrasonography. After successful therapy, mean EPS pH decreased significantly from 7.95 to 7.35. Significant bacteriospermia with E. coli was detected in 21/22 (95.5%) patients before treatment and in 6/22 (27.3%) patients 6 months after therapy. Our data reconfirm ciprofloxacin as an excellent antimicrobial agent in the therapy of CBP. However, eradication of the pathogen is unpredictable and cannot be achieved in every case. Further studies should correlate microbiological treatment success with symptomatic relief, as assessed by standardised questionnaires.

Adult↗

Ankylosing spondylitis and infections of the female urogenital tract.

Thirty-two female patients with confirmed ankylosing spondylitis (AS) and 33 women of similar age with pure ileitis terminalis Crohn were examined for genitourinary infection. Urethral syndrome was found in 15 out of 32 patients with AS: 11 of them had urethritis and 4 urethritis associated with vaginitis. Five women of the control group suffered from urethritis. In all cases with genitourinary infection, Chlamydia trachomatis was isolated. By comparing the AS-patients (urogenital infection group and the non-infected group) with regard to other present clinical parameters, it was found, as expected, that the erythrocyte sedimentation rate in the 1st hour was significantly higher in the infected group. In addition, the infected patients had a significantly higher incidence of enthesopathy, involvement of the spinal column, and higher C-reactive protein values (CRP > or = 5 mg/l). A family history of AS was equally present. Other clinical parameters, such as inflammatory involvement of the joints and HLA-B27 correlation, did not differ significantly between infected and non-infected patients.

Adult↗

Influence of different uropathogenic microorganisms on human sperm motility parameters in an in vitro experiment.

The influence of different uropathogenic microorganisms (E. coli, enterococcus, Pseudomonas aeruginosa, Staphylococcus saprophyticus, Candida albicans) on human sperm motility was studied in vitro with a computer-assisted sperm analyser (CASA). Native ejaculates were prepared with the swim-up technique and adjusted to 22 x 10(6) spermatozoa ml-1. The sperm suspension was artificially infected with microorganisms in concentrations varying from 2 x 10(3) to 2 x 10(7). Sperm motility was examined directly after incubation, 2, 4 and 6 h later using the Mika motion analysis, a computer-based, automatic motility analysis. Former results with E. coli (serotype 06) could be confirmed that a significant inhibitory effect on sperm motility was associated with bacterial growth. Experiments with the enterococcus strain and Staphylococcus saprophyticus indicated no significant influence on sperm motility parameters. Tests with Pseudomonas aeruginosa showed a decrease of progressive motility according to time, but not to different bacterial concentrations. A significant inhibitory effect of Candida albicans was only detected in the samples with the initial bacterial concentration of 2 x 10(7) microorganisms ml-1.

Bacteria↗

Influence of urogenital infections on sperm functions.

Many studies have examined the impact of genital tract infections on male fertility; however, the effect of bacteriospermia on sperm quality is still controversial. Bacterial infections are more frequently found in semen samples from asymptomatic infertile patients than in those from fertile men. Bacteriospermia is also a common problem of male partners from couples undergoing IVF. Therefore, the effects of microorganisms on human sperm acrosome reaction of oocytes have been studied in vitro and in vivo. Incubation of spermatozoa with Escherichia coli or Mycoplasma hominis in vitro resulted in reduced sperm motility and inducibility of acrosome reaction (delta AR) after exposure to calcium ionophore A23187. To show possible effects of E. coli and mycoplasma species on sperm functions in vivo, data from 488 patients were evaluated, in whose ejaculates microbiological examinations and determinations of acrosome reaction after exposure to low temperature had been performed. U. urealyticum and E. coli were found in semen samples from 52 and 31 men, respectively. M. hominis was only present in a minor number of samples and was not included in this study. Semen concentrations of E. coli and U. urealyticum ranged between 500-100,000 cfu x ml-1 and 100-80,000 cfu x ml-1. No correlation was found between delta AR and concentration of bacteria (Spearman rank correlation coefficient, E. coli: r-0.081, P = 0.6644; U. urealyticum: r = -0.081, P = 0.5698). In 69% of cases with U. urealyticum infection and reduced inducibility of acrosome reaction, this sperm function was normal after antibiotic therapy. However, improvement of acrosomal function may only be due to intra-individual variations of acrosome reaction. While E. coli and mycoplasma species affect sperm functions in vitro, the present data and a review of the literature fail to demonstrate similar effects in vivo.

Acrosome↗

Impaired bacterial clearance after activation of the complement and coagulation systems.

The aim of this study was to investigate the influence of the activation of the complement and coagulation systems on bacterial clearance and killing capacity of the reticuloendothelial system in rabbits. To enable quantification of the clearance process, defined numbers of exogenous Escherichia coli (1.3 x 10(8) colony-forming units) were injected intravenously, after complement activation with inulin-activated rabbit serum (n = 6), after complete defibrination with the snake toxin ancrod (n = 6), and in sham-operated animals (controls, n = 6). During the following 180 min observation period, parameters monitored were arterial pressure, fibrinogen, blood gases, and bacterial counts in blood and tissue samples of liver, kidney, spleen, and lung. Defibrination produced a significant delay in blood clearance (p < .05) compared with controls, coupled with up to four times higher bacterial counts in organ homogenates. Complement activation did not affect bacterial elimination kinetics, but was associated with accumulation of E. coli in lung and kidney (up to 100-fold of control values, p < .001). The impaired bacterial clearance associated with increased organ colonization after activation of the complement and coagulation systems reflect reticuloendothelial system dysfunction, thus pointing toward a weaker resistance against bacterial infection.

Animals↗

Mycoses of the urogenital tract.

Mycotic infections of the urogenital tract are rarely caused by primary fungal pathogens, often however, by opportunistic fungi such as Candida species. Opportunistic fungi infect the urogenital tract either by haematogenous spread from a distant site, or a break of tissue integrity, or by retrograde ascension from the perianal region, or by wound contamination. After an initial polymorphonuclear reaction macrophages may invade giving rise to a granulomatous response. Risk factors for mycotic urogenital infections are extremes of age, long lasting and broad spectrum antimicrobial therapy, diabetes mellitus, immunosuppression, malignancy, x-ray therapy, contaminated i.-v. catheters, oral contraceptives, pregnancy, surgery, obstructive uropathy and indwelling urethral catheters.

Antifungal Agents↗

Impairment of bacterial clearance induced by norepinephrine infusion in rabbits.

OBJECTIVE: Purpose of the study was to investigate the potential influence of norepinephrine (NE) on immune functions in terms of systemic and organ-specific bacterial clearance in rabbits. DESIGN: To enable quantification of the clearance process, defined numbers of exogenous Escherichia coli (1.3 x 10(8) CFU) were injected intravenously 60 min after starting the NE infusion at a low dose (1 microgram/kg per min, n = 6), causing an increase (30 mmHg) in mean arterial pressure without affecting the oxygen uptake, and at a higher dose (7.5 micrograms/kg per min, n = 6), resulting in a marked decrease (20%) in oxygen uptake, after infusion of NaCl solution (control, n = 6). In additional experiments (n = 6) NE (1 microgram/kg per min) was tested in endotoxemia induced by simultaneous infusion of endotoxin (40 micrograms/kg per h). Parameters monitored were arterial pressure, oxygen uptake, and rates of bacterial elimination from the blood. At 180 min after E. coli injection, the animals were sacrificed, and tissue samples of liver, kidney, spleen, and lung were collected for bacterial counts. RESULTS: NE infusion resulted in a dose-dependent prolonged elimination of the injected E. coli from the blood and in significantly higher (p < 0.05) numbers of CFU in liver and lung compared to the controls. Significant impairment of bacterial clearance was found after shock-producing endotoxemia, whereas simultaneous infusion of NE and endotoxin caused only a slightly delayed blood clearance of the injected bacteria. CONCLUSION: NE dose dependently affected bacterial clearance, which might be due to ischemia-derived hypoxic impairment of the phagocytosis and lysis function of the reticuloendothelial system, whereas NE improved elimination of bacteria in a state of endotoxic shock.

Animals↗

Effects of N-acetylcysteine on bacterial clearance.

The aim of this study was to investigate whether the oxygen radical scavenger N-acetylcysteine (N-AC) impairs bacterial clearance, thus predisposing the host to increased risk of disease. Blood clearance of Escherichia coli and organ colonization were investigated in anaesthetized rabbits after pretreatment with N-AC (250 mg kg-1 body weight, n = 16) and in sham-operated animals (n = 12). To enable quantification of the clearance process, defined numbers of exogenous E. coli [1.3 x 108 colony-forming units (CFUs)] were injected intravenously. Parameters monitored were kinetics of bacterial elimination from the blood, and polymorphonuclear leucocyte (PMN) oxidative burst activity. Samples of liver, kidney, spleen and lung were collected for bacterial counts. Compared with controls, pretreatment with N-AC resulted in delayed bacterial elimination from blood and higher organ colonization with increased numbers of E. coli in liver, lung and kidney (P < 0.05). N-AC treatment was associated with a suppressed PMN oxidative burst activity. Impaired bacterial clearance and enhanced organ colonization in N-AC-treated animals correlated with reduced oxidative burst activity, suggesting impaired granulocyte-dependent bacterial killing due to N-AC application.

Acetylcysteine↗

Influence of Escherichia coli on motility parameters of human spermatozoa in vitro.

The influence of E. coli on human sperm motility was studied in vitro. Semen samples were prepared by a swim-up technique and adjusted to 22 x 10(6) spermatozoa/ml. Samples were then inoculated with different concentrations of a uropathogenic strain of E. coli, serotype 06, with initial sperm/bacteria ratios varying between 10:1 and 10000:1. Motion parameters were analysed by computer-aided motility analysis directly, and 2, 4 and 6 h after inoculation. In a second series of experiments, bacterial replication was inhibited by addition of chloramphenicol. In a third series, the effect of E. coli culture filtrates on sperm motility was investigated. The direct inhibitory effect of E. coli on progressive motility of spermatozoa was found to depend upon the bacterial concentration. A distinct inhibitory effect was observed only at a sperm/bacteria ratio of approximately 1, achieved by growth of E. coli during the experiments. For modality of motion, no distinct changes were observed. When growth of bacteria was prevented by chloramphenicol, no inhibitory effect on sperm motility was detected. Sperm motility was not inhibited by E. coli culture filtrates. Analysis by electron microscopy revealed multiple adhesions of E. coli to spermatozoa, causing variable ultrastructural damage as probable morphological correlates of immobilization.

Bacterial Adhesion↗

Transurethral laser therapy and urinary tract infections.

To date transurethral laser ablation of the prostate (TULAP) in benign prostatic hyperplasia (BPH) is the commonest form of transurethral laser surgery. The invention of the so-called "sidefire" laser fibre was the prerequisite condition for effective transurethral laser ablation of the prostate. Since the first transurethral laser ablation in human BPH was performed by Costello in September 1990, a multitude of urologists have adopted this technique. In the meantime, a great many studies have been carried out and a lot of data have been published. The initial, to some extent euphoric, enthusiasm of some urologists as well as some patients, especially in the USA and Europe, has turned into a more critical reflection. There is no doubt at all that TULAP is a feasible alternative treatment method with reasonable results. Especially in the high-risk patient, there is neither severe blood loss nor an uptake of irrigation fluid. It is also beneficial to allow unlimited treatment in patients on anticoagulant medication. Nevertheless, the value of TULAP in comparison to transurethral electroresection of the prostate (TURP), generally accepted as the "gold-standard" in the surgical therapy of BPH, remains unclear. A final assessment will only be possible when further data on mortality, short and long term morbidity and outcome with this method have been presented. Strong evidence exists that the operation can be performed without blood loss and uptake of irrigation fluid. A further advantage seems to be preservation of sexual function, especially anterograde ejaculation in the majority of patients, in comparison to the "gold-standard" TURP. In most studies, the value of TULAP is further compared with regard to the elimination of obstruction by means of pressure-flow-studies. The aspect most frequently neglected by all investigators to date is the frequency and severity of urinary tract infections (UTI) in patients in whom TULAP is performed. Basically, UTI in the form of cystitis, ascending infections such as male adnexitis or pyelonephritis, prostatitis of the remaining parts of the prostate and catheter-induced urethritis are associated with transurethral surgery in general. Certain data indicate an age-related frequency of UTI. From a rate of approximately 1% of UTI in infants, the frequency rises to 30% in the 8th decade of life. According to these data, one can expect that in a study of TULAP in high risk patients, most of whom are elderly, a large number present for surgery with a preexisting UTI. Other data demonstrate that after 4.5 days 50% and more of patients with an indwelling catheter develop an ascending UTI, although a closed urinary drainage system has been used. In most cases enterobacteriaceae, in 80% Escherichia coli, are detected. Especially in TULAP, a period of prolonged catheterisation has to be expected in the majority of patients. The risk of UTI in the perioperative phase is therefore expected to be higher. There are several higher risks and possibilities of complications in transurethral surgery in patients with UTI. Taking this into account, all our patients routinely undergo low dose antibiotic prophylactic treatment. The frequency of infections of the remaining parts of the prostate after prostatic surgery is strongly correlated to the flow characteristics in the prostatic urethra and to the amount of destruction of the prostatic tissue. Here are further reasons for a higher risk of infection after TULAP. Due to the fact that the prostatic tissue is not removed by a clear cut, but coagulated by laser beam, a rough surface due to tissue necrosis results. This is an ideal culture medium for bacteria aggravated by the disturbed laminar flow in the prostatic urethra, which favours an intraprostatic reflux of infected urine. There is evidence that UTI are the most important factor of morbidity during the first weeks after TULAP because of their bothersome symptoms.(ABSTRACT TRUNCATED)

Aged↗

Infection with Chlamydia pneumoniae in infants and children with acute lower respiratory tract disease.

The role of Chlamydia pneumoniae in the etiology of acute lower respiratory tract infections in infants and children is little understood. We studied the prevalence of C. pneumoniae infection in hospitalized infants and children with acute lower respiratory tract disease by cell culture, polymerase chain reaction (PCR), enzyme immunoassay and serology. Of 290 patients with a mean age of 3.7 years, only 3 (1%) were identified to be infected with C. pneumoniae. One child was positive in the cell culture as well as the PCR assay. Another infant was PCR-positive only and serologic evidence of infection was observed in a culture- and PCR-negative child. Chlamydia trachomatis was not detected in any patient specimen by either culture or PCR. Results of this study indicate that C. pneumoniae plays a minor role in the etiology of respiratory tract infections in infants and young children.

Acute Disease↗