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Biomedical subjects

R Hauck

Publications and source records attributed to R Hauck.

At least 19 recordsLinked to original sources
PubMed2006

Detection of Histomonas meleagridis DNA in different organs after natural and experimental infections of meat turkeys.

Histomonas meleagridis infection of turkeys is usually accompanied by a severe disease with unspecific clinical symptoms but with distinct pathological lesions in the ceca and liver. In the literature some macro- and microscopic evidence of the spread of histomonads to the other organs has been provided. The aim of the present investigations was to use real-time polymerase chain reaction (PCR) to demonstrate the dissemination of H. meleagridis DNA to different organs after natural and experimental infection of meat turkeys. Samples from several organs were collected from a meat-turkey flock, which proved to be naturally infected with histomoniasis, and examined for histomonad DNA by real-time PCR. Histomonad DNA was detected in all investigated ceca, livers, spleens, kidneys, and pooled brain swabs. Additionally it was found in 75% of investigated samples from bursae of Fabricius, in 50% of investigated duodenums, and in 40% of investigated jejunum samples. After experimental intracloacal infection of 3-wk-old turkey poults with 147,500 histomonads, similar samples were collected from all turkeys that died. After a 3-wk observation period the surviving birds, as well as the noninfected control group, were euthanatized and samples were taken. During the entire experimental period, 10 birds out the 20 infected birds died. Histomonad DNA was detected in all investigated ceca, livers, lungs, and hearts (100%) and almost all kidneys (90%) and bursae of Fabricius (80%). On the other hand, only 30% of examined spleens and 10% of brain samples revealed positive results. Surviving infected birds were euthanatized and necropsied; histomonad DNA was found in one out of 10 livers but not in any ceca. Also, histomonad DNA could not be detected in examined cecal and lung samples from the noninfected control group.

Animals↗
PubMed2005

Metacognitive deficits in frontotemporal dementia.

OBJECTIVES: To investigate whether metacognitive impairments in self-awareness and self-monitoring occur in patients with frontotemporal dementia (FTD), particularly among those with prominent social and dysexecutive impairments. METHODS: Patients diagnosed with FTD were divided by clinical subtype (social-dysexecutive (n = 12) aphasic (n = 15), and constituent subgroups of progressive non-fluent aphasia and semantic dementia) and compared with subjects with probable Alzheimer's disease (AD, n = 11) and age-matched healthy controls (n = 11). All subjects completed comprehensive behavioural ratings scales, which were compared with caregiver ratings. Subjects also rated their test performances in verbal associative fluency, word list learning, and memory task with comparisons made between actual and judged performance levels. RESULTS: The FTD sample as a whole showed significantly less behavioural self-awareness and self-knowledge than the AD and healthy control samples. FTD patients with prominent social and dysexecutive impairments demonstrated the most extensive loss of self-awareness and self-knowledge, significantly overrating themselves in multiple social, emotional, and cognitive domains, and failing to acknowledge that any behavioural change had occurred in most areas. The remaining clinical samples showed select and minimal discrepancies. All clinical groups were significantly unaware of their apathy levels. Most FTD patients judged episodic cognitive test performance adequately, with partial difficulties observed in the socially impaired and progressive non-fluent aphasia subgroups. CONCLUSIONS: FTD patients, particularly those with prominent social and dysexecutive impairments, exhibit profound metacognitive anosognosia that may represent a loss of self-awareness, self-monitoring, and self-knowledge, likely related to significant prefrontal pathophysiology. Other FTD clinical groups and AD patients showed less pervasive and more select metacognitive deficiencies.

Adult↗
PubMed2005

Comparison of the specificity and sensitivity of PCR, nested PCR, and real-time PCR for the diagnosis of histomoniasis.

Blackhead, also known as enterohepatitis, is caused by a protozoan parasite called Histomonas meleagridis. Clinical symptoms are nonspecific. Until now, diagnosis has been mainly based on postmortem lesions and microscopical and histopathological examination. In many cases, especially in layer flocks, these conventional methods are not sufficient, as the lesions are sometimes not clear. The technique for isolation of histomonads in vitro offers many advantages, but the confirmation of histomonads growing in culture may require a time-consuming procedure of rectal inoculation of culture material into chickens or turkeys. The aim of our investigation was to establish a conventional polymerase chain reaction (PCR), a nested PCR, and a real-time PCR, and to examine their specificity as well as sensitivity in the diagnosis of histomoniasis. The obtained results have shown that the conventional PCR is more sensitive than the real-time PCR. Furthermore, the sensitivity of the PCR can be increased by adding the nested PCR. However, the real-time PCR is more specific.

Amino Acid Sequence↗
PubMed2001

Transformation of 2,2'-dichlorodiisopropyl ether in mixed and pure culture.

An aerobic enrichment culture derived from a groundwater contaminated with organic and chloroorganic compounds was adapted to the transformation of 2,2'-dichlorodiisopropyl ether (DDE) in a continuous fixed-bed bioreactor. Continuous DDE removal efficiencies over 90% were achieved with a model water containing 3.3 mM methanol as co-substrate at DDE loading rates of up to 150 micromol l(-1) day(-1) with a hydraulic retention time of 24 h. In batch cultures, a stoichiometric release of 2 micromol chloride per micromol DDE transformed was observed. From the mixed culture, a strain was isolated that is able to grow on DDE as the sole energy and carbon source, tolerating DDE concentrations of up to 1 mM. Based on 16S rRNA sequencing, the strain is affiliated with the genus Rhodococcus.

Aerobiosis↗
PubMed2001

Development of primers for amplifying genes encoding CprA- and PceA-like reductive dehalogenases in anaerobic microbial consortia, dechlorinating trichlorobenzene and 1,2-dichloropropane.

Gene sequence alignments of the reductive dehalogenases PceA (Dehalospirillum multivorans) and CprA (Desulfitobacterium dehalogenans) were used to develop specific PCR primers binding to conserved regions of these sequences. These primers enabled us to amplify and subsequently sequence cprA-like gene fragments from the chlororespiring species Dehalobacter restrictus, Desulfitobacterium sp. strain PCE1, and D. hafniense. No specific amplicons were obtained from the chlororespiring species D. frappieri, D. chlororespirans, and Desulfomonile tiedjei. Furthermore, we were able to amplify and sequence cprA/pceA-like gene fragments from both trichlorobenzene (TCB)- and 1,2-dichloropropane (DCP)-dechlorinating microbial consortia using the novel primers. Subsequent sequence analysis of the fragments obtained from the microbial consortia revealed a group of four clusters (I-IV). Of these, clusters I and II showed the highest similarities to the cprA-like gene of Dehalobacter restrictus (79.0 and 96.2%, respectively). Cluster III comprised cprA-like sequences found in both the TCB- and the DCP-dechlorinating consortia, whereas sequences of cluster IV were most similar to the pceA gene of Dehalospirillum multivorans (97.8%). Our detection of genes encoding reductive dehalogenases, the key enzymes of chlororespiration, supports the hypothesis that reductive dechlorination of TCB and DCP occurs via a respiratory pathway.

Journal Article↗
PubMed2000

Bacteria of an anaerobic 1,2-dichloropropane-dechlorinating mixed culture are phylogenetically related to those of other anaerobic dechlorinating consortia.

A 16S-rDNA-based molecular study was performed to determine the bacterial diversity of an anaerobic, 1,2-dichloropropane-dechlorinating bioreactor consortium derived from sediment of the River Saale, Germany. Total community DNA was extracted and bacterial 16S rRNA genes were subsequently amplified using conserved primers. A clone library was constructed and analysed by sequencing the 16S rDNA inserts of randomly chosen clones followed by dot blot hybridization with labelled polynucleotide probes. The phylogenetic analysis revealed significant sequence similarities of several as yet uncultured bacterial species in the bioreactor to those found in other reductively dechlorinating freshwater consortia. In contrast, no close relationship was obtained with as yet uncultured bacteria found in reductively dechlorinating consortia derived from marine habitats. One rDNA clone showed >97% sequence similarity to Dehalobacter species, known for reductive dechlorination of tri- and tetrachloroethene. These results suggest that reductive dechlorination in microbial freshwater habitats depends upon a specific bacterial community structure.

Anaerobiosis↗
PubMed1999

[Translaryngeal tracheostomy in Bechterew's disease and Guillain-Barre syndrome].

Recently, the Translaryngeal Tracheostomy (TLT) has been developed by Fantoni [1,2]. This new technique has been suggested for long-term ventilated intensive care patients as an alternative to other minimal invasive tracheostomy techniques like the Percutaneous Dilatational Tracheostomy described by Ciaglia [3] or Griggs [4]. In comparison to these techniques, the main advantage of the TLT seems to be the access to the airway from inside the trachea to outside. This procedure minimizes the risk of luxations of parts of the tracheal wall into the tracheal lumen resulting in obstructive ventilatory problems. The often discussed risk of stomal infections associated with this technique due to a possible bacterial contamination of the mouth seems not to be clinically relevant. In the past minimal invasive tracheostomy techniques have only been recommended for patients with normal anatomical conditions and without any special risk factors. The present case report describes the successful performance of a TLT in a patient with a severe M. Bechterew and respiratory failure due to a Guillain-Barré-syndrome. This patient was at high risk for operative complications during a conventional surgical tracheostomy due to his underlying diseases.

Aged↗
PubMed1997

[Occlusion of an esophagobronchial fistula by implantation of a Montgomery esophageal and a dynamic tracheal stent after failure of conventional endoprosthesis].

Esophagorespiratory fistulas were frequently caused by malignant tumors, bougienage, laser therapy or radiochemotherapy. We here report the case of a patient with inoperable bronchial cancer, who developed a symptomatic esophagorespiratory fistula during combined radiochemotherapy with Cisplatin. A sufficient occlusion of the fistula could not be achieved with conventional plastic tubes or novel self-expanding silicone-coated Gianturco Song stents. After extraction of two Gianturco Song stents we inserted a Montgomery Salivary Bypass Stent into the esophagus and Dynamic stent into the trachea. This resulted in a total occlusion of the fistula. This present case suggests that the Montgomery stent may have little tendency to migrate due to its characteristic configuration and fixation and further demonstrates that the novel self-expanding silicone-coated Gianturco Song stents can be removed, if necessary.

Adenocarcinoma↗
PubMed1991

Nocturnal asthma. Beta 2-adrenoceptors on peripheral mononuclear leukocytes, cAMP- and cortisol-plasma concentrations.

To evaluate pathophysiologic mechanisms of the predominantly nocturnal complaints in atopic bronchial asthma, the expression and function of beta 2-adrenoceptors on peripheral mononuclear leukocytes (pMNL), the cAMP--as well as the cortisol--plasma concentrations were studied in eight healthy men and ten so far untreated male asthmatic patients at 4-h intervals for 24 h. No difference was seen in the beta 2-adrenoceptor density (Bmax) on pMNL between healthy and asthmatic men (24-h means +/- SE: 908 +/- 59 sites per cell and 821 +/- 54 sites per cell, respectively). The equilibrium dissociation constant (Kd), however, was significantly higher in the asthmatic patients (24-h mean +/- SE: 8.8 +/- 1.2 pmol/L vs 3.0 +/- 0.2 pmol/L in healthy men, p less than 0.0001), which is equivalent to a lower affinity of the beta 2-adrenoceptors for the radioligand 125iodocyanopindolol. Bmax showed a statistically significant circadian variation, but Kd did not. The circadian variation in Bmax was reflected in the basal intracellular cyclic adenosine-monophosphate (cAMP) content of the cells investigated. High Kd values (equivalent to low receptor affinities) tended to be associated with small increases of the intracellular cAMP content after in vitro stimulation by 10(-7) mol/L isoprenaline (isoproterenol) (24-h mean +/- SE: 1.4 +/- 0.2 pmol/10(6) cells; r = -0.529, p = 0.05 at r = -0.549, n = 10). Plasma cAMP concentrations were found to be significantly lower in the asthmatic patients (24-h means +/- SE: 22.9 +/- 1.3 nmol/L vs 29.1 +/- 1.1 nmol/L, p less than 0.0001). Plasma cortisol concentrations were significantly higher in the asthmatic patients (24-h means +/- SE: 0.500 +/- 0.084 mumol/L vs 0.319 +/- 0.063 mumol/L). The results support the hypothesis that a lesion of the beta-adrenergic system contributes to the pathophysiology of atopic bronchial asthma. In the patients investigated in this study, such a lesion could be demonstrated in the affinity rather than in the number of beta 2-adrenoceptors expressed on peripheral cells of the immune system (pMNL). According to present-day knowledge of adrenergic effects on pMNL, such an affinity decrease of beta 2-adrenoceptors could account for overshooting immune responses. In association with other factors influencing respiratory function, it could be responsible for the predominantly nocturnal complaints in atopic bronchial asthma. Plasma cortisol concentrations did not appear to be related to the principal cause of "nocturnal asthma;" they rather reflected an endogenous defense mechanism to the disease.

Adult↗
PubMed1990

[Various forms of humidifier lung].

Clinical and immunological investigations of 15 workers in a repro-printing house revealed a prevalence of 7% for the occurrence of humidifier-lung. Serological sensitization to humidifier water and fungi respectively was found in 73%, fragmentary symptoms in 53%. In comparison to smokers, elevated antibody levels occurred more frequently in nonsmokers (33% vs. 100%). The results are supposed to reflect subclinical stages of disease, but they are not yet of a definite predictive value. Reduction of microorganisms in humidifiers seems to be essential for the prevention of disease.

Adult↗
PubMed1988

Acute and chronic effects of nitrendipine on hemodynamics and myocardial ischemia in patients with combined angina pectoris and hypertension.

To examine the antianginal and antihypertensive efficacy of nitrendipine, a new calcium channel blocking agent, 25 patients with chronic stable angina pectoris (NYHA I-III) and systemic hypertension underwent cardiac catheterization and treadmill exercise tests. Acute hemodynamic results were obtained before and 2 h after oral administration of 20 mg nitrendipine. They showed a significant decrease in aortic pressure (162.1 +/- 27.4/80.0 +/- 12.1 vs. 134.9 +/- 23.5/74.2 +/- 13.1 mm Hg), pulmonary arterial pressure (25.4 +/- 5.4/11.3 +/- 3.7 vs. 21.9 +/- 5.4/9.9 +/- 3.7 mm Hg), and pulmonary wedge pressure (10.0 +/- 4.4 vs. 6.6 +/- 3.8 mm Hg). Cardiac index (+31%) and stroke volume (+33%) increased markedly, whereas heart rate remained unchanged (66.9 +/- 11.4 vs. 66.8 +/- 10.8 beats/min). Chronic hemodynamic results and exercise tolerance tests were obtained before and 8 weeks after oral nitrendipine therapy. A significant decrease in arterial blood pressure was observed (167 +/- 22/86 +/- 10 vs. 126 +/- 32/76 +/- 19 mm Hg). Exercise tolerance improved concerning test duration (+22%) and total exercise capacity (+37%). Maximal ST-segment depression decreased by 30% (0.2 +/- 0.03 vs. 0.14 +/- 0.02 mV) and subsequently the anginal frequency was reduced from 7.8 +/- 2.1 to 3.8 +/- 1.7 attacks/week (-50%). The maximal rate-pressure product during exercise remained unchanged. Plasma levels of cholesterol, triglycerides, and LDL- and HDL-cholesterol did not show any significant alterations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Physicians and hospital-based health promotion: formalizing the relationship.

Hospitals and health care organizations today are faced with a multitude of new pressures that threaten their very survival. Redirecting a threat into an opportunity requires close cooperation between a health care institution and its medical staff. One opportunity that has emerged is the development of health promotion programs, whose success depends on medical staff support.

Health Maintenance Organizations↗
PubMed1983

[Clostridium difficile and antibiotic-associated colitis in risk patients: 2-month epidemiologic study in an intensive care unit].

A toxin produced by Clostridium difficile has been implicated in the pathogenesis of antibiotic-associated colitis. It is not known how often the microorganism is encountered in Germany particularly in high risk patients. Therefore, following a lethal case of colitis, stool samples of 90 patients and 30 staff members of an intensive care unit were screened routinely for C. difficile over 2 months. The organism was found in 6 of 41 patients treated with antibiotics (14.6%); four of them apparently acquired C. difficile while in hospital whereas in 2 a pre-existing carrier state could not be excluded. Colitis developed in 3 of the 6 patients as judged from endoscopy or a positive cytotoxin assay; in 2 patients (not subjected to endoscopy) colitis was suspected on clinical grounds, and 1 patient became an asymptomatic carrier. C. difficile was not found in 49 patients without antibiotic medication, in the health personal and in 12 patients of a general ward. Patients harbouring C. difficile were clustered in certain bed sites of the unit. Environmental studies recovered the microorganism from bed pan washing machines of bedridden and from toilets of ambulant patients but not from other sites like the hands of the personal. These results suggest that chronic carriers of C. difficile, as far as they are identified by current bacteriological methods, are rare in Germany (not more than 2 out of 132 persons investigated, i.e. 1.5%). The frequent finding of C. difficile in patients treated in certain bed sites supports the view that the infection may be acquired from exogenous sources. Antibiotic-associated colitis should be considered more often when intensive care patients are treated with antibiotics.

Adult↗
PubMed1975

[Lymph flow following ligation of the ductus thoracicus in dogs].

Already few hours after artificial occlusion of the thoracic duct of dogs different communications appear between the lymphatic and the venous system: 1. Lymphovenous communications in the cervical area leading to the right venous angle. 2. Lymphovenous communications at heart level leading to the right venous angle. These lymphovenous communications seem to be preformed anastomoses, which are opened by an increase of the intralymphatic pressure.

Animals↗