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L Köhler

Publications and source records attributed to L Köhler.

At least 37 records · Page 2Linked to original sources
PubMed2001

Experience as a factor influencing the indications for laparoscopic colorectal surgery and the results.

BACKGROUND: The influence of experience on the results of treatment with laparoscopic surgery is indisputable. The establishment of indications and contraindications is relative, and varies depending on the experience of the surgeon. Learning curves have been described for a number of laparoscopic interventions, in particular laparoscopic cholecystectomy. The current prospective multicenter study investigates, among other things, the interrelation between experience and the results of treatment using laparoscopic colorectal surgery. The study makes no pronouncements on the long-term results achieved in patients with colorectal carcinoma who underwent an operation with curative intent, although relevant data were indeed collected. RESULTS: Between August 1, 1995 and February 1, 1999, a total of 1,658 patients were recruited to the prospective multicenter study initiated by the Laparoscopic Colorectal Surgery Study Group. To investigate the influence of surgical experience, two groups were formed. Group A comprised all the institutions and surgeons with experience of more than 100 laparoscopic colorectal operations. Group B contained institutions and surgeons with experience of fewer than 100 such interventions. The results of this study clearly show that in Group A, significantly more procedures involving the rectum were performed (26.7% vs 9.5%), and significantly more carcinomas were surgically managed (37.3% vs 17.3%). Despite this significantly higher level of technically difficult procedures in the patient population of group A, which was comparable in terms of age, gender, height, and weight with the patient in group B, the postoperative mortality and morbidity was, with the exception of urinary tract infections, identical between the two groups. Conversion to open surgery was significantly less frequent in group A (4.3% vs 6.9%), and, finally, the duration of the procedures performed by the more experienced surgeons of group A was appreciably shorter than in institutions with a smaller frequency of such operations. CONCLUSIONS: Laparoscopic colorectal surgery is very demanding, and can be performed with low morbidity and mortality rates only by a surgeon with above-average experience with this type of surgery and a large caseload of laparoscopic colorectal procedures. The learning curve for such procedures is appreciably longer than for other laparoscopic operations. With increasing experience, technically more demanding operations, including radical oncologic rectal laparoscopic procedures, can be performed with appreciably reduced operating times and conversion rates, but with no increase in morbidity or mortality.

Adult↗
PubMed2001

Expression of Chlamydia trachomatis genes encoding products required for DNA synthesis and cell division during active versus persistent infection.

During persistent infection, the intracellular bacterial pathogen Chlamydia trachomatis is viable but severely attenuates the production of new, infectious elementary bodies (EBs). To investigate the reasons for this lack of new EB output, we analysed the expression of chlamydial genes encoding products required for DNA replication and cell division, using in vitro models of active versus persistent infection and synovial tissue samples from patients with chronic Chlamydia-associated arthritis. Hep-2 cells were infected with K serovar C. trachomatis and harvested at t = 0-48 h post-infection (p.i; active). Human monocytes were infected similarly and harvested at t = 1-7 days p.i. (persistent). RNA preparations from infected/uninfected cells and patient samples were subjected to reverse transcription-polymerase chain reaction (RT-PCR) targeting polA, dnaA, mutS and parB mRNA, related to chlamydial DNA replication/segregation; these were expressed in infected Hep-2 cells from 11 to 48 h p.i; ftsK and ftsW, related to cell division, were expressed similarly. Real-time PCR analyses demonstrated that significant accumulation of chlamydial chromosome began at about 12 h p.i. in infected Hep-2 cells. In infected human monocytes, polA, dnaA, mutS and parB mRNA were produced from days 1-7 p.i. and were weakly expressed in patient samples. Real-time PCR indicated the continuing accumulation of chlamydial chromosome during the 7 day monocyte infection, although the rate of such accumulation was lower than that occurring during active growth. However, transcripts from ftsK and ftsW were detected only at 1 day p.i. in infected monocytes but not thereafter, and they were absent in all patient samples. Thus, genes whose products are required for chlamydial DNA replication are expressed during persistence, but transcription of genes whose products are required for cytokinesis is severely downregulated. These data explain, at least in part, the observed attenuation of new EB production during chlamydial persistence.

Bacterial Proteins↗
PubMed2001

Long-term illness and psychosomatic complaints in children aged 2-17 years in the five Nordic countries. Comparison between 1984 and 1996.

BACKGROUND: The aim of the study was to investigate changes in psychosomatic complaints (PSC) and long-term illness (LTI) and the association between parents' socioeconomic conditions and children's complaints in the five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden). METHODS: The cross-sectional study covered a representative sample of children, aged 2-17 years in each country, altogether 10,219 in 1984 and 10,317 in 1996. The data were collected by mailed questionnaires. The relationship between LTI, PSC and parents' education, income, satisfaction with economy and family situation was analysed using descriptive statistics and logistics regression. RESULTS: LTI and PSC in children have increased in all age groups between 1984 and 1996. The prevalence of LTI was higher among boys than girls, whereas the prevalence of PSC was higher among girls. In both years, the prevalence was higher in low-income, low-educated, one-parent families. The general tendency is the same in all countries, although there are some minor differences. The differences in 1984 remained unchanged in 1996 except for LTI that increased in low-educated families for Nordic children as a whole. CONCLUSION: Socially and economically vulnerable families seem to run the greatest risk of having children with LTI and PSC, although the data do not permit a strict causal relationship to be drawn. Also, families with high formal education, solid economy and general satisfaction with their situation seem to be able to offer their children sheltered and stimulating conditions for growth and development, even in times of economic recession.

Adolescent↗
PubMed2001

Quality of life among children aged 2-17 years in the five Nordic countries. Comparison between 1984 and 1996.

BACKGROUND: The aim of the study was to analyse children's quality of life (QoL) in the five Nordic countries from 1984 to 1996, a period in which major economic recessions occurred. METHODS: The study design was cross-sectional based on a random sample of 3000 children in each country, aged 2 to 17 years, totalling 15,000 in 1984 and 15,000 in 1996. The data were collected by mailed questionnaires. QoL was analysed for three spheres of life: external, interpersonal, personal including both factual and perceived variables. The external sphere represented the socio-economic conditions for the child's family, the interpersonal sphere the structure and the function of the child's social networks and the personal sphere the psychological well-being of the child. RESULTS: The total QoL for Nordic children from 1984 to 1996 increased, but there were differences in the development of QoL between the countries. The objective QoL became better, at the same time the subjective QoL worsened, except in Denmark and Iceland. The external QoL became better, whereas the interpersonal QoL was nearly unchanged but there were differences in the development between countries. The personal QoL worsened slightly except for children in Iceland. The ranking between countries changed. Danish children had the highest subjective and Norwegian children the highest objective and external QoL. Swedish children had the highest personal QoL. Children 7-12 years had the highest QoL. Girls had a tendency to higher QoL in all ages. CONCLUSION: Nordic children still enjoy a high standard of living in spite of economic constraints, and the prerequisites for a high QoL are fulfilled. Further research is suggested for clarifying the complex background of these results.

Adolescent↗
PubMed2001

Effects of azithromycin and rifampin on Chlamydia trachomatis infection in vitro.

An in vitro cell culture model was used to investigate the long-term effects of azithromycin, rifampin, and the combination of azithromycin and rifampin on Chlamydia trachomatis infection. Although standard in vitro susceptibility testing indicated efficient inhibition by azithromycin, prolonged treatment did not reveal a clear elimination of chlamydia from host cells. Chlamydia were temporarily arrested in a persistent state, characterized by culture-negative, but viable, metabolically active chlamydia, as demonstrated by the presence of short-lived rRNA transcripts. Additionally, azithromycin induced generation of aberrant inclusions and an altered steady-state level of chlamydial antigens, with the predominance of Hsp60 protein compared to the level of the major outer membrane protein. Treatment with azithromycin finally resulted in suppression of rRNA synthesis. Chlamydial lipopolysaccharide and processed, functional rRNA were detectable throughout the entire incubation period. These in vitro data show a good correlation to those from some recent clinical investigations that have reported on the persistence of chlamydia, despite appropriate antibiotic treatment with azithromycin. Rifampin was highly active by in vitro susceptibility testing, but prolonged exposure to rifampin alone for up to 20 days resulted in the emergence of resistance. No development of resistance to rifampin was observed when chlamydia-infected cells were incubated with a combination of azithromycin and rifampin. This combination was shown to be more efficient than azithromycin alone, in that suppression of rRNA synthesis occurred earlier. Thus, such a combination may prove more useful than azithromycin alone.

Anti-Bacterial Agents↗
PubMed2001

Optimised sample DNA preparation for detection of Chlamydia trachomatis in synovial tissue by polymerase chain reaction and ligase chain reaction.

OBJECTIVE: Molecular biology techniques such as polymerase chain reaction (PCR) and ligase chain reaction (LCR) are routinely used in research for detection of C trachomatis DNA in synovial samples, and these methods are now in use in some clinical laboratories. This study aimed at determining the method best suited to molecular diagnosis of C trachomatis by examining four standard DNA preparation methods using chlamydia spiked synovial tissue and chlamydia infected monocytes. METHODS: Synovial tissue from a chlamydia negative patient with rheumatoid arthritis was spiked with defined numbers of C trachomatis elementary bodies (EB). Purified human peripheral monocytes from normal donors were infected with the organism at a multiplicity of infection 1:1 in vitro and harvested after four days. DNA was prepared from all samples by four methods: (1) QIAmp tissue kit; (2) homogenisation in 65 degrees C phenol; (3) incubation at 97 degrees C; (4) proteinase K digestion at 97 degrees C. DNA from methods 1 and 2 was subjected to PCR using two different primer sets, each targeting the C trachomatis omp1 gene. LCR was done on DNA prepared by each method. RESULTS: In synovial tissue samples spiked with EB, and in monocytes persistently infected with the organism, preparation of template using the QIAmp tissue kit (method 1) and the hot phenol extraction technique (method 2) allowed sensitive detection of C trachomatis DNA. These methods also produced template from both sample types for LCR. DNA prepared by heat denaturation (method 3) allowed only low sensitivity chlamydia detection in LCR and did not work at all for PCR. Proteinase K digestion plus heat denaturation (method 4) gave template that did not allow amplification in either PCR or LCR assays. CONCLUSIONS: The sensitivity of detection for C trachomatis DNA in synovial tissue by PCR and LCR depends strongly on the method used for preparation of the amplification template. LCR targeting the multicopy chlamydial plasmid and two nested PCR assay systems targeting the single copy omp1 gene showed roughly equivalent sensitivity. Importantly, template preparation method and the specific PCR primer system used for screening must be optimised in relation to one another for highest sensitivity.

Chlamydia Infections↗
PubMed2001

Psychosomatic complaints in schoolchildren: a Nordic comparison.

AIMS: This study investigates the association between psychosomatic complaints (PSC) and background factors from children in the five Nordic countries, their families, and their social context in a model using proximal (child), intermediate (family), and distal (society) levels. Similarities and differences between the countries were compared. METHODS: A questionnaire was sent to the parents of a representative sample of 3,760 Nordic children aged seven to 12 years. The relationship between PSC and background factors was analysed using structural equation modelling. RESULTS: Headaches and stomach complaints were most common. The prevalence was higher in girls than in boys. A LISREL analysis showed that determinants of PSC varied little between countries. The most important factors associated with PSC were the mother's health and well-being, the child's mental stability and social competence, and the family's socioeconomic status. Families with low education, blue-collar work, low income, and unemployed fathers were found to be most vulnerable. High risk factors could be influenced by other intervening protective factors. The greatest country differences were found on the distal level, where macroeconomic, legislative, and social factors dominated. CONCLUSIONS: The pattern of PSC was quite similar between the Nordic countries, although there were some small differences. The results also confirm that the determinants of PSC are multidimensional. Longitudinal studies are needed to clarify the complex reality.

Adolescent↗
PubMed2001

Nephrotoxicity of selective COX-2 inhibitors.

We describe 2 male patients, a 49-year-old with psoriatic arthritis and impaired renal function and a 43-year-old renal transplant recipient, who both sustained a marked decline in glomerular filtration rate in conjunction with a selective inhibitor of cyclooxygenase-2 (COX-2), rofecoxib. In the second patient, acute renal failure necessitated hemodialysis. Both patients made an uneventful recovery. Our report lends further support to the assumption that COX-2 inhibitors, as a class, can be as nephrotoxic as their nonselective predecessors. Therefore, COX-2 inhibitors should be used with caution in renal transplant recipients and in patients with salt depletion and renal insufficiency.

Acute Kidney Injury↗
PubMed2000

Laparoscopic abdominoperineal resection: early postoperative results of a prospective study involving 116 patients. The Laparoscopic Colorectal Surgery Study Group.

PURPOSE: Although laparoscopic colorectal surgery is attracting ever more attention, its use for curative treatment of colorectal carcinoma in particular continues to be controversial. The present study was an attempt to analyze the results of the perioperative course, oncologic quality, and preliminary long-term results. METHOD: The data considered here were collected within the framework of a prospective, observational study initiated on August 1, 1995, and involving a total of 18 institutions in Germany and Austria. At the end of three years, the results are now being presented selectively, i.e., focusing only on abdominoperineal resection. RESULTS: A total of 116 patients underwent laparoscopic abdominoperineal resections, 98 (84.5 percent) of which were performed with curative intent. The mean operating time was 226 (confidence interval, 140-365) minutes. Seven patients (6 percent) experienced an intraoperative complication, which in more than one-half of the cases was a vascular injury involving the presacral venous plexus; the conversion rate was 3.4 percent. Postoperatively, 40 patients developed 97 complications--including those of a very minor nature--giving an overall morbidity rate of 34.4 percent. Reoperation in six patients (5.2 percent) had to be performed for an afterbleed in one-half of the cases and ileus in the other one-half. Postoperative mortality was a low 1.7 percent. In most of the curative resections, an oncologically radical operation with high transection of the inferior mesenteric artery and a complete dissection of the pelvis down to the floor was performed. The median number of lymph nodes investigated was 11.5, and there was wide fluctuation in the numbers among the individual institutions. Tumor cell dissemination occurred intraoperatively in five patients. In the meantime, 79 patients (81 percent) underwent at least one follow-up examination, the mean follow-up period being 491 days. Seven patients developed a local recurrence, and a further six patients developed distant metastases. For recurrence-free survival rate, the Kaplan-Meier estimation calculated a probability of 71 percent. CONCLUSION: Not all of the reservations about laparoscopic abdominoperineal resection, in particular with regard to resection with curative intent, have yet been eliminated. The present study does, however, show that a laparoscopic approach can in principle meet oncologic requirements of radicality and, with regard to the postoperative course, is associated with considerable benefits to the patient.

Abdomen↗
PubMed2000

Frequent contamination of Chlamydia trachomatis and Chlamydia pneumoniae strains with mycoplasma. Biological relevance and selective eradication of mycoplasma from chlamydial cultures with mupirocin.

Several strains of Chlamydia trachomatis (CT) and C. pneumoniae (CP) from different sources were screened for mycoplasma contamination using a sensitive nested 16S rDNA polymerase chain reaction-specific for a broad range of mycoplasma species. Five of nine CT and 5/16 CP isolates were contaminated by mycoplasma. Mycoplasma fermentans, M. hyorhinis and M. hominis were found as contaminating agents. To our knowledge no data are available on whether coinfection of chlamydia with mycoplasma alters the biological behavior of chlamydia. Analysis of the biological effect of mycoplasma on chlamydial infection showed a profound mycoplasma-induced reduction of chlamydial growth. Mycoplasma were efficiently eliminated from chlamydial cultures in HEp-2 cells by treatment with mupirocin without affecting chlamydial replication or host cell growth. Two chlamydial strains, C. trachomatis serovar K and one clinical isolate of C. pneumoniae were purged by this method.

Anti-Bacterial Agents↗
PubMed2000

[Transposition of the gracilis muscle - an option in the surgical treatment of rectovaginal fistulae].

Rectovaginal fistulae following low anterior resection are rare, but if present therapy is difficult. We report on a 52-year-old patient who was operated upon several times, including an endorectal advancement flap procedure and transperineal repair with levator interposition. Closure was only successful after transposition of the M. gracilis between the vagina and rectum.

Adenocarcinoma↗
PubMed2000

[How much pain is tolerable? Target expectations of surgical patients for pain therapy].

INTRODUCTION: Sufficient pain treatment is part of surgical therapy. One popular method of pain control is patient-controlled analgesia (PCA), which allows the patients to apply small doses of analgesics intravenously via a pump. Patient involvement in PCA requires an exact assessment of the patient's expectations as to the treatment of pain. METHODS: In a prospective study the patient's expectations of pain therapy were observed with respect to their disease and the actual intensity of pain during activities measured with a visual analogue scale (VAS). Fifty-three patients were involved, using a pain questionnaire. Healthy nursing staff (n = 44) served as a control group. RESULTS: Patients with benign (n = 29) or malignant (n = 24) disease showed no significant difference in the VAS scores accepted from patients as aim of successful pain therapy (25 points in the conservatively treated group and 27 points in the group of the operatively treated patients with malignant disease, 21 points in the operatively treated group with benign disease, and 18 points in the group suffering from chronic pain of benign causes). The aims for pain therapy showed no correlation with the actually felt pain intensity during movement. The control group of healthy nursing staff felt less actual pain during movement, but their expectations for sufficient pain treatment were not significantly different from the study patients (VAS 25.4 points).

Adult↗
PubMed2000

Micromechanics and anatomical changes during early ontogeny of two lianescent Aristolochia species.

The mechanical properties of young stems of Aristolochia macrophylla Lam. and Aristolochia brasiliensis Mart. et Zucc. were studied during elongation growth and primary differentiation. Data for the modulus of elasticity, for the viscoelastic behaviour caused by longitudinal tension and for the shear modulus resulting from torsion around a longitudinal axis were related to the underlying structural changes by quantitative analysis of stem anatomy, tissue distribution, ultrastructure, and cell wall biochemistry. The orientation of cellulose microfibrils was determined by light microscopy and small-angle X-ray diffraction, and the lignin content was determined by thioglycolic acid derivatization and spectroscopic quantification. It was demonstrated that the increase in stability during early development is due to the complementary effects of increase in cell wall material, lignification, and cellulose microfibril alignment. A detailed micromechanical model, considering internal prestresses, is proposed to explain the characteristic biphasic stress-strain behaviour as well as the strain-hardening observed.

Biomechanical Phenomena↗
PubMed2000

Persistence of Chlamydia trachomatis is induced by ciprofloxacin and ofloxacin in vitro.

An in vitro cell culture model was used to investigate the long-term effect of ciprofloxacin and ofloxacin on infection with Chlamydia trachomatis. Standard in vitro susceptibility testing clearly indicated successful suppression of chlamydial growth. To mimic better in vivo infection conditions, extended treatment with the drugs was started after infection in vitro had been well established. Incubation of such established chlamydial cultures with ciprofloxacin and ofloxacin not only failed to eradicate the organism from host cells, but rather induced a state of chlamydial persistence. This state was characterized by the presence of nonculturable, but fully viable, bacteria and the development of aberrant inclusions. In addition chlamydia exhibited altered steady-state levels of key chlamydial antigens, with significantly reduced major outer membrane protein and near constant hsp60 levels. Resumption of overt chlamydial growth occurred after withdrawal of ciprofloxacin, confirming the viability of persisting chlamydia. In vitro ciprofloxacin results are consistent with clinical data, thereby providing an explanation for treatment failures of ciprofloxacin. Parallel in vitro studies with ofloxacin suggest a better correlation between clinical and laboratory-defined efficacy, although the clinical studies on which this assessment is based did not include monitoring of chlamydial persistence. The data presented here clearly demonstrate that under at least some circumstances, standard determination of MICs and minimal bactericidal concentrations for C. trachomatis allows no more than a simple definition of whether an antibiotic has some anti chlamydial activity; however, such testing is not always sufficient to verify that the antibiotic will eliminate the organism in vivo.

Anti-Infective Agents↗
PubMed2000

Infection of human monocyte-derived macrophages with Chlamydia trachomatis induces apoptosis of T cells: a potential mechanism for persistent infection.

Viruses can escape T-cell surveillance by infecting macrophages and thereby induce apoptosis of noninfected T cells. This ability had not been demonstrated for bacteria. We investigated whether infection of macrophages with the important human pathogen Chlamydia trachomatis can induce T-cell apoptosis. Because Chlamydia-Mycoplasma coinfection is a frequent event, the ability of Mycoplasma fermentans-infected macrophages to induce T-cell apoptosis was also studied. Infected macrophages were cocultivated with autologous T cells in different activation states. Propidium iodide-based fluorescence-activated cell sorter analysis demonstrated that macrophages infected with viable chlamydiae induced T-cell death. Apoptosis was identified as the mode of death induction by using a terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay. Induction of T-cell death was macrophage dependent. Incubation of T cells with infectious chlamydiae in the absence of macrophages did not lead to T-cell apoptosis. UV irradiation of chlamydiae diminished the ability to induce death. T-cell death was induced by a cell-free supernatant of infected macrophages. Not only phytohemagglutinin-preactivated T cells but also non-mitogen-preactivated T cells were susceptible to C. trachomatis-induced apoptosis. In contrast, M. fermentans infection of macrophages did not induce T-cell death. Coinfection had no additional effect. In summary, intracellular chlamydial infection of macrophages can induce T-cell apoptosis. Apoptosis induction by chlamydiae possibly explains how persistently infected macrophages escape T-cell surveillance and why the Chlamydia-specific T-cell response is diminished during persistent chlamydial infection.

Apoptosis↗