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Biomedical subjects

E Ritter

Publications and source records attributed to E Ritter.

At least 37 records · Page 2Linked to original sources
PubMed1998

Acinetobacter baumannii colonization in ventilated preterm infants.

The role of Acinetobacter baumannii in infections in ventilated preterm infants was evaluated in 15 colonized infants (11 male, 4 female) in a pediatric intensive care unit. These cases were randomly matched by birth weight and gestational age with ventilated non-colonized controls (8 male, 7 female). Case records were reviewed for signs and symptoms of infection. Colonized infants were ventilated significantly longer (p < 0.05) than controls, and had body temperatures of > 37 degrees C for a significantly longer period of time (p < 0.05). No other parameter of infection differed significantly between the groups. The duration of intensive care treatment did not differ between cases and controls, nor did the weight gain during intensive care treatment. No fatalities occurred in either group.

Acinetobacter↗
PubMed1998

Management and prevention of cardiovascular hemorrhage associated with mediastinitis.

OBJECTIVE: To elucidate the causes of cardiovascular hemorrhage associated with mediastinitis and to review recommendations for prevention and treatment. SUMMARY BACKGROUND DATA: Mediastinal debridement with immediate or early coverage using healthy, vascularized tissue has lead to greatly reduced morbidity and mortality for patients with mediastinitis. Myocardial hemorrhage has been anecdotally reported. PATIENTS AND METHODS: Over a 36-month period, 7 patients developed massive cardiovascular bleeding after undergoing debridement for poststernotomy mediastinitis. Causes included puncture or erosion by a sternal edge in three and tearing at the myocardial-sternal interface in four. RESULTS: Five patients survived and remain infection-free at an average of 24 months of follow-up. In these patients, ventricular defects were closed with pledgeted sutures and muscle transposition was used concomitantly to reinforce the repair. This involved a slide of the left pectoralis major muscle and turnover of the right pectoralis in three patients, bilateral sliding in one patient, and bilateral pectoralis and an omental flap in one patient who required additional coverage of the lower mediastinum. CONCLUSIONS: When a patient who has undergone mediastinal debridement shows evidence of significant bleeding, we recommend application of pressure for control of hemorrhage, expeditious return to an operating room with available cardiopulmonary bypass, and immediate muscle coverage with healthy, well-vascularized tissue. Finally, early sternectomy might largely prevent this life-threatening complication.

Aged↗
PubMed1998

[Frequency and antibiotic susceptibility of oxacillin resistant Staphylococcus aureus in a teaching hospital].

From October 1993 till October 1994, 115 oxacillin resistant Staphylococus aureus strains were isolated in the laboratory of a teaching hospital. This was 2.4% of all of the Staphylococcus aureus strains. The bacteria were isolated from 30 patients, 7 medical personnel and in the environment of the infected patients. Most of the isolates were cultured from blood cultures, wound swabs and drains. If the referring hospitals has been informed about the MRSA status of the patients, several transmissions could have been prevented. In 10 infected patients, the MRSA strains were isolated from the nose, throat and hands. The isolates were also found on the hands of several personnel and in the patients environment, suggesting that the strains had been widely spread. The MRSA strains predominated in the medical and surgical intensive care units and in 2 general surgical wards. They were only found sporadically in other departments (Ophthalmology, Gynaecology, Paediatrics and Urology). MRSA-strains were more resistant to imipenem, ofloxacin, gentamicin, trimethoprim-sulfamethoxazole, tetracycline, erythromycin and clindamycin as oxacillin-sensitive Straphylococcus aureus strains. Genotyping (Restriction-Fragment-Length-Polymorphism) revealed six different strain patterns. The same RFLP types were mainly found on different wards. We conclude that various clones of MRSA may have emerged independently within one hospital and that their spread between wards was remarkably limited. Subsequent intensive hygiene measures have been successful in reducing the number of new isolates.

Anti-Bacterial Agents↗
PubMed1996

A rapid method for detecting specific amplified PCR fragments in microtiter plates.

A simple method is presented to circumvent laborious and time consuming electrophoretic separations of specific PCR amplification products. Specific target DNA is amplified using nucleotides labelled with DIG-dUTP or biotin-dCTP. The labelled PCR products are separated from unincorporated nucleotides or oligonucleotides by using a positively charged DEAE cellulose matrix. Amplification products are visualized directly in the matrix using immunoenzymatic methods or streptavidin-conjugated enzymes. The detection process can be carried out within 2 h, allows the processing of large sample sizes and can potentially be automated.

DNA↗
PubMed1996

Soft-tissue fungal infections: surgical management of 12 immunocompromised patients.

Isolated fungal soft-tissue infections are uncommon but may cause severe morbidity or mortality among transplant recipients and other immunosuppressed patients. Twelve immunocompromised patients illustrating three patterns of infection were treated recently at the Duke University Medical Center. These groups comprised (I) locally aggressive infections, (II) indolent infections, and (III) cutaneous manifestations of systemic infection. Patient diagnoses included organ transplant, leukemia, prematurity, chronic obstructive pulmonary disease, and rheumatoid arthritis. Time from immunosuppression to biopsy ranged from 5.5 to 31 weeks. Organisms included Aspergillus, Rhizopus, Fusarium, Paecilomyces, Exophiala, and Curvularia. Patients presented with necrotic ulcerations or nodules. Surgical treatment ranged from radical debridement to excisional biopsy to none. Antifungal chemotherapy also was employed in some cases. The mortality rate was 33 percent, two patients dying without evidence of fungal infection. Six of the eight survivors cleared their infections. Necrotic skin lesions with surrounding erythema in this population call for prompt examination, biopsy, and culture. Group I lesions mandate radical excision with rapid intraoperative microscopic control and systemic antifungal medication. Group II requires surgical control with or without antifungal therapy. Group III requires systemic antifungal therapy for metastatic infection. In our opinion, treatment of fungal soft-tissue infection should be tailored to infection type and requires a team approach of surgeon and expert infectious disease consultation.

Adult↗
PubMed1994

Cerebrovascular and neurological disorders associated with antiphospholipid antibodies in CSF and serum.

Paired serum and cerebrospinal fluid (CSF) samples from 70 patients with inflammatory and non-inflammatory neurological diseases, as well as 10 sera from patients with primary antiphospholipid syndrome (PAS), six of which presented with cerebrovascular ischemic syndromes, were studied for the presence of anticardiolipin antibodies (ACA) of the G and M classes. PAS sera and some selected paired CSF and serum specimens, were also analyzed for the presence of anti-phosphatidylserine (PS) and anti-phosphatidylethanolamine (PE) antibodies. High levels of IgG and IgM ACA were synthesized intrathecally only in patients with neurosyphilis. Patients with other infectious or inflammatory neurological diseases very rarely showed detectable levels of ACA in serum and/or CSF. ACA were found not only in patients with untreated PAS but also in the serum of 3/7 patients with migraine, thus confirming a relationship between ACA and vascular disorders. The search for PS and PE antibodies disclosed that in PAS patients the serum titers of these antibodies mirrored ACA IgG and IgM titers, while they were never found in the CSF.

Adolescent↗
PubMed1994

Specificity and structure of murine monoclonal antibodies against GM1 ganglioside.

Anti-GM1 antibodies have been implicated in the pathogenesis of several neurological diseases, but the role of these antibodies is still controversial. An animal model could provide insight into the mechanisms of these human disorders, but obtaining specific anti-GM1 monoclonal antibodies (mAbs) has been extremely difficult because of the weak immunogenicity of GM1 ganglioside. Four murine mAbs against GM1 were elicited by immunization of mice with lyso GM1 coupled to BSA and GM1 glycolipid. All four IgM,k mAbs bound strongly to GM1, three antibodies (125, 360 and 494) also bound very weakly to asialo GM1 (GA1) and one (156) bound weakly to GD1b. Three antibodies (125, 360 and 494) were encoded by the same VH and V kappa genes. The VH gene exhibited 97% homology to VHOX1, a member of the VHQ52N gene family, the D segment was probably derived from DQ52 and JH was identical to JH2. The V kappa gene was approximately 99% homologous to V kappa RF and J kappa was germline J kappa 2. The VH gene of mAb 156 exhibited 98% homology to VH205.12, of the VHJ558 gene family, the D segment was derived from DFL16.1, and JH was germline JH2. The V kappa and J kappa genes of mAb were identical to V kappa 8 and J kappa 1, respectively. The genes encoding these anti-GM1 antibodies were close to germline sequences and have been used to encode other antibodies. This suggests that the unresponsiveness of mice to immunization is probably due to inactivation of self-reactive B cells. These rare anti-GM1 mAbs will be valuable reagents for studies of the pathogenesis of autoimmune neuropathy in animals, and also for analyzing the tissue distribution and functions of GM1.

Amino Acid Sequence↗
PubMed1994

Quantitative resistance to Phytophthora infestans in potato: a case study for QTL mapping in an allogamous plant species.

Phytophthora infestans is the most important fungal pathogen in the cultivated potato (Solanum tuberosum). Dominant, race-specific resistance alleles and quantitative resistance--the latter being more important for potato breeding--are found in the germplasm of cultivated and wild potato species. Quantitative trait loci (QTLs) for resistance to two races of P. infestans have been mapped in an F1 progeny of a cross between non-inbred diploid potato parents with multiple alleles. Interval mapping methods based on highly informative restriction fragment length polymorphism markers revealed 11 chromosome segments on 9 potato chromosomes showing significant contrasts between marker genotypic classes. Whereas phenotypically no difference in quantitative resistance response was observed between the two fungal races, QTL mapping identified at least one race specific QT locus. Two QT regions coincided with two small segments on chromosomes V and XII to which the dominant alleles R1, conferring race specific resistance to P. infestans, Rx1 and Rx2, both inducing extreme resistance to potato virus X, have been allocated in independent mapping experiments. Some minor QTLs were correlated with genetic loci for specific proteins related to pathogenesis, the expression of which is induced after infection with P. infestans.

Alleles↗
PubMed1994

[Nosocomial colonization and infection by multiresistant Enterobacter cloacae strains on a pediatric oncological unit].

A multiresistant E. cloacae strain spread during a six month period in a paediatric oncology ward amongst nine children, who had different tumors and malformations. Three children who had shared a room were especially affected. E. cloacae was isolated 122 times from the children with tumors and five times from their environment. Specimens from which the bacteria were isolated, included blood cultures, catheter tips, wound swabs, drains, skin and mucous membranes from most parts of the body. The majority of the E. cloacae strains were resistant to ampicillin, mezlocillin, piperacillin, azlocillin, doxycycline and cephalosporins of the second and third generation and sensitive to imipenem, aminoglycosides and quinolones. The antimicrobial resistance patterns of the E. cloacae strains from the paediatric oncology ward were compared to those isolated from other wards in the hospital. E. cloacae isolates from the intensive care unit had a reduced sensitivity to beta-lactam antibiotics, whereas the isolates from the other wards were, with the exception of ampicillin, sensitive to beta-lactam antibiotics. The analysis of the E. cloacae strains from the paediatric oncology ward revealed the same antimicrobial resistance pattern, bacteriocin type, RFLP-type and an identical enzyme and whole cell profile. Isolates from other wards showed considerably deviating patterns. The systematic registration and isolation of patients, colonized or infected with multiresistant E. cloacae strains, together with infection control methods, lead to a significant reduction in infections.

Child↗
PubMed1993

Genetic diversity and clonal relationships of Acinetobacter baumannii strains isolated in a neonatal ward: epidemiological investigations by allozyme, whole-cell protein and antibiotic resistance analysis.

Sixty-five strains of Acinetobacter baumannii which had been isolated from patients and the indoor environment of a neonatal intensive care unit and, for comparative purposes, isolates from three other wards, were examined by means of electrotyping and analysis of whole-cell protein and antibiotic resistance patterns. Fourteen different electrotypes were determined. The predominant type, a multiply resistant acinetobacter clone, persisted in the neonatal ward over several months. The results underline the usefulness of electrophoretic subtyping, in particular by means of allozyme pattern and as a supplement to whole-cell protein pattern analysis, in epidemiological investigations into the routes of transmission of nosocomial A. baumannii infections.

Acinetobacter↗
PubMed1993

[Epidemic occurrences of multiresistant Acinetobacter baumannii strains in a neonatal intensive care unit].

In a period of nine months (May 1991 to January 1992), 39 infants were colonized with Acinetobacter baumannii in a paediatric intensive care unit. Colonization was observed mainly in premature infants, weighing between 680 g and 2,000 g, who were artificially ventilated. Shortly after birth, A. baumannii was isolated regularly from tracheal washings, and less frequently from other material, such as gastric juice, catheter tips, and umbilical swabs. In older children or adults, the bacteria were found only in very low frequency. In the intensive care unit, A. baumannii could be isolated from tap water, sinks, water traps of the ventilation devices, the inner wall of incubators, and from the hands of medical personnel. Patients strains of A. baumannii, and those isolated monitoring the intensive care unit had an identical biochemical profile and a similar pattern of antimicrobial resistance, as well as a similar reaction in other typing methods. Anti-infective measures are discussed.

Acinetobacter↗
PubMed1992

Utility of the inferior gluteal vessels in free flap coverage of sacral wounds.

An improved technique for gaining access to the inferior gluteal vessels is presented. This method allows rapid isolation of these vessels, preservation of greater pedicle length, and improved access for the performance of microsurgery. The innervation and function of the gluteus maximus is also preserved. We believe the use of this technique makes the inferior gluteal vessels the receptor vessels of choice for microsurgical procedures in the sacral area. An illustrative patient is presented in whom these vessels were used for a combined serratus anterior-latissimus dorsi free muscle flap for sacral wound coverage.

Aged↗
PubMed1992

[Outbreak of a nosocomial infection of SHV2-beta-lactamase-containing Klebsiella pneumonia strains in an operative intensive care unit].

Resistant strains of Klebsiella pneumoniae were found in increasing frequency as a cause of nosocomial infection in an intensive care unit between July and October 1990. The isolated strains had an almost identical biochemical profile, showed a similar pattern of antibiotic resistance, and produced type SHV2-broad-spectrum betalactamase. Thus, it was assumed that the isolates were copies of identical strains, causing an outbreak of nosocomial infections. The bacteria were resistant to third-generation cephalosporins, such as cefotiam, cefotaxime and ceftriaxone, and also to aminoglycosides and acylaminopenicillins. Approximately half of the strains were resistant to ceftazidim and aztreonam. The bacteria were sensitive in vitro to ciprofloxacin, imipenem, latamoxef and cefotetan. During three months, 10% (11) of all patients became infected; four of these patients (36%) died from septicemia. After conventional hygiene programs had failed to stop the outbreak, the intensive care unit was closed and disinfected, a measure, which effectively interrupted the infection.

Cephalosporins↗
PubMed1991

Restriction fragment length polymorphism-mediated targeting of the ml-o resistance locus in barley (Hordeum vulgare).

The ml-o locus in barley confers resistance to all known races of the fungus Erysiphe graminis f.sp. hordei. Since the molecular mechanisms underlying ml-o-mediated resistance are currently undefined, experiments have been initiated to isolate the gene by means of its map position. A collection of backcross lines containing ml-o alleles derived from six barley genotypes allowed us to identify a set of DNA markers very tightly linked to the resistance locus. These markers span an unexpectedly small segment of 8.6 centimorgans on chromosome 4 that includes the Ml-o locus. Two of the markers cosegregate with the resistance locus on the basis of 44 homozygous resistant plants identified within a segregating F2 population derived from an intravarietal cross. Colinearity of the resistance-linked markers was confirmed in an F2 mapping population derived from a wide cross between Hordeum vulgare subsp. vulgare and Hordeum vulgare subsp. spontaneum. The two markers cosegregating with the resistance locus in the former cross define in the latter cross an interval of 2.4 centimorgans within which Ml-o is most probably situated. The set of linked markers opens up the possibility of carrying out a bidirectional chromosomal walk or jump to the gene.

Journal Article↗
PubMed1991

RFLP mapping on potato chromosomes of two genes controlling extreme resistance to potato virus X (PVX).

Two different chromosomal locations of major genes controlling extreme resistance to potato virus X (PVX) were found by restriction fragment length polymorphism (RFLP) analysis of two populations segregating for the resistance. The resistance gene Rx1 mapped to the distal end of chromosome XII, whereas Rx2 was located at an intermediate position on linkage group V in a region where reduced recombination and segregation distortion have also been observed. These linkage anomalies were due to abnormal behaviour of the chromosome contributed by the resistant parent P34. The results presented were obtained using two different strategies for mapping genes of unknown location. One approach was the use of probes revealing polymorphic loci spread throughout the genome and resulted in the mapping of Rx1. The second approach was based on the assumption of possible linkage between the resistance gene and clone-specific DNA fragments introduced from a wild potato species. Rx2 was mapped by adopting this strategy.

Blotting, Southern↗