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Biomedical subjects

D Adam

Publications and source records attributed to D Adam.

At least 37 records · Page 2Linked to original sources
PubMed1992

[A career in nursing sciences?].

A research study was conducted in a francophone high school in Northern Ontario to examine students' perceptions of nursing and the influence of these perceptions on nursing as a career choice. All students in grades 11, 12 and 13 were invited to participate. Fifty-eight percent (n = 268) completed the questionnaire. Results showed that 37 percent of the respondents considered pursuing a career in the health sciences. Only 14% percent were interested in nursing. Respondents' comments suggest that the nurse is viewed favorably but the profession is perceived as a career that does not involve pleasant tasks, good working conditions or opportunities for professional advancement. Reasons advocated for choosing nursing were altruistic rather than career-oriented. Students saw nursing practice as occurring mainly in a hospital setting. Half of the respondents who had chosen nursing as a career opted to enroll in a university program and the other half chose a college program. Results suggest that nursing continues to face an image problem regarding its role in the health care system. In these times of job losses and budget cuts, the profession still needs to attract young recruits. This is the challenge we have to face.

Adolescent↗
PubMed1991

Comparison between single signed integral pulse frequency and sine wave crossing modulation techniques.

The single signed integral pulse frequency modulation (SS-IPFM) is used in modeling neural communication processes. The reference signal crossing and in particular sine wave crossings (SWC) are used to describe physiological processes like vision. Under some restrictions upon the input signal it is possible to define SS-IPFM and SWC systems with identical output for the same modulation input. These restrictions and the exact compositions of the encoders are examined by comparison of both SS-IPFM and SWC to general form of Pulse Position Modulation (PPM) technique.

Cybernetics↗
PubMed1991

Penicillin concentration in the compact bone of the mandible.

During surgical removal of impacted third molars, the concentration of Penicillin G was determined in the compact bone of the mandible. Fifteen patients received 5 million IU and 15 received 10 million IU of Penicillin G intravenously as a single dose before surgery began. In both groups concentrations of penicillin with a bactericidal effect on most pathogenically relevant oral bacteria were detected during osteotomy. Taking into account the considerable interindividual variation, the one-shot application of 10 million IU of Penicillin G was more effective in certain cases than the 5 million IU dose. The factors influencing the decision on the high single-dose application include expected length of operation, body weight, kidney function, and infusion period. Assuming that in intraoral osteotomies the bone becomes contaminated with bacteria that are highly sensitive to penicillins, the results indicate that preoperative infusion of Penicillin G could be an effective method of preventing wound infection.

Adolescent↗
PubMed1991

Transcriptional activation of the melanoma inducing Xmrk oncogene in Xiphophorus.

The melanoma inducing locus of Xiphophorus encodes a tumorigenic version of a novel putative receptor tyrosine kinase (Xmrk). To elucidate the mechanism of oncogenic activation of Xmrk, we compared the structure and expression of two oncogenic loci with the corresponding proto-oncogene. Only minor structural alterations were found to be specific for the oncogenic Xmrk genes. Marked overexpression of the oncogene transcripts in melanoma, which are approximately 1 kb shorter than the proto-oncogene transcript, correlates with the malignancy of the tumors. The tumor transcripts are derived from an alternative transcription start site that is used only in the oncogenic loci. Thus, oncogenic activation of the melanoma inducing Xmrk gene appears primarily to be due to novel transcriptional control and overexpression.

Animals↗
PubMed1991

Tissue concentrations of ofloxacin in necrotic foot lesions of diabetic and non-diabetic patients with peripheral arterial occlusive disease.

Six diabetic patients with infected foot lesions (mean age 64 years) and six male patients (mean age 71 years) with ischemic acral ulceration due to advanced peripheral arterial occlusive disease were treated with 200 mg ofloxacin b.i.d. The necrotic margin tissue concentrations of ofloxacin determined by HPLC and confirmed by microbiological assay were in the same range (1.6 to 6.4 mg/kg) as plasma levels (1.6 to 5.9 mg/l). No difference of plasma and tissue concentrations was found between patients with peripheral vascular disease and diabetics, respectively. After three weeks treatment bacterial wound pathogens disappeared in 7 subjects, changed in 4 patients and were resistant in one patient. Clinical improvement appeared in 9 of 12 patients after three weeks of therapy. Satisfactory tissue levels of orally administered ofloxacin were achieved in the infected necrotic tissue area of diabetic and non-diabetic patients with impaired peripheral arterial circulation.

Aged↗
PubMed1990

Complete foetal ECG morphology recording by synchronised adaptive filtration.

Present noninvasively measured indices of foetal stress are indirect and not sufficient. Foetal electrocardiography (FECG) is a potential noninvasive measurement of the foetus wellbeing which has been little utilised because of the difficulties of measuring it. The development of time-sequenced adaptive filters which are synchronised to the QRS complex by the use of Doppler echocardiography allowed the recording of relatively noise-free FECG. The paper describes the use of this technique for obtaining the complete complex of the FECG. Several sets of time-sequenced adaptive filters are combined to allow a multilead abdominal recording to produce a measurement system which rejects maternal ECG and enhances the FECG. Five subjects have been analysed, and their FECGs have been accurately reproduced with minimal changes of the filters' parameters.

Electrocardiography↗
PubMed1990

Ceftazidime concentrations in renal cysts.

Levels of ceftazidime (CAZ) in uninfected renal cysts of 25 patients were investigated. Seventeen patients received 2 g CAZ about 140 min prior to puncture of the cysts (group I), and eight patients were treated with 2 x 2 g CAZ one day before, and with a further dose of 2 g 2 h prior to puncture (group II). In eight cases (two of group I and six of group II) the concentration of the cyst fluid was also assessed at 4 h and 6 h after completion of the CAZ infusion. In group I, CAZ concentrations were 0.5 to 1.13, micrograms ml-1, mean 0.71; in group II CAZ concentrations were 3.6 to 6.7 micrograms ml-1, mean 5.55. At 4 h and 6 h after infusion the mean cyst concentrations were 4.4 and 2.9 micrograms ml-1, respectively.

Adult↗
PubMed1990

Interventional antimicrobial strategy in febrile neutropenic patients. Results of a multicenter study in 1,260 patients with hematological malignancies. The Interventional Antimicrobial Strategy Study Group, Paul Ehrlich Society for Chemotherapy.

In a prospective, randomized multicenter trial of the Paul Ehrlich society different concepts for sequential empirical antimicrobial strategy for the treatment of patients with neutropenia less than 1.0/nl and fever greater than 38.5 degrees C and/or documented infection were studied. In phase I, patients with unexplained fever (FUO) were randomized for the combination of acylaminopenicillin plus aminoglycoside or third-generation cephalosporin plus aminoglycoside or double beta lactam therapy. Non-responders received additional vancomycin or all three substances of phase I in phase II. In phase III, all patients with persistent fever were then treated with amphotericin B plus 5-flucytosine and rifampin and randomized for the continuation of the double beta lactam regimen or additional imipenem/cilastatin. 667 (52.9%) of 1260 evaluable patients had FUO during the whole study period, of which 62.5% could be cured in phase I, 43.2% of non-responders in phase II and 55% of persistently febrile patients in phase III. The overall rate of complete response was 79.5%. 2.8% were non-responders, 11.7% were not evaluable for response and 40 patients (6%) died during the study, 24 (60%) of whom due to the underlying disease or the toxicity of antileukemic therapy. A significant difference between the treatment groups could not be detected in either of the three study phases.

Agranulocytosis↗
PubMed1990

Interstitial fluid concentrations of ceftriaxone (1 g.i.v.) in the subperitoneal space after hysterectomy.

The ability of an antibiotic to penetrate into the extravascular site of infection is particularly important for a successful perioperative antibiotic prophylaxis and postoperative therapy of bacterial infection. We, therefore, measured interstitial fluid concentrations of ceftriaxone in the subperitoneal space following hysterectomy using Rubinstein's disc method after intravenous administration of 1 g of ceftriaxone preoperatively. After removal of the uterus, two disc units were implanted intraoperatively in the right and left subperitoneal space of 16 patients and were drawn out through the open vaginal cuff after given periods of time. Five disc and blood specimens were obtained after 90 min and 2, 6, 12, 24, and 48 h, respectively. Ceftriaxone concentrations were determined by bioassay. After administration of 1 g of ceftriaxone, interstitial fluid concentrations following hysterectomy were above the MIC90 of most pathogens encountered in gynecologic infections over a period of 24 h.

Bacteriological Techniques↗
PubMed1989

Novel putative receptor tyrosine kinase encoded by the melanoma-inducing Tu locus in Xiphophorus.

Malignant melanoma in Xiphophorus fish hybrids is caused by the activity of a dominant oncogene Tu. By combining genetic and molecular approaches, we have isolated the melanoma oncogene. We show that its level of expression correlates with the degree of malignancy of the tumour. The corresponding proto-oncogene is developmentally regulated. The Tu gene codes for a novel receptor tyrosine kinase which is closely related to the receptor for epidermal growth factor.

Amino Acid Sequence↗
PubMed1989

[In-vitro activity of enoxacin: a multicenter study].

The in vitro activity of enoxacin was tested in 14 German microbiological centers shortly after the introduction of the drug in Germany. 2748 unselected clinical isolates including 15 bacterial species were analysed using microtiter plates. The MIC90-values were as follows: Staphylococcus aureus 4 mg/l, Enterococcus faecalis 16 mg/l, Enterobacteriaceae 0.5 mg/l, Pseudomonas aeruginosa 8 mg/l. There is good correlation between these results and those of former investigations. It is known that quinolones are only moderately active against enterococci. 8.5% of S. aureus, and 1.4% of Enterobacteriaceae were found to be resistant (MIC greater than 4 mg/l). As to P. aeruginosa, the study revealed that despite a generally low rate of resistance in specific clinical settings, specific problems can arise: in one institution, the MIC90 of P. aeruginosa was 32 mg/l, with a resistance rate of 56.1% (n = 57). In the other centers the MIC90 was 2 mg/l and the resistance rate 5.0% (n = 302). In the first center, many of the isolates were from paraplegic patients or patients with cystic fibrosis pretreated with quinolones. This study will be repeated in two years' time in order to determine an eventual change in resistance.

Bacteria↗
PubMed1989

[Bactericidal activity of enoxacin and ciprofloxacin in body fluids].

Until present studies are lacking which investigate the bactericidal activity of new quinolones in body fluids. Therefore, we determined bactericidal titers of enoxacin (en) and ciprofloxacin (cip) against a typical pathogen in urinary tract infections (Escherichia coli) in urine and against a typical pathogen in respiratory tract infections (Streptococcus pyogenes) in sputum, in each case at the time of peak and trough levels (In vitro data of the test strains: E. coli - MICen = 0.06 mg/l, MICcip = 0.06 mg/l, MBCen = 0.5 mg/l, MBCcip = 0.25 mg/l; Streptococcus pyogenes - MICen = 32 mg/l, MICcip = 1 mg/l, MBCen greater than 64 mg/l, MBCcip greater than 64 mg/l). Following a randomization list, ten healthy volunteers took either 400 mg enoxacin b.i.d. for three days, then (after a break of at least three days) 500 mg ciprofloxacin b.i.d. for three days, or vice versa. Two and 12 hours after the final dose, samples of sputum were taken, urine was collected 2-4 h and 10-12 h after the final dose. The bactericidal titers against E. coli in urine were greater than 1:512 (2-4 h after the final dose) and greater than 1:64 (10-12 h after the final dose) for both quinolones in all cases. On the other hand, as to S. pyogenes were found growth in every dilution of sputum. These results confirm the scepticism against quinolone therapy of respiratory tract infections caused by streptococci.

Ciprofloxacin↗
PubMed1989

[Enoxacin concentrations in lung tissue].

For successful treatment of bacterial lung infections the administered antibiotic must reach sufficiently high concentrations in lung tissue. Therefore, the concentrations of enoxacin in this tissue were measured in ten patients requiring pulmonary surgery. In order to prevent postoperative infection, the patients received 400 mg enoxacin b.i.d. for three days. Eight h after the final dose samples of venous blood were drawn and a sample of lung tissue was removed. Using a microbiological assay, we found the following concentrations (mean +/- S.D.):serum 2.36 (+/- 0.65) mg/l, lung 6.48 (+/- 1.54) mg/kg. With the HPLC-technique the corresponding values method were 2.37 (+/- 0.80) mg/l and 7.41 (+/- 3.01) mg/kg. Thus concentrations of enoxacin in lung tissue are about three times higher than the corresponding serum concentrations.

Aged↗
PubMed1989

[Enoxacin concentration in bone tissue].

For successful treatment of bacterial osteomyelitis the administered antibiotic must reach sufficiently high concentrations in bone tissues. Therefore concentrations of enoxacin in bone in ten patients requiring hip surgery were measured. To prevent a postoperative infection, 400 mg enoxacin b.i.d. for two days were administered. On an average 120 (90-210) min after the final dose samples of venous blood and bone tissue were taken. The bone pieces were divided into corticalis and spongiosa. Using a bio-assay-method the following concentrations were found: (mean +/- S.D.): serum 2.88 ( +/- 0.90) mg/l, corticalis 5.90 ( +/- 0.79) mg/kg, spongiosa 3.95 ( +/- 1.01) mg/kg. Thus enoxacin reaches higher levels in bone tissue than in serum.

Aged↗
PubMed1989

Penetration of ticarcillin/clavulanate into cartilage.

The penetration of ticarcillin and clavulanate into cartilage was investigated in 20 subjects undergoing funnel chest correction. Cartilage samples, obtained 120 or 180 min after administration of ticarcillin/clavulanate (mean dose: ticarcillin 70.0 mg/kg, clavulanate 4.7 mg/kg), were divided into core samples and outer covering portions. After 120 min, the mean ticarcillin in the outer portion was 11.0 mg/kg and that in the core sample was 0.81 mg/kg; at 180 min the mean concentration in the outer portion was 6.47 mg/kg and ticarcillin was undetectable in all but two core samples. Clavulanate was shown to decline with time in spiked cartilage preparations and the results in this investigation may underestimate penetration. Clavulanate was undetectable in most core samples. In the outer portion the mean concentration was 1.30 mg/kg at 120 min and 0.62 mg/kg at 180 min. The penetration gradient requires further elucidation and should be considered when chemotherapy for infection in cartilage is discussed.

Adolescent↗
PubMed1989

Cerebrospinal fluid penetration after single or multiple dosage with ticarcillin/clavulanate.

Penetration of ticarcillin and clavulanate into the cerebrospinal fluid was studied in ten patients with varying degrees of impairment of the blood-brain barrier. In general, penetration of both drugs was relatively low and variable (5.4 +/- 5.8% for clavulanate and 2.0 +/- 4.0% for ticarcillin) but markedly better in those patients with impaired blood/brain barrier.

Adolescent↗