PubMed Health⌕ Search

Biomedical subjects

M Frei

Publications and source records attributed to M Frei.

11 recordsLinked to original sources
PubMed2004

Air leakage around endotracheal tube cuffs.

BACKGROUND AND OBJECTIVE: To compare the recently introduced Microcuff endotracheal tube with conventional tubes in respect of the cuff pressures required to prevent air leakage. METHODS: The following tubes (ID 7.0mm) were compared: Microcuff HVLP ICU, Mallinckrodt HiLo, Portex Profile Soft Seal, Rüsch Super Safety Clear and Sheridan CF. Fifty patients undergoing endotracheal intubation with a cuffed tube of internal diameter 7.0 mm were studied. Tracheas were intubated using one of the endotracheal tubes in random order. Cuff pressure to prevent air leakage at standardized ventilator setting (peak inspiratory pressure 20 cmH2O/PEEP 5 cmH2O/respiratory rate 15 breaths min(-1)) was assessed by auscultation of audible sounds at the mouth. Patients characteristics and cuff pressures from each brand were compared to the Microcuff group using the Mann-Whitney U-test (P < 0.05 was chosen as the level of statistical significance). RESULTS: Patients' median age (range) was 14.2 (12.0-17.1) yr, body weight 57.5 (40.0-81.9) kg and length 164.9 (146.5-190.0) cm. No significant differences in patients' characteristics were found between groups. Mean cuff pressure (all tubes) required for air sealing was 19.1 (8-42) cmH2O. The Microcuff tube required significantly lower sealing pressures (9.5 (8-12) cmH2O) compared to the other brands of endotracheal tube (P < 0.05, Mann-Whitney U-test). CONCLUSION: The Microcuff endotracheal tube with its ultra-thin polyurethane cuff membrane required the lowest sealing pressure to prevent air leakage. These features are potentially of interest for long-term intubated patients and for cuffed endotracheal tubes in children, allowing tracheal sealing at lower cuff pressures implying less damage to the trachea.

Adolescent↗
PubMed1996

Uric acid lowering effect of oxipurinol sodium in hyperuricemic patients - therapeutic equivalence to allopurinol.

OBJECTIVE: Oxipurinol has been shown to be sufficiently absorbed after oral administration as a rapid release preparation of oxipurinol sodium. We compared the uric acid lowering affect of allopurinol and oxipurinol. METHODS: In a multicenter, randomized, double blind crossover trial in 99 hyperuricemic patients with normal renal function we investigated the uric acid lowering effect of oxipurinol sodium (O) in daily amounts equimolar to 300 mg allopurinol (A). Mean pretreatment plasma uric acid concentrations in groups A/O and O/A were 8.3 +/- 1.4 and 8.7 + /- 1.4 mg/dl, respectively. RESULTS: In group A/O the mean plasma uric acid decreased to 5.4 +/- 1.2 mg/dl with allopurinol treatment, and increased slightly to 5.7 + /- 1.3 mg/dl during the consecutive oxipurinol period. In group O/A plasma uric acid declined to 6.0 +/- 1.4 mg/dl with oxipurinol and was 5.6 + /- 1.3 mg/dl at the end of the allopurinol period. The overall average reduction compared to baseline was 3.0 mg/dl with allopurinol and 2.6 mg/dl with oxipurinol. The difference between the 2 treatments was small but significant (multiple p=0.027,2 tailed). The corresponding mean plasma oxipurinol concentrations were 9.24 mu g/dl at the end of the allopurinol period and 9.9 mu g/dl after treatment with oxipurinol (NS). CONCLUSION: Oxipurinol is well absorbed and sufficiently effective in hyperuricemic patients when administered as a rapid release preparation of oxipurinol sodium. Oxipurinol sodium could be a substitute for allopurinol in hyperuricemic patients and possibly also with new uses for allopurinol.

Adult↗
PubMed1994

Moxonidine and hydrochlorothiazide in combination: a synergistic antihypertensive effect.

This study was designed as a multicenter, double-blind, placebo-controlled, parallel-group, prospectively randomized study comparing, after a 4-week placebo run-in phase, moxonidine 0.4 mg once daily (o.d.), hydrochlorothiazide 25 mg o.d., and the combination of the two with placebo. A total of 160 patients were analyzed in an intent-to-treat analysis. Moxonidine 0.4 mg o.d. was effective in significantly lowering blood pressure in this group of mild-to-moderate hypertensive patients in comparison with placebo. The efficacy and the side-effect profile of moxonidine were comparable to those of the first-line antihypertensive agent hydrochlorothiazide. The combination of moxonidine and hydrochlorothiazide in the same dosage as a monotherapy improves efficacy significantly without additive effects on the safety profile. Response rate after monotherapies was calculated with 70.3 and 70.0%, respectively, after combination treatment in 87.8% of all patients in the treatment group. The trial gives support to a recommended dosage regimen of moxonidine 0.4 mg o.d. This profile of moxonidine is highly comparable to a standard first-line antihypertensive drug such as hydrochlorothiazide, without sacrificing tolerance and safety for increased efficacy, in combination with hydrochlorothiazide.

Adult↗
PubMed1990

Protein synthesis in embryonic tissues during mouse postimplantation development.

Mouse embryos of the NMRI strain between the 7th and 9th day of gestation were isolated from the uterus and dissected into the various tissue derivatives in order to investigate newly synthesized proteins during morphogenesis. The day 7 embryo was fragmented into trophoblast and ectoplacental cone, distal and proximal endoderm, extraembryonic and embryonic ectoderm. The day 8 and day 9 embryos were divided into trophoblast and placental anlage, yolk sac, amnion, and allantois, as well as cranial, central, and caudal embryonic tissue. The intact embryos were incubated in Dulbecco's minimum essential medium in the presence of 35S-methionine for 4 h, then dissected into the various fragments, and further processed for two-dimensional gel electrophoresis. Protein synthesis of the isolated tissue derivatives was analyzed and compared for the three developmental stages. Concerning the proteins with isoelectric points in the range of 4.5 to 8.0 and molecular weight ratio (M(r)) values between 20,000 and 200,000, we found several significant quantitative and qualitative differences in the various tissue fragments. In addition, we observed further quantitative and qualitative differences in protein synthesis during the postimplantation period investigated. We propose that the differences reflect some of the cell lineage- and developmental stage-specific changes in gene expression during early mammalian differentiation.

Animals↗
PubMed1990

[AIDS: risk for tourists and assistants in developing countries?].

In developing countries, AIDS is transmitted in essentially the same way as other sexually transmitted diseases. Therefore the spread of AIDS is also associated with travel. Unfortunately, it is still very difficult to assess the distribution of the infection, especially in developing countries, because in these countries often only 10% of the cases are identified and registered. It can, however, be stated that the highest infection rates are found in Central Africa, in some South American cities, and in the Caribbean. Moderately high rates are found in Western Europe, the USA, Canada and Australia. In the Eastern bloc, in Asiatic countries and in the Pacific area, and in considerable parts of North Africa and South America, the pandemic is only just beginning. Sexual intercourse has been found to be the main means of transmission of HIV infection in developing countries. In addition, further risk factors have been identified; venereal disease, and ulcers on the sexual organs. The risk of parenteral transfer is also considerable, because of inadequate testing of blood for transfusion, and the lack of satisfactory facilities for sterilisation. For tourists and development workers, the risk of infection depends very much on their own behaviour when they are overseas. Though the risk of infection is somewhat higher in developing countries, it can clearly be greatly reduced if travellers are adequately informed and are thus equipped to take the necessary precautions.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Physiological measurements during radio-frequency irradiation.

Conventional techniques for monitoring physiological parameters are not suitable for use during RFR exposure. This research note describes transduction methods involving the use of fluorocarbon leads and a pneumatic pressure transducer for reliable measurement of the ECG and respiratory rate in anesthetized or restrained rats during radiofrequency irradiation.

Animals↗
PubMed1988

Physiological effects of 2.8 GHz radio-frequency radiation: a comparison of pulsed and continuous-wave radiation.

Ketamine-anesthetized female Sprague-Dawley rats were exposed individually to far-field 2.8 GHz continuous wave (CW) and pulsed (2 microseconds, 500 pps) radio-frequency radiation (RFR) at average power densities of 30, 45, and 60 mW/cm2 [specific absorption rates (SAR) of 8.4, 12.6, and 16.8 W/kg, respectively] and to pulsed RFR at 75 mW/cm2 (SAR = 21 W/kg). Intermittent exposures were conducted to repeatedly increase colonic temperature from 38.5 to 39.5 degrees C. Colonic, tympanic, and subcutaneous temperatures, electrocardiogram, respiratory rate, and arterial blood pressure were continuously monitored and recorded. The time required to effect a 1 degree C colonic temperature increase varied inversely with the average power density used during exposure; however, the rate of cooling was independent of the heating rate. During pulsed irradiation, heart rate increased significantly at average power densities above 30 mW/cm2; heart rate increase during CW exposure was not significant. Heart rate returned to baseline when exposure was discontinued. Blood pressure and respiratory rate did not significantly change during irradiation. Pulsed RFR exposure caused a significantly greater increase in subcutaneous and tympanic temperatures than did CW exposure; however, no significant difference was noted between the effects of CW or pulsed RFR upon the rats' colonic temperature responses (heating and cooling time), heart rate, blood pressure, and respiratory rate.

Animals↗
PubMed1980

[Diflunisal in the treatment of coxarthrosis and gonarthrosis. A comparative double-blind study with acetylsalicylic acid].

A double-blind study comparing the efficacy and safety of diflunisal (Unisal), a new derivative of salicylic acid, and acetylsalicylic acid (Aspirin) was conducted in the rheumatology clinics of the Cantonal Hospital Beau-Séjour, Geneva, and the Triemli City Hospital, Zurich. A total of 38 patients with established osteoarthritis of the hip and/or knee were studied for 12 weeks. The daily dose of diflunisal was 500-750 mg and that of acetylsalicylic acid 2000-3000 mg. After 12 weeks diflunisal was judged superior to Aspirin by both patients and investigators. Among the most important clinical symptoms evaluated were pain and limitation of motion. Side effects, particularly gastro-intestinal symptoms, of sufficient severity to cause discontinuation of therapy were more frequent in the acetylsalicylic acid-treated patients than in the group receiving diflunisal.

Adult↗