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Biomedical subjects

D D Do

Publications and source records attributed to D D Do.

78 records · Page 5Linked to original sources

[Recent instrumental developments in percutaneous transluminal angioplasty (PTA)].

In addition to the balloon-catheter for PTA a number of new devices have been developed in recent years. Among them the most outstanding are laser beam application, mechanical devices for recanalization and endoprostheses for stenting of the vessels. The initial fascination by laser technique in PTA has given way to a matter-of-fact appreciation of the method. Up to now no available laser system achieves better clinical results than conventional PTA in the long run. Although there is much potential in the laser principle, it still is to be regarded as experimental. As for mechanical devices the fast rotating Kensey-catheter has not been proven superior to balloon PTA in our hands neither to remove organized or fresh thrombotic occlusive matter. A slowly rotating catheter (Rotacs) facilitates primary recanalisation of long occlusions prior to balloon dilatation. Atherectomy by the Simpson-catheter provides samples for histological studies but is indicated only in special situations. Numerous other mechanical percutaneous endarterectomy devices are under development, but clinical long term evaluation is not yet available. Vascular stents - self expandable or balloon expandable systems - may serve to keep the newly dilated arterial lumen open and to prevent late recurrences. While in larger vessels such as iliac arteries or aorta good long-term results after insufficient PTA were shown, other indications are still experimental. For all of these newer technologies both their relative effectiveness and the extent to which they may compare with or complement balloon PTA remain to be determined.

Angioplasty, Balloon↗

Analysis of Distributed Growth of Saccharomyces cerevisiae Cells Immobilized in Polyacrylamide Gel.

A technique is described for the quantitative determination of the distributed growth of Saccharomyces cerevisiae immobilized in polyacrylamide gel. Gel specimens were embedded in paraffin or gelatin and paraffin before sectioning and staining. Photomicrographs of specimen sections were enlarged, and cell microcolony volumes were determined as a function of position in the gel by grid transparency analysis. Overall cell densities within the gel were calculated for a quantitative comparison with values measured by a second spectrophotometric method. The results show good agreement and demonstrate the sigmoidal growth of the immobilized cells, reaching a maximum steady-state value. The technique shows promise as a general method for following the transient growth of organisms immobilized within gel particles.

Journal Article↗

Levonantradol, a new antiemetic with a high rate of side-effects for the prevention of nausea and vomiting in patients receiving cancer chemotherapy.

Levonantradol, a new antiemetic compound pharmacologically related to the cannabinoids, was given to 17 patients who had experienced severe and protracted nausea and vomiting during previous courses of cancer chemotherapy, and to six patients receiving a first course of strongly emetic cytostatic treatment. Eight patients were partially protected from acute gastrointestinal disturbances. Of the 23 patients, 21 exhibited some toxicity, with six patients exhibiting major affective side-effects and 13 patients complaining of pain at the injection site. Levonantradol is an active antiemetic compound. Due to the rate of side-effects observed in our study however, we would not recommend use of this agent as an antiemetic drug.

Adult↗

Angioplasty of the terminal aorta: follow-up of 20 patients treated by PTA or PTA with stents.

Twenty patients with distal aortic stenosis were treated by PTA for intermittent claudication and, in 3, 'blue toe' syndrome. Additionally, a self-expandable endoprosthesis (stent) was inserted into the aorta in three of the patients. The overall primary success rate (including those with a stent) was 100% with all patients becoming free of symptoms. Mean arm-ankle pressure difference decreased from 48 mmHg to 9 mmHg (P less than 0.01). During a median follow-up period of 15 months no patient had recurrence of claudication, embolism, or deterioration of the non-invasive parameters. Thus, PTA seems suitable for treating stenoses of the abdominal aorta, even in the presence of distal microembolization. Balloon dilatation, with the addition of stents in resistant cases, offers a valuable alternative to surgery in distal aortic stenosis.

Adult↗

Iliac graft access to facilitate endovascular repair of a ruptured thoracic aortic aneurysm -- a case report.

Arterial access for endovascular aortic aneurysm repair is usually gained through a common femoral artery approach. In small femoral arteries this can be difficult or even impossible owing to the large size of the introduction sheath of the delivery system. In such cases the iliac arteries or the abdominal aorta can be used for vascular access, although, in heavily calcified arteries,even this can be hazardous. The authors report an 81-year-old woman with a contained rupture of the thoracic aorta in whom a polyester graft was used to facilitate vascular access to the common iliac artery for a safe two-stage endovascular repair of the aneurysm.

Aged↗