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Biomedical subjects

T Mach

Publications and source records attributed to T Mach.

At least 37 records · Page 2Linked to original sources
PubMed1994

Vehicle crashworthiness ratings in Australia.

The paper reviews the published vehicle safety ratings based on mass crash data from the United States, Sweden, and Great Britain. It then describes the development of vehicle crashworthiness ratings based on injury compensation claims and police accident reports from Victoria and New South Wales, the two most populous states in Australia. Crashworthiness was measured by a combination of injury severity (of injured drivers) and injury risk (of drivers involved in crashes). Injury severity was based on 22,600 drivers injured in crashes in the two states. Injury risk was based on 70,900 drivers in New South Wales involved in crashes after which a vehicle was towed away. Injury risk measured in this way was compared with the "relative injury risk" of particular model cars involved in two car crashes in Victoria (where essentially only casualty crashes are reported), which was based on the method developed by Folksam Insurance in Sweden from Evans' double-pair comparison method. The results include crashworthiness ratings for the makes and models crashing in Australia in sufficient numbers to measure their crash performance adequately. The ratings were normalised for the driver sex and speed limit at the crash location, the two factors found to be strongly related to injury risk and/or severity and to vary substantially across makes and models of Australian crash-involved cars. This allows differences in crashworthiness of individual models to be seen, uncontaminated by major crash exposure differences.

Acceleration↗
PubMed1993

Increased susceptibility to injury and normal reactivity to prostaglandin protection of mucous cells isolated from gastric mucosa of portal hypertensive rats.

We examined the susceptibility of mucous cells isolated from gastric mucosa of portal hypertensive rats to ethanol injury. In addition, we assessed their response to protective action of prostaglandin against ethanol injury in vitro. Ethanol significantly decreased cell viability in calcium-containing medium. The injury of mucous cells isolated from portal hypertensive rats was more extensive than those isolated from sham-operated rats. Ethanol-induced cell injury was reduced similarly in both groups by pretreatment with 16,16-dimethyl prostaglandin E2. These results suggest that mucous cells isolated from portal hypertensive gastric mucosa are more susceptible to ethanol injury and this susceptibility is dependent on extracellular calcium. The cells from portal hypertensive gastric mucosa retain, however, sensitivity to protective action of 16,16-dimethyl prostaglandin E2.

16,16-Dimethylprostaglandin E2↗
PubMed1993

[Peroperative transluminal angioplasty as a supplementary procedure to arterial reconstruction surgery].

Patients with affections of the vascular system of the lower extremities at several levels present a complicated problem for vascular surgery. The authors submit their experience with a combination of vascular reconstruction and peroperative transluminal angioplasty. In 25 patients, mean age 64 years, they performed 29 of these combined operations, 10 times on account of claudications, 11 times on account of pain at rest, 8 times on account of trophic defects. The pelvic vessels were dilated 6 times; the dilated vessels as well as the reconstruction remained patent. Peroperative angioplasty of the superficial femoral artery was performed 6 times, occlusion occurred once. Twelve times they dilated the distal portion of the popliteal artery or the vessels of the leg, 3 times the dilated portion became occluded. None of the patients lost the limb, one patient died from acute myocardial infarction shortly after operation. The authors describe the technique of peroperative transluminal angioplasty, evaluate the results and discuss the advantages and disadvantages of this method.

Adult↗
PubMed1993

[The effect of indobufen on aortocoronary bypass patency after 1 week and after 1 year].

A randomized clinical study was conducted to compare the effect of "conventional" antiaggregation therapy (ASA plus dipyridamole) versus indobufen in patients after aortocoronary bypass (ACB) surgery. The patency of venous ACB using coronary DSA one week and one year after surgery was evaluated in 52 patients divided into two groups. The study included only ACB's with intraoperative blood flow rates < or = 40 ml/min as it is just these ACB's which are at the highest risk of early and late occlusions. While, in the ASA plus dipyridamole-treated group, occlusions were found in 11 of the 39 reconstructions (28.2%), the proportion was nine out of 37 procedures (24.3%) in the indobufen group. One year after surgery, occlusion was found in 14 out of 32 ACB's (43.7%) in the ASA plus dipyridamole group compared to 14 occlusions in 31 ACB's (45.2%) in the indobufen group. The difference in the number of occlusions between the two groups was not statistically significant. Because of some benefits of indobufen compared to ASA (shorter time of effect, superior tolerance in patients with ulceration), the former drug can be recommended for use in some indicated cases.

Adult↗
PubMed1992

[In vivo and vitro study of prostaglandins E2 and I2 participation in protective function of antacids on gastric mucosa].

Antacids apart from neutralization of hydrochloric acid possess the gastro-protective properties. In this paper, performed in vivo and in vitro, we studied the effects of antacids (aluminium and magnesium hydroxides) on secretion of PGE2 and 6-keto-PGF1 alpha (a stable metabolite of PGI2) by the gastric mucosa and isolated gastric mucosal cells of rats. We studied protective effects of these drugs on the gastric mucosa and isolated cells as well. It was shown that antacids stimulate generation of PGE2 and PGI2 in the gastric mucosa and protect it against alcohol-induced damage. Indomethacin given prior to antacids in a dose (1 mg/kg) which did not cause any gastric mucosal changes but inhibited generation of both prostaglandins, abolished protective effects of antacids. In comparison with control, surface epithelial cells of the gastric mucosa isolated from the stomachs of rats which were treated with antacids earlier, secreted significantly more PGE2 and PGI2, and were less damaged after incubation with 8% alcohol. Indomethacin inhibited secretion of prostaglandins by isolated surface epithelial cells of the gastric mucosa and abolished protective effects of antacids on these cells. The study confirms both in vivo and in vitro the protective properties of antacids and shows that prostaglandins participate in their action.

Aluminum Hydroxide↗
PubMed1991

Calcium channel blockers and prostaglandin generation by gastric surface epithelial cells.

We investigated the effects of calcium channel blockers on generation of prostaglandin (PG) E2 and 6-keto PGF1 alpha by gastric mucosal surface epithelium. Surface epithelial cells (SEC) isolated from rat gastric mucosa were incubated with either verapamil (1 or 10 micrograms/ml), diltiazem (2.5 or 25 micrograms/ml) or nifedipine (2.5 or 25 micrograms/ml) for 30 min at 37 degrees C in calcium containing or calcium-free medium. Verapamil (both doses) significantly increased PGE2 and 6-keto PGF1 alpha generation by the surface epithelial cells but only in calcium containing medium. Diltiazem did not affect PG generation in calcium containing nor calcium-free medium. Nifedipine 25 micrograms/ml decreased PGE2 but increased 6-keto PGF1 alpha generation. The inhibitory effect of nifedipine on PGE2 generation was abolished in calcium-free medium, while the calmodulin antagonist did not affect verapamil-induced increase in PG generation.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Impaired generation of prostaglandins from isolated gastric surface epithelial cells in portal hypertensive rats.

We studied generation of prostaglandins E2 and 6-keto F1a by surface epithelial cell isolated from the gastric mucosa of portal hypertensive and sham-operated rats. Oxygenated cell suspensions containing 80 +/- 3% of surface epithelial cells were incubated for 30 min at 37 degrees C and the concentration of prostaglandin E2 and 6-keto-prostaglandin F1a in medium was measured by radioimmunoassay. Viability of the cells was assessed with Fast green exclusion at baseline and after 30-min and 60-min incubation. Within 30 minutes the surface epithelial cells obtained from portal hypertensive rats generated 22.0 +/- 1.6 (mean +/- SE) pg prostaglandin E2 and 40.7 +/- 4.7 pg 6-keto prostaglandin F1a, per 10(6) cells. These were significantly less than prostaglandin generation by cells obtained from sham-operated rats. The viability of the surface epithelial cells from portal hypertensive rats was also significantly reduced compared with sham-operated rats after 60 minute incubation. Reduced ability of the surface epithelial cells to generate prostaglandins may be one mechanism for increased susceptibility of portal hypertensive gastric mucosa to injury by noxious agents.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

Comparison of sucralfate and ranitidine in gastroprotection against alcohol in humans.

This endoscopic study was designed to assess histologic and functional features of human gastric mucosal injury by 40 percent ethanol, and to compare the gastroprotective effects of sucralfate with those of ranitidine or sucralfate combined with ranitidine against ethanol damage. A group of 16 young subjects with normal gastric mucosa were divided into two groups (A and B). Group A was pretreated for four days with either sucralfate alone (1 g four times per day) or placebo (one tablet four times per day). Group B received sucralfate (1 g four times per day) plus ranitidine (150 mg three times per day) or placebo plus ranitidine in a double-blind, randomized study. On the fifth morning, two hours after the last treatment, 100 ml of 40 percent ethanol spray was applied via an endoscope onto gastric mucosa. In placebo-treated subjects, ethanol caused widespread endoscopic damage (score = 2.43) with histologic disruption of surface epithelium and deep necrotic lesions accompanied by a decrease of mucosal potential difference from -41.3 to -15.8 millivolts. Pretreatment with sucralfate significantly reduced endoscopic damage (score = 0.75). The surface epithelium was disrupted, but necrotic lesions were greatly reduced and potential difference decreased to -27.1 millivolts. Ranitidine alone or combined with sucralfate did not prevent ethanol-induced histologic or functional changes in the mucosa. Ethanol produces pronounced mucosal damage that can be almost completely prevented by sucralfate.

Adult↗
PubMed1989

Surgery for ischaemic heart disease in the patient aged 40 and younger.

A group of 128 patients with a mean age of 36 years, operated on between 1971 and 1986, were followed up over a period of up to 15 years. Their five-year survival was 90%, and 10-year survival 60%. The main cause of death was progression of ischaemic heart disease. The only factor affecting long-term survival is resection of a left ventricular aneurysm: patients who undergo this procedure exhibit a shorter survival (p less than 0.05). The number of vessels involved, performance of complete or incomplete revascularization, or ejection fraction data had no effect on patient survival. To improve the results of 10-year and longer follow-up, the patient must comply with the principles of secondary prevention of atherosclerosis, and the internal mammary artery should be used for reconstruction.

Adult↗
PubMed1989

Importance of an acid milieu in the sucralfate-induced gastroprotection against ethanol damage.

Sucralfate is known for its gastroprotective properties in humans and rats, but the importance of intragastric pH in this protection is a subject of controversy. This study, performed on healthy young volunteers and rats, was designed to compare the gastroprotective effects of sucralfate with those of sucralfate combined with ranitidine or of sucralfate adjusted to pHs varying from 1 to 7. In humans the mucosal damage induced by 40% ethanol spray after 4 days of pretreatment with placebo, sucralfate (1 g four times daily), ranitidine (150 mg three times daily), or the combination of sucralfate plus ranitidine was evaluated by means of endoscopy with mucosal biopsy and histologic examination. Sucralfate alone reduced the endoscopic score significantly (compared with placebo) and prevented deep necrotic lesions. Neither ranitidine alone nor its combination with sucralfate prevented ethanol-induced endoscopic and histologic mucosal changes. In rats acute gastric lesions were induced by 100% ethanol. Sucralfate was relatively more effective in mucosal protection against ethanol when given at lower pH (1 or 2) than at original pH (4.5) and failed to protect at neutral pH (7.0). Pretreatment with ranitidine, which by itself did not change ethanol damage, greatly reduced the protection afforded by sucralfate. We conclude that sucralfate protects the gastric mucosa against ethanol damage both in humans and in rats and that this protection is dependent on the presence of an acidic intragastric pH.

Adult↗
PubMed1989

[Long-term results of percutaneous transluminal angioplasty in a peripheral region].

The authors performed, in the period of 10/1980 to 12/1985, 102 PTA interventions in 95 patients in the peripheral region. The lasting clinical improvement of early and long-term duration was expressed by the Life-table method. In the whole cohort, 95% of patients proved to be improved clinically in the early period (3 months after the intervention), while 70% of patients were improved for long-term period (up to 66 months). The authors also compare the results reached in PTA of pelvis vascular bed and femoropopliteal region. In the PTA of pelvis vascular bed, improved clinical condition in the early period was reached in 95% of patients, long-term improvement was observed in 73% of individuals. In PTA of femoropopliteal region the early period showed improvement in 96% of patients, the long-term period indicated improvement in 52% of subjects.

Adult↗
PubMed1989

[The significance of the systolic gradient value in percutaneous transluminal angioplasty].

In the period of 10/1980-12/1985 the authors performed 102 percutaneous transluminal angioplasty operations on 95 patients in the area of pelvic vascular bed and arteries of lower extremities. The authors evaluated the values of systolic gradient before and after the intervention. Computer assisted statistical methods were used in the search of relationship between the value of systolic gradient and duration of clinical improvement after the surgery. There was not any statistically significant relation between the values of S-gradient before and after PTA and the long-term fate of the patients treated by this method. The authors are of the opinion, though, that measuring this value provides a useful information in the course of surgery.

Adult↗
PubMed1989

[Percutaneous transluminal angioplasty of the branches of the aortic arch].

Percutaneous transluminal angioplasty (PTA) takes its stable position in the therapy of obliterating arterial diseases. Its indication areas considerably extend. The authors present a survey of their experience and the results of PTA of arteries supplying the brain and upper extremities. This surgery was made in 29 patients on 31 arteries. The authors consider PTA on a. subclavia as a method of choice. In the angioplasty on a. vertebralis there is a very low risk in correctly indicated cases. An atherosclerotic stricture of a. carotis interna is not considered suitable for PTA for the risk of embolism from the exulcerated plaques. However, the method may be used with advantage in the stenosis based on fibromuscular dysplasia and in some cases of early restenoses in a. carotis interna after previous endarterectomy. The authors arrive at the conclusion that PTA, if correctly indicated, is a safe method even in arteries supplying the brain and upper extremities. No complication was observed in the reported group.

Angioplasty, Balloon↗
PubMed1989

[Studies on the effect of Krynica mineral water from the "Zuber" spring on alcohol-damaged gastric mucosa in rats].

The study was performed to investigate the protective effect of mineral water "Zuber", "Zuber" with "Jan" and an antacid on the alcohol induced gastric mucosal injury in rats. It was shown that Alugastrin, a hyperosmotic liquid antacid, protects rat gastric mucosa against alcohol. In opposite, a hyperosmotic and alkaline mineral water "Zuber" increases a vulnerability of the gastric mucosa and worsen the damaging effect of alcohol on it. Izoosmotic mixture of mineral waters "Zuber" and "Jan", similarly to a physiologic saline, do not protect rat gastric mucosa. The study show that mineral waters "Zuber" and "Zuber" with "Jan" have a short-lasting neutralizing effect on the gastric HCl and in opposite to antacids have not protective properties on gastric mucosa.

Aluminum Hydroxide↗
PubMed1989

[Protective effect of alkalies on ethyl alcohol-damaged gastric mucosa].

A few recent reports suggest the protective effect of antacids against gastric mucosal injury. This study was aimed to examine the influence of some antacids on ethanol induced gastric mucosal damage in rats. We have found that Polish antacids (Alugastrin, Gelatum Aluminii Phosphorici, Gastrin) and calcium carbonate diminished gastric mucosal lesions produced by ethanol. Moreover, Alugastrin and Gelatum Aluminii Phosphorici decreased volume of gastric contents, and its pH, as well as lowered sodium, potassium and protein levels and decreased LDH activity in gastric contents. These findings indicate that antacids protect rat gastric mucosa against injury caused by ethanol. We have found also that aspirin given prior to Alugastrin abolished the protective ability of Alugastrin. This suggest that prostaglandins might be involved in antacid cytoprotection. Our studies indicate that antacids can be used prophilactically in the gastric mucosal injuries.

Aluminum↗