[The correlation of results of breath analysers and laboratory blood examinations of blood-ethanol concentration (Czech and Slovak study)]. / Mezirepubliková Cesko-Slovenská studie korelace výsledku dechových analyzátoru a výsledku laboratorní analýzy pri zjistování hladiny alkoholu v krvi.

The target of this study was to compare the results of breath analysers and "lege artis" laboratory blood examinations when determining alcohol levels. This was then used to determine whether any differences exist between the two methods, and how large these differences are. 610 cases from 11 workplaces in the Czech Republic and Slovakia were analysed. The type of breath analyser was not taken into consideration. All cases had to be in the elimination phase. Difference of time between breath test and blood test were rectified through the use of reverse recomputation. It was detected that only 20.8% of the results of respiratory analyser tests correspond to the detected real alcohol level in blood. The maximum difference when a respiratory analyser measured more than a blood test was 1.34 g x kg(-1). and the maximum difference when the analyse measured less was 1.86 g x kg(-1).

[Aortic reconstruction in neonates with hypoplastic left heart syndrome] . / Rekonstrukce aorty u novorozencu se syndromem hypoplastického levého srdce.

The surgical technique and tactics of the Norwood operation in neonates with hypoplastic left heart syndrome represent a surgical challenge. The Norwood operation was performed from the midline sternotomy approach, in extracorporeal circulation and deep hypothermic circulatory arrest was used for reconstruction of the hypoplastic aorta. Operation consisted of reconstruction of the "neoaorta" and the aortic arch from the original hypoplastic ascendent aorta, pulmonary trunk and a patch cut from a pulmonary homograft or pericardium, excision of the atrial septum and an arterial shunt from a Goretex vascular graft 3.5 or 4 mm in diameter. In patients with well developed aortic arch it was possible to reconstruct the aorta using Damus-Kaye-Stansel operation without circulatory arrest. Out of 12 operated patients with this defect, two (16.7%) died during the early postoperative period, one patient died late. The postoperative course was often complicated. In 6 (50.0%) patients the second step of Norwood operation, the bidirectional cavopulmonary anastomosis, was performed without mortality. According to our experience, it was necessary to prepare patients adequately before the first surgery. Perfect reconstruction of the aorta and a well functioning shunt had the crucial significance.

[Occult fibrin production during surgery in cyanotic congenital heart defects and extracorporeal circulation]. / Skrytá produkce fibrinu pri operacích cyanotických vrozených srdecních vad v mimotelním obehu.

In 10 patients with complex cyanotic congenital defects detailed coagulation examinations were made at the beginning and end of the extracorporeal circulation after neutralization of heparin by protamine and the results were compared with a control examination, made before general heparinization, after introduction into general anaesthesia. The authors examined the activated period of blood (ACT) by means of testing tubes with a celite activator (Hemochron) as well as the HR-ACT test with a kaolin activator (Medtronic) for comparison of the results. The authors assessed quantitatively plasma levels of heparin, antithrombin III and fibrinopeptide A which is a sensitive indicator of intravascular coagulation. They assessed also the fibrinogen level and total number of thrombocytes in the blood stream. The degree of haemodilution was recorded as well as the temperature at the periods of assessment. The values of both ACT test were within the range of values above 420 secs., evaluated according to the authors protocol as adequate for total heparinization during operations under conditions of extracorporeal circulation. Despite of this heparin levels lower than those recommended in the literature were found, as well as reduced antithrombin III levels during extracorporeal circulation and a rise of fibronopeptide A levels at the end of extracorporeal circulation which suggest latent fibrin production in the patients. Laboratory results were compared with clinical symptoms of post-operation bleeding. In 50% patients after surgery signs of increased haemorrhage in the surgical field and from thoracic drains were observed, in two patients the surgical wound had to be revised. Laboratory tests revealed in two patients thrombocytopenia after surgery, one patient had a prothrombin test reduced below 45% and in one patient there was a significantly reduced fibrinogen level calling for supplementation of this factor. After improvement of the laboratory results and surgical treatment haemostasis returned to normal. All patients survived the operation and were discharged from hospital to domestic treatment.

[Primary repair of interrupted aortic arch in neonates]. / Zkusenosti s primární korekcí interrupce aortálního oblouku u novorozencu.

In the Kardiocentrum, University Hospital Motol, Prague, protocol of the primary repair of interrupted aortic arch was introduced, and between 1993-1997, 15 neonates aged 1-26 days (median 5 days) were operated on. Treatment with prostaglandins E for maintenance of the ductal patency, correction of metabolic acidosis, and treatment of all complications were necessary before surgery. The correction was performed from the midline sternotomy approach, in extracorporeal circulation and deep hypothermia with circulatory arrest. Direct anastomosis between the ascending and the descending aorta was possible in all the patients. At the same time, associated heart lesions were corrected (ventricular septal defect in 13, persistent truncus arteriosus in 3, subaortic stenosis in 2, transposition of the great arteries, double-outlet right ventricle and aortico-pulmonary window in 1 patient, each). Four (26.7%) patients died after surgery. Out of the first 6 neonates 3 (50.0%) died, but out of the subsequent 9 patients only 1 (11.1%) died. Reoperation was necessary in 2 patients. All 11 early survivors are alive and doing well 8-54 months after the repair. In one of them restenosis at the site of aortic anastomosis and hemodynamically significant subaortic stenosis occurred. All the remaining patients have a nonrestrictive aortic anastomosis. Primary repair of interrupted aortic arch and associated heart lesions can be performed in a neonate with reasonable mortality. Treatment of complications is necessary before surgery. Results depend especially on the patient's clinical condition and experience of the center.

[Combined methods for economic blood utilization in cardiac reoperations in children]. / Kombinované metody pro setrení spotreby krve pri reoperacích srdce u detí.

During 47 re-operations on the open heart the authors used the method of autotransfusion, predeposition of the patient's blood and intravenous administration of aprotinin to reduce postoperative haemorrhage and blood consumption. The patients were classified according to the methods or their combinations used into three groups and the authors compared, using statistical methods the blood losses, blood consumption, haemolysis, renal function and the effect of the methods used on the morbidity. The results were compared with a control group where the mentioned methods of economizing on blood were not used. The authors recorded significantly higher haematocrit values in all three groups where economic methods were used at the end of the extracorporeal circulation (EC), as compared with the control group. The volume of the administered blood transfusion was significantly lower in group 1 where an autotransfusion apparatus Cell saver was used. The volume of the administered blood transfusion in the other groups did not differ when evaluated by statistical methods. The filling of the apparatus for extracorporeal circulation was blood free in 90% in group 1, in 75% in group 2, in 92.2% in group 3 and in 75% in the control group. Blood losses via thoracic drains did not differ significantly in different groups though there was a wide range of recorded values. In both groups 2 and 3 where patients were given aprotinin haemoglobinuria was more frequent, as confirmed by laboratory tests. The authors observed also a greater diuresis, without laboratory evidence of impairment of renal function.(ABSTRACT TRUNCATED AT 250 WORDS)

Removal of nitrate from water by cells of Paracoccus denitrificans in a membrane flow reactor.

A new type of flow bioreactor designed to remove nitrate from water was developed. Denitrification activity of native Paracoccus denitrificans cells was used, the cells being separated from the refined medium by a semipermeable membrane. Relationships between the degree of nitrate conversion and the denitrification rate, on the one hand, and the volume flow rate and the amount of biomass, on the other, together with the results concerning denitrification during closed-circuit recirculation of the medium are discussed.

Determination of nitrate by conversion to nitrite using Paracoccus denitrificans.

A new method of determination of nitrate was developed, utilizing the nitrate reductase activity of Paracoccus denitrificans in which a further reduction of nitrate is blocked either by a mutation affecting formation of cytochromes c or by inhibition of the electron flow to nitrite reductase by mucidin. After deproteinization of the sample with zinc acetate the nitrite produced is determined colorimetrically.

Use of uridine rescue to enhance the antitumor selectivity of 5-fluorouracil.

We examined the ability of uridine to increase the therapeutic index of 5-fluorouracil (FUra) against C57BL/6 X DBA/2 F1 mice bearing a Day 1 B16 melanoma or L1210 leukemia. FUra (400, 600, or 800 mg/kg, i.p.) followed in 24 hr by a 5-day s.c. infusion with uridine (5 g/kg/day, s.c.) was compared with the maximum tolerated dose of FUra (200 mg/kg, i.p.) plus a 5-day infusion with 0.9% NaCl solution. High-dose FUra plus delayed infusion with uridine was more effective than FUra (200 mg/kg) in inhibiting the growth of the B16 melanoma. High-dose FUra plus uridine rescue was, however, no more effective than FUra (200 mg/kg) in increasing the survival times of mice bearing the L1210 leukemia. To see if uridine rescue from FUra toxicity correlated with effects against a sensitive normal tissue, bone marrow nucleated cellularity of normal, non-tumor-bearing mice was monitored after drug treatment. In mice treated with FUra (200 mg/kg) followed in 24 hr by a 5-day infusion with either uridine (5 g/kg/day) or 0.9% NaCl solution, there was not as great a decrease in cellularity at the nadir with uridine, and, in addition, uridine accelerated recovery as compared to 0.9% NaCl solution. Furthermore, uridine (5 g/kg/day), but not thymidine (dThd) (5 g/kg/day) or 2'-deoxyuridine (dUrd) (5 g/kg/day), had a sparing effect on the depression in bone marrow nucleated cellularity seen at the nadir on Day 4 after Fura (200 mg/kg). The specificity of uridine to rescue mice from the lethal toxicity of the related fluorinated pyrimidines, 5-fluorouridine and 5-fluoro-2'-deoxyuridine, was also examined. Mice were treated with 5-fluorouridine (250 mg/kg, i.p.) followed in 24 hr by a 5-day infusion with uridine (1, 5, or 10 g/kg/day), dThd (1, 5, or 10 g/kg/day), or dUrd (1 or 5 g/kg/day). Uridine (1, 5, or 10 g/kg/day) rescued mice from the lethal toxicity of 5-fluorouridine, whereas dThd or dUrd was ineffective. Similarly, a 5-day infusion with uridine, but not dThd or dUrd, rescued mice from the lethal toxicity of 5-fluoro-2'-deoxyuridine (1800 mg/kg, i.p.).

Uridine rescue from the lethal toxicity of 5-fluorouracil in mice.

To determine the relationship between 5-fluorouracil (FUra) toxicity and its RNA- and DNA-directed actions we examined the ability of continuous SC infusions with uridine (Urd), thymidine (dThd), or deoxyuridine (dUrd) to rescue mice from the lethal toxicity of FUra. Male B6D2F1 mice were treated with a single IP injection of FUra (800 mg/kg) followed in 24 h by a 5-day infusion with either 0.9% NaCl or Urd (0.1, 1, 5, or 10 g/kg/day). Survivors were then followed up for 30 days after FUra treatment. Urd (1, 5, or 10 g/kg/day) rescued mice from the lethal toxicity of FUra, whereas Urd (0.1 g/kg/day) was as ineffective as 0.9% NaCl as a rescue agent. With variable doses of FUra followed in 24 h by a Urd infusion (5 g/kg/day) for 5 days. Urd rescued mice treated with FUra (400, 600, or 800 mg/kg) but was ineffective against higher doses of FUra (1,000 or 1,200 mg/kg). Mice treated with FUra (800 mg/kg) followed in 24 h by a 5-day infusion with either dThd (1, 5, or 10 g/kg/day) or a dUrd (1 or 5 g/kg/day) could not be rescued from the lethal toxicity of FUra. In all experiments deaths occurred between 6 and 12 days after FUra. These results, which demonstrate a specificity for Urd, but not for either dThd or dUrd, for rescuing mice from the lethal toxicity of FUra, suggest the importance of the RNA- rather than the DNA-directed actions of FUra as a determinant of its toxicity in mice.

Biochemical and pharmacologic study of therapeutic synergism with cyclophosphamide plus methotrexate in murine L1210 leukemia.

The combination of cyclosphosphamide (CP) plus methotrexate (MTX) was found to be therapeutically synergistic against the L1210 ascites tumor. After inoculation with 1 x 10(6) L1210 cells to (C57BL/6 x DBA/2)F1 mice, ip administration of CP (200 mg/kg on Day 5) plus MTX (15 mg/kg on Days 5, 7, 9, and 11) resulted in a significant increase in mean lifespan, compared to optimal treatment with either CP or MTX alone. The contribution of the single, simultaneous dose of CP plus MTX on Day 5 to therapeutic synergism was examined. The combination of CP plus MTX on Day 5 produced a greater decrease in tumor cell numbers than either drug alone. Measurements of the time course of inhibition and recovery of 3H-deoxyuridine incorporation into DNA showed that within 48 hours, recovery of DNA synthesis in small intestine and bone marrow was almost complete after either CP, MTX, or CP plus MTX. In contrast, tumor, which had recovered within 48 hours after MTX, still remained greater than 90% inhibited after eight CP or CP plus MTX. Measurements of bone marrow nucleated cellularity after therapy showed that the single, simultaneous dose of CP plus MTX was no more toxic to bone marrow than CP alone, although it was more toxic than MTX alone. No alterations in the distribution of either MTX or alkylating metabolites of CP could be detected in tumor or normal tissues when CP and MTX were administered simultaneously.

Effect of concurrent calcium leucovorin infusion on 5-fluorouracil cytotoxicity against murine L1210 leukemia.

We examined the effect of concurrent SC infusion of calcium leucovorin (LV) on the action of 5-fluorouracil (FUra) against mouse L1210 leukemia implanted either SC or IP. Mice bearing the SC tumor treated with FUra (100 mg/kg, IP, day 1) plus infusion with either LV (11.5 mg . kg-1 . day-1, days 1-4), or 0.9% NaCl (days 1-4) resulted in an identical increase in median lifespan (ILS) of 28%. Similar experiments with FUra (100 mg/kg) plus LV infusion (115 mg . kg-1 . day-1) or FUra (200 mg/kg) plus LV infusion (115 mg . kg-1 . day-1) resulted in 50% and 59% ILS, respectively, which were not different from that obtained with the same doses of FUra plus 0.9% NaCl infusion. Mice bearing the IP tumor treated with FUra (100 mg/kg, IP, day 1) plus infusion with either LV (11.5 mg . kg-1 . day-1, days 1-4) or 0.9% NaCl (days 1-4) had an identical 56% ILS. Similar experiments with FUra (100 mg/kg) plus LV infusion (115 mg . kg-1 . day-1) or FUra (200 mg/kg) plus LV infusion (115 mg . kg-1 . day-1) resulted in 67% and 94% ILS, respectively, which were not different from those obtained with the same doses of FUra plus 0.9% NaCl infusion. Treatment of normal mice with FUra (200 mg/kg, IP, day 0) plus LV infusion (115 mg . kg-1 . day-1, days 0-3) was no more toxic than FUra plus 0.9% NaCl infusion, judging by similar transient decreases in body weight and no mortality. The data indicate that concurrent infusion with the LV failed to enhance the action of FUra against the mouse L1210 leukemia.

Effects of 5-fluorouracil on human colon carcinoma and solid rat Walker 256 carcinosarcoma: evaluation as in vitro predictors of clinical response.

Several biochemical effects of 5-fluorouracil (5-FU) including inhibition of the incorporation of 3H-deoxyuridine (3H-UdR) into DNA, inhibition of ribosome formation, and formation of 5-fluoro-2'-deoxyuridine-5'-monophosphate (FdUMP) were examined in samples of human colon carcinomas to determine if any of these drug effects might have predictive value as a reliable guide to 5-FU therapy. For comparison, the solid rat Walker 256 carcinosarcoma, which is only minimally responsive to 5-FU, was also studied. For each of the biochemical effects of 5-FU measured in the various samples of Walker 256 tumors, the responses were consistent and varied within a narrow range. In contrast, the formation of FdUMP from 5-FU and the degree of inhibition of the incorporation of 3H-UdR into DNA by 5-FU were extremely variable in the population of human colon carcinomas examined. In all human tumors examined, 5-FU caused a reduction in the formation of ribosomes, but even in the absence of 5-FU, the total amount of ribosome synthesis was so low that it makes measurement difficult to quantitate. Based on our data, a study might be warranted to determine if there is a correlation between FdUMP formation and responsiveness of colon carcinoma to 5-FU therapy.