Impaired bioavailability and antiplatelet effect of high-dose clopidogrel in patients after cardiopulmonary resuscitation (CPR).

PURPOSE: Bioavailability of clopidogrel in the form of crushed tablets administered via nasogastric tube (NGT) has not been established in patients after cardiopulmonary resuscitation. Therefore, we performed a study comparing pharmacokinetic and pharmacodynamic response to high loading dose of clopidogrel in critically ill patients after cardiopulmonary resuscitation (CPR) with patients scheduled for elective coronary angiography with stent implantation. METHODS: In the NGT group (nine patients, after cardiopulmonary resuscitation, mechanically ventilated, therapeutic hypothermia), clopidogrel was administered in the form of crushed tablets via NGT. Ten patients undergoing elective coronary artery stenting took clopidogrel per os (po) in the form of intact tablets. Pharmacokinetics of clopidogrel was measured with high-performance liquid chromatography (HPLC) before and at 0.5, 1, 6, 12, 24 h after administration of a loading dose of 600 mg. In five patients in each group, antiplatelet effect was measured with thrombelastography (TEG; Platelet Mapping) before and 24 h after administration. RESULTS: The carboxylic acid metabolite of clopidogrel was detected in all patients in the po group. In eight patients, the maximum concentration was measured in the range of 0.5-1 h after the initial dose. In four patients in the of NGT group, the carboxylic acid metabolite of clopidogrel was undetectable and in the remaining patients was significantly delayed (peak values at 12 h). All patients in the po group reached clinically relevant (>50 %) inhibition of thrombocyte adenosine diphosphate (ADP) receptor after 24 h compared with only two in the NGT group (p = 0.012). There was a close correlation between peak of inactive clopidogrel metabolite plasmatic concentration and inhibition of the ADP receptor (r = 0.79; p < 0.001). CONCLUSION: The bioavailability of clopidogrel in critically ill patients after cardiopulmonary resuscitation is significantly impaired compared with stable patients. Therefore, other drugs, preferentially administered intravenously, should be considered.

Porcine model of ruptured abdominal aortic aneurysm repair.

OBJECTIVES: To validate a porcine model of ruptured abdominal aortic aneurysm (rAAA) repair. DESIGN: Experimental study. METHODS: Ten experimental and five sham-operated pigs were studied. Instrumentation for cardiac output (CO) measurement, regional blood flow (renal-REN and portal-PORT) and blood sampling (inferior vena cava (IVC), renal and portal vein) was done. Microcirculation was visualised sublingually and in ileostoma. PROTOCOL: simulation of rAAA with bleeding (mean arterial pressure (MAP) 45 mmHg) and increased abdominal pressure (25 mmHg) for 4 h; 2 h of infrarenal clamp with shed blood retransfusion; 11 h of post-surgery care. RESULTS: Six experimental pigs completed the protocol and are presented. Bleeding decreased CO to 95%, PORT to 80% and REN to 10% of baseline. From clamping on CO and PORT increased above baseline whereas REN (47%) with creatinine clearance remained compromised till the end. Microcirculation was affected more in ileum than sublingually. Approximately threefold increase in cytokines (tumour necrosis factor-α (TNF-alpha), interleukin (IL)-6 and IL-10) and oxidative stress markers (thiobarbituric acid-reactive substances (TBARs) and 4-hydroxy-2-trans-nonenal (HNE) was observed. Only mild increase in IL-6 and TBARs was observed in sham-operated animals. Organ histology did not reveal differences between groups. CONCLUSIONS: This near-lethal model of rAAA induced expected severe deterioration of haemodynamics and metabolism accompanied with a moderate inflammatory and oxidative stress response.

Rare incidence of pulmonary gangrene--algorithm of the treatment.

The pulmonary gangrene is rare and serious disease. Our experience is based on the treatment of the 2 patients with pulmonary gangrene during the last twenty years. The first and lifesaving step in the treatment of sepsis is the early removal of the necrotic tissue. Next surgery succeeds usually after one week after initial treatment. Surgical treatment continues step by step, we do not advise providing of a major anatomical resection in the initial stage of the disease. This policy is effective in the treatment of this serious disease.

Atencion primaria: diagnostico precoz de hipoacucia / Primary health care: early diagnosis of hearing loss

Resumen: La hipoacusia neurosensorial severa o profunda es un importante handicap o discapacidad que afecta del 1 a 3 por ciento de los recién nacidos vivos y del 2 al 4 por ciento de los neonatos egresados de las UTI neonatales. El pronóstico para el intelecto, condición psico-emocional, lenguaje y desarrollo del habla, es mejor cuando el diagnóstico es efectuado tempranamente y la intervención comienza antes de los 6 meses de vida. La edad habitual deldiagnóstico de hipoacusia es entre los 18 y los 30 meses, o aún más tarde, en casos de pérdida auditiva leve a moderada, cuando no hay implementados programas de screening auditivos. El screening auditivo universal efectuado a los RN, puededarle al niño discapacitado por sordera, la mejor oportunidad para un óptimo cuidado y desarrollo. El criterio “universal” es necesario, porque cuando el tamizaje es restringido al grupo de neonatos de alto riesgoauditivo, no son diagnosticados entre el 30 y el 50 por ciento de los RNcon pérdida auditiva.

Radiation methods in research of ancient monuments

A "Laboratory of Quantitative Methods in Monument Research" is being built at the CTU Prague. Its primary orientation is the investigation of historic architecture, although other objects of art can also be investigated. In the first phase, two radiation methods are being established, but it is set up in such a way, that various other methods can readily be added in its future development. The radiation methods chosen for the initial development of the laboratory are: thermoluminescence dating and X-ray fluorescence analysis. The design of the automated TL-reader, built in our laboratories, is adjusted for the purpose of dating of historic brick architecture (which, of course, does not exclude applications for ceramics and other materials). The investigation of renaissance architecture in southern Bohemia and Moravia is under preparation as the first large campaign of this kind in the Czech Republic. Radionuclide X-ray fluorescence analysis has been chosen as the basic analytical method in the laboratory. The possibility of analyses of paintings and fired building materials (bricks, roof tiles) have been investigated. The first results in both the areas are very promising.

Arginine-based structures are specific inhibitors of cathepsin C. Application of peptide combinatorial libraries.

Novel synthetic peptide inhibitors of lysosomal cysteine proteinase cathepsin C have been designed through the use of soluble peptide combinatorial libraries. The uncovered structural inhibitory module consists of the N-terminal cluster of L-arginine residues. Its modification with D-amino acids or arginine derivatives did not increase the inhibition strength. Inhibitory potency of oligoarginines improves with the elongation of peptide chain reaching a maximum for octa-L-arginine. The oligoarginines specifically interact with the cathepsin C active site as shown by competitive-type inhibition kinetics (Ki approximately 10-5 M) and intrinsic fluorescence measurements. The inhibitory interaction of oligoarginines is established through the specific spatial contact of a net of guanidino groups in the arginine side-chains, as indicated by comparison with inhibitory action of low molecular mass guanidine derivatives (Ki approximately 10-3 M). Nonarginine polyionic compounds cannot mimic the inhibitory effect of oligoarginines. The arginine-based peptide inhibitors were selective towards cathepsin C among other cysteine proteinases tested.

A case of a pulmonary arteriovenous malformation treated by lobectomy.

We present a case of pulmonary arteriovenous malformation (PAVM) in central localisation (type IIIa) of the upper lobe of the left lung. We discuss diagnostic (Doppler ultrasonography, CT, MRI, angiography) and therapeutic (embolization therapy) options and a current role of surgery in this uncommon clinical condition. Our patient underwent left upper lung lobectomy as an ultimate therapeutic method without subsequent morbidity. We conclude that surgery is a safe method of treatment of pulmonary arteriovenous malformations in selected cases i.e. when PAVM is solitary and of great diameter (more than two centimeters) and where the risks of embolotherapy are high.

The improvement of arterial oxygenation during one-lung ventilation--effect of different CPAP levels.

Authors studied different continuous positive airway pressure (CPAP) levels and their effect on arterial oxygenation during thoracic surgery. Surgical interference of CPAP was studied as well. No significant difference has been found at 4 cm, 7 cm and 10 cm H2O in the improvement of oxygen content during one-lung ventilation. In contract to the lowest CPAP level, 7 cm and 10 cm H2O made the surgical conditions significantly worse.

[Videothoracoscopy and video-assisted thoracic procedures in the diagnosis and therapy of diseases of the thoracic cavity (experience with 155 procedures)]. / Prínos videotorakoskopie a videoasistovaných hrudních zákroku v diagnostice a lécbe onemocnení hrudní dutiny (zkusenosti se 155 zákroky).

Videothoracoscopic procedures and video-assisted thoracic surgery (V.A.T.S.) are up-to-date procedures in thoracic surgery. The authors evaluated results from 155 cases. They reviewed especially indications, complications and results. The most frequent indications were spontaneous pneumothorax, fluidothorax, interstitial lung disease and lung carcinoma. Staging was main procedure in cases of lung carcinoma. Complications were observed in 14 cases (9%). Of these complications 5 developed at the time of surgery (3.2%) and 9 were postoperative (5.8%).

Pig plasma alpha-protease inhibitors PI2, PI3 and PI4 are members of the antichymotrypsin family.

Three related alpha-protease inhibitors, PI2 I, PI3 C and PI4 C2, of blood serum of the pig (Sus scrofa) were isolated. PI2 I inhibited both trypsin and chymotrypsin; PI3 C and PI4 C2 strongly inhibited chymotrypsin, but did not significantly inhibit trypsin. By using SDS-PAGE, the three proteins were found to be composed of single polypeptide chains, and molecular weights were 63,000 for PI2 I, 58,000 for PI3 C and 64,000 for PI4 C2. All three proteins were shown to be glycoproteins. In PI3 C, eight sialic acid residues were found, and in PI4 C2 (similarly as in PI2 F) 10-11 residues were found. Amino acid composition as well as N-terminal sequences of the three proteins were very similar, indicating close homology. Comparison of these partial amino acid sequences with the cDNA-deduced amino acid sequence of pig alpha-antichymotrypsin (AACT; Buchman, 1989, GenBank, Accession No. M29508) revealed great similarities, the sequence of PI2 I being virtually identical with the pig AACT. On the basis of all available results, PI2 is proposed to be pig AACT, an orthologue of human AACT.

Primary structure of cathepsin D inhibitor from potatoes and its structure relationship to soybean trypsin inhibitor family.

A novel effective procedure for the purification of cathepsin D inhibitor from potatoes (PDI) was developed. The amino acid sequence of PDI was determined by analysis of the cyanogen bromide digest and of the limited tryptic and chymotryptic digest of the protein. The inhibitor is a single polypeptide chain protein consisting of 188 residues with a simple sugar moiety attached to Asn-19. The tentative disulfide pairings are also suggested. The sequence data clearly indicate that PDI is homologous with the soybean trypsin inhibitor (STI) (Kunitz) family. The active center of PDI for trypsin inhibition was identified as Pro-Val-Arg-Phe in analogy to STI.

Protein chemical characterization of Mucor pusillus aspartic proteinase. Amino acid sequence homology with the other aspartic proteinases, disulfide bond arrangement and site of carbohydrate attachment.

The amino acid sequence of Mucor pusillus aspartic proteinase was determined by analysis of fragments obtained from cleavage of the enzyme by CNBr and limited tryptic digestion. The proteinase is a single polypeptide chain protein containing 361 amino acid residues, cross-linked by two disulfide bonds. A sugar moiety composed of two GlcNAc residues and four neutral sugar residues is asparagine-linked to the chain. The sequence of M. pusillus proteinase is highly homologous with the M. miehei proteinase (83% identity). The homology with other aspartic proteinases is low (22-24%) and indicates that the Mucor proteinases diverged at an early evolutionary phase. The most conservative regions of the molecule are those involved in catalysis and forming the binding cleft and the core region of the molecule.

Amino acid sequence of bovine spleen cathepsin B.

The complete amino acid sequence of bovine spleen cathepsin B was determined by manual and automatic Edman degradation of fragments prepared by proteolytic or chemical digestion of the enzyme. The single-chain form of the enzyme consists of 253 amino acid residues and its Mr is 27,468 (carbohydrate moiety not included). The light chain (residues 1-47) and the heavy chain (residues 50-253) of the enzyme are linked by the sequence -Gly-Arg (residues 48 and 49) in the single-chain form. Bovine spleen cathepsin B shows 80% sequence homology with cathepsins B from other species. An outstanding feature of bovine spleen cathepsin B not observed with the other cathepsins B is the presence of two additional half-cystine residues.

Modification of serine residues during sequential degradation of proteins and peptides by the phenylisothiocyanate method.

A novel method of serine determination during Edman degradation of proteins and peptides which is based on the reaction of serine degradation products with alkyl thiols is described. The physicochemical characteristics and the structures of the reaction products, i.e., of 5-[alkyl-thio)methyl)-3-phenyl-2-thioxo-4-imidazolinones, were determined. The procedure described permits the products of serine degradation to be obtained in a 70-80% yield.