The role of thoracic surgery in the management of complicated acute and post-acute COVID-19 pneumonia (PASC).

INTRODUCTION: COVID-19 is considered a respiratory virosis in its classic form, although it may present with heterogeneous symptoms. Thoracic complications occur in a small percentage of patients. Our objective was to evaluate existing experience with this disease and its thoracic manifestations and to determine the real-world status of care of these patients. METHODS: This study is a retrospective, single-institution analysis of a group of patients hospitalized with acute and post-acute COVID-19 pneumonia at Thomayer Hospital in Prague in the period from December 2020 to March 2022 and indicated for a thoracic surgical procedure. RESULTS: During the peak of COVID-19 pandemic, a thoracic intervention was performed in 46 admitted patients. Thoracic drainage (due to pneumothorax in 18 cases, fluidothorax in 3 cases, CT-guided lung abscess drainage in 2 cases, and CT-guided pneumatocele drainage in 2 cases) were the most common thoracic surgical procedures. Pleurectomy/decortication surgery was done in 10 cases. Additionally, 12 lung parenchyma-sparing resections were performed, while lobectomy was required in 2 cases. Resection of postintubation tracheal stenosis due to a severe course of COVID-19 pneumonia was indicated in 2 patients. CONCLUSION: Even mild COVID-19 may cause a considerable morphological a functional alteration of the respiratory system. The most common complications of COVID-19 pneumonia that require a thoracic surgical intervention include pathologies associated with an air leak and accumulation of air (pneumothorax, pneumomediastinum and subcutaneous emphysema). The development of pulmonary necrosis, symptomatic bronchiectasis, pneumatocele, and bullous-fibrotic formations may result in pneumothorax, hemothorax or thoracic empyema in sporadic cases. An early thoracic surgical intervention to treat thoracic complications of COVID-19 pneumonia can improve the survival of COVID-19 patients.

Development of a new peptide-bead coupling method for an all peptide-based Luminex multiplexing assay for detection of Plasmodium falciparum antibody responses.

Using a recombinant protein antigen for antibody testing shows a sum of antibody responses to multiple different immune epitopes existing in the protein antigen. In contrast, the antibody testing to an immunogenic peptide epitope reflects a singular antibody response to the individual peptide epitope. Therefore, using a panel of peptide epitopes provides an advantage for profiling multiple singular antibody responses with potential to estimate recent malaria exposure in human infections. However, transitioning from malaria immune epitope peptide-based ELISA to an all peptide bead-based multiplex Luminex assay presents some challenges including variation in the ability of different peptides to bind beads. The aim of this study was to develop a peptide coupling method while demonstrating the utility of these peptide epitopes from multiple stage antigens of Plasmodium falciparum for measuring antibodies. Successful coupling of peptide epitopes to beads followed three steps: 1) development of a peptide tag appended to the C-terminus of each peptide epitope consisting of beta-alanine-lysine (x 4)--cysteine, 2) bead modification with a high concentration of adipic acid dihydrazide, and 3) use of the peptide epitope as a blocker in place of the traditional choice, bovine serum albumin (BSA). This new method was used to couple 12 peptide epitopes from multiple stage specific antigens of P. falciparum, 1 Anopheles mosquito salivary gland peptide, and 1 Epstein-Barr virus peptide as an assay control. The new method was applied to testing of IgG in pooled samples from 30 individuals with previously repeated malaria exposure in western Kenya and IgM and IgG in samples from 37 U.S. travelers with recent exposure to malaria. The new peptide-bead coupling method and subsequent multiplex Luminex assay showed reliable detection of IgG to all 14 peptides in Kenyan samples. Among 37 samples from U.S. travelers recently diagnosed with malaria, IgM and IgG to the peptide epitopes were detected with high sensitivity and variation. Overall, the U.S. travelers had a much lower positivity rates of IgM than IgG to different peptide epitopes, ranging from a high of 62.2% positive for one epitope to a low of only 5.4% positive for another epitope. In contrast, the travelers had IgG positive rates from 97.3% to 91.9% to various peptide epitopes. Based on the different distribution in IgM and IgG positivity to overall number of peptide epitopes and to the number of pre-erythrocytic, erythrocytic, gametocytic, and salivary stage epitopes at the individual level, four distinct patterns of IgM and IgG responses among the 37 samples from US travelers were observed. Independent peptide-bead coupling and antibody level readout between two different instruments also showed comparable results. Overall, this new coupling method resolves the peptide-bead coupling challenge, is reproducible, and can be applied to any other immunogenic peptide epitopes. The resulting all peptide bead-based multiplex Luminex assay can be expanded to include other peptide epitopes of P. falciparum, different malaria species, or other diseases for surveillance, either in US travelers or endemic areas.

Penetrating abdominal trauma - selected case reports.

We present 3 case-reports with penetrating abdominal injury from our practice in this article. An urgent laparotomy was performed in all cases because of haemodynamic instability or the mechanism of injury. Penetrative abdominal traumas are associated with a high risk of life-threatening intra-abdominal injuries, require urgent revision and are often accompanied by postoperative infections of the peritoneal cavity. In recent years, there has been a growing tendency towards mini-invasive approaches or even non-operative treatment. This trend is particularly evident in the United States of America, where doctors experience a higher number of penetrating injuries compared to the prevalent blunt force trauma in Europe. The authors describe the need to follow all recommended procedures in the pre-hospital and hospital phases of treatment of these patients and compare them with recent literature. Key words: penetrating abdominal trauma.

Metformin attenuates myocardium dicarbonyl stress induced by chronic hypertriglyceridemia.

Reactive dicarbonyls stimulate production of advanced glycation endproducts, increase oxidative stress and inflammation and contribute to the development of vascular complications. We measured concentrations of dicarbonyls - methylglyoxal (MG), glyoxal (GL) and 3-deoxyglucosone (3-DG) - in the heart and kidney of a model of metabolic syndrome - hereditary hypertriglyceridemic rats (HHTg) and explored its modulation by metformin. Adult HHTg rats were fed a standard diet with or without metformin (300 mg/kg b.w.) and dicarbonyl levels and metabolic parameters were measured. HHTg rats had markedly elevated serum levels of triacylglycerols (p<0.001), FFA (p<0.01) and hepatic triacylglycerols (p<0.001) along with increased concentrations of reactive dicarbonyls in myocardium (MG: p<0.001; GL: p<0.01; 3-DG: p<0.01) and kidney cortex (MG: p<0.01). Metformin treatment significantly reduced reactive dicarbonyls in the myocardium (MG: p<0.05, GL: p<0.05, 3-DG: p<0.01) along with increase of myocardial concentrations of reduced glutathione (p<0.01) and glyoxalase 1 mRNA expression (p<0.05). Metformin did not have any significant effect on dicarbonyls, glutathione or on glyoxalase 1 expression in kidney cortex. Chronically elevated hypertriglyceridemia was associated with increased levels of dicarbonyls in heart and kidney. Beneficial effects of metformin on reactive dicarbonyls and glyoxalase in the heart could contribute to its cardioprotective effects.

Visfatin is actively secreted in vitro from U-937 macrophages, but only passively released from 3T3-L1 adipocytes and HepG2 hepatocytes.

Visfatin is a multi-functional molecule that can act intracellularly and extracellularly as an adipokine, cytokine and enzyme. One of the main questions concerning visfatin is the mechanism of its secretion; whether, how and from which cells visfatin is released. The objective of this in vitro study was to observe the active secretion of visfatin from 3T3-L1 preadipocytes and adipocytes, HepG2 hepatocytes, U-937, THP-1 and HL-60 monocytes and macrophages. The amount of visfatin in media and cell lysate was always related to the intracellular enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), to exclude the passive release of visfatin. Visfatin was not found in media of 3T3-L1 preadipocytes. In media of 3T3-L1 adipocytes and HepG2 hepatocytes, the ratio of visfatin to the amount of GAPDH was identical to cell lysates. Hence, it is likely that these cells do not actively secrete visfatin in a significant manner. However, we found that significant producers of visfatin are differentiated macrophages and that the amount of secreted visfatin depends on used cell line and it is affected by the mode of differentiation. Results show that 3T3-L1 adipocytes and HepG2 hepatocytes released visfatin only passively during the cell death. U-937 macrophages secrete visfatin in the greatest level from all of the tested cell lines.

Plasma membrane density of GABA(B)-R1a, GABA(B)-R1b, GABA-R2 and trimeric G-proteins in the course of postnatal development of rat brain cortex.

With the aim to understand the onset of expression and developmental profile of plasma membrane (PM) content /density of crucial components of GABA(B)-R signaling cascade, GABA(B)-R1a, GABA(B)-R1b, GABA(B)-R2, G(i)1/G(i)2alpha, G(i)3alpha, G(o)alpha, G(z)alpha and Gbeta subunit proteins were determined by quantitative immunoblotting and compared in PM isolated from brain cortex of rats of different ages: between postnatal-day-1 (PD1) and 90 (PD90). PM density of GABA(B)-R1a, GABA(B)-R2, G(i)1/G(i)2alpha, G(i)3alpha, G(o)alpha, G(z)alpha and Gbeta was high already at birth and further development was reflected in parallel decrease of both GABA(B)-R1a and GABA(B)-R2 subunits. The major decrease of GABA(B)-R1a and GABA(B)-R2 occurred between the birth and PD15: to 55 % (R1a, **) and 51 % (R2, **), respectively. Contrarily, PM level of the cognate G-proteins G(i)1/G(i)2alpha, G(i)3alpha, G(o)alpha, G(z)alpha and Gbeta was unchanged in the course of the whole postnatal period of brain cortex development. Maturation of GABA(B)-R cascade was substantially different from ontogenetic profile of prototypical plasma membrane marker, Na, K-ATPase, which was low at birth and further development was reflected in continuous increase of PM density of this enzyme. Major change occurred between the birth and PD25. In adult rats, membrane content of Na, K-ATPase was 3-times higher than around the birth.

Reflects the coat protein variability of apple mosaic virus host preference?

Apple mosaic virus (ApMV) is a widespread ssRNA virus which infects diverse species of Rosales. The phylogenetic analysis of complete capsid protein gene of the largest set of ApMV isolates discriminated two main clusters of isolates: one cluster correlates with Maloideae hosts and Trebouxia lichen algae hosts; a second with hop, Prunus, and other woody tree hosts. No correlation was found between clusters and geographic origin of virus isolates, and positive selection hypothesis in distinct hosts was not confirmed: in all virus populations, purifying selection had occurred. GGT→AAT substitution resulted in Gly→Asn change inside the zinc-finger motif in the capsid protein was revealed specific for discrimination of the clusters and we hypothesise that could influence the host preference.

The influence of monovalent cations on trimeric G protein G(i)1α activity in HEK293 cells stably expressing DOR-G(i)1α (Cys(351)-Ile(351)) fusion protein.

The effect of monovalent cations on trimeric G protein G(i)1α was measured at equimolar concentration of chloride anion in pertussis-toxin (PTX)-treated HEK293 cells stably expressing PTX-insensitive DOR- G(i)1α (Cys(351)-Ile(351)) fusion protein by high-affinity [(35)S]GTPgammaS binding assay. The high basal level of binding was detected in absence of DOR agonist and monovalent ions and this high level was inhibited with the order of: Na(+) > K(+) > Li(+). The first significant inhibition was detected at 1 mM NaCl. The inhibition by monovalent ions was reversed by increasing concentrations of DOR agonist DADLE. The maximum DADLE response was also highest for sodium and decreased in the order of: Na(+) > K(+) ~ Li(+). Our data indicate i) an inherently high activity of trimeric G protein G(i)1α when expressed within DOR- G(i)1α fusion protein and determined in the absence of monovalent cations, ii) preferential sensitivity of DOR- G(i)1alpha to sodium as far as maximum of agonist response is involved.

[A different view of acute upper gastrointestinal bleeding in liver cirrhosis patients]. / Jiný pohled na akutní krvácení do horního trávicího traktu u pacientu s jaterní cirhózou.

OBJECTIVES: The study focuses predominantly on non-varicose sources of acute upper gastrointestinal bleeding in liver cirrhosis patients and aims to determine its mortality. METHODS AND SUBJECTS: The prospective examination included 137 liver cirrhosis patients with acute upper GIT bleeding. All the patients underwent an endoscopic examination. In case of multiple findings, defining the bleeding source was based on the specialist's attitude presented as the conclusion of the endoscopic examination. RESULTS: The most frequent causes of acute bleeding included oesophagus varices (57.7%), followed by peptic gastric and duodenal ulcers (18.2%), then portal hypertension gastropathy (9.5%), gastric varices (5.1%), reflux oesophagitis (2.9%), Mallory-Weiss syndrome (2.9%) and erosive gastropathy (1.5%). The endoscopy of the upper digestive tract resulted in a negative diagnosis in not more than 2.2% of patients. The majority of examinations showed multiple findings in the upper digestive tract, each of which could have been a potential cause of bleeding. Mortality in all bleeding cirrhotic patients reached 14.6%, 18.6% of which were related to the varicose type of bleeding and 7.8% to the non-varicose type. CONCLUSION: Portal hypertension led to bleeding (caused by varices and portal hypertension gastropathy) in 72.3% of patients, 62.8% patients suffered from purely varicose bleeding, 37.2% patients from non-varicose bleeding. Mortality was statistically significantly higher on 0.1 level of significance in cases of varicose bleeding in comparison with non-varicose bleeding. An emphasis should be laid on an early and detailed endoscopic examination leading to an appropriate diagnosis and therapy.

[Effects of mental stress on the health status of the accused during a criminal trial]. / Vliv psychického stresu na zdravotni stav obvineného v prubehu trestního rízení.

A court-sworn medical expert is sometimes authorized to pass a medical judgement, whether an older, from serious diseases suffering accused is able to take part in the criminal trial proceedings. The court-sworn medical expert is required to consider the accused's fitness, his mental and physical ability to appear in court, to understand the trial, to answer the questions of the judge, to defend himself, to put questions and objections against the witness's testimony, etc. Such medical expert's opinion is usually a task for a psychiatrist. Judgement of the ability of the accused to take part in the main court trial is of another character, especially when the accused is suffering from a serious disease, e.g. cardiovascular, pulmonary, gastrointestinal, haematological, tumorous or other. In this case the medical judgement is usually required from a doctor of internal medicine. Nevertheless, this is not an easy task for him. As far as these problems are concerned, the expert gathers only little experience of his own during his juridical practice. Similar cases have been extremely sporadically published in medical or juridical literature and if, then in common sense only. It is evident that the expert must face any possible aggravation of the accused's difficulties. At the same time the expert ought to take care lest the court trial should be inadequately extended and even should prevent the accused's avoidance in the main court trial. This paper tries to determine the basic rules for the court-sworn experts in the branch of internal medicine and would like to facilitate them to judge under which circumstances a seriously ill accused may appear in trial proceedings without exposing him to a serious damage of his health or even endangerment of his life.

Subcellular redistribution of trimeric G-proteins--potential mechanism of desensitization of hormone response: internalization, solubilization, down-regulation.

Agonist-induced subcellular redistribution of G-protein coupled receptors (GPCR) and of trimeric guanine-nucleotide binding regulatory proteins (G-proteins) represent mechanisms of desensitization of hormone response, which have been studied in our laboratory since 1989. This review brings a short summary of these results and also presents information about related literature data covering at least small part of research carried out in this area. We have also mentioned sodium plus potassium dependent adenosine triphosphatase (Na, K-ATPase) and 3H-ouabain binding as useful reference standard of plasma membrane purity in the brain.

[Long-term monitoring of patients with clinical symptoms of upper gastrointestinal tract bleeding with a negative endoscopy result]. / Dlouhodobé sledování pacientu s klinickými známkami krvácení do horní cásti trávicího traktu a negativním endoskopickým nálezem.

The authors present the results of a long-term monitoring of patients who presented with clinical signs of bleeding from the upper gastrointestinal tract (GIT) but totally negative endoscopy results on admission. Retrospective-prospective analysis of acute endoscopies in patients with clinical signs of bleeding from the upper gastrointestinal tract performed in the Endoscopy Centre of the OstravaTeaching Hospital from 2002 to 2005, long term monitoring of the sample with negative results on admission. A total of 133 patients, i.e. 16.3 % of all acute procedures, with no source of bleeding detected in the first endoscopy. 26.4% of wrong indications. In the rest of the sample, a source of bleeding was detected by endoscopy in 17 patients (15 in an early examination and 2 within one month from the event), i.e. 17.3%. The rate of bleeding recurrence was 15%. The risk of recurrence was higher in patients with haematemesis and a decrease in the blood count (BC) at the time of the first event. In 19 patients, i.e. 14.3%, the source was not detected. In the remaining 33 patients, the findings were as follows: 1) in 4 patients, the source of bleeding was detected in the small intestine (push enteroscopy or enteroclysis); 2) in 3 patients, the source of bleeding was detected in the colon; 3) in 6 patients, IBD was detected; 4) in 5 patients, cirrhosis of the liver was diagnosed within months or years from the event.

[Endoscopic findings in upper gastrointestinal tract in patients with liver cirrhosis]. / Endoskopické nálezy v horním trávicím traktu u pacientu s jaterní cirhózou.

151 patients suffering from the cirrhosis of the liver underwent a prospective endoscopic examination of the upper digestive tract. The most frequent diagnoses in the group with the cirrhosis of the liver included oesophagus varices (64.9%), portal hypertension gastropathy (45.7%) and the peptic ulcer of the gastroduodenum (25.8%). A normal diagnosis in the endoscopy of the upper digestive tract was found only in 8.6%. Other diagnoses comprised reflux oesophagitis (13.2%), diaphragm hiatus hernia (12.6 %), duodenogastric reflux (8.6 %), gastric antrum erosion (4.6 %), aphthic gastropathy (3.3 %), rhagades of the cardium (2%), gastric polyp (1.3%), mycotic oesophagitis, gastric carcinoma, oesophagus carcinoma and oesophagus achalasy (0.7% each). Further on the study discusses possible causes of the high incidence of peptic ulcers in the patients with the cirrhosis of the liver. All findings are correlated with literary data.

[The etiology of upper gastrointestinal bleeding in patients with liver cirrhosis]. / Príciny akutního krvácení do horního trávicího traktu u pacientu s jaterní cirhózou.

108 patients suffering from the cirrhosis of the liver and acute bleeding into the upper digestive tract underwent a prospective endoscopic examination with diagnostic and therapeutic objectives. The most frequent causes of acute bleeding included oesophagus varices (57.4%) followed by peptic gastric ulcer (13.9%) and peptic ulcer of duodenum (11.1%), then portal hypertension gastropathy (5.6%), gastric varices (4.6%), reflux oesophagitis (2.8%), Mallory-Weiss syndrom (2.8%) and erosive gastropathy (0.9%). The endoscopy of the upper digestive tract in one patient resulted in negative diagnosis. 69% of examinations showed multiple findings in the upper digestive tract, each of which could have been a potential cause of bleeding. To determine the source of bleeding the specialist's attitude presented at the end of the endoscopic examination was taken into consideration. In 67.6% of patients the bleeding was a direct consequence of portal hypertension, in 62% it was caused by varices. The emphasis is put on early and thorough endoscopic examinations aimed at proper diagnosis and therapy.

Proteomic identification of the wt-p53-regulated tumor cell secretome.

Tumor-stroma interactions play a major role in tumor development, maintenance and progression. Yet little is known on how the genetic alterations that underlie cell transformation elicit cell extrinsic changes modulating heterotypic cell interactions. We hypothesized that these events involve a modification in the complement of secreted proteins by the cell, acting as mediators of intercellular communication. To test this hypothesis, we examined the role of wt-p53, a major tumor suppressor, on the tumor microenvironment through its regulation of secreted factors. Using a combination of 2-DE and cICAT proteomic techniques, we found a total of 111 secreted proteins, 39 of which showed enhanced and 21 inhibited secretion in response to wt-p53 expression. The majority of these were not direct targets of p53 transcription factor activity, suggesting a novel role for wt-p53 in the control of intracellular protein trafficking and/or secreted protein stability. Evidence for p53-controlled post-translational modifications on nine secreted proteins was also found. These findings will enhance our understanding of wt-p53 modulated interactions of the tumor with its environment.

Resolution of G(s)alpha and G(q)alpha/G(11)alpha proteins in membrane domains by two-dimensional electrophoresis: the effect of long-term agonist stimulation.

Low-density membrane-domain fractions were prepared from S49 lymphoma cells and clone e2m11 of HEK293 cells expressing a large number of thyrotropin-releasing hormone receptor (TRH-R) and G(11)alpha by flotation on sucrose density gradients. The intact cell structure was broken by detergent-extraction, alkaline-treatment or drastic homogenization. Three types of low-density membranes were resolved by two-dimensional electrophoresis and analyzed for G(s)alpha (S49) or G(q)alpha/G11) (e2m11) content. Four individual immunoblot signals of Gsalpha protein were identified in S49 lymphoma cells indicating complete resolution of the long G(s)alpha L+/-ser and short G(s)alpha S+/-ser variants of G(s)alpha. All these were diminished by prolonged agonist (isoprenaline) stimulation. In e2m11-HEK cells, five different immunoblot signals were detected indicating post-translational modification of G proteins of G(q)alpha/G(11)alpha family. The two major spots corresponding to exogenously (over)expressed G(11)alpha and endogenous G(q)alpha were reduced; the minor spots diminished by hormonal stimulation. Parallel analysis by silver staining of the total protein content indicated that no major changes in protein composition occurred under these conditions. Our data thus indicate that agonist-stimulation of target cells results in down-regulation of all different members of G(s) and G(q)/G(11) families. This agonist-specific effect may be demonstrated in crude membrane as well as domain/raft preparations and it is not accompanied by changes in overall protein composition.

Biochemistry of transmembrane signaling mediated by trimeric G proteins.

Many extracellular signals are at the cell surface received by specific receptors, which upon activation transduce information to the appropriate cellular effector molecules via trimeric G proteins. The G protein-mediated cascades ultimately lead to the highly refined regulation of systems such as sensory perception, cell growth, and hormonal regulation. Transmembrane signaling may be seriously deranged in various pathophysiological conditions. Over the last two decades the major experimental effort of our group has been devoted to better understanding the molecular mechanisms underlying transmembrane signaling regulated by G proteins and to the closely related process of desensitization of hormone response. This review provides general information about the basic principles of G protein-regulated transmembrane signaling as well as about our contribution to the current progress in the field.

Can 8-oxo-dG be used as a predictor for individual radiosensitivity?

PURPOSE: To develop predictive tests for individual radiosensitivity of tumor patients. METHODS AND MATERIALS: Acute skin reactions were clinically scored among 40 women after 46 Gy, given with 2 Gy fractions to breast and regional lymph nodes, adjuvant after surgery. The acute skin reactions were compared to the excretion of 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dG) in urine, determined by high-performance liquid chromatography (HPLC) with electrochemical detector. Specimens of urine were collected before and during postoperative radiation treatment at given intervals. We compared a group of 9 patients with the most pronounced skin reactions with another group of 8 patients with almost no skin reactions at 46 Gy. RESULTS: The level of 8-oxo-dG excreted in urine during 8 h was measured. After normalizing the excretion to irradiated volumes, dose per volume and excretion before irradiation, the 8-oxo-dG level in urine was significantly (p < 0.001) lower for the patients with pronounced skin reactions as compared to patients with minor skin reactions, at an accumulated dose of 12 Gy. In addition, the background level of 8-oxo-dG excreted before treatment started, was significantly (p = 0.043) lower for patients with minor skin reactions as compared to patients with pronounced skin reactions. The background level of 8-oxo-dG was corrected for body weight and normalized to BMI. CONCLUSION: We suggest that the excretion of 8-oxo-dG into urine of breast cancer patients is a possible marker for acute radiosensitivity.

Selective reduction of dormant maternal mRNAs in mouse oocytes by RNA interference.

Specific mRNA degradation mediated by double-stranded RNA (dsRNA), which is termed RNA interference (RNAi), is a useful tool with which to study gene function in several systems. We report here that in mouse oocytes, RNAi provides a suitable and robust approach to study the function of dormant maternal mRNAs. Mos (originally known as c-mos) and tissue plasminogen activator (tPA, Plat) mRNAs are dormant maternal mRNAs that are recruited during oocyte maturation; translation of Mos mRNA results in the activation of MAP kinase. dsRNA directed towards Mos or Plat mRNAs in mouse oocytes effectively results in the specific reduction of the targeted mRNA in both a time- and concentration-dependent manner. Moreover, dsRNA is more potent than either sense or antisense RNAs. Targeting the Mos mRNA results in inhibiting the appearance of MAP kinase activity and can result in parthenogenetic activation. Mos dsRNA, therefore, faithfully phenocopies the Mos null mutant. Targeting the Plat mRNA with Plat dsRNA results in inhibiting production of tPA activity. Finally, effective reduction of the Mos and Plat mRNA is observed with stoichiometric amounts of Mos and Plat dsRNA, respectively.