Lytic Treatment Research Articles

When is Thrombolysis for Acute Lower Limb Ischemia Worthwhile?

Objectives To find variables associated with outcome following thrombolytic treatment for acute lower limb ischemia. Design Re-analysis of a prospective multicentre study. Material and methods One hundred and twenty-one patients with acute lower limb ischemia previously included in a randomised study comparing high- with low-dose thrombolysis were re-analysed ignoring the mode of lytic treatment. All possibly predictive variables were subjected to multivariate analyses to find associations with outcome. Results Previous successful thrombolysis, ankle–brachial index over 0.33, absence of motor dysfunction, presence of cardiac arrhythmia, and lysis of a vascular graft were all associated with successful thrombolysis ( p = 0.003). Previous thrombolysis, age less than 70 years, and ankle–brachial index over 0.33 were all perfect predictors of absence of life-threatening complications or death. Successful lysis, age < 70, and lysis of a native artery as opposed to a vascular graft were all associated with clinical success (preserved patency, limb, and life) after one year ( p = 0.002). Conclusions Previous thrombolysis, age under 70 years, and non-severe ischemia predict successful thrombolysis free from severe complications. Successful thrombolysis is strongly predictive of amputation-free survival with vascular patency for at least one year. Occluded grafts could often be reopened, but long-term outcome is better after thrombolysis of native arteries.

Effect of low frequency ultrasound on combined rt-PA and eptifibatide thrombolysis in human clots

Introduction Fibrinolytics such as recombinant tissue plasminogen activator (rt-PA) are used to treat thrombotic disease such as acute myocardial infarction (AMI) and ischemic stroke. Interest in increasing efficacy and reducing side effects has led to the study of adjuncts such as GP IIb-IIIa inhibitors and ultrasound (US) enhanced thrombolysis. Currently, GP IIb-IIIa inhibitor and fibrinolytic treatment are often used in AMI, and are under investigation for stroke treatment. However, little is known of the efficacy of combined GP IIb-IIIa inhibitor, fibrinolytic and ultrasound treatment. We measure the lytic efficacy of rt-PA, eptifibatide (Epf) and 120 kHz ultrasound treatment in an in-vitro human clot model. Materials and Methods Blood was drawn from 15 subjects after IRB approval. Clots were made in 20 µL pipettes, and placed in a water tank for microscopic visualization during lytic treatment. Clots were exposed to control, rt-PA (rt-PA), eptifibatide (Epf), or rt-PA+eptifibatide (rt-PA + Epf), with (+US) or without (−US) ultrasound for 30 minutes at 37°C in human plasma. Clot lysis was measured over time, using a microscopic imaging technique. The fractional clot loss (FCL) and initial lytic rate (LR) were used to quantify lytic efficacy. Results and Conclusions LR values for (− US) treated clots were 0.8 ± 0.1(control), 1.8 ± 0.3 (Epf), 1.5 ± 0.2 (rt-PA), and 1.3 ± 0.4 (rt-PA + Epf) (% clot width/minute) respectively. In comparison, the (+ US) group exhibited LR values of 1.6 ± 0.2 (control), 4.3 ± 0.4 (Epf), 6.3 ± 0.4 (rt-PA), and 4.6 ± 0.6 (rt-PA + Epf). For (− US) treated clots, FCL was 6.0 ± 0.8 (control), 9.2 ± 2.5 (Epf), 15.6 ± 1.7 (rt-PA), and 28.0 ± 2.2% (rt-PA + Epf) respectively. FCL for (+ US) clots was 13.5 ± 2.4 (control), 20.7 ± 6.4 (Epf), 44.4 ± 3.6 (rt-PA) and 30.3 ± 3.6% (rt-PA + Epf) respectively. Although the addition of eptifibatide enhances the in-vitro lytic efficacy of rt-PA in the absence of ultrasound, the efficacy of ultrasound and rt-PA is greater than that of combined ultrasound, rt-PA and eptifibatide exposure.

Solubilization and characterization of a cell wall-bound trehalase from ascospores of the fission yeast Schizosaccharomyces pombe

The genome of the fission yeast Schizosaccharomyces pombe lacks sequence homologs to ath1 genes coding for acid trehalases in other yeasts or filamentous fungi. However, acid trehalase activity is present at the spore stage in the life cycle of the fission yeast. The enzyme responsible for this activity behaves as a surface enzyme covalently linked to the spore cell walls in both wild-type and ntp1 mutant strains devoid of neutral trehalase. Lytic treatment of particulated cell wall fractions allowed the solubilization of the enzyme into an active form. We have characterized this soluble enzyme and found that its kinetic parameters, optimum pH and temperature, thermal denaturation and salt responses are closely similar to other conventional acid trehalases. Hence, this rather unusual enzyme can be recognized as acid trehalase by its biochemical properties although it does not share genetic homology with other known acid trehalases. The potential role of such acid trehalase in the mobilization of trehalose is discussed.

Fecal Prevalence ofEscherichia coliO157,Salmonella, Listeria,and Bacteriophage InfectingE. coliO157:H7 in Feedlot Cattle in the Southern Plains Region of the United States

Escherichia coli O157:H7, Salmonella, and Listeria are foodborne pathogens of critical importance that often colonize cattle. E. coli O157:H7 can be specifically killed by lytic bacteriophage, and lytic bacteriophage treatment has been suggested as a pre-harvest intervention strategy to reduce foodborne pathogens in cattle. To date, no systematic approach to determine the incidence of E. coli O157:H7-infecting lytic bacteriophage has been published. Therefore, the current study was designed to determine (1) the incidence of E. coli O157, Salmonella spp., and Listeria and (2) the incidence of E. coli O157:H7-infecting bacteriophage in the feces of feedlot steers in commercial feedlots in the United States. Fecal samples (n=60) were collected from four feedlots in two Southern Great Plains states (total (n=240 fecal samples). Salmonella and E. coli O157:H7 were found in 3.8% and 11.7% of the fecal samples, respectively. Bacteriophage targeting E. coli O157:H7 were found in all four feedlots, in 15% of the individual fecal samples, and in 55% of the cattle pens. Our results indicate that such bacteriophage are widespread in feedlot cattle, suggesting that further research into the ecological role of bacteriophage in the gastrointestinal tract is needed.

Surgery versus thrombolysis for acute limb ischaemia: initial management.

Peripheral arterial thrombolysis is a useful technique for the management of peripheral arterial ischaemia. Much is known about the indications, risks and benefits of thrombolysis, although data from randomised controlled studies are not extensive. However, it is not known whether thrombolysis works better than surgery in the initial treatment of acute limb ischaemia. To determine the preferred initial treatment, surgery or thrombolysis, for acute limb ischaemia. The Cochrane Controlled Trials Register (Issue 3, 2001), and the Specialised Trials Register of the Cochrane Peripheral Vascular Diseases Group (September 2001) were searched. Proceedings from all British Vascular Surgical Society, European Vascular Surgical Society and North American Society of Vascular Surgery meetings, Society of Cardiovascular and Interventional Radiology (SCVIR) and Cardiovascular and Interventional Society of Europe (CIRSE), were handsearched. Pharmaceutical firms and trialists were asked for information about unpublished trials. All randomised studies comparing thrombolysis and surgery in the initial management of acute limb ischaemia. Assessment of trial quality and data extraction was done independently by all reviewers. Five trials with a total of 1,283 patients were included. Two trials used a list of procedures of increasing severity of intervention. If lytic treatment were successful, further intervention might prove unnecessary. There was no significant difference in limb salvage or death at 30 days, six months or one year between initial surgery and initial thrombolysis. However, with initial lysis, stroke was significantly more frequent at 30 days, 8/640 patients compared to 0/540 patients receiving initial surgery [Odds ratio (95% CI) 6.41(1.57, 26.22)]; major haemorrhage was more likely at 30 days, 52/588 versus 16/482 [Odds ratio (95% CI) 2.80 (1.70, 4.60)]; and distal embolisation was more likely at 30 days, 42/340 versus 0/338 [Odds ratio (95% CI) 8.35 (4.47, 15.58)]. Patients treated by initial lysis underwent a less severe degree of intervention [Odds ratio (95% CI) 5.37 (3.99, 7.22)], and displayed equivalent overall survival compared to initial surgery [Odds ratio (95% CI) 0.87(0.61, 1.25)]. Universal initial treatment with either surgery or thrombolysis cannot be advocated on the available evidence. There is no overall difference in limb salvage or death at one year between initial surgery and initial thrombolysis. Thrombolysis may be associated with a higher risk of ongoing limb ischaemia, and of haemorrhagic complications, including stroke. The higher risk of complications must be balanced against risks of surgery in each patient.

Multiple intestinal stenoses and peripheral gangrene: A combination of two rare surgical complications in a child with Kawasaki disease

Kawasaki disease (KD) often presents with a challenging variety of clinical symptoms. Severe gastrointestinal complications are rare and mainly appear as pseudo-obstruction. However, the authors report the unique case of a 4-month-old girl with KD suffering from a mechanical ileus. The optimal timing of surgery presented a dilemma, because she received lytic treatment for gangrenes of both her hands and feet and additionally had large coronary artery aneurysms. Finally laparotomy had to be performed while the patient was on an anticoagulant medication, and it showed a 30-cm-long jejunal segment with multiple filiforme stenoses, requiring resection and anastomosis. The postoperative course was uneventful regarding the abdominal situation; however, the left hand and left foot remained gangrenous and had to be amputated. In patients with KD, not only pseudo-obstruction, but irreversible intestinal obliteration has to be encountered. This combination of intestinal stenosis and acral gangrene has not been discribed before. J Pediatr Surg 36:651-653. Copyright © 2001 by W.B. Saunders Company.

Intravenous thrombolytic treatment of mechanical prosthetic valve thrombosis: a study using serial transesophageal echocardiography

OBJECTIVEWe analyzed the results of intravenous thrombolytic treatment under transesophageal echocardiographic (TEE) guidance in prosthetic valve thrombosis.BACKGROUNDThrombotic occlusion of prosthetic valves continues to be an uncommon but serious complication. Intravenous thrombolytic treatment has been proposed as an alternative to surgical intervention.METHODSIn a four-year period, 32 symptomatic patients with prosthetic valve related thrombosis underwent 54 thrombolytic treatment sessions for the treatment of 36 distinct episodes. All patients had low international normalized ratio values at the presentation. Transesophageal echocardiography was performed at baseline and repeated after each thrombolytic treatment session (total 98 TEE examinations). Streptokinase was used as the initial agent with a repeat dose given within 24 h when necessary. Recurrent thrombosis was treated either with tissue plasminogen activator or urokinase.RESULTSThe initial success after first dose was only 53% (17/32) but increased up to 88% (28/32) after repeated thrombolytic sessions upon documentation of suboptimal results on TEE examination (p < 0.01). In addition, four asymptomatic patients with large thrombi were also successfully treated with single infusion. The TEE characteristics of thrombus correlated with clinical presentation and response to lytics. Success was achieved with single lytic infusion in 40% of the obstructive thrombi as compared with 75% of the nonobstructive ones (p < 0.05). The success rates of lytic treatment were similar for mitral versus aortic valves, and for tilting disk versus bileaflet valves. Rapid (3 h) and slow (15 to 24 h) infusion of streptokinase resulted in similar success rates. However, major complications (three patients) occurred only in the rapid infusion group.CONCLUSIONIn patients with prosthetic valve thrombosis, intravenous slow infusion thrombolysis given in discrete, successive sessions guided by serial TEE and transthoracic echocardiography can be achieved with a low risk of complications and a high rate of success.

Comparison of different methods for the isolation and purification of total community DNA from soil

The efficiency and reproducibility of DNA extraction from soil was tested for variations in lytic and purification treatments and their effect on yield and purity of DNA. The extraction yield was improved by increasing the concentration of EDTA or monovalent ions in isolation buffers, by the introduction of mechanical lysis treatments, and by the use of ethanol precipitation in place of PEG precipitation. Purity was improved using buffers with decreasing concentration of EDTA or by reducing the ionic strength of the buffer, and by all mechanical treatments. No lytic treatment was efficient on its own, the highest purity was achieved using Crombach buffer and a combination of bead-beating with lysozyme and SDS lysis followed by potassium acetate and PEG precipitation, phenol/chloroform purification, isopropanol precipitation, and spermine–HCl precipitation. Sonication sheared the DNA more than bead-beating. Lysozyme and SDS lysis without any mechanical treatments allowed isolation of larger fragments (40–90 kb). Denaturing gradient gel electrophoresis analysis of DNA isolated using a range of lytic treatments revealed alterations in band patterns which might reflect differences in the efficiency of lytic treatments.

When is urokinase treatment an effective sole or adjunctive treatment for acute limb ischemia secondary to native artery occlusion?

Background: Intra-arterial thrombolytic therapy is currently a therapeutic option for the treatment of acute limb ischemia. A recent large prospective randomized trial (TOPAS) comparing lytic therapy and operative intervention showed that both forms of treatment had similar results in terms of amputation-free survival. However, the exact role for lytic treatment is unclear. Method: Over a 4-year period we treated 60 cases of acute limb ischemia in 57 patients secondary to native artery occlusion with thrombolytic therapy with urokinase. All patients were evaluated at 1 week, 1 month, and then at 3-month intervals posttreatment. Follow-up evaluations included pulse examination, pulse volume recordings, and duplex examinations to confirm arterial patency. No patients were lost to follow-up with a range of 8 to 54 months (mean 26). Results: Of these 60 native arterial occlusions, complete lysis was achieved in 46 cases (76%). Of these 46 cases, 18 required lysis only, 19 cases (9 iliac, 7 superficial femoral artery (SFA), and 3 popliteal) required angioplasty of lesions uncovered by clot lysis, and 9 patients had lysis and angioplasty of iliac arteries followed by infrainguinal bypasses. Eight of the 57 patients (14%) who had been asymptomatic presented with symptoms limited to new onset claudication, all of which were successfully lysed. Cumulative patency for the 43 successful cases was 90% ± 5% at 1 year and 75% ± 4% at 2 years. The 1-year amputation-free survival for all native artery occlusions was 85% ± 6%. Conclusion: Thrombolysis with urokinase simplified the treatment of native arterial occlusion proving to be the sole therapy in 18 (29%) patients or a valuable adjunct by facilitating the angioplasty of arterial lesions and avoiding open surgery in 60% of patients treated. In addition, the correction of inflow lesions reduced the magnitude of required subsequent bypass procedures to achieve limb salvage. In conclusion, successful thrombolysis of native artery occlusion provided durable arterial patency and limb salvage, particularly in patients with new onset claudication.

Relevance of clinical trial results in myocardial infarction to medical practice: comparison of four year outcome in participants of a thrombolytic trial, patients receiving routine thrombolysis, and those deemed ineligible for thrombolysis

OBJECTIVETo assess the medium to long term outcome of patients ineligible for thrombolysis compared to those enrolled in a clinical trial of thrombolysis and patients receiving non-trial thrombolysis.DESIGNCohort study based...

Prevention of congestive heart failure by early, prehospital thrombolysis in acute myocardial infarction: a long-term follow-up study

The long term impact of pre-hospital thrombolysis in acute myocardial infarction on the subsequent development of heart failure symptoms was investigated in 362 consecutive patients. The pre hospital strategy, used in 61 patients, allowed for very early administration of streptokinase, within 1.2±0.6 (mean±S.D.) hours from pain onset. In contrast, 294 patients treated in hospital received lytic treatment within 2.0±0.9 hours. The pre hospital group showed faster reperfusion, as measured by the time to peak creatine kinase and to ST segment recovery, but only a slightly better ventricular function, as compared to hospital treated patients. Heart failure symptoms were significantly reduced in the pre hospital group during hospitalization and at long term follow up: there were less dyspnea, fatigue, orthopnea, nocturnal dyspnea, nocturia, peripheral edema and episodes of pulmonary edema. Angina was reduced as well. We conclude that the initial benefit of prehospital thrombolysis translates into long term reduction of heart failure symptoms, thus improving quality of life.

In situ trypan blue staining of monolayer cell cultures for permanent fixation and mounting.

In situ trypan blue staining of monolayer cell cultures for permanent fixation and mounting.

GAL4/GAL80-dependent Nucleosome Disruption/Deposition on the Upstream Regions of the Yeast GAL1-10 and GAL80 Genes

Metabolic reactivation (incubating spheroplasts with galactose and casamino acids) causes disruption of nucleosomes from the upstream regions of the yeast GAL1, GAL10, and GAL80 genes. The disruption is specific. It depends on the transcription activator Gal4; it only occurs in galactose-reactivated chromatin from galactose-grown cells; it only affects upstream region, gene-proximal nucleosomes. Due to this specificity and because some of the same regions have shown induction-dependent changes by in vivo analyses, we suggest that the nucleosome-disrupted structure produced by reactivation is the authentic chromatin structure for these regions under conditions of galactose-induced GAL1-10 and GAL80 expression. It is necessary to carry out a spheroplast reactivation treatment in order to observe this disrupted structure in nuclear chromatin because nucleosomes are redeposited onto these regions during the preliminary steps of nuclear isolation (cell harvest/spheroplast preparation) probably in response to the nonphysiological conditions associated with these steps. However, during the same isolation procedures in cells lacking Gal80 protein, there is no nucleosome deposition on these regions, and the in vivo disrupted structure remains present in the nuclear chromatin. Therefore, the nucleosome deposition process that operates in wild-type cells is dependent on Gal80 protein, defining another activity of this negative regulator.

Non-invasive assessment of reperfusion of the infarct-related artery during coronary thrombolysis and its relation with left ventricular function

We monitored ST segment continuously for at least 3 h after the beginning of lytic treatment in 103 patients undergoing early coronary thrombolysis for acute myocardial infarction in order to ascertain whether this technique, which has been shown to be useful to assess recanalization of the infarct-related artery, is also able to identify the improvement in left ventricular function associated with successful reperfusion. Global left ventricular function (assessed in the 30° right anterior oblique projection with the area/length method) and infarct zone wall motion (studied with the centerline method) were evaluated at least 4 weeks after the event. Reperfusion was thought to be achieved when ST segment elevation dropped>50% relative to the most abnormal peak documented at any time in the study. Eighty patients (78%) met the criterium for successful reperfusion (group 1), and 23 (22%) did not (group 2). Both groups had similar clinical and angiographic characteristics. All indexes of global left ventricular function were significantly better in group 1 than in group 2 patients (end-diastolic volume: 176 ± 51 vs. 209 ± 76 ml, end-systolic volume: 66 ± 40 vs. 97 ± 55 ml, ejection fraction: 65 ± 13 vs. 57 ± 11%, respectively, all P < 0.02). Also the severity (−1.6 ± 1.3 vs. − 2.6 ± 1.01 S.D./chord, respectively, P < 0.001) and the extension of hypokinesia in the infarct zone (number of chords with>2 S.D.: 13 ± 16 vs. 28 ± 17, respectively, P < 0.0001) were less in group 1 than in group 2 patients. Furthermore, in reperfused patients, both global left ventricular function and regional wall motion were better in those admitted < 60 min from onset of pain. In conclusion, patients with rapid (> 50%) decrease of ST segment elevation have smaller infarct size and better global left ventricular function than patients without electrocardiographic signs of reperfusion as assessed by continuous ST segment monitoring. This suggests that this non-invasive technique is a powerful tool able to identify patients most benefiting from thrombolytic therapy.

The diversity of potential cheese ripening characteristics of lactic acid starter bacteria: 1. Resistance to cell lysis and levels and cellular distribution of proteinase activities

Abstract By reference to subcellular fraction markers, the resistance to lysis of 23 strains of Lactococcus lactis subsp. cremoris , 30 strains of L. lactis subsp. lactis and five strains of Streptococcus thermophilus and the levels and distribution of proteinase activity in the strains were determined. Strains of L. lactis subsp. cremoris were readily lysed by transfer to hypotonic buffer after treatment with lysozyme alone, whilst strains of L. lactis subsp. lactis and S. thermophilus could be efficiently lysed in this way only after treatment with a combination of lysozyme and mutanolysin. With a few notable exceptions, those strains which gave the fastest rates of acid production also generally presented higher levels of cell surface proteinase, as determined by activity on fluorescein isothiocyanate-labelled β-casein. The highest levels of cell surface proteinase detected were found for strains of L. lactis subsp. cremoris . However, the levels of total proteinase activity in the lactococcal strains did not correlate with the rate of acid production in milk, some slow acid-producers yielding similar or greater total proteinase levels than fast acid-producers. Homology to DNA probes for the lactococcal cell surface proteinase gene and to the conserved region encoding the serine proteinase active site was shown by the fast acid-producing lactococcal strains, but not by most of the slow acid-producing lactococcal strains or by the strains of S. thermophilus . A significant proportion of the total proteinase activity was recovered in the subcellular fractions in which high levels of cytoplasmic marker enzyme activity were found. The total proteinase levels detected in strains of L. lactis subsp. lactis showed a greater range of variation than in the strains of L. lactis subsp. cremoris . High levels of total proteinase activity were found in the slow acid-producers despite the strains having been grown in the presence of yeast extract. For many of the strains, the levels of proteinase released from the cell surface during cell wall degradation with lytic enzyme treatment were higher than those found using whole cells, suggesting that a significant amount of proteolytic activity was either inaccessible to substrate or present in an inactive form.

Is there an age limit for thrombolytic therapy?

Thrombolytic therapy has revolutionized the treatment of acute myocardial infarction. The mortality of infarction increases very steeply with increasing age >65 years. One-month mortality in such patients is in the range of 20–30%. The proportional benefit of lytic treatment is somewhat less in these older patients, but since mortality is high, the absolute benefit is as large or larger than that in younger patients. The risks of stroke due to thrombolysis are balanced between increased risk of cerebral hemorrhage but decreased risk for ischemic/embolie stroke. This trade-off results, overall, in a slightly increased stroke rate of about 1–2 per 1,000 nonfatal strokes, but with about 20 fewer deaths per 1,000 myocardial infarctions. In addition to these striking mortality benefits, there are also important reductions in infarct size, leading to decreased morbidity from heart failure or arrhythmias.

Electrocardiographic diagnosis of postinfarction regional pericarditis. Ancillary observations regarding the effect of reperfusion on the rapidity and amplitude of T wave inversion after acute myocardial infarction.

The ECG recognition of diffuse pericarditis following acute myocardial infarction has been based on changes of the ST segment and, to a lesser extent, alterations of the PQ segment. No ECG criteria exist for the diagnosis of postinfarction regional pericarditis. Recently, it was observed that the T wave evolution follows an atypical pattern before fatal free wall rupture and that this pattern is due to the associated pericarditis. Therefore, this study was conducted on 200 patients with acute myocardial infarction to further elucidate the sensitivity and specificity of the atypical T wave changes in patients with regional postinfarction pericarditis without rupture and to assess the affect of lytic treatment on the rapidity and amplitude of postinfarction T wave evolution. An analysis of the clinical courses and serial ECGs of 200 consecutive patients with acute myocardial infarction was performed. Among 43 patients with postinfarction pericarditis, the pattern of T wave evolution consistently differed from the customary postinfarction pattern of T wave evolution. This unusual evolutionary course was expressed as either persistently positive T waves 48 or more hours after infarction (67%) or premature, gradual reversal of inverted T waves to positive deflections (33%). The sensitivity and specificity of these T wave alterations were 100% and 77%, respectively. The only other processes identified that caused this type of postinfarction T wave evolution were cardiopulmonary resuscitation, reinfarction, and very small infarcts. Both reperfusion, as judged by the creatine kinase-MB curve, and patency, as assessed by the angiogram, were correlated with the rapidity and depth of T wave inversion. Ninety percent of patients with reperfusion attained a maximum T wave negativity of 3 mm or more within 48 hours after the onset of chest pain in the lead that initially displayed the greatest ST segment elevation. Seventy-six percent of patients without reperfusion attained a maximum negativity of 2 mm or less within 72 hours. Thus, like the ST segment, accelerated evolution and deepening of the T wave may be noninvasive markers of reperfusion. First, premature reconcordancy of the ST segment and T wave after acute myocardial infarction is a sensitive, reasonably specific, and easily recognizable ECG manifestation of postinfarction regional pericarditis. Second, reperfusion is associated with accelerated evolution and deepening of the T waves following acute myocardial infarction.

Protoplast production from the unicellular red alga Porphyridium sp. (UTEX 637) by an extracellular bacterial lytic preparation

Protoplasts from the unicellular marine red alga Porphyridium sp. (Porphyridiales, Bangiophyceae, Rhodophyta) were isolated using an extracellular crude enzymatic preparation obtained from a mixture of soil bacteria. Cells incubated with this lytic preparation burst when transferred to distilled water. Culture age, cell density, and concentration of the lytic preparation significantly affected the bursting rates of cells. Fluorescein diacetate staining and the photosynthetic potential of the protoplasts were found to be similar to controls. These findings suggest that the lytic treatment had no effect on cell viability. Similarly, the growth rate and the maximum number of treated cells after 10 d of growth did not differ from those of the untreated cells. The number of regenerating protoplasts of Porphyridium that burst on transferring from the regeneration medium to distilled water rapidly decreased during the first 5 h of regeneration. After 20 h the bursting rates of treated and non-treated cells were similar. This indicates that new capsular polysaccharide resynthesis by treated cells starts at a very early stage.

Thrombolytic therapy in patients requiring cardiopulmonary resuscitation

Cardiopulmonary resuscitation (CPR) is often considered a contraindication to thrombolytic therapy for acute myocardial infarction. Of 708 patients involved in the first 3 Thrombolysis and Angioplasty in Myocardial Infarction trials of lytic therapy for acute infarction, 59 patients required <10 minutes of CPR before receiving lytic therapy (CPR >10 minutes was an exclusion of the trials) or required CPR within 6 hours of treatment. The patients receiving CPR were similar to the remainder of the group with respect to baseline demographics. The indication for CPR was usually ventricular fibrillation (73%) or ventricular tachycardia (24%). The median duration of CPR was 1 minute, with twenty-fifth and seventy-fifth percentiles of 1 and 5 minutes, respectively. The median number of cardioversions/defibrillations performed was 2 (twenty-fifth and seventy-fifth percentiles of 1 and 3 minutes, respectively). Patients receiving CPR were more likely to have anterior infarctions (66 vs 39%), the left anterior descending artery as the infarct-related artery (63 vs 38%) and lower ejection fractions on the initial ventriculogram (46 ± 11 vs 52 ± 12%) than those not receiving CPR. Inhospital mortality was 12 vs 6% with most deaths due to pump failure (57%) or arrhythmia (29%) in the CPR group and pump failure (38%) or reinfarction (25%) in the non-CPR group. At 7 day follow-up the CPR group had a significant increase in ejection fraction (+5 ± 9%) compared with no change in non-CPR group. There were no bleeding complications directly attributed to CPR. In particular, the decrease in hematocrit (median 11) and need for transfusion (37 vs 32%) were the same in both groups. In addition, the CPR group did not spend more days in the cardiac care unit or in hospital than the non-CPR group. In conclusion, patients who have received CPR for <10 minutes had no additional complications attributable to thrombolytic therapy (95% confidence interval 0 to 5%). Therefore, CPR, especially of short duration, should not be considered a contraindication to lytic treatment. In addition, our results suggest that patients requiring CPR during acute infarction constitute a high-risk subgroup which may particularly benefit from receiving thrombolytic therapy.

High efficiency transformation of Tolypocladium geodes conidiospores to phleomycin resistance

A convenient and efficient transformation system has been developed for the filamentous fungus Tolypocladium geodes. In contrast to most of the commonly described techniques requiring prior preparation of protoplasts or spheroplasts, this method leads to high efficiency transformation of T. geodes conidiospores following moderate lytic enzyme treatment. Competent cells so obtained are still resistant to osmotic pressure and can be stored frozen without loss of viability. The highest transformation frequency (3-5 x 10(3) transformants per microgram of DNA) was obtained with plasmid pUT737 containing the Sh ble gene conferring phleomycin resistance under the control of a strong promoter isolated from Trichoderma reesei. Southern hybridization revealed multiple integration sites of plasmid DNA into the T. geodes nuclear DNA despite the absence of homology between the transforming DNA and the recipient genome. Instability could not be detected for the phleomycin phenotype during more than five generations of mitotic growth under non-selective conditions.