Predictors for affected stroke territory and outcome of acute stroke treatments are different for posterior versus anterior circulation stroke.

Distinct patient characteristics have been proposed for ischaemic stroke in the anterior versus posterior circulation. However, data on functional outcome according to stroke territory in patients with acute stroke treatment are conflicting and information on outcome predictors is scarce. In this retrospective study, we analysed functional outcome in 517 patients with stroke and thrombolysis and/or thrombectomy treated at the University Hospital Zurich. We compared clinical factors and performed multivariate logistic regression analyses investigating the effect of outcome predictors according to stroke territory. Of the 517 patients included, 80 (15.5%) suffered a posterior circulation stroke (PCS). PCS patients were less often female (32.5% vs. 45.5%, p = 0.031), received thrombectomy less often (28.7% vs. 48.3%, p = 0.001), and had lower median admission NIHSS scores (5 vs. 10, p < 0.001) as well as a better median three months functional outcome (mRS 1 vs. 2, p = 0.010). Predictors for functional outcome were admission NIHSS (OR 0.864, 95% CI 0.790-0.944, p = 0.001) in PCS and age (OR 0.952, 95% CI 0.935-0.970, p < 0.001), known symptom onset (OR 1.869, 95% CI 1.111-3.144, p = 0.018) and admission NIHSS (OR 0.840, 95% CI 0.806-0.876, p < 0.001) in ACS. Acutely treated PCS and ACS patients differed in their baseline and treatment characteristics. We identified specific functional outcome predictors of thrombolysis and/or thrombectomy success for each stroke territory.

Comparative effectiveness of antitumour necrosis factor agents, biologics with an alternative mode of action and tofacitinib in an observational cohort of patients with rheumatoid arthritis in Switzerland.

BACKGROUND: Multiple biologic and targeted synthetic disease-modifying rheumatic drugs (b/tsDMARDs) are approved for the management of rheumatoid arthritis (RA), including TNF inhibitors (TNFi), bDMARDs with other modes of action (bDMARD-OMA) and Janus kinase inhibitors (JAKi). Combination of b/tsDMARDs with conventional synthetic DMARDs (csDMARDs) is recommended, yet monotherapy is common in practice. OBJECTIVE: To compare drug maintenance and clinical effectiveness of three alternative treatment options for RA management. METHODS: This observational cohort study was nested within the Swiss RA Registry. TNFi, bDMARD-OMA (abatacept or anti-IL6 agents) or the JAKi tofacitinib (Tofa) initiated in adult RA patients were included. The primary outcome was overall drug retention. We further analysed secondary effectiveness outcomes and whether concomitant csDMARDs modified effectiveness, adjusting for potential confounding factors. RESULTS: 4023 treatment courses of 2600 patients were included, 1862 on TNFi, 1355 on bDMARD-OMA and 806 on Tofa. TNFi was more frequently used as a first b/tsDMARDs, at a younger age and with shorter disease duration. Overall drug maintenance was significantly lower with TNFi compared with Tofa [HR 1.29 (95% CI 1.14 to 1.47)], but similar between bDMARD-OMA and Tofa [HR 1.09 (95% CI 0.96 to 1.24)]. TNFi maintenance was decreased when prescribed without concomitant csDMARDs [HR: 1.27 (95% CI 1.08 to 1.49)], while no difference was observed for bDMARD-OMA or Tofa maintenance with respect to concomitant csDMARDs. CONCLUSION: Tofa drug maintenance was comparable with bDMARDs-OMA and somewhat higher than TNFi. Concomitant csDMARDs appear to be required for optimal effectiveness of TNFi, but not for bDMARD-OMA or Tofa.

Socioeconomic status and lifestyle behaviours in cancer survivors: smoking and physical activity.

PURPOSE: Smoking cessation and increased physical activity (pa) have been linked to better outcomes in cancer survivors. We assessed whether socioeconomic factors influence changes in those behaviours after a cancer diagnosis. METHODS: As part of a cross-sectional study, a diverse group of cancer survivors at the Princess Margaret Cancer Centre (Toronto, ON), completed a questionnaire about past and current lifestyle behaviours and perceptions about the importance of those behaviours with respect to their health. The influence of socioeconomic indicators on smoking status and physical inactivity at 1 year before and after diagnosis were assessed using multivariable logistic regression with adjustment for clinico-demographic factors. RESULTS: Of 1222 participants, 1192 completed the smoking component. Of those respondents, 15% smoked before diagnosis, and 43% of those smokers continued to smoke after. The proportion of survivors who continued to smoke increased with lower education level (p = 0.03). Of the 1106 participants answering pa questions, 39% reported being physically inactive before diagnosis, of whom 82% remained inactive afterward. Survivors with a lower education level were most likely to remain inactive after diagnosis (p = 0.003). Lower education level, household income, and occupation were associated with the perception that pa had no effect or could worsen fatigue and quality of life (p ≤ 0.0001). CONCLUSIONS: In cancer survivors, education level was a major modifier of smoking and pa behaviours. Lower socioeconomic status was associated with incorrect perceptions about pa. Targeting at-risk survivors by education level should be evaluated as a strategy in cancer survivorship programs.

Identification of predictive CT angiographic factors in the development of high-risk type 2 endoleaks after endovascular aneurysm repair in patients with infrarenal aortic aneurysms.

PURPOSE: An extensive analysis of the value of computed tomography (CT) parameters as potential predictors of the clinical outcome of type 2 endoleaks after endovascular aortic aneurysm repair (EVAR). MATERIALS AND METHODS: Initial CT scans of 130 patients with abdominal aortic aneurysms (AAAs) were retrospectively reviewed. On the basis of postoperative CT scans and angiographies, patients were stratified into a low-risk group (LRG; without or transient type 2 endoleak; n = 80) and a high-risk group (HRG, persistent type 2 endoleak or need for reintervention; n = 50). Statistical analysis comprised a univariate and multivariate analysis. RESULTS: Anatomical, thrombus-specific, as well as aortic side branch parameters were assessed on the initial CT scan. Of all anatomical parameters, the diameter of the immediate infrarenal aorta was significantly different in the univariate analysis (LRG 22.4 ±â€Š3.8 mm; HRG 23.6 ±â€Š2.5 mm; p = 0.03). The investigation of the thrombus-specific parameters showed a trend towards statistical significance for the relative thrombus load (LRG 31.7 ±â€Š18.0%; HRG 25.3 ±â€Š17.5%; p = 0.09). Assessment of aortic side branches revealed only for the univariate analysis significant differences in the patency of the inferior mesenteric artery (LRG 71.3%; HRG 92.0%; p = 0.003) and their diameter (LRG 3.3 ±â€Š0.7 mm; HRG 3.8 ±â€Š0.9 mm; p = 0.004). In contrast, the number of lumbar arteries (LAs; LRG 2.7 ±â€Š1.4; HRG 3.6 ±â€Š1.2; univariate: p = 0.01; multivariate: p = 0.006) as well as their diameter (LRG 2.1 ±â€Š0.4 mm; HRG 2.4 ±â€Š0.4 mm; univariate: p < 0.001; multivariate: p = 0.006) were highly significantly associated with the development of type 2 endoleaks of the HRG. CONCLUSION: The most important predictive factors for the development of high-risk type 2 endoleaks were mainly the number and the diameter of the LAs which perfused the AAA. KEY POINTS: • This study is a very detailed and comprehensive analysis of the value of various CT parameters as potential predictors of the clinical outcome of type 2 endoleaks after EVAR. • Anatomical as well as thrombus-specific parameters were unsuitable as predictors. • The most important predictive factors were mainly the number and the diameter of the LAs which perfused the AAA.

Can early computed tomography angiography after endovascular aortic aneurysm repair predict the need for reintervention in patients with type II endoleak?

PURPOSE: This study was designed to identify parameters on CT angiography (CTA) of type II endoleaks following endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA), which can be used to predict the subsequent need for reinterventions. METHODS: We retrospectively identified 62 patients with type II endoleak who underwent early CTA in mean 3.7 ± 1.9 days after EVAR. On the basis of follow-up examinations (mean follow-up period 911 days; range, 373-1,987 days), patients were stratified into two groups: those who did (n = 18) and those who did not (n = 44) require reintervention. CTA characteristics, such as AAA, endoleak, as well as nidus dimensions, patency of the inferior mesenteric artery, number of aortic branch vessels, and the pattern of endoleak appearance, were recorded and correlated with the clinical outcome. RESULTS: Univariate and receiver operating characteristic curve regression analyses revealed significant differences between the two groups for the endoleak volume (surveillance group: 1391.6 ± 1427.9 mm(3); reintervention group: 3227.7 ± 2693.8 mm(3); cutoff value of 2,386 mm(3); p = 0.002), the endoleak diameter (13.6 ± 4.3 mm compared with 25.9 ± 9.6 mm; cutoff value of 19 mm; p < 0.0001), the number of aortic branch vessels (2.9 ± 1.2 compared with 4.2 ± 1.4 vessels; p = 0.001), as well as a "complex type" endoleak pattern (13.6 %, n = 6 compared with 44.4 %, n = 8; p = 0.02). CONCLUSIONS: Early CTA can predict the future need for reintervention in patients with type II endoleak. Therefore, treatment decision should be based not only on aneurysm enlargement alone but also on other imaging characteristics.

Open reduction and palmar plate-osteosynthesis in combination with a nanocrystalline hydroxyapatite spacer in the treatment of comminuted fractures of the distal radius.

In a prospective study, we used the nanocrystalline hydroxyapatite paste Ostim (Osartis, Obernburg, Germany) in combination with a palmar plate to treat comminuted radius fractures with a metaphyseal and articular component in order to examine the clinical use of Ostim as a bone substitute. Twenty-one patients with 22 radius fractures of AO types C2 and C3 were included in the study. The measurements, taken 10.2+/-1.3 months after the initial treatment, revealed a dorsopalmar tilt of 8.8+/-3.7 degrees , a radioulnar inclination of 18.8+/-2.8 degrees and an ulnar variance of 0.8+/-1.8mm. According to the Gartland and Werley evaluation, eight of the treated fractures attained an excellent, 11 a good and the remaining three a fair result. The study demonstrates that Ostim, in combination with angularly stable osteosynthesis, can be used as an acceptable bone substitute for the treatment of type C2 and C3 radial fractures.

Detection of high-energy phosphates in cortical bone as an indicator of bone healing and remodelling: use of a rabbit model.

UNLABELLED: PURPOSE; To study high-energy phosphates in cortical bone through experiments on inbred white New Zealand rabbits. METHODS: Tibial fractures were induced in 80 rabbits and then stabilised by screw osteosynthesis. After 3 (group A; n=40) or 7 days (groups B; n=40), the defective tissue was covered by local muscle flaps. At increasing intervals (from 1 to 16 weeks), the screws were removed and the animals were euthanised (n=8 per group). The bone was removed and analysed histomorphologically; adenosine triphosphate (ATP) levels were determined by high-performance liquid chromatography. RESULTS: The mean ATP concentration in healthy cortical bone at 16 weeks was 0.092 (standard error, 0.009) nmol/mg dry mass, which was significantly higher than that in the group with delayed healing: 0.081 (0.011) nmol/mg in group A and 0.005 (0.001) nmol/mg in group B (paired t test, p<0.05). Earlier healing led to lower rates of necrosis (0 vs 38; groups A vs B) and osteomyelitis. CONCLUSION: Early muscle-flap coverage can revascularise the cortical bone, which is reflected in the higher ATP content in the cortical bone measured by high-performance liquid chromatography. Measuring changes of ATP levels can help investigate the metabolism of the pathological bone.

Thermodiffusion for the quantification of tissue perfusion in skeletal muscle--clinical evaluation in standardized traumatological procedures with tourniquet and potential application in the diagnosis of compartment syndrome.

The quantification of tissue perfusion in different parenchymal organs like liver, kidney, and brain by means of thermodiffusion has recently been validated experimentally and was introduced into clinical practice. Traumatology and plastic surgery deal as well with issues of microcirculation. Therefore, it was the aim of this study to validate thermodiffusion for use in skeletal muscle. Eighteen patients were studied during knee arthroscopic procedures that utilized a tourniquet. A thermodiffusion probe was inserted in the tibialis anterior muscle of the side under treatment. Measurement started before the initiation of limb ischemia (by tourniquet) and continued throughout the procedure until tissue perfusion returned to normal values postoperatively. Furthermore, an example of clinical applicability of this technique is given by monitoring muscle tissue perfusion in 3 patients with imminent compartment syndrome. Preoperative values of muscle tissue perfusion in the patients undergoing arthroscopic procedures were 17.74 +/- 4.27 ml/min 100 g. After initiation of tourniquet perfusion quickly decreased to 3.59 +/- 3.53 ml/min 100 g. Upon reperfusion tissue perfusion increased to values above normal for a few minutes and then returned to preischemic values of 20.86 +/- 7.01 ml/min 100 g. There was no significant difference between pre- and postoperative values (P=0.154) but tissue perfusion during tourniquet was significantly reduced (P=0.0001). In 3 patients presenting with the clinical signs of imminent compartment syndrome, thermodiffusion measurement was applied and showed microcirculatory impairment of different degrees. Fasciotomy was followed by a prompt increase of muscle microcirculation to levels slightly above normal. In summary, valid and stable measurements of tissue perfusion in skeletal muscle by means of thermodiffusion are possible under clinical circumstances. Thermodiffusion allows for on-line monitoring of muscle microcirculation, e.g., in compartment syndrome. The clinical potential of thermodiffusion measurements in trauma surgery needs further prospective evaluation.

Laser doppler flow imaging of open lower leg fractures in an animal experimental model.

PURPOSE: Open lower leg fractures are frequently associated with severe soft tissue damage, followed by osteomyelitis. Using an animal experimental model, we investigated the effect of timing of coverage of a tibial fracture with a local muscle flap. METHODS: 80 rabbits had a tibial fracture induced in a standardised fashion, which was stabilised by screw osteosynthesis. After 3 (group A; n=40) and 7 days (group B; n=40), respectively, the tissue defect was covered by a local gastrocnemius flap. In increasing intervals from 1 to 2, 4, 8, and 16 weeks, the rabbits from each group were killed and the bone fracture was analysed histomorphologically. Cortical microcirculation was measured by 2-channel laser doppler flowmetry. RESULTS: Muscle flaps after 3 days improved perfusion significantly as compared with 7 days (24 Flux [standard error, 5 Flux] versus 10 Flux [3 Flux]; baseline, 1.4 Flux). Group A animals also displayed a lower rate of necrosis (0 versus 38). The incidence of osteomyelitis was higher in group B than in group A (24% versus 0%). CONCLUSION: Laser doppler flowmetry was proven to be a reliable, minimally invasive means for identifying avital tissue, leading to reduction in the loss of vital bone tissue in experimental settings.

Glutathione depletion with L-buthionine-(S,R)-sulfoximine demonstrates deleterious effects in acute pancreatitis of the rat.

A common pathway in the pathogenesis of acute pancreatitis is the generation of free oxygen radicals. The most important defense mechanisms are free radical scavengers, especially glutathione. This study evaluates the influence of the inhibition of glutathione synthesis with L-buthionine-(S,R)-sulfoximine (BSO) on the course of experimentally induced acute pancreatitis in rats and the effects on isolated pancreatic acini and their secretion pattern. Thus acute necrotizing pancreatitis was induced with intraductal infusion of low-dose glycodeoxycholic acid and subsequent hyperstimulation with cerulein with and without pretreatment with BSO. In vitro pancreatic acini were isolated and stimulated with different concentrations of cerulein with and without BSO. The BSO-treated group showed a significantly reduced survival, more necrosis, and a decreased secretion of amylase in vivo. No effect on secretion pattern in either groups was seen in vitro and BSO did not exert toxic effects. Based on the data presented, this study demonstrates deleterious effects of scavenger depletion on the course of experimental pancreatitis. This is due to the systemic effects of free oxygen radicals rather than to local effects.

[Psychotropic substances in the area of preclinical intensive care medicine]. / Psychotrope Substanzen im Bereich der präklinischen Intensivmedizin.

The aim of preclinical intensive care is to prevent severe consequences by providing immediate therapeutic aid to emergency patients in a life-threatening condition. We investigated how the abuse of drugs and alcohol influences the frequency and the category of emergency cases as well as the patient outcome. 250 emergency cases were analysed in a prospective study in the area of Heidelberg, Germany, from the summer of 1995 to the spring of 1999. The analysis is based on patient data obtained from the German standardised Emergency Record and on the clinical outcome and influence of drugs and alcohol. A serious level of drugs or alcohol was detected in 17% of the patients (the average level of alcohol was 1.97 promille). 81% of these intoxicated patients were given a NACA (National Advisory Committee for Aeronautics) score of less than 4 (not life-threatening) and therefore were not in need of the a presence of a physician.

[Prevention and treatment of procedural pain in pediatric wards: collected guidelines].

Present knowledge and available pharmacological agents allow for adequate prevention and treatment of pain in children. We present guidelines we prepared for the prevention and treatment of procedural pain in children in our general pediatric ward. This followed extensive review of the literature, participation in scientific meetings, discussions with experts and consultation with interested clinicians. Successful implementation of the guidelines requires increased appreciation of the importance of pain prevention, participation of the nursing, as well as medical staff, and ability to evaluate pain in children of various ages.

[Angle- and rotation-stable internal fixation of proximal humerus fractures with the humerus fixator plate. Early clinical experience with a newly developed implant]. / Die winkel- und rotationsstabile Osteosynthese proximaler Humerusfrakturen mit der Humerus-Fixateurplatte. Erste klinische Erfahrungen mit einem neu entwickelten Spezialimplantat.

INTRODUCTION: The Humerus Fixator Plate is presented as a new implant for angle- and rotation-stable internal fixation for the operative treatment of proximal humerus fractures at the surgical neck. METHODS: In an ongoing two-centre study, 47 patients were treated with the new implant. To date, 31 patients had clinical and radiological postoperative follow-up examinations with a mean interval of 10 months (range: 6-14 months). RESULTS: In 46 patients (97.9%), complete angle and rotational stability was achieved without limiting the range of motion or requiring immobilization. Good pain relief was obtained in 43 patients (91.5 %), and 3 patients (6.4%) showed moderate pain relief following surgery. There was one implant failure. Utilizing the Constant-Raw score (without any correction factors), a mean result of 82.8 points (range: 46-100 points) was ascertained. The majority of the patients (87.1%) achieved "excellent" or "good" clinical results. X-ray analysis revealed no non-union nor humerus head necrosis. In 4 cases (12.9%), protrusion of a humerus head screw was observed which mandated removal of the implant. CONCLUSION: The first clinical investigations of the novel Humerus Fixator Plate are encouraging and provide essential advances in the treatment of unstable proximal humerus fractures.

Congenital insensitivity to pain with anhidrosis (CIPA) in Israeli-Bedouins: genetic heterogeneity, novel mutations in the TRKA/NGF receptor gene, clinical findings, and results of nerve conduction studies.

Congenital insensitivity to pain with anhidrosis (CIPA), a rare and severe disorder, comprises absence of sensation to noxious stimuli, inability to sweat, and recurrent episodes of hyperthermia. It has a relatively high prevalence in the consanguineous Israeli-Bedouins. Clinical studies of 28 patients are reported here. Using the linkage analysis approach, we linked the disease in 9 of 10 unrelated Israeli-Bedouin families with CIPA to the TrkA gene, which encodes the receptor for nerve growth factor. In one family, linkage was excluded, implying that another gene, yet unidentified, is involved. Two new mutations in the tyrosine kinase domain of the TrkA gene were identified in our CIPA patients: a 1926-ins-T in most of the southern Israeli-Negev CIPA patients, and a Pro- 689-Leu mutation in a different isolate of Bedouins in northern Israel. Eight prenatal diagnoses were made in the southern Israeli-Negev Bedouins, two by linkage analysis and six by checking directly for the 1926-ins-T mutation. Three polymorphisms in the TrkA protein kinase encoding domain were also observed.

Vascular structure and microcirculation of experimental pancreatic carcinoma in rats.

OBJECTIVE: To study angiogenesis and microcirculation in experimental pancreatic carcinoma. DESIGN: Open experimental study. SETTING: 2 University hospitals, Germany and USA. ANIMALS: 16 male Lewis rats. INTERVENTIONS: Induction of a duct-like pancreatic cancer in the pancreas and peritoneum by interposition of fragments of tumour between 2 inert transparent polymethylmethacrylate plates. MAIN OUTCOME MEASURES: Microcirculation in the tumour and interaction between leucocytes, tumour, and endothelium investigated by intravital microscopy. RESULTS: The density of vessels in the carcinoma was significantly less than in normal pancreatic tissue (p = 0.0004). The vasculature of the tumour was characterised by a lack of differentiation in architecture of vessels, formation of sinusoidal and lacunar vessels and sudden changes in diameter of vessels. Red blood cell velocity differed among tumour vessels, but mean values were similar to those of normal exocrine pancreas. The mixed lymphocyte culture test indicated that the cell line DSL6A was immunogenic. However, high-affinity leucocyte-endothelium-interaction was significantly reduced in the tumour's microcirculation after both orthotopic and heterotopic implantation (p = 0.002). Rates of apoptosis were suppressed in heterotopic tumours compared with orthotopic ones. Tumour growth was faster in heterotopic tumours. CONCLUSIONS: Experimental duct-like pancreatic carcinoma can be differentiated from normal pancreas by: chaotic arrangement of vessels with loss of differentiation of architecture and heterogeneous distribution; the formation of sinusoidal or lacunar vessels; lower vascular density with similar erythrocyte velocity; increase in mean diameter of vessels; reduced leucocyte-endothelium interaction despite confirmed immunogeneity independent of wall shear rates. The site of implantation influences apoptosis and growth rates.

[Oral rehydration in acute gastroenteritis in infants and children--advantages of a standardized protocol].

Oral rehydration (OR) for acute gastroenteritis in infants and children has been shown to be as effective as IV therapy, with less discomfort and lower costs. In this retrospective study we compared 2 pediatric wards, in 1 of which only a standardized, simplified, bedside protocol, based on American Academy of Pediatrics guidelines, was used. There were no significant clinical characteristics in the 208 patients. In the ward which used the above protocol, OR utilization was significantly more frequent than in the other ward (48% versus 15%), thus saving equipment costs of nearly $1,000/3 months. There were no significant differences in outcome between the wards. We conclude that introducing a standardized management protocol may increase OR utilization in hospitalized children with acute diarrhea.

Caspase-mediated fragmentation of calpain inhibitor protein calpastatin during apoptosis.

Two cysteine protease families (caspase and calpain) participate in apoptosis. Here we report that the endogenous calpain inhibitor calpastatin is fragmented by caspase(s) to various extents during early apoptosis in two cell types. In anti-fas or staurosporine-treated Jurkat T-cells, the high-molecular-weight form (HMW) of calpastatin (apparent Mr 110 K) was extensively degraded to immunoreactive fragments of Mr 75 K and 30 K In apoptotic SH-SY5Y human neuroblastoma cells, HMW calpastatin was degraded to a major immunoreactive fragment of 75 K. In both cell types, fragmentation of HMW calpastatin was blocked by a caspase-specific inhibitor carbobenzoxy-Asp-CH2OC(O)-2,6-dichlorobenzene. In vitro translated HMW calpastatin was sensitive to proteolysis by recombinant caspase-1, -3, and -7. By contrast, in vitro translated LMW calpastatin (which lacks domains L and I) was cleaved into multiple fragments only by caspase-1 and was relatively resistant to caspase-3, -7, and other caspases tested. Consistently with that, purified erythroid LMW calpastatin was also highly susceptible to caspase-1 digestion. Recombinant human calpastatin spanning domain I through III (CAST(DI-III)) was found cleaved by caspase-1 at at least three sites, located in either the A or the C helix of domains I and III (ALDD137*L, LSSD203*F and ALAD404*S), while only a single site (ALDD137*L) was cleaved by caspase-3. These findings suggest that both HMW and LMW calpastatins are more vulnerable to caspase-1 than to caspase-3. Surprisingly, both erythroid LMW calpastatin and recombinant CAST(DI-III) fragmented by caspase-1 suffered only a less than twofold reduction of inhibitory activity toward calpain. We propose that the proteolysis of calpastatin in early apoptosis might have yet unidentified effects on the cross-talk between the two protease systems.

Identification and characterization of the Spodoptera littoralis nucleopolyhedrovirus type B lef-3 gene.

We have identified a gene from the Spodoptera littoralis nucleopolyhedrovirus type B (SpliNPV-B) with several characteristics that suggest that it is homologous to the lef-3 genes of the Autographa californica and Orgyia pseudotsugata NPVs (AcMNPV and OpMNPV, respectively). The SpliNPV-B lef-3 gene was mapped between 43.6 and 45.5 map units of the SpliNPV-B genome. Northern blot analysis showed that SpliNPV-B lef-3 was expressed as a 1.6 Kb transcript at 5 h post infection (p.i.), reached high levels at 24 h p.i., and remained highly expressed at 56 h p.i. Transcription of SpliNPV-B lef-3 initiated at two distinct sites downstream from a TATA-box motif and terminated 25 nucleotides downstream from the translation stop site of the putative LEF-3 polypeptide. The 5'-boundaries of lef-3 promoter elements were investigated by transient expression assays, which revealed that the major components of the lef-3 promoter are within a 183 base pair region upstream of the distal transcription initiation site. Transfection of SpliNPV-B infected Sf9 cells with anti-sense oligonucleotides designed to inhibit LEF-3 expression resulted in substantial reduction of viral DNA replication, suggesting that the role of SpliNPV-B lef-3 may be similar to that of AcMNPV and OpMNPV lef-3 genes, which are essential for viral DNA replication.