Relationship among cattle breed and anabolic implant protocol relative to feedlot performance: Growth, temperament, feeding behavior, carcass traits, and economic return

Recent research has suggested that different cattle breed types may respond differently to anabolic implant protocols of varying intensity. Therefore, the purpose of this research was to compare anabolic implant protocols in feedlot steers of 2 different breed types. Sixty steers were stratified by weight and breed in a 2 × 3 factorial design examining 2 different breeds: Angus (AN; n=38) or Santa Gertrudis influenced (SG; n=22), and 3 implant strategies: no implant (CON; n=20), a moderate intensity implant protocol (d0 implant: Revalor-G, d56 implant: Revalor-IS, d112 implant: Revalor-S; MI; n=20), or a high intensity implant protocol (d0 implant: Revalor-IS, d56 implant: Revalor-S, d112 implant: Revalor-200; HI; n=20). Steers were randomly placed into pens equipped with GrowSafe bunks to collect dry matter intake and feeding behavior. All animals were fed the same diet. Weight, chute score, exit velocity, serum, rectal temperature, hip height and 12th rib fat thickness were collected approximately every 28 d over a 196 d period. Serum urea nitrogen (SUN) was evaluated as well. Total average daily gain was increased (P < 0.0001) in both the HI and MI steers compared to the CON steers by 29.4% and 26%, respectively. A treatment × breed interaction was observed (P < 0.0001) for hip height, with AN-CON steers being shorter (P < 0.0007) than AN-HI, SG-CON, SG-MI, and SG-HI steers. A breed × treatment interaction was observed (P < 0.004) for chute score and rectal temperature, with SG-HI and SG-MI steers having increased chute scores (P < 0.001) when compared to AN-HI, AN-MI, AN-CON, and SG-CON throughout the course of the trial. Additionally, SG-HI and SG-MI steers had an increased rectal temperature (P < 0.004) compared to AN-HI, AN-MI, AN-CON, and SG-CON steers. A breed effect was observed (P = 0.002) for SUN with AN steers having increased (P = 0.002) SUN concentration compared to SG sired steers, in addition to a treatment effect (P < 0.0001), with CON steers having a higher (P < 0.0001) SUN concentration than MI and HI steers, regardless of breed. The MI implant protocol increased net return per head, on average, by $97.28, regardless of breed, while the HI implant protocol increased net return by only $80.84. Taken together, despite the cattle breed types responding differently to the different anabolic implant protocols at times, a moderate intensity anabolic implant protocol was optimal in this experiment for steers raised in a temperate climate.

Vagus Nerve Stimulation Paired With Rehabilitation for Upper Limb Motor Impairment and Function After Chronic Ischemic Stroke: Subgroup Analysis of the Randomized, Blinded, Pivotal, VNS-REHAB Device Trial

BACKGROUND

Vagus Nerve Stimulation (VNS) paired with rehabilitation improved upper extremity impairment and function in a recent pivotal, randomized, triple-blind, sham-controlled trial in people with chronic arm weakness after stroke.

OBJECTIVE

We aimed to determine whether treatment effects varied across candidate subgroups, such as younger age or less injury.

METHODS

Participants were randomized to receive rehabilitation paired with active VNS or rehabilitation paired with sham stimulation (Control). The primary outcome was the change in impairment measured by the Fugl-Meyer Assessment Upper Extremity (FMA-UE) score on the first day after completion of 6-weeks in-clinic therapy. We explored the effect of VNS treatment by sex, age (≥62 years), time from stroke (>2 years), severity (baseline FMA-UE score >34), paretic side of body, country of enrollment (USA vs UK) and presence of cortical involvement of the index infarction. We assessed whether there was any interaction with treatment.

FINDINGS

The primary outcome increased by 5.0 points (SD 4.4) in the VNS group and by 2.4 points (SD 3.8) in the Control group (P = .001, between group difference 2.6, 95% CI 1.03-4.2). The between group difference was similar across all subgroups and there were no significant treatment interactions. There was no important difference in rates of adverse events across subgroups.

CONCLUSION

The response was similar across subgroups examined. The findings suggest that the effects of paired VNS observed in the VNS-REHAB trial are likely to be consistent in wide range of stroke survivors with moderate to severe upper extremity impairment.

Intracerebral Hemorrhage: A Common yet Disproportionately Deadly Stroke Subtype

Spontaneous intracerebral hemorrhage (ICH) is a medical emergency and is disproportionately associated with higher mortality and long-term disability compared with ischemic stroke. The phrase "time is brain" was derived for patients with large vessel occlusion ischemic stroke in which approximately 1.9 million neurons are lost every minute. Similarly, this statement holds true for ICH patients due to a high volume of neurons that are damaged at initial onset and during hematoma expansion. Most cases of spontaneous ICH pathophysiologically stem from chronic hypertension and rupture of small perforating vessels off of larger cerebral arteries supplying deep brain structures, with cerebral amyloid angiopathy being another cause for lobar hemorrhages in older patients. Optimal ICH medical management strategies include timely diagnosis, aggressive blood pressure control, correction of underlying coagulopathy defects if present, treatment of cerebral edema, and continuous assessment for possible surgical intervention. Current strategies in the surgical management of ICH include newly developed minimally invasive techniques for hematoma evacuation, with the goal of mitigating injury to fiber tracts while accessing the clot. We review evidence-based medical and surgical management of spontaneous ICH with the overall goal of reducing neurologic injury and optimizing functional outcome.

Vagus nerve stimulation paired with rehabilitation for upper limb motor function after ischaemic stroke (VNS-REHAB): a randomised, blinded, pivotal, device trial

BACKGROUND

Long-term loss of arm function after ischaemic stroke is common and might be improved by vagus nerve stimulation paired with rehabilitation. We aimed to determine whether this strategy is a safe and effective treatment for improving arm function after stroke.

METHODS

In this pivotal, randomised, triple-blind, sham-controlled trial, done in 19 stroke rehabilitation services in the UK and the USA, participants with moderate-to-severe arm weakness, at least 9 months after ischaemic stroke, were randomly assigned (1:1) to either rehabilitation paired with active vagus nerve stimulation (VNS group) or rehabilitation paired with sham stimulation (control group). Randomisation was done by ResearchPoint Global (Austin, TX, USA) using SAS PROC PLAN (SAS Institute Software, Cary, NC, USA), with stratification by region (USA vs UK), age (≤30 years vs >30 years), and baseline Fugl-Meyer Assessment-Upper Extremity (FMA-UE) score (20-35 vs 36-50). Participants, outcomes assessors, and treating therapists were masked to group assignment. All participants were implanted with a vagus nerve stimulation device. The VNS group received 0·8 mA, 100 μs, 30 Hz stimulation pulses, lasting 0·5 s. The control group received 0 mA pulses. Participants received 6 weeks of in-clinic therapy (three times per week; total of 18 sessions) followed by a home exercise programme. The primary outcome was the change in impairment measured by the FMA-UE score on the first day after completion of in-clinic therapy. FMA-UE response rates were also assessed at 90 days after in-clinic therapy (secondary endpoint). All analyses were by intention to treat. This trial is registered at ClinicalTrials.gov, NCT03131960.

FINDINGS

Between Oct 2, 2017, and Sept 12, 2019, 108 participants were randomly assigned to treatment (53 to the VNS group and 55 to the control group). 106 completed the study (one patient for each group did not complete the study). On the first day after completion of in-clinic therapy, the mean FMA-UE score increased by 5·0 points (SD 4·4) in the VNS group and by 2·4 points (3·8) in the control group (between group difference 2·6, 95% CI 1·0-4·2, p=0·0014). 90 days after in-clinic therapy, a clinically meaningful response on the FMA-UE score was achieved in 23 (47%) of 53 patients in the VNS group versus 13 (24%) of 55 patients in the control group (between group difference 24%, 6-41; p=0·0098). There was one serious adverse event related to surgery (vocal cord paresis) in the control group.

INTERPRETATION

Vagus nerve stimulation paired with rehabilitation is a novel potential treatment option for people with long-term moderate-to-severe arm impairment after ischaemic stroke.

FUNDING

MicroTransponder.

Creation of an optic nerve sheath diameter ultrasound model for NeuroICU education

BACKGROUND

Using ultrasound to measure optic nerve sheath diameter (ONSD) is an emerging bedside technique to noninvasively assess intracranial pressure (ICP) in patients with brain injury. This technique is unique among bedside ultrasonography and is often performed by providers who have no formal ultrasound training. We sought to create a low-cost, 3D, reusable ONSD model to train neurology, neurosurgery, and critical care providers in measuring ICP.

RESULTS

We identified 253 articles, of which 15 were associated with models and 2 with simulation. One gelatin model was reported, upon which we based our initial design. We could not validate the visual findings of this model; however, after constructing multiple beta models, the design most representative of human eye anatomy was a globe made of ballistics gel and either a 3 mm, 5 mm, or 7 mm × 50 mm 3D-printed optic nerve inserted into a platform composed of ballistics gel, all of which sat inside a 3D-printed skull. This model was used to teach ONSD measurements with ultrasound at a continuing medical education event prior to training on a live human model.

CONCLUSION

A simple 3D ballistic ONSD model allows learners to practice proper hand placement and pressure, basic landmarks, and ONSD measurement prior to operating on a human eye. This model is replicable and sustainable given that the globe and platform are composed of ballistics gel.

Topographic correlation of infarct area on CT perfusion with functional outcome in acute ischemic stroke

OBJECTIVE

The role of CT perfusion (CTP) in the management of patients with acute ischemic stroke (AIS) remains a matter of debate. The primary aim of this study was to evaluate the correlation between the areas of infarction and penumbra on CTP scans and functional outcome in patients with AIS.

METHODS

This was a retrospective review of 100 consecutively treated patients with acute anterior circulation ischemic stroke who underwent CT angiography (CTA) and CTP at admission between February 2011 and October 2014. On CTP, the volume of ischemic core and penumbra was measured using the Alberta Stroke Program Early CT Score (ASPECTS). CTA findings were also noted, including the site of occlusion and regional leptomeningeal collateral (rLMC) score. Functional outcome was defined by modified Rankin Scale (mRS) score obtained at discharge. Associations of CTP and CTA parameters with mRS scores at discharge were assessed using multivariable proportional odds logistic regression models.

RESULTS

The median age was 67 years (range 19-95 years), and the median NIH Stroke Scale score was 16 (range 2-35). In a multivariable analysis adjusting for potential confounding variables, having an infarct on CTP scans in the following regions was associated with a worse mRS score at discharge: insula ribbon (p = 0.043), perisylvian fissure (p < 0.001), motor strip (p = 0.007), M2 (p < 0.001), and M5 (p = 0.023). A worse mRS score at discharge was more common in patients with a greater volume of infarct core (p = 0.024) and less common in patients with a greater rLMC score (p = 0.004).

CONCLUSIONS

The results of this study provide evidence that several CTP parameters are independent predictors of functional outcome in patients with AIS and have potential to identify those patients most likely to benefit from reperfusion therapy in the treatment of AIS.

A Multicenter Pilot Study on the Clinical Utility of Computational Modeling for Flow-Diverter Treatment Planning

BACKGROUND AND PURPOSE

Selection of the correct flow-diverter size is critical for cerebral aneurysm treatment success, but it remains challenging due to the interplay of device size, anatomy, and deployment. Current convention does not address these challenges well. The goals of this pilot study were to determine whether computational modeling improves flow-diverter sizing over current convention and to validate simulated deployments.

MATERIALS AND METHODS

Seven experienced neurosurgeons and interventional neuroradiologists used computational modeling to prospectively plan 19 clinical interventions. In each patient case, physicians simulated 2-4 flow-diverter sizes that were under consideration based on preprocedural imaging. In addition, physicians identified a preferred device size using the current convention. A questionnaire on the impact of computational modeling on the procedure was completed immediately after treatment. Rotational angiography image data were acquired after treatment and compared with flow-diverter simulations to validate the output of the software platform.

RESULTS

According to questionnaire responses, physicians found the simulations useful for treatment planning, and they increased their confidence in device selection in 94.7% of cases. After viewing the simulations results, physicians selected a device size that was different from the original conventionally planned device size in 63.2% of cases. The average absolute difference between clinical and simulated flow-diverter lengths was 2.1 mm. In 57% of cases, average simulated flow-diverter diameters were within the measurement uncertainty of clinical flow-diverter diameters.

CONCLUSIONS

Physicians found computational modeling to be an impactful and useful tool for flow-diverter treatment planning. Validation results showed good agreement between simulated and clinical flow-diverter diameters and lengths.

Heart-Shaped Bilateral Medullary Pyramidal Infarction as a Pathognomonic Finding of Anterior Spinal Artery Occlusion

BACKGROUND

Unilateral anterior spinal artery (ASA) occlusion resulting in bilateral medullary pyramidal (BMP) infarction is a rare and devastating stroke subtype. We present two cases highlighting the diagnostic and clinical challenges of BMP infarction.

METHODS

Case reports and literature review.

RESULTS

A 57-year-old man rapidly had severe vomiting and diarrhea 2 h after a meal. Examination revealed bulbar weakness and areflexic tetraplegia. Respiratory failure developed, requiring intubation and mechanical ventilation. Brain magnetic resonance imaging (MRI) showed a heart-shaped region of diffusion abnormality, characteristic of BMP infarction. Cerebral angiography showed an occluded left vertebral artery with unilateral left-sided origin of ASA. The patient required tracheostomy and percutaneous gastrostomy tube and was discharged to rehabilitation, with little improvement of his tetraplegia at 3-month follow-up. A 43-year-old woman presented to the emergency department with acute onset of lower-extremity paresthesia and history of upper respiratory infection 2 weeks prior. Initial examination findings included bulbar weakness, dysphagia, hyporeflexia, and generalized weakness. After admission, she had severe respiratory distress and required intubation. Lumbar puncture was evaluated for Guillain-Barré syndrome, but cerebrospinal fluid protein concentration was normal. Changes on diffusion-weighted MRI of the brain showed the characteristic heart-shaped BMP infarction, indicating occlusion of a unilateral ASA. She required tracheostomy and percutaneous gastrostomy tube placement, with no paralysis resolution.

CONCLUSION

Acute BMP infarction may present with flaccid tetraplegia mimicking neuromuscular disorders. When the infarction is recognized early, intravenous thrombolysis can be considered to reduce morbidity of this rare stroke subtype.

Reducing Door-to-Reperfusion Time for Mechanical Thrombectomy With a Multitiered Notification System for Acute Ischemic Stroke

OBJECTIVE

To reduce door-to-angiographic reperfusion (DTR) time to 120 minutes for patients presenting with acute ischemic stroke attributed to anterior circulation large-vessel occlusion amenable to endovascular mechanical thrombectomy.

PATIENTS AND METHODS

Patients treated with mechanical thrombectomy before (April 10, 2015, through April 11, 2016) and after (April 12, 2016, through May 10, 2017) implementation of a multitiered notification system were studied. Lean process mapping was used to assess inefficiencies with multidisciplinary triage. A 3-tiered paging platform, which rapidly alerts essential personnel of the acute ischemic stroke team at advancing decision points, was introduced.

RESULTS

Sixty-two patients were analyzed before and after implementation (34 vs 28, respectively). Following intervention, DTR time was reduced by 43 minutes (mean DTR, 170 minutes vs 127 minutes; P=.02). At 90-day follow up, 5 of the 28 patients in the postintervention cohort (19%) had excellent neurologic outcomes, defined as a modified Rankin Scale score of 0, compared to 0 of 34 (0%) in the preintervention cohort (P=.89). Reductions were also seen in the length of stay on the neurocritical care service (mean, 6 vs 3 days; P=.006), and total hospital charges for combined groups (mean, $100,083 vs $161,458; P<.001).

CONCLUSION

The multitiered notification system was a feasible solution for improving DTR within our institution, resulting in reductions of overall DTR time, neurocritical care service length of stay, and total hospital charges.

Update on Neurocritical Care of Stroke

PURPOSE OF REVIEW

This review will highlight the recent advancements in acute ischemic stroke diagnosis and treatment, with special attention to new features and recommendations of stroke care in the neurocritical care unit.

RECENT FINDINGS

New studies suggest that pre-hospital treatment of stroke with mobile stroke units and telestroke technology may lead to earlier stroke therapy with intravenous tissue plasminogen activator (tPA), and recent studies show tPA can be given in previously contraindicated situations. More rapid automated CT perfusion and angiography may demonstrate a vascular penumbra for neuroendovascular intervention. Further, the greatest advance in acute stroke treatment since 2014 is the demonstration that neuroendovascular catheter-based thrombectomy with stent retrievers recanalizing intracranial large vessel occlusion (LVO) improves both recanalization and long-term outcomes in several trials. Hemorrhagic transformation and severe large infarct cerebral edema remain serious post-stroke challenges, with new guidelines describing who and when patients should get medical or surgical intervention. The adage "time is brain" directs the most evidence-based approach for rapid stroke diagnosis for tPA eligible and LVO recanalization using an orchestrated team approach. The neurocritical care unit is the appropriate location to optimize stroke outcomes for the most severely affected stroke patients.

The Relationship Between Serum Neuron-Specific Enolase Levels and Severity of Bleeding and Functional Outcomes in Patients With Nontraumatic Subarachnoid Hemorrhage

BACKGROUND

The value of neuron-specific enolase (NSE) in predicting clinical outcomes has been investigated in a variety of neurological disorders.

OBJECTIVE

To investigate the associations of serum NSE with severity of bleeding and functional outcomes in patients with subarachnoid hemorrhage (SAH).

METHODS

We retrospectively reviewed the records of patients with SAH from June 2008 to June 2012. The severity of SAH bleeding at admission was measured radiographically with the Fisher scale and clinically with the Glasgow Coma Scale, Hunt and Hess grade, and World Federation of Neurologic Surgeons scale. Outcomes were assessed with the modified Rankin Scale at discharge.

RESULTS

We identified 309 patients with nontraumatic SAH, and 71 had NSE testing. Median age was 54 years (range, 23-87 years), and 44% were male. In multivariable analysis, increased NSE was associated with a poorer Hunt and Hess grade (P = .003), World Federation of Neurologic Surgeons scale score (P < .001), and Glasgow Coma Scale score (P = .003) and worse outcomes (modified Rankin Scale at discharge; P = .001). There was no significant association between NSE level and Fisher grade (P = .81) in multivariable analysis.

CONCLUSION

We found a significant association between higher NSE levels and poorer clinical presentations and worse outcomes. Although it is still early for any relevant clinical conclusions, our results suggest that NSE holds promise as a tool for screening patients at increased risk of poor outcomes after SAH.

Ambulance-based assessment of NIH Stroke Scale with telemedicine: A feasibility pilot study

Background Ischemic stroke is a time-sensitive disease, with improved outcomes associated with decreased time from onset to treatment. It was hypothesised that ambulance-based assessment of the National Institutes of Health Stroke Scale (NIHSS) using a Health Insurance Portability and Accountability Act (HIPAA)-compliant mobile platform immediately prior to arrival is feasible. Methods This is a proof-of-concept feasibility pilot study in two phases. The first phase consisted of an ambulance-equipped HIPAA-compliant video platform for remote NIHSS assessment of a simulated stroke patient. The second phase consisted of remote NIHSS assessment by a hospital-based neurologist of acute stroke patients en route to our facility. Five ambulances were equipped with a 4G/LTE-enabled tablet preloaded with a secure HIPAA-compliant telemedicine application. Secondary outcomes assessed satisfaction of staff with the remote platform. Results Phase one was successful in the assessment of three out of three simulated patients. Phase two was successful in the assessment of 10 out of 11 (91%) cases. One video attempt was unsuccessful because local LTE was turned off on the device. The video signal was dropped transiently due to weather, which delayed NIHSS assessment in one case. Average NIHSS assessment time was 7.6 minutes (range 3-9.8 minutes). Neurologists rated 83% of encounters as 'satisfied' to 'very satisfied', and the emergency medical service (EMS) rated 90% of encounters as 'satisfied' to 'very satisfied'. The one failed video attempt was associated with 'poor' EMS satisfaction. Conclusion This proof-of-concept pilot demonstrates that remote ambulance-based NIHSS assessment is feasible. This model could reduce door-to-needle times by conducting prehospital data collection.

The fate of cranial neuropathy after flow diversion for carotid aneurysms

OBJECT

The authors sought to determine whether flow diversion with the Pipeline Embolization Device (PED) can approximate microsurgical decompression in restoring function after cranial neuropathy following carotid artery aneurysms.

METHODS

This multiinstitutional retrospective study involved 45 patients treated with PED across the United States. All patients included presented between November 2009 and October 2013 with cranial neuropathy (cranial nerves [CNs] II, III, IV, and VI) due to intracranial aneurysm. Outcome analysis included clinical and procedural variables at the time of treatment as well as at the latest clinical and radiographic follow-up.

RESULTS

Twenty-six aneurysms (57.8%) were located in the cavernous segment, while 6 (13.3%) were in the clinoid segment, and 13 (28.9%) were in the ophthalmic segment of the internal carotid artery. The average aneurysm size was 18.6 mm (range 4–35 mm), and the average number of flow diverters placed per patient was 1.2. Thirty-eight patients had available information regarding duration of cranial neuropathy prior to treatment. Eleven patients (28.9%) were treated within 1 month of symptom onset, while 27 (71.1%) were treated after 1 month of symptoms. The overall rate of cranial neuropathy improvement for all patients was 66.7%. The CN deficits resolved in 19 patients (42.2%), improved in 11 (24.4%), were unchanged in 14 (31.1%), and worsened in 1 (2.2%). Overtime, the rate of cranial neuropathy improvement was 33.3% (15/45), 68.8% (22/32), and 81.0% (17/21) at less than 6, 6, and 12 months, respectively. At last follow-up, 60% of patients in the isolated CN II group had improvement, while in the CN III, IV, or VI group, 85.7% had improved. Moreover, 100% (11/11) of patients experienced improvement if they were treated within 1 month of symptom onset, whereas 44.4% (12/27) experienced improvement if they treated after 1 month of symptom onset; 70.4% (19/27) of those with partial deficits improved compared with 30% (3/10) of those with complete deficits.

CONCLUSIONS

Cranial neuropathy caused by cerebral aneurysm responds similarly when the aneurysm is treated with the PED compared with open surgery and coil embolization. Lower morbidity and higher occlusion rates obtained with the PED may suggest it as treatment of choice for some of these lesions. Time to treatment is an important consideration regardless of treatment modality.

A Novel Eigenvector-based Method to Detect Mild Alzheimer's Disease Using Event-Related Potentials

Event-related potentials (ERPs) are a physiological measure of cognitive function that have shown diagnostic and prognostic utility in Alzheimer's disease (AD). In this study, we used a novel eigenvector-based technique to better understand brain electrophysiological differences between subjects with mild AD and healthy controls (HC). Using ERPs from 75 subjects with mild AD and 95 HC, we first calculated cognitive task eigenvectors within each subject from three conditions and then calculated second-order eigenvector components to compare the AD group to the HC group. A MANOVA of the three second-level components discriminated between AD and HC multivariately (Wilks' lambda=.4297, p<0.0001, R2 = .5703), and also on each of the three components univariately (all 3 p-values<0.0001). The eigenvector-based technique used in this study accurately discriminated between the mild AD group and HC. As such, this analysis method adds to our understanding of the differences in ERP signal between AD and HC, and could provide a sensitive biomarker for diagnosis and monitoring of AD progression.

Anterior communicating artery aneurysm: Accuracy of CT angiography in determination of inflow dominance

BACKGROUND

Preoperative assessment of anterior communicating artery (AcoA) aneurysms with cerebral angiography is common, but not without risk. Computed tomography angiography (CTA) is a widely available imaging modality that provides quick acquisition, low morbidity, and low cost. One disadvantage is that it does not provide dynamic information. In this study, the authors sought to determine whether CTA alone can reliably predict the inflow dominance to an AcoA aneurysm.

METHODS

Eighty-three patients with ruptured AcoA aneurysms were reviewed retrospectively. Only those patients with both preoperative CTA and cerebral angiogram were included, thus excluding six patients. Four independent observers reviewed the CTAs and attempted to identify the dominant A1. Additionally, three mathematical models were created to identify the dominant A1. These responses were compared to cerebral angiograms.

RESULTS

Four observers were correct in judging the dominant A1 an average of 93% of the time. Seventeen cases were read incorrectly by only one of four observers, and three cases were read incorrectly by two observers. For cases with incorrect readings, the average percentage difference in A1 sizes was 19.6%. For cases read unanimously correct, the average percentage difference in A1 sizes was 42.7%. Mathematical model #3 correctly evaluated the dominant A1 in 97% of the cases.

CONCLUSIONS

This study found CT angiograms can be reliable in predicting the inflow dominance to the majority of AcoA aneurysms.

Flow diversion for complex intracranial aneurysms in young children

Pediatric intracranial aneurysms are exceedingly rare and account for less than 5% of all intracranial aneurysms. Open surgery to treat such aneurysms has been shown to be more durable than endovascular techniques, and durability of treatment is particularly important in the pediatric population. Over the past 2 decades, however, a marked shift in aneurysm treatment from open surgery toward endovascular procedures has occurred for adults. The authors describe their early experience in treating 3 unruptured pediatric brain aneurysms using the Pipeline embolization device (PED). The first patient, a girl with Majewski osteodysplastic primordial dwarfism Type II who was harboring multiple intracranial aneurysms, underwent two flow diversion procedures for a vertebrobasilar aneurysm and a supraclinoid internal carotid artery aneurysm. The second patient underwent PED placement on a previously coiled but enlarging posterior communicating artery aneurysm. All procedures were uneventful, with no postsurgical complications, and led to complete angiographic obliteration of the aneurysms. To the authors' knowledge, this is the first series of flow diversion procedures in children reported in the medical literature. While flow diversion is a new and relatively untested technology in children, outcomes in adults have been promising. For challenging lesions in the pediatric population, flow diversion may have a valuable role as a well-tolerated, safe treatment with durable results. Many issues remain to be addressed, such as the durability of flow diverters over a very long follow-up and vessel response to growth in the presence of an endoluminal device.

Immuno-analysis of phospho-Akt in primary human breast cancers

The aim of this study was to investigate the expression of the activated (phosphorylated) form of Akt (Ser473) in primary breast cancer and to correlate the results with clinicopathological and prognostic variables for clinically relevant associations. Phospho-Akt expression was studied using immunoblot analysis in 49 invasive breast carcinomas (median follow-up time 55 months, range 7-74 months). We assessed the level of phospho-Akt in different types of primary breast cancers and compared the use of autoradiograph X-ray film with a PVDF-DAB-staining system. Twelve percent of the tumours had no phospho-Akt protein, 25% had low phospho-Akt expression, 51% had intermediate expression and 12% had high phospho-Akt expression. No relationship was observed between phospho-Akt and tumour grade, tumour size or nodal status. A significant relationship was demonstrated between phospho-Akt score and oestrogen receptor status (P=0.014). Univariate analysis demonstrated that intermediate levels of phospho-Akt in breast tumour tissue are associated with a lower probability of developing recurrences (P=0.035), while in multivariate analyses, none of the phospho-Akt levels appeared to be independent predictors of disease recurrence or death. In addition, it has been clearly established that a suitable composition of reagents and components such as PVDF membranes treated with DAB substrate will enable the performing of sensitive immuno-analyses.

Inhibition of compensatory renal growth by the N-terminus of a sheep-derived peptide

The N-terminal sequence of a novel sheep-derived peptide with growth inhibitory activity has been obtained. The N-terminal fragment was chemically synthesised and designated EPL001. The kidney was chosen as the first mammalian system in which to study EPL001 since kidney growth can be accurately quantified following a surgical reduction in renal mass. Cell proliferation was measured in mouse collecting duct kidney (MCDK) cells stimulated with insulin-like growth factor I (IGF-I). Compensatory renal growth (CRG) was induced in Wistar rats and either EPL001 or an EPL001 antibody delivered by continuous renal tissue infusion. Mouse monoclonal antibodies to EPL001 were generated for immunoneutralisation, rabbit polyclonal antibodies were generated for immunohistochemistry. EPL001 had no apparent effect on IGF-I stimulated cell proliferation in MCDK cells in vitro, yet provoked a dose-dependent inhibition of CRG in vivo. An EPL001 antibody potentiated CRG, in the absence of exogenous EPL001, consistent with an inhibitory role in kidney growth for an endogenous peptide containing the EPL001 sequence. Tubular staining for epitopes to the EPL001 sequence was detected in normal human kidney sections and enhanced in renal cell carcinoma. Results support the presence of growth inhibitory activity in the N-terminus of a sheep-derived peptide with evidence for both its presence and endogenous activity in the kidney. Attempts to further characterise its structure and activity are ongoing.

Atoms in a radio-frequency-dressed optical lattice

We load cold atoms into an optical lattice dramatically reshaped by radio-frequency coupling of state-dependent lattice potentials. This radio-frequency dressing changes the unit cell of the lattice at a subwavelength scale, such that its curvature and topology departs strongly from that of a simple sinusoidal lattice potential. Radio-frequency dressing has previously been performed at length scales from mm to tens of mum, but not at the single-optical-wavelength scale. At this length scale significant coupling between adiabatic potentials leads to nonadiabatic transitions, which we measure as a function of lattice depth and dressing amplitude. We also investigate the dressing by measuring changes in the momentum distribution of the dressed states.

Controlled exchange interaction between pairs of neutral atoms in an optical lattice

Ultracold atoms trapped by light offer robust quantum coherence and controllability, providing an attractive system for quantum information processing and for the simulation of complex problems in condensed matter physics. Many quantum information processing schemes require the manipulation and deterministic entanglement of individual qubits; this would typically be accomplished using controlled, state-dependent, coherent interactions among qubits. Recent experiments have made progress towards this goal by demonstrating entanglement among an ensemble of atoms confined in an optical lattice. Until now, however, there has been no demonstration of a key operation: controlled entanglement between atoms in isolated pairs. Here we use an optical lattice of double-well potentials to isolate and manipulate arrays of paired (87)Rb atoms, inducing controlled entangling interactions within each pair. Our experiment realizes proposals to use controlled exchange coupling in a system of neutral atoms. Although 87Rb atoms have nearly state-independent interactions, when we force two atoms into the same physical location, the wavefunction exchange symmetry of these identical bosons leads to state-dependent dynamics. We observe repeated interchange of spin between atoms occupying different vibrational levels, with a coherence time of more than ten milliseconds. This observation demonstrates the essential component of a neutral atom quantum SWAP gate (which interchanges the state of two qubits). Its 'half-implementation', the root SWAP gate, is entangling, and together with single-qubit rotations it forms a set of universal gates for quantum computation.

Sublattice addressing and spin-dependent motion of atoms in a double-well lattice

We load atoms into every site of an optical lattice and selectively spin flip atoms in a sublattice consisting of every other site. These selected atoms are separated from their unselected neighbors by less than an optical wavelength. We also show spin-dependent transport, where atomic wave packets are coherently separated into adjacent sites according to their internal state. These tools should be useful for quantum information processing and quantum simulation of lattice models with neutral atoms.

Preparing and probing atomic number states with an atom interferometer

We describe the controlled loading and measurement of number-squeezed states and Poisson states of atoms in individual sites of a double well optical lattice. These states are input to an atom interferometer that is realized by symmetrically splitting individual lattice sites into double wells, allowing atoms in individual sites to evolve independently. The two paths then interfere, creating a matter-wave double-slit diffraction pattern. The time evolution of the double-slit diffraction pattern is used to measure the number statistics of the input state. The flexibility of our double well lattice provides a means to detect the presence of empty lattice sites, an important and so far unmeasured factor in determining the purity of a Mott state.

Coherent control of ultracold molecule dynamics in a magneto-optical trap by use of chirped femtosecond laser pulses

We have studied the effects of chirped femtosecond laser pulses on the formation of ultracold molecules in a Rb magneto-optical trap. We have found that application of chirped femtosecond pulses suppressed the formation of (85)Rb and (87)Rb(2) a(3)sigma(+)(u) molecules in contrast to comparable nonchirped pulses, cw illumination, and background formation rates. Variation of the amount of chirp indicated that this suppression is coherent in nature, suggesting that coherent control is likely to be useful for manipulating the dynamics of ultracold quantum molecular gases.

Peritoneal macrophages express the serotonin transporter

Although it is known that macrophages take up serotonin, a specific monoamine transporter has not been identified in macrophages. In this study, mRNA coding for the serotonin transporter (SERT) was detected with the reverse transcription-polymerase chain reaction (RT-PCR) in recruited mouse peritoneal macrophages. Sequencing confirmed the identity of the RT-PCR product to mouse SERT mRNA. SERT protein was detected by Western blotting. Macrophage activation with lipopolysaccharide had no effect on expression of SERT mRNA or protein. Consistent with expression of a functional SERT, specific uptake of (3)H-serotonin in macrophages was sodium dependent and inhibited by fluoxetine (IC(50) 6.9 nM) and desipramine (IC(50) 32 nM) but not by nisoxetine or reserpine.

Apoptotic mechanisms in T47D and MCF-7 human breast cancer cells

To investigate the mechanisms underlying apoptosis in breast cancer cells, staurosporine was used as an apoptotic stimulus in the human breast cancer cell lines MCF-7 and T47D. Staurosporine induced dose and time dependent increases in DNA fragmentation which was abrogated by z-VAD-fmk. MCF-7 cells did not express caspase-3, suggesting that DNA fragmentation occurred in the absence of caspase-3 and that other caspases may be involved. Staurosporine induced DEVDase activity in T47D cells suggesting the involvement of caspase-3 and/or caspase-7, yet there was no DEVDase activity in MCF-7 cells, probably ruling out the involvement caspase-7. However, staurosporine induced the cleavage of pro-caspase-6 in MCF-7 cells, but not in T47D cells. Caspase dependent PARP cleavage was detected in MCF-7 cells at 3 h, whereas only partial PARP cleavage was detected in T47D cells and then only after 24 h. Moreover, staurosporine led to cytochrome c release at 2 h in MCF-7 cells and 6 h in T47D cells. In addition, a time dependent and caspase-independent reduction of the mitochondrial transmembrane potential was observed; which appeared to occur after the release of cytochrome c. Translocation of Bax from the cytosol to mitochondria was observed in both cell types, and this preceded cytochrome c release in both T47D and MCF-7 cells. Apoptotic events in both cell types differ temporally, involving activation of different caspases and mitochondrial changes.

Cloning of the cDNA for the putative calcium-sensing receptor and its tissue distribution in sea bream (Sparus aurata)

The cDNA for the calcium-sensing receptor (CaSR) gene has been cloned from the marine teleost Sparus aurata, the sea bream. The isolated clones were 3.3 kb long with an open reading frame of 2820 bp, a 5' UTR of 240 bp, and 3' UTR of 248 bp. The gene codes for a mature peptide of 940 amino acids which has three principal domains; the extracellular region is more than half the total protein, there is a seven-transmembrane domain, and there is a short intracellular domain. There is considerable sequence identity, 91%, shared between the CaSR of sea bream and puffer fish but overall similarities with mammalian CaSR peptides vary between 44% for rat and mouse and 48% with human CaSR. Nevertheless, the 18 cysteine residues of the extracellular domain are present in all sequences so far analysed of which 9 form a cysteine-rich region in sea bream similar to mammalian CaSR. The distribution of CaSR in sea bream tissues detected by in situ hybridisation showed gene expression in epithelia associated with ion transport or ion regulation including the hind gut, chloride cells of the gills, operculum, gall bladder, pituitary adenohypophysis, and coronet cells of the saccus vasculosus; this distribution was confirmed by RT-PCR. By in situ hybridisation, CaSR gene expression was also present in olfactory nerves and leucocytes.

STR primer concordance study

Over 1500 population database samples comprising African Americans, Caucasians, Hispanics, Native Americans, Chamorros and Filipinos were typed using the PowerPlex 16 and the Profiler Plus/COfiler kits. Except for the D8S1179 locus in Chamorros and Filipinos from Guam, there were eight examples in which a typing difference due to allele dropout was observed. At the D8S1179 locus in the population samples from Guam, there were 13 examples of allele dropout observed when using the Profiler Plus kit. The data support that the primers used in the PowerPlex 16, Profiler Plus, and COfiler kits are reliable for typing reference samples that are for use in CODIS. In addition, allele frequency databases have been established for the STR loci Penta D and Penta E. Both loci are highly polymorphic.

Interleukin-1 beta induced synthesis of protein kinase C-delta and protein kinase C-epsilon in EL4 thymoma cells: possible involvement of phosphatidylinositol 3-kinase

We present evidence here that the proinflammatory cytokine, interleukin-1 beta (IL-1 beta) stimulates a significant increase in protein kinase C (PKC)-epsilon and PKC-delta protein levels and increases PKC-epsilon, but not PKC-delta, transcripts in EL4 thymoma cells. Incubation of EL4 cells with IL-1 beta induced protein synthesis of PKC-epsilon (6-fold increase) by 7 h and had a biphasic effect on PKC-delta levels with peaks at 4 h (2-fold increase) and 24 h (4-fold increase). At the level of mRNA, PKC-epsilon, but not PKC-delta levels, were induced after incubation of EL4 cells with IL-1 beta. The signalling mechanisms utilized by IL-1 beta to induce the synthesis of these PKC isoforms were investigated. Two phosphatidylinositol (PI) 3-kinase-specific inhibitors, wortmannin and LY294002, inhibited IL-1 beta-induced synthesis of PKC-epsilon. However, the PI 3-kinase inhibitors had little effect on the IL-1 beta-induced synthesis of PKC-delta in these cells. Our results indicate that IL-1 beta induced both PKC-delta and PKC-epsilon expression over different time periods. Furthermore, our evidence suggests that IL-1 beta induction of PKC-epsilon, but not PKC-delta, may occur via the PI 3-kinase pathway.

The effects of inhalation exposure to bromo-dichloromethane on specific rat CYP isoenzymes

Several cytochrome P450 (CYP) isoenzymes may be involved in the metabolism of bromo-dichloromethane (BDCM), a drinking water disinfection byproduct. After 4-h inhalation exposures of male F344 rats to BDCM between 100 and 3200 p.p.m., hepatic microsomal methoxyresorufin demethylase (MROD), ethoxyresorufin de-ethylease (EROD) and pentoxyresorufin dealkylase (PROD) activities showed modest increases at low exposure levels and larger decreases at high exposure levels, compared with controls. Western blots for CYP1A2 and CYP2B1 showed similar trends. In addition, p-nitrophenol hydroxylase (PNP) activity was measured and Western blots for CYP2E1 were performed. CYP2E1 and CYP2B1 isoenzymes are known to metabolize BDCM (Thornton-Manning, J.R., Gao, P., Lilly, P.D., Pegram, R.A., 1993. Acute bromodichloromethane toxicity in rats pretreated with cytochrome P450 inducers and inhibitors. The Toxicologist 13: 361). When compared with a multiple gavage study of BDCM in female F344 rats (Thornton-Manning, J.R., et al., 1994. Toxicology 94, 3-18), the results of the two studies for EROD, PROD, and PNP activities were qualitatively the same; PNP activity did not change, while both PROD and EROD activities decreased at high exposures. In the current work, Western blots for CYP2E1, CYP2B1 and CYP1A2 supported the results from the PNP, PROD and MROD activities, respectively. The decreases in MROD and PROD activities and in Western blots for CYP1A2 and CYP2B1 at high exposures suggest that BDCM may be a suicide substrate for these CYP isoenzymes. Other important conclusions that can be drawn from the comparison between the current and prior work are that the liver response is similar for both sexes, and it is also similar for inhalation and gavage exposures under these conditions. Finally, the decrease in EROD activity at high doses, found in both studies, may be a further reflection of CYP1A2 activity, since little or no CYP1A1 activity is normally found in uninduced rat liver and CYP1A2 is known to metabolize ethoxyresorufin, although much more slowly than CYP1A1.

Possible role for protein kinase B in the anti-apoptotic effect of prolactin in rat Nb2 lymphoma cells

Prolactin (PRL) is a mitogen for a number of cell types and its action as a survival factor has recently been demonstrated in Nb2 lymphoma cells. However, the intracellular signalling pathways by which PRL promotes the survival of Nb2 cells is unknown. In previous studies, we have shown that PRL caused the activation of phosphatidylinositol 3-kinase (PI3-kinase) and its association with tyrosine phosphorylated fyn. Protein kinase B (PKB), a serine/threonine kinase, is now known to be a downstream component of the PI3-kinase pathway. The aim of the present study was to examine the effect of PRL on the activation of PKB and to find out whether this has any role on the PRL-induced survival of Nb2 cells. Our studies have revealed the phosphorylation and activation of PKB in PRL-stimulated Nb2 cells. We have also observed, using confocal microscopy, translocation of PKB to the membrane of Nb2 cells in response to PRL. These effects were blocked by the PI3-kinase inhibitor, LY294002 (10 microgram/ml). Apoptosis was induced by the general protein kinase inhibitor, staurosporine (STS; 0.1-1 microM), the synthetic glucocorticoid, dexamethasone (Dex; 100 nM) or ionising radiation by exposing Nb2 cells to X-irradiation (IR; 10 Gy). PRL had no effect on STS-induced apoptosis. On the other hand, PRL (100 ng/ml) inhibited apoptosis induced by Dex or IR; this effect of PRL was reversed by the addition of LY294002 (10 microgram/ml). Furthermore, Western blot analysis using phosphospecific PKB antibody on lysates from PRL-treated Nb2 cells showed that phosphorylation of PKB in response to PRL was inhibited by STS (0.5 microM), but not by Dex (100 nM). These results suggest that the PI3-kinase/PKB pathway may mediate the anti-apoptotic effect of PRL in Nb2 cells.

Cloning of the cDNA for sea bream (Sparus aurata) parathyroid hormone-related protein

This paper reports cloning of the cDNA for sea bream (Sparus aurata) parathyroid hormone-related protein (PTHrP). The gene codes for a 125-amino acid mature protein with a 35-residue prepeptide. The total gene sequence is 1.8 kb with approximately 75% noncoding. The N-terminus of the protein resembles mammalian and chicken PTHrP peptides with 12 of the first 21 amino acids identical and for which there is homology with mammalian parathyroid hormone. Toward the C-terminus, the nuclear transporter region between residues 79 and 93 in sea bream is 73% homologous to tetrapod PTHrP, and the RNA binding domain, 96-117, is 50% homologous, moreover starting with the conserved lysine and terminating with the lysine/arginine sequence. Sea bream PTHrP differs significantly from mammalian and chicken PTHrP, having a novel 16-amino acid segment between residues 38 and 54 and completely lacking the terminal domain associated in mammals with inhibition of bone matrix lysis. RT-PCR and in situ hybridization of sea bream tissues show that the gene is expressed widely and the results confirm observations of a PTHrP-like factor in sea bream detected with antisera to human PTHrP.

Caspase-3-like activity is necessary but not sufficient for daunorubicin-induced apoptosis in Jurkat human lymphoblastic leukemia cells

In the present study we have shown that the cancer therapeutic drug, daunorubicin, induces apoptosis in the human lymphoblastic leukemia cell line Jurkat E6.1. This effect was both dose-and time-dependent with nuclear fragmentation detectable by 8 h. Caspases have been implicated in pro-apoptotic events. By utilizing synthetic fluorochrome-linked substrates of the caspases, we observed that a caspase-3-like enzyme had dramatically increased activity (3340 130% with respect to basal levels) in response to daunorubicin treatment. Furthermore, by using an inhibitor to caspase-3, Ac-DEVD-CHO, we have shown that activation of a caspase-3-like enzyme appears to be necessary for nuclear fragmentation and apoptotic body formation, but is not required for chromatin condensation. In contrast, a general caspase inhibitor, Z-VAD-fmk, inhibited all apoptotic parameters measured. Ceramide has been implicated in daunorubicin-induced apoptosis in human myeloid leukemia cells. However, in Jurkat cells, caspase activation does not appear to be a consequence of ceramide generation since, although ceramide levels were elevated through the action of ceramide synthase in response to daunorubicin treatment, this occurred with slower kinetics than either nuclear fragmentation or caspase activation. In contrast, caspase inhibitors abrogated ceramide elevation induced by DNR treatment, suggesting that ceramide synthase may be a downstream target for caspase action. Therefore, daunorubicin-induced apoptosis does not appear to be mediated by ceramide in the lymphoblastic leukemia cell line, Jurkat E6.1. Instead, caspase 3 activity appears to be necessary, but not sufficient for this process.

The role of caspase 3 and BclxL in the action of interleukin 7 (IL-7): a survival factor in activated human T cells

The effects of interleukin 7 (IL-7) on apoptosis in interleukin 2 (IL-2)-dependent, activated, primary, human T lymphocytes (hT cells) was examined. IL-7 (like IL-2) rescued cells from apoptosis, as measured by their cellular DNA profile and fragmentation. IL-2 also acted as a mitogen in these T cells. Both cytokines abrogated the dexamethasone-induced stimulation of Caspase 3 and prevented the cleavage of poly (ADP-ribose) polymerase (PARP), a substrate for the Caspase 3. IL-7 upregulated the expression of Bc1xL and counteracted the downregulation of this anti-apoptotic protein by the synthetic glucocorticoid, dexamethasone. Bcl-2 protein expression was uupregulated by IL-7 with or without dexamethasone, but Bc1-2 was expressed at a much lower level than BclxL in these cells. Levels of Bax did not markedly change on either cytokine stimulation or dexamethasone treatment. An unidentified 23-kDa band, which was recognized by the anti-Bc1-2 antibody, was induced by dexamthasone and suppressed by IL-7 and IL-2. This protein was subject to independent regulation as compared to the p26 Bc1-2 protein, suggesting that it may be a novel factor, possibly involved in the regulation of apoptosis. A clear role for IL-7 as a survival factor for cytokine withdrawal and glucocorticoid induced apoptosis in activated primary hT cells is implicated. In addition, regulation of BclxL and downstream inhibition of Caspase 3 activity may mediate this rescue signal.

The start-stop procedure: estimation of temporal intervals by human subjects

In four experiments investigating human timing, subjects produced estimates of sample durations by bracketing their endpoints. On each trial, subjects reproduced a sample duration by pressing a button before the estimated sample duration elapsed (start time) and releasing it after the estimated duration elapsed (stop time). From these responses, middle time (start + stop/2) and spread time (stop - start) were calculated, representing the point of subjective equality and the difference limen, respectively. In all experiments, subjects produced middle times that varied directly with sample duration. In Experiment 2, middle times lengthened when feedback was withheld. Consistent with Weber timing, spread times, as well as the standard deviation of middle times, varied directly with middle time (Experiments 1, 3, and 4). On the basis of an internal clock model of timing (Gibbon & Church, 1990), the data permitted inferences regarding memory processes and response threshold. Correlations between start and stop times and between start and spread times agreed with earlier findings in animals suggesting that the variance of temporal estimates across trials is based in part upon the selection of a single temporal memory sample from a reference memory store and upon one or two threshold samples for initiating and terminating each estimate within a trial.

Prolactin induced tyrosine phosphorylation of p59fyn may mediate phosphatidylinositol 3-kinase activation in Nb2 cells

Our previous studies indicated that PI3-kinase is involved in prolactin (PRL) signalling. We have now examined the involvement of the src tyrosine kinase, fyn, in PRL-induced the activation of PI3-kinase in the rat lymphoma cell line, Nb2. Cells were stimulated with increasing doses of PRL, lysed and immunoprecipitated with anti-fyn specific antibody. Then PI3-kinase activity was measured as the increase in the phosphorylation of phosphatidylinositol to phosphatidylinositol 3-phosphate separated by TLC. Our data indicated that, in PRL treated cells, co-precipitation of PI3-kinase with anti-fyn antiserum led to time and dose-dependent activation of PI3-kinase in vitro and that this activation was blocked by the addition of LY294002. However, LY294002 appeared to have no effect on fyn autophosphorylation. Furthermore, the physical association of PI3-kinase with fyn was confirmed by Western blot analysis employing the same specific antisera. These data provide evidence that PRL-induced activation of PI3-kinase may be mediated by the tyrosine phosphorylation of fyn in Nb2 cells.

Interleukin-1beta-induced expression of protein kinase C (PKC)-delta and epsilon in NIH 3T3 cells

NIH 3T3 cells express the alpha, delta, epsilon and zeta isoenzymes of protein kinase C(PKC). Following stimulation of cells (24 h) with the pro-inflammatory cytokine, interleukin 1beta (IL-1beta), we observed, by Western blotting, a dose-dependent effect on the levels of PKC-epsilon and delta, but not on alpha or zeta. Moreover, time course analysis revealed that the isoenzymes, PKC-delta and epsilon were induced by IL-1beta after 7 h. Again, no change in PKC-alpha or zeta levels after IL-1beta treatment were detected. Incubation with selective PKC inhibitor peptides blocked the PKC-alpha, delta, epsilon and zeta antibodies binding to their respective isoenzyme bands. We also observed that the addition of the tumour-promoting phorbol ester, Phorbol 12-myristate 13-acetate (PMA), downregulated PKC-alpha, delta and epsilon by 7 h in NIH 3T3 cells. PMA did not affect constitutively produced PKC-zeta protein levels even after 24-h treatment. In summary, these results demonstrate that IL-1beta induces protein synthesis of the Ca2+-independent PKC-delta and epsilon isoforms in NIH 3T3 cells. The differences observed here between PKC isoenzymes in response to IL-1beta suggest that each isoenzyme may have a unique role in the signal transduction pathways of IL-1beta and that such isoenzyme may have a unique role in the signal transduction pathways of IL-1beta and that such selective expression may influence the action of agents which require PKC for signal transduction acting in concert with IL-1.

A 70-kDa protein facilitates interleukin-4 signal transduction in the absence of the common gamma receptor chain

Interleukin-4 signal transduction (and activation of STAT 6) is known to be mediated via its binding to a p140 receptor chain and the common gamma chain (gamma c). In non-activated monocytes, neither the gamma c nor its associated signal transducing molecule, Jak3, is expressed. We nevertheless show that IL-4 can initiate the tyrosine phosphorylation and DNA binding of STAT 6 in these cells. We present evidence for an additional 70 kDa IL-4 receptor chain which mediates the tyrosine phosphorylation of STAT 6 via Jak2, and suggest that this is the means by which IL-4 can signal in cells lacking the gamma c.

Methanol potentiation of carbon tetrachloride hepatotoxicity: the central role of cytochrome P450

Evidence to explain the enhanced hepatotoxicity of carbon tetrachloride (CCl4) following methanol exposure by inhalation is presented. Hepatic microsomes prepared from male F344 rats exposed to methanol at concentrations up to 10,000 ppm showed increased p-nitrophenol hydroxylase activity but no increase in pentoxyresorufin-O-dealkylase or ethoxyresorufin-O-deethylase activities. Hepatic antioxidant levels, glutathione levels and glutathione-S-transferase activity in methanol-treated animals were not different from controls. In vitro metabolism of CCl4 was also increased in microsomes from methanol-treated animals. Pretreatment with allyl sulfone, a specific chemical inhibitor of cytochrome P450 2E1, abolished the difference in microsomal metabolism between exposed and control animals. This study shows that methanol exposure induces cytochrome P450 2E1, which appears to be the principal toxicokinetic mechanism responsible for the increased metabolism and thus the increased hepatotoxicity of CCl4.

Activation of phosphatidylinositol 3-kinase by prolactin in Nb2 cells

In the present studies, using anti-phosphotyrosine (PY20) and PI3-kinase (p85) antibodies, we have shown that PRL causes activation of phosphatidyl inositol 3-kinase (PI3-kinase) in vitro in a dose- and time-dependent manner in Nb2 cells. PRL activated PI3-kinase was completely inhibited by LY294002 (1 microgram/ml). Stimulation of the cells with PRL also increased tyrosine phosphorylation of the 85-kDa regulatory subunit. Moreover, in vitro kinase assay followed by SDS-PAGE protein separation demonstrated the phosphorylation of several other proteins besides the p85. However, no direct association between p85 and JAK2 tyrosine kinase was observed. These results indicate, for the first time, the involvement of PI3-kinase in PRL-stimulated Nb2 cell growth.

Fasting for less than 24 h induces cytochrome P450 2E1 and 2B1/2 activities in rats

Cytochrome P450 (CYP) 2E1 activity is induced after 24 h of fasting but no information is available for shorter fasting periods. We investigate the induction of CYP 2E1, 2B1/2 and 1A1 in young adult male F344 rats after 8, 16 and 24 h of fasting compared to control. Liver microsomes were analyzed for the following enzyme activities: p-nitrophenol hydroxylase (PNP) for CYP 2E1, pentoxyresorufin-O-dealkylase (PROD) for CYP 2B1/2 and ethoxyresorufin-O-deethylase (EROD) for CYP 1A1. After each fasting interval, the activities per mg microsomal protein for PNP and PROD increased but the activity of EROD remained unchanged. Western blots for CYP 2E1 and CYP 2B1 showed increases comparable to the PNP and PROD activities, respectively. On a whole organ basis, increases were found for PNP and PROD activities, while decreases were found for EROD activity and total microsomal protein. The results are consistent with an induction of CYP 2E1 and CYP 2B1/2 activities after as little as 8 h of fasting.

Interleukin-1 beta induces the synthesis of adenylyl cyclase in Swiss 3T3 fibroblasts and MG-63 osteosarcoma cells

In this study, the longer term (> or = 6 hours) effect of interleukin-1 beta on adenylyl cyclase activity was investigated in Swiss 3T3 and MG-63 cells. No change was evident after 6 hours but after 1, 7 or 15 day incubations a significant increase in basal (1.5- 2 fold) and NaF-stimulated (2-4 fold) adenylyl cyclase activity was observed in interleukin-1 beta pre-treated cell membranes compared with non pre-treated controls. The response to forskolin, a direct stimulus of adenylyl cyclase, was also significantly enhanced, indicating that the effect of interleukin-1 beta was targeted to the enzyme itself. This action of interleukin-1 beta was blocked by co-incubation with cycloheximide, an inhibitor of protein synthesis, which demonstrated that de novo protein synthesis was required. It is concluded that interleukin-1 induces the expression of adenylyl cyclase in 3T3 and MG-63 cells, leading to enhanced activation by NaF and forskolin.

Adjunctive treatment of cranial base malignacies

The indications for skull base tumor surgery have increased in recent years primarily because of improving surgical techniques and adjunctive treatment modalities. In this article we review current and future adjunctive treatment for cranial base malignancies. Surgically clear tumor margins are often difficult to achieve in skull base surgery because of unacceptable morbidity to surrounding structures. Current phase I and II trials of adjunctive radiation and chemotherapy are discussed. Future advances in radiation therapy and chemotherapy are introduced.

The mitogenic action of recombinant basic FGF in Swiss 3T3 cells is independent of early diradylglycerol production and downregulatable protein kinase C activity

In this study we have investigated the requirement for phosphoinositide metabolism, diradylglycerol (DG) production and protein kinase C (PKC) activation in recombinant basic fibroblast growth factor (rbFGF)-mediated reinitiation of DNA synthesis in Swiss 3T3 cells. We have assessed the involvement of PKC activation in rbFGF-induced DNA synthesis by two approaches; enzymic inhibition by H7 and down-regulation by prolonged phorbol-ester treatment. In both conditions we observed that rbFGF was able to sustain a significant component of its mitogenic response, therefore denying an exclusive role for the activation of downregulatable and H7-sensitive PKC isoforms in rbFGF-induced reinitiation of DNA synthesis. Moreover, we have found no evidence for diacylglycerol accumulation in response to rbFGF by 3T3 cells. In previous studies, we observed that rbFGF caused a moderate and slow accumulation of total inositol phosphates. This effect was significant only after a 60 min incubation. It is our contention that rbFGF, in our culture system, does not exert a direct effect on phosphoinositide metabolism.