Initial Report of Boswellia Serrata for Management of Cerebral Radiation Necrosis after Stereotactic Radiosurgery for Brain Metastases

PURPOSE/OBJECTIVE(S)

Radiation necrosis (RN) is a concerning late toxicity after radiation therapy (RT) for brain metastases. Oral corticosteroids are the mainstay of management; however, they are not optimal for long-term use given multiple side effects and drug interactions, particularly with the emergence of immunotherapy for several cancers. Boswellia serrata (BS) is an over-the-counter supplement used for its anti-inflammatory properties and has been recently shown to reduce cerebral edema after brain RT. We evaluated the response rates with BS in a series of patients with brain metastases treated with stereotactic radiosurgery (SRS) who developed RN.

MATERIALS/METHODS

We included patients who developed RN after SRS for brain metastases at our institution from 2020-2022 and were treated with BS. Patients were prescribed over the counter BS 4.2-4.5g daily in divided doses. Follow-up MRI imaging was obtained every 2-3 months after starting BS. Response was assessed using Response Assessment in Neuro-Oncology (RANO) criteria. Primary endpoint was ≥25% decrease in edema volume on T2-FLAIR MRI from baseline. Patients were censored if they had tumor progression or repeat RT to necrotic area, or death. Kaplan-Meier curves were used for survival estimates.

RESULTS

A total of 50 patients received BS for Grade 1-3 CTCAE v5.0 RN (G1 = 11, G2 = 36, and G3 = 3). Median age was 62.8 years (range 36.9 - 50) and median RT dose was 24 Gy in 3 fractions. Median time to RN after SRS was 10 months(m). Median follow-up after starting BS was 6m and 40 patients had at least 1 follow up MRI available to evaluate response. The best response was complete response (CR) in 15% patients and partial response (PR) in 40% while 35% had stable disease (SD) and 10% had progressive disease. Median time to CR was 9m (6-12m) and PR was 6m (3-12m). Percentage of patients who had any response (CR or PR) at 3, 6, 9 and 12 months was 25%, 60%, 43% and 50%, respectively. 56% patients had symptomatic RN, of which 35.7% had improvement in symptoms with BS alone, while 64% required steroid use. Overall, median duration of response in patients with CR, PR or SD was 7.5m(range 2-31m). Salvage treatment for RN was steroids (33), surgery (4), Bevacizumab (5) or hyperbaric oxygen therapy (1). No patients had any CTCAE grade 3 or higher toxicities. 3 patients (6%) had any side-effects all of whom had Grade 1-2 gastrointestinal intolerance or diarrhea. 2 patients stopped treatment due to enrolment on an immunotherapy clinical trial. Overall, 39 patients remained on BS at last follow-up or death.

CONCLUSION

We observed >50% response rates with use of BS in our cohort of patients with Grade 1-3 RN after SRS. More than 1/3rd patients with symptomatic RN were able to avoid long-term steroid use. BS is an easily available over-the-counter drug that appears to be a safe and promising treatment option for RN, and can potentially decrease steroid dependence in these patients, reducing the risk of several side-effects. Further prospective studies to compare Boswellia with placebo is warranted.

WBRT is Associated with Higher Rates of Hematologic Toxicity than Stereotactic Radiosurgery in Brain Metastasis Patients

PURPOSE/OBJECTIVE(S)

Whole brain radiotherapy (WBRT) has historically been a standard of care in patients with multiple brain metastases. Studies show that WBRT may be associated with a transient detriment in hematological parameters because of exposure to a larger proportion of circulating lymphocytes, platelets and hematopoietic cells within the bone marrow of the cranium. In this study, we tested the hypothesis that stereotactic radiotherapy (SRS) may cause reduced hematologic toxicity in patients compared to WBRT.

MATERIALS/METHODS

We retrospectively identified 100 patients treated for brain metastasis, with either SRS or WBRT from 2016 to 2019, and queried their pre- and post-treatment hematological parameters including hemoglobin, total white blood cell (WBC), absolute neutrophil count (ANC), absolute lymphocyte count, and platelet count. CTCAE v5.0 was used for grading hematologic toxicities. Serial values were compared by treatment type and controlled for age, gender, and systemic therapy. Student t-test was used for intergroup comparison and p-value <0.05 was considered significant.

RESULTS

Of 100 patients, median brain metastases was 3 (range 1-22), 51 received SRS and 49 received WBRT. We observed that patients treated with WBRT had a significantly higher post-treatment reduction in platelet count (-51.2 vs 9.8; p = 0.001) and higher incidence of any grade thrombocytopenia (31.2% vs 10%; p = 0.019) compared to patients treated with SRS. We also noted that compared with SRS, WBRT was associated with a higher post-treatment reduction in circulating lymphocytes (-0.80 vs 0.14; p = 0.071) and higher incidence of G3+ lymphopenia (43.2% vs 22.2%; p = 0.07). Numerical incidence of any G3+ hematological toxicity was also higher in the WBRT group but the difference was not statistically significant (40% vs 28%, p = 0.162). Hemoglobin count, WBC, and ANC were not meaningfully different pre- and post-treatment for either group.

CONCLUSION

WBRT results in an increased amount and duration of radiation exposure to circulating intracranial blood volume. In our study, patients treated with WBRT experienced higher rates of clinically significant lymphopenia & thrombocytopenia compared to patients treated with SRS. In addition to the cognitive benefits of SRS compared to WBRT, there may be significant hematologic benefits as well. Further studies are warranted to clarify and validate these findings.

Volumetric Modulated Arc Therapy Craniospinal Irradiation Utilizing a Vertebral Body Sparing Approach: A Toxicity Analysis

PURPOSE/OBJECTIVE(S)

Craniospinal irradiation (CSI) is indicated for adult patients diagnosed with leptomeningeal disease (LMD). Proton-based vertebral-body-sparing (VBS) CSI has been explored with pediatric patients to minimize hematologic toxicity; however, utilization of VBS in an adult population is limited. A recent phase II trial (Yang et al, JCO 2022) has shown efficacy of proton-based CSI to treat non-small cell lung and breast cancer with LMD. We hypothesize that VBS-CSI utilizing volumetric modulated arc therapy (VMAT) could also effectively reduce dose to vertebral bodies and surrounding organs-at-risk (OARs), minimizing toxicity for adult patients with LMD and comparing favorably to proton-based CSI.

MATERIALS/METHODS

Consecutive patients with leptomeningeal disease received VMAT VBS-CSI, 30 Gy in 10 fractions, as a part of a prospective registry. Full VMAT arcs for the brain fields matched to two spine isocenters for the upper and lower spine were created utilizing limited posterior arcs. The PTV was created with margins of 3mm uniformly around the brain contour and 7mm around the spinal canal. To further decrease the vertebral body dose, an avoid entry and exit contour was created. This structure was a margin on the PTV anteriorly designed to carve dose out of the vertebral bodies while still maintaining coverage to the PTV. Acute toxicity data were collected using Common Terminology Criteria for Adverse Events (CTCAE) v5 and was defined as toxicity occurring within 30 days of treatment conclusion.

RESULTS

Ten adult patients were treated in this cohort. All patients completed radiation treatment. One patient experienced Grade 2 neutropenia with the remaining nine experiencing Grade 1 hematologic toxicity (three Grade 1 pancytopenia, six Grade 1 thrombocytopenia). Three patients experienced Grade 2 gastrointestinal toxicity (Grade 2 nausea, Grade 2 esophagitis, Grade 2 esophagitis/Grade 2 diverticulitis) with the remaining seven experiencing Grade 1 nausea. No patient experienced Grade 3+ toxicities in this cohort. One patient experienced a 5-day delay in systemic therapy initiation due to neutropenia; otherwise, all patients planned for systemic therapy started without delay.

CONCLUSION

VMAT VBS-CSI is an effective technique to reduce dose to surrounding OARs and vertebral bodies. In this study, VMAT VBS-CSI led to acceptable toxicity compared to patients treated with proton CSI on a phase 2 clinical trial. An NRG phase 3 clinical trial may be developed to evaluate the efficacy of proton-based CSI for patients with LMD. However, these data show how VMAT VBS-CSI may be an acceptable alternative for centers without proton therapy capabilities. Given its promising early results, future prospective evaluation of the technique is warranted.

Patient-Reported Cognitive Outcomes and Survival after Stereotactic Radiosurgery for 15 or More Brain Metastases

PURPOSE/OBJECTIVE(S)

Overall survival (OS) in metastatic cancer patients has been improving with continued advancements, necessitating greater attention to treatment related toxicities. Patients with ≥ 15 brain metastases (BM) continue to be treated with whole brain radiation therapy (WBRT), despite poor neurocognitive outcomes. We analyzed our institutional experience of treating these patients with stereotactic radiosurgery (SRS), with the aim of evaluating safety, cognitive outcomes, and survival metrics.

MATERIALS/METHODS

Patients who received SRS for ≥ 15 BMs in 1-5 fractions from 2014-2022 using the previously described single isocenter multi-target technique were included. Cognitive outcomes were objectively evaluated using serial Patient-Reported Outcome Measurement Information System (PROMIS) scores. Kaplan-Meier method was used for survival analysis and log-rank test was used for intergroup comparisons.

RESULTS

A total of 118 patients underwent 124 courses of LINAC-based SRS. The mean and median number of lesions treated per patient was 24.8 and 20, respectively (range 15 - 94). Most common primary histologies were lung (47.6%), melanoma (21.0%), and breast (14.5%). The median SRS dose was 24 Gy (range 18 - 30 Gy) with 87.9% receiving 3 fraction SRS. At the time of SRS, 19.4% patients had received prior WBRT and 24.2% had received at least one prior SRS course. The rate of any grade radiation necrosis (RN) and ≥ grade 3 RN were 15.3% and 3.2% respectively. New onset seizures were seen in 2.4%, alopecia in 2.4%, and subjective cognitive decline in 4% of patients. Median follow-up by reverse Kaplan-Meier method was 17.8 months (m). Cognitive data was available for 38 patients. Mean PROMIS scores at baseline, 3m, 6m and 9m after SRS were 32.0, 31.6, 30.4 and 28.7 out of 40, respectively. When longitudinal trends were available, 25 of 31 patients had a stable or improved PROMIS score. The 12m local control was 97.6%. Cumulative incidence of distant intracranial failure was 79.2%. One year freedom from neurological death, leptomeningeal disease, and salvage WBRT were 85.6%, 87.6% and 71.7% respectively. Median OS from brain metastases diagnosis was 11.3m (95% CI 7.2m - 15.3m) overall, while it was 9.2m (6.5 - 11.8m) after excluding patients who had prior WBRT or SRS (n = 79). One-year survival was 40% from diagnosis and 38.7% from SRS. On Cox regression analysis, prior WBRT (p = 0.002), higher KPS (p = 0.050), systemic therapy after SRS (p<0.001), and controlled extracranial disease (p = 0.007) predicted for improved OS.

CONCLUSION

We present here the largest study evaluating SRS for patients with ≥ 15 BMs. We found that SRS was safe, had favorable cognitive outcomes, and comparable survival outcomes to contemporary studies evaluating WBRT in this patient population. Treatment-naïve patients had a median survival of > 6 months, long enough to benefit from cognitive sparing with SRS. Our study supports further randomized studies comparing SRS and memory avoidance WBRT approaches for patients with ≥ 15 BMs.

Advancing beyond the Hippocampus to Preserve Cognition for Patients with Brain Metastases: Dosimetric Results from a Phase 2 Trial of Memory-Avoidance Whole Brain Radiotherapy

PURPOSE/OBJECTIVE(S)

Recent advances to preserve neurocognitive function in patients treated for brain metastases include stereotactic radiosurgery (SRS), hippocampal avoidance whole brain radiation therapy (HA-WBRT), and memantine administration. However, 23% of patients receiving HA-WBRT and memantine on NRG-CC001 still experienced executive function deterioration at 4 months, with 12% experiencing total recall and delayed recognition deterioration at 6 months. The hippocampus, corpus callosum, fornix, and amygdala are key neurocognitive substructures with a low propensity for brain metastases. Herein, we report our preliminary experience using an advanced "memory-avoidance" WBRT (MA-WBRT) approach sparing these substructures for patients with multiple (>15) brain metastases.

MATERIALS/METHODS

Ten consecutive patients treated with MA-WBRT on a phase 2 clinical trial (OSU-21074) were reviewed. In each patient, the hippocampi, amygdalae, corpus callosa, and fornix were contoured. Patients were not eligible for MA-WBRT if they had metastases in these substructures. A memory- avoidance region created using a 5mm volumetric expansion around these substructures. Hotspots were avoided in the hypothalamus and pituitary gland. Dose constraints for these avoidance structures were modeled after NRG CC-001 and include a D100% ≤ 9 Gy and a D0.03 cc ≤ 16 (acceptable to 20 Gy). Coverage of brain metastases was prioritized over memory avoidance dose constraints. Linac-based volumetric modulated arc therapy (VMAT) plans were generated for a prescription dose of 30 Gy in 10 fractions.

RESULTS

On average, the memory avoidance structure volume was 37.1 ccs (Range: 25.2-44.6 ccs), occupying 2.5% of the entire whole brain target volume. All treatment plans met the D100% dose constraint, and 8/10 plans met the D0.03cc constraint, with priority given to tumor coverage for the remaining 2 cases. VMAT spared the memory avoidance structures with a median dose range of 10.8-14.2 Gy and a maximum dose (D0.03cc) range of 15.6-22.7 Gy. The mean dose to the memory avoidance structures was 12.7 Gy (Range: 11.5-13.8 Gy). Target coverage (D98% > 25 Gy) and homogeneity (D2% ≤ 37.5 Gy) were achieved for all plans.

CONCLUSION

Modern VMAT techniques allow for sparing of the hippocampus, amygdala, corpus callosum, and fornix with good target coverage and homogeneity. Prospective quality of life and cognitive data including are being collected and include the Functional Assessment of Cancer Therapy - Brain (Fact-Br), Hopkins Verbal Learning Test (HLVT-R), Trail Making Test A/B (TMT-A/B) and Controlled Oral Word Association Test (COWAT). After enrollment is completed, these data will be evaluated to assess the efficacy of MA-WBRT to mitigate declines in quality of life and cognition after whole brain radiation.

Vertebral Compression Fracture Post Spine Stereotactic Body Radiotherapy: The Role of Vertebral Endplate

PURPOSE/OBJECTIVE(S)

Maintaining hydrostatic pressure -via Pascal's Principle- between vertebral bodies is essential to decrease the chance of vertebral compression fracture (VCF). Vertebral endplates (EP) play an essential role in this matter through maintaining the mechanical environment as well as the proper nutrition of avascular discs. The purpose of this study is to establish the correlation of VCF with disrupted EP by tumor involvement.

MATERIALS/METHODS

A retrospective analysis of de novo spine metastases treated with stereotactic body radiotherapy (SBRT) between 2013-2019. Patients (pts) with previous surgical intervention were excluded. VCF defined as new or progression of existing loss of vertebral body height. The vertebral EP region defined in relation to the vertebral body as superior EP vs inferior EP. Kaplan-Meier curves used to analyze the variables. A multivariate proportional hazard model used to assess the risk of all covariates.

RESULTS

A total of 111 pts were treated with SBRT with a median dose of 27 Gy (10-35 Gy). Median follow-up was 18 months (1.2-107). The median age was 60 years (24-87) and 59 were males (53%) and 52 were females (47%). The median body mass index (BMI) was 27 kg/m2 (16-47). Almost 9 pts diagnosed with osteoporosis prior radiation. Twelve pts received prolonged steroids. Twenty pts received bisphosphonate and 8 pts received denosumab. The median PTV was 50cc (8-465) and median Conformity Index was 1.05 (0.42-1.4). Almost 75% of pts received >95% of the dose covering 100% of the PTV. The most common histopathologies were renal cell carcinoma (25%), lung (13%) and breast (11%). Most of the pts (77%) had SINS score of 7 or less. 48 pts (43%) had either superior or inferior EP disruption secondary to the tumor at the time of radiation. Twenty pts (18%) had both superiorly and inferiorly disrupted EP. Around 20 pts (18%) developed VCF. The median time to VCF was 5.2 months (1.1-57.4). The one-year cumulative incidence of VCF was 18%. The 1-year cumulative incidence of VCF with either superiorly and/or inferiorly disrupted EP was 29% vs 6%, p value <0.001. The 1-year cumulative incidence of VCF with both superiorly and inferiorly disrupted EP was 57% vs 7% (p value <0.001). The median time to VCF was earlier in pts with both disrupted EP (2.4 months vs 5.7 months, p value <0.05). Other risk factors like SINS score of >7 and local recurrence (LR) associated with higher risk of VCF. On multivariate analysis, LR (HR 8.2 [CI 2.4-28, p- value <0.001]), tumor disrupting the EP (HR 4.5 [CI 1.3-16, p-value<0.018]) and SINS score of seven and above (HR 1.7 [CI 1.3-2.25, p-value <0.001]) correlated with the VCF risk.

CONCLUSION

In this retrospective analysis, tumor disrupting the EP, disease recurrence and high SINS score increased the risk of VCF. Cement augmentation either prophylactically or immediately following SBRT is currently being studied in a prospective trial within our institution.

Frameless LINAC-Based Stereotactic Radiosurgery is Safe and Effective for Essential and Parkinsonian Tremor

PURPOSE/OBJECTIVE(S)

Stereotactic radiosurgery (SRS) to the thalamus is an ablative technique used for treatment of refractory tremor of essential or Parkinsonian origin. Because of the high dose, small target, and required precision, framed SRS on the Gamma Knife has been the historical platform of choice. We tested our recently developed technique to emulate GK dose distributions on a multi-leaf collimator (MLC)-equipped linear accelerator (LINAC) without cumbersome, inefficient cones in a prospective trial of safety and efficacy.

MATERIALS/METHODS

We quantified pre-treatment contralateral tremor according to FTM scoring system. We obtained MPRAGE, FGATIR, DTI, and RS-fMRI sequences. We identified the VIM via classical stereotactic reference location and connectomically, and then targeted it to 135 Gy dmax in a manner dosimetrically roughly equivalent to 4 mm GK shot. We adjusted each target such that the 25 Gy isodose line did not overlap the posterior limb of the capsule. We immobilized patients in a highly rigid thermoplastic mask and delivered treatment on an Edge™ LINAC with HDMLC. Intrafraction optical surface monitoring (OSMS) ensured patient immobility. We surveilled post-treatment imaging and recorded tremor scoring, QOL outcomes, and adverse events.

RESULTS

We accrued 42 patients (16 female, 26 males; median age 72.5) over 36 months. 38 had essential tremor, 4 had tremor-dominant Parkinson's; 2 withdrew prior to treatment. Ten patients were on therapeutic anti-coagulation, and were not required to discontinue. At time of submission 39 patients had follow-up ≥ 6 months. 35/39 (89.7%) exhibited clinically meaningful tremor reduction. Mean limb tremor reduction among responders was 43.5% (range: 9 - 100%). Time to patient-reported tremor improvement was 0.3 to 15 months. One patient experienced Gr 3, and 4 patients experienced Gr 1-2 toxicity.

CONCLUSION

MLC-based SRS thalamotomy is safe and effective for refractory tremor treatment. Multidisciplinary management is key for proper patient selection, treatment, and monitoring. Our outcomes appear congruent to historical GK controls as well as more modern MRgFUS outcomes.

Connectomic Basis for Tremor Control in Stereotactic Radiosurgical Thalamotomy

BACKGROUND AND PURPOSE

Given the increased use of stereotactic radiosurgical thalamotomy and other ablative therapies for tremor, new biomarkers are needed to improve outcomes. Using resting-state fMRI and MR tractography, we hypothesized that a "connectome fingerprint" can predict tremor outcomes and potentially serve as a targeting biomarker for stereotactic radiosurgical thalamotomy.

MATERIALS AND METHODS

We evaluated 27 patients who underwent unilateral stereotactic radiosurgical thalamotomy for essential tremor or tremor-predominant Parkinson disease. Percentage postoperative improvement in the contralateral limb Fahn-Tolosa-Marin Clinical Tremor Rating Scale (TRS) was the primary end point. Connectome-style resting-state fMRI and MR tractography were performed before stereotactic radiosurgery. Using the final lesion volume as a seed, "connectivity fingerprints" representing ideal connectivity maps were generated as whole-brain R-maps using a voxelwise nonparametric Spearman correlation. A leave-one-out cross-validation was performed using the generated R-maps.

RESULTS

The mean improvement in the contralateral tremor score was 55.1% (SD, 38.9%) at a mean follow-up of 10.0 (SD, 5.0) months. Structural connectivity correlated with contralateral TRS improvement (r = 0.52; P  = .006) and explained 27.0% of the variance in outcome. Functional connectivity correlated with contralateral TRS improvement (r = 0.50; P  = .008) and explained 25.0% of the variance in outcome. Nodes most correlated with tremor improvement corresponded to areas of known network dysfunction in tremor, including the cerebello-thalamo-cortical pathway and the primary and extrastriate visual cortices.

CONCLUSIONS

Stereotactic radiosurgical targets with a distinct connectivity profile predict improvement in tremor after treatment. Such connectomic fingerprints show promise for developing patient-specific biomarkers to guide therapy with stereotactic radiosurgical thalamotomy.

Shifts of trade in Javan ferret badgers Melogale orientalis from wildlife markets to online platforms: implications for conservation policy, human health and monitoring

Wildlife trade is increasingly impeding the conservation of imperilled wildlife and is a potential threat to human health. Ferret badgers are extensively traded in China, although the trends, drivers and health implications of ferret badger trade in other parts of Asia remain poorly known. Here, we focus on the pet trade of a little known endemic small carnivore species, Javan ferret badger Melogale orientalis in Indonesia, over a 10 yr period (2011-2020). The Javan ferret badger is listed as Least Concern on the IUCN Red List of Threatened Species with an unknown population trend. We aimed to gain insight into the magnitude of this trade, its purposes, price trends, distribution records, health risks and shifts to online platforms. We documented 44 ferret badgers in 11 wildlife markets in Java and Bali and 100 ferret badgers for sale on online platforms. We observed a shift in trade from traditional animal markets only, to trade in these markets as well as online. Asking prices, corrected for inflation, declined significantly from ~USD 37 in 2012 to ~USD 22 in 2020, and were related to the purchasing power in cities where trade occurred. Widespread sale of the species highlights that enforcement continues to be overly passive as any trade in the species is illegal. We recommend that the Javan ferret badger be afforded full national protection and prioritised in monitoring efforts to establish its true conservation status. Additionally, concerted efforts are needed to determine if online trade poses a risk to conservation and human health.

Meat eating and nutritional quality of lambs sired by high and low muscle density rams

Intramuscular fat (IMF) content affects eating and nutritional quality of lamb meat. Muscle density measured by computer tomography is an in vivo proxy measure of IMF content that affects eating and nutritional quality of lamb meat. Lambs sired by high muscle density (HMD) or low muscle density (LMD) rams, selected for slaughter on commercial criteria were measured for meat quality and nutritional traits. A restricted maximum likelihood model was used to compare lamb traits. Additionally, regression analysis of sire estimated breeding value (EBV) for muscle density was performed for each meat quality trait. Muscle density EBV had a negative regression with IMF content (P < 0.001). For each unit increase in muscle density EBV, there was a significant decrease in loin (-1.69 mg/100 g fresh weight) and topside IMF (-0.03 mg/100 g fresh weight). Muscle density EBV had a negative regression with grouped saturated and monounsaturated fatty acids concentration (and monounsaturated proportion P < 0.001). Muscle density EBV had a negative regression with loin sensory traits tenderness, juiciness and overall liking and many novel tenderness sensory traits measured (P < 0.05). Selecting for LMD EBV increased IMF content and favourable meat eating quality traits. In contrast, sire muscle density EBV had a positive regression with loin polyunsaturated:saturated fat ratio and grouped polyunsaturated proportion traits (including total polyunsaturated proportion, total omega-6 (n-6) and total omega-3 (n-3) fatty acids (P < 0.001). This is explained by the fact that as sire muscle density EBV increases, polyunsaturated fatty acid proportion increases and the proportion of saturated and monounsaturated fatty acid content decreases. Muscle density EBV had a positive regression with shear force and the novel toughness sensory traits (P < 0.05). Selection for HMD EBV's increased shear force and toughness traits, which is unfavourable for the consumer. Low muscle density sired meat had higher meat colour traits chroma/saturation (+0.64, SD 2.30, P = 0.012), redness (+0.52, SD 1.91, P = 0.012) and yellowness (+0.31, SD 1.49, P = 0.08) compared to HMD sired meat. Selection for LMD could be used within a breeding programme to increase IMF content and enhance both meat colour and improve eating quality parameters.

Review: The Perioperative Use of Thromboelastography for Liver Transplant Patients

Thromboelastography (TEG) is a viscoelastic test that allows rapid evaluation of clot formation and fibrinolysis from a sample of whole blood. TEG is increasingly utilized to guide blood product resuscitation in surgical patients and transfusions for liver transplant patients. Patients with severe liver failure have significant derangement of their clotting function due to impaired production of procoagulant and anticoagulant factors. Traditional coagulation studies are limited by the short time needed for the result and provide little information about the dynamics and strength of clot formation. In addition, traditional coagulation studies do not correlate well with bleeding episodes and may lead to over-transfusion of various blood products. Evidence is less robust regarding the use of TEG for transfusion management decisions in severe liver failure patients awaiting, undergoing, or immediately after liver transplant surgery. However, the available evidence suggests that systematic implementation of TEG rather than traditional coagulation studies results in the administration of fewer blood products without increased mortality or complications. The purpose of this study is to review the literature regarding the use of TEG in liver failure patients prior to liver transplant, intraoperatively, and postoperatively. Additional high-quality randomized controlled studies should be performed to evaluate the use of TEG to guide transfusion decisions, particularly in the postoperative period following liver transplantation.

A Dose Ranging Study to Evaluate Dermatan Sulphate in Preventing Deep Vein Thrombosis following Total Hip Arthroplasty

Dermatan sulphate catalyses thrombin inhibition by heparin cofactor II; it has a lower haemorrhagic to antithrombotic ratio than that of heparin in animal models. Consecutive patients aged forty years or more, electively undergoing total hip replacement under general anaesthesia, were randomly allocated to one of three dosage regimens of dermatan sulphate (MF701, Mediolanum Farmaceutici) given intramuscularly. These were 200 mg once daily (n = 50), 200 mg twice daily (n = 52) and 300 mg twice daily (n = 51), administered from twenty-four hours pre-operatively until the tenth postoperative day. The overall incidence of DVT assessed by bilateral venography was 53%, 51% and 34% respectively (Chi-square test for trend p = 0.06). The incidence of major proximal DVT was 10.6%, 8.5% and 2.1% respectively. Pulmonary embolism (PE) and bleeding were assessed in all 153 patients. There was one case of PE in each dose group. The incidence of bleeding episodes, volume of blood lost and blood transfusion requirements were low and showed no increase with increasing dose. The patients were followed up 4-8 weeks after discharge.

We conclude that the two lower doses were subtherapeutic in this population, however dermatan sulphate given 300 mg twice daily, proved to be efficacious with an incidence of proximal major DVT of 2.1% and a low incidence of bleeding complications. A trial of dermatan sulphate 300 mg twice daily compared to standard prophylactic agents is needed.

The Mayak Worker Dosimetry System (MWDS 2013): Soluble Plutonium Retention in the Lungs of An Occupationally Exposed USTUR Case

For the first time, plutonium retention in human upper airways was investigated based on the dosimetric structure of the human respiratory tract proposed by the International Commission on Radiological Protection (ICRP). This paper describes analytical work methodology, case selection criteria, and summarizes findings on soluble (ICRP 68 Type M material) plutonium distribution in the lungs of a former nuclear worker occupationally exposed to plutonium nitrate [239Pu(NO3)4]. Thirty-eight years post-intake, plutonium was found to be uniformly distributed between bronchial (BB), bronchiolar (bb) and alveolar-interstitial (AI) dosimetric compartments as well as between the left and right lungs. 239+240Pu and 238Pu total body activity was estimated to be 2333 ± 23 and 42.1 ± 0.7 Bq, respectively. The results of this work provide key information on the extent of plutonium binding in the upper airways of the human respiratory tract.

Quantification of various factors influencing the precision of thermoluminescent detector calibrations for new and used chip sets

Factors affecting the random and systematic error in calibrating three sets of 100 LiF:Mg,Ti thermoluminescent detector chips were investigated. The chips were held in a polymethyl methacrylate plate with 0.3 cm deep wells covered with a thin top plate, affixed to a polymethyl methacrylate phantom 150 cm from a 3.2 × 10(10) GBq 137Cs source, used to irradiate the chips to 4.52 mGy. Three sets of chips were used: one new, one heavily used, and one having relatively high degrees of visible physical damage. Variations in the exposure rate across the plate were measured with an ion chamber. Experimental drift was judged by performing successive calibrations on subsequent days, while always reading the chips in the same order. The chips were subject to manual examination to determine variations in mass and physical quality. This study indicates that more accurate calibrations can be obtained by accounting for the error caused by nonuniformity in the delivered dose, which was in this study as high as 4.4% from the center to the edges of the target. Making use of more than three calibrations only reduces the standard deviation as a percentage of the mean of a set by less than 1%. Desirable dosimeters in commercially rejected sets were identified by comparing each dosimeter's standard deviation of response across all calibrations to a commercially acceptable control set. Up to 50% variations in mass and visual quality, including opacity, fracture, and surface scratches to chips, showed little to no correlation with their response.

Gaussian mixture models for classification of neonatal seizures using EEG

A real-time neonatal seizure detection system is proposed based on a Gaussian mixture model classifier. The system includes feature transformation techniques and classifier output postprocessing. The detector was evaluated on a database of 20 patients with 330 h of recordings. A detailed analysis of the choice of parameters for the detector is provided. A mean good detection rate of 79% was obtained with only 0.5 false detections per hour. A thorough review of all misclassified events was performed, from which a number of patterns causing false detections were identified.

Seizure detection in neonates: Improved classification through supervised adaptation

The goal of neonatal seizure detection is the development of a patient independent system to alert staff in the neonatal intensive care unit of ongoing seizures. This study demonstrates the potential in adapting a patient independent classifier using patient specific data. Supervised adaptation is investigated using the basic gradient descent algorithm and least mean squares procedures. An increase in mean ROC area of 3% is obtained for the best performing learning algorithm, yielding an increase in mean accuracy of 7.7% compared to the patient independent algorithm.

Photic entrainment of circannual rhythms in golden-mantled ground squirrels: role of the pineal gland

Entrainment of circannual rhythms of body mass and reproduction was monitored for 3 years in female golden-mantled ground squirrels maintained in a simulated natural photoperiod. Both pinealectomized and pineal-intact squirrels generated circannual rhythms of body mass and estrus, but only the intact animals entrained these rhythms to a period of 365 days. In the second and third years after treatment, the period of the body mass rhythm was significantly shorter than 365 days for pinealectomized squirrels, and variance in tau among these animals was significantly greater than for intact squirrels. A similar pattern was evident in the rhythm of reproduction, which was phase-disrupted in pinealectomized squirrels but entrained in intacts. Seasonal changes in duration of nocturnal melatonin secretion by the pineal appear to be necessary to produce phase-delays required to entrain the circannual clock to a period of 12 months.

Nonpharmacological interventions with chronic cancer pain in adults

BACKGROUND

Pain is often poorly controlled in cancer patients. Chronic pain affects adult patients at all stages of cancer management. Optimal pain management may require attention to psychosocial variables and the inclusion of nonpharmacological techniques.

METHODS

Three nonpharmacological strategies that are effective in reducing pain caused by cancer--patient psycho-education, supportive psychotherapy, and cognitive-behavioral interventions--are reviewed. Recommendations for physicians to facilitate a mental health referral are also discussed.

RESULTS

Effective treatment of cancer pain begins with assessing the severity, characteristics, and impact of pain. Emotional distress (especially anxiety, depression, and beliefs about pain) has emerged as predictive of patient pain levels. Appropriate pain management may require a multidisciplinary approach.

CONCLUSIONS

Patient psycho-education has empowered patients to actively participate in pain control strategies. Supportive psychotherapy can assist patients in managing the stressors associated with cancer, and cognitive-behavioral therapy helps patients to recognize and modify the factors that contribute to physical and emotional distress.

Synthesis and biological activity of anthelmintic thiadiazoles using an AF-2 receptor binding assay

Following our discovery of the strong binding of thiadiazole 1 to the AF-2 neuropeptide receptor of gastrointestinal nematodes (e.g., Ascaris suum), we prepared two series of analogs. Only the series containing the thiadiazole ring had potencies comparable to that of compound 1. Analog 50 exhibited an apparent potency in the AF-2 binding assay 300 times that of compound 1.

Stage-specific activity in vitro on the Theileria infection process of serum from calves treated prophylactically with buparvaquone

An in vitro method for testing activity of buparvaquone in serum on the infection and development of Theileria in its bovine host mononuclear cells is described and results compared with the effect exhibited in vivo. Serum samples were collected over a time course from calves in a clinical trial of 5 mg kg(-1) buparvaquone prophylaxis on Theileria annulata or T. parva experimental infection. To evaluate drug levels and persistence in each animal for a period of 14 days and its effect on the early infection stages, the sera were tested on established macroschizont infected cell lines and against the in vitro infection and development process of the sporozoite and trophozoite stages of the two Theileria species. Results from the in vitro assays show that buparvaquone in serum can completely prevent the establishment of Theileria infection during the first 48 h after administration at 5 mg kg(-1). After seven days, levels are sufficient to delay the establishment of infection. The drug is more effective in the prevention of the de novo development of the parasite in cells than against established macroschizont infected cell culture. At low concentrations, it is more effective against T. parva than against T. annulata. Drug effect peaks during the first 24 h but residual effect persists for 14 days, particularly against T. parva infection. These novel findings demonstrate how high doses of buparvaquone could over-protect calves if used in the 'infection-and-treatment' method of immunisation when drug is administered prophylactically at the same time as infection with live sporozoites. It is suggested that in certain high Theileria risk situations there may be potential for the immunoprophylactic use of buparvaquone without simultaneous infection. The in vitro assay itself has been shown to be of value as a model for Theileria establishment in cattle.

Comparative in vitro effects of closantel and selected beta-ketoamide anthelmintics on a gastrointestinal nematode and vertebrate liver cells

PNU-87407 and PNU-88509, beta-ketoamide anthelmintics that are structurally related to each other and to the salicylanilide anthelmintic closantel, exhibit different anthelmintic spectra and apparent toxicity in mammals. The basis for this differential pharmacology was examined in experiments that measured motility and adenosine triphosphate (ATP) levels in larval and adult stages of the gastrointestinal nematode, Haemonchus contortus, and in a vertebrate liver cell line and mitochondria. PNU-87407 and PNU-88509 both exhibited functional cross-resistance with closantel in larval migration assays using closantel-resistant and -sensitive isolates of H. contortus. Each compound reduced motility and ATP levels in cultured adult H. contortus in a concentration- and time-dependent manner; however, motility was reduced more rapidly by PNU-88509, and ATP levels were reduced by lower concentrations of closantel than the beta-ketoamides. Tension recordings from segments of adult H. contortus showed that PNU-88509 induces spastic paralysis, while PNU-87407 and closantel induce flaccid paralysis of the somatic musculature. Marked differences in the actions of these compounds were also observed in the mammalian preparations. In Chang liver cells, ATP levels were reduced after 3 h exposures to > or = 0.25 microM PNU-87407, > or = 1 microM closantel or > or = 10 microM PNU-88509. Reductions in ATP caused by PNU-88509 were completely reversible, while the effects of closantel and PNU-87407 were irreversible. PNU-87407, closantel and PNU-88509 uncoupled oxidative phosphorylation in isolated rat liver mitochondria, inhibiting the respiratory control index (with glutamate or succinate as substrate) by 50% at concentrations of 0.14, 0.9 and 7.6 microM, respectively.

Haemonchus contortus: cloning and functional expression of a cDNA encoding ornithine decarboxylase and development of a screen for inhibitors

Polyamines (PA) are essential for viability and replication of all cells; organisms either synthesize PA or acquire them from the environment. How nematodes that parasitize the gut satisfy their PA requirement has not been resolved. The primary regulatory enzyme in PA biosynthesis in most animals is ornithine decarboxylase (ODC). This enzyme has recently been characterized in free-living nematodes and in the parasitic species. Haemonchus contortus. Nematode and mammalian ODC are reported to differ in subcellular localization, kinetics, and sensitivity to inhibitors. We cloned an H. contortus cDNA that encodes a full-length ODC (sequence data from this article have been deposited with the GenBank Data Library under Accession Nos. AF016538 and AF016891). This cDNA was functionally expressed in strains of Escherichia coli and Saccharomyces cerevisiae that lack ODC and are dependent upon exogenous PA for survival. Expression of nematode ODC reversed the PA-dependence phenotype of both microorganisms. The complemented yeast strain was used to develop a nutrient-dependent viability screen for selective inhibitors of nematode ODC. The antiprotozoal drug stilbamidine isethionate was identified as active in this screen, but biochemical characterization revealed that this compound did not inhibit ODC. Instead, like other cationic diamidines, stilbamidine probably inhibits yeast S-adenosylmethionine decarboxylase. Nonetheless, the activity in the screen of the known ODC inhibitor difluoromethylornithine (DFMO) validates the concept that specific recombinant microorganisms can serve as the basis for extremely selective and facile screens.

An effective shield for free: pulsed lavage in total knee replacement

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Influence of organic acid excretion on cuticle pH and drug absorption by Haemonchus contortus

To determine if a cuticle microenvironment pH is maintained by adult Haemonchus contortus, organic acid excretion kinetics and absorption kinetics of selected model weak acids and a weak base were measured in incubation media that varied in buffer capacity (0.25-20 mM HEPES or 5 mM glycine) and initial pH (7.5 or 3.5). To evaluate the importance of the cuticle as a pathway for organic acid excretion and drug absorption the pharynx was paralyzed with 1 nM ivermectin. H. contortus changed the media pH from initial values of 7.5 or 3.25 to an asymptotic value of approximately 5.6. The rate of pH change depended on the buffer capacity, but was not affected by chemical ligation with ivermectin. The intrinsic rate of excretion of organic acids (0.045 +/- 0.016 micromol/cm2 x h) was constant during the first 8-12 h of incubation and was independent of initial pH, buffer capacity or ivermectin ligation. The rates of absorption of the model weak acids, benzoic acid and p-nitrophenol, and the model weak base, aniline, were not affected by initial pH, buffer capacity or ivermectin ligation. These results suggest that H. contortus excretes organic acid endproducts of carbohydrate metabolism across its cuticle, and that these acids maintain a microenvironment pH within the water-filled pores of the cuticle that controls the rate of adsorption of weakly acidic or basic drugs.

Anthelmintic profile of the cyclodepsipeptide PF1022A in in vitro and in vivo models

A novel cyclodepsipeptide of fungal origin, PF1022A, recently was reported to have anthelmintic activity. To supplement published reports and determine potential utility of PF1022A as a ruminant anthelmintic, the compound was examined in in vitro and in vivo models. Assays used measured motility of Haemonchus contortus (intrinsic drug potency), ATP levels (parasite death), and activity against H. contortus, Ostertagia ostertagi, and Trichostrongylus colubriformis in the jird (spectrum, potency, and efficacy by various routes). The potency of PF1022A in reducing motility is greater than commercial anthelmintics. Examination of ATP levels in PF1022A-paralyzed H. contortus indicates that worms are not killed, suggesting the compound acts as a neurotoxin in nematodes. In the jird, PF1022A has activity orally against each of the parasites studied and at doses comparable to all commercial anthelmintics, except the macrocyclic lactones which are more potent. Unfortunately, for some nematode species, parenteral delivery is ineffective at realistic doses.

A dose ranging study to evaluate dermatan sulphate in preventing deep vein thrombosis following total hip arthroplasty

Dermatan sulphate catalyses thrombin inhibition by heparin cofactor II; it has a lower haemorrhagic to antithrombotic ratio than that of heparin in animal models. Consecutive patients aged forty years or more, electively undergoing total hip replacement under general anaesthesia, were randomly allocated to one of three dosage regimens of dermatan sulphate (MF701, Mediolanum Farmaceutici) given intramuscularly. These were 200 mg once daily (n = 50), 200 mg twice daily (n = 52) and 300 mg twice daily (n = 51), administered from twenty-four hours pre-operatively until the tenth postoperative day. The overall incidence of DVT assessed by bilateral venography was 53%, 51% and 34% respectively (Chi-square test for trend p = 0.06). The incidence of major proximal DVT was 10.6%, 8.5% and 2.1% respectively. Pulmonary embolism (PE) and bleeding were assessed in all 153 patients. There was one case of PE in each dose group. The incidence of bleeding episodes, volume of blood lost and blood transfusion requirements were low and showed no increase with increasing dose. The patients were followed up 4-8 weeks after discharge. We conclude that the two lower doses were subtherapeutic in this population, however dermatan sulphate given 300 mg twice daily, proved to be efficacious with an incidence of proximal major DVT of 2.1% and a low incidence of bleeding complications. A trial of dermatan sulphate 300 mg twice daily compared to standard prophylactic agents is needed.

Theoretical perspectives on anthelmintic drug discovery: interplay of transport kinetics, physicochemical properties, and in vitro activity of anthelmintic drugs

This multidisciplinary study demonstrates the utility of the biophysical model approach to assess biological activity of anthelmintics in light of drug-delivery principles. The relationships between drug absorption and efficacy for a set of structurally disparate anthelmintics were determined in cultures of Haemonchus contortus, a nematode that parasitizes the ruminant gastrointestinal tract. Uptake, parameterized by the permeability coefficient, Pe, was shown to occur by absorption across the cuticle. Rates of drug appearance in nematode carcasses paralleled rates of drug disappearance from the medium, and absorption reached an apparent equilibrium within a few hours. The parasite/medium partition coefficient, K, was derived from the ratio of drug concentration in the parasite vs the medium at equilibrium. Pe and K values for each anthelmintic were correlated with lipophilicity (as measured by the partition coefficient (PC) in n-octanol/water) and both parameters plateaued at log PC approximately 2.5, with maximum Pe approximately 8 x 10(-4) cm/min and log K < or = 2.0. Absorption kinetics were related to in vitro potency by monitoring motility of H. contortus. The time required to reduce motility by 50% (t* 50) and Pe were used to calculate Cn*, the drug concentration in the parasite at t* 50, as an indicator of intrinsic potency. The quantitative interplay of apparent biological activity expressed as t* 50, dose, and intrinsic potency highlights the important contribution of drug-uptake kinetics.

Melatonin binding sites in sciurid and hystricomorph rodents: studies on ground squirrels and guinea pigs

Little is known about the distribution of binding sites for the pineal hormone melatonin in non-myomorph rodents. We used 2-[125I]iodomelatonin (IMEL) to analyze the distribution, affinity, and specificity of binding sites in the golden-mantled ground squirrel, a sciurid rodent that reportedly lacks IMEL binding sites in the brain. Specific binding was found not only in the pars tuberalis, but also in several telencephalic and diencephalic areas including the hypothalamic suprachiasmatic region. The affinity and specificity of IMEL binding are comparable to those reported in other rodents. IMEL binding studies in a hystricomorph rodent, the guinea pig, revealed high concentrations of receptor in the nucleus accumbens and dorsolateral thalamus. Central melatonin binding sites have now been demonstrated in species of all three rodent families. The heterogeneous distribution of melatonin receptors appears similar in the species studied, and no evidence is found to link IMEL binding sites at any particular locus to photoperiodic, circannual, or non-seasonal breeding patterns.

Torpor shortens the period of Siberian hamster circadian rhythms

We investigated the influence of ambient and body temperature (Ta and Tb) on circadian rhythms of gonadectomized male Siberian hamsters. Animals that entered torpor (Tb < 30 degrees C) had significantly shorter circadian periods (tau s) than did nontorpid hamsters at a Ta of 13 degrees C (24.17 +/- 0.05 vs. 24.33 +/- 0.04 h). The tau s of homeothermic hamsters were not affected by Ta change. Short-term decreases in Tb, rather than changes in Ta, appear to affect tau. Access to activity wheels inhibited expression of torpor in short daylengths and was associated with significant increases in body mass. Running wheel activity can mask or block specific short-day responses.

Haemonchus contortus: ivermectin-induced paralysis of the pharynx

How the avermectins cause the elimination of gastrointestinal nematodes from host animals has not yet been clearly identified. Using visual and radiometric parameters to measure oral ingestion in Haemonchus contortus, we showed that ivermectin (IVM) rapidly inhibited ingestion at concentrations > or = 10(-10) M. Motility, monitored quantitatively with an automated motility meter, was unaffected by IVM at concentrations < or = 10(-8) M, while ATP levels were unaffected at concentrations < or = 10(-6) M. Since motility and ATP levels, independent measures of short-term viability, are unaffected by concentrations of IVM that effectively block oral ingestion, the drug can be used as a chemical ligature. Although H. contortus was shown to be dependent upon an exogenous supply of glucose for survival in culture, IVM (10(-9) and 10(-7) M) altered neither the uptake of 3-O-[3H]methylglucose nor the metabolism of [13C]glucose by the parasite. These data suggest that H. contortus depends upon the transcuticular uptake of glucose in culture. If oral ingestion of other nutrients is essential for long-term survival in vivo, disruption of this process may represent the primary mechanism of IVM action.

Thrombo-embolic prophylaxis in total knee replacement. Evaluation of the A-V Impulse System

We performed a prospective randomised controlled trial of a new mechanical method of prophylaxis for venous thrombo-embolism in 60 patients undergoing knee replacement surgery. The method uses the A-V Impulse System to produce cyclical compression of the venous reservoir of the foot. The overall incidence of deep-vein thrombosis was 68.7% in patients receiving no prophylaxis and 50% in those using the device. The difference was not significant. There was, however, a reduction of the extent of thrombosis in the treated group. There were 13 major calf-vein thrombi and six proximal-vein thrombi in the control group compared with only five major calf-vein thrombi in the treated group. This difference was significant (p = 0.014). No patient developed clinical features of a pulmonary embolism.

Predicting outcome in hypoxic-ischemic coma. A prospective clinical and electrophysiologic study

A prospective analysis of 40 patients with hypoxic-ischemic coma lasting at least 6 h following sudden cardiac arrest was undertaken. The patients, all of whom had preserved brain-stem function, were studied electrophysiologically with electroencephalography (EEG), and median nerve somatosensory evoked potentials (SEPs) within 48 h to establish prognostic indices. Our results indicate that preserved brain-stem function does not necessarily predict favorable outcome following cardiac arrest as 26 of 40 (65%) patients died without awakening. The bilateral absence of cortical evoked potentials predicted death without awakening in 19 of 26 patients (73%) while malignant EEG change was similarly predictive in 11 patients (42%). Bilateral absence of cortical evoked potentials and/or malignant EEG change reliably predicted unfavorable outcome in 21/26 patients (81%). Patients with normal or delayed central conduction time (CCT) as well as 'benign' or 'uncertain' EEG findings had an uncertain prognosis as some entered a persistent vegetative state (PVS) or died without awakening. Fourteen patients (35%) awakened of whom 5 (13%) recovered completely while another 9 (23%) had varying degrees of motor or cognitive impairment. SEP and EEG findings did not distinguish between these outcomes.

A novel anthelmintic model utilizing jirds, Meriones unguiculatus, infected with Haemonchus contortus

Currently, no in vivo laboratory model is available for evaluating anthelmintics against the important ruminant helminth Haemonchus contortus. This report outlines a novel anthelmintic assay utilizing immunosuppressed (0.02% hydrocortisone in feed) jirds, Meriones unguiculatus, infected with H. contortus. Immunosuppressed jirds were inoculated with approximately 1,000 exsheathed infective larvae of H. contortus, treated per os on day 10 postinoculation (PI), and necropsied on day 13 PI. Each stomach was removed, opened longitudinally, incubated in distilled water at 37 C for 5 hr, fixed in formaldehyde solution, and stored for subsequent examination. Stomach contents were examined using a stereomicroscope (15-45x). A variety of standard anthelmintics has been evaluated in the model; modern broad-spectrum ruminant anthelmintics (benzimidazoles, febantel, ivermectin, levamisole hydrochloride, and milbemycin D) are active uniformly and in most cases at doses (mg/kg) comparable to those required for efficacy against H. contortus in ruminants. This model provides an important new tool to assess preliminarily the activity of experimental drugs against H. contortus in vivo prior to studies in ruminants and also may provide a useful tool for studying host-parasite interactions for H. contortus.

Design and synthesis of 4H-3,1-benzoxazin-4-ones as potent alternate substrate inhibitors of human leukocyte elastase

4H-3,1-Benzoxazin-4-ones are alternate substrate inhibitors of the serine proteinase human leukocyte elastase (HL elastase) and form acyl enzyme intermediates during enzyme catalysis. We have synthesized a large variety of benzoxazinones using specific methods that have been adapted to achieve the pattern of ring substitution dictated by theoretical considerations. The results of the inhibition of HL elastase by 175 benzoxazinones are reported herein with reference to hydrophobicity constants D, alkaline hydrolysis rates kOH-, inhibition constants Ki, and their component acylation and deacylation rate constants, kon and koff, respectively. The ranges for the compounds are considerable; alkaline hydrolysis rates and kon span 6, koff covers 5, and ki spans 8 orders of magnitude. Multiple regression on this large data set has been used to isolate the contributions of electronic and steric effects, as well as other factors specific to compound stability and elastase inhibition. Essentially, a simple electronic parameter is sufficient to account for almost all the variance in the alkaline hydrolysis data, indicating that electronic factors are the major determinants of this type of benzoxazinone reactivity. Factors that significantly enhance the potency of benzoxazinones I are R5 alkyl groups and electron withdrawal by R2. Bulk in R7 and R8 and compound hydrophobicity are not significant, but substitution in R6 is highly unfavorable as are substituents linked via carbon to C2. The physiochemical factors that underlie these trends in Ki are further analyzed in terms of equations that describe kon and koff. A conclusion that emerges is that chemically stable, potent benzoxazinone inhibitors of HL elastase with inhibition constants in the nanomolar range can be designed with (1) R5 alkyl groups to inhibit enzyme-catalyzed deacylation, (2) small alkyl substituents linked via heteroatoms to C2 to enhance acylation and limit deacylation rates, and (3) strongly electron-donating groups at C7 to stabilize the oxazinone ring to nucleophilic attack. Thus, 2-(isopropylamino)-5-n-propyl-7-(dimethylamino)benzoxazinone 95 has kOH = 0.01 M-1 s-1, which extrapolates to a half-life at pH 7.4 of over 8.5 years, and 2-ethoxy-5-ethylbenzoxazinone 38 has Ki = 42 pM.

Effect of ovariectomy and estradiol on unity of female rat circadian rhythms

Sixteen rats were ovariectomized and given either a 1-cm implant of crystalline estradiol-17 beta (eight rats) or an empty implant (eight rats). A further six rats were sham ovariectomized and given empty implants, and eight rats were left unoperated. The rats were exposed to 70 days of constant dim light (LL) with a maximum illumination level of 20 lx, and circadian running and drinking rhythms were monitored. In LL, both the running and drinking activity rhythms of the ovariectomized, blank-implanted rats became markedly disrupted, whereas unoperated and sham-operated rats maintained unified rhythms. Estradiol-implanted rats developed fewer rhythm desynchronies, and the majority displayed a single band of free-running activity. Rather than being arrhythmic, the activity of the LL-exposed ovariectomized rats appeared to contain several free-running components. Thus these data are consistent with the concept of a multioscillatory basis to the circadian system and support a role for the ovary and its hormone estradiol in the maintenance of coherence between component oscillators.

Deep vein thrombosis after elective knee surgery. An incidence study in 312 patients

The incidence of venous thromboembolism after elective knee surgery has previously been studied almost exclusively in patients receiving total knee replacements, in whom the risk of a deep vein thrombosis is approximately 60%. We report the results of ipsilateral ascending venography in 312 patients undergoing a wide variety of elective knee operations under tourniquet ischaemia, none of whom received any specific prophylaxis against thromboembolism. Total knee replacement was confirmed to carry a high risk with ipsilateral deep vein thrombosis in 56.4% and symptomatic pulmonary embolism in 1.9%. By contrast, arthroscopy was associated with a low incidence of venous thrombosis (4.2%). Meniscectomy, arthrotomy, patellectomy, synovectomy and arthrodesis were all high-risk procedures, particularly in patients over 40 years of age, and were associated with deep vein thrombosis rates of 25% to 67%. On the basis of these findings, we advise prophylaxis against venous thromboembolism in all patients over 40 years of age undergoing elective knee surgery other than arthroscopy.

Use and abuse of performance indicators

An audit was performed by this department after allegations by the regional health authority of low productivity. It was found that the health authority had underestimated the number of operations performed in 1983 by only 5%, but an inexact classification and grading of operations had led to errors in the performance indicators of 19.8% for the "weighted number of operations" and 34.5% for the "number of major operations per consultant." When the throughput of orthopaedic departments in districts was compared by the regional health authority it was found that such errors in performance indicators had been further compounded by the inconsistent use of population data and incorrect data on medical staffing. Medical practitioners and the health authorities are alerted to this amplification of inaccurate data. Other methods for assessing trauma and orthopaedic surgery are proposed, such as a simplification of the Office of Population Censuses and Surveys classification of surgical operations, grading operations based on time spent in the operating theatre, and provision of computer programs to code for diagnosis and operation when writing discharge summaries.

In vitro response of Haemonchus contortus larvae harvested during different times of the patent period to anthelmintics

Three commercially available ruminant anthelmintics and an investigational drug were evaluated for effects on the motor function/motility of third stage (ensheathed) Haemonchus contortus. Helminth ova were collected at one, five, nine and 13 weeks during the patent period, cultured to the third larval stage and assayed for sensitivity to four different drugs. All four drugs (100 and 10 micrograms ml-1) significantly affected the motility of third stage H contortus larvae cultured from eggs passed at each of the times examined. However, the investigational drug (p-toluoyl chloride phenylhydrazone, 10 micrograms ml-1) had a significantly greater effect on the motility of larvae harvested at 13 weeks than those cultured at nine weeks (32 per cent difference). No other significant differences in the motility response during the patent period were observed.

Melatonin administration entrains female rat activity rhythms in constant darkness but not in constant light

In female rats the luteinizing hormone (LH) is timed by the circadian system and is followed by a display of intense, estrogen-induced running behavior. This proestrous running on the night of ovulation can be used as a marker of the estrous cycle. Entrainment of the mammalian circadian system by exogenous melatonin (MT) has been demonstrated only in the activity rhythms of male rats. The present experiments were designed to study the effect of daily MT injections on activity rhythms and proestrous running of female rats in 1) continuous dim white light (LL) and 2) continuous darkness (DD). In LL, MT injections (50 micrograms/kg or 1 mg/kg) had no discernible effect on activity rhythms. In DD, four of the six MT-treated rats (100 micrograms/kg) entrained to the injection, and a fifth animal showed phase advances in its activity rhythm when onset of activity passed through injection time. The sixth animal was not injected with MT at activity onset time. None of the six control animals showed either effect. MT had no effect on the length of the estrous cycle. Thus MT injections can entrain circadian rhythms of activity and proestrous running in female rats in DD but not in LL.

Development of a novel in vitro equine anthelmintic assay

An in vitro assay involving the use of a horse strongyle (Strongylus edentatus) and the micromotility meter has been developed to test for equine anthelmintic activity. Three commercially available equine anthelmintics (dichlorvos, ivermectin, and pyrantel pamoate) and an investigational drug (p-toluoyl chloride phenylhydrazone) were evaluated in this assay at four concentrations. After a 24-h incubation, greater than or equal to 10 micrograms/ml of all four drug treatments significantly (P less than or equal to 0.05) reduced the motility of ensheathed L-3 S. edentatus larvae, thereby indicating anthelmintic activity. Pyrantel pamoate also reduced motility at 1 microgram/ml, while the hydrazone significantly increased movement at this level. At 0.1 microgram/ml, none of the treatments significantly reduced motility; one treatment (dichlorvos) significantly increased larval motility. Incubation for 48 h resulted in significant activity (reduction in motility) at greater than or equal to 1 microgram/ml with two drugs (ivermectin, pyrantel pamoate); dichlorvos and the hydrazone reduced motility at greater than or equal to 10 micrograms/ml. None of the treatments significantly reduced motility at the lowest concentration (0.1 microgram/ml); however, at 48 h, two treatments (dichlorvos, hydrazone) significantly increased motility at the lowest concentration (0.1 microgram/ml). The in vitro S. edentatus motility assay proved to be sensitive, accurate and rapid. This assay system should be a valuable addition to tests used to identify potential equine anthelmintics, monitor helminth resistance to drugs, and perhaps define the kinetics and mode of action for drugs.

Use of an intraruminal soluble glass bolus containing melatonin for early lamb production

The use of melatonin to advance the onset of seasonal oestrus is potentially useful for early lamb production. A number of delivery systems for melatonin have been developed and this study evaluates an intraruminal soluble glass bolus under field conditions. Anoestrous, non-lactating mule and Dorset cross mule ewes were treated in late June with two types of bolus of different solubilities (melatonin 1, 'slow release' and melatonin 2, 'extra slow release'). Rams were introduced in mid-August for a target lambing pattern in mid-January. The percentage pregnancy/lambing rates were 80/78, 97/92 and 100/100 in the control, melatonin 1 and melatonin 2 groups, respectively. The number of lambs born per ewe put to the ram was significantly increased by treatment with melatonin 2 (P less than 0.05) from 1.17 to 1.64 in the mule ewes and 1.64 to 1.72 in the Dorset cross mule ewes. The melatonin containing soluble glass bolus is a novel and convenient method of reducing the number of barren ewes in an early lambing flock.