Cabozantinib plus durvalumab in advanced gastroesophageal cancer and other gastrointestinal malignancies: Phase Ib CAMILLA trial results

This is the phase Ib part of the phase I/II CAMILLA trial evaluating cabozantinib plus durvalumab in advanced chemo-refractory proficient mismatch repair or microsatellite stable (pMMR/MSS) gastrointestinal malignancies including gastric/gastroesophageal junction/esophageal (G/GEJ/E) adenocarcinoma, colorectal cancer (CRC), and hepatocellular carcinoma (HCC). Thirty-five patients are enrolled. There are no observed dose-limiting toxicities during dose escalation. The overall grade 3/4 treatment-related adverse event rate is 34%. Among evaluable patients (n = 30), the objective response rate (ORR) is 30%, disease control rate (DCR) 83.3%, 6-month progression-free survival (PFS) 36.7%, median PFS 4.5 months, and median overall survival (OS) 8.7 months. Responses are seen in 4 of 17, 3 of 10, and 2 of 3 patients with CRC, G/GEJ/E adenocarcinoma, and HCC, respectively. Participants with a PD-L1 combined positive score (CPS) ≥5 have numerically higher ORR, PFS, and OS. Cabozantinib plus durvalumab demonstrates a tolerable safety profile and potential efficacy in previously treated advanced pMMR/MSS gastrointestinal malignancies.

Blueprint for Implementing and Improving Eligible Inferior Vena Cava (IVC) Filter Retrieval Across Institutions

INTRODUCTION. Placement of removable filters (rIVCFs) has increased, but this has not been accompanied by timely removal, with retrieval rates as low as 8.5% at some institutions. Studies demonstrate failure to remove rIVCFs that are not medically necessary result in increased complications. This study discusses the development of an IVC filter follow up protocol. METHODS. A method to monitor IVC filter placement and retrieval was developed. A weekly report was generated detailing placement and removal of rIVCFs. A standardized retrieval calculator was utilized to determine efficacy of removal. An IVC filter Retrieval Assessment Form was developed. Managing physicians and patients with medically unnecessary filters were sent letters with a retrieval checklist and order form. If not removed within one year, additional letters were sent. Standardized IVC filter reporting templates were created and utilized after insertion of all filters with retrieval status. Letters were eventually built into the EMR for direct routing. RESULTS. From 2015 to 2020, IVC filters were placed in 719 patients. Of those, 58% were eligible for retrieval. Initial rates of rIVCF removal in eligible patients were as low as 30-33% in 2015. The retrieval rate of eligible filters rose to 44% in September 2018. The rate of retrieval rose to 61% in January 2021. CONCLUSIONS. Employing a systemic protocol to aid in follow-up of patients following rIVCF placement can improve rates of retrieval in the appropriate clinical setting. Regular evaluation and revision of the process played a significant role in achieving an increase in retrieval rates.

Phase II trial of cabozantinib (Cabo) plus durvalumab (Durva) in chemotherapy refractory patients with advanced mismatch repair proficient/microsatellite stable (pMMR/MSS) colorectal cancer (CRC): CAMILLA CRC cohort results

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Background: Cabo is an anti-VEGFR2/MET/AXL drug with broad multi-kinase inhibitory spectrum. Preclinical and clinical studies in various solid tumors demonstrated favorable immune modulatory activity of Cabo with clinical synergy seen when combined with PD-1/ PD-L1 inhibitors like Durva. Upon completion of phase Ib gastrointestinal (GI) basket CAMILLA trial evaluating Cabo + Durva in 30 patients (pts) demonstrating favorable safety & efficacy, the trial was expanded to phase 2 multi-cohort, multi-center trial of 117 pts. Herein, we report results of the phase 2 CRC cohort, the first evaluation of cabo + IO in this population. Methods: Pts enrolled in this cohort were administered Cabo + Durva at the RP2D of 40mg QD and 1500mg IV Q4W respectively. Enrolled pts must have progressed on 2 or more lines of therapy. Primary outcome measure was investigator assessed overall response rate (ORR) and secondary outcomes were rate of treatment related adverse events (TRAE), investigator assessed disease control rate (DCR), progression free survival (PFS), and overall survival (OS). Subgroup analysis was done in pts with RAS wild type tumors. Exploratory analysis of pathogenic molecular tumor alterations using next generation sequencing (NGS) was done in pts who achieved confirmed partial response (PRc)/ stable disease (SD) > 6 months. Results: Of the 36 pts enrolled, 29 (16F, 13M) were evaluable for efficacy. Median age 57 years (27-76). 90% (26) had ECOG of 1. All had pMMR/MSS, 41% (12) had RAS wild type tumors, and 6.9% (2) had HER2 amplification. 52% (15) had received ≥ 3 lines of therapy. All had metastases at ≥ 3 sites and 79% (23) metastases in the liver. Among 36 pts evaluable for safety, treatment related serious adverse events (SAEs) occurred in 31% (11/36). Most common TRAEs were grade 1-2 fatigue (53%), nausea (42%), diarrhea (36%), anorexia (31%), hand-foot syndrome (22%), & hypertension (16%). Grade ≥ 3 immune-related adverse events (IRAE) occurred in 16.6% (6/36). Efficacy analysis revealed an ORR 27.6% (8/29); PRc 21% (6/29); DCR 86.2% (25/29); median DOR was not reached (NR); median PFS 4.4 months; 6-month PFS 28% & median OS 9.1 months. In the RAS wild type subgroup, ORR (PRc) was 50.0%; DCR 83.3%; median PFS 6.3 months and median OS was NR. Of the 7 pts who achieved PRc/SD > 6 months, one had KRAS G12V tumor mutation along with mutations in ARID1A & IDH1. Remaining pts had RAS wild type tumors & among those, the following NGS alterations were detected: 1 HER-2 amplification, 1 MET amplification, & 2 alterations in ATM. Conclusions: Cabo + Durva demonstrated promising efficacy and was fairly tolerated without new safety signals in heavily treated pMMR/MSS CRC pts. These encouraging results warrant further evaluation of this regimen in a randomized setting as salvage therapy in pMMR/MSS CRC. Clinical trial information: NCT03539822.

Discovering dominant tumor immune archetypes in a pan-cancer census

Cancers display significant heterogeneity with respect to tissue of origin, driver mutations, and other features of the surrounding tissue. It is likely that individual tumors engage common patterns of the immune system-here "archetypes"-creating prototypical non-destructive tumor immune microenvironments (TMEs) and modulating tumor-targeting. To discover the dominant immune system archetypes, the University of California, San Francisco (UCSF) Immunoprofiler Initiative (IPI) processed 364 individual tumors across 12 cancer types using standardized protocols. Computational clustering of flow cytometry and transcriptomic data obtained from cell sub-compartments uncovered dominant patterns of immune composition across cancers. These archetypes were profound insofar as they also differentiated tumors based upon unique immune and tumor gene-expression patterns. They also partitioned well-established classifications of tumor biology. The IPI resource provides a template for understanding cancer immunity as a collection of dominant patterns of immune organization and provides a rational path forward to learn how to modulate these to improve therapy.

A case of two shunts in the endovascular treatment of type II Abernethy syndrome

Background

Abernethy malformation is a rare condition defined by a congenital extrahepatic portosystemic shunt, often leading to absence or hypoplasia of the intrahepatic portal venous system. Although there are no consensus treatment guidelines, interventional techniques now offer minimally invasive treatment options for Abernethy malformations. This case report describes a case of Abernethy Syndrome Type II where the patient had two separate extrahepatic portosystemic shunts treated with endovascular occlusion with two Amplatzer plugs and demonstrates the feasibility of this treatment for this rare condition. This case was in a young adult, adding to the scarce literature of treatment for Abernethy syndrome in the adult population.

Case presentation

We report a case of a 20-year-old female patient with neurocognitive behavioral difficulty, voracious appetite, and chronic encephalopathy secondary to type II Abernethy malformation with not one, but two extrahepatic portosystemic shunts. The patient had failed medical management and was not a liver transplant candidate. Therefore, she presented to us for an endovascular treatment option. The two shunts were treated with endovascular occlusion using Amplatzer vascular plugs. Following embolization, flow into the hypoplastic portal vein improved with near complete occlusion of flow into the portosystemic shunts, thus restoring blood flow into the native portal system. At 3 month follow up, a CT demonstrated complete occlusion of the two portosystemic shunts, and a portal vein diminutive in caliber. The portal vein measured 7 mm in diameter on both pre and post-procedure CT scans. The total volume of the liver was found to be 843 cm3 on pre-procedure CT & 1191 cm3 on post-procedure CT.

Conclusions

This report demonstrates the feasibility of using endovascular embolization to treat Abernethy II malformations. The management strategy of Type II Abernethy Syndrome should be to redirect blood flow into the hypoplastic native portal system, allowing for physiologic hepatic metabolism of splanchnic blood, hypertrophy of the portal system, and growth of the liver from the increased trophic flow.

345 Phase I/II trial of cabozantinib plus durvalumab in advanced gastroesophageal cancer and other gastrointestinal malignancies (CAMILLA): phase Ib safety and efficacy results

Background

Cabozantinib is a multi-tyrosine kinase inhibitor primarily targeting VEGFR, MET, and AXL. These targets promote a tumor immune permissive microenvironment. Cabozantinib has demonstrated immunomodulatory properties & clinical synergy when paired with PD-L1 inhibitors such as durvalumab. Here, we present final results of phase Ib of the Camilla trial assessing cabozantinib plus durvalumab in advanced GE adenocarcinoma (GEA), colorectal cancer (CRC), and hepatocellular carcinoma (HCC). This is an investigator-initiated trial funded by Exelixis & Astrazeneca.

Methods

Patients were administered cabozantinib + durvalumab in a dose escalation (3+3) then expansion to find the Dose Limiting Toxicities (DLTs), Recommended Phase 2 Dose (RP2D), ORR, PFS, and OS. Subgroup analysis was conducted to assess efficacy in patients with PD-L1 Combined Positive Score (CPS) ≥ 5. Dosing of cabozantinib was 20mg QD, 40mg QD, and 60mg QD PO in the 1st, 2nd, and 3rd cohorts. Dosing of durvalumab was 1500mg IV Q4W in all cohorts. DLT window was 28 days. Treatment beyond progression was allowed following modified RECIST v1.1 criteria.

Results

35 patients (14F, 21M), median age 53 years (range 27–79) were enrolled. 10 patients had GEA, 20 had CRC, and 5 had HCC; none had MMR deficiency. Median number of prior systemic therapies was 3 (range 0–3). No DLTs were observed during dose escalation. Per mature tolerability data, 11/14 patients receiving cabozantinib 60mg required dose-reduction post cycle 2 to 40mg. RP2D was determined to be cabozantinib 40mg QD plus durvalumab 1500mg Q4W. Of the 247 observed Treatment-Related Adverse Events (TRAEs), 10% (24) were grade≥3. Most common TRAEs were grade 1–2 fatigue (57%), nausea (43%), anorexia (40%), diarrhea (37%), transaminitis (34%), hand-foot syndrome (23%), & weight loss (23%). 2 patients each developed grade≥3 fatigue, weight loss, & abdominal pain. Overall, 30 pts were evaluable for efficacy. ORR 26.7%; DCR 83.3%; median PFS 4.5 months; 6-month PFS 36.7%; and median OS 9.1 months. 12 patients had PD-L1 CPS ≥5. In this subgroup, ORR 33.33%; DCR 91.67%; median PFS 6.13 months; 6-month PFS 50%; and median OS was not reached.

Conclusions

Cabozantinib plus durvalumab demonstrated promising efficacy and was fairly tolerated without new safety signals. High PD-L1 expression defined as CPS ≥ 5 was associated with improved efficacy & survival. The phase II multi-cohort part of the trial is currently ongoing.

Trial Registration

NCT03539822

Ethics Approval

The study was approved by the participating site’s local IRB.

Consent

All study participants granted a written informed consent prior to treatment initiation.

Do Video Games Predict an Early Advanced Capacity to Learn Interventional Radiology Skills?

PURPOSE

To elucidate the relationship between video game (VG) play and interventional radiology (IR) technical skills in medical students.

MATERIALS AND METHODS

Twenty medical students recruited at our institution's IR symposium completed a survey to ascertain demographics and prior VG experience, then participated in a 3-part trial of skills assessing IR and VG skill and visuospatial aptitude (VSA). IR skill was evaluated via an endovascular simulation task, VG skill by performance on three separate VGs, and VSA using the Cube Comparison test. Regression analysis was tested the strength of relationship between IR skill and VG experience, VG skill, and VSA, respectively, and participants were stratified by IR skill to top and bottom halves for survey-response comparison.

RESULTS

There was no correlation between either VG skill or visuospatial aptitude and IR skill (r = -0.22, p = 0.35; and r = 0.14, p = 0.57). Greater number of years playing VGs correlated with superior IR skill (Spearman's rho=-0.45, p<0.05). Students who selected IR as their specialty of interest had extensive VG experience, playing for > 15 years (n = 4, 80%), at least 10 hours per week at their peak (n = 3, 60%), and reported being either "skilled" or "highly skilled" at VGs (n = 3, 60%).

CONCLUSIONS

In our study, though limited by power, number of years playing VGs correlated positively with IR skills in medical students. Prior VG experience may predict an early advanced capacity to learn IR skills and an interest in the specialty.

Lidocaine Versus Bupivacaine in the Treatment of Headache with Intranasal Sphenopalatine Nerve Block

BACKGROUND

Intranasal sphenopalatine ganglion (SPG) block has been shown to be an effective treatment for headaches. Multiple therapeutic agents have been studied, although the wide availability and low cost of lidocaine and bupivacaine have made them attractive treatment options. To the authors knowledge, no study has yet demonstrated superiority of one anesthetic over the other.

OBJECTIVE

To determine the efficacy of lidocaine versus bupivacaine when performing intranasal sphenopalatine ganglion (SPG) block for the treatment of headaches.

STUDY DESIGN

Retrospective cohort study.

SETTING

A single tertiary care academic institutionMETHODS: This retrospective study identified patients who underwent SPG block at a single institution from January 1, 2014 to December 20, 2017. Patients were included if they were treated with either lidocaine or bupivacaine and had both pre- and post-procedure pain scores recorded on a 0-10 scale. Patients were excluded if they were less than 18 years of age.

RESULTS

386 total procedures were performed. 303 (78.5%) were lidocaine delivered via the SphenoCath device, and 83 (21.5%) were bupivacaine delivered via the Tx360 device. 90.2% of treatments (n = 348) decreased the patient's pain level. Of the treatments performed with lidocaine, 89.1% (n = 270) resulted in improvement of the patient's pain level with a mean decrease in pain level of 3.1 (SD ± 2.3). Of the treatments performed with bupivacaine, 94.0% (n = 78) resulted in improvement of the patient's pain level, with a mean decrease in pain level of 3.0 (SD ± 1.9). No statistically significant difference was found between the 2 anesthetics.

LIMITATIONS

The retrospective study design may introduce selection bias. Both lidocaine and bupivacaine were administered by different devices (Sphenocath and Tx360 respectively) which may account for differences in initial treatment success. There were differences in the size of the two groups, which may also introduce error.

CONCLUSIONS

This study demonstrates similar efficacy of SPG block performed with lidocaine or bupivacaine. While no difference was found, the particular advantages and disadvantages of the intranasal delivery device may influence physician choice.

KEY WORDS

Sphenopalatine ganglion nerve block, lidocaine, bupivacaine, sphenocath, Tx360, pain intervetnio, headache, miimally invasive therapy.

Cabozantinib (cabo) combined with durvalumab (durva) in gastroesophageal (GE) cancer and other gastrointestinal (GI) malignancies: Preliminary phase Ib CAMILLA study results

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Background: Cabo targets multiple tyrosine kinases, including VEGFR, MET, and AXL, and has been reported to show immunomodulatory properties that may counteract tumor-induced immunosuppression, providing a rationale for combining it with PD-L1 inhibitors like durva. We conducted a phase Ib GI basket trial to evaluate the safety & efficacy of this regimen in advanced GE adenocarcinoma (GEA), colorectal cancer (CRC), & hepatocellular carcinoma (HCC). Methods: Patients received cabo and durva in 3+3 dose escalation then expansion to determine the dose limiting toxicity (DLT), Recommended Phase 2 Dose (RP2D), ORR, PFS & OS. Cabo was dosed at 20mg QD, 40mg QD, and 60mg QD in the first, second, and third cohorts respectively. Durva was dosed at 1500mg IV Q4W in all cohorts. DLT window was 28 days. Scans were obtained every 8 wks. Treatment beyond progression was allowed. Results: 23 Pts (16 M, 7 F), median age 60 yrs (range 33-79) were currently enrolled. 12 in the dose escalation cohort with cabo 20mg (6 pts), or 40mg (3 pts), or 60mg (3 pts). 11 pts enrolled in the dose expansion cohort with cabo 60mg. 8 pts had GEA, 13 pts had CRC, and 2 pts had HCC. Median number of prior chemotherapies was 3 (range 1-3). 3 pts were not evaluable for DLT due to missing ≥30% of DLT window doses, not related to DLT. No DLTs were observed. Drug-related Grade (G) 1&2 AEs included fatigue (83%), abnormal LFTs (39%), anorexia (26%), diarrhea (26%), nausea (13%), & hand foot syndrome (13%). One pt each developed drug related G3 hypertension, hyperthyroidism, thrombocytopenia, & thromboembolic event, all occurring outside the DLT window. 19 pts were evaluable for response: 4 PR (2 GEA & 2 CRC), 12 SD, 3 PD; ORR 21%; clinical benefit rate 84%; median time to PD 16 wks (range 8-40+). Conclusions: RP2D was determined to be Cabo 60mg QD and Durva 1500mg Q4W. Enrollment to phase I dose expansion is ongoing. RP2D may be adjusted based on additional experience & long-term tolerability. Early efficacy data was encouraging. This is an investigator-initiated trial funded by Exelixis & Astrazeneca. Clinical trial information: NCT03539822 .

Successful Percutaneous Treatment of an Arteriovenous Malformation of the Toe

Arteriovenous malformations (AVMs) of the toe are a rare entity. To the author's knowledge, there are only 2 published case reports, and both patients underwent amputation of the affected digits. Little is known about the optimal treatment of AVMs involving the toe. The authors present the case of a 20-year-old male with a large AVM of the second toe, which was successfully treated with intra-arterial sodium tetradecyl sulfate. Percutaneous treatment of these lesions is possible and should be considered before amputation.

Cervical cancer screening decentralized policy adaptation: an African rural-context-specific systematic literature review

Background: Worldwide, nearly 570,000 women are diagnosed with cervical cancer each year, with 85% of new cases in low- and middle-income countries. The African continent is home to 35 of 40 countries with the highest cervical cancer mortality rates. In 2014, a partnership involving a rural region of Senegal, West Africa, was facing cervical cancer screening service sustainability barriers and began adapting regional-level policy to address implementation challenges.

Objective: This manuscript reports the findings of a systematic literature review describing the implementation of decentralized cervical cancer prevention services in Africa, relevant in context to the Senegal partnership. We report barriers and policy-relevant recommendations through Levesque’s Patient-Centered Access to Healthcare Framework and discuss the impact of this information on the partnership’s approach to shaping Senegal’s regional cervical cancer screening policy.

Methods: The systematic review search strategy comprised two complementary sub-searches. We conducted an initial search identifying 4272 articles, then applied inclusion criteria, and ultimately 19 studies were included. Data abstraction focused on implementation barriers categorized with the Levesque framework and by policy relevance.

Results: Our findings identified specific demand-side (clients and community) and supply-side (health service-level) barriers to implementation of cervical cancer screening services. We identify the most commonly reported demand- and supply-side barriers and summarize salient policy recommendations discussed within the reviewed literature.

Conclusions: Overall, there is a paucity of published literature regarding barriers to and best practices in implementation of cervical cancer screening services in rural Africa. Many articles in this literature review did describe findings with notable policy implications. The Senegal partnership has consulted this literature when faced with various similar barriers and has developed two principal initiatives to address contextual challenges. Other initiatives implementing cervical cancer visual screening services in decentralized areas may find this contextual reporting of a literature review helpful as a construct for identifying evidence for the purpose of guiding ongoing health service policy adaptation.

Case report: interventional radiology's potential role for in vitro fertilization post ovarian transposition and pelvic radiation

Introduction

Ovarian transposition is a procedure that can help preserve fertility for female patients requiring radiation in the abdominopelvic region. However, the displacement of ovaries from its original anatomic location can make oocyte retrieval challenging.

Case presentation

A 24-year-old nulligravid patient recently diagnosed with colorectal carcinoma [CRC] underwent ovarian transposition prior to radiation. After radiation and chemotherapy, she began in vitro fertilization [IVF] by reproductive endocrinology and infertility physicians. Right ovary demonstrated nonviability due to failed transposition and radiation. Left ovarian oocytes were not able to be harvested due to risk of left kidney puncture via transvaginal ultrasound [TVUS]. Interventional Radiology [IR] was involved and performed a transabdominal ultrasound guided egg retrieval which led to successful IVF.

Conclusion

This case highlights the utility of IR-assisted transabdominal ultrasound approach for oocyte retrieval in patients with history of ovarian transposition.

MRI findings of absorbable hydrogel spacer for prostate cancer therapy: a pictorial review

Prior studies have shown that dose-escalated radiation therapy for prostate cancer improves clinical outcomes. However, this is associated with increased rectal toxicity. Hydrogel spacer for prostate cancer therapy is an effective way of decreasing rectal toxicity in the late post-therapeutic stages. In some occasions, the gel spacer may not be placed symmetrically between the rectum and prostate. There are several forms of a malpositioned spacer, including lateral displacement, rectal wall infiltration, and prostate capsule infiltration. This manuscript is aimed at evaluating appropriately positioned and malpositioned gel spacers, primarily via magnetic resonance imaging. There are limited educational imaging guides that address what radiologists should evaluate on post-spacer placement imaging. This pictorial review will specifically evaluate post-injection pitfalls such as asymmetry, rectal wall infiltration, and subcapsular injection.

The Utility of a Benign Biliary Stricture Protocol in Preventing Symptomatic Recurrence and Surgical Revision

PURPOSE

To determine whether treating benign biliary strictures via a stricture protocol reduced the probability of developing symptomatic recurrence and requiring surgical revision compared to nonprotocol treatment.

MATERIALS AND METHODS

A stricture protocol was designed to include serial upsizing of internal/external biliary drainage catheters to a target maximum dilation of 18-French, optional cholangioplasty at each upsizing, and maintenance of the largest catheter for at least 6 months. Patients were included in this retrospective analysis if they underwent biliary ductal dilation at a single institution from 2005 to 2016. Forty-two patients were included, 25 women and 17 men, with an average age of 51.9 years (standard deviation ± 14.6). Logistic regression models were used to determine the probability of symptomatic recurrence and surgical revision by stricture treatment type.

RESULTS

Twenty-two patients received nonprotocol treatment, while 20 received treatment on a stricture protocol. After treatment, 7 (32%) patients in the nonprotocol group experienced clinical or laboratory recurrence of a benign stricture, whereas only 1 patient in the stricture protocol group experienced symptom recurrence. Patients in the protocol group were 8.9 times (95% confidence interval [CI] = 1.4-175.3) more likely to remain symptom free than patients in the nonprotocol group. Moreover, patients in the protocol group had an estimated 89% reduction in the probability of undergoing surgical revision compared to patients receiving nonprotocol treatment (odds ratio = .11, 95% CI = .01-.73).

CONCLUSIONS

Establishing a stricture protocol may decrease the risk of stricture recurrence and the need for surgical revision when compared to a nonprotocol treatment approach.

Divergent lactate dehydrogenase isoenzyme profile in cellular compartments of primate forebrain structures

The compartmentalization and association of lactate dehydrogenase (LDH) with specific cellular structures (e.g., synaptosomal, sarcoplasmic or mitochondrial) may play an important role in brain energy metabolism. Our previous research revealed that LDH in the synaptosomal fraction shifts toward the aerobic isoforms (LDH-B) among the large-brained haplorhine primates compared to strepsirrhines. Here, we further analyzed the subcellular localization of LDH in primate forebrain structures using quantitative Western blotting and ELISA. We show that, in cytosolic and mitochondrial subfractions, LDH-B expression level was relatively elevated and LDH-A declined in haplorhines compared to strepsirrhines. LDH-B expression in mitochondrial fractions of the neocortex was preferentially increased, showing a particularly significant rise in the ratio of LDH-B to LDH-A in chimpanzees and humans. We also found a significant correlation between the protein levels of LDH-B in mitochondrial fractions from haplorhine neocortex and the synaptosomal LDH-B that suggests LDH isoforms shift from a predominance of A-subunits toward B-subunits as part of a system that spatially buffers dynamic energy requirements of brain cells. Our results indicate that there is differential subcellular compartmentalization of LDH isoenzymes that evolved among different primate lineages to meet the energy requirements in neocortical and striatal cells.

Differences in Radiation Activity Between Glass and Resin 90Y Microspheres in Treating Unresectable Hepatic Cancer

The purpose of this study was to compare the difference in prescribed radiation activity between glass and resin yttrium-90 (Y) microspheres for radioembolization of unresectable hepatocellular carcinoma (HCC) or liver metastases at a tertiary care teaching institution. The authors performed a retrospective analysis on 126 patients with primary HCC and hepatic metastatic disease from extrahepatic primary cancers who underwent radioembolization with glass or resin particles between 2008 and 2013 at their institution. Radiation activity estimates for prescribed treatments, as well as for the alternate embolization particles, were calculated using commonly employed formulae for both glass and resin particles for all treatments. A total of 217 treatments were performed on 126 patients, with 136 (62.7%) using glass particles and 81 (37.3%) using resin particles. Forty-six (36.5%) patients had metastatic colorectal cancer (CRC), 51 (40.5%) had primary HCC, while 11 (8.7%) had neuroendocrine carcinoma, and 18 (14.3%) had metastases from other primary tumors. The average prescribed activity was 2.66 GBq for glass treatments and 1.06 GBq for resin treatments across all cancer types. When the alternative treatment activity was calculated, activities were projected to decrease by an average of 1.52 GBq per treatment if resin microspheres were used instead of glass microspheres (-52.5%), while activities were projected to increase by an average of 1.57 GBq per treatment if glass microspheres were used instead of resin microspheres (148.9%; p < 0.001). Similar results were seen within each malignancy type and all projected changes were statistically significant (p < 0.001). In conclusion, prescribed radiation activity for radioembolization of unresectable hepatic cancer was significantly lower for resin compared to glass microspheres.

Synaptosomal lactate dehydrogenase isoenzyme composition is shifted toward aerobic forms in primate brain evolution

With the evolution of a relatively large brain size in haplorhine primates (i.e. tarsiers, monkeys, apes, and humans), there have been associated changes in the molecular machinery that delivers energy to the neocortex. Here we investigated variation in lactate dehydrogenase (LDH) expression and isoenzyme composition of the neocortex and striatum in primates using quantitative Western blotting and isoenzyme analysis of total homogenates and synaptosomal fractions. Analysis of isoform expression revealed that LDH in synaptosomal fractions from both forebrain regions shifted towards a predominance of the heart-type, aerobic isoform LDH-B among haplorhines as compared to strepsirrhines (i.e. lorises and lemurs), while in the total homogenate of the neocortex and striatum there was no significant difference in LDH isoenzyme composition between the primate suborders. The largest increase occurred in synapse-associated LDH-B expression in the neocortex, with an especially remarkable elevation in the ratio of LDH-B/LDH-A in humans. The phylogenetic variation in the ratio of LDH-B/LDH-A was correlated with species-typical brain mass but not the encephalization quotient. A significant LDH-B increase in the subneuronal fraction from haplorhine neocortex and striatum suggests a relatively higher rate of aerobic glycolysis that is linked to synaptosomal mitochondrial metabolism. Our results indicate that there is a differential composition of LDH isoenzymes and metabolism in synaptic terminals that evolved in primates to meet increased energy requirements in association with brain enlargement.

Hybridization of Glucose-6-Phosphate Dehydrogenase from Rat and Human Erythrocytes

Glucose-6-phosphate dehydrogenase from rats and from humans was partially purified and was inactivated (dissociated) by removing triphosphopyridine nucleotide by repeated washing and dialysis, and then it was reactivated by addition of triphosphopyridine nucleotide and incubation at 25 degrees C. When enzyme from each species was mixed with enzyme from the other during or after inactivation, a new electrophoretic band located between the fast-moving rat dehydrogenase and the slow-moving type B human enzyme appeared. This band is interpreted as representing a hybrid composed of polypeptide chains from each enzyme.