COVID-19: responding to a pandemic on Operation TORAL

Operation TORAL was the UK's contribution to NATO's Operation RESOLUTE SUPPORT in Kabul, Afghanistan. Approximately 1000 British troops were deployed in Kabul when the arrival of the COVID-19 pandemic in Afghanistan was declared. This article will describe the challenges faced due to COVID-19 in Kabul.Medical planning considerations, occupational health issues, implementation of behaviour change and operating as part of a multinational organisation are all discussed, with challenges encountered detailed and potential solutions offered. The use of a suggested framework for ensuring the medical estimate process covered all areas relevant to an emerging viral pandemic -the 4Ds and 4Cs approach-proved particularly useful in the early stages of the pandemic in Afghanistan.

Haemostatic resuscitation in practice: a descriptive analysis of blood products administered during Operation HERRICK, Afghanistan

INTRODUCTION

Life-threatening haemorrhage is the leading cause of potentially survivable injury in battlefield casualties. During Operation HERRICK (Afghanistan), mortality rates improved year on year due to a number of advances in trauma care, including haemostatic resuscitation. Blood transfusion practice has not previously been reported in detail during this period.

METHODS

A retrospective analysis of blood transfusion at the UK role 3 medical treatment facility (MTF) at Camp Bastion between March 2006 and September 2014 was performed. Data were extracted from two sources: the UK Joint Theatre Trauma Registry (JTTR) and the newly established Deployed Blood Transfusion Database (DBTD).

RESULTS

3840 casualties were transfused 72 138 units of blood and blood products. 2709 adult casualties (71%) were fully linked with JTTR data and were transfused a total of 59 842 units. Casualties received between 1 unit and 264 units of blood product with a median of 13 units per patient. Casualties wounded by explosion required almost twice the volume of blood product transfusion as those wounded by small arms fire or in a motor vehicle collision (18 units, 9 units, and 10 units, respectively). More than half of blood products were transfused within the first 2 hours following arrival at the MTF. There was a trend towards balanced resuscitation with more equal ratios of blood and blood products being used over time.

CONCLUSION

This study has defined the epidemiology of blood transfusion practice during Operation HERRICK. The DBTD is the largest combined trauma database of its kind. It will ensure that lessons learnt during this period are defined and not forgotten; it should also allow further research questions to be answered in this important area of resuscitation practice.

Abdominal aortic junctional tourniquet (AAJT-S): a systematic review of utility in military practice

INTRODUCTION

Haemorrhage is the leading cause of potentially survivable death on the battlefield. Despite overall improvement in battlefield mortality, there has been no improvement in survival following non-compressible torso haemorrhage (NCTH). The abdominal aortic junctional tourniquet-stabilised (AAJT-S) is a potential solution that may address this gap in improving combat mortality. This systematic review examines the evidence base for the safety and utility of the AAJT-S for prehospital haemorrhage control in the combat setting.

METHODS

A systematic search of MEDLINE, Cumulated Index to Nursing and Allied Health Literature and Embase (inception to February 2022) was performed using exhaustive terms, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The search was limited to English-language publications in peer-reviewed journals; grey literature was not included. Human, animal and experimental studies were included. Papers were reviewed by all authors to determine inclusion. Each study was assessed for level of evidence and bias.

RESULTS

14 studies met the inclusion criteria: 7 controlled swine studies (total n=166), 5 healthy human volunteer cases series (total n=251), 1 human case report and 1 mannikin study. The AAJT-S was demonstrated to be effective at cessation of blood flow when tolerated in healthy human and animal studies. It was easy to apply by minimally trained individuals. Complications were observed in animal studies, most frequently ischaemia-reperfusion injury, which was dependent on application duration. There were no randomised controlled trials, and the overall evidence base supporting the AAJT-S was low.

CONCLUSIONS

There are limited data of safety and effectiveness of the AAJT-S. However, there is a requirement for a far-forward solution to improve NCTH outcomes, the AAJT-S is an attractive option and high-quality evidence is unlikely to be reported in the near future. Therefore, if this is implemented into clinical practice without a solid evidence base it will need a robust governance and surveillance process, similar to resuscitative endovascular balloon occlusion of the aorta, with regular audit of use.

A versatile microtomography system to study in situ the failure and fragmentation in geomaterials

This article describes a microtomography experimental platform enabling in situ micro-mechanical study of failure and fragmentation in geomaterials. The system is based on an original high-pressure triaxial flow cell, which is fully integrated into a custom built microtomography scanner equipped with a laboratory x-ray source. The design of the high-precision mechanical apparatus was informed by the concurrent development of advanced tomographic reconstruction methods based on helical scanning and of algorithms correcting for hardware inaccuracies. This experimental system produces very high-quality 3D images of microstructural changes occurring in rocks undergoing mechanical failure and substantial fragmentation. We present the results of two experiments as case studies to demonstrate the capabilities and versatility of this instrumental platform. These experiments tackle various questions related to the onset of rock failure, the hydromechanical coupling and relaxation mechanisms in fractured rocks, or the fragmentation process in geomaterials such as copper ores.

140 Killed in Action (KIA): an analysis of military personnel who died of their injuries before reaching a definitive medical treatment facility in Afghanistan (2004–2014)

Aims/Objectives/Background

Most fatalities from trauma, in civilian and military settings, die before reaching a hospital. However, no previous studies have comprehensively examined this phase of care. The aim of this study was to define the time interval between injury and death in UK military personnel who died pre-hospital from enemy action (Killed in Action, KIA).

Methods/Design

The UK Joint Trauma Theatre Registry (JTTR) was used to identify all UK military personnel who died in Afghanistan (2004–2014). Through novel linkage of medical and tactical databases, an accurate timeline of events was obtained. Cause of death was determined from post mortem review. The primary objective was to report time between injury and death. Secondary objectives: mortality at key timepoints, the temporal lethality of different anatomical injuries, and trends in the case fatality rate (CFR, defined as deaths/injuries x100). Data are reported as n(%), and median [inter-quartile range]. Proportions compared with a Fisher’s exact test, and survival was with a Gehan-Breslow-Wilcoxon test; level of significance was corrected by Bonferroni.

Results/Conclusions

2413 UK personnel were injured in Afghanistan from 2004–2014; 448 died, a CFR of 18.6%. 390 (87.1%) of total deaths (KIA + Killed Non-Enemy Action) were prehospital. Complete timeline data were available for n=303 (87.1%) KIA – this cohort had a median injury severity score of 75.0 [55.5–75.0]. The median time between injury and death in KIA was 0.0 [0.0–21.8] minutes; 173 (57.1%) died immediately, and by 10 min more than two-thirds had died. Primary injury to the head had a significantly shorter time to death compared to the abdomen and lower extremity (both p<0.01). Significant improvement in survival over the decade was due to a reduction in pre-hospital CFR without an increase in in-hospital CFR.

Over two-thirds of KIA deaths occurred within 10 min of injury. Improvement in the CFR in Afghanistan was predominantly in the prehospital phase.

Killed in action (KIA): an analysis of military personnel who died of their injuries before reaching a definitive medical treatment facility in Afghanistan (2004-2014)

INTRODUCTION

The majority of combat deaths occur before arrival at a medical treatment facility but no previous studies have comprehensively examined this phase of care.

METHODS

The UK Joint Theatre Trauma Registry was used to identify all UK military personnel who died in Afghanistan (2004-2014). These data were linked to non-medical tactical and operational records to provide an accurate timeline of events. Cause of death was determined from records taken at postmortem review. The primary objective was to report time between injury and death in those killed in action (KIA); secondary objectives included: reporting mortality at key North Atlantic Treaty Organisation timelines (0, 10, 60, 120 min), comparison of temporal lethality for different anatomical injuries and analysing trends in the case fatality rate (CFR).

RESULTS

2413 UK personnel were injured in Afghanistan from 2004 to 2014; 448 died, with a CFR of 18.6%. 390 (87.1%) of these died prehospital (n=348 KIA, n=42 killed non-enemy action). Complete data were available for n=303 (87.1%) KIA: median Injury Severity Score 75.0 (IQR 55.5-75.0). The predominant mechanisms were improvised explosive device (n=166, 54.8%) and gunshot wound (n=96, 31.7%).In the KIA cohort, the median time to death was 0.0 (IQR 0.0-21.8) min; 173 (57.1%) died immediately (0 min). At 10, 60 and 120 min post injury, 205 (67.7%), 277 (91.4%) and 300 (99.0%) casualties were dead, respectively. Whole body primary injury had the fastest mortality. Overall prehospital CFR improved throughout the period while in-hospital CFR remained constant.

CONCLUSION

Over two-thirds of KIA deaths occurred within 10 min of injury. Improvement in the CFR in Afghanistan was predominantly in the prehospital phase.

Rapid Iododeboronation with and without Gold Catalysis: Application to Radiolabelling of Arenes

Radiopharmaceuticals that incorporate radioactive iodine in combination with single‐photon emission computed tomography imaging play a key role in nuclear medicine, with applications in drug development and disease diagnosis. Despite this importance, there are relatively few general methods for the incorporation of radioiodine into small molecules. This work reports a rapid air‐ and moisture‐stable ipso‐iododeboronation procedure that uses NIS in the non‐toxic, green solvent dimethyl carbonate. The fast reaction and mild conditions of the gold‐catalysed method led to the development of a highly efficient process for the radiolabelling of arenes, which constitutes the first example of an application of homogenous gold catalysis to selective radiosynthesis. This was exemplified by the efficient synthesis of radiolabelled meta‐[¹²⁵I]iodobenzylguanidine, a radiopharmaceutical that is used for the imaging and therapy of human norepinephrine transporter‐expressing tumours.

Chirality Transfer in Gold(I)-Catalysed Hydroalkoxylation of 1,3-Disubstituted Allenes

Gold(I)-catalysed intermolecular hydroalkoxylation of enantioenriched 1,3-disubstituted allenes was previously reported to occur with poor chirality transfer due to rapid allene racemisation. The first intermolecular hydroalkoxylation of allenes with efficient chirality transfer is reported here, exploiting conditions that suppress allene racemisation. A full substrate scope study reveals that excellent regio- and stereoselectivities are achieved when a σ-withdrawing substituent is present.

Tackling the burden of the hepatitis C virus in the UK: characterizing and assessing the clinical and economic consequences

OBJECTIVES

The hepatitis C virus (HCV) remains a significant public health issue. This study aimed to quantify the clinical and economic burden of chronic hepatitis C in the UK, stratified by disease severity, age and awareness of infection, with concurrent assessment of the impact of implementing a treatment prioritization approach.

STUDY DESIGN AND METHODS

A previously published back projection, natural history and cost-effectiveness HCV model was adapted to a UK setting to estimate the disease burden of chronic hepatitis C and end-stage liver disease (ESLD) between 1980 and 2035. A published meta-regression analysis informed disease progression, and UK-specific data informed other model inputs.

RESULTS

At 2015, prevalence of chronic hepatitis C is estimated to be 241,487 with 22.20%, 33.72%, 17.22%, 16.67% and 10.19% of patients in METAVIR stages F0, F1, F2, F3 and F4, respectively, but is estimated to fall to 193,999 by 2035. ESLD incidence is predicted to peak in 2031. Assuming all patients are diagnosed and treatment is prioritized in F3 and F4 using highly efficacious direct-acting antiviral (DAA) regimens, a 69.85% reduction in ESLD incidence is predicted between 2015 and 2035, and the cumulative discounted medical expenditure associated with the lifetime management of incident ESLD events is estimated to be £1,202,827,444.

CONCLUSIONS

The prevalence of chronic hepatitis C is expected to fall in coming decades; however, the ongoing financial burden is expected to be high due to an increase in ESLD incidence. This study highlights the significant costs of managing ESLD that are likely to be incurred without the employment of effective treatment approaches.

Gold-Catalyzed Proto- and Deuterodeboronation

A mild gold-catalyzed protodeboronation reaction, which does not require acid or base additives and can be carried out in "green" solvents, is described. As a result, the reaction is very functional-group-tolerant, even to acid- and base-sensitive functional groups, and should allow for the boronic acid group to be used as an effective traceless directing or blocking group. The reaction has also been extended to deuterodeboronations for regiospecific ipso-deuterations of aryls and heteroaryls from the corresponding organoboronic acid. Based on density functional theory calculations, a mechanism is proposed that involves nucleophilic attack of water at boron followed by rate-limiting B-C bond cleavage and facile protonolysis of a Au-σ-phenyl intermediate.

Dehydrative thiolation of allenols: indium vs gold catalysis

Intermolecular additions of thiols to allenols via formal S(N)2' selectivity to produce functionalized dienes are described. Although this dehydrative reaction was initially developed using gold(I) catalysis, indium(III) proves to be a far superior catalyst in terms of selectivity and substrate scope.

In vivo RAF signal transduction as a potential biomarker for sorafenib efficacy in patients with neuroendocrine tumours

BACKGROUND

Targeted therapies elicit anticancer activity by exerting pharmacodynamic effects on specific molecular targets. Currently, there is limited use of pharmacodynamic assessment to guide drug administration in the routine oncology setting.

METHODS

We developed a phosphoshift (pShift) flow cytometry-based test that measures RAF signal transduction capacity in peripheral blood cells, and evaluated it in a phase II clinical trial of oral sorafenib plus low-dose cyclophosphamide in patients with advanced neuroendocrine tumours (NETs), in order to predict clinical course and/or guide individual dose-titration.

RESULTS

Twenty-two patients were enrolled. Median progression-free survival (PFS) was 3 months (95% CI 2-10.7), and one patient had a partial response. PFS was longer among five patients who demonstrated an increase in pShift after 7 days of sorafenib compared with those who did not (14.9 months vs 2.8 months; P=0.047). However, pShift did not add value to toxicity-based dose-titration.

CONCLUSION

The pharmacodynamic assessment of RAF transduction may identify selected patients with advanced NETs most likely to benefit from the combination of sorafenib plus cyclophosphamide. Further investigation of this test as a potential biomarker is warranted.

Raman Characterization of Nitrogen Doped Multiwalled Carbon Nanotubes

N-type multi-walled nanotubes were synthesized by nitrogen doping using pyridine and pyridine-melamine mixtures in chemical vapor deposition, and their donor states were verified by Scanning Tunneling Spectroscopy. Tunneling Electron Microscopy reveals small amounts of residual catalyst and Scanning Electron Microscopy show well aligned mats of the Nitrogen doped nanotubes. Nitrogen is present in the lattice of these MWNTs as pyridine structures and CNx structures. Raman scattering measurements were performed as a function of increasing growth temperature and the results compared to previously studied boron doped multiwalled nanotubes.

An assessment of the efficiency of the Glostavent ventilator

In parts of the world where supplies of oxygen and electricity are erratic, ventilating patients' lungs can be problematic. Should the electricity supply fail, gas driven ventilators have an advantage as they can continue functioning. However, many are extravagant in their requirement for the driving gas. The Glostavent ventilator was designed to minimise these requirements. We measured the duration of ventilation achieved by the Glostavent ventilator using an E-size oxygen cylinder at a range of minute volumes, and the inspired oxygen concentration achieved by recycling the driving gas. The period of mechanical ventilation from a single E-size cylinder ranged from 11 h 8 min (SD 4 min) with a minute volume of 7 l min(-1) to 18 h 15 min (SD 7 min) with a minute volume of 3 l min(-1). The mean fractional inspired oxygen concentration achieved by recycling the driving gas without further inspired oxygen supplementation was 0.33. We conclude that the Glostavent ventilator performs as efficiently and cost effectively as predicted.

Phase II trial of pharmacodynamically (PDally)-guided optimal biologic dose titration (OBDT) of sorafenib (S) in combination with metronomic cyclophosphamide (mC) in advanced neuroendocrine tumors (aNET)

3526

Background: There is a paucity of reliable PD assays for guiding individual OBDT. PD effects of kinase inhibitors have been previously measured in static tissues. We developed a dynamic flow-cytometric PD assay that quantitates RAF signal transduction capacity (STC) based on the differential MEK´s phosphor-status in stimulated vs. basal conditions (phosphor-shift [PS]) in PBMCs. In a pilot study of 7 patients (pt) with advanced solid tumors in a phase I trial (unpublished data) the % of PS inhibition (I) 7 days after starting S at 400 mg BID showed a 10-fold interpatient variation and correlation with TTP. PDGFR-B/VEGFR2 blockade plus mC showed synergistic effect in the RIP1-Tag2 mouse NET model (J Clin Oncol. 23:939) In this phase II trial of aNET a double antiagniogenic strategy is undertaken: PD-guided OBDT of S + mC. Methods: Eligibility criteria included: unresectable NET with documented PD within 6 months prior to entry; ECOG 0–2; unlimited prior therapy but S; octreotide allowed. Therapy: pt start run-in phase with S at 200mg bid + 50 mg QD fixed dose of mC. After 7 d they escalate to 400 mg BID of S regardless of RAF STC assay results. RAF STC and toxicity are then assessed Q14d, escalating S at 200 mg BID increments until any of the following is achieved: a) 90% RAF STC I; b) maximum S dose of 800 mg BID; or c) intolerable Gr 2 or G3+ toxicity. Once S dose is determined based on these criteria, cycle 1 begins. Design: Simon 2-stage optimal; P0 = 0.05 P1 = 0.2; α =0.05 β = 0.1. Results: Accrual: 10 pt M:F = 6:4, islet cell:carcinoid = 5:5, age median 56 (40–79), ECOG 0:1 = 5:5. S doses (mg BID) at cycle 1 were 200 (2 pt)/400 (5)/600 (2)/800 (1); corresponding cycle 1 day 1RAF STC I (%) were 5, 53/94, 100, 95, 16, 65/25, 41/71, respectively (R2 = 0.13 p = 0.72) Most frequent Gr 3 non-hematologic possibly related adverse events in 30 cycles: hand-foot (2 pt), hypertension, abdominal pain, diarrhea, vomiting, lipase, ileal perforation (1 each). Disease control rate (9 evaluable pt): 78% (95% CI: 52–100%) (1PR, 6 SD). Conclusions: This approach appears feasible/safe. Large interpatient S dose differences are needed to achieve RAF SCT I/toxicity balance. No S dose-RAF SCT I relation is shown. Disease control rate is promising.

No significant financial relationships to disclose.

Phase I study of intravenous decitabine in combination with oral vorinostat in patients with advanced solid tumors and non-Hodgkin's lymphomas (NHL)

3528

Background: Decitabine (D), a hypomethylating agent, and vorinostat (V), a histone deacetylase inhibitor, belong to two different classes of drugs with an epigenetic effect. The ideal dose scheduling of these drugs remains controversial. This phase I study aims to determine the recommended phase II dose (RPTD) of the combination, their toxicity profile, pharmacokinetic (PK) interaction and preliminary clinical activity. Methods: Patients (pts) with advanced solid tumors or relapsed/refractory NHL are eligible. Two different schedules of D and V are being evaluated: sequential administration of D followed by V and concurrent administration of D and V. Dose escalation of D and V on the sequential schedule is described in Table. Results: To date, 27 pts have been entered into dose levels 1, -1, 1a, 1b, -1b, -2b of the sequential schedule. Demographics: median age 61 (range 31–76), F:M = 13:14, ECOG 0:1:2 = 8:16:3, tumor types: 24 solid tumor and 3 NHL. Pts received a total of 77 cycles with a median of 2 cycles (range 1–8). Adverse events (AE) of grade 3 or higher of at least possible attribution to the study treatment were neutropenia (16 pts), thrombocytopenia (4), febrile neutropenia (2), fatigue (2), and 1 pt each for constipation, dehydration, nasal bleeding, elevated alanine aminotransferase, and hyponatremia. Dose limiting toxicities (DLT) consisted mainly of myelosuppression, constitutional and gastrointestinal symptoms occurred in 7/27 (26%) of pts so far. Disease stabilization for 4 or more cycles was observed in 7 out of 22 (31.8%) evaluable pts (two with breast and one each of thymus, colon, pancreatic, appendix and non-small cell lung cancers). Conclusions: The sequential combination of D and V seems to be tolerable after some adjustments in the doses and duration of drug administration. Prolonged disease stabilization has been observed in multiple tumor types. Accrual is ongoing and RPTD will likely be dose level -1b or -2b. ( Supported by NCI Grant No. U01CA132123.)

[Table: see text]

No significant financial relationships to disclose.

A phase I study of vorinostat (VOR) in combination with capecitabine (CAP) in patients (pts) with advanced solid tumors

3576

Background: VOR (suberoylanilide hydroxamic acid; SAHA) is a small molecule inhibitor of histone deacetylase (HDAC) that binds directly to the enzyme’s active site in the presence of a zinc ion. Aberrant HDAC activity has been implicated in a variety of cancers. The combination of 5-fluorouracil and VOR is synergistic in preclinical tumor models. Methods: This phase I study evaluated safety, tolerability, and the recommended phase II dose (RPTD) of VOR and CAP in pts with advanced solid tumors. VOR was administered orally daily while CAP was administered orally bid on days 1–14 of a 21 d cycle. Results: Three dose levels have been evaluated (VOR (mg/d)/CAP (mg/bid)): 300/750, 300/1,000 and 400/1,000. Twenty-three pts have been treated: 6M/17F, median age 59 (range 41–73), ECOG 0:1:2 = 9:13:1, prior therapy 1:2:3 or more = 3:7:13. Pts had colorectal cancer (n=6), nasopharyngeal (n=3) and various other tumors. A total of 104 cycles have been administered, with median = 2 (range 1–15). One dose limiting toxicity (DLT) (grade 3 diarrhea) occurred in 6 patients at dose level 1. No DLT were observed at dose level 2, and 2 DLTs (grade 3 fatigue and grade 3 nausea/vomiting) occurred at dose level 3. RPTD was determined to be VOR 300 mg/d and CAP 1,000 mg/bid. Most common toxicities of any grade and at least possibly attributable (n=22) are: thrombocytopenia (59% of pts), fatigue (55%), nausea (55%), vomiting (50%), hypoalbuminemia (45%), anemia (41%), diarrhea (41%), anorexia (41%), elevated creatinine (36%), lymphopenia (36%), hyponatremia (36%), and hyperglycemia (36%). Common grade 3 toxicities included: hand-foot syndrome (23% of pts), diarrhea (14%), fatigue (14%), and lymphopenia (14%). One pt died on study from ventricular fibrillation due to sotalol and hypocalcemia from pre-existing hypoparathyroidism. Five patients with various tumor types had PR (2 confirmed, 3 unconfirmed) (2 nasopharyngeal, 1 each of ovarian, endometrial and squamous cell carcinoma of head and neck). In addition, disease stabilization was seen in 12 patients. Conclusions: VOR and CAP are well tolerated, and this combination is active in several tumor types. Further evaluations of VOR and CAP are warranted.

No significant financial relationships to disclose.

Optical properties of vanadium oxide nanotubes

The optical properties of vanadium oxide nanotube dispersions have been characterized using visible and near infrared absorption spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and nonlinear transmission of optical intensities in the visible and near infrared. Using transmission electron microscopy, optical properties have been correlated to the occurrence of two distinct nanoparticle morphologies: nanotubes and unrolled tubes or platelets. Raman spectroscopy indicates that color changes associated with tub unrolling can be attributed to V2O5 formation. The nanotube and platelet morphologies both show strong optical intensity limiting at 532 and 1064 nm. However, dependencies on repetition rate suggest that slightly different mechanisms dominate at the two wavelengths.

The multidisciplinary approach to mental health crisis management: an Australian example

Changes within the Australian health care system have led many people with mental health disorders to use emergency departments as the point of access to mental health services. Staff in emergency departments are not necessarily equipped to assess the needs of such clients. This paper briefly describes the development of a multidisciplinary mental health liaison team, within the emergency department of one hospital in Sydney, which was designed to assist both staff and clients. Available evidence suggests the implementation of the team has been a success, however, more research is required to confirm the effectiveness of this approach. Questions are raised about appropriate referral and follow-up for some clients. The study also found deficiencies in the method of routine data collection (Emergency Department Identification System), which makes formal auditing of the team and the services it provides a difficult task.

High-protein diets augment albuminuria in rats with Heymann nephritis by angiotensin II-dependent and -independent mechanisms

Urinary albumin excretion (U(alb)V) increases following dietary protein augmentation (DPA) in nephrotic humans and rats. Angiotensin-converting enzyme inhibitors (ACEI) blunt, but do not entirely prevent, increased U(alb)V at doses that reduce blood pressure and entirely block the pressor effect of exogenously administered angiotensin I (Ang-I), suggesting that angiotensin II (Ang-II) might not mediate the effect of DPA on U(alb)V. We determined the effect of losartan (Los), a specific Ang-II receptor antagonist, and compared its effect to that of enalapril (En), an ACEI, on DPA-induced increase in U(alb)V in rats with passive Heymann nephritis (HN). When Los was administered to HN rats for 48 h prior to DPA from 8.5 to 40% casein. U(alb)V increased in an identical fashion in treated and untreated rats, even though Los caused hypotension and prevented the pressor effect of infused Ang-II. Only on day 6 after DPA did U(alb)V decrease. We then measured the effect of duration of pretreatment with Los on Ang-II binding to isolated glomeruli. Maximal inhibition of Ang-II binding required treatment with Los for 6 days. We then pretreated HN rats with either En or Los for 6 days prior to DPA. In contrast to administration of Los for 2 days prior to DPA, pretreatment with either Los or En for 6 days entirely prevented any increase in U(alb)V. We then increased dietary NaCl from 0.2% to 2% (HS) to determine whether En or Los would modulate U(alb)V after DPA when Ang-II activity was suppressed. En reduced the DPA-mediated increase in U(alb)V regardless of dietary NaCl, while Los was effective only in when dietary NaCl was reduced (0.2%), suggesting that under these conditions ACEI reduces U(alb)V by a mechanism that is independent of inhibition of Ang-II and that high protein diets augment U(alb)V by both Ang-II-independent and Ang-II-dependent mechanisms.