Ibrutinib as first-line therapy for mantle cell lymphoma: a multicenter, real-world UK study

ABSTRACT

During the COVID-19 pandemic, ibrutinib with or without rituximab was approved in England for initial treatment of mantle cell lymphoma (MCL) instead of immunochemotherapy. Because limited data are available in this setting, we conducted an observational cohort study evaluating safety and efficacy. Adults receiving ibrutinib with or without rituximab for untreated MCL were evaluated for treatment toxicity, response, and survival, including outcomes in high-risk MCL (TP53 mutation/deletion/p53 overexpression, blastoid/pleomorphic, or Ki67 ≥ 30%). A total of 149 patients from 43 participating centers were enrolled: 74.1% male, median age 75 years, 75.2% Eastern Cooperative Oncology Group status of 0 to 1, 36.2% high-risk, and 8.9% autologous transplant candidates. All patients received ≥1 cycle ibrutinib (median, 8 cycles), 39.0% with rituximab. Grade ≥3 toxicity occurred in 20.3%, and 33.8% required dose reductions/delays. At 15.6-month median follow-up, 41.6% discontinued ibrutinib, 8.1% due to toxicity. Of 104 response-assessed patients, overall (ORR) and complete response (CR) rates were 71.2% and 20.2%, respectively. ORR was 77.3% (low risk) vs 59.0% (high risk) (P = .05) and 78.7% (ibrutinib-rituximab) vs 64.9% (ibrutinib; P = .13). Median progression-free survival (PFS) was 26.0 months (all patients); 13.7 months (high risk) vs not reached (NR) (low risk; hazard ratio [HR], 2.19; P = .004). Median overall survival was NR (all); 14.8 months (high risk) vs NR (low risk; HR, 2.36; P = .005). Median post-ibrutinib survival was 1.4 months, longer in 41.9% patients receiving subsequent treatment (median, 8.6 vs 0.6 months; HR, 0.36; P = .002). Ibrutinib with or without rituximab was effective and well tolerated as first-line treatment of MCL, including older and transplant-ineligible patients. PFS and OS were significantly inferior in one-third of patients with high-risk disease and those unsuitable for post-ibrutinib treatment, highlighting the need for novel approaches in these groups.

An automated method for BRISQUE quantification of image quality in echocardiography

Background

Echocardiography (echo) remains the most widely used imaging modality for the assessment, monitoring, and prognostication of the heart. Despite its prevalence, standardisation efforts for echo chamber quantification are ongoing, with challenges owing to subjectivity during acquisition and analysis. Furthermore, the confidence in derived functional indices is often dependent on the quality of the acquired images. However, few studies have investigated the accuracy of echo measurements compared to a reference modality such as cardiac magnetic resonance (CMR) imaging, when stratified by image quality.

Purpose

To develop an objective and automated method to quantify echo image quality, and subsequently to investigate the relationship between image quality and patient demographics, as well as the magnitude of bias in left ventricular (LV) functional indices compared with CMR.

Methods

Transthoracic apical 2D echo (2DE) and 3D echo (3DE) data from 128 participants (72 healthy controls and 56 patients with acquired heart disease) were used to train a BRISQUE (Blind/Referenceless Image Spatial Quality Evaluator) algorithm [1]. Briefly, feature extraction was performed by fitting pixel luminances to a generalised Gaussian distribution (GGD), followed by support vector regression to correlate features (i.e., shape, variance, and mean parameters of the GGD) to quality scores (Fig. 1). Independent BRISQUE models were trained on 580 2DE images (consisting of 2-, 3-, and 4-chamber views) and 128 targeted LV 3DE acquisitions at end-diastole, each assigned a subjective perceived quality score between 1 (poor) and 9 (excellent) by a single observer. LV indices including end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and global longitudinal strain (GLS), were assessed according to standard guidelines. Resultant BRISQUE scores were plotted against patient demographics (age, height, weight) and the measurement bias by comparison to CMR (acquired within 1 hour of echo).

Results

Several linear relationships (where P-value of slope <0.05) were observed between demographics, cardiac indices, and BRISQUE scores. Increasing patient weight (and height in 3DE) were found to be associated with poorer image quality. There was no apparent relationship between image quality and age. Of interest, EF exhibited a relationship with image quality in both 2DE and 3DE (Fig. 2), whereby higher quality images tended to overestimate EF, while lower quality images underestimated EF. For 3DE, image quality dependency was also observed for ESV and GLS biases.

Conclusions

BRISQUE can objectively quantify image quality to produce scores which correlate to those of an expert observer, with potential utility for the standardised quantification of echo image quality. Using this method, it may be possible to predict patient characteristics which adversely impact echo quality, as well as the magnitude of measurement biases for certain functional indices.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council (HRC) of New Zealand; National Heart Foundation (NHF) of New Zealand

Right ventricular quantification using 3D echocardiography: a comparison with CMR

Background

Volumetric and functional right ventricular (RV) indices such as ejection fraction (EF) and global strains are known independent predictors of adverse cardiovascular events. While cardiac magnetic resonance (CMR) imaging remains the reference standard for volume quantification, echocardiography is more accessible and allows for rapid ventricular assessment. Compared to conventional 2D echocardiography, 3D echocardiography (3DE) enables full volume acquisitions and the ability to circumvent geometric assumptions. Given the complexity of RV geometry and sensitivity to image plane positioning, this advantage offers the potential to obtain more accurate diagnostic measurements.

Purpose

Tools for RV analysis in 3DE have been less extensively studied compared to those for the left ventricle (LV). We sought to quantify discrepancies in RV indices derived from 3DE and CMR.

Methods

Transthoracic real-time 3DE and cine CMR imaging were performed in 20 prospectively recruited participants (12 patients with acquired cardiac disease and 8 healthy controls), <1 hour apart. Dynamic 3D biventricular models were constructed semi-automatically from CMR by identifying fiducial landmarks, correcting in-plane breath-hold mis-registrations, and interactively fitting contours to the endocardial and epicardial borders on long- and short-axis slices. For 3DE, right ventricular endocardial models were created by fitting contours on 2D image planes resampled from the 3D volume at end-diastole and end-systole, which were subsequently tracked over one cardiac cycle (Figure 1). RV indices including end-diastolic volume (EDV), end-systolic volume (ESV), EF, global longitudinal strain (GLS), and global circumferential strain (GCS) were calculated from the 3DE- and CMR-derived 3D geometric models and compared. Paired-sample t-tests were performed to identify statistically significant differences (where P<0.05), and intraclass correlation coefficients (ICC) for absolute agreement were computed to assess the reliability for each measurement.

Results

Differences (mean ± SD) in RV indices between 3DE and CMR, with corresponding ICCs are presented in Table 1. Statistically significant differences in RV EDV, ESV, EF, and GLS were observed, with 3DE consistently underestimating volumes and overestimating function when compared to CMR. Although a statistically significant difference in RV GCS was not observed, a low ICC score indicated poor reliability.

Conclusions

Volume underestimation in RV indices between 3DE and CMR were found to be larger than those previously reported for the LV, which is likely due to the increased geometric complexity and surface area to volume ratio for the RV. Moreover, 3DE tends to overestimate RV function in terms of EF and GLS, which may impact treatment pathways if used in a clinical setting. Recognising systematic differences between modalities reinforces the need to further develop 3DE technologies for more accurate RV quantification.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council (HRC) of New Zealand;National Heart Foundation (NHF) of New Zealand

Leveraging CMR for 3D echocardiography: an annotated multimodality dataset for AI

Funding Acknowledgements: Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council of New Zealand (HRC)

National Heart Foundation of New Zealand (NHF)

Segmentation of the left ventricular myocardium and cavity in 3D echocardiography (3DE) is a critical task for the quantification of systolic function in heart disease. Continuing advances in 3DE have considerably improved image quality, prompting increased clinical uptake in recent years, particularly for volumetric measurements. Nevertheless, analysis of 3DE remains a difficult problem due to inherently complex noise characteristics, anisotropic image resolution, and regions of acoustic dropout.

One of the primary challenges associated with the development of automated methods for 3DE analysis is the requirement of a sufficiently large training dataset. Historically, ground truth annotations have been difficult to obtain due to the high degree of inter- and intra-observer variability associated with manual 3DE segmentation, thus, limiting the scope of AI-based solutions. To address the lack of expert consensus, we instead used labels derived from cardiac magnetic resonance (CMR) images of the same subjects. By spatiotemporally registering CMR labels to corresponding 3DE image data on a per subject basis (Figure 1), we collated 520 annotated 3DE images from a mixed cohort of 130 human subjects (2 independent single-beat acquisitions per subject at end-diastole and end-systole) consisting of healthy controls and patients with acquired cardiac disease. Comprising images acquired across a range of patient demographics, this curated dataset exhibits variation in image quality, 3DE acquisition parameters, as well as left ventricular shape and pose within the 3D image volume.

To demonstrate the utility of such a dataset, nn-UNet, a self-configuring deep learning method for semantic segmentation was employed. An 80/20 split of the dataset was used for training and testing, respectively, and data augmentations were applied in the form of scaling, rotation, and reflection. The trained network was capable of reproducing measurements derived from CMR for end-diastolic volume, end-systolic volume, ejection fraction, and mass, while outperforming an expert human observer in terms of accuracy as well as scan-rescan reproducibility (Table I).

As part of ongoing efforts to improve the accuracy and efficiency of 3DE analysis, we have leveraged the high resolution and signal-to-noise-ratio of CMR (relative to 3DE), to create a novel, publicly available benchmark dataset for developing and evaluating 3DE labelling methods. This approach not only significantly reduces the effects of observer-specific bias and variability in training data arising from conventional manual 3DE analysis methods, but also improves the agreement between cardiac indices derived from 3DE and CMR.

Figure 1. Data annotation workflow Table I. Results

Longitudinal strain measurement by 3D modelling from cine CMR: feasibility and comparison to 2D speckle tracking echocardiography

Background

Global longitudinal strain (GLS) has emerged as a sensitive index of left ventricular (LV) systolic function with greater prognostic value than LV ejection fraction (LVEF) in a variety of cardiac disorders. While GLS is routinely derived from 2D speckle tracking echocardiography (STE) and feature tracking in cardiac magnetic resonance (CMR) imaging, calculation of strain via 3D geometric modelling enables analyses of deformation that are independent of 2D image plane constraints.

Purpose

We sought to compare longitudinal strain measurements extracted from geometric 3D analysis of CMR against values obtained from conventional 2D-STE.

Methods

Consecutive 2D-echocardiography (2D-echo) and steady-state free precession multiplanar cine CMR scans were performed in 80 prospectively recruited participants (48 healthy controls with LVEF range 53–74%, 30 patients with non-ischaemic cardiac disease with LVEF range 25–77%, and 2 heart transplant recipients with LVEF 53% and 58%), <1 hour apart. Average endocardial peak GLS from 2D-STE was calculated offline using vendor-independent clinical software from apical triplane (2, 3 and 4-chamber) images for each of the standardised LV walls (anterior, anteroseptal, inferoseptal, inferior, inferolateral, anterolateral). Dynamic 3D geometric models of the LV were reconstructed from 3 long- and 6 short-axis CMR slices over one cardiac cycle. Corresponding longitudinal strain measurements were then evaluated by extracting analogous endocardial arc lengths (apex to base of each LV wall) from the 3D LV model. Finally, an average peak GLS was calculated as the mean of the peak longitudinal strains in each LV wall.

Results

GLS measured by 2D-STE ranged between −6.5% and −27.9% for the study population. A two-way mixed-effects intraclass correlation coefficient (ICC) for absolute agreement of 0.820 (95% CI: [0.720, 0.885]) demonstrated good correlation between average GLS obtained from 2D-STE and CMR. A Bland-Altman analysis revealed a minimal bias (<1%) and 95% limits of agreement (LOA) between −6.3% and 5.5% (Fig. 1), with no apparent proportional bias. Comparatively lower correlation and wider LOA between longitudinal strains from 2D-STE and CMR were observed for each LV wall (Table I).

Conclusions

Fully automated calculation of LV GLS can be obtained from geometric 3D CMR analysis. Average peak GLS from cine CMR exhibits good agreement with 2D-STE, despite showing only moderate agreement at each LV wall. The increased discrepancy in regional longitudinal strain may be attributed to subjective plane positioning in 2D-echo, which can be expected to improve with advances in 3D-STE. The calculation of GLS by 3D geometric modelling may enhance the diagnostic value of routine cine CMR examinations for LV systolic function assessment.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council (HRC) of New Zealand and National Heart Foundation (NHF) of New Zealand Figure 1. Bland-Altman analysisTable I. Regional correlations

P757Methamphetamine-associated cardiomyopathy: a case-controlled study of clinical characteristics, management and outcomes

Background

Methamphetamine-associated cardiomyopathy (MAC) is an increasingly diagnosed condition with poor prognosis, and there remains paucity of literature including how MAC differs from other cardiomyopathies. We compared the characteristics and outcomes MAC patients with non-ischaemic cardiomyopathy controls at our centre.

Methods

Clinical profile, management and outcomes were prospectively assessed in consecutive patients with MAC at our hospital from 2006–2018. They were compared with randomly chosen controls with non-ischaemic dilated cardiomyopathy of similar age-group (20–65 year).

Results

Both groups had 62 patients followed for 3.0±2.9 years. MAC patients were younger, with higher proportion of Maori ethnicity, unemployment and cardiogenic shock during index admission and lower proportion of Pacific ethnicity, cardiovascular risk factors and atrial fibrillation. MAC patients also had higher peak NT-proBNP, lower ejection fraction, and lower attendance rate to outpatient appointments. There was no index admission mortality in both groups. MAC had higher mortality and trend to higher heart failure re-admissions rates during follow-up (Figure 1). Amongst MAC patients, baseline left ventricular end diastolic diameter and failure of improvement in right ventricular systolic function by one category during follow-up were independent predictors of mortality, while failure of improvement of left ventricular ejection fraction by one category predicted heart failure readmission.

Figure 1

Conclusions

MAC patients were younger but sicker on presentation, with higher mortality and trend towards higher heart failure readmission rates during medium-term follow-up than controls. Adherence to therapy and attendance to appointments may improve cardiac systolic function over time to reduce adverse clinical endpoints.

Performance on the Modified Card Sorting Test and its relation to psychopathology in adolescents and young adults with 22q11.2 deletion syndrome

BACKGROUND

Approximately one-third of individuals with 22q11.2 deletion syndrome (22q11DS), a common genetic disorder highly associated with intellectual disabilities, may develop schizophrenia, likely preceded by a mild to moderate cognitive decline.

METHODS

We examined adolescents and young adults with 22q11DS for the presence of executive function deficits using a modified version of the Wisconsin Card Sorting Test (MCST) and assessed whether specific performances were associated with concurrent schizophrenia-prodrome symptoms. We also examined possible relationships between MCST performance and broader indices of psychopathology, including self-reported internalising and externalising behavioural symptoms.

RESULTS

Participants with 22q11DS scored significantly below age-matched controls on seven out of nine MCST measures, and poorer MCST performance was associated with increased positive prodromal and internalising behavioural symptoms.

CONCLUSIONS

The schizophrenia-prodrome in 22q11DS involves executive dysfunction, and longitudinal investigation is necessary to examine if specific executive function impairments precedes or co-occurs with the emergence of behavioural psychopathology.

Evaluating the financial impact of clinical trials in oncology: results from a pilot study from the Association of American Cancer Institutes/Northwestern University clinical trials costs and charges project

PURPOSE

Medical care for clinical trials is often not reimbursed by insurers, primarily because of concern that medical care as part of clinical trials is expensive and not part of standard medical practice. In June 2000, President Clinton ordered Medicare to reimburse for medical care expenses incurred as part of cancer clinical trials, although many private insurers are concerned about the expense of this effort. To inform this policy debate, the costs and charges of care for patients on clinical trials are being evaluated. In this Association of American Cancer Institutes (AACI) Clinical Trials Costs and Charges pilot study, we describe the results and operational considerations of one of the first completed multisite economic analyses of clinical trials.

METHODS

Our pilot effort included assessment of total direct medical charges for 6 months of care for 35 case patients who received care on phase II clinical trials and for 35 matched controls (based on age, sex, disease, stage, and treatment period) at five AACI member cancer centers. Charge data were obtained for hospital and ancillary services from automated claims files at individual study institutions. The analyses were based on the perspective of a third-party payer.

RESULTS

The mean age of the phase II clinical trial patients was 58.3 years versus 57.3 years for control patients. The study population included persons with cancer of the breast (n = 24), lung (n = 18), colon (n = 16), prostate (n = 4), and lymphoma (n = 8). The ratio of male-to-female patients was 3:4, with greater than 75% of patients having stage III to IV disease. Total mean charges for treatment from the time of study enrollment through 6 months were similar: $57,542 for clinical trial patients and $63,721 for control patients (1998 US$; P =.4)

CONCLUSION

Multisite economic analyses of oncology clinical trials are in progress. Strategies that are not likely to overburden data managers and clinicians are possible to devise. However, these studies require careful planning and coordination among cancer center directors, finance department personnel, economists, and health services researchers.

Histologic effects of holmium:YAG laser resection versus transurethral resection of the prostate

BACKGROUND AND PURPOSE

Holmium laser resection (HoLRP) is an effective surgical alternative to transurethral resection of the prostate (TURP). We investigated whether an adequate histologic diagnosis could be made from HoLRP tissue specimens.

PATIENTS AND METHODS

A series of 120 patients were randomized to TURP (N = 59) or HoLRP (N = 61). Each histologic specimen was reviewed by a single pathologist, who was blinded to the treatment. Weight of tissue, histologic diagnosis, and degree of thermal artifact were assessed. Thermal damage was graded as follows: 1 = no significant thermal injury; 2 = <25% of the tissue damaged (minimal); 3 = 25% to 80% of the tissue damaged (moderate); and 4 = >80% of the tissue damaged, with loss of prostatic architecture (extensive).

RESULTS

The mean weight of the TURP and HoLRP specimens was 15.6 g and 9.6 g, respectively. The mean grade of thermal artifact for the TURP group was 1.8 and for the HoLRP group 2.6. Of the HoLRP specimens, 56 (92%) were grade < or = 3. Of the entire series of 120 specimens, 5 contained malignant tissue, all of which were from the TURP group. Four of these specimens were adenocarcinoma of the prostate, whereas the other was a transitional-cell carcinoma. Of the four specimens that contained prostate cancer, two were stage pTla tumors.

CONCLUSIONS

Although identifiable prostatic architecture was maintained in the majority of histologic specimens from the HoLRP group, the tissue quality was inferior to that of TURP. There was significantly more vaporization and subsequent tissue loss with HoLRP, and the thermal damage to tissue was greater.

Venturi vacuum systems for hypobaric chamber operations

Physiological studies of the effects of high altitude on man often require the use of a hypobaric chamber to simulate the reduced ambient pressures. Typical "altitude" chambers in use today require complex mechanical vacuum systems to evacuate the chamber air, either directly or via reservoir system. Use of these pumps adds to the cost of both chamber procurement and maintenance, and service of these pumps requires trained support personnel and regular upkeep. In this report we describe use of venturi vacuum pumps to perform the function of mechanical vacuum pumps for human and experimental altitude chamber operations. Advantages of the venturi pumps include their relatively low procurement cost, small size and light weight, ease of installation and plumbing, lack of moving parts, and independence from electrical power sources, fossil fuels and lubricants. Conversion of three hyperbaric chambers to combined hyper/hypobaric use is described.

The relationship of root canal enlargement to finger-spreader induced vertical root fracture

The purpose of this study was to assess the effect of lateral condensation forces on the development of vertical root fracture (VRF) in teeth that have undergone controlled, measured internal root reduction (i.e. canal preparation). Thirty-four straight-rooted maxillary anterior teeth were used. For each tooth a simulated PDL was fabricated from a uniform 0.15 mm layer of silicone impression material. The teeth were mounted in resin to facilitate removal for observation. They were radiographed and measured at 2, 4, 6, and 8 mm from the apex. They were prepared with the step-back method so that the canal width was 20% of the total root width at 2, 4, 6, and 8 mm from the apex. They were obturated using a fine finger spreader attached to a jig that produced a static force of 3.3 kg for 15 s after placement of each gp point. Obturation was complete when the spreader did not penetrate apical to 8 mm from the apex. Twenty-four h after obturation the teeth were examined by transillumination for VRF. Teeth not exhibiting VRF were tested further after gp removal and canal enlargement of 30%, 40%, and 50% The teeth were sectioned at 2-mm increments with a diamond wafering saw and examined under stereomicroscope. No VRF occurred at 20% or 30%; 5 teeth fractured at 40% and 7 at 50%. These teeth had root surface craze lines that developed during testing. Craze lines had also developed in all 17 of the remaining unfractured samples. No VRF occurred after testing unless craze lines were previously present.

Occupational toxicology: test methods and approaches for the pharmaceutical industry

Occupational toxicologists consider the intended pharmacologic effects of active substances to be adverse and undesirable in healthy workers, because of the absence of any therapeutic benefit. This chapter covers testing of finished agents as well as intermediates and related materials for determining exposure routes and potential toxicity.

Diagnostic accuracy of stereotactic core biopsy in a mammographic breast cancer screening programme

Stereotactic core biopsy was performed on 200 women for 206 mammographically suspicious non-palpable lesions detected over a period of 2 years as part of the Australian national programme for early detection of breast cancer. This study aimed to assess the reliability of stereotactic core biopsy in this context and to develop a protocol for the evaluation of stereotactic core biopsy in mammographically detected non-palpable breast lesions. Fifty-one of 52 malignant lesions found by stereotactic core biopsy were confirmed by excision biopsy (one women declined excision). Nine (4.5%) women had atypical ductal hyperplasia on stereotactic core biopsy; at excision, six were low grade carcinomas (in situ or invasive carcinomas), one was a 3 mm focus of grade 3 invasive duct carcinoma, one was atypical ductal hyperplasia, and one patient refused excision biopsy. In 29 (14.5%) women the histology of the stereotactic core biopsy was considered not to correlate with the radiological abnormality, and excision biopsy was advised: in four of these women carcinomas were found. One hundred and ten (55%) women had 116 benign lesions on stereotactic core biopsy: on follow-up, one of these patients has been found to have a carcinoma. Core biopsy number and sequence were analysed demonstrating that no particular biopsy was more diagnostic than any other, and that the diagnostic yield of three cores was statistically equal to that of five cores. The procedure was well-tolerated and there were few complications. Thus, stereotactic core biopsy is an accurate and safe method for diagnosis of mammographically detected non-palpable breast lesions, and we believe it is the diagnostic technique of choice in breast cancer screening programmes. However, a stereotactic core biopsy diagnosis of atypical ductal hyperplasia requires excision biopsy since a diagnosis of low grade intraduct carcinoma cannot be excluded. Furthermore, if tissue obtained by stereotactic core biopsy does not correlate with the mammographic abnormality, excision biopsy should be performed.

beta-Amyloid-mediated vasoactivity and vascular endothelial damage

Deposits of beta-amyloid are apparent in ageing and Alzheimer's disease, but the role of this peptide in neurodegeneration is unclear. The free-radical theory of ageing may also account for Alzheimer-type degeneration and consequently links between free-radical generation and beta-amyloid have been sought. We demonstrate here that beta-amyloid interacts with endothelial cells on blood vessels to produce and excess of superoxide radicals, with attendant alterations in endothelial structure and function. The superoxide radical can scavenge endothelium-derived relaxing factor and produce potent oxidizing agents, which can cause lipid peroxidation and other degenerative changes. The alterations in vascular tone and endothelial damage are prevented by the oxygen-radical-scavenging enzyme superoxide dismutase. These observations suggest a normal vasoactive role for beta-amyloid as well as a mechanism by which beta-amyloid may play a role in vascular abnormalities and neurodegeneration mediated by free radicals.

Cardiovascular pressures with venous gas embolism and decompression

Venous gas embolism (VGE) is reported with decompression to a decreased ambient pressure. With severe decompression, or in cases where an intracardiac septal defect (patent foramen ovale) exists, the venous bubbles can become arterialized and cause neurological decompression illness. Incidence rates of patent foramen ovale in the general population range from 25-34% and yet aviators, astronauts, and deepsea divers who have decompression-induced venous bubbles do not demonstrate neurological symptoms at these high rates. This apparent disparity may be attributable to the normal pressure gradient across the atria of the heart that must be reversed for there to be flow patency. We evaluated the effects of: a) venous gas embolism (0.025, 0.05 and 0.15 ml.kg-1.min-1 for 180 min.); b) hyperbaric decompression; and c) hypobaric decompression on the pressure gradient across the left and right atria in anesthetized dogs with intact atrial septa. Left ventricular end-diastolic pressure was used as a measure of left atrial pressure. In a total of 92 experimental evaluations in 22 dogs, there were no reported reversals in the mean pressure gradient across the atria; a total of 3 transient reversals occurred during the peak pressure gradient changes. The reasons that decompression-induced venous bubbles do not consistently cause serious symptoms of decompression illness may be that the amount of venous gas does not always cause sufficient pressure reversal across a patent foramen ovale to cause arterialization of the venous bubbles.

Use of a disposable carbon dioxide detector with emergency intubation in a hyperbaric chamber

Emergency intubation in a hyperbaric chamber can be complicated by the confined space, inadequate lighting and high levels of background noise. Inadvertent esophageal intubation may be difficult to recognize in these conditions. In more controlled settings such as the operating room, the detection of end-tidal carbon dioxide is the standard procedure for verifying proper placement of the endotracheal tube. Within a hyperbaric chamber, a capnograph may not be readily available for this purpose. We present a case report describing the use of a simple disposable colorimetric carbon dioxide detector for rapid verification of endotracheal tube position following emergency intubation in a hyperbaric chamber.

Doppler detection of decompression bubbles with computer assisted digitization of ultrasonic signals

Precordial Doppler ultrasonic monitoring is routinely used for detection of venous gas bubbles resulting from decompression in hypobaric or hyperbaric applications. Bubble scoring codes have been devised in an attempt to quantify the number of audible bubble signals heard over the background sounds of the cardiac cycle. The audio interpretation of these ultrasonic backscatter signals remains the most common method for decompression evaluation. We report on the use of an inexpensive, commercially available audio digitizer in conjunction with a personal computer to digitize Doppler bubble signals for visual and electronic evaluation. This device can be operated simultaneously with Doppler audio monitoring. Precordial and arterial Doppler recordings of gas bubbles were obtained from anesthetized dogs after intravascular infusion or following decompression. Additional evaluations were conducted on Doppler bubble recordings obtained from human decompression studies. The device can be used in real-time or for later signal analysis. Accompanying menu-driven software provides for numerous signal modification options and visual displays. This device can provide a simultaneous visual display of Doppler signals normally only available for audio evaluation.

Comparative toxicology of temelastine. A novel H1 antagonist in dog, rat, and monkey

The toxicity of temelastine 2-[4-(5-bromo-3-methylpyrid-2-yl)butylamino]-5-[(6-methylpyrid+ ++-3-yl) methyl]-4-pyrimidone a potent, selective, competitive histamine H1-receptor antagonist was examined in dogs and rats. The major toxicological response seen in the dog was marked, but intermittent and reversible, increases in the plasma activity of a number of liver-associated enzymes, viz alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), and alkaline phosphatase (ALP). The increases first seen in two male dogs treated for 30 consecutive days at a dose of 300 mg/kg became apparent at lower doses, i.e., 100 and 33.3 mg/kg/day, in 6- and 12-month studies. Although the increases were suggestive of hepatotoxicity, the only histological changes were increases in hepatocellular lipofuscin pigment and foci of macrophages seen in dogs treated at 300 mg/kg for 12 months. Rats treated for up to 12 months at doses as high as 300 mg/kg/day showed no treatment-related increases in plasma enzymes although increases in liver weights and hepatocellular lipofuscin pigment together with centrilobular hypertrophy were seen in the 300 mg/kg/day treatment group. To investigate differences in hepatic responsiveness between species dogs, rats, and monkeys were exposed to high concentrations of temelastine by continuous 24-hr intravenous infusion. The results of the study showed the dog to be most sensitive to the hepatic effects of temelastine. The major toxicological effect of temelastine in the rat was a histopathological lesion of the thyroid gland characterized by agglomeration and depletion of colloid, follicular epithelial hypertrophy and reduced follicular size. The no-effect dose for this lesion was between 10 and 33.3 mg/kg/day. These histopathological changes, characteristic of a "TSH-driven" thyroid gland, were not seen in the thyroid glands of dogs.

Effect of the Trendelenburg position on the distribution of arterial air emboli in dogs

We examined the effects of buoyancy on the distribution of arterial gas bubbles using in vitro and in vivo techniques in dogs. A simulated carotid artery preparation was used to determine the effects of bubble size and vessel angle on the velocity and direction of bubble movement in flowing blood. Because buoyancy tends to float bubbles away from dependent areas, bubble velocity would be expected to decrease as the vessel angle increased. We found that larger bubbles increased in velocity in the same direction as the blood flow at 0-, 10-, and 30-degree vessel angles and decreased when the vessel was positioned at 90 degrees. Smaller bubbles did not change velocity from 0 to 30 degrees and increased in velocity in the same direction as blood flow at 90 degrees. In 10 anesthetized dogs, we studied the effects of 0-, 10-, 15-, and 30-degree Trendelenburg's position on carotid artery distribution of gas bubbles injected into the left ventricle or ascending aorta. Regardless of the degree of the Trendelenburg position, the bubbles passed into the carotid artery simultaneously with passage into the abdominal aorta. We conclude that the forces of buoyancy do not overcome the force of arterial blood flow and that the Trendelenburg position does not prevent arterial bubbles from reaching the brain.

Villous and tubulovillous adenomas of the colon and rectum. A retrospective review, 1964-1985

The records of 1,040 patients with 1,440 villous and tubulovillous adenomas of the colon and rectum treated at the Cleveland Clinic over a 21 year period were reviewed. The incidence of invasive adenocarcinoma was higher in patients with multiple adenomas at the time of presentation, in patients with a family history of colorectal cancer, and in those with adenomas greater than 4 cm in diameter. Eighty percent of the adenocarcinomas were Dukes' A or B, 15 percent were Dukes' C, and 5 percent presented with distant metastases. Clinical impression on examination was more accurate than biopsy in assessing the presence of malignancy in these tumors. Recurrence after local treatment of both benign and malignant tumors was high. Recurrence was significantly related to the size of the adenoma (more common when the tumor was more than 4 cm in diameter), location (more common when it was located in the rectum), and the type of treatment. Only 4 percent of the patients had died from colorectal cancer at the time of follow-up. The overall 5 year actuarial survival rate was 85 percent.

Unusual aspects of Kawasaki syndrome

Kawasaki syndrome (mucocutaneous lymph node syndrome) occurs predominantly in children. The criteria for diagnosis include unresponsive fever; lesions of the skin and conjunctival mucous membrane; edema, rashes and other abnormalities of the hands and feet, and cervical lymphadenopathy. Unusual features occur in the cardiovascular, gastrointestinal and central nervous systems, as well as elsewhere. The variety of findings may be misleading, and the diagnostic criteria must be kept in mind.

The syndrome of accelerated bone maturation in the newborn infant with dysmorphism and congenital malformations. (The so-called Marshall-Smith syndrome)

A new case of the syndrome of "accelerated skeletal maturation, facial dysmorphism, failure to thrive and psychomotor retardation" is presented. The syndrome was noted in the neonatal period. The diagnosis can be readily suggested by the radiologist because ossification centers show exceptionally early maturation. This case history increases to at least five the number of cases so far reported following the initial publication by Marchall and al. in 1971. If the two cases described in 1974 by Weaver and al. (as a distinct entity) are also included then the total of cases reported rises to seven.