Burden of Hidradenitis Suppurativa: A Systematic Literature Review of Patient Reported Outcomes

INTRODUCTION

Hidradenitis suppurativa (HS) has a profound negative impact on patients' health-related quality of life (HRQoL). Here we summarize the evidence on HRQoL and Patient Reported Outcomes (PROs) in patients with HS in real-world settings by conducting a systematic literature review (SLR) of observational studies.

METHODS

Data sources included MEDLINE, Embase & PsycINFO between January 1, 2010 and August 29, 2021, and conference proceedings between 2019 and 2021. Identified abstracts were reviewed and screened independently by two reviewers. Eligibility criteria included patients with HS of any severity, sample size ≥ 100, reporting PROs including HRQoL measures. Included studies were critically appraised.

RESULTS

Fifty-eight observational studies matched inclusion criteria. Dermatology Life Quality Index (DLQI) was the most commonly utilized instrument: 57% of included studies reported mean baseline DLQI scores, ranging between 8.4 and 16.9, indicating a very large impact on the patients' HRQoL. Higher scores were reported with increasing disease severity and among female patients. Pain was assessed mostly by an 11-point (0-10) numeric rating scale (NRS) with a mean baseline score ranging from 3.6 to 7.7 indicating moderate to high pain levels. There was a negative impact of HS on patients' psychological well-being, based on PRO scores related to depression and anxiety. A high proportion of sexual dysfunction was reported, with a larger impact on women than men. Work productivity and leisure activity were consistently found to be impaired in patients with HS.

CONCLUSIONS

All included studies reported a negative impact of HS on patients' lives. A diverse set of disease- and non-disease-specific PRO instruments were utilized highlighting the need for more consistent use of HS-specific validated PRO instruments to assess the impact of HS on the different aspects of patients' HRQoL to allow for data to be more meaningfully interpreted and compared in real-world settings. Patients with HS need better disease management approaches that address the observed low quality of life.

Electronic Patient-Reported Outcomes in Hidradenitis Suppurativa: Content Validity and Usability of the Electronic Hidradenitis Suppurativa Symptom Daily Diary, Hidradenitis Suppurativa Symptom Questionnaire, and Hidradenitis Suppurativa Quality of Life Questionnaire

BACKGROUND

Hidradenitis suppurativa (HS), a chronic skin condition that causes pain and physical dysfunction, can impact significantly on quality of life. Disease-specific tools have been designed to assess the impact of HS on patients, including the HS Symptom Daily Diary (HSSDD), the HS Symptom Questionnaire (HSSQ), and the HS Quality of Life (HiSQOL©) questionnaire, which have been developed into electronic instruments (eHSSDD, eHSSQ, and eHiSQOL©).

OBJECTIVES

The objective of this study was to establish the content validity of the electronic version of the HSSDD and HSSQ, and the acceptability and usability of the HSSDD, HSSQ, and HiSQOL©, using concept elicitation and cognitive debriefing interviews.

METHODS

This was a non-interventional qualitative video interview study involving participants aged ≥18 years with moderate to severe HS recruited from a single clinical site in the USA. Interviews gathered feedback on participants' symptom experience, followed by training and completion of the eHSSDD, eHSSQ, and eHiSQOL© questionnaires on electronic handheld devices. Participants were then interviewed on the content of the eHSSDD and eHSSQ and the acceptability and usability of all three instruments. Interviews were transcribed and qualitatively analysed.

RESULTS

Twenty participants with moderate to severe HS (median age: 41.5 [range: 20.0-64.0]; n = 16/20 female) were included. All participants found the eHSSDD, eHSSQ, and eHiSQOL© instructions clear and described the instruments as "easy", "simple" and "self-explanatory". Overall understanding of individual items within the eHSSDD and eHSSQ was high; however, 6/20 participants had difficulty in understanding the average skin pain item in the eHSSDD. All participants were able to accurately recall their symptoms within the recall periods of the eHSSDD and eHSSQ, although 4/20 participants found the 24-h recall period of the eHSSDD limiting. Completion time was quick across all instruments, and usability was high, with the majority of participants reporting no difficulty in completing questionnaires on electronic devices.

CONCLUSION

The concepts covered in the eHSSDD and eHSSQ are relevant and important to patients, supporting their content validity. The findings also provide evidence of acceptability and usability of the eHSSDD, eHSSQ, and eHiSQOL©. A limitation was that all participants were recruited from a single site, which may have introduced selection bias and thus limited the generalisability of results.

Validation of the Hidradenitis Suppurativa Investigator Global Assessment: A Novel Hidradenitis Suppurativa-Specific Investigator Global Assessment for Use in Interventional Trials

Importance

Few simplified instruments exist for use in hidradenitis suppurativa (HS) trials.

Objective

To assess psychometric properties of the Hidradenitis Suppurativa Investigator Global Assessment (HS-IGA) score using a clinical trial data set.

Design, Setting, and Participants

This retrospective analysis of a phase 2 randomized double-blind, placebo-controlled, active-reference arm trial (UCB HS0001) included adults with moderate-to-severe HS.

Exposures

Trial participants were randomized at baseline to receive bimekizumab, adalimumab, or placebo.

Main Outcomes and Measures

The HS-IGA score at prespecified time points up to 12 weeks after randomization.

Results

The HS-IGA score showed strong convergent validity with IHS4 and HS-PhGA scores at baseline (Spearman correlation, 0.86 [P < .001] and 0.74 [P < .001], respectively) and at week 12 (Spearman correlation, 0.73 [P < .001] and 0.64 [P < .001], respectively). The HS-IGA scores assessed during predosing visits at screening and baseline showed good test-retest reliability (intraclass correlation coefficient [ICC] = 0.92). At week 12, HS-IGA responders were significantly associated with HiSCR-(50/75/90) responders (χ2 = 18.45; P < .001; χ2 = 18.11; P < .001; and χ2 = 20.83; P < .001, respectively). The HS-IGA score was predictive of HiSCR-50/75/90 and HS-PhGA response at week 12 (AUC, 0.69, 0.73, 0.85, and 0.71, respectively). However, the HS-IGA as a measure of disease activity showed low predictive validity with patient-reported outcomes at week 12.

Conclusions and Relevance

The HS-IGA score demonstrated good psychometric properties compared with existing measures and may be considered for use as an end point in clinical trials for HS.

Bimekizumab maintenance of response through three years in patients with moderate to severe plaque psoriasis: Results from the BE BRIGHT open-label extension trial

Background

Given the chronic nature of psoriasis and the loss of response that can be observed with therapies over time, it is important to understand the long-;term efficacy of new treatments.

Objective

To evaluate maintenance of Week 16 responses with bimekizumab treatment through Year 3, in patients with moderate to severe plaque psoriasis.

Methods

Data were pooled from bimekizumab-treated patients in the 52-week (BE VIVID) and 56-week (BE READY and BE SURE) phase 3 studies, and their ongoing open-label extension (OLE), BE BRIGHT. Efficacy outcomes are reported through three years of bimekizumab treatment in patients with an efficacy response at Week 16. Missing data were imputed primarily using modified non-responder imputation (mNRI), with non-responder imputation and observed case data also reported.

Results

A total of 989 patients were randomized to bimekizumab at baseline in BE VIVID, BE READY, and BE SURE. At Week 16, 693 patients achieved ≥90% reduction from baseline in Psoriasis Area and Severity Index (PASI 90), 503 achieved 100% reduction from baseline in PASI (PASI 100), 694 achieved absolute PASI ≤2, and 597 achieved body surface area (BSA) ≤1%, and continued into the OLE. Of these, 93.0% maintained PASI 90, 80.8% maintained PASI 100, 94.0% maintained PASI ≤2, and 90.3% maintained BSA ≤1% responses through to three years of bimekizumab treatment (mNRI). Among Week 16 PASI 90 responders, 96.8% and 72.5% also achieved Investigator’s Global Assessment (IGA) 0/1 and PASI 100 at Week 16, respectively, and 92.2% and 73.4% achieved these responses at Year 3 (mNRI). Among Week 16 PASI 100 responders, 76.3% also achieved Dermatology Life Quality Index (DLQI) 0/1 at Week 16, and DLQI 0/1 response increased with continuous bimekizumab treatment to 89.0% at Year 3 (mNRI).

Conclusions

High levels of clinical response were maintained through to three years of bimekizumab treatment in the vast majority of Week 16 responders. Long-term treatment with bimekizumab was efficacious, with important benefits on health-related quality of life (HRQoL), in patients with moderate to severe plaque psoriasis.

Psychometric Validation of the Psoriasis Symptoms and Impacts Measure (P-SIM): A Novel Patient-Reported Outcome Instrument for Patients with Plaque Psoriasis, Using Reported Data from the BE RADIANT Phase 3b Trial

Introduction

This analysis assessed the psychometric properties of the Psoriasis Symptoms and Impacts Measure (P-SIM), a novel patient-reported outcome (PRO) tool designed to capture patient experiences of the signs, symptoms and impacts of psoriasis.

Methods

Blinded data from the BE RADIANT phase 3b trial of bimekizumab were analysed. In BE RADIANT, patients were randomised 1:1 to bimekizumab 320 mg every 4 weeks (Q4W) or secukinumab 300 mg (weekly until Week 4, then Q4W). Three items (itching, skin pain and scaling) of the P-SIM were electronically assessed throughout the trial and were scored from 0 to 10 (none to very severe signs/symptoms/impacts). Test–retest reliability was determined using intraclass correlations. Convergent validity was assessed between P-SIM and other relevant PRO and clinician-reported outcome (ClinRO) scores. Known-groups validity was assessed by comparing mean P-SIM item scores between patient subgroups based on the Psoriasis Area and Severity Index (PASI)/Investigator’s Global Assessment (IGA) scores. Responsiveness was assessed via correlations between changes from baseline in P-SIM item scores and other relevant PRO and ClinRO scores. Anchor-based responder analyses and empirical cumulative distribution function (eCDF) curves determined responder thresholds.

Results

The three P-SIM items yielded high intraclass coefficients (> 0.70). By Week 48, the three P-SIM items had moderate (> 0.30 and ≤ 0.50) to strong (> 0.50) correlations with other PROs and weaker correlations with ClinROs, demonstrating good convergent validity. For almost all known-group comparisons, statistically significant between-subgroup score differences were seen across all three P-SIM items. Changes from baseline in the P-SIM and other relevant outcomes were above the acceptable threshold of ≤ 0.30, demonstrating sensitivity to change. Anchor-based analyses determined a ≥ four-point reduction from baseline to indicate marked clinically meaningful improvement for the P-SIM.

Conclusion

These results support the validity, reliability and sensitivity to change of the P-SIM in assessing key symptoms (itching, skin pain and scaling) in patients with moderate to severe plaque psoriasis.

Trial registration

NCT03536884.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01836-1.

Development and psychometric evaluation of the assessment of self-injection questionnaire: an adaptation of the self-injection assessment questionnaire

BACKGROUND

Patient-reported outcome (PRO) instruments provide robust and effective means of evaluating patients' treatment experience; however, none adequately cover experience using self-injection devices with enhanced features, such as an electromechanical autoinjector (e-Device). The aim of this study was to develop a PRO instrument that accurately assesses patient experience of using an e-Device and to evaluate its psychometric properties.

METHODS

A mixed-methods approach was taken; two parallel, targeted literature reviews were conducted to identify relevant concepts and existing self-injection PRO instruments that could be adapted. Patient feedback obtained from two focus groups was used to inform initial instrument development. The pilot instrument was then administered in a multicenter, open-label, phase 3 clinical study in which patients self-injected certolizumab pegol using an e-Device, to gather evidence of its psychometric qualities. Exit interviews were conducted with a sub-sample of patients enrolled in the study to confirm the appropriateness and clarity of the items included and cognitively debrief the instrument. Confirmatory factor analysis (CFA) was conducted on all items, and each domain's internal consistency was measured using Cronbach's ɑ.

RESULTS

The literature searches identified several e-Device-specific concepts related to device features, device function, side effects/reactions/pain, confidence, and interference/convenience in daily life. Seven existing PRO instruments were identified. The Self-Injection Assessment Questionnaire (SIAQ), containing pre- and post-injection questionnaire modules, was selected as most suitable and adapted using feedback from 19 patients in the two focus groups to form the pilot Assessment of Self-Injection (ASI) questionnaire. CFA resulted in some changes to the grouping of items in the post-injection module domains following psychometric evaluation of the ASI. Internal consistency was satisfactory for all pre- and post-injection domains (ɑ > 0.8). Cognitive debriefing results from 12 patient exit interviews confirmed the ASI's appropriateness and clarity.

CONCLUSIONS

The ASI was developed iteratively with patient input and was evaluated in its intended clinical context of use. Psychometric analyses indicated promising cross-sectional results; the ASI was well understood and considered relevant by patients self-injecting using the e-Device, suggesting that it could be used in real-world settings to aid with clinical decision making.

TRIAL REGISTRATION

NCT03357471.

Development and Content Validation of the Psoriasis Symptoms and Impacts Measure (P-SIM) for Assessment of Plaque Psoriasis

Introduction

Patients with plaque psoriasis experience a variety of signs and symptoms that can impact daily life, which may not be evaluated by clinician-reported outcomes. This study aimed to develop and assess the content validity of a new patient-reported outcome (PRO) measure to capture patient experiences of the signs, symptoms and impacts of psoriasis and aid integration of the patient perspective in treatment benefit-risk decision-making.

Methods

The psoriasis symptoms and impacts measure (P-SIM) was developed based on a literature search and interviews with five clinical experts in psoriasis to identify frequent signs, symptoms and impacts of psoriasis. Hybrid concept elicitation, cognitive debriefing and usability testing interviews were conducted with moderate to severe psoriasis patients to evaluate the content validity and patient understanding of the preliminary P-SIM. The preliminary P-SIM was refined using initial quantitative analyses of phase 2b data from psoriasis patients to inform the removal of any items.

Results

A preliminary 19-item P-SIM was developed for administration on a hand-held electronic tablet device using a 0–10 numerical response scale over a 24-h recall period. Patient interviews and testing demonstrated most patients interpreted the items and responses as intended, would not re-word any items, felt the responses matched the items and rated the device as easy to use. After quantitative testing, five items were removed from the preliminary 19-item measure because of conceptual overlap, floor effects and/or skewed distributions to generate the final 14-item P-SIM.

Conclusions

The P-SIM questionnaire has good content validity; patients reported it was easy to understand and reflective of their experiences. Following psychometric validation, the P-SIM may be a useful PRO measure for capturing the signs, symptoms and impacts of psoriasis and may support clinician-reported outcomes when assessing treatment benefits in clinical trials.

Electronic supplementary material

The online version of this article (10.1007/s13555-020-00434-3) contains supplementary material, which is available to authorized users.

Syndromic surveillance system based on near real-time cattle mortality monitoring

Early detection of an infectious disease incursion will minimize the impact of outbreaks in livestock. Syndromic surveillance based on the analysis of readily available data can enhance traditional surveillance systems and allow veterinary authorities to react in a timely manner. This study was based on monitoring the number of cattle carcasses sent for rendering in the veterinary unit of Talavera de la Reina (Spain). The aim was to develop a system to detect deviations from expected values which would signal unexpected health events. Historical weekly collected dead cattle (WCDC) time series stabilized by the Box-Cox transformation and adjusted by the minimum least squares method were used to build the univariate cycling regression model based on a Fourier transformation. Three different models, according to type of production system, were built to estimate the baseline expected number of WCDC. Two types of risk signals were generated: point risk signals when the observed value was greater than the upper 95% confidence interval of the expected baseline, and cumulative risk signals, generated by a modified cumulative sum algorithm, when the cumulative sums of reported deaths were above the cumulative sum of expected deaths. Data from 2011 were used to prospectively validate the model generating seven risk signals. None of them were correlated to infectious disease events but some coincided, in time, with very high climatic temperatures recorded in the region. The harvest effect was also observed during the first week of the study year. Establishing appropriate risk signal thresholds is a limiting factor of predictive models; it needs to be adjusted based on experience gained during the use of the models. To increase the sensitivity and specificity of the predictions epidemiological interpretation of non-specific risk signals should be complemented by other sources of information. The methodology developed in this study can enhance other existing early detection surveillance systems. Syndromic surveillance based on mortality monitoring can reduce the detection time for certain disease outbreaks associated with mild mortality only detected at regional level. The methodology can be adapted to monitor other parameters routinely collected at farm level which can be influenced by communicable diseases.

Preclinical safety profile of plasma prepared using the INTERCEPT Blood System

BACKGROUND AND OBJECTIVES

The newly developed INTERCEPT Blood System for plasma uses the addition of a new psoralen, amotosalen HCl (AMOTOSALEN), followed by illumination with ultraviolet A light, to inactivate viruses, bacteria, protozoa and leucocytes that may contaminate fresh-frozen plasma (FFP). Extensive toxicology studies were performed to characterize the safety of the photochemical treatment process for its intended use with plasma.

MATERIALS AND METHODS

The studies of general toxicology, safety pharmacology, phototoxicity, reproductive toxicity and venous irritation, summarized in this review, provide a comprehensive toxicology profile for photochemically treated 100% plasma.

RESULTS

No specific target organ toxicity (based on clinical or histological pathology), phototoxicity, or reproductive toxicity was observed.

CONCLUSIONS

The results of an extensive series of studies have demonstrated no toxicologically relevant effects of photochemically treated 100% plasma prepared using the INTERCEPT Blood System for plasma.

Preclinical safety of a nucleic acid-targeted Helinx compound: a clinical perspective

Helinx technology (Cerus Corp, Concord, CA) uses amotosalen HCl (S-59) and ultraviolet A (UVA) light in an ex vivo photochemical treatment (PCT) to inactivate viruses, bacteria, and leukocytes in platelet concentrates while preserving therapeutic function. A comprehensive preclinical safety program was conducted, which included carcinogenicity, single-dose and multiple-dose (up to 13 weeks' duration) toxicity, safety pharmacology (central nervous system [CNS], renal, and cardiovascular), reproductive toxicity, genotoxicity, vein irritation, phototoxicity, and toxicokinetic testing. The results of the toxicokinetic analyses indicated that the test articles provided large multiples of the clinical exposure to S-59, whether the comparison was based on dose, maximum plasma concentration, or area under the concentration-time curve. No specific target organ toxicity, reproductive toxicity, or carcinogenicity was observed. S-59 and/or PCT formulations demonstrated CNS toxicity, electrocardiographic (ECG) effects, and phototoxicity at supraclinical doses. On the basis of the extremely large safety margins, the CNS and ECG observations (at >30,000-fold the expected clinical exposure) as well as the results of genotoxicity and phototoxicity studies are not considered to be of toxicological relevance. The results of an extensive series of studies have thus demonstrated no toxicologically relevant effects of platelets treated with Helinx technology.

The genotoxicity profile of atorvastatin, a new drug in the treatment of hypercholesterolemia

While HMG-CoA reductase inhibitors such as fluvastatin, lovastatin, pravastatin and simvastatin demonstrate lack of in vitro and in vivo mutagenicity and clastogenicity in bacterial and mammalian cells, long term rodent carcinogenicity studies resulted in an increased incidence in neoplasms at high doses. These effects may be attributable to an exaggeration of the desired biochemical effect of the drug and/or a tumor promoting effect. The genotoxicity of atorvastatin, a newly developed HMG-CoA reductase inhibitor, was evaluated in a variety of test systems. In bacterial mutagenicity tests, the E. coli tester strain WP2(uvrA) and S. typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538 were exposed to concentrations of atorvastatin as high as 5000 micrograms/plate both in the absence (S9-) and presence (S9+) of metabolic activation. Atorvastatin was not mutagenic in either E. coli or S. typhimurium. Chinese hamster lung V79 cell cultures were exposed to atorvastatin at concentrations of 50-300 micrograms/ml (S9-) and 100-300 micrograms/ml (S9+) and structural chromosome aberrations were assessed. Mutation at the hgprt locus was assessed at concentrations of 100-300 micrograms/ml (S9-) and 150-275 micrograms/ml (S9+). Atorvastatin was neither mutagenic nor clastogenic in the absence or presence of S9. The lack of in vitro genotoxicity was corroborated in vivo in a mouse micronucleus study in which single oral doses of atorvastatin were administered to male and female CD-1 mice at 1, 2500, or 5000 mg/kg. No biologically significant increases in the frequency of micronucleated polychromatic erythrocytes in bone marrow at 24, 48, or 72 h postdosing were observed. Thus, atorvastatin, as with the other tested HMG-CoA reductase inhibitors, is not genotoxic.

Hyperbaric oxygen as prophylaxis or treatment for radiation myelitis

This animal study was designed to investigate HBO as a treatment or prophylaxis for radiation myelitis. All animals received identical spinal cord radiation doses of 69 Gy in 10 daily fractions. Group I received no HBO; group II began HBO at the onset of signs of myelitis; group III received HBO with prophylactic intent beginning 6 wk after irradiation; and group IV received both modalities on the same day, but radiation always preceded HBO by at least 4 h. HBO consisted of 90 min oxygen at 2.4 atm abs for 20 daily treatments. Animals were objectively assessed for the loss of certain neurologic reflexes indicative of four levels of myelitis. Although all animals progressed to severe myelitis, group III animals had group-averaged levels of myelitis consistently less than control. The differences were statistically significant for several weeks. Group IV animals progressed to severe myelitis much more rapidly than any other group. Additional study is justified by this trial. Key questions to be answered include the optimal timing of HBO to produce a beneficial rather than detrimental effect.

High capacity in vitro micronucleus assay for assessment of chromosome damage: results with quinolone/naphthyridone antibacterials

A high capacity in vitro micronucleus assay was developed to evaluate the ability of selected 6-fluorinated quinolone and naphthyridone antibacterial compounds to induce micronuclei (MN) in vitro in V79 Chinese hamster lung cells. Log-phase cells in six-well cluster dishes were exposed for 3 h in the absence of S9 to 34 compounds. After treatment, cells were refed with media containing cytochalasin B, incubated for 16 h, and harvested for cell-cycle kinetics (CCK) and MN analyses. The quinolones tested were grouped according to the substituent at the 8-position. All 4 compounds having a halogen substitution at position 8, five of the six 8-trifluoromethyl quinolones, and all eight 8-methoxy-substituted compounds induced a significant increase in MN. Only 5 of the 10 naphthyridone compounds tested, having a variety of substituents at the 7-position, were inducers of MN and the overall magnitude of the response was less than with the quinolones. The minimum clastogenic concentration for the quinolones ranged from 4 to 400 micrograms/ml and for the naphthyridones this range was from 22.5 to 100 micrograms/ml. In the groups examined, napthyridone compounds were less likely than quinolones to induce in vitro MN, particularly when the substituent at the 7-position in the naphthyridone contains some bulk (methyl groups) around the amine side-chain. Most of the quinolones tested induced MN, irrespective of the substituents at positions 7 or 8.

Genotoxicity assessment of pirmenol, a new antiarrhythmic drug

The genotoxicity of pirmenol was tested in the E. coli and S. typhimurium mutagenesis assay, an in vitro mammalian cell chromosome-aberration assay and an in vivo mouse micronucleus assay. The E. coli tester strain WP2s was exposed to concentrations of pirmenol as high as 10,000 micrograms/plate both in the absence (S9-) and presence (S9+) of metabolic activation. Five strains of S. typhimurium (TA98, TA100, TA1535, TA1537, TA1538) were exposed to concentrations of pirmenol as high as 5000 micrograms/plate in the absence and presence of S9. Pirmenol was not mutagenic toward either E. coli or S. typhimurium. Chinese hamster lung V79 cell cultures were exposed to pirmenol at concentrations of 500-2500 micrograms/ml (S9-) and 500-3000 micrograms/ml (S9+). Pirmenol increased the frequency of structural chromosome aberrations (SCAs). The minimum clastogenic concentration was 1500 micrograms/ml (both S9- and S9+) with a peak clastogenic response of 6% (S9-) and 34% (S9+) cells with aberrations. Although there were statistically significant results in the S9- experiment, the percent cells with aberration values for treated groups were within the historical control range (0-6%) of this laboratory. The observed effects in both the absence and presence of S9 appear at high concentrations compared to human circulating plasma levels of 1-3 micrograms/ml and the clastogenicity was confined to chromosome gaps and breaks. Consequently, this in vitro effect would not be expected to be reflected by either in vivo clastogenic or carcinogenic activity. This was supported by findings in the mouse micronucleus study of pirmenol in which single oral doses administered to male CD-1 mice at 5, 55, or 115 mg/kg (80% LD50) produced no statistically significant increases in the frequency of micronucleated polychromatic erythrocytes in bone marrow at 24, 48 or 72 h postdosing. Additionally, no evidence of carcinogenicity was seen in a mouse or rat bioassay.

Simultaneous micronucleus and chromosome aberration assessment in the rat

Using a cellulose column fractionation procedure to eliminate nucleated cells for micronucleus assessment, micronucleus and chromosome aberration endpoints in the same animal were compared in male and female rats following i.p. injection with cyclophosphamide (CP). Groups of 5 Wistar rats per sex were given single doses of CP at 0, 20, or 40 mg/kg. Two hours prior to sacrifice, animals were given colchicine (4 mg/kg) to arrest cells in metaphase. One femur from each animal was used for micronucleus assessment and the other for chromosome aberration assessment. In the micronucleus assessment, 2000 polychromatic erythrocytes (PCEs) per animal and in the chromosome aberration assessment, 50 metaphase cells per animal were scored. This experiment was repeated once. In both experiments, significant increases in micronucleated PCEs and chromosome aberrations were noted at both doses of CP in both sexes. In general, the clastogenic effects of CP were more pronounced in males than females. Both doses of CP caused a decrease in the proportion of PCEs and in mitotic index in both experiments, indicating toxicity of CP to the bone marrow. These results show the usefulness of this rat model for simultaneous evaluation of two cytogenetic endpoints in the same animal and indicate that assessment of MNPCE frequency in the bone marrow of male rats may be an appropriate model for screening test substances for in vivo clastogenic activity in this species.

Absence of a synergistic effect between moderate-power radio-frequency electromagnetic radiation and adriamycin on cell-cycle progression and sister-chromatid exchange

In our laboratories we are conducting investigations of potential interactions between radio-frequency electromagnetic radiation (RFR) and chemicals that are toxic by different mechanisms to mammalian cells. The RFR is being tested at frequencies in the microwave range and at different power levels. We report here on the 1) ability of simultaneous RFR exposures to alter the distribution of cells in first and second mitoses from that after treatment by adriamycin alone, and 2) on the ability of simultaneous RFR exposure to alter the extent of sister chromatid exchanges (SCEs) induced by adriamycin alone. This chemical was selected because of its reported mechanism of action and because it is of interest in the treatment of cancer. In our studies, Chinese hamster ovary (CHO) cells were exposed for 2 h simultaneously to adriamycin and pulsed RFR at a frequency of 2,450 MHz and a specific absorption rate of 33.8 W/Kg. The maximal temperature (in the tissue-culture medium) was 39.7 +/- 0.2 degrees C. The experiments were controlled for chemical and RFR exposures, as well as for temperature. Verified statistically, the data indicate that the RFR did not affect changes in cell progression caused by adriamycin, and the RFR did not change the number of SCEs that were induced by the adriamycin, which adriamycin is known to affect cells by damaging their membranes and DNA.

DSA in acute gastrointestinal hemorrhage: clinical and in vitro studies

Selective intraarterial digital subtraction angiography (DSA) was used to examine 37 patients with acute gastrointestinal (GI) tract bleeding. Conventional screen-film angiography was used as an adjunct to DSA when a larger field of view was needed (five patients) and when bowel motion prevented the acquisition of adequate image quality with DSA (two patients). Conventional angiography was also performed in all cases in which there were negative DSA examinations. DSA reduced the mean examination time considerably (20% reduction overall), especially for cases involving embolization therapy (35% reduction). DSA was especially valuable in the upper GI tract, where it was used to rapidly locate and/or assist in the embolization of bleeding sites in 19 of 20 patients with positive angiograms. There were 12 true-negative DSA examinations and one false-negative examination due to the limited field of view (9 inches [22.9 cm]). Bowel and respiratory motion were not important problems in the upper GI tract. In the lower GI tract, the usefulness of DSA was severely limited by the small field of view and the misregistration artifact caused by bowel motion. In an in vitro study, DSA and conventional angiography were compared as to their ability to depict several rates of extravasation of contrast material in a model of GI bleeding. DSA tended to be more sensitive for the detection of simulated extravasation (P less than .07).

Weak low frequency electromagnetic fields and chick embryogenesis: failure to reproduce positive findings

Fertilised chicken eggs were incubated for 48 hours while exposed to pulsed trains of magnetic fields having a duration of 0-5 ms, a rise time of 42 microsecond, and a pulse repetition rate of 100 at a magnetic field flux density of 1 microT. Some eggs were exposed to 1,552 rad X-rays as a positive control. After exposure the embryos were scored blind for a variety of morphological features. X-irradiated eggs displayed highly significant and repeatable anatomical alterations. There were no differences between magnetic field-exposed, sham-exposed and control eggs.

Effects of radiofrequency radiation and simultaneous exposure with mitomycin C on the frequency of sister chromatid exchanges in Chinese hamster ovary cells

Chinese hamster ovary (CHO) cells were exposed for 2 hr with and without mitomycin C (MMC) (1 X 10(-8)M) to pulsed wave radiofrequency radiation (RFR) at 2450 MHz. The repetition rate of 25,000 pulses per sec (pps), pulse width of 10 microseconds, and exposure geometry used, resulted in a specific absorption rate (SAR) of 33.8 W/kg. The following exposure regimens were used: a 37 degrees C water bath control; a water bath temperature control (TC) in which the continuously monitored medium temperature closely followed the temperature rise in the RFR-exposed flasks; and the RFR-exposed cells in a water bath set at 37 degrees C prior to exposure. RFR exposure resulted in a maximum cell culture medium temperature of 39.2 degrees C. In the absence of MMC, there was no significant increase in sister chromatid exchange (SCE) in the RFR-exposed or TC groups over that of the 37 degrees C control. When a simultaneous treatment of RFR and MMC occurred there was no statistical difference in SCE frequency from that caused by chemical treatment alone.

Sister-chromatid exchanges in human lymphocytes exposed in vitro to therapeutic ultrasound

Human lymphocytes were exposed in vitro to therapeutic levels of ultrasound (1 W/cm2, CW, 0.87 MHz, durations of 80 and 160 sec). There were no significant differences in sister-chromatid exchange frequencies between controls and ultrasound-exposed cells. Exposure of lymphocytes to the positive control (mitomycin C) resulted in a significant increase in sister-chromatid exchanges. The data do not verify a report by Stella et al. (Mutation Res., 138 (1984) 75-85) that such exposures result in increased frequencies of SCEs.

Factors modifying contrast media induced fibrillation

Factors effecting contrast media induced ventricular fibrillation were studied in anesthetized dogs using contact time as the measured parameter. Injections of meglumine/sodium diatrizoate (370 mg I/ml) were made into the right coronary artery at 0.4 ml/s until fibrillation occurred. A contrast medium containing calcium chelators was found to produce fibrillation in a significantly shorter contact time than a similar medium without calcium chelators. Pre-treatment by the cardiac glycoside, ouabain, increased the contact time for fibrillation as did the production of a sub-acute infarction in the left coronary artery and a previous fibrillation and resuscitation. The data suggest that calcium binding additives increase the risk of fibrillation while pre-treatment with cardiac glycosides, the presence of stable infarcts in the non-injected areas, or a previous fibrillation and resuscitation do not increase risk.

Diagnostic ultrasound and sister chromatid exchanges: failure to reproduce positive findings

Human lymphocytes were exposed in vitro to ultrasound from two clinical devices, one of which was previously reported to have increased the frequency of sister chromatid exchanges. The ultrasonic exposures had no significant effect on the frequency of sister chromatid exchanges from three blood donors. Exposure to ultrasound also had no effect on cell cycle progression. A concomitant positive control (mitomycin C) resulted in a significant increase in sister chromatid exchanges.

Diagnostic insonation of extra utero human placentas: no effect of lymphocytic sister chromatid exchange

Freshly delivered human placentas were exposed to ultrasound for 30 min using a diagnostic linear array unit. Blood was then drawn and cultured in the presence of bromodeoxyuridine, and the frequencies of sister chromatid exchanges (SCE) in the lymphocytes determined. There was no statistically significant difference in SCE frequencies between control and exposed cells; the frequencies of SCEs per cell ranged from 4.50 to 6.02 for control and from 4.66 to 6.10 for exposed cells in five separate experiments. Positive control mitomycin C treated cells were significantly affected, with more than 50 SCEs per cell.

Lack of ultrasound effect on in vitro human lymphocyte sister chromatid exchange

The frequency of sister chromatid exchanges (SCEs) in human lymphocytes cultured in vitro was not affected by a 30 min exposure to a 2.25 MHz focused ultrasound beam (from a clinical diagnostic unit with a pulse repetition rate of 1000 Hz, a 1 mu sec burst duration, and a 2-200 W/cm2 maximum intensity). A 30 sec exposure to continuous wave 1 MHz 2 W/cm2 (SP) ultrasound from an experimental device lysed 10-15% of the lymphocytes; there was no increase in SCEs in the survivors relative to unexposed controls. Treatment of lymphocytes with 0.033 micrograms/ml mitomycin-C, a known SCE inducer, increased the frequency of SCEs about 4 times above control levels.

Failure of iosulamide to enhance hepatic tumors in rats

Iosulamide, an experimental cholangiographic agent recently being evaluated for hepatic contrast enhancement in computed tomography, has been investigated in the rat for the differential enhancement between the liver and three histologically different experimental tumors (a well differentiated mammary adenocarcinoma, a poorly differentiated colon carcinoma, and a hepatoma). After intravenous injection of iosulamide in dosages of 140 and 280 mg iodine per kg, iodine concentrations were determined in blood, liver and tumors at 1, 5, 10, and 30 minutes, using x-ray energy spectrometry. Compared with the surrounding liver parenchyma, the iodine concentrations were generally higher in the breast carcinoma. With respect to the liver, iodine concentrations varied greatly in the colon carcinoma and hepatoma. The iodine washout from all three tumors was relatively slow. Since the distribution volume of cholangiographic contrast agents includes both vascular and interstitial space, the relatively high and prolonged iosulamide accumulation in tumors can be explained by a relatively large interstitial compartment, which is apparently characteristic of neoplastic lesions. This, together with the modest iodine concentrations found in the liver, suggests that iosulamide is of little use in computed tomography for the differential enhancement of liver and hepatic tumors.

Effect of 2 MHz ultrasound on DNA, RNA and protein synthesis in Pisum sativum root meristem cells

The amounts of DNA, RNA and protein synthesis were determined in Pisum sativum root meristem cells at various times after a 1 min exposure to 1 MHz ultrasound at a power density of 30 W/cm2. Immediate depressions in all three macromolecular syntheses occurred after sonication, followed by an apparent recovery several hours later. These events appear to correlate in time with the subsequent reduction and recovery in mitotic index in Pisum sativum root meristem cells exposed to 2 MHz ultrasound.