Patient satisfaction with oncological care during the virus pandemic - SARS-CoV-2 taking into account social and demographic factors

INTRODUCTION AND OBJECTIVE

The aim of the study was to examine the perception of medical services by oncological patients during the pandemic, identifying the key factors influencing it. The assessment of patient satisfaction with the treatment and care provided by doctors and other hospital staff provides important information on the quality of health services.

MATERIAL AND METHODS

The study involved 394 patients diagnosed with cancer treated as inpatients in five oncology departments. The diagnostic survey method was used with a proprietary questionnaire and the standardized EORTC IN-PATSAT32 questionnaire. Calculations were carried out using Statistica 10.0 with p≤0.05 s considered statistically significant.

RESULTS

Overall patient satisfaction with cancer care was 80.77/100. Higher values were shown for the competences of nurses than for doctors, especially for their interpersonal skills (79.34 - nurses vs. 74.13 - doctors) and availability (80.11 - nurses vs. 75.6 - doctors). It was also shown that the level of satisfaction with cancer care increased with age; women rated cancer care lower than men (p = 0.031), particularly its aspect related to the competences of doctors. A lower degree of satisfaction was observed among rural residents (p=0.042). Other demographic data, such as marital status and education, determined satisfaction with cancer care on the selected scale although it did not affect the overall level of satisfaction.

CONCLUSIONS

The analysed socio-demographic factors, primarily age, gender and place of residence, determined some of the scales concerning patient satisfaction with cancer care during the COVID-19 pandemic. The results of this and other studies of a similar profile should be used in the formation of health policy, particularly in implementing programmes to improve the quality of cancer care in Poland.

Abstract P6-08-13: Home-based treatment with subcutaneous (SC) trastuzumab - only a pandemic solution? Real world evidence (RWE) analysis

Background The pandemic has accelerated the introduction of more flexible and cost-effective treatment forms. The efficacy of trastuzumab in the intravenous (IV) and SC forms is similar both in early and advanced HER2-positive breast cancer (BC) patients. Compared to IV administration, SC enables reduction of treatment costs and time, and saves equipment and human resources. SC formulation is more convenient for both patients and healthcare providers and may be implemented as a home-based therapy. Recently, systemic anticancer treatment (including chemotherapy) has been increasingly performed at home, improving patient comfort and reducing the burden on the healthcare system. Poland has already implemented home-based treatment with some biologic compounds; however, they have not included trastuzumab in BC patients. Objectives This RWE analysis aims to evaluate the organizational and therapeutic procedures related to the home-based treatment with SC trastuzumab and the attitudes of patients and healthcare providers to this approach. Material and methods The study enrolled early HER2(+) BC patients treated with trastuzumab during the COVID-19 pandemic. Monitoring and treatment duration were consistent with SmPC and reimbursement regulations in Poland. The first 3-6 doses of SC trastuzumab (alone or in combination with CHT) were administered at a cancer center in outpatient and inpatient settings. Subsequent doses were administered at home by 3 qualified breast nurses. Post-injection follow-up was used for educational purposes. Data were analyzed with descriptive statistics. The study was reviewed and approved by the local Bioethics Committee. Results The analysis included 20 patients treated in two comprehensive cancer centers in Poland with a median age of 59 years (range, 36-72 years). Seven patients (35%) were professionally active. The average distance from the place of residence to the cancer center was 24 km (range, 2-65 km). A total of 232 doses were administered (mean 11.6 doses per patient; range 6-14), 133 doses at home and 99 at the cancer center. The overall tolerance of trastuzumab was good and consistent with the known safety profile described in Summary of Product Characteristics. Only 1 patient (5%) discontinued treatment prematurely due to decreased LVEF; another 19 patients completed treatment as planned. For 19 patients (95%), the benefits of SC treatment included time savings, the ability to continue working, and avoiding crowded places and infection risk. 2 patients (10%) considered the nurse’s visit privacy disturbing, while 18 (90%) would recommend home-based drug administration. The average duration of a nurse’s stay at home was 60 minutes (range 30 to 130 minutes). No logistical or technical problems were reported, except for occasional patient lateness. Nurses positively assessed the treatment provided in the nursing office, which was a source of additional knowledge, and experience. The overall impression of home-based therapy was positive for both patients and nurses. The limitation of the study is the declarative nature of the data. Conclusions Home-based treatment with SC trastuzumab should be pursued due to its safety, ease of organization, positive perception by patients and nurses, and reducing healthcare system resources. It can be particularly valuable for disabled patients who have difficulty reaching the hospital and professionally active patients. Specialized, trained nurses can self-sufficiently carry out part of the prolonged trastuzumab treatment, reducing physician involvement.

Citation Format: Barbara Radecka, Hudała-Klecha Joanna, Dariusz Sawka, Jolanta Sarga, Bożena Noworolska, Jolanta Sawicka, Elżbieta Duda, Natalia Obruśnik, Patryk Zając. Home-based treatment with subcutaneous (SC) trastuzumab - only a pandemic solution? Real world evidence (RWE) analysis [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-08-13.

Pre-arrest doxycycline protects donation after circulatory death kidneys

Kidney injury during donation after circulatory determination of death (DCDD) includes warm ischemic (WI) injury from around the time of asystole, and cold ischemic (CI) injury during cold preservation. We have previously shown that Matrix Metalloproteinases (MMPs) are involved in CI injury and that Doxycycline (Doxy), an antibiotic and known MMP inhibitor, protects the transplant kidney during CI. The purpose of our study was to determine if Doxy given before asystole can also prevent injury during WI. A rat model of DCDD was used, including Control, Preemptive Doxy (45 mg/kg iv), and Preemptive and Perfusion (100 microM) Doxy groups. Thirty minutes after asystole, both kidneys were removed. The left kidney was perfused at 4 °C for 22 h, whereas the right was used to establish the degree of warm ischemic injury prior to cold preservation. MMP-2 in the perfusate was significantly reduced in both treatment groups [Control 43.7 ± 7.2 arbitrary units, versus Preemptive Doxy group 23.2 ± 5.5 (p = 0.03), and 'Preemptive and Perfusion' group 18.0 ± 5.6 (p = 0.02)]. Reductions in NGAL, LDH, and MMP-9 were also seen. Electron microscopy showed a marked reduction in mitochondrial injury scores in the treatment groups. Pre-arrest Doxy was associated with a reduction in injury markers and morphologic changes. Doxy may be a simple and safe means of protecting transplant kidneys from both WI and CI.

Protection of the transplant kidney during cold perfusion with doxycycline: proteomic analysis in a rat model

BACKGROUND

It has been previously shown that doxycycline (Doxy) protects the kidney from preservation injury by inhibition of matrix metalloproteinase. However, the precise molecular mechanism involved in this protection from injury is not known. We used a pharmaco-proteomics approach to identify potential molecular targets associated with kidney preservation injury.

METHODS

Rat kidneys were cold perfused with or without doxycycline (Doxy) for 22 h. Kidneys perfusates were analyzed for the presence of injury markers such as lactate dehydrogenase (LDH), and neutrophil-gelatinase associated lipocalin (NGAL). Proteins extracted from kidney tissue were analyzed by 2-dimensional gel electrophoresis. Proteins of interest were identified by mass spectrometry.

RESULTS

Triosephosphate isomerase, PGM, dihydropteridine reductase-2, pyridine nucleotide-disulfide oxidoreductase, phosphotriesterase-related protein, and aminoacylase-1A were not affected by cold perfusion. Perfusion with Doxy increased their levels. N(G),N(G)-dimethylarginine dimethylaminohydrolase and phosphoglycerate kinase 1 were decreased after cold perfusion. Perfusion with Doxy led to an increase in their levels.

CONCLUSIONS

This study revealed specific metabolic enzymes involved in preservation injury and in the mechanism whereby Doxy protects the kidney against injury during cold perfusion.

Novel and recurrent variants of ATP2C1 identified in patients with Hailey-Hailey disease

Hailey-Hailey disease (HHD) is a rare, late-onset autosomal dominant genodermatosis characterized by blisters, vesicular lesions, crusted erosions, and erythematous scaly plaques predominantly in intertriginous regions. HHD is caused by ATP2C1 mutations. About 180 distinct mutations have been identified so far; however, data of only few cases from Central Europe are available. The aim was to analyze the ATP2C1 gene in a cohort of Polish HHD patients. A group of 18 patients was enrolled in the study based on specific clinical symptoms. Mutations were detected using Sanger or next generation sequencing. In silico analysis was performed by prediction algorisms and dynamic structural modeling. In two cases, mRNA analysis was performed to confirm aberrant splicing. We detected 13 different mutations, including 8 novel, 2 recurrent (p.Gly850Ter and c.325-3 T > G), and 6 sporadic (c.423-1G > T, c.899 + 1G > A, p.Leu539Pro, p.Thr808TyrfsTer16, p.Gln855Arg and a complex allele: c.[1610C > G;1741 + 3A > G]). In silico analysis shows that all novel missense variants are pathogenic or likely pathogenic. We confirmed pathogenic status for two novel variants c.325-3 T > G and c.[1610C > G;1741 + 3A > G] by mRNA analysis. Our results broaden the knowledge about genetic heterogeneity in Central European patients with ATP2C1 mutations and also give further evidence that careful and multifactorial evaluation of variant pathogenicity status is essential.

L-NAME improves doxycycline and ML-7 cardioprotection from oxidative stress

Matrix metalloproteinase-2 (MMP-2) mediated degradation of myosin light chain 1 (MLC1) and troponin I (TnI) contributes to myocardial ischemia/reperfusion (I/R) injury. Modifications of MLC1 triggered by oxidative stress are mediated by myosin light chain kinase (MLCK), nitric oxide synthase (NOS), and MMP-2. Previous studies have shown that inhibiting both MLCK and MMP-2 protects against I/R injury. Here, we hypothesized that the addition of NOS inhibitor (L-NAME) at subprotective concentration to the mixture of subprotective concentrations of ML-7 and doxycycline (Doxy), will increase a synergistic cardioprotection of Doxy and ML-7 during I/R. Isolated rat hearts were subjected to global ischemia without or with administration of the mixture of inhibitors. Markers of I/R injury were measured in hearts and coronary effluents. Addition of L-NAME to the mixture of Doxy and ML-7 led to full recovery of heart contractility in comparison to combination of Doxy and ML-7. Improved heart contractility was associated with reduced degradation of TnI and MLC1. The combined administration of NOS, MMP-2 and MLCK inhibitors provides a novel strategy to protect heart from I/R injury.

Proteomic Analysis of Perfusate from Machine Cold Perfusion of Transplant Kidneys: Insights Into Protection from Injury

Background

Machine cold perfusion is beneficial to the preservation of kidneys for transplantation. At the end of preservation, the perfusion solution contains many proteins. Using a proteomics approach, we searched for useful biomarkers and potential therapeutic targets in the perfusate. Our program is unique in that all transplant kidneys (even living donor kidneys, LKD) are placed on machine cold perfusion prior to transplantation.

Material/Methods

Perfusates from donation after neurological and circulatory determination of death (DNDD and DCDD respectively) and LKD were collected (n=41) and analyzed for LDH, neutrophil gelatinase-associated lipocalin (NGAL), and matrix metalloproteinase-2 (MMP-2) as markers of injury. Perfusate from each kidney was subjected to 2-dimensional gel electrophoresis, then analyzed using software to identify those spots which are significantly different between the 3 groups. Mass spectrometry was used to identify the proteins and their identity was confirmed with Western blot.

Results

The highest levels of MMP-2, LDH, and NGAL were seen for the DCDD kidneys, followed by the DNDD kidneys and then LDK. Peroxiredoxin-2, NGAL, and alpha-1-antitrypsin were identified as significantly different between the different types of donor kidneys, and their role and possible therapeutic strategies are discussed. Collagen fragments, albumin, and immunoglobulin were also identified as possible byproducts of the injury and may be useful is assessing the degree of injury.

Conclusions

Comparison of the perfusates from the different types of kidneys has allowed us to identify proteins that will be useful in future research into reducing injury in transplant kidneys.

The need for support among cancer patients - a preliminary study

PURPOSE

To analyze the demand for support among cancer patients subjected to systemic treatment or radiotherapy.

METHODS

The study included 321 cancer patients treated in three Polish oncology centers. More than 73% of the responders were diagnosed with cancer not earlier than a year prior to the study. Most of the patients received chemotherapy (74.8%); nearly a half of the subjects (46.7%) were subjected to radiotherapy and every tenth person received hormonal therapy. The subjects were examined with the Berlin Social Support Scales (BSSS).

RESULTS

Emotional and informative support were the most frequently needed forms of support. Age and sex did not exert significant effect on the need for support and the level of received support. Individuals with higher education showed the lowest scores of support seeking. The availability of instrumental support displayed the lowest score, especially among the individuals treated at daily chemotherapy units. The type of oncological treatment did not change the patients' perception of support.

CONCLUSIONS

Irrespective of their demographic and clinical characteristics, cancer patients should be provided with emotional, informative and instrumental support.

Protection of the Transplant Kidney from Preservation Injury by Inhibition of Matrix Metalloproteinases

Background

Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, play an important role in ischemic injury to the heart, yet it is not known if these MMPs are involved in the injury that occurs to the transplant kidney. We therefore studied the pharmacologic protection of transplant kidneys during machine cold perfusion.

Methods

Human kidney perfusates were analyzed for the presence of injury markers such as cytochrome c oxidase, lactate dehydrogenase, and neutrophil-gelatinase associated lipocalin (NGAL), and MMP-2 and MMP-9 were measured. The effects of MMP inhibitors MMP-2 siRNA and doxycycline were studied in an animal model of donation after circulatory determination of death (DCDD).

Results

Markers of injury were present in all analyzed perfusates, with higher levels seen in perfusates from human kidneys donated after controlled DCDD compared to brain death and in perfusate from kidneys with delayed graft function. When rat kidneys were perfused at 4°C for 22 hours with the addition of MMP inhibitors, this resulted in markedly reduced levels of MMP-2, MMP-9 and analyzed injury markers.

Conclusions

Based on our study, MMPs are involved in preservation injury and the supplementation of preservation solution with MMP inhibitors is a potential novel strategy in protecting the transplant kidney from preservation injury.

Subthreshold nitric oxide synthase inhibition improves synergistic effects of subthreshold MMP-2/MLCK-mediated cardiomyocyte protection from hypoxic injury

Injury of myocardium during ischaemia/reperfusion (I/R) is a complex and multifactorial process involving uncontrolled protein phosphorylation, nitration/nitrosylation by increased production of nitric oxide and accelerated contractile protein degradation by matrix metalloproteinase‐2 (MMP‐2). It has been shown that simultaneous inhibition of MMP‐2 with doxycycline (Doxy) and myosin light chain kinase (MLCK) with ML‐7 at subthreshold concentrations protects the heart from contractile dysfunction triggered by I/R in a synergistic manner. In this study, we showed that additional co‐administration of nitric oxide synthase (NOS) inhibitor (1400W or L‐NAME) in subthreshold concentrations improves this synergistic protection in the model of hypoxia–reoxygenation (H‐R)‐induced contractile dysfunction of cardiomyocytes. Isolated cardiomyocytes were subjected to 3 min. of hypoxia and 20 min. of reoxygenation in the presence or absence of the inhibitor cocktails. Contractility of cardiomyocytes was expressed as myocyte peak shortening. Inhibition of MMP‐2 by Doxy (25–100 μM), MLCK by ML‐7 (0.5–5 μM) and NOS by L‐NAME (25–100 μM) or 1400W (25–100 μM) protected myocyte contractility after H‐R in a concentration‐dependent manner. Inhibition of these activities resulted in full recovery of cardiomyocyte contractility after H‐R at the level of highest single‐drug concentration. The combination of subthreshold concentrations of NOS, MMP‐2 and MLCK inhibitors fully protected cardiomyocyte contractility and MLC1 from degradation by MMP‐2. The observed protection with addition of L‐NAME or 1400W was better than previously reported combination of ML‐7 and Doxy. The results of this study suggest that addition of NOS inhibitor to the mixture of inhibitors is better strategy for protecting cardiomyocyte contractility.

Combined subthreshold dose inhibition of myosin light chain phosphorylation and MMP-2 activity provides cardioprotection from ischaemic/reperfusion injury in isolated rat heart

BACKGROUND AND PURPOSE

Phosphorylation and degradation of myosin light chain 1 (MLC1) during myocardial ischaemia/reperfusion (I/R) injury is a well-established phenomenon. It has been established that MMP-2 is involved in MLC1 degradation and that this degradation is increased when MLC1 is phosphorylated. We hypothesized that simultaneous inhibition of MLC1 phosphorylation and MMP-2 activity will protect hearts from I/R injury. As phosphorylation of MLC1 and MMP-2 activity is important for normal heart function, we used a cocktail consisting combination of low (subthreshold for any protective effect alone) doses of MLC kinase, MMP-2 inhibitors and subthreshold dose of an MLC phosphatase activator.

EXPERIMENTAL APPROACH

Isolated rat hearts were subjected to 20 min of global, no-flow ischaemia and 30 min reperfusion in the absence and presence of inhibitors of MLC1 phosphorylation and degradation.

KEY RESULTS

The recovery of cardiac function was improved in a concentration-dependent manner by the MLC kinase inhibitor, ML-7 (1-5 μM), the MLC phosphatase activator, Y-27632 (0.05-1 μM) or the MMP inhibitor, doxycycline (Doxy, 1-30 μM). Co-administration of subthreshold doses of ML-7 (1 μM) and Y-27632 (0.05 μM) showed a potential synergistic effect in protecting cardiac contractility and MLC1 levels in I/R hearts. Further combination with a subthreshold concentration of Doxy (1 μM) showed additional protection that resulted in full recovery to control levels.

CONCLUSIONS AND IMPLICATIONS

The results of this study exemplify a novel low-dose multidrug approach to pharmacological prevention of reperfusion injury that will enable a reduction of unwanted side effects and/or cytotoxicity associated with currently available MMP-2 and kinase inhibiting drugs.

Matrix metalloproteinase-2 is activated during ischemia/reperfusion in a model of myocardial infarction

BACKGROUND

The degradation of myosin light chain 1 (MLC1) by matrix metalloproteinase-2 (MMP-2) during ischemia/reperfusion has been implicated in the development of cardiac dysfunction. Our objective was to elucidate the role of MMP-2 and MLC1 in the development of cardiac injury and dysfunction in a model of left anterior descending (LAD) coronary artery occlusion.

METHODS

Adult rats (300-350 g) were anaesthetized, and the isolated hearts were retrogradely perfused in a Langendorff apparatus. The LAD was stabilized for 25 minutes and occluded for either 45 or 90 minutes and then reperfused. Cardiac function (evaluated as rate-pressure product) was significantly decreased in the reperfused hearts subjected to 90 minutes of LAD occlusion in comparison with hearts subjected to either sham or 45 minutes of occlusion. Ninety minutes of occlusion resulted in 60% of infarct.

RESULTS

MMP-2 activity, measured by gelatin zymography, was significantly increased following occlusion as well as reperfusion. An increased degradation of MLC1 was observed at the end of reperfusion, but not at the end of occlusion, which most likely was because of the compensatory increase in tissue inhibitor of matrix metalloproteinases-4 (TIMP-4) during occlusion, but not reperfusion.

CONCLUSION

We demonstrate that MMP-2 activation is an ischemic event that extends into the reperfusion phase, while MLC1 degradation in response to ischemia/reperfusion is strictly a reperfusion event. MLC1 degradation during occlusion is prevented by a compensatory increase in the levels of TIMP-4.

Proteomic analysis of right and left cardiac ventricles under aerobic conditions and after ischemia/reperfusion

Ischemia/reperfusion (I/R) injury is a major consequence of a cardiovascular intervention. The study of changes of the left and right ventricle proteomes from hearts subjected to I/R may be a key to revealing the pathological mechanisms underlying I/R-induced heart contractile dysfunction. Isolated rat hearts were perfused under aerobic conditions or subjected to 25 min global ischemia and 30 min reperfusion. At the end of perfusion, right and left ventricular homogenates were analyzed by 2DE. Contractile function and coronary flow were significantly reduced by I/R. 2DE followed by mass spectrometry identified ten protein spots whose levels were significantly different between aerobic left and right ventricles, eight protein spots whose levels were different between aerobic and I/R left ventricle, ten protein spots whose levels were different between aerobic and I/R right ventricle ten protein spots whose levels were different between the I/R groups. Among these protein spots were ATP synthase beta subunit, myosin light chain 2, myosin heavy chain fragments, peroxiredoxin-2, and heat shock proteins, previously associated with cardiovascular disease. These results reveal differences between proteomes of left and right ventricle both under aerobic conditions and in response to I/R that contribute to a better understanding of I/R injury.

Effect of the myosin light chain kinase inhibitor ML-7 on the proteome of hearts subjected to ischemia-reperfusion injury

In the development of ischemia/reperfusion (I/R) injury, the role of the myosin light chain (MLC) phosphorylation has been given increased consideration. ML-7, a MLC kinase inhibitor, has been shown to protect cardiac function from I/R, however the exact mechanism remains unclear. Isolated rat hearts were perfused under aerobic conditions (controls) or subjected to I/R in the presence or absence of ML-7. Continuous administration of ML-7 (5 μM) from 10 min before onset of ischemia to the first 10 min of reperfusion resulted in significant recovery of heart contractility. Analysis of gels from two-dimensional electrophoresis revealed eight proteins with decreased levels in I/R hearts. Six proteins are involved in energy metabolism:ATP synthase beta subunit, cytochrome b-c1 complex subunit 1, 24-kDa mitochondrial NADH dehydrogenase, NADH dehydrogenase [ubiquinone] iron-sulfur protein 8, cytochrome c oxidase subunit, and succinyl-CoA ligase subunit. The other two proteins with decreased levels in I/R hearts are: peroxiredoxin-2 and tubulin. Administration of ML-7 increased level of succinyl-CoA ligase, key enzyme involved in the citric acid cycle. The increased level of succinyl-CoA ligase in I/R hearts perfused with ML-7 suggests that the cardioprotective effect of ML-7, at least partially, also may involve increase of energy production.

Ischemia/reperfusion-induced myosin light chain 1 phosphorylation increases its degradation by matrix metalloproteinase 2

Degradation of myosin light chain 1 (MLC1) by matrix metalloproteinase 2 (MMP-2) during myocardial ischemia/reperfusion (I/R) has been demonstrated. However, the exact mechanisms controlling this process remain unknown. I/R increases the phosphorylation of MLC1, but the consequences of this modification are not known. We hypothesized that phosphorylation of MLC1 plays an important role in its degradation by MMP-2. To examine this, isolated perfused rat hearts were subjected to 20 min global ischemia followed by 30 min of aerobic reperfusion. I/R increased phosphorylation of MLC1 (as measured by mass spectrometry). When hearts were subjected to I/R in the presence of ML-7 (a myosin light-chain kinase inhibitor) or doxycycline (an MMP inhibitor), improved recovery of contractile function was observed compared to aerobic controls, and MLC1 was protected from degradation. Enzyme kinetic studies revealed an increased affinity of MMP-2 for the phosphorylated form of MLC1 compared to non-phosphorylated MLC1. We conclude that MLC1 phosphorylation is an important mechanism controlling the intracellular action of MMP-2 and promoting degradation of MLC1. These results further support previous findings implicating post-translational modifications of contractile proteins as a key factor in the pathology of cardiac dysfunction during and following ischemia.

Effect of the Rho kinase inhibitor Y-27632 on the proteome of hearts with ischemia-reperfusion injury

Growing attention has been given to the role of the Rho kinase pathway in the development of heart disease and ischemia/reperfusion (I/R) injury. Y-27632 is a Rho kinase inhibitor demonstrated to protect against I/R injury, but the exact mechanism by which it does so remains to be elucidated. The goal of this project was to determine new targets by which Y-27632 can protect the heart against I/R injury. Isolated rat hearts were perfused under aerobic conditions or subjected to I/R in the presence or absence of Y-27632. Administration of Y-27632 (1 μM) before ischemia and during the first 10 min of reperfusion resulted in complete recovery of cardiac function. 2-D electrophoresis followed by MS identified four proteins whose levels were affected by Y-27632 treatment. Lactate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase were significantly increased in the Y-27632 treated group, while creatine kinase was normalized to control levels. In addition, we found increased level of two different molecular fragments of ATP synthase, which were normalized by Y-27632. This increase suggests that during ischemia ATP synthase is subjected to degradation. The changes in metabolic enzymes' levels and their regulation by Y-27632 suggest that the cardioprotective effect of Y-27632 involves increased energy production.

Ischemia induced peroxynitrite dependent modifications of cardiomyocyte MLC1 increases its degradation by MMP-2 leading to contractile dysfunction

Damage to cardiac contractile proteins during ischemia followed by reperfusion is mediated by reactive oxygen species such as peroxynitrite (ONOO⁻), resulting in impairment of cardiac systolic function. However, the pathophysiology of systolic dysfunction during ischemia only, before reperfusion, remains unclear. We suggest that increased ONOO⁻ generation during ischemia leads to nitration/nitrosylation of myosin light chain 1 (MLC1) and its increased degradation by matrix metalloproteinase-2 (MMP-2), which leads to impairment of cardiomyocyte contractility. We also postulate that inhibition of ONOO⁻ action by use of a ONOO⁻ scavenger results in improved recovery from ischemic injury. Isolated rat cardiomyocytes were subjected to 15 and 60 min. of simulated ischemia. Intact MLC1 levels, measured by 2D gel electrophoresis and immunoblot, were shown to decrease with increasing duration of ischemia, which correlated with increasing levels of nitrotyrosine and nitrite/nitrate. In vitro degradation of human recombinant MLC1 by MMP-2 increased after ONOO⁻ exposure of MLC1 in a concentration-dependent manner. Mass spectrometry analysis of ischemic rat cardiomyocyte MLC1 showed nitration of tyrosines 78 and 190, as well as of corresponding tyrosines 73 and 185 within recombinant human cardiac MLC1 treated with ONOO⁻. Recombinant human cardiac MLC1 was additionally nitrosylated at cysteine 67 and 76 corresponding to cysteine 81 of rat MLC1. Here we show that increased ONOO⁻ production during ischemia induces MLC1 nitration/nitrosylation leading to its increased degradation by MMP-2. Inhibition of MLC1 nitration/nitrosylation during ischemia by the ONOO⁻ scavenger FeTPPS (5,10,15,20-tetrakis-[4-sulfonatophenyl]-porphyrinato-iron[III]), or inhition of MMP-2 activity with phenanthroline, provides an effective protection of cardiomyocyte contractility.

Effects of MMP-9 inhibition by doxycycline on proteome of lungs in high tidal volume mechanical ventilation-induced acute lung injury

Background

Although mechanical ventilation (MV) is a major supportive therapy for patients with acute respiratory distress syndrome, it may result in side effects including lung injury. In this study we hypothesize that MMP-9 inhibition by doxycycline might reduce MV-related lung damage. Using a proteomic approach we identified the pulmonary proteins altered in high volume ventilation-induced lung injury (VILI). Forty Wistar rats were randomized to an orally pretreated with doxycycline group (n = 20) or to a placebo group (n = 20) each of which was followed by instrumentation prior to either low or high tidal volume mechanical ventilation. Afterwards, animals were euthanized and lungs were harvested for subsequent analyses.

Results

Mechanical function and gas exchange parameters improved following treatment with doxycycline in the high volume ventilated group as compared to the placebo group. Nine pulmonary proteins have shown significant changes between the two biochemically analysed (high volume ventilated) groups. Treatment with doxycycline resulted in a decrease of pulmonary MMP-9 activity as well as in an increase in the levels of soluble receptor for advanced glycation endproduct, apoliporotein A-I, peroxiredoxin II, four molecular forms of albumin and two unnamed proteins. Using the pharmacoproteomic approach we have shown that treatment with doxycycline leads to an increase in levels of several proteins, which could potentially be part of a defense mechanism.

Conclusion

Administration of doxycycline might be a significant supportive therapeutic strategy in prevention of VILI.

Effect of duration of ischemia on myocardial proteome in ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury is a serious problem resulting from clinical setting of coronary revascularization. Despite extensive studies on I/R injury, the molecular bases of cardiac dysfunction caused by I/R are still unknown, but are likely to result from alterations in protein expression. Isolated rat hearts were subjected to 15-30 min of no-flow ischemia without (Ischemia protocol) or with 30 min of reperfusion (I/R protocol). 2-DE analysis of heart proteins from both experimental protocols showed wide-ranging changes in protein levels. In the Ischemia protocol, 39 protein spots were changed in ischemic groups and those changes correlated with duration of ischemia. Ninety percent of the affected proteins were increased. In contrast to increased protein levels, the total messenger RNA (mRNA) level decreased approximately two fold. Compared to the Ischemia protocol, changes in protein levels in the I/R protocol did not correlate with the duration of ischemia and the degree of recovery of mechanical function. The decrease of affected protein from I/R protocol was associated with the increase in total protein level in reperfusate. Our studies show that the protein increase is correlated with the mechanical function of the I/R hearts and the increase is not likely associated with an increase in protein synthesis.

Inhibiting matrix metalloproteinase-2 reduces protein release into coronary effluent from isolated rat hearts during ischemia-reperfusion

BACKGROUND

Previous studies have shown that the disruption of the coronary endothelium and the increase in its permeability during ischemia-reperfusion (I/R), are linked to matrix metalloproteinase-2 (MMP-2) activity. Studies from our group have shown that during I/R, activity of MMP-2 in the coronary effluent increases and this increase is associated with cardiac dysfunction, which in turn, can be prevented by MMP inhibitors. Therefore, we hypothesize that inhibiting MMPs reduces the MMP-2 dependent disruption of the coronary endothelium and subsequent protein release during I/R.

METHODS

Isolated rat hearts were perfused in the Langendorff mode at a constant pressure and subjected to 15, 20 or 30 min no-flow ischemia followed by 30 min of reperfusion. The MMP inhibitors, o-phenanthroline (Phen, 100 microM) or doxycycline (Doxy, 30 microM) an inhibitors of MMPs, were added to the perfusion solution 10 min before ischemia and for the first 10 min of reperfusion. The coronary effluents were collected during perfusion for protein analysis. Creatine kinase was measured as an index of cellular damage. Endothelial integrity was assessed by measuring coronary flow and by measuring the levels of serotransferrin and interstitial albumin in the coronary effluent. Additionally, damage to the endothelium was assessed histologically by light microscopy analysis of the cellular structure of the myocardium. MMP-2 activity was measured by zymography in hearts subjected to 15, 20 and 30 min of ischemia without reperfusion.

RESULTS

MMP-2 activity was increased in heart tissue at the end of ischemia and was correlated with duration of ischemia. The post-ischemia decrease in coronary flow, and the increase in the release of serotransferrin and albumin were attenuated by Phen. Edema (another indirect marker of endothelial damage) was observed in I/R heart and the edema was abolished in I/R heart treated with MMP inhibitors.

CONCLUSION

MMP inhibition not only reduces cardiac mechanical dysfunction but also reduces endothelial damage resulting from cardiac I/R injury.

Hydrogen peroxide causes cardiac dysfunction independent from its effects on matrix metalloproteinase-2 activation

Hydrogen peroxide (H2O2) causes cardiac dysfunction through multiple mechanisms. As oxidative stress can activate matrix metalloproteinases (MMPs) and, in particular, MMP-2 activity is associated with oxidative stress injury in the heart, we hypothesized that MMP-2 activation by H2O2 in isolated rat hearts contributes to cardiac dysfunction in this model. Isolated working rat hearts were perfused at 37 degrees C with a recirculating Krebs-Henseleit buffer+/-5 mmol/L pyruvate, known to protect hearts from oxidative stress. H2O2 (300 micromol/L) was added as a single bolus after 20 min of equilibration, and cardiac function was monitored for 60 min. MMPs activities in both the heart and perfusate samples were assessed by gelatin zymography. Tissue high energy phosphates were analysed by HPLC. The actions of 2 MMP inhibitors, doxycycline (75 micromol/L) or Ro 31-9790 (3 micromol/L), were also assessed. H2O2 at 300 micromol/L produced a rapid decline in cardiac mechanical function, which was maximal at 5 min. A peak in perfusate MMP-2 activity was also observed at 5 min. The deleterious effect of H2O2 on cardiac function was abolished by pyruvate but not by the MMPs inhibitors. This study suggests that in intact hearts, H2O2 induces contractile dysfunction independent of MMPs activation.

Regulation of matrix metalloproteinase-2 (MMP-2) activity by phosphorylation

The regulation of matrix metalloproteinases (MMP) has been studied extensively due to the fundamental roles these zinc-endopeptidases play in diverse physiological and pathological processes. However, phosphorylation has not previously been considered as a potential modulator of MMP activity. The ubiquitously expressed MMP-2 contains 29 potential phosphorylation sites. Mass spectrometry reveals that at least five of these sites are phosphorylated in hrMMP-2 expressed in mammalian cells. Treatment of HT1080 cells with an activator of protein kinase C results in a change in MMP-2 immunoreactivity on 2D immunoblots consistent with phosphorylation, and purified MMP-2 is phosphorylated by protein kinase C in vitro. Furthermore, MMP-2 from HT1080 cell-conditioned medium is immunoreactive with antibodies directed against phosphothreonine and phosphoserine, which suggests that it is phosphorylated. Analysis of MMP-2 activity by zymography, gelatin dequenching assays, and measurement of kinetic parameters shows that the phosphorylation status of MMP-2 significantly affects its enzymatic properties. Consistent with this, dephosphorylation of MMP-2 immunoprecipitated from HT1080 conditioned medium with alkaline phosphatase significantly increases its activity. We conclude that MMP-2 is modulated by phosphorylation on multiple sites and that protein kinase C may be a regulator of this protease in vivo.

The involvement of superoxide and iNOS-derived NO in cardiac dysfunction induced by pro-inflammatory cytokines

Pro-inflammatory cytokines have been shown to depress myocardial mechanical function by enhancing peroxynitrite generation in the heart. The contribution of NO synthesized by different NOS isoforms, as well as the contribution of superoxide to this mechanism are still not clear. Isolated working hearts of iNOS(-/-) and wildtype mice were perfused for 120 min in the presence or absence of a mixture of pro-inflammatory cytokines (IL-1beta, TNF-alpha, and IFN-gamma). iNOS mRNA was detected only in cytokine-treated wildtype hearts. In wildtype hearts, cytokine treatment significantly decreased cardiac work, calculated as cardiac output times peak systolic pressure, to 31+/-9% of original values by the end of perfusion (P <0.05). The decline of cardiac work induced by cytokine treatment was significantly reduced in iNOS(-/-) hearts (63+/-5% of original value). Only cytokine-treated wildtype hearts showed decreased aconitase activity, indicating a higher level of oxidative stress in these hearts. Cytokines increased NADPH oxidase activity in both wildtype and iNOS(-/-) hearts, whereas NADH oxidase and xanthine oxidase/xanthine dehydrogenase activities were unaffected. The SOD mimetic MnTE2PyP prevented the cytokine-induced decline of cardiac work in both wildtype and iNOS(-/-) hearts. Cardiac p38 MAPK activation was unaltered in all experimental groups. Although genetic disruption of the iNOS gene provides partial protection against cytokine-induced cardiac dysfunction, iNOS-independent mechanisms, including contribution of NO from other NOS enzymes and the generation of superoxide, are also important contributors.

Inhibition of endogenous nitric oxide in the heart enhances matrix metalloproteinase-2 release

Matrix metalloproteinase (MMP) activity is upregulated in pathologies such as atherosclerosis during which endogenous nitric oxide (NO) biosynthesis is reduced. Diminished levels of NO, an antioxidant species, may result in higher oxidative stress. Oxidants are capable of activating MMPs from their zymogen forms. We examined whether basal biosynthesis of NO in the coronary circulation regulates MMP-2 activity. In isolated rat hearts perfused with Krebs-Henseleit buffer at a constant flow of 10 ml min(-1), we measured the release of MMP-2 into the coronary effluent by gelatin zymography. The main gelatinolytic activity of 72-kDa corresponds to MMP-2. Infusion of the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) concentration dependently increased coronary perfusion pressure (CPP) (by 48+/-11 mmHg with 100 microM) and enhanced the release of the 72-kDa MMP-2 in the effluent. Coinfusion of the NO donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP, 1 microM) with L-NAME abolished both the increase in CPP and the enhanced MMP-2 release. The thromboxane A2 mimetic U46619 increased CPP to the same extent as L-NAME without increasing 72-kDa activity in the effluent, suggesting that MMP-2 release is not caused simply by enhanced perfusion pressure. Infusion of either L-NAME or U46619 did not significantly enhance LDH release. L-NAME infusion concentration dependently increased the level of lipid hydroperoxides in homogenates prepared from the perfused hearts. Coinfusion of SNAP prevented this increase. These data reveal another cytoprotective mechanism of endogenous NO biosynthesis in the heart, the inhibition of MMP-2 release.

Degradation of myosin light chain in isolated rat hearts subjected to ischemia-reperfusion injury: a new intracellular target for matrix metalloproteinase-2

BACKGROUND

Matrix metalloproteinase-2 (MMP-2) contributes to cardiac dysfunction resulting from ischemia-reperfusion (I/R) injury. MMP-2 not only remodels the extracellular matrix but also acts intracellularly in I/R by degrading troponin I. Whether other intracellular targets exist for MMP-2 during I/R is unknown.

METHODS AND RESULTS

Isolated rat hearts were subjected to 20 minutes of ischemia and 30 minutes of reperfusion. The impaired recovery of mechanical function of the heart was attenuated by the MMP inhibitors o-phenanthroline or doxycycline. Quantitative 2D electrophoresis of homogenates of aerobically perfused hearts (control) or those subjected to I/R injury (in the presence or absence of MMP inhibitors) showed 3 low-molecular-weight proteins with levels that were significantly increased upon I/R injury and normalized to control levels by MMP inhibitors. Mass spectrometry analysis identified all 3 proteins as fragments of myosin light chain 1, which possesses theoretical cleavage recognition sequences for MMP-2 and is rapidly degraded by it in vitro. The association of MMP-2 with the thick myofilament in fractions prepared from I/R hearts was observed with immunogold electron microscopy, gelatin zymography for MMP-2 activity, and immunoprecipitation. MMP-2 was found to cleave myosin light chain 1 between tyrosine 189 and glutamine 190 at the C terminus.

CONCLUSIONS

Our results demonstrate that myosin light chain 1 is another novel substrate for MMP-2 in the cardiomyocyte and that its degradation may contribute to contractile dysfunction resulting from I/R injury to the heart.

Pyruvate prevents cardiac dysfunction and AMP-activated protein kinase activation by hydrogen peroxide in isolated rat hearts

Ischemia-reperfusion injury in the heart results in enhanced production of H2O2 and activation of AMP-activated protein kinase (AMPK). Since mutations in AMPK result in cardiovascular dysfunction, we investigated whether the activation of AMPK mediates the H2O2-induced reduction in cardiac mechanical function. Isolated working rat hearts were perfused at 37 degrees C with Krebs-Henseleit solution. Following a 20-minute equilibration period, a single bolus of H2O2 (300 micromol/L) was added and the hearts were perfused for an additional 5 min. H2O2 induced a dramatic and progressive reduction in cardiac function. This was accompanied by rapid and significant activation of AMPK, an increase in Thr-172 phosphorylation of AMPK, and an increase in the creatine to phosphocreatine (Cr/PCr) ratio. Addition of pyruvate (5 mmol/L) to the perfusate prevented the H2O2-mediated reduction in cardiac mechanical dysfunction, activation of myocardial AMPK activity, increase in AMPK phosphorylation and the increase in the Cr/PCr ratio. Hearts challenged with H2O2 (300 micromol/L) in presence of either AMPK inhibitor Compound C (10 micromol/L) or its vehicle (dimethyl sulfoxide (DMSO), 0.1%) showed reduced impairment in cardiac mechanical function. Compound C but not its vehicle significantly inhibited myocardial AMPK activity. Thus, H2O2 induces cardiac dysfunction via both AMPK-dependent and independent mechanisms.

Matrix metalloproteinase-2 (MMP-2) is present in the nucleus of cardiac myocytes and is capable of cleaving poly (ADP-ribose) polymerase (PARP) in vitro

Matrix metalloproteinases (MMPs) are traditionally known for their role in extracellular matrix remodeling. Increasing evidence reveals several alternative substrates and novel biological roles for these proteases. Recent evidence showed the intracellular localization of MMP-2 within cardiac myocytes, colocalized with troponin I within myofilaments. Here we investigated the presence of MMP-2 in the nucleus of cardiac myocytes using both immunogold electron microscopy and biochemical assays with nuclear extracts. The gelatinase activity found in both human heart and rat liver nuclear extracts was blocked with MMP inhibitors. In addition, the ability of MMP-2 to cleave poly (ADP-ribose) polymerase (PARP) as a substrate was examined as a possible role for MMP-2 in the nucleus. PARP is a nuclear matrix enzyme involved in the repair of DNA strand breaks, which is known to be inactivated by proteolytic cleavage. PARP was susceptible to cleavage by MMP-2 in vitro in a concentration-dependent manner, yielding novel degradation products of ~66 and <45 kDa. The cleavage of PARP by MMP-2 was also blocked by MMP inhibitors. This is the first characterization of MMP-2 within the nucleus and we hereby suggest its possible role in PARP degradation.

Imbalance between tissue inhibitor of metalloproteinase-4 and matrix metalloproteinases during acute myocardial [correction of myoctardial] ischemia-reperfusion injury

BACKGROUND

We have previously reported that matrix metalloproteinase-2 (MMP-2) contributes to myocardial ischemia-reperfusion injury by degradation of troponin I, a regulatory element of the contractile proteins. MMP activities are also tightly regulated by tissue inhibitors of metalloproteinase (TIMPs). The change in TIMPs during acute myocardial ischemia-reperfusion injury is not clear.

METHODS AND RESULTS

Isolated rat hearts were perfused either aerobically for 75 minutes or subjected to 15, 20, or 25 minutes of global, no-flow ischemia followed by 30 minutes of aerobic reperfusion. During reperfusion after ischemia, there was a rapid, enhanced release of TIMP-4, the most abundant TIMP in the heart, into the coronary effluent, as shown both by reverse zymography and Western blot. There was a negative correlation between the recovery of cardiac mechanical function and the release of TIMP-4 during reperfusion in hearts subjected to different durations of ischemia. Immunogold electron microscopy revealed a close association of TIMP-4 with the sarcomeres in aerobically perfused hearts. Moreover, TIMP-4 was present only in thin myofilaments prepared from aerobically perfused hearts but not in ischemic-reperfused hearts. An enhanced MMP activity was shown in ischemic-reperfused hearts by in situ zymography.

CONCLUSIONS

Loss of TIMP-4 from the cardiac myocyte leads to an increase in net myocardial MMP activity that contributes to acute myocardial stunning injury.

[Effect of lanreotide on prolactin level in patients with pituitary mixed tumors]

Acromegaly is a disease caused by a pituitary tumor (somatotropinoma) or by ectopic secretion of GH or IGF-1. About 15% of tumors secrete not only GH but PRL as well. Last time a lanreotide and an octreotide (the somatostatine analogues) are useful in the therapy of acromegaly. We observed the influence of the lanreotide on GH and prolactin. We noticed that the lanreotide caused not only serum level reduction of a growth hormone but also prolactine in patients with mixed pituitary tumors.

Regulation of K(+) current in human airway epithelial cells by exogenous and autocrine adenosine

The regulatory actions of adenosine on ion channel function are mediated by four distinct membrane receptors. The concentration of adenosine in the vicinity of these receptors is controlled, in part, by inwardly directed nucleoside transport. The purpose of this study was to characterize the effects of adenosine on ion channels in A549 cells and the role of nucleoside transporters in this regulation. Ion replacement and pharmacological studies showed that adenosine and an inhibitor of human equilibrative nucleoside transporter (hENT)-1, nitrobenzylthioinosine, activated K(+) channels, most likely Ca(2+)-dependent intermediate-conductance K(+) (I(K)) channels. A(1) but not A(2) receptor antagonists blocked the effects of adenosine. RT-PCR studies showed that A549 cells expressed mRNA for I(K)-1 channels as well as A(1), A(2A), and A(2B) but not A(3) receptors. Similarly, mRNA for equilibrative (hENT1 and hENT2) but not concentrative (hCNT1, hCNT2, and hCNT3) nucleoside transporters was detected, a result confirmed in functional uptake studies. These studies showed that adenosine controls the function of K(+) channels in A549 cells and that hENTs play a crucial role in this process.

Matrix metalloproteinase 2 in tumor cell-induced platelet aggregation: regulation by nitric oxide

A correlation exists between the ability of tumor cells to aggregate platelets and their tendency to metastasize. Tumor cell-induced platelet aggregation (TCIPA) facilitates the embolization of the vasculature with tumor cells and the formation of metastatic foci. It is well documented that matrix metalloproteinases (MMPs) play an integral part in tumor spread and the metastatic cascade. Therefore, we have examined the role of MMPs during TCIPA and its regulation by nitric oxide (NO) in vitro. Human HT-1080 fibrosarcoma and A549 lung epithelial cancer cells induced TCIPA in a concentration-dependent manner that was monitored by aggregometry. This aggregation resulted in the release of MMIP-2 from platelets and cancer cells, as measured by zymography. HT-1080 cells released significantly more MMP-2 than A549 cells and were more efficacious in inducing TCIPA. Inhibition of MMP-2 with phenanthroline (1-1000 microM), a synthetic inhibitor of MMPs, and by neutralizing anti-MMIP-2 antibody (10 microg/ml) reduced TCIPA induced by HT-1080 cells. TCIPA was abolished by simultaneous inhibition of platelet function with acetylsalicylic acid (100 microM; thromboxane pathway inhibitor), apyrase (250 microg/ml; ADP pathway inhibitor), and phenanthroline. NO donors such as S-nitroso-n-acetylpenicillamine and S-nitrosoglutathione (both at 0.01-100 microM) inhibited TCIPA and MMP-2 release from platelets and tumor cells. The inhibitory actions of S-nitroso-n-acetylpenicillamine and S-nitrosoglutathione were reversed by 1H-[1,2,4]oxadiazole[4,3]quinoxalin-1-one (0.01-30 microM), a selective inhibitor of the soluble guanylyl cyclase. We conclude that (a) human fibrosarcoma cells aggregate platelets via mechanism(s) that are mediated, in part, by MMP-2; (b) NO inhibits TCIPA, in part, by attenuating the release of MMP-2; and (c) these effects of NO are cGMP-dependent.

Short-term pre-surgical treatment with somatostatin analogues, octreotide and lanreotide, in acromegaly

Eighteen patients with symptoms of active acromegaly were treated with somatostatin analogues for 4 weeks before surgery. Both before and after the treatment, levels of growth hormone (GH), prolactin (PRL), insulin growth factor -I (IGF-I), luteotropin (LH), folliculostimulin (FSH) and subunit alpha of glycoprotein hormones were estimated. Glucose tolerance test, magnetic resonance imaging (MRI) examination, sight acuity and field of vision tests were also performed. The same tests were performed on ten control patients with clinically and biochemically active acromegaly, subjected to surgery but not treated with somatostatin analogues. In six patients treated with somatostatin analogues GH levels decreased significantly to less than 5 ng/ml and in two patients remained elevated while in 10 patients GH level decreased and ranged from 6.1 to 42.9 ng/ml. In 13 patients we observed a decrease in IGF-I to normal levels (<400 ng/dl) and in 3 patients we noted a decrease to levels slightly higher than normal. There was also a slight decrease in alpha subunit concentration. In the glucose inhibition test 4 patients demonstrated normalized GH levels. In patients with elevated PRL and TSH levels, treatment with somatostatin analogues induced their decrease. No changes were observed in levels of LH and FSH. After therapy MRI examination disclosed a decrease in tumor volume in two patients (by 20 and 25%, respectively) and no changes in tumor size in 16 patients. The two patients with a decreased tumor volume also showed normalized glucose tolerance tests. All patients manifested an improved clinical condition. Neurosurgeons disclosed a decreased tumor consistency which greatly facilitated surgical procedure. Our studies documented favourable effects of somatostatin analogues on the assayed hormone levels, and on the general condition of the patients as well as on the course of the surgical procedure itself.

[Detection of pituitary autoantibody in patients with pituitary tumors and hypopituitarism]

In 80 patients, 73 cases of pituitary tumours and 7 cases of hypopituitarism, we performed pituitary autoantibodies assays in serum samples because in our previous studies we had found a high prevalence of pituitary autoantibodies in several autoimmune endocrine disorders. To detect the presence of pituitary autoantibodies we applied 2 methods, radioimmunoassay (RIA) and immunoblotting. The RIA was performed by solid phase technique in human pituitary microsome-coated polyethylene tubes. Following incubation with diluted sera of the patients labelled 125I-protein A was added to the tubes to detect the retained antibodies. In the sera of 33 patients we detected the presence of antibodies; in the other 47 patients no antibodies were found. The majority of the patients with positive antibody results were previously treated by pituitary irradiation. To evaluate the molecular weights of pituitary autoantigens the microsomal proteins were separated on SDS PAGE, then electrophoretically transferred to nitrocellulose membranes and reacted with diluted sera of 30 antibody-positive patients. The nitrocellulose strips were incubated with labelled 125I-protein A and autoradiographed. Using immunoblotting, 13 out of these 30 patients we found autoantibodies reacting with pituitary microsomal antigens of different molecular weights, most frequently reacting with a 68 kDa autoantigen.

CONCLUSIONS

The prevalence of pituitary autoantibodies in patients with pituitary diseases is 41% lower than in autoimmune endocrine diseases. Pituitary autoantibodies usually appear in patients after pituitary irradiation or after neurosurgery followed by irradiation, but occur rarely in untreated patients with pituitary adenomas.

Analysis of autoantibody epitopes on steroid 21-hydroxylase using a panel of monoclonal antibodies

A panel of five mouse monoclonal antibodies (MAbs) to human recombinant steroid 21-hydroxylase (21-OH) were produced, characterized, and used to study the interaction of 21-OH autoantibodies (AAbs) with different epitopes on human 21-OH. AAbs in patients with isolated autoimmune Addison's disease, autoimmune polyglandular syndromes types I and II, and 21-OH antibody-positive patients without overt Addison's disease (25 patients in total) were studied. Four MAbs were IgG1 subclass, one was IgG2a, and all had kappa light chains. The affinities of four of the antibodies were in the range 2.0 x 10(8) M(-1) to 7.0 x 10(8) M(-1), and the affinity of the other was 2.3 x 10(7) M(-1) 21-OH MAbs did not cross-react with 17alpha-hydroxylase (17alpha-OH)) or P450 side chain cleavage enzyme. Studies using a series of 21-OH fragments allowed the identification of short stretches of amino acids (AA) that were involved in forming the MAb binding sites. AA 391-405, defined as epitope region (ER) 1, were found to be important for binding of M21-OH1 and M21-OH2, AA 406-411 (ER2) were important for M21-OH3 and M21-OH4 binding, and AA 335-339 (ER3) for M21-OH5 binding. In addition, MAb Fab or F(ab')2 fragments were used to study 21-OH AAb epitopes in competition experiments. These investigations demonstrated that 21-OH AAbs recognize similar epitopes to the MAbs, with ER2 and ER3 being part of two distinct major epitopes, and ER 1 being part of a minor epitope. Mixtures of M21-OH antibody Fab or F(ab')2 fragments caused almost complete inhibition (80%-95%) of AAb binding in 24 out of 25 sera, and in the case of the remaining serum, the effect was marked but incomplete (67% inhibition). There were no major differences between the binding characteristics of AAbs from patients with different forms of autoimmune adrenal disease. All five 21-OH MAbs reacted with human adrenal tissue in an immunofluorescence test, but only M21-OH1 and M21-OH2 reacted with bovine adrenal tissue in these experiments. None of the MAbs reacted with human ovarian tissue in an immunofluorescence test. Overall, these studies indicate that 21-OH AAbs bind to at least three different epitopes in the C-terminal part of 21-OH, and two of these epitopes appear to be human 21-OH specific.

Steroid 21-hydroxylase autoantibodies: measurements with a new immunoprecipitation assay

Autoantibodies (Abs) to steroid 21-hydroxylase (21-OH) are a major component of adrenal cortex Abs and are characteristic of autoimmune Addison's disease. We have developed a new method for measuring Abs to 21-OH based on 125I-labeled recombinant human 21-OH produced in yeast. With this assay, 21-OH Abs were detected in 43 of 60 (72%) sera from patients with isolated Addison's disease, 11 of 12 (92%) autoimmune polyglandular syndrome type I sera, 27 of 27 (100%) autoimmune polyglandular syndrome type II sera, and 24 of 30 (80%) sera from patients who were positive for adrenal cortex antibodies by immunofluorescence but had no overt Addison's disease. 21-OH Abs were found by 125I assay in 4 of 150 (2.7%) sera from patients with insulin-dependent diabetes mellitus, 1 of 77 (1.3%) Graves' sera, 1 of 67 (1.5%) Hashimoto's sera, and 6 of 243 (2.5%) sera from healthy blood donors. 21-OH Abs were not detected in 9 sera from patients with Addison's disease due to tuberculosis, 32 sera from patients with noninsulin-dependent diabetes mellitus, 35 sera from patients with myasthenia gravis, or 17 sera from patients with premature ovarian failure. There was good agreement between the 125I-labeled 21-OH assay and an assay based on 35S-labeled 21-OH produced in an in vitro transcription/translation system (r = 0.86; n = 129; P < 0.001). In the case of sera from patients with Addison's disease, insulin-dependent diabetes mellitus, Graves' disease, and Hashimoto's disease and from healthy blood donors that were low positive in the 125I assay, neutralization studies with unlabeled 21-OH confirmed the presence of specific 21-OH Abs. Overall, the 21-OH Ab assay based on 125I-labeled 21-OH showed good sensitivity, precision, and disease group specificity. This, combined with a simple assay protocol and the convenience of 125I handling and counting, make it attractive for routine use. Further investigations with the new assay should allow wider assessment of the prevalence and pattern of inheritance of adrenal autoimmunity. In addition, studies of the effect of treatment or possible preventative measures on 21-OH Ab levels in individuals without overt adrenal failure may suggest ways of delaying the onset of autoimmune Addison's disease.

Thyrotropin (TSH) receptor autoantibodies do not appear to bind to the TSH receptor produced in an in vitro transcription/translation system

An in vitro transcription/translation (TnT) system was used to produce 35S-labeled full-length TSH receptor (TSHR) and TSHR extracellular domain (TSHRex). The interaction of the labeled proteins with TSHR autoantibodies in Graves' sera was then studied using an immunoprecipitation assay. In the assay, 35S-labeled TSHR or TSHRex were incubated with test sera, and any immune complexes formed were precipitated with protein A-Sepharose (in the case of mouse monoclonal antibodies, antimouse IgG-agarose was used). Rabbit antibodies to the TSHR and a mouse monoclonal antibody precipitated as much as 50% of the 35S-labeled TSHR preparations compared with about 2% for normal rabbit serum and 4% for a control monoclonal antibody. However, none of 34 Graves' sera (TSHR autoantibody levels ranging from 14-95% inhibition of [125I]TSH binding) were able specifically to immunoprecipitate 35S-labeled TSHR or TSHRex. These negative findings were confirmed by analysis of the immunoprecipitates on SDS-PAGE followed by autoradiography. Our results indicate that the TnT system is not useful for producing labeled TSHR preparations that can bind TSHR autoantibodies well. This is in contrast to TnT produced 35S-labeled glutamic acid decarboxylase, thyroid peroxidase, and 21-hydroxylase, which react well with their respective autoantibodies. One main difference between these 3 autoantigens and the TSHR is that the receptor is highly glycosylated, and this extensive glycosylation may be of critical importance for correct folding of the receptor. Consequently, the inability of the TnT system to glycosylate proteins could explain in part why TnT-produced 35S-labeled TSHR and TSHRex do not bind TSHR autoantibodies.

Thyroid volume and function in patients with acromegaly living in iodine deficient areas

The aim of our study was to evaluate the size and function of the thyroid in patients with acromegaly. In 39 patients concentrations of HGH, PRL, TSH, T3 and T4 were measured and the thyroid volume was calculated with the using of ultrasound examination. The control group comprised 5 patients with acromegaly in a stage of remission and 98 controls. We concluded that the size of the goiter in patients with acromegaly depends on serum concentration of HGH, but it does not depend on the concentration of TSH, T3, T4 and PRL. Goiter is present in 87% of patients with acromegaly, 46% of them are nodular goiters. The thyroid function in acromegaly is normal.

Glutamic acid decarboxylase autoantibody assay using 125I-labelled recombinant GAD65 produced in yeast

We describe a new method for measuring autoantibodies (Ab) to the 65 kDa isoform of glutamic acid carboxylase (GAD65). In particular, GAD65 without the hydrophobic N-terminal region has been produced in yeast, purified, labelled with 125I and reacted with GAD65 Ab. Antibody bound 125I-GAD65 is then precipitated by the addition of solid phase protein A. With the assay, GAD65 Ab were detected in 59 of 71 (83%) islet cell antibody (ICA) positive IDDM patients and in 8 of 23 (35%) ICA negative IDDM patients (overall 67 of 94 (71%) of IDDM patients). Low concentrations of GAD65 Ab were also detected in 2/98 (2%) healthy blood donors and 1/27 (4%) Graves' disease patients had a high level of antibody. GAD65 Ab were not detected in any of 10 Hashimoto's thyroiditis, 20 Addison's disease or 19 myasthenia gravis sera. There was good agreement between the 125I assay and the current reference method based on 35S-labelled full-length GAD65 (produced by in vitro transcription/translation reaction) and solid phase protein A (r = 0.91, n = 108). Overall, our 125I assay showed sensitivity, precision and disease group specificity at least as good as any assay so far described. These features, combined with a simple assay protocol and the convenience of 125I counting and handling indicate that the method is suitable for routine GAD65 Ab measurements.

Autoantibodies to steroidogenic enzymes in autoimmune polyglandular syndrome, Addison's disease, and premature ovarian failure

Autoantibodies to steroidogenic enzymes, steroid 17 alpha-hydroxylase (17 alpha-OH), cytochrome P450 side-chain cleavage enzyme (P450scc), and steroid 21-hydroxylase (21-OH), were measured using specific and sensitive immunoprecipitation assays (IPAs) in patients with various forms of autoimmune adrenal disease. Autoantibodies to 17 alpha-OH were detected in 6 of 11 (55%) patients with autoimmune polyglandular syndrome (APS) type I, 8 of 24 (33%) patients with APS type II, 11 of 56 (20%) patients with adrenal cortex antibody (ACA; measured by immunofluorescence)-positive patients without Addison's disease, and only 3 of 64 (5%) patients with Addison's disease. Autoantibodies to P450scc were found at a prevalence similar to those to 17 alpha-OH: in 5 of 11 (45%) APS type I patients, 10 of 24 (42%) APS type II patients, 11 of 56 (20%) ACA-positive patients without Addison's disease, and only 6 of 64 (9%) patients of the Addison disease group. Autoantibodies to 21-OH were found in a majority of patients with APS type I (7 of 11;64%), APS type II (23 of 24; 96%), Addison's disease (41 of 64; 64%), and ACA-positive patients without Addison's disease (48 of 56; 86%). All sera that were positive for 17 alpha-OH or P450scc were also positive for 21-OH autoantibodies, except in 1 case. There was good agreement between the presence of ACA measured by immunofluorescence and 21-OH antibodies measured by IPA in all patient groups studied, and this indicates that 21-OH is a major autoantigen in adrenal autoimmune disease regardless of whether the disease presents as isolated Addison's disease or APS type I or type II. Autoantibodies to 17 alpha-OH and P450scc appeared to be the major components of the steroid-producing cell antibodies measured by immunofluorescence. No autoantibodies to 21-OH, 17 alpha-OH, or P450scc were detected in 17 sera from patients with premature ovarian failure without evidence of adrenal autoimmunity (as judged by immunofluorescence studies), except for 1 serum in which low levels of 17 alpha-OH antibodies were found. Overall, our studies indicate that 35S-labeled 17 alpha-OH, P450scc, and 21-OH can be used successfully in IPAs for their respective autoantibodies. Assays such as these may well be valuable in the immunological assessment of patients at risk for or suspected of adrenal autoimmunity.

[Isolation and purification of transcortin (cortisol binding globulin--CBG) using two-step chromatography]

The isolation of cortisol and progesterone binding globulin (CBG) from pregnant women serum was performed using affinity and hydrophobic chromatography. The purity and specificity of isolated transcortin was tested by agarose gel electrophoresis using racket and cross immunoelectrophoresis and specific CBG antibodies. High purity and immunoreactivity of the isolated globulin destitute of other proteins contamination, were obtained.

Mutagenicity of B(a)P in the presence of some hydralazine derivatives

Hydralazine, dihydralazine and todralazine were tested in the aspect of their mutagenic potency, and the influence upon the mutagenicity of standard promutagen--B(a)P. Hydralazine exhibited strong mutagenic activity in the Ames test while mutagenic activity of dihydralazine was relatively weak. Todralazine had no mutagenic activity, and significantly decreased mutagenicity of B(a)P. It was concluded that todralazine could be a good antimutagenic substance.

Calcified suture material in the breast after radiation therapy

Of 335 women who underwent lumpectomy and radiation therapy for breast cancer, 42 subsequently developed calcifications. Particles typical of calcified suture material were identified in 21 of the 42 women (50%). No obvious calcified suture material was found in approximately 1,140 women of 38,000 (3%) who had undergone mammography after they had previously undergone breast biopsy for a benign lesion and thus had not undergone radiation therapy. Calcified suture material rarely develops in the nonirradiated breast, but it is common after radiation therapy and should not be confused with recurrent breast cancer. These calcifications are likely the result of delayed resorption of catgut sutures, which provide a matrix on which calcium can precipitate in a suitable local environment.

Fatigue syndrome due to localized radiation

For cancer patients, fatigue is a disturbing symptom caused by many factors. Since fatigue is the most common side effect of localized radiation to the breast, this treatment provides a unique opportunity to follow patients prospectively as they develop one type of fatigue. We evaluated the effect of radiation treatment in 15 women with Stage I or II node-negative breast cancer who were otherwise healthy. Fatigue, contrary to our hypothesis, did not increase linearly with cumulative radiation dose over time. It dropped from the first to second week and rose in the third week. The cumulative effects reached a plateau in the fourth week (after an average of 17 fractions), which was maintained during the remaining weeks of treatment. Within 3 wk after treatment, fatigue had diminished. No patient had sustained depressive symptoms. Cardiopulmonary exercise capacity in 5 patients at 6 and 12 wk did not change from just before radiation. Other markers, including reverse triiodothyronine and pulse change with orthostatic stress, did not correlate with subjective fatigue nor cumulative radiation in 15 patients. The curve of the fatigue syndrome during treatment conforms to the adaptation of the organism to a continuing stress and begins to describe a mild fatigue syndrome associated with radiation.