Novel, non-conventional pathways of necroptosis in the heart and other organs: Molecular mechanisms, regulation and inter-organelle interplay

Necroptosis, a cell death modality that is defined as a necrosis-like cell death depending on the receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like pseudokinase (MLKL), has been found to underlie the injury of various organs. Nevertheless, the molecular background of this cell loss seems to also involve, at least under certain circumstances, some novel axes, such as RIPK3-PGAM5-Drp1 (mitochondrial protein phosphatase 5-dynamin-related protein 1), RIPK3-CaMKII (Ca2+/calmodulin-dependent protein kinase II) and RIPK3-JNK-BNIP3 (c-Jun N-terminal kinase-BCL2 Interacting Protein 3). In addition, endoplasmic reticulum stress and oxidative stress via the higher production of reactive oxygen species produced by the mitochondrial enzymes and the enzymes of the plasma membrane have been implicated in necroptosis, thereby depicting an inter-organelle interplay in the mechanisms of this cell death. However, the role and relationship between these novel non-conventional signalling and the well-accepted canonical pathway in terms of tissue- and/or disease-specific prioritisation is completely unknown. In this review, we provide current knowledge on some necroptotic pathways being not directly associated with RIPK3-MLKL execution and report studies showing the role of respective microRNAs in the regulation of necroptotic injury in the heart and in some other tissues having a high expression of the pro-necroptotic proteins.

Health and wellbeing implications of adaptation to flood risk

Adaptation strategies to ameliorate the impacts of climate change are increasing in scale and scope around the world, with interventions becoming a part of daily life for many people. Though the implications of climate impacts for health and wellbeing are well documented, to date, adaptations are largely evaluated by financial cost and their effectiveness in reducing risk. Looking across different forms of adaptation to floods, we use existing literature to develop a typology of key domains of impact arising from interventions that are likely to shape health and wellbeing. We suggest that this typology can be used to assess the health consequences of adaptation interventions more generally and argue that such forms of evaluation will better support the development of sustainable adaptation planning.

Intermittent Hypoxic Preconditioning Plays a Cardioprotective Role in Doxorubicin-Induced Cardiomyopathy

Intermittent hypoxic preconditioning (IHP) is a well-established cardioprotective intervention in models of ischemia/reperfusion injury. Nevertheless, the significance of IHP in different cardiac pathologies remains elusive. In order to investigate the role of IHP and its effects on calcium-dependent signalization in HF, we employed a model of cardiomyopathy induced by doxorubicin (Dox), a widely used drug from the class of cardiotoxic antineoplastics, which was i.p. injected to Wistar rats (4 applications of 4 mg/kg/week). IHP-treated group was exposed to IHP for 2 weeks prior to Dox administration. IHP ameliorated Dox-induced reduction in cardiac output. Western blot analysis revealed increased expression of sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA2a) while the expression of hypoxia inducible factor (HIF)-1-α, which is a crucial regulator of hypoxia-inducible genes, was not changed. Animals administered with Dox had further decreased expression of TRPV1 and TRPV4 (transient receptor potential, vanilloid subtype) ion channels along with suppressed Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) activation. In summary, IHP-mediated improvement in cardiac output in the model of Dox-induced cardiomyopathy is likely a result of increased SERCA2a expression which could implicate IHP as a potential protective intervention in Dox cardiomyopathy, however, further analysis of observed effects is still required.

Sex-Dependent Mechanisms of Cell Death Modalities in Cardiovascular Disease

Despite currently available therapies, cardiovascular diseases (CVD) are among the leading causes of death globally. Biological sex is a critical determinant of the occurrence, progression and overall outcome of CVD. However, the underlying mechanisms are incompletely understood. A hallmark of CVD is cell death. Based on the inability of the human heart to regenerate, loss of functional cardiac tissue can lead to irreversible detrimental effects. Here, we summarize current knowledge on how biological sex affects cell death-related mechanisms in CVD. Initially, we discuss apoptosis and necrosis, but we specifically focus on the relatively newly recognized programmed necrosis-like processes: pyroptosis and necroptosis. We also discuss the role of 17β-estradiol (E2) in these processes, particularly in terms of inhibiting pyroptotic and necroptotic signaling. We put forward that a better understanding of the effects of biological sex and E2 might lead to the identification of novel targets with therapeutic potential.

Relevance of necroptosis in the hearts subjected to acute versus chronic ischemia/reperfusion injury

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Slovak Research and Development Agency

Medical Research Council Grant

Necroptosis, a necrosis-like programmed cell death modality dependent on the activity of receptor-interacting protein kinase 3 (RIP3) and mixed lineage domain kinase domain-like pseudokinase (MLKL), plays a prominent role in mediating myocardial ischemia/reperfusion injury. However, the extent to which necroptosis contributes to such damage under short and long reperfusion has not been evaluated in detail. In Wistar rat hearts, subjected to global 30-min ischemia followed by an acute 10-min reperfusion period, with compromised cardiac function, no changes in the protein expression of the main necroptotic markers (pThr231/Ser232-RIP3, MLKL) were found. Likewise, the non-canonical pathways of necroptosis involving Ca2+/calmodulin dependent protein kinase II–mitochondrial permeability transition pore (CaMKII–mPTP) or phosphoglycerate mutase 5–dynamin-related protein 1 (PGAM5–Drp1) axes were unlikely affected by such short reperfusion. In contrast, hearts subjected to global 30-min ischemia followed by a prolonged 40-min reperfusion period exhibited worsened hemodynamic parameters what was accompanied by the increased levels of RIP3, pSer229-RIP3 and MLKL. Moreover, this reperfusion period induced MLKL translocation to the plasma membrane, indicating necroptosis execution with resultant very likely cell disruption. Similarly, activated necroptosis, evidenced by the higher levels of proteins of the canonical pathway, has been suggested to contribute to the pathogenesis of post-infarction heart failure (30-min ischemia, 42-day reperfusion). Collectively, these findings suggest that short reperfusion seems to be insufficient to induce necroptosis in the heart and the molecular mechanisms being activated during the longer reperfusion phase are needed to promote necroptotic cell dying. Therefore, inhibition of necroptosis might represent a cardioprotective strategy in the settings of chronic, but not acute myocardial ischemia/reperfusion injury.

Necroptosis, unlike pyroptosis mediates right ventricular damage in pulmonary arterial hypertension

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic

The Slovak Research and Development Agency

Introduction

Necroptosis has been found to underlie myocardial damage in various pathological states, however its role as well as its potential interconnection to another cell damaging processes under conditions of pulmonary arterial hypertension (PAH) remains insufficiently understood.

Purpose

In view of these facts, we aimed to investigate the signalling of both necroptosis and pyroptosis in the lung and right ventricular (RV) tissue affected by PAH and we also examined the circulating levels of receptor-interacting protein kinase 3 (RIP3).

Methods

Male Wistar rats were administrated either vehicle (Control group) or monocrotaline (MCT) (60 mg/kg, s. c.) to induce PAH. The MCT-treated animals were sacrificed 4 weeks after the treatment (MCT group) or prematurely, based on rapid health deterioration, thereby indicating the advanced stage of PAH (ptMCT group). Pulse oximetry, gravimetry and evaluation of myocardial damage markers were used to assess the development of PAH. The molecular analyses (ELISA, RT-qPCR and immunoblotting) were used to examine the potential underlying mechanisms of tissue damage due to cell death.

Results

In the RVs, the expression of both pThr231/Ser232-RIP3 and pSer345-mixed linkage kinase domain-like protein was elevated equally in both PAH stages, strongly indicating promotion of necroptosis. Contrary in the lungs affected by PAH, the upregulation of pThr231/Ser232-RIP3 likely proceeded to pyroptotic rather than necroptotic cell death activation, as evidenced by caspase-1 and N-terminal gasdermin D increase. Moreover, we found that the plasma RIP3 levels increased with the severity of PAH stage and positively correlated with RV hypertrophy, but not with cardiac hemodynamic stress markers.

Conclusions

In summary, we showed for the first time that PAH-induced damage of RV and lung tissue might be mediated by different necrosis-like cell death forms with a crucial role pThr231/Ser232-RIP3. Furthermore, we suggested that the plasma RIP3 might serve as an additional diagnostic and prognostic marker of cardiac damage due to PAH.

POS0044-HPR FEASIBILITY OF FITNESS ASSESSMENTS IN GROUP EXERCISE THERAPY FOR INDIVIDUALS WITH AXIAL SPONDYLOARTHRITIS

Background

Assessments should be standard in individual as well as group physical therapy. The Ankylosing Spondylitis Association of Switzerland has translated the EULAR recommendations for physical activity (PA) in a concept for group exercise therapy, which, in addition to guidance on exercising in all four fitness dimensions (aerobic, strength, flexibility, neuromotor function), also includes PA counselling and regular fitness assessments for the planning and documentation of the individual therapy progress as well for quality monitoring of the exercise groups.

Objectives

To evaluate the feasibility of the selected assessments across all four fitness dimensions, rating the acceptance, practicability, and integration by physiotherapists (PTs) and people with axSpA.

Methods

A feasibility study was conducted in four pilot exercise therapy groups. PTs performed the assessment battery, consisting of a) the Chester Step Test (CST) for aerobic fitness; b) the modified Core Strength Test for core strength, c) the Bath Ankylosing Spondylitis Metrology Index (BASMI) for spinal mobility and d) the Single Leg Stance Test (SLST) for balance, with the participants of the exercise therapy groups. Subsequently, the PTs and the participants with axSpA rated the acceptance, practicability, and integration by means of questionnaires.

Acceptance was operationalised as satisfaction and perceived applicability, practicability was operationalised as feasibility and comprehensibility, and integration was operationalised as usefulness and repeatability. An ordinal scale with four answer options (very good, good, moderate, bad) and a free text field for comments was used. The categories ‘very good’ and ‘good’ were interpreted as ‘positive evaluation’. The feasibility of the assessments was defined based on three levels (I-III): with a positive evaluation of >80% (level I) a specific assessment was considered suitable, with a positive evaluation of 50-80% (level II) adjustments were necessary, with a positive evaluation of <50% (level III) a specific assessment was not considered suitable for group exercise therapy and a new choice had to be made.

Results

The BASMI was rated level I by people with axSpA and PTs, no adaptations were necessary. The CST was rated level I by people with axSpA and level II by PTs (too time consuming and failure-prone software), resulting in the adaptation that the test can now be performed without software, and a training will make the testing PTs more efficient. The modified Core Strength Test was rated level I by people with axSpA and level II by PTs (instructions unclear), leading to adaptations in the instruction manual. The SLST was rated level I by people with axSpA and level II by PTs (instruction “standing on one leg as long as possible” not useful for persons without balance deficit), leading to the adaptation that the test can be stopped after 60 seconds as the normal values are below that threshold.

Conclusion

From patient perspective, the feasibility of the tests was evaluated positive in terms of acceptance, practicability and integration (all level I). From PTs’ perspective some adaptations were necessary (level II, except BASMI). After the adaptations, the assessment battery can now be used in group exercise therapy for individuals with axSpA. In this way, the individual fitness status can be evaluated, and interventions can be adapted, and thus the quality of group exercise therapy can be continuously monitored and improved if necessary.

Acknowledgements

We thank all participants and the SVMB for their support.

Disclosure of Interests

None declared

Interplay of Oxidative Stress and Necrosis-like Cell Death in Cardiac Ischemia/Reperfusion Injury: A Focus on Necroptosis

Extensive research work has been carried out to define the exact significance and contribution of regulated necrosis-like cell death program, such as necroptosis to cardiac ischemic injury. This cell damaging process plays a critical role in the pathomechanisms of myocardial infarction (MI) and post-infarction heart failure (HF). Accordingly, it has been documented that the modulation of key molecules of the canonical signaling pathway of necroptosis, involving receptor-interacting protein kinases (RIP1 and RIP3) as well as mixed lineage kinase domain-like pseudokinase (MLKL), elicit cardioprotective effects. This is evidenced by the reduction of the MI-induced infarct size, alleviation of myocardial dysfunction, and adverse cardiac remodeling. In addition to this molecular signaling of necroptosis, the non-canonical pathway, involving Ca2+/calmodulin-dependent protein kinase II (CaMKII)-mediated regulation of mitochondrial permeability transition pore (mPTP) opening, and phosphoglycerate mutase 5 (PGAM5)–dynamin-related protein 1 (Drp-1)-induced mitochondrial fission, has recently been linked to ischemic heart injury. Since MI and HF are characterized by an imbalance between reactive oxygen species production and degradation as well as the occurrence of necroptosis in the heart, it is likely that oxidative stress (OS) may be involved in the mechanisms of this cell death program for inducing cardiac damage. In this review, therefore, several observations from different studies are presented to support this paradigm linking cardiac OS, the canonical and non-canonical pathways of necroptosis, and ischemia-induced injury. It is concluded that a multiple therapeutic approach targeting some specific changes in OS and necroptosis may be beneficial in improving the treatment of ischemic heart disease.

Quercetin alleviates diastolic dysfunction and suppresses adverse pro-hypertrophic signaling in diabetic rats

INTRODUCTION

Quercetin (Que) is a potent anti-inflammatory and antioxidant flavonoid with cardioprotective potential. However, very little is known about the signaling pathways and gene regulatory proteins Que may interfere with, especially in diabetic cardiomyopathy. Therefore, we aimed to study the potential cardioprotective effects of Que on the cardiac phenotype of type 2 diabetes mellitus (T2DM) accompanied by obesity.

METHODS

For this experiment, we used Zucker Diabetic Fatty rats (fa/fa) and their age-matched lean controls (fa/+) that were treated with either vehicle or 20 mg/kg/day of Que for 6 weeks. Animals underwent echocardiographic (echo) examination before the first administration of Que and after 6 weeks.

RESULTS

After the initial echo examination, the diabetic rats showed increased E/A ratio, a marker of left ventricular (LV) diastolic dysfunction, in comparison to the control group which was selectively reversed by Que. Following the echo analysis, Que reduced LV wall thickness and exhibited an opposite effect on LV luminal area. In support of these results, the total collagen content measured by hydroxyproline assay was decreased in the LVs of diabetic rats treated with Que. The follow-up immunoblot analysis of proteins conveying cardiac remodeling pathways revealed that Que was able to interfere with cardiac pro-hypertrophic signaling. In fact, Que reduced relative protein expression of pro-hypertrophic transcriptional factor MEF2 and its counter-regulator HDAC4 along with pSer²⁴⁶-HDAC4. Furthermore, Que showed potency to decrease GATA4 transcription factor, NFAT3 and calcineurin, as well as upstream extracellular signal-regulated kinase Erk5 which orchestrates several pro-hypertrophic pathways.

DISCUSSION

In summary, we showed for the first time that Que ameliorated pro-hypertrophic signaling on the level of epigenetic regulation and targeted specific upstream pathways which provoked inhibition of pro-hypertrophic signals in ZDF rats. Moreover, Que mitigated T2DM and obesity-induced diastolic dysfunction, therefore, might represent an interesting target for future research on novel cardioprotective agents.

Inhibition of Cardiac RIP3 Mitigates Early Reperfusion Injury and Calcium-Induced Mitochondrial Swelling without Altering Necroptotic Signalling

Receptor-interacting protein kinase 3 (RIP3) is a convergence point of multiple signalling pathways, including necroptosis, inflammation and oxidative stress; however, it is completely unknown whether it underlies acute myocardial ischemia/reperfusion (I/R) injury. Langendorff-perfused rat hearts subjected to 30 min ischemia followed by 10 min reperfusion exhibited compromised cardiac function which was not abrogated by pharmacological intervention of RIP3 inhibition. An immunoblotting analysis revealed that the detrimental effects of I/R were unlikely mediated by necroptotic cell death, since neither the canonical RIP3-MLKL pathway (mixed lineage kinase-like pseudokinase) nor the proposed non-canonical molecular axes involving CaMKIIδ-mPTP (calcium/calmodulin-dependent protein kinase IIδ-mitochondrial permeability transition pore), PGAM5-Drp1 (phosphoglycerate mutase 5-dynamin-related protein 1) and JNK-BNIP3 (c-Jun N-terminal kinase-BCL2-interacting protein 3) were activated. Similarly, we found no evidence of the involvement of NLRP3 inflammasome signalling (NOD-, LRR- and pyrin domain-containing protein 3) in such injury. RIP3 inhibition prevented the plasma membrane rupture and delayed mPTP opening which was associated with the modulation of xanthin oxidase (XO) and manganese superoxide dismutase (MnSOD). Taken together, this is the first study indicating that RIP3 regulates early reperfusion injury via oxidative stress- and mitochondrial activity-related effects, rather than cell loss due to necroptosis.

The forgotten drought of 1765-1768: Reconstructing and re-evaluating historical droughts in the British and Irish Isles

Historical precipitation records are fundamental for the management of water resources, yet rainfall observations typically span 100-150 years at most, with considerable uncertainties surrounding earlier records. Here, we analyse some of the longest available precipitation records globally, for England and Wales, Scotland and Ireland. To assess the credibility of these records and extend them further back in time, we statistically reconstruct (using independent predictors) monthly precipitation series representing these regions for the period 1748-2000. By applying the Standardized Precipitation Index at 12-month accumulations (SPI-12) to the observed and our reconstructed series we re-evaluate historical meteorological droughts. We find strong agreement between observed and reconstructed drought chronologies in post-1870 records, but divergence in earlier series due to biases in early precipitation observations. Hence, the 1800s decade was less drought prone in our reconstructions relative to observations. Overall, the drought of 1834-1836 was the most intense SPI-12 event in our reconstruction for England and Wales. Newspaper accounts and documentary sources confirm the extent of impacts across England in particular. We also identify a major, "forgotten" drought in 1765-1768 that affected the British-Irish Isles. This was the most intense event in our reconstructions for Ireland and Scotland, and ranks first for accumulated deficits across all three regional series. Moreover, the 1765-1768 event was also the most extreme multi-year drought across all regional series when considering 36-month accumulations (SPI-36). Newspaper and other sources confirm the occurrence and major socio-economic impact of this drought, such as major rivers like the Shannon being fordable by foot. Our results provide new insights into historical droughts across the British Irish Isles. Given the importance of historical droughts for stress-testing the resilience of water resources, drought plans and supply systems, the forgotten drought of 1765-1768 offers perhaps the most extreme benchmark scenario in more than 250-years.

The beliefs which motivate young male and female drivers to speed: a comparison of low and high intenders

In Australia, young drivers aged 17-24 years, and particularly males, have the highest risk of being involved in a fatal crash. Investigation of young drivers' beliefs allows for a greater understanding of their involvement in risky behaviours, such as speeding, as beliefs are associated with intentions, the antecedent to behaviour. The theory of planned behaviour (TPB) was used to conceptualise beliefs using a scenario based questionnaire distributed to licenced drivers (N=398). The questionnaire measured individual's beliefs and intentions to speed in a particular situation. Consistent with a TPB-based approach, the beliefs of those with low intentions to speed ('low intenders') were compared with the beliefs of those with high intentions ('high intenders') with such comparisons conducted separately for males and females. Overall, significant differences in the beliefs held by low and high intenders and for both females and males were found. Specifically, for females, it was found that high intenders were significantly more likely to perceive advantages of speeding, less likely to perceive disadvantages, and more likely to be encouraged to speed on familiar and inappropriately signed roads than female low intenders. Females, however, did not differ in their perceptions of support from friends, with all females reporting some level of disapproval from most friends and all females (i.e., low and high intenders) reporting approval to speed from their male friends. The results for males revealed that high intenders were significantly more likely to speed on familiar and inappropriately signed roads as well as having greater perceptions of support from all friends, except from those friends with whom they worked. Low and high intending males did not differ in their perceptions of the advantages and disadvantages of speeding, with the exception of feelings of excitement whereby high intenders reported speeding to be more exciting than low intenders. The findings are discussed in terms of how they may directly inform the content of mass media and public education campaigns aimed at encouraging young drivers to slow down.

Correlation between laminin-5 immunohistochemistry and human papillomavirus status in squamous cervical carcinoma

BACKGROUND

Human papillomavirus (HPV) plays a critical role in the carcinogenesis of squamous cervical carcinoma. Integration of viral DNA into the host genome is a major contributing factor to malignant transformation. Viral load may influence integration.

AIMS

To compare HPV status (type, viral load, integration status) between normal samples, carcinoma in situ and invasive carcinoma in order to elucidate the role of HPV in progression to invasive lesions.

METHODS

The study population comprised 10 biopsy samples from each diagnostic group. Laminin-5 immunohistochemistry was performed to distinguish invasive carcinoma from non-invasive high-grade lesions. Real-time PCR was used to detect specific HPV types, viral load and integrated HPV, with quantification of viral E2 and E6 genes.

RESULTS

Invasive carcinomas contained a higher number of laminin-5 immunoreactive cells as compared to non-invasive lesions. Almost all samples contained HPV, with a higher viral load and copy number of HPV16 integrated in E2 in cases of laminin-5 immunoreactivity and cases of invasive carcinoma. High HPV16 viral load was associated with more integrated copies in E2.

CONCLUSIONS

HPV is important in progression from carcinoma in situ to invasive carcinoma. Viral load and HPV integration influence the development of cervical cancer towards invasiveness. Overall HPV status may be more predictive of patient outcome and may influence patient management.

Blood vitamin concentrations in privately owned dogs fed non-standardized commercial diets and after intake of diets with specified vitamin concentrations

The objective was to investigate in a survey study the blood vitamin concentrations in healthy dogs fed non-specified commercial complete diets and in an intervention study to determine the effects of defined dietary vitamin intakes on blood vitamin levels and hair and skin condition. Sixty-four privately owned dogs, aged from 1 to 8 years, without history of skin or coat problems were included. All animals were fed commercial complete diets with uncertain vitamin concentrations before enrolment. The animals were assigned, according to weight and gender, to four groups with graded vitamin intakes. The blood vitamin levels and skin and coat quality of the dogs were investigated at days 0 and day 122. Coat and hair condition was not influenced by the experimental diets. The retinol concentrations were reduced at the end of the experiment compared with the baseline levels, retinyl esters were not influenced. 25-Hydroxycholecalciferol decreased in all groups, alpha-tocopherol was constant or tended to decrease. Ascorbic acid, thiamine pyrophosphate and riboflavin concentrations were not affected by treatment, flavin adenine dinucleotide and pyridoxal-5'-phosphate were partially reduced on day 122. Cobalamin, pantothenate and biotin concentrations increased with higher dietary intakes, folate levels in tendency. In conclusion, this study gives a survey of blood vitamin concentrations in healthy dogs and provides a data base for the evaluation of the vitamin status in health and disease.

Increased bone fracture prevalence in postmenopausal women suffering from pollen-allergy

INTRODUCTION

Our aim was to investigate whether pollen-allergy can affect bone mass and fractures in postmenopausal women.

METHODS

A total of 125 postmenopausal pollen-allergic women (mean age: 61.26 yr) were split into four groups: (1) treated with neither H1 histamine receptor (H1R) antagonist nor inhaled corticosteroid (n=43); (2) treated only with H1R antagonist (n=53); (3) treated with both H1R antagonist and inhaled corticosteroid (n=17); (4) treated with only inhaled corticosteroid (n=12). Treatment, in the appropriate groups, had occurred for at least 5 years, seasonally. One-hundred non-allergic postmenopausal subjects matched for age, body mass index (BMI), and age at menopause served as controls.

RESULTS

Overweight and obesity (25 kg/m(2) < or =BMI) were common among the allergic women (76%). Allergic patients without treatment had a slightly lower bone density than their non-allergic counterparts. The rate (34.9%) of prevalent low-energy fractures (distal forearm, hip, and clinical vertebral fractures) in untreated allergic patients was almost triple that observed in non-allergic women (13%, chi(2) p=0.003). Bone fracture occurred more often in H1R-only treated patients (30.19%) than in controls (chi(2) p=0.01); however, clinical vertebral or hip fractures developed neither in those treated only with H1R antagonist nor in those who received both H1R antagonist and inhaled corticosteroid. Bone fractures were more frequent among patients with inhaled steroid treatment than among patients with a combined treatment of inhaled steroid and antihistamine (50 versus 29.4%). BMI predicted prevalent fractures at 1.278 (95% CI: 1.047-1.559, p=0.016) for a 1 kg/m(2) increase among untreated allergic patients.

CONCLUSION

In conclusion, we found a high prevalence of low-energy fractures among pollen-allergic postmenopausal women which was associated with obesity. It is possible that the H1R antagonists compensate for both the negative effect of pollen-allergy and the adverse effect of inhaled corticosteroid treatment on bone fracture risk.

Is There Any Connection Between the Presence of Kidney Stones in Primary Hyperparathyroidism and the Location of an Underlying Adenoma?

The majority of the patients with primary hyperparathyroidism (pHPT) recurrently produce kidney stones, while the rest have other clinical manifestations. The aim of this study was to examine the possibility of an association between the presence of kidney stones and the location of an underlying adenoma. This was a retrospective evaluation of the records of 91 patients (10 males, 81 females, mean age: 61.9 years [20 - 70 yrs]) operated for primary hyperparathyroidism between 1995 and 2000. One patient was excluded due to carcinoma. Kidney stones were found in 55 cases and other clinical symptoms in 35 cases. In 50 of the 55 patients (91 %) with kidney stones, the adenoma was located in the left inferior parathyroid gland (chi2 = 67.5, p < 0.00,001), while in 24 of the 35 patients (69 %) without kidney stones, the adenoma was in the right inferior parathyroid gland (chi2 = 43.9, p < 0.0001). These results suggest that the location of the adenoma may influence the presence of kidney stones in pHPT. It is proposed that the biologic effects of parathyroid hormone could differ depending on which of the four parathyroid glands it was secreted in, or the four glands may produce different biologically active fragments.

Targeted deletion of histidine decarboxylase gene in mice increases bone formation and protects against ovariectomy-induced bone loss

Targeted disruption of the histidine decarboxylase gene (HDC(-/-)), the only histamine-synthesizing enzyme, led to a histamine-deficient mice characterized by undetectable tissue histamine levels, impaired gastric acid secretion, impaired passive cutaneous anaphylaxis, and decreased mast cell degranulation. We used this model to study the role of histamine in bone physiology. Compared with WT mice, HDC(-/-) mice receiving a histamine-free diet had increased bone mineral density, increased cortical bone thickness, higher rate of bone formation, and a marked decrease in osteoclasts. After ovariectomy, cortical and trabecular bone loss was reduced by 50% in HDC(-/-) mice compared with WT. Histamine deficiency protected the skeleton from osteoporosis directly, by inhibiting osteoclastogenesis, and indirectly, by increasing calcitriol synthesis. Quantitative RT-PCR showed elevated 25-hydroxyvitamin D-1alpha-hydroxylase and markedly decreased 25-hydroxyvitamin D-24-hydroxylase mRNA levels. Serum parameters confirming this indirect effect included elevated calcitriol, phosphorus, alkaline phosphatase, and receptor activator of NF-kappaB ligand concentrations, and suppressed parathyroid hormone concentrations in HDC(-/-) mice compared with WT mice. After ovariectomy, histamine-deficient mice were protected from bone loss by the combination of increased bone formation and reduced bone resorption.

Decreased bone density, elevated serum osteoprotegerin, and beta-cross-laps in Wilson disease

Osteopathia has been reported in Wilson disease (WD), but bone density has not been measured; therefore, we performed bone mineral density (BMD), bone mineral content (BMC), and quantitative bone ultrasound (QUS) assessments, as well as measured the serum levels of osteocalcin (OCN), beta-cross-laps (beta-CTx's), and the recently discovered osteoprotegerin (OPG) and its ligand RANKL to investigate the underlying mechanism of osseous disorders. Serum OCN, beta-CTx, OPG, and RANKL levels were measured by ELISA in 21 WD patients and in 20 age- and gender-matched healthy subjects. BMD, BMC, and QUS parameters were also determined. Osteoporosis was present in 9/21 (43%) WD patients. Abnormal QUS parameters were found in 7 (33%) of the patients. Although serum OCN levels were similar in patients and controls (29.93 +/- 24.65 mg/ml vs. 29.84 +/- 6.89 mg/ml), beta-CTx and OPG levels were significantly increased in WD compared with the healthy controls (625.4 +/- 312.3 pg/ml vs. 423.6 +/- 144.3 pg/ml and p = 0.022 and 7.2 +/- 3.4 pM vs. 3.5 +/- 1.0 pM and p < 0.001, respectively). No difference was observed in the RANKL level. There was a positive correlation between OCN and beta-CTx (r = 0.55; p = 0.01). We proved high occurrence of osteoporosis in WD. Negative bone remodeling balance is a consequence of increased bone resorption, which is indicated by elevated beta-CTx. The novel finding of elevated serum OPG may reflect a compensatory reaction to enhanced osteoclast activity, despite the normal OCN level.

Ultra-short pulse (femtosecond) laser surgery: initial use in LASIK flap creation

The highly localized tissue effects of low energy femtosecond duration (ultrashort) laser pulses may be used to create three-dimensional intrastromal resections with micron precision and minimized collateral tissue damage. A surgical laser system that produces and delivers such pulses has been developed and tested clinically for creation of a corneal flap in LASIK. Expanded evaluation of this technology in this and additional keratorefractive applications is currently underway.

Prevention of corticosteroid-induced osteoporosis by alfacalcidol

We studied the effect of alphacalcidol (1-alpha-hydroxycholecalciferol) on bone metabolism in patients who were placed on glucocorticoid therapy. We selected 41 women (age: 32-52 yrs) who were recently diagnosed with systemic lupus erythematodes, multiple sclerosis, rheumatoid arthritis or asthma bronchiale. Patients did not have other disease or take drugs known to influence bone metabolism. Patients were randomly enrolled into two groups and were given 5-25 mg prednisone daily. After 4 weeks, group A (n = 21) received 0.5-1.0 microgram (mean = 0.54 +/- 0.03 microgram) alphacalcidol and group B (control; n = 20) was given 500 mg calcium daily for three years. There were no significant differences in age and steroid doses between groups. Serum calcium (Ca), osteocalcin (OC), collagen I C-terminal propeptide (PICP), parathyroid hormone (PTH), and urinary calcium and deoxypyridinoline crosslink excretion (DPD) were measured before corticosteroid administration, and before alphacalcidol or calcium treatment as well as 6 weeks, 6 months, and 1, 2, and 3 years later. Bone mineral density (BMD) was examined before treatment and 6 months, 1, 2, and 3 years later by DEXA and SPA. OC and PICP decreased significantly after 4 weeks on steroid in both groups and increased in group A but not in group B after 6 weeks of treatment with alphacalcidol and remained unchanged for 3 years. Serum PTH increased in both groups after 4 weeks of glucocorticoid treatment and was reduced in group A, but not in group B, after 6 weeks on alphacalcidol. Serum Ca, urinary Ca, and DPD did not change significantly in either group during the study period. Lumbar spine and femoral neck BMD were significantly reduced in group B after 6 months and 1 year, respectively, and continued to decrease during the study, while no significant change in group A was observed. BMD of the radius did not change in either group for 2 years but there was a significant reduction by the third year in group B. Based on these results, alphacalcidol treatment appears to be effective in preventing glucocorticoid-induced bone loss in these patients by reducing secondary hyperparathyroidism and stimulating bone formation.

Mechanism of STAT3 activation by insulin-like growth factor I receptor

Recent evidence indicates that STAT proteins can be activated by a variety of receptor and non-receptor protein-tyrosine kinases. Unlike cytokine-induced activation of STATs, where JAKs are known to play a pivotal role in phosphorylating STATs, the mechanism for receptor protein-tyrosine kinase-mediated activation of STATs remains elusive. In this study, we investigated the activation of STAT proteins by the insulin-like growth factor I receptor (IGF-IR) in vitro and in vivo and assessed the role of JAKs in the process of activation. We found that STAT3, but not STAT5, was activated in response to IGF-I in 293T cells cotransfected with IGF-IR and STAT expression vectors. Moreover, tyrosine phosphorylation of STAT3, JAK1, and JAK2 was increased upon IGF-I stimulation of endogenous IGF-IR in 293T cells transfected with the respective STAT or JAK expression vector. Supporting the observation in 293T cells, endogenous STAT3 was tyrosine-phosphorylated upon IGF-I stimulation in the muscle cell line C2C12 as well as in various embryonic and adult mouse organs during different stages of development. Dominant-negative JAK1 or JAK2 was able to block the IGF-IR-mediated tyrosine phosphorylation of STAT3 in 293T cells. A newly identified family of proteins called SOCS (suppressor of cytokine signaling), including SOCS1, SOCS2, SOCS3 and CIS, was able to inhibit the IGF-I-induced STAT3 activation as well with varying degrees of potency, in which SOCS1 and SOCS3 appeared to have the higher inhibitory ability. Inhibition of STAT3 activation by SOCS could be overcome by overexpression of native JAK1 and JAK2. We conclude that IGF-I/IGF-IR is able to mediate activation of STAT3 in vitro and in vivo and that JAKs are essential for the process of activation.

Serum insulin-like growth factor-I, insulin-like growth factor binding proteins, and bone mineral content in hyperthyroidism

The mechanism by which thyroid hormones promote bone growth has not yet been elucidated. In vitro, thyroid hormones stimulate insulin-like growth factor-I (IGF-I) production by osteoblasts, which is important for the anabolic effects of the hormone on bone. To determine whether the IGF-I/IGF binding protein (IGFBP) profile is affected when thyroid hormone production is altered in vivo, we studied 36 women who had recently been diagnosed with hyperthyroidism (age: 29-67 years; 19 with Graves' disease, 17 with toxic nodular goiter) and 36 age-matched healthy women as controls. Serum IGF-I, and its binding proteins (IGFBP-3, IGFBP-4, and IGFBP-5), as well as bone mineral density (BMD) at the lumbar spine, femoral neck, and radius midshaft were measured before and 1 year after antithyroid (methimazole) treatment. Serum IGF-I levels were significantly increased in the hyperthyroid patients before treatment (214 +/- 18.2 ng/mL vs. 145 +/- 21.3 ng/mL; p < 0.05). There was no difference in IGF-I levels of patients with Graves' disease and toxic nodular goiter. Serum IGF-I concentrations returned to normal after treatment with methimazole. Serum IGFBP-3 and IGFBP-4 values were significantly elevated in the hyperthyroid group before treatment (3960 +/- 220 ng/mL and 749.7 +/- 53.1 ng/mL vs. 2701 +/- 180 ng/mL and 489.9 +/- 32.4 ng/mL; p < 0.05 and p < 0.01, respectively) and were reduced to those of controls after treatment. Serum IGFBP-5 of hyperthyroid subjects was not different from that of controls either before or after therapy. Serum free thyroxine showed a positive correlation with serum levels of IGF-I (r = 0.73, p < 0.05), IGFBP-3 (r = 0.59, p < 0.05), and IGFBP-4 (r = 0.67, p < 0.05) but not IGFBP-5. BMD at the radius midshaft was significantly lower in hyperthyroid patients at the start of the study and showed a positive correlation with serum IGF-I (r = 0.58; p < 0.001) and a negative correlation with IGFBP-4 (r = -0.61; p < 0.05). Radius BMD showed a 7.2% increase in the hyperthyroid group after 1 year of methimazole treatment, and the correlation between BMD and serum IGF-I disappeared. Our data indicate that thyroid hormones may influence the IGF-I/IGFBP system in vivo in hyperthyroidism. The anabolic effects of increased levels of IGF-I may be limited in hyperthyroidism due to the increases of inhibitory IGFBPs that can counteract the anabolic effects and contribute to the observed net bone loss.

Plasma and lymph pharmacokinetics of recombinant human interleukin-2 and polyethylene glycol-modified interleukin-2 in pigs

Modification of recombinant human interleukin-2 (IL-2) with polyethylene glycol (PEG-IL-2) decreases clearance and might favor absorption into the lymphatics, due to its increased molecular weight. In the present study, we compared the plasma and lymph concentrations of IL-2 and PEG-IL-2 in Yorkshire pigs. The IL-2 regimens were i.v. bolus (0.1-1.6 x 10(6) I.U., MIU/kg), 15-min i.v. infusion (0.1 MIU/kg), or s.c. bolus (0.1-3.0 MIU/kg). The PEG-IL-2 doses were 15-min i.v. infusion (0.01 MIU/kg) or s.c. bolus (0.01-0. 10 MIU/kg). Lymph and plasma data were analyzed using noncompartmental methods and NONMEM. Bioavailability of IL-2 was route- and dose-dependent. Bioavailability of i.v. bolus doses of >/=0.16 MIU/kg was complete but only 39% at 0.1 MIU/kg. For the infusion and s.c. doses, bioavailability was 28 and 42%, respectively. Noncompartmental and NONMEM estimates of clearance and volume of distribution at steady state agreed: 300 ml/h/kg and 570 ml/kg, respectively, for IL-2. The ratio of the area under the curve in lymph and plasma increased from 0.67 to 3.4 when comparing i.v. and s.c. routes, and the s.c. delivery advantage (ratio of dose-normalized ratio of the area under the curve in lymph after s.c. and i.v. administration) was 6.6 to 16. For PEG-IL-2, bioavailability was 100%, clearance was 5.9 ml/h/kg, and volume of distribution at steady state was 370 ml/kg. The ratio of the area under the curve in lymph and plasma increased from 0.33 (i.v.) to 1. 2 (s.c.), and the s.c. delivery advantage was 3.8. Subcutaneous dosing would be favored over i.v. dosing, and IL-2 would be favored over PEG-IL-2 to maximize lymph and minimize plasma exposure. Because IL-2 efficacy may be related to lymph concentrations, dosing regimens can now be designed to test this hypothesis.

Familial aspects of male homosexuality

Research has generally supported the existence of familial-genetic factors for male sexual orientation, but has not shed much light on the specific nature of those influences. Gay men with gay brothers provide the opportunity to examine several hypotheses. Sixty-six men, representing 37 gay male sibling pairs, completed questionnaires assessing behavior on various measures including childhood and adult gender nonconformity, timing of awareness of homosexual feelings, self-acceptance, and the quality of family relationships. Consistent with prior findings using twins, gay brothers were similar in their degree of childhood gender non-conformity, suggesting that this variable may distinguish etiologically (e.g., genetically) heterogeneous subtypes. The large majority of gay men with brothers knew about their own homosexual feelings before they learned about their brothers' homosexual feelings, suggesting that discovery of brothers' homosexuality is not an important cause of male homosexuality.

An in vivo model of femtosecond laser intrastromal refractive surgery

BACKGROUND AND OBJECTIVE

To develop an animal model for evaluation of femtosecond laser intrastromal refractive surgery.

METHODS

Intrastromal photodisruption was performed in New Zealand Albino rabbits using a femtosecond laser system. This surgical pattern consisted of a 100 microm-tick pyramid of laser pulses starting 180 microm below the corneal surface. Animals underwent serial slit lamp examinations and corneal thickness measurements at 1,3,7,14, and 28 days, then monthly up to 1 year.

RESULTS

Approximately 70 microm of central corneal thinning were seen at 1 week, remaining stable up to 7 months.

CONCLUSIONS

Intrastromal photodisruption with femtosecond lasers produced consistent changes in corneal thickness without loss of corneal transparency. These changes were more stable than those produced with excimer laser procedures in a similar animal model.

Naturally occurring extracellular matrix as a scaffold for musculoskeletal repair

The use of naturally occurring extracellular matrix materials as scaffolds for the repair and regeneration of tissues is receiving increased attention. The present study evaluates the use of the extracellular matrix derived from porcine small intestinal submucosa as a scaffold for anterior cruciate ligament replacement in a goat model. Sixty healthy adult female goats were divided into two equal groups of 30 each. The right anterior cruciate ligament of each goat was removed surgically and replaced with either a patellar tendon autograft or a small intestinal submucosa anterior cruciate ligament scaffold. Three animals from each group were sacrificed at 6 weeks, 3 months, 6 months, and 1 year after surgery and grafts were harvested for histopathologic examination. Six animals from each group were sacrificed immediately after surgery, 3 months, and 1 year after surgery and the grafts were harvested for biomechanical testing. There was no evidence for an adverse clinical response to the xenogeneic small intestinal submucosa scaffold. Anterior drawer values were not different between the two groups at any point. The failure force of the patellar tendon autograft increased from 253 N at Time 0 to 879 N at 12 months. The failure force for the small intestinal submucosa repair device was 721 N at Time 0, decreased to 293 N at 3 months, followed by an increase to 706 N at 12 months. Histopathologic analysis showed a mixed inflammatory cell presence within the small intestinal submucosa scaffold including macrophages and lymphocytes in the early months after surgery. The inflammatory cells disappeared in the later stages of remodeling and the histologic appearance of the small intestinal submucosa remodeled grafts and the patellar tendon autografts were indistinguishable at 12 months. Xenogeneic small intestinal submucosa holds promise as a resorbable bioscaffold for anterior cruciate ligament repair in the goat model.

Lamellar Refractive Surgery with Scanned Intrastromal Picosecond and Femtosecond Laser Pulses in Animal Eyes

PURPOSE

To evaluate the use of scanned intrastromal picosecond and femtosecond laser pulses in lamellar refractive surgical procedures.

METHODS

Intrastromal corneal photodisruption was performed in fresh porcine and primate cadaver eyes with a solid-state femtosecond laser. Laser pulses were focused 150 to 200 microns below the epithelial surface and scanned in a spiral pattern to create a plane. A flap was made by scanning an arc pattern from the plane of the spiral to the surface of the cornea. Tissue plane separation was graded using a standard scale, while internal surfaces were analyzed by scanning electron microscopy. Comparison was made to a picosecond laser system using the same delivery system device. Creation of a stromal lenticule for in situ keratomileusis was also demonstrated and compared with both laser systems.

RESULTS

For femtosecond pulses, tissue separation was achieved best with pulse energies from 4 to 8 microJ and spot separations from 10-15 microns. Picosecond pulses accomplished less complete separations with pulse energies of 25 microJ and spot separations from 10 to 20 microns. Surface quality corresponded to dissection results, with high-grade dissections resulting in a smooth surface appearance, versus a more irregular surface for low-grade dissections. Although high-grade dissections could be created with picosecond pulses (with optimal parameters) in ex vivo porcine eyes, only femtosecond parameters produced similar results in ex vivo primate eyes.

CONCLUSION

In contrast to previous attempts using picosecond lasers which require additional mechanical dissection, high precision lamellar refractive surgery may be practical with femtosecond laser pulses.

The efficiency of antigen recognition by CD8+ CTL clones is determined by the frequency of serial TCR engagement

Using H-2Kd-restricted CTL clones, which are specific for a photoreactive derivative of the Plasmodium berghei circumsporozoite peptide PbCS(252-260) (SYIPSAEKI) and permit assessment of TCR-ligand interactions by TCR photoaffinity labeling, we have previously identified several peptide derivative variants for which TCR-ligand binding and the efficiency of Ag recognition deviated by fivefold or more. Here we report that the functional CTL response (cytotoxicity and IFN-gamma production) correlated with the rate of TCR-ligand complex dissociation, but not the avidity of TCR-ligand binding. While peptide antagonists exhibited very rapid TCR-ligand complex dissociation, slightly slower dissociation was observed for strong agonists. Conversely and surprisingly, weak agonists typically displayed slower dissociation than the wild-type agonists. Acceleration of TCR-ligand complex dissociation by blocking CD8 participation in TCR-ligand binding increased the efficiency of Ag recognition in cases where dissociation was slow. In addition, permanent TCR engagement by TCR-ligand photocross-linking completely abolished sustained intracellular calcium mobilization, which is required for T cell activation. These results indicate that the functional CTL response depends on the frequency of serial TCR engagement, which, in turn, is determined by the rate of TCR-ligand complex dissociation.

Differential requirement for CD4 help in the development of an antigen-specific CD8+ T cell response depending on the route of immunization

Previous studies in our laboratory have shown that DBA/2 mice injected i.p. with syngeneic P815 tumor cells transfected with the HLA-CW3 gene (P815-CW3) showed a dramatic expansion of activated CD8+CD62L- T cells expressing exclusively the Vbeta10 segment. We have used this model to study the regulatory mechanisms involved in the development of the CW3-specific CD8+ response, with respect to different routes of immunization. Whereas both intradermal (i.d.) and i.p. immunization of DBA/2 mice with P815-CW3 cells led to a strong expansion of CD8+CD62L-Vbeta10+ cells, only the i.d. route allowed this expansion after immunization with P815 cells transfected with a minigene coding for the antigenic epitope CW3 170-179 (P815 miniCW3). Furthermore, depletion of CD4+ T cells in vivo completely abolished the specific response of CD8+CD62L-Vbeta10+ cells and prevented the rejection of P815-CW3 tumor cells injected i.p., whereas it did not affect CD8S+CD62L-Vbeta10+ cell expansion after i.d. immunization with either P815-CW3 or P815 miniCW3. Finally, the CW3-specific CD8+ memory response was identical whether or not CD4+ T cells were depleted during the primary response. Collectively, these results suggest that the CD8+ T cell response to P815-CW3 tumor cells injected i.p. is strictly dependent upon recognition of a helper epitope by CD4+ T cells, whereas no such requirement is observed for i.d. injection.

Flow-microfluorometric monitoring of oligoclonal CD8+ T cell responses to an immunodominant Moloney leukemia virus-encoded epitope in vivo

The TCR repertoire of CD8+ T cells specific for Moloney murine leukemia virus (M-MuLV)-associated Ags has been investigated in vitro and in vivo. Analysis of a large panel of established CD8+ CTL clones specific for M-MuLV indicated an overwhelming bias for V beta4 in BALB/c mice and for V beta5.2 in C57BL/6 mice. These V beta biases were already detectable in mixed lymphocyte:tumor cell cultures established from virus-immune spleen cells. Furthermore, direct ex vivo analysis of PBL from BALB/c or C57BL/6 mice immunized with syngeneic M-MuLV-infected tumor cells revealed a dramatic increase in CD8+ cells expressing V beta4 or V beta5.2, respectively. M-MuLV-specific CD8+ cells with an activated (CD62L-) phenotype persisted in blood of immunized mice for at least 2 mo, and exhibited decreased TCR and CD8 levels compared with their naive counterparts. In C57BL/6 mice, most M-MuLV-specific CD8+ CTL clones and immune PBL coexpressed V alpha3.2 in association with V beta5.2. Moreover, these V beta5.2+ V alpha3.2+ cells were shown to recognize the recently described H-2Db-restricted epitope (CCLCLTVFL) encoded in the leader sequence of the M-MuLV gag polyprotein. Collectively, our data demonstrate a highly restricted TCR repertoire in the CD8+ T cell response to M-MuLV-associated Ags in vivo, and suggest the potential utility of flow-microfluorometric analysis of V beta and V alpha expression in the diagnosis and monitoring of viral infections.

Compact directly diode-pumped femtosecond Nd:glass chirped-pulse-amplification laser system

An all-solid-state longitudinally diode-pumped Nd:glass chirped-pulse-amplification laser system producing pulses of 50-MW peak power has been developed. The diode-pumped Nd:glass regenerative amplifier produces pulses with energies as great as 56microJ at a 1-kHz repetition rate and pulse durations as short as 450 fs after compression in a compact single holographic-transmission-grating stretcher-compressor arrangement. Further, spectral gain shaping was shown to extend the bandwidth that was supported in the low-gain amplifier. To the best of our knowledge, this system provides the highest peak and average power obtained from a directly diode-pumped femtosecond laser.

Serum interleukin-6 and bone metabolism in patients with thyroid function disorders

To determine the possible involvement of interleukin-6 (IL-6) in the bone loss of hyperthyroidism, relationships between thyroid status, biochemical and densitometric parameters of bone metabolism, and IL-6 were studied in female subjects. Patients with hyperthyroidism caused by either toxic nodular goiter or Graves' disease had significantly higher serum IL-6 concentrations than normal controls. Within the control group, serum IL-6 was higher in postmenopausal than in premenopausal women, but this influence of menopausal status was not seen in the hyperthyroid patients. The production of IL-6 by blood mononuclear cells was higher in cells from the hyperthyroid women. Bone turnover was increased in the hyperthyroid patients based on serum osteocalcin and urinary deoxypyridinoline excretion, and the hyperthyroid group also had reduced radius bone mineral content (BMC). A subgroup of hyperthyroid patients who had the lowest BMC (values more than 1 SD below normal age-matched controls) also had serum IL-6 concentrations significantly greater than those of hyperthyroid patients showing less reduction of BMC. The correlations observed in this study support the possibility that IL-6 plays a role in mediating the bone loss that results from excess thyroid hormone.

The reproducibility of nuclear morphometric measurements in invasive breast carcinoma

The intraobserver and interobserver reproducibility of computerized nuclear morphometry was determined in repeated measurements of 212 samples of invasive breast cancer. The influence of biological variation and the selection of the measurement area was also tested. Morphometrically determined mean nuclear profile area (Pearson's r 0.89, grading efficiency (GE) 0.95) and standard deviation (SD) of nuclear profile area (Pearson's r 0.84, GE 0.89) showed high reproducibility. In this respect, nuclear morphometry equals with other established methods of quantitative pathology and exceeds the results of subjective grading of nuclear atypia in invasive breast cancer. A training period of eight days was sufficient to produce clear improvement in consistency of nuclear morphometry results. By estimating the sources of variation it could be shown that the variation associated with the measurement procedure itself is small. Instead, sample associated variation is responsible for the majority of variation in the measurements (82.9% in mean nuclear profile area and 65.9% in SD of nuclear profile area). This study points out that when standardized methods are applied computerized morphometry is a reproducible and reliable method of assessing nuclear atypia in invasive breast cancer. For further improvement special emphasize should be put on sampling rules of selecting the microscope fields and measurement areas.

An educational intervention to increase use of the Glasgow Coma Scale by emergency department personnel

Data from a large series of acutely injured patients revealed the Glasgow Coma Score was acquired in less than one half of those for whom it should have been documented. To improve these statistics, a five-part educational intervention based on an application of the PRECEDE-PROCEED model was developed. The study populations consisted of hospital-based nurse-managers and their emergency department nursing staff. Evaluation of the educational intervention's effectiveness suggested (1) simply conveying benefits of a particular patient care practice is insufficient to bring about immediate and permanent changes and (2) the most significant changes occurred in settings in which a formal policy and formal data collection procedures were established to accompany and reinforce the educational intervention. On-site advocacy and physician support are essential if changes in nursing practice are to occur in hospital emergency departments.

Induction of CTL in vivo by major histocompatibility complex class I-peptide complexes covalently associated on the cell surface

The identification of endogenously produced antigenic peptides presented by MHC class I molecules has opened the way to peptide-based strategies for CTL induction in vivo. Here we demonstrate that the induction in vivo of CTL directed against naturally processed antigens can be triggered by injection of syngeneic cells expressing covalent major histocompatibility complex class I-peptide complexes. In the model system used, the induction of HLA-Cw3 specific cytotoxic T lymphocytes (CTL) in mice by cell surface-associated, covalent H-2Kd (Kd)-Cw3 peptide complexes was investigated. The Kd-restricted Cw3 peptide 170-179 (RYLKNGKETL), which mimics the major natural epitope recognized by Cw3-specific CTL in H-2d mice, was converted to a photoreactive derivative by replacing Arg-170 with N-beta-(4-azidosalicyloyl)-L-2,3-diaminopropionic acid. This peptide derivative was equivalent to the parental Cw3 peptide in terms of binding to Kd molecules and recognition by Cw3-specific CTL clones and could be cross-linked efficiently and selectively to Kd molecules on the surface of Con A-stimulated spleen cells from H-2d mice. Photocross-linking prevented the rapid dissociation of Kd-peptide derivative complexes that takes place under physiological conditions. Cultures of spleen cells or peritoneal exudate cells from mice inoculated i.p. with peptide-pulsed and photocross-linked cells developed a strong CTL response following antigenic stimulation in vitro. The cultured cells efficiently lysed not only target cells sensitized with the Cw3 170-179 peptide but also target cells transfected with the Cw3 gene. Moreover, their TCR preferentially expressed V beta 10 and J alpha pHDS58 segments as well as conserved junctional sequences, as has been observed previously in Cw3-specific CTL responses. In contrast, no Cw3-specific CTL response could be obtained in cultures derived from mice injected with Con A-stimulated spleen cells pulsed with the peptide derivative without photocross-linking.

Immunohistochemical localization of Trk receptor protein in pediatric small round blue cell tumors

Expression of Trk protein has been documented by Northern analysis in neuroblastomas with good prognosis. To localize the expression of this protein at the cellular level within individual tumors, we adapted a recently characterized pan-Trk antibody for use in formalin fixed, paraffin-embedded tissue. We have examined a group of small round blue cell tumors occurring in children, including both high and low stage neuroblastomas, to assess the presence or absence of Trk expression and its cellular localization. Positive staining for Trk protein was observed in four of four low stage (good prognosis) neuroblastomas, five of five primitive neuroectodermal tumors/Ewing's sarcoma, five of five rhabdomyosarcomas, and no lymphomas. Within the neuroblastomas, expression of Trk protein was most striking in ganglion cells, in which positive cytoplasmic staining was demonstrated regardless of tumor stage. The latter observation may lend further insight into the pathobiology of this malignant childhood tumor.