Editorial: Oral Health: luxury or a fundamental human right? The necessity of introducing a dedicated oral health budget and Proportionate Universalism in Greece

Oral health is an integral part of overall health and critically affects quality of life as well as personal and social well-being. Poor oral health negatively influences general health and creates medical, financial and social burdens for individuals, families and health systems. The US Office of Disease Prevention and Health Promotion (2021) sees use of the oral health care system as a leading health indicator. Oral health improvement is an important step to reduce socioeconomic inequalities and promote the UN Sustainable Development Strategy (Wang et al., 2020, Huang and Chang 2022). Moreover, "achieving the highest attainable standard of oral health is a fundamental human right of every human being" (WHO 2022a).

Surface waves and crustal structure on Mars

We detected surface waves from two meteorite impacts on Mars. By measuring group velocity dispersion along the impact-lander path, we obtained a direct constraint on crustal structure away from the InSight lander. The crust north of the equatorial dichotomy had a shear wave velocity of approximately 3.2 kilometers per second in the 5- to 30-kilometer depth range, with little depth variation. This implies a higher crustal density than inferred beneath the lander, suggesting either compositional differences or reduced porosity in the volcanic areas traversed by the surface waves. The lower velocities and the crustal layering observed beneath the landing site down to a 10-kilometer depth are not a global feature. Structural variations revealed by surface waves hold implications for models of the formation and thickness of the martian crust.

Largest recent impact craters on Mars: Orbital imaging and surface seismic co-investigation

Two >130-meter-diameter impact craters formed on Mars during the later half of 2021. These are the two largest fresh impact craters discovered by the Mars Reconnaissance Orbiter since operations started 16 years ago. The impacts created two of the largest seismic events (magnitudes greater than 4) recorded by InSight during its 3-year mission. The combination of orbital imagery and seismic ground motion enables the investigation of subsurface and atmospheric energy partitioning of the impact process on a planet with a thin atmosphere and the first direct test of martian deep-interior seismic models with known event distances. The impact at 35°N excavated blocks of water ice, which is the lowest latitude at which ice has been directly observed on Mars.

Declining Levels and Bioavailability of IGF-I in Cardiovascular Aging Associate With QT Prolongation-Results From the 1946 British Birth Cohort

Background

As people age, circulating levels of insulin-like growth factors (IGFs) and IGF binding protein 3 (IGFBP-3) decline. In rat cardiomyocytes, IGF-I has been shown to regulate sarcolemmal potassium channel activity and late sodium current thus impacting cardiac repolarization and the heart rate-corrected QT (QTc). However, the relationship between IGFs and IGFBP-3 with the QTc interval in humans, is unknown.

Objectives

To examine the association of IGFs and IGFBP-3 with QTc interval in an older age population-based cohort.

Methods

Participants were from the 1946 Medical Research Council (MRC) National Survey of Health and Development (NSHD) British birth cohort. Biomarkers from blood samples at age 53 and 60-64 years (y, exposures) included IGF-I/II, IGFBP-3, IGF-I/IGFBP-3 ratio and the change (Δ) in marker levels between the 60-64 and 53y sampled timepoints. QTc (outcome) was recorded from electrocardiograms at the 60-64y timepoint. Generalized linear multivariable models with adjustments for relevant demographic and clinical factors, were used for complete-cases and repeated after multiple imputation.

Results

One thousand four hundred forty-eight participants were included (48.3% men; QTc mean 414 ms interquartile range 26 ms). Univariate analysis revealed an association between low IGF-I and IGF-I/IGFBP-3 ratio at 60-64y with QTc prolongation [respectively: β -0.30 ms/nmol/L, (95% confidence intervals -0.44, -0.17), p < 0.001; β-28.9 ms/unit (-41.93, -15.50), p < 0.001], but not with IGF-II or IGFBP-3. No association with QTc was found for IGF biomarkers sampled at 53y, however both ΔIGF-I and ΔIGF-I/IGFBP-3 ratio were negatively associated with QTc [β -0.04 ms/nmol/L (-0.08, -0.008), p = 0.019; β -2.44 ms/unit (-4.17, -0.67), p = 0.007] while ΔIGF-II and ΔIGFBP-3 showed no association. In fully adjusted complete case and imputed models (reporting latter) low IGF-I and IGF-I/IGFBP-3 ratio at 60-64y [β -0.21 ms/nmol/L (-0.39, -0.04), p = 0.017; β -20.14 ms/unit (-36.28, -3.99), p = 0.015], steeper decline in ΔIGF-I [β -0.05 ms/nmol/L/10 years (-0.10, -0.002), p = 0.042] and shallower rise in ΔIGF-I/IGFBP-3 ratio over a decade [β -2.16 ms/unit/10 years (-4.23, -0.09), p = 0.041], were all independently associated with QTc prolongation. Independent associations with QTc were also confirmed for other previously known covariates: female sex [β 9.65 ms (6.65, 12.65), p < 0.001], increased left ventricular mass [β 0.04 ms/g (0.02, 0.06), p < 0.001] and blood potassium levels [β -5.70 ms/mmol/L (-10.23, -1.18) p = 0.014].

Conclusion

Over a decade, in an older age population-based cohort, declining levels and bioavailability of IGF-I associate with prolongation of the QTc interval. As QTc prolongation associates with increased risk for sudden death even in apparently healthy people, further research into the antiarrhythmic effects of IGF-I on cardiomyocytes is warranted.

Assessment of InSight Landing Site Predictions

Comprehensive analysis of remote sensing data used to select the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) landing site correctly predicted the atmospheric temperature and pressure profile during entry and descent, the safe landing surface, and the geologic setting of the site. The smooth plains upon which the InSight landing site is located were accurately predicted to be generally similar to the Mars Exploration Rover Spirit landing site with relatively low rock abundance, low slopes, and a moderately dusty surface with a 3-10 m impact fragmented regolith over Hesperian to Early Amazonian basaltic lava flows. The deceleration profile and surface pressure encountered by the spacecraft during entry, descent, and landing compared well (within 1σ) of the envelope of modeled temperature profiles and the expected surface pressure. Orbital estimates of thermal inertia are similar to surface radiometer measurements, and materials at the surface are dominated by poorly consolidated sand as expected. Thin coatings of bright atmospheric dust on the surface were as indicated by orbital albedo and dust cover index measurements. Orbital estimates of rock abundance from shadow measurements in high-resolution images and thermal differencing indicated very low rock abundance and surface counts show 1-4% area covered by rocks. Slopes at 100 to 5 m length scale measured from orbital topographic and radar data correctly indicated a surface comparably smooth and flat as the two smoothest landing sites (Opportunity and Phoenix). Thermal inertia and radar data indicated the surface would be load bearing as found.

A new strategy for the treatment of atherothrombosis - inhibition of inflammation

Improvement in the prognosis of patients at risk of atherothrombotic events is based on three pillars - slowing down the process of atherogenesis (i.e. the development of atherosclerotic plaque), stabilizing the current atherosclerotic plaque, and reducing the risk of thrombotic occlusion in cases with unstable atherosclerotic plaque. The current prophylaxis has so far taken into consideration the adjustment of several risk factors, including dyslipidemia, arterial hypertension, smoking, and diabetes through lifestyle changes or pharmacological therapies. An essential part of prophylaxis is the anti-thrombotic strategy, especially anti-platelet therapy. Recently, a new pathway has been developed, based on reducing the activity of the inflammatory process with NLRP3 inflammasome, specifically a monoclonal antibody against interleukin 1beta (canakinumab). The efficacy and safety of this treatment, in secondary prevention, were documented in the CANTOS study. Other therapeutic procedures, including suppression of the inflammatory component of atherogenesis, are at the stage of clinical assessment.

SEIS: Insight's Seismic Experiment for Internal Structure of Mars

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars' surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking's Mars seismic monitoring by a factor of ∼ 2500 at 1 Hz and ∼ 200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars' surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of M w ∼ 3 at 40 ∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (10.1007/s11214-018-0574-6) contains supplementary material, which is available to authorized users.

Using Polarons for sub-nK Quantum Nondemolition Thermometry in a Bose-Einstein Condensate

We introduce a novel minimally disturbing method for sub-nK thermometry in a Bose-Einstein condensate (BEC). Our technique is based on the Bose polaron model; namely, an impurity embedded in the BEC acts as the thermometer. We propose to detect temperature fluctuations from measurements of the position and momentum of the impurity. Crucially, these cause minimal backaction on the BEC and hence, realize a nondemolition temperature measurement. Following the paradigm of the emerging field of quantum thermometry, we combine tools from quantum parameter estimation and the theory of open quantum systems to solve the problem in full generality. We thus avoid any simplification, such as demanding thermalization of the impurity atoms, or imposing weak dissipative interactions with the BEC. Our method is illustrated with realistic experimental parameters common in many labs, thus showing that it can compete with state-of-the-art destructive techniques, even when the estimates are built from the outcomes of accessible (suboptimal) quadrature measurements.

Fast and selective separation of carbon dioxide from dilute streams by pressure swing adsorption using solid ionic liquids

The need to create a new approach to carbon capture processes that are economically viable has led to the design and synthesis of sorbents that selectively capture carbon dioxide by physisorption. Solid Ionic Liquids (SoILs) were targeted because of their tunable properties and solid form under operational conditions. Molecular modelling was used to identify candidate SoILs and a number of materials based on the low cost, environmentally friendly acetate anion were selected. The materials showed excellent selectivity for carbon dioxide over nitrogen and oxygen and moderate sorption capacity. However, the rate of capture was extremely fast, in the order of a few seconds for a complete adsorb-desorb cycle, under pressure swing conditions from 1 to 10 bar. This showed the importance of rate of sorption cycling over capacity and demonstrates that smaller inventories of sorbents and smaller process equipment are required to capture low concentration CO₂ streams. Concentrated CO₂ was isolated by releasing the pressure back to atmospheric. The low volatility and thermal stability of SoILs mean that both plant costs and materials costs can be reduced and plant size considerably reduced.

Short-term abstinence from alcohol and changes in cardiovascular risk factors, liver function tests and cancer-related growth factors: a prospective observational study

OBJECTIVE

To assess changes in metabolic risk factors and cancer-related growth factors associated with short-term abstinence from alcohol.

DESIGN

Prospective, observational study.

SETTING

Single tertiary centre.

PARTICIPANTS

Healthy subjects were recruited based on intention to: (1) abstain from alcohol for 1 month (abstinence group), or (2) continue to drink alcohol (control group). Inclusion criteria were baseline alcohol consumption >64 g/week (men) or >48 g/week (women). Exclusion criteria were known liver disease or alcohol dependence.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was change in insulin resistance (homeostatic model assessment (HOMA) score). Secondary outcomes were changes in weight, blood pressure (BP), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and liver function tests. Primary and secondary outcomes were adjusted for changes in diet, exercise and cigarette smoking.

RESULTS

The abstinence group comprised 94 participants (mean age 45.5 years, SD ±1.2) and the control group 47 participants (mean age 48.7 years, SD ±1.8). Baseline alcohol consumption in the abstinence group was 258.2 g/week, SD ±9.4, and in the control group 233.8 g, SD ±19.0. Significant reductions from baseline in the abstinence group (all p<0.001) were found in: HOMA score (-25.9%, IQR -48.6% to +0.3%), systolic BP (-6.6%, IQR -11.8% to 0.0%), diastolic BP (-6.3%, IQR -14.1% to +1.3%), weight (-1.5%, IQR -2.9% to -0.4%), VEGF (-41.8%, IQR -64.9% to -17.9%) and EGF (-73.9%, IQR -86.1% to -36.4%). None of these changes were associated with changes in diet, exercise or cigarette smoking. No significant changes from baseline in primary or secondary outcomes were noted in the control group.

CONCLUSION

These findings demonstrate that abstinence from alcohol in moderate-heavy drinkers improves insulin resistance, weight, BP and cancer-related growth factors. These data support an independent association of alcohol consumption with cancer risk, and suggest an increased risk of metabolic diseases such as type 2 diabetes and fatty liver disease.

Transient subdiffusion from an Ising environment

We introduce a model in which a particle performs a continuous-time random walk (CTRW) coupled to an environment with Ising dynamics. The particle shows locally varying diffusivity determined by the geometrical properties of the underlying Ising environment, that is, the diffusivity depends on the size of the connected area of spins pointing in the same direction. The model shows anomalous diffusion when the Ising environment is at critical temperature. We show that any finite scale introduced by a temperature different from the critical one, or a finite size of the environment, cause subdiffusion only during a transient time. The characteristic time, at which the system returns to normal diffusion after the subdiffusive plateau depends on the limiting scale and on how close the temperature is to criticality. The system also displays apparent ergodicity breaking at intermediate time, while ergodicity breaking at longer time occurs only under the idealized infinite environment at the critical temperature.

Loss of motivation and frustration for visitor surgeons in provincial health centers or psychiatric hospitals in Greece

Introduction

The core workplace for a surgeon is the operating theatre. Secondary duties may include visits to small health centers for outpatient examinations and visitor work to psychiatric hospitals.

Objective

The objective of our study is to highlight the mistakes of management that lead to half-empty provincial health centers and psychiatric hospitals.

Methods

Presentation of the 2-year-experience of a surgeon visitor in provincial health centers and in a large psychiatric hospital in Greece.

Results

The provincial health center of Lagada needs at least 4 surgeons to serve; too many patients to be examined or/and operated in 2–3 hours only. Subsequently problems arise, as simultaneously in the emergencies department a surgical eye for an abdominal pain or a bad looking leg is needed every 15 minutes. The health center of Koufalia needs 3 hours of driving per day for 3–8 surgical patients only. The psychiatric hospital offered work for 3 surgeons 5 days a week for a long period of time. During 2012–2014, only one surgeon visited the hospital once a week. The work needed to be done may kill the surgeon or force him to receive antidepressants in order to keep his functions alive.

Conclusions

Not a hint of scientific motivation for two years is a strong reason for a surgeon to avoid the duty to provincial health centers and psychiatric hospitals which is obligatory according to our national health system Laws until two years are completed for newly appointed surgeons. Managers might encourage surgeons if some balancing convenience was offered.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Nonergodic subdiffusion from transient interactions with heterogeneous partners

Spatiotemporal disorder has been recently associated to the occurrence of anomalous nonergodic diffusion of molecular components in biological systems, but the underlying microscopic mechanism is still unclear. We introduce a model in which a particle performs continuous Brownian motion with changes of diffusion coefficients induced by transient molecular interactions with diffusive binding partners. In spite of the exponential distribution of waiting times, the model shows subdiffusion and nonergodicity similar to the heavy-tailed continuous time random walk. The dependence of these properties on the density of binding partners is analyzed and discussed. Our work provides an experimentally testable microscopic model to investigate the nature of nonergodicity in disordered media.

Optimal selection policies for a sequence of candidate drugs

Pharmaceutical companies have to face huge risks and enormous costs of production before they can produce a drug. Efficient allocation of resources is essential to help in maximizing profits. Yu and Gittins (2007) described a model and associated software for determining efficient allocations for a preclinical research project. This is the starting point for this paper. We provide explicit optimal policies for the selection of successive candidate drugs for two restricted versions of the Yu and Gittins (2007) model. To some extent these policies are likely to be applicable to the unrestricted model.

A maximally sensitive clinical decision rule to reduce the need for radiography in mandibular trauma

INTRODUCTION

To identify clinical symptoms and signs that exclude the presence of mandibular fracture in patients presenting with mandibular trauma and thus devise a clinical decision rule that will rule out the need for radiography in some patients.

PATIENTS AND METHODS

A prospective study was conducted of consecutive patients with a possible diagnosis of mandibular fracture who attended a city-centre emergency department between July 2000 and December 2001. Clinical symptoms and signs were recorded for each patient using a predesigned proforma. Radiographic evaluation of a suspected mandibular fracture consisted of lateral-oblique and postero-anterior mandibular views. The presence of a fracture was based on the interpretation of the X-rays by a radiologist who was blinded to the clinical probability of a fracture. Data were initially analysed using the chi-square test. Recursive partitioning was then performed to create a maximally sensitive decision tree.

RESULTS

280 patients were included in the study, 65 of whom had a mandibular fracture. A maximally sensitive decision rule was found that identified 5 parameters (malocclusion, trismus, broken teeth, pain with mouth closed, step deformity) whose absence excluded mandibular fracture. This rule has a sensitivity of 100% and specificity of 39% in identifying patients with mandibular fracture. If applied to our patient cohort, this rule would have saved 83 radiographs without missing any fractures.

CONCLUSIONS

A simple decision rule is presented that can be used to exclude the need for radiography in a subset of patients with mandibular trauma.

Foot pump prophylaxis for deep venous thrombosis-rate of effective usage following knee and hip arthroplasty

We recorded the usage of foot pumps during the post-operative period in 29 patients undergoing knee or hip arthroplasty and made 621 recordings. Effective utilisation of foot pumps was seen in 37.2% of cases. There was a gradual reduction in correct utilisation with each day that passed post-operatively (day 1, 60.4%; day 2, 48.8%; day 3, 28.8%; day 4, 21.4%; day 5, 23%). This gradual reduction was statistically significant ( P=0.001) and mainly occurred between the second and third post-operative days. Effective usage was 60.2% overall at night and 36.4% during the day. Our results question the efficiency of foot pumps in deep venous thrombosis prophylaxis in the context of a true clinical setting.

Comparison of peripheral and central venous pressures in critically Ill patients

We conducted a prospective study to determine the relationship between central (CVP) and peripheral (PVP) venous pressures in critically ill patients. CVP and PVP were measured on five different occasions in 20 critically ill patients in the intensive care unit. Results showed that the mean difference between PVP and CVP was 4.4 mmHg (95% CI = 3.7 to 5.0). However, PVP might be 1.9 mmHg below (95% CI = 0.7 to 3.1) or 10.6 mmHg above (95% CI = 9.4 to 11.8) the CVP. The mean difference between changes in PVP and corresponding changes in CVP was 0.3 mmHg (95% CI = -0.1 to 0.7). The actual change in PVP could be 3.0 mmHg below (95% CI = 2.3 to 3.7) or 3.6 mmHg above (95% CI = 2.9 to 4.3) the change in CVP. Overall, the direction of change in PVP (rise or drop) predicted a same direction of change in CVP with an accuracy of 78%. Changes in PVP > or = 2 mmHg predicted a change in same direction of CVP with an accuracy of 90%. The direction of changes in CVP > or = 2 mmHg were predicted by the direction of change in PVP with an accuracy of 91%. We conclude that PVP measurement does not give an accurate estimate of the absolute value of CVP in individual patients. However, as changes in PVP parallel, in direction, changes in CVP, serial measurements of PVP may have a value in determining volume status and guiding fluid therapy in critically ill patients.

Weight bearing following intra-articular steroid injection of the knee: survey of current practice and review of the available evidence

INTRODUCTION

Intra-articular steroid therapy is one of the most common clinical procedures performed by rheumatologists. There is wide variation in the postoperative instructions given to patients following such injections.

AIM

The aim of this study was to determine what advice is given with regards to non-weight-bearing following steroid injections of the knee by rheumatologists, orthopaedic surgeons, and general practitioners (GPs).

METHOD

A questionnaire examining advice on non-weight-bearing following knee steroid injections was posted to 100 rheumatologists, 100 orthopaedic surgeons, and 50 GPs.

RESULTS

A significant proportion of respondents advised patients to avoid weight bearing after injection (42.4%). Most of these advised patients to do so for one (16.3%) or two (25.1%) days. As compared to 57.1% of general practitioners and 2.8% of orthopaedic surgeons, 70.7% of rheumatologists advised patients to avoid weight bearing (P < 0.05).

CONCLUSION

A significant proportion of rheumatologists and general practitioners performing steroid injections of the knee advise patients not to weight-bear postinjection. Examination of the available literature fails to reveal strong evidence to support such a practice, which has potentially significant implications with regards to loss of working days, costs of mobility aids, and patient inconvenience.

Gastric adenocarcinoma metastatic to the skin: a report

Metastases to the skin from internal tumours are uncommon, yet they may be the first presentation of such malignancies. They usually arise from the breast, lung and large bowel. Skin metastases from gastric adenocarcinoma are extremely rare. We report a case of a patient with gastric adenocarcinoma who at presentation had multiple, clinically benign-looking skin nodules. Biopsy of these revealed metastatic deposits.

Risk factors and clinical impact of central line infections in the surgical intensive care unit

OBJECTIVE

To determine the risk factors and clinical impact of central line infections in critically ill surgical patients.

DESIGN

Retrospective study.

SETTING

The surgical intensive care unit of a large tertiary care university hospital.

PATIENTS

A total of 232 consecutive central line catheters sent for culture from patients in a surgical intensive care unit during 1996 and 1997. Catheters were sent for microbiologic analysis when the patient was clinically infected and the central line was a possible source.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Risk factors associated and clinical impact of a positive catheter culture.

RESULTS

Of 232 consecutive catheters from 93 patients sent for microbiologic analysis, 114 catheters (49%) had no growth, 40 (17%) were colonized (<15 colonies), and 78 (34%) were considered infected (> or =15 colonies). Univariate analysis showed that site (internal jugular vs subclavian, P<.001), catheter use (monitoring > dialysis > fluid > nutrition, P=.006), placement in the operating room vs the intensive care unit (P=.02), and placement of a new catheter (> guide wire, > new site, P=.003) were all significant factors. Surprisingly, neither the number of lunmens nor the duration of the catheter in situ were predictors when a catheter was suspected and not proved infected compared with a suspected and proved catheter infection. In the multiple regression model, the placement of the catheter in the internal jugular position was the single most important predictor of a catheter infection (P<.001; odds ratio, 1.83; 95% confidence interval [CI], 1.41-2.37). The presence or absence of a specific clinical sign of infection was not predictive of a proved catheter infection. Eighty-six percent of patients had gram-positive bacteria identified on the culture, while the remaining patients had gram-negative bacteria or Candida identified. Of the catheter infections, 68% were monomicrobial, whereas 32% were polymicrobial. Of the catheters sent for microbiologic analysis, 209 (90%) had concurrent peripheral blood cultures for analysis. Nineteen (32%) with no growth from the catheter, and 14 (23%) of colonized catheters had concurrent bacteremia; all had another identifiable cause of infection. Twenty-seven (45%) of infected catheters had a concurrent bacteremia, and 9 of 27 had a second site positive for the same organism. Death related to the infection occurred in 15 patients, 2 in the first 72 hours and 13 in the following 14 days.

CONCLUSIONS

Central line infections remain an important cause of morbidity and mortality. Comprehensive review of hospital practices may show a directed focus for performance improvement practices. At our institution, internal jugular catheters have the highest rate of infection. This may suggest breaks in technique during catheter insertion or during catheter maintenance and care.

Immunohistochemical analysis of Hodgkin's disease using microwave heating

AIMS

To assess the effect of microwave heating on immunohistochemical staining of CD15 and CD30 antigens in Hodgkin's disease tissue samples.

METHODS

Formalin fixed, paraffin wax embedded sections from 20 cases of Hodgkin's disease (six mixed cellularity, 14 nodular sclerosis) were immunostained for CD15, using two antibodies (DAKO-M1 and Leu-M1) and for CD30 using the antibody Ber-H2. The staining was carried out by conventional techniques which included pretreatment of sections with trypsin and on untreated sections following heating with microwaves. With antibody Leu-M1 an additional method, using a specific antimouse IgM bridge both with and without microwave heating, was also included. The results for each method were compared by counting positively stained Reed-Sternberg cells and estimating the staining intensity.

RESULTS

Microwave heating resulted in a substantial increase in the number of cells stained with antibodies to CD15 and also in the staining intensity. The best results were obtained using Leu-M1 with specific rabbit anti-mouse IgM bridge and microwave heating. Dramatic enhancement of the staining of Reed-Sternberg cells for CD30 was achieved following microwave heating, together with disappearance of the non-specific staining of plasma cells.

CONCLUSION

Microwave heating is strongly recommended for the immunohistochemical staining of CD15 and CD30 expressed by Reed-Sternberg cells in Hodgkin's disease.

Two iterative image restoration algorithms with applications to nuclear medicine

Two methods for recovering an image that has been degraded while being processed are presented. The restoration problem is formulated as a constrained optimization problem in which a measure of smoothness based on the second derivatives of the restored image is maximized subject to the constraint that noise energy is equal to the energy in the difference between the distorted and blurred images. The approach is based on the Lagrange multiplier method. The first algorithm reduces the problem to the computation of few discrete Fourier transforms and allows control of the degree of sharpness and smoothness of the restored image. The second algorithm with weight matrices included allows the handling of edges and flat regions in the image in a pleasing manner for the human visual system. In this case the iterative conjugate gradient method is used in conjunction with the discrete Fourier transform to minimize the Lagrangian function. The application of these algorithms to nuclear medicine images is presented.