Design of a wearable device for physiological parameter monitoring in a COVID setting

The study focuses on the realization of an accurate device for the detection of different physiological parameters. It has been realized a simple portable system containing the necessary electronics and ensuring the monitoring of the blood oxygenation, the body temperature, the air quality, the respiratory rate and the ECG. The main processing unit consists in a Raspberry Pi Zero W connected to the Healthy Pi4. The latter provides the interface for the clinical pulse-oxymeter while the measures of temperature and quality air are provided using the I2C protocol. The Bluetooth module is finally used to provide the ECG and blood rate data. The collected data are elaborated using Matlab and Python. To evaluate the accuracy of the realized device some experimental tests have been conducted on different subjects, comparing subjects working in Covid area with others resting at home. In both cases the monitoring time was 4 hours. Results have shown good performances of the system, detecting accurately the differences of the parameters values between the two situations. The usability of the device was assessed by administering a questionnaire to the healthcare personnel involved in the experimentation. The outcome shows a good usability of the system as well as an acceptable dressing time.

Effects of ultrasound and selenium on human neurons in vitro

As the effects of ultrasound on human brain functions might bear therapeutic potential, in this study, we examined the effects of diagnostic, i.e. non-thermal, ultrasound, on morphology, networking, and metabolic activity of SH- SY5Y human neurons in culture, as well as on the expression of GAP-43, Hsp90 and VEGF proteins, with and without selenium in the culture medium. The rationale for studying selenium lays in the observation that selenium improves functional neurologic outcome in traumatic brain injury and, therefore, analysis of the interactions between ultrasound and selenium may be of clinical interest. In the presence of selenium, ultrasound increased the overall number and length of elongations arising from the neuron bodies, thus reflecting an increase in the complexity of neuronal networks and circuits. The expression of GAP-43, Hsp90 and VEGF and metabolic activity of SH-SY5Y neurons, studied as markers of cell damage, were not affected by ultrasound or selenium. This study suggests that ultrasound may modulate neuronal networking in vitro without inducing cellular or molecular damage and highlights the potential role of selenium in the ultrasound-elicited cellular responses.

Real-time optical manipulation of cardiac conduction in intact hearts

Key points

Although optogenetics has clearly demonstrated the feasibility of cardiac manipulation, current optical stimulation strategies lack the capability to react acutely to ongoing cardiac wave dynamics.

Here, we developed an all‐optical platform to monitor and control electrical activity in real‐time.

The methodology was applied to restore normal electrical activity after atrioventricular block and to manipulate the intraventricular propagation of the electrical wavefront.

The closed‐loop approach was also applied to simulate a re‐entrant circuit across the ventricle.

The development of this innovative optical methodology provides the first proof‐of‐concept that a real‐time all‐optical stimulation can control cardiac rhythm in normal and abnormal conditions.

Abstract

Optogenetics has provided new insights in cardiovascular research, leading to new methods for cardiac pacing, resynchronization therapy and cardioversion. Although these interventions have clearly demonstrated the feasibility of cardiac manipulation, current optical stimulation strategies do not take into account cardiac wave dynamics in real time. Here, we developed an all‐optical platform complemented by integrated, newly developed software to monitor and control electrical activity in intact mouse hearts. The system combined a wide‐field mesoscope with a digital projector for optogenetic activation. Cardiac functionality could be manipulated either in free‐run mode with submillisecond temporal resolution or in a closed‐loop fashion: a tailored hardware and software platform allowed real‐time intervention capable of reacting within 2 ms. The methodology was applied to restore normal electrical activity after atrioventricular block, by triggering the ventricle in response to optically mapped atrial activity with appropriate timing. Real‐time intraventricular manipulation of the propagating electrical wavefront was also demonstrated, opening the prospect for real‐time resynchronization therapy and cardiac defibrillation. Furthermore, the closed‐loop approach was applied to simulate a re‐entrant circuit across the ventricle demonstrating the capability of our system to manipulate heart conduction with high versatility even in arrhythmogenic conditions. The development of this innovative optical methodology provides the first proof‐of‐concept that a real‐time optically based stimulation can control cardiac rhythm in normal and abnormal conditions, promising a new approach for the investigation of the (patho)physiology of the heart.

Although optogenetics has clearly demonstrated the feasibility of cardiac manipulation, current optical stimulation strategies lack the capability to react acutely to ongoing cardiac wave dynamics.

Here, we developed an all‐optical platform to monitor and control electrical activity in real‐time.

The methodology was applied to restore normal electrical activity after atrioventricular block and to manipulate the intraventricular propagation of the electrical wavefront.

The closed‐loop approach was also applied to simulate a re‐entrant circuit across the ventricle.

The development of this innovative optical methodology provides the first proof‐of‐concept that a real‐time all‐optical stimulation can control cardiac rhythm in normal and abnormal conditions.

Oxygen-ozone in Orthopaedics: EPR Detection of Hydroxyl Free Radicals in Ozone-Treated “Nucleus Pulposus” Material

The direct and indirect application of oxygen-ozone in several orthopaedic affections was briefly reviewed, trying to understand possible mechanisms of action explaining the surprisingly good results and no toxicity. Moreover, by using EPR spin trapping technique with DEPMPO the generation of free radicals by treating human “nucleus pulposus” material with oxygen-ozone (O2-O3) was investigated. The DEPMPO spin adduct of hydroxyl radical (DEPMPO-OH) was detected. The presence of ·OH even at a very low ozone concentration (5 μg/mL) may explain why this material undergoes to a progressive breakdown with re-absorption and consequent disappearance of a hernial disk. Thus the intradiscal insufflation of a minute volume of O2-O3 may represent a new efficient, inexpensive and atoxic chemionucleolytic approach.

La nucleoaspirazione secondo Onik nel trattamento dell'ernia discale lombare analisi multicentrica dei primi risultati su oltre 650 trattamenti

Gli autori espongono i risultati ottenuti applicando la nucleotomia percutanea secondo Onik al trattamento dell'ernia discale lombare. Le casistiche sommate complessivamente ammontano a oltre 600 pazienti. Nel complesso i risultati sono buoni o ottimi nel 72% circa dei casi. I risultati insoddisfacenti, considerando globalmente i modest e gli invariati, corrispondonoal 26% circa. Eccezionali le complicanze (meno dell' 1 %): 1 discite (risolta con intervento chirurgico). La metodica di Onik può già essere serenamente considerata una possibilitanon trascurabile nel campo vasto e variegato dei trattamentidisponibili per l'ernia discale lombare

Analysis of the microcirculatory pulse wave: age-related alterations

Morphological analysis of the pulse wave of central blood pressure signal is commonly used for the study of cardiac and vascular properties, but very few attempts were performed for analyzing the peripheral pulse wave of blood flow. In this work, we analyzed this waveform using classical methods, based on the application of FFT, followed by principal components analysis, for assessing the properties of the blood flow. As a sample problem, we evaluated the capability of the proposed method of assessing the alterations correlated with the aging of the vascular system. Results show a good discrimination between the different age groups, confirming the validity of the approach.

Shape analysis of the microcirculatory flow wave

The cardiovascular system and its alterations are a crucial aspect of physiology and medicine. Non-invasive assessment of the functional properties of circulation is of considerable interest to clinicians and physiologists. In this work we investigate the possibility of detecting alterations of the flow waveform in microcirculation, using non-invasive measurements based on a laser Doppler flowmeter. As a test case, we focus on the effect of ageing. Skin is warmed up to a fixed temperature (44 °C) during measurement, to increase blood flow. The shape of the perfusion waveform during each heart beat after the flow was stabilized was used to estimate dynamic parameters of the microcirculatory system. Both the wave rise time, defined as the delay between the diastolic minimum and the following systolic maximum, and the oscillation fraction, defined as the normalized difference between the maximum and minimum flow, present significant variation with age.

Resonance artefacts in modern pressure monitoring systems

Resonance in pressure monitoring catheters is a well-known problem which was studied several years ago. Current piezoelectric devices have mechanical properties providing a resonance frequency and damping factor that theoretically assure resonance-free data. However, in particular cases, the coupling between the device, the catheter, and the vascular compliance of the patient could introduce artefacts in clinical settings leading to wrong pressure waveforms and values displayed in the monitor. In this research work we study a laboratory model of a clinical setting to evaluate in which cases the compound (catheter and device) could cause resonances in an unacceptable range. The classical pop-test is expanded for analysing the effect of the catheter. Results indicate that the presence of different catheters may alter significantly the acquired signal, up to an unacceptable level. Particular care should be used in the selection of the appropriate catheter. In particular, smaller diameters introduce higher damping coefficient that could help in avoiding undesired oscillations.

Morphological analysis of neurons: Automatic identification of elongations

Our study is focused on the development of a new method for the automatic analysis of cell images. We focused on neurons (cells line SH-SY5Y) treated/untreated with ultrasound and stained with Haematoxylin-Eosin. The aim of the algorithm is the automatic detection of the cell body as well as the determination of the number and the length of neuron elongations. Starting point of the algorithm was the convolution of an image with a bank of rotating Gaussian kernels and the construction of a module map. Then several strategies were implemented to detect cell bodies and to detect and extract data about cell elongations. We have also realized a graphical user interface allowing the loading, saving and processing of images. Results show that this method is able to properly and efficiently detect cell contours and elongations. The automated evaluation is in strong agreement with manual evaluation performed by an expert operator, with an average error of 11% with most parameter combinations. This tool constitutes an important support in biological research activities, where operators need to analyze a large number of images to investigate about cell morphology before and after a treatment.

Monitoring the microcirculation at the bedside using hand-held imaging microscopes: Automatic tracking of erythrocytes

In recent years, the development of portable microscopy devices that enable the noninvasive bedside evaluation of the mucosal microcirculation in critically ill patients has expanded the research on this level of the cardiovascular system. Several semi-quantitative scores have been defined to assess the peripheral perfusion, based on videos of the microcirculation. However, they are cumbersome and time-consuming processes, highlighting the need for the development of automated software techniques, to reduce physicians workload and ensure prompt and objective patient evaluation. We developed a rapid, automatic method for the quantitative assessment of erythrocyte velocities in Incident Dark Field (IDF) illumination videos of capillary flow. The technique, based on Kalman filter object tracking, was tested in 35 IDF videos against space-time diagrams, showing high correlation (r = 0.96) and agreement (bias = 3.3 μm/s) with space-time diagrams (STD), below 200 μm/s.

Bioaccumulation of resveratrol metabolites in myocardial tissue is dose-time dependent and related to cardiac hemodynamics in diabetic rats

BACKGROUND AND AIMS

Trans-resveratrol (RSV) is a natural compound occurring in different foods and plants, which in vivo is rapidly conjugated with glucuronic acid and sulfate. Despite its demonstrated cardioprotective activity, the bioaccumulation of RSV or its metabolites in cardiac tissue is still unknown.

METHODS AND RESULTS

Diabetic rats were randomized to 1, 3 or 6 weeks of RSV treatment at two different doses (1 or 5 mg/kg/day). A dose and time-dependent accumulation was observed, with no detectable levels of RSV metabolites found in heart tissues after 1 week and significant concentrations of RSV-3-sulfate and RSV-3-glucuronide after 6 weeks of treatment (0.05 nmol/g of tissue and 0.01 nmol/g of tissue, respectively). Tissue accumulation of RSV metabolites was accompanied by an improvement of cardiac function in long-term diabetes, when myocardial morpho-functional damage is more evident, with an almost complete recovery of all hemodynamic parameters, at the highest RSV dose.

CONCLUSION

Even if a higher concentration of RSV in tissues cannot be ruled out after constant oral administration, an accumulation coherent with what is usually evaluated in cell based mechanistic studies is largely unattainable and the RSV unconjugated form would not be present in this paradigm. The current investigation provides data on myocardial tissue concentrations of RSV metabolites, after short/medium term RSV treatment. This knowledge constitutes a basic requirement for future studies aimed at reliably defining the molecular pathways underlying RSV-mediated cardioprotective effects and opens up new perspectives for research focused on testing phenolic compounds as adjuvants in degenerative heart diseases.

Automatic newborn cry analysis: a non-invasive tool to help autism early diagnosis

Autism Spectrum Disorders (ASD) are complex developmental disabilities that cause problems with social interaction and communication. ASD are associated with motor development problems, more or less blurred, and with perceptual and sensory brain areas. Crying is the infant's earliest form of communication and recent studies connect this original "language" form with autism disturbs. Being completely non-invasive, cry analysis is an appealing approach for early ASD diagnosis to improve rehabilitation. To this aim, we have developed an automatic system to record newborn cry and movements, during the first six months of life with a specific recording protocol. In this work we present first results of acoustic cry analysis in newborns classified as high-risk subjects being siblings of children already diagnosed as autistics. The work aims at finding possible early ASD signs in high-risk subjects as compared to a group of control subjects based on the fundamental frequency and the vocal tract resonance frequencies. Also, voiced and unvoiced parts of signal and cry-episodes duration are analyzed.

DIFFERENCES IN IONIC CURRENTS BETWEEN CANINE MYOCARDIAL AND PURKINJE CELLS

An electrophysiological analysis of canine single ventricular myocardial (VM) and Purkinje (P) cells was carried out by means of whole cell voltage clamp method. The following results in VM versus P cells were obtained. I_Na3 was present, had a threshold negative to the fast activating-inactivating I_Na1, its slow inactivation was cut off by I_Na1, and contributed to Na⁺ influx at I_Na1 threshold. I_Na1 was smaller and had a less negative threshold. There was no comparable slowly inactivating I_Na2, accounting for the shorter action potential. Slope conductance at resting potential was about double and decreased to a minimum value at the larger and less negative I_K1 peak. The negative slope region of I-V relation was smaller during fast ramps and larger during slow ramps than in P cells, occurred in the voltage range of I_K1 block by Mg²⁺, was not affected by a lower V_h and TTX and was eliminated by Ba²⁺, in contrast to P cells. I_Ca was larger, peaked at positive potentials and was eliminated by Ni²⁺. I_to was much smaller, began at more positive values, was abolished by less negative V_h and by 4-aminopyridine, included a sustained current that 4-aminopyridine decreased but did not eliminate. Steeper ramps increased I_K1 peak as well as the fall in outward current during repolarization, consistent with a time-dependent block and unblock of I_K1 by polyamines. During repolarization, the positive slope region was consistently present and was similar in amplitude to I_K1 peak, whereas it was small or altogether missing in P cells. The total outward current at positive potentials comprised a larger I_K1 component whereas it included a larger I_to and sustained current in P cells. These and other results provide a better understanding of the mechanisms underlying the action potential of VM and P cells under normal and some abnormal (arrhythmias) conditions.

Severe HDL deficiency due to novel defects in the ABCA1 transporter

OBJECTIVES

The objective was the identification and functional characterization of mutations in the ABCA1 gene in four patients with severe HDL deficiency.

SUBJECTS

Patients were referred to the clinic because of almost complete HDL deficiency.

METHODS

The ABCA1 gene was sequenced directly. The analysis of the ABCA1 protein, ABCA1 mRNA and ABCA1-mediated cholesterol efflux was performed in cultured fibroblasts. Intracellular localization of ABCA1 mutants was investigated in transfected HEK293 cells.

RESULTS

Two patients were homozygous for mutations in the coding region of the ABCA1 gene, resulting in an amino acid substitution (p.A1046D) and a truncated protein (p.I74YFsX76). The third patient was homozygous for a splice site mutation in intron 35 (c.4773 + 1g>a), resulting in an in-frame deletion of 25 amino acids (del p.D1567_K1591) in ABCA1. These patients had clinical manifestations of accumulation of cholesterol in the reticulo-endothelial system. The fourth patient, with preclinical atherosclerosis, was a compound heterozygote for two missense mutations (p.R587W/p.W1699C). ABCA1-mediated cholesterol efflux was abolished in fibroblasts from patients with p.A1046D and del p.D1567_K1591 mutants and in fibroblasts homozygous for p.R587W. A reduced ABCA1 protein content was observed in these cells, suggesting an increased intracellular degradation. The mutant p.W1699C was largely retained in the endoplasmic reticulum, when expressed in HEK293 cells.

CONCLUSIONS

The homozygotes for mutations which abolish ABCA1 function showed overt signs of involvement of the reticulo-endothelial system. This was not the case in the compound heterozygote for missense mutations, suggesting that this patient retains some residual ABCA1 function that reduces cholesterol accumulation in the reticulo-endothelial system.

High-resolution cry analysis in preterm newborn infants

Infant monitoring is a common procedure in clinical practice in neonatal critical care units. A number of vital functions are monitored, such as heart beat, breathing, blood flow, etc. Specifically, preterm and/or low-birth-weight infants often present respiratory problems that require monitoring. These may range from insufficient ventilation to apnoea. One of the most common events that may affect the respiratory flow is crying, a physiological action made by the infant to communicate and draw attention, but, for a preterm infant, this action requires great effort, which may cause distress and even may have an adverse impact on blood oxygenation. Acoustic analysis of newborn infant cry is thus of importance, since it is related to other basic neuro-physiological parameters. Being easy to perform, cheap and completely non-invasive, it can be successfully applied in many circumstances. The newborn infant cry is characterised by very high fundamental frequency (F(0)) and resonance frequency (RFs) values, with abrupt changes and voiced/unvoiced features of very short duration in a single utterance. To deal with such signals, a new user-friendly software tool has been developed, that allows robust tracking of main acoustic parameters on very short and time-varying signal frames. The software developed provides the user with a high-resolution picture of the cry signal characteristics.

A comparison between internal and surface temperature measurement techniques during phacoemulsification cataract surgery: thermocamera versus thermocouple

PURPOSE

Corneal and scleral burns, one of the main complications that can occur during a cataract operation, are produced by overheating due to the use of the phacoemulsifier. The temperature of the anterior chamber of the eye can be measured both invasively using thermocouples and non-invasively, but only superficially, using a thermocamera.

METHODS

To compare the measures obtained from both techniques an in vitro experimental analysis was conducted on pigs' eyes. During a simulated phacoemulsification cataract operation both the surface temperature with a thermocamera and the temperature inside the anterior chamber with a thermocouple were recorded. For each procedure, the maximum temperature values measured by each technique were compared.

RESULTS

The results of this research show that the difference between the maximum values measured with the two techniques is on average 0.5 degrees C.

CONCLUSIONS

It is possible to employ a thermocamera technique instead of a thermocouple technique to provide an indication of the temperature inside the anterior chamber.

Non-invasive distress evaluation in preterm newborn infants

With the increased survival of very preterm infants, there is a growing concern for their developmental outcomes. Infant cry characteristics reflect the development and possibly the integrity of the central nervous system. In this paper, relationships between fundamental frequency (F(0)) and vocal tract resonance frequencies (F(1)-F(3)) are investigated for a set of preterm newborns, by means of a multi-purpose voice analysis tool (BioVoice), characterised by high-resolution and tracking capabilities. Also, first results about possible distress occurring during cry in preterm newborn infants, as related to the decrease of central blood oxygenation, are presented. To this aim, a recording system (Newborn Recorder) has been developed, that allows synchronised, non-invasive monitoring of blood oxygenation and audio recordings of newborn infant's cry. The method has been applied to preterm newborns at the Intensive Care Unit, A.Meyer Children Hospital, Firenze, Italy.

Characterization of the slowly inactivating sodium current INa2 in canine cardiac single Purkinje cells

The aim of our experiments was to investigate by means of a whole cell patch-clamp technique the characteristics of the slowly inactivating sodium current (I(Na2)) found in the plateau range in canine cardiac Purkinje single cells. The I(Na2) was separated from the fast-activating and -inactivating I(Na) (labelled here I(Na1)) by applying a two-step protocol. The first step, from a holding potential (V(h)) of -90 or -80 mV to -50 mV, led to the quick activation and inactivation of I(Na1). The second step consisted of depolarizations of increasing amplitude from -50 mV to less negative values, which led to the quick activation and slow inactivation of I(Na2). The I(Na2) was fitted with a double exponential function with time constants of tens and hundreds milliseconds, respectively. After the activation and inactivation of I(Na1) at -50 mV, the slope conductance was very small and did not change with time. Instead, during I(Na2), the slope conductance was larger and decreased as a function of time. Progressively longer conditioning steps at -50 mV resulted in a progressive decrease in amplitude of I(Na2) during the subsequent test steps. Gradually longer hyperpolarizing steps (increments of 100 ms up to 600 ms) from V(h) -30 mV to -100 mV were followed on return to -30 mV by a progressively larger I(Na2), as were gradually more negative 500 ms steps from V(h) -30 mV to -90 mV. At the end of a ramp to -20 mV, a sudden repolarization to approximately -35 mV fully deactivated I(Na2). The I(Na2) was markedly reduced by lignocaine (lidocaine) and by low extracellular [Na(+)], but it was little affected by low and high extracellular [Ca(2+)]. At negative potentials, the results indicate that there was little overlap between I(Na2) and the transient outward current, I(to), as well as the calcium current, I(Ca). In the absence of I(to) and I(Ca) (blocked by means of 4-aminopyridine and nickel, respectively), I(Na2) reversed at 60 mV. In conclusion, I(Na2) is a sodium current that can be initiated after the inactivation of I(Na1) and has characteristics that are quite distinct from those of I(Na1). The results have a bearing on the mechanisms underlying the long plateau of Purkinje cell action potential and its modifications in different physiological and pathological conditions.

[Anabolic effects and inhibition of interleukin 6 production induced by neridronate on human osteoblasts]

Bisphosphonates (BPs) are pharmacological compounds widely used in the treatment of a variety of bone-related diseases, particularly where the bone-turnover is skewed in favour of osteolysis. The mechanisms by which BPs reduce bone-resorption directly acting on osteoclasts (OCs) are now largely clarified even at molecular level. The researches concerning the BPs effects on osteoblasts (OBs) have instead shown variable results.

OBJECTIVES

We have investigated the efficacy of neridronate (NER), an amino-BP, as anabolic agent on human OBs. Moreover, we have tried to verify if NER is able to negatively modulate the production of IL-6 on OBs stimulated or not by the pro-inflammatory cytokine IL-1beta.

METHODS

We have tested if different concentrations of NER (from 10-11 M to 10-3 M), added to primary human OB cultures, could affect the cells number, the endogenous cellular alkaline phosphatase (ALP) activity, the collagen I (COL-I) synthesis, the formation of mineralized nodules and the IL-6 production. Our experimental approach was performed testing a wide range of NER concentrations because, under physiological conditions, OBs seems to be exposed to variable and transient levels of the drug.

RESULTS

Our results show that NER doesn't negatively affect in vitro the viability, proliferation and cellular activity of human OBs, even after 20 days of exposure to concentrations < or =10-5 M (therapeutic dose). In addition, NER seems to enhance the differentiation of cultured OBs in mature bone-forming cells. A maximum increase of COL-I synthesis (+25% after 4 days; p < 0.05), ALP activity (+50% after 10 days; p < 0.01) and mineralized nodules (+48% after 20 days; p < 0.05) was observed in cultures treated with NER 10-8 M. A maximal reduction of IL-6 secretion (-24% on IL-1beta stimulated cultures and -29% on unstimulated cultures) was observed for NER 10-9 M.

CONCLUSIONS

These results encourage the use of neridronate in therapy of demineralizing metabolic bone disorders.

Shape analysis of microcalcifications using Radon transform

Microcalcifications are one of the early signs of breast cancer, and they are of great importance for an early diagnosis. Moreover, the spatial distribution and the shape of the microcalcifications have a significant impact in medical practice to evaluate the probability of malignancy of the tumor. In this work a method, performing computer-aided classification of the shape of calcifications accordingly to the classification scheme proposed by Le Gal, is presented. In the first stage, in order to remove mammographic background, the image is preprocessed with a matched filter, designed by modeling the microcalcifications as Gaussian spots and the image as a Fractional Brownian Motion. Afterwards, morphology of spots has been evaluated using two different sets of parameters. The first set utilizes the moments of inertia of the second and third order to compute a set of features, which are invariant to rotations and translations of the image. The second set of parameters is derived from the evaluation of the Radon transform, as computed along eight axes. The results of the Radon transform are used to associate to each lesion a set of features, which are invariant to rotation and scaling of the image. In the final stage, a multilayer neural network has been used to assign each microcalcification to the classes introduced by Le Gal. The topology of the neural network is the same for both sets of descriptors, in order to allow comparison of the discriminative power of the two feature sets. Experimental results obtained with the proposed method from a set of digitized mammograms are reported and discussed.

Long-term effects of neridronate on human osteoblastic cell cultures

Bisphosphonates (BPs) are widely used in the treatment of a variety of bone-related diseases, particularly where the bone turnover is skewed in favor of osteolysis. The mechanisms by which BPs reduce bone resorption directly acting on osteoclasts are now largely clarified even at molecular level. Researches concerning the BP's effects on osteoblast have instead shown variable results. Many in vitro studies have reported positive effects on osteoblasts proliferation and mineralization for several BPs; however, the observed effects differ, depending on the variety of different model system that has been used.

OBJECTIVES

We have investigated if neridronate, an aminobisphosphonate suitable for pulsatory parenteral administration, could have an effect on human osteoblastic proliferation and differentiation in vitro.

METHODS

We have investigated whether prolonged addition of neridronate (from 10(-3) to 10(-11) M) to different human osteoblasts cultures, obtained from 14 different bone specimens, could affect the cells number, the endogenous cellular alkaline phosphatase (ALKP) activity, and the formation of mineralized nodules.

RESULTS

Our results show that neridronate does not negatively affect in vitro the viability, proliferation, and cellular activity of normal human osteoblasts even after a long period addition of the drug (20 days) at concentrations equal or lower than 10(-5) mol/l (therapeutic dose). In addition, neridronate seems to enhance the differentiation of cultured osteoblasts in mature bone-forming cells. A maximum increase of alkaline phosphatase activity (+50% after 10 days; P < 0.01) and mineralized nodules (+48% after 20 days; P < 0.05) was observed in cultures treated with neridronate 10(-8) M.

CONCLUSIONS

These results encourage the use of neridronate in long-term therapy of demineralizing metabolic bone disorders.

Detection of single and clustered microcalcifications in mammograms using fractals models and neural networks

Microcalcifications (microCas) are often early signs of breast cancer. However, detecting them is a difficult visual task and recognizing malignant lesions is a complex diagnostic problem. In recent years, several research groups have been working to develop computer-aided diagnosis (CAD) systems for X-ray mammography. In this paper, we propose a method to detect and classify microcalcifications. In order to discover the presence of microCas clusters, particular attention is paid to the analysis of the spatial arrangement of detected lesions. A fractal model has been used to describe the mammographic image, thus, allowing the use of a matched filtering stage to enhance microcalcifications against the background. A region growing algorithm, coupled with a neural classifier, detects existing lesions. Subsequently, a second fractal model is used to analyze their spatial arrangement so that the presence of microcalcification clusters can be detected and classified. Reported results indicate that fractal models provide an adequate framework for medical image processing; consequently high correct classification rates are achieved.

The in vitro elution characteristics of vancomycin combined with imipenem-cilastatin in acrylic bone-cements: a pharmacokinetic study

The aim of this in vitro study was to compare the elution characteristics of vancomycin alone and in combination with imipenem-cilastatin from 3 acrylic bone-cements (CMW1 [DePuy International, Blackpool, UK], Palacos R [Schering-Plough, Wehrheim, Germany], and Simplex P [Howmedica International, London, UK]). Six groups of 3 antibiotic-loaded cement disks were prepared, incorporating 2 g of vancomycin (3 groups) and 2 g of vancomycin plus 2 g of imipenem-cilastatin (3 groups). The disks were placed in saline baths for 5 weeks, with the baths being sampled periodically and the elution rates calculated. The total amount of vancomycin released by the cements treated with vancomycin alone was 7.98 mg for CMW1, 7.74 mg for Palacos R, and 6.76 mg for Simplex P; with the addition of imipenem-cilastatin, the total amount of vancomycin released by the 3 cements increased by 30.58%, 50.52%, and 50.15%. CMW1 had better elution characteristics than the other cements when treated with vancomycin alone; the elution of Palacos R and Simplex P was better than that of CMW1 when vancomycin was combined with imipenem-cilastatin.

Compression hip screw nail-plate system for intertrochanteric fractures

BACKGROUND

The worldwide increased incidence in fractures of the proximal end of the femur is increasing with the parallel increase in the average age of the population. The advanced age and poor physical condition of these patients render surgery necessary.

METHODS

In 1999, at the Orthopaedic Clinic of the University of Siena, 56 patients were treated with the compression hip nail-plate system, a new synthesis device for the treatment of peritrochanteric fractures. The system consists of a new dynamic cephalic screw that could be combined with a plate or a femoral nail. The dynamic cephalic screw of the BCM system has a limited sliding method, impeding excursions greater than 10 mm and preventing excessive collapse of the fracture fragments that can evolve into a shortening of the limb. The canulated nail has a diameter of only 9 mm, which permits insertion into the shaft canal without reaming.

RESULTS

Four patients with a follow-up of less than 3 months, 2 patients lost to control, and 1 patient who died were excluded from the study. All 49 remaining patients healed clinically and radiographically within 3 months.

CONCLUSIONS

The possibility of the double combination of the screw with a plate or with an intramedullary nail permits the surgeon to have a double solution with a single instrument at hand, and offers the opportunity of changing the choice of synthesis method to implant even during surgery.

Social stress, myocardial damage and arrhythmias in rats with cardiac hypertrophy

In rat models of cardiac hypertrophy (moderate aortic coarctation: ACm, n=18; severe aortic coarctation: ACs, n=27; aging: OLD, n=25; spontaneous chronic hypertension: SHR, n=18) and properly matched control animals (C(ACm), n=17; C(ACs), n=19; C(OLD), n=24; C(SHR), n=22), we investigated the relative contribution of intense autonomic activity and cardiac structural damage to ventricular arrhythmogenesis. We used an "in vivo" to tissue level approach, by correlating in the same animal: (i) social stress-induced ventricular arrhythmias, telemetrically recorded, and (ii) left ventricular weights (LVW) and amount and geometrical properties of myocardial fibrosis (MF). Arterial blood pressure was significantly higher in ACm (+11%), ACs (+28%) and SHR (+34%) than in controls. LVW were approximately 20% greater in ACm, ACs and OLD and 50% greater in SHR. MF was about twice as great and characterized by more frequent occurrence of microscopic scarring in ACm and ACs, and eight times greater and associated with both a higher number and a larger size of fibrotic foci in OLD and SHR compared to controls. Social stress increased ventricular arrhythmia vulnerability in all models of cardiac hypertrophy, as well as in controls. The arrhythmogenic action of stress was facilitated in ACs, OLD and SHR. A correlation between structural cardiac remodeling and ventricular arrhythmias was found only in SHR and OLD, which exhibited the greatest increase in LVW and/or MF. Social stress proved to be a valuable tool for analyzing the combined effects of autonomic stimulation and altered myocardial substrate on the genesis of potentially life-threatening arrhythmias in social animals.

A new method of repair for quadriceps tendon ruptures. A case report

Rupture of the quadriceps tendon is an uncommon injury observed predominantly in subjects over 40 years old. Multiple surgical techniques have been employed to repair fresh and neglected ruptures; methods that make use of allograft and augmentation with tissues harvested from around the knee have been reported. We describe a case of surgical repair of a tendon-bone junction rupture in a 64-year-old patient by use of suture anchors to attach the tendon to bone and improve fixation of the soft tissue elements. Clinical diagnosis of rupture was confirmed radiographically and echographically. Surgical repair was performed within 24 hours of injury. Active movement of the knee started after 3 weeks and the patient was permitted to walk without weight-bearing with a knee cage. Three weeks later, he was permitted to walk with full weight-bearing unassisted by crutches; the knee cage was removed 6 weeks after surgery. At his most recent follow-up 24 months postoperative, quadriceps strength was equal to that of the controlateral knee and the patient has returned to sports and daily activities. The surgical method presented here provides a suture of the tendon ends without putting excess stress on the suture line during the period of early knee mobilization. Advantages over other techniques include reduced operative time, easy access to the implantation site, and better resistance of the suture material: the patient is thus able to initiate physical therapy earlier and more aggressively.

A simple modified arthroscopic procedure for fixation of displaced tibial eminence fractures

SUMMARY

Avulsion fractures of the tibial eminence have been well described in children and adults with an increased in incidence resulting from road traffic and athletic accidents. According to the literature, only surgical treatment is advocated because of the high incidence of the nonunion and instability following conservative treatment. Open reduction can cause some morbidity and, therefore, arthroscopic techniques have been developed. The limitations of the techniques are related to technical difficulty and unstable fixation. We report a simple and effective method of fixation with the following advantages: (1) use of metallic suture for stable fixation, (2) the fixation device is easily removed in the office, (3) there is no need of additional instruments, and (4) the minimal size of the fixation device avoids damage to the anterior cruciate ligament insertion. This technique has been used in a series of 10 consecutive patients treated for avulsion fractures of the tibial spine since 1991, resulting in a high rate of excellent and good results without any case of nonunion fracture or related complication.

Effect of hydrostatic pressure on morphological and ultrastructural aspects of normal and osteoarthritic human articular chondrocytes

In this work we studied the morphological and ultrastructural aspects of normal and osteoarthritic (OA) human articular chondrocytes cultivated in alginate gel for 48 hours. After this period the chondrocytes in Petri dishes were exposed to cyclic pressurization (minimum pressure 1 MPa and maximum pressure 5 MPa) at 0.25 Hz frequency for three hours. In other loading procedures the cells were exposed to continuous pressure (24 MPa) for three hours. Some dishes were not pressurised and these served as controls. The cells were then fixed for transmission electron microscopy (T.E.M.) and for scanning electron microscopy (S.E.M.). No ultrastructural changes were observed in normal chondrocytes exposed at physiological pressure. OA cells placed under physiological pressure showed a partial recovery on morphological and ultrastructural aspects. Normal and OA samples exposed to continuous pressure (24 MPa) showed a morphological worsening in both T.E.M. and S.E.M. studies.

[Computerized tomography of the meniscus with a stress device]

PURPOSE

We investigated the usefulness of a mechanical stress device to increase widening of the articular rima in CT studies of the meniscus on forced varus and valgus.

MATERIAL AND METHODS

September 1997 to October 1998, we examined 284 patients with symptoms and clinical signs of meniscal injury. CT was performed during forced varus and valgus, depending on the site of the suspected damage, in 70 of 284 patients. We used an FOV of 18 cm, with a potential difference of 140 kVp and power of 170 mA. The reconstruction matrix was 512 x 512 and acquisition time was 3 s. A set of 8-10 partially overlapping scans were acquired craniocaudally, with slice thickness of 1.5 mm and gap of 1 mm. The mechanical strainer was locked in the correct position and a second set of 4-5 images acquired at the meniscus. Then the patients were submitted to arthroscopy to check the radiological findings.

RESULTS

CT performed in forced varus and valgus had 96.8% specificity, 97.3% sensitivity and 97.1% diagnostic accuracy. Sensitivity was 100%, specificity 96% and diagnostic accuracy 98% in the medial meniscus, while we had 88.9%, 100% and 94.7% respectively in the external meniscus.

CONCLUSIONS

CT with a mechanical stress device was extremely useful in defining the meniscal loose edge. It also showed the exact shape and complexity of meniscal injury, even in the cases with narrow articular rima or those where conventional CT had performed poorly.

Our experience in the arthroscopic treatment of fracture-avulsion of the tibial spine

The authors present their experience in the arthroscopic treatment of fracture-avulsion of the intercondyloid eminence in the adult with a variation in the original method. In fact, an ACUFEX tibial guide is used for reconstruction of the ACL positioning 2 Kirschner wires with hole at the margins of the fragment, successively sliding the metal wire through the hole. Successive traction on the outside of the wires allows the metal wires to be arranged dome-like to stabilize the avulsed fragment. The distal ends of the wires are stabilized with a metal pull-out in the area corresponding to the anteromedial surface of the tibia. In the 10 patients treated by this method, evaluated after a minimum follow-up of 6 months, we obtained overall satisfactory clinical and functional results. There was significant residual ligamentous laxity in 2 patients with no clinical symptoms of instability. Variations in arthroscopic technique described in the literature are analyzed.

Tissue characterization from X-ray images

The study of the fine-scale structure of biological tissues is crucial for diagnosing a wide number of different diseases. In X-ray images, fine structures usually induce a correlation among image gray levels and are commonly perceived as textures. In this paper, we report on a Computer Vision approach to the characterization of biological tissues as imaged by standard X-ray techniques. In particular, using features derived from co-occurrence matrices, we have assessed spatial gray-level dependence of bone tissue and lung parenchyma images. A hybrid neural network was adopted to distinguish pathological tissues from normal ones and to classify different pathologies.

A new cervical orthosis with multiplanar adjustment

It is the purpose of this paper to introduce a new cervical orthosis with multiplanar adjustment. Many orthoses are available to the physician today, but all of them may be classified based on function into two groups: 1) orthoses that immobilize the neck in a fixed position; 2) orthoses that immobilize the patient in a position that may be set in the sagittal plane. At present no orthosis are available to immobilize the neck in a position to anything but the sagittal plane. This new orthosis, with four tridimensional swinging posters, allows for immobilization of the neck in the desired position, according to the clinical evaluation performed. This treatment offers advantages in terms of patient compliance and functional results. An alternative model, with increased stability, has especially been planned for the treatment of pathology at C1-C2.

Comparison of the antiinflammatory efficacy of chondroitin sulfate and diclofenac sodium in patients with knee osteoarthritis

OBJECTIVE

To assess the clinical efficacy of chondroitin sulfate (CS) in comparison with the nonsteroidal antiinflammatory drug (NSAID) diclofenac sodium (DS) in a medium/longterm clinical study in patients with knee osteoarthritis (OA).

METHODS

This was a randomized, multicenter, double blind, double dummy study. 146 patients with knee OA were recruited into 2 groups. During the first month, patients in the NSAID group were treated with 3 x 50 mg DS tablets/day and 3 x 400 mg placebo (for CS) sachets; from Month 2 to Month 3, patients were given placebo sachets alone. In the CS group, patients were treated with 3 x 50 mg placebo (for diclofenac) tablets/day and 3 x 400 mg CS sachets/day during the first month; from Month 2 to Month 3, these patients received only CS sachets. Both groups were treated with 3 x 400 mg placebo sachets from Month 4 to Month 6. Clinical efficacy was evaluated by assessing the Lequesne Index, spontaneous pain (using the Huskisson visual analog scale), pain on load (using a 4 point ordinal scale), and paracetamol consumption.

RESULTS

Patients treated with the NSAID showed prompt and plain reduction of clinical symptoms, which, however, reappeared after the end of treatment; in the CS group, the therapeutic response appeared later in time but lasted for up to 3 months after the end of treatment.

CONCLUSION

CS seems to have slow but gradually increasing clinical activity in OA; these benefits last for a long period after the end of treatment.

The diagnosis of acute complete tears of the anterior cruciate ligament. Comparison of MRI, arthrometry and clinical examination

We reviewed 38 patients with arthroscopically-proven complete ACL tears operated on less than three weeks after injury. Their average age was 26 years (16 to 43), with 27 males and 11 females. All patients had had MRI preoperatively. The same examiner performed the Lachman, anterior-drawer, and pivot-shift tests without anaesthesia, recording the differences between the injured and the normal knees. The patients then had KT-1000 arthrometry by the same examiner at 15 lb (6.8 kg) and 20 lb (9 kg), with active displacement, and with maximum manual displacement. All scored positive for differences greater than 3 mm. The results of physical examination, KT-1000 tests and MRI were analysed using McNemar's test for matched data with continuity correction and a 95% confidence interval for each test. The sensitivity of the KT-1000 manual maximum test was 97% for 3 mm and 100% for 2 mm; this was the most useful arthrometric result. The Lachman test gave 95% sensitivity, providing the best simple clinical assessment. MRI was 97% sensitive for the detection of all ACL injuries, but this fell to 82% with respect to complete rupture. We found no significant differences between the results of the Lachman test and the KT-1000 manual maximum test, but these were significantly better than all other tests. In an era of cost-containment, we have shown that inexpensive tests in the clinic can allow treatment to proceed rapidly and in the most economical manner without the routine use of MRI.

Titanium anchors for the repair of rotator cuff tears: preliminary report of a surgical technique

We used titanium anchors for the surgical repair of rotator cuff tears in 34 selected patients, all of whom were < 60 years of age, had good bone quality, and had no known metabolic bone diseases. Nine tears were repaired within 6 months, 15 within 6-12 months, and 10 later than 12 months after injury. Tear size was graded as small (10 patients), medium (15 patients), and large (nine patients) during open operation. After 6-24 months of follow-up, 30 patients reported satisfactory pain relief, function, active forward flexion, and muscle strength [18 excellent and 12 good results based on the University of California at Los Angeles rating system (UCLA scores)]; there were no implant failures (p < 0.001). Two patients had unsatisfactory function but good relief of pain, whereas two patients were dissatisfied with their overall result (four poor results based on UCLA scores). Although trans-bone suturing is presently the most common and successful surgical technique for rotator cuff tears, we found that use of titanium anchors shortens operative time and has results comparable with the traditional technique. Titanium anchors should not be used when bone quality is poor or good patient compliance is doubtful. They are also contraindicated, as our four poor results indicate, when the tear is old (> 6 months) and large (diameter > 5 cm with significant tissue degeneration).

Partial lateral meniscectomy in athletes

Arthroscopic partial lateral meniscectomies performed for isolated meniscal tears, without associated ligamentous injury, in 41 athletes between August 1, 1988 and June 1, 1991 were reviewed for clinical and functional outcome. The study population was composed of 27 males and 14 females, with an average age of 26 years (range 17-40). Thirty-seven patients (90%) reported previous trauma to the knee. At an average follow-up of 3 years (range 2-5), 85% of the patients had excellent/good results, and 98% of the athletes returned to full sports activities after an average of 55 days. Patients' prognoses depended on (a) type of meniscal tear and (b) presence/absence of an articular cartilaginous lesion. Athletes who had isolated, longitudinal type tears of the lateral meniscus had the best outcome: 100% achieved excellent/good results and averaged 41 days to return to full sports activities. Athletes with complex meniscal tears and tears associated with articular cartilaginous lesions had the poorest results, achieving 79% and 64% excellent/good results, respectively, and averaging 64 and 78 days, respectively, for return to full sports activities.

Meniscal ossicles: two case reports and a review of the literature

Intrameniscal ossicles of the knee are rare lesions. We present two cases. The first case occurred in a male soccer player who had knee trauma, with radiographic findings of a meniscal ossicle. Meniscal motions were normal, and symptoms resolved with conservative measures. The second case was found in a male athlete with acute medial compartment instability and complex meniscal tears. His medial meniscus, containing the ossicle, was removed. Initial conservative management is recommended for all cases of meniscal ossicle, and arthroscopic resection of the ossicle is recommended for symptomatic cases.

Trends in the incidence of hip fracture in Siena, Italy, from 1980 to 1991

There is general agreement that the crude incidence of proximal femur (hip) fractures is rising in conjunction with the ageing of the underlying population. To explore possible changes in hip fracture incidence over time we analysed all femoral fractures occurring in the county of Siena from 1980 to 1991. Data were collected from hospital record charts of the Department of Orthopaedics, recording all hip fractures occurring during the 12-year period. In this period, the mean resident population in Siena was 238,369 inhabitants (aged 0 to 90+ years) and the crude number of all femoral fractures was 2,238. However, in calculating incidence rates, only hip fractures occurring in the population aged over 50 years were considered. In this population, the number of hip fractures was 1,825 with a male/female ratio of 1:2.8. A time-series data analysis (temporal trend) of the incidence of hip fracture during the 12-year period revealed a linear and significant (p < 0.001) trend to increase, but only in males, with an annual increasing rate of 3.62 per 100,000 person-years. In the female population, the temporal analysis did not show any significant trend during the observation period.

The Onik method of automated percutaneous lumbar diskectomy (A.P.L.D.). Criteria of selection, technique, and evaluation of results

The Onik method of automated percutaneous lumbar diskectomy is a new type of percutaneous surgery for the treatment of herniated lumbar disk. Candidates for this procedure should be carefully evaluated on the basis of precise clinical criteria and instrumental diagnosis. The goal is to select patients in whom excellent results can be achieved, recognizing the limitations as well as the merits of the technique. The surgical approach is described and the potential difficulties are discussed, since this technique must be performed with precision and without trauma in order to obtain good results. The clinical results of 500 patients treated by the Onik method of automated percutaneous lumbar diskectomy are reported. The follow-up period ranged from 6 months to 2 1/2 years. The patients were divided into three groups according to the strength of the indication for A.P.L.D.; the quality of the result is reported for each group.

The surgical treatment of metastases in long bones

The authors report their experience in the treatment of metastases in long bones. Between 1980 and 1985, 51 cases were submitted to surgical treatment. They comprised osteolytic lesions in the femur (44), tibia (2), and humerus (5). The most frequent primary tumours were: carcinoma of the breast (37%), lung (25%), kidney (16%), rectum (9%). The remaining 13% were from the prostate gland, bladder, ovaries, uterus, chronic lymphatic leukemia, and haemangiopericytoma. Surgical treatment was supplemented by medication and physiotherapy. The choice of instrumentation (prosthesis, total prosthesis, plates, endomedullary nailing) was based on the site of the metastasis and the general condition of the patient. Palliative surgery in these cases was fully justified by the results in that it achieved the aim we set ourselves, namely to restore these unfortunate patients to as normal a lifestyle as possible.

Atherosclerosis of the vessels in the ligamentum teres. Optical and electron microscopy findings in elderly patients with femoral neck fractures

The ligamentum teres was studied in 20 subjects, aged from 64 to 83 years, with fractures of the femoral neck treated by prosthetic replacement during 1985. The arterioles were examined under a stereoscopic dissection microscope; they were further studied by optical and electron microscopy. Almost complete occlusion by typical proliferative atherosclerotic changes was a constant finding, thereby cutting off any significant vascular supply to the femoral head.