Posterolateral approaches to the thoracic spine for calcific disc herniation: is wider exposure always better?

OBJECTIVE: To compare the costotransversectomy (CTV) and transpedicular (TP) approaches versus the transfacet (TF) approach for the surgical treatment of calcific thoracic spine herniations (cTDH), in terms of surgical and clinical outcomes. BACKGROUND: Surgical approaches for cTDH are debated. Anterior approaches are recommended, while posterolateral approaches are preferred for non-calcific, paramedian, and lateral hernias. Currently, there is limited evidence about the superiority of a more invasive surgical approach, such as CTV or TP, over TF, a relatively less invasive approach, in terms of neurological outcome, pain, and surgical complications, for the treatment of cTDH. METHODS: A retrospective, observational, monocentric study was conducted on patients who underwent posterolateral thoracic approaches for symptomatic cTDH, between 2010 and 2023, at our institute. Three groups were drafted, based on the surgical approach used: TF, TP, and CTV. All procedures were assisted by intraoperative CT scan, spinal neuronavigation, and intraoperative neuromonitoring. Analyzed factors include duration of surgery, amount of bone removal, intraoperative blood loss, CSF leak, need of instrumentation for iatrogenic instability, degree of disc herniation removal, myelopathy recovery. Afterwards, a statistical analysis was performed to investigate the bony resection of the superior posterior edge of the vertebral soma. The primary outcome was the partial or total herniation removal. RESULTS: This study consecutively enrolled 65 patients who underwent posterolateral thoracic surgery for cTDH. The TF approach taking the least, and the CTV the longest time (p < 0.01). No statistical difference was observed between the three mentioned approaches, in terms of intraoperative blood loss, dural leakage, post-resection instrumentation, total herniation removal, or myelopathy recovery. An additional somatic bony resection was successful in achieving total herniation removal (p < 0.01), and the extent of bony resection was directly proportional to the extent of hernia removal (p < 0.01). CONCLUSIONS: No statistically significant differences were highlighted between the TP, TF, and CTV regarding the extent of cTDH removal, the postoperative complications, and the neurological improvement. The described somatic bone resection achieved significant total herniation removal and was directly proportional to the preop against postop anteroposterior diameter difference.

Does Laminectomy Affect Spino-Pelvic Balance in Lumbar Spinal Stenosis? A Study Based on the EOS X-Ray Imaging System.

PURPOSE: Lumbar spinal stenosis (LSS) is a degenerative disorder causing the forward bending of the trunk and pelvic retroversion with the consequent loss of lumbar lordosis; surgical treatment is intended to enlarge the canal and foramina and decompress the nerve roots. The purpose of our study is to determine whether and to what extent facet-sparing laminectomy affects the spino-pelvic balance. METHODS: The spino-pelvic balance of 26 patients was analysed before and after surgery through the EOS X-ray Imaging System. The following parameters were considered: thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). Clinical data were expressed in numeric values according to the Oswestry Disability Index (ODI), the visual analogue scale (VAS) and the modified Japanese Orthopaedic Association (mJOA) scoring system. RESULTS: Significant SS decreases and PT increases were noticed after surgery, without modification in LL, axial vertebral rotation (AVR) and the general alignment. Pain and disability had a significant improvement, as represented by a decrease in scores on the VAS and ODI scales and an increase in scores on the mJOA functional scale. CONCLUSION: The most important parameter seems to be a congruence between pelvic and spinal parameters, which achieves an economic posture with the physiologic position of the axis of gravity. According to the literature, a standard sagittal balance (SB) has not been defined.

Multiple univariate analysis of radiologic and clinical features on 168 patients with lumbar spinal stenosis: what is the role of the erector spinae in the development of a patient's disability?

BACKGROUND: The weakening of paraspinal muscles in the paravertebral area may play a role in developing central lumbar spinal stenosis, resulting in lower back discomfort. OBJECTIVE: The study thoroughly examined the correlation between the Oswestry Disability Index, Dural Sac cross-sectional area, Schizas grading Scale, Body Mass Index, and the cross-sectional areas of Erector Spinae, Multifidus, and Psoas muscles. The findings were also compared between patients with central Lumbar Spinal Stenosis and healthy individuals. STUDY DESIGN: Retrospective monocentric observational study. METHODS: The study recruited 168 consecutive patients aged 60 or older diagnosed with central Lumbar Spinal Stenosis between January 2020 and July 2022. The patients' condition was evaluated by administering a preoperative Oswestry Disability Index questionnaire, measuring their Body Mass Index, and performing preoperative Magnetic Resonance Imaging. The analyzed parameters were the cross-sectional area of paraspinal muscles at the L4-L5 level, dural sac cross-sectional area, and Schizas grading Scale at the most stenotic level, using multiple linear univariate analyses. Two groups of healthy individuals were recruited: Group A (under 60 years old) and Group B (over 60 years old). The same data extrapolated from these groups were compared with those of patients with central lumbar stenosis using a two-tailed Mann-Whitney test. RESULTS: As the Erector Spinae degenerates, the Oswestry Disability Index tends to increase. Similarly, an increase in Body Mass Index is often accompanied by a decrease in the cross-sectional area of the Erector Spinae. Low dural sac cross-sectional area is statistically linked to a reduced Multifidus cross-sectional area. Interestingly, the Schizas grading scale does not appear to correlate with changes in the cross-sectional area of the paraspinal muscles. Additionally, there is no significant difference in the cross-sectional area of the Psoas muscle between individuals with central lumbar spinal stenosis and healthy individuals. CONCLUSIONS: Our study found that degeneration of the Erector Spinae plays a crucial role in the progression of perceived disability in Lumbar Spinal Stenosis. Prospective studies should investigate the long-term evolution of paraspinal muscles in decompressed patients.

Evaluating the Use of a Robot in a Hematological Intensive Care Unit: A Pilot Study.

The aim of the SYRIACA project was to test the capability of a social robot to perform specific tasks in healthcare settings, reducing infection risks for patients and caregivers. The robot was piloted in an Intensive Hematological Unit, where the patients' and healthcare operators' acceptability of the robot was evaluated. The robot's functions, including logistics, surveillance, entertainment, and remote visits, were well accepted. Patients expressed interest in having multiple interactions with the robot, which testifies to its engaging potential and that it provides useful services. During remote visits, the robot reduced perceived stress among patients, alleviating feelings of isolation. The successful implementation of the robot suggests its potential to enhance safety and well-being in healthcare settings.

Does Navigation Improve Pedicle Screw Placement Accuracy? Comparison Between Navigated and Non-navigated Percutaneous and Open Fixations.

BACKGROUND: The aim of our study was to assess how a preoperative computed tomography (CT)-based navigation system affected the correctness and safety of transpedicular screw insertion, compared with standard techniques. METHOD: Between January 2012 and February 2014, 203 patients underwent thoracic and lumbar fixation, with open and percutaneous techniques; 218 screws were implanted through an open navigated technique (1.0 Spine & Trauma 3d ver. 2.0 BrainLab, Feldkirchen Germany) in 43 patients; 220 screws were inserted with an open free-hand technique in 45 patients; 230 screws were implanted in 56 patients using percutaneous CT-based navigation; and 236 screws were inserted in 59 patients using a percutaneous fluoroscopy-guided technique. To our knowledge, this is the first work comparing these four different techniques. The position of each screw was evaluated on CT scan reconstruction and classified according to a four-point grading scale (grade 0: no breach, grade 1: breach < 2 mm, grade 2: breach between 2 and 4 mm; grade 3: breach >4 mm). Statistical analysis was assessed by two-way analysis of variance (ANOVA) t test, while the Fisher least significant difference (LSD) method was employed to determine statistical significance. RESULTS: Statistical analysis showed a significant difference in accuracy between the open CT-based navigation and the percutaneous CT-based navigation techniques (P= 0.0263) and between the open CT-based navigation and the percutaneous fluoroscopy-guided techniques (P=0.0258): a particular difference was observed in anterior misplacement between open CT-based navigation and the percutaneous fluoroscopy-guided technique (P= 0.0153). CONCLUSIONS: Our results confirm the advantages of the navigation technique, which ensures greater accuracy, in open as well as percutaneous procedures.

Transpedicular Approach to Thoracic Disc Herniaton Guided by 3D Navigation System.

BACKGROUND: The choice of surgical approach for thoracic disc herniation should consider the location on the axial plane and the consistency of the herniated disc. Calcified midline disc herniations are difficult to remove with a transpedicular approach because of limitations due to blind spots; so they are usually treated via a transthoracic approach, although this entails a high risk of thoracopulmonary injuries. METHODS: In this work we present two cases of calcified midline thoracic disc herniations treated with a transpedicular approach, improved by using a three-dimensional (3D) neuronavigation system to verify the extent of removal on the blind side. RESULTS: Postoperative computed tomography (CT) scans demonstrated that this original technical innovation, in the two present cases, allowed us to reach the side opposite the disc herniation and to assess the extent of resection at the end of the procedure. CONCLUSIONS: The employment of a neuronavigation system in the transpedicular approach allowed safe and effective removal of calcified midline thoracic disc herniations. We did not observe any postoperative neurological worsening, onset of spinal instability, or other adverse events.

The Goutallier Classification System: How Does Paravertebral Adipose Degeneration Change in Patients With Symptomatic Lumbar Spinal Stenosis?

STUDY DESIGN: Retrospective, observational study. OBJECTIVE: To determine the relationship between the Goutallier classification system (GS) and anthropometric, clinical, and radiologic features in 168 patients with lumbar spinal stenosis (LSS). BACKGROUND: There is no agreement on a classification system that is both reliable and easy to use for describing the severity of fatty degeneration in the paravertebral muscles of the lower back in patients with symptomatic LSS. This study aimed to determine the statistical relationship between the GS and anthropometric, clinical, and radiologic factors in 168 patients with LSS. MATERIALS AND METHODS: This study was conducted on 168 patients with LSS scheduled for elective decompressive surgery. A control group of 110 healthy individuals was enrolled. The study assessed paralumbar musculature fatty infiltration using GS on preoperative magnetic resonance imaging. The authors evaluated the statistical association between patient age, body mass index (BMI), preoperative Oswestry disability index (ODI) questionnaire, and cross-sectional areas (CSAs) of the dural sac and lumbar paraspinal muscles. Multivariate analysis was performed to adjust for confounding. RESULTS: This study enrolled 168 patients with symptomatic LSS (95 men, 73 women); mean±SD age: 67.81±9.38 (range: 32.78-92.34) years; BMI: 28.29±3.36 (19.95-38.10) kg/m 2 . The control group was comprised of 110 healthy patients (61 men and 49 women). Age, sex, BMI, and erector spinae (ES)-CSA were not significantly different between the two groups. The authors found a direct relationship between GS grade and age and an inverse relationship between GS grade and dural sac-, multifidus lumbaris (LM)-, ES-, and psoas muscle (PM)-CSAs. Univariate analyses showed the variables statistically related to a higher GS grade included patient age ( P <0.001), ODI ( P =0.136), dural sac-CSA ( P =0.011), LM-CSA ( P < 0.001), ES-CSA ( P <0.001), and PM-CSA ( P <0.001). Multivariate least squares analysis showed the GS grade to be influenced by patient age ( P =0.01), LM-CSA ( P =0.002), ES-CSA ( P =0.002), and PM-CSA ( P =0.003). CONCLUSIONS: GS shows great potential as a tool for evaluating fat infiltration in the paralumbar muscles. This measure does not correlate with the ODI and BMI but is related to all radiologic parameters and patient age. Further prospective studies are required to establish a link between preoperative and postoperative outcomes in the setting of paraspinal fat infiltration.

Design and Adoption of a FHIR IG to Support a Telemonitoring Environment in Gatekeeper Project.

Telemedicine can provide benefits in patient affected by chronic diseases or elderly citizens as part of standard routine care supported by digital health. The GATEKEEPER (GK) Project was financed to create a vendor independent platform to be adopted in medical practice and to demonstrate its effect, benefit value, and scalability in 8 connected medical use cases with some independent pilots. This paper, after a description of the GK platform architecture, is focused on the creation of a FHIR (Fast Healthcare Interoperability Resource) IG (Implementation Guide) and its adoption in specific use cases. The final aim is to combine conventional data, collected in the hospital, with unconventional data, coming from wearable devices, to exploit artificial intelligence (AI) models designed to evaluate the effectiveness of a new parsimonious risk prediction model for Type 2 diabetes (T2D).

Cervical spine arachnoid cyst complicated by spontaneous intracystic hemorrhage: Case report and review of the literature.

Background: Spinal intradural extramedullary arachnoid cysts represent about 1-3% of all primary spinal space-occupying lesions often causing spinal cord and/or radicular nerve compression. Spontaneous intralesional hemorrhages are extremely rare and are typically found within intracranial arachnoid cysts. Here, a 55-year-old female presented with a spontaneous hemorrhage into a cervical spine arachnoid cyst warranting surgical intervention (i.e., fenestration/excision/occlusion). Case Description: A 55-year-old female presented with 3 weeks of dull pain in the cervicothoracic region. She subsequently developed paresthesias and progressive lower extremity weakness with (urinary incontinence. The cervical magnetic resonance revealed a right anterolateral intradural extramedullary "cystic" lesion extending from C7 to T2; it contained a heterogeneous signalon T2W sequences, and a fluid-fluid level was documented on the T2-GRE and FLAIR sequences. At surgery, consisting of a laminectomy, two hemorrhagic cystic lesions were identified and removed. Histological findings were consistent with hemorrhagic into an arachnoid cyst. Conclusion: Only rarely hemorrhages develop in intraspinal intradural extramedullary spinal arachnoid cysts.

Management Strategies and Nursing Activities for Nutritional Care in Hospitalized Patients with Cognitive Decline: A Scoping Review.

Cognitive impairment and dementia can negatively impact the nutritional capacities of older people. Malnutrition is common in hospitalized frail elderly people with cognitive impairment and negatively affects prognosis. Malnutrition worsens the quality of life and increases morbidity and mortality. This scoping review aimed to identify factors affecting the risk of malnutrition and preventive strategies in hospitalized patients with cognitive impairment, focusing on nursing interventions. The authors researched population, context, and concept in international databases of nursing interest. Full texts that met the inclusion criteria were selected and reviewed. The extracted data were subject to thematic analysis. A five-stage approach, already reported in the scientific literature, was utilized in the following scoping review. Of 638 articles yielded, 9 were included. Two focus areas were identified as follows: (1) prevalence and risk factors of malnutrition in older patients with cognitive decline; (2) nursing strategies used to enhance clinical outcomes. Nursing health interventions aim to recognize and reduce malnutrition risk, positively impacting this phenomenon. A multidisciplinary team is essential to meet the nutritional needs of these patients.

Prognostic Value of Michigan State University (MSU) Classification for Lumbar Disc Herniation: Is It Suitable for Surgical Selection?

BACKGROUND: Lumbar disc herniation (LDH) is the most common cause of radiculopathy; patients with severe pain refractory to conservative management or neurological deficits are candidates to surgical procedures. Michigan State University (MSU) classification is a radiological codification considering both the size of the LDH and its medial to lateral location on the axial plane. The purpose of this retrospective study is to identify which kind of LDH, according to the MSU scheme, is more likely to cause a motor deficit. METHODS: We performed a retrospective analysis on data obtained from 114 patients treated with 117 lumbar microdiscectomies after failure of non-operative care. All patients underwent neurological and functional evaluation before and after surgery according to the following: Oswestry Disability Index, visual analog scale, and Japanese Orthopaedic Association back pain evaluation questionnaire. Magnetic resonance imaging proved that disc herniation was classified according to the MSU scheme and was correlated with motor disturbances expressed according to Medical Research Council grade. RESULTS: Statistical analysis showed a significant correlation between the lateral location of disc herniation (preforaminal and extraforaminal LDH, respectively MSU B and MSU C) and the grade of muscle weakness, given that the LDH in these locations poorly responded to medical therapy and was at higher risk for motor deficit onset; no significant correlation with the size was observed. CONCLUSIONS: Beyond standardization of radiologic description, MSU classification proved to be useful in definition of prognosis and possibly in selection of surgical candidates. However, these data should be confirmed by prospective studies on a larger sample of patients, also including those under way for conservative treatment.

The Use of mHealth in Orthopedic Surgery: A Scoping Review.

(1) Background: It is well known that the success of surgical procedures is related to optimal postoperative management and follow-up. In this regard, mHealth technologies could potentially improve perioperative care. Based on these considerations, the objective of this scoping review is to evaluate the current status and use of mHealth interventions designed to provide perioperative care in orthopedic surgery. (2) Methods: This scoping review was conducted in accordance with the PRISMA statement (Extension for Scoping Review) and follows the framework of Arskey and O'Malley. (3) Results: The use of mHealth in the surgical setting is mainly oriented towards the development of applications for monitoring post-operative pain and optimizing communication between the various health professionals involved in patient care. (4) Conclusions: The mHealth systems can have a positive impact both on patient participation in the therapeutic process and on the communication between health professionals, increasing the quality of care.

The Perceptions of People with Dementia and Key Stakeholders Regarding the Use and Impact of the Social Robot MARIO.

People with dementia often experience loneliness and social isolation. This can result in increased cognitive decline which, in turn, has a negative impact on quality of life. This paper explores the use of the social robot, MARIO, with older people living with dementia as a way of addressing these issues. A descriptive qualitative study was conducted to explore the perceptions and experiences of the use and impact of MARIO. The research took place in the UK, Italy and Ireland. Semi-structured interviews were held in each location with people with dementia (n = 38), relatives/carers (n = 28), formal carers (n = 28) and managers (n = 13). The data was analyzed using qualitative content analysis. The findings revealed that despite challenges in relation to voice recognition and the practicalities of conducting research involving robots in real-life settings, most participants were positive about MARIO. Through the robot's user-led design and personalized applications, MARIO provided a point of interest, social activities, and cognitive engagement increased. However, some formal carers and managers voiced concern that robots might replace care staff.

The Functional Relevance of Diffusion Tensor Imaging in Patients with Degenerative Cervical Myelopathy.

(1) Background: In addition to conventional magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) has been investigated as a potential diagnostic and predictive tool for patients with degenerative cervical myelopathy (DCM). In this preliminary study, we evaluated the use of quantitative DTI in the clinical practice as a possible measure to correlate with upper limbs function. (2) Methods: A total of 11 patients were enrolled in this prospective observational study. Fractional anisotropy (FA) values was extracted from DTI data before and after surgery using a GE Signa 1.5 T MRI scanner. The Nine-Hole Peg Test and a digital dynamometer were used to measure dexterity and hand strength, respectively. (3) Results: We found a significant increase of FA values after surgery, in particular below the most compressed level (p = 0.044) as well as an improvement in postoperative dexterity and hand strength. Postoperative FA values moderately correlate with hand dexterity (r = 0.4272, R2 = 0.0735, p = 0.19 for the right hand; r = 0.2087, R2 = 0.2265, p = 0.53 for the left hand). (4) Conclusion: FA may be used as a marker of myelopathy and could represent a promising diagnostic value in patients affected by DCM. Surgical decompression can improve the clinical outcome of these patients, especially in terms of the control of finger-hand coordination and dexterity.

Insomnia and Information and Communication Technologies (ICT) in Elderly People: A Systematic Review.

Background: Insomnia seems to be related to disability, risk of injury, metabolic syndrome, risk for cardiovascular diseases, cognitive impairment, depression and impaired quality of life. Objectives: The goals in this paper was (1) to keep track of technological concepts and approaches to improve insomnia in elderly people, and (2) to define the effect that information and communication technologies (ICT) is having on patients' care. Design: A systematic review was conducted from existing literature. Our selection criteria included: (1) age ≥ 60 years; (2) diagnosis of insomnia with the International Classification of Sleep Disorders (ICSD-II), (3) CBTi (cognitive behavioural therapy insomnia), (4) use of technological tools, and (5) associations between insomnia-related variables and indices of disability, quality of life, and global clinical assessments. Data analysis: 11 articles were included. An inductive content analysis was used for data extraction. Results: Our review revealed any technological systems that could purportedly rehabilitate elderly patients with insomnia. Three categories of research were identified from the review: (1) Internet Deliver-CBTi, (2) virtual coaches, and (3) sleep technologies. Conclusions: The potential for ICT to support insomnia care at home can improve the quality of life for families and reduce health care costs and premature institutional care.

Dialogue Systems and Conversational Agents for Patients with Dementia: The Human-Robot Interaction.

This study aimed to identify and describe the fundamental characteristics of spoken dialogue systems, and their role in supporting human-robot interaction and enabling the communication between socially assistive robots and patients with dementia. First, this work provides an overview of spoken dialogue systems by considering the underlying technologies, approaches, methods, and general issues. Then, the analysis focuses on studies, systems, and approaches that have investigated the role of dialogue systems and conversational agents in the interaction with elderly people with dementia by presenting the results of a literature review. While the overview of spoken dialogue systems relies on existing surveys and reviews, a research was conducted to identify existing works in the literature that have investigated the role of conversational agents and dialogue systems in the elderly and people with cognitive impairments. Inclusion criteria were as follows: (1) use of conversational agents, dialogue systems, or language processing tools for people with cognitive impairments; (2) age ≥60 years; (3) diagnosis of dementia according to National Institute on Aging-Alzheimer's Association (NIAAA) criteria; (4) presence of tests or experiments with qualitative or quantitative results. Initially 125 studies published between 2000 and 2017 were identified, of which 12 met the inclusion criteria. The review identifies the issues and challenges that are reported when conversational agents and speech-based interfaces have been used for interacting with people with cognitive impairments. In addition, the review led to the identification of studies that have investigated speech processing and natural language processing capabilities to assess the cognitive status of people with dementia.

MARIO Project: Validation and Evidence of Service Robots for Older People with Dementia.

BACKGROUND: In the EU funded MARIO project, specific technological tools are adopted for the people living with dementia (PLWD). In the final stage of the project, a validation of the MARIO companion robot was performed from August to October 2017. OBJECTIVE: The aims of the present study are: 1) to illustrate the key results and evidence obtained in the final evaluation phase of the project across the three different pilot sites; 2) to assess the engagement dimensions of the PLWD who interacted with the MARIO robot; and 3) to assess the acceptability and efficacy of the MARIO companion robot on clinical, cognitive, neuropsychiatric, affective and social aspects, resilience, quality of life in PLWD, and burden level of the caregivers. METHODS: 38 people (M = 14; F = 24) with Alzheimer's disease were screened for eligibility and all were included. The following tests were administered Pre and Post interactions with MARIO: Observational Measurement of Engagement (OME), Mini-Mental State Examination (MMSE), Clock Drawing Test (CDT), Frontal Assessment Battery (FAB), Neuropsychiatric Inventory (NPI), Cornell Scale for Depression in Dementia (CSDD), Multidimensional Scale of Perceived Social Support (MSPSS), 14-item Resilience Scale (RS-14), Quality of Life in Alzheimer's Disease (QOL-AD), Caregiver Burden Inventory (CBI), Tinetti Balance Assessment (TBA), and Comprehensive Geriatric Assessment (CGA) was carried out. RESULTS: In Post-MARIO interactions, significant improvements were observed in RS-14 (p = 0.020).Considering the age of the people, PLWD with 68-76 years perceived that they had major social support (MSPSS Total: p = 0.016) and friends to support them (MSPSS Fri: p = 0.014). Indeed, the younger people (55-67 years) were less depressed (CSDD: p = 0.033), and more resilient (RS-14: p = 0.003). The people aged 77-85 years perceived they had major family support (MSPSS Fam: p = 0.018). The participants were gender and education matched without any statistically significant difference. CONCLUSION: MARIO may be a useful tool in mitigating depression and loneliness, while enhancing social connectedness, resilience, and overall quality of life for people with dementia.

Vitellogenin as a biomarker of exposure to estrogenic compounds in aquatic invertebrates: a review.

Vitellogenins (Vg) are the major precursor of the egg-yolk proteins, vitellins (Vn), which provide energy reserves for embryonic development in oviparous organisms. In mature females, Vg are generally synthesised in response to endogenous estrogens, such as 17beta-estradiol (E2), released into the bloodstream and then stored in developing oocytes. In males, the Vg gene, although present, is normally silent. However, it may be activated by (xeno)-estrogens. These substances belong to a large and heterogeneous group of environmental contaminants capable of altering endocrine functions in organisms. For this reason, they are named endocrine disrupting chemicals (EDCs). Natural steroidal estrogens [E2, estrone (E1), estriol (E3)] and synthetic chemicals, such as pesticides, polychlorinated biphenyls (PCBs) and household products (surfactants) are estrogenic compounds widespread in aquatic ecosystems. The main sources of contamination mostly stem (or originate) from municipal and industrial effluents, agricultural practices, livestock wastes and sewage treatment plants (STP). Recently, Vg induction, mainly in males and immature females, has been proposed as a useful biomarker to assess estrogenic contamination in aquatic environments. Indeed, estrogenicity of individual chemicals and mixtures has extensively been evaluated, in both laboratory and field studies, albeit mostly in fish. In contrast, limited attention has centred on evaluating xenoestrogen effects in aquatic invertebrates, probably owing to limited knowledge of their endocrinology. This review focuses on a brief description of xenoestrogens and their occurrence in aquatic environments, and on Vg induction in aquatic invertebrates in response to both experimental and environmental exposure to estrogenic compounds. Results of recent field and laboratory studies are presented. In addition, new perspectives about the use of Vg induction as a biomarker of exposure to estrogenic compounds are also discussed.

Effects of 4-nonylphenol exposure in mussels (Mytilus galloprovincialis) and crabs (Carcinus aestuarii) with particular emphasis on vitellogenin induction.

Since it is often difficult to estimate possible adverse effects due to contamination in selected ecosystems, multi-species biomonitoring may provide more information, taking into account different routes of exposure, ecological roles and metabolic capabilities of animals. In this context, we exposed for 7 days the mussel Mytilus galloprovincialis and the crab Carcinus aestuarii to 4-nonylphenol (NP), a well-known xenoestrogen. In mussels (0-0.2 mg NP l(-1)), we measured NP bioaccumulation in soft tissues and vitellogenin (Vg)-like protein levels in digestive glands from both males and females by the alkali-labile phosphate assay (ALP). As no reference data were available for crab exposure, the NP 96-h LC(50) value was previously determined. Then, in sublethally exposed (0-1.0 mg NP l(-1)) male crabs, NP bioaccumulation and Vg levels were measured in hemolymph, gonads and digestive gland. Bioaccumulation of NP increased from 43 to 371 microg g(-1) d.w. in mussels, and from 3.6 to 37 microg g(-1) d.w. in crabs, depending on the NP concentration in water. Dose-dependent Vg-like protein induction was observed in both species, appearing to be related to NP bioaccumulation, although a partial decrease was recorded at the highest concentration tested. A similar trend was observed in both digestive gland and gonad of exposed crabs; Vg increased to a lesser extent, although significantly, in hemolymph. Results demonstrated that NP induces Vg synthesis both in male and female mussels, as well as in male crabs. On the basis of the responsiveness of both species investigated, a multi-species approach is indicated in biomonitoring programmes.