Development and validation of INTENSS, a need-supportive training for nurses to support patients' self-management

BACKGROUND

The growing prevalence of chronic illnesses requires nurses to support self-management and help patients integrate the chronic illness into their life. To our knowledge there are currently no training programs that combine the necessary components to adequately enhance nurses' competencies in self-management support.

OBJECTIVE

The systematic development and validation of a need-supportive training in self-management support for nurses.

DESIGN

A three-phased study, according to van Meijel et al. (2004), with collection of building blocks, design, and validation of the need-supportive character of the training.

SETTING AND PARTICIPANTS

Eight training groups with 30 nurses, 34 nursing students and nine social healthcare workers from different nursing colleges in Flanders, Belgium.

METHODS

In phase one a literature review, current practice analysis, and problem and needs analysis were performed. In phase two, the INTENSS training intervention was developed, framed within the Self-Determination Theory and the 5A's-Model. The training consisted of a basic training module and a video-interaction guidance module. The intervention was subsequently tested in eight training groups (N = 73). Participants provided feedback during focus group discussions. The intervention was cyclically adapted to trainees' experiences and suggestions. In phase three, we evaluated the need-supportive character of the training intervention.

RESULTS

Phase one indicated the need for training, since nurses' application of self-management support was limited and practiced from a narrow medical point of view. In phase two we developed a theory-driven and multifaceted training, building on attitude, knowledge, skills and reflection in the training. The training was framed within the Self-Determination Theory both at the didactical level as well as on content and format. Overall, participants appreciated the building blocks of the training as supporting their basic needs for autonomy, relatedness and competence.

CONCLUSIONS

INTENSS, a multifaceted need-supportive training in self-management support was developed, successfully taking into account participants' needs.

Psychiatric and physical outcomes of long-term use of lithium in older adults with bipolar disorder and major depressive disorder: A cross-sectional multicenter study

OBJECTIVE

Although lithium is widely used in current practice to treat bipolar disorder (BD) and treatment-resistant major depressive disorder (MDD) among older adults, little is known about its efficacy and tolerability in this population, which is generally excluded from randomized clinical trials. The objective of this study was to evaluate the efficacy and tolerability of long-term use of lithium among older adults with BD and MDD.

METHOD

Data from the Cohort of individuals with Schizophrenia and mood disorders Aged 55 years or more (CSA) were used. Two groups of patients with BD and MDD were compared: those who were currently receiving lithium versus those who were not. The effects of lithium on psychiatric (i.e., depressive symptoms severity, perceived clinical severity, rates of psychiatric admissions in the past-year), geriatric (overall and cognitive functioning) and physical outcomes (i.e., rates of non-psychiatric medical comorbidities and general hospital admissions in the past-year) were evaluated. All analyses were adjusted for age, sex, duration of disorder, diagnosis, smoking status, alcohol use, and use of antipsychotics, antiepileptics or antidepressants.

RESULTS

Among the 281 older participants with BD or MDD, 15.7% were taking lithium for a mean duration of 12.5(SD = 11.6) years. Lithium use was associated with lower intensity of depressive symptoms, reduced perceived clinical global severity and lower benzodiazepine use (all p < 0.05), without being linked to greater rates of medical comorbidities, except for hypothyroidism.

LIMITATIONS

Data were cross-sectional and data on lifetime history of psychotropic medications was not assessed.

CONCLUSION

Our results suggest that long-term lithium use may be efficient and relatively well-tolerated in older adults with BD or treatment-resistant MDD.

Mechanistic overview of immune checkpoints to support the rational design of their combinations in cancer immunotherapy

Checkpoint receptor blockers, known to act by blocking the pathways that inhibit immune cell activation and stimulate immune responses against tumor cells, have been immensely successful in the treatment of cancer. Among several checkpoint receptors of immune cells, cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), programmed cell death protein-1 (PD-1), T-cell immunoglobulin and ITIM domain (TIGIT), T-cell immunoglobulin-3 (TIM-3) and lymphocyte activation gene 3 (LAG-3) are the most commonly targeted checkpoints for cancer immunotherapy. Six drugs including one CTLA-4 blocker (ipilimumab), two PD-1 blockers (nivolumab and pembrolizumab) and three PD-L1 blockers (atezolizumab, avelumab and durvalumab) are approved for the treatment of different types of cancers including both solid tumors such as melanoma, lung cancer, head and neck cancer, bladder cancer and Merkel cell cancer as well as hematological tumors such as classic Hodgkin's lymphoma. The main problem with checkpoint blockers is that only a fraction of patients respond to the therapy. Insufficient immune activation is considered as one of the main reason for low response rates and combination of checkpoint blockers has been proposed to increase the response rates. The combination of checkpoint blockers was successful in melanoma but had significant adverse events. A combination that is selected based on the mechanistic differences between checkpoints and the differences in expression of checkpoints and their ligands in the tumor microenvironment could have a synergistic effect in a given cancer subtype and also have a manageable safety profile. This review aims to help in design of optimal checkpoint blocker combinations by discussing the mechanistic details and outlining the subtle differences between major checkpoints targeted for cancer immunotherapy.

Anisotropic optical and conductive properties of oriented 1D-nanoparticle thin films made by spray-assisted self-assembly

We report on the fabrication of oriented anisotropic metal nanoparticle thin films made by Grazing Incidence Spraying (GIS) and on the anisotropic plasmonic properties of the resulting thin films. Gold nanorods of two different aspect ratios and silver nanowires were self-assembled as a uniaxially aligned monolayer with the GIS approach. In particular, we examine the influence of the nanowire/nanorod length and diameter on the degree of ordering determined by electron microscopy pictures. Furthermore, we show that the anisotropy of the optical properties (probed by polarized UV-visible-near infrared spectroscopy) strongly depend on the quality of alignment. The prepared monolayer thin films have an orientation order parameter of up to 0.83 for silver nanowires, which is reflected in an optical anisotropy of 0.57 in the UV-visible and 0.76 in the near infrared through the selective excitation of transverse and longitudinal surface plasmon resonance modes. The electronic transport in oriented silver nanowire monolayers is also shown to be highly directional, with the sheet resistance varying over almost an order of magnitude depending on the transport direction. Such anisotropic conductive plasmonic thin films may find applications in various fields like biochemical sensing, energy transport and harvesting or optoelectronic devices.

Influence of ontogenetic age on the role of dentate granule neurons

New neurons are continuously produced in the adult dentate gyrus of the hippocampus, a key structure in learning and memory. It has been shown that adult neurogenesis is crucial for normal memory processing. However, it is not known whether neurons born during the developmental period and during adulthood support the same functions. Here, we demonstrate that neurons born in neonates (first postnatal week) are activated in different memory processes when they are mature compared to neurons born in adults. By imaging the activation of these two different neuron generations in the same rat and using the IEG Zif268 and Fos, we show that these neurons are involved in discriminating dissimilar contexts and spatial problem solving, respectively. These findings demonstrate that the ontogenetic stage during which neurons are generated is crucial for their function within the memory network.

[Giant lipoma on the back]

Solitary lipoma is the most frequent soft tissue tumor, often appearing between 40 and 60 years of age. It is described as "giant" beyond 1 kg of weight and 10 cm of diameter. Its volume is the source of a good many problems in social life (camouflage, difficulties to dress) and causes multiple health problems such as pain, difficulties to sleep, compressions of nerves or vital structures, infections, etc. The diagnosis is primarily clinical. However, it is necessary to systematically exclude a malignant process. Surgical biopsy is recommended if the diagnosis cannot be asserted by the clinic or an imagery. The therapeutic attitude is abstention in case of small volume without functional impairment. Otherwise, total surgical excision is indicated with pathological analysis. We describe the clinical history of a patient suffering from a giant dorsal lipoma.

Treatment of a groin lymphatic fistula with negative pressure wound therapy

INTRODUCTION

Groin lymphatic fistulas are a troublesome finding after limb revascularization surgery. Its management represents a difficult task for the clinician.

REPORT

We report our experience in the treatment of such a condition with negative-pressure wound therapy (NPWT) in a 70-year-old man which benefited from extra-anatomic prosthetic axillofemoral bypass. After a week of treatment, the fistula dried up and closure was obtained with simple suture under local anaesthesia. Follow-up at 9 months showed stable coverage without any sign of leakage.

DISCUSSION

This study depicts NPWT as an effective non-invasive treatment in the management of groin lymphocutaneous fistula.

Current concepts in breast reconstruction

As the incidence of breast cancer increases, breast reconstruction is more and more often proposed and its indications are viewed in terms of quality of life. In the past, delayed reconstruction was the rule. Progress in reconstructive techniques currently allows performing immediate reconstruction in selected cases, even when the operative field has to be irradiated. These new techniques generally improve the result of breast reconstruction. Moreover, expansion of screening techniques allows detection of small tumors for which a conservative excision is sufficient. Nevertheless, this kind of less aggressive surgery may require a reconstructive procedure in order to maximise the aesthetic result.

Vacuum-assisted closure of enterocutaneous fistula

The authors report their experience in the treatment of a posttraumatic enterocutaneous fistula with negative-pressure therapy. After sustaining an epigastric shot wound, a 33-year-old woman underwent three consecutive laparotomies, which eventually led to an open abdomen with the interposition of a surgical mesh. Enterocutaneous fistulae were subsequently documented and vacuum-assisted closure therapy was instituted along with total parenteral nutrition and systemic antibiotics. Development of a suitable granulation bed and closure of the fistulae were noted after two weeks of treatment and a split-thickness skin graft was applied to the wound. Follow-up at 8 months showed stable coverage and a return to normal enteral feeding.

Motherhood-induced memory improvement persists across lifespan in rats but is abolished by a gestational stress

Motherhood modifies the biology and behavior of the female, a process which prepares the mother's cognitive systems that are needed for nurturance. It has recently been shown that motherhood enhances hippocampal-mediated spatial learning and synaptic plasticity. Deleterious and long-term effects of a stress experienced during gestation have been demonstrated on progeny. Surprisingly little is known about the effect of such stress on mothers. Here, we investigated the effect of gestational stress on the adaptive changes due to motherhood. Female rats were mated and stressed during the last week of gestation. Two weeks after weaning, they were submitted to behavioral tests or electrophysiological study. A group of females were then kept for 16 months after motherhood experience to study the long-term effect of gestational stress and motherhood on memory when they were 22 months old. We confirm that a single motherhood experience selectively increases hippocampal-mediated spatial memory during the entire lifespan of female rats and protects them from age-associated memory impairments. However, we demonstrate that a stressful experience during gestation totally abolishes the positive effects of motherhood both on spatial memory and on hippocampal synaptic plasticity (long-term potentiation). Environmental factors that induce biological vulnerability have negative effects even for fundamental biological behaviors.

Primary Stenting for the Acute Treatment of Carotid Artery Dissection

OBJECTIVES

To review and evaluate our experience with carotid artery stenting in the acute treatment of carotid artery dissection (CAD).

PATIENTS AND METHODS

Reviewing the charts of our hospital between 2000 and 2001, we found two consecutive patients who benefited from primary stenting for the acute treatment of spontaneous extracranial internal CAD.

RESULTS

Primary stenting of the internal carotid artery was successful in both cases without any post-operative complications. Clinical and US duplex scan follow-up confirmed the absence of neurological symptoms and the patency of the internal carotid artery with complete disappearance of the dissection at 36 and 42 months after the procedure, respectively.

CONCLUSION

Despite the small number of patients, primary stenting for acute CAD seems to be safe and effective.

Does prenatal stress affect latent inhibition? It depends on the gender

The present experiment was designed to examine the effects of prenatal stress and gender in latent inhibition. Prenatal stress has been proposed as a risk factor both for depression and for schizophrenia, and both of these syndromes are associated with alterations in the functional state of the dopamine system. There is also some evidence that prenatal stress can produce changes in dopamine activity, although the details of the stress-induced changes are a matter of debate. Latent inhibition (LI), which is strongly dependent on dopaminergic activity, consists in delayed Pavlovian conditioning about a stimulus that previously signalled no consequence. We induced prenatal stress by exposing gestating dams to a daily constraint stress during the last week of pregnancy. We tested the rats for LI of conditioned taste aversion by exposing them to sucrose for 3 days prior to conditioning. Irrespective of stress or gender, latent inhibition was observed but the degree of LI varied as a function of both prenatal stress and gender. Unstressed males showed less LI than unstressed females, but prenatal stress increased the amount of LI only in the males. These results are inconsistent with the use of prenatal stress as an animal model for schizophrenia. A model is proposed that accounts for the relationships between gender, dopamine function, cognitive changes and psychiatric pathology.

Pregnenolone sulfate enhances neurogenesis and PSA-NCAM in young and aged hippocampus

Age-dependent cognitive impairments have been correlated with functional and structural modifications in the hippocampal formation. In particular, the brain endogenous steroid pregnenolone-sulfate (Preg-S) is a cognitive enhancer whose hippocampal levels have been linked physiologically to cognitive performance in senescent animals. However, the mechanism of its actions remains unknown. Because neurogenesis is sensitive to hormonal influences, we examined the effect of Preg-S on neurogenesis, a novel form of plasticity, in young and old rats. We demonstrate that in vivo infusion of Preg-S stimulates neurogenesis and the expression of the polysialylated forms of NCAM, PSA-NCAM, in the dentate gyrus of 3- and 20-month-old rats. These influences on hippocampal plasticity are mediated by the modulation of the gamma-aminobutyric acid receptor complex A (GABA(A)) receptors present on hippocampal neuroblasts. In vitro, Preg-S stimulates the division of adult-derived spheres suggesting a direct influence on progenitors. These data provide evidence that neurosteroids represent one of the local secreted signals controlling hippocampal neurogenesis. Thus, therapies which stimulate neurosteroidogenesis could preserve hippocampal plasticity and prevent the appearance of age-related cognitive disturbances.

Tip of the greater horn of the hyoid bone: a landmark for cervical surgery

The purpose of this study was to assess the relevance of the tip of the greater horn of the hyoid bone (THB) in the localization of the carotid bifurcation, the superior thyroid and lingual arteries, and the hypoglossal and superior laryngeal nerves. Measurements of these structures with respect to the THB were also made. Thirty perfusion-fixed human cadavers (60 specimens) were studied. Sharp measurements were made along two orthogonal axes crossing exactly on the THB. The vertical axis was parallel to the craniocaudal axis of the body. Taking the THB as a landmark, the five structures were identified in all the specimens. The mean value, standard deviation, and range of measurements for each structure studied are given in the text. This study shows the THB to be a useful landmark which is an aid to locating the aforementioned structures with confidence, and concludes that knowledge of this landmark would be beneficial for the surgeon dealing with the mid neck area.

Combined Reconstruction of the Diabetic Foot Including Revascularization and Free-Tissue Transfer

Diabetic patients, presenting with both peripheral vascular disease and large soft-tissue defects, are too often treated by primary amputation. A combined revascularization and free-tissue transfer procedure can extend limb salvage in these patients. The authors report their experience over 4 years with 19 diabetic patients with peripheral vascular disease and large soft-tissue defects of the foot requiring free-tissue transfer. Although there was a 100 percent flap survival, early local wound problems occurred in three patients (16.6 percent). The recurrence rate was about 18.7 percent, but no complementary flap procedures were mandatory. With a mean follow-up of 38 months (range: 23 to 55 months), the limb salvage rate was 94.4 percent. Although there was one limb loss and one patient with ambulation difficulties, 16 patients (84.2 percent) were fully rehabilitated and were able to function independently. Despite a rather small series, this study confirms that in selected diabetic patients, a combined approach of vascular and reconstructive surgeons can reduce the limb amputation rate with acceptable complication rates. This combined approach offers major benefits to these patients, especially stable coverage and preservation of ambulation, and should always be considered before amputation.

Environmentally induced long-term structural changes: cues for functional orientation and vulnerabilities

Environmental challenges profoundly modify phenotypes and disrupt inherent developmental programs both at functional and structural levels. As an example, we have studied the impact of these environmental influences on adult neurogenesis in the dentate gyrus. Neurogenesis results from an inherent program, participates to hippocampal network organization and, as a consequence, to the various functional abilities depending on this region, including memories. In preclinical studies of aging we have shown that phenotypes vulnerable to the development of spatial memory disorders are characterized by lower hippocampal neurogenesis. We have hypothesized that these interindividual variations in functional expression of neurogenesis in senescent subjects could be predicted early in life. Indeed, a behavioral response (novelty-induced locomotor reactivity) and a biological trait (hypothalamo-pituitary-adrenal axis activity), which are predictive of cognitive impairments later in life, are related to neurogenesis in young adult rats. This suggests that subjects starting off with an impaired neurogenesis, here rats that are high reactive to stress, are predisposed for the development of age-related cognitive disorders. We have further shown that these inter-individual differences result from early deleterious life events. Indeed, prenatal stress orients neurogenesis in pathological ways for the entire life, and precipitates age-related cognitive impairments. Altogether these data suggest first that hippocampal neurogenesis plays a pivotal role in environmentally-induced vulnerability to the development of pathological aging, and second that environmental challenges and life events orient structural developments, leading to different phenotypes.

[Free flap pedicle loss: clinical study on 8 cases]

The authors report on 8 cases of free flaps with vascular pedicle disruption that were encountered between postoperative days 8 to 18. In one case, the inflow disappeared 18 months after the transfer without any trouble. This resulted in 2 partial and one complete flap losses. The 4 other flaps survived completely. This complete survival is related to the angiogenesis process coming from the surrounding tissues. The most obvious causal factor responsible for the 2 partial losses was the coverage of large, non viable areas, such as a prosthetic material and bone deprived of periosteum. The only causal factor that could be assessed in the case of total necrosis was the presence of an immunosuppressive treatment. Variables participating in the installation of an adequate angiogenic response are then discussed in accordance to this experience and to the literature. Limited contact with viable tissue, ischemia-reperfusion or drugs limiting the angiogenesis seems to promote failure when the pedicle is quickly disrupted. Hypoxia seems to be the most important cellular mechanism promoting the angiogenesis in this context.

Structural modeling of drug release from biodegradable porous matrices based on a combined diffusion/erosion process

Biodegradable, porous microspheres exhibit a wide range of release profiles. We propose in this paper a unifying approach based on the dual action of diffusion and erosion to establish which mechanisms are responsible for the variety of release kinetics observed during in vitro experiments. Our modeling procedure leads to the partitioning of the matrix into multiple, identical elements, thus simplifying significantly the mathematical and numerical treatment of the problem. The model equations cannot be solved analytically, since the domain contains a moving interface, and must therefore be solved numerically, using specific methods designed for that purpose. Our model confirms the major role that the relative dominance between diffusion and erosion plays in the release kinetics. In particular, the velocity of erosion, the effective diffusion coefficient of the drug molecule in the wetted polymer, the average pore length, and the initial pore diameter are sensitive parameters, whereas the porosity and the effective diffusion coefficient of the drug in the solvent-filled pores is seen to have little influence, if any, on the release kinetics. The model is confirmed by using release data from biodegradable microspheres with different ratios of low and high molecular weight PLA. Excellent goodness of fit is achieved by varying two parameters for all types of experimental kinetics: from the typical square root of time profile to zero-order kinetics to concave release curves. We are also able to predict, by interpolation, release curves from microspheres made of intermediate, untested ratios of PLA by using a relation between two model parameters.

A low rate of trisomy 21 in twin-pregnancies: a cytogenetics retrospective study of 278 cases

From January 1st 1990 until December 31st 2001, we collected 19686 prenatal diagnosis (on amniocentesis and chorius villus sampling). Five hundred twelve samples (2.6%) concerned 278 twin pregnancies. The most frequent indications were maternal age > or = 35 years (108/278 = 38.8%), medically assisted procreation (34/278 = 12.3%), positive ultrasound (20/278 = 7.2%). Chromosome abnormalities were found in eight twin-pregnancies (2.9%): five with only one fetus affected [47,XX,+ 18; 45,XX,t( 13;14); 47,XYY; 47,XXX; 45,XX, t(13;14)], two with both fetuses showing the same chromosomal abnormality [inv(11)(q21q25); 47,XX,+ 18] and one with only one fetus tested [47,XX,+ 18]. In total, we found eight autosomal abnormalities, four inherited balanced rearrangements (two robertsonian translocations and two paracentric inversions of chromosome 11) and four trisomies 18. We also observed two sex chromosome abnormalities interesting only one of the two fetuses. Surprisingly, we did no detect any Down Syndrome among this population. The frequency of Down Syndrome was significantly (p < 0.05) lower in our population of twin pregnancies (0.0%) as compared to the observed incidence in singleton pregnancies during the same period (163/19162 = 0.9%).

[Deep vein thrombosis in a burn patient]

Association between deep venous thrombosis (DVT) and pulmonary embolism is probably an underestimated problem in the thermally injured patients. However, those patients display important risk factors according to Virchow's triad. This article reports on three unrecognised DVT's accompanying burns which were characterized by absence of healing or edema. The pathophysiology of this issue is then discussed with respect to the specific area of the thermally injured patient. It is our belief that local inflammatory phenomenon play a major part in the genesis of DVT associated with chronic non-healing burns.

[Arterial revascularization with free tissue transfer for salvage of ischemic limbs with extensive tissue loss: an alternative to amputation]

Severe limb ischemia is a common problem encountered in medical practice. Aggressive attempts at revascularization have extended the limits of limb salvage. However, in certain cases, extended tissue loss compromises the healing process. It often results in amputation despite bypass graft patency. Microvascular free tissue transfer combined with arterial revascularization allows healing of these wounds and limb preservation. This combined approach is the ultimate alternative to amputation.

Individual vulnerability to substance abuse and affective disorders: role of early environmental influences

One of the most important questions raised by modern psychiatry and experimental psychopathology is the origin of mental diseases. More concisely, clinical and experimental neurosciences are increasingly concerned with the factors that render one individual more vulnerable than another to a given pathological outcome. Animal models are now available to understand the sources of individual differences for specific phenotypes prone to behavioral disadaptations. Over the last 10 years we have explored the consequences of environmental perinatal manipulations in the rat. We have shown that prenatal stress is at the origin of a wide range of physiological and behavioral aberrances such as alterations in the activity of the hormonal stress axis, increased vulnerability to drug of abuse, emotional liability, cognitive impairments and predisposition to pathological aging. Taken together, these abnormalities define a bio-behavioral syndrome. Furthermore, the cognitive disabilities observed in prenatally-stressed rats were recently related to an alteration of neurogenesis in the dentate gyrus, thus confirming the impact of early life events on brain morphology. A second model (handling model) has also been developed in which pups are briefly separated from their mothers during early postnatal life. In contrast with prenatally-stressed animals, handled rats exhibited a reduced emotion response when confronted with novel situations and were protected against age-induced impairments of both the hormonal stress axis and cognitive functions. Taken together, the results of these investigations show that the bio-behavioral phenotype that characterizes each individual is strongly linked to the nature and timing of perinatal experience. Furthermore, data collected in prenatally-stressed animals indicate that this model could be used profitably to understand the etiology and pathophysiology of affective disorders.

[Chronic ulcer and wound dehiscence..when the origin is unknown and therapy is ineffective!]

The authors report on two cases of factitious disorders in the field of surgery. The discussion is focused on the different aspects of this pathology that are encountered by a plastic surgeon, in order to provide him with more confidence when dealing with this too-often ignored disease.

Thyrolingual trunk arising from the common carotid artery: a case report

During a cadaver dissection in the anatomy department of the University of Liege, Belgium, an anatomic variation of the superior thyroid and lingual arteries was observed on the right side in a 68-year-old woman. Both arteries arose from a common trunk located 30 mm beneath the carotid bifurcation. After a 5.2 mm course, the thyrolingual trunk divided into superior thyroid and lingual arteries which followed an unusual course towards their respective organs. Knowledge of this anomaly is important for those who are involved with neck surgery and anatomy.

Bilateral case of superficial ulnar artery originating from axillary artery

During the dissection of an 86-year-old male human cadaver, superficial ulnar arteries were found in both upper limbs. These arteries branched from the axillary arteries. In the left arm, the artery crossed ventral to the medial root of the median nerve before running towards the medial part of the arm. The persistence of the median artery was noted. In the right arm, the ulnar artery had a common origin with the subscapular artery. It crossed anterior to the lateral root of the median nerve and then, in the arm, ran alongside the anterolateral aspect of the median nerve, near the biceps brachii muscle, which was supplied by this superficial ulnar artery. Then the artery crossed the median nerve and the brachial artery. The embryology, incidence and clinical relevance of this anatomical variation are discussed. So this was a rare case where the ulnar arteries originated from the axillary artery on both sides, but then followed different courses in the arm and, on the right side, the superficial ulnar artery partly supplied the biceps brachii muscle.

Numerical bifurcation analysis of delay differential equations arising from physiological modeling

This paper has a dual purpose. First, we describe numerical methods for continuation and bifurcation analysis of steady state solutions and periodic solutions of systems of delay differential equations with an arbitrary number of fixed, discrete delays. Second, we demonstrate how these methods can be used to obtain insight into complex biological regulatory systems in which interactions occur with time delays: for this, we consider a system of two equations for the plasma glucose and insulin concentrations in a diabetic patient subject to a system of external assistance. The model has two delays: the technological delay of the external system, and the physiological delay of the patient's liver. We compute stability of the steady state solution as a function of two parameters, compare with analytical results and compute several branches of periodic solutions and their stability. These numerical results allow to infer two categories of diabetic patients for which the external system has different efficiency.

[Pneumomediastinum in children]

Pneumomediastinum in children is diagnosed in two circumstances: cervical subcutaneous emphysema or radiological findings. The predominant symptoms are dyspnoea, stabbing chest pain, sore throat and dysphagia. Traumatic injuries and pulmonary diseases such as asthma are the most common causes of pneumomediastinum. It may rarely result from iatrogenic manoeuvres or acidocetosis. Spontaneous mediastinal emphysema is seldom reported in children. Chest X-ray films are essential investigations. The treatment is directed towards the underlying cause, with conservative management being sufficient in most cases. However, the risk of surveying of pneumothorax or tension pneumomediastinum justifies close clinical follow-up in a specialised care unit. The onset of these pathologies necessitates a more aggressive therapy by aspiration through percutaneous catheter placed in the mediastinum.

Specific expression of matrix metalloproteinases 1, 3, 9 and 13 associated with invasiveness of breast cancer cells in vitro

Several matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) were studied in highly invasive (MDA-MB-231) and slightly invasive (MCF-7, T47D, BT-20) breast cancer cell lines. Investigations were carried out at the protein level and/or at the mRNA level, either in cells cultured as monolayers on plastic, or in cells seeded on a thin layer of Matrigel basement membrane matrix. Analysis of MMP expression by RT-PCR showed expression of MMP-1. MMP-3, and MMP-13 in highly invasive MDA-MB-231 cells, but not in slightly invasive cell lines. The extracellular secretion of MMP-1 and MMP-3 by MDA-MB 231 cells could be also shown by ELISA. TIMP-1 and TIMP-2 mRNAs were found in all cell lines, however, the extracellular secretion of both TIMPs was much higher in MDA-MB-231 cells than in the other cell lines. When the cells were cultured on Matrigel matrix, MMP-9 expression was induced in MDA-MB-231 cells only, as assessed by RT-PCR and zymography experiments. The invasive potential of MDA-MB-231 cells evaluated in vitro through Matrigel was significantly inhibited by the MMP inhibitor BB-2516, by 25% and 50% at the concentrations of 2 x 10(-6) M and 10(-5) M, respectively. In conclusion, our data show that highly invasive MDA-MB-231 cells but not slightly invasive T47D, MCF-7 and BT-20 cells express MMP-1, MMP-3, MMP-9 and MMP-13. MMP-9 which is specifically up-regulated by cell contact to Matrigel, may play a key role in the invasiveness of MDA-MB-231 cells through basement membranes.

Long term neurodevelopmental and behavioral effects of perinatal life events in rats

Modern neurosciences are now able to open new avenues concerning an experimental approach to clinical neurosciences and psychiatry. Detection and prediction of potential vulnerabilities such as behavioral disturbances and neurodegenerative diseases, are urgent tasks leading to prevention that must be encouraged in parallel to the enormous efforts displayed for treatments. Besides possible genetic origins of diseases, environmental factors are now coming under scrutiny, and especially deleterious and challenging life events and stress occurring during prenatal and postnatal critical periods may orient brain functions towards deleterious developments. The hypothesis that will be examined is that early events might be at the origin of pathological transformations and symptoms after long periods of apparent normal abilities and behavioral homeostasis. We used models of prenatal stress and postnatal manipulations such as cross-fostering. It will be demonstrated that such events induce long-term changes, cognitive and emotional modifications appearing first, when offspring are adults, followed by cognitive defects later in life. Increased sensitivity of the hypothalamic pituitary-adrenal axis (HPA), the endocrine system controlling the secretion of stress hormones (corticoids), appears to be a major element of pathogenesis. HPA axis dysfunction appears very early after birth (3 days) and lasts for months. Cumulative exposure to high levels of hormones seems to be detrimental for some brain regions, especially the hippocampus and major neurotransmitter systems such as dopamine neurons. We evidenced that neuronal modifications in hippocampal region are correlated with behavioral and cognitive defects, relating environment, stress in early life, hormonal changes, long-term neuropathological processes and impaired cognition in aging. Moreover appears in offspring, when adults, a proneness to engage in drug dependence. These data emphasize the need to consider early environmental life events as etiological factors for delayed neuropsychiatric disturbances, neurodegenerative defects included. Moreover, they strengthen the interest for a longitudinal approach to promote experimental psychopathology.

Prenatal stress produces learning deficits associated with an inhibition of neurogenesis in the hippocampus

Early experiences such as prenatal stress significantly influence the development of the brain and the organization of behavior. In particular, prenatal stress impairs memory processes but the mechanism for this effect is not known. Hippocampal granule neurons are generated throughout life and are involved in hippocampal-dependent learning. Here, we report that prenatal stress in rats induced lifespan reduction of neurogenesis in the dentate gyrus and produced impairment in hippocampal-related spatial tasks. Prenatal stress blocked the increase of learning-induced neurogenesis. These data strengthen pathophysiological hypotheses that propose an early neurodevelopmental origin for psychopathological vulnerabilities in aging.

Deletion of the 5'-ABL region: a recurrent anomaly detected by fluorescence in situ hybridization in about 10% of Philadelphia-positive chronic myeloid leukaemia patients

Inclusion of the BCR-ABL ES probe in routine cytogenetics led to the identification of a subgroup of Philadelphia positive (Ph+) chronic myeloid leukaemia patients characterized by a 5'-ABL deletion. This anomaly was observed in 5/51 cases (9.8%). Cytological and clinical data suggest that the 5'-ABL deletion may be associated with dysplastic features of polymorphonuclear cells and metamyelocytes and a short chronic phase duration.

[Joint manifestations related to Clostridium difficile]

BACKGROUND

Reactional joint disease subsequent to digestive tract infections have been well studied for Salmonella, Shigella, Yersinia and Campylobacter. Association with HLA B27 is well documented. A review of the literature since 1976 disclosed 23 cases of articular and extra-articular inflammatory reactions following pseudomembranous Clostridium difficile infection.

CASE REPORT

We describe 2 new cases which followed a favorable course. This is the usual outcome although inflammatory manifestations may persist or relapse.

DISCUSSION

The pathophysiological interest of this condition lies in the pathogenic potential of Clostridium difficile which appears to be directly related to toxin production. This would suggest an immune mechanism rather than pure infection.

Behavioural trait of reactivity to novelty is related to hippocampal neurogenesis

The hippocampal formation is one of the brain areas where neurogenesis persists during adulthood, with new neurons being continuously added to the population of dentate granule cells. However, the functional implications of this neurogenesis are unknown. On the other hand, the hippocampal formation is particularly concerned with the detection of novelty, and there are indications that dentate granule cells play a significant role in this function. Recently, the existence of inter-individual differences in behavioural reactivity to novelty has been evidenced, related to differences in the reactivity of the hypothalamic-pituitary-adrenal axis (HPA). Rats that are highly reactive to novelty (HR) exhibit a prolonged corticosterone secretion in response to novelty and to stress when compared with low reactive rats (LR). Taking advantage of the existence of these inter-individual differences, we investigated whether neurogenesis in the dentate gyrus is correlated with the behavioural trait of reactivity to novelty. Rats were first selected according to their locomotor reactivity to a novel environment. Two weeks later, cell proliferation, evaluated by the incorporation of 5-bromo-2'-deoxyuridine (BrdU) in progenitors, was studied by immunohistochemistry. We found that cell proliferation in the dentate gyrus was negatively correlated with locomotor reactivity to novelty. Indeed, cell proliferation in LR rats was twice that observed in HR rats. In contrast, survival of nascent neurons was not influenced by the behavioural trait of reactivity to novelty. Using an unbiased stereology, we show that LR rats had more cells within the granule cell layer of the dentate gyrus than did HR rats. These results demonstrate the existence of inter-individual differences in neurogenesis and total granule cell number within the dentate gyrus. These differences in hippocampal plasticity can be predicted by the behavioural trait of reactivity to novelty.

Comparison of the neuroendocrine responses to stress in outbred, inbred and F1 hybrid rats

In order to study the genetic factors involved in the neuroendocrine responses to stress, we have compared the intensity of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system activation following a 60 minute-restraint stress or after a 10 minute-exposure to a novel environment in three rat strains : outbred Wistar, inbred Brown Norway and Fischer 344, and F1 hybrid Brown Norway x Fischer 344 rats. The basal activity of the HPA axis did not differ between the four groups of rats whereas Brown Norway rats had the lowest release of corticosterone following restraint stress. Although differences in plasma adrenocorticotropic hormone failed to reach significance after exposure to a novel environment, the lowest level of corticosterone was found in Brown Norway rats. This lower release of corticosterone in Brown Norway rats has probably an adrenal origin as suggested by the ratios of corticosterone to ACTH levels following exposure to a novel environment: 632 +/- 222, 200 +/- 45, 636 +/- 89, 258 +/- 65 in Wistar, Brown Norway, Fischer 344 and F1 hybrids, respectively. This trait was dominant over the "adrenal responsive" phenotype of the Fischer 344 rat strain. In response to novelty, the lowest levels of prolactin and renin activity were found in plasma of Brown Norway and Wistar rats and the highest in Fischer 344 and F1 hybrid Brown Norway x Fischer 344 rats, the "high response" phenotype of the Fischer 344 strain being dominant. No strain-related difference was found in plasma glucose and either adrenal tyrosine hydroxylase or phenylethanolamine N-methyl transferase activity. Taken together, these data suggest that 1) genetic factors might contribute to the interindividual differences in neuroendocrine responses to stress and 2) subsets of these responses are controlled by specific genetic factors.

Social motivation in recently weaned rats is modified by opiates

An open field choice test was used to determine whether maternal deprivation enhanced the motivation to stay close to the mother. Pups could choose between the dam, 3 sisters and 3 unknown animals of the same age. In addition, an empty enclosure identical to those that contained the stimulus animals were present as a nonsocial choice. Rats that were separated from their mother at 20 days of age and tested about 13 h later were compared to animals that had stayed with the mother until just before the test. It was found that maternal separation increased the time spent close to the mother and reduced that spent close to strangers or an empty enclosure. In fact, weaned animals spent far more time close to the mother than they spent close to any other available choice. Moreover, the mean duration of visits to the mother was much increased during the latter half of the 60-min test. These data were interpreted as showing that the mother had rewarding properties, and that maternal deprivation increased her reward value. In further experiments, the role of opioids for this increase in reward value was evaluated. Morphine enhanced the time spent close to the mother, but only in animals that had been subjected to maternal deprivation for about 13 h. Naloxone had the opposite effect. These data show that the mother's reward value is altered when the activity of opioid systems is modified. It is suggested that the mother acquires rewarding properties because of association with nutritive suckling-induced opioid release.

Adrenal axis activation by chronic social stress fails to inhibit gonadal function in male rats

Stress in males via the hypothalamic-pituitary-adrenal (HPA) axis may set into motion varied physiological alterations, including dysfunction of the hypothalamic-pituitary-gonadal (HPG) axis. However, the influence of the HPA on the HPG axis may not always be inhibitory. Presence or absence of stimuli of sexual significance that typically activates the HPG axis may alter the influence of the adrenal axis on gonadal axes. In this project, we used male rats and chronic social stimulation that included brief or extended periods with female rats to examine HPA-HPG axes interactions. In experiment 1, we used intact males and a 'chronic social stress' paradigm developed in our previous research that induces social instability by daily changing the membership of group-housed males with females. Thymus weight was reduced and corticosterone levels were marginally increased by chronic social stress, indicating a HPA axis hyperactivity. The HPG axis was also activated as shown by the increased weight of the androgen-sensitive sex structures. These results indicate that when these two axes are stimulated together, neither interferes with nor suppresses activities of the other. Implants of corticosterone pellets to adrenalectomized animals that maintained constant, high corticosterone levels failed to reverse the gonadal hyperactivity induced by sexual stimulation. In a second experiment, we studied the influence of different intensity of sexual stimulations on HPA-HPG axes interactions. Increased corticosterone levels and adrenal weight, indicating a HPA hyperactivity, failed to inhibit HPG hyperactivity as measured by the increased sexual organs weight, whatever the sexual intensity of the stimulation. This work demonstrates that the gonadal axis is freed from suppression when sexual stimulation occurs together with stress. The general conclusion is that the nature of complex social settings is important in determining interactions between the two neuroendocrine axes.

Telemetered recording of blood pressure and heart rate in different strains of rats during chronic social stress

The role of stress in the etiology of high blood pressure and the biological mechanisms involved are still not clear. We have recently developed a paradigm of chronic social stress based on social instability and cohabitation with females, in which the different neuroendocrine responses to stress can be independently triggered. In this work, we used a telemetry technique to record blood pressure and heart rate chronically in freely moving undisturbed rats to study the influence of chronic social stress on blood pressure and heart rate in normotensive rats (Wistar and Long-Evans) and in Borderline Hypertensive Rats (BHR). No increase of blood pressure could be seen for one month of social stress in either strain. Wistar and Long-Evans rats were fully sensitive to social pressure, as shown by the changes in body weight, but may lack a specific vulnerability of the cardiovascular system. Conversely, Borderline Hypertensive rats have the genetic predisposition to develop hypertension but do not appear to be sensitive to social stimulations in the present experimental conditions. The experimental protocol used here should allow further investigation of the various possible sources of failure to induce chronic cardiovascular changes by social stress, such as blood pressure measurement techniques, social stress protocols, and genetic aspects of psychobiological and cardiovascular vulnerability to stress.

Chronic social stress conditions differentially modify vulnerability to amphetamine self-administration

Using social instability and cohabitation with females as chronic stress, we observed that neuroendocrine systems were differentially activated according to the experimental design. We show here that amphetamine self-administration, a paradigm to study the reinforcing effects of psychostimulants, is also differentially affected by these conditions. Coexistence with females increases amphetamine self-administration and this effect is reduced when social instability is superimposed. On the other hand, locomotor response to amphetamine is not modified by either social factor, suggesting a specific involvement of a subset of dopaminergic neurons.

[Bone metastases in epidural invasion of gastrinoma]

Malignant gastrinoma is a nonbeta islet cell tumor which rarely disseminates to the bone. However, in the case reported herein, diffuse metastatic bone disease with symptomatic epidural spread developed. Somatostatin and 99mTc-HDP bone scans demonstrated hot spots in the same sites, establishing that the bone lesions contained somatostatin receptor. Irradiation was effective in relieving pain.

Psychosocial stress can induce chronic hypertension in normotensive strains of rats

We report on five 6-month experiments during which five colonies of four male and four female rats were exposed to psychosocial stress. Monthly blood pressure measurements by a tail-cuff method showed a modest (10 mm Hg) increase in two studies using Sprague-Dawley rats. In two further studies using the more aggressive Long-Evans strain, terminal direct carotid arterial pressures were taken as well, and in one study the differences exceeded 20 mm Hg. A fifth study used the Wistar-Kyoto, hyperactive (WKHA) strain developed by Hendley, and no differences were observed. Heart and adrenal weights; adrenal catecholamine synthetic enzymes; and heart, aortic, and kidney histology were measured and showed significant changes, which for the most part paralleled blood pressure changes. Social instability and the associated blood pressure changes were made more severe by periodic mixing of males from different colonies. This had no effect on the peaceable WKHA rats, some effect on the Sprague-Dawley rats, and a severe effect on the Long-Evans rats. The WKHA rats failed to show blood pressure changes despite stress-induced increases in heart and adrenal weights. Thus, different types of psychosocial stress and different genetics combine to induce a variety of neuroendocrine changes, not all of which necessarily lead to increased blood pressure.