Comparison of leg dynamic models for quadrupedal robots with compliant backbone

Many quadrupeds are capable of power efficient gaits, especially trot and gallop, thanks to their flexible trunk. The oscillations of the system that includes the backbone, the tendons and musculature, store and release elastic energy, helping a smooth deceleration and a fast acceleration of the hindquarters and forequarters, which improves the dynamics of running and its energy efficiency. Forelegs and hindlegs play a key role in generating the bending moment in the trunk. In this paper we present our studies aimed at modeling and reproducing such phenomena for efficient quadrupedal robot locomotion. We propose a model, called mass-mass-spring model, that overcomes the limitation of existing models, and demonstrate that it allows studying how the masses of the legs generate a flexing force that helps the natural bending of the trunk during gallop. We apply our model to six animals, that adopt two different galloping patterns (called transverse and rotatory), and compare their energy efficiency.

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

BACKGROUND

Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV-HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV-HCV co-infected cannabis users and to characterize persons who reduced their use.

METHODS

We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not.

RESULTS

Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one's dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction).

CONCLUSIONS

Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment.

Prise en charge de Luc confronté au cancer chronique de sa mère

Luc a vécu depuis sa naissance avec une mère atteinte d’une maladie chronique, et dont le cancer a été ressenti d’emblée comme létal. Son père l’emmène en consultation psychologique alors qu’il est âgé de six ans et un suivi s’engage. Nous exposerons le travail effectué avec l’enfant, appuyé sur deux médiateurs, le dessin et le jeu, également nourri de beaucoup de parole. Nous observerons comment il a intégré la maladie chronique et l’enjeu létal, et mis en œuvre des tentatives de solutions et exploité le transfert. Nous nous interrogerons sur la pertinence de l’alternative d’un relais extérieur éventuel.

Efficacy, safety and patient-reported outcomes of ledipasvir/sofosbuvir in NS3/4A protease inhibitor-experienced individuals with hepatitis C virus genotype 1 and HIV coinfection with and without cirrhosis (ANRS HC31 SOFTRIH study)

OBJECTIVES

Studies evaluating the efficacy and safety of the fixed-dose combination ledipasvir (LDV)/sofosbuvir (SOF) in patients coinfected with HIV-1 and hepatitis C virus (HCV) have mainly included treatment-naïve patients without cirrhosis. We aimed to evaluate the efficacy and safety of this combination in treatment-experienced patients with and without cirrhosis.

METHODS

We conducted a multicentre, open-label, double-arm, nonrandomized study in patients coinfected with HIV-1 and HCV genotype 1 with and without cirrhosis, who had good viral suppression on their antiretroviral regimens. All patients were pretreated with a first-generation NS3/4A protease inhibitor (PI) plus pegylated interferon/ribavirin. Patients received a fixed-dose combination of LDV/SOF for 12 weeks, or for 24 weeks if cirrhosis was present. The primary endpoint was a sustained virological response (SVR) 12 weeks after the end of therapy. Secondary endpoints included safety, pharmacokinetics and patient-reported outcomes.

RESULTS

Of the 68 patients enrolled, 39.7% had cirrhosis. Sixty-five patients [95.6%; 95% confidence interval (CI): 87.6-99.1%; P < 0.0001] achieved an SVR, with similar rates of SVR in those with and without cirrhosis. Tolerance was satisfactory, with mainly grade 1 or 2 adverse events. Among patient-reported outcomes, only fatigue significantly decreased at the end of treatment compared with baseline [odds ratio (OR): 0.36; 95% CI: 0.14-0.96; P = 0.04]. Mean tenofovir area under the plasma concentration-time curve (AUC) at week 4 was high, with mean ± SD AUC variation between baseline and week 4 higher in cirrhotic than in noncirrhotic patients (3261.57 ± 1920.47 ng/mL vs. 1576.15 ± 911.97 ng/mL, respectively; P = 0.03). Mild proteinuria (54.4%), hypophosphataemia (50.0%), blood bicarbonate decrease (29.4%) and hypokalaemia (13.2%) were reported. The serum creatinine level was not modified.

CONCLUSIONS

LDV/SOF provided a high SVR rate in PI-experienced subjects coinfected with HCV genotype 1 and HIV-1, including patients with cirrhosis.

Magnetically recoverable TiO2-WO3 photocatalyst to oxidize bisphenol A from model wastewater under simulated solar light

A novel magnetically recoverable, visible light active TiO₂-WO₃ composite (Fe₃O₄@SiO₂@TiO₂-WO₃) was prepared to enable the photocatalyst recovery after the degradation of bisphenol A (BPA) under simulated solar light. For comparison, the photocatalytic activity of other materials such as non-magnetic TiO₂-WO₃, Fe₃O₄@SiO₂@TiO₂, TiO₂, and the commercial TiO₂ P25 was also evaluated under the studied experimental conditions. The structure and morphology of the synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and electron dispersion spectroscopy (EDS). Moreover, Brunauer-Emmett-Teller (BET) surface area and magnetic properties of the samples were determined. The Fe₃O₄@SiO₂@TiO₂-WO₃ and TiO₂-WO₃ led to a BPA degradation of 17.50 and 27.92 %, respectively, after 2 h of the simulated solar light irradiation. Even though their activity was lower than that of P25, which degraded completely BPA after 1 h, our catalysts were magnetically separable for their further reuse in the treatment. Furthermore, the influence of the water matrix in the photocatalytic activity of the samples was studied in municipal wastewater. Finally, the identification of reaction intermediates was performed and a possible BPA degradation pathway was proposed to provide a better understanding of the degradation process. Graphical abstract ᅟ.

The Still-Face: A Greater Challenge for Infants of Mothers With Borderline Personality Disorder

The main aim of this study was to ascertain whether infants as young as 3 months of age, whose mothers suffer from borderline personality disorder (BPD), are already at risk of greater dysregulation than infants of mothers without BPD when faced with a minor stressful experience. Nineteen mothers diagnosed with BPD and 41 controls with no history of psychopathology and their 3-month-old infants were observed using Tronick's Face-to-Face Still-Face paradigm. The authors found that infants whose mothers have BPD express less positive vocalizations and less nonautonomic self-regulation than infants of mothers with no psychopathology. The stress of the Still-Face episode affects their gaze and self-regulation behaviors more strongly than those of infants of controls. The Reunion episode seems particularly challenging for mothers with BPD, who show fewer smiles and an increase in intrusive behavior. Because infants and their mothers with BPD are already dysregulated at 3 months postpartum, envisaging very early intervention seems warranted.

Treatment of inflammatory arthritis via targeting of tristetraprolin, a master regulator of pro-inflammatory gene expression

OBJECTIVES

Tristetraprolin (TTP), a negative regulator of many pro-inflammatory genes, is strongly expressed in rheumatoid synovial cells. The mitogen-activated protein kinase (MAPK) p38 pathway mediates the inactivation of TTP via phosphorylation of two serine residues. We wished to test the hypothesis that these phosphorylations contribute to the development of inflammatory arthritis, and that, conversely, joint inflammation may be inhibited by promoting the dephosphorylation and activation of TTP.

METHODS

The expression of TTP and its relationship with MAPK p38 activity were examined in non-inflamed and rheumatoid arthritis (RA) synovial tissue. Experimental arthritis was induced in a genetically modified mouse strain, in which endogenous TTP cannot be phosphorylated and inactivated. In vitro and in vivo experiments were performed to test anti-inflammatory effects of compounds that activate the protein phosphatase 2A (PP2A) and promote dephosphorylation of TTP.

RESULTS

TTP expression was significantly higher in RA than non-inflamed synovium, detected in macrophages, vascular endothelial cells and some fibroblasts and co-localised with MAPK p38 activation. Substitution of TTP phosphorylation sites conferred dramatic protection against inflammatory arthritis in mice. Two distinct PP2A agonists also reduced inflammation and prevented bone erosion. In vitro anti-inflammatory effects of PP2A agonism were mediated by TTP activation.

CONCLUSIONS

The phosphorylation state of TTP is a critical determinant of inflammatory responses, and a tractable target for novel anti-inflammatory treatments.

Growing teratoma syndrome: an unusual evolution of treated ovarian immature teratoma - a case report

Growing teratoma syndrome (GTS) is a rare condition among germ cell tumor (GCT) patients during treatment with systemic chemotherapy. It is characterized by the development of enlarging masses, the normalization of tumor markers, and the presence of only mature teratoma in the pathological specimen. The authors present the unusual case of a 15-year-old girl with an immature teratoma treated with conventional surgery and systemic chemotherapy. On her follow up, although tumor markers returned to normal, there was an enlargement of abdomino-pelvic masses confirmed by a PET/TC study. With the diagnosis of a GTS, the patient underwent a com- plete cytoreduction. Histologically, all the specimens contained mature teratoma tissue. The patient remains clear with no signs of recurrence with no further treatment. The knowledge and awareness of this syndrome are highlighted in order to prevent further unnecessary chemotherapy and allow an optimal cytoreduction, which seems to be the most effective therapy so far.

Periodic nanostructures on unpolished substrates and their integration in solar cells

We present a novel fabrication process based on laser interference lithography, lift-off and reactive ion etching, which allows us to fabricate periodic nanostructures on photovoltaic substrates with an average root mean square (RMS) roughness of 750 nm. We fabricate nanostructures on unpolished crystalline silicon substrates, which reduces their reflectance 30% as fabricated. When an additional passivation layer is deposited, the light trapping grows, achieving a reflectance reduction of 60%. In addition, we have successfully integrated the nanostructured substrates in silicon wafer-based solar cells following standard processes, achieving a final efficiency of 15.56%.

A posterior approach pancreaticoduodenectomy with portal vein resection in a large adenocarcinoma of the uncinate process of the pancreas - case report

A portal vein invasion is no longer a contraindication for resection in pancreatic cancer, but increased morbidity and mortality rates can be encountered. Hereby it is presented the case of a patient diagnosed with a large adenocarcinoma of the uncinate process of the pancreas, who underwent aposterior approach pancreaticoduodenectomy, with en bloctang ential resection of the portal vein, and total mesopan creasexcision. A posterior approach allows a negative resection margins pancreaticoduodenectomy, with a good local control of the disease, despite the in creas.

Understanding cohort differences in appraisals of reconstruction priorities of mental health systems in postconflict Liberia

OBJECTIVE

This study analyzes the relationship between informants' age and their assessment of mental health needs in postconflict society and examines if mental health needs assessment priorities differ depending upon whether or not the informant was exposed to the Liberian civil war.

METHODS

cross-sectional survey was conducted in March 2009 to obtain data on mental health needs of Liberian children, adolescents and young adults. A total of 171 individuals were interviewed. The data were analyzed using a two- way ANOVA.

RESULTS

Elder respondents expressed a preference for young adults to receive services in a church/mosque (F = 4.020, p < .05); for adolescents in volunteer programs (F = 3.987, p < .05) and for children in sports programs (F = 4.396, p < .05). Experiencing conflict did exert some influence on treatment setting preferences. Those who resided outside Liberia during the conflict cited a preference for traditional healers and medical clinics. However, this preference was for the children and young adult age categories. Those who experienced the civil war reported significantly higher preferences for adolescent services to be located in medical clinics, with traditional healers, and in churches/mosques.

CONCLUSION

This study provides additional support for the premise that the utilization of psychiatric services needs to be viewed from the perspective of Liberians and that there are differences in preferences across groups. Our results suggest that service providers and policy makers take into account the age of the patient when deciding where to locate treatment settings for the population.

Assessment of the needs of vulnerable youth populations in post-conflict Liberia

OBJECTIVE

The study examined key informants' perceptions of the emotional impact of traumatic events, major problems, functional limitations and appropriate treatment settings for children, adolescents, and young adults in post-conflict Liberia.

METHOD

This research is a based on cross-sectional survey conducted between March 30, 2009 and April 30, 2009 in Liberia with 171 local key Liberian informants. Analysis was conducted using mixed methods. The findings we will report were collected in the qualitative portion of the survey.

RESULTS

We found that while different interventions were preferred for different types of young people, some interventions were mentioned for all youth and by all age and gender groups of key informants. These included counseling, education, and skills training. Also frequently chosen were housing, community reintegration, recreation, and medical care. In general, key informants reported similar concerns regardless of their ages or genders. Notable exceptions to this were in interventions for youth who joined fighting forces. Men over 50 were the only ones to recommend apology and reparations. Similarly, in recommendations for criminals and violent youth, a number of men mentioned prison, whereas the women did not.

CONCLUSION

Our findings suggest that the needs of post-conflict Liberian youth span a variety of domains, including physical, emotional, medical, psychological, and educational. These findings can be used to guide the development of treatment programs for these young people.

Automatic assignment of 1H-NMR spectra of small molecules

A novel data-evaluation procedure for the automatic atom to peak or multiplet assignment of 1H-NMR spectra of small molecules has been developed using a fast and robust expert system. The applicability and reliability of the method are demonstrated by comparison of a manually assigned database of 1H-NMR spectra with the assignments produced by the automatic procedure. The results of this analysis show an excellent success ratio, indicating that this new algorithm can have a major impact as a time saving tool for the organic chemist. A new graphical feature used to illustrate both the stability and quality of the elementary assignments is also introduced.

Effects of Photoperiod on Epididymal and Sperm Morphology in a Wild Rodent, the Viscacha (Lagostomus maximus maximus)

The viscacha (Lagostomus maximus maximus) is a seasonal South American wild rodent. The adult males exhibit an annual reproductive cycle with periods of maximum and minimum gonadal activity. Four segments have been identified in the epididymis of this species: initial, caput, corpus, and cauda. The main objective of this work was to relate the seasonal morphological changes observed in the epididymal duct with the data from epididymal sperm during periods of activity and gonadal regression using light and scanning electron microscopy (SEM). Under light and electron microscopy, epididymal corpus and cauda showed marked seasonal variations in structural parameters and in the distribution of different cellular populations of epithelium. Initial and caput segments showed mild morphological variations between the two periods. Changes in epididymal sperm morphology were observed in the periods analyzed and an increased number of abnormal gametes were found during the regression period. During this period, anomalies were found mainly in the head, midpiece, and neck, while in the activity period, defects were found only in the head. Our results confirm that the morphological characteristics of the epididymal segments, as well as sperm morphology, undergo significant changes during the reproductive cycle of Lagostomus.

Seasonal changes of the Leydig cells of viscacha (Lagostomus maximus maximus). A light and electron microscopy study

The Leydig cells of viscacha (seasonal rodent) show cytoplasmic hypertrophy and regional distribution during the breeding period (summer-autumn). The dominant organelles are smooth endoplasmic reticulum (SER) and mitochondria. A moderately well-developed Golgi, abundant lipid inclusions, dense bodies like lysosomes in different stages, and centrioles are observed. Extensive or focal desmosome and gap-like junctions between neighbouring Leydig cells are present. These cells exhibit an evident hypotrophy and an increase in the number of dense bodies during the gonadal regression in winter (July and August). Cells in different stages of involution are observed in this period. Their nuclei are irregular and heterochromatic. The cytoplasm contains few mitochondria. The vesicular SER is scarse. Irregular and large intercellular spaces with microvilli and amorphous material are present. The junctional complexes are absent. The nuclear and cytoplasmic volume and development of SER and mitochondria increase during the recovery period (spring). The lipid inclusions decrease. Dilatations of the intercellular space with microvilli and limited by focal desmosome-like junctions are observed. In conclusion, the Leydig cells of Lagostomus maximus maximus show deep changes alongside the reproductive cycle. The photoperiod variations, through pineal hypothalamus pituitary axis and the hormone melatonin, are probably responsible for them. Moreover, the fall of serum and tubular testosterone would be one of the factors responsible for gonadal regression.

[Acute small bowel obstruction: conservative or surgical treatment?]

Small bowel obstruction (SBO) is a common clinical syndrome caused mainly by postoperative adhesions. In complement to clinical and biological evaluations, CT scan has emerged as a valuable imaging modality and may provide reliable information. The early recognition of signs suggesting bowel ischemia is essential for urgent operation. However appropriate management of SBO remains a common clinical challenge. Although a conservative approach can be successful in a substantial percentage of selected patients, regular and close re-assessement is mandatory. Any persistance or progression of the critical symptoms and signs should indeed lead to surgical exploration. Here we review the principles of adhesive SBO management and suggest a decision procedure for conservative versus surgical treatment.

Interaction between chromaffin and sustentacular cells in adrenal medulla of viscacha (Lagostomus maximus maximus)

New evidence provides valuable information about the participation of sustentacular cells in chromaffin cell catecholamine secretion. In this process, calcium ions play an important role. It has been shown that there is an intense ionic traffic between both types of cells. Moreover, sustentacular cells take an active part in calcium metabolism, regulating levels of the ion and indirectly, the synthesis and release of catecholamines. This background information encouraged us to study the sustentacular population of Lagostomus adrenal medulla and its morphologic relationship with the chromaffin population. The animals were captured, transported to the animal facilities, anaesthetized and killed. The adrenal gland was processed by immunohistochemistry using antiserum against S-100 (subunit alpha and beta), a specific marker. Through the morphological and immunohistochemical study, it was found that there are sustentacular cells in deferent regions of adrenal medulla, mainly in the basal zone of chromaffin cells, which constitute the glomerular structure around blood capillaries. Cytoplasmic extentions of sustentacular cells penetrate into chromaffin cells and make contact with the basal membrane of the capillary endothelium. The relationship among chromaffin cells, capillaries and sustentacular cells suggests that they may intervene actively in the adrenal medulla metabolism.

Intérêt d'un nouveau test combiné antigène–anticorps pour le dépistage de l'infection par le virus de l'hépatite C : réduction de la fenêtre sérologique au cours de l'hépatite C aiguë chez le sujet co-infecté par le VIH

BACKGROUND

The aim of this study was to determine the clinical benefit of a new combined antigen-antibody immunoenzymatic assay (Monolisa HCV Ag-Ab Ultra, Biorad) in the setting of acute HCV infection in HIV infected patients.

PATIENTS AND METHODS

The performance of this assay was first evaluated in 160 HIV positive samples from uninfected and chronically HCV infected patients. To assess the performance of the Ag-Ab assay in the context of acute hepatitis C, 94 stored frozen serums from 20 recently diagnosed cases were retrospectively tested for HCV-RNA and presence of anti-HCV antibodies, in parallel with the new assay.

RESULTS

In HIV infected patients, the sensitivity and specificity of the Ultra assay was 100% with a strong discrimination between positive and negative samples. In HCV acutely infected patients, the Ag-Ab assay significantly reduced the seronegative period, allowing an earlier diagnosis compared to a 3rd generation ELISA in 65% of the cases. The combined assay became positive on the same bleed as the first HCV-RNA detection for 13 patients out of 20. Nevertheless, in one case, characterized by an absence of seroconversion over one year but a continuous viral replication above 1 million IU/ml, the combined assay did not improve HCV infection diagnosis.

CONCLUSION

Use of this new assay as a first line screening would significantly reduce the long seronegative window period seen in HCV infection allowing earlier HCV diagnosis and rapid clinical management. However, in case of clinical acute hepatitis C, sensitive HCV-RNA detection should remain the gold standard.

Early detection of hepatitis C virus infection by use of a new combined antigen-antibody detection assay: potential use for high-risk individuals

The performance of a new combined antigen-antibody assay (Monolisa HCV Ag-Ab Ultra; Bio-Rad Laboratories) was evaluated in the context of acute hepatitis C in human immunodeficiency virus-infected patients. The combined assay became positive as early as the first PCR and earlier than a third-generation enzyme-linked immunosorbent assay in 65% of the cases. Reduction of the long period of HCV seronegativity should improve the diagnosis of hepatitis C infection, especially in high-risk populations.

Acute hepatitis C infection in HIV positive men who have sex with men in Paris, France, 2001-2004

In mid-2004, three Parisian hospital wards informed the Institut de veille sanitaire of recent acute hepatitis C in HIV-infected (HIV+) men who had sex with men (MSM). These cases for whom none of the usual bloodborne routes for hepatitis C (HCV) transmission was found, reported having had unprotected sex. In October 2004, we conducted a retrospective investigation in Parisian hospital wards to explore HCV modes of transmission in recent acute hepatitis C in HIV+ MSM. Patient demographics, clinical and biological status of HIV infection, reasons for HCV testing, sexual behaviour and risk factors for HCV transmission within the 6 months before hepatitis onset were collected from medical records. An anonymous self-administered questionnaire on sexual behaviour within the six months before hepatitis onset was also offered to all cases. We identified 29 cases of acute hepatitis C in HIV+ MSM with onset from April 2001 to October 2004. HIV infection was asymptomatic for 76%. Median age at hepatitis C onset was 40 (28-54) years. In all records, were noted unprotected anal sex, fisting in 21% and a concomitant sexually transmitted infection (STI) in 41%. Median time between HIV diagnosis and HCV infection was 6.5 years (0-22). From the 11 self-administered questionnaires completed, 10 reported an STI, 8 'hard' sexual practices, 6 bleeding during sex and 5 fisting. HCV transmission probably occurred through bleeding during unprotected traumatic anal sex among HIV+ MSM and may be facilitated by STI mucosal lesions. This report stresses the continuous need to strongly advocate safer sex to MSM.

Acute hepatitis C in HIV-infected men who have sex with men

BACKGROUND

Hepatitis C virus (HCV) is usually transmitted via the parenteral route, but there are widely discrepant findings on its possible sexual transmission. Thus there are no recommendations concerning protected sex for couples in which only one partner is HCV-infected. Whether HIV or other sexually transmitted diseases could favour HCV transmission remains unclear, but recent data suggesting an increasing incidence of acute HCV in HIV-infected men underline the major public health implications of this issue.

CASE REPORTS

Between June 2002 and July 2003, five HIV-infected homosexually active men presented with primary (n=4) and secondary (n=1) syphilis and concomitant abnormal liver function tests revealing acute asymptomatic HCV seroconversion. Other causes of acute viral hepatitis were inquired into and excluded. Highly at-risk sexual behaviour, including unprotected anal intercourse and unsafe oral sex, with concomitant syphilis, was found to be the only identifiable important risk factor for transmission of HCV.

CONCLUSIONS

Sexual transmission may be fuelling a significant increase in HCV seroconversions among HIV-infected men who have highly risky sexual behaviours. Given the recent data suggesting the spread of sexually transmitted infections among HIV-infected gay men, specific recommendations concerning safe sex are urgently needed.

Oxaliplatin- or irinotecan-based chemotherapy for metastatic colorectal cancer in the elderly

The tolerance and efficacy of oxaliplatin and irinotecan for metastatic colorectal cancer are unknown in elderly patients. Methods. All consecutive patients over 74 years treated with oxaliplatin or irinotecan for metastatic colorectal cancer were enrolled. The tumour response was assessed every 2–3 months and toxicity was collected at each cycle according to World Health Organisation criteria. A total of 66 patients were enrolled from 12 centres. The median age was 78 years (range, 75–88 years); 39 patients had no severe comorbidity according to the Charlson score. In total, 44 and 22 patients received oxaliplatin or irinotecan, respectively, in combination with 5-fluororuracil±folinic acid or raltitrexed in 64 patients. A total of 545 chemotherapy cycles were administered in first (41%), second (51%) or third line (8%). A dose reduction occurred in 190 cycles (35%). Complete response, partial response and stabilisation occurred in 1.5, 20 and 47% of patients, respectively. The median time to progression and overall survival were 6.8 and 11.2 months in first line and 6.3 and 11.6 months in second line, respectively. Grade 3 and 4 toxicity occurred in 42% of patients: neutropenia 17%, diarrhoea 15%, neuropathy 11%, nausea and vomiting 8% and thrombopenia 6%. There was no treatment-related death. In selected elderly patients, chemotherapy with oxaliplatin or irinotecan is feasible with manageable toxicity.

[Cancers of the stomach]

Although its declining incidence in most Western countries, gastric cancer remains a leading cause of cancer death. In France, it ranks second after colorectal cancer in terms of frequency. Chronic gastritis is the most frequent pathological condition that predispose to gastric cancer. One of the most important aetiological factor of gastric carcinogenesis is obviously the infection by Helicobacter pylori. Positive diagnosis of gastric cancer is made by upper gastrointestinal endoscopy combined with biopsies. Surgical resection is currently the only potentially curative treatment. However, the 5-year-survival rate after apparently curative surgical resection remains only 15% in Western populations. The studies on adjuvant treatment after surgical resection, have failed to demonstrate any improvement in overall or disease-free survival. Although promising in the locally advance setting, the pre-operative cytotoxic approach with or without radiation therapy remains experimental. In advanced disease the so-called ECF regimen results in delayed symptoms-free survival, increased survival (median: 9 months) and better quality of life.

Beryllium(II) Complexes of the Kläui Tripodal Ligand Cyclopentadienyltris(diethylphosphito-P)cobaltate(−)

The interactions of the beryllium(II) ion with the cyclopentadienyltris(diethylphosphito-P)cobaltate monoanion, L(-), have been investigated, in aqueous solution, by synthetic methods, potentiometry, ESMS, and (1)H, (31)P, and (9)Be NMR spectroscopy. L(-) has been found able to displace either two or three water molecules in the beryllium(II) coordination sphere, to form mononuclear, dinuclear, and trinuclear derivatives, in which the metal ion is pseudotetrahedrally coordinated. The species [BeL(H(2)O)](+) and [Be(2)L(2)(mu-OH)](+) have been identified in solution while complexes of formula BeL(2) and [Be(3)L(4)](ClO(4))(2) have been isolated as solid materials. The species [BeL(OPPh(2))](+), closely related to [BeL(H(2)O)](+), has been characterized in acetone solution and isolated as tetraphenylborate salt. The structure of the unusual trimeric complex [Be(3)L(4)](2+) has been elucidated by an unprecedented 2D (9)Be-(31)P NMR correlation spectrum showing the presence of a single central beryllium nucleus and two equivalent terminal beryllium nuclei. The three beryllium centers are held together by four cobaltate ligands, which display two different bonding modes: two ligands are terminally linked with all the three oxygen donors to one terminal beryllium, and the other two bridge two metal centers, sharing the oxygen donors between central and terminal beryllium atoms.

Ultrastructural and morphometric study of the Sertoli cell of the viscacha (Lagostomus maximus maximus) during the annual reproductive cycle

Changes in the morphology of viscacha Sertoli cells were studied during the annual reproductive cycle. Sertoli cells exhibited marked nuclear and cytoplasmic changes. Seasonal variation in nuclear size and shape, chromatin texture, and nucleolus characteristics was observed. The seasonal patterns of the volume densities of the endoplasmic reticulum (ER), mitochondria, Golgi complex, dense bodies and lipid inclusions were distinct. Morphometric analysis revealed that the Golgi complex is the organelle most sensitive to seasonal change. It declined drastically in the regressed testes and its recovery was slow. The ER and mitochondria exhibited seasonal variations in their pattern and content, that was minimal during winter. In contrast, an accumulation of lipid and dense bodies, such as primary and secondary lysosomes, accompanied the spermatogenic arrest. The volume densities of both organelles were maximum during the restoration of spermatogenesis. The length and organization of the inter-Sertoli junctions also changed with the reproductive cycle. The Sertoli cell number per tubular cross section decreased significantly during the testicular regression, coincident with the presence of Sertoli cells with marked signs of involution. The degree of regression and recovery exhibited by the viscacha Sertoli cells was closely related to that shown by the associated germ cells. Therefore, seasonal endocrine fluctuations and local factors could be involved in the regulation of the morphological and functional characteristics of the viscacha Sertoli cells. These hormonal fluctuations are synchronized by the photoperiod through the pineal gland and its hormone, melatonin.

[Antiretroviral therapies]

SPARING ANTIPROTEASES: An antiprotease-sparing strategy can improve compliance and adhesion to antiretroviral treatments. Several studies have demonstrated that switching to neviparin or efavirenz can maintain viral suppression and allow satisfactory rise in CD4 counts with a significant reduction in the neviparin group. A switch to a tritherapy with nucleosides (abacavir) can increase the risk of virological failure but allows an improvement in lipid anomalies, simplified treatment, and better patient adhesion. LIPODYSTROPHY SYNDROMES: These syndromes develop in 30 to 50% of the cases depending on the study and appear to be linked to the duration of exposure to antiretroviral agents. Along with the associated metabolic anomalies, lipodystrophy plays a role in the cardiovascular risk related to these treatments. NEW ANTIRETROVIRAL DRUGS: Several clinical trials have been devoted to new antiretroviral drugs. DAPD was found to have a dose-dependent antiretroviral effect with good tolerance. A new antiprotease (BMS 232 632) offers the advantage of a single daily dose with good tolerance and good effectiveness compared with the reference treatment including nelfinavir. TDF (tenofovir disoproxyl fumarate) is a nucleotidic analogue of reverse transcriptase. Given in a single daily dose monotherapy regimen, it can provide prolonged retroviral suppression. Compared with nelfinavir, ABT 378 gave significantly higher viral loads < 400 copies/ml at 24 weeks with an identical clinical tolerance but with an advantage for cholesterol and triglyceride levels.

Cytokeratin, vimentin and E-cadherin immunodetection in the embryonic palate in two strains of mice with different susceptibility to glucocorticoid-induced clefting

An immunohistochemical study analyzing the pattern of distribution of some intermediate filament proteins, keratin and vimentin and, one adhesion molecule, cadherin in different stages of developing secondary palate in two strains of mice with different H-2 backgrounds was undertaken to investigate differences between a strain that is susceptible to glucocorticoid-induced cleft palate (A/Sn) and one that is resistant to glucocorticoid-induced cleft palate (C57/BL). The heads of embryos were processed by standard immunohistochemistry with antipancytokeratin (KAE1), antikeratins 18 (K18) and 19 (K19), antivimentin, and anti E-cadherin antibodies. Immunostaining with KAE1 antibody showed differences between the strains. The reaction was stronger in the medial edge epithelia of palatal processes in the A/Sn strain at all stages of palatogenesis. The C57/BL strain showed a weak immunostain to KAE1. Antivimentin antibody stained the mesenchymal cells of palatal processes and K18 and K19 showed no reaction in either strain of mice. Anti E-cadherin antibody was detected in the medial palatal epithelium of both strains of mice and in all stages of palate development. No differences were observed in E-cadherin and vimentin immunostain in palatal epithelium between the strains. The different expression of some cytokeratins in the embryonic palatal epithelium suggests that these intermediate filament proteins may be involved in different susceptibility to glucocorticoid-induced cleft palate in the mouse. The decreased immunoreaction of cytokeratins observed in the resistant strain would facilitate the disappearance of this molecule during the transformation from an epithelial to a mesenchymal phenotype that takes place during the development of the palate. These results may be related to the loss of cytokeratin expression observed during epithelial-mesenchymal transformation in the embryonic palate.

Lithium effect on testicular tissue and spermatozoa of viscacha (Lagostomus maximus maximus). A comparative study with rats

We investigated the effect of lithium chloride administration (Sigma): 1 mmol/kg b.w. i.p./day for 35 days on the testes and sperm of viscacha (Lagostomus maximus maximus), a nocturnal rodent found only in the pampas of Argentina. The histological study showed that hypospermatogenesis and the sperm number per mL decreased markedly in comparison with the controls (treatment group: 315 x 10(6) +/- 77 x 10(6); control group: 693 x 10(6) +/- 39 x 10(6), Means +/- SEM, Student's t-test: p < 0.05). The sperm motility and viability were also affected. Under the same treatment, the testicular tissue and the sperm of rats were not damaged. Moreover, lithium induced these changes when the plasm levels were within the therapeutic range in humans. Our results provide evidence for the claim that viscacha testes and sperm react very sensitively to low doses of lithium, whereas these concentrations do not produce damage in rats.

Colloid in the pituitary pars distalis of viscacha (Lagostomus maximus maximus): ultrastructure and occurrence in relation to season, sex, and growth

Randomly distributed extracellular colloidal accumulations were observed in the pars distalis of viscacha (Lagostomus maximus maximus). They were preferentially located in the peripheral zone of the gland and showed variability in shape and size. Two different types of colloidal accumulations were found by electron microscopy: 1) those surrounded by nongranulated follicular cells that correspond to characteristic follicles, and 2) those surrounded by granulated cells. In the follicles lined by nongranulated follicular cells, long, prominent microvilli and cytoplasmic processes protruded into the lumen. The frequency of these accumulations varies during the year in adult male animals, showing an increase in number during summer and a decrease during winter. The lowest value was registered in August (winter). The mean follicular diameter did not vary seasonally. The number of colloidal accumulations did not vary seasonally in adult female viscachas, but a significant difference in the mean follicular diameter between pregnant and non-pregnant females was observed. Pituitaries of immature animals contain fewer colloidal accumulations than those of adults. In fetuses, these accumulations were absent. The administration of melatonin provoked a decrease in the number of these structures. The numeric changes of the colloidal accumulations observed in this study are associated with: 1) the seasonal reproductive activity in adult males, and 2) the reproductive condition, body weight and sexual maturity in males and females. The fact that melatonin administration decreases the population of colloidal accumulations in males suggests participation of the pineal gland in these changes.

Hepatic arterial chemoembolization with streptozotocin in patients with metastatic digestive endocrine tumours

BACKGROUND

Hepatic arterial chemoembolization (CE) with anthracyclines is an effective treatment for progressive liver metastases of digestive endocrine tumours. Streptozotocin (STZ) is widely used for systemic chemotherapy, but its efficacy by the hepatic arterial route has not been evaluated.

PATIENTS AND METHODS

Fifteen consecutive patients, mean age 57.8 years, were prospectively included between July 1993 and January 1997. All patients had progressive liver metastases from either a carcinoid tumour (eight patients) or an islet cell carcinoma (ICC) (seven patients) that had increased in size (> or = 25%) before CE. Five patients had the carcinoid syndrome. STZ was administered, as an emulsion with iodized oil, into the hepatic artery before embolization with gelatin sponge particles. Two to six procedures (median, 3) were performed in 12 patients (one in three patients). Changes in the size of the liver metastases were evaluated by CT scan or MRI according to WHO criteria. The median follow-up was 15 months (1-50).

RESULTS

An objective response was achieved in 8/15 patients (53%; median duration of 10.5 months) whatever the primary tumour (carcinoid or ICC). The carcinoid syndrome disappeared in 3/5 patients for 10, 11 and 17 months, respectively. CE effectively controlled hypoglycaemic attacks (decrease of > 50%) in the patient with insulinoma. The biological response was complete in four patients for a median duration of 7 months. CE induced minor side effects, namely nausea, fever and abdominal pain. Acute and reversible tubular necrosis due to CE was observed in one patient who had previously undergone a nephrectomy.

CONCLUSION

Hepatic arterial chemoembolization with STZ is an effective treatment for patients with liver metastases caused by digestive endocrine tumours.