Control of Particle Properties in Thermally-Induced Precipitation of Polyetherimide

The feasibility of thermally-induced phase separation and crystallization for the production of semi-crystalline polyetherimide (PEI) microparticles from an amorphous feedstock has been reported recently. Here, we investigate process parameter dependencies for designing and control of particle properties. A stirred autoclave was used to extend the process controllability, as the applied process parameters, e.g., stirring speed and cooling rate, were adjusted. By increasing the stirring speed, the particle size distribution was shifted to larger values (correlation factor ρ = 0.77). Although, the enhanced droplet breakup, induced by the higher stirring speed, led to the formation of smaller particles (ρ = -0.68), broadening the particle size distribution. The cooling rate showed a significant influence on the melting temperature, reducing it with a correlation factor of ρ = -0.77, as confirmed by differential scanning calorimetry. Lower cooling rates led to larger crystalline structures and enhanced the degree of crystallinity. The polymer concentration mainly affected the resulting enthalpy of fusion, as an increased polymer fraction enhanced the latter (correlation factor ρ = 0.96). In addition, the circularity of the particles was positively correlated to the polymer fraction (ρ = 0.88). The structure assessed via X-ray diffraction, was not affected.

Suicide attempts in LGBTQ+ youth in Switzerland: Qualitative insights in school-based risk factors

Background

Studies show that the LGBTQ+ population is particularly vulnerable to suicidal thoughts and behavior. This vulnerability is even more pronounced in the younger population. However, in Switzerland, qualitative studies on this topic are missing. Our study investigates the processual dynamics and background of suicide attempts of LGBTQ+ youths while looking into their subjective meaning. Here, behaviors of help-seeking are also from interest. In addition, the burdens and resources associated with being LGBTQ+ are explored. By better understanding the process of suicide attempts, we can identify relevant contexts of the respondents’ experiences and illustrate how to enhance suicide prevention strategies. We are referring here to the school context.

Methods

From 2021 until 2024, we interview LGBTQ+ youths in the German- and French-speaking parts of Switzerland who have tried to end their lives between the ages of 14 to 25 (max. three attempts). Applying a multi-perspective approach, we interview persons from their social environment if agreed. Recruitment is based on ‘theoretical sampling’. Data collection and analysis follow the grounded theory methodology. As of July 2022, the sample consists of 18 persons: 3 bisexual women, 1 lesbian woman, 2 gay men, 7 transgender persons, and 5 persons with fluid identities.

Results

Through preliminary analysis, the school context could be identified as one relevant burdening context in the respondents’ experience and suicide attempt process. In this respect, respondents experienced complicated social relationships: e.g., bullying, social exclusion, and pressure to conform. Moreover, the school environment was experienced by some as LGBTQ+ hostile.

Conclusions

Our current findings support the necessity to integrate schools as important stakeholders in suicide prevention but highlight a need for LGBTQ-specific and LGBTQ-sensitive orientations to suicide prevention strategies.

Respiratory pandemic and indoor aeraulics of classrooms

Respiratory pandemics, such as COVID19, may be transmitted by several modes. The present work focuses on the transmission through small droplets released by people from their mouth by breathing, speaking, coughing, sneering, and possibly aspirated by other people around through their respiration. An analysis of droplet evolution in simplified situations shows that the droplets reach very quickly a quasi-equilibrium temperature before encompassing an isothermal evaporation process. The removal of droplets from suspension is thus piloted by balance between evaporation and sedimentation. It is shown that ambient relative humidity is a major factor influencing the lifetime of droplets and the distance they may travel. As a consequence, and independently of any other health consideration linked to ambient humidity, it is seen that a dry air is a favourable factor for limiting risk of contamination from COVID19. Further investigation is made using computational fluid dynamics (CFD) in a classroom geometry. Several ventilation strategies are investigated: classical regulatory mechanical ventilation, open window natural ventilation and displacement natural ventilation. Ventilation has several effects which influence contamination risk: by introducing fresh air, it reduces droplet concentration; humidity released by human occupants is also limited. However, these effects are not uniform in space, and depend on ventilation strategy. Application of a dose-effect model calibrated for COVID19 to CFD results allows to estimate contamination risk. It is shown that contamination risk is higher for regulatory mechanical ventilation, and may be reduced, using natural ventilation in the absence of wind, by a factor 2.3 to nearly 3 when the teacher is sick, and by a factor 6 to 500 when a student is sick. In the presence of wind, the reduction factor is as high as 13 when the teacher is sick and 17 when a student is sick.

Limited access to family-based addiction prevention services for socio-economically deprived families in Switzerland: a grounded theory study

Background

Families living in poor socio-economic circumstances, already confronted with social and health inequalities, are often not reached by family-based addiction prevention services. Besides quantitative models and health literacy approaches, qualitative research is lacking that could shed light on the exact circumstances and processes that lead to hindered addiction prevention service uptake by these families. Drawing on the concept of candidacy, we therefore reconstructed how socio-economically deprived parents and their (pre) adolescent children in the German-speaking part of Switzerland (non-)identified their candidacy for family-based addiction prevention services.

Methods

Following grounded theory, we collected and analysed data in an iterative-cyclical manner using theoretical sampling and theoretical coding techniques. Sixteen families with children aged 10–14 years were interviewed in depth (parent/s and child separately). All but one family lived below the at-risk-of-poverty threshold.

Results

Socio-economically deprived families’ modes of recognizing and handling problems in everyday life were found to be core phenomena that structure the process towards (non) identification of candidacy for family-based addiction prevention services. Four modes anchored within socio-demographic resources were found: Families with mode A perceived their current life situation as existentially threatening and focused daily coping on the main pressing problem. Others (mode B) perceived prevalent multiple problems as normal (now); problems were normalized, often not recognized as such. In mode C families, problems were pragmatically recognized at a low threshold and pragmatically dealt with, mostly within the family. In mode D families, problems were constantly produced and dealt with early by the worried and anxious parents monitoring their child. From modes D to A, vulnerability increased concerning non-identification of candidacy for family-based addiction prevention services. Further, thematic relevance of addiction prevention, past experience with offers, integration in systems of assistance, strategies to protect the family, and families’ search for information influenced whether identification of candidacy took place.

Conclusions

Socio-economically deprived families differ in modes of problem construction and handling in everyday life; this differently opens up or closes routes to family-based addiction prevention. Addiction prevention practice should build on a bundle of diverse strategies for outreach to these families, stressing especially interventions on the structural and environmental level.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-020-01305-1.

Socio-economically deprived families’ routes to family-based addiction prevention services

Background

Families living in poor socio-economic circumstances, already confronted with social and health inequalities, are often not reached by family-based addiction prevention programmes. Besides quantitative models and health literacy approaches, qualitative research is lacking that could shed light on the exact circumstances and processes that lead to hindered addiction prevention service uptake by these families. Drawing on the concept of 'candidacy', we aimed to reconstruct how socio-economically deprived parents and their (pre-)adolescent children in German-speaking Switzerland identify their candidacy for family-based addiction prevention services.

Methods

Following grounded theory, we collected and analysed data in an iterative-cyclical manner using theoretical sampling and theoretical coding techniques. Sixteen families with children aged 10-14 years were interviewed in depth (parent/s and one child separately). All but one family lived below the at-risk-of poverty threshold.

Results

Families' modes of recognising and handling problems in everyday life were found to be core phenomena that structure the process towards (non-)identification of candidacy for family-based addiction prevention services. Further, thematic relevance of addiction prevention, past experience with offers, integration in systems of assistance (social welfare, etc.), strategies to protect the family, and parents' search movements for support were important for families' identification of candidacy.

Conclusions

Socio-economically deprived families are not a homogeneous group. They differ in modes of problem construction and handling in everyday life; this differently opens up or closes routes to family-based addiction prevention services. Policy and practice should build on a bundle of diverse strategies for outreach to these vulnerable families.

Key messages

Our qualitative study adds scientific knowledge to a better understanding of socio-economically deprived families’ complex routes to family-based addiction prevention services. Results provide evidence that policy and practice should build on a bundle of diverse strategies to reach these vulnerable families. Equity in access to services can thus be improved.

Participation of adults with cognitive, physical, or psychiatric impairments in family of origin and intimate relationships: a grounded theory study

BACKGROUND

How adults with disabilities perceive participation has received little attention. Our purpose was to formulate a grounded theory on participation, based on the subjective experience of adults with cognitive, physical, or psychiatric impairment(s), and to identify barriers, facilitators, and support needs concerning participation in different areas of life. We aimed to explore whether the United Nations' Convention on the Rights of Persons with Disabilities (CRPD), ratified by Switzerland in 2014, and its principles are being met. Here we report on the main category and focus on the participation areas 'family of origin' and 'intimate relationships.'

METHODS

In a qualitative, grounded theory study, we conducted problem-centered interviews with 23 adults with cognitive, physical, or psychiatric impairments (30-53 years; 11 men, 12 women), with different housing (on their own, assisted living, with parents) and work situations (primary vs. secondary labor market) in nine German-speaking Swiss cantons.

RESULTS

Participation can be understood as a continuum that extends on a horizontal level (from participation is restricted to participation takes place) and a vertical level (separative setting vs. inclusive setting). In separative as well as in inclusive settings, diverse levels of participation are possible. Many participants were stuck in an 'in-between' area between separative and inclusion-oriented settings. In the family of origin, there was a thin line between fulfilling relations that enhance participation and conflictual relations and overprotective parenting that limit participation. In intimate relationships, opportunities for participation were limited overall. Many interviewees were single. Social environment and family of origin (e.g., parents) can enable and facilitate intimate relationships and sexual contacts but can also be an important barrier.

CONCLUSIONS

Participation can be understood as a continuum. Participation restrictions exist in separative as well as in inclusive-oriented settings, also in the areas of family of origin and intimate relationships. Participation barriers must be torn down in separative as well as in inclusion-oriented settings. Trajectories to inclusive settings should be facilitated. Families with children with impairment(s) should be supported from early on to create the best possible participation possibilities for the (adult) person with impairment(s) and to support the family of origin itself.

Development of a solvent-free polylactide/calcium carbonate composite for selective laser sintering of bone tissue engineering scaffolds

Since large bone defects cannot be healed by the body itself, continuous effort is put into the development of 3D scaffolds for bone tissue engineering. One method to fabricate such scaffolds is selective laser sintering (SLS). However, there is a lack of solvent-free prepared microparticles suitable for SLS. Hence, the aim of this study was to develop a solvent-free polylactide/calcium carbonate composite powder with tailored material properties for SLS. Four composite powders with a composition of approximately 75 wt% polylactide (PLLA as well as PDLLA) and 25 wt% calcium carbonate (calcite) were prepared by a milling process based on GMP standards. Four different grades of polylactide were chosen to cover a broad inherent viscosity range of 1.0-3.6 dl/g. The composite material with the lowest inherent viscosity (1.0 dl/g) showed the best processability by SLS. This was caused by the small polymer particle diameter (50 μm) and the small zero-shear melt viscosity (400 Pa·s), which led to fast sintering. The SLS process parameters were developed to achieve low micro-porosity (approx. 2%) and low polymer degradation (no measurable decrease of the inherent viscosity). A biaxial bending strength of up to 75 MPa was achieved. Cell culture assays indicated good viability of MG-63 osteoblast-like cells on the SLS specimens. Finally, the manufacture of 3D scaffolds with interconnected pore structure was demonstrated. After proving the biocompatibility of the material, the developed scaffolds could have great potential to be used as patient-specific bone replacement implants.

Affektionen der Lendenwirbelsäule bei rheumatoider Arthritis

In rheumatoid arthritis the anatomical structures of the lumbar spine are affected by the same mechanisms of destruction as are known from other skeletal regions. Although spinal symptoms do not become apparent until the later stages of rheumatoid arthritis, patients do sometimes complain of typical symptoms. We present data recorded in 19 patients with seropositive rheumatoid arthritis who underwent hospital treatment directed exclusively at isolated low-back pain. The patients were questioned in some detail with the aid of instruments including the Oswestry, TypE, HAQ and RADAI questionnaires and a visual-analogue-pain scale. Roentgen exposures were also evaluated. A comparison was drawn between patients treated surgically with decompression and various spondylodeses (n=13) and those who received conservative treatment (n=6). Better results were obtained in the group of patients treated surgically, though a statistical evaluation was not possible. No histological evidence of rheumatoid alterations was found in the intervertebral disc tissue samples available.

CD4+ T-Cell Responses Against the VP1-Unique Region in Individuals with Recent and Persistent Parvovirus B19 Infection

To date cellular immune responses against parvovirus B19 (B19) have not been studied extensively. The aim of this study was to examine the T-cell response against the VP1-unique region as the immunodominant part of the viral structural protein VP1 in individuals with different courses of B19 infection. Therefore, a group of 13 parvovirus-positive probands was separated into subgroups characterized for recent or acute, past or persistent infection by means of the presence of specific immunoglobulin (Ig)M and IgG isotypes and of viral DNA in blood and tissue. Transiently transfected B-cells expressing VP1-unique region were used in ELISpot assays to investigate T-cell responses directed against the VP1-unique region in peripheral blood mononuclear cells (PBMC) of individual donors. Significant numbers of interferon-gamma (IFN-gamma) secreting lymphocytes were detectable in PBMC of all individuals with recent, acute or persistent B19 infection, but not in PBMC of donors with past B19 infection and seronegative individuals. A more detailed analysis of IFN-gamma producing cells by intracellular cytokine staining by flow cytometry revealed, that CD4(+) T cells but not CD8(+) cytotoxic lymphocytes (CTL) were the major subpopulation of IFN-gamma producing cells. These data strongly suggest the need of virus protein production for the maintenance of VP1-unique region-specific CD4(+) T-helper cell responses in B19-infected individuals.

Unexpected formation and structural characterisation of a novel rhodium B12 analogue

The metalation reactions of the 2,2'-bidipyrrin 4 with different rhodium(I) precursors yield the complexes 5 and 6 and the unusual corrinoid 7, depending only on the type of the ancillary ligand employed.

Lesional effects of primary cosmic heavy ions on rat brain

Heavy ions were detected with nuclear emulsions plates fixed on the skulls of 20 rats which were exposed to cosmic rays at an altitude of 32,000 metres. Eight cases are described of correlations between ions tracks and brain lesions. The passage of heavy ions seems to cause functional rather than destructive alterations in the cells. The metabolic disturbances give a dark aspect to the neurons. The lesions generally appear in wide areas around the track and this fact suggests a physiopathological phenomenon of amplification. An evaluation of this biological hazard during flights of long duration at high altitude will be possible when the mechanism of action of heavy ions on nervous tissue is better known, and particularly if experiments carried out in accelerators confirm the small number of results obtained in flight.

Comparative study of lesions in the brain of rats exposed to heavy ions: accelerator and stratospheric flight research

Irradiations of rat's brain with heavy ionized particles (12/6C, 291 Mev/nucleon, 100 to 300 ions/mm2) have been carried out at the Lawrence Berkeley Laboratory. Exposures were made with slowed ions which stopped within the brain as well as with more energetic particles which passed through. Histological examination of irradiated encephalons by optical microscopy showed zones of glial reaction and an increased number of darkly staining cells. By electron microscopy, intercellular edema, various alterations of nervous cells and macrophagy were observed, especially with stopped ions.

Use of the fork plate for internal fixation of periprosthetic fractures and osteotomies in connection with total knee replacement

Six cases of periprosthetic fractures of the distal femur following total knee arthroplasty were treated with a newly developed fork plate. Instead of the blade of the condylar plate, this implant features two prongs that are adaptable in length. Because of the space between the prongs, the distal femoral fragment surrounds the anchorage pegs of the prosthesis and can be gripped near the joint line. The average patient age was 74 years. Follow-up ranged between 2 and 54 months. All patients were mobilized immediately postoperatively. Full weight bearing and bone consolidation was achieved by 9 weeks postoperatively.

Diagnostic value of nasal provocation challenge with allergens in children

A total of 106 children suffering from perennial rhinitis and/or asthma, and all allergic to Dermatophagoides pteronyssinus (DP), underwent nasal provocation challenge (NPC) with DP to determine the best method of diagnosis. Posterior rhinomanometry was uninterpretable in 17 patients and gave negative results in 31. Clinical scores for sneezing and rhinorrhea were more effective but did not diagnose the disorder in 11 children. However, nine of the 11 had significant increases in eosinophil count in the late phase. Clinical scores and cytology were also useful for assessing whether NPC with allergens was positive in children. The feasibility and safety of NPC with DP are high for rhinitic and stable asthmatic patients, but mild reactions may occur during the late phase.

Nasal cytology in rhinitis children: comparison between brushing and blowing the nose

Allergic rhinitis is a common disease in childhood, but nasal cytology is rarely used by pediatricians. We compared two techniques of cell sampling, brushing and blowing the nose, among 77 children suffering from chronic rhinitis, of whom 59 were allergic. Staining by the May-Grunwald-Giemsa method enabled the evaluation of the density of cells and especially differential counting of the inflammatory cells. Staining by the Luna method was used as a control for the eosinophils. For the eosinophil count, we found a strong correlation between the two methods of collecting the nasal secretions (r = 0.96). Because blowing the nose is painless and easy to perform, it is more appropriate than brushing in routine use for the diagnosis of allergic rhinitis in children and in nasal challenge with allergens.

Congenital soft tissue dysplasias: a morphological and biochemical study

The term congenital soft tissue dysplasias (CSTDs) regroups some localized malformations of covering soft tissues in children, presenting as various clinical entities, either recognized as particular syndromes (e.g., Parkes-Weber, Klippel-Trenaunay, Proteus) or, most often, appearing less stereotyped (e.g., segmental hypertrophy or gigantism, lymphedema, angiodysplasia, phakomatosis), with a common histopathological lesion, the hamartoma. The aim of this paper is to report a morphological and biochemical study of the extracellular matrix of skin and subcutaneous tissue in children with CSTD. For every patient, pathological tissues were compared with contralateral, symmetrical tissues, taken as controls. In all CSTDs, pathological samples were characterized by an increase in water and total glycosaminoglycan (GAG) content with a decrease in collagen content. Other results lead the authors to distinguish two main entities, segmental dysplasia (SeD) and neuroectodermal dysplasia (NeD). Elastic fiber content was increased in SeD and decreased in NeD. Hyaluronic acid (HA) and dermatan sulfate (DS) were increased in NeD, whereas in SeD, HA was decreased with an increase in the DS/HA ratio. Cultured fibroblasts from dysplastic skin had slower proliferation in vitro than fibroblasts from control skin, whereas their biosynthetic activity concerning collagen and GAGs was greater. The difference in the composition of extracellular matrix supports the clinical classification of CSTDs in two main groups: segmental dysplasia with or without gigantism and neuroectodermal dysplasia (in von Recklinghausen's disease and nevi).

[Analysis of migration of screwed acetabular components following revision arthroplasty of the hip joint. Results of single-image roentgen analysis]

Out of 57 revised acetabular components, which were regularly checked, 47 had been replaced by a cemented Müller's acetabular reinforcement ring resp. a cementless Müller's Sl-shell with flange. Both types of cups are anchored in the acetabular roof with cancellous bone screws (tab. 1). 42 cases with radiograph series permitted a detailed analysis with the EBRA-method, a computer aided method for the evaluation of acetabular spatial migration based on standard radiographs of the pelvis. The clinical results were very satisfying (tab. 6). The screwed acetabular components migrated little, although, some essential displacements of the center of rotation (in relation to the anatomical position) had to be accepted. As was recognizable with today's inaccurate methods of measuring the center of the head, the displacement too far towards cranial influenced the migration tendency less than an excessive lateralisation. Especially satisfying is the fact, that no increased migration was observed after reconstruction bone grafting of severe acetabular defects, provided that at least a partly direct contact between the acetabular component and the original bone stock was obtained. For the first time EBRA shall be introduced here as a method which shows the migration and the spatial inclination of the acetabular cup in a vector chart.

[Bone biopsies of cortical bone segments (technique, evaluation)]

13 drill biopsies were microscopically examined and evaluated in respect of their histologic quality. 8 biopsies were obtained with a diamond hollow cutter, the other 5 specimens were sampled with a modified milling cutter according to Burkhardt. Regarding proper evaluation of bone biopsies e.g. in cases of osteomyelitis, factors as presence of bone marrow cavity or drill powder play an important role. Considering these factors the modified milling cutter according to Burkhardt yields, precise and careful handling provided, better results than the diamond hollow cutter.

Granulosa cells improve human embryo development in vitro

A total of 17 couples with repetitive implantation failure after transfer of fresh or frozen-thawed embryos had half of their zygotes cultured in standard conditions and frozen at day 2 after insemination, and the other half cocultured with autologous granulosa cells and transferred at the morula or blastocyst stage at day 5 or 6 after oocyte retrieval. At the end of the culture period, supernatants of cocultures were recovered for steroid assays. Monolayers were stained for granulosa cell growth and morphological assessment. We observed that granulosa cells improve embryo development in vitro since 32 out of 60 (53%) reached the morula stage and 18 (30%) the blastocyst stage, leading to a total of 83% embryos available for transfer (compared with 3% without coculture). The ongoing pregnancy rate of these patients who were selected because they had at least three previous implantation failures, is only 5.9%, however, which is similar to the control group without coculture (6.3%). To conclude, granulosa cells improve embryo development but not the pregnancy rate after transfer of cocultured embryos in patients with multiple previous implantation failures.

[Experiences with closed irrigation-suction drainage and simultaneous administration of an antiseptic]

In 47 patients a closed instillation drainage system was used with concomitant systemic antibiotic therapy. The schedule was strictly followed and is described in detail in the text. Prerequisites for a successful therapy are thorough surgical débridement, good coverage with soft tissue and a very careful skin closure. We propose a shortened duration of instillation of 3 to a maximum of 5 days. The Draintec suction pumps now used evidently create less problems than the classic pumps. During a mean follow-up of 3 years a definite recurrence was observed in two cases and a possible recurrence in one. In view of these results we consider this mode of treatment is still valid. Lavasept was added as an antiseptic drug in three quarters of the cases and was tolerated well. In view of the low rate of recurrence in all cases its potential cannot yet be fully estimated. We recommend the instillation-drainage system for use in thigh, upper arm and pelvic areas in the hands of a fully cooperating management team with some experience in the application of instillation-drainage systems.

Melanotic neuroectodermal tumor of the skull and meninges in infancy

Three cases of melanotic neuroectodermal tumors of infancy are presented. Two were localized on the midline, involving the skull and extending subdurally. One was located on the inner aspect of the dura and developed intracranially. Two had a benign course following gross total removal. One had a malignant course, recurring locally and spreading within the brain. The difficulties of removing these tumors when they are implanted on the midline are stressed. Histological features of prognostic value are pointed out. Further support for neural crest origin of these tumors is given.

Effect of long-term infusion of platelet-activating factor on pulmonary responsiveness and morphology in the guinea-pig

The effect of chronic administration of platelet-activating factor (PAF) on airway reactivity, cell recruitment and lung morphology in the guinea-pig has been investigated. Alzet osmotic minipumps delivering either PAF (7.2 mg/kg/14 days) in 0.25% (w/v) bovine serum albumin in saline (saline-BSA), acetylcholine or saline-BSA alone were implanted s.c. in the neck region of guinea-pigs and connected to the jugular vein. In some experiments, implanted and non-implanted animals were treated daily with the PAF antagonist, BN 52021 (15 mg/kg, twice a day, p.o.). On day 15 after minipump implantation, the animals were anesthetized with urethane (1.2 g/kg, i.p.) and tracheal cannula was inserted for mechanical ventilation. Pulmonary inflation pressure (PIP) was monitored and airway responsiveness was assessed by administration of increasing doses of histamine (0.2-100 micrograms/kg, i.v.). As compared to saline-BSA-treated or non-implanted guinea-pigs, chronic treatment of the animals with PAF induced a significant (p less than 0.01) increase in airway response. No significant change in airway responsiveness was observed following chronic acetylcholine administration. In contrast, regardless of the treatment of the animals, no change in the threshold dose of histamine inducing alteration in PIP was noted, suggesting that PAF induces bronchopulmonary hyperreactivity rather than hyperresponsiveness. In addition, no significant difference was observed in the in vitro responsiveness to histamine of lung parenchymal strips from animals having received PAF or saline-BSA.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of fresh muscle injury]

A prospective double-blind randomized study comparing the results of a protein-free-haemodialisate (Actovegin) with placebo was performed in 103 patients. There has been 68 patients in the haemodialysate group. In acute muscle injuries we find a dent in the muscle and a loss of function. There has been three injections in the injured muscle every three to four days. The follow up examination occurred at least three months after the beginning of the study. Full sports activity was reached in the haemodialysate group after 5.5 weeks, in the non-haemodialysate group after 8.3 weeks. There has been a significant difference in the time of rehabilitation between the shank and the thigh muscles. The results show a high statistic significance.

Effects on rats of subacute intoxication with deltamethrin via an osmotic pump

To explore the possibility of liver enzyme induction by deltamethrin, subacute intoxication was carried out in rats for 28 days, by administration 7.2 mg.Kg-1.day-1 of deltamethrin i.p. delivered by an osmotic pump inserted in the peritoneal cavity. The body weight curve of the treated rats increased slightly but not significantly compared to the controls. No neurotoxic effect was observed. Blood parameters were unchanged, except for eosinophilia and an increase in the plasma Na+ level. Cytochrome P-450, cytochrome b5, NADPH-cytochrome c reductase, esterases and the activities of six mixed function oxidases were assayed. No variation was noted. Ultrastructural study of the liver, more specially in midlobular region, showed that deltamethrin increased the number of mitochondria and altered their shape which became irregular. These findings were consistent with morphometric results. Succinate cytochrome c reductase, citrate synthase and cytochrome c oxidase were essayed, only this last showed a significant enhancement in deltamethrin treated rats.

Congenital ciliary aplasia in two siblings. A primitive disregulation of ciliogenesis?

Congenital ciliary aplasia was demonstrated in two siblings with clinical history of primary ciliary dyskinesia. Ultrastructural histochemistry of successive bronchial biopsies revealed the predominance of immature mucous cells and the total absence of ciliated or preciliated cells in the respiratory epithelium. This original disorder may represent a unique variant of primary ciliary dyskinesia with primitive disregulation of ciliogenesis.

Benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children

The authors review 42 consecutive cases of benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children undergoing surgery in the pediatric service of the Hôpital des Enfants Malades between 1975 and 1987. Epilepsy was the presenting sign in 76% of the children and remained the only clinical sign at diagnosis in 62%. Partial or complex partial seizures were observed in half of the cases, but other seizure types were also frequent. Diagnosis of the tumor as the etiological agent rested upon the results of computerized tomography or magnetic resonance imaging. Postoperative mortality (5%) and morbidity (16%) rates were low. The postoperative intelligence quotient was above 80 in 71% of the patients, and 77% of the children had no major problem in school. Although only two of the 42 patients were given postoperative radiotherapy, there were no recurrences in 82% of the survivors. The actuarial probability of nonrecurrence of the tumor was 95% at 5 years. Three patients with recurrent tumor underwent further surgery and are, at the present time, recurrence-free. The incidence of epilepsy fell from 76% before surgery to 19% after removal of the tumor alone; therefore, intraoperative electrocorticography and resection of the electrically abnormal cortex at the time of the first surgical procedure do not appear necessary. It is possible that tumor removal restores a mechanism that limits the spread of seizures and, thus, the clinical manifestations of epilepsy. Benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children should not be treated with adjuvant radiotherapy, at least initially.

Effect of long-term administration of platelet-activating factor on pulmonary responsiveness and morphology in the guinea pig

To further substantiate the possible role of platelet-activating factor (PAF) in the development of bronchial hyperreactivity, Alzet osmotic minipumps loaded with the autacoid or solvent alone were placed under the back skin of male Hartley guinea pigs and connected to the jugular vein for 15 days. As compared to the animals treated with solvent alone, guinea pigs receiving PAF (20 micrograms/kg/h, 15 days) exhibited a hyperresponsiveness to histamine that was not observed in those simultaneously treated with PAF and the PAF antagonist BN 52021. Lungs from PAF-treated animals were congestive in appearance, bronchi and bronchioli were contracted, Reisseisen muscles were markedly hypertrophied, and a muciparous metaplasia of the endothelium was observed. The number of eosinophils was significantly increased in the parenchyma, as was the number of mast cells in the peribronchial zones in the lungs from guinea pigs chronically treated with PAF. Lungs from control animals did not show morphologic alterations or eosinophil and mast cell infiltration. These data indicate that long-term treatment with PAF induces profound alterations in the respiratory system, resembling those observed in asthmatic patients. This result is in keeping with the possible role of this autacoid in the development of bronchial hyperreactivity.

[Effect of long-term administration of platelet activating factor on pulmonary response and morphology in the guinea pig]

The possible role of PAF in the development of bronchial hyperreactivity was investigated using Alzet osmotic minipumps loaded with PAF or solvent alone and implanted in male Hartley guinea-pigs. Compared to animals treated with solvent alone, those receiving PAF (20 micrograms/kg/h for 15 days) exhibited a hyperreactivity to histamine. The lungs from PAF-treated were congestive in appearance, bronchi and the bronchioli were contracted, Reisseissen muscles were markedly hypertrophied and a muciparous metaplasia of the epithelium was observed. In addition, the number of eosinophils was significantly increased in the parenchyma, as was the number of mast cells in the peribronchial regions. These data indicate that long term-treatment with PAF induces profound alterations in the respiratory system resembling those observed in asthmatic patients. They also strengthen the also strengthen the role of PAF in the development of bronchial hyperreactivity.

Eosinophil recruitment into guinea pig lungs after PAF-acether and allergen administration. Modulation by prostacyclin, platelet depletion, and selective antagonists

Intravenous administration of PAF-acether to the guinea pig induces bronchoconstriction, hypotension, intravascular platelet aggregation, endothelial disruption, and platelet and neutrophil diapedesis. These effects are followed within 1 h by an eosinophilic infiltration into the bronchial walls, which was also noted after the administration of antigen to passively sensitized guinea pigs. Bronchoconstriction and eosinophil infiltration are 2 major features of asthma, and selective bronchial eosinophilia characterizes late asthmatic reactions. We compared the histologic effects of PAF-acether 6 and 24 h after its intravenous injection with those of experimental passive anaphylactic shock, which is used as a model for asthma. Six hours after PAF-acether or antigen (ovalbumin) administration, a marked lung eosinophil infiltration, particularly in the bronchial walls, was noted, together with mucous plugs containing eosinophils in the bronchial lumen. Epithelial desquamation was followed after 24 h by mucous metaplasia of the bronchial epithelium. These effects were not observed when the inactive metabolite lyso-PAF was used. Our results agree fully with the suggestion that the eosinophil mediates the pathophysiology of bronchial asthma and releases materials toxic for the respiratory epithelium. Two PAF-acether antagonists (BN 52021 and WEB 2086) prevented the eosinophil infiltration triggered by PAF-acether and by antigen. When PAF-acether or ovalbumin were injected into guinea pigs after antiplatelet serum or prostacyclin, the eosinophil infiltration was significantly reduced, suggesting that platelets or another adenylate cyclase-sensitive cell are important for the subsequent PAF-acether-induced eosinophil infiltration. Our results support an essential role for PAF-acether in an experimental model of allergic asthma.

Nasal eosinophilia in children: its use in the nasal allergen provocation test

This pediatric cytological and clinical study aimed at assessing the value of nasal eosinophilia during nasal provocation tests for identifying an offending allergen. The population studied comprised 50 children aged from 4 to 18 yr; 39 of these had well-characterized allergic rhinitis, which in 21 cases was combined with asthma, and the remaining 11 had nonatopic chronic rhinitis. Nasal secretions, collected by nose blowing, were stained with May-Grünwald-Giemsa or Wright stain. The percentage of nasal eosinophils was obtained by examining the cells in the whole slides. Counts were carried out on secretions collected before challenge, after insufflation of saline solution (for verification), and 40 min after insufflation into each nostril of an allergen (housedust mite extract). The nasal provocation test was considered positive when insufflation of the allergen increased nasal eosinophilia by more than 10%, provided that the prechallenge proportion of eosinophils was less than 50%. No increase in specific bronchial resistance was noted. These results indicate that nasal provocation tests are safe, even in asthmatic children.

[Experimental and clinical results of ultrasound imaging in sports orthopedic soft tissue diseases]

Ultrasound scanning of the shoulders, knee joints, Achilles' tendon and muscles is presented as a noninvasive technique for the diagnosis of joint and soft tissue disorders. In experimental ultrasound studies on shoulders, knee joints, tendons and muscles of cadavers the diagnostic value of the method is assessed. The experimental observations were compared with clinical results collected in three years from 610 patients. Particularly characteristic findings in sports-induced soft tissue lesions are reviewed as examples.

[Ultrasound diagnosis of soft tissue injuries of the locomotor system]

We report on our first experience with ultrasonography in soft tissue lesions. The normal and pathological anatomy of the shoulder joint, knee joint, achilles tendon and muscle is demonstrated. The technical equipment of real-time sonography is demonstrated.

Interactions between granulocytes and platelets with the guinea-pig lung in passive anaphylactic shock. Correlations with PAF-acether-induced lesion

To compare the bronchopulmonary effects of anaphylactic shock with those of platelet-activating factor (PAF-acether), antigen (ovalbumin) was administered intravenously to passively sensitized guinea-pig. Subsequent lung alterations were assessed histologically. Within 1 min following ovalbumin, bronchial and arterial constrictions were observed, accompanied by platelet thrombi in the pulmonary microcirculation, intravascular leucocyte accumulation with diapedesis, disruption of endothelium and alterations of type II pneumocytes. Free eosinophilic granules were scattered in the bronchial submucosa. One h after the infusion of ovalbumin, platelet aggregates had disappeared, bronchoconstriction was over, and denudation of the bronchial epithelium was observed. These alterations resemble to those induced by intravenous PAF-acether, which led us to compare the effects of inhaled PAF-acether and antigen at bronchoconstrictor concentrations. In both cases, leucocytes were aggregated in the microcirculation within 2 min and persisted 1 h later. Massive infiltration of eosinophils and activation and clumping of alveolar macrophages were also noted. Our findings support the involvement of PAF-acether in acute anaphylaxis in the guinea-pig.

Left ventricular ultrastructure in pulmonary stenosis and in tetralogy of Fallot

Twelve patients underwent haemodynamic studies and myocardial biopsies: 7 with pulmonary stenosis (PS) and 5 with tetralogy of Fallot (TOF). Their ages ranged between 2 and 43 years. Right ventricular pressure was 128 +/- 43 mmHg in PS and 98 +/- 8 mmHg in TOF. Aortic blood oxygen saturation was 97.0% +/- 1.4% in PS, and 88.4% +/- 6.3% in TOF. Left ventricular (LV) weight was normal in TOF while it was increased in PS: 140.7 +/- 74.3 vs 74.0 +/- 8.7 g/m2 (P less than 0.001). Contractility was altered in both PS and TOF: ejection fractions were 56% +/- 7% vs 65% +/- 6% (P less than 0.001). Light microscopy showed abnormal transverse diameter of left ventricular myocytes in both PS and TOF: 18.6 micron +/- 4.0 micron vs 19.4 micron +/- 4.9 micron. The percentage of interstitium was normal: 29.6% +/- 3.9% vs 26.2 +/- 5.1%. Transmission electron microscopic examination revealed hypertrophic changes in all patients and degeneration in 7 of them. Hyperfunctional alterations of the myocytes were characterized by the increased number and reduced size of mitochondria, the enlarged Golgi complex, the increased number of ribosomes, the marked folding and convolutions of the nuclear membrane, the dilatation and tortuosity of T tubules. Myofibrillar lysis was the major degenerative change, which was also observed in the right ventricle (RV) of the same patients. No correlation was observed between these alterations and the patient ages, RV pressures, aortic blood oxygen saturations and ejection fractions. These findings led us to conclude that: (1) suprasystemic pressure overload of the RV induces macroscopic LV hypertrophy; (2) mild and suprasystemic pressure overload of the RV induces hyperfunctional changes in the LV; (3) myocardial degeneration is not related to hypertrophy nor to hypoxia, but is part of a more widespread cardiovascular fetopathy.

Neuropeptide Y normalizes renin secretion in adrenalectomized rats without changing blood pressure

In the periphery, neuropeptide Y is present in plasma, in the adrenal medulla as well as in sympathetic nerve endings and in the juxtaglomerular apparatus. The aim of the present study was to assess the effect of this peptide on renin secretion. Normotensive rats were adrenalectomized or sham-operated and made hypertensive with methylprednisolone acetate (20 mg/kg s.c. once weekly). Deoxycorticosterone pivalate (10 mg/kg s.c. once weekly) was also given to prevent mineralocorticoid deficiency. Two weeks after initial surgery, 12 adrenalectomized and 8 sham-operated conscious rats were infused for 30 min with neuropeptide Y (0.1 micrograms/min) whereas 8 other adrenalectomized and 9 sham-operated conscious rats received under similar conditions the vehicle of neuropeptide Y (10 microliter/min). Neither before nor during the infusions was there a significant difference in blood pressure and heart rate between the 4 groups of animals. Plasma renin activity, measured at the end of the infusion, was 30.5 ng/ml/hr in the adrenalectomized group receiving vehicle and 6.3 ng/ml/hr in that infused with neuropeptide Y (p less than 0.001). This latter value did not differ from that found in sham-operated rats. These results suggest that neuropeptide Y may play an important role in regulating renin secretion.

Association with HeLa cells of Campylobacter jejuni and Campylobacter coli isolated from human feces

We developed a rapid in vitro test for determining the association of Campylobacter jejuni and C. coli with HeLa cells. Association was expressed as a weighted mean of the number of bacteria associated with one cell in an association index (AI). The reproducibility of the AI was checked by repeating the test six times, using four strains chosen at random. Means and standard deviations of the means were 7.3 +/- 1.2, 6.8 +/- 0.9, 1.8 +/- 1.2, and 0.1 +/- 0.2. The experimental conditions for which the results are reliable have been standardized. Among 42 strains from human feces, two groups appeared: for 22 nonassociative strains (52%), AI values ranged from 0.0 to 2.1 (mean +/- SD, 0.5 +/- 0.6); for 20 associative strains (48%), AI values ranged from 3.5 to 8.3 (mean +/- SD, 6.2 +/- 1.4). Of these 42 strains, 17 were clinically documented. Diarrhea occurred more frequently in patients infected with associative strains than in those infected with noninvasive strains (7/7 versus 3/10, P = 0.01). Fever also occurred more frequently in patients infected with associative strains (6/7 versus 2/10, P = 0.03). Transmission electron microscopy and viable counts made after killing of extracellular bacteria by gentamicin support the fact that associated Campylobacter spp. are adherent to the cell membrane and are internalized into cytoplasmic vacuoles. The described test seems to be a convenient and rapid method for estimating the pathogenicity of a given strain.

[Filamentary granules in human bronchi]

Mucous cells of human bronchial glands contain secretory granules with 5,5-7 nm parallel filaments. In contrast with the glycoproteic-rich mucous granules, filamentary granules exhibit weak reactivity with tannic acid, indicative of proteins. Exocytosis or discharge in glandular lumen are sometimes observed. These original granules may probably represent an additional component of fibrillar matrix in mucus.

[Normalization of renin secretion by neuropeptide Y in adrenalectomized rats with glucocorticoid-induced hypertension]

In the periphery, neuropeptide Y is present in the circulation, in the adrenal medulla as well as at the level of nerve endings and of the juxtaglomerular apparatus. The aim of the present study was to assess the effect of this neuropeptide on renin secretion. Normotensive rats were biadrenalectomized or sham-operated and made hypertensive with methylprednisolone acetate (20 mg/kg s.c. once weekly). Deoxycorticosterone pivalate (10 mg/kg s.c. once weekly) was also given to prevent mineralocorticoid deficiency. Two weeks after that initial surgery 12 adrenalectomized rats and 8 sham-operated rats were infused for 30 min with neuropeptide Y (0.1 microgram/min) whereas 8 adrenalectomized rats and 9 sham-operated rats received in similar conditions the vehicle of neuropeptide Y (10 microliters/min). At that time, the rats were conscious and there was no significant difference in blood pressure and heart rate between the 4 groups of rats. At the end of the experiment, adrenalectomized rats exhibited a markedly stimulated renin-angiotensin system. Neuropeptide Y made it possible to normalize plasma renin activity in these rats, thus suggesting that neuropeptide Y plays an important role in regulating renin secretion.