Primate phylogeny: molecular evidence from retroposons

In these postgenomic times where aspects of functional genetics and character evolution form a focal point of human-mouse comparative research, primate phylogenetic research gained a widespread interest in evolutionary biology. Nevertheless, it also remains a controversial subject. Despite the surge in available primate sequences and corresponding phylogenetic interpretations, primate origins as well as several branching events in primate divergence are far from settled. The analysis of SINEs - short interspersed elements - as molecular cladistic markers represents a particularly interesting complement to sequence data. The following summarizes and discusses potential applications of this new approach in molecular phylogeny and outlines main results obtained with SINEs in the context of primate evolutionary research. Another molecular cladistic marker linking the tarsier with the anthropoid primates is also presented. This eliminates any possibility of confounding phylogenetic interpretations through lineage sorting phenomena and makes use of a new point of view in settling the phylogenetic relationships of the primate infraorders.

Induction of T lymphocyte apoptosis by sulphasalazine in patients with Crohn's disease

BACKGROUND

Lamina propria T lymphocytes (LPL) of the intestinal mucosa are chronically activated in Crohn's disease (CD). Defective apoptosis of activated LPL was proposed as a key pathogenic mechanism. In fact, increased expression of antiapoptotic molecules was observed in CD LPL. In the present work, we aimed to analyse the effects and underlying molecular mechanisms of 5-amino salicylic acid (5-ASA) and derivatives on apoptosis of LPL and peripheral blood lymphocytes (PBL) in patients with CD compared with ulcerative colitis (UC) and in non-inflammatory controls.

METHODS

PBL and LPL were isolated by Ficoll-Hypopaque gradient centrifugation and the EGTA-collagenase method, respectively. PBL/LPL were stimulated with FasL, 5-ASA, sulphapyridine, and sulphasalazine for 24/48 hours and apoptosis was quantified by flow cytometry (annexin V- propidium iodide method) and immunofluorescence. The molecular mechanisms of drug induced apoptosis were analysed in wild-type and FADD-/- Jurkat T cells using western blots and caspase assays.

RESULTS

While PBL displayed a normal apoptosis pattern after Fas stimulation in patients with active CD, LPL from inflammatory areas were highly resistant. Comparable resistance to apoptosis was observed in LPL of UC patients. In contrast with 5-ASA, which did not induce apoptosis in lymphocytes, sulphasalazine proved to be a potent proapoptotic agent. Sulphasalazine induced T lymphocyte apoptosis was independent of the Fas pathway but associated with marked downregulation of antiapoptotic bcl-xl and bcl2, activation of the mitochondrial apoptosis signalling pathway, and subsequent activation of caspase-9 and caspase-3.

CONCLUSION

The beneficial effect of sulphasalazine in treating inflammatory bowel disease is at least in part attributable to its proapoptotic effects on LPL which allows potent downregulation of lymphocyte activation.

Adaptive control for insect leg position: controller properties depend on substrate compliance

This paper concentrates on the system that controls the femur-tibia joint in the legs of the stick insect, Carausius morosus. Earlier investigations have shown that this joint is subject to a mixture of proportional and differential control whereby the differential part plays a prominent role. Experiments presented here suggest another interpretation: single legs of a stick insect were systematically perturbed using devices of different compliance and compensatory forces and movements monitored. When the compliance is high (soft spring), forces are generated that return the leg close to its original position. When the compliance is low (stiff spring), larger forces are generated but sustained changes in position occur that are proportional to the force that is applied. Selective ablation of leg sense organs showed that the leg did not maintain its position after elimination of afferents of the femoral chordotonal organ. Ablation of leg campaniform sensilla had no effect. These data support the idea that different control strategies are used, depending upon substrate compliance. In particular, what we and other authors have called a differential controller, is now considered as an integral controller that "intelligently gives up" when the correlation between motor output and movement of the leg is low.

[Plastic bronchitis]

Bronchitis plastica is a rare disorder that can occur at any age. It is characterised by formation of large, branching bronchial casts, which are often expectorated, but may be discovered only by bronchoscopy. In most cases, bronchial casts are secondary to underlying diseases of the lung, heart or lymph vessels. We report a case of plastic bronchitis associated with bilateral chylothorax. Progressive respiratory failure could be controlled by repeated bronchoscopic extraction of casts and inhalation of 20,000 units of heparin twice a day. Inhalation of heparin should be considered, when treatment of the underlying disorders is not successful and the casts consist largely of fibrin. Histological examination of the casts may be useful for therapeutic decisions and can point additionally to an underlying disease.

The role of the inhibitors of interleukin-6 signal transduction SHP2 and SOCS3 for desensitization of interleukin-6 signalling

The immediate early response of cells treated with IL-6 (interleukin-6) is the activation of the signal transducer and activator of transcription (STAT)3. The Src homology domain 2 (SH2)-containing protein tyrosine phosphatase SHP2 and the feedback inhibitor SOCS3 (suppressor of cytokine signalling) are potent inhibitors of IL-6 signal transduction. Impaired function of SOCS3 or SHP2 leads to enhanced and prolonged IL-6 signalling. The inhibitory function of both proteins depends on their recruitment to the tyrosine motif 759 within glycoprotein gp130. In contrast to inactivation, desensitization of signal transduction is regarded as impaired responsiveness due to prestimulation. Usually, after activation the sensing receptor becomes inactivated by modifications such as phosphorylation, internalization or degradation. We designed an experimental approach which allows discrimination between desensitization and inactivation of IL-6 signal transduction. We observed that pre-stimulation with IL-6 renders cells less sensitive to further stimulation with IL-6. After several hours, the cells become sensitive again. We show that not only signal transduction through previously activated receptors is affected by desensitization but signalling through receptors which were not targeted by the first stimulation was also attenuated ( trans -desensitization). Interestingly, in contrast to inhibition, desensitization does not depend on the presence of functional SHP2. Furthermore, cells lacking SOCS3 show constitutive STAT3 activation which is not affected by pre-stimulation with IL-6. All these observations suggest that desensitization and inhibition of signalling are mechanistically distinct.

[Implementation of paragraph 11b of the German Animal Welfare Act on the basis of the so-called "Quality Breeding" Report]

Enforcement of paragraph 11b of the German Animal Welfare Act is a responsibility of breeders and their organisations as well as executive local authorities. The Report on Defective Breeds of the Federal Ministry of Agriculture describes numerous breeding traits which are in conflict with animal welfare and gives valuable information for fancy or pet breeding. Yet a selection has to be made for taking legal actions, following specific criteria. With four examples different cases are presented, each requiring a different approach by the veterinarian authorities. Court decisions in Hessen concerning bans on breeding white cats and crested ducks show that the paragraph 11b is executable.

[Topical methylprednisolone vs lidocaïne for the prevention of postoperative sore throat]

OBJECTIVE

We assessed the efficacy of topical methylprednisolone or lidocaine for prevention of postoperative sore throat.

STUDY DESIGN

Randomised, prospective in single blind study.

PATIENTS AND METHODS

Sixty patients ASA 1 or 2 undergoing tracheal intubation for dental surgery received before intubation either topical lidocaine 5% (15 puffs) or aerosolized methylprednisolone (80 mg). Postoperative pain was assessed by the patients using a VAS and a specific scoring system for sore throat, cough and hoarseness. Evaluations were performed immediately after emergence from anaesthesia, 1 h later, at time of the first postoperative drink, at time of the first postoperative meal and 24 h after surgery.

RESULTS

Patients receiving methylprednisolone showed slightly better scores for sore throat and cough 1 h after surgery.

CONCLUSION

Topical methylprednisolone may therefore be a useful adjuvant in the prevention of sore throat after intubation.

[Placement of wild animals in sanctuaries]

In Germany and other european countries some sanctuaries for wild animals in hardship exist. For some species however the lack of available places is striking. As a consequence, not only is it impossible to help the animals, but also legislative rules are not enforceable in these cases. This situation can be remedied by a) increasing the number of places, which would require governmental measures as well as the engagement of zoological gardens, b) decreasing the necessity for the use of sanctuaries by measures, which prevent wild animals from falling into unsuitable conditions, and c) improving the availability of information about placement possibilities. If a place is found numerous points must be settled previous to the actual transfer, especially concerning the suitability of the facility and the conditions for the placement.

[Can costs be lowered by post-hospital patient management with telecare]

The idea of Televisite is to equip the patients with a camera and a communication panel at the time of their discharge from the hospital. In that way patients and physicians are able to continue the treatment and the rehabilitation program. An easy to handle interface helps the patient to answer simple questions or to send voice recordings, pictures or videos via a service centre to the doctor in attendance. This concept has the great advantage that the patients has to visit the physician in the office or in the hospital only when absolute required. Routine checks can be done by telecommunication. Thus the efficiency of the system may significantly contribute to lower costs in the health care system.

SHP2 and SOCS3 contribute to Tyr-759-dependent attenuation of interleukin-6 signaling through gp130

Interleukin-6 (IL-6) activates the Jak/STAT pathway as well as the mitogen-activated protein kinase cascade. Tyrosine 759 of the IL-6 signal-transducing receptor subunit gp130 has been identified as being involved in negative regulation of IL-6-induced gene induction and activation of the Jak/STAT pathway. Because this site is known to be a recruitment motif for the protein-tyrosine phosphatase SHP2, it has been suggested that SHP2 is the mediator of tyrosine 759-dependent signal attenuation. We recently observed that the suppressor of cytokine-signaling SOCS3 also acts through the tyrosine motif 759 of gp130. However, the relative contributions of SHP2 and SOCS3 to the repression of IL-6 signaling are not understood. Therefore, we designed experiments allowing the independent recruitment of each of these proteins to the IL-6-receptor complex. We show that receptor- and membrane-targeted SHP2 counteracts IL-6 signaling independent of SOCS3 binding to gp130. On the other hand, SOCS3 inhibits signaling in cells expressing a truncated SHP2 protein, which is not recruited to gp130. These data suggest, that there are two, largely distinct modes of negative regulation of gp130 activity, despite the fact that both SOCS3 and SHP2 are recruited to the same site within gp130.

Detection and characterization of plasma cells in peripheral blood: correlation of IgE+ plasma cell frequency with IgE serum titre

In atopic patients and patients with hyper-IgE syndrome (HIE) highly elevated IgE serum levels can be detected. Due to their very low frequency little is known about IgE-producing plasma cells (PC) in peripheral blood. We used CD138 MACS microbeads to enrich plasma cells from peripheral blood of normal donors, atopic patients and one HIE patient. CD138+ cells were mainly CD45+, CD44++, CD19dim, CD38++, CD27++, CD86+, HLA-DR+/++, CD71dim, VLA-4+, VLA-5-, CD28-, CD25-, CD69-, CLA-, CD20-, CD21- and CD22-. They show weak expression of surface Ig but high levels of intracellular Ig and they secrete Ig in culture. Thus CD138+ cells from peripheral blood show characteristics of early plasma cells. IgE+ CD138+ plasma cells could be detected in 19 of 24 normal donors with an average frequency of 0.06% IgE+ cells among CD138+ cells. Higher frequencies were detected in atopic patients, atopic patients with markedly elevated serum IgE levels and the hyper-IgE patient with an average of 0.32%, 7.21% and 6.54%, respectively. Additionally, using the recently developed cellular affinity matrix technology, we were able to detect IgE secreting plasma cells and thereby could demonstrate that most of the IgE secreting cells express CD138. The frequency of IgE+ CD138+ cells among PBMC correlated highly significantly with serum IgE titres (r = 0.8532***), indicating that IgE secreting CD138+ cells in peripheral blood are directly related to the plasma cell pool contributing to the IgE titre.

1.9- m and 2.0- m laser diode pumping of Cr(2+) :ZnSe and Cr(2+) :CdMnTe

Efficient diode pumping at wavelengths of 1.9 and 2.0microm of a Cr(2+): ZnSe laser with an output power of 105 mW and a slope efficiency of 35% with respect to the absorbed pump power is presented. In addition, Cr(2+): CdMnTe has been laser diode pumped as well as operated in the continuous-wave regime, to the best of our knowledge for the first time.

[Study of psychological repercussions of 2 modes of treatment of adolescents with Crohn's disease]

No study has yet compared the respective psychological impact of corticotherapy and enteral nutrition in the treatment of Crohn's disease, and especially, the psychological problems linked to the wearing of a nasogastric tube 24 hours a day. The goal of this study was to collect comparative information regarding the real-life experience and the feeling of these two treatments.

PATIENTS AND METHODS

From September 1997 to February 1998 at the clinic of inflammatory bowel diseases of the hospital Necker-Enfants malades, 51 patients aged 12 to 18 (average 15) participated in this study. Thirty [15 on corticotherapy (CT); 15 on enteral nutrition (EN)] answered a questionnaire inspired by a similar Canadian questionnaire (Inflammatory Bowel Disease Questionnaire), and 21 passed Spielberger's anxiety tests, Beck's depression tests and a psychological interview.

RESULTS

TREATMENT

According to the 30 questionnaires the appreciation of the therapeutic results was similar in the two treatments, the majority of patients respected their treatment (only one patient on EN ate secretly and two on CT stopped their corticotherapy). Of the 15 EN questionnaires: nine out of 15 patients responded well to the suspension of oral feeding, two were hungry, nine experienced cravings and ten avoided meals during their treatment. From a cosmetic point of view, six/14 (43%) found it difficult putting up with the nasogastric tube 24 hours a day, and eight/15 (53%) on CT found the facial swelling difficult to bear. According to the 21 psychological interviews, eight patients deemed EN efficient, while only four felt the same about CT. Of the 11 EN psychological interview, no adolescent patients were hungry, eight had cravings and nine avoided meals during their treatment, seven mentioned they felt different and seven described how EN had upset the family's routine. Nine (82%) talked about how difficult it was to put up with the nasogastric tube 24 hours a day from a cosmetic standpoint while eight/ten (80%) on CT found the facial swelling difficult to live with. Seven complained that they had been the victims of verbal abuse. Quality of life: According to the 30 questionnaires, eight/15 patients on EN missed an average of 15 days of school against five/15 patients on CT, ten patients judged that EN restricted their daily lives and nine mentioned the daily difficulties to wear a tube 24 hours a day.

TESTS

Spielberger's test of anxiety revealed that on average, the 11 patients on EN who were interviewed suffered the first level of anxiety, while the ten patients on CT felt the second level. As for the Beck's depression test, the 11 patients on NE suffered the first level of depression on average, while those on CT were subject to the second level.

CONCLUSION

This study demonstrated that EN was perceived as being more disruptive to patients daily lives than CT and defines the difficulties linked to the suspension of oral feeding and the wearing of a naso-gastric tube. The study also describes the difficulties involved in coping with the side effects of CT, one example being facial swelling which can be as unpleasant from a cosmetic point of view as wearing of a naso-gastric tube.

BDCA-2, a novel plasmacytoid dendritic cell-specific type II C-type lectin, mediates antigen capture and is a potent inhibitor of interferon alpha/beta induction

Plasmacytoid dendritic cells are present in lymphoid and nonlymphoid tissue and contribute substantially to both innate and adaptive immunity. Recently, we have described several monoclonal antibodies that recognize a plasmacytoid dendritic cell-specific antigen, which we have termed BDCA-2. Molecular cloning of BDCA-2 revealed that BDCA-2 is a novel type II C-type lectin, which shows 50.7% sequence identity at the amino acid level to its putative murine ortholog, the murine dendritic cell-associated C-type lectin 2. Anti-BDCA-2 monoclonal antibodies are rapidly internalized and efficiently presented to T cells, indicating that BDCA-2 could play a role in ligand internalization and presentation. Furthermore, ligation of BDCA-2 potently suppresses induction of interferon alpha/beta production in plasmacytoid dendritic cells, presumably by a mechanism dependent on calcium mobilization and protein-tyrosine phosphorylation by src-family protein-tyrosine kinases. Inasmuch as production of interferon alpha/beta by plasmacytoid dendritic cells is considered to be a major pathophysiological factor in systemic lupus erythematosus, triggering of BDCA-2 should be evaluated as therapeutic strategy for blocking production of interferon alpha/beta in systemic lupus erythematosus patients.

Interleukin-6-induced proliferation of pre-B cells mediated by receptor complexes lacking the SHP2/SOCS3 recruitment sites revisited

Interleukin-6 (IL-6) induces B-cell proliferation by binding to receptor complexes composed of a specific alpha-receptor (gp80; CD126) and the signal transducing receptor subunit gp130 (CD130). Immediately after receptor complex activation, signal transducers and activators of transcription (STATs) 1 and 3 and the Src-homology domain-containing protein tyrosine phosphatase 2 (SHP2) are recruited to gp130 and subsequently tyrosine phosphorylated. The activated dimerized STATs translocate to the nucleus and bind to enhancer elements of IL-6-inducible genes. SHP2 acts as an adapter and links the Jak/STAT pathway to the Ras/Raf/MAPK cascade but it is also involved in signal attenuation. Whereas STAT3 activation appears to be crucial for all biological activities of IL-6, the requirement of SHP2-activation depends on the individual biological response analyzed. The requirement of SHP2 activation for the pre-B cell (Ba/F3) proliferation has been reported previously [Fukada, T., Hibi, M., Yamanaka, Y., Takahashi-Tezuka, M., Fujitani, Y., Yamaguchi, T., Nakajima, K. & Hirano, T. (1996) Immunity 5, 449-460]. In contrast, we have recently demonstrated that the presence of a single STAT-recruitment site within gp130 is sufficient for IL-6- induced proliferation of Ba/F3 cells [Schmitz, J., Dahmen, H., Grimm, C., Gendo, C., Müller-Newen, G., Heinrich, P.C. & Schaper, F. (2000) J. Immunol. 164, 848-854]. To unravel this discrepancy we analyzed the IL-6-induced dose-dependent proliferation of Ba/F3 cells mediated by receptor complexes lacking SHP2/SOCS3 recruitment sites. Surprisingly, pre-B cells, after stimulation with low amounts of IL-6, proliferate much more efficiently in the absence of the activated SHP2 than in the presence of the tyrosine phosphatase. Therefore, SHP2 activation appears to be relevant for IL-6-induced proliferation only after stimulation with very large amounts of IL-6.

Apolipoprotein B48 glycosylation in abetalipoproteinemia and Anderson's disease

BACKGROUND & AIMS

Abetalipoproteinemia and Anderson's disease are hereditary lipid malabsorption syndromes. In abetalipoproteinemia, lipoprotein assembly is defective because of mutations in the microsomal triglyceride transfer protein. Here, we evaluated the intracellular transport of apolipoprotein B48 to localize the defect in Anderson's disease.

METHODS

Asparagine-linked oligosaccharide processing of apolipoprotein B48 in normal and affected individuals was determined by the endoglycosidase H and F sensitivities of the protein after metabolic labeling of intestinal explants in organ culture. Cell ultrastructure was evaluated with electron microscopy.

RESULTS

In Anderson's disease as in normal individuals, there was a time-dependent transformation of high mannose endoglycosidase H-sensitive oligosaccharides, of endoplasmic reticulum origin, to complex endoglycosidase H-resistant oligosaccharides, added in the Golgi network. In contrast, despite the translocation of apolipoprotein B48 into the endoplasmic reticulum in patients with abetalipoproteinemia and in biopsies treated with Brefeldin A, which blocks anterograde transport between the endoplasmic reticulum and the Golgi network, there was no transformation of endoglycosidase H-sensitive oligosaccharides.

CONCLUSIONS

In abetalipoproteinemia and Anderson's disease, apolipoprotein B48 is completely translocated into the endoplasmic reticulum, but only in Anderson's disease is the protein transported to the Golgi apparatus. This suggests that Anderson's disease is caused by a post-Golgi cargo-specific secretion defect.

Dextroamphetamine for cocaine-dependence treatment: a double-blind randomized clinical trial

A properly implemented agonist treatment regimen should improve retention and reduce illicit drug use. Cocaine-dependent subjects (N = 128) were enrolled in a 12-week randomized, double-blind, placebo-controlled trial. In the multistage dosing design, subjects initially received placebo (PBO) or 15 to 30 mg of dextroamphetamine sulfate, sustained-release capsules. At week 5, the dose doubled to 30 mg or 60 mg for active groups. Subjects attended the clinic twice a week, provided urine samples, obtained medication, and had one behavioral therapy session a week. Retention was best for the 15- to 30-mg group, whereas the proportion of benzoylecgonine-positive urine screens was, from lowest to highest, 30 to 60 mg, 15 to 30 mg, and PBO at study end. Dosing must be refined. The results provide support for additional examination of the agonist model in psychostimulant-dependence treatment.

[Etiological diagnosis of villous atrophy]

Villous atrophy may have various etiologies. The diagnosis of villous atrophy relies on an intestinal biopsy which necessitates a perfect histological technique to assert the villous atrophy and its degree. The most frequent etiology is coeliac disease. Villous atrophy regresses with gluten free diet. The failure of a strict gluten free diet implies to exclude a refractory sprue thought to be the earliest form of enteropathy associated T cell lymphoma. The other etiologies of villous atrophy are unusual and could be observed in alpha chain disease, inflammatory and infectious diseases, immune disorders, and primitive ileal villous atrophy. Other etiologies characterize villous atrophy in children as cow milk allergy and epithelial abnormalities.

Early feeding resistance: a possible consequence of neonatal oro-oesophageal dyskinesia

Paediatricians frequently find early feeding disorders in neonates and infants that result in poor weight gain and which sometimes have no clear organic basis. For many years, we have observed infants with unexplained poor feeding skills and excessive regurgitation, and since 1992 we have prospectively performed oesophageal manometry in infants hospitalized for retarded growth and "unexplained" feeding disorders. From the group of infants hospitalized for growth failure in the General Paediatric Unit of Necker-Enfants Malades Hospital from 1992 to 1997, we identified 16 children (3%) with abnormal feeding behaviour who had an abnormal oesophageal manometry. The manometric data of these children were compared with those of a group of 16 age-matched children who underwent oesophageal manometry for other reasons, and served as controls. The affected children had precocious feeding skills disorders: prolonged bottle-feeding (75%), bottle refusal (75%), unexplained crying (63%) and excessive regurgitation (94%). Half of them had mild anatomical facial consequences of their poor foetal sucking, and mild pharyngolaryngeal hypotonia, which could not be considered as malformations. Apart from these disorders, their clinical status was normal. At inclusion, their oesophageal manometry was abnormal, showing in 70% of cases specific anomalies: lower oesophageal sphincter hypertonia and/or partial failure to relax, and giant waves of oesophagus body. Their course was good and their feeding difficulties decreased around the end of the first year, with the acquisition of normal voluntary mastication.

CONCLUSION

We suggest that the early feeding resistance of this group of children could be related to an organic and transient neonatal oro-oesophageal dyskinesia.

[Intestinal malabsorption in the child]

Intestinal malabsorption in the child usually manifests by chronic diarrhoea and (or) deficiency of growth and weight gain. Given the wide diversity of causes, diagnosis is primarily based on history-taking and clinical examination, which subsequently directs investigations. Stool examination was long the reference to confirm malabsorption and to determine its mechanisms: impaired digestion (external pancreatic insufficiency), malabsorption (intolerance to cow's milk proteins or to gluten), fermentation (intolerance to primary or secondary sugars). Presently, however, the diagnosis is usually made on the basis of several simple examinations.

Expression of suppressors of cytokine signaling during liver regeneration

The cytokines TNF and IL-6 play a critical role early in liver regeneration following partial hepatectomy (PH). Since IL-6 activates signal transducers and activators of transcription (STATs), we examined whether the suppressors of cytokine signaling (SOCS) may be involved in terminating IL-6 signaling. We show here that SOCS-3 mRNA is induced 40-fold 2 hours after surgery. SOCS-2 and CIS mRNA are only weakly induced, and SOCS-1 is not detectable. SOCS-3 induction after PH is transient and correlates with a decrease in STAT-3 DNA binding and a loss of tyrosine 705 phosphorylation. This response is markedly reduced in IL-6 knockout (KO) mice. TNF injection induces SOCS-3 mRNA in wild-type mice (albeit weakly compared with the increase observed after PH) but not in TNF receptor 1 or IL-6 KO mice. In contrast, IL-6 injection induces SOCS-3 in these animals, demonstrating a requirement for IL-6 in SOCS-3 induction. IL-6 injection into wild-type mice also induces SOCS-1, -2, and CIS mRNA, in addition to SOCS-3. Together, these results suggest that SOCS-3 may be a key component in downregulating STAT-3 signaling after PH and that SOCS-3 mRNA levels in the regenerating liver are regulated by IL-6.

A biologically inspired controller for hexapod walking: simple solutions by exploiting physical properties

The locomotor system of slowly walking insects is well suited for coping with highly irregular terrain and therefore might represent a paragon for an artificial six-legged walking machine. Our investigations of the stick insect Carausius morosus indicate that these animals gain their adaptivity and flexibility mainly from the extremely decentralized organization of the control system that generates the leg movements. Neither the movement of a single leg nor the coordination of all six legs (i.e., the gait) appears to be centrally pre-programmed. Thus, instead of using a single, central controller with global knowledge, each leg appears to possess its own controller with only procedural knowledge for the generation of the leg's movement. This is possible because exploiting the physical properties avoids the need for complete information on the geometry of the system that would be a prerequisite for explicitly solving the problems. Hence, production of the gait is an emergent property of the whole system, in which each of the six single-leg controllers obeys a few simple and local rules in processing state-dependent information about its neighbors.

Rapid enrichment and detection of melanoma cells from peripheral blood mononuclear cells by a new assay combining immunomagnetic cell sorting and immunocytochemical staining

Commonly used methods for detection of melanoma cells in blood, including RT-PCR and immunocytochemistry, display only a limited sensitivity and specificity. Reliable detection of less than one melanoma cell per ml of blood is hardly possible using these methods. To obtain greater sensitivity so that a single melanoma cell in up to 25 ml of blood can be detected (5 x 10(7) peripheral blood mononuclear cells, or PBMC), we developed a new assay for combined enrichment and immunocytochemical detection of disseminated melanoma cells from PBMC of patients with malignant melanomas. Melanoma cells are directly magnetically labeled using colloidal superparamagnetic microparticles approximately 60 nm in diameter conjugated to the anti-melanoma monoclonal antibody 9.2.27, with no reactivity to normal cells in blood. Magnetically labeled melanoma cells are enriched from PBMC by magnetic cell separation and detected by a new approach for immunocytochemical staining with monoclonal mouse anti-melanoma antibodies (anti-MelanA and HMB-45). The efficiency of this assay was demonstrated in a model system in which 5-500 tumor cells from the melanoma cell line SK-MEL-28 were seeded into PBMC samples from healthy donors containing 5 x 10(7) leukocytes. Mean recovery of the seeded tumor cells was 47.4 +/- 13.99% (n = 15). Applying the assay to 20-50 ml blood samples of patients with stage III-IV malignant melanomas, we were able to detect melanoma cells in two of eight patients (25%).

SINE insertions in cladistic analyses and the phylogenetic affiliations of Tarsius bancanus to other primates

Transpositions of Alu sequences, representing the most abundant primate short interspersed elements (SINE), were evaluated as molecular cladistic markers to analyze the phylogenetic affiliations among the primate infraorders. Altogether 118 human loci, containing intronic Alu elements, were PCR analyzed for the presence of Alu sequences at orthologous sites in each of two strepsirhine, New World and Old World monkey species, Tarsius bancanus, and a nonprimate outgroup. Fourteen size-polymorphic amplification patterns exhibited longer fragments for the anthropoids (New World and Old World monkeys) and T. bancanus whereas shorter fragments were detected for the strepsirhines and the outgroup. From these, subsequent sequence analyses revealed three Alu transpositions, which can be regarded as shared derived molecular characters linking tarsiers and anthropoid primates. Concerning the other loci, scenarios are represented in which different SINE transpositions occurred independently in the same intron on the lineages leading both to the common ancestor of anthropoids and to T. bancanus, albeit at different nucleotide positions. Our results demonstrate the efficiency and possible pitfalls of SINE transpositions used as molecular cladistic markers in tracing back a divergence point in primate evolution over 40 million years old. The three Alu insertions characterized underpin the monophyly of haplorhine primates (Anthropoidea and Tarsioidea) from a novel perspective.

[Incidence of symptomatic celiac disease in French children]

OBJECTIVE

The study was carried out by the GFHGNP to determine the annual incidence of symptomatic celiac disease in children.

PATIENTS AND METHODS

The diagnostic criteria were: symptomatic patients diagnosed under 15 years of age during 1996, villous atrophy and positivity of antigliadin and/or other antibodies. Cases were collected from referral centers, general hospital pediatric departments and private pediatricians with endoscopic practice.

RESULTS

The study involved roughly half of the French pediatric population in 41 out of the 95 French districts. In all, 124 patients were collected: 76 girls and 48 boys. By geographical areas, in 30 districts where collection of data was complete which counted 186,285 births, the yearly incidence varied from 1/1731 births to 1/3110. (0.57@1000 to 0.32@1000). On the whole there were 77 cases i.e. an annual incidence of 1/2419 or 0.41@1000 (confidence interval 95%: 0.32 to 0.50@1000). Lower incidences were observed in the district of Paris: 1/4865 (0.21@1000) and Lyon: 1/3310 (0.27@1000). Those lower incidences could be explained by the difficulties of collecting the data in the biggest urban areas. The first signs occurred before one year of age in 73% of the cases, during the second year of life in 20.5% and after 3 in only 6.5%. The diagnosis was made before 2 years of age in 77% of the cases and after 3 in only 13%. In order of frequency symptoms were: failure to thrive (80%), diarrhea (59%), anorexia (59%), abdominal distension (57%), weight under 2 standard deviations (43%), short stature (43%).

CONCLUSION

Compared with previous studies in two French districts between 1975 and 1990, the annual incidence of symptomatic celiac disease in children appears to be on the rise. The usual clinical signs continue to be observed.

A broad spectrum of clinical presentations in congenital disorders of glycosylation I: a series of 26 cases

INTRODUCTION

Congenital disorders of glycosylation (CDG), or carbohydrate deficient glycoprotein syndromes, form a new group of multisystem disorders characterised by defective glycoprotein biosynthesis, ascribed to various biochemical mechanisms.

METHODS

We report the clinical, biological, and molecular analysis of 26 CDG I patients, including 20 CDG Ia, two CDG Ib, one CDG Ic, and three CDG Ix, detected by western blotting and isoelectric focusing of serum transferrin.

RESULTS

Based on the clinical features, CDG Ia could be split into two subtypes: a neurological form with psychomotor retardation, strabismus, cerebellar hypoplasia, and retinitis pigmentosa (n=11), and a multivisceral form with neurological and extraneurological manifestations including liver, cardiac, renal, or gastrointestinal involvement (n=9). Interestingly, dysmorphic features, inverted nipples, cerebellar hypoplasia, and abnormal subcutaneous fat distribution were not consistently observed in CDG Ia. By contrast, the two CDG Ib patients had severe liver disease, enteropathy, and hyperinsulinaemic hypoglycaemia but no neurological involvement. Finally, the CDG Ic patient and one of the CDG Ix patients had psychomotor retardation and seizures. The other CDG Ix patients had severe proximal tubulopathy, bilateral cataract, and white matter abnormalities (one patient), or multiorgan failure and multiple birth defects (one patient).

CONCLUSIONS

Owing to the remarkable clinical variability of CDG, this novel disease probably remains largely underdiagnosed. The successful treatment of CDG Ib patients with oral mannose emphasises the paramount importance of early diagnosis of PMI deficiency.

BDCA-2, BDCA-3, and BDCA-4: three markers for distinct subsets of dendritic cells in human peripheral blood

We have generated a panel of mAbs that identify three presumably novel human dendritic cell Ags: BDCA-2, BDCA-3, and BDCA-4. In blood, BDCA-2 and BDCA-4 are expressed on CD11c(-) CD123(bright) plasmacytoid dendritic cells, whereas BDCA-3 is expressed on small population of CD11c(+) CD123(-) dendritic cells. All three Ags are not detectable on a third blood dendritic cell population, which is CD1c(+) CD11c(bright) CD123(dim), or on any other cells in blood. BDCA-4 is also expressed on monocyte-derived and CD34(+) cell-derived dendritic cells. Expression of all three Ags dramatically changes once blood dendritic cells undergo in vitro maturation. BDCA-2 is completely down-regulated on plasmacytoid CD11c(-) CD123(bright) dendritic cells, expression of BDCA-3 is up-regulated on both plasmacytoid CD11c(-) CD123(bright) dendritic cells and CD1c(+) CD11c(bright) CD123(dim) dendritic cells, and expression of BDCA-4 is up-regulated on CD1c(+) CD11c(bright) CD123(dim) dendritic cells. BDCA-2 is rapidly internalized at 37 degrees C after mAb labeling. The three presumably novel Ags serve as specific markers for the respective subpopulations of blood dendritic cells in fresh blood and will be of great value for their further analysis and to evaluate their therapeutic potential.

The complete mitochondrial genome of Tupaia belangeri and the phylogenetic affiliation of scandentia to other eutherian orders

The complete mitochondrial genome of Tupaia belangeri, a representative of the eutherian order Scandentia, was determined and compared with full-length mitochondrial sequences of other eutherian orders described to date. The complete mitochondrial genome is 16, 754 nt in length, with no obvious deviation from the general organization of the mammalian mitochondrial genome. Thus, features such as start codon usage, incomplete stop codons, and overlapping coding regions, as well as the presence of tandem repeats in the control region, are within the range of mammalian mitochondrial (mt) DNA variation. To address the question of a possible close phylogenetic relationship between primates and Tupaia, the evolutionary affinities among primates, Tupaia and bats as representatives of the Archonta superorder, ferungulates, guinea pigs, armadillos, rats, mice, and hedgehogs were examined on the basis of the complete mitochondrial DNA sequences. The opossum sequence was used as an outgroup. The trees, estimated from 12 concatenated genes encoded on the mitochondrial H-strand, add further molecular evidence against an Archonta monophyly. With the new data described in this paper, most of both the mitochondrial and the nuclear data point away from Scandentia as the closest extant relatives to primates. Instead, the complete mitochondrial data support a clustering of Scandentia with Lagomorpha connecting to the branch leading to ferungulates. This closer phylogenetic relationship of Tupaia to rabbits than to primates first received support from several analyses of nuclear and partial mitochondrial DNA data sets. Given that short sequences are of limited use in determining deep mammalian relationships, the partial mitochondrial data available to date support this hypothesis only tentatively. Our complete mitochondrial genome data therefore add considerably more evidence in support of this hypothesis.

Signal transduction of IL-6, leukemia-inhibitory factor, and oncostatin M: structural receptor requirements for signal attenuation

Stimulation of the IL-6R complex leads to Src homology domain containing tyrosine phosphatase 2 (SHP2) recruitment to the receptor subunit gp130 and its subsequent tyrosine phosphorylation. SHP2 is a two-SH2 domain-containing protein tyrosine phosphatase that is activated by many cytokines and growth factors. SHP2 counteracts the activation of transcription factors of the STAT family and the induction of IL-6-responsive genes. Tyrosine 759 of gp130, the signal transducing subunit of the IL-6R complex, is essential for the phosphorylation of SHP2. Mutation of tyrosine 759 to phenylalanine leads to an enhanced inducibility of IL-6-dependent genes. Here we demonstrate that no further tyrosines in the cytoplasmic part of gp130 are required for the phosphorylation of SHP2. We also tested whether the tyrosine 759 motifs in both subunits of the gp130 dimer are required for SHP2 association and tyrosine phosphorylation. Interestingly, one SHP2-recruiting phosphotyrosine motif in a single chain of the gp130 dimer is sufficient to mediate SHP2 association to the gp130 receptor subunit and its tyrosine phosphorylation as well as to attenuate IL-6-dependent gene induction. Furthermore, we show that repression of gene induction via Y759 does not require the presence of the SHP2 and STAT recruitment sites within the same receptor subunit, but within the same receptor complex. The Y759 motif in gp130 also attenuates gene induction mediated by the oncostatin M and leukemia inhibitory factor receptor complexes, which both contain gp130 as the shared subunit.

Congenital sucrase-isomaltase deficiency arising from cleavage and secretion of a mutant form of the enzyme

Congenital sucrase-isomaltase deficiency (CSID) is an autosomal recessive human intestinal disorder that is clinically characterized by fermentative diarrhea, abdominal pain, and cramps upon ingestion of sugar. The symptoms are the consequence of absent or drastically reduced enzymatic activities of sucrase and isomaltase, the components of the intestinal integral membrane glycoprotein sucrase-isomaltase (SI). Several known phenotypes of CSID result from an altered posttranslational processing of SI. We describe here a novel CSID phenotype, in which pro-SI undergoes an unusual intracellular cleavage that eliminates its transmembrane domain. Biosynthesis of pro-SI in intestinal explants and in cells transfected with the SI cDNA of this phenotype demonstrated a cleavage occurring within the endoplasmic reticulum due to a point mutation that converts a leucine to proline at residue 340 of isomaltase. Cleaved pro-SI is transported to and processed in the Golgi apparatus and is ultimately secreted into the exterior milieu as an active enzyme. To our knowledge this is the first report of a disorder whose pathogenesis results not from protein malfolding or mistargeting, but from the conversion of an integral membrane glycoprotein into a secreted species that is lost from the cell surface.

[Maintenance of African ostriches (Struthio carnelus) under Hessian climatic conditions--analysis of metereological data for the application of BML's expert recommendations of 1996]

A report is given on an analysis of meteorological data on five locations in the region of Hessia in order to apply the BML's expert recommendation concerning ostrich farming. According to this recommendation black ice, very strong frost and continuous rain should not make it necessary to keep the animals in pens longer than 3 days or more often than 10 days per month. Otherwise a dry paddock must be provided. It was investigated whether and how often the above mentioned weather conditions exceeded the critical duration or frequency in the last decades at the different locations. Previously the weather related terms which were used in the BML-recommendation were defined more precisely in order to provide an objective basis for the analysis. Frequent periods of frost lasting longer than 3 days with temperatures below -5 degrees C were found to be a critical factor. They occurred in 79 to 90% of the winter seasons under investigation, although the climate was thought to be rather mild in comparison to other regions. Frost can not be remedied by a dry paddock. Therefore the locations in question are not suitable for ostrich farming. The same conclusion holds at least for all locations with a colder climate. Black ice occurred only scarcely. At none of the investigated locations periods of continuous rain were longer than 3 days or occurred more often than 10 days per month. This result might not only be due to the given climatic conditions but also due to methodological reasons. It seems that the meteorological definition of continuous rain is too restricted to take the relevant precipitation for ostriches into account. It is suggested to find a new definition and consider factors like humidity and wind speed as well.

Hepatocellular carcinoma and focal hepatic glycogenosis after prolonged azathioprine therapy

A 22-year-old woman without predisposing liver disease developed focal hepatic glycogenosis and hepatocellular carcinoma after 6 years of azathioprine therapy for Crohn's disease. Hepatocellular carcinoma without cirrhosis has previously been described during immunosuppression, but this is the first report of disseminated focal hepatic glycogenosis after long-term azathioprine therapy.

Selective expansion of intraepithelial lymphocytes expressing the HLA-E-specific natural killer receptor CD94 in celiac disease

BACKGROUND & AIMS

Celiac disease is a gluten-induced enteropathy characterized by the presence of gliadin-specific CD4(+) T cells in the lamina propria and by a prominent intraepithelial T-cell infiltration of unknown mechanism. The aim of this study was to characterize the subset(s) of intraepithelial lymphocytes (IELs) expanding during active celiac disease to provide insights into the mechanisms involved in their expansion.

METHODS

Flow-cytometric analysis of isolated IELs and/or immunohistochemical staining of frozen sections were performed in 51 celiac patients and 50 controls with a panel of monoclonal antibodies against T-cell and natural killer (NK) receptors. In addition, in vitro studies were performed to identify candidate stimuli for NK receptor expression.

RESULTS

In normal intestine, different proportions of IELs, which were mainly T cells, expressed the NK receptors CD94/NKG2, NKR-P1A, KIR2D/3D, NKp46, Pen5, or CD56. During the active phase of celiac disease, the frequency of CD94(+) IELs, which were mostly alphabeta T cells, was conspicuously increased over controls. In contrast, the expression of other NK markers was not modified. Furthermore, expression of CD94 could be selectively induced in vitro by T-cell receptor activation and/or interleukin 15, a cytokine produced by intestinal epithelial cells.

CONCLUSIONS

The gut epithelium favors the development of T cells that express NK receptors. In active celiac disease, there is a specific and selective increase of IELs expressing CD94, the HLA-E-specific NK receptor that may be related to T-cell receptor activation and/or interleukin 15 secretion.

SOCS3 exerts its inhibitory function on interleukin-6 signal transduction through the SHP2 recruitment site of gp130

Interleukin-6 is involved in the regulation of many biological activities such as gene expression, cell proliferation, and differentiation. The control of the termination of cytokine signaling is as important as the regulation of initiation of signal transduction pathways. Three families of proteins involved in the down-regulation of cytokine signaling have been described recently: (i) SH2 domain-containing protein-tyrosine phosphatases (SHP), (ii) suppressors of cytokine signaling (SOCS), and (iii) protein inhibitors of activated STATs (PIAS). We have analyzed the interplay of two inhibitors in the signal transduction pathway of interleukin-6 and demonstrate that the tyrosine phosphatase SHP2 and SOCS3 do not act independently but are functionally linked. The activation of one inhibitor modulates the activity of the other; Inhibition of SHP2 activation leads to increased SOCS3-mRNA levels, whereas increased expression of SOCS3 results in a reduction of SHP2 phosphorylation after activation of the interleukin-6 signal transduction pathway. Furthermore, we show that tyrosine 759 in gp130 is essential for both SHP2 and SOCS3 but not for SOCS1 to exert their inhibitory activities on interleukin-6 signal transduction. Besides SHP2, SOCS3 also interacts with the Tyr(P)-759 peptide of gp130. Taken together, our results suggest differences in the function of SOCS1 and SOCS3 and a link between SHP2 and SOCS3.

Reaction to disturbances of a walking leg during stance

The ground reaction forces exerted by the legs of freely walking stick insects, Carausius morosus, were recorded during normal and perturbed locomotion. The animals walked along a path into which a three-dimensional force transducer was integrated. The transducer registered all three components of the forces produced by a single leg when, by chance, it walked on the force platform. The stiffness of the walking surface was found to be a critical variable affecting the forces and the trajectories of leg movements during undisturbed walking. The forces produced by a leg were considerably smaller and the trajectories were closer to the body during walking on soft versus stiff surfaces. Perturbations during stance were generated by moving the platform in various directions within the horizontal plane and at two different rates. Perturbations were applied either immediately after leg contact or after a delay of 300 ms. The reactions to these disturbances were compatible with the hypothesis that the velocity of leg movement is under negative feedback control. This interpretation is also supported by comparison with simulations based upon other control schemes. We propose a model circuit that provides a combination of negative and positive feedback control mechanisms to resolve the apparent discrepancies between our results and those of previous studies.

Cloning, mapping and expression analysis of barley MADS-box genes

Six MADS-box cDNA clones were isolated by heterologous screening from a barley inflorescence cDNA library. Based on sequence comparison to known MADS-box genes, the barley MADS-box (BM) genes were grouped into three distinct phylogenetic subclasses of the MADS-box gene family. The three MADS-box genes BM3, BM5 and BM8 share similarities with genes of the SQUAMOSA (SQUA) subgroup, while BM7 and BM9 belong to the AGAMOUS-LIKE 2 (AGL2) subgroup. BM1 resembles MADS-box genes described as solitary sequences or orphan genes. Expression analysis of the barley MADS-box genes revealed expression patterns that are not characteristic of the barley MADS-box genes of the SQUA subgroup. while expression of BM7 and BM9 was largely as expected for the AGL2 subgroup. BM1 is mainly expressed in vegetative tissues and its primary transcript undergoes alternative splicing such that the corresponding mRNAs differ by two codons. The genes BM1, BM3 and BM8 were mapped by analysis of single-nucleotide polymorphisms onto barley chromosomes 4, 2 and 7, respectively.

Severe osteopenia in symptom-free adults with a childhood diagnosis of coeliac disease

The frequency of osteopenia in symptom-free adults diagnosed with coeliac disease during childhood and who resumed a normal diet during adolescence is unknown. Severe osteopenia (a bone mineral density below two standard deviations of the mean) was found in up to a third of symptom-free young adults on a normal diet. These patients should not be thought to be disease-free but should receive long-term follow-up and most of them should be advised to resume a gluten-free diet.

Convergence of load and movement information onto leg motoneurons in insects

The interaction of two feedback loops was investigated: one regulating cuticular stress in the stick insect's leg and the other controlling leg posture. Exclusive stimulation of either of the two relevant sense organs, the load-sensitive trochantero-femoral campaniform sensilla (CS) or the position-/movement-sensitive ventral coxal hairplate (cxHPv), elicits resistance reflex responses in the retractor and the protractor coxae motoneuron pools. Concurrent application of both stimulus modalities reveals that the strength of the postural feedback response is dependent on sign and amplitude of the load feedback response and vice versa. This superposition of the two reflex responses appears to be non-linear. The results indicate that the CS information is underlying a force control function in this six-legged animal. It is hypothesized that the force control of each single leg could help to optimize the force distribution of the six-legged system, even - due to the mechanical coupling - without explicit neuronal pathways. On the level of the single leg control it was studied whether the different information provided by the two feedback transducers converge on the level of retractor coxae motoneurons or whether this information is fully preprocessed at the level of premotor interneurons. It is shown here that the hairplate afferents make direct, excitatory connections with the retractor motoneurons. Studies of the motoneurons' membrane conductances during exclusive CS stimulation reveal that both, excitatory as well as inhibitory synaptic drive is delivered onto the retractor motoneurons. Thus, the motoneuronal membrane is shown to be an important stage for the sensor fusion of the two modalities.