[Positioning of the premaxilla in cases of bilateral cleft lip, alveolus and palate using Latham's appliance]

SUBJECT MATTER: In cases of bilateral cleft lip, alveolus and palate, preoperative positioning of the premaxilla using Latham's appliance has been described. This method is controversial, since it may cause growth defects.

PATIENTS AND METHODS

From 1992 to 2000, Latham's appliance was inserted preoperatively into 20 patients with bilateral lip, alveolus and palate clefts with extreme premaxillary protrusion. Pin fixation ensued at the age of 3 months. After adjustment of the premaxilla, the soft palate was closed and bilateral lip adhesion as well as bilateral gingivoperiosteoplasty were performed directly after the removal of the appliance. Final lip closure took place 4-6 weeks later. At the age of 2 years, the hard palate was closed. Evaluation was based on combined face-maxilla models, standard photographs and, when available, lateral skull x-rays showing the relative position of the segments, the influence of Latham's appliance on the nasal septum and the relation of the upper jaw to the skull base and mandibula.

RESULTS

In all cases, a satisfactory alveolar alignment was achieved; thickening and curvature of the nasal septum occurred but receded. Neither growth disturbances nor dental germ damage were seen. In two cases, complications arose from suture dehiscence of the lip adhesion: in one patient, a screw defect caused a loosening of the appliance and there was also a transmigration of the postpremaxillary pin.

CONCLUSIONS

On the basis of our experience, the use of Latham's appliance, combined with consistent orthodontic supervision and, if necessary, treatment, represents a practical option for the treatment of bilateral cleft lip, alveolus and palate, especially in cases with extreme protrusion of the premaxilla.

A pervaporation-bio-hybridreactor (PBHR) for improved aroma biosynthesis with submerged culture of Ceratocystis fimbriata

In the present study a Pervaporation-bio-hybridreactor was investigated for the improved biotechnological production of volatile flavour compounds. The mixture of esters and alcohols produced by the fungus Ceratocystis fimbriata had a fruity, banana-like odour and can legally be defined as "natural flavour". Increasing consumer demand and high market prices make the production of bioflavours an attractive alternative to chemical synthesises. However, the yield of biotechnological flavour production is often very low due to product inhibition. In situ product-removal processes can yield higher productivities by preventing product inhibition. A bioreactor with an integrated pervaporation membrane was used to determine the effects of in-situ product removal on the metabolic productivity of C. fimbriata. Fed-batch fermentations with and without integrated product removal were conducted and the performance of the processes in terms of productivities was compared. Improved productivities were observed for all products. Figure 1a and 1b show the increased amount of product gained through the application of the PBHR with fed-batch fermentation.

Test-retest-reliability and validity of the Kinesiology muscle test

OBJECTIVES

To assess the test-retest-reliability and validity of the Health Kinesiology muscle test.

PATIENTS

Seven patients with clinically and allergologically confirmed wasp venom allergy.

DESIGN

Four Health Kinesiology-examiners tested each patient in a random order for 10 verum and 10 placebo bottles. All examiners used the anterior deltoid as indicator muscle. Patients and examiners were completely blinded.

OUTCOME MEASURES

Weak muscle holds were rated as 'sensitivity' towards the test substance, stable holding as normal (not sensitive).

RESULTS

An overall kappa of 0.03 (95%-CI: -0.02-0.07) indicates the test is not reliable. Individual kappas do not substantially vary from examiner to examiner. Sensitivity and specificity were estimated at 40% and 60%.

CONCLUSIONS

The results suggest that the use of Health Kinesiology as a diagnostic tool is not more useful than random guessing. This should at least be true in patients with insect venom allergy that are tested by examiners with average skills.

Positive and negative roles of the trans-acting T cell factor-1 for the acquisition of distinct Ly-49 MHC class I receptors by NK cells

Members of the Ly-49 gene family code for class I MHC-specific receptors that regulate NK cell function. Due to a combinatorial distribution of Ly-49 receptors, NK cells display considerable clonal heterogeneity. The acquisition of one Ly-49 receptor, Ly-49A is strictly dependent on the transcriptional trans-acting factor T cell-specific factor-1 (TCF-1). Indeed, TCF-1 binds to two sites in the Ly-49a promoter and regulates its activity, suggesting that the Ly-49a gene is a direct TCF-1 target. TCF-1 deficiency resulted in the altered usage of additional Ly-49 receptors. We show in this study, using TCF-1 beta(2)-microglobulin double-deficient mice, that these repertoire alterations are not due to Ly-49/MHC class I interactions. Our findings rather suggest a TCF-1-dependent, cell autonomous effect on the acquisition of multiple Ly-49 receptors. Besides reduced receptor usage (Ly-49A and D), we also observed no effect (Ly-49C) and significantly expanded (Ly-49G and I) receptor usage in the absence of TCF-1. These effects did not in all cases correlate with the presence of TCF binding sites in the respective proximal promoter. Therefore, besides TCF-1 binding to the proximal promoter, Ly-49 acquisition may also be regulated by TCF-1 binding to more distant cis-acting elements and/or by regulating the expression of additional trans-acting factors. Consistent with the observed differential, positive or negative role of TCF-1 for Ly-49 receptor acquisition, reporter gene assays revealed the presence of an inducing as well as a repressing TCF site in certain proximal Ly-49 promoters. These findings reveal an important role of TCF-1 for the formation of the NK cell receptor repertoire.

Amino acid sequences and hapten binding of catalytic and noncatalytic antibodies against N(alpha)-(5'-phosphopyridoxyl)-L-lysine

Upon immunization with a transition-state analog, only a minority of the hapten-binding antibodies will possess catalytic activity, which will vary in efficacy and substrate specificity. Here, the amino acid sequences of the variable domains of two pyridoxal-5'-phosphate-dependent catalytic and five noncatalytic hapten-binding antibodies raised by immunization with protein-conjugated N(alpha)-(5'-phosphopyridoxyl)-L-lysine (Gramatikova, S., Christen, P., 1997. J. Biol. Chem. 272, 9779-9784) were determined by sequencing their cDNAs. The analysis revealed that the light chains of this set of antibodies were closely related (pairwise identity 65-80%), whereas the heavy chains could be traced back to two different but related groups (intergroup identity 50-54%). The majority of the antibodies proved not to be clonally related, a finding which correlates with their differences in enantiomeric selectivity in ligand binding and reaction specificity. Only one noncatalytic antibody was found to be clonally related with a catalytic antibody, the sequence identity being >95% in both the V(H) and V(L) domains. The complementarity-determining regions were invariably abundant in tyrosine residues. Nitration of three to four tyrosine residues with tetranitromethane abolished hapten binding and catalytic activity. Partial protection by pyridoxal-5'-phosphate against inactivation suggested the presence of functionally important tyrosine residues in the binding sites of the antibodies.

Impaired natural killing of MHC class I-deficient targets by NK cells expressing a catalytically inactive form of SHP-1

NK cell function is negatively regulated by MHC class I-specific inhibitory receptors. Transduction of the inhibitory signal involves protein tyrosine phosphatases such as SHP-1 (SH2-containing protein tyrosine phosphatase-1). To investigate the role of SHP-1 for NK cell development and function, we generated mice expressing a catalytically inactive, dominant-negative mutant of SHP-1 (dnSHP-1). In this paper we show that expression of dnSHP-1 does not affect the generation of NK cells even though MHC receptor-mediated inhibition is partially impaired. Despite this defect, these NK cells do not kill syngeneic, normal target cells. In fact dnSHP-1-expressing NK cells are hyporesponsive toward MHC-deficient target cells, suggesting that non-MHC-specific NK cell activation is significantly reduced. In contrast, these NK cells mediate Ab-dependent cell-mediated cytotoxicity and prevent the engraftment with beta2-microglobulin-deficient bone marrow cells. A similar NK cell phenotype is observed in viable motheaten (mev) mice, which show reduced SHP-1 activity due to a mutation in the Shp-1 gene. In addition, NK cells in both mouse strains show a tendency to express more inhibitory MHC-specific Ly49 receptors. Our results demonstrate the importance of SHP-1 for the generation of functional NK cells, which are able to react efficiently to the absence of MHC class I molecules from normal target cells. Therefore, SHP-1 may play an as-yet-unrecognized role in some NK cell activation pathways. Alternatively, a reduced capacity to transduce SHP-1-dependent inhibitory signals during NK cell development may be compensated by the down-modulation of NK cell triggering pathways.

Hopelessness and its impact on rehabilitation outcome in schizophrenia -an exploratory study

The primary focus in contemporary psychiatry on symptoms and their neurobiological basis, although fundamentally important, is nevertheless incomplete. The long-term course and outcome of schizophrenia are determined not only by the disorder, but also by the interaction between the person and the disorder. Not only psychopathological symptoms but also cognitive variables such as negative self-concepts, low expectations and external loci of control can influence the patient's coping strategies and may lead to hopelessness and chronicity. Hopelessness here refers to a cognitive-affective state in which the patient perceives the disorder and its consequences to be beyond his control, feels helpless and has given up expecting to influence its course positively, thereby abandoning responsibility and active coping strategies. In a prospective study, we examined these relationships by using logistic regression in data from 46 schizophrenic outpatients who were participating in a vocational rehabilitation program. Negative self-concepts, external loci of control, and depression correlated to a higher extent with depressive-resigned coping strategies than did schizophrenic symptoms. Thus, poor rehabilitation outcome may be predicted to a high degree by the presence of external loci of control, pessimistic outcome expectancies, negative symptoms, and depressive-resigned coping strategies. After having eliminated the influence of negative symptoms, external control beliefs still had significant predictive value for the outcome. Rehabilitation outcome in schizophrenic patients can be only partially predicted by negative symptoms; the other predictive factor is whether the patient has already given up or not.

Mono-allelic Ly49 NK cell receptor expression

Each cell is equipped with two copies (alleles) of each autosomal gene. While the vast majority use both alleles, occasional genes are expressed from a single allele. The reason for mono-allelic expression is not always evident and can serve distinct purposes. First, it may facilitate the tight control over the dosage of certain gene products such as some growth factors and their receptors or X-linked genes. Second, the differential usage of the two parental alleles may reflect the mechanisms that ensure mono-specificity, e.g. olfactory receptors, T and B cell receptors. The context of allele-specific expression of the murine Ly49 natural killer (NK) cell receptor genes suggests that their allele-specific expression reflects a process that generates clonal variability.

Disposable-sheath, flexible gastroscope system versus standard gastroscopes: a prospective, randomized trial

BACKGROUND

Endoscopically transmitted infections due to inadequate disinfection are rare but well-recognized complications. A new prototype of a flexible, fiberoptic endoscope has been developed that uses a disposable sheath to cover and protect all working surfaces of the endoscope from contamination. The present study investigated the function, reprocessing, and hygienic status of this endoscope system in comparison with standard systems.

METHODS

In a prospective, randomized trial, 100 upper endoscopic procedures (50 standard, 50 sheathed) were performed. Analog rating scales were used to evaluate endoscopic performance and reprocessing. Reprocessing time, procedure duration, insertion depth, total instrument downtime, and problems occurring during the procedure were recorded. Microbiologic swabs were obtained from each endoscope.

RESULTS

Mean procedure duration was slightly longer with the sheathed system than with standard endoscope (9.9 vs. 8.4 min). Set up and reprocessing times, however, were significantly shorter with the Endosheath (8.9 vs. 48.4 min with the standard endoscope). The disposable-sheath endoscope system permits the rate of performance of procedures to be increased by a factor of up to 3.0. Both endoscopists and reprocessing personnel preferred the standard endoscope. No post-procedure sheath leakage or rupture was seen.

CONCLUSION

Our results suggest that the "disposable endoscope" may have important advantages in terms of decreased instrument turn-around time and potentially improved safety.

Clonal acquisition of the Ly49A NK cell receptor is dependent on the trans-acting factor TCF-1

Families of clonally expressed major histocompatibility complex (MHC) class I-specific receptors provide specificity to and regulate the function of natural killer (NK) cells. One of these receptors, mouse Ly49A, is expressed by 20% of NK cells and inhibits the killing of H-2D(d) but not D(b)-expressing target cells. Here, we show that the trans-acting factor TCF-1 binds to two sites in the Ly49A promoter and regulates its activity. Moreover, we find that TCF-1 determines the size of the Ly49A NK cell subset in vivo in a dosage-dependent manner. We propose that clonal Ly49A acquisition during NK cell development is regulated by TCF-1.

Neurotoxicity of prion peptide 106-126 not confirmed

Prion-related diseases are accompanied by neurodegeneration, astroglial proliferation and formation of proteinase K-resistant aggregates of the scrapie isoform of the prion protein (PrPSc). The synthetic PrP fragment 106-126 was reported to be neurotoxic towards cultured rat hippocampal neurons (Forloni, G., Angeretti, N., Chiesa, R., Monzani, E., Salmona, M., Bugiani, O. and Tagliavini, F. (1993) Nature 362, 543-546) and mouse cortical cells (Brown, D.R., Herms, J. and Kretzschmar, H.A. (1994) Neuroreport 5, 2057-2060). However, we found the viability of these and other neuronal cell types not to be impaired in the presence of PrP106-126 under widely varied sets of conditions. Aged preparations of the peptide as well as synthetic deamidated and isomerized derivatives that correspond to the aging products of the peptide proved also to lack neurotoxicity. Apparently, PrP106-126 cannot serve as a model for the interaction of PrP with neuronal cells.

Spontaneous deamidation and isomerization of Asn108 in prion peptide 106-126 and in full-length prion protein

In prion-related encephalopathies, the cellular prion protein (PrP(C)) undergoes a change in conformation to become the scrapie prion protein (PrP(Sc)) which forms infectious deposits in the brain. Conceivably, the conformational transition of PrP(C) to PrP(Sc) might be linked with posttranslational alterations in the covalent structure of a fraction of the PrP molecules. We tested a synthetic peptide corresponding to residues 106-126 of human PrP for the occurrence of spontaneous chemical modifications. The only asparagine residue, Asn108, was deamidated to aspartic acid and isoaspartic acid with a half-life of about 12 days. The same posttranslational modifications were found in recombinant murine full-length protein. On aging, 0.8 mol of isoaspartyl residue per mole of protein was detected by the protein-l-isoaspartyl methyltransferase assay (t(1/2) approximately 30 days). Mass spectrometry and Edman degradation of Lys-C fragments identified Asn108 in the amino-terminal flexible part of the protein to be partially converted to aspartic acid and isoaspartic acid. A second modification was the partial isomerization of Asp226' which is only present in rodents.

Neurite fasciculation mediated by complexes of axonin-1 and Ng cell adhesion molecule

Neural cell adhesion molecules composed of immunoglobulin and fibronectin type III-like domains have been implicated in cell adhesion, neurite outgrowth, and fasciculation. Axonin-1 and Ng cell adhesion molecule (NgCAM), two molecules with predominantly axonal expression exhibit homophilic interactions across the extracellular space (axonin- 1/axonin-1 and NgCAM/NgCAM) and a heterophilic interaction (axonin-1-NgCAM) that occurs exclusively in the plane of the same membrane (cis-interaction). Using domain deletion mutants we localized the NgCAM homophilic binding in the Ig domains 1-4 whereas heterophilic binding to axonin-1 was localized in the Ig domains 2-4 and the third FnIII domain. The NgCAM-NgCAM interaction could be established simultaneously with the axonin-1-NgCAM interaction. In contrast, the axonin-1-NgCAM interaction excluded axonin-1/axonin-1 binding. These results and the examination of the coclustering of axonin-1 and NgCAM at cell contacts, suggest that intercellular contact is mediated by a symmetric axonin-12/NgCAM2 tetramer, in which homophilic NgCAM binding across the extracellular space occurs simultaneously with a cis-heterophilic interaction of axonin-1 and NgCAM. The enhanced neurite fasciculation after overexpression of NgCAM by adenoviral vectors indicates that NgCAM is the limiting component for the formation of the axonin-12/NgCAM2 complexes and, thus, neurite fasciculation in DRG neurons.

An allele-specific, stochastic gene expression process controls the expression of multiple Ly49 family genes and generates a diverse, MHC-specific NK cell receptor repertoire

Mouse NK cells express MHC class I-specific inhibitory Ly49 receptors. Since these receptors display distinct ligand specificities and are clonally distributed, their expression generates a diverse NK cell receptor repertoire specific for MHC class I molecules. We have previously found that the Dd (or Dk)-specific Ly49A receptor is usually expressed from a single allele. However, a small fraction of short-term NK cell clones expressed both Ly49A alleles, suggesting that the two Ly49A alleles are independently and randomly expressed. Here we show that the genes for two additional Ly49 receptors (Ly49C and Ly49G2) are also expressed in a (predominantly) mono-allelic fashion. Since single NK cells can co-express multiple Ly49 receptors, we also investigated whether mono-allelic expression from within the tightly linked Ly49 gene cluster is coordinate or independent. Our clonal analysis suggests that the expression of alleles of distinct Ly49 genes is not coordinate. Thus Ly49 alleles are apparently independently and randomly chosen for stable expression, a process that directly restricts the number of Ly49 receptors expressed per single NK cell. We propose that the Ly49 receptor repertoire specific for MHC class I is generated by an allele-specific, stochastic gene expression process that acts on the entire Ly49 gene cluster.

Fungitoxicity of chemical analogs with heartwood toxins

Trans-stilbene and tropolone as chemical analogs with naturally occurring fungitoxic heartwood compounds were studied with respect to their fungitoxic potency. While stilbene showed no fungitoxic activity towards the fungi Aureobasidium pullulans var. melanogenum, Penicillium glabrum, and Trichoderma harzianum in the concentrations tested, the minimal inhibiting concentration of tropolone was 10(-3) M for Penicillium glabrum and Trichoderma harzianum, and 10(-5) M for Aureobasidium pullulans var. melanogenum. In all cases, the effect of tropolone was a fungistatic one. Using chemical analogs for assessing the chemical basis of the fungitoxicity of tropolone, this substance proved to be the only compound tested which possesses fungitoxic properties.

[Disposable protection for flexible gastroenterologic endoscopy: prospective comparative evaluation of a new gastroscopy system (Endosheath) compared to the standard fiberglass gastroscope]

The reprocessing of flexible gastrointestinal endoscopes is time-consuming and expensive. Endoscopically transmitted infections due to insufficient disinfection are already of clinical importance. A new developed prototype of a flexible, fiberoptic gastroscope was tested in a prospective open randomized trial to evaluate the function. reprocessing and hygienical safety of this disposable, sheathed endoscopic system and was compared with a standard gastroscope. This new endoscopical system utilizes a disposable sheath to cover and protect all working surfaces of the endoscope from contamination. A prospective, randomized trial was performed in our unit to compare the disposable gastroscope (G-F100) with a standard-gastroscope of the newest Generation (GIF-Q 30). Visual analog rating scales were used to record evaluations of endoscope performance and reprocessing by endoscopists and reprocessing personnel. We recorded the time of reprocessing, the time to perform the procedures, depth of insertion, total instrument downtime and any problems which occurred during the procedure. Microbiological swabs were taken from each endoscope. 40 procedures (20 standard, 20 sheathed) were performed. The sheathed gastroscope 8.9 min versus 7.1 min. The overall instrument downtime was significantly shortened by the endosheath (9.8 min versus 47.5 min with the standard gastroscope). The disposable gastroscope-system permits an increase of procedure-frequency up to a factor of 2.9. The standard gastroscope was preferred by the endoscopists and the reprocessing personnel. No microbiological contaminations of the sheathed or the standard gastroscopes could be demonstrated, and no leak of the sheaths was recorded after gastroscopy. The disposable gastroscope has important advantages of decreased instrument turn-around time and potentially increased staff and patient safety.

Predicting schizophrenic outpatients' behavior by symptomatology and social skills

Though social skills have been identified as an independent construct, recent studies have revealed that schizophrenic symptomatology and social skills are interrelated. The nature and extent of this relationship, however, are far from clear. To address this issue, we examined 33 schizophrenic outpatients participating in a rehabilitation program for an average of 10 months. The object of this study was to investigate to what extent behavior can be predicted by symptomatology and social skills, and whether social skills have a significant effect on outpatients' behavior independently of schizophrenic symptoms and vice versa. Regression analyses revealed good prediction of outpatients' behavior by conceptual disorganization and disorder of relating from the PANSS and, to a lesser degree, social skills. After having eliminated the influence of psychopathology on social skills and behavior, social skills variables still had significant predictive value for social competence, social interest, and irritability. These findings imply specific contributions of both symptomatology and social skills to future behavior of chronic schizophrenic outpatients.