Porosity Engineering of Dried Smart Poly(N-isopropylacrylamide) Hydrogels for Gas Sensing

A recent study unveiled the potential of acrylamide-based stimulus-responsive hydrogels for volatile organic compound detection in gaseous environments. However, for gas sensing, a large surface area, that is, a highly porous material, offering many adsorption sites is crucial. The large humidity variation in the gaseous environment constitutes a significant challenge for preserving an initially porous structure, as the pores tend to be unstable and irreversibly collapse. Therefore, the present investigation focuses on enhancing the porosity of smart PNiPAAm hydrogels under the conditions of a gaseous environment and the preservation of the structural integrity for long-term use. We have studied the influence of polyethylene glycol (PEG) as a porogen and the application of different drying methods and posttreatment. The investigations lead to the conclusion that only the combination of PEG addition, freeze-drying, and subsequent conditioning in high relative humidity enables a long-term stable formation of a porous surface and inner structure of the material. The significantly enhanced swelling response in a gaseous environment and in the test gas acetone is confirmed by gravimetric experiments of bulk samples and continuous measurements of thin films on piezoresistive pressure sensor chips. These measurements are furthermore complemented by an in-depth analysis of the morphology and microstructure. While the study was conducted for PNiPAAm, the insights and developed processes are general in nature and can be applied for porosity engineering of other smart hydrogel materials for VOC detection in gaseous environments.

Smart Hydrogel Swelling State Detection Based on a Power-Transfer Transduction Principle

Stimulus-responsive (smart) hydrogels are a promising sensing material for biomedical contexts due to their reversible swelling change in response to target analytes. The design of application-specific sensors that utilize this behavior requires the development of suitable transduction concepts. The presented study investigates a power-transfer-based readout approach that is sensitive to small volumetric changes of the smart hydrogel. The concept employs two thin film polyimide substrates with embedded conductive strip lines, which are shielded from each other except at the tip region, where the smart hydrogel is sandwiched in between. The hydrogel's volume change in response to a target analyte alters the distance and orientation of the thin films, affecting the amount of transferred power between the two transducer parts and, consequently, the measured sensor output voltage. With proper calibration, the output signal can be used to determine the swelling change of the hydrogel and, consequently, to quantify the stimulus. In proof-of-principle experiments with glucose- and pH-sensitive smart hydrogels, high sensitivity to small analyte concentration changes was found along with very good reproducibility and stability. The concept was tested with two exemplary hydrogels, but the transduction principle in general is independent of the specific hydrogel material, as long as it exhibits a stimulus-dependent volume change. The application vision of the presented research is to integrate in situ blood analyte monitoring capabilities into standard (micro)catheters. The developed sensor is designed to fit into a catheter without obstructing its normal use and, therefore, offers great potential for providing a universally applicable transducer platform for smart catheter-based sensing.

Magnetization Dynamics of an Individual Single-Crystalline Fe-Filled Carbon Nanotube

The magnetization dynamics of individual Fe-filled multiwall carbon-nanotubes (FeCNT), grown by chemical vapor deposition, are investigated by microresonator ferromagnetic resonance (FMR) and Brillouin light scattering (BLS) microscopy and corroborated by micromagnetic simulations. Currently, only static magnetometry measurements are available. They suggest that the FeCNTs consist of a single-crystalline Fe nanowire throughout the length. The number and structure of the FMR lines and the abrupt decay of the spin-wave transport seen in BLS indicate, however, that the Fe filling is not a single straight piece along the length. Therefore, a stepwise cutting procedure is applied in order to investigate the evolution of the ferromagnetic resonance lines as a function of the nanowire length. The results show that the FeCNT is indeed not homogeneous along the full length but is built from 300 to 400 nm long single-crystalline segments. These segments consist of magnetically high quality Fe nanowires with almost the bulk values of Fe and with a similar small damping in relation to thin films, promoting FeCNTs as appealing candidates for spin-wave transport in magnonic applications.

Effective sensor properties and sensitivity considerations of a dynamic co-resonantly coupled cantilever sensor

Background: Co-resonant coupling of a micro- and a nanocantilever can be introduced to significantly enhance the sensitivity of dynamic-mode cantilever sensors while maintaining the ease of detection. Experimentally, a low-stiffness nanocantilever is coupled to an easy to read out microcantilever and the eigenfrequencies of both beams are brought close to one another. This results in a strong interplay between both beams and, hence, any interaction applied at the nanocantilever alters the oscillatory state of the coupled system as a whole and can be detected at the microcantilever. The amplitude response curve of the microcantilever exhibits two resonance peaks and their response to an interaction applied to the sensor depends on the properties of the individual beams and the degree of frequency matching. Consequently, while an individual cantilever is characterized by its eigenfrequency, spring constant, effective mass and quality factor, the resonance peaks of the co-resonantly coupled system can be described by effective properties which are a mixture of both subsystem's characteristics. These effective properties give insight into the amount of sensitivity of the nanocantilever that can be accessed and, consequently, into the sensitivity gain associated with the co-resonance. In order to design sensors based on the co-resonant principle and predict their behaviour it is crucial to derive a description for these effective sensor properties. Results: By modeling the co-resonantly coupled system as a coupled harmonic oscillator and using electromechanical analogies, analytical expressions for the effective sensor properties have been derived and discussed. To illustrate the findings, numerical values for an exemplary system based on experimental sensor realizations have been employed. The results give insight into the complex interplay between the individual subsystem's properties and the frequency matching, leading to a rather large parameter space for the co-resonant system's effective properties. While the effective spring constant and effective mass mainly define the sensitivity of the coupled cantilever sensor, the effective quality factor primarily influences the detectability. Hence, a balance has to be found in optimizing both parameters in sensor design which becomes possible with the derived analytic expressions. Besides the description of effective sensor properties, it was studied how the thermal noise and, consequently, minimal detectable frequency shift for the co-resonantly coupled sensor represented by a coupled harmonic oscillator could be derived. Due to the complex nature of the coupled system's transfer function and the required analysis, it is beyond the scope of this publication to present a full solution. Instead, a simplified approach to estimate the minimal detectable frequency shift for the co-resonant system based on the effective sensor properties is given. Conclusion: By establishing a theoretical description for the effective sensor properties of a co-resonantly coupled system, the design of such systems is facilitated as sensor parameters can easily be predicted and adapted for a desired use case. It allows to study the potential sensitivity (gain) and detectability capabilities before sensor fabrication in a fast and easy way, even for large parameter spaces. So far, such an analysis of a co-resonantly coupled sensor was only possible with numerical methods and even then only with very limited capability to include and understand the complex interplay between all contributions. The outlined calculation steps regarding the noise considerations in a coupled harmonic oscillator system can provide the basis for a thorough study of that question. Furthermore, in a broader scope, the investigations presented within this work contribute towards extending and completing the already established theoretical basics of this novel co-resonant sensor concept and open up new ways of studying the coupled system's behaviour.

Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor

Cantilever magnetometry is a measurement technique used to study magnetic nanoparticles. With decreasing sample size, the signal strength is significantly reduced, requiring advances of the technique. Ultrathin and slender cantilevers can address this challenge but lead to increased complexity of detection. We present an approach based on the co-resonant coupling of a micro- and a nanometer-sized cantilever. Via matching of the resonance frequencies of the two subsystems we induce a strong interplay between the oscillations of the two cantilevers, allowing for a detection of interactions between the sensitive nanocantilever and external influences in the amplitude response curve of the microcantilever. In our magnetometry experiment we used an iron-filled carbon nanotube acting simultaneously as nanocantilever and magnetic sample. Measurements revealed an enhancement of the commonly used frequency shift signal by five orders of magnitude compared to conventional cantilever magnetometry experiments with similar nanomagnets. With this experiment we do not only demonstrate the functionality of our sensor design but also its potential for very sensitive magnetometry measurements while maintaining a facile oscillation detection with a conventional microcantilever setup.

Genetic deletion of JNK1 and JNK2 aggravates the DSS-induced colitis in mice

The c-Jun N-terminal kinases (JNKs) are considered as novel targets for therapy of inflammatory bowel diseases (IBD). However, the relevant JNK isoforms have to be elucidated. Here, we analyze the individual contribution of the JNK1 and JNK2 isoforms in a dextran sulfate sodium (DSS) model of experimental colitis. JNK1 and JNK2 knockout mice (JNK1 ko, JNK2 ko) and their wild-type controls (WT1, WT2) received three cycles of DSS treatment, each consisting of 1.7% DSS for 5 days, followed by 5 days with water. Animals were daily evaluated by a disease activity index (DAI) comprising measurement of body weight, estimation of stool consistency, and test for occult blood/gross rectal bleeding. After 30 days all animals were sacrificed, and the inflamed intestine was histologically evaluated by a crypt damage score. Unexpectedly, neither JNK1 ko nor JNK2 ko prevented mice from developing a chronic colitis when compared to wild-type controls WT1 and WT2, respectively. On the contrary, DAI and mortality were aggravated in JNK2 ko compared to WT2. DAI and mortality did not differ between JNK1 ko and WT1, but the histological crypt damage score was significantly enhanced in the cecum of JNK1 ko mice. Genetic deletion of JNK2 worsens the disease outcome in an experimental model of murine colitis. We hypothesize that the functional deletion of the otherwise proapoptotic JNK2 prolongs the activity of proinflammatory immune cells with deterioration of disease activity.

HPLC evaluation of diclofenac in transdermal therapeutic preparations

High-performance liquid chromatography (HPLC) was selected for analytical evaluation of sodium diclofenac in original transdermal therapeutic preparations containing adjuvant substances (capsaicin, hyoscyamine). After isolation from laminated adhesive patches, diclofenac was analysed on columns with reversed phase, using the mobile phase ethanol and phosphate buffer (pH 6.5) with an addition of tetrabutylammonium iodide and detection at 284 nm. Not only the total amount of diclofenac in the patch was evaluated, but HPLC methodology was also employed to select a suitable acceptor medium for permeation experiments. In patches manufactured in the tested series, HPLC was also employed to examine the release of diclofenac and its in vitro permeation through the human skin.

Plasma and membrane Ca2+ and Mg2+ concentrations in normal pregnancy and in preeclampsia

OBJECTIVE

Changes in intracellular Ca2+ and Mg2+ concentrations seem to be involved in the pathogenesis of preeclampsia, whereas the role of cell membranes has not been studied in detail yet. To investigate the changes in Ca2+ and Mg2+ metabolism in normal pregnancy and preeclampsia, plasma and membrane Ca2+ and Mg2+ concentrations were determined in a clinical study as compared to healthy subjects.

STUDY DESIGN

25 healthy female subjects, 22 untreated healthy pregnant and 20 preeclamptic women were investigated. In each patient, plasma and membrane Ca2+ and Mg2+ content were measured. Ca2+ and Mg2+ concentrations were measured by atomic absorption spectroscopy. Erythrocyte membranes were chosen for membranous Ca2+ and Mg2+ determination.

RESULTS

Plasma Mg2+ concentrations were significantly lowered in the healthy pregnant group and the preeclamptic group as compared to controls (p < 0.0001). In erythrocyte membranes, Mg2+ content was found significantly decreased in the preeclamptic women as compared to healthy subjects (p < 0.001). In plasma Ca2+ concentrations there was a significant decrease in the preeclamptic group as compared to controls or healthy pregnant women (p < 0.05). Membranous Ca2+ content was significantly increased in the preeclamptic group versus controls or healthy pregnant women (p < 0.001).

CONCLUSION

Lowered plasma and membrane Mg2+ concentrations in preeclampsia may contribute to the development of hypertension in pregnancy. Additionally, a disturbed Ca2+ homeostasis is observed in preeclampsia.

HPLC evaluation of drugs in transdermal therapeutic preparations. I. Glycerol trinitrate

In connection with the development of transdermal delivery systems (TTS) of the laminated adhesive patches type, HPLC was selected for analytical evaluation of active principles. It was employed for analysis of glycerol trinitrate (GTN) as one of the drugs administered in the form of medicinal adhesive patches. After isolation from the patch, GTN was analysed by reverse phase HPLC, employing methanol and water as the mobile phase, and detected at 206 nm. The total amount of GTN in the patch was evaluated and its concentrations in a lactose trituration and the reservoir layer were determined. In the patches manufactured in a test series, the elaborated HPLC method was used to investigate the release of GTN in a liberation study and its permeation through excised human skin in experiments performed in vitro. In connection with the stability study, the decomposition products of GTN were also determined.

The human serotonin 7 (5-HT7) receptor gene: genomic organization and systematic mutation screening in schizophrenia and bipolar affective disorder

In the present study, we evaluated the possible contribution of genetic variation of the serotonin 5-HT7 receptor to the development of schizophrenia and bipolar affective disorder. Cloning and characterization of exon-flanking intronic sequences enabled us to investigate the whole coding region and the exon-intron boundaries of the human 5-HT7 receptor gene. Using single-strand conformational analysis, we screened for presence of DNA sequence variation in a sample of 137 unrelated individuals including 45 schizophrenic and 46 bipolar affective patients, as well as 46 healthy controls. We detected two rare naturally occurring receptor variants (Pro-279-Leu, Thr-92-Lys) and a silent nucleotide substitution (A-->G) at position +1233. The occurrence of the Pro-279-Leu and Thr-92-Lys substitutions was studied in an extended sample of patients (n = 462) and controls (n = 335). The Leu-279 variant was found in similar frequency in all groups, indicating that presence of this variant is not causally related to the development of schizophrenia or bipolar affective disorder. The Lys-92 variant was found in a single individual who suffered from bipolar affective disorder. Investigation of the patient's family revealed independent segregation between the Lys-92 variant and psychiatric illness. Our data suggests that genetic variation of the 5-HT7 receptor does not play a major role in the development of bipolar affective disorder and schizophrenia.

Systematic screening for mutations in the 5'-regulatory region of the human dopamine D1 receptor (DRD1) gene in patients with schizophrenia and bipolar affective disorder

A possible dysregulation of dopaminergic neurotransmission has been implicated in a variety of neuropsychiatric diseases. In the present study we systematically searched for the presence of mutations in the 5'-flanking region of the dopamine D1 receptor (DRD1) gene. This region has previously been shown to contain a functional promoter [Minowa et al., 1992: Proc Natl Acad Sci 89:3045-3049; Minowa et al., 1993: J Biol Chem 268:23544-23551]. We investigated 119 unrelated individuals (including 36 schizophrenic patients, 38 bipolar affective patients, and 45 healthy controls) using single-strand conformation analysis (SSCA). Eleven overlapping PCR fragments covered 2,189 bp of DNA sequence. We identified six single base substitutions: -2218T/C, -2102C/A, -2030T/C, -1992G/A, -1251G/C, and -800T/C. None of the mutations was found to be located in regions which have important influence on the level of transcriptional activity. Allele frequencies were similar in patients and controls, indicating that genetic variation in the 5'-regulatory region of the DRD1 gene is unlikely to play a frequent, major role in the genetic predisposition to either schizophrenia or bipolar affective disorder.

Systematic screening for mutations in the human serotonin-2A (5-HT2A) receptor gene: identification of two naturally occurring receptor variants and association analysis in schizophrenia

A statistically significant association between a silent mutation (102T/C) in the serotonin-2A (5-HT2A) receptor gene and schizophrenia has recently been reported in a sample of Japanese patients and healthy controls. This finding suggests that genetic predisposition to schizophrenia may be affected by a functional 5-HT2A receptor variant that is in linkage disequilibrium with 102T/C. In the present study, we have sought to identify genetic variation in the 5-HT2A receptor gene by screening genomic DNA samples from 91 unrelated subjects comprising 45 patients with schizophrenia and 46 healthy controls by using single-strand conformation analysis. We have identified four nucleotide sequence variants. Two sequence changes would result in protein alterations: a substitution of threonine by asparagine at position 25 (Thr25Asn), and a substitution of histidine by tyrosine at position 452 (His452Tyr). In order to test for a possible contribution to the development of schizophrenia, we have determined allele frequencies in extended samples of unrelated patients and healthy controls. The two amino acid substitutions are found with similar frequencies in patients and controls, indicating that the presence of these variants is not causally related to the development of schizophrenia. However, the reported association of the non-coding polymorphism 102T/C with the disease has also been detected in our sample (P=0.041, odds ratio=1.28, 95% confidence interval 1.012-1.623).

Dopamine D3 receptor Gly9/Ser9 polymorphism and schizophrenia: no increased frequency of homozygosity in German familial cases

Disturbances in the dopaminergic transmission have been implicated in the etiology of schizophrenia. Recently, an association of schizophrenia with increased homozygosity of a Gly9/Ser9 polymorphism in the dopamine D3 receptor gene (DRD3) has been reported (Crocq et al., 1992; Mant et al., 1994). This finding reflected a departure from the Hardy-Weinberg equilibrium in the genotype distribution observed in schizophrenic patients. The effect was found to be at its strongest in patients with a high familial loading. In the present study, we tried to replicate this finding in a sample of 146 German patients with a DSM-III-R diagnosis of schizophrenia. All patients had a positive family history of major psychiatric disorder including 70 patients with a family history of schizophrenia. Given our sample size, we have a power of 99.8% to detect 2. deviation from the Hardy-Weinberg equilibrium of the reported magnitude. However, we found no evidence of an excess of homozygosity in our schizophrenic patients. This seems to indicate that homozygosity for the Gly9/Ser9 polymorphism at the DRD3 locus is unlikely to confer susceptibility to schizophrenia in the German population. This held true whether the psychiatric diagnoses in the affected relatives of the patient samples was established by the family history or family interview method.

Systematic screening for mutations in the human serotonin 1F receptor gene in patients with bipolar affective disorder and schizophrenia

Using single strand conformational analysis we screened the complete coding sequence of the serotonin 1F (5-HT1F) receptor gene for the presence of DNA sequence variation in a sample of 137 unrelated individuals including 45 schizophrenic patients, 46 bipolar patients, as well as 46 healthy controls. We detected only three rare sequence variants which are characterized by single base pair substitutions, namely a silent T-->A transversion in the third position of codon 261 (encoding isoleucine), a silent C-->T transition in the third position of codon 176 (encoding histidine), and an C-->T transition in position -78 upstream from the start codon. The lack of significant mutations in patients suffering from schizophrenia and bipolar affective disorder indicates that the 5-HT1F receptor is not commonly involved in the etiology of these diseases.

Sulbactam/ampicillin versus cefoxitin in the treatment of gynaecological infections: an antibiotic therapeutic study

Seventy-six women with gynaecological infections such as endometritis, salpingitis, tubo-ovarian abscess and pelvic peritonitis were treated with sulbactam/ampicillin (SBT/AMP) (50% of patients) or cefoxitin (CFN) (50% of patients) in a randomized, controlled study. The diagnosis was based on the history, clinical findings and microbiological culture findings. The disease was assumed to be of bacterial origin if leukocytosis was present with a left shift or if the causative organism was identified. Of the group of patients treated with SBT/AMP, 33 (87%) were cured and 4 (10.5%) showed improvement; 1 patient (2.5%) failed to respond to treatment. The equivalent figures for the CFN group were: 30 patients (79%) cured, 4 (10.5%) showed improvement and 4 (10.5%) failed to respond to treatment. The causative organism was eradicated in 29 (91%) patients in the SBT/AMP group and 20 (59%) patients in the CFN group. Reinfection occurred in 1 (3%) patient in the SBT/AMP group and 4 (12%) patients in the CFN group. The causative organism persisted in 1 (3%) patient in the SBT/AMP group and 4(12%) patients in the CFN group. The superiority of SBT/AMP in microbiological terms was statistically significant, but the superiority of SBT/AMP in terms of clinical efficacy was not. The combination of SBT and AMP was efficacious and well tolerated in the treatment of gynaecological infections. This combination offers the advantage of being effective against Streptococcus faecalis and beta-lactamase producing organisms.

Assessing the statistical power to detect linkage in a sample of 51 bipolar affective disorder pedigrees

We used computer simulation method to address the question of power in an initial collaborative sample of 51 bipolar affective disorder pedigrees. Simulations were performed for all possible combinations using (1) two levels of diagnostic stringency, (2) three transmission models, (3) locus heterogeneity, and (4) different assumed phenocopy rates. Some of the factors affect the power to detect linkage are (1) the specification of the correct genetic model, (2) the degree of locus heterogeneity, and (3) the frequency of phenocopies. The first two assertions were supported by our simulation results, but varying the rates of phenocopy did not substantially alter the power of the sample until a critical point. However, it is important to point out that these results are dependent on the genetic models under study and on the use of the "correct" model (i.e., the one used to simulate the data). If we assume a dominant mode of inheritance and locus homogeneity, the power to detect linkage is 97.5% at a theta of .01. However, the power declines dramatically, to 60.5% and 14.7%, if only 75 and 50% of the families are linked, respectively. Locus heterogeneity has a similar effect on the power of the sample to exclude linkage. The relative lack of power in our data, in the presence of significant locus heterogeneity, and for an intermediate mode of inheritance, underscores the need for multicenter collaboration.

Apolipoprotein E genotype distribution in schizophrenia

We examined the hypothesis that apolipoprotein E (apoE) isoforms-besides their well-established role in the aetiology of early and late onset Alzheimer's disease (AD)-may be involved in the development of schizophrenia. We determined apoE genotypes in 98 schizophrenic patients and 98 sex and age matched controls. No significant difference in apoE allele frequencies were observed between schizophrenic patients, subpopulations of schizophrenics, or controls. There was also no difference in the mean age at onset depending on the number of apoE epsilon 4 alleles found in the patients. Our data do not support an association between AD and schizophrenia based on apoE acting as a common denominator in the pathogenesis of both diseases.

[Genetic counseling in psychiatric diseases]

We review current knowledge and application of genetic counselling for psychiatric disorders. Empirical data for genetic counselling exist for affective disorder, schizophrenia, Alzheimer's and Huntington's disease. In Huntington's chorea and partly in Alzheimer's disease molecular genetic methodology may be applied, whereas for affective disorder and schizophrenia only empirical risk figures are available. We describe the principles of genetic counselling and their application in the respective diseases. Problems of presymptomatic testing are particularly outlined. In addition, teratogenic aspects of therapy with psychopharmacological agents during pregnancy are discussed.

An association study of a neurotrophin-3 (NT-3) gene polymorphism with schizophrenia

Since abnormalities of brain development play a role in the aetiology of schizophrenia, growth factors, known to play a role in neurodevelopment, such as neurotrophin-3 (NT-3), are therefore candidate genes for this disorder. The A3/147 bp allele of a dinucleotide repeat polymorphism in the promoter region of the NT-3 gene has been reported as occurring more frequently in a sample of Japanese schizophrenics compared to controls. We have determined the frequency of alleles of this polymorphism in 175 Caucasian schizophrenic patients and 147 control subjects. The patient and control samples showed no significant deviation from Hardy-Weinberg equilibrium and, in a test of allalleles, the patients and controls did not differ significantly in allele frequencies. However, the male schizophrenics were more likely than male controls to have the A3/147 bp allele (P = 0.029).

Partial trisomy 16p in an adolescent with autistic disorder and Tourette's syndrome

A partial trisomy 16p was identified in a 14-year-old male adolescent with autistic disorder. He additionally showed complex motor and vocal phenomena, including some simple tics which had first appeared in childhood. Whereas these simple tics were of subclinical significance, an additional diagnosis of Tourette's syndrome (TS) appears justified. The case report illustrates the diagnostic difficulties in assessing psychiatric symptomatology associated with both disorders, especially complex motor and vocal phenomena. The cytogenetic finding is discussed critically in the light of other chromosome abnormalities reported in both TS and autistic disorder. Chromosome 16p should be considered as a candidate region especially for autistic disorder.

No evidence of association between dopamine D4 receptor variants and bipolar affective disorder

Disturbance in the dopamine neurotransmitter system has been implicated in the pathogenesis of affective disorder. In this study, we examine the possibility that functional variants of the recently cloned dopamine D4 receptor gene contribute to the genetic component of manic depression. The polymorphism, a 48 bp tandem repeat coding for part of the third cytoplasmic loop, was detected using a PCR based method. In a first sample of 57 patients and 59 controls, we found allele 7 to be in excess in the patients. In contrast, allele 3 was less frequent in patients. A second, larger sample of 90 patients and 91 controls was utilized to test these hypotheses. Data from the two samples were then pooled together for further analyses. We calculated the power of our samples, and if the frequency of 7 repeat allele obtained from sample 1 is true, i.e., 25% (28/114) for patients and 14% (16/118) for controls, then the power of the combined sample is 62% at 5% (two-tailed) significance level. However, both observations were not replicated; we therefore conclude that variations in this repeat at the DRD4 gene do not contribute to the genetic component of manic depression.

[Pemphigus chronicus benignus familiaris (Hailey-Hailey disease) and bipolar affective disease in 3 members of a family]

We report on three family members suffering from both autosomal dominant Hailey-Hailey disease and bipolar affective disorder. As molecular biology techniques have made the localization of genes causing simple Mendelian traits possible as a routine task, the gene for Hailey-Hailey disease will presumably be localized in the foreseeable future. The Hailey-Hailey gene and its chromosomal surrounding will then be a region of interest for linkage studies in bipolar affective disorder.

Association and haplotype analysis at the tyrosine hydroxylase locus in a combined German-British sample of manic depressive patients and controls

Tyrosine hydroxylase (TH) is the key enzyme in the synthesis of catecholamines and may therefore be of aetiological relevance in the development of psychiatric illness. Hipolar affective disorder association studies, with restriction fragment length polymorphisms located in flanking regions of the TH gene, have shown conflicting results. Alleles of a tetranucleotide repeat polymorphism (TH4) located in intron 1 of the gene were tested for association with bipolar affective disorder in a combined German and British sample of 183 bipolar patients and 209 healthy control probands. No differences in TH4 allele frequencies were found in the two groups. A subset of patients and controls was typed with the flanking markers Ty7/BglII and pJ4.7/TaqI and frequencies of two-locus haplotypes were estimated. Linkage disequilibrium was found between TH4-Ty7 and TH4-pJ4.7. Haplotype frequencies did not differ between patients and controls.

An association study of debrisoquine hydroxylase (CYP2D6) polymorphisms in schizophrenia

The cytochrome P450 mono-oxygenases are a group of enzymes that metabolize a variety of exogenous and endogenous compounds, some of which are potentially toxic. Individual variations in the metabolism of potential toxins could influence susceptibility to disorders having genetic and environmental components, such as schizophrenia. The frequency of two common mutant alleles of the gene for the cytochrome P450 enzyme debrisoquine-4-hydroxylase (CYP2D6) was determined in 264 Caucasian schizophrenic patients and 217 controls, using the polymerase chain reaction and restriction enzyme digestions. The patient and control samples showed no significant deviation from Hardy-Weinberg equilibrium and the frequency of each mutant allele (CYP2D6A and CYP2D6B) did not differ between patients and controls.

Familial cosegregation of affective disorder and Hailey-Hailey disease

We report on a family with co-occurrence of affective disorder and Hailey-Hailey disease in two brothers and the mother. The putative chromosomal locus of Hailey-Hailey disease, which is a rare dominantly inherited dermatosis, may be a promising candidate region for genetic studies in affective disorder.

A serine to glycine substitution at position 9 in the extracellular N-terminal part of the dopamine D3 receptor protein: no role in the genetic predisposition to bipolar affective disorder

Association studies offer a promising tool to investigate the potential role of DNA sequence variation affecting the expression or sequence of proteins in susceptibility to common diseases. We determined the frequency of a DNA polymorphism resulting in a glycine to serine substitution at position 9 in the extracellular N-terminal part of the dopamine D3 receptor protein in a sample of 83 patients suffering from bipolar affective disorder and 100 control subjects. No significant differences between the groups were found. Thus, this substitution, which is the first sequence variation identified in the dopamine D3 receptor gene altering the amino acid sequence of the protein, can be regarded as a protein variant with no major effect on the susceptibility to bipolar affective disorder.

Chronic palinopsia in schizophrenia

Palinopsia seems to be a very rare phenomenon in functional psychotic disorders. In this paper, we report on a patient with chronic schizophrenia who displayed chronic persisting palinopsia embedded in a plethora of rare mental phenomena. The possible theoretical relevance of this observation is discussed.

Lack of association between dopamine D1 and D2 receptor genes and bipolar affective disorder

Fifty-six patients with bipolar affective disorder and 69 healthy control subjects were tested for association of restriction fragment length polymorphism alleles at the dopamine D1 and D2 receptor loci. No significant associations were found; thus, the hypothesis that a single mutant form of either receptor gene is responsible for the phenotype of patients with bipolar affective disorder was not supported.

RFLP alleles at the tyrosine hydroxylase locus: no association found to affective disorders

Affective disorders are usually referred to as being inherited multifactorially. The contribution of a gene locus in illnesses displaying multifactorial inheritance may be assessed by searching for associations of alleles to the illness. The tyrosine hydroxylase gene encodes the rate-limiting enzyme in the synthesis of catecholamines and might be a candidate for causing the manic-depressive phenotype. Therefore, we tested 88 patients with affective disorders and 99 healthy control persons for association of restriction fragment length polymorphism (RFLP) alleles at the tyrosine hydroxylase locus. The comparison of allele or genotype frequencies did not reveal any significant differences between the two groups.

[Critique of the "therapeutic ego split"]

The technical relevance of the concept of a therapeutic ego split is rigorously examined. In the author's view, the distinction between a neurotic transference and a non-neurotic working alliance serves the therapist as a defense against anxiety rather than as a clarification of his intricate involvement with the patient.

Further RFLPs at the human tyrosine hydroxylase locus

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Determination of the new monoamine oxidase inhibitor moclobemide and three of its metabolites in biological fluids by high-performance liquid chromatography

A sensitive high-performance liquid chromatographic method has been developed for the determination of moclobemide and three of its metabolites in plasma and urine. The four substances and the internal standard were extracted from basified plasma (pH 11) with dichloromethane, with recoveries of generally more than 70%. A column packed with 5-microns Spherisorb hexyl phase and an eluent consisting of acetonitrile and aqueous phosphate buffer 30:320 (v/v) with a pH of 3.9 were found most suitable for the chromatographic separation of the four compounds of interest. Non-ideal interactions of the basic compounds and the N-oxide metabolite occurred with many other reversed-phase materials, as indicated by broad and tailing peaks. Limits of quantitation for moclobemide and its three metabolites in the range 20-30 ng/ml and a good intra-assay reproducibility ranging between 2 and 5% for concentrations over 100 ng/ml could be achieved for plasma, which increased to ca. 8-10% at a concentration of 50 ng/ml.

[Spontaneous liver rupture in eclampsia]

We report on a case of a 34-year old nullipara who suffered from rupture of the liver during eclampsia and survived despite most serious complications. Most cases of rupture of a non-traumatic subcapsular haematoma of the liver during pregnancy are associated with symptoms of pre-eclampsia. The pathogenesis of this severe complication as well as diagnostic imaging and surgical treatment are discussed. The classical trias of pre-eclampsia, epigastric pain and sudden circulary collapse may vary considerably. Since early diagnosis is crucial for maternal and foetal outcome, a subcapsular haematoma of the liver should be considered in women during pregnancy and childbed presenting with pre-eclampsia and upper abdominal pain. Here ultrasonographic imaging is a valuable and readily available diagnostic tool for the obstetrician.

Determination of tenoxicam in human plasma by high-performance liquid chromatography

A high-performance liquid chromatographic method for the determination of tenoxicam in plasma has been developed. Tenoxicam was extracted from buffered plasma (pH 3 or 4, respectively) with dichloromethane and the evaporated extracts were analysed on a C18 reversed-phase column using a methanol-phosphate buffer mobile phase and with UV detection at 371 nm. The detection limit was 20 ng/ml using a 0.5-ml sample. The method is selective with respect to the 5'-hydroxy metabolite, which is present in plasma after multiple administration of tenoxicam; this metabolite may also be determined using this procedure.