Expansion of recipient-derived antiviral T cells may influence donor chimerism after allogeneic stem cell transplantation.

Donor chimerism (DC) analysis is an important marker in the hematopoietic stem cell transplant follow-up. Here, we present evidence for a possible relationship of infectious complications and declines in DC. We analyzed the DC in patients experiencing cytomegalovirus (CMV) reactivation. In addition, in some patients chimerism analyses of T-cell subsets were performed. CMV-specific cytotoxic T-lymphocytes (CMV-CTL) were monitored using human leukocyte antigen-restricted multimer staining. Interestingly, CMV reactivation was accompanied by changes in DC in 11 of 67 patients transplanted. For example, DC declined in a cord blood recipient, in both total leukocytes and CD4 and CD8 T-cell subsets upon CMV reactivation. The latter was controlled after only 5 days through expanding CMV-CTL of 96% recipient origin, according to chimerism analysis of CMV-CTL (enriched beyond 50%). In another patient, transplanted after reduced-intensity conditioning from a DQB1 mismatched, CMV seronegative donor, incipient CMV reactivation was completely aborted by CMV-CTL of recipient origin. However, at the same time, mixed chimerism dropped from 51% to 0% donor type, resulting in late graft rejection. Our data indicate that chimerism analyses in subset populations lead to a better understanding of declining total leukocyte chimerism. Furthermore, recipient-derived CMV-CTL may be able to control CMV reactivation after reduced-intensity conditioning. We speculate that autologous CMV-CTL may be instrumental to overcome recurrent CMV reactivations, especially in patients transplanted from CMV-seronegative donors. In addition, the expansion of recipient-derived CMV-CTL may contribute to both, graft failure or to conversion to full DC.

[Tetrasomy 18p syndrome and hearing loss. An unusual case]. / Tetrasomie 18p und Innenohrschwerhörigkeit. Ein ungewöhnlicher Fall.

Tetrasomy 18p is a rare chromosomal disease (1:140,000 live births), which affects females and males equally, and might be hereditary or caused by spontaneous changes (de novo formation) within the chromosome. The phenotype results from the presence of a small extra metacentric marker chromosome, an isochromosome 18p. The syndrome is characterized by mild-to-moderate mental retardation, poor language acquisition, seizures, microcephaly, short statue, minor facial dysmorphic features, congenital heart diseases, uro/renal malformations, abnormal muscle tone, spasticity of the lower limbs, and delayed ability to stand and walk. To our knowledge sensorineural hearing loss is described in the literature but has not been described as a typical phenotypic symptom of tetrasomy 18p.In the following report, a boy with tetrasomy 18p is described. In addition to psychomotor retardation with muscular hypotonia and orofacial dismorphysms, bilateral severe hearing loss was diagnosed. Thus, in all infants with known chromosomal aberration, early diagnostic procedures must be performed to unveil sensorineural hearing loss that might be overseen because of mental retardation. In particular, a brainstem-evoked response audiometry (BERA) should be considered for early diagnosis and treatment of possible hearing loss. Furthermore, in all children with developmental delay and dysmorphic features a chromosomal analysis should be initiated.

Basal ganglia calcification and psychosis in 22q11.2 deletion syndrome.

Intracerebral calcifications are a facultative symptom of hypoparathyreoidism in 22q11.2 deletion syndrome (22qDS). We describe a patient with 22qDS, basal ganglia calcification (BGC) and psychotic symptoms and discuss the etiological connection of BGC with psychiatric symptoms. Future work needs to determine the prevalence of BGC in 22qDS and psychiatric disorders.

Diffusive transport through a model host-biofilm system.

Free-living biofilms have been subject to considerable attention, and basic physical principles for them are generally accepted. Many host-biofilm systems, however, consist of heterogeneous mixtures of aggregates of microbes intermixed with host material and are much less studied. Here we analyze a key property, namely reactive depletion, in such systems and argue that two regimes are possible: (1) a homogenizable mixture of biofilm and host that in important ways acts effectively like a homogeneous macrobiofilm and (2) a distribution of separated microbiofilms within the host with independent local microenvironments.

The application of region-specific probes for the resolution of duplication 8p: a case report and a review of the literature.

The structural rearrangement in the short arm of a chromosome 8 in a clinically affected patient has been reinvestigated by FISH using whole chromosome painting and region specific YAC probes. An inverted duplication of the segment p22-->p11.2 and a deletion of the subtelomeric region were demonstrated. By this approach, a more detailed resolution of the duplication/deletion 8p was possible. With the application of molecular cytogenetic methods the existence of different duplication segments within the clinical entity of duplication/deficiency 8p can be shown.

Randomized controlled evaluation of the effects of cognitive-behavioral stress management on cortisol responses to acute stress in healthy subjects.

Psychosocial stress is a potent activator of the hypothalamus-pituitary-adrenal (HPA) axis. While neuroendocrine stress responses are essential for the maintenance of homeostasis, evidence suggests that excessive activation of the HPA axis constitutes a risk for disease and psychopathology. The purpose of the present study was to assess the effect of cognitive-behavioral stress management training on endocrine stress responses and cognitive appraisal under acute psychosocial stress among healthy young subjects. Forty-eight healthy, non-smoking male students without acute or chronic medical or psychiatric disorder on self report were randomly assigned to receive group-based cognitive-behavioral stress management training either before or after a standardized psychosocial stress test (Trier Social Stress Test, TSST). Endocrine and psychological stress responses were assessed with salivary free cortisol response and cognitive appraisal processes to the TSST. In comparison with the control group, subjects in the treatment group showed an attenuated endocrine response (F (2.55/117.41) = 3.81; P = 0.02; effect size f(2) = 0.35) to the TSST. In addition, subjects in the SIT group had lower stress appraisal and higher control expectancies (F (2/45) = 6.56; P = 0.003, effect size f(2) = 0.29) compared to controls. Short group-based cognitive-behavioral stress management training reduces the neuroendocrine stress response to an acute stressor in healthy subjects. Therefore, stress management training may prove useful in preventing detrimental effects of stress-induced neuroendocrine activation

Distribution of epidermal growth factor receptor gene amplification in brain tumours and correlation to prognosis.

In 75 gliomas and 31 meningiomas, mutations at the epidermal growth factor receptor (EGFR) gene locus were restricted to gliomas. The ligands of this receptor, epidermal growth factor and transforming growth factor alpha, lacked quantitative changes at their loci in gliomas and meningiomas. EGFR gene amplification occurred in astrocytomas, oligodendrogliomas, ependymomas and glioblastomas. The frequency of this mutation significantly increased with the malignancy grade and the patient's age. Especially in glioblastomas of individuals aged over 64 years, EGFR gene mutations were observed without chromosome-10-specific allele losses. This finding contradicts the hypothesis that deletion of one entire chromosome 10 regularly precedes EGFR gene amplification in primary glioblastomas of patients aged over 50 years. It was found that most individuals whose gliomas carry an EGFR gene mutation have a poor prognosis, comparable to that of glioblastoma patients even when the tumour is graded as benign.

Loss of alleles in brain tumours: distribution and correlations with clinical course.

Gliomas (n = 44) and meningiomas (n = 24) of different grades of malignancy were analysed for allele losses at loci on chromosomes 10, 13, 17 and 22. Deletions of genetic material on these chromosomes occurred in gliomas without being restricted to any histological entity. The frequency of chromosome-10-specific allele losses increased significantly with the age of the patients and with the grade of malignancy of the tumours. Deletions of chromosome 10 material were associated with a poor prognosis. The glioblastomas of patients aged over 70 years lacked the loss of the entire chromosome 10, even in tumours with EGFR gene amplification. Deletions at loci of chromosomes 13, 17 and 22 were observed in 18-32% of all gliomas, independent of grade of malignancy, patients' age, EGFR gene amplification and clinical course. Only chromosome-22-specific allele losses were found preferentially in gliomas of female patients. Loss of chromosome 22 alleles in 44% was the only mutation detected in meningiomas. This occurred independently of grade of malignancy and biological factors.

Analysis of K-ras mutations in pancreatic tissue after fine needle aspirates.

The majority of pancreatic carcinomas contain a mutation at codon 12 of the K-ras oncogene. We have analysed 87 samples from 76 patients who underwent surgery because of different pancreatic diseases to evaluate whether the detection of K-ras mutations may be helpful to discriminate between chronic inflammation and neoplastic growth. Mutation analysis was performed using a semi-nested PCR followed by a selective restriction enzyme digestion. The correlation of clinical follow ups with the results of the molecular analysis was performed from 47 patients. K-ras mutations were detected in 50% of adenocarcinomas and no point mutation was found in normal pancreatic tissue and in tumor tissue from entities other than pancreas. Otherwise, K-ras mutations were detected in tissue samples from two patients with chronic pancreatitis, and one patient was found to have an adenocarcinoma after additional clinical investigation. Further studies especially follow ups will be helpful to get a better insight into the pathogenesis of pancreatic tumors and may be useful as an early diagnostic test.

Search for deletion 22q11.2 in interphase nuclei of buccal mucosa of patients ascertained by isolated cleft palate: a new diagnostic approach.

A new approach for the detection of chromosome deletion 22q11.2 in interphase nuclei from buccal mucosa cells obtained by a non-invasive procedure is described. FISH analysis has been performed on samples from a group of 101 patients that presented consecutively for speech therapy and/or surgical correction of cleft palate. A normal result has been obtained in 98 patients; a deletion 22q11.2 was present in three patients (2.8%) with cleft palate.

Haematological and biochemical findings in cattle with dilatation and torsion of the caecum.

A biochemical examination was made of the blood and rumen fluid of 111 heifers and cows suffering from caecal dilatation, with or without torsion. Haematological values were normal in the majority of cattle. Concentrations of chloride were normal in the rumen fluid of 83 per cent of the animals and higher in the remainder. Nine cows that had to be slaughtered had higher bile concentrations than those which recovered. Twenty-eight per cent had increased blood urea concentrations probably due to dehydration.

[Emergency treatment of limb fractures in large and small ruminants]. / Erste Hilfe bei Gliedmassenfrakturen von grossen und kleinen Wiederkäuern.

Limb fractures in cattle have to be treated as emergencies. The success or failure of treatment depends on a careful examination and adequate emergency treatment by the veterinarian. The most important rules in an emergency treatment are the evaluation of the general systemic conditions and the initiation of whatever supportive care is required. Further attention should be paid to thoroughly rinsing and disinfecting open wounds and to immobilizing fractures for transport purposes. In 39 cases the localisation and the type of fracture were determined and the clinical relevance of a careful examination and emergency treatment was evaluated. Metacarpal fractures were the most common type of fracture. Open fractures were more likely to occur in cases of insufficient immobilisation than with properly attended patients (p less than 0,01). Open fractures have a poorer prognosis than closed fractures (p less than 0.002).

[Spectrum of neuropsychiatric features associated with velocardiofacial syndrome (Deletion 22q11.2)]. / Das neuropsychiatrische Spektrum des Velokardiofazialen Syndroms (Deletion 22q11.2).

Microdeletion 22q11.2 (22q11DS) is the most frequent chromosomal deletion known in man. Velocardiofacial syndrome is one of numerous clinical syndromes that can be attributed to this micro deletion. There is an increasing recognition of associations with neuropsychiatric disorders. Particularly, schizophrenic psychosis, attention-deficit/hyperactivity disorder (ADHD), intellectual impairment and learning disabilities, seizures and motoric abnormalities have been identified in patients with 22q11DS. Recent studies supported the association of schizophrenia and 22q11DS, but the pathogenetic implications for idiopathic schizophrenia are still controversial. We report on two clinical cases in which psychotic symptoms led to the molecularcytogenetic diagnosis of microdeletion 22q11.2. Additionally, this article gives a systematic review of literature regarding psychiatric disorders, neurologic symptoms and partly corresponding morphological brain abnormalities in 22q11 deletion syndromes.

[An unusual complication after the partial resection of the ascending duodenum of a cow]. / Eine ungewöhnliche Komplikation nach partieller Resektion des Duodenum ascendens bei einer Kuh.

In a heifer portions of the ascending duodenum, which had been perforated by an obstructing phytobezoar, were resected. This resulted in an unexpected complication. The shortened ligamentum duodenocolicum exerted steady traction on the descending colon. This traction caused a kink and finally resulted in a total obstruction of the colon. The pathogenesis of this complication is illustrated. Surgical--possibly preventive--procedures are discussed.

MECHANISMS OF NONDISJUNCTION AND IMPLICATIONS FOR TESTING ANEUGENS.

THE HUMAN SPECIES IS AFFECTED BY A HIGH FREQUENCY OF CONSTITUTIONAL ANEUPLOIDY WHICH IS MAINLY DERIVED FROM NONDISJUNCTION DURING PARENTAL MEIOSIS AND PREFERENTIALLY DURING MATERNAL MEIOSIS I. IN UNRAVELLING THE MECHANISMS INVOLVED WE STUDIED VARIOUS CONDITIONS CAUSING AND ASSOCIATED WITH NONDISJUNCTION IN OOCYTES FROM DJUNGARIAN HAMSTERS. CONSIDERING OUR OBSERVATIONS WE SUGGEST THAT THE ORDERLY SEGREGATION OF CHROMOSOMES AT MEIOSIS APPEARS TO RESULT FROM A CASCADE OF DIFFERENTIATION PROCESSES REQUIRING THE INTERACTION OF AN EXTRA-, TRANS- AND INTRACELLULAR SIGNALLING. FAILURES MAY OCCUR AT ANY LEVEL ALTERING E.G.: (1) THE CONTROL OF FOLLICULAR MATURATION/FUNCTION (OR GENERALLY THE FUNCTION OF THE SOMATIC COMPARTMENT WITHIN THE GONADS) (2) THE SIGNALLING BETWEEN SOMA AND MEIOCYTE (3) THE FUNCTION OF THE CYTOPLASM AND CYTOPLASMIC ORGANELLES SUCH AS THE SPINDLE AND MITOCHONDRIA (BEERMANN ET AL. 1988) (3) THE RATE OF MEIOSIS (5) CHROMOSOME BEHAVIOR AND THEIR INTERACTION WITH MICROTUBULI. NONDISJUNCTION APPEARS TO BE ONE CONSEQUENCE OF A DISTURBED CONTROL OF MEIOCYTE PROLIFERATION. THE CAUSES MIGHT, IN ANALOGY, BE AS DIVERSE AS THOSE LEADING TO NEOPLASTIC GROWTH OF SOMATIC CELLS. NOTWITHSTANDING THE NECESSITY FOR SIMPLIFICATION IN MUTAGENICITY TESTING ONE HAS TO REMIND THAT THE MAJORITY OF TRISOMIES ORIGINATE FROM A MEIOSIS I ERROR. SO FAR WE CAN NOT BE SURE THAT SOMATIC CELL TESTING MAY INDICATE PUTATIVE EVENTS DURING THE ABOVE DESCRIBED COMPLICATED INTERACTIVE MATURATION PROCESS OF GERM CELLS.

Chromosome 18 replaced by two ring chromosomes of chromosome 18 origin.

We here describe the first example of the replacement of an autosome by two ring chromosomes originating from the missing chromosome, presented in a patient with a single chromosome 18 and two additional ring chromosomes. Detailed fluorescence in situ hybridization (FISH) analysis revealed the chromosome 18 origin of both ring chromosomes and characterized the small and the large ring chromosome as derivatives of the short and long arm of chromosome 18, respectively. The loss of subtelomeric regions of the short and the long arm of chromosome 18 in the ring chromosomes was confirmed by FISH studies. Molecular studies showed the exclusive presence of the paternal alleles for microsatellite markers located distal to the short and long arm loci D18S843 and D18S474, respectively. This indicates the maternal origin of both rings and provides evidence for substantial deletions of the distal parts of both arms of chromosome 18 in the ring chromosomes. The dysmorphic features of the patient can be explained by these deletions in both chromosome arms, as the clinical findings partly overlap with observations in 18p- and 18q-syndrome and are similar to some cases of ring chromosome 18. Centromere misdivision is suggested as one mechanism involved in the formation of the ring chromosomes.

Role of CtBP in transcriptional repression by the Drosophila giant protein.

The giant protein is a short-range transcriptional repressor that refines the expression pattern of gap and pair-rule genes in the Drosophila blastoderm embryo. Short-range repressors including knirps, Krüppel, and snail utilize the CtBP cofactor for repression, but it is not known whether a functional interaction with CtBP is a general property of all short-range repressors. We studied giant repression activity in a CtBP mutant and find that this cofactor is required for giant repression of some, but not all, genes. While targets of giant such as the even-skipped stripe 2 enhancer and a synthetic lacZ reporter show clear derepression in the CtBP mutant, another giant target, the hunchback gene, is expressed normally. A more complex situation is seen with regulation of the Krüppel gene, in which one enhancer is repressed by giant in a CtBP-dependent manner, while another is repressed in a CtBP-independent manner. These results demonstrate that giant can repress both via CtBP-dependent and CtBP-independent pathways, and that promoter context is critical for determining giant-CtBP functional interaction. To initiate mechanistic studies of the giant repression activity, we have identified a minimal repression domain within giant that encompasses residues 89-205, including an evolutionarily conserved region bearing a putative CtBP binding motif.

Transcriptional repression by the Drosophila giant protein: cis element positioning provides an alternative means of interpreting an effector gradient.

Early developmental patterning of the Drosophila embryo is driven by the activities of a diverse set of maternally and zygotically derived transcription factors, including repressors encoded by gap genes such as Krüppel, knirps, giant and the mesoderm-specific snail. The mechanism of repression by gap transcription factors is not well understood at a molecular level. Initial characterization of these transcription factors suggests that they act as short-range repressors, interfering with the activity of enhancer or promoter elements 50 to 100 bp away. To better understand the molecular mechanism of short-range repression, we have investigated the properties of the Giant gap protein. We tested the ability of endogenous Giant to repress when bound close to the transcriptional initiation site and found that Giant effectively represses a heterologous promoter when binding sites are located at -55 bp with respect to the start of transcription. Consistent with its role as a short-range repressor, as the binding sites are moved to more distal locations, repression is diminished. Rather than exhibiting a sharp 'step-function' drop-off in activity, however, repression is progressively restricted to areas of highest Giant concentration. Less than a two-fold difference in Giant protein concentration is sufficient to determine a change in transcriptional status of a target gene. This effect demonstrates that Giant protein gradients can be differentially interpreted by target promoters, depending on the exact location of the Giant binding sites within the gene. Thus, in addition to binding site affinity and number, cis element positioning within a promoter can affect the response of a gene to a repressor gradient. We also demonstrate that a chimeric Gal4-Giant protein lacking the basic/zipper domain can specifically repress reporter genes, suggesting that the Giant effector domain is an autonomous repression domain.