Characterization of genomic rearrangements of the alpha1-acid glycoprotein/orosomucoid gene in Ghanaians

In this study, the structure of the α₁-acid glycoprotein (AGP), or orosomucoid (ORM), gene was investigated in a Ghanaian mother and her child, who shared an unusual variant, ORM1 S2(C), found by isoelectric focusing. Three remarkable changes of nucleotide sequence were observed: (1) The two ORM1 alleles, ORM1 ^* S and ORM1 ^* S2(C), had the AGP2 gene-specific sequence at one and three regions, respectively, in exon 5 to intron 5. The variant allele originating from ORM1 ^* S was characterized by a G-to-A transition, resulting in an amino acid change from valine to methionine, which is also detected in ORM1 F2, a form that is common in Europeans. (2) The AGP2 gene of the child, inherited from the father, was duplicated, as revealed by long-range polymerase chain reaction. (3) Three new mutations were observed in two exons of the AGP2 genes of the mother and child. All of these novel genomic rearrangements, which were not observed in Japanese subjects, may have arisen through point mutation, gene conversion, and unequal crossover events. It is likely that the rearrangement of the AGP gene has often occurred in Africans. Received: June 15, 2001 / Accepted: July 10, 2001     

Genetic polymorphisms and cerebrospinal fluid levels of tissue inhibitor of metalloproteinases 1 in sporadic Alzheimer's disease

Tissue inhibitor of metalloproteinases 1 (TIMP-1) inhibits several proteinases including a disintegrin and metalloproteinase 10 (ADAM10), a major alpha-secretase that cleaves the beta-amyloid precursor protein within its amyloidogenic Abeta domain. The gene encoding TIMP-1 (TIMP 1) maps to the short arm of the X chromosome, in a region previously suggested as conferring genetic susceptibility for Alzheimer's disease (AD). To determine whether genetic variability of TIMP 1 contributes to the pathogenesis of AD, we analysed one single nucleotide polymorphism within TIMP 1 and one single nucleotide polymorphism in the 5'-untranslated region of TIMP 1 in patients with AD and control subjects from two independent and ethnically different populations. We did not observe any association between TIMP 1 genotypes and the diagnosis of AD in men or women. We also measured TIMP-1 protein levels in the cerebrospinal fluid of patients with AD, healthy control subjects, and patients with other neurological disorders. TIMP-1 levels were similar in all groups. In addition, no significant differences were observed after stratification for TIMP 1 genotypes. Our data show that neither genetic variability nor protein levels of TIMP-1 are associated with AD.     

Defects in neurofibromatosis 2 protein function can arise at multiple levels

Neurofibromatosis 2 (NF2) is an inherited cancer syndrome resulting from mutations in the NF2 tumor suppressor gene. Analysis of NF2 mutations has revealed some general genotype-phenotype correlations. Severe disease has been associated with mutations that produce a premature termination while more mild disease has been associated with missense mutations. Here, we provide experimental proof for these genotype-phenotype correlations by demonstrating that nonsense mutations fail to produce stable merlin protein while missense mutations result in the generation of merlin proteins defective in negative growth regulation. This inability to suppress cell growth may result from defects in the function of merlin at several levels, including failure to form an intramolecular complex. Based on these findings, we propose a model for merlin growth suppression that provides a framework for analyzing NF2 patient mutations and merlin function.      

Uterine myomata and outcome of assisted reproduction

The aim of this work was to study the effect of uterine myomata on the implantation rate and outcome in in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Among 406 patients, 51 (12.6%) were found to have uterine corporeal myomata. Twelve patients were excluded from the study as they had large myomata, submucous myomata or intramural myomata encroaching on the cavity. These patients were advised to have myomectomy before being enrolled in the IVF/ICSI programme. The remaining patients (n = 39) were sorted according to the number, site and size of the myomata as assessed by transvaginal sonography. Three patients had more than one myoma. Most of the myomata were subserous (72.7%) and the mean diameter of the myomata was 3.5 +/- 0.9 cm. A control group (n = 367) was chosen with normal uteri and no history of uterine reconstruction surgery. The mean age of myoma patients was 34.7 +/- 3.6 years as compared to 34.0 +/- 4.4 years in the control group. The age, period of infertility, body mass index, duration and number of human menopausal gonadotrophin ampoules needed for stimulation, oestradiol levels, number of oocytes retrieved and the fertilization rate were not significantly different in the myoma patients compared to the control group. Fifteen myoma patients (38.5%) subsequently showed one or more pregnancy sacs on ultrasonography of which three (20%) spontaneously aborted during the first trimester and two (13.3%) had preterm labour, as compared to 123 (33.5%), 19 (15.5%) and nine (7.3%) respectively, among the control group (P = 0.27, 0.33 and 0.21). In conclusion, uterine corporeal myomata, not encroaching on the cavity and <7 cm in mean diameter, do not affect the implantation or miscarriage rates in IVF or ICSI.      

Immunohistochemistry (S 100, KL 1) and human papillomavirus DNA hybridization on Morbus Bowen and bowenoid papulosis

Summary In this study 55 paraffin embedded samples defined as Bowen's disease or bowenoid papulosis were investigated with antibodies against S 100 protein and keratins (KL 1). S 100-positive cells were quantified and related to defined section area of the epidermal compartment by computer-assisted image analysis. The density of S 100-positive cells was compared with normal skin and was particularly related to growth patterns and keratinization of the different lesions under study. S 100-positive dendritic cells were found to be reduced overall in bowenoid lesions when compared with normal skin. Lesions with high counts of S 100-positive dendritic cells most frequentty showed a solitary growth pattern with highly conserved architecture and differentiation and no tendency to stromal invasion. In contrast, cases with low counts of S 100-positive cells very often showed multifocal development, a high degree of architectural disturbance and dedifferentiation. In this group, stromal invasion (cases of invasive carcinoma associated with Bowen's disease) was seen more often. Interestingly, this latter group of cases also revealed a peculiar keratin pattern. Frequently, the basal cell layer was decorated with KL 1 antibody, which usually recognizes only suprabasaly located keratinocytes. No differences between Bowen's disease and bowenoid papulosis were found in terms of densities of S 100-positive dendritic cells and keratin pattern. In our experience, extragenital Bowen's disease and genital Bowen's disease can not be distinguished on purely morphological grounds or with the immunocytochemical approach presented here. Interestingly, when employing in situ hybridization with HPV 16 probes three of seven samples of genital Bowen's disease harboured HPV 16 DNA, whereas six cases of extragenital disease were negative.Supported by the Deutsche Forschungsgemeinschaft (Lo 285/2-4)     

Covariances of Mitogenic Responses in Leukaemic Blood Lymphocytes: a Functional Marker System for the Human B Lymphocyte Differentiation

Various polyclonal activating substances have been shown to stimulate human chronic lymphatic leukaemic (CLL) cells to undergo blast transformation, to divide and to secrete monoclonal immunglobulin. CLL cells from different patients show distinct response patterns to these ligands. We have statistically analysed these response patterns and found that responses to certain ligands demonstrate covariance; that is, a high response to one ligand is statistically associated with a high response to another ligand. A factor analysis of these data on the basis of responses of CLL cells from twenty-one patients and from the use of five different ligands in three different concentrations has shown that as few as two factors can account for as much as 63% of the total variance of these responses. On the assumption that these two factors were T-cell dependency of CLL responses and stage of maturity of the responding CLL cell, we have formulated a theory that explains the basis for this functional marker system for CLL cells. It is possible application to the characterization of individual CLL clones has been discussed.     

Noradrenergic mechanisms in the central amygdalar nucleus and gastric stress ulcer formation in rats

Microinjections of noradrenaline (NA, 0.3, 3.0 and 30.0 micrograms) into the central amygdalar nucleus (CEA) produced dose-related attenuations of cold restraint (3 h at 4 degrees C) induced gastric ulcer formation in rats. On the other hand, stress ulcer aggravating effects were seen with beta-adrenoceptor antagonist, propranolol (10 micrograms) but not with the alpha-adrenoceptor antagonist, prazosin (1 and 10 micrograms). Moderate enhancements of gastric stress lesions were also seen with the NA release inhibitor clonidine (1 microgram) and the neurotoxin DSP-4 (25 micrograms). Further, pretreatment of rats with intra-amygdalar (i.am.) propranolol but not prazosin, antagonized and reversed the gastric cytoprotective effects of NA. The results indicate that beta-adrenoceptor-mediated NAergic mechanisms at the level of the CEA are important for the maintenance of gastric mucosal integrity during immobilization stress.     

Localization of CEA,HCG, Lysozyme,alpha-1-antitrypsin,and alpha-1-antichymotrypsin in gastric cancer and prognosis

Summary Carcinoembryonic antigen (CEA),-human chorionic gonadotropin (HCG), alpha-1-antichymotrypsin (ACT), alpha-1-antitrypsin (AAT) and Lysozyme (LYS) were traced by immunoperoxidase staining in gastric carcinomas. The immunohistological results were evaluated in relation to histological types (WHO and Laurén), stage of disease, grade and survival time. CEA was demonstrated in 96% of the tumours, HCG in 34%, ACT in 78%, AAT in 42%, and LYS in 71%. Comparing the staining patterns of the antigens and the intensity of staining some differences were notable. Except for signet-ring cell carcinomas, all of which were intensively positive, CEA expression decreased significantly with loss of differentiation. This observation was not seen with the other marker substances. None of the tested markers was characteristic for one particular histological type, nor could they be correlated with the tumour stage or grade. The marker positivity of CEA, ACT and LYS was not related to survival time. For HCG only, a correlation between tissue expression and a restricted survival time was established. Patients with AAT positive carcinomas had a significantly better survival probability.     

Numerical chromosomal aberrations in papillary renal cortical tumors: relationship with histopathologic features

Previous studies have indicated that a combined trisomy of chromosomes 7 and 17 is a constant finding in papillary renal cortical adenomas and that papillary renal cell carcinomas are marked by additional trisomies such as trisomy 12, 16, and 20. The aim of our study was to compare this cytogenetic classification of papillary renal cortical tumors with conventional histopathologic classification. We performed interphase cytogenetics with enumeration probes for chromosomes 7, 12, 16, 17, and 20 on 41 papillary tumors found in 21 nephrectomy and 10 autopsy kidneys. A total of 38 tumors harbored gains of chromosomes 7 or 17, and most of these showed a trisomic signal distribution. The three tumors with normal copy numbers for chromosomes 7 and 17 were a papillary grade-2 carcinoma, a small adenoma (both with distinctive oxyphilic cytoplasm), and a papillary carcinoma with focally clear cells. Gains for chromosomes 12, 16, or 20 were found in 21 tumors and were significantly associated with the presence of histologic criteria of malignancy ( P<0.0001). Histopathologic and cytogenetic features of malignancy were found in eight tumors smaller than 10 mm. There is a good agreement of cytogenetic and histopathologic criteria of malignancy in papillary renal cell tumors. Interphase cytogenetics might give useful additional information in cases of doubt or when only small biopsy specimens are available.     

Inflammatory mediators in cotton-top tamarins (CTT) with acute and chronic colitis

Spontaneous colitis in CTT's presents cytological characteristics similar to chronic ulcerative colitis in humans, e.g. inflammatory cell infiltrate and crypt abscesses. To better characterize CTT colitis as a potential model for human inflammatory bowel disease (IBD), inflammatory mediators identified in colonic tissue of human IBD patients and/or experimental colitis models were assayed. Inflammatory mediator changes in plasma and colon from tamarins with acute (n=10) and chronic (n=10) colitis (by mucosal biopsy) were assayed by RIAs. Similar inflammatory mediators were found in the CTT's with acute colitis. In the plasma, PAF and PGE₂ levels were lower in acute colitis CTT's, no LTB₄ was detected, and histamine levels were not different from chronic colitic animals. In the colon, myeloperoxidase and interleukin-1 were significantly higher in acute colitis, PGE₂ and LTB₄ were higher but not significantly, and PAF was not different from chronic CTT's. These data suggest that a combination of events are occurring in the pathogenesis of tamarin colitis that involves some of the same mediators that are found in the human disease and in other experimental models. The importance of these findings to human IBD remains for further investigation; however, the spontaneous primate model offers an exciting approximation of the disease development and merits further investigation for understanding the pathogenesis of human IBD as well as to aid in development of targeted therapeutics.