The great mimicker: Phenotypic overlap between constitutional mismatch repair deficiency and Tuberous Sclerosis complex

Constitutional mismatch repair deficiency is a rare cancer predisposition syndrome caused by biallelic mutations in one of the four mismatch repair genes. Patients are predisposed to various tumors including hematological malignancies, brain tumors and colorectal carcinomas. Phenotypic overlap with Neurofibromatosis-1 is well known, with most patients presenting with café-au-lait macules. Other common features include axillary and/or inguinal freckling and intracranial MRI foci of high T2W/FLAIR signal intensity similar to the typical FASI seen in Neurofibromatosis-1. In this cohort of eight patients with constitutional mismatch repair deficiency we describe overlapping phenotypical features with Tuberous Sclerosis complex. In addition to “ash-leaf like” hypomelanotic macules (five patients), we detected intracranial tuber-like lesions (three patients), renal cysts (three patients) and renal angiomyolipomas (two patients). All our patients also had Neurofibromatosis-1 like features, mainly café-au-lait macules. This study suggests that features of Tuberous sclerosis especially when overlapping with those of Neurofibromatosis 1 or malignancies atypical for these syndromes should raise the possibility of constitutional mismatch repair deficiency. Correct diagnosis is essential for appropriate genetic counseling and pre-emptive cancer surveillance.     

Aldosterone

Aldosterone is one the representative cardiovascular hormones involved in the blood pressure and body-fluid homeostasis. Elevation of aldosterone leads to systemic hypertension through its action on the mineralocorticoid receptor (MR) in the kidney. More recent studies demonstrated that aldosterone may produce target organ damage through its direct actions on the non-epithelial MR of the heart in addition to its systemic effects. Clinical experience in primary aldosteronism supports the concept that aldosterone is a risk factor of cardiovascular complications, since concentric type of cardiac hypertrophy is most common in primary aldosteronism among various types of endocrine hypertension. Clinical mega-trial in congestive heart failure (RALES study, EPHESUS study) demonstrated blocking angiotensin II action is not sufficient for cardioprotection unless aldosterone action is equally blocked. An important phenomenon related to this issue is the aldosterone breakthrough which implies a reelevation of plasma aldosterone during chronic administration of ACE inhibitors and Angiotensin receptor antagonists. Normal level of aldosterone could still be a risk factor. Combination of ACE inhibitor or ARB with aldosterone antagonist could result in a better cardioprotection in cardiovascular diseases. Although spironolactone has been the only one aldosterone antagonist, a new antagonist eplerenone has been developed. Eplerenone is specific to MR and is practically devoid of the major side effect gynecomastia of spironolactone. Another topic of aldosterone is its very quick cardiovascular effect presumably via a non-genomic action. All these recent findings support that this adrenocortical steroid hormone is as important as angiotensin II. Determining aldosterone levels is therefore much morel important than before in the diagnosis and treatment of cardiovascular diseases.     

Usefulness of skin prick test using bifurcated needle for the diagnosis of food allergy among infantile atopic dermatitis--1st report. In the case of egg allergy

OBJECTIVE: We investigated the usefulness of skin prick test (SPT) for the diagnosis of egg white (EW) allergy in infants with atopic dermatitis who showed negative to EW CAPRAST, and followed up the EW-CAPRAST in this study. SUBJECTS AND METHODS: Data of negative SPT using Bifurcated needle (BN) were analyzed from the data of 202 atopic dermatitis infants, who had received SPT from January in 2001 to April in 2005. From the negative SPT value (average and standard deviation) positive SPT value was obtained. Among 202 cases, 89 suspected-egg allergy infants with negative IgE CAPRAST against EW at the time of first visit were recruited to examine the usefulness of SPT. Positive conversion of EW-CAPRAST was checked in 78 cases (65: egg allergy+, 13: egg allergy(-)) who had been followed up in our outpatient clinic. RESULTS: Range of negative SPT control value (mean+2SD) using BF among infants could be set as less than 2 mm for wheal and/or 5 mm for erythema. Among 89 suspected-egg allergy infants with negative EW-CAPRAST, 72 infants (80.9%) were diagnosed as egg allergy by the combination of elimination and provocation test, interestingly 39 infants (54.2%) showed positive SPT results. In the follow up study of 78 negative EW-CAPRAST cases, 47 EW-CAPRAST out of 65 egg-allergy cases turned positive later infantile period (mean EW-CAPRAST: 9.6+/-16.7 Ua/ml at 9.9+/-5.6 months old). EW-CAPRAST of 7 cases in 13 non-egg allergies also turned positive in the follow up, however EW-CAPRAST titer was relatively lower compared to that of egg allergies (1.1+/-1.5 Ua/ml at 13.3+/-2.6 months old). CONCLUSIONS: We experienced fairly number of atopic infants with negative EW-CAPRAST at the first outpatient visit, who were later diagnosed as egg allergy. In about half of these cases, SPT egg-allergy infants, three quarter of EW-CAPRAST turned positive around 10 months old. EW-CAPRAST of atopic infants without egg allergy also turned transiently and slightly positive. In the conclusions, SPT seemed to be more useful than EW-CAPRAST for the diagnosis of egg allergy in early infantile period, however provocation test should be required for the definitive diagnosis in suspected-egg allergy infants without any proof of egg-sensitization.     

Detection of a soluble form of the complement membrane attack complex inhibitor CD59 in plasma after acute myocardial infarction

Activation of the complement system has been documented in both experimental and clinical studies of acute myocardial infarction (AMI). Our earlier immunohistochemical studies have shown that the deposition of the membrane attack complex (MAC) of complement is associated with the loss of protectin (CD59), a glycosyl-phosphatidylinositol (GPI)-anchored sarcolemmal regulator of MAC, from the human and rat infarcted myocardium. In this study we detected, using an enzyme immunoassay (EIA), CD59 in the plasma of AMI patients at a concentration of 23.0+/-8.4 ng/ml (mean +/- SD; n = 17) at 4 h and 27.3+/-11.8 ng/ml (n = 24) at 24 h after AMI. Both values were significantly higher than in healthy controls (7.8+/-6.4 ng/ml; n = 20; P<0.001). The amount of CD59 correlated with the level of soluble terminal complement complexes (SC5b-9; r = 0.84; P<0.01) in the plasmas of AMI patients. Our results suggest that myocardial damage leads to release of CD59 from the sarcolemmal cell membranes during AMI.     

Expression of CD80 and CD86 on Peripheral Blood T Lymphocytes in Patients with Systemic Lupus Erythematosus

CD80 and CD86 were detected in high amounts on circulating T cells in the peripheral blood of some patients with systemic lupus erythematosus (SLE), using flow cytometry and monoclonal antibodies. Patients with other connective tissue diseases did not have a high percentage of T cells expressing CD80 or CD86 in their peripheral blood. CD80 was expressed mainly on CD4 T cells, whereas CD86 was expressed on CD8 T cells, and these two populations were associated with paticular clinical features. These two molecules were expressed on different T-cell populations and might have different roles in the generation and regulation of immune responses. Since high expression of CD86 on T cells was detected much earlier than the appearance of clinical features and a high titer of anti-DNA antibody, it may be a useful parameter for predicting the flare of SLE.     

Grading score system: A method for evaluation of the degree of senescence in Senescence Accelerated Mouse (SAM)

For evaluation of the degree of senescence in SAM-P, accelerated senescence prone mouse, formerly called SAM or prone series or P-series, consisting of SAM-P/1, SAM-P/2, SAM-P/3 and SAM-P/4 corresponding to P-1, P-2, P-3 and P-4 series, respectively, in the previous reports, and in SAM-R, accelerated senescence resistant mouse, formerly called resistant series or R-series, consisting of SAM-R/1, SAM-R/2 and SAM-R/3 corresponding to R-1, R-2 and R-3 series, respectively, in the previous reports, the grading score system was adopted. The items to be examined in this system include 11 categories selected from the clinical signs and gross lesions considered to be associated with the aging process. The degree of the senescence in each category was graded from 0 to 4 according to the detailed criteria devised in our laboratory. After 8 months of age each mouse was examined every 4 months, and some of the mice were examined after 2 months of age.In almost all categories, the grading score and incidence began to increase from 4 or 6 months of age and continued to increase with advancing age in both SAM-P and SAM-R. The increase, however, was more marked in SAM-P than in SAM-R. The slow but steady increase in the SAM-R levelled out at 24 months of age and was comparable to that of 12 months of age in SAM-P. In both SAM-P/1 at 8 months of age and SAM-R/2 at 12 months of age, there was a significant reverse correlation between total score of this grading score system and length of residual life after examination.Systematic and extensive studies using the grading score system showed that if the validity of the system is, based on “irreversibility” and “universality” of the changes in     

Analysis of the floral transcriptome uncovers new regulators of organ determination and gene families related to flower organ differentiation in Gerbera hybrida (Asteraceae)

Development of composite inflorescences in the plant family Asteraceae has features that cannot be studied in the traditional model plants for flower development. In Gerbera hybrida, inflorescences are composed of morphologically different types of flowers tightly packed into a flower head (capitulum). Individual floral organs such as pappus bristles (sepals) are developmentally specialized, stamens are aborted in marginal flowers, petals and anthers are fused structures, and ovaries are located inferior to other floral organs. These specific features have made gerbera a rewarding target of comparative studies. Here we report the analysis of a gerbera EST database containing 16,994 cDNA sequences. Comparison of the sequences with all plant peptide sequences revealed 1656 unique sequences for gerbera not identified elsewhere within the plant kingdom. Based on the EST database, we constructed a cDNA microarray containing 9000 probes and have utilized it in identification of flower-specific genes and abundantly expressed marker genes for flower scape, pappus, stamen, and petal development. Our analysis revealed several regulatory genes with putative functions in flower-organ development. We were also able to associate a number of abundantly and specifically expressed genes with flower-organ differentiation. Gerbera is an outcrossing species, for which genetic approaches to gene discovery are not readily amenable. However, reverse genetics with the help of gene transfer has been very informative. We demonstrate here the usability of the gerbera microarray as a reliable new tool for identifying novel genes related to specific biological questions and for large-scale gene expression analysis.     

Peritubular myoid cells of human and rat testis are smooth muscle cells that contain desmin-type intermediate filaments

We studied the cytoskeletal composition of human and rat testicular myoid cells by using immunofluorescence microscopy with polyclonal and monoclonal antibodies. In adult human and rat testis, the peritubular myoid cell layer was brightly positive for desmin, the muscle type of intermediate filament protein, and a faint reaction was also seen with antibodies to vimentin, the intermediate filament protein of fibroblasts and diverse other mesenchymal cells. The desmin-positive myoid cell layer could already be identified in newborn rat testis but was more compact in appearance 23 days after birth. Both squash preparations and cultured cells from adult rat seminiferous tubules revealed distinct cell populations positive for desmin. The adult myoid cells of both species also showed a strong reaction with antibodies to myosin and p230, a nonerythroid avian alpha-spectrin analogue. The immunostaining results could be confirmed by the western blotting technique: Experiments with isolated seminiferous tubules showed a specific reaction with a 55,000-dalton and a 58,000-dalton polypeptide when desmin and vimentin antibodies were used, respectively. The present results show that the peritubular myoid cells are genuine smooth muscle cells with desmin-type intermediate filament cytoskeleton and suggest that these cells can be identified by this feature before their ultrastructural maturation.     

Cellular origin and differentiation of renal carcinomas. A fluorescence microscopic study with kidney-specific antibodies, antiintermediate filament antibodies, and lectins

Frozen sections of human renal carcinomas were studied in indirect immunofluorescence using antibodies against intermediate filaments of cytokeratin, desmin and vimentin type, and against proximal tubular brush border and distal tubular Tamm-Horsfall glycoprotein antigens, as well as with fluorochrome-labeled lectins in an attempt to study the origin and stage of differentiation of renal carcinomas. Eighty per cent of the renal carcinomas expressed the brush border antigens, whereas the Tamm-Horsfall glycoprotein could not be found. Antibodies against epidermal cytokeratins reacted only with collecting ducts in normal kidney, whereas antibodies against cytokeratins of Madin-Darby canine kidney epithelial cell line also reacted with glomerular and tubular epithelium. In 93% of the carcinomas tumor cells showed reactivity with both types of antikeratin antibodies. Vimentin, the cytoskeletal protein of mesenchymal cells, was present in the carcinoma cells of 53% of the tumors, although it was not present in normal tubular epithelium. Moreover, vimentin was expressed together with cytokeratin in the carcinoma cells in 57% of the keratin-positive samples as judged by double immunostaining, whereas the muscle type of intermediate filament protein, desmin, was not seen in the malignant cells. Binding sites for Lotus tetragonolobus agglutinin and soybean agglutinin, normally present in the cells of proximal tubules, were lacking or only faintly detectable in the neoplastic cells. Dolichos biflorus agglutinin, normally present in collecting ducts, was not detected in the tumors. The results show that most renal carcinomas express cytokeratin antigens as a sign of their epithelial origin and also show characteristics of proximal tubular cells. On the other hand, the results indicate that lectin-binding sites typical for normal differentiated tubular cells are profoundly modified in renal carcinomas. Ulex europaeus agglutinin did not bind to the malignant cells but decorated the endothelial cells of the tumors.