Association of natural anti-platelet factor 4/heparin antibodies with periodontal disease

Platelet factor 4 (PF4) and heparin (H) form PF4/H complexes, the target of the immune reaction in heparin-induced thrombocytopenia (HIT). HIT seems to be a secondary immune response as anti-PF4/H-IgG antibodies occur as early as day 4 of heparin treatment. This study investigated whether prevalent infections such as periodontitis may induce the PF4/H immune response as: (1) natural anti-PF4/H Abs are present in the normal population; (2) PF4 bound to bacteria exposes the same antigen(s) as PF4/H complexes; and (3) sepsis induces PF4/H Abs in mice. We found PF4 bound to periodontal pathogens (Aggregatibacter actinomycetemcomitans; Porphyromonas gingivalis) enabling subsequent binding of human anti-PF4/H Abs. The association of natural PF4/H Abs and periodontitis was assessed in a case-control study, enrolling individuals with natural anti-PF4/H Abs (n = 40 matched pairs), and in the cross-sectional population-based Study of Health in Pomerania (SHIP; n = 3500). Both studies showed a robust association between periodontitis and presence of anti-PF4/H Abs independent of inflammation markers (case-control study: lowest vs highest tertile, odds ratio, 7.12 [95% confidence interval, 1.73-46.13; P = .005]; SHIP study, p(trend) ≤ 0.001). Thus, preimmunization to PF4/bacteria complexes by prevalent infections, for example, periodontitis, likely explains the presence of natural anti-PF4/heparin Abs and the early occurrence of anti-PF4/H-IgG in HIT.     

Tissue microarrays: a new approach for quality control in immunohistochemistry

AIMS: To improve the interpretation of immunohistochemistry (IHC) staining results the use of a tissue microarray technique was established in a routine setting. METHODS: A tissue microarray was constructed by harvesting 600 microm tissue cores from paraffin wax embedded samples available in a routine pathology department. The punches originating from non-tumorous tissue were placed on host paraffin wax blocks. The microarray contained 12 different tissue samples, with a wide antigen profile and a dimension of 3.5 x 3 mm. One section of the multitissue array was placed as an "internal" positive control on each slide of the patient tissue to undergo identical immunohistochemical procedures. RESULTS: Using the tissue microarray technique as a tool for internal quality control, the interpretation of immunohistochemical staining of more than 20 different antigens in routine IHC was improved. The tissue microarray did not influence the staining results in conventional IHC or in different automated IHC settings. CONCLUSION: The regular use of an institution adapted tissue microarray would be useful for internal positive control in IHC to enable different laboratory demands. Furthermore, this technique improves the evaluation of staining results in IHC.     

Cryptic genomic imbalances in de novo and inherited apparently balanced chromosomal rearrangements: Array CGH study of 47 unrelated cases

Investigations of apparently balanced chromosomal rearrangements in patients with abnormal phenotype by molecular cytogenetics tools, especially by array CGH, revealed a proportion of unsuspected imbalances. It was estimated recently that 40% of apparently balanced de novo translocations with abnormal phenotype were associated with cryptic deletion.We explored 47 unrelated mental retardation patients carrying an apparently balanced chromosomal rearrangement with high-resolution oligonucleotides arrays. We included 33 de novo cases (21 translocations, 7 inversions and 5 complex chromosomal rearrangements (CCR)) and 14 inherited cases (7 translocations, 5 inversions and 2 CCR).Twenty of the 47 cases (42.6%) carried a cryptic deletion ranging from 60 kb to 15.37 Mb. It concerned 16/33 de novo rearrangements (8/21 translocations, 4/7 inversions and 4/5 CCR) and 4/14 inherited rearrangements (1/7 translocations, 2/5 inversions and 1/2 CCR). The proportion of imbalances was not statistically different between de novo and inherited cases.Our results support that about 40% apparently balanced chromosomal rearrangements with abnormal phenotype are in fact imbalanced and that these rearrangements should be systematically investigated by array CGH independently of their de novo or inherited character.     

Methylmalonic aciduria: Follow-up and enzymology on the original case after 36 years

Summary A 36-year follow-up on the original patient described with methylmalonic aciduria has shown that she has methylmalonyl-CoA apomutase deficiency. The main clinical problem associated with her methylmalonic aciduria is progressive renal impairment requiring commencement of haemodialysis at 42 years of age.     

Correction of SMN2 Pre-mRNA splicing by antisense U7 small nuclear RNAs.

Mutations in one of the duplicated survival of motor neuron (SMN) genes lead to the progressive loss of motor neurons and subsequent development of spinal muscular atrophy (SMA), a common, and usually fatal, hereditary disease. Homozygous absence of the telomeric copy (SMN1) correlates with development of SMA because differential splicing of the centromeric copy (SMN2) leads to exon 7 skipping and predominantly produces a biologically inactive protein isoform. To increase exon 7 inclusion of SMN2, we have designed a series of vectors that express modified U7 snRNAs containing antisense sequences complementary to the 3' splice site of SMN exon 8. Over 20 anti-SMN U7 snRNAs were tested for their ability to promote exon 7 inclusion in the SMN2 gene. Transient expression of anti-SMN U7 snRNAs in HeLa cells modulated SMN2 splicing to approximately 70% exon 7 inclusion in a sequence-specific and dose-dependent manner. Significantly, the administration of anti-SMN U7 snRNPs results in an increase in the concentration of SMN protein. These results suggest that modulation of SMN2 pre-mRNA splicing by modified U7 snRNAs provides a promising form of gene therapy for the treatment of SMA.     

Basophil recruitment and IL-4 production during human allergen-induced late asthma

BACKGROUND: Basophils represent an important source of inflammatory mediators and cytokines after IgE-dependent activation in human beings. OBJECTIVE: To assess the role of basophils in allergic asthma, we measured the number of basophils in the bronchial mucosa and their capacity to express IL-4 mRNA and protein during allergen-induced late asthmatic responses. METHODS: Fiberoptic bronchoscopic bronchial biopsies were obtained at 24 hours from sites of segmental bronchial allergen challenge and control sites in 19 patients with atopic asthma and 6 nonatopic healthy volunteers. Basophil numbers were assessed by immunohistochemistry through use of mAb 2D7. IL-4 mRNA--positive cells were detected through use of in situ hybridization and colocalized to basophils through use of sequential immunohistochemistry/in situ hybridization. IL-4 protein was detected and colocalized to basophils through use of dual immunohistochemistry. RESULTS: After allergen challenge, there was an increase in the median number of 2D7-positive basophils per square millimeter in the bronchial mucosa in patients with asthma (0.9 cells/mm(2) at baseline to 8.8 cells/mm(2) after challenge; P =.002), which also was significantly higher than what was seen in nonasthmatic controls (P =.01). Similarly, IL-4 mRNA--positive cells were increased at 24 hours in patients with asthma (1.4 to 14) in comparison with controls (0 to 0; P =.02). Colocalization studies revealed that 15% and 41% of the basophil population in patients with asthma after allergen-challenge expressed, respectively, IL-4 mRNA and protein. Conversely, 19% of IL-4 mRNA-positive cells and 72% of IL-4 protein--positive cells were accounted for by basophils. CONCLUSION: After allergen provocation in sensitive patients with atopic asthma, basophils are recruited to the bronchial mucosa and express IL-4 mRNA and protein, which might contribute to local IgE synthesis and/or tissue eosinophilia or other aspects of allergic inflammation during late responses and ongoing asthma.     

Behavioral abnormalities precede neuropathological markers in rats transgenic for Huntington's disease

Huntington's disease (HD) is caused by an expanded CAG repeatleading to the synthesis of an aberrant protein and to the formationof polyglutamine (polyQ)-containing inclusions and aggregates.Limited information is available concerning the associationof neuropathological markers with the development of behavioralmarkers in HD. Using a previously generated transgenic rat modelof HD (tgHD rat), we performed association studies on the time-courseof behavioral symptoms (motor function, learning, anxiety) andthe appearance of striatal atrophy, 1C2 immunopositive aggregatesand polyQ recruitment sites, a precursor to these aggregates.At the age of 1 month, tgHD rats exhibited reduced anxiety andimproved motor performance, while at 6 months motor impairmentsand at 9 months cognitive decline occurred. In contrast, polyQrecruitment sites appeared at around 6–9 months of age,indicating that HD-like behavioral markers preceded the appearanceof currently detectable neuropathological markers. Interestingly,numerous punctate sites containing polyQ aggregates were alsoseen in areas receiving afferents from the densely recruitingregions suggesting either transport of recruitment-competentaggregates to terminal projections where initially 1C2 positiveaggregates were formed or different internal properties of neuronsin different regions. Furthermore, striatal atrophy was observedat the age of 12 months. Taken together, our findings supportthe hypothesis of a dynamic process leading to region- and age-specificpolyQ recruitment and aggregation. The dissociation of onsetbetween behavioral and neuropathological markers is suggestiveof as yet undetected processes, which contribute to the earlyphenotype of these HD transgenic rats.     

Less increase of BNP and NT-proBNP levels in obese patient with decompensated heart failure: interpretation of natriuretic peptides in obesity

ObjectivePlasma brain natriuretic peptide (BNP) is a useful adjunct to diagnose and monitor patient with heart failure, but there are comorbidities such as chronic kidney disease or chronic pulmonary disease, which influence the interpretation of BNP levels.PatientWe present a case of a young and very obese patient (body mass index [BMI] 72.6 kg/m²), who was presented with acute global heart decompensation. Echocardiography revealed a dilated left ventricle with an ejection fraction of 20% by global distributed heart with enlarged right heart caves. Computed tomography and X-ray demonstrated an extreme cardiomegaly with cardio-thoracic ratio of 0.71. Remarkably, laboratory measurements revealed only a slight elevated concentrations of brain natriuretic peptide (BNP) (443.2 pg/ml) and his inactive component NT-proBNP (1710 pg/ml).Despite maximized heart care clinical condition of the patient aggravated continuously so that the patient died after 6 days because of heart insufficiency.ConclusionObese patients (body mass index [BMI] > 30 kg/m²) with any given severity of heart failure obviously express lower levels of BNP. Until now, the cause for this phenomenon is unclear. Therefore caution should be exercised in interpreting BNP levels in such patients.