Drawbacks of GENEHUNTER for larger pedigrees: application to panic disorder

Large pedigrees can pose a problem for GENEHUNTER linkage analysis software. Differences in two-point and multipoint lodscores were observed when comparing GENEHUNTER to other linkage software. Careful consideration must be given when selecting linkage analysis programs. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:781-783, 2000.     

Infection of immunodeficient horses with Sarcocystis neurona does not result in neurologic disease

Equine protozoal myeloencephalitis is a progressive neurologic disease of horses most commonly caused by infection with the apicomplexan parasite Sarcocystis neurona. Factors affecting neuroinvasion and neurovirulence have not been determined. We investigated the pathogenesis of infection with S. neurona in horses with severe combined immune deficiency (SCID). Two immunocompetent (IC) Arabian horses and two Arabian horses with SCID were infected orally with 5 x 10(5) sporocysts of S. neurona. Four IC horses and one SCID horse were infected intravenously (i.v.) with 5 x 10(8) merozoites of the WSU-1 isolate of S. neurona. Despite prolonged parasitemia and persistent infection of visceral tissues (skeletal muscle, cardiac muscle, lung, liver, and spleen) as demonstrated by PCR and culture, SCID horses did not develop neurologic signs after oral or i.v. infection. S. neurona was undetectable in the neuronal tissues of SCID horses by either PCR, immunohistochemistry, or culture. In contrast, although parasitemia was undetectable in orally infected IC horses and of only short duration in i.v. infected IC horses, four of six IC horses developed neurologic signs. S. neurona was detectable by PCR and/or culture of neural tissue but not visceral tissue of IC horses with neurologic disease. Infected SCID horses are unable to clear S. neurona from visceral tissues, but the infection does not result in neurologic signs; in contrast, IC horses rapidly control parasitemia and infection of visceral tissues but frequently experience neuroinvasion and exhibit clinical signs of neurologic disease.     

FURTHER ANALYSIS OF THE MONOCLONAL ANTIOBODY H8 DEMONSTRATING A JMH-RELATED SPECIFICITY

The monoclonal antibody H8, previously described as anti-JMH, has the same specificity as a JMH-related antibody, R.M. H8 blocks the reaction of human anti-JMH and related antibodies with JMH+ cells, suggesting that the JMH-related antigens are very closely situated to each other on the red cell membrane.     

Mapping of a restriction fragment length polymorphism associated with defective DR beta 4 chain expression to the HLA-DRB1 gene

The HLA-DR beta 4 chain, encoded by the DRB4 gene, carries two DRw53 determinants normally expressed by DR4, DR7, and DR9 individuals. However, some DR7 individuals (DR7, Dw11) fail to express the DR beta 4 chain. At the genomic level, a HindIII restriction fragment length polymorphism can be detected in these individuals with a DR beta cDNA probe. The association of this altered HindIII fragment with defective beta 4 chain expression suggested the possibility that the polymorphic fragment was derived from the DRB4 gene and might, therefore, be related to the defect in expression. However, detailed Southern blot analysis has now mapped the polymorphic fragment to the 3' end of the DRB1 gene, approximately 100 kb away from the defective DRB4 gene. Although the alteration in the DRB1 gene might involve sequences important in regulating the expression of the DRB4 gene, it is more likely that the association results from strong positive linkage disequilibrium between these DR beta chain genes.     

Phosphate glasses for tissue engineering: Part 2. Processing and characterisation of a ternary-based P2O5-CaO-Na2O glass fibre system

This paper presents the results of a study of the thermal properties, solubility and dimensions of a range of phosphate-based glass fibres (PB-GFs). The glass compositions were limited by fixing the P2O5 content to 45, 50 and 55 mol%, and varying the CaO mol% at 30, 35 and 40. PB-GFs were obtained from the 50 and 55 mol% P2O5 compositions; however, we were unable to obtain fibres from the 45 mol% compositions. This was linked to the cross-linked density, network connectivity and average chain length of the compositions studied. With regards to thermal parameters investigated, initial data showed an increase of the Tg and crystallisation temperatures with increasing CaO mol% at each fixed phosphate content. A decrease in Tg temperatures was also observed with increasing P2O5 content to 55 mol%. The crystallisation temperatures obtained for compositions with fixed phosphate at 55 mol%, showed a reverse pattern, with a decrease in values as compared to the fixed 50 mol% phosphate compositions. The diameters of the fibres all decreased with increasing RPMs as expected, and the solubility also increased with increasing RPMs. This was related to the increased surface area of the higher RPM fibres. There was also a decrease seen in solubility with increasing CaO mol%.     

Hydroxyapatite and gelatin composite foams processed via novel freeze-drying and crosslinking for use as temporary hard tissue scaffolds

Hydroxyapatite (HA) and gelatin composites were fabricated in a foam type via a novel freeze-drying and crosslinking technique. The morphological and mechanical properties of and in vitro cellular responses to the foams were investigated. The HA powder was added at up to 30 wt % into the gelatin solution, and the mixtures were freeze-dried and further crosslinked. The pure gelatin foam had a well-developed pore configuration with porosity and pore size of approximately 90% and 400-500 microm, respectively. With HA addition, the porosity decreased and pore shape became more irregular. The HA particulates, in sizes of about 2-5 microm, were distributed within the gelatin network homogeneously and made the framework surface rougher. All the foams had high water absorption capacities, showing typical hydrogel characteristics, even though the HA addition decreased the degree of water absorption. The HA addition made the foam much stronger and stiffer (i.e., with increasing HA amount the foams sustained higher compressive stress and had higher elastic modulus in both dry and wet states). The osteoblast-like human osteosarcoma cells spread and grew actively on all the foams. The cell proliferation rate, quantified indirectly on the cells cultured on Ti discs coated with gelatin and gelatin-HA composites using MTT assay, exhibited an up-regulation with gelatin coating compared with bare Ti substrate, but a slight decrease on the composite coatings. However, the alkaline phosphatase activities expressed by the cells cultured on composites foams as well as their coatings on Ti discs were significantly enhanced compared with those on pure gelatin foam and coating. These findings suggest that the gelatin-HA composite foams have great potential for use as hard tissue regeneration scaffolds.     

Bone morphogenetic protein receptor type II C-terminus interacts with c-Src: implication for a role in pulmonary arterial hypertension

Mutations of bone morphogenetic protein receptor type II (BMPR-II) have been associated with familial and idiopathic pulmonary arterial hypertension (PAH). BMPR-II is a member of the transforming growth factor-beta receptor superfamily. It consists of extracellular, transmembrane, and kinase domains, and a unique C-terminus with mostly unknown function. However, a number of PAH-causing mutations are predicted to truncate the C-terminus, suggesting that this domain plays an important role in the homeostasis of pulmonary vessels. In this study, we sought to elucidate the functional role of this C-terminus by seeking its interacting partners. Using yeast two-hybrid screening, we identified c-Src tyrosine kinase as a binding partner of this C-terminus. In vitro co-immunoprecipitation confirmed their interaction. Mutations truncating the C-terminus disrupted their interaction, while missense mutation within kinase domain reduced their interaction. In addition, BMPR-II and c-Src tyrosine kinase colocalized within intracellular aggregates when overexpressed in HEK293 cells. Moreover, mutations truncating the C-terminus disrupted their colocalization, whereas missense mutation within kinase domain had no effect on their colocalization. Furthermore, BMP ligand stimulation decreased c-Src-activating phosphorylation at Tyrosine 418 in pulmonary smooth muscle cells in both time- and concentration-dependent manners. Mutations that truncated the C-terminus abolished this response. Taken together, these results suggest a model in which proliferative effect of c-Src by vasoactive molecules is balanced by opposing effect of BMP signaling in basal state, and the loss of this balance due to BMPR2 mutations leads to increased c-Src activity and subsequently cell growth.     

De novo CD5-positive and Richter's syndrome-associated diffuse large B cell lymphomas are genotypically distinct.

Diffuse large B cell lymphomas (DLBLs) represent a heterogeneous collection of aggressive non-Hodgkin's lymphomas that can arise either de novo or as a result of transformation from chronic lymphocytic leukemia, small lymphocytic lymphoma, follicular lymphomas, or lymphomas of mucosa-associated lymphoid tissue. A small percentage of DLBLs express the CD5 antigen. The majority of these cases have evolved from a pre-existing low grade non-Hodgkin's lymphoma (Richter's syndrome). However, we identified and characterized nine CD5-positive DLBLs in which the patients did not have a previous history or concomitant evidence of chronic lymphocytic leukemia, small lymphocytic lymphoma, follicular lymphoma, or mucosa-associated lymphoid tissue-associated non-Hodgkin's lymphoma, suggesting that they arose de novo. All nine cases expressed CD20 and monotypic immunoglobulin, all eight cases examined expressed CD19, CD22 and CD43, eight of the nine cases expressed HLA-DR, and two of eight cases expressed CD11c. None of the cases expressed CD3, CD10, CD11b, CD21, CD23 or CD30. CD5 expression by these cells was found to be identical to that of CD5-positive B cell chronic lymphocytic leukemia by quantitative polymerase chain reaction analysis of CD5 mRNA. These nine de novo CD5-positive DLBLs exhibited clonal immunoglobulin heavy and light chain gene rearrangements but lacked integration of the Epstein-Barr virus genome and structural alterations of the bcl-1, bcl-2, c-myc, H-ras, K-ras, and N-ras proto-oncogenes and the p53 tumor suppressor gene. However, bcl-6 proto-oncogene rearrangement, which is involved in chromosome band 3q27 aberrations, was found in four cases (44.4%). This is comparable with the frequency of bcl-6 gene rearrangement in CD5-negative DLBL. In contrast, bcl-6 gene rearrangement was absent in six cases of DLBL associated with Richter's syndrome. These findings suggest that de novo CD5-positive DLBLs are genotypically similar to CD5-negative DLBLs and may be pathogenetically distinct from the DLBLs associated with Richter's syndrome.     

Interstitial nephritis related to nonsteroidal anti-inflammatory agents and beta-lactam antibiotics: a comparative study of the interstitial infiltrates using monoclonal antibodies

Acute interstitial nephritis (AIN) is a common pattern of renal injury induced by therapeutic agents. In order to characterize the types of mononuclear leukocytes infiltrating the kidney in drug-induced interstitial nephritis, a panel of monoclonal antibodies (Leu1, Leu3a, OKT8, OKM1, Leu14, OKT17, IL-2) was applied to cryostat sections of 13 renal biopsies (five non-steroidal anti-inflammatory agents (NSAID) (Group I); five beta-lactam antibiotics (Group II), 3 miscellaneous (Group III]. The majority of infiltrating mononuclear leukocytes were Leu1-positive T cells (71.7 +/- 18.7%), followed by monocytes (15.2 +/- 7.7%) and B cells (7.4 +/- 9.1%). Leu3a/OKT8 ratio was 0.954 +/- 0.341. Rare cells reacted with antibody to the interleukin-2 receptor (1.4 +/- 1.2%). No statistically significant differences could be found in the percentages of T lymphocytes, B lymphocytes, monocytes, activated (IL-2+) T cells or Leu3a/OKT8 (helper/suppressor) ratios in the three groups. In Group II, the following pathologic correlations were seen: Leu3a/OKT8 versus interstitial inflammation (R = -0.848), percent Leu3a versus interstitial inflammation (R = -0.818), percent OKT17 versus tubulitis (R = 0.785), percent Leu14 versus tubular atrophy (R = -0.891), and interstitial edema (R = 0.965). Our findings support a role for cellular immune mechanisms in the pathogenesis of AIN related to both NSAIDs and beta-lactam antibiotics.