Adsorption and dissolution behavior of human plasma fibronectin on thermally and chemically modified titanium dioxide particles.

Titanium is known for its biocompatibility and is widely used in dental and orthopedic reconstructive surgery. There are reports that osteointegration of these implants is not optimal. The objective of this study was to modify titanium dioxide particles and examine the resultant effects on protein adsorption to these altered surfaces using a model cell binding protein, human plasma fibronectin (HPF). HPF is an important matrix glycoprotein that plays a major role in cell and protein attachment, Titanium dioxide surfaces were modified by heating the titanium dioxide powder at 800 degrees C for 1 h or treating with an oxidizing agent: peroxide in ammonium hydroxide followed by peroxide in hydrochloric acid. Oxidized and control samples were further treated with 9:1 butanol:water for 30 min. Brunauer-Emmett-Teller showed no change in particle surface area as a result of thermal or chemical treatment. Hydrophobicity increased with butanol treatment of titanium dioxide. Diffuse reflectance Fourier transform infrared spectroscopy showed the presence of -CH2 and -CH3 vibrations in the region of 2850-3000 cm(-1) for both the heated, butanol and peroxide/butanol-treated samples. The absence of increased C-O and O-C=O features as determined by electron spectroscopy for chemical analysis indicates that butanol adsorption is not occurring via an esterification mechanism. The interaction between butanol and pre-heated or peroxide-treated titanium dioxide may be one of association (weak electrostatic and/or Van der Waals forces) rather than direct ionic bonding. Maximum HPF adsorption on modified or unmodified titanium dioxide occurred within 30 min, with greater protein adsorption occurring on butanol-treated samples. Desorption was minimal with all modifications. Zeta potential measurements showed that HPF adsorption caused an increase in the negative zeta potential with the greatest change noted for the butanol-treated samples. These findings suggest that wettability and surface charge both play an important role in protein adsorption to titanium dioxide. Thus, by modifying the physico-chemical properties of titanium dioxide surfaces, it may be possible to alter protein adsorption and hence optimize cell attachment.     

Association of oestrogen receptor alpha gene polymorphisms with postmenopausal bone loss, bone mass, and quantitative ultrasound properties of bone

Background: The gene encoding oestrogen receptor α (ESR1) appears to regulate bone mineral density (BMD) and other determinants of osteoporotic fracture risk.

Objective: To investigate the relation between common polymorphisms and haplotypes of the ESR1 gene and osteoporosis related phenotypes in a population based cohort of 3054 Scottish women.

Results: There was a significant association between a common haplotype "px", defined by the PvuII andXbaI restriction fragment length polymorphisms within intron 1 of the ESR1 gene, and femoral neck bone loss in postmenopausal women who had not received hormone replacement therapy (n = 945; p = 0.009). Annual rates of femoral neck bone loss were ~14% higher in subjects who carried one copy of px and 22% higher in those who carried two copies, compared with those who did not carry the px haplotype. The px haplotype was associated with lower femoral neck BMD in the postmenopausal women (p = 0.02), and with reduced calcaneal broadband ultrasound attenuation (BUA) values in the whole study population (p = 0.005). There was no association between a TA repeat polymorphism in the ESR1 promoter and any phenotype studied, though on long range haplotype analysis subjects with a smaller number of TA repeats who also carried the px haplotype had reduced BUA values.

Conclusions: The ESR1px haplotype is associated with reduced hip BMD values and increased rates of femoral neck bone loss in postmenopausal women. An association with BUA may explain the fact that ESR1 intron 1 alleles predict osteoporotic fractures by a mechanism partly independent of differences in BMD.

     

Phenotypic expansion of Bosch–Boonstra–Schaaf optic atrophy syndrome and further evidence for genotype–phenotype correlations

Bosch–Boonstra–Schaaf Optic Atrophy Syndrome (BBSOAS) is an autosomal dominant neurodevelopmental disorder caused by loss‐of‐function variants in NR2F1 and characterized by visual impairment, developmental delay, and intellectual disability. Here we report 18 new cases, provide additional clinical information for 9 previously reported individuals, and review an additional 27 published cases to present a total of 54 patients. Among these are 22 individuals with point mutations or in‐frame deletions in the DNA‐binding domain (DBD), and 32 individuals with other types of variants including whole‐gene deletions, nonsense and frameshift variants, and point mutations outside the DBD. We corroborate previously described clinical characteristics including developmental delay, intellectual disability, autism spectrum disorder diagnoses/features thereof, cognitive/behavioral anomalies, hypotonia, feeding difficulties, abnormal brain MRI findings, and seizures. We also confirm a vision phenotype that includes optic nerve hypoplasia, optic atrophy, and cortical visual impairment. Additionally, we expand the vision phenotype to include alacrima and manifest latent nystagmus (fusional maldevelopment), and we broaden the behavioral phenotypic spectrum to include a love of music, an unusually good long‐term memory, sleep difficulties, a high pain tolerance, and touch sensitivity. Furthermore, we provide additional evidence for genotype–phenotype correlations, specifically supporting a more severe phenotype associated with DBD variants.     

Decreased mucosal interleukin-4 (IL-4) production in gut inflammation.

AIMS--To determine the prevalence of cells secreting interleukin-4 (IL-4) in the gut mucosa of children with chronic inflammatory bowel disease. METHODS--Mononuclear cells were isolated from intestinal biopsy specimens from control children (n = 10) and children with active inflammatory bowel disease (Crohn's disease n = 15, ulcerative colitis n = 9, indeterminate colitis n = 3). Spontaneous IL-4 production was then measured by SPOT-enzyme linked immunosorbant assay (ELISA) using a pair of non-competing anti-IL-4 monoclonal antibodies. The percentage of T cells in the isolated cells were also determined and the prevalence of IL-4 secreting cells calculated per 10,000 T cells. RESULTS--In control children the mean number of IL-4 secreting cells was 15.1 per 10,000 T cells. In Crohn's disease and ulcerative colitis the means were 5.3 and 5.2, respectively. In two children with indeterminate colitis numbers were also low. There was no difference in the percentage of T cells in the cell preparations isolated from each patient group. The reduction of IL-4 secreting cells in patients with Crohn's disease was not caused by steroids. CONCLUSIONS--In idiopathic inflammatory bowel disease IL-4 secreting cells are reduced in diseased mucosa.     

Nonmyeloablative bone marrow transplantation: Infectious complications in 65 recipients of HLA-identical and mismatched transplants.

Infections are a common complication of allogeneic bone marrow transplantation and the leading cause of transplantation-related mortality. It had been hypothesized that transplantation following nonmyeloablative preparative regimens would result in fewer infections by causing less mucosal injury, less graft-versus-host disease, and allowing earlier immune reconstitution. We have retrospectively reviewed the infectious complications of 65 consecutive patients with advanced hematologic malignancies who underwent bone marrow transplantation using a novel preparative regimen consisting of cyclophosphamide, thymic irradiation, and in vivo T-cell depletion. Cytomegalovirus (CMV) infection occurred in 52% of cases in which the donor or recipient had evidence of prior CMV exposure. Using a strategy of preemptive therapy and secondary prophylaxis with ganciclovir, no CMV disease occurred. Infections with gram-positive bacteria predominated over the first 100 days after bone marrow transplantation. Thereafter, the relative proportion of gram-negative infections increased without a significant increase in episodes of neutropenia. The rate of bacterial infections was not influenced by relapse of the underlying malignancy. Seven patients developed infections with Aspergillus species, which was the most common infectious cause of death in these patients. Infections with viruses other than CMV (n=10) and with protozoan organisms (n=2) also occurred. The use of HLA-mismatched donors, the occurrence of grade II-IV acute graft-versus-host disease, and treatment with corticosteroids did not influence the risk of CMV or bacterial or fungal infections in patients who underwent transplantation following this preparative regimen. Overall, the incidence and spectrum of infections in this series was similar to the reported incidence of infections following conventional myeloablative allogeneic stem cell transplantation. We conclude that a quantitative T-cell deficiency in these extensively T-cell depleted patients may be a risk factor for infection, even in the absence of graft-versus-host disease.     

A method for real-time, evidence-based general medical attending rounds.

PURPOSE: To assess the utility and practicality of an evidence-based format in internal medicine attending rounds. METHOD: Two randomly selected teams of residents and medical students in the internal medicine program at the Montefiore Medical Center participated in "Evidence-Based Medicine Attending Month." The process entailed the development of patient-based, searchable questions, a search for the evidence, the critical appraisal of the retrieved literature, and the application of the evidence to the care of the patient. At the last meeting, participants evaluated each case by answering three questions about whether the process (1) had changed the medical management of the patient during the admission, (2) had changed the way they would manage similar patients in the future, and (3) had informed them about the disease process in general. RESULTS: A total of 12 of 16 formal EBM questions were developed and assessed (75% completion rate) during the four-week period, in addition to the standard background literature reviews usually performed. Twenty-two articles were retrieved and critically appraised. The evaluation demonstrated that 50% of the participants felt the process had changed the active management of patients currently treated by the team, 75% reported that the process would affect the care of future patients with comparable medical problems, and over 90% believed the program had informed them about the disease process. CONCLUSIONS: The formal EBM approach was conveniently implemented and enhanced the learning experience of the participants. It helped inform students' and residents' patient care at the time and their attitudes towards future patients. Hence, it is both practical and useful to perform formal EBM attending rounds.     

Incidence of intraglomerular platelets in steroid sensitive nephrotic syndrome.

Renal biopsies from 44 patients with steroid sensitive nephrotic syndrome were examined with respect to the content of their intraglomerular platelets and compared with 18 normal control patients and with 51 patients with membranous glomerulonephritis and the nephrotic syndrome. The results suggested that platelet activity was not involved in the pathogenesis of steroid sensitive nephrotic syndrome; in the active phase of the number of platelets in glomeruli is lower than that of normal controls, and this may be associated with increased sensitivity to aggregating agents as part of the nephrotic syndrome. After steroid treatment and disappearance of proteinuria, the number of intraglomerular platelets rises to normal values.     

Molecular epidemiology of Mycobacterium avium subsp. paratuberculosis isolates recovered from wild animal species

Mycobacterial isolates were obtained by radiometric culture from 33 different species of captive or free-ranging animals (n = 106) and environmental sources (n = 3) from six geographic zones within the United States. The identities of all 109 isolates were confirmed by using mycobactin J dependence and characterization of five well-defined molecular markers, including two integration loci of IS900 (loci L1 and L9), one Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis)-specific sequence (locus 251), and one M. avium subsp. avium-specific marker (IS1245), as well as hsp65 and IS1311 restriction endonuclease analyses. Seventy-six acid-fast isolates were identified as M. paratuberculosis, 15 were identified as belonging to the M. avium-M. intracellulare complex (but not M. paratuberculosis), and the remaining 18 were identified as mycobacteria outside the M. avium-M. intracellulare complex. Fingerprinting by multiplex PCR for IS900 integration loci clustered 67 of the 76 M. paratuberculosis strains into a single clade (designated clade A18) and had a Simpson's diversity index (D) of 0.53. In contrast, sequence-based characterization of a recently identified M. paratuberculosis short sequence repeat (SSR) region enabled the differentiation of the M. paratuberculosis isolates in clade A18 into seven distinct alleles (D = 0.75). The analysis revealed eight subtypes among the 33 species of animals, suggesting the interspecies transmission of specific strains. Taken together, the results of our analyses demonstrate that SSR analysis enables the genetic characterization of M. paratuberculosis isolates from different host species and provide evidence for the host specificity of some M. paratuberculosis strains as well as sharing of strains between wild and domesticated animal species.