Glycoprotein 330/megalin: probable role in receptor-mediated transport of apolipoprotein J alone and in a complex with Alzheimer disease amyloid beta at the blood-brain and blood-cerebrospinal fluid barriers

A soluble form of Alzheimer disease amyloid beta-protein (sA beta) is transported in the blood and cerebrospinal fluid mainly complexed with apolipoprotein J (apoJ). Using a well-characterized in situ perfused guinea pig brain model, we recently obtained preliminary evidence that apoJ facilitates transport of sA beta (1-40)-apoJ complexes across the blood-brain barrier and the blood-cerebrospinal fluid barrier, but the mechanisms remain poorly understood. In the present study, we examined the transport process in greater detail and investigated the possible role of glycoprotein 330 (gp330)/megalin, a receptor for multiple ligands, including apoJ. High-affinity transport systems with a Km of 0.2 and 0.5 nM were demonstrated for apoJ at the blood-brain barrier and the choroid epithelium in vivo, suggesting a specific receptor-mediated mechanism. The sA beta (1-40)-apoJ complex shared the same transport mechanism and exhibited 2.4- to 10.2-fold higher affinity than apoJ itself. Binding to microvessels, transport into brain parenchyma, and choroidal uptake of both apoJ and sA beta (1-40)-apoJ complexes were markedly inhibited (74-99%) in the presence of a monoclonal antibody to gp330/megalin and were virtually abolished by perfusion with the receptor-associated protein, which blocks binding of all known ligands to gp330. Western blot analysis of cerebral microvessels with the monoclonal antibody to gp330 revealed a protein with a mass identical to that in extracts of kidney membranes enriched with gp330/megalin, but in much lower concentration. The findings suggest that gp330/megalin mediates cellular uptake and transport of apoJ and sA beta (1-40)-apoJ complex at the cerebral vascular endothelium and choroid epithelium.

Ex vivo programmed macrophages ameliorate experimental chronic inflammatory renal disease

Macrophage infiltration of the kidney is a prominent feature associated with the severity of renal injury and progressive renal failure. To determine the influence of macrophages in renal disease models in the absence of endogenous T and B cells, we performed adoptive transfer of macrophages into severe combined immunodeficient (SCID) mice. In this study, macrophages were isolated from the spleens of BALB/c mice and stimulated with lipopolysaccharide to induce classically activated M1 macrophages or with interleukin-4 (IL-4) and IL-13 to induce alternatively activated M2 macrophages. These macrophages were then infused into SCID mice with adriamycin nephropathy; an in vivo model of chronic inflammatory renal disease analogous to human focal segmental glomerulosclerosis. Mice infused with M1 macrophages had a more severe histological and functional injury, whereas M2 macrophage-induced transfused mice had reduced histological and functional injury. Both M1 and M2 macrophages localized preferentially to the area of injury and maintained their phenotypes even after 4 weeks. The protective effect of M2 macrophages was associated with reduced accumulation and possibly downregulated chemokine and inflammatory cytokine expression of the host infiltrating macrophages. Our findings demonstrate that macrophages not only act as effectors of immune injury but can be induced to provide protection against immune injury.

Advancing porphyrin's biomedical utility via supramolecular chemistry

Porphyrins are organic heterocyclic macrocycles with photophysical properties well-suited for clinical phototherapy and cancer imaging. However, their wider application in the clinical management of disease is barred by poor aqueous solubility, bioavailability, tumour accumulation and skin phototoxicity. These limitations instigated the development of supramolecular platforms that improved porphyrin pharmacokinetics and tumour-homing. The supramolecular formulation of porphyrins also facilitates single agent-mediated deeper tissue photoactivation, extended imaging and theranostic multimodality, and synergistic application of multiple therapies. Supramolecular porphyrin structures can overcome additional limitations of porphyrin-mediated photodynamic therapy (PDT), including low depths of tissue penetration that restrict PDT to superficial lesions, inability to treat hypoxic tumours, and incomplete tumour damage. In this review, we discuss the photophysical properties of porphyrins, and overview the clinically-relevant advantages and challenges arising from their incorporation within supramolecular platforms. Specifically, fundamentals underlying the ability of these platforms to ameliorate passive and active porphyrin delivery to tumours, achieve deeper tissue PDT via red-shifted porphyrin Q-bands, energy transfer and sonodynamic effects, and enable new porphyrin-mediated theranostics and synergistic therapeutic capabilities will be explained and exemplified with seminal and cutting-edge in vivo studies.

Organ distribution in rats of two members of the low-density lipoprotein receptor gene family, gp330 and LRP/alpha 2MR, and the receptor-associated protein (RAP)

We investigated immunohistochemically the distribution in rats of the homologous proteins gp330 and the LDL receptor-related protein (LRP/alpha 2MR), and a receptor-associated protein (RAP), and the sites to which soluble exogenous RAP binds. We found gp330 in a restricted group of epithelial cells, including renal proximal tubule cells, podocytes, Type II pneumocytes, cells of the parathyroid, thyroid, epididymis, lining of the uterus, ependyma, retina, ciliary body, yolk sac, and placenta. In these cells gp330 was detected mainly at the cell surface, except for parathyroid and retinal epithelial cells, where diffuse cell staining was found. LRP/alpha 2MR was widely distributed in interstitial cells, notably in fibroblasts and macrophages, and was also present in a selected group of epithelial or specialized cells, including hepatocytes, adrenal cortical cells, follicular cells of the ovary, cells of the choroid plexus, ciliary body, mesangial cells, and some neurons. In certain cells, notably hepatocytes and adrenal cortical cells, LRP/alpha 2MR was detected mainly on the surface, but in others, including macrophages, fibroblasts, and epithelial cells of the choroid plexus and ciliary body, staining throughout the cell was seen. The only cells that clearly expressed both LRP/alpha 2MR and gp330 were retinal and ciliary epithelial cells. RAP was found in intracellular vesicles in all cells that expressed gp330 or LRP/alpha 2MR. RAP was not definitely detected on the cell surface. Binding sites for RAP were found on the surface of those cells with surface gp330 or LRP, and also throughout the cytoplasm in cells with diffuse cellular LRP/alpha 2MR or gp330. Because of their different locations, we conclude that gp330 and LRP/alpha 2MR serve distinct functions in vivo, despite similarities in ligand-binding properties observed in vitro. Since RAP is found largely within cells, its major physiological function may be concerned with intracellular assembly or trafficking of the receptors to which it binds.

Trend tests for case-control studies of genetic markers: power, sample size and robustness

The Cochran-Armitage trend test is commonly used as a genotype-based test for candidate gene association. Corresponding to each underlying genetic model there is a particular set of scores assigned to the genotypes that maximizes its power. When the variance of the test statistic is known, the formulas for approximate power and associated sample size are readily obtained. In practice, however, the variance of the test statistic needs to be estimated. We present formulas for the required sample size to achieve a prespecified power that account for the need to estimate the variance of the test statistic. When the underlying genetic model is unknown one can incur a substantial loss of power when a test suitable for one mode of inheritance is used where another mode is the true one. Thus, tests having good power properties relative to the optimal tests for each model are useful. These tests are called efficiency robust and we study two of them: the maximin efficiency robust test is a linear combination of the standardized optimal tests that has high efficiency and the MAX test, the maximum of the standardized optimal tests. Simulation results of the robustness of these two tests indicate that the more computationally involved MAX test is preferable.

Tilt and rotation correction of acetabular version on pelvic radiographs

Anteroposterior pelvic radiographs are the gold standard of imaging for mechanical hip problems. However, correct interpretation is difficult because the projected morphologic features of the acetabulum and nearly all routinely used hip parameters depend on individual pelvic position, which can vary considerably during acquisition. We developed software that recreates the projected acetabular rim and the measured hip parameters as if obtained in a standardized orientation. The vertical and horizontal distances between two easy identifiable points were used as indicators of tilt and rotation. These points were the middle of the sacrococcygeal joint and the middle of the upper border of the symphyseal gap. Calibration of the indicators was achieved by means of serial pelvic radiographs of 20 cadaver pelves. Validation of tilt indicator in 100 patients and a theoretical error analysis revealed that for accurate tilt prediction an additional one-time lateral radiograph of the pelvis is mandatory. The computer-assisted method allows standardized evaluation of anatomic morphologic differences of femoral coverage (dysplasia, retroversion), making their clinical relevance for development of early osteoarthritis more valuable.

Synthesis, photophysical properties, tumor uptake, and preliminary in vivo photosensitizing efficacy of a homologous series of 3-(1'-alkyloxy)ethyl-3-devinylpurpurin-18-N-alkylimides with variable lipophilicity

Starting from methylpheophorbide-a, a homologous series of purpurinimides containing alkyl substituents at two different positions [as 3-(1(1)-O-alkyl) and 13(2)-N-alkyl] were synthesized. These compounds with variable lipophilicity (log P 5.32-16.44) exhibit long wavelength absorption near lambda(max)700 nm (epsilon: 45 000 in dichloromethane) with singlet oxygen ((1)O2) production in the range of 57-60%. The shifts in in vivo absorptions and tumor/skin uptake of these compounds were determined in C3H mice bearing RIF tumors by in vivo reflectance spectroscopy. The results obtained from a set of photosensitizers with similar lipophilicity (log P 10.68-10.88) indicate that besides the overall lipophilicity, the presence and position of the alkyl groups (O-alkyl vs N-alkyl) in a molecule play an important role in tumor uptake, tumor selectivity, and in vivo PDT efficacy. At present, all purpurinimide analogues are being evaluated at various doses, and experiments are underway to establish a quantitative structure-activity relationship on a limited set of compounds. The 1D and 2D NMR and mass spectrometry analyses confirmed the structures of the desired purpurinimides and the byproducts formed during various reaction conditions. The mechanisms of the formation of the unexpected 12-formyl- and 12-(hydroxymethyl)purpurinimides under certain reaction conditions are also discussed.

Photochemical and electrochemical properties of zinc chlorin-C60 dyad as compared to corresponding free-base chlorin-C60, free-base porphyrin-C60, and zinc porphyrin-C60 dyads

The photochemical and electrochemical properties of four chlorin-C60 or porphyrin-C60 dyads having the same short spacer between the macrocycle and the fullerene are examined. In contrast with all the previous results on porphyrin-fullerene dyads, the photoexcitation of a zinc chlorin-C60 dyad results in an unusually long-lived radical ion pair which decays via first-order kinetics with a decay rate constant of 9.1 x 10(3) x s(-1). This value is 2-6 orders of magnitude smaller than values reported for all other porphyrin or chlorin donor-acceptor of the molecule dyad systems. The formation of radical cations of the donor part and the radical anion of the acceptor part was also confirmed by ESR measurements under photoirradiation at low temperature. The photoexcitation of other dyads (free-base chlorin-C60, zinc porphyrin-C60, and free-base porphyrin-C60 dyads) results in formation of the ion pairs which decay quickly to the triplet excited states of the chlorin or porphyrin moiety via the higher lying radical ion pair states as is expected from the redox potentials.

Genes of the sbo-alb locus of Bacillus subtilis are required for production of the antilisterial bacteriocin subtilosin

Bacillus subtilis JH642 and a wild strain of B. subtilis called 22a both produce an antilisterial peptide that can be purified by anion-exchange and gel filtration chromatography. Amino acid analysis confirmed that the substance was the cyclic bacteriocin subtilosin. A mutant defective in production of the substance was isolated from a plasmid gene disruption library. The plasmid insertion conferring the antilisterial-peptide-negative phenotype was located in a seven-gene operon (alb, for antilisterial bacteriocin) residing immediately downstream from the sbo gene, which encodes the precursor of subtilosin. An insertion mutation in the sbo gene also conferred loss of antilisterial activity. Comparison of the presubtilosin and mature subtilosin sequences suggested that certain residues undergo unusual posttranslational modifications unlike those occurring during the synthesis of class I (lantibiotic) or some class II bacteriocins. The putative products of the genes of the operon identified show similarities to peptidases and transport proteins that may function in processing and export. Two alb gene products resemble proteins that function in pyrroloquinoline quinone biosynthesis. The use of lacZ-alb and lacZ-sbo gene fusions, along with primer extension analysis, revealed that the sbo-alb genes are transcribed from a major promoter, residing upstream of sbo, that is very likely utilized by the sigma(A) form of RNA polymerase. The sbo and alb genes are negatively regulated by the global transition state regulator AbrB and are also under positive autoregulation that is not mediated by the subtilosin peptide but instead requires one or more of the alb gene products.

Serum microRNA panel as biomarkers for early diagnosis of colorectal adenocarcinoma

Background:

Currently, none of the available colorectal adenocarcinoma (CAC) testing has been established as a well-accepted diagnosis tool, particularly for the early stage of CAC. The recent discovery of serum microRNA (miRNA) profile has provided a new auxiliary approach for tumour diagnosis. Our study is involved in the global analysis of serum miRNAs during the normal–colorectal adenoma (CA)–CAC sequence.

Methods:

Serum samples were collected from 307 CAC patients, 164 CA patients and 226 healthy controls. Differentially expressed serum miRNAs were screened with Miseq sequencing followed by the reverse transcription PCR (RT–qPCR) validation. The miRNA panel was developed with a logistic regression model and validated using an independent cohort. The miRNA levels in CAC patients of different clinical stages and CA patients of different grades were compared. Receiver operating characteristic curves were constructed to evaluate the diagnostic accuracy of the panel.

Results:

The Miseq sequencing results revealed 15 differentially expressed miRNAs in the intersection of CAC vs CA and CA vs healthy controls according to our criteria. After the selection and validation process via RT–qPCR, we identified a four-miRNA panel (miR-19a-3p, miR-223-3p, miR-92a-3p and miR-422a) with a high diagnostic accuracy of CAC. Even in the low-carcinoembryonic antigen level group, the diagnostic accuracy of this miRNA panel was still acceptable (AUC=0.810). Surprisingly, our results indicated that the miRNA panel could differentiate stage I/II CAC from controls. In addition, this panel could also differentiate CA from CAC (AUC=0.886) and healthy controls (AUC=0.765).

Conclusions:

We established a serum four-miRNA panel with considerable clinical value in the early-stage diagnosis of CAC.

Navigated open-wedge high tibial osteotomy: advantages and disadvantages compared to the conventional technique in a cadaver study

High tibial osteotomy (HTO) is an established therapy for the treatment of symptomatic varus malaligned knees. A main reason for disappointing clinical results after HTO is the under- and overcorrection of the mechanical axis due to insufficient intraoperative visualisation. Twenty legs of fresh human cadaver were randomly assigned to navigated open-wedge HTO (n=10) or conventional HTO using the cable method (n=10). Regardless of the pre-existing alignment, the aim of all operations was to align the mechanical axis to pass through 80% of the tibial plateau (beginning with 0% at the medial edge of the tibial plateau and ending with 100% at the lateral edge). This overcorrection was chosen to ensure a sufficient amount of correction. Thus, the medial proximal tibia angle (MPTA) increased by 9.1+/-2.9 degrees (range 5.2 degrees -12.3 degrees ) on the average after navigated HTO and by 8.9+/-2.9 degrees (range 4.7 degrees -12.6 degrees ) after conventional HTO. After stabilization with a fixed angle implant, the alignment was measured by CT. After navigated HTO, the mechanical axis passed the tibial plateau through 79.7% (range 75.5-85.8%). In contrast, after conventional HTO, the average intersection of the mechanical axis was at 72.1% (range 60.4-82.4%) (P=0.020). Additionally, the variability of the mean corrections was significantly lower in the navigated group (3.3% vs. 7.2%, P=0.012). Total fluoroscopic radiation time was significantly lower in the navigated group (P=0.038) whereas the mean dose area product was not significantly different (P=0.231). The time of the operative procedure was 23 min shorter after conventional HTO (P<0.001). Navigation systems provide intraoperative 3-dimensional real time control of the frontal, sagittal, and transverse axis and may increase the accuracy of open-wedge HTO. Future studies have to analyse the clinical effects of navigation on corrective osteotomies.

Plant adaptation to frequent alterations between high and low temperatures: remodelling of membrane lipids and maintenance of unsaturation levels

One major strategy by which plants adapt to temperature change is to decrease the degree of unsaturation of membrane lipids under high temperature and increase it under low temperature. We hypothesize that this strategy cannot be adopted by plants in ecosystems and environments with frequent alterations between high and low temperatures, because changes in lipid unsaturation are complex and require large energy inputs. To test this hypothesis, we used a lipidomics approach to profile changes in molecular species of membrane glycerolipids in two plant species sampled from alpine screes and in another two plant species grown in a growth chamber, with the temperature cycling daily between heat and freezing. We found that six classes of phospholipid and two classes of galactolipid showed significant changes, but the degree of unsaturation of total lipids and of three lysophospholipid classes remained unchanged. This pattern of changes in membrane lipids was distinct from that occurring during slow alterations in temperature. We propose two types of model for the adaptation of plants to temperature change: (1) remodelling of membrane lipids but maintenance of the degree of unsaturation are used to adapt to frequent temperature alterations; and (2) both remodelling and changes in the degree of unsaturation to adapt to infrequent temperature alterations.

Synthesis of beta-galactose-conjugated chlorins derived by enyne metathesis as galectin-specific photosensitizers for photodynamic therapy

A first report on the synthesis and biological evaluation of the beta-galactose-conjugated purpurinimides (a class of chlorins containing a six-membered fused imide ring system) as Gal-1 (galectin-1) recognized photosensitizers, prepared from purpurin-N-propargylimide via enyne metathesis, is discussed. On the basis of examination of the available crystal structure of the galectin-1 N-acetyllactose amine complex, it was considered that the chlorin-based photosensitizers could be introduced into a carbohydrate skeleton to expand the repertoire of the galectin-1-specific ligands. Preliminary molecular modeling analysis utilizing the modeled photosensitizers and the available crystal structures of galectin-carbohydrate complexes indicated that addition of the photosensitizer to the carbohydrate moiety at an appropriate position does not interfere with the galectin-carbohydrate recognition. Under similar drug and light doses, compared to the free purpurinimide analogue, the purpurinimides conjugated either with galactose or with lactose (Gal(beta1-4)-Glc) produced a considerable increase in photosensitizing efficacy in vitro. This indicates the possibility for development of a new class of specific photosensitizers for photodynamic therapy (PDT) based on recognition of a cellular receptor.

NADPH oxidase activation increases the sensitivity of intracellular Ca2+ stores to inositol 1,4,5-trisphosphate in human endothelial cells

Many stimuli that activate the vascular NADPH oxidase generate reactive oxygen species and increase intracellular Ca(2+), but whether NADPH oxidase activation directly affects Ca(2+) signaling is unknown. NADPH stimulated the production of superoxide anion and H(2)O(2) in human aortic endothelial cells that was inhibited by the NADPH oxidase inhibitor diphenyleneiodonium and was significantly attenuated in cells transiently expressing a dominant negative allele of the small GTP-binding protein Rac1, which is required for oxidase activity. In permeabilized Mag-indo 1-loaded cells, NADPH and H(2)O(2) each decreased the threshold concentration of inositol 1,4,5-trisphosphate (InsP(3)) required to release intracellularly stored Ca(2+) and shifted the InsP(3)-Ca(2+) release dose-response curve to the left. Concentrations of H(2)O(2) as low as 3 microm increased the sensitivity of intracellular Ca(2+) stores to InsP(3) and decreased the InsP(3) EC(50) from 423.2 +/- 54.9 to 276.9 +/- 14. 4 nm. The effect of NADPH on InsP(3)-stimulated Ca(2+) release was blocked by catalase and by diphenyleneiodonium and was not observed in cells lacking functional Rac1 protein. Thus, NADPH oxidase-derived H(2)O(2) increases the sensitivity of intracellular Ca(2+) stores to InsP(3) in human endothelial cells. Since Ca(2+)-dependent signaling pathways are critical to normal endothelial function, this effect may be of great importance in endothelial signal transduction.

Synthesis, photophysical properties, in vivo photosensitizing efficacy, and human serum albumin binding properties of some novel bacteriochlorins

The synthesis, photophysical characteristics, in vivo photosensitizing efficacy, human serum albumin (HSA) binding properties, and skin phototoxicity of some stable bacteriochlorins were investigated. The novel bacteriochlorins, obtained from chlorophyll-a, have long-wavelength absorptions in the range lambda max = 734-758 nm. Preferential migration of ethyl over methyl substituents among ketobacteriochlorins obtained in the pinacol-pinacolone rearrangements of vic-dihydroxybacteriochlorins was confirmed by NOE studies. The bacteriochlorins show relatively low fluorescence quantum yields. Among all the bacteriochlorins the triplet states were quenched by ground state molecular oxygen in a relatively similar manner, yielding comparable singlet oxygen quantum yields. In preliminary in vivo studies (DBA/2 mice, transplanted with SMT/F tumors), ketobacteriochlorins were found to be more photodynamically active than the related vic-dihydroxy analogues. Replacement of the methyl ester functionalities with di-tert-butylaspartic acids enhanced the in vivo efficacy. Site specific human serum albumin (HSA) binding studies indicated a direct correlation between the ability of the compound to bind to the diazepam binding site (albumin site II) and the in vivo photosensitizing efficacy.

Strong spin-photon coupling in silicon

Long coherence times of single spins in silicon quantum dots make these systems highly attractive for quantum computation, but how to scale up spin qubit systems remains an open question. As a first step to address this issue, we demonstrate the strong coupling of a single electron spin and a single microwave photon. The electron spin is trapped in a silicon double quantum dot, and the microwave photon is stored in an on-chip high-impedance superconducting resonator. The electric field component of the cavity photon couples directly to the charge dipole of the electron in the double dot, and indirectly to the electron spin, through a strong local magnetic field gradient from a nearby micromagnet. Our results provide a route to realizing large networks of quantum dot-based spin qubit registers.

Inhibition of cellular proliferation by the Wilms tumor suppressor WT1 requires association with the inducible chaperone Hsp70

The Wilms tumor suppressor WT1 encodes a zinc finger transcription factor that is expressed in glomerular podocytes during a narrow window in kidney development. By immunoprecipitation and protein microsequencing analysis, we have identified a major cellular protein associated with endogenous WT1 to be the inducible chaperone Hsp70. WT1 and Hsp70 are physically associated in embryonic rat kidney cells, in primary Wilms tumor specimens and in cultured cells with inducible expression of WT1. Colocalization of WT1 and Hsp70 is evident within podocytes of the developing kidney, and Hsp70 is recruited to the characteristic subnuclear clusters that contain WT1. The amino-terminal transactivation domain of WT1 is required for binding to Hsp70, and expression of that domain itself is sufficient to induce expression of Hsp70 through the heat shock element (HSE). Substitution of a heterologous Hsp70-binding domain derived from human DNAJ is sufficient to restore the functional properties of a WT1 protein with an amino-terminal deletion, an effect that is abrogated by a point mutation in DNAJ that reduces binding to Hsp70. These observations indicate that Hsp70 is an important cofactor for the function of WT1, and suggest a potential role for this chaperone during kidney differentiation.

Mutational analysis of the sbo-alb locus of Bacillus subtilis: identification of genes required for subtilosin production and immunity

The Bacillus subtilis 168 derivative JH642 produces a bacteriocin, subtilosin, which possesses activity against Listeria monocytogenes. Inspection of the amino acid sequence of the presubtilosin polypeptide encoded by the gene sboA and sequence data from analysis of mature subtilosin indicate that the precursor subtilosin peptide undergoes several unique and unusual chemical modifications during its maturation process. The genes of the sbo-alb operon are believed to function in the synthesis and maturation of subtilosin. Nonpolar mutations introduced into each of the alb genes resulted in loss or reduction of subtilosin production. sboA, albA, and albF mutants showed no antilisterial activity, indicating that the products of these genes are critical for the production of active subtilosin. Mutations in albB, -C, and -D resulted in reduction of antilisterial activity and decreased immunity to subtilosin, particularly under anaerobic conditions. A new gene, sboX, encoding another bacteriocin-like product was discovered residing in a sequence overlapping the coding region of sboA. Construction of an sboX-lacZ translational fusion and analysis of its expression indicate that sboX is induced in stationary phase of anaerobic cultures of JH642. An in-frame deletion of the sboX coding sequence did not affect the antilisterial activity or production of or immunity to subtilosin. The results of this investigation show that the sbo-alb genes are required for the mechanisms of subtilosin synthesis and immunity.

Isolation, partial purification and characterization of a bacteriocin produced by a newly isolated Bacillus subtilis strain

A wild type micro-organism producing antibacterial substances has been isolated from a Chinese fermented soybean seasoning and identified as Bacillus subtilis. A crude antibacterial preparation (CABP) was obtained by ammonium sulphate precipitation. Isoelectric focusing assay revealed at least four antimicrobial components in the CABP. However, in SDS-PAGE analysis, only one peptide band displayed antimicrobial activity against pathogenic Bacillus cereus and Listeria monocytogenes. This inhibitory peptide had a molecular weight of approximately 3.4 kDa and a pI value of approximately 4.7. Results of this study suggest that at least one antimicrobial substance produced by this wild type strain of B. subtilis may be a new bacteriocin. Its sensitivity to gastric peptidases and activity against the food-borne pathogens make this bacteriocin potentially useful as an antimicrobial agent in foods.

Role of megalin (gp330) in transcytosis of thyroglobulin by thyroid cells. A novel function in the control of thyroid hormone release

When thyroglobulin (Tg) is endocytosed by thyrocytes and transported to lysosomes, thyroid hormones (T4 and T3) are released. However, some internalized Tg is transcytosed intact into the bloodstream, thereby avoiding proteolytic cleavage. Here we show that megalin (gp330), a Tg receptor on thyroid cells, plays a role in Tg transcytosis. Following incubation with exogenous rat Tg at 37 degrees C, Fisher rat thyroid (FRTL-5) cells, a differentiated thyroid cell line, released T3 into the medium. However, when cells were incubated with Tg plus either of two megalin competitors, T3 release was increased, suggesting that Tg internalized by megalin bypassed the lysosomal pathway, possibly with release of undegraded Tg from cells. To assess this possibility, we performed experiments in which FRTL-5 cells were incubated with either unlabeled or (125)I-labeled Tg at 37 degrees C to allow internalization, treated with heparin to remove cell surface-bound Tg, and further incubated at 37 degrees C to allow Tg release. Intact 330-kDa Tg was released into the medium, and the amount released was markedly reduced by megalin competitors. To investigate whether Tg release resulted from transcytosis, we studied FRTL-5 cells cultured as polarized layers with tight junctions on permeable filters in the upper chamber of dual chambered devices. Following the addition of Tg to the upper chamber and incubation at 37 degrees C, intact 330-kDa Tg was found in fluids collected from the lower chamber. The amount recovered was markedly reduced by megalin competitors, indicating that megalin mediates Tg transcytosis. We also studied Tg transcytosis in vivo, using a rat model of goiter induced by aminotriazole, in which increased release of thyrotropin induces massive colloid endocytosis. This was associated with increased megalin expression on thyrocytes and increased serum Tg levels, with reduced serum T3 levels, supporting the conclusion that megalin mediates Tg transcytosis. Tg transcytosis is a novel function of megalin, which usually transports ligands to lysosomes. Megalin-mediated transcytosis may regulate the extent of thyroid hormone release.

Hip2Norm: an object-oriented cross-platform program for 3D analysis of hip joint morphology using 2D pelvic radiographs

We developed an object-oriented cross-platform program to perform three-dimensional (3D) analysis of hip joint morphology using two-dimensional (2D) anteroposterior (AP) pelvic radiographs. Landmarks extracted from 2D AP pelvic radiographs and optionally an additional lateral pelvic X-ray were combined with a cone beam projection model to reconstruct 3D hip joints. Since individual pelvic orientation can vary considerably, a method for standardizing pelvic orientation was implemented to determine the absolute tilt/rotation. The evaluation of anatomically morphologic differences was achieved by reconstructing the projected acetabular rim and the measured hip parameters as if obtained in a standardized neutral orientation. The program had been successfully used to interactively objectify acetabular version in hips with femoro-acetabular impingement or developmental dysplasia. Hip(2)Norm is written in object-oriented programming language C++ using cross-platform software Qt (TrollTech, Oslo, Norway) for graphical user interface (GUI) and is transportable to any platform.