Influence of severity of myocardial injury on distribution of macromolecules: extravascular versus intravascular gadolinium-based magnetic resonance contrast agents.

Objectives: This study sought to 1) compare the distribution of extravascular (573 Da) and intravascular (92 kDa) magnetic resonance (MR) contrast agents in reperfused infarcted myocardium, and 2) investigate the effect of injury severity on these distribution patterns.

Background: Myocardial distribution of low and high molecular weight contrast agents depends on vascular permeability, diffusive/convective transport within the interstitium and accessibility of the intracellular compartment (cellular integrity).

Methods: To vary the severity of myocardial injury, 72 rats were subjected to 20, 30, 45 or 75 min (n = 18, respectively) of coronary artery occlusion.

Necrotizing enterocolitis: diagnosis with CT examination of urine after enteral administration of iodinated water-soluble contrast material.

Purpose: To develop a new method for diagnosing necrotizing enterocolitis with use of computed tomography (CT).

Materials And Methods: Urine specimens from 22 neonates were obtained 8-12 hours after iohexol was administered enterally. Twelve neonates had suspected (n = 5) or definite (n = 7) necrotizing enterocolitis, and 10 neonates without necrotizing enterocolitis underwent routine upper gastrointestinal study.

Two genitourinary manifestations of Wegener's granulomatosis.

Genitourinary manifestations of Wegener's granulomatosis (WG) are rare. We report 2 unusual cases of genitourinary WG, one in which the diagnosis was suggested by a cervical biopsy, and one case of recurrent WG presenting exclusively at a genitourinary site while the patient was taking methotrexate for maintenance of remission.

Multiunit normalized cross correlation differs from the average single-unit normalized correlation.

As the technology for simultaneously recording from many brain locations becomes more available, more and more laboratories are measuring the cross-correlation between single-neuron spike trains, and between composite spike trains derived from several undiscriminated cells recorded on a single electrode (multiunit clusters). The relationship between single-unit correlations and multiunit cluster correlations has not yet been fully explored. We calculated the normalized cross-correlation (NCC) between single-unit spike trains and between small clusters of units recorded in the rat somatosensory cortex.

Pattern of ocular dominance columns and cytochrome oxidase activity in a macaque monkey with naturally occurring anisometropic amblyopia.

Unilateral eyelid suture, a model for amblyopia induced by congenital cataract, produces shrinkage of the deprived eye's ocular dominance columns in the striate cortex. Loss of geniculocortical projections are thought to account for the poor vision in the amblyopic eye. It is uncertain whether ocular dominance columns become shrunken in other forms of amblyopia.

Enhanced transepithelial transport of peptides by conjugation to cholic acid.

The potential of the intestinal bile acid transporter to serve as a shuttle for small peptide molecules was investigated. Eleven peptides with a 2-6 amino acid backbone were conjugated to the 24-position of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholan-24-oic acid (cholic acid) via an amide bond using an automated peptide synthesizer. In a human intestinal cell line (CaCo-2), cholic acid-peptide conjugates were able to inhibit the transepithelial transport of [3H]taurocholic acid, a natural substrate for the bile acid carrier, at a 100:1 conjugate/substrate ratio.

Effects of Matrigel on the SF-767 malignant glioma athymic mouse tumor model.

Matrigel, an extracellular matrix material, has been used to promote growth of experimental tumors. SF-767, a human glioblastoma cell line, is used in brain tumor research. We investigated Matrigel induced changes in tumor latency, growth rate, cell yield, plating efficiency, and histology of SF-767 tumors in athymic mice.

Pain management in osteoarthritis: the role of COX-2 inhibitors.

Pain is the major symptom that leads patients to consult their physicians for the treatment of arthritis; therefore, effective pain control is an important goal in the management of this disorder. Pharmacologic therapy begins with simple analgesics and education. In many patients, simple analgesics do not adequately control moderate arthritis pain, and nonsteroidal antiinflammatory drugs (NSAID) are substituted for or added to the analgesic therapy.

Conformational substates in enzyme mechanism: the 120 K structure of alpha-lytic protease at 1.5 A resolution.

Insight into the dynamic properties of alpha-lytic protease (alpha LP) has been obtained through the use of low-temperature X-ray crystallography and multiple-conformation refinement. Previous studies of alpha LP have shown that the residues around the active site are able to move significantly to accommodate substrates of different sizes. Here we show a link between the ability to accommodate ligands and the dynamics of the binding pocket.

Fas ligand expression in islets of Langerhans does not confer immune privilege and instead targets them for rapid destruction.

Fas ligand is believed to mediate immune privilege in a variety of tissues, including the eye, testis, and a subset of tumors. We tested whether expression of Fas ligand on pancreatic islets either following adenoviral or germline gene transfer could confer immune privilege after transplantation. Islets were infected with an adenoviral vector containing the murine Fas ligand cDNA (AdFasL), and were transplanted into allogenic diabetic hosts.

Differentiation of rat neonatal ventral prostates grown in a serum-free organ culture system.

Background: Organ culture methods have long been used in the study of the prostate because effects of drugs and hormones can be examined in the absence of systemic effects.

Methods: Neonatal rat ventral prostates (VP) were grown on Millipore filters floating on fluid medium composed of Dulbecco's modified Eagle's medium/Ham's F-12 supplemented with insulin, transferrin, and hydrocortisone, and in the presence or absence of testosterone (T, 10(-8)M).

Results: In the presence of T, ductal lumen formation occurred, ductal branching was extensive, and basal and luminal epithelial cells were identified by immunocytochemistry based on their distinctive cytokeratin profile.

Of mites and men: trypsin-like proteases in the lungs.

It is no surprise to anyone who has tried to memorize clotting and complement cascades that there are a great many trypsin-like proteases-too many, it may seem. This fecund enzyme family encompasses such a range of biological roles that other important members and functions are sure to await discovery. Of known trypsin-like proteases, few, if any, are lung-specific.

DNA copy number changes associated with characteristic LOH in islet cell carcinomas of transgenic mice.

Comparative genomic hybridization (CGH) provides a method of surveying the entire tumor genome for regional variations in DNA sequence copy number. Such variations, if found recurrently, may indicate the locations of genes that contribute to tumor development through upregulation of oncogenes (copy number increase), inactivation of tumor-suppressor genes (copy number decrease), or changes in the level of expression through gene dosage effects. Thus, CGH is a powerful tool for screening for new cancer genes.

Endoscopic sclerotherapy compared with percutaneous transjugular intrahepatic portosystemic shunt after initial sclerotherapy in patients with acute variceal hemorrhage. A randomized, controlled trial.

Background: Hemorrhage from esophageal varices remains a substantial management problem. Endoscopic sclerotherapy was preferred for more than a decade, but fluoroscopically placed intrahepatic portosystemic stents have recently been used with increasing frequency.

Objective: To compare sclerotherapy with transjugular intrahepatic portosystemic shunt (TIPS) in patients with bleeding from esophageal varices.

The beta cell transcription factors and development of the pancreas.

The pancreatic beta cell is the major source of circulating insulin in adult mammals. In the multistep process of insulin synthesis it is initiation of transcription that restricts insulin synthesis to the beta cell since all subsequent steps can be performed by other cell types. Many of the transcription factors that bind to the insulin promoter and activate insulin gene transcription have been isolated.

Measurement of collateral blood flow in a porcine model of aortic coarctation by velocity-encoded cine MRI.

The purpose of this study was to investigate the time course of development of collateral blood flow in an animal model of aortic coarctation. A juxtaductal aortic stenosis (model coarctation) was surgically created in five juvenile pigs. MRI was performed preoperatively, 1 to 2 days postoperatively, and 2 to 10 weeks postoperatively.

High resolution T2-weighted imaging of the human brain using surface coils and an analytical reception profile correction.

High spatial resolution T2-weighted MR images of the human brain were obtained at 1.5 T. An optimized fast spin-echo (FSE) sequence and 1.

Ras inhibits Jun-activated human atrial natriuretic peptide gene transcription in cultured ventricular myocytes.

p21ras is a potent regulator of myogenic cell growth and differentiation. It has been implicated as playing a major role in the genesis of cardiac hypertrophy. We examined the effect of Ras overexpression on human atrial natriuretic peptide (hANP) gene expression, a marker of hypertrophy, in neonatal rat ventricular myocytes.

The cellular basis of aqueous outflow regulation.

This review begins with an introduction to the concept of the cellular regulation of aqueous outflow, current methods used for its study, and the cell types that are known to participate in this process. Current research in the field is divided into work on cell properties, cell products and extracellular matrix, cytoskeletal and structural changes, and drug interactions.

Heat-induced cobalt entry: an assay for heat transduction in cultured rat dorsal root ganglion neurons.

A histochemical stain to detect cobalt in cells was used to investigate the ionic basis of heat transduction in mammalian primary afferent neurons. Cultured dorsal root ganglion neurons from the adult rat were exposed to 10-min heat stimuli in an extracellular solution containing cobalt ions. When accumulated intracellular cobalt was precipitated, a subpopulation of neurons was darkly stained.

Bone marrow transplantation for inherited diseases.

Allogeneic bone marrow transplantation has been used successfully for the treatment of a variety of inherited diseases. The goal of transplantation in this setting is to provide a sufficient degree of sustained marrow engraftment to allow longterm amelioration of the inherited disease phenotype. Many factors influence the likelihood of achieving this goal, including donor availability, conditioning regimen, marrow processing, and the nature and extent of progression of the disease.

Dental development in Apert syndrome.

Objective: Apert syndrome has been extensively studied and described. However, an area that has not been studied is the dental development of these individuals. The purpose of this study was to evaluate the development of the dentition and compare it with that of unaffected children.