Subthalamic and nigral neurons are differentially modulated during parkinsonian gait

The parkinsonian gait disorder and freezing of gait are therapeutically demanding symptoms with considerable impact on quality of life. The aim of this study was to assess the role of subthalamic and nigral neurons in the parkinsonian gait control using intraoperative microelectrode recordings of basal ganglia neurons during a supine stepping task. 12 male patients (56±7 years) suffering from moderate idiopathic Parkinson's disease (disease duration 10±3 years, Hoehn & Yahr stage 2) participated in the study. After 10 seconds resting period, stepping at self-paced speed for 35 seconds was followed by short intervals of stepping in response to random "start" and "stop" cues. Single- and multi-unit activity was analysed offline in relation to different aspects of the stepping task (attentional "start" and "stop" cues, heel strikes, stepping irregularities) in terms of firing frequency, firing pattern, and oscillatory activity. Subthalamic nucleus and the substantia nigra neurons responded to different aspects of the stepping task. 24% of the subthalamic nucleus neurons exhibited movement-related activity modulation as an increase of the firing rate, suggesting a predominant role of the subthalamic nucleus in motor aspects of the task, while 8% of subthalamic nucleus neurons showed a modulation in response to the attentional cues. In contrast, responsive substantia nigra neurons showed activity changes exclusively associated with attentional aspects of the stepping task (15%). The firing pattern of subthalamic nucleus neurons revealed gait-related firing regulation and a drop of beta oscillations during regular stepping performance. During freezing episodes instead, there was a rise of beta oscillatory activity. This study shows for the first time specific, task-related, subthalamic nucleus and substantia nigra single unit activity during gait-like movements in humans with differential roles in motor and attentional control of gait. The emergence of perturbed firing patterns in the subthalamic nucleus indicates a disturbed information transfer within the gait network, resulting in freezing of gait.

Combined Subthalamic and Nigral Stimulation Modulates Temporal Gait Coordination and Cortical Gait-Network Activity in Parkinson’s Disease

Background

Freezing of gait (FoG) is a disabling burden for Parkinson’s disease (PD) patients with poor response to conventional therapies. Combined deep brain stimulation of the subthalamic nucleus and substantia nigra (STN+SN DBS) moved into focus as a potential therapeutic option to treat the parkinsonian gait disorder and refractory FoG. The mechanisms of action of DBS within the cortical-subcortical-basal ganglia network on gait, particularly at the cortical level, remain unclear.

Methods

Twelve patients with idiopathic PD and chronically-implanted DBS electrodes were assessed on their regular dopaminergic medication in a standardized stepping in place paradigm. Patients executed the task with DBS switched off (STIM OFF), conventional STN DBS and combined STN+SN DBS and were compared to healthy matched controls. Simultaneous high-density EEG and kinematic measurements were recorded during resting-state, effective stepping, and freezing episodes.

Results

Clinically, STN+SN DBS was superior to conventional STN DBS in improving temporal stepping variability of the more affected leg. During resting-state and effective stepping, the cortical activity of PD patients in STIM OFF was characterized by excessive over-synchronization in the theta (4–8 Hz), alpha (9–13 Hz), and high-beta (21–30 Hz) band compared to healthy controls. Both active DBS settings similarly decreased resting-state alpha power and reduced pathologically enhanced high-beta activity during resting-state and effective stepping compared to STIM OFF. Freezing episodes during STN DBS and STN+SN DBS showed spectrally and spatially distinct cortical activity patterns when compared to effective stepping. During STN DBS, FoG was associated with an increase in cortical alpha and low-beta activity over central cortical areas, while with STN+SN DBS, an increase in high-beta was prominent over more frontal areas.

Conclusions

STN+SN DBS improved temporal aspects of parkinsonian gait impairment compared to conventional STN DBS and differentially affected cortical oscillatory patterns during regular locomotion and freezing suggesting a potential modulatory effect on dysfunctional cortical-subcortical communication in PD.

Hydrated electrons induce the formation of interstrand cross-links in DNA modified by cisplatin adducts

Double-stranded oligonucleotides containing cisplatin adducts, with and without a mismatched region, were exposed to hydrated electrons generated by gamma-rays. Gel electrophoresis analysis demonstrates the formation of cisplatin-interstrand crosslinks from the cisplatin-intrastrand species. The rate constant per base for the reaction between hydrated electrons and the double-stranded oligonucleotides with and without cisplatin containing a mismatched region was determined by pulse radiolysis to be 7 × 109 and 2 × 109 M-1 s-1, respectively. These results provide a better understanding of the radiosensitizing effect of cisplatin adducts in hypoxic tumors and of the formation of interstrand crosslinks, which are difficult for cells to repair.

Pulsatile Hematuria From Procurement Core Needle Biopsy: A Case Report

Core needle biopsies are still widely performed to evaluate the pathologic suitability of a kidney allograft. Here, we report a case of pulsatile hematuria from a procurement core needle biopsy where the patient had to be taken emergently to interventional radiology for coil embolization immediately after organ reperfusion.

Macrophage migration inhibitory factor downregulation: a novel mechanism of resistance to anti-angiogenic therapy

Anti-angiogenic therapies for cancer such as VEGF neutralizing antibody bevacizumab have limited durability. While mechanisms of resistance remain undefined, it is likely that acquired resistance to anti-angiogenic therapy will involve alterations of the tumor microenvironment. We confirmed increased tumor-associated macrophages in bevacizumab-resistant glioblastoma patient specimens and two novel glioblastoma xenograft models of bevacizumab resistance. Microarray analysis suggested downregulated macrophage migration inhibitory factor (MIF) to be the most pertinent mediator of increased macrophages. Bevacizumab-resistant patient glioblastomas and both novel xenograft models of resistance had less MIF than bevacizumab-naive tumors, and harbored more M2/protumoral macrophages that specifically localized to the tumor edge. Xenografts expressing MIF-shRNA grew more rapidly with greater angiogenesis and had macrophages localizing to the tumor edge which were more prevalent and proliferative, and displayed M2 polarization, whereas bevacizumab-resistant xenografts transduced to upregulate MIF exhibited the opposite changes. Bone marrow-derived macrophage were polarized to an M2 phenotype in the presence of condition-media derived from bevacizumab-resistant xenograft-derived cells, while recombinant MIF drove M1 polarization. Media from macrophages exposed to bevacizumab-resistant tumor cell conditioned media increased glioma cell proliferation compared with media from macrophages exposed to bevacizumab-responsive tumor cell media, suggesting that macrophage polarization in bevacizumab-resistant xenografts is the source of their aggressive biology and results from a secreted factor. Two mechanisms of bevacizumab-induced MIF reduction were identified: (1) bevacizumab bound MIF and blocked MIF-induced M1 polarization of macrophages; and (2) VEGF increased glioma MIF production in a VEGFR2-dependent manner, suggesting that bevacizumab-induced VEGF depletion would downregulate MIF. Site-directed biopsies revealed enriched MIF and VEGF at the enhancing edge in bevacizumab-naive patients. This MIF enrichment was lost in bevacizumab-resistant glioblastomas, driving a tumor edge M1-to-M2 transition. Thus, bevacizumab resistance is driven by reduced MIF at the tumor edge causing proliferative expansion of M2 macrophages, which in turn promotes tumor growth.

Radiosensitization of DNA by Cisplatin Adducts Results from an Increase in the Rate Constant for the Reaction with Hydrated Electrons and Formation of Pt(I)

Pulse radiolysis measurements of the decay of hydrated electrons in solutions containing different concentrations of the oligonucleotide GTG with and without a cisplatin adduct show that the presence of a cisplatin moiety accelerates the reaction between hydrated electrons and the oligonucleotide. The rate constant of the reaction is found to be 2.23 × 10(10) mol(-1) L s(-1), which indicates that it is diffusion controlled. In addition, we show for the first time the formation of a Pt(I) intermediate as a result of the reaction of hydrated electrons with GTG-cisplatin. A putative reaction mechanism is proposed, which may form the basis of the radiosensitization of cancer cells in concomitant chemoradiation therapy with cisplatin.

Determination of hydration properties and thermal behavior of Paecilomyces variotii by differential scanning calorimetry

Due to the structure and the composition of Paecilomyces variotii, the mycelia of this fungus could have potential applications as ingredients in wettable foods. For this use, drying could be employed, justifying the study of thermal behavior of P. variotii. The objectives of this work were to perform a study of thermal behavior of P. variotii isolates, to evaluate the hydration properties of these mycelia and to analyze the effect of different technological parameters on the latter properties. Wet cultures exhibited a wide endothermic transition, with mean values of peak temperature of 61 degrees C and denaturation enthalpy of4 J/g dry matter. Initial (50 degrees C) and final (80 degrees C) temperatures of the endothermic transition were used to dry the mycelia. Freeze-drying was also assayed. For all dried mycelia, a decrease in denaturation enthalpy between 40 and 50% was observed for drying at 50 degrees C and freeze-drying, and a drastic decrease of almost 100% for drying at 80 degrees C. According to the hydration properties, wet mycelia exhibited water holding capacity (WHC) value of 45 g water/g dry matter. Significant differences among dried mycelia, resulting WHC values in order: 50 degrees C > freeze-dried > 80 degrees C (p < 0.05) were revealed for each P. variotii strain. Fungi obtained by drying at 50 degrees C and by freeze-drying, showed a rapid water absorption (t(1/2) < 0.1 min). Ionic strength, pH and particle size of dried mycelia influenced the hydration properties.

Hydrated electrons react with high specificity with cisplatin bound to single-stranded DNA

Short oligonucleotides TTTTTGTGTTT and TTTTTTTGTTT in solution with and without cisplatin (cisPt) bound to the guanine bases were irradiated with γ-rays at doses varying from 0 to 2500 Gy. To determine the effect of hydrated electrons from water radiolysis on the oligonucleotides, we quenched (•)OH radicals with ethylenediaminetetraacetic acid (EDTA) and displaced oxygen, which reacts with hydrated electrons, by bubbling the solution with wet nitrogen. DNA strand breaks and platinum detachment were quantified by gel electrophoresis. Our results demonstrate that hydrated electrons react almost exclusively at the position of the cisPt adduct, where they induce cisPt detachment from one or both guanines in the oligonucleotide. Given the high yield of hydrated electrons in irradiated tissues, this reaction may be an important step in the mechanism of radiosensitization of DNA by cisPt.

[Beta-glucan content and hydration properties of filamentous fungi]

The aim of this work was to isolate and identify filamentous fungi from several sources to study the dietary fiber and beta-glucan content. The fungal hydration properties such as water absorption and water holding capacities were also evaluated. Total dietary fiber of isolates exhibited a noticeable variability from 16 to 53% and the highest values were obtained for the genera Paecilomyces and Penicillium, a fact consistent with a higher content of beta-glucans (24 and 17%, respectively), higher than previously reported for Basidiomycetes and yeast. We observed a large decrease (75%) in the water holding capacity when the mycelia were dried. Isolates of filamentous fungi with greater water holding capacity also exhibited greater absorption capacity. Paecilomyces variotii and Penicillium nalgiovense had the best hydration properties. Our results contribute to the search for new unconventional ingredients providing a high protein and beta-glucans content. The addition of these dried mycelia could change the hydration properties in the food system.

Evaluation of the prediction of alternative measures of pork carcass composition by three optical probes

The accuracy of 3 optical probes (HGP4 Hennessey Grading Probe, Destron-Feering PG-100 probe, and Giraldo OPTO-Electronic PG-200 probe) to predict the carcass percentage of 5 alternative measures of carcass composition (fat-tissue-free lean, lipid-free soft tissue, lipid-free lean, total fat tissue, and soft tissue lipid) was evaluated on 203 barrows and gilts of 7 genetic populations. The optical probe backfat depths were more closely correlated (P < 0.001, 0.963 to 0.983) than the LM depths (r = 0.695 to 0.734). The optical probe backfat depths were related to lean percentage (r = -0.82 to -0.88), total fat tissue percentage (r = 0.84 to 0.88), and soft tissue lipid percentage (r = 0.86 to 0.87). Optical probe LM depths were weakly related (P < 0.05; r = 0.23 to 0.34) to measures of carcass lean percentage and total fat tissue percentage (r = -0.16 to -0.26). Fat-free lean percentage was predicted with residual SD (RSD) of 3.7% for equations including last-rib midline backfat thickness, 2.4 to 2.7% for equations including optical probe backfat and LM depth, and 2.3% for ribbed carcass measurements. The RSD for the optical probe equations ranged from 2.1 to 2.4% for lipid-free soft tissue percentage and from 2.0 to 2.3% for lipid-free lean percentage. The RSD for the optical probe equations ranged from 2.9 to 3.3% for total fat tissue percentage and 2.5 to 2.8% for soft tissue lipid percentage. Quadratic and cross-product variables of optical probe fat depth, LM depth, and carcass weight were significant (P < 0.05) and reduced the RSD of the equations. Optical probe backfat and LM measurements can be used to predict alternative measures of carcass composition. The predicted relationships in fat-free lean percentage to backfat depth were nearly identical for each optical probe.

Conversion of a tumor-binding peptide identified by phage display to a functional chimeric T cell antigen receptor

Adoptive transfer of ex vivo expanded tumor-specific T cells is a promising therapeutic modality for promoting or augmenting antitumor immunity. Several groups, including ours, are developing antigen receptor gene transfer strategies as a means of generating effector cells for adoptive therapy. Chimeric antigen receptors (CARs) have been described that use single-chain antibodies or cytokine ligands as tumor targeting domains. Here, we describe the capacity of a tumor-binding peptide identified by phage display combinatorial library screening to serve as a CAR targeting domain. A phage library-selected high-affinity 12-mer peptide (Bpep) specific for alpha(v) beta(6) integrin (alpha v beta6) was chosen for these studies. Primary human T cells were genetically modified to express the Bpep-CAR consisting of an alpha v beta6-specific peptide and human IgG4 hinge-Fc extracellular domain fused to the cytoplasmic tail of CD3-zeta. T cell expression of the Bpep-CAR was assessed by Western blot analysis, and trafficking of the Bpep-CAR to the cell surface was demonstrated by flow cytometry. Functionally, Bpep-CAR redirected cytotoxic T lymphocytes specifically kill integrin alpha v beta6+ ovarian tumor targets, and are activated for interferon gamma secretion. Our data suggest that large new repertoires of tumor-specific T cell antigen receptor transgenes might be available through merging combinatorial peptide libraries with CAR construct design.

The effect of dietary ractopamine concentration and duration of feeding on growth performance, carcass characteristics, and meat quality of finishing pigs

A total of 400 barrows from Dekalb EB and 83 terminal sires mated to 43 and 45 maternal lines were used to evaluate the effects of dietary ractopamine (RAC; Paylean, Elanco Animal Health, Greenfield, IN) concentrations (0, 5, 10, or 20 ppm; as-fed basis) and feeding durations (6 to 34 d) on growth, efficiency, carcass, and meat quality characteristics of finishing pigs. Barrows were weighed and sorted into five weight blocks, each block consisting of 16 pens (five pigs per pen). Weight blocks were allocated to feeding duration treatments and assigned consecutively by weight from lightest to heaviest to represent 34, 27, 20, 13, and 6 d on test, respectively. The lightest and heaviest blocks averaged 79.8 and 103.8 kg, respectively, at the start of the test. Within a weight block, pens (four per treatment) were randomly assigned to one of four dietary concentrations of RAC in a basal diet containing 18.5% CP and 1.13% lysine. The experiment-wide target slaughter weight was 109 kg, and pigs and feeders were weighed weekly. Weight blocks (80 barrows per block) were slaughtered at a commercial packing plant after 6, 13, 20, 27, or 34 d on test. Overall, RAC supplementation improved (P < 0.05) ADG; however, ADG was not different (P > 0.08) from controls for pigs fed 5, 10, and 20 ppm RAC for 27, 34, and 6 d, respectively. During each feeding period, RAC-fed pigs had improved (P < 0.05) G:F, and, after 20, 27, and 34 d on test, pigs fed 20 ppm RAC had greater (P < 0.05) G:F compared with those fed 0 or 5 ppm RAC. Hot carcass weight was increased (P < 0.05) by RAC feeding after 13 and 27 d of feeding, and by feeding 10 and 20 ppm RAC after 20 d of feeding. After 34 d, pigs fed 20 ppm RAC had heavier (P < 0.05) hot carcass weight than pigs fed 10 ppm RAC. Fat-free lean estimates and the 10th-rib LM area were increased (P < 0.05) by feeding 10 and 20 ppm RAC after 27 d, and by feeding 20 ppm RAC after 34 d compared with controls. Japanese and American color scores, as well as L*, a*, and b* values of the LM, were not affected (P > 0.11) by 5 and 10 ppm RAC compared with controls during each feeding period. Visual marbling score for the LM was decreased (P < 0.05) when RAC was fed at 10 and 20 ppm compared with 0 ppm RAC when fed for 34 d. Dietary RAC improved growth performance at all feeding durations, whereas carcass composition was improved at longer feeding durations. In addition, 5 and 10 ppm RAC did not affect objective and subjective measures of pork quality.

Relationships between different hydration properties of commercial and laboratory soybean isolates

Functional properties related to water protein interactions of soy protein isolates depend on the structural and aggregation characteristics of their major components (storage globulins 7S and 11S) that could be modified by the preparation procedure, thermal and/or chemical treatments, and drying methods. Commercial and laboratory isolates with different functionalities resulting from their structural modifications were compared. Isolates with high solubility or excessive thermally induced insolubilization or compact calcium-induced aggregates caused low water-imbibing capacity (WIC) values. The highest WIC results from the balance between intermediate solubility and the formation of aggregates with good hydration properties. The apparent viscosity of dispersions of commercial (spray dried) and laboratory (lyophilized) isolates depends on the WIC, the morphology and size of the particles, and the interaction of the hydrated particles. The hydration properties and viscosity of protein isolate suspensions were strongly determined by the amount and properties of the insoluble fraction.

The Neurospora crassa genome: cosmid libraries sorted by chromosome

A Neurospora crassa cosmid library of 12,000 clones (at least nine genome equivalents) has been created using an improved cosmid vector pLorist6Xh, which contains a bacteriophage lambda origin of replication for low-copy-number replication in bacteria and the hygromycin phosphotransferase marker for direct selection in fungi. The electrophoretic karyotype of the seven chromosomes comprising the 42.9-Mb N. crassa genome was resolved using two translocation strains. Using gel-purified chromosomal DNAs as probes against the new cosmid library and the commonly used medium-copy-number pMOcosX N. crassa cosmid library in two independent screenings, the cosmids were assigned to chromosomes. Assignments of cosmids to linkage groups on the basis of the genetic map vs. the electrophoretic karyotype are 93 +/- 3% concordant. The size of each chromosome-specific subcollection of cosmids was found to be linearly proportional to the size of the particular chromosome. Sequencing of an entire cosmid containing the qa gene cluster indicated a gene density of 1 gene per 4 kbp; by extrapolation, 11,000 genes would be expected to be present in the N. crassa genome. By hybridizing 79 nonoverlapping cosmids with an average insert size of 34 kbp against cDNA arrays, the density of previously characterized expressed sequence tags (ESTs) was found to be slightly <1 per cosmid (i.e., 1 per 40 kbp), and most cosmids, on average, contained an identified N. crassa gene sequence as a starting point for gene identification.

Evaluation of alternative measures of pork carcass composition

Carcass and live measurements of 203 pigs representing seven genetic populations and four target live weights (100, 114, 128, and 152 kg) were used to evaluate alternative measures of carcass composition. Measures of carcass lean (fat tissue-free lean, FFLM; lipid-free soft tissue, LFSTIS; and dissected lean in the four lean cuts, DL), fat (total carcass fat tissue, TOFAT), and lipid mass (soft tissue lipid, STLIP) were evaluated. Overall, LFSTIS was 22.8% greater than FFLM (47.8 vs 38.9 kg) and TOFAT was 30% greater than STLIP (38.5 vs 29.6 kg). The allometric growth coefficients relative to carcass weight were different for the measures: b = 0.776, 0.828, 0.794, 1.37, and 1.49 for FFLM, LFSTIS, DL, TOFAT, and STLIP, respectively. At 90 kg carcass weight, the predicted growth of FFLM, LFSTIS, TOFAT, and STLIP was 0.314, 0.420, 0.553, and 0.446 kg/kg increase in carcass weight. The difference between FFLM and LFSTIS, representing nonlipid components of the carcass fat tissue, was greater for barrows than for gilts (9.2 vs 8.6 kg). Lipid-free soft tissue mass was predicted more accurately from carcass or live animal measurements than FFLM with smaller relative RSD (4.6 vs 6.5% of their mean values). The alternative measures of carcass composition were evaluated as predictors of empty body protein (MTPRO) and lipid (MTLIP) mass. Empty body protein was predicted with similar accuracy (R2 = 0.74 to 0.81) from either DL, FFLM, LFSTIS, or ribbed carcass measurements. Empty body lipid was predicted more accurately from TOFAT (R2 = 0.92) or STLIP (R2 = 0.93) than ribbed carcass measurements (R2 = 0.88). Although the alternative measures of lean mass (LFSTIS vs FFLM) and lipid mass (TOFAT vs STLIP) were highly related to each other (r = 0.93 to 0.98), they had different relative growth rates (allometric coefficients) and thus cannot be predicted as linear functions of the similar alternative variable without significant weight group biases. From the 100- to 152-kg target weight groups, gilts gained 12.9% greater FFLM and 12.1% greater MTPRO but only 4.4% greater LFSTIS than barrows. Fat-free lean mass is more precise as a measure of muscle growth and as a predictor of lysine requirements. Lipid-free soft tissue can be obtained more quickly and predicted more accurately from carcass or live animal measurements.

Analysis of biofluids for flunitrazepam and metabolites by electrospray liquid chromatography/mass spectrometry

A rapid and sensitive liquid chromatography/electrospray ionization mass spectrometry (LC/MS) procedure has been developed for the analysis of biofluids containing flunitrazepam and its metabolites. Specimens were spiked with deuterated analogs of the analytes. Urine specimens were enzymatically hydrolyzed and blood specimens were untreated. Extractions were carried out using CleanScreen DAU SPE cartridges. The drugs were separated on a C18 column using a methanol-water-ammonium hydroxide (60:40: 0.03 v/v) mobile phase. After determination of base peaks using full scan mass spectrometry, the mass spectrometry method was optimized to operate in selected-ion monitoring (SIM) mode for the base peak of each analyte. Positive findings were confirmed by LC/MS/MS using the same mobile phase and column. This analytical procedure allows for the detection of low levels of flunitrazepam and metabolites in biofluids. It is useful for ascertaining the role of flunitrazepam in cases of drug-facilitated sexual assault.

Relation between solubility and surface hydrophobicity as an indicator of modifications during preparation processes of commercial and laboratory-prepared soy protein isolates

Because water solubility is the main hydration property of proteins, solubility values of commercial and laboratory soy protein isolates, prepared under different conditions, were comparatively analyzed. In contrast, the surface hydrophobicity manifested by proteins is a physicochemical property that determines, to a great extent, the tendency of protein molecules to aggregate and so to lose solubility. On these grounds, the solubility of isolates was analyzed as a function of the surface hydrophobicity of their proteins, and, as a result, three well-defined groups of laboratory isolates were identified: (A) native, (B) partially or totally denatured with high solubility and surface hydrophobicity, and (C) totally denatured with low solubility and surface hydrophobicity. Commercial isolates could not be included in any of these groups; they were grouped as (A') partially native and (C') totally denatured. Solubility values in these two groups were similar to those of group C, but the surface hydrophobicity levels were much lower. The different processes leading to the groups mentioned above are discussed, along with the way the soy proteins are influenced by the specific preparation conditions, namely, protein concentration, chemical or thermal treatments, presence of salts, drying, and phospholipid addition, among others.

Direct correlation of glutathione and ascorbate and their dependence on age and season in human lymphocytes

BACKGROUND

Endogenous reactive oxygen species appear to contribute to aging and cancer and dietary antioxidants, present in fruit and vegetables, counteract these effects.

OBJECTIVE

The objective was to examine the association between intracellular glutathione, ascorbate (vitamin C), and alpha-tocopherol (vitamin E) in human lymphocytes.

DESIGN

The study group consisted of 240 healthy nonsmoking volunteers with an approximately equal number of male and female subjects subdivided into 3 age groups: 18-39, 40-59, and >/=60 y). Glutathione, glutathione disulfide, ascorbate, and alpha-tocopherol were measured in lymphocytes by HPLC.

RESULTS

The average concentration of antioxidants in lymphocytes was 27 +/- 8 nmol/mg protein for glutathione, 21 +/- 8 nmol/mg protein for ascorbate, and 0.4 +/- 0.2 nmol/mg protein for alpha-tocopherol. There was a strong positive correlation between glutathione and ascorbate (r = 0.62, P < 0.001). No correlation was observed for glutathione and ascorbate with alpha-tocopherol. The concentration of glutathione in lymphocytes was inversely correlated with age (r = -0.19, P < 0.01), as was that of ascorbate (r = -0.22, P < 0.01), with 10-20% lower values in elderly than in young and elderly subjects. The concentrations of glutathione in lymphocytes were as much as 25% higher and those of ascorbate were as much as 38% higher during the summer than during the winter. The seasonal variation of ascorbate in lymphocytes was described by a linear function for age and a periodic sine function for season.

CONCLUSION

Glutathione and ascorbate are directly correlated in human lymphocytes.

Urologic complications of major pelvic surgery

The close proximity of pelvic organs makes the genitourinary system susceptible to injury during major pelvic surgery. Iatrogenic injury remains the most common cause of lower urinary tract trauma. Recent modifications in surgical technique, such as sharp mesorectal incision and nerve-sparing radical prostatectomy, have decreased the incidence of many of these complications. Genitourinary complications due to pelvic surgery remain common, however, and as new surgical advancements are made, new complications may present. An understanding of the prevention, recognition, and treatment of urologic complications is important for every surgeon performing major pelvic surgery.

Analysis of glutathione and glutathione disulfide in whole cells and mitochondria by postcolumn derivatization high-performance liquid chromatography with ortho-phthalaldehyde

A method is described for the detection of glutathione (GSH) and glutathione disulfide (GSSG) based on a HPLC postcolumn reaction with ortho-phthalaldehyde (OPT) at pH 12 followed by fluorescence detection. Although similar methods have been reported, the high pH of the postcolumn reaction adds considerable selectivity and sensitivity to the measurement of GSH and glutathione disulfide. The limit of detection approaches 100 fmol, which is sufficient to detect whole-cell glutathione disulfide in 10,000 cells or mitochondrial glutathione disulfide in 20 million cells. Using this method, glutathione and glutathione disulfide were measured in human lymphocytes, granulocytes, and cultured Jurkat T cells, as well as in the corresponding samples of mitochondria. The percentage of glutathione disulfide to total glutathione in whole-cell extracts was approximately 1%. In contrast, the percentage was relatively high in mitochondria, with the mitochondria of granulocytes having the highest (25%) followed by those of lymphocytes (15%) and finally by cultured Jurkat T cells (9%). This method extends the analysis of glutathione and glutathione disulfide to mitochondria obtained from a relatively small number of cells.

2'-Deoxycytidine glycols, a missing link in the free radical-mediated oxidation of DNA

2'-Deoxycytidine glycols (5,6-dihydroxy-5, 6-dihydro-2'-deoxycytidine) are major products of the hydroxyl radical-induced oxidation of 2'-deoxycytidine resulting from either a Fenton reaction or exposure to ionizing radiation. Because of their instability, however, the glycols have not previously been characterized. Instead, the impetus has been placed on the primary decomposition products of 2'-deoxycytidine glycols, which includes 5-hydroxy-2'-deoxycytidine, 5-hydroxy-2'-deoxyuridine, and 2'-deoxyuridine glycols. Here, we have identified one of the four possible diastereomers of 2'-deoxycytidine glycols by product analyses of decomposition products, (1)H NMR, and mass spectrometry. This glycol was observed to decompose with a half-life of 50 min at 37 degrees C in buffered neutral solutions and preferentially undergo dehydration to 5-hydroxy-2'-deoxycytidine. The rate of decomposition was strongly dependent on pH (2-10) and the concentration of phosphate ion (10-300 mM). Next, we report on the deamination of cytosine glycols to uracil glycols in oxidized DNA using acid hydrolysis and high performance liquid chromatography analysis with electrochemical detection to monitor 5-hydroxycytosine and 5-hydroxyuracil. The results showed that the lifetime of cytosine glycols is greatly enhanced in DNA (34-fold; half-life, 28 h), and that deamination accounts for at least one-third of the total decomposition. The relatively long lifetime of cytosine glycols in DNA suggests that this important class of DNA oxidation products will be significantly involved in repair and mutagenesis processes.

Interleukin-2 based immunotherapy for metastatic renal cell carcinoma with the kidney in place

PURPOSE

We assessed morbidity, response and survival in patients with metastatic renal carcinoma treated with high dose intravenous interleukin-2 (IL-2) based immunotherapy with the primary renal tumor in place.

MATERIALS AND METHODS

We retrospectively analyzed the records of patients with metastatic renal carcinoma and the primary kidney tumor in situ who were treated at the surgery branch of the National Cancer Institute. Of the patients 607 were treated with IL-2 based therapy. Patient age, sex, sites of extrarenal disease, morbidity, and response and survival rates were examined.

RESULTS

From 1986 to 1996, 51 patients with the majority of disease at extrarenal sites were treated with the primary tumor in place. Treatment involved IL-2 based regimens, reflecting the evolution of immunotherapy at the National Institutes of Health. When evaluating only extrarenal sites, response was complete in 1 and partial in 2 of the 51 cases (6%). No responses were noted in the primary renal tumor. Three patients with responses at extrarenal sites underwent nephrectomy. The duration of response in these 3 cases was greater than 88, 11 and 4 months, respectively. Median survival in all 51 patients was 13 months (range 1 to 86).

CONCLUSIONS

Select patients may be treated with IL-2 based immunotherapy with the primary renal tumors in place with morbidity. A randomized study is needed to assess the role of cytoreductive nephrectomy for treating metastatic renal cell carcinoma.

Surface functional properties of native, acid-treated, and reduced soy glycinin. 1. Foaming properties

Foaming properties of native and chemically modified glycinin were evaluated. Effects of ionic strength and glycinin composition and concentration on foam formation and stabilization were studied. Glycinin was modified by means of combined treatments: cold or hot acidic treatments, with or without later disulfide bridges reduction. Modified proteins obtained from glycinin present different degrees of dissociation, deamidation, and as consequence, varied surface hydrophobicity and molecular size. Parameters of forming and stabilizing of foam were correlated with both deamidation and dissociation degrees of modified and native glycinin samples. A positive relationship was observed between surface behavior and foaming properties of different protein species. Results show that dissociation, deamidation, and reduction have produced structural changes on glycinin (increased surface hydrophobicity, increased net charge, decreased molecular size) which enhance the adsorption and anchorage of proteins at the air-water interface and, consequently, improve the foam forming and stabilizing capacities.

Surface functional properties of native, acid-treated, and reduced soy glycinin. 2. Emulsifying properties

Emulsifying properties of native and chemically modified soy glycinins were studied. The influence of ionic strength, protein sample composition and concentration, and assay conditions on the flocculation-creaming process and coalescence resistance was analyzed. Differences in these emulsifying properties were exhibited by native glycinins, which have a variable content of 4S, 11S, and 15S forms. Structure and functionality of native glycinin were modified by means of combined treatments: mild acidic treatments without heating or with heating at variable time and with or without disulfide bonds reduction. Modified glycinins presented different degrees of deamidation, surface hydrophobicity, and molecular mass. A slight enhancement of emulsifying stability at moderated deamidation degrees was observed. In different protein samples, a positive relationship between the flocculation-creaming rate constant and equilibrium oil volume fraction of emulsions with surface hydrophobicity was detected. A remarkable difference was observed between reduced and nonreduced samples, mainly with respect to behavior at low or high ionic strength.

Analysis of body composition changes of swine during growth and development

This study was conducted to model the growth of carcass, viscera, and empty body components and component composition of pigs. Quantitative tissue and chemical composition of 319 swine, representative of barrows and gilts from five commercial genetic populations, was determined at eight stages of growth between 25 and 152 kg. After whole body grinding and carcass dissection, proximate analyses were performed to calculate concentrations of protein, lipid, moisture, and ash of carcass, viscera, empty body, carcass lean, and carcass fat. Linear and nonlinear equations were developed to investigate the growth patterns of each component. Nonlinear growth functions accounted for the greatest amount of variation in empty body protein, lipid, moisture, and ash mass. Differences (P < .05) existed between barrows and gilts for nearly all components investigated. Carcass lean and fat tissues significantly increased in lipid percentage and decreased in moisture percentage as live weight increased. There were significant changes in the ratio and composition of the tissues of barrows and gilts during growth. Nonlinear models fitted the data better than allometric equations for nearly all of the components investigated.

Glutathione and ascorbate are negatively correlated with oxidative DNA damage in human lymphocytes

Intracellular antioxidants, glutathione and ascorbate, and two molecular markers of oxidative DNA damage, 5-hydroxy-2'-deoxycytidine (5-OH-dCyd) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo), were measured in lymphocytes from 105 healthy volunteers. The analysis of 5-OH-dCyd and 8-oxo-dGuo was carried out by HPLC with electrochemical detection such that both compounds were detected on the same chromatography run. There was no significant difference in oxidative DNA damage when the extraction of DNA from cells using phenol was carried out under anaerobic conditions or in the presence of metal ion chelators. This indicates that auto-oxidation of DNA during sample preparation was minimal. Using the above methods, the average level of oxidative DNA damage in lymphocytes was 2.9 +/- 1.4 for 5-OH-dCyd and 4.5 +/- 1.8 for 8-oxo-dGuo lesions per 10(6) dGuo (n = 105). It is unlikely that artifactual oxidation contributed to the observed damage because the level of 5-OH-dCyd was comparable with that of 8-oxo-dGuo in lymphocyte DNA, whereas 8-oxo-dGuo outnumbers 5-OH-dCyd by a ratio of >5:1 when DNA is exposed to various oxidants, including ionizing radiation or Fenton reagents. Rather, the nearly equal levels of 5-OH-dCyd and 8-oxo-dGuo in cellular DNA implies that 8-oxo-dGuo may be more efficiently removed by DNA repair. Finally, and most importantly, the correlation of our endpoints revealed that the naturally occurring level of intracellular antioxidants was negatively correlated to the level of oxidative DNA damage with the strongest correlation observed for glutathione and 8-oxo-dGuo (r = -0.36; P < 0.001). These results strongly suggest that intracellular glutathione and ascorbate protect human lymphocytes against oxidative DNA damage.

Relationship between the response to influenza vaccination and the nutritional status in institutionalized elderly subjects

BACKGROUND

Influenza is a major health problem among elderly people in industrialized countries. Nursing homes may be a particularly good setting for outbreaks of influenza. Thus, the aim of the present study was to evaluate some aspects of the nutritional status of institutionalized elderly subjects in relation to their response to influenza vaccination. Certain aspects of the cellular immune response were also investigated.

METHODS

Twenty-three patients participated in this cross-sectional study. All patients were vaccinated on day 0 with FluviralR, 1994-95 preparation: A/Shangdong/09/93, A/Texas/36/91, B/Panama/45/90. At the same time the prevaccination antibody titer, the nutritional status by the Mini Nutritional Assessment, biochemical parameters, and lymphocyte proliferation were assessed. On day 28, the postvaccination antibody titer was determined. The determination of pre- and postvaccination antibody titers against the various influenza antigens was carried out by the hemagglutination inhibition test. An increase of 4x for any of the virus antigens was considered as a seroconversion. A titer higher than 40 at the prevaccination period was considered as protective.

RESULTS

Eleven elderly subjects were responsive and 12 were not. We have shown that the nutritional parameters such as hemoglobin, hematocrit, total protein, iron and vitamin E levels, as well as the DHEA level and the cellular immune response were significantly lower in the nonresponsive group as compared to the responsive group. Thus, they might be associated with the influenza vaccine responsiveness of institutionalized elderly subjects.

CONCLUSIONS

These results will help design intervention studies for improving the immune response by achieving an optimal nutritional status, mainly in the frail elderly population, that could have a great public health impact.

Tripodal mandibular subperiosteal implant: basic sciences, operational procedures, and clinical data

A tripodal mandibular subperiosteal dental implant is a three piece cast metal framework that fits on the residual ridge beneath the periosteum and provides support for a dental prosthesis by means of posts or other mechanisms protruding through the oral mucosa. This implant is indicated in patients with advanced atrophy of the mandible where the unstable alveolar bone has completely disappeared, leaving in place the more stable basal bone with specific anatomical contours. The authors present their experience of 317 cases carried out in three different centers related to this implant modality and underline the importance of the basic anatomic, physiologic, and medical knowledge required to optimize the results.

Biases associated with genotype and sex in prediction of fat-free lean mass and carcass value in hogs

Carcass and live measurements of 165 market hogs that represented seven genotypes were used to investigate genotype and sex biases associated with the prediction of fat-free lean mass (FFLM) and carcass value. Carcass value was determined as the sum of the product of weight of individual cuts and their average unit prices adjusted for slaughter and processing costs. Independent variables used in the prediction equations included carcass measurements, such as optical probe, midline ruler, ribbed carcass measurements, and electromagnetic scanning (EMSCAN), and live animal ultrasonic scanning. The effect of including subpopulation mean values of independent variables in the prediction equations for FFLM and carcass value was also investigated. Genotype and sex biases were found in equations in which midline backfat, ribbed carcass, EMSCAN, and live ultrasonic scanning were used as single technology sets of measurements. The prediction equations generally undervalued genotypes with above-average carcass value. Biases were reduced when measurements of combined technologies and mean adjusted variables were used. The FFLM and carcass value of gilts were underestimated, and they were overestimated of barrows. Equations that combined OP and EMSCAN technologies were the most accurate and least biased for both FFLM and carcass value. Equations that included carcass weight and midline last-rib backfat thickness measurements were the least accurate and most biased. Genotype and sex biases must be considered when predicting FFLM and carcass value.

Incorporation of two deoxycytidine oxidation products into cellular DNA

The oxidation of cytosine in DNA by free radicals and other oxidants leads to an assortment of products including pyrimidine ring 5,6-saturated, 5,6-unsaturated, contraction, and fragmentation products. The formation of these products in cellular DNA may explain in part the preponderance of C to T transitions induced spontaneously and by H2O2 or ionizing radiation. Our studies have focused on the biological effects of two major 5,6-unsaturated oxidation products of cytosine: 5- hydroxycytosine and 5-hydroxyuracil. In the present work, we have attempted to study the repair of these two lesions by specifically incorporating them into cellular DNA upon incubation of cells with 5-hydroxy-2'deoxycytidine and 5-hydroxy-2'-deoxyuridine. Incubation of mouse L1210 cells with 250 M 5-hydroxy-2'-deoxycytidine led to the incorporation of this lesion to a level 20 times higher (43 lesions/10(5) cytosines) than base-line levels; however, there was no evidence for its repair following a 15-h chase. In contrast, we did not observe any significant incorporation of 5-hydroxy-2'-deoxyuridine into the DNA of L1210 cells but did observe an unidentified product, presumably an oxidation product. This unidentified pyrimidine was incorporated at a very high level (about 2000 lesions/10(5) cytosine residues) and then partially repaired in chase experiments.

Renal cancer: preoperative evaluation with dual-phase three-dimensional MR angiography

PURPOSE

To evaluate the use of dual-phase three-dimensional magnetic resonance (MR) angiography in the preoperative staging of renal cancer.

MATERIALS AND METHODS

MR angiography was performed in 18 patients before performance of partial (n = 7), radical (n = 10), or laparoscopic (n = 1) nephrectomy to treat renal cancer. Dynamic, three-dimensional MR angiograms were obtained with gadoteridol enhancement, breath holding, and a three-dimensional spoiled gradient-echo sequence. Images were obtained at 15-second intervals to achieve opacification of arteries and veins. Source, maximum intensity projection, and multiplanar reconstruction images were evaluated. Imaging results were compared with surgical findings.

RESULTS

Renal arterial phase MR angiograms depicted 30 of 31 (97%) surgically confirmed renal arteries, with one false-positive result (an artery that arose from an early-branching single main renal artery, interpreted as a separate accessory artery). Renal venous phase MR angiograms depicted all seven instances of renal vein involvement, including extension to the inferior vena cava in two patients. Collateral vessels around the tumor, including prominent gonadal veins in three patients, were demonstrated. Additional findings included adenopathy and adrenal and pulmonary metastases.

CONCLUSION

Dual-phase MR angiography of the kidney may be a useful technique in depicting renal vessels before nephrectomy.

Pulmonary infarcts can mimic pulmonary metastases from renal cancer

PURPOSE

Spontaneous regression of pulmonary metastases from renal cell carcinoma is a rare but well documented event. We present 2 recent cases that were radiographically consistent with pulmonary metastases from renal cell carcinoma but were pathologically shown to be pulmonary infarcts with no evidence of metastatic cells. Stable pulmonary infarcts can be misconstrued as metastatic disease in patients with renal cell carcinoma while resolving pulmonary infarcts may represent a subpopulation of patients with apparent spontaneous regression. Clinical implications of these findings are discussed.

MATERIALS AND METHODS

Clinical and pathological data from 2 patients with large primary renal tumors, venous thrombi and lung masses were reviewed. Data from these cases, as well as pertinent urological and pathological literature, are presented.

RESULTS

Although preoperative assessment was consistent with stage IV renal cell carcinoma, pathological examination of the lung masses in these patients showed no evidence of tumor cells.

CONCLUSIONS

Pulmonary infarcts may mimic resolving or stable pulmonary metastasis in patients with renal cell carcinoma. Accurate clinical staging is crucial for the prognosis and treatment of renal cell carcinoma. Mistaking pulmonary infarcts for metastatic lesions can lead to inaccurate prognoses and inappropriate treatment.

Imaging features of hereditary papillary renal cancers

PURPOSE

Our goal was to describe the imaging features of hereditary papillary renal cancer syndrome (HPRC), a new familial cancer syndrome.

METHOD

Members of seven kindreds with HPRC comprising 78 individuals were screened with contrast-enhanced CT and abdominal US. MRI was performed in three patients. Enhancement values and doubling times of solid masses were determined from CT scans.

RESULTS

Seventeen of 78 (22%) patients were affected. The HPRCs demonstrated lower enhancement (mean change in enhancement = 31 HU) than a comparable group of clear cell tumors (mean change in enhancement = 67 HU: p = 0.00001). The median tumor doubling time on serial CT was 18 months. The HPRCs were relatively hypovascular, enhanced uniformly, and grew slowly. Therefore, careful measurements of the region of interest should be obtained before and after intravenous administration of contrast medium. Though US detected only 45% of the lesions visualized on CT, it was useful in determining if lesions were cystic. Contrast-enhanced MRI demonstrated similar characteristics to contrast-enhanced CT.

CONCLUSION

The tumors of patients with HPRC pose some diagnostic difficulties because they can be missed by US, are small, and enhance poorly on CT. CT is preferable to US as a screening tool because of its higher sensitivity in detecting small lesions, and when contrast media cannot be administered, MR is a suitable alternative to CT.

Defective placental vasculogenesis causes embryonic lethality in VHL-deficient mice

Inheritance of an inactivated form of the VHL tumor suppressor gene predisposes patients to develop von Hippel-Lindau disease, and somatic VHL inactivation is an early genetic event leading to the development of sporadic renal cell carcinoma. The VHL gene was disrupted by targeted homologous recombination in murine embryonic stem cells, and a mouse line containing an inactivated VHL allele was generated. While heterozygous VHL (+/-) mice appeared phenotypically normal, VHL -/- mice died in utero at 10.5 to 12.5 days of gestation (E10.5 to E12.5). Homozygous VHL -/- embryos appeared to develop normally until E9.5 to E10.5, when placental dysgenesis developed. Embryonic vasculogenesis of the placenta failed to occur in VHL -/- mice, and hemorrhagic lesions developed in the placenta. Subsequent hemorrhage in VHL -/- embryos caused necrosis and death. These results indicate that VHL expression is critical for normal extraembryonic vascular development.

Changes in apoptosis of human polymorphonuclear granulocytes with aging

Many alterations with aging occur at the cellular and organic levels in the immune system ultimately leading to a decrease in the immune response. Our aim in the present work was to study apoptosis of polymorphonuclear granulocytes (PMN) with aging under various stimulations since apoptosis might play an important role in several pathologies encountered with aging. The PMN of healthy young (20-25 years) and elderly (65-85 years) subjects were examined after 24 h of sterile culture with and without stimulation. The stimulating agents included: phorbol myristate acetate (PMA), hydrogen peroxide (H2O2), N-formyl-methionyl-leucyl phenylalanine (FMLP), granulocyte-macrophage colony stimulating factor (GM-CSF), reduced glutathione (GSH), lipopolysaccharide (LPS) and interleukin 2 (IL-2). Apoptosis was assessed by traditional staining of the plates, by flow cytometric staining and DNA gel electrophoresis. It was found that without stimulation the susceptibility of PMN to apoptosis was slightly increased with aging. Under various stimulations, such as PMA. H2O2, apoptosis was almost 100%, while the treatment by FMLP, oxLDL and GSH did not change its extent in PMN obtained either from young or elderly subjects. Marked age-related changes were observed in the extent of apoptosis under stimulation with GM-CSF, IL-2 and LPS. These agents were able to significantly prevent apoptosis in PMN of young subjects, while only the GM-CSF was able to slightly modulate it in neutrophils of elderly subjects. From these results, we suggest that changes in apoptosis of PMN with aging could play a role in the increased incidence of certain immune system related pathologies of aging, such as cancer, infections and autoimmune disorders.

Laparoscopic adrenalectomy: a new standard of care

OBJECTIVES

Adrenalectomy is the mainstay of treatment for adrenal tumors. A variety of surgical approaches to the adrenal gland have been described. We studied the feasibility of laparoscopic adrenalectomy (LA), compared laparoscopic with open adrenalectomy (OA), and studied the hemodynamic changes in patients with pheochromocytoma.

METHODS

Our early experience with 20 consecutive LAs is compared with a contemporaneous, matched control cohort of 20 patients who underwent OA via a flank or subcostal incision. LA was performed via a transperitoneal approach, following a standardized surgical technique.

RESULTS

LA was successfully completed in 18 of 20 cases. Average operating time in the first 5 cases was 261 minutes, but, with further experience, a significant decrease in operative time was seen in the last cohort of 4 patients (155 minutes) (P = 0.0018). There was no significant difference in operative time or degree of blood loss between LA and OA groups. Patients who underwent LA required lower doses of postoperative parenteral narcotics (P = 0.0169), had a shorter hospital stay (mean 3.2 days) (P < 0.0001), and had a shorter convalescent period (mean 3.1 weeks) (P < 0.0001). Complications in the laparoscopic group (chronic port site pain in 1 patient, intra-abdominal fluid collection in another) occurred in the 2 patients who required open conversion. These 2 patients had large adrenal tumors (9 and 7 cm in diameter, respectively). LA resulted in similar hemodynamic changes as OA in patients with pheochromocytoma.

CONCLUSIONS

LA is a safe and effective approach in most patients with adrenal pathology. Benefits include excellent operative exposure and visualization, less postoperative pain, shorter hospital stay and convalescent period, and improved cosmetic result. Pheochromocytoma is not a contraindication to LA. Patients with large adrenal tumors (larger than 6 cm), evidence of venous involvement, or invasion into surrounding tissue should be approached cautiously.

Rupture of the triceps muscle at the musculotendinous junction: a case report

Rupture of the triceps brachii at the musculotendinous junction is reported in a patient with diabetes mellitus and hypertension. Successful reconstruction was achieved by delayed primary repair. V-Y advancement of the triceps, and a plantaris tendon graft.

Perirenal myelolipoma

Extra-adrenal myelolipomas are rare, benign tumors composed of hematopoietic and adipose elements. Although these tumors can cause local symptoms or hemorrhage, they are generally asymptomatic. However, when discovered intraoperatively, they pose a diagnostic dilemma to the urologic surgeon. We present a case of perirenal extra-adrenal myelolipoma discovered intraoperatively in a patient with von Hippel-Lindau disease undergoing partial nephrectomy.

Molecular genetics of renal cell carcinoma

Renal cell carcinoma can be divided into sporadic and inheritable forms. One of the most common inheritable forms occurs in von Hippel-Lindau disease (VHL). VHL is a multisystem neoplastic disorder in which individuals develop tumors and cysts in multiple organs including the kidneys. Careful linkage analysis and cloning identified the VHL gene on chromosome 3p. In accordance with Knudson's hypothesis and tumor suppression theory, the VHL gene has been shown to have an important role in sporadic renal carcinoma as well. Further understanding of the VHL protein is likely to enhance our understanding of renal carcinogenesis, and clinical implications are beginning to evolve.

Post-transcriptional regulation of vascular endothelial growth factor mRNA by the product of the VHL tumor suppressor gene

The VHL tumor suppressor gene is inactivated in patients with von Hippel-Lindau disease and in most sporadic clear cell renal carcinomas. Although VHL protein function remains unclear, VHL does interact with the elongin BC subunits in vivo and regulates RNA polymerase II elongation activity in vitro by inhibiting formation of the elongin ABC complex. Expression of wild-type VHL in renal carcinoma cells with inactivated endogenous VHL resulted in unaltered in vitro cell growth and decreased vascular endothelial growth factor (VEGF) mRNA expression and responsiveness to serum deprivation. VEGF is highly expressed in many tumors, including VHL-associated and sporadic renal carcinomas, and it stimulates neoangiogenesis in growing solid tumors. Despite 5-fold differences in VEGF mRNA levels, VHL overexpression did not affect VEGF transcription initiation or elongation as would have been suggested by VHL-elongin association. These results suggest that VHL regulates VEGF expression at a post-transcriptional level and that VHL inactivation in target cells causes a loss of VEGF suppression, leading to formation of a vascular stroma.

Increased susceptibility of low-density lipoprotein (LDL) to oxidation by gamma-radiolysis with age

The susceptibility to oxidation of freshly isolated LDL from healthy normolipidemic individuals in three age groups was estimated by exposure of LDL to ionizing radiation followed by analyses of vitamin E, TBARS, conjugated dienes, and fluorescent products. The results clearly showed that LDL from elderly subjects was the most susceptible to oxidative damage in vitro. In particular, the greater susceptibility of LDL from elderly subjects in comparison to that from young subjects may be attributed to the much lower (4-fold) concentration of LDL vitamin E in the elderly subjects. The present study reinforces the notion that the susceptibility of LDL to oxidation increases with age.

Congenital posterior urethral perineal fistulae: a unique form of urethral duplication

Three unique cases of urethral duplication, often referred to as congenital posterior urethral perineal fistulae, are presented. Presenting signs and symptoms, evaluation, and treatment are discussed, and the literature is reviewed. Although labeled as a fistula in the literature, this entity most likely represents a distinct type of urethral duplication. A functional dorsal urethra separates it from the other forms of urethral duplication.

Renal arterioureteral hemorrhage: a complication of acucise endopyelotomy

The Acucise ureteral catheter is a ureteral cutting balloon device that recently received approval for retrograde endopyelotomy. We report a case of a postoperative lower pole renal arterioureteral hemorrhage after retrograde endopyelotomy requiring interventional radiographic treatment. Significant gross hematuria after Acucise endopyelotomy may indicate a communication between the vasculature and collecting system. Prompt arteriography with embolization should be considered in this clinical situation.

The Virtual Hospital: an IAIMS integrating continuing education into the work flow

Researchers at the University of Iowa are developing an integrated academic information management system (IAIMS) for use on the World Wide Web. The focus is on integrating continuing medical education (CME) into the clinicians' daily work and incorporating consumer health information into patients' life styles. Phase I of the project consists of loosely integrating patients' data, printed library information, and digital library information. Phase II consists of more tightly integrating the three types of information, and Phase III consists of awarding CME credits for reviewing educational, material at the point of patient care, when it has the most potential for improving outcomes. This IAIMS serves a statewide population. Its design and evolution have been heavily influenced by user-centered evaluation.