Oral vitamin D supplementation induces transcriptomic changes in rectal mucosa that are linked to anti-tumour effects.

BACKGROUND: The risk for several common cancers is influenced by the transcriptomic landscape of the respective tissue-of-origin. Vitamin D influences in vitro gene expression and cancer cell growth. We sought to determine whether oral vitamin D induces beneficial gene expression effects in human rectal epithelium and identify biomarkers of response. METHODS: Blood and rectal mucosa was sampled from 191 human subjects and mucosa gene expression (HT12) correlated with plasma vitamin D (25-OHD) to identify differentially expressed genes. Fifty subjects were then administered 3200IU/day oral vitamin D3 and matched blood/mucosa resampled after 12 weeks. Transcriptomic changes (HT12/RNAseq) after supplementation were tested against the prioritised genes for gene-set and GO-process enrichment. To identify blood biomarkers of mucosal response, we derived receiver-operator curves and C-statistic (AUC) and tested biomarker reproducibility in an independent Supplementation Trial (BEST-D). RESULTS: Six hundred twenty-nine genes were associated with 25-OHD level (P < 0.01), highlighting 453 GO-term processes (FDR<0.05). In the whole intervention cohort, vitamin D supplementation enriched the prioritised mucosal gene-set (upregulated gene-set P < 1.0E-07; downregulated gene-set P < 2.6E-05) and corresponding GO terms (P = 2.90E-02), highlighting gene expression patterns consistent with anti-tumour effects. However, only 9 individual participants (18%) showed a significant response (NM gene-set enrichment P < 0.001) to supplementation. Expression changes in HIPK2 and PPP1CC expression served as blood biomarkers of mucosal transcriptomic response (AUC=0.84 [95%CI 0.66-1.00]) and replicated in BEST-D trial subjects (HIPK2 AUC=0.83 [95%CI 0.77-0.89]; PPP1CC AUC=0.91 [95%CI 0.86-0.95]). CONCLUSIONS: Higher plasma 25-OHD correlates with rectal mucosa gene expression patterns consistent with anti-tumour effects, and this beneficial signature is induced by short-term vitamin D supplementation. Heterogenous gene expression responses to vitamin D may limit the ability of randomised trials to identify beneficial effects of supplementation on CRC risk. However, in the current study blood expression changes in HIPK2 and PPP1CC identify those participants with significant anti-tumour transcriptomic responses to supplementation in the rectum. These data provide compelling rationale for a trial of vitamin D and CRC prevention using easily assayed blood gene expression signatures as intermediate biomarkers of response.

Ciliary protein conservation during development in the ciliated protozoan, Oxytricha.

The ciliated protozoan Oxytricha fallax possesses multiple highly localized clusters of basal bodies and cilia, all of which are broken down and rebuilt during prefission morphogenesis-with one major exception. The adoral zone of membranelles (AZM) of the ciliate oral apparatus contains approximately 1,500-2,000 basal bodies and cilia, and it is the only compound ciliary structure that is passed morphologically intact to one daughter cell at each cell division. By labeling all proteins in cells, and then picking the one daughter cell possessing the original labeled AZM, we could then evaluate whether or not the ciliary proteins of the AZM were diluted (i.e., either by degradation to constituent amino acids or by subunit exchange) during cell division. Autoradiographic analysis demonstrated that the label was highly conserved in the AZM (i.e., we saw no evidence of turnover), and electrophoretic data illustrate that at least one of the proteins of the AZM is tubulin. We, therefore, conclude that for at least some of the ciliary and basal body proteins of Oxytricha fallax, AZM morphological conservation is essentially equivalent to molecular conservation.

Nuclear gene dosage effects on mitochondrial mass and DNA.

In order to assess the effect of nuclear gene dosage on the regulation of mitochondria we have studied serial sections of a set of isogenic haploid and diploid cells of Saccharomyces cerevisiae, growing exponentially in the absence of catabolite repression, and determined the amount of mitochondrial DNA per cell. Mitochondria accounted for 14% of the cytoplasmic and 12% of the total cellular volume in all cells examined regardless of their ploidy or their apparent stage in the cell cycle. The mean number of mitochondria per cell was 22 in the diploid and 10 in the haploids. The volume distribution appeared unimodal and identical in haploids and diploids. The mitochondrial DNA accounted for 12.6 +/- 1.2% and 13.5 +/- 1.3% of the total cellular DNA in the diploid and haploid populations, respectively. These values correspond to 3.6 x 10(-15) g, 2.2 x 10(9) daltons, or 44 genomes (50 x 10(6) daltons each) per haploid and twice that per diploid cell. On this basis, the average mitochondrion in these cells contains four mitochondrial genomes in both the haploid and the diploid.

Patterning and assembly of ciliature are independent processes in hypotrich ciliates.

Mirror-imaged doublets of the hypotrich ciliate Pleurotricha lanceolata were induced and analyzed with respect to the overall patterning (structural asymmetry and polarity) of the individual components of the ciliature. The overall pattern is arranged as a mirror image, but the individual components in the two halves of the doublet show the same organizational asymmetry. These data demonstrate the independence of the mechanisms for this kind of large-scale (global) patterning and control of assembly of the individual ciliary components.

PDQ Wizard: automated prioritization and characterization of gene and protein lists using biomedical literature.

SUMMARY: PDQ Wizard automates the process of interrogating biomedical references using large lists of genes, proteins or free text. Using the principle of linkage through co-citation biologists can mine PubMed with these proteins or genes to identify relationships within a biological field of interest. In addition, PDQ Wizard provides novel features to define more specific relationships, highlight key publications describing those activities and relationships, and enhance protein queries. PDQ Wizard also outputs a metric that can be used for prioritization of genes and proteins for further research. AVAILABILITY: PDQ Wizard is freely available from http://www.gti.ed.ac.uk/pdqwizard/.

A prospective trial of telepathology for intraoperative consultation (frozen sections).

Telepathology is a maturing technology that, for a variety of reasons, has not been widely deployed. In addition, clinical validation is relatively modest compared with accepted telemedicine applications such as teleradiology. A prototype telepathology system (Tele-Path(sm)) featuring high-resolution images selected from a remote microscope site has been developed at the University of Alabama at Birmingham (UAB). To validate the diagnostic efficacy of the system, a prospective study was undertaken of parallel diagnoses by conventional microscopy and telepathology with a remotely operated microscope. Slides from 99 intraoperative consultations from 29 tissue/ organ sites in the University of Alabama Hospitals by 9 academic pathologists were used in the study. Each microscopic and telepathology diagnosis was compared with the final diagnosis rendered by a referee pathologist. Diagnoses were classified as correct, false positive, or false negative or classification error. Of the 99 frozen sections evaluated, 3 cases were deferred. Of the remaining 96 cases, 2 received incorrect diagnoses in both the microscopic and telepathology arms of the study. Three errors occurred only in the telepathology arm. There was 1 false-positive diagnosis, 1 false-negative diagnosis, and 1 classification error. Statistical analysis indicated no significant difference between telepathology and conventional microscopy. Qualitative data indicated that the pathologists were generally satisfied with the performance of the system. Telepathology using this system paradigm is sufficiently accurate for real time utilization in a complex surgical environment. Telepathology therefore may be an effective model to support the surgical services of hospitals lacking full-time pathology coverage, resulting in full-time access to anatomic pathology services.

Double-blind comparison of weekend and daily regimens of oral acyclovir for suppression of recurrent genital herpes.

The potential utility of intermittent regimens of oral acyclovir for suppression of recurrent genital herpes depends on how long the suppressive effect of the drug persists during pauses in treatment. To study this question, we admitted 38 patients in a double-blind controlled trial comparing the results of daily acyclovir treatment (200 mg t.i.d.) with treatment on weekend days only (400 mg t.i.d. on Saturday and Sunday) for suppression of recurrent genital herpes. Of the 35 patients completing the study, significantly more failures occurred in the weekend group (13/17) than in the daily group (3/18, P less than 0.001). Failures on the weekend regimen were more frequent as the week progressed (P = 0.005). The findings suggest a short-term persistence of suppression by acyclovir and hence that intermittent regimens with more closely spaced periods of treatment may be more effective than the regimen we studied. Most virus isolates studied, including all of those isolated from the patients during treatment, were sensitive to acyclovir.

An initial trial of a prototype telepathology system featuring static imaging with discrete control of the remote microscope.

Routine diagnosis of pathology images transmitted over telecommunications lines remains an elusive goal. Part of the resistance stems from the difficulty of enabling image selection by the remote pathologist. To address this problem, a telepathology microscope system (TelePath, TeleMedicine Solutions, Birmingham, Ala) that has features associated with static and dynamic imaging systems was constructed. Features of the system include near real time image transmission, provision of a tiled overview image, free choice of any fields at any desired optical magnification, and automated tracking of the pathologist's image selection. All commands and images are discrete, avoiding many inherent problems of full motion video and continuous remote control. A set of 64 slides was reviewed by 3 pathologists in a simulated frozen section environment. Each pathologist provided diagnoses for all 64 slides, as well as qualitative information about the system. Thirty-one of 192 diagnoses disagreed with the reference diagnosis that had been reached before the trial began. Qf the 31, 13 were deferrals and 12 were diagnoses of cases that had a deferral as the reference diagnosis. In 6 cases, the diagnosis disagreed with the reference diagnosis yielding an overall accuracy of 96.9%. Confidence levels in the diagnoses were high. This trial suggests that this system provides high-quality anatomic pathology services, including intraoperative diagnoses, over telecommunications lines.

Glutathione aerosol suppresses lung epithelial surface inflammatory cell-derived oxidants in cystic fibrosis.

Cystic fibrosis (CF) is characterized by accumulation of activated neutrophils and macrophages on the respiratory epithelial surface (RES); these cells release toxic oxidants, which contribute to the marked epithelial derangements seen in CF. These deleterious consequences are magnified, since reduced glutathione (GSH), an antioxidant present in high concentrations in normal respiratory epithelial lining fluid (ELF), is deficient in CF ELF. To evaluate the feasibility of increasing ELF GSH levels and enhancing RES antioxidant protection, GSH aerosol was delivered (600 mg twice daily for 3 days) to seven patients with CF. ELF total, reduced, and oxidized GSH increased (P < 0.05, all compared with before GSH therapy), suggesting adequate RES delivery and utilization of GSH. Phorbol 12-myristate 13-acetate-stimulated superoxide anion (O2-.) release by ELF inflammatory cells decreased after GSH therapy (P < 0.002). This paralleled observations that GSH added in vitro to CF ELF inflammatory cells suppressed O2-. release (P < 0.001). No adverse effects were noted during treatment. Together, these observations demonstrate the feasibility of using GSH aerosol to restore RES oxidant-antioxidant balance in CF and support the rationale for further clinical evaluation.

Absorption of micronized progesterone from a nonliquefying vaginal cream.

An improved delivery method to achieve sustained physiological P levels would be useful. Based on this single-dose pharmacokinetic study, micronized P prepared in a nonliquefying vaginal cream holds promise as a convenient method to achieve this goal with a single daily application.

Pharmacokinetics of methyl palmoxirate, an inhibitor of beta-oxidation, in rats and humans.

Recent studies from our laboratory have shown that methyl palmoxirate (MEP), an inhibitor of mitochondrial beta-oxidation of long chain fatty acids, can be used to increase incorporation of radiolabeled palmitic acid into brain lipids and reduce beta-oxidation of the fatty acid. Thus, MEP allows the use of carbon labeled palmitate for studying brain lipid metabolism in animals and humans by quantitative autoradiography or positron emission tomography (PET). As it is essential to pretreat human subjects with an acute dose of MEP prior to intravenous injection of [1-11C]palmitate for PET scanning, this study was undertaken to determine the plasma elimination half-life of MEP in rats and human subjects and to provide insight about the drug's absorption and metabolism. A gas chromatographic method was developed to measure MEP in body fluids. Following oral administration of MEP to rats (2.5 and 10 mg/kg) and to humans, the unmetabolized drug could not be detected in plasma or urine (sensitivity of detection was 1 ng). However, when MEP was injected intravenously (10 mg/kg) in rats, a peak initial concentration could be measured in plasma (7.7 microg/mL), the clearance of the drug from plasma was rapid (t1/2 = 0.6 min), which indicates that MEP readily enters tissue lipid pools or is metabolized like long-chain fatty acids. As no adverse experience occured in the 11 human subjects studied, oral administration of a single dose of MEP was safe under the conditions of this study and may be used to increase the incorporation of positron labeled palmitic acid for studying brain lipid metabolism in vivo by PET.

Formulation and evaluation of ethiodized oil emulsion for intravenous hepatography.

A study was conducted to prepare and evaluate an ethiodized oil emulsion for intravenous administration that would selectively opacify the liver. Several formulations with differing globule size were prepared and compared for their in vivo activity (degree of liver opacification obtained) and stability. Results of studies conducted in rabbits and monkeys revealed that the oil globules that concentrate most in liver were 2.0--3.0 micrometer in diameter. The formulation of choice was stable for 6 months at refrigeration temperature (2--6 degree). In monkeys, this formulation produced an improved diagnostic image of the liver using computerized tomography at a dose of 0.2 ml/kg. The potential use of such emulsions in diagnostic radiology is briefly discussed.

Qualitative and morphometric evaluation of vocal cord lesions produced by the carbon dioxide laser.

The canine larynx was studied to obtain qualitative and quantitative data accurately defining the destructive effects of the carbon dioxide laser on epithelial tissue by administering doses of varied energy to the dorsal surface of the vocal cords. Resultant lesions subsequently were analyzed by light, transmission, and scanning microscopy. Three major morphologic patterns of vocal cord lesions were observed: 1. cup shape, 2. doughnut shape and, 3. complex star shape. The patterns produced in the laryngeal tissue reflect the operative mode (energy distribution within the focused spot of energy) of the laser at the time of surgery. The mode resulting in the doughnut shaped pattern (energy distribution around the periphery of the spot) produced deepest lesions, with minimal thermal conduction laterally, whereas the mode resulting in the cup-shaped pattern (energy distribution uniform throughout the spot) produced at comparable doses shallower lesions with larger diameter. Too few star-shaped patterns were observed to permit meaningful morphometric analysis.

Handling of gene-transfer products by the National Institutes of Health Clinical Center pharmacy department.

Policies and procedures for handling gene-transfer products at the National Institutes of Health (NIH) Clinical Center pharmacy department are described. The pharmacy at the Clinical Center is responsible for handling in vivo gene-transfer delivery systems, which are gene-transfer products that are prepared for direct administration to patients. The gene-transfer products currently handled by the pharmacy are investigational and are composed of viruses containing the gene encoding either of the melanoma antigens MART-1 and gp100. The pharmacy has prepared guidelines, based on the principles of aseptic technique and FDA guidelines for manufacturing facilities, intended to help pharmacy personnel safely dilute a concentrated gene-transfer product into a dose suitable for administration. Before a product is handled, the biological safety level is determined and a biohazard sign is posted. Worksheets detailing all supplies, calculations for dilutions, and procedures that will be required are prepared in advance; the worksheets are part of a drug fact sheet prepared for all investigational drugs dispensed. Personnel must be properly trained and dressed in protective clothing. Aseptic technique and decontamination procedures are used as specified in the guidelines, and all materials used are disposed of as biohazardous waste. All work is documented. If a worker is accidentally exposed, standard procedures are followed. The handling of gene-transfer products at the NIH Clinical Center pharmacy is based on the principles of aseptic technique, FDA guidelines, and experience.

Aflatoxin levels in corn available as wild turkey feed in Georgia.

Samples of corn available as wildlife feed from retailers throughout Georgia (USA) were collected during April 1997 and analyzed for aflatoxin to determine if levels harmful to wild turkeys (Meleagris gallopavo) were present. Three of 31 (10%) samples collected from a 40-country area were positive. An enzyme-linked immunosorbent assay qualitatively determined that two samples contained from 0 to 20 ppb aflatoxin. A chromatography analysis of a third sample measured 380 ppb total aflatoxin. A small percentage of our sample of wildlife feed collected during one season contained levels of aflatoxin that may cause harm to turkeys, especially poults. However, because aflatoxin levels ranging from 100 to 400 ppb may cause liver dysfunction and immunosuppression in turkey poults and other wildlife, grains known to be contaminated with aflatoxin at levels unacceptable for domestic animal feeds (> or =100 ppb) should not be sold as wildlife feed. Further analyses of grains sold as wildlife feed should be conducted to address this potential problem.

Telerehabilitation services using web-based telecommunication.

A World Wide Wide-based telerehabilitation platform has been demonstrated in a laboratory environment. This platform allows a rehabilitation provider to thoroughly evaluate the progress of a patient remotely with the same care and measurement precision that would be possible if the provider and the patient were in the same room. The platform was designed to be Web-based so that the service could be offered at the same price without regard to long distance telecommunication facility charges. The Web-based implementation allows enough bandwidth for a simultaneous video teleconference and a precision data acquisition mode even when the Web connection is a low cost analog modem computer interface at both ends of the connection.

Applications of virtual reality technology in pathology.

TelePath(SM) a telerobotic system utilizing virtual microscope concepts based on high quality still digital imaging and aimed at real-time support for surgery by remote diagnosis of frozen sections. Many hospitals and clinics have an application for the remote practice of pathology, particularly in the area of reading frozen sections in support of surgery, commonly called anatomic pathology. The goal is to project the expertise of the pathologist into the remote setting by giving the pathologist access to the microscope slides with an image quality and human interface comparable to what the pathologist would experience at a real rather than a virtual microscope. A working prototype of a virtual microscope has been defined and constructed which has the needed performance in both the image quality and human interface areas for a pathologist to work remotely. This is accomplished through the use of telerobotics and an image quality which provides the virtual microscope the same diagnostic capabilities as a real microscope. The examination of frozen sections is performed a two-dimensional world. The remote pathologist is in a virtual world with the same capabilities as a "real" microscope, but response times may be slower depending on the specific computing and telecommunication environments. The TelePath system has capabilities far beyond a normal biological microscope, such as the ability to create a low power image of the entire sample using multiple images digitally matched together; the ability to digitally retrace a viewing trajectory; and the ability to archive images using CD ROM and other mass storage devices.

Risk of death among Honolulu fire fighters.

To examine possible health risks associated with fire fighting, a 20-year Proportionate Mortality Ratio (PMR) study was conducted involving all male fire fighters with at least one year of service in the City of Honolulu Fire Department. The observed cause of death, as determined by the death certificates, was compared statistically to the expected numbers of deaths for all males over age 20 in Hawaii's general population. Significant increases in risk of death were found for brain cancer (Risk Ratio = 3.78), prostate cancer (Risk Ratio = 2.61), and cirrhosis of the liver (Risk Ratio = 2.3). A significant decrease in mortality was found for lung disease with a risk ratio of 0.37. No deaths were attributed to suicide nor to a category which included allergic, endocrine and nutritional diseases. Since fire fighters are known to suffer exposure to carcinogens and toxins, additional studies would be helpful in order to clarify possible risks to health associated with fire fighting on a long-term exposure basis.