A novel mechanism for endocrine-disrupting effects of polychlorinated biphenyls: direct effects on gonadotropin-releasing hormone neurones

Polychlorinated biphenyls (PCBs) cause abnormal development and physiology of the reproductive system. We hypothesized that these effects may be mediated, at least in part, by neuroendocrine cells in the hypothalamus that integrate inputs to and outputs from the central nervous system and reproductive systems. The effects of two PCB mixtures, Aroclor 1221 and Aroclor 1254, were tested on the hypothalamic GT1-7 cells, which synthesize and secrete the key hypothalamic hormone, gonadotropin-releasing hormone (GnRH). GT1-7 cells were treated for 24 h in dose-response experiments and GnRH gene expression and release were quantified. Aroclor 1221 was stimulatory to GnRH gene expression, particularly at post-transcriptional levels (GnRH cytoplasmic mRNA), and increased GnRH peptide levels, suggesting a post-translational regulation of GnRH biosynthesis. It also caused a qualitative increase in GT1-7 neurite outgrowth and cell confluency. Aroclor 1254 had very different effects from Aroclor 1221. It inhibited GnRH nuclear mRNA levels at high dosages, and stimulated GnRH mRNA at low doses, suggesting a post-transcriptional mechanism of regulation. Aroclor 1254 did not alter GnRH peptide levels. Qualitatively, Aroclor 1254 caused a retraction of GT1-7 cell processes and neurotoxicity at high dosages. In order to gauge the involvement of the oestrogen receptor in these responses, the oestrogen receptor antagonist, ICI 182,780 (ICI) was coadministered in other studies with the PCBs. While effects of Aroclor 1221 on GnRH gene expression were not blocked by ICI, its effects on GnRH peptide levels were blocked by ICI, indicating that some but not all of the effects of Aroclor 1221 are mediated by the classical oestrogen receptor alpha and/or beta. The inhibitory effects of Aroclor 1254 on GnRH gene expression were not prevented by ICI, although ICI itself had stimulatory effects on GnRH gene expression that were blocked by cotreatment with Aroclor 1254. These results demonstrate a novel mechanism for effects of the two PCBs directly on GnRH gene expression, and indicate a hypothalamic level for endocrine disruption by these environmental toxicants.

Disfiguring cutaneous manifestation of sarcoidosis treated with thalidomide: a case report

A patient with sarcoidosis was treated with thalidomide for disfiguring and painful steroid unresponsive sarcoidal granulomas of the skin. The duration of the therapy was 14 months, during which time, the skin lesions resolved almost completely. The initial dosage was 200 mg a day, which was increased to 400 mg a day after 4 months. Episodic paresthesia of the finger tips and one lower extremity was the only side effect noted, which resolved promptly after discontinuation of the drug. The dramatic response of sarcoidal granulomas of the skin to thalidomide observed in this patient demonstrates the usefulness of this drug as a possible long-term monotherapeutic or steroid-sparing agent in the treatment of sarcoidosis.

Treatment of Bowen's disease with a specially designed radioactive skin patch

Bowen's disease can be treated by various methods, including surgical excision, cryosurgery, laser ablation, curettage, Mohs' microsurgery and ionizing radiation. Radiotherapy has been a useful therapeutic modality in the treatment of Bowen's disease and other skin cancers in areas which are difficult to excise, especially the central areas of the face, including eyelids, nose and lips. To overcome some of the disadvantages of external radiotherapy, a specially designed skin patch coated with high-energy beta-emitter holmium-166 was made for topical application at our institute. Twenty-nine sites of Bowen's disease in eight patients, confirmed by skin biopsy, were treated with 166Ho patches. The patches were applied to the surface of skin cancers for 30-60 min for a total radiation dose of 35 Gy (3500 rads). One to two weeks after application of the 166Ho patch, desquamation, erythema or erosion developed in treated sites, but these acute radiation reactions healed gradually with epithelial regeneration, and they showed good functional and cosmetic results without any complications. Follow-up biopsies were performed 1-5 months after 166Ho patch therapy, and they did not show any signs of Bowen's disease. One to two years after treatment with 166Ho skin patches, there were no recurrences of Bowen's diseases and no late complications. The 166Ho patch is an effective and convenient alternative method for the treatment of Bowen's disease that yields good cosmetic and functional results.

Sequence variation of mitochondrial DNA control region in Koreans

The sequencing data for two mtDNA segments in control region I and II, 385 and 341 nucleotides long, respectively, for 306 unrelated Koreans are presented. In regions I and II, 139 and 58 polymorphic sites, respectively, were noted. These were distributed evenly along the control region, though the frequency of each site was variable. Nucleotide substitution rather than insertion/deletion was the prevalent pattern of variation. A total of 265 different mtDNA lineages in region I and 154 in region II were revealed. This result represents a substantial level of polymorphism in a defined population, and presents the possibility that mtDNA polymorphism could be used as an individual identification marker, especially when nuclear DNA is not available. In view of the complex pattern of variation, meticulous test-sequencing is thought to be more appropriate than RFLP analysis using restriction endonuclease or hybridization using an SSO probe. Racial differences with genealogical usage are also described.

Radioimmunoassay of prostaglandin A. Intrarenal PGA2 as a factor mediating saline-induced natriuresis

A highly specific, sensitive (25 pg) radioimmunoassay for prostaglandin A is described; the assay is characterized by high reproducibility (coefficient of variation 1-2%) and low cross-reactivity with respect to PGE 1 and PGE 2 (10%), PGB 2 (15%), and PGF 2α (0.01%). High specificity for PGA was obtained by chromatographic separation of the prostaglandins. Since it has been suggested that PGA is a natriuretic "hormone," the concentration of PGA in the renal cortex, outer medulla, and papilla was determined in rabbits on low-sodium and high-sodium diets in the presence and the absence of the prostaglandin synthetase inhibitor indomethacin. In rabbits on the low-sodium diet (12 mEq/24 hours). PGA2 was 15 ± 4 pg/mg in the cortex, 502 ± 67 pg/mg in the outer medulla, and 3740 ± 640 pg/mg in the papilla. In rabbits on saline loading (56 mEq/24 hours), cortical and outer medullary PGA2 rose to 32 ± 6 pg/mg and 1275 ± 290 pg/mg, respectively, but papillary PGA decreased to 1842 ± 480 pg/mg. PGA concentration in the outer medulla and papilla was markedly inhibited by indomethacin (50 mg/day), and this inhibition was associated with sodium retention. The results indicated that sodium induced papillary synthesis of PGA and intrarenal circulation of the prostaglandin to the outer medulla and the cortex possibly via the long veins of the outer medulla occurred. The results are compatible with PGA 2 involvement in salineinduced natriuresis.

Conservative treatment for closed fifth (small finger) metacarpal neck fractures

BACKGROUND

Subcapital fractures of the fifth metacarpal bone, meaning fractures just below the knuckle of the little finger, account for approximately 20% of all hand fractures. Currently, there is no consensus concerning the optimal management of these fractures. Traditionally, treatment consists of closed reduction and external splinting in a neutral position using plaster of Paris (POP), involving the metacarpal joint, the proximal interphalangeal joint and the carpo-metacarpal joint. An alternative treatment strategy is functional treatment using taping or bracing that does not restrict movement.

OBJECTIVES

To compare functional treatment with immobilization, and to compare different periods and types of immobilization, for the treatment of closed fifth metacarpal neck fractures in adults.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialized Register (July 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2004), OVID OldMEDLINE (1951 to 1965), OVID MEDLINE (1966 to July 2004), OVID MEDLINE In-Process (July 2004), EMBASE (1988 to 2004, week 29), the Internet, and reference lists of articles. No language restrictions were applied.

SELECTION CRITERIA

All randomized and quasi-randomized controlled trials which compare functional treatment with immobilization or different types of immobilization for closed fifth metacarpal neck fractures.

DATA COLLECTION AND ANALYSIS

Two review authors assessed abstracts of all studies identified by the initial search, identified studies meeting the selection criteria, independently assessed the quality of the trial reports, and extracted and analysed the data.

MAIN RESULTS

Five studies met the inclusion criteria including a total of 252 participants. Most studies were of poor quality. The primary outcome measure, function of the hand, was not used in any studies. There was no evidence that any of the treatment modalities was statistically significantly superior.

AUTHORS' CONCLUSIONS

No included studies reported our primary outcome measure of interest, validated hand function. There was heterogeneity between the studies, which were of limited quality and size. No single non-operative treatment regimen for fracture of the neck of the fifth metacarpal can be recommended as superior to another in result. Further research is definitely warranted.

Biological responses of anodized titanium implants under different current voltages

The oxide layer of a titanium surface is very stable, and seems to result in excellent biocompatibility and successful osseointegration. The purpose of this study was to investigate the effects of high anodic oxidation voltages on the surface characteristics of titanium implants and the biologic response of rabbit tibiae. Bone tissue responses were evaluated by removal torque tests and histomorphometric analysis. Screw-shaped implants with microthreads were made of commercially pure titanium (Grade II). We prepared anodized implants under 300 V (group I), 400 V (group II), 500 V (group III) and 550 V (group IV). The surface characteristics of specimens were inspected according to three categories: surface morphology, surface roughness and oxide layer thickness. The screw-shaped implants were installed in rabbit tibiae. The removal torque values were measured and histomorphometric analysis was done after 1- and 3-month healing periods. Data indicate that as anodic oxidation voltage increased above 300 V, oxide layer thickness increased rapidly and pore size also increased. The roughness values of the implants increased with voltage up to 500 V, but decreased at 550 V. In the removal torque test, group III showed higher values than groups I and II at a statistically significant level (P < 0.05) after a 1-month healing period. In histomorphometric analysis, groups III and IV, after a 3-month healing period, showed greater bone to implant contact ratios for the total implant surface than did group I (P < 0.05).

Influence of examiner experience and gender on interrater reliability of KT-1000 arthrometer measurements

BACKGROUND AND PURPOSE

Measurements of the integrity of knee ligaments are used to diagnose injuries as well as to document the state of recovery. Many factors, such as gender and experience of the examiner, are capable of influencing the reliability of such measurements. The purpose of this study was to determine the effects on interrater reliability of measurements obtained using the KT-1000 arthrometer of experience, gender, and leg tested.

SUBJECTS

Two experienced examiners (1 male, 1 female) and two inexperienced examiners (1 male, 1 female) tested 22 subjects with unilateral anterior cruciate ligament (ACL) pathology.

METHODS

The leg with an ACL injury and the uninjured leg of each subject were evaluated by all four examiners within one test session using 67-N, 89-N, maximum manual, and active anterior drawer tests.

RESULTS

Greater anterior displacement values were found in the legs with ACL injury than in the uninjured legs. Reliability estimates, as assessed by intraclass correlation coefficients (2,k) and measurement error (SEM), suggest that therapist experience may be a more important factor influencing reliability than gender.

CONCLUSION AND DISCUSSION

Given the magnitude of the errors obtained for tests routinely conducted in the clinic using the KT-1000 arthrometer, we recommend that repeated measurements should be taken by the same examiners whenever possible. [Ballantyne BT, French AK, Heimsoth SL, et al. Influence of examiner experience and gender on interrater reliability of KT-1000 arthrometer measurements.

Nucleotide sequence and transcription map of porcine adenovirus type 3

The complete nucleotide sequence of porcine adenovirus type 3 was determined and a transcriptional map for the genome was constructed. The size of the genome is 34094 bp in length with an unusually high G + C content (63.7%), the highest thus far reported for any adenovirus. Overall organization of the genome is similar to that for previously sequenced adenoviral DNAs, but there also were distinct differences. The late regions genes are organized into six families, instead of five as they are in human adenovirus type 2. In contrast to bovine adenovirus type 3 and ovine adenovirus, which lack virion-associated RNA genes, the nucleotide sequence analysis of the viral genome indicates that it encodes one short VA RNA species. With the exception of the fiber and a 33-kDa nonstructural protein, the predicted amino acid sequences of the open reading frames in the late regions and the E2 region and IVa2 exhibited a high level of homology, whereas the deduced amino acid sequences of ORFs in E1, E3, and E4 regions, and the pIX showed a lesser homology with the corresponding proteins of other adenoviruses. The proteins V, VII, and IX are unusually long, and the protein VII lacks the consensus protease cleavage site. Genomic and cDNA sequence analysis has identified promoters, cap sites, intron-exon boundaries, polyadenylation signals, and polyadenylation sites in the viral genome.

QTL analysis of white blood cell, platelet and red blood cell-related traits in an F2 intercross between Landrace and Korean native pigs

Haematological traits play important roles in disease resistance and defence functions. The objective of this study was to locate quantitative trait loci (QTL) and the associated positional candidate genes influencing haematological traits in an F(2) intercross between Landrace and Korean native pigs. Eight blood-related traits (six erythrocyte traits, one leucocyte trait and one platelet trait) were measured in 816 F(2) progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We report that nine chromosomes harboured QTL for the baseline blood parameters: genomic regions on SSC 1, 4, 5, 6, 8, 9, 11, 13 and 17. Eight of twenty identified QTL reached genome-wide significance. In addition, we evaluated the KIT locus, an obvious candidate gene locus affecting variation in blood-related traits. Using dense single nucleotide polymorphism marker data on SSC 8 and the marker-assisted association test, the strong association of the KIT locus with blood phenotypes was confirmed. In conclusion, our study identified both previously reported and novel QTL affecting baseline haematological parameters in pigs. Additionally, the positional candidate genes identified here could play an important role in elucidating the genetic architecture of haematological phenotype variation in swine and in humans.

Activation of heparin cofactor II by calcium spirulan

Heparin cofactor II (HCII) is a plasma serine protease inhibitor whose ability to inhibit alpha-thrombin is accelerated by a variety of sulfated polysaccharides in addition to heparin and dermatan sulfate. Previous investigations have indicated that calcium spirulan (Ca-SP), a novel sulfated polysaccharide, enhanced the rate of inhibition of alpha-thrombin by HCII. In this study, we investigated the mechanism of the activation of HCII by Ca-SP. Interestingly, in the presence of Ca-SP, an N-terminal deletion mutant of HCII (rHCII-Delta74) inhibited alpha-thrombin, as native recombinant HCII (native rHCII) did. The second-order rate constant for the inhibition of alpha-thrombin by rHCII-Delta74 was 2.0 x 10(8) M(-1) min(-1) in the presence of 50 microgram/ml Ca-SP and 10, 000-fold higher than in the absence of Ca-SP. The rates of native rHCII and rHCII-Delta74 for the inhibition of gamma-thrombin were increased only 80- and 120-fold, respectively. Our results suggested that the anion-binding exosite I of alpha-thrombin was essential for the rapid inhibition reaction by HCII in the presence of Ca-SP and that the N-terminal acidic domain of HCII was not required. Therefore, we proposed a mechanism by which HCII was activated allosterically by Ca-SP and could interact with the anion-binding exosite I of thrombin not through the N-terminal acidic domain of HCII. The Arg(103) --> Leu mutant bound to Ca-SP-Toyopearl with normal affinity and inhibited alpha-thrombin in a manner similar to native rHCII. These results indicate that Arg(103) in HCII molecule is not critical for the interaction with Ca-SP.

Structural analysis of calcium spirulan (Ca-SP)-derived oligosaccharides using electrospray ionization mass spectrometry

Detailed structural analyses of calcium spirulan (Ca-SP)-derived oligosaccharides were performed by ESI-MS and collision-induced dissociation tandem mass spectrometry. This study indicates that Ca-SP is composed of two types of disaccharide repeating units, O-rhamnosyl-acofriose and O-hexuronosyl-rhamnose (aldobiuronic acid).

Effects of structural modification of calcium spirulan, a sulfated polysaccharide from Spirulina platensis, on antiviral activity

Calcium ion binding with the anionic part of a molecule was replaced with various metal cations and their inhibitory effects on the replication of herpes simplex virus type 1 were evaluated. Replacement of calcium ion with sodium and potassium ions maintained the antiviral activity while divalent and trivalent metal cations reduced the activity. Depolymerization of sodium spirulan with hydrogen peroxide decreased in antiviral activity as its molecular weight decreased.

Anti-influenza virus activity of green tea by-products in vitro and efficacy against influenza virus infection in chickens

Polyphenolic compounds present in green tea, particularly catechins, are known to have strong anti-influenza activity. The goal of this study was to determine whether green tea by-products could function as an alternative to common antivirals in animals compared to original green tea. Inhibition of viral cytopathic effects ascertained by neutral red dye uptake was examined with 50% effective (virus-inhibitory) concentrations (EC₅₀)determined. Against the H1N1 virus A/NWS/33, we found the anti-influenza activity of green tea by-products (EC₅₀ = 6.36 µg/mL) to be equivalent to that of original green tea (EC₅₀= 6.72 µg/mL). The anti-influenza activity of green tea by-products was further examined in mouse and chicken influenza infection models. In mice, oral administration of green tea by-products reduced viral titers in the lungs in the early phase of infection, but they could not protect these animals from disease and death. In contrast, therapeutic administration of green tea by-products via feed or water supplement resulted in a dose-dependent significant antiviral effect in chickens, with a dose of 10 g/kg of feed being the most effective (P < 0.001). We also demonstrated that unidentified hexane-soluble fractions of green tea by-products possessed strong anti-influenza activity, in addition to ethyl acetate-soluble fractions, including catechins. This study revealed green tea by-product extracts to be a promising novel antiviral resource for animals.

Absent or delayed preovulatory luteinizing hormone surge in experimental diabetes mellitus

The proestrus preovulatory luteinizing hormone (LH) surge was absent or delayed in more than 56% of untreated streptozotocin-diabetic rats. Absence of LH surge was associated with anovulation. Insulin treatment for 10-14 days restored the diminished surge and ovulation frequency. Pituitary LH release in response to exogenous gonadotropin-releasing hormone administration in diabetic rats was not different from controls. Impaired hypothalamic function may comprise the basis for the increased incidence of infertility in diabetes mellitus.

Physiology of Pea Fruits I. the Developing Fruit

Pea fruits from two crops were sampled at different times from flowering. Changes in the fresh weight, dry weight, starch, soluble carbohydrate, protein nitrogen, and soluble nitrogen in both seeds and hulls were followed in two seasons and related Jo the changes in cell volume in the seeds. In one season respiration rates and phosphate, pectin, and ascorbic acid contents were also investigated. The seeds gained more carbohydrate and nitrogen than was lost by the hulls. Starch and protein were synthesized rapidly by the seeds. The increase in starch content in the seeds was followed by a decrease in soluble carbohydrate content, after which the seed ceased to accumulate water. These metabolic changes are discussed in the light of recent biochemical knowledge, and in relation to more detailed biochemical investigations in progress.

Sonographic evaluation of inferior vena caval obstruction: correlative study with vena cavography

Sonographic findings of obstruction of the inferior vena cava (IVC) in 14 cases are described and correlated with venographic findings. The causes of the obstruction were membrane (five cases), thrombosis (three), and intraluminal tumor invasion by hypernephroma, hepatoma, and adrenal carcinoma in six. Sonographic examination revealed highly echogenic segmental obliteration or membrane in membranous obstruction and echogenic intraluminal mass in thrombotic occlusion. Absence of an identifiable patent lumen in a technically satisfactory study was another finding in thrombotic obstruction. On real-time sonograms, the normal respiratory changes of the IVC were absent when there was complete occlusion. Transhepatic collaterals, patency of other segments of the IVC, and associated malignancy were additional sonographic findings. Comparison to venography suggested that in addition to ease and safety, sonography has advantages in delineation of the cephalad extent of occlusion, dynamic evaluation of the IVC below the obstruction, and the simultaneous evaluation of adjacent organs.

An abutment screw loosening study of a Diamond Like Carbon-coated CP titanium implant

The aim of this study was to quantify the extent of abutment screw loosening and thus understand the role of frictional and wear factors in abutment screw loosening by using a cyclic loading device to compare Diamond Like Carbon (DLC)-coated and non-coated implants. The properties of DLC films, including hardness, wear resistance, chemical stability, and biocompatibility, are similar to those of real diamond materials. In this study, a 1-mum thick DLC film served to protect and lubricate a layer of commercially-pure titanium affixed to the top of a dental implant (external hexagon-shaped implant). A cyclic loading force was then applied to the top of the prosthetic portion of the implants in order to determine the difference in looseness of the titanium abutment screw between ten DLC-coated implants and ten non-coated implants. The abutment screw loosening tests were performed with 100 N of force at a frequency of 20 Hz. Data indicate that implants with a DLC coating are more resistant to an applied force (P = 0.002) than are those without the coating. We hope these results will be useful for preventing implant abutment screw loosening.