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Biomedical subjects

C Green

Publications and source records attributed to C Green.

At least 19 recordsLinked to original sources
PubMed1999

Constitutive activation of toll-mediated antifungal defense in serpin-deficient Drosophila.

The antifungal defense of Drosophila is controlled by the spaetzle/Toll/cactus gene cassette. Here, a loss-of-function mutation in the gene encoding a blood serine protease inhibitor, Spn43Ac, was shown to lead to constitutive expression of the antifungal peptide drosomycin, and this effect was mediated by the spaetzle and Toll gene products. Spaetzle was cleaved by proteolytic enzymes to its active ligand form shortly after immune challenge, and cleaved Spaetzle was constitutively present in Spn43Ac-deficient flies. Hence, Spn43Ac negatively regulates the Toll signaling pathway, and Toll does not function as a pattern recognition receptor in the Drosophila host defense.

Animals↗
PubMed1999

The balance between isoforms of the prickle LIM domain protein is critical for planar polarity in Drosophila imaginal discs.

The tissue polarity mutants in Drosophila include a set of conserved gene products that appear to be involved in the control of cytoskeletal architecture. Here we show that the tissue polarity gene prickle (pk) encodes a protein with a triple LIM domain and a novel domain that is present in human, murine, and Caenorhabditis elegans homologs which we designate PET. Three transcripts have been identified, pk, pkM, and sple, encoding 93-, 100-, and 129-kD conceptual proteins, respectively. The three transcripts span 70 kb and share 6 exons that contain the conserved domains. The pk and sple transcripts are expressed with similar tissue-specific patterns but have qualitatively different activities. The phenotypes of pk mutants, and transgenic flies in which the different isoforms are overexpressed show that the balance between Pk and Sple is critical for the specification of planar polarity. In addition, these phenotypes suggest a tessellation model in which the alignment of wing hairs is dependent on cell shape and need not reflect fine-grained positional information. Lack of both pk and sple transcripts gives a phenotype affecting the whole body surface that is similar to those of dishevelled and frizzled (fz) suggesting a functional relationship between pk and fz signaling.

Amino Acid Sequence↗
PubMed1999

Fine-needle aspiration cytology of adenoid cystic carcinoma of the breast.

Adenoid cystic carcinoma (ACC) of the breast is a rare variant of breast malignancy and has a better prognosis than its counterpart in the salivary glands. In this communication, our experience with seven cases of ACC of the breast is presented in which the diagnosis was established on fine-needle aspiration cytology (FNAC). The cytologic samples in all cases were cellular and featured three-dimensional clusters of uniform ductal epithelial cells with cystic spaces, bland nuclei, fine chromatin, and scanty cytoplasm arranged around spheres or cores of homogenous material. The cytodiagnosis of ACC in all cases correlated with subsequent examination of cell blocks of the aspirate and tissue. The cytodiagnostic criteria for ACC of the breast which are useful in a correct FNAC diagnosis are discussed.

Adult↗
PubMed1999

Connexins in the lens: are they to blame in diabetic cataractogenesis?

The pathohistology of the diabetic lens is an enigma. Under normal conditions the lens behaves as a functional syncitium, whereas the diabetic lens exhibits a localized zone of fibre cell swelling and rupture that is confined to the lens outer cortex. Because the lens fibre cells are extensively coupled by gap junction channels, it is believed that the abnormal closure of these channels is responsible for this phenomenon. New evidence concerning regional differences in gap junction gating supports this contention, and it is used to propose a new hypothesis that may explain the cellular changes observed in the diabetic lens.

Animals↗
PubMed1999

Cytokine-induced tendinitis: a preliminary study in rabbits.

This study was designed to determine the effects of a single injection of a species-specific preparation of cytokines into rabbit patellar tendons and to compare the results with a known model of tendinitis, the collagenase-injection model. New Zealand White rabbits were divided into two groups and two time periods (4 and 16 weeks) and injected in the midsubstance of the right patellar tendon with either cytokines or collagenase under ultrasound guidance to confirm intratendinous needle placement. The left patellar tendon was injected with 0.025 ml of saline solution and served as a control. The rabbits were returned to cage activity after injection. At death, two rabbits in each group underwent histological analysis; the remaining eight animals in each time frame were evaluated biomechanically and then biochemically with use of the patella/whole patellar tendon/tibia complex. Histologic results at 4 weeks in the tendons injected with cytokines demonstrated increased cellularity, which was resolving by 16 weeks. The matrix appeared unchanged. The tendons injected with collagenase demonstrated increased angiogenesis of the matrix, hypercellularity, and fibrosis around the tendon at 4 weeks. At 16 weeks, myxoid changes, focal fibrosis, and collagen-bundle disarray with persistent increase in cellularity were noted. Biomechanically, a significant decrease in ultimate load at 16 weeks was seen in the tendons injected with cytokines but no change was seen in cross-sectional area. The tendons injected with collagenase demonstrated a significant increase in cross-sectional area at 4 and 16 weeks compared with those injected with cytokines. Biochemically, there was no significant difference in collagen content between the two groups at 4 or 16 weeks but the tendons injected with collagenase demonstrated a significant increase in crosslinking at 16 weeks. Our conclusion is that the tendons injected with the cytokine preparation represent a model of mild, seemingly reversible tendon injury. The cytokine preparation produces no matrix damage or evidence of collagen degradation and is species specific.

Animals↗
PubMed1999

Leginon: a system for fully automated acquisition of 1000 electron micrographs a day.

We have developed a system to automatically acquire large numbers of acceptable quality images from specimens of negatively stained catalase, a biological protein which forms crystals. In this paper we will describe the details of the system architecture and analyze the performance of the system as compared to a human operator. The ultimate goal of the system if to automate the process of acquiring cryo-electron micrographs.

Automation↗
PubMed1999

Gabapentin as an adjunct to standard mood stabilizers in outpatients with mixed bipolar symptomatology.

Gabapentin is a new adjunctive medication to antiseizure therapies. Anecdotal evidence suggests that it may also help to alleviate mood symptoms in patients with bipolar illness. An open-label study examined the effects of adjunctive gabapentin in bipolar patients with mixed symptoms who had previously demonstrated only partial treatment responses. Mood ratings and side-effect profiles were followed weekly in 10 patients for 1 month. Decreases in Hamilton depression (P < 0.05) and Bech mania ratings (P < 0.01) were evident in the first week of treatment and were sustained. Potent early improvements were noted in early, middle, and late insomnia. The results suggest that gabapentin may be of benefit to bipolar patients who only partially respond to other mood stabilizers. A favorable side-effect profile and rapid action make this drug an attractive choice as an adjunctive therapy.

Acetates↗
PubMed1999

Hair removal using the ruby laser: clinical efficacy in Fitzpatrick skin types I-V and histological changes in epidermal melanocytes.

The ruby laser is effective in removing unwanted body hair. The occurrence of cutaneous side-effects such as blistering, hypopigmentation and hyperpigmentation, however, remains problematic. These side-effects are more commonly seen in patients with dark coloured skin, which partly explains the relative scarcity of information on the efficacy of ruby laser hair removal in such patients. The mechanisms of the occurrence of these side-effects are also not known. It was the aim of this study to evaluate the efficacy of ruby laser-assisted hair removal in patients with Fitzpatrick skin type V in a retrospective clinical study and to evaluate the mechanism of post-treatment pigmentary change in a prospective clinical study. The percentage reduction in hair density in patients with skin type V was assessed after a variable period following treatment with the Chromos 694 Depilation Ruby Laser, and was compared with the results of those with skin types I-IV. To study the pigmentary change and melanocyte numbers after laser irradiation, ex-vivo scalp skin and serial patient biopsies were taken and stained with S-100, dopa oxidase and Masson-Fontana methods. Laser treatment reduced melanocyte numbers as measured by DOPA stain but not by S100. Laser treatment resulted in the clearance of pigment from the epidermis on histology. Ruby laser was shown to be effective in removing unwanted hair from patients with dark coloured skin, but with a higher incidence of cutaneous side-effects. The occurrence of hypopigmentation after laser irradiation was thought to be due to the suppression of melanogenesis in the epidermis rather than to destruction of the melanocytes.

Analysis of Variance↗
PubMed1999

Development of autologous human dermal-epidermal composites based on sterilized human allodermis for clinical use.

The aim of this study was to identify a sterilization technique for the preparation of human allodermis which could be used as a dermal component in wound healing and as the dermal base for production of dermal-epidermal composites for one-stage grafting in patients. We report that it is possible to produce dermal-epidermal composites which perform well in vitro and in vivo using a standard ethylene oxide sterilization methodology. Prevention of ethylene oxide-induced damage to the dermis was achieved using gentle dehydration of the skin prior to ethylene oxide sterilization. The issue of whether viable fibroblasts are required for composite production was examined in comparative studies using glycerol vs. ethylene oxide sterilized dermis. Where good collagen IV retention was achieved following preparation of acellular de-epidermized dermis there was no advantage to having fibroblasts present in vitro or in vivo; however, where collagen IV retention was poor or where keratinocytes were initially expanded in culture then there was a significant advantage to introducing fibroblasts to the composites during their preparative 10-day period in vitro. The requirement for fibroblasts became less evident when composites were grafted on to nude mice. In conclusion, we report a protocol for the successful sterilization of human allodermis to achieve an acellular dermis with good retention of collagen IV. This acellular dermis would be appropriate for clinical use as a dermal replacement material. It can also be used for the production of dermal-epidermal composites using autologous keratinocytes (with or without fibroblasts).

Adult↗
PubMed1999

A new resorbable wrap-around implant as an alternative nerve repair technique.

Poly-3-hydroxybutyrate (PHB), a bacterial storage product, is available as bioabsorbable sheets and has been used in this study for primary nerve repair. The aim was to assess axonal regeneration following such repair and determine the inflammatory response to PHB. In 20 adult cats, the transected superficial radial nerve was wrapped in PHB sheets, while primary epineural repair was carried out in the contralateral limb. At 6 and 12 months, the repair sites were assessed immunohistochemically for macrophage infiltration and myelinated axons were counted in the distal nerve. Mean macrophage counts across the whole width of the nerve in both groups at 6 and 12 months showed no statistically significant difference. Nor was there any significant difference between the two groups at both time-points in axon counts, axon diameter, myelin thickness and g-ratio. There was a statistically significant increase in fibre diameters at 12 months, indicating that fibres were undergoing continuous maturation.

Animals↗
PubMed1999

Ruby laser-assisted hair removal: a preliminary report of the correlation between efficacy of treatment and melanin content of hair and the growth phases of hair at a specific site.

An unpredictable response, even in patients with dark hair, often undermines successful ruby laser hair removal. A prospective clinical study was carried out to evaluate the roles of melanin content and growth phases of hair in treatment efficacy. Thirty-six volunteers with white skin and dark hair were recruited for the study, and were all treated using the Chromos 694 Depilation Ruby Laser. The overall efficacy of treatment was assessed at the end of 3 months. The efficacy of laser treatment is not due solely to the proportion of hair in the growing or static phase of the hair cycle. There is a lack of correlation between the melanin content and the overall efficacy of laser hair removal in those treated once, but patients with darker hair responded better after repeated treatments. The proportion of hair in the growth phase and the melanin content of hair do not contribute solely to the efficacy of ruby laser hair removal.

Hair↗
PubMed1999

A review of the use of health status measures in economic evaluation.

OBJECTIVE: To review the use of measures of health status in the assessment of benefits in economic evaluation, whether or not the measures were designed for this purpose. METHODS: The review was based on a systematic search of the literature. It provides a comprehensive assessment of the evidence where it exists and a balanced overview of opinion otherwise. RESULTS: Over 3000 papers were identified, of which 632 were found to be relevant. The review provides a set of recommendations. These include: a checklist of questions for selecting a measure for use in economic evaluation; a list of circumstances in which non-preference-based measures can be used; and recommendations surrounding the use of health state valuation techniques and multi-attribute utility scales. CONCLUSION: These recommendations should help to identify poor economic evaluations and hence guard against inefficient conclusions being drawn regarding the provision of health services.

Cost-Benefit Analysis↗