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Biomedical subjects

C J Jones

Publications and source records attributed to C J Jones.

At least 19 recordsLinked to original sources
PubMed2006

Glucose transporter 1 localisation throughout pregnancy in the carnivore placenta: light and electron microscope studies.

Glucose is one of the major fetal nutrients. Maternofetal transfer requires transport across the several placental membranes. This transfer is mediated by one or more of the fourteen known isoforms of glucose transporter. So far only Glucose Transporters 1 and 3 (GT1, GT3) have been shown to be located in placental membranes. GT1 may be the only one on the syncytiotrophoblast (human) or both may be present on the same membrane (rodents) or be required in sequence (ruminants, horses and elephant). This paper shows GT1 to be the only transporter demonstrable by immunocytochemistry in carnivore (cat, dog and mink) endotheliochorial placental membranes. GT1 is invariably present on both apical and basal surfaces of the cyto- and syncytiotrophoblast in all carnivore species examined and the pattern of development is described from implantation to term.

Animals↗
PubMed2006

Pre-emptive treatment for cytomegalovirus viraemia to prevent cytomegalovirus disease in solid organ transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in solid organ transplant recipients. Pre-emptive treatment with antiviral agents of patients with CMV viraemia has been widely adopted as an alternative to routine prophylaxis to prevent CMV disease. OBJECTIVES: This review was conducted to evaluate the efficacy of pre-emptive treatment in preventing symptomatic CMV disease. SEARCH STRATEGY: The Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library Issue 2, 2005), MEDLINE (1966 to February 2005), EMBASE (1980 to February 2005) and reference lists and conference proceedings were searched. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of pre-emptive treatment versus placebo, no treatment or antiviral prophylaxis in solid organ transplant recipients. DATA COLLECTION AND ANALYSIS: Two authors assessed the quality and extracted all data. Analysis was with a random-effects model and results expressed as relative risk (RR) and 95% confidence intervals (CI). MAIN RESULTS: Ten eligible trials (476 patients) were identified, six of pre-emptive treatment versus placebo or treatment of CMV when disease occurred (standard care), three of pre-emptive treatment versus antiviral prophylaxis and one of oral versus intravenous pre-emptive treatment. Compared with placebo or standard care, pre-emptive treatment significantly reduced the risk of CMV disease (six trials, 288 patients: RR 0.29, 95% CI 0.11 to 0.80) but not acute rejection (three trials, 185 patient: RR 1.06, 95% CI 0.64 to 1.76) or all-cause mortality (two trials, 176 patients: RR 1.23, 95% CI 0.35 to 4.30). Comparative trials of pre-emptive therapy versus prophylaxis showed no significant difference in the risks of CMV disease, acute rejection or all-cause mortality. AUTHORS' CONCLUSIONS: Few RCTs have evaluated the effects of pre-emptive therapy to prevent CMV disease. Pre-emptive therapy is effective compared with placebo or standard care, but additional head-to-head trials are required to determine the relative benefits and harms of pre-emptive therapy and prophylaxis to prevent CMV disease in solid organ transplant recipients.

Acyclovir↗
PubMed2006

Core beliefs, recalled parental rearing and eating psychopathology across different age groups.

This study explored and compared the patterns of core beliefs, recalled parental rearing behaviours and eating psychopathology in non-clinical females of different ages; university staff and university students. No differences were found between the two age groups except that younger women had higher Drive for Thinness scores. However, core beliefs were associated with eating attitudes and behaviours in younger women and with recalled parental rearing behaviours in older women. The results suggest that younger women tend to externalise their negative core beliefs in the form of disordered eating behaviour whereas older women appear to express their dysfunctional core beliefs in ways other than weight and shape-related issues. The possible mechanisms behind these findings require further investigation.

Adult↗
PubMed2003

Catalytic, oxidative condensation of CH4 to CH3COOH in one step via CH activation.

Acetic acid is an important petrochemical that is currently produced from methane (or coal) in a three-step process based on carbonylation of methanol. We report a direct, selective, oxidative condensation of two methane molecules to acetic acid at 180 degrees C in liquid sulfuric acid. Carbon-13 isotopic labeling studies show that both carbons of acetic acid originate from methane. The reaction is catalyzed by palladium, and the results are consistent with the reaction occurring by tandem catalysis, involving methane C-H activation to generate Pd-CH3 species, followed by efficient oxidative carbonylation with methanol, generated in situ from methane, to produce acetic acid.

Journal Article↗
PubMed2001

Preventing transmission of Sarcoptes scabiei var. suis from infested sows to nursing piglets by a prefarrowing treatment with doramectin injectable solution.

Studies were conducted at swine facilities in Illinois and North Carolina to evaluate the effect of treatment with doramectin injectable solution on transmission prevention of Sarcoptes scabiei var. suis from sows to nursing piglets. Approximately 42 days prefarrowing, 58 mange-free sows were experimentally infested with 200 S. scabiei in each ear. Seven to fourteen days prior to farrowing, 22 sows were given doramectin injectable intramuscularly at a dose of 300 microg/kg of body weight. A total of 21 sows served as untreated controls. Skin scrapings for mite counts and lesion scoring were performed on sows before treatment on day 21, and on either day 35 or 42. Each sow was observed on days 0, 7, 14, 21, 28, and 35 or 42 for the incidence of scratching/rubbing. Skin scrapings, lesion scoring, and observation of scratching/rubbing were performed on the piglets after weaning and at the end of the nursery stage. Geometric mean mite counts of the untreated sows were 0.70 and 0.26 on days 21 and 35 or 42, respectively, and 0.00 for doramectin-treated sows over the same time periods (P<0.05). Lesions scores and the incidence of scratching/rubbing were both higher in the untreated sows as compared to the doramectin-treated sows during the same time periods (P<0.05). Geometric mean mite counts of piglets farrowed by untreated sows were 0.50 and 0.60 after weaning and at the end of the nursery stage, respectively, and 0.00 for piglets from doramectin-treated sows over the same time periods (P>0.05). Lesion scores and the incidence of scratching/rubbing were both higher in piglets from untreated sows as compared to those piglets from doramectin-treated sows (P<0.05). Treating S. scabiei-infested sows with doramectin injectable solution before farrowing eliminated mite infestation and prevented the transmission of S. scabiei to piglets.

Animal Husbandry↗
PubMed2001

Epithelial development and differentiation in the mammary gland is not dependent on alpha 3 or alpha 6 integrin subunits.

In the mammary gland, both laminin and integrins have been shown to be required for normal ductal morphogenesis during development in vivo, and for functional differentiation in culture models. Major integrin receptors for laminins in the mammary gland are alpha 3 beta 1, alpha 6 beta 1, and alpha 6 beta 4. However, the specific subunits that contribute to laminin-mediated mammary cell function and development have not been identified. In this study, we use a genetic approach to test the hypothesis that laminin-binding integrins are required for the function of the mammary gland in vivo. Rudiments of embryonic mammary gland were shown to develop in the absence of these integrin subunits. Postnatal development of the mammary gland was studied in integrin null tissue that had been transplanted into the mammary fat pads of syngeneic hosts. In mammary epithelium lacking alpha 6 integrin, the beta 4 subunit was not apparent and hemidesmosome formation was only rudimentary. However, despite this deficiency, normal ductal morphogenesis and branching of the mammary gland occurred and myoepithelial cells were distributed normally with respect to luminal cells. Mammary alveoli devoid of alpha 3 or alpha 6 integrin formed in pregnancy and were histologically and functionally identical to those in wild-type mammary gland. The tissue underwent full morphological differentiation, and the epithelial cells retained the ability to synthesize beta-casein. This work demonstrates that mammary tissue genetically lacking major laminin-binding integrin receptors is still able to develop and function.

Animals↗
PubMed2001

Simian virus 40 detection in human mesothelioma: reliability and significance of the available molecular evidence.

Simian virus 40 was discovered as a contaminant of early poliovirus vaccines that were inadvertently administered to millions of people in Europe and the United States between 1955 and 1963. Although SV40 was proven to be oncogenic in rodents and capable of transforming human and animal cells in vitro, its role in human cancer could not be proven epidemiologically. The matter was forgotten until 1993 when SV40 was accidentally found to cause mesotheliomas in hamsters injected intra-cardially. Subsequently, DNA sequences associated with its powerful oncogenic principal, the large T antigen, were found with high frequency in human pleural mesothelioma using the polymerase chain reaction (PCR). Since then many laboratories have confirmed the human findings. However, a few laboratories have failed to reproduce these data and the authors of the studies have claimed that the detection of SV40 DNA may simply represent PCR contamination artefacts. The controversy raised by this viewpoint is reviewed in this article together with a critical appraisal of the reliability of the molecular techniques used to detect SV40 DNA, in order to evaluate the potential aetiopathogenic role of SV40 in human mesothelioma.

Animals↗
PubMed2001

Telomerase activity and telomere length in thyroid neoplasia: biological and clinical implications.

Despite several recent studies, the biological status and clinical relevance of telomerase expression in tumours derived from the thyroid follicular cell remain controversial. This study has analysed a series of normal, benign, and malignant thyroid samples using two novel approaches: the use of purified epithelial cell fractions to eliminate false-positives due to telomerase-positive infiltrating lymphocytes; and the simultaneous measurement of telomere length to provide a clearer interpretation of telomere dynamics in thyroid neoplasia. The data obtained support the prediction that the epithelial component of non-neoplastic thyroid and of follicular adenomas is telomerase-negative, any positive results being explicable by lymphocyte infiltration. In contrast, many malignant tumours, both follicular and papillary, were telomerase-positive. However, serial dilution of extracts indicated a wide spectrum of activity in these cancers, possibly related to variation in the proportion of telomerase-positive cells. Furthermore, an unexpectedly high proportion were telomerase-negative, a finding which was not explicable by technical problems such as TRAP (telomeric repeat amplification protocol) assay sensitivity. Many of these apparently telomerase-negative tumours had abnormally long telomeres. Correlation of telomerase and telomere length data suggests that thyroid cancers fall into three biological groups: telomerase-positive lesions, consistent with the conventional model of telomere erosion followed by telomerase reactivation; telomerase-negative tumours, which maintain telomere length by a mechanism independent of telomerase; and telomerase-negative tumours which are still undergoing telomere erosion and may therefore be composed of mortal cancer cells. From a clinical standpoint, it is concluded that telomerase detection on unfractionated tissue, such as fine needle aspirates, is of no value as a marker of malignancy in follicular lesions, due to both low sensitivity and specificity.

Adenoma↗
PubMed2001

Is the fatty meal a trigger for acute coronary syndromes.

This hypothesis paper aims to illustrate the role of fatty meal ingestion has on the vascular endothelium and coagulation system. In particular highlighting the potential risk of fatty meal ingestion both as a trigger to an adverse factor in patients with acute coronary syndromes. We propose that as a result of ingesting fatty meals as a part of daily living, there occurs a constellation of changes in the vasculature that results in both a hypercoagulable and a provasoconstrictor state. These acute changes in response to a fatty meal on endothelial function, prothrombosis, and platelet activation can potentially trigger, facilitate and propagate the forces that drive acute coronary syndromes. In type 2 diabetes, adverse postprandial phenomena are exaggerated and prolonged and may therefore be expected to contribute significantly to the excess risk of acute coronary syndromes and atherosclerotic development in these subjects.

Acute Disease↗
PubMed2001

Predicting work outcomes and service use in supported employment services for persons with psychiatric disabilities.

New funding policies make it timely to identify correlates of effectiveness and effciency in supported employment (SE) programs for persons with psychiatric disabilities. In a statewide sample of SE participants with serious mental illness, individual clinical characteristics were unrelated to competitive work or hours of services consumed. However, amounts of SE provider time devoted to travel, training, and nonemployment advocacy were independently related to the likelihood of obtaining competitive work. These results suggest that SE providers should pursue an individualized, participant-driven model of services that includes active efforts to remove logistical barriers to community employment.

Adolescent↗
PubMed2001

MUC1, glycans and the cell-surface barrier to embryo implantation.

As it approaches the maternal surface, the attaching embryo encounters the epithelial glycocalyx, which contains the mucin, MUC1. A high density of MUC1 at the cell surface can inhibit cell adhesion. This raises the possibility of the existence of a uterine barrier to implantation that might allow maternal rejection of poorer quality embryos. To investigate the mechanism of implantation, human embryos were incubated with endometrial epithelial monolayers. Hatched blastocysts were found to attach readily to the epithelial surface. MUC1 was lost from epithelial cells beneath and near to the attached embryo, while normal expression persisted in neighbouring cells.

Animals↗
PubMed2001

Clinical implications of telomerase detection.

In 1994 a sensitive method for the detection of telomerase was described. This assay, which was based on the polymerase chain reaction, suggested that telomerase activity was associated with immortal and cancer cells. Since then more than a thousand studies have documented the expression and activity of the enzyme in diseased tissues, primarily tumours. This review gives an overview of the biological significance of telomerase expression and methods for detecting its activity. This is followed by an organ system-based discussion of expression in normal tissues and disease states. We finish with speculation as to the future role of telomerase detection in diagnostic histopathology.

Cellular Senescence↗
PubMed2001

A short-term screening protocol, using fibrillin-1 as a reporter molecule, for photoaging repair agents.

Photoaged skin is characterized by coarse and fine wrinkles. The mechanisms of wrinkle formation are undetermined, but appear to be due to changes within the matrix of the dermis and at the dermal-epidermal junction. Previous studies have identified marked reductions in procollagens I and III, collagen VII, and the fibrillin-rich microfibrillar apparatus in this area. Topically applied all-trans retinoic acid can repair photoaged dermal matrix, but this takes at least 6 mo of treatment. In this study, we have examined the abundance and distribution of fibrillin-1 prior to, and following, 192 wk of all-trans retinoic acid treatment. We have further developed a short-term protocol to determine the utility of potential repair agents, using fibrillin-1 as the marker for outcome. Individuals with clinically assessed severe photoaging were recruited to the study (n = 8). 0.025% all-trans retinoic acid, 5% sodium lauryl sulfate (irritant control), or vehicle were applied under occlusion to photoaged extensor forearm. A fourth control area was also occluded. After 96 h, punch biopsies were taken under local anesthesia and processed for either transmission electron microscopy or snap frozen. Frozen sections were prepared for immunohistochemistry and in situ hybridization immunohistochemistry. Electron microscopy revealed aberrant elastic fibers in the papillary dermis of photoaged forearm skin, with sparse microfibrillar apparatus and interstitial collagen. After application of 0.025% all-trans retinoic acid, there was increased deposition of both these dermal matrix components, with the aberrant elastic fibers no longer apparent. Significant increases (p < 0.05) were observed at the protein and mRNA levels for fibrillin-1 following all-trans retinoic acid and sodium lauryl sulfate treatments, with all-trans retinoic acid having a significantly greater effect than irritant control (p < 0.001); however, neither application had significant effect on the abundance of collagen VII or its mRNA. Investigation of collagen I synthesis revealed no difference following treatments. To ascertain the clinical relevance of using fibrillin-1 as a marker for photoaging, facial skin was biopsied at baseline and after long-term (192 wk) topical all-trans retinoic acid treatment (n = 5). Biopsies were wax-embedded and sections prepared for immunohistochemistry for fibrillin-1. Significant increases in the abundance of the microfibrillar apparatus was observed proximal to the dermal- epidermal junction (p < 0.001) following long-term all-trans retinoic acid application. This study indicates that all-trans retinoic acid can significantly affect fibrillin-1 content in photoaged skin. Furthermore, fibrillin-1 can be used as a "reporter" molecule in short-term protocols for testing the utility of topical agents in the repair of photoaged skin.

Aged↗
PubMed2001

Structure of anchoring villi and the trophoblastic shell in the human, baboon and macaque placenta.

Anchoring villi of first trimester placentae of the macaque, baboon and human were examined by light and electron microscopy. The anchoring villi of the baboon and macaque are similar in having more elongated cell columns than those of the human and in having more extracellular matrix between cytotrophoblast cells. These species also have a thicker and more uniform trophoblastic shell. The generative region of cytotrophoblast cells adjacent to the villous mesenchyme is similar in all three species, with the aspect of the core abutting this area being lined by a thickened basal lamina. Similarly, migratory cytotrophoblast cells form extracellular matrix in all three species, but matrix-rich regions of the anchoring villi and shell are more extensive in the non-human primates. The extracellular matrix and especially the material resembling fibrillin may serve to strengthen the villi, particularly the elongated villi of the non-human primate, and also may prevent maternal cells migrating into the trophoblastic shell. The baboon and macaque cytotrophoblast cells that form this matrix tend to be linked by gap and desmosomal junctions and are in contiguous arrays, whereas those in the human that are blocked from reaching normal decidua form abundant extracellular matrix but have no gap junctions. Whether the lack of extensive invasion of the endometrium by baboon and macaque cytotrophoblast cells is related to the increased amount of extracellular matrix, their greater distance from the mesenchymal core, or their intercellular linkages is not known. The investigation of isolated villi from the macaque or baboon, as has been extensively carried out in the human, might help to determine whether the cytotrophoblast cells are intrinsically different or are responding to different environmental cues.

Animals↗