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Biomedical subjects

S Chapman

Publications and source records attributed to S Chapman.

At least 181 records · Page 10Linked to original sources
PubMed1998

Protection by extracellular glutathione against sulfur mustard induced toxicity in vitro.

1. The present study characterizes the role of extracellularly added glutathione in protection against sulfur mustard (HD) toxicity in a macrophage monocyte cell line J774. 2. Toxic effects of HD depend on dose and duration of exposure with an ED50 of 50 and 75 microM for dividing and confluent cells respectively. 3. Exposure to HD, 100-200 microM caused approximately 15% decrease in the cellular glutathione (GSH) content 2 h after exposure, pretreatment with GSH, 0.2-10 mM, elevated cellular GSH approximately x 1.5. 4. GSH pretreatment increased cell viability after HD 2-3-fold. Similar protective effects of GSH treatment were found in a human epidermoid carcinoma cell line (KB). 5. Protection by post treatment with GSH was apparent even 60 min post HD exposure. 6. No protection was afforded when the intracellular GSH concentration was elevated prior to exposure and the extracellular GSH had been washed out. However, GSH depleted cells were more sensitive to HD than normal cells, and were also protected by addition of GSH to the growth medium, although the intracellular GSH content remained low. 7. We conclude that it is essential for the GSH to be present extracellularly in order to protect cells from HD toxicity. 8. Our findings have therapeutic implications in particular for the protection of lungs after inhalation exposure to HD vapor.

Cell Line↗
PubMed1998

Hybridization between wapiti (Cervus elephus manitobensis) and sika deer (Cervus nippon): a comparison of two artificial insemination techniques.

The present study compared pregnancy rates of sika deer (Cervus nippon) hinds artificially inseminated with frozen-thawed wapiti (Cervus elephus manitobensis) semen by laparoscopic intrauterine or transvaginal/cervical artificial insemination (AI) techniques. Estrous cycles of 59 sika hinds were synchronized with one-half of a norgestomet ear implant. Fourteen days after implant insertion, norgestomet ear implants were removed and hinds received 50 IU of PG-600 intramuscularly, a combination of 50 IU PMSG and 25 IU hCG. Hinds were then randomly allotted for laparoscopic (n = 25) or transvaginal/cervical (n = 34) AI. AI of the hinds with frozen-thawed wapiti semen (40 x 10(6) spermatozoa) was time-fixed to occur at 55 hr for transvaginal/cervical AI and 65 hr for laparoscopic AI postnorgestomet implant removal. Semen deposition for hinds inseminated by transvaginal/cervical AI occurred as follows: vagina. 8.8% (3/34); os cervix, 67.6% (23/34); intracervical, 20.5% (7/34); and uterus, 2.9% (1/34). On day 42 post-AI, transrectal ultrasonography was performed to determine pregnancy rates. Pregnancy rates were not significantly different (P > 0.10) between laparoscopic (8/25, 32.0%) and transvaginal/cervical AI (9/34, 26.4%), with an overall conception rate of 28.8% (17/59). These results indicate that transvaginal/cervical AI techniques can be as effective as laparoscopic AI under some circumstances. Further refinement of the transvaginal/cervical AI technique to improve pregnancy rates might lead to more widespread use of this technique when laparoscopic AI is not possible.

Administration, Intravaginal↗
PubMed1997

How the NHMRC got its fingers burnt.

On 20 December 1996, Justice J Finn of the Federal Court of Australia handed down his judgment in the case of the Tobacco Institute of Australia (TIA) Ltd and others v the National Health and Medical Research Council (NHMRC) and others. Justice Finn concluded that, in developing its recommendations for control of environmental tobacco smoke, the NHMRC's Working Party on Passive Smoking erred significantly in regard to the consultative procedures that it employed. As the following discussion shows, the legal decision has profound implications for the NHMRC and the provision of expert advice to Australian governments on matters of health and health policy. The discussion has been prepared by three members of the NHMRC Working Party, but reflects their personal views and not necessarily those of the Working Party as a whole or those of the NHMRC.

Australia↗
PubMed1997

A multicomponent insulin response sequence mediates a strong repression of mouse glucose-6-phosphatase gene transcription by insulin.

Glucose-6-phosphatase (G6Pase) catalyzes the final step in the gluconeogenic and glycogenolytic pathways. The transcription of the gene encoding the catalytic subunit of G6Pase is stimulated by glucocorticoids, whereas insulin strongly inhibits both basal G6Pase gene transcription and the stimulatory effect of glucocorticoids. To identify the insulin response sequence (IRS) in the G6Pase promoter through which insulin mediates its action, we have analyzed the effect of insulin on the basal expression of mouse G6Pase-chloramphenicol acetyltransferase (CAT) fusion genes transiently expressed in hepatoma cells. Deletion of the G6Pase promoter sequence between -271 and -199 partially reduces the inhibitory effect of insulin, whereas deletion of additional sequence between -198 and -159 completely abolishes the insulin response. The presence of this multicomponent IRS may explain why insulin potently inhibits basal G6Pase-CAT expression. The G6Pase promoter region between -198 and -159 contains an IRS, since it can confer an inhibitory effect of insulin on the expression of a heterologous fusion gene. This region contains three copies of the T(G/A)TTTTG sequence, which is the core motif of the phosphoenolpyruvate carboxykinase (PEPCK) gene IRS. This suggests that a coordinate increase in both G6Pase and PEPCK gene transcription is likely to contribute to the increased hepatic glucose production characteristic of patients with non-insulin-dependent diabetes mellitus.

Animals↗
PubMed1997

Use of an extension-assisting brace following anterior cruciate ligament reconstruction.

Despite changes in rehabilitation protocols, an extension deficit remains an important potential cause of significant morbidity following anterior cruciate ligament (ACL) reconstruction. An extension-assisting brace was designed using a limited motion brace and an elastic strap across a fulcrum on the anterior aspect of the knee joint. The effects of the brace were investigated in 40 patients undergoing primary ACL reconstruction using an autogenous central third patellar tendon graft. The patients were randomized either to use the brace in the first 6 weeks postoperatively or to undertake the same accelerated rehabilitation programme but without any brace, and they were reviewed at 4 months postoperatively. The following data were recorded: passive and active extension and flexion deficits compared with the non-operated limb. KT-1000 assessment of anterior laxity and isometric quadriceps and hamstring strength. There was no difference between the two groups for any of the recorded variables. This was largely attributed to satisfactory tunnel placement and emphasis on the restoration of extension and quadriceps function during the early postoperative rehabilitation.

Adult↗
PubMed1997

Non-accidental injury or brittle bones.

When a child presents with one or more unexplained fractures, non-accidental injury (NAI) should be considered in the differential diagnosis. This article reviews some of the other differential diagnoses, particularly osteogenesis imperfecta and the alleged "temporary brittle bone disease".

Accidents↗
PubMed1997

When outcomes threaten incomes: a case study of the obstruction of research to reduce teenage smoking.

A case study is presented of Australian efforts to promote an evidence-based, outcome-oriented intervention designed to reduce purchasing of cigarettes by minors. The intervention was supported by a wealth of international research literature, yet for several years was declared unethical by local institutional ethics committees. Eight objections that were raised are reviewed. Each of these objections was spurious yet initially influential. Various advocacy strategies were employed by proponents of the intervention to reframe its public definition. These gradually transformed perceptions of the intervention from one that considered it unethical, to one that considered it a virtual 'vaccine against teenage access to cigarettes' that should be incorporated into routine public health best practice. Those advocating outcome-oriented interventions should not assume that the imperative of influencing health outcomes will dominate perceptions of best practice within the health care system. In situations where competing definitions of the meaning of an intervention dominate decision makers' perceptions of outcome-oriented research, advocacy can be used to reframe these definitions more toward perceptions which are conducive to support and implementation.

Adolescent↗
PubMed1997

Transverse leukonychia in patients receiving cancer chemotherapy.

Transverse white nail banding can be inherited or caused by a variety of diseases and medications, including cancer chemotherapeutic agents. We report three cases in which patients with cancer had antineoplastic therapy-induced transverse leukonychia and summarize previously published reports. There is no specific cancer chemotherapeutic drug, combination of drugs, or drug class that causes transverse leukonychia; however, cyclophosphamide, doxorubicin, and vincristine are the therapeutic agents most frequently involved. For patients receiving cancer chemotherapy, white transverse nail banding is a side effect of the medication rather than a consequence of underlying malignancy.

Adult↗
PubMed1997

Not in our back yard: media coverage of community opposition to mobile phone towers--an application of Sandman's outrage model of risk perception.

Australia has the world's second highest per capita use of mobile phones. To meet rapid expansion in use, transmission towers are being erected hastily, backed by federal government exemptions from normal local government planning procedures. In a case study of media reportage of a successful resident protest about the placement of transmitters adjacent to a kindergarten, uncertain risks to health were the ostensible concerns voiced by the protesters. Eleven of the 12 primary components and six out of eight secondary components of Sandman's model of community risk perception were consistent with both the protesters' expressed concerns about the transmission towers and the way in which the issues involved were framed by the media.

Attitude↗
PubMed1997

Podophyllin 0.5% or 2.0% v podophyllotoxin 0.5% for the self treatment of penile warts: a double blind randomised study.

OBJECTIVE: To compare the effectiveness and cost of self treatment of penile warts with a commercial preparation of podophyllotoxin 0.5% (PDX 0.5%) with podophyllin 0.5% and podophyllin 2.0% sourced from Podophyllum emodii. DESIGN: A prospective double blind randomised study. SUBJECTS: 315 patients with penile warts attending two departments of genitourinary medicine. MAIN OUTCOME MEASURES: Absence of warts, cessation of treatment due to severe side effects at 5 weeks. RESULTS: Of the 315 patients, 244 conformed to the protocol. Analysis was on an intention to treat basis. At 5 weeks no significant differences were found in the extent of healing of warts or in side effects for the three treatment groups. The costs of drug treatment (excluding staff time) are at least pounds 10.00 less for podophyllin than podophyllotoxin. A fourfold variation in the active constituents of the podophyllin preparations did not produce appreciably different clinical responses. In a subanalysis no evidence of deterioration in effectiveness of podophyllin over time was demonstrated. CONCLUSIONS: Penile warts in selected cases can be safely treated with 0.5-2.0% podophyllin self applied by the patient at a fraction of the cost of commercially available podophyllotoxin. The shelf life of the podophyllin extracts is at least 3 months. These findings may be especially relevant in countries where resources for health care are limited.

Condylomata Acuminata↗