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R C Russell

Publications and source records attributed to R C Russell.

At least 37 records · Page 2Linked to original sources
PubMed1999

Augmentation of cAMP improves muscle-flap survival and tissue inflammation in response to ischemia/reperfusion injury.

The authors hypothesized that augmenting skeletal muscle adenosine 3',5'-cyclic monophosphate (cAMP) levels could reduce tissue inflammation and improve muscle survival in response to ischemia/ reperfusion (I/R) injury. Gracilis muscle flaps in male Wistar rats were subject to 4 hr of ischemia followed by 3 hr of reperfusion, to assess neutrophil accumulation and microvessel tone, or by 24 hr to evaluate percentage of muscle survival. Animals were grouped as follows: positive (saline) or negative (sham) control, or with infused cAMP elevating agents (8 Bromo-cAMP (8 Br-cAMP) or forskolin). Radioimmunoassay demonstrated significant increases in tissue cAMP levels throughout 3 hr of reperfusion with forskolin, while the 8 Br-cAMP-treated group showed only a temporary increase. Compared with vehicle-infused controls, forskolin administered 5 min prior to reperfusion and repeated as an infusion during the first 45 min of reperfusion, resulted in reduced neutrophil adherence and transmigration, and muscle edema with sustained vasodilatation. The percentage of muscle survival using nitro-blue tetrazolium staining demonstrated enhanced muscle-flap preservation with forskolin. There was no beneficial change in the presence of 8 Br-cAMP These observations suggested that sustained elevation of the cAMP pathway may reduce ischemia-reperfusion injury by decreasing neutrophil-mediated injury and improving vessel tone. Elucidation of the cAMP pathway may provide novel opportunities to modulate ischemia/ reperfusion injury.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1999

Barmah Forest virus epidemic on the south coast of New South Wales, Australia, 1994-1995: viruses, vectors, human cases, and environmental factors.

In 1995, the largest recorded outbreak of human disease resulting from infection with the mosquito transmitted alphavirus Barmah Forest (BF) virus occurred along the south coast of New South Wales, Australia. The virus was first isolated in early January from mosquitoes collected at Batemans Bay and predisposed the recognition of 135 human clinical cases. The cases of BF virus were identified initially from Batemans Bay during late January, and the majority (30%) of all cases came from this town. After 5 wk, all major centers on the south coast had clinical patients. Aedes vigilax (Skuse) were especially abundant at Batemans Bay, with levels up to 8 times greater than normal. This species yielded 111 isolates and appeared to be the major vector of BF virus. Attempts to examine if BF virus was maintained in the field by vertical transmission within Ae. vigilax populations were unsuccessful; no evidence of vertical transmission with BF virus, nor any other arbovirus, was found in > 17,000 adults emerging from field-collected larvae from the region following peak virus activity. In addition to BF virus, other viruses were recovered from field-collected adult mosquitoes, including Ross River (10 isolates), Edge Hill (21), and Stratford (10). Ae. vigilax again yielded the majority of these viral isolates. The BF virus outbreak appeared to be associated with several factors. A lack of recent BF virus activity in the region provided a highly susceptible human population, and unusual weather conditions of above average rainfall coupled with high tides resulted in extraordinarily large populations of Ae. vigilax.

Aedes↗
PubMed1999

Epidural analgesia provided during labor by obstetricians: outcome analysis.

BACKGROUND: Epidural analgesic has been given during labor by attending obstetricians at Minden Medical Center since 1976. This outcome analysis was done to determine the frequency, effectiveness, and complications of epidural analgesia from January 1, 1993 through December 31, 1995. METHODS: Each of the 1,851 obstetric patient charts for the 3-year period was reviewed retrospectively. RESULTS: Among the 1,704 patients who had labor, 1,565 (91.8%) received epidural analgesia. Epidural analgesia was effective for adequate pain relief in 1,484 patients (94.8%). Hypotension was treated by ephedrine in 24 patients (1.53%). Subarachnoid puncture necessitating a blood patch for treatment of postural headache occurred in 4 patients (0.26%), and unexpected spinal anesthesia occurred in 3 patients (0.19%). A high level of analgesia, above the T5 dermatome, occurred in 16 patients (1.02%). CONCLUSION: Obstetricians at this hospital provided epidural analgesia for a high percentage (91.8%) of patients in labor. Adequate pain relief was obtained in 94.8% of the patients who received epidural analgesia. No serious complications occurred.

Analgesia, Epidural↗
PubMed1999

Towards management of mosquitoes at Homebush Bay, Sydney, Australia. I. Seasonal activity and relative abundance of adults of Aedes vigilax, Culex sitiens, and other salt-marsh species, 1993-94 through 1997-98.

The mosquitoes associated with 2 saline wetlands at Homebush Bay, Sydney, Australia, were investigated over 5 consecutive seasons. Twenty-one species were collected in adult traps at the 2 sites but the saline wetlands supported larvae of only 4 species: Aedes alternans, Aedes camptorhynchus, Aedes vigilax, and Culex sitiens. Of these, Ae. vigilax and Cx. sitiens were the most common, and their peak abundances generally occurred during February and April, respectively. Both wetlands were influenced by tides and rainfall-runoff, and a lack of regular tidal exchange in the mangroves and inadequate drainage of the saltmarsh provided potential habitat. Populations of Ae. vigilax and Cx. sitiens at the Newington site were greater than those at the Bicentennial Park site, because of more extensive habitat at the former, but were diminished by irregular ground-based applications of temephos during the middle 3 years of the study. Populations at the Bicentennial Park site, not subjected to the larvicide, were typically smaller but more consistently related to influences of tide and rainfall through the 5 seasons. During the final season, populations of both species in both wetlands were enhanced by exceptional tide penetration and rainfall. Helicopter applications of Bacillus thuringiensis israelensis larvicide were employed at both sites and effectively suppressed populations of both pest species. For future management, provision of full tidal exchange and water recirculation to reduce the area of water impounded within the mangroves and retained in depressions on the marshes should significantly suppress the pest populations and relieve reliance on control agents.

Aedes↗
PubMed1999

Palliation of pain and jaundice: an overview.

Between 70 and 90 percent of patients with pancreatic cancer will present with jaundice, and 90% will have pain at some stage of their illness. Resection for cure is possible in less than 5% of patients, thus a palliative approach is of necessity the appropriate management in 95% of patients. A palliative approach demands an attitude of mind which objectively defines relief of symptoms as the end point of treatment. Regional surveys show clearly that the care offered to the pancreatic cancer patient is poor with a high mortality (18%) for both resection and palliative bypass. The evidence that symptoms are managed well is unclear. The approach to pancreatic pain should follow the stepwise progression advocated by the World Health Organisation with a progression from minor to major analgesics and due attention to control of associated symptoms and mood. Surgery for pain relief is limited to thoracoscopic splanchnicectomy--a technique yet to be fully evaluated or a peroperative coeliac plexus block, which appears to be an important part of palliative surgery. Alternative approaches, such as chemotherapy and radiotherapy have been less well evaluated in terms of symptom control. The relief of jaundice may provide dramatic but short-lived remission in the patients' well-being--it is a mandatory part of palliation but must be undertaken with minimal disruption to the patients' life. For the majority, an endoscopic stent achieves this goal, but for the minority with a resectable or possibly resectable tumour a surgical bypass is preferable enabling a biliary and gastric bypass and a coeliac plexus block to be performed during the procedure.

Humans↗
PubMed1998

Arboviruses in the Australian region, 1990 to 1998.

Arboviruses continue to be major human pathogens in the Australian region. This report provides a summary of the activities of these viruses over the past eight years, and comments on new findings relevant to their respective ecologies. Of particular interest and concern is the propensity of these viruses to spread. The examples discussed include the initiation of dengue epidemics in north Queensland by virus imported in viraemic travellers; the spread of Japanese encephalitis virus to the Australasian region and its probable enzootic establishment in the south-west of Papua New Guinea; the potential spread of Ross River virus to other countries, as demonstrated by the 1979-80 outbreak in the South Pacific, and the recent occurrence in military personnel from the United States of America after an exercise; and the recent spread of Barmah Forest virus into Western Australia.

Animals↗
PubMed1998

Mosquito-borne arboviruses in Australia: the current scene and implications of climate change for human health.

Of the mosquito-borne arboviruses, the encephalitic Murray Valley encephalitis and Kunjin viruses are a major public health concern, but the arthritides Ross River and Barmah Forest viruses are more important in a public health sense, being responsible for a far greater number of infections. Reported cases of Ross River totalled approximately 30,000 during 1991-1996; there have been several widely separated outbreaks of Barmah Forest in recent years and case reports are increasing annually. Surveillance programmes have increased our understanding of the geographic regions, climatic conditions and vector factors associated with viruses. Virus activity is widespread but is often localised, is driven primarily by mosquito abundance and various species are involved; host factors are involved also, but are not well understood. Typically, mosquito populations are governed by availability of habitat and environmental conditions. Models of climate change predict increases in rainfall, tides and temperature for parts of Australia, and such changes have the potential to increase the risk of arbovirus transmission by increasing the distribution and abundance of vectors, and duration of mosquito and arbovirus seasons. However, the amplitude of climate change is uncertain and the ecology of arbovirus transmission is complex. It is likely that some areas will have increases in arbovirus activity and human infection with predicted climate change, but risk of increased transmission will vary with locality, vector, host and human factors.

Alphavirus Infections↗
PubMed1998

Teaching on gender-related issues; a survey of psychiatry faculty and residents.

A survey was distributed to 299 members of the McGill Department of Psychiatry regarding the teaching of gender-related issues. The response rate was 62.5%. The majority of respondents indicated that they were moderately or very knowledgeable about, and moderately or very interested in gender issues. Current teaching was rated as less than adequate, while future teaching was rated as very important. Women rated personal interest and importance of future teaching higher than men, but rated adequacy of current teaching lower. Residents rated personal interest higher than certified psychiatrists, but rated self-assessed knowledge lower, and tended to rate adequacy of current teaching lower.

Adult↗
PubMed1998

Stimulation of angiogenesis to improve the viability of prefabricated flaps.

The cutaneous area in a prefabricated myocutaneous flap surviving after elevation is dependent on the rate and amount of vascular ingrowth that occurs from the underlying muscle. Two modalities, basic fibroblast growth factor and hyperbaric oxygen, were used separately and together in a prefabricated myocutaneous flap animal model to improve flap survival. The semimembranous muscle, based on the saphenous vessels of 40 female Wistar rats weighing between 250 and 325 grams, was tunneled under the ipsilateral abdominal skin and sutured in place. A 3 x 5-cm silicone sheet was placed beneath the muscle flap, and the ipsilateral epigastric vessels were ligated. Four groups of 10 animals each received one of the following treatment regimes: a 1-ml normal saline infusion into the saphenous arterial pedicle, a 1-ml infusion of basic fibroblast growth factor (1.0 microg/gm of muscle), a 1-ml normal saline infusion and 14 hyperbaric oxygen treatments, or a 1-ml basic fibroblast growth factor infusion and 14 hyperbaric oxygen treatments. After 1 week, the muscle, still based on the saphenous vessels, was elevated with a 3 x 5-cm abdominal skin paddle. The flap was sutured back in place, leaving the silicone sheet intact. The surviving area of each flap was measured 1 week later after it had demarcated into viable and necrotic regions. Laser Doppler skin perfusion measurements were taken before and after flap elevation and before animal euthanasia. Sixteen flaps, 4 in each group, were examined histologically for vascularity by means of hematoxylin and eosin staining. There was a statistically significant increase in flap survival area when either basic fibroblast growth factor or hyperbaric oxygen was used alone. Further improvement was noted with combination therapy. Histology confirmed improved vascularity in the basic fibroblast growth factor and hyperbaric oxygen-treated flaps. This study shows a significant and reliable increase in the area of prefabricated myocutaneous flap survival using either basic fibroblast growth factor or hyperbaric oxygen. There is a further complementary effect when these two modalities are combined, leading to near complete flap survival through improved vascularity.

Abdomen↗
PubMed1998

ABS to MRCS at the RCS: philosophy, format and future.

After considering the ABS and CSiG parts of the FRCS examination and the standard for the new MRCS examination, it became important that the MRCS evolved away from the template of multiple true-false questions. Formats other than true-false questions can be used to test mental processes that are not simple factual recall. Formal mathematical tests can be evolved to equate different parts of the examination so that raw marks can be more clearly related to grades. Dispensing with the arbitrary requirement for five items in an MCQ question will enable better questions to be asked. Finally, an examination must be valid in context. With the above advances the examination will be effective, but its goal can be assessed only if the vision of the MRCS learning course is attained. The course aims to prepare surgeons for higher surgical training with a good general knowledge of surgery and an in-depth knowledge of the basic principles of surgery. The surgical trainee who has attained the MRCS should be able to manage a sick patient who suffers from the complications associated with surgery by using the principles of surgical anatomy, physiology and pathology. The trainee should know what to do initially during the 'golden hour' of opportunity, whom to call for help, and when.

Education, Medical, Graduate↗
PubMed1998

Vectors vs. humans in Australia--who is on top down under? An update on vector-borne disease and research on vectors in Australia.

Australia has a diversity of vectors and vector-borne human diseases. Mosquito-borne arboviruses are of greatest concern, but there are issues with other vector and pathogen systems. Mosquitoes were responsible for more than 35,000 cases of Ross River virus during 1991-1997. Barmah Forest virus is increasing nationwide, and unidentified bunyaviruses suspected of causing illness have been isolated. Cases of Murray Valley encephalitis have occurred in 14 of the past 20 years in northern Australia. Dengue is a continuing problem for northern Queensland, with various serotypes being active. Japanese encephalitis has appeared in the Torres Strait Islands and threatens mainland Australia. Although malaria is eradicated, almost 1,000 cases are imported annually and occasional cases of local transmission occur. With ticks, paralysis in children occurs annually in eastern Australia. Tick typhus (Queensland Tick Typhus--Rickettsia australis) occurs down the east coast, and (Flinders Island Spotted Fever--Rickettsia honei) in Bass Strait and probably Tasmania. Lyme disease is reported but its presence is controversial. Fleas were responsible for a recent outbreak of murine typhus (Rickettsia typhi) in Western Australia. Mites cause scrub typhus (Orientia tsutsugamushi), and there was a recent fatality in the Northern Territory. Overall, resources for investigation and control of vector-borne disease have generally been meager. However, various avenues of basic and applied research have been pursued, and have included investigations into mosquito ecology, vector competence, disease epidemiology, and vector control. Disease surveillance programs vary between states, and mosquito control programs are organized and effective in only a few regions. There are concerns for import of vectors such as Aedes albopictus and export of pathogens such as Ross River virus; the former has occurred but the species has not become established, and the latter has occurred and has resulted in a major outbreak in the South Pacific. The predicted scenarios of increased temperature and rainfall with global warming are also causing concern for increases in vector-borne diseases, particularly the endemic arboviruses. Interest by health authorities is gravitating more towards epidemiological reporting and less towards public health action. In many respects, humans have much to do to get 'on top' of vectors and their pathogens 'down under' in Australia.

Animals↗
PubMed1998

Fibrin glue as a delivery vehicle for autologous urothelial cell transplantation onto a prefabricated pouch.

PURPOSE: The purpose of the study was to investigate how in vivo expanded urothelium can be transplanted onto a prefabricated capsule-pouch for urinary reconstruction. MATERIALS AND METHODS: Urothelial cells from 40 rats were harvested for culture. A tissue expander was used to induce a capsule-pouch on which the cell culture were reimplanted ten days later. As delivery vehicle we compared standard culture media and fibrin glue. RESULTS: The histology demonstrated viable, multilayered clusters of urothelium cells only in the group using the fibrin glue delivery vehicle. CONCLUSION: We conclude that cultured urothelial cells can be successfully reimplanted onto a prefabricated capsule-pouch via fibrin glue, showing potential for urinary reconstructions.

Animals↗
PubMed1997

Evaluation of penicillin and hyperbaric oxygen in the treatment of streptococcal myositis.

The purpose of this study was to evaluate effects of hyperbaric oxygen (HBO) and penicillin (PCN) therapy in a murine model of streptococcal myositis. The thighs of Swiss Webster mice were inoculated with Streptococcus pyogenes. Four groups were evaluated: (1) control (N = 10), (2) HBO treatment (N = 10), (3) PCN treatment (N = 8), and (4) PCN and HBO treatment (N = 6). Mortality (day of death) and the number of colony-forming units (cfu) were measured. PCN significantly lowered cfu from control (p < 0.05). Cfu in group 4 was significantly lower than PCN alone (p = 0.006). Survival was significantly longer in the PCN group compared with the control (p < 0.01). Survival in the combined treatment group was significantly longer than PCN alone (p < 0.01). These results suggest that (1) HBO treatment alone does not decrease mortality or bacterial proliferation in vivo significantly, (2) PCN therapy alone improves outcome significantly, and (3) the combined treatment of PCN and HBO exerts at least additive effects in both decreasing bacterial counts in vivo and increasing survival in this model.

Animals↗
PubMed1997

Ischemia-reperfusion injury in skeletal muscle: CD 18-dependent neutrophil-endothelial adhesion and arteriolar vasoconstriction.

The purpose of this study was to evaluate if the venular neutrophil-endothelial adhesion associated with ischemia-reperfusion of skeletal muscle is dependent on leukocyte adhesion glycoprotein CD18 function and to determine if this interaction influences the vasoactive response in nearby arterioles. An in vivo microscopy preparation of transilluminated gracilis muscle in 13 male Wistar rats was used for this experiment. Observations of nonischemic muscle (sham) demonstrated this preparation to be stable for 8 hours with negligible change in neutrophil adherence or arteriole diameter. Three groups were evaluated in this study: (1) sham, no ischemia, no treatment (n = 5, 20 arterioles. 20 venules), (2) 4 hours of global ischemia only (n = 4, 19 venules, 22 arterioles), and (3) 4 hours of ischemia plus monoclonal antibody against CD18 (n = 4, 12 venules, 9 arterioles). The murine monoclonal antibody (WT.3, Seikagaku America, Inc.), which binds the rat leukocyte function antigen I CD18 chain, was infused into the contralateral femoral vein 30 minutes prior to reperfusion. The number of leukocytes rolling and adherent to endothelium (15 seconds of observation) was counted in 100-microns venular segments, and arteriole diameters were measured at various times during reperfusion. All counts and measurements were normalized to baseline preischemic readings for each animal. Mean changes from baseline were compared between groups. The increase in ischemia-reperfusion-induced neutrophil-endothelial adherence in venules was blocked by monoclonal antibody, but rolling behavior was not changed. The ischemia-reperfusion-induced progressive vasoconstriction in arterioles was blocked by monoclonal antibody. These results suggest that (1) neutrophil-endothelial adherence function associated with ischemia-reperfusion in this model is CD18-dependent, (2) neutrophil rolling function does not appear to be dependent on CD18, and (3) neutrophil CD18 function is a prerequisite for ischemia-reperfusion-induced arteriolar vasoconstriction. These findings provide important mechanistic information that may help explain the deleterious microcirculatory events associated with ischemia-reperfusion injury skeletal muscle.

Animals↗