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Biomedical subjects

W J Russell

Publications and source records attributed to W J Russell.

At least 37 records · Page 2Linked to original sources
PubMed2000

The effects on increasing cardiac output with adrenaline or isoprenaline on arterial haemoglobin oxygen saturation and shunt during one-lung ventilation.

Theoretically, if the cardiac output were increased in the presence of a given intrapulmonary shunt, the arterial haemoglobin oxygen saturation (SaO2) should improve as the venous oxygen extraction per ml of blood decreases. To test this hypothesis, eight pigs were subjected to one-lung ventilation and adrenaline and isoprenaline infusions used to increase the cardiac output. The mixed venous oxygen, shunt fraction and oxygen consumption were measured. With both adrenaline and isoprenaline, although there was a small rise in mixed venous oxygen content, there was a fall in SaO2. With adrenaline, the mean shunt rose from 48% to 65%, the mean oxygen consumption rose from 126 ml/min to 134 ml/min and the mean SaO2 fell from 86.9% to 82.5%. With isoprenaline, the mean shunt rose from 45% to 59%, the mean oxygen consumption rose from 121 ml/min to 137 ml/min and the mean SaO2 fell from 89.5% to 84.7%. It is concluded that potential improvement in SaO2, which might occur from a catecholamine-induced increase in mixed venous oxygen content during one-lung ventilation, is more than offset by increased shunting and oxygen consumption which reduce SaO2.

Adrenergic beta-Agonists↗
PubMed2000

Can insertion length for a double-lumen endobronchial tube be predicted?

It has been suggested that the appropriate length of insertion for double-lumen tubes can be estimated by external measurement. This study examined the accuracy of external measurement in estimating the actual length of insertion required in 130 patients. It also examined the relationship between the length inserted and the patient's height in 126 patients and their weight in 125 patients. Although there was a fair correlation between the measured external length and the final inserted length (r = 0.61), the 95% confidence intervals of slope and intercept allowed a large variation and the prediction was too wide to be clinically useful. Height was reasonably well correlated with the final length (r = 0.51) but an equally wide 95% confidence interval rendered it of little clinical value. There was no correlation between weight and final tube length. It is concluded that external measurement alone is not adequate to predict a clinically acceptable position of the double-lumen tube.

Adolescent↗
PubMed1998

The preoperative management of phaeochromocytoma.

Although the preoperative use of alpha-receptor antagonist drugs is generally accepted for patients with phaeochromocytoma, evidence on the most appropriate treatment and its timing is scarce. In this retrospective study, the effectiveness of the preoperative preparation of fourteen patients who required surgical excision of a phaeochromocytoma was examined in the light of their operative stability. A simple score was developed of blood pressure stability by scoring the need for additional antihypertensive agents intraoperatively before, and blood pressure support after, tumour removal. A higher score indicated greater instability. Twelve patients received phenoxybenzamine and their stability was superior to the two patients treated with labetalol and with prazosin. There was no correlation between the duration of treatment with phenoxybenzamine and the operative stability (r = 0.18 P = 0.55 Spearman). The five patients who were treated with phenoxybenzamine for longer than 10 days did not have better perioperative blood pressure stability than the five patients who had treatment for less than a week. Predictive factors for intra-operative blood pressure stability were also sought. The degree of postural hypotension after treatment with phenoxybenzamine did not predict operative stability (r = -0.31, P = 0.33 Spearman). However, the peak total catecholamine level found during surgery correlated quite well with more operative instability (r = 0.65, P = 0.031, Spearman), suggesting that patients with phaeochromocytomas with high production of catecholamines are more likely to show cardiovascular instability.

Adolescent↗
PubMed1998

In vitro modulation of AL-amyloid formation by human mesangial cells exposed to amyloidogenic light chains.

We have shown in vitro AL-amyloid formation by human mesangial cells (HMCs). AL-amyloid formation may require lysosomal processing of the light chains (LCs) by HMCs for amyloidogenesis to occur. Chloroquine inhibits lysosomal activity. TGF-beta mediates extracellular matrix formation in many glomerulopathies. Thrombospondin (TSP) has been proposed as a mediator of cell proliferation and a marker of early fibrosis. We investigated amyloid formation by HMCs exposed to AL-LCs in the absence of amyloid enhancing factor (AEF). The effects of TGF-beta, TSP and chloroquine on in vitro amyloid formation were studied. HMCs were incubated with two AL-LCs, a light chain deposition disease (LCDD)-LC, or one of two tubulopathic LCs (T-LCs). Additional cells were treated with an AL-LC and chloroquine, TGF-beta, or TSP. Amyloid formation was evaluated microscopically using hematoxylin and eosin, Congo red and Thioflavin-T stains, as well as ultrastructurally. Amyloid was formed only when HMCs were incubated with AL-LCs. Addition of TSP significantly enhanced amyloid formation. In contrast, exogenous TGF-beta and chloroquine significantly attenuated amyloid formation. These findings show that some AL-LCs do not require AEF for amyloidogenesis to occur, and that chloroquine, TGF-beta and sTSP modulate in vitro AL-amyloidosis.

Amyloid↗
PubMed1998

Radiation therapy among atomic bomb survivors, Hiroshima and Nagasaki.

As a follow-up to the two previous surveys of radiation therapy among the atomic bomb survivors, a large-scale survey was performed to document (1) the number of radiation therapy treatments received by the atomic bomb survivors and (2) the types of radiation treatments conducted in Hiroshima and Nagasaki. The previous two surveys covered the radiation treatments among the Radiation Effects Research Foundation Adult Health Study (AHS) population, which is composed of 20,000 persons. In the present survey, the population was expanded to include the Life Span Study (LSS), including 93,611 atomic bomb survivors and 26,517 Hiroshima and Nagasaki citizens who were not in the cities at the times of the bombings. The LSS population includes the AHS population. The survey was conducted from 1981 to 1984. The survey teams reviewed all the medical records for radiation treatments of 24,266 patients at 11 large hospitals in Hiroshima and Nagasaki. Among them, the medical records for radiation treatments of 1556 LSS members were reviewed in detail. By analyzing the data obtained in the present and previous surveys, the number of patients receiving radiation therapy was estimated to be 4501 (3.7%) in the LSS population and 1026 (5.1%) in the AHS population between 1945-1980. During 1945-1965, 98% of radiation treatments used medium-voltage X rays, and 66% of the treatments were for benign diseases. During 1966-1980, 94% of the radiation treatments were for malignant neoplasms. During this period, 60Co gamma-ray exposure apparatus and high-energy electron accelerators were the prevalent mode of treatment in Hiroshima and in Nagasaki, respectively. The mean frequency of radiation therapy among the LSS population was estimated to have been 158 courses/year during 1945-1965 and 110 courses/year during 1966-1980. The present survey revealed that 377 AHS members received radiation therapy. The number was approximately twice the total number of cases found in the previous two surveys. Thus the data on radiation therapy in the AHS members have been updated well by this survey, and will provide information for more precise dose-response analyses of radiation effects in the AHS population. The information extracted from the medical records of the hospitals consisted of hospital names, treatment periods, body sites treated, diagnoses, treatment doses, radiation sources, the field sizes of the exposures and the data for identification of the patients. These data will be essential in estimating the organ doses from scattered radiation and in evaluating the effects of therapeutic radiation.

Adolescent↗
PubMed1997

Accidental bronchial intubation. An analysis of AIMS incident reports from 1988 to 1994 inclusive.

Accidental bronchial intubation was examined in the first 3947 cases reported to the Australian Incident Monitoring Study and was found to have accounted for 154 (3.7%) of the total incidents reported. Most incidents were detected in the operating theatre (93.5%) and during maintenance of anaesthesia (77.9%), by unexplained oxygen desaturation alone (63.6%). Capnography remained normal or unremarkable during 88.5% of the episodes. One-third of cases were associated with head or neck surgery and possible flexion of the patient's head. A RAE tube was used in 20% of incidents, a greater frequency than occurred in the study overall. A third party was implicated in 36 (23.4%) of cases. Ninety per cent of cases were considered preventable. Major morbidity occurred in three cases and unplanned intensive care admission was required in a further five. Almost two-thirds (61.1%) of the incidents might have been avoided by the proposed markings on the tracheal tube. We conclude that when arterial desaturation occurs at any stage during anaesthesia the possibility of bronchial intubation must be considered. Asymmetrical ventilation may be difficult to detect clinically and in most cases there is no change in capnography.

Australia↗
PubMed1997

A prospective clinical comparison of two intravenous polyurethane cannulae.

Tissue irritation, as evidenced by phlebitis, associated with Optiva (Johnson & Johnson Medical) and Insyte (Becton Dickinson) polyurethane cannulae was studied. The integrity of the cannulae on removal, the incidence of infection at the cannula site and the factors which influence phlebitis were also examined. One thousand and eight patients had a polyurethane cannula placed for induction of anaesthesia for cardiac surgery. After surgery, the cannula was examined every 24 hours. If evidence of phlebitis occurred, the cannula was removed and sent for culture. All remaining cannulae were removed at 72 hours and the site examined daily for a further three days. There were 503 Optiva and 505 Insyte cannulae studied. The distributions between the two cannulae with respect to patient characteristics, gauge of cannula, number of attempts and difficulty of insertion, cannula site and anaesthetist inserting were similar. The early removal rate for both groups was 47%. Overall phlebitis rate with Optiva was 31% and Insyte 33%. This difference is not statistically significant. The cumulative phlebitis rate increased with time but did not differ between the two types of cannulae. Minor tip distortion or shaft kinking of the cannulae occurred in 16.2% of Optiva and 23.5% of Insyte. This difference is statistically significant and may relate to the slightly more acute taper at the Optiva cannula tip. Both cannulae were similar in clinical performance.

Adolescent↗
PubMed1996

The taste of intravenous thiopentone.

Patients sometimes notice an onion or garlic taste before losing consciousness with thiopentone. An assessment of 113 patients revealed that 42% of patients noticed this taste. The effect was observed less in older patients. There was no statistically significant difference in the incidence between men and women. Premedicated patients had a lower incidence, but this was explained by the greater proportion of older patients receiving a premedication. If the taste effect of thiopentone is genetically determined then it is a different gene to thiocarbamate which has about 75% tasters.

Adolescent↗
PubMed1996

A prospective clinical comparison of two intravenous polyurethane cannulae.

Tissue irritation, as evidenced by phlebitis, associated with Optiva (Johnson & Johnson Medical) and Insyte (Becton Dickinson) polyurethane cannulae was studied. The integrity of the cannulae on removal, the incidence of infection at the cannula site and the factors which influence phlebitis were also examined. One thousand and eight patients had a polyurethane cannula placed for induction of anaesthesia for cardiac surgery. After surgery, the cannula was examined every 24 hours. If evidence of phlebitis occurred, the cannula was removed and sent for culture. All remaining cannulae were removed at 72 hours and the site examined daily for a further three days. There were 503 Optiva and 505 Insyte cannulae studied. The distributions between the two cannulae with respect to patient characteristics, gauge of cannula, number of attempts and difficulty of insertion, cannula site and anaesthetist inserting were similar. The early removal rate for both groups was 47%. Overall phlebitis rate with Optiva was 31% and Insyte 33%. This difference is not statistically significant. The cumulative phlebitis rate increased with time but did not differ between the two types of cannulae. Minor tip distortion or shaft kinking of the cannulae occurred in 16.2% of Optiva and 23.5% of Insyte. This difference is statistically significant and may relate to the slightly more acute taper at the Optiva cannula tip. Both cannulae were similar in clinical performance.

Adolescent↗
PubMed1995

Increased expression and activity of sodium channels in alveolar type II cells of hyperoxic rats.

We investigated the cellular and molecular events associated with the increase in sodium transport across the alveolar epithelium of rats exposed to hyperoxia (85% O2 for 7 days followed by 100% O2 for 4 days). Alveolar type II (ATII) cell RNA was isolated and probed with a cDNA for one of the rat colonic epithelial sodium channel subunits (alpha rENaC). The alpha rENaC mRNA (3.7-kb transcript) increased 3-fold in ATII cell RNA isolated from rats exposed to 85% O2 for 7 days and 6-fold after 4 days of subsequent exposure to 100% O2. In situ hybridization revealed increased expression of alpha rENaC mRNA transcripts in both airway and alveolar epithelial cells of hyperoxic rats. When immunostained with a polyclonal antibody to kidney sodium channel protein, ATII cells from hyperoxic rats exhibited a significant increase in the amount of immunogenic protein present in both the plasma membrane and the cytoplasm. When patched in the whole-cell mode, ATII cells from hyperoxic rats exhibited amiloride and 5-(N-ethyl-N-isopropyl)-2',4'-amiloride (EIPA)-sensitive currents that were 100% higher compared with those obtained from air-breathing rats. Single-channel sodium currents (mean conductance of 25 pS) were seen in ATII cells patched in both the inside-out and cell-attached modes. The number and open probability of these channels increased significantly during exposure to hyperoxia. Exposure to sublethal hyperoxia up-regulated both alpha rENaC mRNA and the functional expression of sodium channels in ATII cells.

Animals↗