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Biomedical subjects

S J Ellis

Publications and source records attributed to S J Ellis.

At least 73 records · Page 4Linked to original sources
PubMed1988

Hand preference in a normal population.

The Edinburgh Inventory was used to assess handedness in a normal population. The incidence of strong right-handedness increased with age and the incidence of left-handedness fell with age, both significantly. A non-significant increase in the incidence of left-handedness in twins was observed. The difference in the incidence of left-handedness for males and females failed to reach significance but more males were left-handed than females. Any difference in the incidence of left-handedness between the sexes must be small (less than 1.5%) and this has major theoretical implications.

Adolescent↗
PubMed1986

Time-dependent attenuation of water flow in antidiuretic hormone-treated toad bladder.

Toad urinary bladders were subjected to sequential 30-min stimulation with antidiuretic hormone (ADH) followed by 30-min hormone washout over 4 h in the absence of a transmural osmotic gradient. Immediately thereafter, during test stimulation with hormone in the presence of a transmural gradient, transbladder water flow was profoundly inhibited, but intra(luminal)membrane particle aggregates, presumed markers of luminal membrane water permeability, were as numerous as in fully responsive controls. The protocol followed was designed to eliminate any distorting effect of prior water flow on cytoplasmic organization and to equalize, for both experimental and control tissues, the time of aggregate presence in the luminal membrane during final test stimulation. On the assumption that cytoplasmically stored and/or newly synthesized aggregates would be unaffected by the protocol followed, these observations appear to be consistent with the view that bladder refractoriness to prolonged ADH treatment may involve regulation of tissue water permeability at a resistance distal to the luminal membrane.

Animals↗
PubMed1982

Comparison of bupivacaine and prilocaine used in Bier block--a double blind trial.

The value of Bier blocks for the manipulation of fractures and for operations on the upper limb is well recognized. Two anaesthetic agents, bupivacaine and prilocaine, are widely used for this purpose. A prospective double blind trial of 200 patients has been carried out to compare the efficacy of each drug and the incidence of side effects. The study shows that bupivacaine was associated with a greater number of successful fracture reductions than prilocaine with little difference in their analgesic effects, but this was balanced by more minor side effects with bupivacaine. There was little difference in the time from injection to analgesia in the two groups. All intravenous regional analgesia procedures were carried out by junior orthopaedic or accident and emergency doctors. The overall success rate for analgesia was 91 per cent but marked cuff discomfort occurred in 9 per cent of patients. There was a clear association between failure of analgesia and two of the doctors carrying out the procedure.

Adolescent↗
PubMed1980

Effect of osmotic gradient on ADH-induced intramembranous particle aggregates in toad bladder.

Paired toad urinary bladders were prepared without or with an osmotic gradient (175 mosM) across them, stimulated for 2.5 (n = 6), 5 (n = 6), 30 (n = 6) or 60 (n = 6) min with ADH (20 mU/ml), and studied by freeze-fracture electron microscopy. Water permeability at these times was assessed in additional bladders (n = 6 for each case) after tissue fixation according to the technique of Eggena. After both 60 and 30 min of ADH stimulation, the presence of a gradient compared with the absence of one was associated with fewer aggregates (242 +/- 35 vs. 382 +/- 14 x 235 micron-2 at 60 min, P less than 0.01; 279 +/- 36 vs. 470 +/- 51 x 235 micron-2 at 30 min, P less than 0.01) and lower water permeability (8.4 +/- 1.1 vs. 18.8 +/- 1.8 microgram x min-1 x cm-1 x mosM-1 at 60 min, P less than 0.005; 9.2 +/- 1.0 vs. 22.0 +/- 2.1 microgram x min-1 x cm-2 x mosM-1 at 30 min, P less than 0.001). In addition, with a gradient both maximum water permeability and maximum aggregate frequency were reached nearly together; a similar correspondence occurred without a gradient. We conclude that in the presence of an osmotic gradient both the ADH-associated aggregates and the water permeability response to ADH are prevented from reaching the higher levels observed in bladders not exposed to a gradient.

Animals↗
PubMed1979

Possible roles for microtubules and microfilaments in ADH action on toad urinary bladder.

Intramembranous particle aggregates in the luminal membrane of toad bladder granular cells after vasopressin stimulation have been found to correlate closely and specifically with induced alterations of water permeability. Roles for microtubules and microfilaments in mediating the latter response have been proposed on the basis of studies involving colchicine and cytochalasin B, respectively. In the present investigation the effects of these agents on both initiating and sustaining vasopressin-induced osmotic water flow and the particle aggregation phenomenon were studied. The results indicate that during initiation the aggregation and water flow responses to vasopressin are each colchicine- and cytochalasin B-sensitive and that these sensitivities can be wholly additive. However, after full vasopressin stimulation is established, the same responses demonstrate sensitivity only to cytochalasin B, not to colchicine. The findings, therefore, suggest that microtubules and microfilaments may be independently necessary for the initiation of the aggregation and water flow responses to vasopressin, and that microfilaments, but not microtubules, are required for their maintenance.

Animals↗
PubMedDate not supplied

Acute respiratory distress syndrome and acute interstitial pneumonia: comparison of thin-section CT findings.

PURPOSE: The purpose of this work was to compare the thin-section CT findings of acute respiratory distress syndrome (ARDS) with those of acute interstitial pneumonia (AIP). METHOD: The thin-section CT scans from 25 patients with ARDS and 25 with AIP were independently assessed by two observers without knowledge of clinical and pathologic data. The presence, extent, and distribution of various CT findings were independently analyzed. RESULTS: Honeycombing was seen more frequently in lobes of patients with AIP (26%) than in lobes with ARDS (8%) (p < 0.001). Compared with patients with ARDS, a greater number of patients with AIP had a predominantly lower lung zone distribution (p < 0.05) and a symmetric distribution (p < 0.05) of the parenchymal abnormalities. CONCLUSION: Patients with AIP have a greater prevalence of honeycombing and are more likely to have a symmetric bilateral distribution and a lower lung zone predominance than patients with ARDS. However, significant overlap exists among the CT findings.

Acute Disease↗
PubMedDate not supplied

Invasive and noninvasive thymoma: distinctive CT features.

PURPOSE: The purpose of this work was to evaluate the CT features of thymoma and to determine the most helpful findings in differentiating invasive from noninvasive thymoma. METHOD: The CT scans from 27 patients with invasive thymoma and 23 with noninvasive thymoma were independently assessed by two observers without knowledge of their invasiveness. The presence and distribution of various CT findings were independently analyzed. RESULTS: Invasive thymomas were more likely to have lobulated (16/27, 59%) or irregular (6/27, 22%) contours than noninvasive thymomas (8/23, 35% and 1.5/23, 6%, respectively) (p < 0.05). Invasive thymomas had a higher prevalence of low attenuation areas within the tumor (16/27, 60%) than noninvasive thymomas (5/23, 22%) (p < 0.001) as well as foci of calcification (14.5/27, 54% vs. 6/23, 26%; p < 0.01). CONCLUSION: The presence of lobulated or irregular contour, areas of low attenuation, and multifocal calcification is suggestive of invasive thymoma.

Adult↗