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Biomedical subjects

C Reid

Publications and source records attributed to C Reid.

At least 91 records · Page 5Linked to original sources
PubMed1991

Tooth size and the Carabelli trait.

The Carabelli trait and its association with maxillary molar crown base and cusp size was studied in a group of 128 Kwengo, a San-Negro hybrid community living in Western Caprivi, Namibia. The trait was classified according to a modification of the scheme put forward by Dahlberg and by Scott (In: Dental Anthropology, New York: Pergamon, 1963) (Hum. Biol. 52:63-78, 1980). Crown base areas were larger in trait-positive than in trait-negative molars, and this difference existed for all eight categories of the trait in the first molar and for most of the categories in the second and third molars. The degree of expressivity of the trait seems to be associated with molar size, but this is more apparent in the first than in the second and third molars.

Adult↗
PubMed1991

Successful treatment of acute myeloid leukemia beyond first remission with autologous bone marrow transplantation using busulfan/cyclophosphamide and unpurged marrow: the British autograft group experience.

The results in 34 adult patients with acute myeloid leukemia (AML) who have undergone autologous bone marrow transplantation (ABMT) using busulfan and cyclophosphamide (Bu/Cy) in 12 United Kingdom (UK) centers have been analyzed. There were 19 females and 15 males; median age was 40 years (range, 21 to 62 years). Nine patients were in first relapse; 25 were in second remission. The median time of first remission for the whole group was 11.5 months (range, 1 to 56 months). All the patients in first relapse and six patients in second remission received first remission marrow. The leukemia-free survival (LFS) for the patients in first relapse was 33%, with a median follow-up of 20 months. The LFS for the patients in second remission was 48% with a median follow-up of 26 months. The length of second remission exceeds the length of first remission in 14 patients. Considerable toxicity with hemorrhagic cystitis (four patients; none fatal), venoocclusive disease (four patients; one fatal), pneumonitis (four patients; one fatal), intracranial hemorrhage (two patients; two fatal) has occurred. There have been four procedure-related deaths (12%). Hematologic recovery was satisfactory for neutrophils (median time to 0.5 x 10(9)/L, 22 days [range, 11 to 101 days]), but very slow for platelets (median time to 50 x 10(9)/L, 62 days [range, 15 to 1,080 days]). This study suggests that the use of Bu/Cy with ABMT for patients beyond first remission in AML compares favorably with chemotherapy, and although the procedure-related mortality is acceptable, it is associated with protracted platelet recovery.

Acute Disease↗
PubMed1991

Use of technetium-HMPAO to demonstrate changes in cerebral blood flow reserve following carotid endarterectomy.

Cerebral perfusion through stenosed internal carotid arteries is usually maintained by autoregulation. However, flow reserve may be reduced, suggesting hemodynamically significant stenosis, and such reduction should be improved by carotid endarterectomy. This concept was studied in 20 subjects with unilateral internal carotid artery stenosis (major stenosis greater than or equal to 70%, minor stenosis less than or equal to 50%). Thirteen had experienced recent transient ischemic attacks and seven had no definite focal symptoms. Subjects underwent Tc-HMPAO cerebral SPECT during acetazolamide dysautoregulation before and after internal carotid endarterectomy. Nine (45%) had perfusion defects that improved after surgery, suggesting surgery had improved cerebral flow reserve. Seven had defects that did not improve after surgery. Four had worsened or new defects after surgery, suggesting perioperative infarcts. The relatively large proportion of patients with improved cerebral blood flow reserve after surgery suggests that this technique may have a significant role to play in assessing which patients might benefit from carotid endarterectomy.

Aged↗
PubMed1988

Regional depletion of adenosine triphosphate, phosphocreatine, and glucose in ischemic hippocampus.

The selective vulnerability of pyramidal neurons in the CA1 hippocampal region in ischemic rat brain may be preceded by regional alterations of energy metabolism during early reperfusion. We measured ATP, phosphocreatine (PCr), and glucose in paramedian and lateral CA1 and in an area showing little postischemic cell loss, CA2. ATP levels in paramedian CA1 were depressed immediately after 30 min of ischemia (P less than or equal to 0.02) and remained abnormal after 2 hr of reperfusion (P less than or equal to 0.05). PCr was reduced substantially in both subdivisions of CA1 immediately after ischemia (P less than or equal to 0.04) but returned to normal levels after 2 hr. Glucose levels were depressed in paramedian CA1 and CA2 after ischemia (P less than or equal to 0.02) but corrected with reperfusion. We determined approximately P, the sum of ATP and PCr, in separate experiments investigating regional differences in consumption of high-energy phosphate metabolites during complete ischemia. The approximately P levels of rats subjected to 30 min of reversible ischemia followed by 2 hr of reperfusion showed a different pattern of regional differences from those seen in sham-ischemic animals (P less than or equal to 0.01), indicating a persistent depression of metabolic rate in CA1 during reperfusion. We conclude that regional depletion of high-energy phosphates and alteration of metabolic rate may contribute to the selective vulnerability of the CA1 region during brain ischemia.

Adenosine Triphosphate↗
PubMed1988

Salbutamol induced hypokalaemia: the effect of theophylline alone and in combination with adrenaline.

1. We have previously shown that salbutamol induced hypokalaemia, like adrenaline induced hypokalaemia, is the result of stimulation of a membrane bound beta 2-adrenoreceptor linked to Na+/K+ ATPase. We have also demonstrated that adrenaline induced hypokalaemia is potentiated by therapeutic concentrations of theophylline. 2. In a single-blind study of 14 normal volunteers, we infused salbutamol in doses used in clinical practice and examined the effects of the addition of theophylline alone or combined with (-)-adrenaline on plasma potassium levels, heart rate and blood pressure. The combinations studied were (i) salbutamol + vehicle control adrenaline infusion + placebo theophylline; (ii) salbutamol + vehicle control adrenaline infusion + theophylline; (iii) salbutamol + adrenaline + theophylline. 3. In a randomised, balanced placebo controlled design oral slow release theophylline or placebo was given for 9 days. Subjects were studied twice on the active limb (days 7 and 9) and once on the placebo limb (day 9) and the procedure was identical on each of the 3 study days except for the solutions administered. 4. Theophylline increased salbutamol induced hypokalaemia and in some individuals profound hypokalaemia (less than 2.5 mmol l-1) was observed with these relatively low doses of salbutamol and theophylline. Adrenaline did not further increase the magnitude of the fall in potassium observed. Combining theophylline with salbutamol increased the tachycardia resulting from the salbutamol infusion. Salbutamol infusion caused a fall in diastolic and rise in systolic blood pressure on all 3 study days and this was not altered by either theophylline or adrenaline alone or together.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Cost-efficiency of a long-acting cephalosporin agent.

In a prospective longitudinal study of patients in a general surgical ward, the relative cost-efficiencies of a long-acting third generation cephalosporin (ceftriaxone--mean plasma elimination t 1/2 390 min) and a short-acting second generation cephalosporin (cephamandole: mean plasma elimination t 1/2 32 min) were determined. The total cost of therapy for 24 h was +32.88 for cephamandole and +22.78 for ceftriaxone, that is, a reduction of 31%. Considerable cost containment can be achieved by using third generation cephalosporin agents that only require the administration of one intravenous injection per day.

Abdomen↗
PubMed1988

Efficacy and mechanism of action of a calcium channel blocker after global cerebral ischemia in rats.

Dihydropyridine calcium channel blockers such as nicardipine are under evaluation for treating acute cerebral ischemia because they may increase cerebral blood flow by causing vasodilation and because they may be cytoprotective in part by limiting production of arachidonic acid metabolites. We demonstrated in a previous study that nicardipine improves postischemic neuronal function, as measured by somatosensory evoked potentials, without reducing the extent of light-microscopic CA-1 hippocampal histologic damage. To characterize further the effect of nicardipine on global ischemic injury, we administered the drug beginning 24 hours before 30 minutes of four-vessel ischemia in Wistar rats. We then measured hippocampal ATP, phosphocreatine, and glucose contents immediately and 2 hours after ischemia, and measured learning ability (working and reference errors) on an eight-arm radial maze beginning 30 days after ischemia. To gain insight into the possible mechanism of action, we measured production of arachidonic acid metabolites (eicosanoids: TXB2 and 6-keto-PGF1 alpha) and hemispheric and hippocampal cerebral blood flow by the [14C]butanol indicator fractionation technique immediately and 2 hours after ischemia. Nicardipine was associated with fewer working errors (p less than 0.02) but no difference in reference errors. The drug had no effect on energy metabolites, cerebral blood flow, or eicosanoids immediately after ischemia, but ATP, phosphocreatine, and cerebral blood flow all returned to normal levels significantly more rapidly during reperfusion in treated rats. Nicardipine improves behavioral, electrophysiologic, and mitochondrial function after ischemia without preventing cellular damage and improves postischemic reperfusion. The drug's positive effect appears to occur during reperfusion.

Adenosine Triphosphate↗
PubMed1987

Brain extraction of a calcium channel blocker.

Dihydropyridine calcium channel blockers may be effective treatment for acute cerebral ischemia, but the uptake of these drugs into the brain is unknown. A 0.2-ml bolus of [14C]nicardipine hydrochloride and [3H]water was injected into the common carotid arteries of 7 normal and 7 ischemic rats. The corrected first-pass extraction of nicardipine, compared to water, was calculated to be 30.7% into the hemispheres and 42.3% into the hippocampi. The uptake was greater into the ischemic hemispheres (p less than 0.001). These data suggest that dihydropyridines are available to binding sites and calcium channels in neurons.

Animals↗
PubMed1987

Does colchicine work? The results of the first controlled study in acute gout.

We have performed the first controlled study of colchicine in acute gout, to determine its efficacy and toxicity, and to define the natural history of acute gout. Two-thirds of colchicine-treated patients improved after 48 hours, but only one-third of the patients receiving placebo demonstrated similar improvement. The colchicine-treated patients responded earlier; significant differences from placebo were shown after 18-30 hours. All patients given colchicine developed diarrhea after a median time of 24 hours (mean dose of colchicine 6.7 mg). This side effect occurred before relief of pain in most patients.

Acute Disease↗
PubMed1987

Cardiac glycoside poisoning in sheep caused by Urginea physodes (Jacq.) Bak. and the isolated physodine A.

Urginea physodes (Jacq.) Bak., a species closely related to or possibly synonymous with U. pusilla, is described and its distribution given. Four bufadienolides were isolated from U. physodes and the approximated LD50 and cumulative effect of some of them determined in guinea pigs. The most toxic one proved to be mildly cumulative. Typical signs of acute cardiac glycoside poisoning, involving the locomotory, gastro-intestinal, respiratory and cardiac system, were seen in the field cases and/or were experimentally induced by the plant. Similar signs could also be induced by injecting the isolated bufadienolide, physodine A, to a sheep.

Animals↗
PubMed1986

Effect of human erythropoietin derived from recombinant DNA on the anaemia of patients maintained by chronic haemodialysis.

Ten patients with end-stage renal failure and anaemia (mean haemoglobin 6.1 g/dl, range 4.6-8.8 g/dl) on thrice-weekly haemodialysis were treated with human erythropoietin derived from recombinant DNA (rHuEPO). This was given as an intravenous bolus after each dialysis in rising doses within the range 3-192 IU/kg. All patients showed increases in reticulocyte numbers and haemoglobin concentration and after the first week of treatment none of the four previously transfusion-dependent patients needed further transfusions. In nine patients treated for 12 weeks haemoglobin rose to a mean of 10.3 g/dl, range 9.5 to 12.8 g/dl. Thereafter the dose of erythropoietin was adjusted to avoid a further rise in haemoglobin. During treatment one patient had an episode of hypertensive encephalopathy and two had clotting in their arteriovenous fistulas (complete in one). rHuEPO is an effective treatment for the anaemia of end-stage renal failure but longer-term observations are needed on the consequences of increasing the haematocrit.

Adult↗