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Biomedical subjects

D Bruce

Publications and source records attributed to D Bruce.

At least 91 records · Page 5Linked to original sources
PubMed1983

Electron Transport-Dependent Chlorophyll-a Fluorescence Quenching by O(2) in Various Algae and Higher Plants.

A comparison of chlorophyll-a fluorescence in brown algae (Macrocystis integrifolia, Fucus vesiculosis), green algae (Scenedesmus obliquus, Ulva sp.) and higher plants (bean, corn) show differences in the relative fluorescence intensities and induction time courses which characterize each type of plant. These differences are not reflected in either the maximum fluorescence emission in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (F(max)) or the nonvariable fluorescence (F(o)). Constancy of F(o) and F(max) suggests functional similarities of photosystem II and associated antennae pigments in the various classes of plants. The time course differences are observed only in the absence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea and appear, therefore, to be electron transport dependent. During induction, the peak in fluorescence (F(p)) is much lower in all of the algae studied than in the higher plants. Exogenous O(2) strongly quenches F(p) in all plants studied and our data indicate that the low F(p) in the algae can be partially accounted for by endogenous O(2) quenching.

Journal Article↗
PubMed1983

Evolution of o(2) in brown algal chloroplasts.

A METHOD IS DESCRIBED FOR THE ISOLATION OF PHOTOSYNTHETICALLY ACTIVE CHLOROPLASTS FROM FOUR SPECIES OF BROWN ALGAE: Fucus vesiculosis, Nereocystis luetkeana, Laminaria saccharina, and Macrocystis integrifolia. When compared to lettuce and spinach chloroplasts, the algal chloroplasts all showed lower activities for both photosystems II and I. Chloroplasts from all the plants produced H(2)O(2), with photosystem I functioning as the O(2) reductant in the light. In contrast to the green plants, however, brown algal chloroplasts strongly reduced O(2) under conditions where both photosystems II and I remain active. Relative variable fluorescence values were lower both in intact plants and chloroplasts of the brown algae than for either spinach or lettuce. It is suggested that although light harvesting activities appear similar in all the plants, details of electron transport in brown algae may differ from those of green plants.

Journal Article↗
PubMed1982

Clostridium difficile-associated colitis: cross infection in predisposed patients with renal failure.

Four men with renal failure developed Clostridium difficile-associated diarrhoea while being cared for in the same ward at about the same time. Cross infection appeared to play a role. All patients had received antibiotics; three were treated for chest infections and one for a urinary tract infection. The antibiotics implicated were cefoxitin alone in two patients, cefoperazone alone in one patient and cloxacillin, cefoperazone and amoxycillin in the last patient. Two patients had received immunosuppressive agents as well. Clostridium difficile cytotoxin was detected in stools from all patients using a cell culture assay. Pseudomembranous colitis was demonstrated in two patients at sigmoidoscopy and in one at post mortem. All patient were given oral vancomycin. Two died with the disease, one following relapse in the absence of antibiotics, and two patients were cured only to die later of unrelated diseases. Isolation of affected patients seems prudent as the disease may be infectious.

Anti-Bacterial Agents↗
PubMed1979

Measurement of pregnancy associated plasma protein A (PAPP-A).

A method is described for measuring pregnancy associated plasma protein A (PAPP-A) in the maternal circulation during the 3rd trimester of pregnancy. The method used is a modification of Laurell's electroimmunodiffusion technique.

Antibody Specificity↗
PubMed1979

Computed tomography of craniocerebral injury in the abused child.

Computed tomography (CT) was performed in 26 infants and children with craniocerebral trauma related to abuse during a 41-month period. The pattern of brain injury differed from that seen in the nonabused traumatized infant or child. Parieto-occipital acute interhemispheric subdural hematoma (AIHSH) with associated parenchymal injury was the most frequent finding (58%). Follow-up by CT in patients with AIHSH demonstrated infarction in half and cerebral atrophy in all.

Brain Injuries↗
PubMed1978

Interhemispheric acute subdural hematoma: a computed tomographic manifestation of child abuse by shaking.

Parieto-occipital interhemispheric acute subdural hematomas (IASH) were found in 17 (61%) of 28 abused children examined by computed tomography, presenting with neurologic symptoms. CT demonstration of IASH correlated with injury due to severe shaking, the presence of retinal hemorrhages, and the absence of the stigmata of battering. Subsequent computed tomographic examination in these patients demonstrated infarction in 50%, and cerebral atrophy in 100%.

Acute Disease↗
PubMed1978

Computed tomography of pediatric head trauma: acute general cerebral swelling.

General cerebral swelling was the most common CT finding in 100 pediatric patients with acute head injury, and was demonstrated by CT as absence or compression of the lateral and third ventricles and perimesencephalic cisterns. Up to 50% of the children who die from head injury are conscious on admission. The most common pathological findings are diffuse cerebral swelling, loss of cerebrospinal fluid spaces, and venous congestion of the cortex.

Adolescent↗
PubMed1978

Cranial computed tomography in diagnosis and management of acute head trauma.

Review of the computed tomographic findings in 286 patients with acute craniocerebral trauma revealed several types of lesions: hemorrhagic contusion, intracerebral and extracerebral hematomas, general and focal cerebral swelling, and shearing injury of the cerebral white matter. Hemorrhagic contusions are the most frequent lesion and may result in focal neurologic deficits. General cerebral swelling occurs frequently in children and necessitates prompt medical management for complete recovery. Mortality rates for intracerebral, subdural, and epidural hematomas were lower for this series than for series that preceded computed tomography. Because of the availability of computed tomography, there was an 84% reduction in arteriography, 58% reduction in surgical intervention, and a 24% reduction in skull radiography.

Acute Disease↗
PubMed1975

The early detection of airway obstruction.

To assess the sensitivity of tests for early, small airway obstruction, we selected 52 cigarette smokers with a ratio of 1-sec forced expiratory volume to forced vital capacity greater than 70 per cent from a smoking cessation clinic. From these subjects, 29 of the 46 tested demonstrated frequency dependence of dynamic compliance, a finding arbitrarily defined as indicative of small airway obstruction in this group. Dynamic compliance was correlated with the British Medical Research Council questionnaire, routine pulmonary function tests, closing volume as a per cent of vital capacity, maximal expiratory flow-volume curves, and flow dependence of distribution of inhaled boluses of xenon-133 (finite difference Xe). Symptoms of respiratory disease, and abnormal flow-volume curves, specific conductances, and ratios of residual volume to total lung capacity were also present in some subjects, but they correlated very poorly with frequency dependence of dynamic compliance. On the other hand, finite difference Xe was abnormal in 85 per cent of cases with frequency dependence of compliance and closing volume was abnormal in 70 per cent. In 8 of 12 subjects restudied 2 months after they stopped smoking, dynamic compliance was less frequency dependent than before smoking cessation. Similar improvements were noted in finite difference Xe, but closing volume was unchanged. Although closing volume and dynamic compliance tended to be abnormal in the same subject, concordance was not excellent, and the effects of smoking cessation suggested that the 2 tests had different determinants.

Adult↗