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Biomedical subjects

D Buckley

Publications and source records attributed to D Buckley.

At least 73 records · Page 4Linked to original sources

Combined blunt traumatic rupture of the heart and aorta: two case reports and review of the literature.

Blunt chest trauma resulting in combined aortic disruption and cardiac rupture, although a common autopsy finding, was found reported only once previously in a surviving patient. We report two cases repaired through a left posterolateral thoracotomy in which the cardiac injury was unsuspected and presented as an intraoperative finding of hemopericardium. With improved emergency resuscitation in the field and faster transport of these cases to tertiary care centers, this combination of lesions may be seen more frequently. Suggestions for their diagnosis and management are presented.

Adult↗

Assessment of inhaler technique in general practice.

71 Patients who were using inhalers in an inner city Dublin teaching practice were assessed by the author over a four month period to see if they were using their inhalers properly. 18 (25%) had perfect technique, 26 (37%) had adequate technique and 27 (38%) had poor technique. The patients most likely to have poor technique were those using a Metered Dose Inhaler (M.D.I.), patients using inhalers for less than one year and patients with a diagnosis of C.O.A.D. as opposed to Asthma. Of the 53 patients who had less than perfect technique 37 showed an initial improvement with training. This Author suggests that all patients should be fully evaluated before starting on inhalers and the most appropriate delivery system selected for them. They should be carefully instructed on its correct use and arrangements made for regular follow up to ensure good inhaler technique. This should lead to a greater clinical response and improved patient compliance.

Administration, Inhalation↗

Serum vitamin D metabolites in very low birth weight infants with and without rickets and fractures.

Seventy-one very low birth weight (less than or equal to 1500 gm) infants were studied to determine the sequential changes in serum vitamin D metabolite concentrations between infants with and without radiographically documented rickets, fractures, or both (R/F). Usual intake of vitamin D included 20 IU/kg/day from parenteral nutrition or 400 IU/day supplementation with enteral feeding. Radiographs of both forearms and serum samples were obtained at 3, 6, 9, and 12 months. Twenty-two infants had R/F. At 3 months, significantly lower mean (+/- SEM) serum phosphorus levels (4.5 +/- 0.4 vs 6.1 +/- 0.2 mg/dl), higher 1,25-dihydroxyvitamin D (1,25-[OH]2D) concentrations (96 +/- 5 vs 77 +/- 4 pg/ml), and higher free 1,25-(OH)2D index (1,25-[OH]2D:vitamin D binding protein ratio; 5.2 +/- 0.3 x 10(5) vs 4.0 +/- 0.2 x 10(5] were found in the R/F group. These values returned to normal and were similar between groups on subsequent measurements. Serum calcium, magnesium, and 25-hydroxyvitamin D (25-OHD) concentrations were normal and similar between groups. In both groups, serum vitamin D binding concentrations increased initially but remained stable and normal beyond 6 months. We conclude that in very low birth weight infants with R/F, the vitamin D status (as indicated by serum 25-OHD concentrations) is normal, and that lowered serum phosphorus levels, higher serum 1,25-(OH)2D levels, and a higher free 1,25-(OH)2D index support the thesis that mineral deficiency (especially of phosphorus) may be important in the pathogenesis of R/F in small preterm infants.

Calcifediol↗

Integration of stereo and texture cues in the formation of discontinuities during three-dimensional surface interpolation.

A series of stereograms are presented which demonstrate that texture boundaries can strongly influence the perception of discontinuities between neighbouring three-dimensional (3-D) surfaces portrayed by means of stereo cues. In these demonstration figures, no stereo information is available in the immediate vicinity of the boundary between the two 3-D stereo surfaces because all texture in that region is removed in one eye's view. On the other hand, various forms of texture boundary information are provided in the resulting monocular region. This stimulus paradigm is used to explore the question: what influence does texture boundary information have on the nature of the perceived 3-D surface that is interpolated between two stimulus regions which carry stereo cues? It is shown that if a clear-cut texture boundary is present in the monocular region then this is used by the human visual system to fix the perceived location of 3-D crease and step surface discontinuities between the stereo regions. Collett (1985) explored this issue with a similar methodology and reported weak and unreliable assistance from monocular texture boundaries in helping shape 3-D stereo surface discontinuities. The strong and robust phenomena demonstrated here seem to rely on two main differences between the present stimuli and those of Collett. In the present stimuli, figurally continuous textures containing strong texture boundaries are used, together with a technique for minimising the complications, including binocular rivalry, that arise from the borders of the stimulus regions present in only one half of each stereogram.

Cues↗

Management of spontaneous intracranial haemorrhage.

One hundred and six patients with suspected or confirmed spontaneous intracranial haemorrhage were analysed to determine the management and referral patterns. The cases were classified into six groups on the basis of the computerised tomography (CT) scan/lumbar puncture (LP) findings. Subarachnoid haemorrhage was the commonest lesion. Thirty-four point four per cent of these were complicated. LP was performed inappropriately in a large number of cases. Late referral was a problem in some instances. In suspected intracranial haemorrhage CT scan is the investigation of choice. Lumbar puncture should be deferred and only performed following consultation with a neurosurgeon.

Cerebral Hemorrhage↗

Occult gastrointestinal carcinoma causing metastatic clostridial soft-tissue infection. Report of two cases.

The association between nontraumatic, metastatic, clostridial soft-tissue infection and malignancy is well recognized, particularly when Clostridium septicum is involved. This report presents two patients with nontraumatic, metastatic, soft-tissue infection due to C. septicum and reviews the English medical literature. Eighty-four percent of the reported patients were found to have colon carcinoma, which was postulated to be the portal of entry. Prognosis is poor, but early recognition and antimicrobial therapy with prompt and aggressive surgical intervention, both for the soft-tissue infection and the abdominal process, may lower the high mortality.

Adenocarcinoma↗

Cardiac and peripheral circulatory responses to angiotension and vasopressin in dogs.

To determine the cardiac and peripheral circulatory responses to changes in afterload with angiotension and vasopressin, we increased mean aortic pressure 25% and 50% above control in splenectomized and ganglion-blocked dogs. We compared these responses to similar mechanical increases in aortic pressure produced by partial balloon occlusion of the descending aorta. With 25% or 50% increases in aortic pressure, angiotensin, vasopressin, and balloon inflation produced no changes in heart rate, right atrial, and mean pulmonary artery pressures. At 25% increase in aortic pressure, cardiac output was maintained with angiotensin and balloon occlusion but decreased with vasopressin. At 50% increase in aortic pressure, cardiac output was maintained with only balloon occlusion and decreased with both angiotensin and vasopressin. Whenever cardiac output fell, central blood volume did not increase as after-load increased. These changes in preload can be explained by alterations in the venous circulation. Vasopressin did not alter venous compliance or unstressed vascular volume but increased resistance to venous return. Angiotensin also increased resistance to venous return but decreased venous compliance and did not change unstressed vascular volume. Balloon occlusion had no effects on these parameters. We conclude that: (a) angiotensin caused significant venoconstriction resulting in maintenance of cardiac output at 25% but not 50% increase in aortic pressure; (b) vasopressin increased the resistance to venous return without venoconstriction; this resulted in a fall in cardiac output even with a 25% increase in aortic pressure; and (c) the effects of the agents on the venous circulation were independent of the mechanical effects of a pressure increase in the arterial circulation.

Angiotensin II↗

The major lung surfactant protein, SP 28-36, is a calcium-dependent, carbohydrate-binding protein.

SP 28-36, a major protein of pulmonary surfactant, has striking amino acid sequence homology with soluble mannose-binding proteins isolated from rat liver and contains residues common to the carbohydrate-binding domains of other mammalian lectins. We have used carbohydrate-affinity chromatography to investigate carbohydrate-binding properties of SP 28-36 isolated from canine and human (alveolar proteinosis patients) lung lavage. SP 28-36 binds to immobilized D-mannose, L-fucose, D-galactose, and D-glucose. The protein binds only weakly to N-acetyl-D-galactosamine and N acetyl-D-glucosamine. Binding is Ca2+-dependent. The threshold Ca2+ concentration is 0.6 mM and maximal binding occurs with 1 mM Ca2+. Bound protein is quantitatively recovered by elution with 2 mM EDTA. Ba2+, Sr2+, and Mn2+, but not Mg2+, can substitute for Ca2+. Unlike some other mammalian lectins, SP 28-36 binds to carbohydrate at pH 5.0. Recombinant human SP 28-36 isolated from the media of Chinese hamster ovary cells, transfected with a DNA construct encoding SP 28-36, has similar carbohydrate-binding activity to the native proteins. Mannose affinity chromatography of the culture medium of Chinese hamster ovary cells results in an efficient purification of the secreted recombinant human SP 28-36.

Animals↗

Peripheral circulatory control of preload-afterload mismatch with angiotensin in dogs.

To determine whether changes in the venous circulation were responsible for preload-afterload mismatch with angiotensin, we examined the changes in the heart and the peripheral circulation in six splenectomized dogs after ganglion blockade during an angiotensin infusion to increase mean aortic pressure 25 and then 50%. The peripheral circulation was evaluated by measuring mean circulatory filling pressure (MCFP), arterial compliance, and venous compliance. A 25% increase in mean aortic pressure increased MCFP from 6.2 +/- 0.3 to 7.6 +/- 0.3 mmHg (P less than 0.001) but did not change cardiac output, heart rate, or stroke volume. Systemic vascular resistance increased (P less than 0.01) from 0.50 +/- 0.02 to 0.59 +/- 0.03 mmHg X min X kg X ml-1. Arterial and venous compliances decreased (P less than 0.01) from 0.08 +/- 0.03 to 0.06 +/- 0.03 ml X mmHg-1 X kg-1 and from 2.1 +/- 0.1 to 1.6 +/- 0.1 ml X mmHg-1 X kg-1, respectively. A 50% elevation in mean aortic pressure increased MCFP from 7.1 +/- 0.4 to 9.5 +/- 0.9 mmHg (P less than 0.001) but did not change heart rate. At this level of aortic pressure, cardiac output and stroke volume decreased (P less than 0.01) 12 and 19%, respectively, whereas systemic vascular resistance increased (P less than 0.001) from 0.48 +/- 0.03 to 0.83 +/- 0.05 mmHg X min X kg X ml-1. Arterial and venous compliances decreased (P less than 0.01) from 0.08 +/- 0.01 to 0.05 +/- 0.01 ml X mmHg-1 X kg-1 and from 2.1 +/- 0.1 to 1.4 +/- 0.1 ml X mmHg-1 X kg-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗

Elevated serum calcium and osteocalcin levels from calcitriol in preterm infants. A prospective randomized study.

The hypothesis of this study was that pharmacologic doses of calcitriol (1,25-dihydroxyvitamin D3) would result in elevated levels of serum osteocalcin, the major noncollagenous bone protein, and calcium in infants of very low birth weight (less than 1500 g). Twenty-four infants of very low birth weight but of the appropriate weight for gestational age were matched in 250-g weight ranges and randomized into calcitriol treatment and control groups on the first day after birth. Treated infants received 4 micrograms/kg of calcitriol intravenously on entry and on the second and third study days. Controls did not receive calcitriol. Four infants from each group were hypocalcemic (serum calcium level, less than 7.0 mg/dL [less than 1.75 mmol/L]) on entry (five to 20 hours after birth) to the study. Seven infants received calcium replacement; data analyses with and without these infants were similar. Of the remaining 17 infants, eight were in the treatment group and nine were in the control group. Calcitriol significantly increased serum calcium and osteocalcin concentrations on days 2, 3, and 4 after birth compared with the control group. None of eight treated infants manifested hypocalcemia after calcitriol vs eight of nine controls. There were no acute changes in heart rate, respiratory rate, systolic blood pressure, or urinary calcium loss nor were there changes at the infusion site, but the diastolic blood pressure increased with treatment. Although high doses of calcitriol may elevate serum calcium concentrations in infants of very low birth weight, we suggest that the long-term or subtle biologic effects of high doses of calcitriol remain to be studied and that its routine use not be recommended at present.

Calcitriol↗

Specific immune response in the respiratory tract after administration of an oral polyvalent bacterial vaccine.

An oral killed polyvalent bacterial vaccine was assessed in a double-blind trial involving healthy volunteers. Three courses of oral vaccine were given over a 2-month period; each course contained 10(10) Haemophilus influenzae and 7 X 10(9) Staphylococcus aureus organisms. Immunity was assessed by monitoring antibody in saliva and serum over a 3-month period. No evidence of a nonspecific effect on immune parameters (immunoglobulin levels and Escherichia coli antibody) was detected in saliva or serum. An increase in H. influenzae antibody in saliva was detected in 55% of subjects receiving the vaccine compared with 6.7% of the placebo group. Antibody was associated with immunoglobulin A (IgA), IgG, and IgM, but the greatest increases over preimmunization levels were detected in the IgA class. No increase in serum antibody levels was detected. Subjects with higher preimmunization levels of salivary antibody to H. influenzae were less likely to respond to the oral bacterial vaccine. No increase in S. aureus antibody was detected in saliva or serum.

Administration, Oral↗

Dermatitis herpetiformis: a comparative assessment of skin and bowel abnormality.

We reviewed 18 patients with a clinical diagnosis of dermatitis herpetiformis who were being treated with dapsone and were on an unrestricted diet. Diagnosis was confirmed by finding IgA deposits in the dermal papillae of unaffected skin. Dapsone was discontinued and biopsy of affected skin was carried out when the typical rash reappeared. The biopsy findings were graded according to the severity of the histological changes. Small bowel tissue from each patient was examined and graded by stereo- and routine microscopy. Thirteen specimens (72%) were stereomicroscopically abnormal; all 18 showed villous atrophy, either partial or subtotal; and in 13 (72%) the interepithelial lymphocyte count was increased. No correlation was found between the histological severity of the skin and the small bowel lesions. Seemingly the severity of the skin rash in dermatitis herpetiformis is no guide to the degree of small bowel abnormality.

Adolescent↗

Effect of monosodium n-alkylsalicylates on spores of Bacillus subtilis.

The effects of several monosodium n-alkylsalicylates on washed spores of Bacillus subtilis have been examined. None of the compounds was sporicidal, but in general they prevented dormancy induced by incubating the spores in water. This effect was related to the position in the ring and size of the alkyl groups substituted on the salicylic acid nucleus.

Bacillus subtilis↗

Antimicrobial activity of sodium n-alkylsalicylates.

The activities are reported of sodium salts of several n-alkylsalicylic acids against Staphylococcus aureus, Pseudomonas aeruginosa, Mycobacterium phlei, and Candida albicans. The acids had alkyl substituents of 1 to 18 carbon atoms in the 3, 4, or 5 positions relative to the carboxyl group of salicylic acid. Generally, the antimicrobial properties were typical of anionic surface-active agents although the salicylates are more potent than most of these, particularly against S. aureus.

Anti-Bacterial Agents↗