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Biomedical subjects

P Lewis

Publications and source records attributed to P Lewis.

At least 163 records · Page 9Linked to original sources
PubMed1988

Respiratory failure in children with acquired immunodeficiency syndrome and acquired immunodeficiency syndrome-related complex.

Acute respiratory failure has a high mortality in patients with acquired immunodeficiency syndrome (AIDS). This study was undertaken to determine the etiology of acute respiratory failure and the outcome of children with AIDS and AIDS-related complex. Records of 31 children with AIDS or AIDS-related complex admitted to the pediatric intensive care unit for acute respiratory failure throughout a 46-month period were reviewed. Acute respiratory failure was due to Pneumocystis carinii pneumonia in 13, cytomegalovirus pneumonia in six, bacterial pneumonia in five, severe bacterial sepsis in four, Candida pneumonia in two, and a giant cell pneumonia in one patient. In addition, 11/19 patients with acute respiratory failure due to P carinii pneumonia or cytomegalovirus had superinfections with bacteria or Candida. Of the total of 19 primary and secondary bacterial infections, Pseudomonas aeruginosa was responsible in ten and Klebsiella pneumoniae in three children. Five children (16%) survived until pediatric intensive care unit discharge; three died within 6 months. The causes of acute respiratory failure were not significantly different in survivor and nonsurvivor groups. It is concluded that, in addition to P carinii pneumonia and cytomegalovirus pneumonia, bacterial infections (especially due to Pseudomonas and other Gram-negative organisms) are important causes of respiratory failure. The high mortality and grim ultimate prognosis seen may have implications for pediatricians attempting to identify the proper limits of medical intervention for this group of patients.

AIDS-Related Complex↗
PubMed1987

Correction of deep anterior overbite. A report of three cases.

The maintenance of deep overbite correction is one of the criteria by which we judge the long-term success of orthodontic treatment. To correct and maintain an excessive overbite, the orthodontist must intrude the overerupted teeth and establish a more ideal interincisal angle. The mechanical means to achieve this have been discussed. Three case reports have been presented to illustrate that attention to these details during treatment is of importance in achieving long term results.

Adolescent↗
PubMed1987

Nifedipine in patients with Raynaud's syndrome--effects on radial artery blood flow.

The acute effect of nifedipine on hand blood flow of 20 patients with Raynaud's phenomenon, treated in a double-blind, crossover study, is reported. Radial artery blood flow was found to correlate with the reciprocal of the pulsatility index. This simple Doppler technique gave an instantaneous record of the effect of cooling on hand blood flow. In patients with Raynaud's phenomenon, nifedipine prevents the reduction of hand blood flow that is induced by cooling in untreated patients.

Administration, Sublingual↗
PubMed1987

The effects of nifedipine on blood flow in peripheral vascular disease of the lower limbs.

The effects of nifedipine on blood flow to the lower limb have been investigated in 19 patients with calf claudication, and in 8 patients with critical leg ischaemia, using Doppler techniques. In claudicants, common femoral artery blood flow increased by 55% after sublingual nifedipine, despite a fall in systolic blood pressure and no alteration in the ankle/brachial index. In patients with critical ischaemia given intravenous nifedipine, common femoral blood flow increased to reach a peak 90 minutes after the start of the infusion. The femoral artery pulsatility index, derived from the Doppler waveform, is a reliable guide to changes in blood volume flow.

Administration, Sublingual↗
PubMed1986

Measurement of volume flow in the human common femoral artery using a duplex ultrasound system.

A duplex ultrasound system was used to measure volumetric flow in the human common femoral artery. The accuracy of the technique was validated using a flow rig. The average resting common femoral artery flow rate in a population of subjects clinically unaffected by peripheral vascular disease was 350 +/- 141 mls min-1. Although mean common femoral artery diameter was greater in males (10 +/- 0.9 mm) than in females (7.8 +/- 0.7 mm) (p less than 0.01), there was no significant difference in resting blood flow. Repeated measurements in individual subjects showed a high variability, largely due to physiological fluctuations (75 percent of total variability). There was a close correlation between volume flow and the reciprocal of pulsatility index (100/PI). In normal subjects 100/PI represents a simpler method of determining individual changes in blood flow. The temporal variations in volume flow during periods of reactive hyperaemia had a characteristic profile, which was dependent on the duration of circulatory arrest. The data derived from the resting hyperaemia flow profile provides normal ranges for future comparison with patients suffering from peripheral vascular disease.

Adult↗
PubMed1985

Management of obstructing carcinoma of the left colon by extended right hemicolectomy.

In obstructing carcinomas of the left colon, primary resection with immediate colocolonic anastomosis is associated with a high risk of anastomotic dehiscence, and therefore, it has become traditional to manage such patients with staged resection. In obstructing carcinomas of the right colon, immediate resection of the lesion with ileocolonic anastomosis is acceptable. The scope of right hemicolectomy can be extended to encompass obstructing carcinomas of the left colon by performing subtotal or total colectomy with ileosigmoid or ileorectal anastomosis. Herein, we have reported the outcome in 16 patients treated in this manner. The operative mortality was 12.5 percent, which compared favorably the mortality of other methods of surgical management. Extended right hemicolectomy achieves in one operation relief of intestinal obstruction, tumor resection, restoration of gut continuity, elimination of the risks of synchronous or metachronous colonic tumors, and a possible increase in the 5 year survival rate. In our experience, the frequent passage of liquid stools is not a problem. This approach justifies further study.

Aged↗
PubMed1985

Contributions of elicitation to measures of self-control.

Pigeons' not pecking or pecking constituted choice between a delayed, large reinforcer and an immediate, small reinforcer (self-control) and at other times between a delayed reinforcer and no reinforcer (omission). Both a tone and a keylight were tested as choice signals, and the delayed reinforcer was either response independent or response dependent. Pigeons pecked during the choice signals on over 95% of the trials in the self-control procedure, and pecked during the choice signals on over 75% of the trials in the omission procedure. Consistent pecking was observed with either the tone or the keylight as a choice signal, with the exception that a tone paired with a response-independent delayed reinforcer did not maintain pecking in the omission procedure. Pigeons pecked during more choice signals when delayed reinforcers were response dependent than when the delayed reinforcers were response independent. These results indicate that Pavlovian conditioning influences self-control experiments, especially in single-key procedures.

Journal Article↗
PubMed1984

A comparative outcome study of individual, group, and conjoint psychotherapy.

Sixty-four outpatients were assigned to individual, group, or conjoint psychotherapy with experienced private clinicians. The length of the treatments ("cognitive insight" or "affective insight" therapies) averaged 26.8 sessions. To examine comparative outcomes, patients and significant others were assessed on both general outcome measures (eg, symptoms, target complaints) and mode-specific indexes (eg, private self-awareness, interpersonal functioning, and family environment). The most notable finding was the significant improvement of the sample as a whole at both termination and follow-up (average, 31 weeks). When differential outcomes did appear, they were more often attributable to differences among therapists and to interactive effects (ie, a particular fit between specific patient characteristics and a specific mode of therapy) than to main effects for any single therapy. The findings also demonstrated the importance of a systems approach to understanding fully the effects of psychotherapy because the patient's view of the family, the significant other's view of the patient, and the significant other's own adjustment tended to vary together, regardless of the mode of treatment.

Adolescent↗
PubMed1984

Heterogeneity of T-lymphocyte chronic lymphatic leukaemia (CLL). Study with conventional surface markers and monoclonal antibodies.

Lymphocyte surface markers (E-SRBC, EAC, EA gamma and SmIg) and monoclonal antibodies (OKT3, OKT4, OKT8 and OKIa) were used to characterise the blood and bone marrow lymphocytes of T-cell CLL (8 patients). The diagnosis of T-cell CLL was made primarily as the majority of blood lymphocytes formed E-SRBC in each patient. Other markers-EAC, EA gamma and SmIg--showed different patterns of association with E-SRBC. These findings considered together described 4 different phenotypes amongst these patients: (a) E+ (3 patients), (b) E+, EAC+ (1 patient), (c) E+, EA gamma + (2 patients), and (d) E+, SmIg+ (2 patients). Similarly, 4 different groups were defined with the help of monoclonal antibodies. Helper T-cell (3 patients) and suppressor T-cell (1 patient) CLL showed predominantly helper T- and suppressor T-lymphocytes respectively. Mixed T-cell CLL (1 patient) comprised an equal proportion of both subpopulations, while the remaining 3 patients, with excess of one or other subpopulations along with a considerable proportion of Ia antigen-bearing lymphocytes, formed the indeterminate cell type CLL.

Adult↗
PubMed1983

Measurement of K cell activity: use of human OR1R1 red cells and anti-D to study the role of different leucocytes as effector cells.

A method for quantitative assay of K cell activity (KCA) with an allogenic combination of human OR1R1 red cells and anti-D (IgG, incomplete antibody) as target cells is described. Lymphocytes alone have been shown to cause lysis of these target cells. Fc receptor-bearing lymphocytes appear to be the chief mediators of KCA. This sub-population is a heterogeneous mixture of sub-sets of other sub-populations defined on the basis of different surface markers and likely to show variable expression of Fc receptors by the EA gamma rosette method. Monocytes and neutrophils (and possibly eosinophils), most of which bear Fc receptors, are ineffective as effector cells. Monocytes may in some instances have an inhibitory effect on the expression of KCA of lymphocytes. The method described has the advantage of simplicity (easy availability of OR1R1 cells and anti-D) and a high degree of sensitivity (marked lysis at low L/T ratio) and appears suitable for routine use in clinical practice.

ABO Blood-Group System↗