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Biomedical subjects

C D May

Publications and source records attributed to C D May.

At least 19 recordsLinked to original sources
PubMed1995

The impact of the implantable cardioverter defibrillator on quality-of-life.

The implantable cardioverter defibrillator (ICD) is an established treatment for patients with life-threatening ventricular arrhythmias. While it clearly reduces the incidence of death from recurrent arrhythmia, little is known about the impact on patients' quality-of-life. In this prospective study, quality-of-life was assessed by questionnaire before and after ICD implantation. The "Sickness Impact Profile" (SIP), which evaluates physical, psychosocial, and other activities, as well as functions of daily life, was used. Employment and rehospitalization rates were also examined. Twenty-one of 23 consecutive patients, aged 58 +/- 11 years, undergoing ICD implantation at Royal Perth Hospital were studied. During the 14 +/- 8 month follow-up, 4 patients died. Functional capacity was unchanged in all but one of the survivors in whom it improved from New York Heart Association Class III to II. Four of 8 survivors employed before implant have since retired. Six patients required rehospitalization on 13 occasions, problems related to arrhythmias or the ICD. Overall SIP scores preimplant (11.2 +/- 9.3; P < 0.05) were significantly worse at 6-month follow-up (21.7 +/- 18.2), but returned to preimplant levels by 12-month follow-up (8.8 +/- 10.8; NS). This was primarily due to transient problems in the areas of emotional behavior, alertness, and social interaction. SIP psychosocial dimension scores: preimplant: 7.2 +/- 9.0; 6-month: 17.8 +/- 18.1 (P < 0.05); and 12-month: 8.6 +/- 10.3 (NS). Early retirement and hospitalizations due to arrhythmias may still be expected even after implantation of an ICD; however, quality-of-life appears only to temporarily decline.

Arrhythmias, Cardiac↗
PubMed1993

Undesirable mode switching with a dual chamber rate responsive pacemaker.

The Telectronics 1250 Meta MV DDDR pacemaker is a new device featuring automatic mode switching from DDDR to VVIR pacing in the event of an atrial arrhythmia. Although mode switching is a valuable feature, sinus tachycardia can cause an undesirable mode switch to occur. Of 24 implants at this institution, 11 have been for an AV conduction disorder. Eight of these 11 patients were specifically evaluated for undesirable mode switching. During exercise testing and/or Holter monitoring, mode switching was repeatedly seen in seven of the eight at low levels of exercise. Factors precipitating mode switching were a low rate response factor, low upper rate setting, long base postventricular atrial refractory period (PVARP) and a long AV delay. During Holter monitoring, patients spent up to 50% of the time in VVIR pacing as opposed to DDDR pacing. It is concluded that patients with intact sinus node function are at risk of undesirable mode switching and should probably be programmed to the DDD mode unless there is a specific indication for DDDR pacing. If the DDDR mode is chosen, careful selection of the aforementioned pacing parameters is required.

Adult↗
PubMed1992

The safety and economic advantages of day case electrophysiologic studies.

Electrophysiologic Studies (EPS) have been performed as 'day case' procedures in selected patients at Royal Perth Hospital since April 1987. Previously, EPS had involved hospitalisation for two to ten days. During the 51 month period to June 1991, 484 EPS were performed in total. Of these, 153 (105 males and 48 females aged 46 +/- 31y) were day case procedures. Studies were baseline in 60 cases and included drug evaluation in 30. Sixty-one additional studies were performed solely to evaluate therapy. Twenty-one patients required cardioversion. One hundred and fifty one patients were discharged on the same day and two required prolonged observation. The financial cost savings to the hospital for day case EPS is estimated to be $115 per patient and to the community potentially a further $108 per patient. This study demonstrates that in selected patients undergoing elective EPS, day case management is a safe and economic alternative to hospital admission.

Adolescent↗
PubMed1992

Radiofrequency catheter ablation of the AV node to improve the function of an antitachycardia implantable defibrillator.

A case of coexisting atrial fibrillation and ventricular tachycardia in a patient with an implantable cardioverter defibrillator is described. Despite careful reprogramming, the device was not always able to distinguish between the two arrhythmias and continued to deliver inappropriate antitachycardia therapy including DC shocks. Attempts to pharmacologically control the atrial fibrillation were unsuccessful so radiofrequency ablation of the atrioventricular node was performed. Following successful ablation, there have been no further false detections no episodes of further ventricular tachycardia.

Aged↗
PubMed1985

The ancestry of allergy: being an account of the original experimental induction of hypersensitivity recognizing the contribution of Paul Portier.

The Nobel Prize in Medicine/Physiology for 1913 was awarded to Charles Richet, French physiologist, for studies of "anaphylaxis." The earliest articles on what was actually the original experimental induction of hypersensitivity were the result of collaborative studies of Paul Portier and Charles Richet. This article presents an account of the discovery based on an extensive examination of original sources with attention to the particulars of the contributions of each of the codiscoverers. An unusually complete and intimate story of the unfolding of the discovery could be pieced together from the findings in the original sources. The contributions of Paul Portier in the experiments leading to the recognition of a relationship between hypersensitivity and immunity earned him a more prominent position in the ancestry of allergy.

Anaphylaxis↗
PubMed1982

Food allergy: lessons from the past.

Because finite studies are customarily published as the observations are completed, general principles and unifying concepts may be difficult to discern. When the contributions to a field of study are viewed in retrospect and in their entirety, the concepts and common understanding that influenced the kind of observations made and the interpretations of the findings may be more apparent. Periodic attempts to identify obstacles to scientific progress in the past should serve to lessen the clutter in the path of further advancement of knowledge. The need for this exercise in the field of food allergy has been urgent, and this is an effort to that end.

Anaphylaxis↗
PubMed1982

Observations on high spontaneous release of histamine from leucocytes in vitro.

Clinical and laboratory observations are provided on high, spontaneous, in vitro histamine release (HSHR) from leucocytes (basophils), meaning without addition of antigen or other inducers of histamine release. HSHR has been observed predominantly in persons with a high degree of reaginic sensitivity to food; the leucocytes of forty-eight of fifty-eight individuals (83%), who had positive reactions to foods in double-blind challenges, exhibited HSHR. HSHR resembles antigenic release in a wide variety of characteristics. HSHR does not occur in vivo but only in vitro after compaction of leucocytes by centrifugation at room temperature. An indispensable requirement for HSHR to occur appears to be a high degree of reaginic sensitization.

Adolescent↗
PubMed1982

Immunologic consequences of feeding infants with cow milk and soy products.

Various products and regimens proposed for feeding infants when the mother's milk is not available have been evaluated intensively for capacity to achieve optimal nutrition. The immunologic consequences of feeding the foreign proteins contained in the various products have received much less attention and no systematic investigations have been done for comparable immunologic evaluation. Sera obtained at intervals from normal infants fed cow milk and soybean products from birth in different regimens were analyzed for antibodies to five major milk proteins and a soy protein isolate. Antibody levels increased slowly during the first 4 months, reaching a peak about 6 months of age. In infants fed cow milk products or a soy product from birth to 112 days of age and then given various cow milk products the following antibody responses were observed: The level of serum antibodies attained was highest with pasteurized cow milk and lower with heat-treated cow milk or a milk base formula of lower protein content. Feeding a soy product from birth for 112 days did not prevent a brisk antibody response to cow milk introduced subsequently, comparable to or greater than the antibody response seen when cow milk products were fed from birth. Clinically no immunologic disorders were detected in association with antibody responses to the various products and regimens. The implications of the findings for infant feeding and immunologic disorders are discussed.

Adolescent↗
PubMed1980

Usefulness of measurement of antibodies in serum in diagnosis of sensitivity to cow milk and soy proteins in early childhood.

A noteworthy feature of this study is that comparisons were made between specific, sensitive, quantitative measurements of serum antibodies to food proteins and objective appraisal of clinical manifestations by double-blind food challenges. Over 50 children, 4-30 months of age, with suspicious histories of adverse reactions to cow milk or soy products were investigated. Levels of serum antibodies to cow-milk proteins were clearly higher in children with adverse reactions to milk, confirmed by blind challenge; there was no overlap with the lower levels of serum antibodies in children without confirmed reactions. Findings with serial determinations of serum antibodies to cow milk in selected cases are also presented. The levels of serum antibodies evoked by cow milk and soy formulae fed from birth until 4 months of age were similar. The levels of serum antibodies to soy protein in children with and without adverse reactions to soy products were not definitive. The bearing of these data on the comparative "antigenicity" of cow milk and soy products and the distinction between asymptomatic and clinically significant, symptomatic, sensitivity are discussed.

Animals↗