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Biomedical subjects

D Mercer

Publications and source records attributed to D Mercer.

At least 37 records · Page 2Linked to original sources
PubMed1997

Open-chest cardiac massage without major thoracotomy: metabolic indicators of coronary and cerebral perfusion.

OBJECTIVE: To compare the coronary and cerebral perfusion achieved using a novel method of minimally-invasive, direct cardiac massage to that obtained using bimanual, open-chest cardiac massage. DESIGN: Prospective, controlled animal study with repeated measures. SETTING: University research laboratory. SUBJECTS: Large domestic swine. INTERVENTIONS: Aortic, coronary sinus, jugular venous and pulmonary artery catheters were placed. Following an equilibration period, ventricular fibrillation was induced. After 4 min of untreated ventricular fibrillation, animals underwent bimanual, open-chest cardiac massage (N = 6) or minimally-invasive, direct cardiac massage using a novel device for direct cardiac compression (N = 6). Adrenaline was administered at a dose of 1 mg intravenously every 5 min. MEASUREMENTS: Systemic metabolic parameters, (arterial PO2, PCO2 and lactate concentration) and coronary sinus and jugular venous metabolic parameters (pH, PVO2, SVO2, PVCO2 and lactate concentration) were measured and calculated (coronary sinus/jugular-arterial SVO2, coronary sinus/jugular-arterial PCO2 and lactate differences) at baseline and at 10, 20 and 30 min following induction of ventricular fibrillation. Animals were euthanised after 30 min with no attempt at defibrillation. MAIN RESULTS: Oxygen tension and oxygen saturation of coronary sinus blood declined significantly during the experimental period, but no differences were noted between treatment groups. The coronary sinus-arterial oxygen saturation difference increased during the study with no significant differences between groups. Coronary sinus PCO2 and the coronary sinus-arterial PCO2 difference increased significantly in both experimental groups during cardiac massage. No inter-group differences were noted. A similar relationship was noted in coronary sinus lactate values. The coronary sinus-arterial lactate difference displayed a positive balance at all intervals with no differences noted between group values. The oxygen tension and oxygen saturation of jugular venous blood, were reduced from baseline levels with both treatments. The jugular-arterial oxygen saturation difference increased in both groups compared to baseline values. Between group values were significantly different only at the 20 min interval. Both the jugular venous PCO2 and the jugular-arterial PCO2 gradient were elevated at all intervals, but no inter-group differences were noted. Jugular venous lactate concentration rose steadily with time in both groups. No significant increase in the jugular-arterial lactate gradient was noted at any time point. CONCLUSIONS: Minimally-invasive, direct cardiac massage provides coronary and cerebral perfusion similar to that achieved using standard open-chest cardiac massage. This method may provide a more effective substitute for standard, closed-chest cardiac massage in cases of refractory cardiac arrest.

Animals↗
PubMed1996

Development of an adherence/competence rating scale for individual drug counseling.

This paper reports on the development of a 43 item rating scale that assesses therapist adherence and competence in individual drug counseling (IDC) for the treatment of cocaine dependence. Three independent judges rated 41 audiotaped IDC sessions from the pilot/training phase of the NIDA collaborative cocaine study. Judges also rated 11 tapes of Cognitive sessions and ten tapes of Supportive Expressive psychodynamic sessions. Interjudge reliability for the total scale score and subscales ranged from 0.55 to 0.89 and internal consistency coefficients ranged from 0.43 to 0.95. Ratings indicated that IDC counselors used IDC techniques more frequently and competently than did therapists from other modalities.

Cocaine↗
PubMed1996

Self-help activities in cocaine dependent patients entering treatment: results from NIDA collaborative cocaine treatment study.

Although little is known about self-help attendance among cocaine dependent patients, clinicians frequently recommend this treatment. Cocaine dependent patients (519) entering a psychotherapy study were therefore surveyed regarding their recent self-help group attendance and participation. During the previous week, 34% had attended a self-help group. Of self-help attenders who actively participated 55% initiated abstinence within the next month, compared with 40% of non-attenders and 38% of non-participating attenders (P < 0.01). These findings support the potential short-term positive prognostic significance of self-help attendance and participation in cocaine dependent patients.

Alcoholics Anonymous↗
PubMed1996

Latex rubber condoms: predicting and extending shelf life.

Condoms from five manufacturers were subjected to controlled exposures of heat, humidity, and air and to different natural environments in five countries. Under aerobic conditions (condoms in permeable packages or unpackaged), stress properties declined. The relationship between rate of decline as a function of temperature was quadratic. Under oxygen-restricted conditions (foil-wrapped packages) at average storage temperatures of 30 degrees C and lower, strain properties declined with little or no significant change in stress properties. The effect is to cause condoms to become stiffer; high-breakage rates in use have been correlated with product stiffening. A new rationale for accelerated-aging tests to predict condom shelf stability is suggested, including a test to control the trend of condoms to stiffen. Silicone lubricant, impermeable packaging, and inclusion of antioxidants in the condom formulation can prevent or minimize aerobic breakdown of latex condoms. Specifying low-modulus condoms can prevent excessive stiffening.

Air↗
PubMed1996

Forensic psychiatric nursing: visions of social control.

Forensic nursing is a relatively recent, and fast developing, specialization within the wider field of psychiatry. The construction of professional practice at the interface of medical and legal services reflects larger ideological shifts in the management of human difference. Central to this trend is the posited relationship between mental disorder and criminality. The expanding loci of forensic expertise, beyond traditional institutional and health service settings, calls for a critical appraisal of present and proposed provision. Focusing on the British experience, in particular, this paper outlines the historical development of treatment for disordered offenders and explores contemporary initiatives. Deployment of nursing staff in the community, police stations, law courts and prisons, as an adjunct of medicalized crime, confuses further professional care with political control. The main conclusions presented are that the encroachment of psychiatry can be understood in terms of surveillance and social control. It is essential that nurses working in this field are aware of the power/knowledge equation that frames their practice, research and education. The penetration of forensic nursing into realms of society otherwise bereft of psychiatric intervention can be seen to have a darker dimension.

Attitude to Health↗
PubMed1995

To use or to refuse cocaine--the deciding factors.

Two types of narratives were obtained from 35 cocaine-addicted patients: narratives about using cocaine and narratives about not using cocaine. The most prevalent factors in using cocaine were (a) having enough money, (b) wish to end physical/emotional pain, and (c) wish/decision to use. The factors in narratives about not using cocaine were (a) patient arranged conditions to be nonstimulating for using cocaine, (b) recognition of bad consequences, and (c) wish/decision not to use. It is clear in both the cocaine-using episodes and not-using episodes that the patient's wish/decision is important. The conditions for using cocaine tended to be more external, whereas those for not using tended to be more internal. Similar conditions were found by a questionnaire method. A major treatment implication of these findings is that the focus of therapy can be directed to planning strategies to minimize influence of the external factors and to rehearse strategies to prepare for situations involving cues that influence use of cocaine.

Adult↗
PubMed1994

Changes in biliary (high-molecular-mass) and liver isoforms of alkaline phosphatase after baboon-to-human liver transplantation.

We report a case of hyperphosphatasemia in a 35-year-old patient with hepatitis B who underwent an orthotopic xenogeneic liver transplant. Marked increases in total alkaline phosphatase (ALP; EC 3.1.3.1) activity began 5 days posttransplantation (six times human normal) and increased to approximately 17 times normal at day 11. Increased ALP persisted for > 40 days and steadily increased to 75 times normal in the patient's last 30 days. Gel electrophoresis detected both liver (LALP) and biliary (high-molecular-mass, BALP) isoforms. LALP measured with ion-exchange columns revealed an activity time course pattern similar to that of total ALP. Results for BALP activity also obtained with ion-exchange columns exhibited broad variability, ranging from 2 to 428 times normal.

Adult↗
PubMed1993

Maternal behavioural risk factors for severe childhood diarrhoeal disease in Kinshasa, Zaire.

This study examines the relationship between severe diarrhoeal disease and maternal knowledge and behaviours related to hygiene and sanitation. Some 107 paediatric cases admitted to two hospitals in Kinshasa, Zaire in 1988 were matched on age and nearest-neighbour status to 107 controls. Personal interviews and observational methods were used to assess knowledge and behaviours related to hygiene and sanitation. Cases and controls had equivalent socioeconomic status, demographic profiles and access to water and sanitation facilities. However, cases generally exhibited lower levels of knowledge and less sanguine sanitary practices than did controls. Of particular interest was the finding that very specific behavioural items distinguished cases from controls. The disposal of the child faeces and household garbage and mother's knowledge that poor caretaker cleanliness was a cause of diarrhoea in children showed the strongest associations with risk of diarrhoea. There was an exponential relationship between the number of these items a mother answered incorrectly and the odds of diarrhoeal disease. The risk attributable to these three variables was as high as 70%. These findings provide further support for the view that focused educational interventions may have a substantial impact on the occurrence of severe diarrhoeal disease in low-income countries.

Adult↗
PubMed1992

Comparison of two new immobilization collars.

STUDY OBJECTIVE: To evaluate the limitation of movement of four cervical collars, with emphasis on two new extrication collars. DESIGN: Ranges of motion permitted by four extrication collars, measured by two goniometric techniques, were compared. Times required to apply each collar were noted and compared. SETTING: In a laboratory setting, volunteers were asked to flex, extend, laterally bend, and rotate their necks, first without restriction and then with each of the collars applied. TYPE OF PARTICIPANTS: Participants were healthy volunteers who worked either in the Department of Physical Therapy or in the Emergency Department of Tulane Medical Center Hospital. INTERVENTIONS: The collars used were the Nec-Loc Extrication Collar, Philadelphia Collar, Philadelphia Red EM Collar with Immobilizer, and Vacuum Splint Cervical Collar. MEASUREMENTS: Measurements were performed first using the head goniometer and then the hand-held goniometer. Time required for application was measured in seconds. Statistical evaluation was performed using repeated measure analysis of variance and then Newman-Keuls multiple comparison procedure. MAIN RESULTS: The Vacuum Splint Cervical Collar restricted range of motion of the cervical spine most effectively. CONCLUSION: A cervical collar with design characteristics similar to the Vacuum Splint Cervical Collar (ie, a rigid collar that incorporates part of the thorax) will restrict movement of the neck more effectively than shorter, less rigid collars.

Adult↗
PubMed1991

Mediators of bile acid-induced alterations in gastric mucosal blood flow.

The topical application of acidified (pH 1.2) bile acids to acid-peptic-secreting gastric mucosa increases mucosal blood flow, an important protective event because, when it is blunted, gross mucosal injury occurs. The mediators of this response are unknown. The current study examined the potential roles of luminal pH, luminal bile acid concentration, and, indirectly, endogenous prostaglandin generation in groups of dogs prepared with ex vivo chambered wedges of proximal gastric wall. Parameters evaluated included H+ fluxes, mucosal blood flow using radiolabeled microspheres, and the severity of gross mucosal injury induced at high and low intraluminal pH (7 and 1.2), at differing concentrations of bile acid (0, 2.5, 5.0 mM), in the presence of indomethacin pretreatment with or without concomitant close intra-arterial infusion of prostacyclin. The results indicate that topical bile acids increase mucosal blood flow in proportion to their capacity to induce H+ loss. This response is blunted (but not ablated) by indomethacin, resulting in gross mucosal injury, effects that are reversed by prostacyclin infusion. Thus, in large part, endogenous prostaglandins are its likely mediators.

Animals↗
PubMed1990

Merkel cell carcinoma: the clinical course.

Merkel first discovered the cells named after him in the snout skin of voles in 1875. These cells are thought to originate from the neural crest and act as mechanoreceptors. When they have undergone malignant change, the neurosecretory granules in the cytoplasm may release various polypeptides, suggesting that the tumor is an APUDoma. In a computer search of the literature 121 cases were identified. It was revealed that the most common lesion is an erythematous nodule arising in the face or lower limb and occurring predominantly in women in their late 60s. The regional nodes became involved in half the patients, and the three-year survival was approximately 60%. Two unusual cases, in women 72 and 73 years old respectively, with metastasizing lesions that responded to a combination of surgery and radiotherapy are reported, and the literature is discussed.

Aged↗
PubMed1990

Percutaneous automated biopsy in the diagnosis of primary infectious spondylitis.

Three cases of primary infectious spondylitis, two caused by Staphylococcus aureus and one by tuberculosis, were diagnosed using the method previously described for automated percutaneous discectomy. All three patients, in whom biopsy using fine needle techniques previously was unsuccessful, had positive cultures from specimens obtained using the automated method. The method combines the advantages of local anesthesia and minimal morbidity with the obtaining of adequate material for culture and pathological examination.

Adult↗
PubMed1989

Biosynthetic human growth hormone in burned patients: a pilot study.

A 15-day, open trial was conducted in 12 adult burned patients of whom six were randomly allocated to form a control group and six to receive biosynthetic human growth hormone (somatropin). All were fed enterally and treated according to a standard burn protocol. The mean age, burn size, energy and nitrogen intakes were well matched in each group. The resting energy expenditures (REE) were comparable in each group and the REEs exceeded the calculated basal energy expenditures by a mean of 36.8 +/- 4.1 per cent for both groups. Blood urea values were significantly lower in somatropin-treated patients but there was no significant difference in nitrogen balance, protein oxidation or the rate of plasma protein recovery between the two groups. The basal plasma insulin concentration and basal insulinogenic index were significantly higher in somatropin-treated patients but insulin release, in response to injected glucose, was comparable in both groups. All patients had impaired glucose disposal due to insulin resistance but the area under the glucose curve increased significantly during somatropin treatment. It is concluded that somatropin administration did not significantly improve nutrition in burned patients but has been shown to exacerbate the existing insulin resistance.

Adult↗