Biomedical subjects
Publications and source records attributed to C M Smith.
The TDX fluorescence polarization assays (FPIA) for procainamide (PA) and n-acetylprocainamide (NAPA) were evaluated. Coefficients of variation for within- and between-assay precision studies were less than 6%. Both methods correlated well with a referenced HPLC technique; r2 values for PA and NAPA were 0.980 and 0.986, respectively.
A 53-year-old man with chronic back and leg pain developed recurrent painful ecchymoses after lumbar laminectomy. No hematologic abnormality could be detected, but an ecchymosis developed after subcutaneous injection of his blood into the region of pain. A detailed study of the psychological setting of the illness and his personality revealed this to be an example of psychogenic purpura. This is the third report of the syndrome in a male.
This case report describes the presence of numerous intradural spinal and cranial epidermoids and lipomata, as an incidental finding, 14 years after a spinal gunshot injury. The aetiological factors operating in the development of such tumours are discussed with reference to the general literature and to this case.
A 53 year old woman presented with enlargement of a sacral meningocoele and pain in the back and legs. She died from a pulmonary embolus. Fibrosarcoma, apparently arising in the sacral region, involved the leptomeninges and nerve roots as far rostrally as the pons. Nine previously reported cases are discussed.
Nursing literature concerned with epidural anesthesia in obstetrics is scant and does not offer a synopsis of the pharmacology of local anesthetic agents employed in epidural block. A comprehensive review of the pharmacology and clinical uses of the common agents used in obstetrical epidural anesthesia is presented. Implications for nursing care are also described.
The present study examined the influence of activation on platelet deformability. Aspiration of cells after exposure to thrombin, adenosine 5' -diphosphate, or the calcium ionophore A23187 at concentrations producing shape change and stickiness revealed significant changes from control cells. At the lowest negative pressure, 4 X 10(-2) dynes/cm (-1 cm H2O), there were no differences in lengths of membrane segments aspirated from control and activated platelets. Each subsequent increase in negative pressure up to 35 X 10(-2) dynes/cm (-7.5 cm H2O) resulted in significantly longer aspirated segments on activated cells compared to control cells. Greater negative pressures did not cause further increases in lengths of membrane segments drawn into the pipette. Thus, activation, which results in constriction of the circumferential microtubule, makes more membrane available for aspiration as negative pressure is increased. In both control and activated platelets, the microtubule coils served as a barrier to further lengthening of aspirated membrane segments as negative pressure was increased beyond 35 X 10(-2) dynes (-7.5 cm H2O).
The present investigation has evaluated the influence of aspirin, its constituents, and other nonsteroidal anti-inflammatory agents on the resistance of human platelets to aspiration into micropipettes. Aspirin increased the length of platelet extensions into the micropipette over the entire negative tension range of 0.04 to 0.40 dynes/cm after exposure to the drug in vitro or after ingestion of the agent. Other cyclooxygenase inhibitors, ibuprofen and indomethacin, did not increase platelet deformability. The influence of aspirin was mimicked to some degree by high concentrations of salicylic acid, but acetylation of platelets with acetic anhydride had little influence on platelet deformability. Incubation of platelets with both salicylic acid and acetic anhydride had no more effect than salicylic acid alone. Benzoic acid, chemically similar to salicylic acid, had a minimal effect. The studies demonstrate that aspirin makes platelets more deformable, while components of the drug or other nonsteroidal antiinflammatory agents and cyclooxygenase inhibitors do not have the same influence on resistance to deformation.
There has been some controversy regarding the mechanism whereby exercise can provoke an attack of asthma. It is generally agreed that heat and water are lost from the respiratory tract in bringing the air inspired to body conditions. During strenuous exercise, there is a marked increase in ventilation rate and some of the burden to heat and humidify the inspired air is transferred to the intrathoracic airways. The net effect of the air conditioning process is to cool and dehydrate these airways. There have been two hypotheses put forward to account for the mechanism whereby these events lead to exercise-induced asthma (EIA). One hypothesis proposes that cooling of the airways followed by rapid rewarming, at the end of exercise, leads to a reactive hyperemia and edema of the bronchial vascular bed "which if sufficiently severe results in the airway obstruction of EIA." The other hypothesis proposes that the rate of loss of water from the periciliary fluid during exercise exceeds the rate of return and, as a result, there is an increase in ion concentration and subsequent hyperosmolarity of the periciliary fluid. Thus the events related to drying rather than cooling are the stimulus to EIA. This paper presents the case against rapid rewarming of the bronchial vasculature as the stimulus to EIA and puts forward an argument and data in support of the case for airway drying and an increase in osmolarity being the critical event which determines the presence and severity of EIA.
Forty-one children were identified with autoimmune neutropenia of infancy and early childhood (absolute neutrophil count [ANC] less than 500/microliters and demonstrable serum antineutrophil antibodies). There were 21 boys and 20 girls; the median age at diagnosis was 11 months (range 5-38 months). No life-threatening infections occurred. There was a gradual upward trend in ANC in all patients over many months, with 87% having an ANC > 1000/microliters by 24 months from diagnosis. Among various clinical and laboratory parameters analyzed statistically, only younger age at diagnosis was associated with earlier neutrophil recovery. There was no association between degree or duration of neutropenia and sex, race, antibody reactivity, or presence of serious illness at diagnosis.
Darifenacin, (S)-2-[1-[2,3-dihydrobenzofuran-5-yl]-3- pyrrolidinyl]-2,2-diphenylacetamide, is a novel muscarinic M3 antagonist. In this study we have compared the binding of [3H]-darifenacin to the five cloned human muscarinic receptors (m1-m5) expressed in CHO cells. [3H]-darifenacin binds with 6 fold higher affinity to m3 (KD = 0.33 nmol/l) over m1 (KD = 1.6 nmol/l) receptors. There was no specific binding of [3H]-darifenacin to m2 receptors and specific binding to m4 and m5 receptors was insufficient to determine a KD. Binding of [3H]-darifenacin to m1 and m3 was displaced by atropine (m1 pKi = 9.36, m3 pKi = 9.4), 4-DAMP (m1 pKi = 9.04, m3 pKi = 9.19), pirenzepine (m1 pKi = 8.63, m3 pKi = 6.85), methoctramine (m1 pKi = 7.28, m3 pKi = 6.63), and darifenacin (m1 pKi = 8.36, m3 pKi = 9.14), demonstrating that [3H]-darifenacin represents the first selective m3 radioligand.
BACKGROUND: Ophthalmic examinations performed in infants undergoing extracorporeal membrane oxygenation (ECMO) are recommended because ocular abnormalities have been known to occur after this procedure. METHODS: We reviewed medical records of infants treated with ECMO was subsequently underwent routine ophthalmic examination prior to or immediately after hospital discharge. Examinations were performed in a fashion similar to that for retinopathy of prematurity screening. RESULTS: Eye examinations were recorded for 171 patients (342 eyes). Fundus examination was normal in 302 eyes (88%). Abnormal retinovascular findings such as venous dilation or intraretinal hemorrhages, when present, were not considered vision threatening and required no treatment. CONCLUSION: Clinically important retinal findings were not identified in our patients undergoing postECMO screening. Routine dilated fundus examination is probably not cost effective and places additional and potentially unnecessary stress on these infants.
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Survival, infection, and rejection rates and functional data are reported in 35 lung recipients treated with triple-drug immunosuppression without antilymphocytic antibody therapy. Early mortality (less than 60 days) was 6%. Thirty recipients (86%) are alive, with a mean follow-up period of 16 months (range, 1 to 36 months). Actuarial survival was 91% at 1 year and 83% at 2 years. Thirty-seven infections occurred in 24 patients. Actuarial freedom from infection was 61% at 3 months and 27% at 1 year. Only one patient died of infection (aspergillosis). Thirty-six episodes of acute rejection were treated in 23 patients. Time to first rejection was 14 +/- 7.8 days. Actuarial freedom from acute rejection was 36% at 2 months. Significant functional improvement was evident in all operative survivors. Pulmonary function and exercise performance data in patients without bronchiolitis obliterans remain stable 1 year after transplantation. We conclude that the use of triple-drug immunosuppression without antilymphocytic antibody preparations in lung transplantation provides effective immunosuppression with a low risk of serious infectious complications.
We studied the efficacy and feasibility of using computer-based instruction to provide medication information to hospitalized patients with acute psychotic conditions. Patients were randomly assigned to receive computer-based (n = 21) or personal instruction (n = 21); for the final analyses the computer group was expanded to include 13 patients from a pilot study. Outcome measures were knowledge retention (indicated by changes in test scores) and compliance with medication regimens after discharge (indicated by telephone follow-up at one week, one month, and three months). The subjects reacted positively to the computer program. Knowledge retention and compliance were similar in the computer and control groups. We conclude that psychiatric inpatients admitted for acute care can participate in, and learn from, computerized medication instruction.