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Biomedical subjects

M Parker

Publications and source records attributed to M Parker.

At least 235 records · Page 13Linked to original sources

Excessive serum lidocaine levels during maintenance infusions: mechanisms and prevention.

Clinical and pharmacokinetic data were reviewed in 72 patients who developed excessive lidocaine serum levels during maintenance infusions. Fifty-one of the 72 (70%) were cardiac patients who had mean lidocaine excretory clearances less than one half of normal. Forty percent of these became toxic in spite of a reduced infusion rate (30 micrograms/kg/min). Seven patients with normal excretory mechanisms became toxic when they received large doses of lidocaine. The remaining 14 cases lacked an identifiable cause to explain the development of higher than therapeutic serum levels. Inordinately high serum levels of monoethylglycinexylidide (MEGX), an active lidocaine metabolite, were found in seven patients, but in only one was MEGX greater than lidocaine. Prolonged infusions (24 hours or greater) were not clearly associated with the worst lidocaine elimination clearances. Lidocaine toxicity was life-threatening or significantly complicated the management of 15 patients. Based on the data presented, guidelines are offered as an approach to the prevention of toxicity from maintenance lidocaine infusions.

Aged↗

Use of conventional and IgM-specific radioimmunoassays for anti-hepatitis A antibody in an outbreak of hepatitis A.

During a common source outbreak of hepatitis A, we studied the characteristics and utility of commercially available radioimmunoassays for total and IgM-specific antibody to hepatitis A virus. IgM hepatitis A antibody was detectable in all serum specimens obtained up to 119 days following onset from the seven persons with hepatitis A, and as long as 347 days in one person. Acute infection could also be documented by a four-fold or greater increase in titers of hepatitis A antibody, although as long as nine weeks was required between the times acute and convalescent specimens were obtained. The radioimmunoassay for IgM-specific hepatitis A antibody had greater specificity (99 percent versus 84 percent) and a higher positive prediction value (88 percent versus 23 percent) for the diagnosis of acute hepatitis A than did the radioimmunoassy for hepatitis A antibody. Uses of the radioimmunoassay for IgM-specific hepatitis A antibody include rapid diagnosis of acute hepatitis A, differentiation between recent and past hepatitis A infection, and screening for recent hepatitis A infection in epidemiologic investigation.

Adult↗

Phase I trial of Staphylococcus aureus Cowan I immunoperfusion.

Staphylococcus aureus Cowan I has shown antitumor activity in in vitro and in animal tumor models. It is hypothesized that this antineoplastic effect results from the interaction of protein A on the cell surface of Cowan I strain S. aureus and immunosuppressive circulating immune complexes. Therefore, we treated five patients with ex vivo plasma immuno-perfusion over killed and fixed S. aureus Cowan I. Toxic effects were marked in all patients and appeared to be related to the plasma volume infused and rate of infusion. Toxic reactions occurred in the cardiovascular, respiratory, and hematopoietic systems. No responses even minimal or transient, were observed in this phase I trial. This toxicity may be reduced if the rate of plasma infusion decreases.

Adult↗

Fitting images.

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Adolescent↗

Hypothyroidism presenting as muscle stiffness and pseudohypertrophy: Hoffmann's syndrome.

There is a spectrum of muscular abnormalities that occurs in patients with hypothyroidism. Alterations in deep tendon reflexes are commonly observed although more extensive muscle disease is less frequently seen. Two patients who demonstrated increased muscle mass, muscle stiffness with variable degrees of muscle weakness and low levels of serum thyroxine (Hoffmann's syndrome) are described. At the time of presentation, the serum creatinine phosphokinase level was more than 10 times greater than normal, and electromyography revealed repetitive positive waves. After therapy with thyroid hormone, there was complete resolution of the muscle abnormalities, and laboratory studies were performed. In this report, we review the clinical syndrome of muscle dysfunction that can be seen with the more severe forms of hypothyroid myopathy.

Female↗

Intracardiac injections during cardiopulmonary resuscitation. A low-risk procedure.

Fifty-three patients were observed prospectively for the development of complications resulting from 147 intracardiac injections (ICIs) received during cardiopulmonary resuscitation (CPR). Although pericardial effusion was noted in six of 17 echocardiograms and a hemopericardium found in eight of 28 autopsies, cardiac tamponade was not observed. A pneumothorax developed in one patient. None of the autopsies disclosed coronary artery or ventricular lacerations. Percutaneous puncture of the heart during CPR seldom results in serious complications. When other sites are not readily available, ICIs are safe and valid for the administration of emergency medication.

Epinephrine↗

Silent thyrotoxic thyroiditis in association with chronic adrenocortical insufficiency.

A 23-year-old woman had silent thyrotoxic thyroiditis and chronic adrenocortical insufficiency (Addison's disease). Recent evidence suggests that silent thyroiditis is an autoimmune disease characterized by lymphocytic infiltration of the thyroid and by transient hyperthyroidism, followed occasionally by transient hypothyroidism and eventual recovery. This case would seem to expand the spectrum of autoimmune thyroid diseases (Graves' disease, lymphocytic [Hashimoto's] thyroiditis, and hypothyroidism) associated with chronic adrenocortical insufficiency.

Addison Disease↗

Cardiopulmonary manifestations of progressive systemic sclerosis: associations with circulating immune complexes and fluorescent antinuclear antibodies.

Sixteen patients with progressive systemic sclerosis were evaluated for cardiopulmonary manifestations of their disease and for serologic immune abnormalities. Twenty-five percent of patients had abnormal echocardiograms, and 81% had a significant reduction in pulmonary function by spirometry. Circulating immune complexes (IC) were detected in 44% of patients by using a fluorescent Raji cell assay, and these patients were more likely to have an abnormal echocardiogram (P less than 0.02). Seventy-five percent of the patients had fluorescent antinuclear antibodies (FANA) and these patients were more likely to have pulmonary disease (P less than 0.01).

Antibodies, Antinuclear↗

Isolation of Pseudomonas pseudomallei from clay layers at defined depths.

Twelve strains of Pseudomonas pseudomallei were isolated from the soil and water of a sheep paddock over a two-year period. The organism was recovered from the clay layer of the soil profile as well as from water that seeps into this layer during the "wet" season. Five isolates were obtained before the commencement of the "wet" season; environmental factors appear to play an important role in the survival of Ps. pseudomallei during the "dry" season. Lower isolation rates were recorded than those indicated by workers in southeast Asia and Iran.

Animals↗

Chemotherapy of acute bovine anaplasmosis.

The efficacy of a standard tetracycline, imidocarb and a new experimental long-acting tetracycline (T-200) in the treatment of anaplasmosis was examined in 5 groups of 9 nonsplenectomised, adult, 4-year-old, speyed cattle. The efficacy of T-200 was further examined using 9 splenectomised calves. One treatment of imidocarb (3.5 mg/kg) or T-200 (20 mg/kg) or 2 treatments (10 mg/kg) of a standard tetracycline were very effective in controlling the infection in the intact cattle. On inoculation of T-200 (20 mg/kg) controlled infection in 5 splenectomized calves, whereas all 4 untreated control calves died. T-200 did not sterilise either intact or splenectomised cattle.

Acute Disease↗