Neutrophil response to endotoxin in the adult respiratory distress syndrome: role of CD14.

The role of both endotoxin and neutrophils in the development of acute lung injury continues to be debated. We hypothesized that early in the course of the development of the adult respiratory distress syndrome (ARDS) circulating neutrophils could be primed by endotoxin and that subsequent stimulated responses could be enhanced. Accordingly, neutrophils were isolated from patients at risk for and with ARDS. Unstimulated neutrophils from these patients neither produced nor were primed for superoxide production. Whereas phorbol myristate acetate-stimulated superoxide production was preserved, indicating that the cells were capable of a response, patient neutrophils produced less superoxide than did cells from normal subjects when primed with endotoxin (lipopolysaccharide [LPS]) and stimulated with formyl-methionyl-leucine-phenylalanine (FMLP), suggesting that there was a defect in the signal transduction mechanism for LPS. This was confirmed by the finding that patient neutrophils also had both decreased baseline CD14 expression and less CD14 upregulation after LPS stimulation compared with neutrophils from normal subjects. The mechanisms that could account for the decreased CD14 expression were studied in vitro. Neutrophils from normal subjects both upregulate CD14 in response to LPS and shed CD14 over time, suggesting that in patients CD14 receptors could have been previously upregulated and shed. In addition, there is an association between CD14 expression and retention such that normal LPS-stimulated neutrophils which are not retained in a filtration system have decreased CD14 expression. Thus, in patients, those PMN most responsive to LPS could be preferentially sequestered and not available in the circulation for study.

Tremor.

Tremor is a rhythmic, involuntary muscular contraction with consistency of rate, amplitude and pattern. It is the most common of all involuntary movements. Several systems for classifying tremor exist with the most frequent system classed according to behavioral context, ie, resting, postural and action. Clinical recognition of tremor type is extremely important as type determines prognosis, treatment and need for genetic counseling. The most common forms are parkinsonian, physiological, cerebellar intention and essential tremor. Essential or hereditary tremor is the most common of all neurologic conditions with 3-4 million Americans affected. Nursing implications of caring for essential tremor patients are presented.

A double-blind trial of isoniazid for essential tremor and other action tremors.

We conducted a double-blind trial of isoniazid in 11 patients with essential tremor and four patients with other types of postural action tremor. The tremor had not been helped by beta-blockers or primidone. Isoniazid was given in doses up to 1,200 mg daily, together with 100 mg pyridoxine, for four weeks. Results were assessed with subjective and objective scales. Only two patients with essential tremor appeared to benefit enough to continue the drug after the trial, and only one has benefited from its long-term use. Isoniazid may be useful in rare cases of essential tremor, but must be monitored carefully because of its toxicity.

T-cell proliferation involving the CD28 pathway is associated with cyclosporine-resistant interleukin 2 gene expression.

CD28 is a homodimeric glycoprotein expressed on the surface of a major subset of human T cells that has recently been identified as a member of the immunoglobulin supergene family. The binding of monoclonal antibodies to the CD28 antigen on purified T cells does not result in proliferation; however, previous studies have shown that the combination of CD28 stimulation and protein kinase C activation by phorbol myristate acetate (PMA) results in T-cell proliferation that is independent of both accessory cells and activation of the T-cell receptor-CD3 complex. In the present study, effects of stimulation by anti-CD28 on cell cycle progression and on the interleukin 2 (IL-2) and IL-2 receptor system have been investigated on primary cultures of purified peripheral-blood CD28+ T cells. There was no measurable effect on cell size or on DNA synthesis after stimulation of resting (G0) cells by CD28 alone. After 3 h of activation of T cells by PMA alone, a slight (8%) increase in cell volume occurred that did not progress to DNA synthesis. In contrast, T-cell stimulation by CD28 in combination with PMA resulted in a progressive increase in cell volume in approximately 100% of cells at 12 to 14 h after stimulation. Northern blot (RNA blot) analysis revealed that CD28 stimulation alone failed to cause expression of the alpha chain of the IL-2 receptor or of IL-2 mRNA, and in accord with previous studies, stimulation by PMA alone resulted in the accumulation of IL-2 receptor transcripts but no detectable IL-2 mRNA. In contrast, T-cell stimulation by the combination of CD28 and PMA resulted in the appearance of IL-2 transcripts and enhanced expression of IL-2 receptor mRNA. Functional studies revealed that the proliferation induced by CD28 and PMA stimulation was entirely resistant to cyclosporine, in contrast to T-cell activation induced by the CD3-T-cell receptor complex. Cyclosporine was found not to affect the accumulation of IL-2 mRNA after CD28 plus PMA stimulation, although there was no detectable IL-2 mRNA after stimulation by CD3 in the presence of the drug. Furthermore, stimulation by CD28 in combination with immobilized CD3 antibodies caused a striking enhancement of IL-2 mRNA expression that was, in part, resistant to the effects of cyclosporine. These studies indicate that the CD28 molecule synergizes with protein kinase C activation to induce IL-2 gene expression and demonstrate that stimulation by the CD28 pathway can cause vigorous T-cell proliferation even in the presence of cyclosporine and that cyclosporine does not prevent transcription of 16-2 mRNA, as has been suggested previously. Moreover, these findings suggest that a potential role for the CD28 molecule in vivo may be to augment IL-2 production after stimulation of the CD3-T-cell receptor molecular complex and thereby to amplify an antigen-specific immune response. Finally, these results provide further evidence that the CD28 molecule triggers T-cell proliferation in a manner that differs biochemically from CD3-T-cell receptor-induced proliferation.

Cerebral mapping of apraxia in Alzheimer's disease by positron emission tomography.

The ability to mimic skilled movements or to pantomime them in response to spoken command was compared with psychometric performance and with regional glucose utilization as estimated by [18F]fluorodeoxyglucose positron emission tomography in 17 right-handed patients with Alzheimer's disease and 6 age-matched normal subjects. Apraxia scores, both on tests to command and to imitation, were significantly lower in the Alzheimer patients. Imitation scores correlated best with performance on tests of visual--spatial ability and with cortical metabolism in the right parietal lobe; command scores related most closely with the results of tests reflecting verbal proficiency and with cortical metabolism in the left inferior hemisphere, especially frontally. Apraxia to command and imitation may thus reflect neuronal dysfunction in distinct cerebral regions in patients with Alzheimer's disease.

Treatment of resting tremor by beta-adrenergic blockade.

The effect of nadolol, a peripherally acting beta-adrenergic blocker, on resting tremor was examined in eight patients with idiopathic Parkinson's disease. With the use of a double-blind, placebo-controlled study of crossover design, patients received 80 to 320 mg of nadolol for 6 weeks while continuing their previous treatment regimen. Accelerometer readings showed a progressive reduction in tremor amplitude, but no change in tremor frequency, with increasing nadolol dosage. Maximum benefit was achieved at 240 mg, when resting tremor improved 50% (p less than 0.01). Physician ratings confirmed these findings. The results suggest that response to beta-adrenergic blockade may not be limited to postural or intention tremor and that such agents may not reliably differentiate between the tremor of Parkinson's disease and essential tremor.

Peripheral beta-adrenergic blockade treatment of parkinsonian tremor.

The effect of nadolol, a peripherally acting beta-adrenergic blocker, on resting, postural, and intention tremor was examined in 8 patients with idiopathic Parkinson's disease whose motor symptoms, other than tremor, were well controlled with conventional medications. In a double-blind, placebo-controlled, crossover design, patients received 80 to 320 mg of nadolol for six weeks while continuing their previous therapeutic regimen. Accelerometer readings showed a 34% reduction (p less than 0.025) in tremor distance, but no change in tremor frequency, during nadolol therapy. Maximum benefit was achieved with a dose of 240 mg, when resting tremor improved 54%, postural tremor 32%, and intention tremor 54%. Physician ratings and patient reports supported the accelerometer results. Nadolol appears to be a safe, effective adjunct to current dopaminergic and anticholinergic therapy for severe tremor in Parkinson's disease.

Amyotrophic lateral sclerosis. No increase among US construction workers in Guam.

The rate of amyotrophic lateral sclerosis (ALS) among stateside construction workers on Guam was similar to that of US resident white men. Of 12,601 men who worked on Guam for one year or more from 1945 to 1954, we were able to follow up 10,049 until 1970 through the Social Security Administration. Of these workers, 1,958 had died, and the cause of death was recorded for all but 335. There were three deaths from ALS. Residence on Guam as an adult did not predispose to a high rate of ALS.

Childhood polymyositis: a case-control study.

A case-control epidemiologic study of childhood polymyositis is presented. Parents of 42 cases of childhood polymyositis were interviewed along with parents of controls matched for sex and age. Extensive review of past medical history, animal exposure history, residential and family history, and immunization history failed to reveal any significant differences between the two groups. The only suggestive difference was exposure to bacteriologically confirmed streptococcal diseases in 20 cases as compared to 13 controls.

Bromocriptine and levodopa (with or without carbidopa) in parkinsonism.

Bromocriptine, a dopamine receptor agonist, was administered to 20 patients with idiopathic parkinsonism taking levodopa (L-dopa) or "Sinemet" (levodopa combined with carbidopa in a 10/1 ratio) at optimum doses. In a double-blind randomised cross-over study lasting 6 months, the addition of bromocriptine (mean daily dose 79 mg) led to a significant (P less than 0.01) 74% reduction in the dose of sinemet and levodopa. "Total disability score" showed a significant (P less than 0.01) improvement at both low and high doses of bromocriptine. Tremor improved 50% (P less than 0.01), with significant improvements in gait, posture, writing, balance, rigidity, finger dexterity, and drooling. Adverse reactions were similar to those observed with sinemet and levodopa. Although both the cause and the cure of idiopathic parkinsonism remain elusive, bromocriptine appears to represent a therapeutic advance.