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Biomedical subjects

J L Cobb

Publications and source records attributed to J L Cobb.

68 records · Page 4Linked to original sources
PubMed1970

An ultrastructural and histochemical study of the short-term effects of 6-hydroxydopamine on adrenergic nerves in the domestic fowl.

1. The effects of 6-hydroxydopamine (6-OHDA) on adrenergic nerves in the domestic fowl have been investigated with ultrastructural and fluorescence histochemical methods.2. 6-OHDA depletes the nerves of catecholamine, initially by displacing it from the storage vesicles. 6-OHDA enters large as well as small vesicles, indicating that large granular vesicles in adrenergic nerves are sites of amine storage.3. Doses of 6-OHDA, insufficient to cause degeneration, still cause loading of the vesicles.4. The effects of various drugs on the action of 6-OHDA indicate that this drug must be taken up by the nerves and reach a critical extragranular axoplasmic concentration before degeneration will occur; 6-OHDA bound in the vesicles plays no part in the degenerative process.

Amphetamine↗
PubMed1969

A study of nexuses in visceral smooth muscle.

Nexuses are described between the smooth muscle cells of the gizzard of the chick and the pigeon, the vas deferens of the mouse and the guinea pig, and the taenia coli of the guinea pig. The nexuses in the gizzard were examined after osmium tetroxide and potassium permanganate had been used as fixatives. Although differences in the dimensions of the unit membranes and the nexuses were noted, the results with the two fixation techniques were complementary. The distribution of nexuses within the smooth muscle tissues examined was uneven. Nexuses were still present in both small and large pieces of tissue incubated in hypertonic solutions at varying temperatures. Other experiments showed that the degree of contraction at the time of fixation did not affect the presence of nexuses in the tissue. These results indicate that nexuses between smooth muscle cells are stable under a variety of conditions.

Animals↗
PubMedDate not supplied

Delirium in patients with cancer at the end of life.

PURPOSE: Delirium is a common and distressing syndrome seen in patients with advanced cancer. Behavioral manifestations of delirium, such as agitation, may result in medical intervention, stress to family caregivers, and inpatient hospice admission. The purpose of this study was to examine the frequency, characteristics, and presumed causes of delirium in patients with advanced cancer. DESCRIPTION OF STUDY: Records of all patients with cancer who were admitted to an inpatient hospice facility in 1995 were reviewed retrospectively (N = 210). Patients were classified as delirious based on the clinical judgment of the admitting physician. RESULTS: Delirium was the third most common reason for admission (20%). Male gender (P = .04) and the presence of a primary or metastatic brain tumor (P = .03) were significant risk factors for delirium, while advanced age and primary or metastatic liver, lung, or bone cancer were not. Resolution of the agitation, the most disruptive symptom of delirium, occurred in 69% of patients before death or discharge. CLINICAL IMPLICATIONS: Delirium is common in hospice patients with cancer and is an important cause of family distress and increased cost of care. The recognition of early clinical signs and predisposing factors should facilitate prompt diagnosis. Appropriate intervention is usually successful in alleviating the most distressing symptoms of delirium.

Adult↗