Biomedical subjects

R S Allen

Publications and source records attributed to R S Allen.

14 recordsLinked to original sources

PubMed1990

Geriatric sleep apnea syndrome: a preliminary description.

We compared 8 patients diagnosed with geriatric sleep apnea syndrome (GSAS) with 12 healthy older controls (GCON) matched on age, sex, weight, education, and socioeconomic standing. GSAS was diagnosed if patients had an apnea + hypopnea index (AHI) greater than or equal to 10 and an impairment involving at least two of the following: hypertension, cardiac arrhythmias, or daytime hypersomnolence. In addition to significant differences on selection variables (e.g., AHI, frequency of hypertension, Multiple Sleep Latency Test), GSAS patients had significantly more sleep disturbance, were sleepier on subjective measures, were more depressed, and had lower scores on tests of nonverbal problem solving and nonverbal memory. Thus, GSAS resembles SAS described in middle-aged populations. More research is needed to determine the most efficient diagnostic parameters for identifying pathological levels of SDB in older persons.

Aged↗

PubMed1989

Elevation of plasma neuropeptide Y levels in congestive heart failure.

PURPOSE: Our objectives were to assess whether plasma neuropeptide Y (NPY) levels are elevated in patients with congestive heart failure (CHF) and whether or not NPY levels can serve as a reliable indicator of sympathetic activity in CHF. PATIENTS AND METHODS: Plasma levels of the sympathetic neurotransmitters norepinephrine and epinephrine and of the sympathetic co-transmitter NPY were measured in 17 patients with CHF and 14 healthy control subjects at rest and after maximal exercise. RESULTS: Under resting conditions, plasma NPY and norepinephrine levels were elevated in patients with CHF compared with control subjects (551 +/- 48 pg/ml versus 311 +/- 22 pg/ml, p less than or equal to 0.001 for NPY, and 306 +/- 73 pg/ml versus 124 +/- 22 pg/ml, p less than or equal to 0.02 for norepinephrine). Plasma NPY correlated better with plasma norepinephrine than with epinephrine, indicating its origin from sympathetic nerve terminals. Acute stimulation of sympathetic activity by dynamic exercise increased plasma norepinephrine levels in control subjects and patients with CHF, but did not significantly alter the mean plasma NPY value in the latter group. CONCLUSION: NPY may play a role in the pathophysiology of CHF.

Adult↗

PubMed1989

Sleep-disordered breathing in healthy aged persons: one-year follow-up of daytime sequelae.

We studied the waking medical, sleep, and psychological status of 28 healthy older persons who had undergone nocturnal polysomnography and daytime assessment approximately 1-year earlier. In a previous report based on this sample, we found that sleep-disordered breathing (SDB) indices were not related to concurrent measurements of daytime functioning. However, in the present study, we observed relationships between the original SDB indices and several measures of cardiopulmonary functioning obtained 1 year later. At follow-up, subjects with originally high levels of SDB had significantly higher systolic blood pressure and poorer pulmonary function test results, were more likely to report irregular heartbeats in the previous year, and had experienced more disruptive snoring than the remaining subjects. When combined with other recent data, these results raise the possibility that SDB exerts an insidious pathological influence on the health and daytime functioning of otherwise healthy older persons.

Aged↗

PubMed1987

Pseudopseudotumor cerebri: meningeal carcinomatosis presenting as benign intracranial hypertension.

We have described a 63-year-old man, taking diethylstilbestrol for adenocarcinoma of the prostate, who had papilledema. Lumbar puncture revealed intracranial hypertension without pleiocytosis. CT scan was normal, consistent with the diagnosis of pseudotumor cerebri. At craniotomy for placement of a ventriculoperitoneal shunt, the dura was found to be infiltrated with adenocarcinoma. In patients with known malignancy and elevated intracranial pressure, lumbar puncture and CT scan alone are not enough to rule out meningeal carcinomatosis; repeated lumbar puncture or cervical cisternal puncture may be necessary to document malignant cytology.

Adenocarcinoma↗

PubMed1977

Failure of T cells specific for strong histocompatibility antigens to cooperate with B cells for a humoral response.

Thymus-derived lymphocytes (T cells) selected for reactivity to strong histocompatibility antigens over a period of one to twelve months in vitro were tested for their ability to cooperate with bone marrow-derived lymphocytes (B cells) for a humoral response. If cultured with normal syngeneic or allogeneic spleen cells and sheep erythrocytes (SRBC) as immunogen, inhibition of the anti-SRBC response was observed. Similarly, in T cell-free spleen cells the alloreactive T cells did not stimulate a humoral response, indicating that they cannot exert cooperative activity on B cells. Since it was possible that the alloreactive T cells may cooperate with B cells in a humoral response to immunogens carrying histocompatibility antigens, hapten-coupled tumor cells were also used as immunogen. Though it is demonstrated that the alloreactive T cells do recognize the tumor cell immunogen, no stimulation of the B cells for a humoral response against the tumor cell is observed. This result, as well as the finding that the antigenic requirements for T helper cell priming and cell proliferation of the alloreactive T cells are different, suggests that these alloreactive T cells and helper T cells belong to different T cell subsets.

Animals↗

PubMed1976