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Biomedical subjects

W Mason

Publications and source records attributed to W Mason.

50 records · Page 3Linked to original sources
PubMed1985

Sleep apnea and periodic movements in an aging sample.

Individuals 65 years of age and older were randomly selected, from a primarily white upper-class population, to participate in a study of sleep disorders in elderly adults. One hundred forty-five volunteers had a brief telephone interview, a home interview, and a portable sleep recording using the Medilog and Respitrace systems. By research classifications, we found that 18% of the elderly participants had sleep apnea (apnea index greater than 5), 34% had periodic movements in sleep (myoclonus index greater than 5) (PMS), and 10% had both sleep apnea and PMS. These were not clinical diagnoses. The home recording indicated that the individuals with PMS slept significantly less than other older adults.

Age Factors↗
PubMed1981

Comparisons of home sleep recordings and polysomnograms in older adults with sleep disorders.

A major problem with studying the prevalence of sleep disorders is the high cost. We tested a portable home recording system which can decrease the cost of screening sleep recordings. Twenty-four senior volunteers and 12 patients referred to our sleep disorders clinic were studied for two nights. On one night, recordings were done in the laboratory with a traditional polysomnogram and the portable home recorder. On another night, portable home recorders were used in the subjects' homes. Of 36 subjects, 42% had sleep apnea and 39% had nocturnal myoclonus. Intermethod correlations were highly significant for sleep apnea index, nocturnal myoclonus index, total sleep period (TSP), total sleep time (TST), and wake time after sleep onset (WASO). The portable home recorder detected sleep apnea on 100% of nights during which sleep apnea was diagnosed by polysomnogram. The labor-saving and cost-saving benefits of home recordings as well as the increased comfort, privacy, and convenience will make the portable home recording the preferred method for many research and clinical applications.

Aged↗
PubMed1981

Sleep apnea and nocturnal myoclonus in a senior population.

Studies have suggested that sleep apnea is especially prevalent among seniors. We recruited and recorded senior volunteers who reported symptoms raising suspicion of sleep apnea or nocturnal myoclonus. Of 24 subjects, 62.5% had one of these disorders-six had sleep apnea alone, three had sleep apnea and nocturnal myoclonus, ans six had nocturnal myoclonus alone. Sleep stages were also analyzed. Subjects with sleep apnea and/or nocturnal myoclonus had significantly less rapid eye movement sleep, significantly more stage 1 sleep, and significantly more awakenings than other subjects. This sample suggests that the prevalence of sleep apnea and nocturnal myoclonus may be very substantial among seniors. Because of this high prevalence, extreme caution is needed in prescribing hypnotics for older patients with sleep complaints, since most hypnotics are respiratory depressants. We must rethink our approach to treating sleep disorders in the older population.

Aged↗
PubMed1981

Virus-coded DNA endonuclease from avian retrovirus.

Reverse transcriptase from avian retrovirus has a physically associated DNA endonuclease with novel substrate and cofactor requirements. A similar endonuclease activity copurifies with pp32, a protein from viral cores that has been identified with the non-alpha region of the beta subunit of reverse transcriptase. Several temperature-sensitive mutants of avian retrovirus with thermolabile DNA polymerase were tested for thermal sensitivity of their DNA endonuclease activity. Two pol mutants of Rous sarcoma virus, ts335 and ts337, had thermolabile DNA endonuclease; a temperature-resistant revertant of ts335 had a heat-stable DNA endonuclease. DNA endonuclease is therefore a product of the pol gene and an integral part of the reverse transcriptase. A second class of pol mutants, typified by ts568 and ts553, had thermolabile DNA polymerase, but heat-stable DNA endonuclease.

Avian Leukosis Virus↗
PubMed1979

Meningococcal sepsis with endophthalmitis.

Endophthalmitis is a rare complication of meningococcemia. A child had endophthalmitis as the initially occurring complaint. Although both eyes appeared inflamed, the pupil in the right eye was fixed and dilated, the fundus could not be seen, and a hypopyon was seen in the right anterior chamber. There was gradual improvement when the child received antibiotic therapy. Since the introduction of antimicrobial drugs, endophthalmitis has rarely been observed as a complication of meningococcal disease. However, this report is evidence that meningococcemia may occur with unusual sites of local infection.

Child, Preschool↗
PubMed1979

The effect of some general anaesthetics on the surface potential of lipid monolayers.

1 This study sought to investigate the report by Ginsberg (1978) that 0.7 M ethanol brought about a + 100 mV change (DeltaDeltaV) in the surface potential of glyceryl monooleate (GMO) monolayers formed on KCl, although he predicted that a DeltaDeltaV of -10 mV should have been found.2 The effect of general anaesthetics such as n-alkyl alcohols and pentobarbitone on surface potential (DeltaV) and surface tension (gamma) of lipid monolayers formed on 145 mM KCl from either glyceryl monooleate (GMO) or phosphatidyl choline (PC) was examined with an Americium-241 air electrode assembly (DeltaV) and a platinized platinum dipping plate and force balance (gamma).3 It was found that, as predicted by Ginsberg (1978), addition of 0.7 M ethanol to the aqueous phase bathing either PC or GMO monolayers brings about a negative-going change in interfacial potential (DeltaDeltaV).4 The magnitude of DeltaDeltaV is dependent in a linear fashion on ethanol concentration.5 Longer chain length alcohols up to n-decanol also bring about a negative going change in DeltaDeltaV, and the dependence of DeltaDeltaV on anaesthetic activity, with respect to increasing chain length of anaesthetic, is consistent with Traube's law.6 Pentobarbitone added to the aqueous phase bathing the monolayer also elicits a negative DeltaDeltaV, a finding which rules out the possibility of adsorption of the volatile alcohols to the measuring electrode.7 The findings are discussed in terms of the proposition that increasing disorder in an array of fixed dipoles, such as might occur in a bilayer exposed to anaesthetic, would result in a lowering of the electrostatic barrier to the predominantly impermeable cation.

Anesthetics↗
PubMed1976

Necrotizing fasciitis in narcotic addicts.

In its early stages necrotizing fasciitis may mimic an uncomplicated cellulitis, with erythema and only mild swelling and minimal pain. The combination of physical findings in a patient with a current history of drug addiction should arouse suspicion of an underlying fasciitis. An aggressive diagnostic approach including incisional biopsy, visual inspection of the underlying subcutaneous tissue, fasica and muscle, along with a Gram stain is suggested. Extensive and frequent debridement, appropriate antibiotics and physical therapy remain the essentials of treatment. A patient is discussed in whom a delay in diagnosis lead to near-fatal sepsis.

Anti-Bacterial Agents↗
PubMedDate not supplied

Evaluation of sleep disordered breathing with unattended recording: the Nightwatch System.

There is a need for studies to determine how new ambulatory systems compare to traditional polysomnography (PSG). Thirty-four subjects were recorded with the Nightwatch (NW) System (Heathdyne Inc.) at home and then recorded with PSG in the laboratory. NW records were scored automatically using the NW algorithm with manual editing. There were no significant differences in mean RDI, AI, number of apneas or hypopneas or oximetry varibles between the systems. Correlations of RDI on the Nightwatch system and laboratory nights were significant (r = 0.63). Every case of RDI > or = 10 on the PSG was also identified by Nightwatch. Specificity was lower on Nightwatch (66%); however, all three cases of false positives could be explained physiologically, i.e. by body position. Overall the NW system correlated well with traditional PSG for respiratory disturbance.

Algorithms↗