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Biomedical subjects

R McAllister

Publications and source records attributed to R McAllister.

13 recordsLinked to original sources
PubMed1994

Muscarinic receptor M1 and M2 subtypes in the human eye: QNB, pirenzipine, oxotremorine, and AFDX-116 in vitro autoradiography.

Muscarinic cholinergic agents are used to lower intraocular pressure in the medical management of glaucoma and subtypes of muscarinic receptors have now been recognised in many tissues including the eye. To localise muscarinic receptors and their M1 and M2 subtypes in the human eye, in vitro ligand binding and autoradiographic techniques with densitometric quantitation on postmortem eye sections were used. As ligands, [3H] quinuclydinyl benzylate (QNB) (non-subtype specific muscarinic antagonist), [3H]pirenzipine (M1 antagonist), [3H]oxotremorine (M2 muscarinic agonist), [3H]AFDX-116(11[(2[diethylaminomethyl]1-piperidinyl)acetyl]5 , 11dihydro-6H-pyrido [2,3b][1,4]benzodiazepine-6-one) (M2 antagonist) were studied. Specific binding sites for QNB, pirenzipine, and AFDX-116 were localised in the entire ciliary muscle, the iris, and ciliary epithelium. [3H]oxotremorine localised only in the longitudinal portion of the ciliary muscle, and additionally, was not localised in the iris or ciliary epithelium. These results suggest that oxotremorine, by binding selectively to receptors on the longitudinal ciliary muscle and inducing its contraction, may modulate outflow facility independently from accommodation and miosis.

Adult↗
PubMed1994

Serial MRI of the brain in asymptomatic patients infected with HIV: results from the UCMSM/Medical Research Council neurology cohort.

Seventy-six homosexual or bisexual men underwent two cranial MRI studies at a mean interval of 13 months; 23 were HIV seronegative, 41 seropositive but asymptomatic (Center for Disease Control (CDC) groups II/III), and 12 had AIDS related complex (ARC)/AIDS (CDC group IV). Agreement between two neuroradiologists was rated as very good for assessment of enlargement of ventricles and good for widening of cerebral sulci and the presence of focal lesions. For assessment of serial studies, the agreement was moderate. The prevalence of cerebral atrophy and focal white matter lesions was no higher in the asymptomatic patients (CDC group II/III) than in appropriate seronegative controls. Some patients with ARC/AIDS showed evidence of developing cerebral atrophy during the study period when serial scans were compared. The imaging evidence supports the other data obtained from this cohort, which suggest that no significant CNS involvement occurs in HIV infection before the development of ARC/AIDS.

Adult↗
PubMed1994

Localization of M3 muscarinic receptor subtype and mRNA in the human eye.

Cholinergic agents used to lower intraocular pressure in the medical management of glaucoma act on muscarinic receptors in the eye. Recently, subtypes of muscarinic receptors have been recognized in many tissues including the eye. To localize the M3 muscarinic receptor subtype and m3 messenger RNA (mRNA) in the human eye, we used in vitro ligand binding and in situ hybridization techniques on post-mortem sections. We used an M3 antagonist, [3H]-4-DAMP ([3H]-4-diphenylacetoxy-N-methylpiperidine methiodide) to identify M3-binding sites and a [35S]-labelled oligonucleotide probe to detect and localize m3 mRNA. M3 and m3 mRNA were both localized in the ciliary muscle, ciliary epithelium, iris, corneal epithelium and anterior lens epithelium. The m3 transcript was also detected in the trabecular meshwork and corneal endothelium.

Acetylcholine↗
PubMed1994

Self-esteem, body-image and weight in noneating-disordered women.

The self-esteem of 69 women attending weight-loss centres was examined in relation to attitudes towards body and weight, actual weight, number of diets undergone and weight fluctuations. Rosenberg's Self-esteem Scale was used to measure self-esteem. Attitudes towards the body and weight were assessed using Freedman's Body-Love Questionnaire. The Body Mass Index was used as a weight-range classification for the women. Body image was assessed using the silhouette chart of Bell, Kirkpatrick, and Rinn. Women with stable weight had the highest self-esteem. The number of diets undertaken was associated with lowered self-esteem. High scores on evaluation of appearance were positively correlated with scores on self-esteem. No association was found between self-esteem and either eating restraint or significant others' attitudes. There was good agreement between the women's perceptions of their own bodies and independent raters' perceptions indicating a lack of body-image distortion for this non-eating-disordered group.

Adult↗
PubMed1993

Mood and psychiatric disturbance in HIV and AIDS: changes over time.

A sample of 26 HIV seronegative, 59 HIV seropositive asymptomatic and 7 HIV seropositive symptomatic homosexual and bisexual men were assessed over two visits, a mean of 11 months apart, using the BDI, STAI, and CIS. Significant differences emerged between the symptomatic group and the other two groups. Past psychiatric history and the somatic items in the assessments accounted for some of these differences. The seropositive asymptomatic and the seronegative groups did not differ on any of the mood or psychiatric assessments, suggesting minimal effect on psychological well-being of seroconversion in the absence of symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Intrathecal IgG synthesis and specificity of oligoclonal IgG in patients infected with HIV-1 do not correlate with CNS disease.

The CSF/serum immune response to HIV 1 was studied in 24 patients admitted for investigation. The level of antibody to HIV-1 and specificity of oligoclonal IgG were determined in blood and cerebrospinal fluid (CSF). The majority of patients demonstrated elevated levels of intrathecal IgG synthesis, with levels of HIV-1-specific antibody frequently being significantly higher in CSF than in serum. In 16 of 21 patients the CSF/serum antibody ratio indicated active intrathecal synthesis. Oligoclonal banding was present in CSF from all 24 patients. Immunoprinting of serum and CSF demonstrated antigenic specificity (p24, gp 160, RT) of the clonal antibodies in all of 12 patients though the patterns of reactivity in CSF did not necessarily correspond with that of serum. Although a specific association of particular patterns with HIV CNS disease was not found we feel that these markers should be included in longitudinal studies of HIV-related diseases of the CNS. The specificity of oligoclonal antibodies, both in CSF and in serum was demonstrated, and this specificity may be a useful marker for longitudinal studies in HIV-1 antibody-positive asymptomatic patients.

AIDS Dementia Complex↗
PubMed1979

Search for specificity in natural cell-mediated cytotoxicity.

Differences in antigenicity between the human osteosarcoma cell line TE 85/B and its feline sarcoma virus-infected subline NIH E1041 were detected by competitive inhibition of natural cell-mediated cytotoxicity (NCMC). Whether the differences could be attributed to the viral infection was investigated by absorption and elution studies of antibodies that determine the specificity of NCMC against the cell lines. Antibodies from the serum of healthy individuals were first absorbed onto target cells against which they were to be tested and then eluted to provide antibodies putatively specific for the target cells. Trypsin-treated effector cells were restored with the absorbed serum or eluted antibodies and tested against TE 85/B and its intentionally infected sublines. The differences observed previously between TE 85/B and NIH E1041 were extended to the detection of small differences in antigenicity among all sublines. Separately maintained sublines from the same culture became antigenically different with continuous passage. The causes for these specific changes were unknown, but a role for the control of these antigens by NCMC was suggested. Differences in antigenicity between virus-infected sublines cultured separately need not be related to the virus infection.

Antigens, Neoplasm↗
PubMed1976

Aids for speech-handicapped.

An improved electrolarynx is described. It provides handcontrolled fundamental frequency which enables the user to approximate natural intonation patterns, thus overcoming the monotony of speech with conventional aids. Training experiments with normal and with laryngectomized subjects have given promising results. A voice amplifier has been developed. Special care has been taken to minimize acoustic feedback problems. It is used for compensation of any weak voice, including esophageal speech and as a supplement to the electrolarynx for increasing the sound output and improving the signal-to-noise ratio. The use of synthetic speech in aids for anarthric patients is discussed.

Amplifiers, Electronic↗