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Biomedical subjects

C M Stewart

Publications and source records attributed to C M Stewart.

At least 37 records · Page 2Linked to original sources

An immunohistologic analysis of murine uterine T cells between birth and puberty.

Murine uterine T cells were analysed on the basis of surface phenotype expression from birth to adulthood. T cells were rare in the uterus from birth until 2 weeks of age. In genetically immunocompetent mice, mature T cells expressing either TCR alpha/beta or TCR gamma/delta were first present as a major cell population at 3 weeks of age. The ratio of TCR alpha/beta to TCR gamma/delta was 1:1 at 3 weeks of age and this ratio did not change during sexual maturation. Almost all uterine T cells were CD8+ and the majority of these cells expressed CD8 alpha/beta rather than CD8 alpha/alpha. Cells expressing Thy1.2 were less frequent than cells expressing CD3 while cells expressing CD5 were rare. No major changes in T cell subsets occurred at puberty. Further, the microbial flora of the mice did not alter the time of appearance, frequency or subset distribution of uterine TCR+ cells. In the uteri of immunodeficient mice of genotype scid/scid TCR+ cells were found in low numbers and the initial appearance of TCR+ cells was delayed until 5 weeks of age.

Animals↗

Degenerative joint disease. Part I: Diagnosis and management considerations.

Degenerative joint disease, primarily in the form of osteoarthrosis, affects the temporomandibular joints (TMJs) with symptoms similar to those found in other body joints. These symptoms include stiffness, pain, restriction of movement, inflammation, crepitus and radiographic changes. Symptoms can occur in both males and females at any age, starting with pre-adolescent, but most often occur in females age 30 and over. Most symptoms will last nine to 18 months (followed by remission) and are managed using anti-inflammatory medications, physical therapy, occlusal splints and dietary changes. Major areas for consideration in this article include epidemiology, signs and symptoms, radiography, etiopathology and symptom management.

Adult↗

Validation of estimates of energy intake by weighed dietary record and diet history in children and adolescents.

Energy intakes assessed by 7-d weighted dietary records (EI-WDRs) and diet histories (EI-DHs) were compared with concurrent estimates of total energy expenditure (TEE) by the doubly labeled water method in 78 subjects aged 3-18 y. EI-WDRs were not obtained from the 3- and 5-y-old subjects. EI-WDRs in the 7- and 9-y-old children were 108 +/- 25% (n = 12) and 97 +/- 15% (n = 12), respectively, of corresponding TEE values showing good agreement. However in the 12-, 15-, and 18-y-old subjects EI-WDR averaged 89 +/- 12% (n = 12), 78 +/- 18% (n = 12), and 73 +/- 25% (n = 10), respectively, of corresponding TEE values. The difference was greater than or equal to 20% in 13 adolescents. Mean EI-DHs were 114 +/- 19% (3 y), 111 +/- 19% (5 y), 111 +/- 23% (7 y), 106 +/- 9% (9 y), 114 +/- 17% (12 y), 101 +/- 21% (15 y), and 98 +/- 21% (18 y) of TEE estimates. Differences were significant in the 3-, 9-, and 12-y-old subjects. Results suggest that 7-d EI-WDRs tend to underestimate food intake of adolescents. Although EI-DHs were biased towards overestimation in most age groups and individual measurements lacked precision, EI-DHs were more representative of habitual intake than were EI-WDRs.

Adolescent↗

Daily energy expenditure in free-living children: comparison of heart-rate monitoring with the doubly labeled water (2H2(18)O) method.

Total energy expenditure (TEE) was measured simultaneously in 36 free-living children aged 7, 9, 12, and 15 y over 10-15 d by the doubly labeled water (DLW) method and for 2-3 separate days by heart-rate (HR) monitoring. The 95% confidence limits of agreement (mean difference +/- 2SD) were -1.99 to +1.44 MJ/d. HR TEE discrepancies ranged from -16.7% to +18.8% with 23 values lying within +/- 10% of DLW TEE estimates. Boys and girls spent 462 +/- 108 and 318 +/- 120 min/d, respectively, in total physical activity (P less than 0.01). Time spent in moderate and vigorous physical activity (MVPA) was 68 +/- 37 min/d by younger children (7-9 y) and 34 +/- 24 min/d by older children (12-15 y) (P less than 0.001). Younger boys engaged in MVPA (91 +/- 33 min/d) and vigorous physical activity (VPA) (35 +/- 15 min/d) significantly longer than younger girls (MVPA, 39 +/- 16 min/d, P less than 0.001; VPA, 10 +/- 4 min/d, P less than 0.01) as did older boys (MVPA, 52 +/- 21 min/d; VPA, 30 +/- 18 min/d) compared with older girls (MVPA, 15 +/- 10 min/d; VPA, 8 +/- 5 min/d). HR monitoring provides a close estimation of the TEE of population groups and objective assessment of associated patterns of physical activity.

Adolescent↗

Atypical odontalgia: phantom tooth pain.

The findings in 30 cases diagnosed as atypical odontalgia are presented. The clinical characteristics of these cases are compared with other cases reported in the literature. Three cases are described in detail. Patient understanding and treatment with tricyclic antidepressants are discussed together with medication side effects and interactions. The importance of deferring invasive procedures is emphasized.

Aged↗

Electron microscopic observation of the aggregation of membrane proteins in human erythrocyte by melittin.

Human erythrocytes and erythrocyte ghost membranes were treated with native and modified melittins, up to 250 nmol/mg membrane protein. Native melittin induced aggregation of intramembranous particles (IMPs, observed by freeze-fracture electron microscopy), and created large, smooth bilayer areas devoid of IMP. The degree of IMP aggregation increased with increasing concentration of melittin, corresponding to hemolysis results. Membrane ghosts were slightly more susceptible to IMP aggregation than membranes on intact cells. The potency of inducing IMP aggregation was ranked in the order of: native melittin greater than acetylated melittin greater than succinylated melittin = 0. The concentration range of melittin which caused IMP aggregation corresponded to that which caused the immobilization of band 3 proteins as detected by measurement of rotational mobility by transient dichroism (Dufton et al. (1984) Eur. J. Biophys. 11, 17-24). Because both IMP aggregation and band 3 protein immobilization decreased with decreasing positive charge of the melittins used, the nature of melittin-protein interaction is likely to be at least in part electrostatic in the case of human erythrocyte membranes. Possible roles of IMP aggregation and the consequent creation of 'exposed' bilayer areas in the cytotoxic reaction of melittins are discussed.

Bee Venoms↗

Experimental oral foreign body reactions. Commonly employed dental materials.

Foreign bodies and tissue reactions to foreign materials are commonly encountered in the oral cavity. The more common lesions include apical deposition of endodontic materials, mucosal amalgam and graphite tattoos, myospherulosis, oil granulomas, and traumatically introduced dental materials and instruments. Since many foreign materials are unidentifiable histologically, commonly used dental materials were experimentally implanted subcutaneously in rats to assess local host responses and characterize the nature of these materials microscopically. The histologic characteristics of these foreign body reactions are detailed herein. The implanted materials corresponded to reactions seen in human subjects.

Animals↗

Effects on birth weight of smoking, alcohol, caffeine, socioeconomic factors, and psychosocial stress.

OBJECTIVE: To investigate the effects of smoking, alcohol, and caffeine consumption and socio-economic factors and psychosocial stress on birth weight. DESIGN: Prospective population study. SETTING: District general hospital in inner London. PARTICIPANTS: A consecutive series of 1860 white women booking for delivery were approached. 136 Refused and 211 failed to complete the study for other reasons (moved, abortion, subsequent refusal), leaving a sample of 1513. Women who spoke no English, booked after 24 weeks, had insulin dependent diabetes, or had a multiple pregnancy were excluded. MEASUREMENTS: Data were obtained by research interviewers at booking (general health questionnaire, modified Paykel's interview, and Eysenck personality questionnaire) and at 17, 28, and 36 weeks' gestation and from the structured antenatal and obstetric record. Variables assessed included smoking, alcohol consumption, caffeine consumption, and over 40 indicators of socio-economic state and psychosocial stress, including social class, tenure of accommodations, education, employment, income, anxiety and depression, stressful life events, social stress, social support, personality, and attitudes to pregnancy. Birth weight was corrected for gestation and adjusted for maternal height, parity, and baby's sex. MAIN RESULTS: Smoking was the most important single factor (5% reduction in corrected birth weight). Passive smoking was not significant (0.5% reduction). After smoking was controlled for, alcohol had an effect only in smokers and the effects of caffeine became non-significant. Only four of the socioeconomic and stress factors significantly reduced birth weight and these effects became non-significant after smoking was controlled for. CONCLUSIONS: Social and psychological factors have little or no direct effect on birth weight corrected for gestational age (fetal growth), and the main environmental cause of its variation in this population was smoking.

Adolescent↗

Association between keratoconus and atopy.

Sixty-seven patients with keratoconus were classified according to atopic status. Keratoconus patients with and without atopy did not differ significantly with regard to sex, age of onset, or rate of keratoplasty, but patients with very high IgE levels were more prone to graft rejection. Atopy was less common in patients with unilateral keratoconus, and keratoconus occurred more frequently on the side of the dominant hand. There was a significantly lower frequency of HLA B7 in the keratoconus group than in the controls. No abnormalities of essential fatty acid metabolism were found in keratoconus patients with or without atopy. There was no social class bias in the group. The study included a brother and sister with keratoconus and atopy, and a non-atopic patient whose identical twin did not have keratoconus.

Asthma↗

Oral granular cell tumors: a clinicopathologic and immunocytochemical study.

To investigate the histogenesis of the granular cell, a large series of granular cell tumors was studied for clinical and histopathologic features with emphasis on immunocytochemical markers. The nongingival granular cell tumors (NGGCT) were found to be more prevalent among females than males by a ratio of 2:1 and arose on the tongue (67%), the buccal mucosa (13%), the lips (8%), the soft palate (6%), and other sites (6%). With the use of the avidin-biotin-peroxidase method, polyclonal rabbit antisera were employed. The antisera were directed to the following antigens: S-100 protein, myoglobin, myosin, actin, desmin, alpha-1-antitrypsin, and muramidase. Results indicated that granular cell tumors are not homogenous for immunocytochemical markers. Nongingival granular cell tumors were universally positive for S-100 protein and failed to exhibit immunoreactivity for myogenous or histiocytic markers. Alternatively, the gingival granular cell tumor of infancy was negative for all markers, whereas rhabdomyoma was reactive with myogenous markers and a subpopulation of tumor cells displayed S-100 protein immunoreactivity. The granular cell ameloblastoma was reactive only with antiserum to alpha-1-antitrypsin. Ultrastructurally, granular cells from one of two NGGCT showed a direct evolution from skeletal muscle fibers. It is concluded that the oral NGGCT is a tumor positive for S-100 protein that may arise from muscle or nerve sheath.

Adolescent↗

Temporomandibular joint disk position as determined by a simple recorder.

A method that will determine the condyle position necessary to keep the disk in place during splint fabrication has been described. The equipment used is simple and relatively inexpensive, and the entire procedure can be accomplished chairside in a matter of minutes. In those instances in which splint therapy does not result in significant improvement in symptoms, the Quick Set recorder can be used to repeat the initial condyle path recordings. A comparison of these sets of recordings can be used to determine whether the disk is in place. If doubt exists about the diagnosis, arthrography can be done to determine whether a closed locked disk position exists.

Cartilage, Articular↗

Perinatal listeriosis. A report of six cases.

The clinical and pathological findings in six patients with perinatal listeriosis are presented. One pregnancy resulted in a live-born infant who developed listerial septicaemia but made a complete recovery following prompt treatment. The other pregnancies ended in intrauterine death. Often antecedent maternal prodromal illness preceded expulsion of a macerated fetus by only a matter of hours making early diagnosis difficult. In all cases the diagnosis of listerial infection was apparent only after the birth of the fetus or new born.

Adult↗