PubMed Health⌕ Search

Biomedical subjects

G S Anderson

Publications and source records attributed to G S Anderson.

14 recordsLinked to original sources
PubMed1992

A comparison of predictive tests of aerobic capacity.

This study examined the relationship among three predictive tests of aerobic capacity when analyzed within and across gender. Sixty-three active college students (37 males, 26 females) performed the multistage 20-metre shuttle run (SR), the Canadian Aerobic Fitness Test (ST), and the 1.5-mile run (DR). Predicted VO2max (ml.kg-1 x min-1) scores were obtained for each subject. Significant correlations were found among the VO2max results on all possible pairings of tests analyzed as a group, and by gender (p < .001) except for the females' SR and ST pairing (p > .05). One-way analysis of variance was performed for each of the three subject pools with significant F values for the grouped (F = 5.8, p < .01) and male (F = 30.7, p < .01) samples. Tukey HSD post hoc comparison identified significant differences among the SR and ST, and ST and DR VO2 max scores for both samples. However, there were no significant differences between the cell means when females were analyzed separately.

Adult↗
PubMed1991

Relationship between blood lactate and excess CO2 in elite cyclists.

This study examined the relationship between expired non-metabolic CO2 (exCO2) and the accumulation of blood lactate. Particular emphasis was placed on the ventilatory (exCO2 and VE/VO2) and lactate threshold relationship. A total of 21 elite cyclists (15 males, 6 females) performed a progressive intensity bicycle ergometer test during which ventilatory parameters were monitored on-line at 15-s intervals, and blood lactate sampling occurred at each minute. Transition threshold values were determined for each of the three indices: excess CO2 (TexCO2), VE/VO2 (Tvent) and blood lactate (Tlac). The three threshold values (TexCO2, Tvent, Tlac) all correlated significantly (P less than 0.001) when each was expressed as an absolute VO2 (l min-1). A significant ANOVA (F = 8.41, P less than 0.001) and post-hoc correlated t-tests demonstrated significant differences between the TexCO2 and Tlac (P less than 0.001) and the TexCO2 and Tvent values (P less than 0.025). The Tlac occurred at an average blood lactate concentration of 3.35 mM, while the mean expired excess CO2 volume at the TexCO2 was 14.04 ml kg-1 min-1. Over an 11-min range across the threshold values (TexCO2 and Tlac), which were used as relative points of reference, the expired excess CO2 volume (ml kg-1 min-1) and blood lactate concentration (mM) correlated significantly (r = 0.69, P less than 0.001). Higher individual correlations over the same period of time (r = 0.82-0.96, P less than 0.001) stress the individual nature of this relationship. These results indicate a strong relationship between the three threshold values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Culicoides obsoletus (Diptera: Ceratopogonidae) as a causal agent of Culicoides hypersensitivity (sweet itch) in British Columbia.

Six horses severely affected by a seasonal dermatitis similar in both histopathology and epidemiology to Culicoides hypersensitivity (CH) and six unaffected or normal horses were inoculated intradermally with an extract of Culicoides obsoletus (Meigen), the most common Culicoides in southwestern British Columbia. Affected horses developed large welts within 20 min after injection, representing an immediate (type I) reaction; welts were largest 24 h or more after challenge, indicating in addition a delayed (type IV) reaction. This reaction was discernible for greater than 3 wk in some of the affected horses. Normal horses developed small welts which peaked 2-4 h after challenge. Affected horses were irritated by the injections and developed characteristically ridged skin at the injection sites, similar to that seen in natural lesions, whereas the normal horses showed neither discomfort nor clinical signs. C. obsoletus is one of the most numerous Culicoides species biting horses, feeds on parts of the body where lesions are found, and is, we believe, responsible for dermatitis in the Pacific Northwest. The skin test was repeated 2 yr later in three of the affected horses. In two, the reactions were similar to those in the first test, but in the third horse, the reaction was greatly reduced after the second test. This paralleled a decrease in the severity of its natural clinical signs. Thus, a skin test may be useful in the diagnosis of Culicoides hypersensitivity.

Animals↗
PubMed1991

Individualization and enamel histology: a case report in forensic anthropology.

The cranium of a native Indian child about six years old was found in 1979 near Taseko River, British Columbia, Canada. While the remains matched the report of a child missing for eight years in terms of race, age at death, locale, and elapsed time since death, the cranium and dentition were basically unidentifiable because of the claimed lack of medical or dental history. There was no dental work, and the parents were unknown or dead. We report the presence, in the dental enamel of the primary and secondary dentition, of stress markers, termed striae of Retzius, whose locations correspond well with anecdotal reports and recently discovered medical records which describe the timing of specific episodes of stress. The enhanced probability of personal identification from dental histological stress markers is evaluated.

British Columbia↗
PubMed1989

A review of blood lactate and ventilatory methods of detecting transition thresholds.

As far back as the 1930s exercise physiologists recognised the existence of critical levels of work intensity above which lactate accumulation increased drastically and energy production was affected. Investigation of these transition points (thresholds) both invasively and non-invasively has led to much recent controversy. Respiratory exchange variables such as Ve, Ve/VO2, VCO2, excess CO2 and blood lactate have been monitored for simple, double and exponential breakaway points to elucidate these critical work intensities. A number of studies have produced high correlations between endurance performance and anaerobic threshold calculations, further demonstrating the potential existence of critical work intensities. Much of the controversy surrounding these phenomena has centered on mechanisms and nomenclature. The term 'anaerobic threshold' has been severely criticised because in addition to the tissues being oxygen insufficient, an imbalance in the energy systems may have resulted. The anaerobic condition or lactate accumulation may be due to changes in lactate production and removal. Muscle fibre type and the fibre type recruitment patterns may also be important factors in threshold transitions. Further examination is made in this review of non-invasive measures for determining transition thresholds and protocols for elucidating the critical points.

Anaerobic Threshold↗
PubMed1988

Enteric tumours of the lower female genital tract: a report of three cases.

Three enteric-type neoplasms of the lower female genital tract are described; an enteric adenocarcinoma of the cervix, an enteric adenocarcinoma of the vagina and a tubulo-villous adenoma of the vagina. The two adenocarcinomas were characterized by the presence of columnar cells with a prominent brush border and an abundance of goblet cells. The tubulovillous adenoma was identical to similar lesions found in the large intestine. The criteria for diagnosis of an enteric adenocarcinoma of the female genital tract are discussed and it is concluded that the histochemical demonstration of o-acetylated sialomucin is the most specific marker of intestinal differentiation. It is suggested that enteric tumours of the cervix arise from foci of gastrointestinal metaplasia. Enteric tumours of the vagina are more likely to develop from cloacal remnants.

Adenocarcinoma↗
PubMed1973

An outbreak of diphtheria in a hospital for the mentally subnormal.

An account is given of two separate outbreaks of diphtheria amongst mentally subnormal patients and nursing staff. In a total hospital population of about 1000 the number of people involved as carriers or cases was 60 and there were five deaths. The 60 people comprised 56 patients, of whom four were involved in both outbreaks, and four nurses. The organisms isolated were C. diphtheriae mitis but five strains were non-toxigenic. It is postulated that the outbreak began following the conversion of a non-toxigenic organism to a toxigenic one by bacteriophage action. The fatal cases were examples of membranous pharyngo-laryngo-tracheo-bronchial diphtheria with well marked pseudo-casts of the upper air passages.

Adult↗
PubMedDate not supplied

Antineoplastic effects of gallium nitrate on human medulloblastoma in vivo.

Gallium nitrate possesses antineoplastic activity against certain solid tumors and has been demonstrated to be an effective agent in reducing cell proliferation and DNA synthesis in the medulloblastoma Daoy cell line in vitro. In prior studies, gallium inhibited the cellular uptake of 59Fe by brain tumor cells; however, this block in 59Fe uptake was variable and closely paralleled the inhibitory effects of gallium on cell growth. In vivo trials now have been conducted and have yielded some promising results. Nude mice received intradermal injections of medulloblastoma Daoy and then allowed to grow tumors. When the mice had developed at least one tumor between 9 to 10 mm in diameter, a 10-day course of intraperitoneal gallium nitrate injections was initiated. Gallium nitrate treatment reduced overall tumor growth rate and reduced actual tumor size. Nephrotoxicity was severe, but may be preventable by continuous gallium infusion and use of diuretics and hyperhydration.

Animals↗