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Biomedical subjects

L Gibbons

Publications and source records attributed to L Gibbons.

At least 91 records · Page 5Linked to original sources
PubMed1998

Monograph series on aging-related diseases: X. Prostate cancer.

Prostate cancer is the most commonly diagnosed cancer among Canadian men, excluding non-melanoma skin cancer. Prostate cancer incidence increases almost exponentially with age; most cases are diagnosed in men aged 65 years or older. With the possible exception of animal fat consumption, no known widespread modifiable risk factors have been identified. Although the prognosis is good if appropriate treatment occurs in the early stages of disease, the ability of existing early detection techniques to decrease mortality has not yet been demonstrated. The considerable economic and societal burden of prostate cancer and its treatment, coupled with the projected large increase in the number of new prostate cancer cases as the population ages, make this disease a very important public health issue.

Aged↗
PubMed1997

A cross-sectional study of helminths in rural scavenging poultry in Tanzania in relation to season and climate.

A cross-sectional study on the prevalence of helminths in rural scavenging poultry on six hundred adult chickens selected randomly from six villages in the Morogoro Region, Tanzania during the wet and the dry seasons, was conducted. The trachea and gastrointestinal tract of each bird were examined for the presence of parasites. All chickens were infected with one or several species of helminths, the average being 4.8 +/- 1.7 helminths per chicken during the wet season and 5.1 +/- 1.8 during the dry season. A total of 29 different helminth species were shown in the trachea or the gastrointestinal tract. The following species were identified: Syngamus trachea (0.7% (wet season), 2% (dry season)); Gongylonema ingluvicola (6.3%, 17.7%); Tetrameres americana (54.3%, 60.3%); Dispharynx nasuta (0%, 2.7%); Acuaria hamulosa (8.3%, 19.3%); Ascaridia galli (28.3%, 32.3%); Heterakis gallinarum (74.0%, 78.7%); H. isolonche (18.7%, 5.0%); H. dispar (25.7%, 6.3%); Allodapa suctoria (40.0%, 52.0%); Subulura strongylina (3.3%, 1.0%); Strongyloides avium (0.3%, 3.0%); Capillaria annulata (2.0%, 0.0%); C. contorta (9.0%, 1.0%); C. caudinflata (2.0%, 4.3%); C. obsignata (8.7%, 25.0%); C. anatis (4.0%, 9.0%); C. bursata (1.0%, 2.7%); Raillietina echinobothrida (41.3%, 46.3%); R. tetragona (25.3%, 21. 3%); R. cesticillus (8.7%, 2.7%); Choanotaenia infundibulum (0.0%, 3. 7%); Hymenolepis carioca (9.0%, 18.0%); H. cantaniana (48.0%, 43. 0%); Amoebotaenia cuneata (39.3%, 36.0%); Metroliasthes lucida (1.0%, 0.3%); Davainea proglottina (5.7%, 0.3%) and Polymorphus boschadis (0.3%, 0.0%). No trematodes were found. No correlation was found between season and prevalence, or season and mean worm burdens. Twelve helminths of the species recovered represent new local records.

Animals↗
PubMed1996

Nutritional status and mortality in chronic obstructive pulmonary disease.

The role of nutritional status in the prognosis of subjects with severe chronic obstructive pulmonary disease was studied in a cohort of Canadian men and women followed for 3 to 5 yr. A total of 348 subjects who were recruited for a study of negative pressure ventilation were evaluated for lung function and body weight, and a subset who entered hospital for the study (n=184) had baseline measures of diffusing capacity, maximal inspiratory and expiratory mouth pressure (PImax and PEmax), and blood gases. Predictors of survival were analyzed using Cox regression models. In the total cohort, low body mass index (BMI) and use of home oxygen were independently associated with reduced survival. In the hospitalized group, predictors of respiratory mortality were elevated PaCO2 and low BMI, PImax, and diffusing capacity. PaO2 (measured on oxygen therapy), FEV1, PEmax, age, smoking behavior, and gender were not associated with survival. The predictors of total mortality were similar, except that BMI was no longer significant. In conclusion, low body weight, a potentially modifiable factor, was associated with respiratory mortality, but whether it has a casual effect or is a marker of declining health can only be resolved through an intervention trial.

Adult↗
PubMed1996

Lumbar disc degeneration and sagittal flexibility.

It is uncertain whether intervertebral disc degeneration is associated with reduced or increased flexibility, although lumbar flexibility is known to reduce with advancing age. This cross-sectional study of 214 middle-aged men attempted to determine the influence on lumbar sagittal flexibility from intervertebral disc degeneration parameters measured from magnetic resonance images (disc height, signal intensity, bulging, osteophytes). Multivariate analyses showed that a reduced extent of lumbar flexibility could be accounted for by the combined effect of decreasing disc height together with increasing age, weight, and back pain frequency. Although it remains possible that single degenerate discs will display increased mobility, the presence of discs at various stages of degeneration results in a net reduction of flexibility. The factors studied here explained only 31% of the variance in flexibility; the major determinants remain to be identified and quantified.

Adult↗
PubMed1995

The long-term effects of physical loading and exercise lifestyles on back-related symptoms, disability, and spinal pathology among men.

STUDY DESIGN: Historical cohort, including selected subgroups. OBJECTIVES: To understand the long-term effects of exercise on back-related outcomes, back pain, sciatica, back-related hospitalizations, pensions, and magnetic resonance imaging findings were studied among former elite athletes. SUMMARY OF BACKGROUND DATA: Exercise and sports participation have become increasingly popular, as have recommendations of exercises for back problems, but little is known about their long-term effects. METHODS: Questionnaires were returned by 937 former elite athletes and 620 control subjects (83% response rate). Identification codes allowed record linkage to hospital discharge and pension registers. Magnetic resonance images were obtained of selected subgroups with contrasting physical loading patterns. RESULTS: Odds ratios for back pain were lower among athletes than among control subjects, with significant differences in endurance, sprinting and game sports, and wrestling and boxing. No differences in the occurrence of sciatica or in back-related pensions and hospitalizations were seen. When comparing lumbar magnetic resonance images of 24 runners, 26 soccer players, 19 weight lifters, and 25 shooters, disc degeneration and bulging were most common among weight lifters; soccer players had similar changes in the L4-S1 discs. No significant differences were seen in the magnetic resonance images of runners and shooters. CONCLUSIONS: Maximal weight lifting was associated with greater degeneration throughout the entire lumbar spine, and soccer with degeneration in the lower lumbar region. No signs of accelerated disc degeneration were found in competitive runners. However, back pain was less common among athletes than control subjects and there were no significant differences in hospitalizations or pensions. No benefits were shown for vigorous exercise compared with lighter exercise with respect to back findings.

Adolescent↗
PubMed1995

Production of eicosanoids and cytokines by Kupffer cells from young and old rats stimulated by endotoxin.

1. The clinicopathological features of endotoxaemia have been ascribed to cytotoxic mediators such as tumour necrosis factor, interleukins and eicosanoids. Macrophages, particularly Kupffer cells, are an important source of these mediators. Mortality from endotoxaemia is highly age related. 2. These studies focus on the role of hepatic Kupffer cells in the increased sensitivity of old rats to bacterial endotoxins. Possible age-related changes in the production of eicosanoids and induction of gene expression and secretion of interleukin 1, tumour necrosis factor and interleukin 6 were investigated in Kupffer cells derived from both young and old animals. 3. Basal production of biological response modifiers was low in cells of both young and old rats. Lipopolysaccharide stimulated production of the same types of monokines as described for other types of macrophages, although the pattern was specific for Kupffer cells. 4. Eicosanoids, predominantly prostaglandin D2 and prostaglandin F2 alpha, were produced mainly during the first hour after exposure to lipopolysaccharide. Endotoxin stimulated synthesis of mRNAs of interleukin 1, interleukin 6 and tumour necrosis factor alpha resulting in increased secretion of these cytokines into the medium. 5. Kupffer cells from both young and aged animals appear to be exquisitely sensitive to endotoxin in respect of expression of mRNA for both interleukin 1 alpha and interleukin 1 beta and less sensitive with respect to interleukin 6 and tumour necrosis factor alpha gene expression. At relatively high lipopolysaccharide concentrations interleukin 6 was secreted in particularly large amounts. 6. The effects of ageing on any of these responses of Kupffer cells were minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1993

Prostate cancer trends in Canada: rising incidence or increased detection?

OBJECTIVES: To analyse trends in the incidence and mortality rates of prostate cancer in Canada according to age distribution, temporal pattern and provincial variation; to determine any association with the rate of prostatectomy; and to determine whether any observed increase in the rate of prostate cancer was due to an increase in the detection rate. DESIGN: Descriptive epidemiologic study based on Canadian population data from 1959 to 1989 and chart review from one Canadian hospital. SETTING: The chart review was conducted at the Ottawa Civic Hospital. SUBJECTS: The data on prostate cancer trends were obtained from the Canadian population. Charts were reviewed for two groups of patients: (a) men discharged from inpatient care during 1976 and 1986-87 with prostate cancer first diagnosed in the same year and (b) men who underwent transurethral resection of the prostate (TURP) during 1976 and 1986. OUTCOME MEASURES: Incidence and mortality rates of prostate cancer, rates of prostatectomy and TURP, and correlations between them. From the hospital data, changes between 1976 and 1986-87 in distribution of cancer stages, distribution of cases detected incidentally after surgery for suspected benign prostatic hypertrophy and average number of slides analysed per gram of tissue obtained from prostatectomy. RESULTS: The epidemiologic data showed that the age-adjusted incidence rates increased by 72% overall, an increase seen in all age groups over 60 years. The mortality rates increased by 29% overall, primarily in men over 85 years old. The prostatectomy rate increased by 55%. There were significant linear correlations between the national and provincial incidence rates of prostate cancer and the TURP rates. The chart review revealed that during 1976, 53% of the cases of prostate cancer diagnosed were localized, as compared with 75% in 1986-87 (p < 0.01). The proportion of tumours diagnosed incidentally in men undergoing TURP increased by 11%, whereas the number of procedures did not increase. Significantly more slides per gram of tissue were analysed in 1986-87 than in 1976 (p < 0.01). CONCLUSIONS: The correlations between the incidence rates of prostate cancer and those of TURP suggest that increased treatment of benign prostatic disease has led to increased detection of prostate cancer. Extrapolation of the data obtained from the chart review indicates that the increase in observed incidence rates can be attributed to an increase in the rate of localized disease and thus primarily to early detection rather than to elevated risk. However, because the rate of death from prostate cancer was elevated in elderly men, increases in exposure to unestablished risk factors cannot be ruled out.

Age Factors↗