Northern environment predisposes birches to ozone damage.

Ozone sensitivity of silver birch ( BETULA PENDULA Roth) has been thoroughly investigated since early 1990's in Finland. In our long-term open-field experiments the annual percentage reduction in basal diameter and stem volume increment were the best non-destructive growth indicators for ozone impact when plotted against AOTX. Remarkable differences in defence strategies, stomatal conductance, and defence compounds (phenolics), clearly indicate that external exposure indices are ineffective for accurate risk assessment for birch. For flux-based approaches, site-specific values for G(max) and G(dark) are necessary, and determinants for detoxification capacity, ageing of leaves, and cumulative ozone impact would be needed for further model development. Increasing CO(2) seems to counteract negative ozone responses in birch, whereas exposure to spring time frost may seriously exacerbate ozone damage in northern conditions. Therefore, we need to proceed towards incorporating the most important climate change factors in any attempts for ozone risk assessment.

Hypolipidemia and peroxisome proliferation induced by phenoxyacetic acid herbicides in rats.

Male Wistar rats were treated daily by gavage with two phenoxy herbicides, 2,4-dichlorophenoxyacetic acid (2,4-D)(100-200 mg/kg body wt) and 4-chloro-2-methylphenoxyacetic acid (MCPA) (100-200 mg/kg body wt), and with the chemically different glyphosate N-phosphonomethyl glycine (300 mg/kg body wt) 5 days per week for 2 weeks. A hypolipidemic drug, clofibrate [ethyl-2-(4-chlorophenoxy)-2-methylpropionate], which is structurally related to phenoxy acids, was used as a positive control (200 mg/kg body wt). 2,4-D and MCPA had several effects similar to those of clofibrate: all three compounds induced proliferation of hepatic peroxisomes, decreased serum lipid levels, and increased hepatic carnitine acetyltransferase and catalase activities. 2,4-D and MCPA, but not clofibrate, decreased lipoprotein lipase activity in the adipose tissue to about a third of the control value but did not change the lipoprotein lipase activity in the heart muscle. The data suggest that these compounds cause hypolipidemia not by enhancing the storage of peripheral lipids in adipose tissue but by preferentially increasing lipid utilization in the liver. Glyphosate caused no peroxisome proliferation or hypolipidemia, suggesting that these effects are associated with the structural similarity between phenoxy acid herbicides and clofibrate.

Changes in serum lipids, lipoproteins, and heparin releasable lipolytic enzymes during moderate physical training in man: a longitudinal study.

Serum lipids, postheparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) activity, and furthermore adipose tissue LPL activity were studied in 20 middle-aged men undergoing a moderate training program of 15-wk. These same parameters were also measured in 7 nontraining control subjects. The training caused a significant (P less than 0.001) increase in physical fitness, and also considerable changes in serum lipid levels and lipolytic enzymes activities. In the trainers, serum HDL cholesterol increased by about 7% (P less than 0.01 and HDL/total cholesterol ratio by 11% (P less than 0.001). Decreases were observed in serum total (P less than 0.10 and LDL (P less than 0.05) cholesterol levels and in insulin values (P less than 0.05). No changes in these parameters occurred in the reference group. Postheparin plasma and adipose tissue LPL activity increased by 33% (P less than 0.001) and 56%, respectively, in the trainers. Postheparin plasma HL activity remained essentially the same in both groups, although a trend towards decreased values was seen in the trainers. On the other hand, postheparin plasma HL activity correlated negatively with serum HDL cholesterol levels both before and after the training period. The present results suggest that even with a moderate training program, beneficial effects on serum lipids in middle-aged men can be accomplished. There is also reason to believe that these changes are, at least in part, mediated by changes in the activities of lipolytic enzymes involved in lipoprotein metabolism, namely LPP and HL.

Validity of radiological examinations of patients with breast cancer in different age groups in a population based study.

By studying which radiological examinations had been performed before breast cancer operations the aim was to assess, how much benefit ultrasonography (US) and fine or core needle biopsy (FNAB, CNB) gave in addition to mammography, and whether the sensitivity of these examinations varied with the age of the patient. There were 659 consecutive histologically and six cytologically verified breast cancer cases included in the study. Information on mammography, US and FNAB findings were retrieved from the original patient files and classified as malignant or benign. The sensitivity (Se) of these was compared in three age groups (26-49, 50-59 and 60-92). Seventeen (3%) tumours had operations without any radiological examination and 73 (11%) without cytological or histological verification. The sensitivity of mammography (Se=0.92) was statistically significantly higher than the sensitivity of FNAB (Se=0.85, P=0.002) or US (Se=0.86, P=0.003). The sensitivity of mammography increased with age; US sensitivity was slightly higher amongst younger than older patients; the sensitivity of FNAB did not depend on the age of the patient. The sensitivity using a cutoff level of class 5 for mammography was higher (50% typical malignant findings) than for US (45%) or FNAB (30%). Among cases with benign mammographic finding (classes 1-2), the US finding was malignant (classes 3-5) in 4% and FNAB was malignant in 7%. Mammography is a reliable method of breast examination especially for women over 50 years of age. Ultrasonography is beneficial, particularly in younger women, but it is mainly performed as a complementary examination to a mammography and therefore could not be evaluated as an independent examination. FNAB and CNB results were not related to the age of the patient.

Lipoprotein lipase of human postheparin plasma and adipose tissue in relation to physical training.

Adipose tissue lipoprotein lipase and postheparin plasma triglyceride lipase activities were measured in 28 men differing in their physical training activity. They were divided into 4 subclasses based on their training intensity. The two most active classes (17 subjects) having regular heavy exercise at least 4 times a week were considered as the actively training group, and the other two (11 subjects) classes not training regularly as the control group. In postheparin plasma, the lipoprotein lipase activities were not different between the two groups, whereas training subjects had significantly (P less than 0.02) lower hepatic lipase activities. Adipose tissue lipoprotein lipase activity was in the training group at about 70% higher level on an average than in the controls (P less than 0.10). A significant positive correlation (r = 0.38, P less than 0.05) was obtained between the adipose tissue lipoprotein lipase activity and the level of physical activity. Our data suggest that even moderate inter-group differences in the physical training activity are reflected as measurable alterations in the adipose tissue lipoprotein lipase activity in man.

Effect of pindolol on serum lipids and lipid metabolizing enzymes.

1 The effect on plasma lipids of pindolol given orally over a 6 month period to 20 patients with essential hypertension was studied. 2 During therapy an adipose tissue biopsy was taken from nine patients for the determination of lipoprotein lipase (LPL) activity and serum samples were taken for lecithin cholesterol acyltransferase (LCAT) assays. An additional biopsy and serum samples were taken after a 3 weeks' break in pindolol treatment. 3 Plasma free fatty acid and triglyceride concentrations remained similar during treatment. 4 Plasma total cholesterol was slightly lower (P less than 0.05) at 6 months than at 1 month. 5 HDL cholesterol concentration and the ratio of HDL to total cholesterol increased slightly, and the increase of HDL-cholesterol was significant (P less than 0.05) at 1 month. 6 LCAT activity was significantly higher (P less than 0.01) during pindolol treatment than after the break in it. No significant changes in adipose tissue LPL activities were found before and after the break of treatment.

Metabolic changes induced by combined prolonged exercise and low-calorie intake in man.

Thirteen middle-aged women and 10 men walked 344 km during 7 days. The daily walking distances were 57, 53, 67, 53, 41, 36, and 37 km at an average speed of 3.5 km X h-1. During the hike the subjects drank water, mineral drinks, and juices ad libitum. Except for some natural products, no food intake was allowed. During the hike the body weight and serum protein concentration of the subjects decreased by about 7%, on average. Serum triglyceride and total cholesterol decreased drastically, about 30-40% during the hike, but HDL-cholesterol showed a tendency to increase, giving a 40% increment in HDL/total cholesterol ratio. Serum free fatty acids rose 1.5-2 times above the starting level. Serum glucose and evening insulin levels decreased significantly during the hike. Serum cortisol in evening samples after the daily walking and plasma norepinephrine concentrations were significantly increased, reflecting the immediate daily response to the combined fasting and walking. Serum testosterone levels decreased in men but not in women, indicating the involvement of the LH-testis pathway in the decrease obtained. Serum ASAT activity rose to about three times the starting level during the hike, whereas gamma-GT activity gradually decreased. These marked metabolic changes caused by combined fasting and several days exercise were in many respects (as in cholesterol, HDL/total cholesterol ratio or testosterone levels) more pronounced than those earlier reported to be caused by exercise or fasting alone.

Effect of sotalol withdrawal on serum lipids and lipoprotein lipase activity.

Serum total cholesterol, HDL cholesterol, triglycerides, and adipose tissue lipoprotein lipase activity were analyzed in seven hypertensive subjects using 160-480 mg sotalol daily, before and after a 3-week pause in the treatment. Triglycerides decreased and HDL cholesterol increased significantly during the break in sotalol treatment, whereas no changes occurred in total cholesterol and lipoprotein lipase. A positive correlation was found after the interruption between the lipoprotein lipase activity and the HDL cholesterol concentration. This correlation did not exist before the break in the drug treatment. On the basis of these results the effects of sotalol on lipoprotein metabolism do not seem to be mediated by lipoprotein lipase.

Effects of high dose progestin on serum lipids and lipid metabolizing enzymes in patients with endometrial cancer.

The effect of high dose medroxyprogesterone acetate (MPA) on serum lipids, on adipose tissue lipoprotein lipase (LPL) and serum lecithin cholesterol acyltransferase activities were studied in 15 postmenopausal patients with endometrial cancer. After 2 weeks of MPA treatment total cholesterol decreased by 14% (P less than 0.001) and HDL cholesterol by 33% (P less than 0.01) from the respective pretreatment values; correspondingly the ratio of HDL to total cholesterol decreased (P less than 0.05). The decrease of HDL2 cholesterol was 35% (P less than 0.01) and that of HDL3 cholesterol 15% (P less than 0.01). The levels of serum triglycerides decreased significantly (P less than 0.05) during the treatment period. Serum LCAT activity was significantly lower (P less than 0.05) after treatment than before, but adipose tissue LPL activity was not altered. The mean serum testosterone level decreased significantly (P less than 0.001) from the pretreatment values. Significant positive correlations were present between LPL activity and MPA concentrations and between LPL activity and testosterone concentrations after the drug treatment.

The effect of age and density of the breast on the sensitivity of breast cancer diagnostic by mammography and ultasonography.

PURPOSE: We studied which, age of the patient or density of the breast accounts for the sensitivity of mammography and ultrasonography (US). Furthermore we studied whether the overall impression on the density of the breast or the density in tumour area accounts for the sensitivity of mammography and ultrasonography. MATERIALS AND METHODS: The material consisted of 572 consecutive histologically and 5 cytologically verified breast cancer cases. Mammography and US examinations were performed immediately before breast cancer operations and information on the findings were received from the original patient files and classified as malignant or benign. The density of breast parenchyma to fatty, mixed or dense in total breast and separately in tumour area was defined by a radiologist group from the original mammograms by comparing to model mammograms. The sensitivity (Se) of mammography and US was compared in 3 age groups (26-49, 50-59 and 60-92) and in the different density classes. RESULTS: Sensitivity of mammography increased by age (density-adjusted OR = 0.2, 95%, CI 0.1-0.5) in age group 26-49 compared to age group 60-92) and with fattiness of the breast (age-adjusted OR= 0.4, 95%, CI 0.1-1.0 for dense breast parenchyma in tumour area compared to fatty breast). Sensitivity of US was inversely related to age (density-adjusted OR = 2.3, 95%, CI 1.0-5.2 in age group 26-49 compared to age group 60-92) and directly related with fattiness of breast (age-adjusted OR = 0.5, 95%, CI 0.2-0.9 by dense breast parenchyma in tumour area compared to fatty breast). Density in the tumour area compared to total breast density was related only mariginally better sensitivity both of mammography (0.4 vs. 0.6) and of US (0.5 vs. 0.6). CONCLUSION: Sensitivity of both mammography and sensitivity of US are independently related both to the age of the patient and to the density of the breast. The effect of age is inverse and that of density parallel between mammography and US on sensitivity. The effect of overall breast density was close to the effect of density at the site of the tumour on the sensitivity of both mammography and US.

The visibility of cancer on previous mammograms in retrospective review.

AIM: To study how many tumours were visible in restrospect on mammograms originally reported as normal or benign in patients coming to surgery with proven breast cancer. The effect of making the pre--operative mammogram available was also assessed. MATERIALS AND METHODS: Three hundred and twenty initial mammograms of consecutive new breast cancer cases were analysed by a group of radiologists in the knowledge that all patients were later diagnosed with breast cancer. The films were read twice, first without and then with the later (pre-operative) mammograms available. The parenchymal density in the location of the tumour was classified as fatty, mixed or dense, and the tumours were classified as visible or not visible. The reasons for the invisibility of the tumour in the earlier examination were analysed. RESULTS: Fourteen per cent (45) of cancers were retrospectively visible in earlier mammograms without the pre-operative mammograms having been shown, and 29% (95) when pre-operative mammograms were shown. Breast parenchymal density decreased with age and the visibility of tumours increased with age. When considered simultaneously, the effect of age (over 55 vs under 55) was greater (OR = 2.9) than the effect of density (fatty vs others) (OR = 1.5). The most common reasons for non-detection were that the lesion was overlooked (55%), diagnosed as benign (33%) or was visible only in one projection (26%). Growing density was the most common (37%) feature of those lesions originally overlooked or regarded as benign. CONCLUSIONS: Tumours are commonly visible in retrospect, but few of them exhibit specific signs of cancer, and are recognized only if they grow or otherwise change. It is not possible to differentiate most of them from normal parenchymal densities. Saarenmaa, I. (2001). Clinical Radiology56, 40-43.