Molecular analysis of commensal host-microbial relationships in the intestine.

Human beings contain complex societies of indigenous microbes, yet little is known about how resident bacteria shape our physiology. We colonized germ-free mice with Bacteroides thetaiotaomicron, a prominent component of the normal mouse and human intestinal microflora. Global intestinal transcriptional responses to colonization were observed with DNA microarrays, and the cellular origins of selected responses were established by laser-capture microdissection. The results reveal that this commensal bacterium modulates expression of genes involved in several important intestinal functions, including nutrient absorption, mucosal barrier fortification, xenobiotic metabolism, angiogenesis, and postnatal intestinal maturation. These findings provide perspectives about the essential nature of the interactions between resident microorganisms and their hosts.

Elevation of plasma epinephrine concentrations inhibits proteolysis and leucine oxidation in man via beta-adrenergic mechanisms.

The role of elevated plasma epinephrine concentrations in the regulation of plasma leucine kinetics and the contribution of beta-receptors were assessed in man. Epinephrine (50 ng/kg per min) was infused either alone or combined with propranolol (beta-blockade) into groups of six subjects fasted overnight; leucine flux, oxidation, and net plasma leucine forearm balance were determined during 180 min. Constant plasma insulin and glucagon concentrations were maintained in all studies by infusing somatostatin combined with insulin and glucagon replacements. Plasma leucine concentrations decreased from baseline during epinephrine infusion by 27 +/- 5 mumol/liter (P less than 0.02) due to a 22 +/- 6% decrease in leucine flux (P less than 0.05 vs. controls receiving saline) and to an increase in the metabolic clearance rate of leucine (P less than 0.02). Leucine oxidation decreased by 36 +/- 8% (P less than 0.01 vs. controls). beta-Blockade abolished the effect of epinephrine on leucine flux and oxidation. Net forearm release of leucine increased during epinephrine (P less than 0.01), suggesting increased muscle proteolysis; the fall of total body leucine flux was therefore due to diminished proteolysis in nonmuscle tissues, such as splanchnic organs. Nonoxidative leucine disappearance as a parameter of protein synthesis was not significantly influenced by epinephrine. Plasma glucose and FFA concentrations increased via beta-adrenergic mechanisms (P less than 0.001). The results suggest that elevation of plasma epinephrine concentrations similar to those observed in severe stress results in redistribution of body proteins and exerts a whole body protein-sparing effect; this may counteract catabolic effects of other hormones during severe stress.

Effect of squalestatin 1 on the biosynthesis of the mevalonate pathway lipids.

The effects of squalestatin 1 on rat brain and liver homogenates and on Chinese hamster ovary tissue culture cells have been investigated. This compound effectively inhibits squalene biosynthesis in a highly selective manner. Cytoplasmic farnesyl pyrophosphate and geranylgeranyl pyrophosphate synthases are not affected, which is also the case for microsomal cis-prenyltransferase. In tissue culture cells, squalestatin 1 inhibits cholesterol biosynthesis completely, but does not alter dolichol synthesis or protein isoprenylation to a great extent. Incorporation of [3H]mevalonate into ubiquinone-9 and -10 increases 3-4-fold, probably as a result of increased synthesis of this lipid. Squalestatin 1 appears not only to be an effective inhibitor of cholesterol biosynthesis, but also to be more specific than other inhibitors used earlier in various in vitro and in vivo systems.

Monitoring of the subtraction process in solid-phase representational difference analysis: characterization of a candidate drug.

In this study, we have applied and evaluated a modified cDNA representational difference analysis (RDA) protocol based on magnetic bead technology to study the molecular effects of a candidate drug (N,N'-diacetyl-L-cystine, DiNAC) in a model for atherosclerosis. Alterations in a gene expression profile induced by DiNAC were investigated in a human monocytic cell line (THP-1) differentiated into macrophage-like cells by lipopolysaccharide and further exposed to DiNAC. Three rounds of subtraction have been performed and the difference products from the second and third rounds have been characterized in detail by analysis of over 1000 gene sequences. Two protocols for analysis of the subtraction products have been evaluated, a shotgun approach and size selection of both distinct fragments and band-patterned smear. We demonstrate that in order to obtain a representative view of the most abundant gene fragments, the shotgun procedure is preferred. The obtained sequences were analyzed against the UniGene and Expressed Gene Anatomy Database (EGAD) databases and the results were visualized and analyzed with the ExProView software enabling rapid pair-wise comparison and identification of individual genes or functional groups of genes with altered expression levels. The identified differentially expressed gene sequences were comprised of both genes with known involvement in atherosclerosis or cholesterol biosynthesis and genes previously not implicated in these processes. The applicability of a solid-phase shotgun RDA protocol, combined with virtual chip monitoring, results in new starting points for characterization of novel candidate drugs.

Half-life of ubiquinone-9 in rat tissues.

The half-life of ubiquinone-9 in various rat tissues was determined. Rats were injected intraperitoneally with [3H]mevalonate and the decay of radioactivity incorporated into ubiquinone-9 was followed using reverse-phase HPLC. The half-life varied between 49 h (testis) and 125 h (kidney).

Contribution of 500 g naturally labeled 13C dextrin maltose to total carbohydrate utilization and the effect of the antecedent diet, in man.

Exogenous carbohydrate oxidation was studied for 24 h in 14 healthy young male volunteers after ingestion of 500 g naturally labeled 13C carbohydrate. Prior to the test, the antecedent diet was high in fat (4 subjects), mixed (4 subjects), or high in carbohydrate (6 subjects). The rate of exogenous carbohydrate oxidation was greater in the high carbohydrate and mixed diet groups than in the high fat group and endogenous carbohydrate continued to contribute to total carbohydrate oxidation for approximately 10 h after ingestion of the carbohydrate load in all groups. After 14 h, 178 +/- 5 g, 241 +/- 11 g and 260 +/- 9 g carbohydrate had been utilized of which 130 +/- 8 g, 155 +/- 6 g and 180 +/- 7 g was of exogenous origin in the high fat, mixed and high carbohydrate groups respectively. At the end of the test, postabsorptive glucose oxidation was of exogenous origin whatever the antecedent diet indicating that much of basal hepatic glucose production was covered by glycogenolysis of recently synthesized labeled glycogen.

Energy expenditure of Chinese infants in Guangdong Province, south China, determined with use of the doubly labeled water method.

The doubly labeled water method was used to measure the energy expenditure of a group of 41, 4- or 6-mo-old infants with a cross-sectional design. The infants were divided into two groups according to whether they were breast-fed (11 at 4 mo, 9 at 6 mo) or formula fed (11 at 4 mo, 10 at 6 mo). Anthropometric measurements were recorded at birth and at the beginning and end of the 8-d study. Anthropometric data, which were supported by the food intake and energy expenditure results, indicated that the infants were within the norms for European and American infants of the same age. Mean energy intakes of 352 kJ (84 kcal) kg(-1) x d(-1) at 4 and 6 mo were lower than the FAO/WHO/UNU recommended value of 452 kJ (108 kcal) x kg(-1) x d(-1)) and Chinese recommendations of 502 kJ (120 kcal) kg(-1) x d(-1). However, some authors believe that values of 398 kJ (95 kcal) kg(-1) x d(-1) at 4 mo and 356 kJ (85 kcal) kg(-1) x d(-1) at 6 mo are more appropriate. At 6 mo the infants' length-for-age and weight-for-age were at the National Center for Health Statistics 55th and 47th percentiles, respectively, whereas 58% were below the 50th percentile for weight-for-length. We conclude that at 4 mo infants receive sufficient energy for their requirements. However, at 6 mo energy requirements might well be greater than the revised recommendations, when infants are being weaned to alternative foods and are more prone to the influence of diet on their growth and development.

PIP: This cross-sectional study uses the doubly labeled water method to measure energy intake, energy expenditure, and energy used for growth in groups of 4- and 6-month old Chinese infants who were predominantly either breast-fed or formula fed. Anthropometric measurements were recorded at birth and at the beginning and end of the 8-day study. Anthropometric data, which were supported by the food intake and energy expenditure results, indicated that the infants were within the norms for European and American infants of the same age. Mean energy intakes were lower than the WHO recommended value. However, some authors believe that values of 398 kilojoule (kJ) at 4 months and 356 kJ at 6 months were more appropriate. At 6 months old, the infants¿ length-for-age and weight-for-age were at the National Center for Health Statistics 55% and 47%, respectively, whereas 58% were below the 50% for weight-for-length. Therefore, infants at 4 months were able to receive sufficient energy for their requirements. However, at 6 months energy requirements might be greater than the revised recommendations, when infants were being weaned to alternative foods and were more prone to the influence of diet on their growth and development.

Age-dependent changes in rat liver prenyltransferases.

Mevalonate pathway lipids including cholesterol, ubiquinone and dolichol, are of great importance for cellular function. Many of the enzymes of this pathway are thus strictly regulated. During development of the rat, the cellular levels of certain of these lipids vary. Prenyltransferases have been investigated and it is reported here that farnesyl pyrophosphate synthase activity in rat liver cytosol decreases after birth to a lower, steady level. This decrease is not paralleled by the level of synthase protein, which shows two maxima, one immediately after birth and the other 30 days later. cis-Prenyltransferase activity is low after birth, increases continuously up to day-54 and then decreases to a low level which was maintained throughout the remainder of the study (365 days). Squalene synthase exhibits high activity after birth, but decreases during the first 100 days thereafter, and subsequently remains at the low level thus reached. In contrast to these changes in the activities of the prenyltransferases, the level of cholesterol is constant and the dolichol concentration increases continuously throughout the entire period studied.

Weekly-dose doxorubicin (WDA) in advanced breast cancer.

Doxorubicin in a weekly fixed dose of 20 mg as i.v. bolus (WDA) was given to 48 patients with mostly pretreated progressing breast cancer. The response rate (CR + PR) was 9/48 (19%), and a further 16 (33%) of the patients achieved stable disease. Myelosuppression was mild and without clinical significance. Other side effects, particularly nausea, vomiting and hair loss were also relatively mild. Cardiac toxicity, however, was seen in six patients. Five of these six patients were previously treated with mitoxantrone or combination chemotherapy containing doxorubicin. Median response duration was 10+ months for responders and 11+ months in patients who had stable disease. It is concluded that weekly-dose doxorubicin has a favourable profile with a low frequency of side effects and that this treatment is an alternative to other cancer chemotherapy in breast cancer, especially when not only CR and PR but even stabilization of disease is considered of benefit to the patient.

A prospective study of morbidity and mortality rates among farmers and rural and urban nonfarmers.

Farmers are known to have lower morbidity and mortality rates than the mean for other occupational groups in the general population. Whether this is due to the urban-rural health gradient or to occupational factors related to farming is not clear. To explore this issue, we conducted a prospective study of farmers and matched rural and urban referents. Official hospital admission and mortality data for the years 1989-1996 were obtained. The relative risk of being admitted to hospital were 10% higher among rural and urban referents than among the farmers. The biggest differences were seen for mental and cardiovascular disorders. The odds of dying during follow-up did not differ between the two rural groups but were doubled among urban referents. In conclusion, the lower morbidity and mortality rates among farmers are partly due to the urban-rural health gradient but in addition salutogenic factors linked to farming seem to be active.

Morbidity in Swedish farmers, 1978-1983, according to national hospital records.

A number of epidemiological studies have shown that farmers have low mortality rates. To examine morbidity risks for male and female farmers in Sweden, the national hospital care registry was updated with information on occupation derived from the census of 1980. The cause-specific morbidity of farmers was compared with the morbidity of all economically active individuals in the same areas. A total of 60,515 farmers and 2,843,217 controls have been studied. The morbidity rates of the farmers were generally low. Male farmers had a significantly lower risk for cancer diseases, mental diseases, cardiovascular diseases, diseases of the digestive system, the uro-genital system, and skin diseases. Female farmers had a lower risk for diseases of the respiratory system, uro-genital system, skin diseases, diseases of the locomotor system, and accidents. A notable discrepancy between males and females concerning cardiovascular diseases was observed Male farmers had a significantly lower risk than other men while female farmers had the same risk level as other economically active women. The relative risk of hospitalization for mental disease was also low. Male farmers had a risk for alcohol-dependent diseases and attempted suicides which was less than one-third of the risk for all economically active men. Concerning work-environment-related diseases in farming, it was shown that young male farmers had low rate ratios. However, the risks were found to increase with every decade, indicating that occupational health risks contribute to morbidity with advancing age.

Change of occupation and retirement among Swedish farmers and farm workers in relation to those in other occupations. A study of "elimination" from farming during the period 1970-1988.

A number of studies carried out in different countries have shown that farmers have a low morbidity and mortality in comparison to those in other occupations. However, this has been questioned on the basis that some type of selective process may be operating, in that persons having health problems will avoid farming, or are forced to leave farming for other occupations. To determine the occurrence of a so-called 'healthy worker effect', this postal survey of 'elimination' from farming and farming-associated occupations has been carried out. A total of 1283 male farmers and 334 male farm workers born in 1935 and active in Sweden in 1970 were taken as the study group. As controls, a similar number of occupationally active men of the same age and living in the same municipalities were randomly chosen. The results showed that farmers changed occupation or retired early less often than those in other occupations did, whereas more farm workers changed occupation and retired than did other workers of the same age. Among the different reasons given for work change/retirement, low income/poor earning capacity was more common among the farmers and farm workers than among the controls. Illness was less common among farmers but tended to be more common among farm workers as cause of work change. Few farmers changed their occupation because they were offered other work, in comparison to those in other occupations. Allergic disease more often led to an occupation change among farmers, while they less often gave cardiac disease and locomotor problems as a reason for change of occupation, this was probably also true for the farm workers.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein metabolism assessed by 1-13C leucine infusions in patients undergoing bone marrow transplantation.

Patients receiving cytoreductive therapy and bone marrow transplantation (BMT) are known to develop marked protein catabolism. To assess the contribution of whole body protein breakdown, amino acid oxidation and incorporation into proteins, plasma leucine kinetics (1-13C-leucine infusion technique) were determined in six patients five times within 14 days before and after cytoreductive therapy (Cyclophosphamide and total body irradiation) and marrow transplantation. Nitrogen balance became negative (-0.20 +/- 0.04 g/Kg/24 hr) after cyclophosphamide (p less than 0.01) and was -0.25 +/- 0.05 g/Kg/24 hr 7 days after BMT in spite of total parenteral nutrition. Plasma leucine concentration increased after BMT by 67% (p less than 0.0015). Leucine plasma appearance was 1.20 +/- 0.15 mumol/kg/min before treatment, it increased slightly and transiently after cyclophosphamide, and increased again from day 5 to day 7 after BMT (p less than 0.01), suggesting increased protein break-down. Leucine oxidation increased from 0.27 +/- 0.07 before therapy to 0.97 +/- 0.16 mumol/kg/min (p less than 0.02) after cyclophosphamide and BMT. Nonoxidative leucine disappearance rate decreased slightly from 0.92 +/- 0.08 to 0.75 +/- 0.16 mumol/kg/min after BMT (ns). Leucine metabolic clearance rate decreased from 11.8 +/- 1.65 before therapy to 6.9 +/- 0.70 ml/kg/min (p less than 0.02) after cytoreductive therapy. After BMT it increased again to 9.9 +/- 1.5 ml/kg/min (p less than 0.02). The results demonstrate that patients undergoing cytoreductive therapy and bone marrow transplantation develop negative nitrogen balance due to increased protein breakdown associated with increased leucine oxidation and increased metabolic clearance rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Reported health status among farmers and nonfarmers in nine rural districts.

Farmers appear to have a lower morbidity and mortality rate than other occupational groups. Whether this better health is due to exposure to farming or to the well-known fact that rural populations have better health than urban ones, irrespective of occupation, is not clear. To explore this problem, all male farmers in nine administrative areas and age-matched nonfarmers from the same rural areas were sampled and invited to participate in a survey. 1782 (76%) men responded. We found that farmers had somewhat lower rates of outpatient health care utilization for causes other than trauma and fewer hospital admissions. These differences were independent of the urban-rural factor and could not be explained by traditional determinants of health and health care utilization. Other factors, linked to farming or to farmers' lifestyles, are probably involved.

Prevalence of antibodies specific to Puumala virus among farmers in Sweden.

OBJECTIVES: The Puumala virus is the causative agent of nephropathia epidemica, a European form of hemorrhagic fever with a renal syndrome. From its reservoir in bank voles, the virus is spread by airborne transmission to humans. Occupational risks for the acquisition of nephropathia epidemica are not well defined. The prevalence of serum antibodies to Puumala virus was determined for Swedish farmers. From a comparison of the prevalence among farmers from various parts of the country, the assumption that Puumala virus occurs endemically only in the northern and central parts of Sweden was also tested. METHODS: Serum samples from 910 farmers and 663 referents living in various rural parts of Sweden were tested with an enzyme-linked immunosorbent assay, using a recombinant nucleocapsid protein of Puumala virus as the antigen. RESULTS: North of a latitude of 59 degrees N, the prevalence of Puumala virus antibodies was significantly higher among farmers (12.9%) than among referents (6.8%). In the southern areas, antibodies to Puumala virus were rare, and altogether only 2 of 459 persons had antibodies. Seropositive persons did not differ from seronegative ones with regard to blood pressure, and they did not comprise cases of chronic renal disease. CONCLUSIONS: Serological evidence confirmed that the exposure of humans to Puumala virus is firmly restricted to the northern and central parts of Sweden. In addition the evidence indicated that, in this region, farming is associated with an increased risk of contracting hantavirus infection.

Psychosocial conditions and access to an occupational health service among farmers.

To determine whether membership in an occupational health service program varies with correlation with psychosocial risk factors, this study was carried out among farmers in connection with a larger investigation of salutogenic factors. The study was based on information collected via questionnaires (answered on location) and standardized interviews. The material consists of 364 farmers or persons engaged in agriculture who had occupational health care and 548 without it. There were clear differences in psychosocial patterns between the groups. Those with occupational health care were less often single and had more education and more social contacts than did those without such care. Eating times were more regular and meals were better in those with occupational health care. Karasek-Theorell's indices for psychological demands and decision latitude at work were also higher in this group. Better-educated farmers and those with larger farms were more often members of an occupational health care program. In addition, this group had fewer psychosocial risk factors.

Differences in the use of health care facilities and patterns of general risk factors in farmers with and without occupational health care programs.

To investigate whether differences in the use of health care facilities and the distribution of risk factors were related to the accessibility of occupational health services, 912 farmers in a large research project were studied. Information was collected from nine different localities in rural areas, using questionnaires, standardized interviews, physical examinations, and blood tests. The results showed that there was hardly any difference in the use of general health care facilities between the groups. Those with occupational health services generally had more medical visits, but also had fewer diagnoses of cardiac disease. Known risk factors were present more often in the group without occupational health services. The work of the occupational health care service and the individual's interest in health questions appeared to be of significance in the way the risk factors were distributed.

Working environment conditions in rural areas according to psychosocial indices.

The aim of this work was to study psychosocial working environment factors among farmers and other people living in rural areas. The study was carried out as a cross-section investigation. All persons visiting local occupational health service centres for a health check up have been asked to answer an inquiry which was based on the Karasek-Theorell questionnaire on job strain. Five extra items on worry about the future were added. The questionnaire was completed by over 3,800 persons. Three of four indices showed significant difference with respect to sex. Women experienced less stimulance at work, authority over work and had a greater fear of the future. Farmers had a significantly higher index for psychological demands, stimulance at work as well as authority over work than other occupational groups. The index for authority over work was very high in comparison with presented results for different occupations in other studies. With respect to worry about the future, the farmers had a significantly higher index than nearly all the other occupational groups. The low risk of coronary heart disease (CHD) among farmers reported in other studies can probably be related to good psychosocial working environment as measured by the indices in this study as well as other known life style factors.

Clinical and surgical staging of Hodgkin's disease.

Staging laparotomy was performed in 36 patients with Hodgkin's disease. The surgical procedure changed the stage in 14 cases or 36% and also revealed subdiaphragmatic disease in 14 patients. Mixed cellularity and nodular sclerosis were the main histopathological types, contributing 44% and 42%, respectively, of the whole material. Postoperative complications occurred in 8 cases (22%)--none was fatal. The average hospital stay was 9.5 days, the longest being 22 days.