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PubMed1997

From population control politics to chemicals: the WHO as an intermediary organization in contraceptive development.

Studies of laboratory work have rarely focused on the role of intermediary organizations in developing R&D activities. Most studies focus on a single university-based research laboratory or an industrial R&D unit. Moreover the rejection by social constructivist scholars of universalistic, deterministic explanations of the development of science and technology has led to an overemphasis on the local features of scientific and technological work. Based on a case study of the role of the World Health Organization (WHO) in contraceptive R&D, this paper suggests that an analysis of the role of intermediary organizations enables us to go beyond a too-narrow focus on the micro-sociological dynamics of laboratory work, to include the macro- and meso-sociological dimensions of science and technology. First, a focus on intermediary organizations enables us to learn more about the manner in which locally specific laboratory cultures are transformed into translocal research practices. This paper shows how literary technologies, and to an even greater extent material technologies, are important tools in accomplishing standardization of local laboratory cultures. Second, a focus on intermediary organizations enables us to study how concerns that go beyond the laboratory--in this case, population control policies and the agenda of the WHO--help to shape laboratory practices.

Contraceptive Devices↗
PubMed2001

Further studies of blood levels of some tumor markers in the area polluted by polychlorinated biphenyls and control population.

The levels of beta2-microglobulin (beta2-m), alpha-fetoprotein (AFP) and thyroglobulin (TG) were measured in the serum of 245 employees of chemical factory formerly producing polychlorinated biphenyls (PCB) consisting of 54 males (age range 24-65 years, median 45) and 191 females (age range 20-69 years, median 45). The control population consisted of 636 adults from control areas of northwest and east Slovakia. The frequency of beta2-microglobulin levels lower than 1.6 microg/ml in 242 employees of chemical factory was 76.8% (186/242) which was three times higher (P<0.001) than 24.4% (155/635) in 636 controls. Still more remarkable difference was obtained when using the cut/off level of 1.2 microg/ml, the frequency of such values in the employees being 45.4% (110/242) vs. 4.4% (28/635) in the controls. In contrast, no difference in alpha-fetoprotein levels was observed between the employees and the controls, the respective frequency of these < 5.0 ng/ml being 87.6% (212/242) vs. 86.2% (389/451) and these < 10.0 ng/ml being 100.0% (242/242) vs. 97.8% (441/451). Similarly, the frequency of normal thyroglobulin levels < 50.0 ng/ml) did not differ, being 95.6% (174/182) in the employees and 87.9% (87/99) in the controls. Most of a total of 20 cases with thyroglobulin level > 50.0 ng/ml showed sonographicaly enlarged and multinodular thyroid with focal or diffuse hypoechogenicity, three of them showed solitary nodule with a diameter > 10 mm. Although the decreased levels of beta2-microglobulin might be somehow related to the modulation of immune system, more plausible explanation appears to be the possible impairment of renal tubules by PCB similar to that caused by heavy metals resulting in increased urinary excretion of beta2-microglobulin and decrease of its blood level.

Adult↗
PubMed1989

Seasonality of birth in schizophrenia. An insufficient stratification of control population?

The seasonality of birth in 142 schizophrenics from Barcelona (Spain) has been studied, showing a pattern similar to that described by other authors, with a maximum in winter. If sample is compared with the local general population there are significant differences, but these disappear when the comparison is made with a control population properly stratified by age, sex, place of birth, place of residence and social status. The same results are obtained using statistical methods suggested by other authors. The seasonality pattern usually obtained in schizophrenia could be due to a selective stratification of the ill population based on variables that might or might not be related to illness.

Adolescent↗
PubMed2004

Population control of the malaria vector Anopheles pseudopunctipennis by habitat manipulation.

Insect vector-borne diseases continue to present a major challenge to human health. Understanding the factors that regulate the size of mosquito populations is considered fundamental to the ability to predict disease transmission rates and for vector population control. The mosquito, Anopheles pseudopunctipennis, a vector of Plasmodium spp., breeds in riverside pools containing filamentous algae in Mesoamerica. Breeding pools along 3 km sections of the River Coatan, Chiapas, Mexico were subjected to algal extraction or left as controls in a cross-over trial extending over 2 years. Initial densities of An. pseudopunctipennis larvae were directly proportional to the prevalence of filamentous algae in each breeding site. The extraction of algae brought about a striking decline in the density of An. pseudopunctipennis larvae sustained for about six weeks, and a concurrent reduction in the adult population in both years of the study. Mark-release experiments indicated that dispersal from adjacent untreated areas was unlikely to exert an important influence on the magnitude of mosquito control that we observed. Habitat manipulation by extraction of filamentous algae offers a unique opportunity for sustainable control of this malaria vector. This technique may represent a valuable intervention, complimenting insecticide spraying of households, to minimize Plasmodium transmission rates in Mesoamerica.

Analysis of Variance↗
PubMed1963

Population control in animals by overloading resources with sterile animals.

Sterile animals might be introduced into a population to overload a resource. As a result, some of the original fertile animals might be lost by migration or death. This process could be repeated until the fertile population was eradicated without the mating required by Knipling's models. This method may be of use in ecology and in economic control of populations.

Animals↗
PubMed2005

Increased length of hospital stay in underweight and overweight patients at hospital admission: a controlled population study.

BACKGROUND: Reduced lean tissue as well as high fat mass may be independent nutritional risk factors resulting in increased length of hospital stay (LOS). This controlled population study (1707 patients, 1707 volunteers) aimed to evaluate the association between LOS in Geneva and Berlin patients at hospital admission and high fat mass index (FMI, kg/m2) and low fat-free mass index (FFMI, kg/m2), and the respective value of body mass index (BMI) and of FFMI and FMI for nutritional assessment. METHODS: Patients (891 men, 816 women) were prospectively recruited at hospital admission and compared to gender-, age- and height-matched healthy volunteers. Fat-free mass and fat mass, determined at admission by 50 kHz-bioelectrical impedance analysis, were expressed as indices (FFMI and FMI-kg/m2) to normalize for height. Patients were classified in four groups: normal, low FFMI, high FMI, or low FFMI and high FMI. Logistic regressions were used to determine the association between body composition and LOS. RESULTS: Higher FMI and lower FFMI were found in patients at hospital admission than in sex- and age-matched healthy volunteers. Low FFMI, high FMI, and low FFMI/high FMI combined, adjusted for age, were all significantly associated with longer LOS (high FFMI: 1-5 days OR 2.4, CI 2.0-2.9; 6-10 days OR 2.3, CI 1.8-3.0; 11 days OR 2.8, CI 2.2-3.5); low FMI: 1-5 days OR 1.9, CI 1.6-2.2; 6-10 days OR 2.7, CI 2.0-3.5, 11 days OR 2.1, CI 1.7-2.7; low FFMI/high FMI: 1-5 days OR 7.8, CI 5.3-11.4; 6-10 days OR 13.6, CI 7.8-23.5, 11 days OR 11.8, CI 7.0-19.8). CONCLUSION: Increased LOS is associated with adiposity (high FMI) and low muscle mass (low FFMI). The current study shows that both depletion of lean tissue and excess of fat mass negatively affect the LOS. Finally, we found that excess fat mass reduces the sensitivity of BMI to detect nutritional depletion.

Adipose Tissue↗
PubMed2005

Long-term monitoring of bacteria undergoing programmed population control in a microchemostat.

Using an active approach to preventing biofilm formation, we implemented a microfluidic bioreactor that enables long-term culture and monitoring of extremely small populations of bacteria with single-cell resolution. We used this device to observe the dynamics of Escherichia coli carrying a synthetic "population control" circuit that regulates cell density through a feedback mechanism based on quorum sensing. The microfluidic bioreactor enabled long-term monitoring of unnatural behavior programmed by the synthetic circuit, which included sustained oscillations in cell density and associated morphological changes, over hundreds of hours.

4-Butyrolactone↗
PubMed2001

Differential interactions between GSTM1 and NAT2 genotypes on aromatic DNA adduct level and HPRT mutant frequency in lung cancer patients and population controls.

We have studied the influence of GSTM1 and NAT2 genotypes on aromatic DNA adduct level (AL) and HPRT mutant frequency (MF) in smokers with newly diagnosed lung cancer and matched population controls. AL was analyzed in relation to genotypes in 170 cases and 144 controls (113 current/recent smokers and 201 former/never smokers), and MF in 157 cases and 152 controls (155 ever smokers and 154 never smokers). Both genotypes exhibited the a priori expected effects on AL and MF among controls only, especially among smoking controls [significantly lower pack-years (a pack-year is defined as 1 pack of cigarettes/day for 1 year) than among cases]. Among the 42 currently smoking controls, the NAT2 slow genotype [odds ratio (OR), 7.5; 95% confidence interval (CI), 1.5-38.4], in particular in combination with the GSTM1 null genotype (OR, 19.3, 95% CI, 1.1-338.6 for null/slow versus positive/rapid) was strongly associated with high AL. The null/slow combination was also significantly associated with high MF among ever smokers (cases and controls pooled) with lower pack-years (OR, 3.7; 95% CI, 1.3-10.7 versus all of the other genotypes; OR, 5.1; 95% CI, 1.2-22.4 versus positive/rapid). In contrast, an antagonistic gene-gene interaction was seen among smoking cases for both AL and MF. Only currently smoking cases with the combined GSTM1 null and NAT2 rapid genotype showed a positive correlation between InAL and InMF (r, 0.64; P = 0.1), and an increase of AL with both age and daily cigarette use. This genotype combination was also associated with high MF among ever-smoking cases (OR, 4.0; 95% CI, 0.9-17.7 versus positive/rapid). There was a significant interaction between NAT2 genotype and pack-years of smoking among cases, so that the rapid genotype was associated with high MF among ever-smoking cases diagnosed at higher pack-years, whereas the slow genotype was associated with high MF at lower pack-years. These findings suggest that the influence of NAT2 genotype on AL and MF and its interaction with GSTM1 genotype may be dose dependent. The NAT2 slow genotype, in particular when combined with the GSTM1 null genotype, may confer increased susceptibility to adduct formation, gene mutation, and lung cancer when the smoking dose is low.

Adult↗
PubMed2004

Programmed population control by cell-cell communication and regulated killing.

De novo engineering of gene circuits inside cells is extremely difficult, and efforts to realize predictable and robust performance must deal with noise in gene expression and variation in phenotypes between cells. Here we demonstrate that by coupling gene expression to cell survival and death using cell-cell communication, we can programme the dynamics of a population despite variability in the behaviour of individual cells. Specifically, we have built and characterized a 'population control' circuit that autonomously regulates the density of an Escherichia coli population. The cell density is broadcasted and detected by elements from a bacterial quorum-sensing system, which in turn regulate the death rate. As predicted by a simple mathematical model, the circuit can set a stable steady state in terms of cell density and gene expression that is easily tunable by varying the stability of the cell-cell communication signal. This circuit incorporates a mechanism for programmed death in response to changes in the environment, and allows us to probe the design principles of its more complex natural counterparts.

Cell Division↗
PubMed2004

Driving behavior of alcohol, cannabis, and cocaine abuse treatment clients and population controls.

BACKGROUND/INTRODUCTION: A paucity of research exists on driving after use of cannabis or cocaine among clients in substance abuse treatment and changes in this behavior after treatment. OBJECTIVES: The objectives of this research are to compare treatment clients and population controls before and after treatment in terms of: 1) amount of driving; 2) alcohol, cannabis, and cocaine consumption; 3) driving after use of alcohol, cannabis, and cocaine; and 4) driving infractions. METHOD: Telephone interviews were conducted with a sample of 110 clients who received treatment in 1995 for a primary problem of alcohol (n = 44), cannabis (n = 37), or cocaine (n = 29) abuse. A random sample of 104 drivers from the general population, frequency matched by age and sex was also interviewed. Participants were asked to describe their driving habits and driving infractions before and after 1995. RESULTS: Both treatment and control groups reported about the same amount of driving. The treatment group reported significantly more consumption of alcohol, cannabis, and cocaine than did the control group before treatment. Significant declines in use for each substance were found for the treatment group after treatment, but use for the control group remained stable over the two time periods. Similarly significant declines in driving after use of alcohol, cannabis, and cocaine were found for the treatment group but the control group remained stable. Finally driving infractions, including speeding tickets, collisions, and license suspensions, significantly declined for the treatment group but not the control group. DISCUSSION: The results confirm that before treatment, the treatment subjects drove more frequently after consuming alcohol, cannabis, or cocaine than the control group. Declines in substance use and driving after treatment were accompanied by reductions in some types of driving infractions. Differences between groups, and over time in terms of driving while under the influence of psychoactive substances better explain the results than differences between groups in impulsivity/risk-taking or sleep problems.

Adult↗