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Biomedical subjects

G Salem

Publications and source records attributed to G Salem.

At least 19 recordsLinked to original sources
PubMed2005

Sizing up human health through remote sensing: uses and misuses.

Following the launch of new satellites, remote sensing (RS) has been increasingly implicated in human health research for thirty years, providing a growing availability of images with higher resolution and spectral ranges. However, the scope of applications, beyond theoretical large potentialities, appears limited both by their technical nature and the models developed. An exhaustive review of RS applications in human health highlights the real implication thus far regarding the diversity and range of health issues, remotely sensed data, processes and interpretations. The place of RS is far under its expected potential, revealing fundamental barriers in its implementation for health applications. The selection of images is done by practical considerations as trivial as price and availability, which are often not relevant to addressing health questions requiring suitable resolutions and spatio-temporal range. The relationships of environmental variables from RS, geospatial data from other sources for health investigations are poorly addressed and usually simplified. A discussion covering the potential of RS for human health is developed here to assist health scientists deal with spatial and temporal dynamics of health, by finding the most relevant data and analysis procedures.

Animals↗
PubMed2003

[African towns and health: references and stakes].

Urbanization is a fairly recent phenomenon. Thus during the 19th century, only 5% of the population was living in town. However it is more and more important as urban population has been multiplied by 15 since 1900. In Africa, this evolution is still more recent and the continent remains poorly urbanized. But the rate of urbanization is the fastest in the world and demographic forecasts indicate that by 2025, more than 50% of the African population will live in towns. Consequences of urbanization on human development are not well known. Concepts of demographic and epidemiological transitions were widely used for health. Health transition is another concept, including cultural, social and behavioural determining factors as well as ways of caring and being cared for. These processes account for the reduction of infectious diseases through a fall of mortality and birth rates and the emergence of non-transmissible diseases like cardiovascular diseases, cancers, mental diseases.... Although health situation is depicted as better in towns (better immunization, health care offer, better access to health care...), mortality and morbidity patterns seem to change more quickly in towns than in rural areas. However this is not true everywhere in urban areas where several towns are to be found within the same town and for example, health of populations living on margins may be worse than that of rural populations. Urban people resort to modern health care together with traditional healers, even informal, sometimes illegal health care, involving heavy costs but offering no guarantee as regards their quality and their efficiency for patients and society. It appears that developing countries have to face a new health care demand quite different from the one they used to face before, when they have simultaneously to cope with uncontrolled town growth. Under these conditions, urban health should become a priority.

Africa↗
PubMed2000

[Surgical quality assurance in the largest federal district of Austria--introduction of a project].

On the basis of permanently rising costs in health care on the one hand and limited budgets on the other hand as well as the increasing importance of correct and comprehensive quality assurance, we developed protocols for nine different surgical tracer-diagnosis. These protocols include the minimum standards of the medical, nursing and administrative area per day of treatment. After one year of trial at three surgical departments of different capacity, treatment-spectrum and equipment, revised protocols will be implemented at all 23 surgical departments in our federal state if necessary.

Austria↗
PubMed1999

[Geographic differences of bronchopulmonary cancer mortality in France and spatial scales of analysis: significance of scale change in health geography].

BACKGROUND: It is important to choose a valid spatial scale to study health differences in a geographical perspective. Many scales can be valid and a combination is required to understand the spatial distribution of a given health problem. Geographic distribution of lung cancer was studied in France using different scales to illustrate the importance of changing scales in health geography. METHODS: Standardized rates (direct method) for lung cancer were calculated for the period 1988-92 and mapped at different scales. RESULTS: Original spatial structure was observed for each scale. This proved that different interactions occur at each scale between environmental and social factors. Changing the scale allowed a better understanding of variations in the spatial distribution of lung cancer. CONCLUSIONS: The validity of a regional scale to study health geographical distributions is questioned. Changing the scale would allow proposing action to improve health promotion.

Bronchial Neoplasms↗
PubMed1998

Combined intravenous and intraperitoneal chemotherapy with fluorouracil + leucovorin vs fluorouracil + levamisole for adjuvant therapy of resected colon carcinoma.

Adjuvant chemotherapy with fluorouracil (FU) and levamisole or FU/leucovorin (LV) has been established as effective adjuvant treatment for patients with stage III colon cancer. Among several other promising treatment strategies in resected colon cancer, intraperitoneal anti-cancer drug administration with its appealing rationale of counteracting microscopic residual disease on peritoneal surfaces and occult metachronous liver metastases by achieving high intraportal drug concentrations has not yet undergone sufficient clinical evaluation. To determine whether a combination of this locoregional therapeutic concept with systemic intravenous administration of FU/LV would yield better results than conventional adjuvant chemoimmunotherapy with FU/levamisole, the present randomized study was initiated. A total of 241 patients with resected stage III or high-risk stage II (T4N0M0) colon cancer were randomly assigned to 'standard therapy' with FU and levamisole, given for a duration of 6 months, or to an investigational arm, consisting of LV 200 mg m(-2) plus FU 350 mg m(-2), both administered intravenously (days 1-4) and intraperitoneally (days 1 and 3) every 4 weeks for a total of six courses. In patients with stage II disease, no significant difference was noted between the two arms after a median follow-up time of 4 years (range 2.5-6 years). Among 196 eligible patients with stage III disease, however, a comparative analysis of the two treatment groups suggested both an improvement in disease-free survival (P = 0.0014) and a survival advantage (P = 0.0005), with an estimated 43% reduction in mortality rate (95% confidence interval 26-70%) in favour of the investigational arm. In agreement with its theoretical rationale, combined intraperitoneal and intravenous FU/LV was particularly effective in reducing locoregional tumour recurrences with or without liver or other organ site involvement (9 vs 25 patients in the FU/levamisole arm; P = 0.005). Treatment-associated side-effects were infrequent and generally mild in both arms, although a lower rate of severe (WHO grade 3) adverse reactions was noted in patients receiving locoregional plus intravenous chemotherapy (3% vs 12%; P = 0.01). The results of this trial suggest that combined intraperitoneal plus systemic intravenous chemotherapy with FU/LV is a promising adjuvant treatment strategy in patients with surgically resected stage III colon carcinoma.

Adenocarcinoma↗
PubMed1997

Fluorouracil plus racemic leucovorin versus fluorouracil combined with the pure l-isomer of leucovorin for the treatment of advanced colorectal cancer: a randomized phase III study.

PURPOSE: To compare the efficacy and toxicity of fluorouracil (FU) and racemic leucovorin (d,l-LV) versus FU combined with the l-isomer of leucovorin (l-LV) in the treatment of advanced colorectal cancer. PATIENTS AND METHODS: A total of 248 patients with advanced measurable colorectal cancer previously unexposed to chemotherapy were randomly assigned to treatment with either FU (400 mg/m2/d by intravenous [I.V.] infusion for 2 hours) and racemic LV (100 mg/m2/d by I.V. bolus injection) given for 5 consecutive days, or the combination of FU and the pure l-isomer of LV using the same dose schedule. In both treatment arms, courses were administered every 28 days if toxicity allowed for a total of 6 months, unless evidence of tumor progression was documented earlier. RESULTS: There were no significant differences between the FU/racemic LV and the FU/l-LV arm in the overall response rate (25% v 32%), duration of response (7.2 v 8.0 months), median time to progression or death (6.25 v 8.0 months), or median overall survival time (14.5 v 15.0 months). Except for minor myeloid toxic effects associated with FU/l-LV, there was also no significant difference in terms of adverse reactions. Gastrointestinal symptoms, specifically mucasitis and diarrhea, were less frequent and less severe in both treatment arms compared with other trials with FU/racemic LV reported in the literature, which might be because of the prolonged administration of FU used in both arms. CONCLUSION: The combination of FU/l-LV produced response rates, response durations, and survival times similar to those with FU/d,l-LV. Biochemical modulation of FU by either pure l-LV or racemic LV thus appears to result in equivalent clinical efficacy.

Adult↗
PubMed1994

[Intestinal parasitic diseases and environment in Sahelo-Sudanese towns: the case of Pikine (Senegal)].

A survey carried out in Pikine (Senegal) on a sample of 5 groups of children drawn from ecologically representative sections of the town confirms the high prevalence in urban areas of Africa of intestinal infection, especially A. lumbricoides (35.6%), T. trichiura (35.4%), and Giardia (43.7%). The prevalence of A. lumbricoides (35.6%), T. trichiura (35.4%), and Giardia (43.7%). The prevalence of A. lumbricoides and T. trichiura are appreciably higher in the oldest sectors of the town or in those with a better sanitary standard: up to 47.7% for Ascaris and 46% for Trichuris. The use of X2 tests and log-linear analysis demonstrates a significant association between Ascaris and Trichuris. The highest prevalence for Giardia (56.8%) were to be found on the outskirts of the town, where the lowest prevalence of Ascaris (21.7%) and Trichuris (22.9%) were noted; moreover, age-based prevalence for the three parasites vary from one ecological area to another. The relationship between the urbanization process, the variation in environmental factors and intestinal parasitic infection, and the operational implications arising from this geographically-based approach are discussed.

Animals↗
PubMed1993

[Geography of mortality and birth in Pikine (Senegal): value and limitations of findings of the Civil State in African villages].

Research conducted in Third World towns show the heterogeneity of health population status. Among the indicators, mortality and birth are the most frequent, but the quantity of data and the classical methods in demography make the localisation of high-risk population difficult. Civil Registration Data Base are seldom studied, especially by geographers. The author analyses the interest and limits of these data in a spatial perspective, i.e. mortality and birth rates, mortality and birth volumes, seasonal variations of mortality, and relations between seasonal variations and health system activities. The author's conclusion is on the necessity to include these indicators in the health information system after complementary research on possible bias.

Adolescent↗
PubMed1993

Site and mechanical conditions for failure of skeletal muscle in experimental strain injuries.

Failure in muscle strain injuries has been reported to occur within the muscle belly, at the myotendinous junction, or within muscle near the myotendinous junction. The goal of this investigation was to determine by electron-microscopic examination the site of lesion in whole muscle strained to failure. In addition, site and conditions for failure of stimulated and unstimulated muscle were compared. Frog semitendinosus myotendinous units with intact tendon-bone junctions were strained at physiological strain rates to failure. All failures occurred at or near the proximal myotendinous junction in both stimulated and unstimulated muscle. Stimulated muscle required approximately 30% more force and approximately 110% more energy to reach failure. Electron-microscopic examination of longitudinal sections of small bundles of fibers showed that unstimulated muscle failed within the muscle near the myotendinous junction. Failure occurred in a single transverse plane of each cell within Z disks. Other Z disks near the failure site displayed strains of several hundred percent. Stimulated muscle failed within the lamina lucida at the myotendinous junction in most fibers. No Z-disk strain was observed in those fibers. We conclude that the site of failure in muscle strain injuries varies with the state of activation of the cell at the time of injury. Furthermore, the data show that the breaking strength of the Z disk varied with muscle stimulation and indicate the existence of two load-bearing systems in parallel within Z disks.

Animals↗
PubMed1993

Hypertension during pregnancy in Africa and infants' health. A cohort study in an urban setting.

The objective of the study was to assess the prevalence of unclassified hypertension during pregnancy and its consequences on infant's health in an African urban setting: Pikine, a suburb of Dakar, Senegal. A cross-sectional study of a random sample of pregnant women and a prospective study, from the inclusion to seven days after delivery, were performed. 886 women attending the prenatal centers were included in the cross-sectional study. 471 pregnant women were included in the follow-up study. The prevalence of DBP > or = 120 mmHg was 0.7%; 5.7% of the women had DBP > or = 95 mmHg. Longitudinal data were available for 425 deliveries. Two spontaneous abortions, 25 stillbirths, and 12 deaths during the early neonatal period were recorded. Among babies living at birth, the percentage of LBW (> or = 2500 g) was 8.5%. The percentages of adverse outcome of pregnancy (death and/or low birth weight) was associated with mothers' diastolic BP: < 85 mmHg: 13%; 85 to 89: 16%; 90 to 94: 9%; DBP > or = 95: 32%, (p < 0.01). Using 95 mmHg as a cutpoint, the relative risk of adverse outcome associated with a DBP > or = 95 mmHg was 2.5 (CI 95%: 1.4-4.3). This risk was significantly increased among women who reported difficult living conditions. Eight percent of the adverse outcomes of pregnancy, 10% of the low birth weights and 8% of the perinatal mortality were found to be associated with DBP > or 95 mmHg.

Adolescent↗
PubMed1993

Malaria morbidity among children exposed to low seasonal transmission in Dakar, Senegal and its implications for malaria control in tropical Africa.

To measure morbidity due to malaria and to study its relationship with transmission and parasitemia in children living in an area of low malaria endemicity, a cohort study of 343 schoolchildren was undertaken during a one-year period in Dakar, Senegal. From parallel investigations on transmission and the frequency of malaria as a cause for outpatient visits, three different seasons were chosen for close monitoring of different clinical parasitologic, and sero-immunologic parameters. The daily incidence rates of malaria parasitemia and primary attacks were at a maximum level during the high transmission season (0.00198 and 0.00185 new cases/person/day, respectively) and decreased considerably during the season of low transmission. For each given period, the values of these two rates were close to each other, suggesting that each new infection was followed by a clinical attack. During the period of maximum transmission, clinical malaria prevalence was 1.36% and malaria was responsible for 36% of school absences due to medical reasons. At the end of the period of minimum transmission, clinical malaria prevalence was 0.15% and malaria was responsible for 3% of school absences due to medical reasons. In contrast, parasite prevalence hardly varied with the season (minimum 3.6%, maximum 7.5%). In a one-year period, the total number of new malarial infections was estimated between 173 and 230. Because of the existence of a vector density gradient in the area concerned, the annual malaria incidence varied considerably according to the children's place of residence.(ABSTRACT TRUNCATED AT 250 WORDS)

Absenteeism↗
PubMed1992

Vector density gradients and the epidemiology of urban malaria in Dakar, Senegal.

The dispersion of anopheline mosquitoes from their breeding places and its impact on malaria epidemiology has been investigated in Dakar, Senegal, where malaria is hypoendemic and almost exclusively transmitted by Anopheles arabiensis. Pyrethrum spray collections were carried out along a 910-meter area starting from a district bordering on a permanent marsh and continuing into the center of the city. According to the distance from the marsh, vector density (the number of An. arabiensis per 100 rooms) at 0-160, 160-285, 285-410, 410-535, 535-660, 660-785, and 785-910 meters was 84, 40, 5, 2, 2, 0.4, and 0, respectively, during the dry season, and 414, 229, 110, 84, 99, 69, and 21, respectively, during the rainy season. The proportion of 8-11-year-old children with negative immunofluorescent antibody test results for Plasmodium falciparum was 17%, 28%, 44%, 54%, 50%, 63%, and 73%, respectively, in these different sections. Malaria prevalence in the community was maximum in the area bordering on the marsh where it ranged from 1% to 15% (average 6%) according to age and season of the year. These findings show the epidemiologic importance of vector density gradients in Dakar. The implications for malaria control in urban areas are discussed.

Adolescent↗