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At least 811 records · Page 45Linked to original sources

PubMed2003

Evaluation of the measurement of the fetal fat layer, interventricular septum and abdominal circumference percentile in the prediction of macrosomia in pregnancies affected by gestational diabetes.

OBJECTIVES: To evaluate the measurement of the fetal abdominal fat layer (FFL), cardiac interventricular septum (IVS) and abdominal circumference (AC) percentile in the early third trimester as predictors of macrosomia at birth in the fetuses of women with gestational diabetes. METHODS: Ninety patients attending the hospital's special diabetic clinic were recruited prospectively. FFL and IVS were measured in addition to the routine biometry in the early third trimester. AC was measured routinely and AC percentile was determined from established antenatal charts. These measurements were then assessed as predictors of macrosomia. RESULTS: A fetal fat layer of >/=5 mm was the most useful predictor of macrosomia at term as assessed using the likelihood ratio. An AC >/=90th percentile, however, had a better sensitivity. CONCLUSION: The usefulness of routine FFL measurement in the early third trimester in the management of diabetic pregnancies is worthy of further evaluation.

Abdomen↗

PubMed2004

Sex-specific fetal weight prediction by ultrasound.

OBJECTIVE: To improve sonographic birth-weight prediction by developing fetal gender-specific formulae. METHODS: This was a retrospective cross-sectional study. Two gender-specific formulae were produced from the data of 527 patients and the data of a further 349 patients were used to evaluate the formulae. Inclusion criteria were a singleton live fetus, gestational age above 25 weeks, birth weight between 1000 g and 4500 g and fetal biometry within 8 days of delivery. Data retrieval was specifically for the purpose of this study. RESULTS: To yield the best-fit weight formula for each fetal gender we employed step-wise regression analysis based on fractional polynomials with the biometric parameters biparietal diameter (BPD), head circumference (HC), transverse abdominal diameter (TAD), abdominal circumference (AC) and femur length (FL): estimated fetal weight for girls (g) = - 4035.275 + 1.143 x BPD3 + 1159.878 x AC1/2 + 10.079 x FL3 - 81.277 x FL2 [in cm]; estimated fetal weight for boys (g) = 43576.579 + 1913.853 x log10BPD + 0.01323 x HC3 + 55.532 x AC2 - 13602.664 x AC1/2 - 0.721 x AC3 + 2.31 x FL3 [in cm]. These formulae showed superior results compared with those of conventional weight formulae. CONCLUSION: Gender-related fetal weight calculation allows optimized prediction of fetal weight at birth.

Adolescent↗

PubMed2004

Sex-specific antenatal reference growth charts for uncomplicated singleton pregnancies at 15-40 weeks of gestation.

OBJECTIVE: Female fetuses, on average, weigh less than male fetuses at all gestational ages. The purpose of this study was to compare female and male fetuses in terms of intrauterine ultrasound growth measurements and to develop gestational-age-related charts based on a computerized perinatal database. METHODS: This was a retrospective study of unselected women in the second and third trimesters of pregnancy, who had a normal scan at 10-14 weeks. Data analysis was performed using measurements obtained from a mixed-race population of 4234 women, who underwent 5198 ultrasound examinations. The scans were performed by four trained sonographers, according to a standardized protocol. Routine measurements included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). The main end-points were sex- and race-specific differences in fetal biometry, which were also used to estimate fetal weight. RESULTS: The base-line demographic characteristics and risk factors were comparable in female and male fetuses. Significant differences in fetal BPD, HC, AC and estimated fetal weight, but not FL, were seen between male and female fetuses. Centile charts for each of these variables were constructed for both male and female fetuses. CONCLUSIONS: This study suggests that small but consistent sex-related differences in prenatal BPD, HC and AC measurements are established by as early as 15 weeks of gestation. The use of sex-specific nomograms may improve the prenatal assessment of fetal growth as well as the diagnosis of structural abnormalities.

Embryonic and Fetal Development↗

PubMed1988

Renal growth in patients nephrectomized for Wilms tumour as compared to renal agenesis.

Compensatory growth in 27 undiseased congenital solitary kidneys and in 31 solitary kidneys in patients with Wilms tumour was monitored in long-term follow-up studies by ultrasound volume biometry. In congenital solitary kidneys hypertrophy was not detectable at the time of birth. Parenchymal mass increase achieved 188% of the volume of a healthy kidney within at least 4 years of life and afterwards paralleled the physiological growth documented in healthy kidney pairs. Disease-free kidneys in Wilms tumour patients all developed a similar 180% volume augmentation within 2-4 years after nephrectomy, irrespective of the chosen mode of radiation and single or triple chemotherapy. The age of the patient at onset of surgical and concomitant conservative therapy determined slight differences in kinetics but not in degree of compensatory growth.

Adolescent↗

PubMed1993

Heritability of myopic refractive errors in identical and fraternal twins.

The existence of a visual feedback control of eye growth in humans is controversial, as the contributions of genetic and environmental factors are still unknown. To evaluate the heritability of refractive defects, we measured ocular refraction in 19 monozygote and 20 dizygote twin pairs (mean age 5 years). Monozygosity was ascertained by a common chorion, similarity of somatic traits, and identical dermatogliphes and was confirmed in myopes by blood marker diagnosis. Ocular refractive defects and axial length were evaluated by cycloplegic autorefractometry and biometry. By comparing identical and fraternal twins heritability of refractive defects was estimated to be 0.08-0.14; this low value indicates that the observed variability in refractive errors is nongenetic in origin. Three monozygote pairs were anisomyopic; differences between eyes in identical twins were related to the increased axial length of myopic eyes. In one eye, myopia was attributed to visual deprivation induced by a congenital cataract, while in five eyes it was correlated directly to the degree of astigmatic defects. The discordant axial length observed in monozygote twins is nongenetic. In agreement with previous findings reported in the literature, it is proposed that visual impoverishment of retinal images may play an early regulatory role in postnatal eye growth.

Blood Grouping and Crossmatching↗

PubMed1995

The exponentiation formula of reliability and survival: does it always hold?

In reliability and biometry, it is common practice to choose a failure model by first assessing the failure rate function subjectively, and then invoking the well known "exponentiation formula". The derivation of this formula is based on the assumption that the underlying failure distribution be absolutely continuous. Thus, implicit in the above approach is the understanding that the selected failure distribution will be absolutely continuous. The purpose of this note is to point out that the absolute continuity may fail when the failure rate is assessed conditionally, and in particular when it is conditioned on certain types of covariates, called "internal covariates". When such is the case, the exponentiation formula should not be used.

Ceramics↗

PubMed1998

New approaches to human facial morphology using automatic quantification of the relative positions of the orbital and nasal apertures.

The purpose of this study was to define and quantify the relative positions of the orbital and nasal apertures in the human face. The material consisted of 44 skulls (32 males, 12 females). For each skull, an image of the projection of the face was captured perpendicular to the palatal plane, using a CCD camera. The orbital and nasal apertures were segmented and characterized using classical image analysis procedures. New quantitative parameters were automatically determined from the centres of area of the facial apertures, and from horizontal and vertical lines of reference. Sexual differences were only significant for orbital height, nasal height, and orbitonasal height. A medio-lateral orbitonasal overlap, as well as a vertical orbitonasal overlap, existed in all individuals; the vertical overlap was always much more marked than the medio-lateral overlap. Significant proportions of the human face were also demonstrated: on average, the interorbital breadth corresponded to a fifth of the biorbital breadth, and thus to half of the mean orbital breadth; the nasal breadth corresponded to one fourth of the biorbital breadth, and the vertical orbitonasal overlap to one fourth of the orbitonasal height. Some instructive significant correlations were observed between these new parameters. The applications of the present methodology seem of great potential interest in anthropology and clinical biometry.

Adult↗

PubMed1999

Study of the variations in length of the anterior cruciate ligament during flexion of the knee: use of a 3D model reconstructed from MRI sections.

The aim of this study is to suggest an anatomic study of the modifications of the length of the anterior cruciate ligament (ACL) and its bundles during flexion with the aid of a 3D computerized model of the knee in a living subject. The method of evaluation suggested is a 3D computerized reconstruction based on MRI sections, reproducing the movement of flexion of the knee from 0 to 75 degrees. Twenty-one sections were made for each of the 13 positions of flexion. The reconstruction of Delaunay and the realignment of each position provided a 3D model which allowed monitoring of a bony point during the movement. By knowing the relative displacement of the ligamentous attachments it was possible to define the biometry of the ligament by calculating the length of the bundles of the ACL in each position and to demonstrate the variations in length during the movement. The mean length of the ligament was 3.4 mm. The anteromedial bundle was longer by 30% compared with the other two bundles. During flexion the anteromedial bundle was not much modified (this feature seems to provide a reference position for a ligamentoplasty), the posterolateral bundle became taut after 30 degrees, and the intermediate bundle relaxed from the beginning of movement. Based on the data from the literature, this method allows an anatomic approach to the ACL, bundle by bundle, during flexion movement.

Anterior Cruciate Ligament↗

PubMed1989

[The importance of animal models for progress in science].

Experimental animals may serve as models for human beings, if analogies between animal and human functions exist. Therefore, the selection of species and strain plays an important role in the development of such models. Knowledge of the nutritional and physiological characteristics of a species is a prerequisite for the composition of complete diets. Often, preliminary work has to begin at the breeding farm in order to make use of such curative models possible. Only when the high requirements of standardization of experimental animals are met can clinical and subclinical symptoms be determined distinctly. By means of sensitive biochemical reactions, imbalances and interactions of nutritive and active ingredients, as well as successful substitutions, can be recorded. The study of absorption and metabolism of preparations is made possible by observing these reactions. However, negative influence on the results of analysis must be eliminated by correct selection of narcotics, and the proper excision and storage of organs. Because of its importance for the planning and evaluation of experiments, biometry is an integral part of every research project. The scientific information which must be gained from the whole experimental animal cannot be substituted by either isolated organs and cell cultures, or by means of computer simulation. A demanding effort, which includes biotechnological methods, is necessary to further reduce the number of experimental animals and, simultaneously, to enhance experimental evidence. In any case, all scientific aims must be in accordance with the ethical principles of the Society for the Prevention of Cruelty to Animals.

Animal Feed↗

PubMed1988

Anatomic basis of vascular exclusion of the liver.

Segmental occlusive phlebography of the IVC, coupled with a slit in its posterior wall, injection of corrosive substances into the portal and hepatocaval network, biometry of the retrohepatic IVC and serial sections of injected livers from 64 subjects allowed a study of the anatomica aspects of VEL: the Pringle maneuver and clamping of the IVC above and below the hepatocaval connexion. Surgery for hepatic tumors close to the connexion can benefit from VEL but the right suprarenal and inferior phrenic veins must be clamped. Clamping of the suprahepatic IVC is dependent on the site at which the clamp is applied in relation to the diaphragm; an abdominal approach is possible in 79% of cases. The principal right hepatic vein, lacking a collateral over 1 cm external to the liver in one of every 2 cases, can be controlled outside the liver after mobilization of the lobe right of the liver, but caution is needed because of the predominance of "accessory" hepatic veins in 20% of cases. Control of the hepatic veins external to the liver on the left side is dangerous since a common trunk between the middle and left veins is frequent (84%). Collateral branches are also numerous and often vulnerable. Section of the left triangular ligament must be cautious. The relations between the hepatocaval connexion, diaphragm and right atrium also define modalities in the treatment of hepatic lesions such as membranes in the terminal IVC and the Budd-Chiari syndrome.

Adrenal Glands↗

PubMed1985

Kidney size in childhood. Sonographical growth charts for kidney length and volume.

Kidney size was determined in a sonographic study of 325 children without kidney pathology. Real-time ultrasound equipment adjusted for the pediatric age group, provided standardized renal biometry. Outer kidney diameters showed a linear correlation to somatic developmental parameters. Renal volume was established by the formula for an ellipsoid and showed good correlation to body weight. Growth charts for kidney length and volume in childhood are constructed and provide the basis for objective intra- and interindividual determination of renal size.

Adolescent↗

PubMedDate not supplied

Analysis of accommodation function with ultrasonography.

The aim of this study was to present a new method that uses ultrasonography to analyse accommodation function, and to do a preliminary investigation of its possible use in clinical practice. Using the method of continuous ultrasonographic biometry, changes in lens thickness were measured during accommodation. From these measurements response latency and duration were determined. Normal values for latency and duration were obtained by measuring 20 healthy subjects of different ages. Measurements were also performed on three patients with different accommodation disorders: diabetes, Adie's syndrome and third nerve palsy. Normal response latency is 394 ms (+/-46 SD) and independent of are. Normal response duration increases with age from an average 306 ms at 15 years-of-age to an average 954 ms at 55 years-of-age. Normal latency as well as duration appear to have a large interindividual variability. The diabetic patient had a delayed latency but a normal response duration. The patient with Adie's syndrome had a delayed latency and prolonged duration. The patient with third nerve palsy had a normal latency and duration. We conclude that ultrasonographically determine latency and duration give additional information on accommodation function that is more complete and objective than maximum accommodative amplitude alone. The results in our patients suggest that, in selected cases, this information may aid in the diagnosis and management of patient's complaints.

Accommodation, Ocular↗

PubMed2002

Effects of intense exercise training on rainbow trout growth, body composition and metabolic responses.

Cultured fish are bound to experience a variety of potentially stressful situations. In principle, stress may be reduced by adapting fish to intense exercise. This article addresses the effects of chase-induced intense exercise training on rainbow trout. Training reduced fish growth and worsened their nutritional use of food, but had no effect on food intake, biometry or body composition, indicating that a significant fraction of the diet's energy was being used for exercising rather than growth. Regarding metabolic responses, training significantly counterbalanced lactate, glucose and cortisol plasma concentration increases induced by intense exercise, while completely abolishing that of plasmatic proteins. These data suggest that this type of training adversely affects fish growth and food conversion, whereas it improves their metabolic response capacity and reduces the stress component of forced exercise.

Animal Nutritional Physiological Phenomena↗

PubMed1993

Established populations for epidemiologic studies of the elderly: study design and methodology.

A project initiated by the intramural Epidemiology, Demography and Biometry Program of the National Institute on Aging, entitled "Established Populations for Epidemiologic Studies of the Elderly" (EPESE), has developed information on death, chronic conditions, disabilities, and institutionalization for representative samples of elderly people living in communities. The EPESE consists of prospective epidemiologic studies of approximately 14,000 persons 65 years of age and older in four different communities: East Boston, Massachusetts; two rural counties in Iowa; New Haven, Connecticut; and segments of five counties in the north-central Piedmont area of North Carolina. The study design includes an initial baseline household interview followed by continued surveillance of morbidity and mortality. Participants are re-contacted annually in conjunction with the collection of data on cause of death and factors related to hospitalization and nursing home admissions. Concurrently, the investigators developed substudies focused on specific problems of the elderly. The value of this research lies in the longitudinal design which allows for analyses aimed at identifying risk factors of diseases, disabilities, hospitalizations, institutionalization, and mortality.

Aged↗

PubMed2000

[Career opportunities for female and male physicians in the pharmaceutical industry].

INTRODUCTION: Pharmaceutical medicine is not only a mainstay in clinical drug development and marketing of drugs in pharmaceutical industry but also a challenging alternative to the clinic and outpatient practice for physicians. Since most of them have only a vague notion of what a career in this sector of industry involves, this paper attempts to display the scope of opportunities and responsibilities for physicians and to answer some of the most frequently asked questions. JOB PROFILES: Areas for physicians are preclinical research, clinical research, drug safety, biometry, scientific relations, marketing and sales departments, working as company physician, training of sales representatives, health policy and project management. Earnings, continued and postgraduate training, job changing as well as possibilities of information on a career in the pharmaceutical industry are described. CONCLUSION: Despite the wide range of job profiles, a physician is still a physician in the pharmaceutical industry: his or her aim is to help patients and relieve their suffering through ethical and innovative therapeutic research. This aim is achieved through committed involvement in the development and marketing of new, effective and safe drugs.

Career Choice↗

PubMed2006

[Clinical research within the German competence net "acute and chronic leukemias"].

BACKGROUND: Leukemias are a challenge and a cost factor to society because of their frequency in all age groups. They also serve as a model for a variety of diseases and possess exemplary relevance for basic research and patient care. Leukemia research and therapy have achieved high standards and even a leading position in Germany with regard to clinical trials, standardization of diagnostics and molecular studies of prognostic factors, signal transduction and gene expression. Progress is hampered, however, by fragmentation of leukemia trial groups, diagnostic approaches and treatment research activities. GOALS: A network was therefore created to integrate the leading leukemia trial groups on chronic myeloid leukemia (CML), acute myeloid leukemia (AML), acute lymphatic leukemia (ALL), myelodysplastic syndromes (MDS) and chronic myeloproliferative diseases (CMPD) and their interdisciplinary partners (diagnostics, treatment research, biometry) in cooperation with basic research and pharmaceutical industry to foster advancements in leukemiarelated research and health care through clinical trials, promotion of translational research, introduction of standards for diagnostics and therapy, and development of evidence-based guidelines. ACHIEVEMENTS: Achievements include establishment of central information, communication and management structures, creation of an AML intergroup comprising five study groups, formation of an MDS study group and establishment of platforms for diagnostics, genomics and proteomics, and medical informatics. Exchange of scientific progress is mediated by intra- and internet, biannual newsletters, regular project group meetings, and annual network symposia. PERSPECTIVES: On the basis of experience with the Competence Network "Acute and chronic leukemias" with its management, communication and information structures, the "European LeukemiaNet" (ELN) has been established within the 6th Framework Program of the European Union. The ELN integrates 78 leading leukemia trial groups (AML, ALL, CML, CLL, MDS, and CMPD), their 83 interdisciplinary partner groups (diagnostics, treatment research, registry, guidelines), industry and SMEs (small- and medium-sized enterprises) across Europe to form a cooperative network for advancements in leukemia-related research and health care.

Acute Disease↗

PubMed2004

Magnification-corrected indirect biomicroscopy of the optic nerve head.

BACKGROUND: Proper use of the new Super VitreoFundus and SuperPupil XL non-contact slit-lamp lenses for clinical disc biometry requires knowledge of their comparative magnification. METHODS: The optical performance of each fundus lens is described in terms of axial magnification, lens position, and the correction factor p (in degrees per millimeter) using a calibrated Gullstrand-type model eye adjusted for axial ametropia between -12.5 D and +12.6 D. RESULTS: The total change in axial magnification from myopia to hyperopia was -13.3% to +15.6% (Super VitreoFundus lens), and -13.9% to +14.1% (SuperPupil XL lens). When the fundus lens position was altered with respect to the model eye by +/-2 mm under myopic conditions the change in axial magnification was -5.1% to +7.7% (Super VitreoFundus lens), and -6.5% to +9.7% (SuperPupil XL lens). In the hyperopic condition the change was -3.8% to +5.8%, and -4.9% to +7.3%. Both fundus lenses exhibited a linear relationship between p and degree of ametropia of the model eye, while only the Super VitreoFundus lens displayed a constant relationship between p and ametropia of -5 D to +5 D. CONCLUSIONS: Using the fundus lens correction factor (p), the clinician may be able to estimate the dimensions of optic nerve head features with sufficient accuracy to allow clinical decisions to be made in the evaluation of patients with diagnosed or suspected glaucoma.

Fundus Oculi↗

PubMed1998

Morphologic, biometric, and isoenzyme characterization of Trichuris suis.

Trichuris suis isolates were collected from the cecum of Sus scrofa domestica (pig) and S. s. scrofa (wild boar). Morphology and biometry studies were carried out. Morphology studies showed the existence of typical caudal papillae in males of T. suis from wild boars, but no other difference was observed in the biometric parameters (total length, esophageal length, posterior-portion body length, and spicular length) of T. suis isolated from either host. Individual extracts were subjected to malate dehydrogenase (MDH), malic enzyme (ME), glucose 6-phosphate dehydrogenase (G6PD), lactate dehydrogenase (LDH), and superoxide dismutase (SOD) isoenzyme analysis following starch-gel electrophoresis, and the isoenzyme patterns were compared with those obtained from other species of trichurids. MDH, ME, G6PD, LDH, and SOD isoenzyme patterns were identical for T. suis from both hosts. MDH isoenzyme patterns were characterized by the presence of one cathodic isoenzyme. ME, G6PD, and LDH isoenzyme patterns indicated the presence of three phenotypes, whereas the SOD isoenzyme pattern showed only one phenotype characterized by the existence of two (anodic and cathodic) bands. Different LDH and SOD isoenzyme patterns observed for T. suis, T. ovis, and T. skrjabini confirm once more that isoenzyme patterns have potential as a diagnostic tool for differentiation of different species of Trichuris.

Animals↗