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C Berg

Publications and source records attributed to C Berg.

At least 109 records · Page 6Linked to original sources
PubMed1994

A QUANTITATIVE, THREE-DIMENSIONAL METHOD FOR ANALYZING ROTATIONAL MOVEMENT FROM SINGLE-VIEW MOVIES

The study of animal movement is an important aspect of functional morphological research. The three-dimensional movements of (parts of) animals are usually recorded on two-dimensional film frames. For a quantitative analysis, the real movements should be reconstructed from their projections. If movements occur in one plane, their projection is distorted only if this plane is not parallel to the film plane. Provided that the parallel orientation of the movement with respect to the film plane is checked accurately, a two-dimensional method of analysis (ignoring projection errors) can be justified for quantitative analysis of planar movements. Films of movements of skeletal elements of the fish head have generally been analyzed with the two-dimensional method (e.g. Sibbing, 1982; Hoogenboezem et al. 1990; Westneat, 1990; Claes and de Vree, 1991), which is justifiable for planar movements. Unfortunately, the movements of the head bones of fish are often strongly non-planar, e.g. the movement of the pharyngeal jaws and the gill arches. The two-dimensional method is inappropriate for studying such complex movements (Sibbing, 1982; Hoogenboezem et al. 1990). For a qualitative description of movement patterns, the conditions for the use of the two-dimensional method may be somewhat relaxed. When two (or more) views of a movement are recorded simultaneously, the three-dimensional movements can readily be reconstructed using two two-dimensional images (e.g. Zarnack, 1972; Nachtigall, 1983; van Leeuwen, 1984; Drost and van den Boogaart, 1986). However, because of technical (and budget) limitations, simultaneous views of a movement cannot always be shot. In this paper, a method is presented for reconstructing the three-dimensional orientation and rotational movement of structures using single-view films and for calculating rotation in an object-bound frame. Ellington (1984) presented a similar method for determining three-dimensional wing movements from single-view films of flying insects. Ellington's method is based upon the bilateral symmetry of the wing movements. The present method does not depend on symmetry and can be applied to a variety of kinematic investigations. It eliminates a systematic error: the projection error. The measuring error is not discussed; it is the same in the two-dimensional and three-dimensional method of analysis.

Journal Article↗
PubMed1994

[Relation of Doppler ultrasound to hemostaseologic and hemorheologic parameters in pregnancy-induced hypertension].

During this study we investigated 23 patients with preeclampsia and 23 women with normal pregnancies. The hemorheological, the hemostasiological and the dates of doppler ultrasound were evaluated. High values of D-Dimer as a sign for a rapidly turnover of fibrin, are a poor prognostical symptom for gestational hypertension. There is a close correlation between doppler ultrasound indices and the maternal D-Dimer. Nearly 80% of the new born babies with growth retardation suffered by a high blood viscosity of the umbilical artery. We postulate that the changes of maternal and fetal blood viscosity are very important to estimate the doppler flow velocity by patients with gestational hypertension.

Adult↗
PubMed1993

Effects of citrate on the different phases of calcium oxalate crystallization.

Urinary citrate appears to be an important factor in the crystallization process of calcium oxalate and calcium phosphate. The urinary excretion of citrate was found to be significantly lower in patients with calcium oxalate stone disease as compared with normal subjects, and about 30 per cent of the calcium stone formers can be considered as hypocitraturic. The lowest excretion of citrate was recorded in urine collected during the night. Citrate has significant effects on supersaturation with respect to both calcium oxalate and calcium phosphate, it also inhibits the growth of these crystals. In addition, citrate appears to be capable of inhibiting the aggregation of crystals composed of calcium oxalate, brushite, and hydroxyapatite. The heterogenous growth of calcium oxalate on calcium phosphate is also counteracted by citrate. As a consequence of the crucial role of citrate in these processes, stone prevention with alkaline citrate has become an attractive form of treatment in patients with recurrent stone formation. Single evening dose administration of sodium potassium citrate resulted in an of sodium potassium citrate resulted in an increased excretion of citrate, reduced levels of the calcium/citrate ratio as well as supersaturation with respect to calcium oxalate and a decreased rate of stone formation. However, conflicting results of stone preventive treatment with alkaline citrate have been reported by different groups, and long-term follow-up of patients treated in a randomized way is necessary to definitely assess the efficacy of alkaline citrate.

Calcium Oxalate↗
PubMed1992

The effects of a single evening dose of alkaline citrate on urine composition and calcium stone formation.

The effects on urine composition and pH of a single evening dose of alkaline potassium sodium citrate were studied in healthy subjects and recurrent calcium oxalate stone formers. This treatment resulted in a prompt and significantly increased urinary pH with a duration until 10 a.m. the next day and a reduced risk of calcium oxalate crystallization between 10 p.m. and 10 a.m. In a retrospective study alkaline citrate was given in a single evening dose of 3.75 or 5 gm. to 55 patients with calcium oxalate stone disease and a total dose of 5.0 or 7.5 gm. was administered 2 or 3 times daily in 17 patients. The mean plus or minus standard deviation for duration of treatment was 3.5 +/- 1.7 years. Significantly reduced stone formation was recorded only in those on the evening dose regimen, which was associated with significant improvement of urine composition. Patients who continued to form new stones or who had growth of residual stones despite treatment also had improved urine composition but the calcium excretion and the calcium/citrate quotient remained elevated. In 4 patients with new stone formation calcium phosphate was the major component and calcium excretion was high but the concomitant increased citrate excretion resulted in a calcium/citrate quotient that was only slightly elevated. In patients forming calcium oxalate stones the only abnormality was a high calcium/citrate quotient. Because of favorable biochemical and clinical effects as well as good patient compliance with a single evening dose of alkaline citrate, this regimen appears to be an attractive alternative for long-term prevention of recurrent calcium stone formation.

Adult↗
PubMed1992

Risk, statistical inference, and the law of evidence: the use of epidemiological data in toxic tort cases.

Toxic torts are product liability cases dealing with alleged injuries due to chemical or biological hazards such as radiation, thalidomide, or Agent Orange. Toxic tort cases typically rely more heavily than other product liability cases on indirect or statistical proof of injury. There have been numerous theoretical analyses of statistical proof of injury in toxic tort cases. However, there have been only a handful of actual legal decisions regarding the use of such statistical evidence, and most of those decisions have been inconclusive. Recently, a major case from the Fifth Circuit, involving allegations that Benedectin (a morning sickness drug) caused birth defects, was decided entirely on the basis of statistical inference. This paper examines both the conceptual basis of that decision, and also the relationships among statistical inference, scientific evidence, and the rules of product liability in general.

Abnormalities, Drug-Induced↗
PubMed1991

[Insulin consumption in Norway 1975-89. How much did the change to insulin 100 cost?].

The consumption of the various types of insulin in the period 1975-89 has been examined. Norway changed from insulin U-40 to insulin U-100 on 1 April 1987. This led to a marked increase in sales of insulin. Sales from the Norwegian Medicinal Depot (the national drug wholesale monopoly) in 1989 were 23% higher than average sales for the three years preceding the change (1984-86). This increase represents a retail value of NOK 59 million. The main reason for the increase is probably a disproportionate relationship between the amount of insulin in each vial (10 ml) and the recommended deadline for using the rest of the insulin in the vial after the first withdrawal. This has most likely led to an extensive discarding of vials containing surplus insulin. Vials with a smaller volume (5 ml) and/or re-assessment of the recommended lifespan of an opened vial might decrease the amount of insulin discarded as waste.

Costs and Cost Analysis↗
PubMed1990

Effects of different doses of alkaline citrate on urine composition and crystallization of calcium oxalate.

Prophylactic treatment with alkaline citrate in patients with recurrent calcium oxalate (CaOx) stone disease results in reduced CaOx supersaturation and increased urinary citrate. The effects of a single evening dose were compared with those of two and three daily doses in six recurrent CaOx stone formers with hypercalciuria, hypocitraturia or raised calcium/citrate quotients. While on a standardized hospital diet the patients were given 7.5 g (28 mmol) of sodium potassium citrate (URALYT-U) in one, two, and three doses. Fractional urine collections during 24 hours were analyzed for pH, composition, and crystallization risk (CR). All dosage regimens had favourable effects on urinary calcium, citrate, calcium/citrate quotients, and CaOx-CR. The most sustained effect was recorded with three divided doses. Single evening doses resulted in the most pronounced effects between 22.00-06.00 h, thereby counteracting the increased risk of CaOx crystallization during that period. In terms of 24h urine composition the best effect was recorded with alkaline citrate administered three times daily, but because of the favourable response by a single evening dose between 22.00-06.00 h the assumption was made that this dosage regimen might be sufficient to reduce the risk of CaOx crystallization and stone formation. However, the validity of such an assumption can only be established by long-term clinical studies.

Calcium Oxalate↗
PubMed1990

Barriers and motivators to prenatal care among low-income women.

Substantial evidence exists which links prenatal care to improved birth outcomes. However, low-income and nonwhite women in the United States, who are at greatest risk for poor birth outcomes, continue to receive the poorest prenatal care. The purpose of this study was to identify and compare barriers and motivators to prenatal care among women who lived in low-income census tracts. The stratified sample included recently delivered white, black and American Indian women who received adequate, intermediate, and inadequate prenatal care. Interviews were conducted which focused primarily on the women's perceptions of problems in obtaining prenatal care and getting to appointments. Results indicated that women with inadequate care identified a greater number of barriers and perceived them as more severe. Psychosocial, structural, and socio-demographic factors were the major barriers, while the mother's beliefs and support from others were important motivators. The predictive power of selected barrier variables was examined by a regression analysis. These variables accounted for 50% of the variance in prenatal care use. The results affirm the complexity of prenatal care participation behavior among low-income women and the dominant influence of psychosocial factors. Comprehensive, coordinated and multidisciplinary outreach and services which address psychosocial and structural barriers are needed to improve prenatal care for low-income women.

Adult↗
PubMed1990

Nematode related spinal myelomeningitis and posterior ataxia in muskoxen (Ovibos moschatus).

In the fall of 1988 all five animals in a herd of muskoxen (Ovibos moschatus) developed clinical signs of posterior ataxia. Postmortem investigation revealed inflammatory lesions of the caudal part of the spinal cord, mainly as leptomeningitis. Nematodes were seen in close association with the lesions. Although not identified, the parasites were probably an Elaphostrongylus sp.

Animals↗
PubMed1990

Alkaline citrate in prevention of recurrent calcium oxalate stones.

Calcium oxalate (CaOx) is the most common constituent of calcium renal stones, often mixed with calcium phosphate (CaP). The recurrence rate of these stones is high and their aetiology complex. Despite new effective, less invasive methods to remove the stones, preventive treatment is often necessary to avoid recurrence. Alkaline citrate is a relatively new medical treatment reported to give a stone free rate of between 67-92 per cent in long term studies with three daily doses. The present investigation was undertaken in order to study further the risk factors in CaOx stone formation, the influence and usefulness of a single evening dose of alkaline citrate, and the value of a four hour morning urine sample in the evaluation of patients who form stones. The highest CaOx crystallisation risk (CaOx-CR) in whole urine was recorded in the pH range 4.5-5.5, with lower values above this pH. Between pH 6.5-7.5 the number of small CaP crystals was considerably increased. The crystallisation of CaOx on hydroxyapatite (HAP) was inhibited for four hours by 1 and 2% whole urine or citrate in concentrations of 1% that in normal urine. The formation of CaP crystals in a supersaturated system was considerably reduced when citrate concentrations exceeded 0.5 mmol/l. The number of medium sized (6.5-14 microns) and large crystals (15.5-27 microns) was reduced, and small crystals (3.5-5 microns) predominated at higher citrate concentrations. The correlation between the composition of 24-h urine samples and 4-h urine specimens collected between 0600-1000, from patients with CaOx stones before and during a course of alkaline citrate given as a single evening dose was good, with the best correlation recorded during treatment. These results suggest that the 4-h urine sample might be adequate for the follow up of patients treated with alkaline citrate. A total amount of 7.5 g of potassium sodium citrate (PSC) in 1, 2, and 3 doses favourably affected urine composition in patients with CaOx stones. Three doses gave the most sustained effect, and a single evening dose gave the most pronounced effect between 2200-0600. Long term treatment (mean +/- SD duration 3.5 +/- 1.7 years) of patients who formed calcium stones with PSC in a single evening dose of 3.75 or 5.0 g (n = 55) gave a stone free rate of 75 per cent, but no clinical effect was apparent when 5.0 or 7.5 g were given in two or three doses (n = 17).(ABSTRACT TRUNCATED AT 400 WORDS)

Antacids↗
PubMed1989

The effects of citrate on hydroxyapatite induced calcium oxalate crystallization and on the formation of calcium phosphate crystals.

The addition of different amounts of hydroxyapatite crystals (HAP) to a solution, metastably supersaturated with respect to calcium oxalate (CaOx) resulted in heterogenous crystallization at seed concentrations exceeding 0.2 mmol/l. The induction period varied between 1 and more than 8 h with the shortest period for a seed concentration of 2 mmol/l. Addition to the system of 1 and 2% of whole urine and citrate in concentrations corresponding to approximately 1% of that found in normal urine inhibited the crystallization for as long as 4 h. In a system supersaturated with respect to calcium phosphate (CaP) the total number of crystals was markedly reduced by citrate concentrations exceeding 0.5 mmol/l. The fractions of medium sized and large crystals were sharply reduced and small crystals predominated at higher citrate concentrations. This might indicate effects of citrate on both crystal growth and crystal aggregation. We conclude that increased citrate concentrations during treatment with alkali leads to a significant inhibition of CaOx growth on HAP as well as to a prevention of the formation of large CaP crystals from solutions supersaturated with respect to CaP.

Calcium Oxalate↗
PubMed1988

A 5S rRNA/L5 complex is a precursor to ribosome assembly in mammalian cells.

A novel 5S RNA-protein (RNP) complex in human and mouse cells has been analyzed using patient autoantibodies. The RNP is small (approximately 7S) and contains most of the nonribosome-associated 5S RNA molecules in HeLa cells. The 5S RNA in the particle is matured at its 3' end, consistent with the results of in vivo pulse-chase experiments which indicate that this RNP represents a later step in 5S biogenesis than a previously described 5S*/La protein complex. The protein moiety of the 5S RNP has been identified as ribosomal protein L5, which is known to be released from ribosomes in a complex with 5S after various treatments of the 60S subunit. Indirect immunofluorescence indicates that the L5/5S complex is concentrated in the nucleolus. L5 may therefore play a role in delivering 5S rRNA to the nucleolus for assembly into ribosomes.

Animals↗