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Biomedical subjects

R Eggers

Publications and source records attributed to R Eggers.

At least 37 records · Page 2Linked to original sources
PubMed1996

The ossification centre of the talus.

The ossification of the talus was studied in plastinated and histological preparations of normal feet of eight newborn children. Quantitative data on the newborn talus were obtained with the IBAS image analysis system and by point counting methods. In the newborn talus up to 24 percent of the talar anlage already consists of bony tissue. The ossification centre is situated in the neck, which includes the non-articulating surfaces of the talus. Periosteal bone joins the endochondral centre below and, in well-differentiated specimens also above. The basal periosteal collar forms the surfaces of the sinus and canalis tarsi, whereas the cranial bony collar is included in the tibiotalar joint. The histological architecture of these periosteal collars differs. Four arteries contribute to the blood supply of the talar ossification centre.

Bone Development↗
PubMed1996

[Intraluminal expansion of a small intestine segment--animal experiment principles and possible clinical application].

In this study we expanded ileal segments of 8 pigs with an intraluminal expander over a period of 6 to 8 weeks till the volume had reached approximately sixfold of the starting volume. The morphological and morphometrical examinations showed flattened villi with elongated crypts and especially an increase in the thickness of the muscularis. The villi appeared flattened through scanning microscopy as well, but the structure of the microvilli was nearly normal. The proliferative activity in the muscularis, estimated immunohistochemically by a monoclonal antibody against PCNA, showed a threefold increase. So it can be assumed, that the increased thickness of the muscle layer was caused not only by muscle cell hypertrophy but also by hyperplasia. The activity of the alpha-glucosidase, a brush border enzyme, was clearly reduced. The minor cause of this effect was the direct damage of the microvilli from the expander, but the major cause was the exclusion of the ileal segment from the small bowel passage and the resulting lack of nutrients. With our technique it seems possible to create an ileum pouch, a stomach substitute or a urinary bladder substitute.

Animals↗
PubMed1995

Quantitative investigations into the histostructural nature of the human putamen. II. The differentiated topological distribution of certain neuron type arrangements.

Several mathematical procedures have been worked out for describing quantitative arrangements of neurons, and especially subpopulations of neurons, in the human putamen. Visual point field analysis is a newly developed method for the qualitative recognition of the fuzzy clustering of types of neurons. Nearest neighbourhood analysis is an established procedure in stochastic geometry and image analysis. These cluster-analytical methods make possible the determination of local neuron topology. They represent an extension and application of the point pattern analysis (Diggle 1983), and are used here to calculate the statistical significance of certain arrangements of cells. The application of all these methods together revealed an interesting neuronal arrangement: type 1 neurons tend to remain at a certain distance from other type 1 neurons, whereas type 6 neurons lie close together.

Animals↗
PubMed1995

Quantitative investigations into the histostructural nature of the human putamen. I. Staining, cell classification and morphometry.

Combined staining with aldehyde and cresyl violet allows a reliable morphological distinction to be made between seven different types of neurons in the human putamen. We examined the age distribution of nearly 42,000 neurons in 27 normal putamina, using a semiautomatic morphometric procedure on defined tissue blocks. For morphometric evaluation and stereological calculations a section thickness of 20 microns is recommended. We modified routine aldehyde fuchsin cresyl violet combination staining for nervous tissue, since Braak's original method (Braak 1978, 1980) was developed for thick sections. The results show that neuronal density varies with age for the different types of neurons.

Adult↗
PubMed1994

Histopathological features of neuronal intestinal dysplasia of the plexus submucosus in whole mounts revealed by immunohistochemistry for PGP 9.5.

Neuronal intestinal dysplasia (NID) is wellknown, but its definition is a topic of debate. The histopathological diagnosis of NID is based on traditional enzyme-histochemical methods such as the acetylcholinesterase and dehydrogenase reaction on native cryosections. In this study, we have investigated the enteric nervous system in whole mount preparations of resected intestinal segments affected by NID of the plexus submucosus (type B). The plexuses of the tunica mucosa and tunica submucosa were visualized by immunohistochemical methods using a polyclonal antibody to protein gene produce 9.5 (PGP 9.5). PGP 9.5 is a novel general cytoplasmatic marker specific for the nervous system. The morphology of the plexuses is revealed in full, making possible changes easily discernible. Known pathological findings of the NID can be identified and judged more precisely with this method. Numerous enlarged nerve trunks run within the tunica submucosa and tunica mucosa. Hyperplastic ganglia with an unusually high nerve cell number in the tunica submucosa can be demonstrated as well as heterotopic nerve cells in the tunica mucosa.

Adolescent↗
PubMed1994

Eradication of poliomyelitis in South Africa.

An international campaign under the leadership of the World Health Organisation is underway to eradicate polio from the world by the year 2000. South Africa may already be free of polio. However, to ensure eradication we need to move from a polio control programme to a polio eradication programme. This necessitates the institution of a surveillance programme for acute flaccid paralysis (AFP) and improvement of the delivery of polio vaccine. All children with AFP (including those with suspected Guillain-Barré syndrome) should be investigated with stool culture to exclude polio. Primary care services need strengthening so that oral polio vaccine coverage greater than 90% is achieved in all regions by all authorities. Outbreak response activities need to be developed. Consideration needs to be given to national immunisation days and mopping-up activities.

Child↗
PubMed1993

Evaluation of the 13CO2 kinetics in humans after oral application of sodium bicarbonate as a model for breath testing.

The kinetics of 13CO2 have been investigated following oral administration at five doses between 12.5 and 100 mg of 13C labelled sodium bicarbonate to 10 healthy subjects in a randomized study. Sodium bicarbonate in this study served as a model compound for carbon dioxide/bicarbonate generated in breath tests. Exhalation of 13CO2 into breath was monitored by stable isotope ratio mass spectrometry. The kinetics of 13CO2 were characterized by an apparent terminal elimination half-life of 1 h and a mean recovery of 0.630 of the dose administered. The kinetics were not dose-dependent. These results were in agreement with the findings reported previously after i.v. application of sodium bicarbonate.

Administration, Oral↗
PubMed1990

Triple staining of brain tissue for neuronal classification.

The described triple staining (PAP, aldehydefuchsin, and cresyl violet) enables the distinction of different neuronal types with regard to their content of neurotransmitters or neuropeptides and their lipofuscin pigmentation respectively. The use of filters improves the contrast of immunohistochemical and lipofuscin staining, and facilitates the differentiation of neurons under the microscope. An additional important point is the advantage that perikaria can be measured in the usual morphometric manner.

Brain↗
PubMed1989

Is there a correlation between morphological and cytogenetic findings in placental tissue from early missed abortions?

A retrospective study of 200 missed abortions was performed to determine whether morphological criteria alone are sufficient to ascertain a chromosomal aetiology. Placental changes were classified into five morphological and four morphometric groups, according to the severity of alterations, and were then correlated with the cytogenetic data. The rate of chromosome anomalies was approximately 50% and was thus not significantly different within the groups II-V, but it was 80% in group I, which covered the most severe placental alterations, namely the partial hydatidiform moles. There was a high incidence of triploidies in group I, trisomies with obligatory early lethality in groups II and III, and X-monosomies in group III. Our findings do not support previous evidence regarding the specificity of certain villous alterations in association with chromosome aberrations. Indeed, they indicate that the placental villi may react similarly to chromosomal and non-chromosomal disturbances and that placental morphology depends on the severity and the temporal onset of the underlying disorder rather than on its type. With respect to chorionic villus samplings (CVS), this would mean that an abnormal villous structure may be suggestive for a chromosome anomaly but does not exclude a normal karyotype.

Abortion, Missed↗
PubMed1988

Increased systemic availability of albendazole when taken with a fatty meal.

We have studied the systemic availability of oral albendazole in 6 patients with echinococcosis either fasting or with breakfast. Albendazole sulphoxide, the pharmacologically active principle, was assayed by HPLC. Mean plasma concentrations and AUCs were 4.5 times higher when albendazole was given with breakfast than when administered in the fasting state. We conclude that therapy of echinococcosis with albendazole requires the drug to be taken with meals and that administration on an empty stomach might be more appropriate when intraluminal effects are desired, e.g. for intestinal parasites.

Adult↗
PubMed1988

Steady-state extrarenal sorbitol clearance as a measure of hepatic plasma flow.

Hepatic plasma flow was assessed with sorbitol (hepatic extraction = 0.96) at steady state. After infusion of 50 mg/min for 3 h, total and renal sorbitol clearances were calculated, and the extrarenal clearance was obtained by taking the difference between the two. In normal volunteers, the mean (+/- SD) extrarenal sorbitol clearance was 10.6 +/- 2.1 ml/min.kg. In patients with various liver diseases, it was correlated more closely to the fractional clearance of indocyanine green (r = 0.83, n = 57) than the galactose elimination capacity (r = 0.66, n = 55). Hepatic vein catheterization showed that the hepatic extraction of sorbitol was always much higher than the extraction of indocyanine green; there was no evidence for extrahepatic, extrarenal sorbitol elimination. On the basis of these findings, sorbitol is kinetically superior to indocyanine green and, although the noninvasively determined extrarenal sorbitol clearance at steady state may not be equal to total hepatic plasma flow, it may at least be regarded as a measure of parenchymal liver plasma flow.

Adult↗
PubMed1985

Thiamine deficiency and nervous system function disturbances.

Thiamine is important for oxidative metabolism, and B1 deficiency is thought to give rise to polyneuropathies. A group of male Wistar rats (n = 15) received a vitamin B1 deficient diet (group-a), and the pair fed control group (n = 20, group-b) received a normal diet with no vitamin deficiency. A second control group (group-c) was fed unrestrictedly with a standard diet (n = 19). All animals were examined for 25 weeks. The sensory nerve conduction velocity, the compound radicular, spinal and brain stem responses and the SEP were derived for tail and hind paw stimulation. The examination was repeated at 6-week intervals. There was no difference in nerve conduction between group-a and -b, but for both groups the conduction velocity was significantly slower than in group-c. The SEP latencies were significantly increased in group-a compared with group-b and also with group-c. The spinal and cerebral latencies were delayed in group-a. The diameters of myelinated nerve fibres were decreased in group-a compared with group-b, and in group-b compared with group-c. The results indicate that a specific polyneuropathy exists as a result of B1 deficiency, and that the sequelae of the lack of thiamine are pronounced in the CNS.

Afferent Pathways↗
PubMed1985

Ethanol and polyneuropathy.

Two groups of alcoholics (30 patients each)--identified by the MALT score--were examined. Clinical and laboratory investigations showed no connection between thiamine, riboflavin, or Vitamin B6 deficiency and development of the polyneuropathy. Neither the polyneuropathy nor the diminished sensory conduction velocity were related to malnutrition. The relation between the duration of alcoholism and symptoms of polyneuropathy was highly significant in one group. The neurotoxicity of ethanol was confirmed in an experiment with rats.

Adult↗
PubMed1984

Preliminary report on macroscopic age changes in the human prosencephalon. A stereologic investigation.

The studies here reported were performed on the prosencephalons of 12 human brains between 37 and 86 years of age having no signs of neuropathological alteration. The evaluation was carried out on serial frontal sections with a mean thickness of 5 mm with stereological point counting procedures for volume and surface area. The results were mainly given in relative values since the range of variation is very high and the sample small. The aging process was evaluated with the aid of a linear regression function. The stereological investigation regarding the absolute values of volume and surface area (border face) of the macroscopical brain parts show a high interindividual variability. However, the relative volume of brain parts shows only small variations. Changes during aging could consequently only be revealed with the help of the relative values. The relative volumes and surface areas of the frontal lobe and the prosencephalic ganglia decrease with aging, while the parieto-occipital lobe and the striate cortex increase. However, if we refer these relative increases to the absolute decrease of brain volume, corresponding changes cannot be found in the parieto-occipital lobe until old age. The shrinkage of the frontal lobe, of the centrum semiovale and of the prosencephalic ganglia exceeds 10%. In the grays it is probably accompanied by a loss of neurons. The relative sizes of the surface area do not change significantly during aging with exception of the frontal cortex. The thickness of the cortex remains probably constant. The size of lateral ventricles increases with aging.

Adult↗
PubMedDate not supplied

Morphometry of the human cortex cerebri and corpus striatum during aging.

The commentary is based on our results of biological aging research with the following findings: a loss of neurons cannot be found, the size of neurons and the number of synapses decrease with age, the various regions of brain react quite differently. Altogether, these results speak for "use it or lose it." However, the genetically determined decreased brain function during aging can only be inhibited, not permanently preserved.

Aged↗
PubMedDate not supplied

Public-health impact of accelerated measles control in the WHO African Region 2000-03.

BACKGROUND: In 2000, the WHO African Region adopted a plan to accelerate efforts to lower measles mortality with the goal of decreasing the number of measles deaths to near zero. By June, 2003, 19 African countries had completed measles supplemental immunisation activities (SIA) in children aged 9 months to 14 years as part of a comprehensive measles-control strategy. We assessed the public-health impact of these control measures by use of available surveillance data. METHODS: We calculated percentage decline in reported measles cases during 1-2 years after SIA, compared with 6 years before SIA. On the basis of data from 13 of the 19 countries, we assumed that the percentage decline in measles deaths equalled that in measles cases. We also examined data on routine and SIA measles vaccine coverage, measles case-based surveillance, and suspected measles outbreaks. FINDINGS: Between 2000 and June, 2003, 82.1 million children were targeted for vaccination during initial SIA in 12 countries and follow-up SIA in seven countries. The average decline in the number of reported measles cases was 91%. In 17 of the 19 countries, measles case-based surveillance confirmed that transmission of measles virus, and therefore measles deaths, had been reduced to low or very low rates. The total estimated number of deaths averted in the year 2003 was 90,043. Between 2000 and 2003 in the African Region as a whole, we estimated that the percentage decline in annual measles deaths was around 20% (90,043 of 454,000). INTERPRETATION: The burden of measles in sub-Saharan Africa can be reduced to very low levels by means of appropriate strategies, resources, and personnel.

Adolescent↗