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Biomedical subjects

P Eggert

Publications and source records attributed to P Eggert.

At least 19 recordsLinked to original sources
PubMed2002

[On the inferior quality of renal sonograms in patients with lumbar meningomyelocele].

AIM: Many examiners complain about the inferior quality of renal sonograms in patients with lumbar, meningomyelocele (MMC), especially about the insufficient contrast. The study was carried out in order to scrutinize these reports and to test the hypothesis that this effect might be caused by the increased echogenicity of the abnormally innervated musculature in these patients. METHODS: In 17 "matched pairs" of patients with lumbar MMC and healthy controls the echogenicity and the contrast of the sonograms of the kidneys, the biceps muscle and the rectus femoris muscle were measured and compared. RESULTS: Echogenicity and contrast of the renal sonograms were significantly lower in patients with MMC (p = 0.004). Sonography of the musculature of the upper extremities revealed no differences, the echogenicity of the rectus femoris muscle, however, was significantly higher (p = 0.001) in patients with MMC. CONCLUSION: The results presented support the hypothesis that the elevated echogenicity of the abdominal wall and trunk musculature in patients with MMC reduce the effective ultrasound signal.

Adolescent↗
PubMed2001

Prolonged dietary calcium restriction: a diagnostic approach in idiopathic hypercalciuria.

BACKGROUND: Although frequently observed, the etiology of idiopathic hypercalciuria (IHC) remains largely unknown. A common hypothesis postulates intestinal hyperabsorption and/or a primary renal leak as the pathophysiological basis. The aim of our study was to investigate the regulation pattern of calcium homeostasis in patients with IHC by using a prolonged period of calcium restriction. METHODS: Twenty-seven patients with IHC were investigated. After a 3-week run-in period (dietary calcium content 700-1,000 mg/24 h), a standard calcium reduced diet (300 mg/24 h) was given for 4 weeks. Thereafter, the participants received again a normal calcium-containing diet. Values for urinary calcium, PTH and calcitriol levels of all participants were obtained at different phases of the study. Forty-three healthy persons served as controls. RESULTS: During calcium restriction, two distinct groups were identified. One group displayed an increase (n = 12) in urinary calcium excretion, the second (n = 15) a marked reduction, respectively. In both groups, the values during calcium restriction were significantly different from baseline (p < 0.01). In the first group, the increase of urinary calcium excretion was accompanied by an increase of PTH and calcitriol. These values were also significantly different from baseline values (p < 0.01). The control group showed decreasing calcium excretion during oral restriction (p < 0.01). CONCLUSION: Prolonged calcium restriction proved to be useful in distinguishing apparently two major forms of IHC. The fact that one group displayed the same excretion pattern as the control group raises the question if this group just represents the upper limit of a physiological range. These findings may shed new light on diagnosis, pathogenesis and treatment of patients with IHC.

Calcitriol↗
PubMed2001

The effect of desmopressin on short-term memory in children with primary nocturnal enuresis.

PURPOSE: The use of desmopressin in patients with primary nocturnal enuresis is based on the hypothesis of a nocturnal lack of endogenous arginine vasopressin. However, in addition to the kidney, other targets of desmopressin are known. Therefore, we examined whether the administration of desmopressin influences central nervous function in children with primary nocturnal enuresis. MATERIALS AND METHODS: Our prospective, randomized, double-blind, placebo controlled cross-over study was performed on 40 children with nocturnal enuresis. Patients were randomly assigned to receive either 20 microg. desmopressin intranasally or 0.9% saline solution. Each group comprised 19 and 21 to children, respectively. After 2 weeks the groups were switched. The children were tested for short-term memory and reaction time to both treatments. Statistical analysis was done using the Wilcoxon matched pairs test. RESULTS: Median patient age was 8.0 years (range 6 to 13). During desmopressin treatment children in both groups had a significant decrease of wet nights (5.3 to 3.2 per week). In contrast to reaction time, short-term memory was significantly different between both groups (p <0.05). CONCLUSIONS: Our results demonstrate an increase in short-term memory after desmopressin treatment in children with nocturnal enuresis. This finding indicates the central nervous system as a target involved in the pathogenesis of nocturnal enuresis as well as the therapeutic benefit of desmopressin treatment.

Adolescent↗
PubMed2000

Molecular cloning, tissue distribution, and chromosomal mapping of the human epithelial Ca2+ channel (ECAC1).

Functional and morphological analyses indicated that the epithelial Ca2+ channel (ECaC), which was recently cloned from rabbit kidney, exhibits the defining properties for being the gatekeeper in transcellular Ca2+ (re)absorption. Its human homologue provides, therefore, a molecular basis for achieving a better understanding of Ca2+ mal(re)absorption. By applying the RACE technique, the full-length cDNA of human ECaC (HGMW-approved symbol ECAC1) was obtained. It consisted of 2,772 bp with an open reading frame of 2,187 bp encoding a protein of 729 amino acids with a predicted molecular mass of 83 kDa. Phylogenetic analysis indicated that this highly selective Ca2+ channel exhibits a low level of homology (<30%) to other Ca2+ channels, suggesting that it belongs to a new family. hECaC was highly expressed in kidney, small intestine, and pancreas, and less intense expression was detected in testis, prostate, placenta, brain, colon, and rectum. These ECaC-positive tissues also expressed the 1,25-dihydroxyvitamin D3-sensitive calcium-binding proteins, calbindin-D9K and/or calbindin-D28K. The human ECaC gene mapped to chromosome 7q31.1-q31.2. Taken together, the conspicuous colocalization of hECaC and calbindins in organs that are not prime regulators of plasma Ca2+ levels could illustrate new pathways in cellular Ca2+ homeostasis.

Amino Acid Sequence↗
PubMed2000

Early tubular proteinuria and the development of nephritis in Henoch-Schönlein purpura.

The prognosis of Henoch-Schonlein purpura (HSP) is mainly determined by the involvement of the kidney, but prognostic markers have not been established. To study the extent of tubular involvement in HSP and its relationship to the development of HSP nephritis, we measured the urinary excretion of two tubular marker proteins in 36 children with HSP. After admission, urinary N-acetyl-beta-D-glucosaminidase (NAG) was determined in 20 children and alpha1-microglobulin (alpha1-MG) in 16 children respectively. These values were compared with the biochemical data on admission, 1 month, 6 months, and 12 months later. A total of 198 24-h urine samples from healthy children were used for the establishment of reference data for NAG and alpha1-MG (mean+/-2 SD). Twenty-one patients had elevated excretion of either NAG (>mean+2 SD, n=12) or alpha1-MG (>mean+2 SD, n=9). The highest values (>mean+4 SD) were found in patients with early kidney involvement. Normal values were accompanied by a benign further clinical course. Children with intermediate high values (>mean+2 SD, <mean+4 SD) developed signs of renal involvement during follow-up. Hence, tubular proteinuria is common during the early stages of HSP. NAG and alpha1-MG levels correlate well with the extent of early and late renal involvement. Tubular marker proteins may be prognostic markers for the development of HSP nephritis.

Acetylglucosaminidase↗
PubMed1999

Tubulointerstitial nephritis and uveitis in association with Epstein-Barr virus infection.

The case of a 13.5-year-old girl with acute tubulointerstitial nephritis and uveitis (TINU syndrome) is presented. The etiology of this rare syndrome, which in most cases involves female adolescents and usually regresses spontaneously, is still unknown. An infection-triggered pathological immune reaction has been considered to play a role in the pathogenesis of this disorder. Here we report for the first time the association of TINU syndrome and Epstein-Barr virus infection.

Adolescent↗
PubMed1999

Influence of hyperfiltration on the measurement of urinary N-acetyl-beta-D-glucosaminidase.

The measurement of urinary enzymes in patients with diabetes mellitus has become a useful additional test for the early detection of nephropathy. Controversy persists concerning methods of measurement since during early stages of insulin-dependent diabetes mellitus children develop the so-called hyperfiltration syndrome. This study was performed to determine whether elevated levels of excreted creatinine influence the determination of the enzyme N-acetyl-beta-D-glucosaminidase (NAG). Reference values for NAG in single-spot urines (units NAG/mmol creatinine) and in 24-h collections (units NAG/l urine) were established in two different groups of 105 and 111 healthy children. NAG was then measured in single-spot urines (as NAG/mmol creatinine) and in collection urines of 30 diabetic children within the same 24-h period and compared with the reference population. These results were compared with hemoglobin (Hb)A1(a-c) and fructosamine values as well as creatinine clearance of the diabetic patients. There was a direct correlation between the NAG levels in single-spot and 24-h urine collections of diabetic patients. However, the NAG/creatinine ratio in the single-spot urines did not correlate with the HbA1(a-c) or fructosamine level. When 24 h collections (expressed as NAG/l) were used, the results correlated well with HbA1(a-c) and fructosamine. There was an inverse correlation between the creatinine clearance and the NAG/creatinine ratio, i.e., a high creatinine clearance correlated with a low NAG/creatinine ratio. This was not the case for 24 h collections (expressed as units/l). Hence, in children with insulin-dependent diabetes mellitus 24-h urine collections should be used for urinanalysis. Parameters should not be related to creatinine, since the ratio of urinary protein and creatinine is unreliable because of the high urinary creatinine during the hyperfiltration state.

Acetylglucosaminidase↗
PubMed1999

Effect of DDAVP on nocturnal enuresis in a patient with nephrogenic diabetes insipidus.

The case of an 8 year old boy with both nocturnal enuresis and nephrogenic diabetes insipidus is presented. Diagnosis of nephrogenic diabetes insipidus was based on a typical medical history, the characteristic result of a fluid restriction test, the lack of an effect of 1-desamino-8-D-arginine (DDAVP) on both urine osmolality and plasma coagulation factors and, finally, the detection of a hemizygous missense mutation within the arginine vasopressin (AVP) receptor gene. Hydrochlorothiazide treatment and dietary measures reduced the patient's urine volume to one third of its original volume. However, this had no effect on enuresis. The daily intranasal application of DDAVP did not further reduce urine output but dramatically decreased the frequency of bed wetting. This observation contradicts the common notion that the therapeutic effect of DDAVP in nocturnal enuresis is the result of compensation for a nocturnal AVP deficit. Rather, it points to a different mode of action of DDAVP in patients with enuresis. It is hypothesised that central AVP receptors are a target of DDAVP and that they might play an important role in the pathogenesis of nocturnal enuresis.

Child↗
PubMed1999

Regulation of arginine vasopressin in enuretic children under fluid restriction.

BACKGROUND: Treatment of primary nocturnal enuresis using 1-deamino-8-D-arginine-vasopressin is based on the hypothesis that antidiuretic hormone (arginine vasopressin [AVP]) secretion is insufficient during the night. Persisting doubts about the theoretical background of this treatment and first results pointing to a different AVP regulation in children with nocturnal enuresis were the motives for the present study. OBJECTIVE: To determine if children with primary nocturnal enuresis have different AVP levels during fluid restriction when compared with normal controls. METHODS: Twenty-three children with nocturnal enuresis (median age, 11 years) were compared with a corresponding control group of 18 healthy children. Plasma osmolality, urine osmolality, and plasma AVP concentrations were determined before and after a defined fluid restriction. RESULTS: Regarding plasma and urine osmolality, no differences were found between the two groups. AVP levels after fluid restriction, however, showed significant differences. To maintain osmolality, the plasma AVP concentrations of the controls rose to a median value of 5.7 pg/mL (range: 0.9-29.0 pg/mL) in comparison to a median of 14.0 pg/mL (range: 3.5-64.0 pg/mL, P =. 015) for the enuretic children. CONCLUSION: The results are consistent with the established fact that AVP secretion is a function of plasma osmolality. They contradict the hypothesis that enuretic children have a AVP deficiency that has to be supplemented. Rather, the results point to a defect at the AVP receptor level or of the signal transduction pathway.

Adolescent↗
PubMed1998

Nephrocalcinosis in three siblings with idiopathic hypercalciuria.

Idiopathic hypercalciuria (IH) associated with nephrocalcinosis was found in three of six siblings. After the three affected children were maintained on a low-calcium diet, they demonstrated increasing hypercalciuria, parathyroid hormone, and vitamin D3 levels. An oral calcium loading test was not necessary to diagnose renal IH. During treatment with hydrochlorothiazide, the calcium excretion was normalized. These patients are remarkable because nephrocalcinosis is generally regarded as a rare complication of renal IH. Moreover, the fact that three of six siblings are affected raises the question of whether the renal form of IH is genetically distinct from other forms of IH.

Adolescent↗
PubMed1996

Physiological bowlegs or infantile Blount's disease. Some new aspects on an old problem.

The differentiation between physiological bowlegs and infantile Blount's disease in patients aged 11-30 months is very difficult. Nevertheless, diagnosis is deemed important because treatment of infantile Blount's disease is recommended. Fourteen patients with severe bowing of the legs seen in our outpatient clinic were investigated retrospectively. We examined them and measured the tibiofemoral and metaphyseal/diaphyseal angles in radiographs taken at their first presentation. The finding that the tibiofemoral angle is not helpful in differential diagnosis could be confirmed but, contrary to reports by other authors, neither was the metaphyseal/diaphyseal angle. In view of the spontaneous recovery of all investigated patients, it must be doubted whether a diagnosis of infantile tibia vara can be made in early infancy, and whether infantile Blount's disease is a diagnosis in its own right.

Bone Diseases, Developmental↗
PubMed1996

Immunohistological studies on an Onchocerca volvulus ankyrin (EI).

The distribution of an Onchocerca volvulus ankyrin, designated E1, was studied in different O. volvulus stages and other helminths by immunohistochemistry using rabbit antibodies raised against the recombinant E1 protein. In adult O. volvulus the protein designated E1 was localized to the extracellular clefts as well as to the cytoplasm adjacent to the cell membrane in the area of the basal labyrinth in hypodermis, intestine and uterus and to a lesser extent in oviduct and vas deferens. Neuronal cell bodies were also labelled. No labelling of the basal laminae, muscles or epithelia of ovary or testis was observed. Detection of the E1 protein was associated with embryonic development. Germ cells and early morulae showed no reaction; labelling was first seen in late morulae, corresponding to the stage of gastrulation, and increased in the following embryonic stages. In microfilariae the nerve ring and the cephalic space, which represents the anterior nerve-enriched portion of the body, were labelled. In third-stage larvae of O. volvulus labelling was associated with the hypodermis, and in those of Anisakis sp. the cytoplasm adjacent to the membrane of the excretory gland cell and the basal labyrinth of the hypodermis were labelled. Following anthelminthic treatment a disruption of the labelling pattern of the E1 protein was observed in adult O. volvulus with leakage of the protein into neighbouring areas. Damage to the worm was associated with reduction and finally loss of E1 protein labelling. No E1 protein was detected in dead adult worms, embryos or microfilariae. Labelling of the same organs was observed in 8 other Onchocerca species and in several other nematodes, but no reaction was seen in trematodes. The results indicate that the EI protein is associated with neuronal structures of O. volvulus, that its presence is developmentally regulated and that it has cross-reactive homologues in other nematodes. The results suggest that E1 is a functional protein. It may be useful for the assessment of parasite damage and death as well as in the characterization of the filarial nervous system.

Animals↗
PubMed1995

Antidiuretic hormone regulation in patients with primary nocturnal enuresis.

Treatment of primary nocturnal enuresis using DDAVP is based upon the hypothesis that antidiuretic hormone (ADH) secretion is insufficient at night. The known efficacy of the treatment on the one hand, and persisting doubts about its theoretical basis on the other, formed the background of the present study. Ten children (mean age 10.5 years) with primary nocturnal enuresis were compared with a corresponding control group of eight patients. Diurnal and nocturnal urine production, ADH secretion, and plasma osmolality were determined. No differences between the two groups were found for urine production, ADH levels during day and night, or plasma osmolality. However, in order to regulate plasma osmolality the enuretic children required a markedly greater output of ADH: 2.87 (95% confidence interval 0.091 to 40.35) pg/ml/mmol/kg v 0.56 (0.08 to 1.03) in the controls (p < 0.01). The results are consistent with the established fact that ADH secretion is a function of plasma osmolality, and they contradict the hypothesis that urine production is increased at night in enuretics because of lower ADH secretion. The findings do not solve the uncertainties in the pathogenesis of enuresis but they suggest there might be a difference between enuretic children and controls at the ADH receptor level.

Child↗
PubMed1995

Prevalence and risk factors of HIV-1 infection in three parishes in western Uganda.

UNLABELLED: A population-based serosurvey was conducted to determine the HIV-1 prevalence and to evaluate various risk factors in three parishes in western Uganda. Adults over 14 years were examined in all 13 villages of Kigoyera parish far from Fort Portal, in two villages of Kyamukoka parish closer to Fort Portal and in the four fishing villages of Ntoroko parish at Lake Albert with a high population mobility. Personal interviews and HIV serology using ELISA and Western blot were performed. Sera showing at least two envelope bands in the Western blot were considered as positive. The coverage of the registered eligible population was 74% in Kigoyera, 67% in Kyamukoka and 25% in Ntoroko. The prevalence of HIV was 4% (97 of 2267 persons examined, 95% CI 3.4-5.1%) in Kigoyera, a typical rural area. Whereas it was 13% (53 of 393 persons examined, 95% CI 10.1-16.9%) in Kyamukoka near to the district capital and exceptionally high with 24% (96 of 399 persons examined, 95% CI 19.9-28.3%) in the comparatively isolated fishing villages of Ntoroko. In a multivariate model the infection risk for HIV was in Kyamukoka two and in Ntoroko five times higher than in Kigoyera. Among the two main ethnic groups one had a significantly lower risk to acquire HIV infection than the other group. CONCLUSIONS: Because of their large proportion of migrating persons the fishing villages presented populations with high risks for HIV infection. The ethnic composition of the village population, representing group specific sexual behaviour, was a risk factor for HIV infection.

Adolescent↗
PubMed1992

[A new method for determining mineral content of bones using ultrasound].

With conventional methods radiation exposure is relatively high, due to frequent examinations. For this reason an alternative method for measuring bone mineral content was sought. Like X-rays, sound waves are subject to an exponential law of attenuation. For this reason the attenuation coefficient of the sound waves was used to describe the sound-conducting medium. With the help of this transmission sonographic method thickness dependence and increase in attenuation were shown as a function of increasing calcium apatite concentration using a reference system and also femoral sections of varying thickness. Examination of the reflected portion indicated that for this type of measurement the reflection at the bone is negligible at least in the first approximation. In the case of bone specimens a linear dependence was demonstrated between half-value thickness and mineral content in the area of bone calcium concentrations of 50-300 mg/cm. For practical employment of the method, a number of patients were examined in whom bone-mineral-content fluctuations were to be expected on the basis of their disease and therapy. As the examinations indicate, fluctuations in vivo can be detected with the help of this method.

Bone Density↗
PubMed1991

Densitometric measurement of renal echogenicity in infants and naked eye evaluation: a comparison.

The sonograms of 115 infants with normal renal function ranging in age from 1 to 120 days used to determine renal parenchymal echogenicity by densitometry. The measured values were contrasted with the evaluations of 4 independent examiners who rated renal echogenicity as "less than", "equal to" or "greater than" that of the liver. The results revealed that naked eye evaluation does not permit a clear distinction between the categories of echogenicity and also that the assessments of the individual examiners differed considerably. Contrary to the previously held view the present findings indicate that the initially increased renal parenchymal echogenicity in neonates has developed into the normal hypoechoic condition after 1 month. One should take these findings into account when evaluating renal sonograms of infants, especially if no densitometric data are available.

Densitometry↗
PubMed1991

[Do strong static magnetic fields in NMR tomography modify tissue perfusion?].

Findings obtained in humans and test animals raised the question whether strong static magnetic fields as used in NMR-tomography may affect tissue perfusion. In two test series including 20 subjects, each skin blood flow at the thumb was determined by heat clearance, and forearm blood flow was measured by venous occlusion plethysmography. For comparative purposes, measurements were carried out bilaterally at both extremities. The experiments consisted of three sections that lasted 10 min each. During the second section the thumb or the forearm were unilaterally exposed to magnetic fields of 0.9 to 1 T and 0.4 to 0.5 T, respectively. The results of this section were compared with the values obtained during the experimental sections prior to and after the exposure to the magnetic field. The results were also compared with the blood flow measured at the contralateral extremity. Neither at the skin of the thumb nor at the forearm were there changes in local blood flow attributable to the magnetic fields applied.

Adult↗