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Biomedical subjects

R Burghard

Publications and source records attributed to R Burghard.

36 records · Page 2Linked to original sources

Microproteins in amniotic fluid as an index of changes in fetal renal function during development.

Protein content and protein composition were studied in amniotic fluid obtained from 171 healthy pregnant women between the 16th and 38th week of gestation, using microgradient gel electrophoresis to separate proteins according to their molecular size into albumin (68 KD), proteins of low molecular weight (LMW proteins, less than 68 KD), and proteins of high molecular weight (HMW proteins, greater than 68 KD). Additionally alpha-1-microglobulin (alpha-1-MG, 33 KD) and beta-2-microglobulin (beta-2-MG, 11,8 KD) were analysed as micromolecular marker proteins. Concentrations of LMW proteins were 0.15-0.22 g/l, of alpha-1-MG 28.4-34.5 mg/l, and of beta-2-MG 7.2-11.6 mg/l during the second trimester of gestation, and thereafter decreased progressively to 0.03 g/l, 14.1 mg/l and 2.4 mg/l respectively near term. The same developmental trends were confirmed by calculating the protein/creatinine ratios in amniotic fluid. The concentrations of LMW proteins found in the first postnatal urine of 73 healthy infants born prematurely or at term were similar to those in amniotic fluid of corresponding fetal age. Concentrations of albumin and HMW proteins in postnatal urine were about 5% and 15% respectively when compared with amniotic fluid concentrations. No strong correlation existed between gestational age and either of the analysed proteins which would allow accurate assessment of fetal maturation by protein analysis in amniotic fluid. It is concluded that fetal urinary excretion is the major determinant of the microprotein content of amniotic fluid. Microproteins seem to reflect an increasing tubular reabsorption capacity, which accelerates rapidly after the second trimester of gestation.

Adult↗

Effect of a modified fluid therapy on renal function during indomethacin therapy for persistent ductus arteriosus.

A rehydration with 7 ml/kg/h for six hours prior to indomethacin administration prevented the adverse effects of this drug on renal function in prematures with persistent ductus arteriosus. During the 36 hour observation period after indomethacin administration, no significant changes in serum creatinine, sodium, and potassium concentrations, or urinary flow, creatinine clearance, or filtered sodium could be detected. The only significant finding was a reduction in fractional sodium excretion. One can assume that this beneficial effect of the fluid load is due to a suppression of some parts of the vasoconstrictor mechanisms, which are responsible for the deterioration of renal function in newborns during indomethacin therapy. Using this modified fluid regimen, no cardiovascular side effects were noticed, a closure of the duct was achieved in 7 of 10 treatment courses.

Creatinine↗

Protein analysis in amniotic fluid and fetal urine for the assessment of fetal renal function and dysfunction.

Micromolecular proteins (molecular weight less than 68 kD) in amniotic fluid are assumed to be derived largely from fetal urinary excretion and therefore may reflect fetal kidney function and maturation. Microprotein concentrations in amniotic fluid, neonatal urine and urine of fetuses with bilateral urinary tract dilation were analyzed using microgradient gel electrophoresis to separate proteins according to their molecular size. Alpha-1-microglobulin and beta 2-microglobulin were assayed as singular micromolecular marker proteins. Microproteins in amniotic fluid decreased progressively with advancing gestation during the 3rd trimester. Micromolecular protein concentrations in the first postnatal urine of healthy infants born prematurely or at term were similar to those in amniotic fluid of corresponding fetal age and yielded an identical developmental pattern. A strong correlation existed between the microprotein concentrations in amniotic fluid and fetal urine. It is concluded that fetal urinary production is the main determinant for the microprotein content of amniotic fluid and that a major fetal pathway exists for the intrauterine metabolism of these proteins. The 3rd trimester decrease in amniotic fluid seems to be dependent on the increasing reabsorption capacity of proximal tubular cells representing morphological and functional kidney maturation. The exact diagnostic value of microprotein analysis for the assessment of disturbed fetal kidney function has still to be defined by further investigation.

Alpha-Globulins↗

[Developmental physiologic aspects of volume and sodium regulation in premature and mature newborn infants].

Concentrations of sodium and creatinine were measured in serum and time collected urine samples of 72 newborn infants in the first ten days of life. Creatinine clearances, fractional and absolute sodium excretions were calculated. For analysis the group of newborns was divided into three according to gestational age: group A: less than 33 weeks; group B: 33-37 weeks; group C: greater than 37 weeks. The GFR was correlated to the conceptional age. Renal sodium losses exceeded alimentary supplementation in premature infants during the observation period. An additional supplementation of sodium seems therefore to be indicated early in life, as sodium balance is negative from the first day on. Individual investigations are necessary to evaluate the amount of sodium needed. 3-5 mMol/kg/day seem to be well tolerated and preventive for hyponatriaemia. Fluid administration during the first days should be calculated so that a weight loss of about 10% of body weight is achieved in premature infants in order to prevent cardiovascular and gastrointestinal complications. Because of a higher insensible water loss the amount of fluids administered per body weight should be higher in prematures than in matures.

Aldosterone↗

[Disorders of kidney function and acute kidney failure in newborn infants].

Compromised kidney function in the perinatal period has been increasingly recognized during recent years, and acute renal failure is a frequent clinical situation in neonatal intensive care units. Renal underperfusion due to various prerenal conditions is assumed to be the most common cause of renal failure in neonates. With rapid restoration of renal blood flow, prerenal failure is completely reversible in the early course of the disease. If adequate treatment is delayed, however, structural damage to the kidneys by prolonged ischemia will ensue leading to a poor prognostic outcome. This review, therefore, mainly focuses on early diagnosis of disturbed neonatal kidney function and prophylactic therapeutical aspects which may be of particular benefit for critically ill newborns at high risk for developing acute renal failure.

Acid-Base Equilibrium↗

The proteinase inhibitor complexes (antithrombin III-thrombin, alpha 2antiplasmin-plasmin and alpha 1antitrypsin-elastase) in septicemia, fulminant hepatic failure and cardiac shock: value for diagnosis and therapy control in DIC/F syndrome.

Thrombin (Thr), plasmin (Pl) and elastase (ELP) are serine proteinases which are quickly inactivated by their specific inhibitors (AT III, alpha 2AP, alpha 1AT), if intravascular activation of coagulation and fibrinolytic system or if release from PMN granulocytes by different stimuli (F.I., endotoxin, activated factor XII, a.o.) occurs. The immunological determination of the developing proteinase inhibitor complexes (PIC) AT III-Thr, alpha 2AP-Pl and alpha 1AT-ELP gives information as to whether intravascular coagulation, hyperfibrinolysis or unspecific proteolysis induced by elastase have taken place. Despite the high antiprotease activity in the plasma the a.m. serine proteinases may exert their proteolytic activity towards their specific substrates in vivo. In infectious diseases, fulminant hepatic failure and cardiac shock a complex consumption of coagulation factors and inhibitors may cause severe coagulation defects, microcirculatory disturbances and bleeding tendency. The PICs behaviour was determined in more than 80 patients with infectious diseases, in 5 patients with fulminant hepatic failure (FHF) and 7 patients with cardiac shock. Only in infectious diseases, mainly in septic complications, and septic complications during FHF and cardiac shock, are alpha 1AT-ELP levels found to be highly elevated. After cardiac shock, in FHF and in infectious diseases coagulation and fibrinolysis may additionally be activated. In this case AT III-Thr and alpha 2AP-Pl complexes could be detected in the patients plasma. This indicates that intravascular coagulation and hyperfibrinolysis has additionally taken place. To prevent bleeding complications a replacement therapy with plasma derivatives (AT III, plasminogen concentrate, PPSB and FFP) has been successfully performed in several patients with septic complications and in the 5 patients with FHF and the 7 patients with cardiac shock. No bleeding complication occurred, and the haemostatic balance could be maintained in the treated patients. AT III replacement therapy is necessary to stop DIC, PPSB improves severe coagulation defects, only FFP may additionally provide alpha 1AT, alpha 2AP and factor V. In acute renal failure sometimes plasminogen replacement is necessary to maintain a normal activity of the fibrinolytic system. The complex consumption of coagulation proteins in infectious diseases, FHF and cardiac shock cannot successfully be treated with an anticoagulant such as heparin alone.

Aged↗

[Pre- and postnatal diagnostic imaging of congenital urinary tract disorders].

The prenatal diagnosis of urinary tract obstruction was made in 10 neonates. These findings were confirmed postnatally by sonography, urography, voiding cystourethrography, and scintigraphy. There were 8 neonates with unilateral obstruction of the ureter, and 2 with urethral valves and reflux. Nephrectomy because of hydronephrosis was necessary in 2 instances. The prenatal diagnosis of a urinary tract obstruction is of great importance, because the neonate may be operated upon without delay. Thus the diseased kidney can be saved. Diuretic radionuclide urography is helpful in differentiating between dilated obstructed and dilated nonobstructed kidneys.

Constriction, Pathologic↗

Urinary protein analysis in the early detection of acute rejection episodes after renal transplantation in children.

The purpose of the present longitudinal investigation was to assess the predictive value of urinary protein analysis in the early detection of rejection crisis after renal transplantation. Forty-one children were studied consecutively over a period of 6 months applying the following methods: creatinine clearance (Ccr); urinary total protein (UTP); and electrophoretic differentiation of urinary proteins according to their molecular size by microgradient-gel electrophoresis (MGGE) with a continuous concentration gradient of 4-40% of polyacrylamide. Protein fractions analyzed were albumin (69,000 d), low molecular weight proteins (LMW-proteins, less than 69,000 d), and high molecular weight proteins (HMW-proteins, greater than 69,000 d). No rejection was observed in 30 children (group A), a total of 18 rejection episodes occurred in 11 children (group B). UTP was significantly lower in group A as compared to group B (107 vs 376 mg/m2/24 h), but no differences in urinary protein pattern were observed between group A and group B prior to rejection. One to two days after rejection UTP increased to 938 mg/m2/24 h, and 3-7 days after rejection LMW-protein fraction increased from 9% to 23% with a corresponding decrease of albumin fraction from 71% to 56% of UTP. No qualitative changes were noted in respect to HMW-protein excretion. It is concluded that changes of UTP and urinary protein pattern occur during rejection episodes but are of no predictive value in detecting rejection before clinical symptoms appear.

Acute Disease↗

Acute interstitial nephritis in childhood.

Three children aged 11 to 14 years with acute interstitial nephritis (AIN) are presented. In one patient AIN developed following antibiotic treatment with trimethoprim/sulfamethoxazole (TMP/SMX). In two patients no infection, drug, or toxin could be implicated. Severe polyuric renal failure without elevation of blood pressure was the predominant clinical feature. Uveitis occurred either simultaneously with the nephritic symptoms or several weeks after complete recovery of renal function. Renal functions were characteristically altered and led to suspicion of AIN even prior to renal biopsy. Renal plasma flow was relatively more reduced than glomerular filtration rate (GFR) with an accordingly increased filtration fraction. Quantitative evaluation of selective tubular functions revealed significant transport deficiencies for glucose, amino acids, inorganic phosphate and low molecular weight proteins. In two patients GFR increased rapidly following initiation of steroid treatment and tubular symptoms simultaneously disappeared. In one patient spontaneous remission occurred. We conclude that--in contrast to adults--the prognosis of AIN in childhood is favorable. Although general clinical features are rather nonspecific, symptoms of decreased tubular reabsorption ability provide a good indication of the diagnosis and may contribute to enhanced recognition of this disease.

Acute Kidney Injury↗

Stevens-Johnson syndrome during an immunosuppressive therapy with cyclophosphamide and prednisone.

Corticosteroids are often recommended for the treatment of severe Stevens-Johnson syndrome. We report about a 12 years old boy, who developed this syndrome during an immunosuppressive therapy with prednisone and cyclophosphamide for a frequent relapsing, steroid-dependent nephrotic syndrome. Most of the commonly mentioned etiologic factors for erythema exudativum multiforme could be excluded. The usefulness of corticosteroids for the therapy seems to be doubtful.

Child↗

[General anesthesia or peridural anesthesia in primary cesarean section; a comparative study].

In a prospective cooperative study of gynecologists, anaesthesiologists and pediatricians we compared the effect of continuous epidural anaesthesia (23 cases) and of general anaesthesia (24 cases) on mother and newborn. All patients were delivered in the 39. to 41. week of an uncomplicated pregnancy by primary caesarean section for breech presentation or disproportion. Nearly one third of the patients with epidural anaesthesia showed an initial transitory decrease in blood pressure- up to 25%. The mean pO2 was higher (155 mmHg) in the group with the general anaesthesia than in the group with epidural anaesthesia (88 mmHg). Corresponding values for pO2 were found in the umbilical artery (22,8 mmHg after general anaesthesia, 16,6 mmHg after epidural anaesthesia). Concerning the pH in the umbilical artery, the better results were obtained in the group with continuous epidural anaesthesia (7,3 versus 7,27). After general anaesthesia 9 children had a one minute Apgar-score below 8 versus 3 children after epidural anaesthesia; five and ten minutes after birth the Apgar scores were practically identical. The neurologic examination 15 min after delivery revealed a pathologic muscle tone in three cases after general anaesthesia and in one case after epidural anaesthesia. After 7 days all children showed a normal neurobehavior. As no severe differences between the two types of anaesthesia in the effect on mother or newborn could be seen, in uncomplicated pregnancies the choice should be left to the mother.

Anesthesia, Epidural↗