Search PubMed⌕ Search

Biomedical subjects

E Schulz

Publications and source records attributed to E Schulz.

At least 145 records · Page 8Linked to original sources
PubMed1986

Circadian rhythm of serotonin binding in rat brain--I. Effect of the light-dark cycle.

High affinity serotonin binding to rat brain membranes showed a circadian rhythm with minimal binding at 1000 and a maximal binding at 0000. Brain serotonin levels were almost inverse to the rhythm of serotonin binding. Under reverse light-dark conditions, lights on from 1900 to 0700, a significant phase shift in serotonin binding and concentration of about 8-10 hr was found. The adaptation of the rats to the inverse light-dark cycle was ascertained by plasma ACTH and corticosterone assay.

Adaptation, Physiological↗
PubMed1986

Circadian rhythm of serotonin binding in rat brain--II. Influence of sleep deprivation and imipramine.

Sleep deprivation (SD) modified the circadian rhythm of specific high affinity serotonin (5-HT) binding to rat brain membranes. In control rats a 24-hr rhythm was evident with a trough at 1000-1200 and a nadir at 0000. During the last 26 hr of a 49 hr SD period, trough and peak values were delayed by 4-6 hr. The 24-hr mean binding was significantly (P less than 0.001) different from that of controls. If sleep deprivation was followed by recovery sleep (RS), the normal rhythm of 5-HT binding was obtained already within 1 hr after SD. The effects of SD and RS were ascertained by plasma ACTH and corticosterone assay. No significant change in the hormone rhythms were observed through the mean plasma level of ACTH and corticosterone were enhanced to about 180 and 150%, respectively. Chronic treatment with the antidepressant imipramine resulted in a decrease of the 24-hr mean 5-HT binding by about 50% and a 2-hr delay of peak and trough values. Imipramine treatment decreased the peak value of 5-HT concentration at 1000 to about 65% and appears to abolish the rhythm of 5-HT concentration.

Adrenocorticotropic Hormone↗
PubMed1986

[Ciprofloxacin and cefotaxim: pharmacokinetic and therapeutic effectiveness in E. coli pyelonephritis in rats].

Ciprofloxacin was tested in the acute and chronic experimental E.coli pyelonephritis in rats. Its therapeutic efficacy was compared with that of cefotaxime. In the acute pyelonephritis increasing doses resulted in increasing elimination of bacteria from the kidneys. Ciprofloxacin and cefotaxime showed no difference in the efficiency in therapy of the acute pyelonephritis. In chronic pyelonephritis ciprofloxacin proved to be more effective than cefotaxime in spite of identical in vitro activity. Pharmacokinetic data showed that ciprofloxacin was eliminated more slowly than cefotaxime. The long serum half-life and the high volume of distribution could be responsible for the high therapeutic efficacy and could outweigh the disadvantage of metabolic instability.

Acute Disease↗
PubMed1985

Influence of immunosuppressive therapy with azathioprine and prednisolone on serum-immunoglobulin concentration in renal transplanted patients.

Serological diagnosis of infectious diseases are based on the assumption that a change in virus-specific antibody - titer reflects the response to a certain viral infection due to changes in the concentration of the respective virus - specific antibodies. On the other hand immunosuppressive medication interacts with that system responsible in producing antigen-specific antibodies. This study was outlined therefore to follow the variation of the concentration of serum immunoglobulins of classes IgG and IgM with regard to a better evaluation of virus-specific antibody titers especially for those viruses that remain persistent after a primary infection and an reactivate. The study followed ten patients after allogenic cadaver kidney transplantation under immunosuppressive medication with azathioprine and corticosteroids. Concentration of serum-IgG and -IgM protein was continuously measured for 6 months after transplantation along with measurement of virus-specific antibody-titers with enzyme immunoassay (Elisa) especially for cytomegalovirus. The results show a drastic decrease in serum immunoglobulins IgG and IgM - the lowest concentration being reached 25-50 days after transplantation. The concentration of IgG increased thereafter if no severe infectious diseases occurred during the post-transplant period. The concentration of IgM seems to react more sensitively upon infectious processes. In general, virus-specific antibody-titers (IgG) follow the sometimes drastic variation in the respective immunoglobulin class. It therefore reveals that antigen-specific antibody-titers in those patients should be controlled continuously during the time after transplantation for better evaluation of titer variations that eventually occur in correlation to the absolute concentration of the immunoglobulin class.

Adult↗
PubMed1985

[Herpes simplex infection after kidney transplantation under immunosuppression by cyclosporin. Diagnostic and therapeutic experiences].

Incidence and course of herpes simplex infections was determined prospectively in 22 patients who had a kidney transplant and were treated with cyclosporin. In addition to clinical findings, serial studies were undertaken of throat washings for herpes simplex virus in cell culture, as well as of patient sera for herpes-specific IgG and IgM antibodies. There were 13 clinically manifest infections, 12 of them localized, while one had dissemination with necrotizing retinitis. Virus demonstration was successful in all cases in which virostatic drugs had not yet been used. Asymptomatic virus excretion was noted in three cases. Significant IgG titre rise occurred in six of the 13 cases, but a positive IgM titre in only two. Acyclovir proved to be an effective virostatic drug with few side effects. The outcome in the localized infections was favourable, but in the disseminated one residual defects remained.

Acyclovir↗
PubMed1985

[Absence of effect of secretin and cholecystokinin on plasma concentrations of vasoactive intestinal polypeptide and pancreatic glucagon].

There is little information about the effect of peptides on the VIPergic system. Reports of the influence of secretin and cholecystokinin (CCK) on pancreatic alpha cells are contradictory. With the help of volunteers we investigated the influence of a new synthetic secretin (1 CU/kg/h, 0 to 120 min) alone and in combination with GIH-CCK (1 IU/kg/h, 60 to 120 min) on the concentrations of VIP (n = 13), pancreatic glucagon (PG) (n = 15) and blood sugar (n = 10). 6 of the volunteers were subjected to a randomized cross-over NaCl infusion study. Neither secretin (0 to 60 min) nor secretin and CCK (60 to 120 min) infusion caused a significant change in VIP (31 +/- 3 vs. 34 +/- 4.5 pg/ml, mean +/- SEM, p greater than 0.05), PG (102 +/- 9 vs. 116 +/- 12 vs. 114 +/- 12 pg/ml, p greater than 0.05) or blood sugar (about 90 mg/dl) concentrations. There is no evidence of an influence of secretin and CCK on te VIPergic system and the pancreatic alpha cells.

Adolescent↗
PubMed1985

Renal tolerance of imipenem/cilastatin and other beta-lactam antibiotics in rats.

Imipenem is inactivated by the renal dehydropeptidase I, which can be inhibited by cilastatin. Therefore, both compounds are administered in combination. According to the manufacturers, they are not nephrotoxic in rats. 70 female Wistar rats (n = 10/test series) were treated over five days at dosage intervals of 12 hours with intraperitoneal injections (injection volume: 10 ml/200 g body weight) of isotonic 0.9% NaCl, cilastatin (1000 mg/kg/day), imipenem (500 and 1000 mg/kg/day), cilastatin + imipenem (500 or 1000 mg/kg/day each) and cefsulodin (1000 mg/kg/day). The nocturnal excretion of renal tubular cells was determined. Furthermore, three rats in each test were treated intraperitoneally with 150 mg/kg imipenem or with the combination of imipenem and cilastatin (150 mg/kg each). Imipenem concentrations were measured over four hours in the blood of the tail vein. Commencing on the second day of study, cilastatin, imipenem and the combination of both substances induced significant surplus excretion of tubular cells compared to the control group. The tubulotoxic effects of imipenem and imipenem + cilastatin in combination were dose-dependent. The toxic effects of imipenem, imipenem + cilastatin and cefsulodin did not significantly differ. Cilastatin prolonged the half-life of imipenem in the blood from 0.4 to 0.9 h and increased the AUC of imipenem from 156 to 325 mg/l/h.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

The therapeutic response of cephalosporin-treated E. coli pyelonephritis of the rat, in relation to variations of the infection model.

In the E. coli pyelonephritis, induced in female Wistar rats by retrograde infection (high pressure reflux), we investigated the influence of 1) the time of commencement of therapy, 2) the renal bacterial counts, i.e. the inflammatory activity of the pyelonephritis after endovesical instillation of cultures with different bacterial concentrations, and 3) the level of infection resistance of the experimental animal strain on the therapeutic response of the model infection with single doses of cefoxitin (150 mg/ml) and cefotaxime (5 mg/ml). Early commencement of therapy post inoculation was therapeutically advantageous provided the intrarenal multiplication of the infective organisms was not delayed or the initial bacterial concentrations were not too high. The mild form of pyelonephritis with lower renal bacterial concentrations and poor inflammatory activity after endovesical instillation of a low inoculum (10(4) cfu/ml) was less amenable to treatment than the inflammatory active pyelonephritis with high renal bacterial counts, using a high inoculum (10(7) cfu/ml). High renal bacterial counts after retrograde inoculation of an E. coli culture of 10(8) cfu/ml resulted in significant reduction of bacterial counts 48, 72 and 96 h post infectionem, with i.m. application of cefoxitin 12 h prior. For Wistar rat strain Bor:WIST, which showed a stronger infection resistance with lower renal bacterial concentrations and a stronger tendency to spontaneous healing, application of a single dose of cefotaxime (5 mg/ml) was therapeutically ineffective, whereas, in contrast, with Han: WIST rats the acute phase of E. coli pyelonephritis could be treated effectively.

Animals↗
PubMed1985

Bactericidal activity and induction of cell volume alterations of cephalosporins in Escherichia coli.

The bactericidal efficacy of cefuroxime and cephacetril on Escherichia coli cultures was measured by killing curves. Simultaneously bacterial cell volumes were analysed by electronic particle counting using a Coulter Counter Channelanalyser system in order to study the relationship between bactericidal activity and bacterial cell volume alterations. Various concentrations (2-120 mg/l cefuroxime and 16-120 mg/l cephacetril) and different exposure times (over a time period of 12 h) were used. Growth medium was human plasma ultrafiltrate. The bactericidal activity of cefuroxime, as measured by the rate of killing of the E. coli culture, was independent of the concentration and constant in the range 4-120 mg/l. The characteristic cefuroxime-induced change in bacterial cell volume was a marked volume increase up to a maximum of 5-fold after 160-200 min exposure with a low-grade bacteriolysis following. The cefuroxime-induced bacterial volume changes were, in accordance with the bactericidal testing, almost independent of the concentration. In contrast, the killing curves for cephacetril strongly depended on the drug concentration. However, this effect was short-lived and regrowth of the E. coli culture followed. The typical cephacetril-induced volume distribution curves were also highly concentration-dependent. With increasing drug levels bacterial cell volume increased up to 20-fold, and regrowth of a persisting bacterial population occurred at lower antibiotic concentrations. Bacteriolysis started earlier than with cefuroxime. The relationship between loss of viability and cell volume increase was more marked with cefuroxime than with cephacetril.

Autoanalysis↗
PubMed1985

[Modification of the incidence and course of CMV infections following kidney transplantation by passive immunization--initial experiences with a hyperimmunoglobulin].

In 45 recipients of a renal transplant the CMV-antibody titer was measured preoperatively (ELISA method). If possible, the donors were examined likewise. All seronegative recipients of grafts of a seropositive donor were immunized passively with a CMV-hyperimmunoglobulin for 6 months (2 ml/kg bw in 3 weeks intervals). 7 patients showed that constellation, and they were treated. 4 of them demonstrated neither serological nor clinical signs of a CMV-infection at any time. In 3 patients an infection was found serologically, but only 2 showed concomitant clinical symptoms. No serious complications (pneumonia etc.) were seen. One year later all patients are doing well with a functioning graft. For this reason we think the passive immunization of a seronegative recipient of a graft from a seropositive or unexamined donor to be advisable.

Adult↗
PubMed1985

Habekacin: nephrotoxicity, pharmacokinetics and prophylactic efficacy in rats.

1-N[(S)-4-amino-2-hydroxybutyryl]-kanamycin B (habekacin), a new aminoglycoside antibiotic found in 1973 was tested for its nephrotoxicity, pharmacokinetics and prophylactic efficacy in 351 female rats. Increased urinary elimination of tubule cells and malate dehydrogenase (MDH) demonstrated tubulotoxicity even at the minimal dosage of 2.5 mg/kg/d. At high dosages (100 or 50 mg/kg/d) habekacin produced more tubule damage than dibekacin. At lower dosages (20, 10 or 5 mg/kg/d) both aminoglycosides showed similar effects. Additionally, possible glomerular lesions were found at high dosages (100 mg/kg/d) as indicated by proteinuria, CAF (cellulose acetate foil)-electrophoresis of the urinary protein and raised albumin/globulin ratio. - Pharmacological studies revealed serum concentrations similar to dibekacin, in renal tissue, however, the concentrations of habekacin were much higher than those of dibekacin. - In experimental E. coli pyelonephritis, 9 single doses of habekacin or dibekacin (5 mg/kg) given prophylactically reduced the bacterial counts significantly; a single dose of the antibiotics (5 mg/kg) was slightly effective.

Aminoglycosides↗
PubMed1985

[Modification of the risk of urolithiasis by changes in magnesium and calcium concentrations in the urine as affected by stress conditions].

Under defined stress conditions, a slight decrease in the calcium concentration in the urine of calcium oxalate stone patients on the first and second experimental days was observed. Taking simultaneously recorded calcium concentrations into consideration, Ca/Mg quotients, were calculated, which, at least in single cases, exceed the limiting range, thus signalling an increased risk of calculus formation.

Adult↗
PubMed1984

[Effect of synthetic secretin and GIH-cholecystokinin on serum gastrin levels].

In response to the report of a false-positive increase in serum gastrin with the use of natural secretin (Boots), 11 test persons were enlisted in order to examine the effect of a new synthetic secretin (Hoechst), both alone and in combination with natural CCK, on serum gastrin concentration. 6 of the test persons were subjected to a randomised cross-over study under NaCl infusion. Under secretin (0 to 60 minutes) there was a significant fall in gastrin from 32 +/- 2.3 pg/ml to 23 +/- 2 pg/ml (p less than 0.01). When CCK was also administered (60 to 120 minutes) the gastrin level increased to 46 +/- 3.5 pg/ml (75 versus 0 minutes: p less than 0.01), 75 versus 60 minutes: p less than 0.001). At the end of the infusion the gastrin level had fallen significantly once more to 21 +/- 2 pg/ml (135 versus 120 minutes: p less than 0.001, 135 versus 0 minutes: p less than 0.01). On the basis of in vitro studies -- which revealed a cross-reaction of 2.4% - the increase in gastrin under CCK is not regarded as being due to cross-reaction with CCK but rather to contamination by other peptides.

Adult↗
PubMed1984

[Endoscopy of the upper gastrointestinal tract: changes in the concentration of vasoactive intestinal polypeptide and gastrin?].

The report of a significant increase in plasma VIP concentration (PVC) during endoscopy of the upper gastrointestinal tract prompted us to examine this question under comparable experimental conditions, with simultaneous determination of serum gastrin concentration (SGC). Thirteen patients took part in a study wherein PVC and SGC were determined before, during and after oesophagogastroduodenoscopy (OGD). Before OGD the value for PVC was 30 +/- 2.5 pg/ml (means +/- SEM); during endoscopy it tended to increase slightly, to 35 +/- 3.2 pg/ml immediately after the examination (p greater than 0.05). By contrast with this finding, the SGC increased rapidly and significantly from 47 +/- 4.7 pg/ml prior to the examination to maximal values up to 68 +/- 6 pg/ml on inspection of the fundus (p less than 0,005), and was at a significantly increased level (p less than 0.05), with a value of 61.5 +/- 7.2 pg/ml, as much as thirty minutes after the examination. Sixty minutes after the examination the values had fallen to their original level (47.5 +/- 7.5 pg/ml). The present study shows that OGD has no significant influence on PVC, but that it is possible that stimulation of the VIP-ergic system is accompanied by a trivial increase in PVC. By contrast with this OGD significantly increases the concentration of endocrinally secreted gastrin, an effect which lasts as much as thirty minutes after the examination. The release of gastrin is a result of the combined effect of mechanical stimulation, distension due to insufflation of air and simultaneously induced neural influences. However, these mechanisms exert at most an insignificant influence on PVC - if indeed they have any effect on it at all.

Adult↗
PubMed1984

[Serologic diagnosis of cytomegalic inclusion disease using the Elisa technic in kidney transplant patients].

During the first six months after transplantation cytomegalovirus-(CMV-)specific serum IgM and IgG antibody titres were determined regularly with the Elisa technique in 25 renal transplant recipients and compared with results of the complement binding reaction (CBR). Active CMV infection was diagnosed in six patients: two primary infections and four reactivations. Titres of 1 : greater than 40 were considered positive. IgG titre increases of up to 1 : 20 000 and of 1 : 4000 for IgM were observed. IgM titres of 1 : greater than 200 are suspicious of active CMV infection, four-fold titre increases establish the diagnosis. Such IgM titres were accompanied by clinical symptoms of active CMV infection. The Elisa technique is a reliable method from the first week of disease for early demonstration of CMV infection. The prognostically relevant differentiation between primary CMV infection and reactivation of latent disease is possible using the IgG/IgM antibody titre relations. IgM titres indicate cure or persistence of infection. CBR with CMV antigen is of no use for diagnosis.

Adult↗