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Biomedical subjects

M Kallerhoff

Publications and source records attributed to M Kallerhoff.

At least 19 recordsLinked to original sources
PubMed1998

Influence of vinblastine on DNA parameters and multidrug resistance in renal cell carcinoma in vitro.

The purpose of this study was to investigate how the vinca alkaloid vinblastine influences DNA parameters and the mechanisms of multidrug resistance in renal cell carcinoma. After exposing cell cultures of human renal carcinoma to progressively increasing concentrations of vinblastine the cell lines were examined by flow cytometric DNA analysis to assess the S-phase and G2/M-phase fraction and by a modified MTT assay. It was shown that the exposed cells became P-glycoprotein-positive by staining the cells with a monoclonal antibody (JSB-1). The flow cytometric analysis revealed, with prolonged vinblastine exposure, correlated increases in the S-phase and G2/M-phase fractions (P = 0.0001). When vinblastine-free medium was used for culturing, the changed DNA characteristics returned to their original values. Comparing the DNA parameters with the IC50 (concentration when cell growth is inhibited by 50%) we found a strong correlation between these parameters (P = 0.0001). In conclusion, DNA analysis of long-term vinblastine exposure may provide insight into events leading to multidrug resistance. Furthermore, analysis of the DNA profile might also be an important investigation before planning therapy with vinblastine for renal cell carcinoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

In vitro investigations of new therapeutic agents on bladder tumor cell lines.

In this study sensitivity of human transitional cancer cells to the anticancer agent paclitaxel, an antimicrotubular drug, and to gallium nitrate, a group IIIa metal, was compared to that of the standard MVAC (methotrexate, vinblastine, doxorubicin and cisplatin) drugs. The reduction of cell proliferation was evaluated after 48 h of incubation of six different cell lines with each agent using the mean transit time (MTT) assay. We investigated both monolayers and spheroids. Paclitaxel showed significantly higher growth inhibitory effects on monolayers than vinblastine, both agents targeting the antimicrotubular apparatus. This could not be reproduced on spheroids, where a survival fraction of 50% was observed even at high concentrations (10 microM). High concentrations of gallium nitrate were needed to achieve sufficient toxicity. These concentrations are beyond the concentration achievable by systemic application. Our findings suggest that paclitaxel may be a clinically useful agent for systemic and intravesical use in bladder cancer.

Antibiotics, Antineoplastic↗
PubMed1997

Electrolyte equilibration of human kidneys during perfusion with HTK-solution according to Bretschneider.

Twelve surgically removed human kidneys (mainly tumor kidneys) were investigated. The investigations comprised perfusion criteria (perfusion flow, perfusion pressure, perfusion resistance, electrolyte equilibration). During perfusion of the kidneys with HTK solution, the perfusion resistance was nearly three times as high in human kidneys as in canine kidneys perfused under the same conditions in previous studies. Beside possible species differences the raised perfusion resistance may be explained by the greater trauma to the human kidneys due to the surgery, the primary ischemic stress which cannot be avoided clinically and the often nonoptimal initial diuresis. Nevertheless definitive perfusion is possible under clinical conditions although pronounced increases of perfusion resistance may occur. As indicated by the raised perfusion resistance of human kidneys under clinical conditions as compared with canine kidneys in an experimental model, electrolyte equilibration of human kidneys was protracted. For this reason, a duration of perfusion of at least 10 min is necessary in clinical application of HTK solution, i.e., longer than in animal experiments.

Glucose↗
PubMed1997

[Microproteinuria and enzymuria in fever and pyelonephritis in childhood. A prospective study of 180 children].

In 180 children (87 children belonging to a control group, 68 with fever of non-renal origin, and 25 with pyelonephritis) albumin and immunoglobulin G (markers for glomerular dysfunction), alpha-1-microglobulin and beta-NAG (markers for proximal tubular dysfunction) and apolipoprotein A1 (marker of "postrenal' dysfunction) were measured in second-voided morning urine. In children with fever of non-renal origin, glomerular dysfunction was encountered in 8.8%, tubular dysfunction in 17.6% and mixed glomerular-tubular dysfunction in 14.7% of cases. Among children with pyelonephritis, 28% revealed glomerular dysfunction and 44% mixed glomerular-tubular dysfunction. No case of solitary proximal tubular dysfunction was observed in children with pyelonephritis. There were highly significant differences in presence and expression of glomerular dysfunction between children with fever of non-renal origin and children with pyelonephritis (P < 0.0001), whereas with regard to proximal tubular dysfunction, the differences were only moderately significant (beta-NAG: P < 0.01) or of low significance (alpha-1-microglobulin: P < 0.05). This may indicate that morphologic changes occur during interstitial pyelonephritis due to inflammation of glomeruli, resulting in glomerular dysfunction, while proximal tubular dysfunction may additionally be due to fever-associated function processes.

Acetylglucosaminidase↗
PubMed1997

[Influence of DNA ploidy and grading on survival in primary metastatic prostate carcinoma].

An aneuploid pattern of prostatic cancer defined by flow cytometry was shown to be of value in predicting progression rates and patient survival times. We evaluated the long-term value of DNA analysis in prostatic cancer in 61 patients with advanced disease. We performed flow cytometry on 61 fresh prostate specimens obtained-from a transrectal needle biopsy or a transurethral resection. All patients received antihormonal therapy. Time until death was evaluated in all patients. Of the DNA histograms analyzed, 37% showed a diploid pattern, 63% an non-diploid pattern, and 37% a tetraploid or hypertetraploid pattern. Kaplan-Meier plots were generated for analysis of the probability of survival. Mean survival time was 44 months for patients with diploid (range 1-126 months) and 40 months for patients with non-diploid tumors (range 1-96 months). This difference is not statistically significant. However, the combination of non-diploid and low-differentiated (G3) tumors reduced survival time significantly (mean 20 months, range 1-62 months). There was no patient with combination of a diploid and highly differentiated tumor.

Aged↗
PubMed1997

Extracellular HTK perfusion and intracellular acidification in ischemic dog kidneys: a 31P NMR spectroscopic study.

PURPOSE: Bretschneider's histidine-tryptophan-ketoglutarate solution (HTK) for organ preservation is in wide clinical use. Its high buffering capacity is its major protective principle. It is assumed that renal ischemic tolerance benefits from this principle. The study was undertaken to determine the degree to which extracellular buffering influences intracellular acid load. MATERIAL AND METHODS: Canine kidneys were investigated for intracellular and extracellular pH changes during a clinically relevant period of ischemia after preperfusion with either HTK or Ringer solution (Ringer) at different temperatures. Extracellular pH (pHe) was measured with ion-sensitive electrodes. Intracellular pH (pHi) was determined with 31P NMRS. Morphologic and functional parameters were assessed in reperfusion experiments. RESULTS: After perfusion with HTK, pHe values of 7.35, 7.25, and 7.30 were determined for 5C, 20C and, normothermia, respectively. The pHe values after 150 minutes were 7.37, 6.84, and 6.76 at the temperatures indicated. The corresponding pHi values 150 minutes after HTK perfusion were 7.20, 6.79 and 6.54. After Ringer perfusion and 150 minutes at 20C and normothermia, pHi values of 6.29 and 5.92 were measured. Reperfusion experiments showed better results in the HTK group. CONCLUSIONS: Preperfusion with HTK considerably decreases ischemic acidification of extracellular and intracellular compartments at 20C and 37C, compared with Ringer. In kidneys preperfused with HTK and kept at 5C, a nearly physiologic pH was maintained during the observation period of 150 minutes and longer, HTK leads to better functional and morphologic preservation compared to Ringer.

Animals↗
PubMed1997

Management of involuntary childlessness.

Any definition of involuntary childlessness has to consider the difference between sterility and subfertility. As the latter affects about 20-30% of all couples at least once in their lives, general practitioners (GPs) may be the first to be confronted with this problem. This review presents the most relevant diagnostic and therapeutic options in cases of female or male infertility, and discusses the new assisted reproductive technologies (such as insemination, in vitro fertilization, gamete transfer and intracytoplasmatic sperm injection) so that GPs may adequately inform their patients about these procedures and their risks and outcomes. Although controversial, involuntary childlessness and its clinical treatment seem to have a strong psychological impact on a couple's social, emotional and sexual life. Being available for discussion with childless couples and offering ongoing support may be the most important role for the GP in this context.

Family Practice↗
PubMed1996

Microcalorimetric measurements carried out on isolated tumorous and nontumorous tissue samples from organs in the urogenital tract in comparison to histological and impulse-cytophotometric investigations.

In this comparative study, microcalorimetric measurements were carried out on a total of 96 tumorous and nontumorous tissue samples taken from organs of the urogenital tract using a thermal activity monitor (TAM). Changes in the heat emission of the tissue samples were measured at 1-min intervals and graphically displayed as a function of time. The aim of the study was to compare the microcalorimetric results with impulse-cytophotometric and histological findings and provide evidence for the metabolic activity of tumorous and nontumorous tissue. In order to obtain the variation in metabolic activity, the maxima (Pmax) of the curves were determined as a value of the maximum thermal power of a tissue sample, the mean values (P) were determined by the mean thermal power and the contour integrals (W) were defined by the behavior of the energy reserves and their mobilization. The first part of the study was carried out to investigate whether tumorous and nontumorous tissue samples differ in general according to their metabolic activity. We discovered, using the parameters described above, that in general tumorous tissue exhibited a higher metabolic activity than nontumorous tissue samples. For example, both W and P in tumorous prostate tissue samples were eightfold higher and the (Pmax) value was 8.4-fold higher than in normal tissue. Additional investigations on testicle and kidney tissues were performed to find a possible correlation between microcalorimetric results and histological grading. We found that an increasing malignancy correlated with a higher metabolic activity of the tissue. Based upon these results we were able to differentiate the various histological gradings of these tumorous tissues by microcalorimetric measurements. The results show it is possible to differentiate between normal and tumorous tissue samples by microcalorimetric measurement based on the distinctly higher metabolic activity of malignant tissue. Furthermore, microcalorimetry allows a differentiation and classification of tissue samples into their histological grading. With the help of microcalorimetry, it might be possible in future to detect and record the metabolic processes of isolated tissue structures and changes in these activities as a result of medical intervention such as cytostatic treatment.

Aged↗
PubMed1996

The influence of temperature on changes in pH, lactate and morphology during testicular ischaemia.

OBJECTIVE: To examine the role of temperature in the irreversible changes that occur within 4-6 h as ischaemic atrophy develops in the testis during testicular torsion, by determining effects on testicular pH, lactate accumulation and morphology. MATERIALS AND METHODS: Tissue acidification (pH), tissue lactate and structural changes were measured at temperatures of 35, 25, 15 and 5 degrees C in 34 human testes obtained as orchidectomy specimens from patients with metastatic prostatic cancer, and in 19 testes taken from young dogs. RESULTS: At a normal testicular temperature of 35 degrees C, the pH decreased to 6.0 within 2 h of the onset of ischaemia; cooling to 15 degrees C extended this delay to 6 h. Tissue lactate increased from 25 mumol/g dry weight to about 200 mumol/g at 35 degrees C. Semi-thin sections of the canine testes showed swelling of the intratubular tissue with loss of interstitial space; lower temperature delayed these changes. CONCLUSIONS: In the present study, 6 h of torsion was relatively prolonged, in that the pH decreased to 5.8 and testicular tissue was destroyed. Acidification and histological damage can be prevented by cooling. The critical pH of the testis beyond which irreversible changes occur is unknown; a pH of < 6.0 is likely to provoke such changes.

Aged↗
PubMed1996

Citrobacter emphysematous pyelonephritis in a tuberculous kidney caused by citrobacter. A case report in a diabetic patient.

Emphysematous pyelonephritis caused by gas-producing bacteria like Escherichia coli or Klebsiella pneumonia is generally observed in female diabetic patients. We report a case in which Citrobacter was the microbiologically documented pathogen. High-dose antibiotic regimen was administered, but nephrectomy was necessary to overcome the life-threatening situation.

Citrobacter freundii↗
PubMed1995

[Change in renin activity and blood pressure in the dog autologous kidney transplant model with modified HTK solution].

Investigations of changes in activity of renin and blood pressure after reperfusion of the kidney transplant using HTK solution were carried out by means of an autologous, heterotopic model of kidney transplantation applied to dogs. Duration of cold ischemia was 48 h. According to variations in the composition of the HTK perfusion solution three test groups were set up. During the first 20 min after recirculation in each test group the renal venous and arterial renin activities were measured. Parallel to renin activity, the arterial blood pressure was recorded. During the first few minutes following recirculation of the kidney transplant the renin levels in the venous blood of the kidney were higher in test group 1 (HTK solution, perfusion height 120 cm) than in either of the other two, showing a median maximal increase of 195 ng/ml.h. In test group 2 the maximal venous renin concentration fell to 145 ng/ml.h, while graphs take a more uniform course. Test group 3 (HTK/tryptophan) differed from the others in having further improved renin values. After the 7.5 min of observation normal venous renin concentrations were measured following earlier values for maximal increase between 23.1 ng/ml.h and 120 ng/ml.h (median 61.5 ng/ml.h). The best reperfusion of the kidney was observed in the tryptophan group, albeit without any recognizable positive effects on the other renal functions. Initially low renin values do not necessarily correlate with a smooth postoperative renal function and vice versa. Initial renin values cannot provide a secure basis for predicting instant as well as long-term postoperative functions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Effects of various HTK solution regimens on proteinuria after renal transplantation in dogs.

Investigations were carried out by means of an autologous, heterotopic model for kidney transplantation applied to dogs. Duration of cold ischemia was 48 h. Four experimental groups were arranged. During the first 20 min following revitalization of the transplanted kidney, group 1 (HTK solution/80 cm perfusion height) showed a significant glomerular and tubular malfunction. In group 2 (HTK solution/120 cm perfusion height), only four urinary proteins with molecular weights of 25 kDa, 67 kDa, 100 kDa and > 100 kDa were found. The excretion of higher molecular proteins receded over the 20-min period of observation. In both group 3 (HTK/aspartate solution) and group 4 (HTK/tryptophan solution) the quantity of excreted glomerular and tubular protein was well above that of group 2. As opposed to the "Tryptophan" group, a complete restoration of renal function was observed in the "Aspartate" group after 4 weeks. In general, the "standard" HTK protective solution delivered with 120 cm perfusion pressure gave the most favorable results, with the lowest levels of proteinuria and a satisfactory recovery of renal function after revitalization.

Albuminuria↗
PubMed1995

[Congenital agenesis of the vas deferens and cystic fibrosis].

Aspermia caused by absence of the vas deferens is well known in cystic fibrosis. It has been suggested that otherwise healthy males with congenital bilateral absence of the vas deferens (CBAVD), which was previously considered a distinct genetic entity, have an increased frequency of CF gene mutations. CBAVD is now considered to be a mild form of cystic fibrosis. We report the case of an azoospermic man who had undergone exploratory scrototomy because of aplasia of the epididymis and vas deferens. Genetic screening for cystic fibrosis revealed a compound heterozygote for CFTR mutations delta F 508 and R 117 H.

Adult↗
PubMed1994

A modified technique for nerve-sparing retroperitoneal lymph node dissection in stage II nonseminomatous germ cell tumors using intraoperative measurement of bladder neck pressure alterations following sympathetic nerve fiber electrostimulation.

We present a simplified method for nerve-sparing retroperitoneal lymph node dissection in patients with nonseminomatous testicular cancer. The sympathetic fibers involved in antegrade ejaculation are identified by intraoperative electrostimulation, resulting in an increase of bladder neck closure pressure. This increase is demonstrated by intraoperative monitoring of both the intravesical pressure and the pressure within the bladder neck by a two-channel microtip measuring catheter. 4 patients with stage I and 6 patients with stage II nonseminomatous testicular cancer were operated on with this modified technique. Ejaculation was preserved in all cases. Semen volume ranged from 2.2 to 4.0 ml. Sperm cell count ranged from 2 to 22 x 10(6)/ml with 20-50% motile spermatozoa, except for 2 of the 3 patients who initially presented with preoperative azoospermia following chemotherapy. In 1 of these 3 patients, postoperative semen analyses revealed a recovery of germ cell function demonstrated by oligoasthenozoospermia.

Adrenergic Fibers↗
PubMed1993

Prenatal diagnosis of congenital nephrosis of the Finnish type (CNF) in the second trimester.

Congenital nephrosis of the Finnish type is an hereditary, autosomal recessive disease which leads to death in early infancy. This is a case report concerning an affected fetus with legal interruption in the 24th week of gestation on the basis of certain sonographic changes in the fetal kidneys and changes in the protein profile in amniotic fluid, which were consistent with nephrotic damage of the kidneys. Light and electron microscopy showed evidence of CNF, i.e. increase of mesangial matrix and cells in glomeruli, dilated tubular segments, and effaced and plumb foot-processes of the glomerular epithelial cells. Antenatal diagnosis of CNF therefore seems feasible in the second trimester of gestation by means of AFP determinations in maternal serum and amniotic fluid as well as by using sonographic criteria and determination of proteins in amniotic fluid.

Amniotic Fluid↗