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Biomedical subjects

A Wolf

Publications and source records attributed to A Wolf.

At least 361 records · Page 20Linked to original sources
PubMed1980

Effect of 1 alpha hydroxylated vitamin D on steroid induced calcium malabsorption.

As persistent bone loss is a major problem of chronic steroid therapy the effects of 3 weeks therapy with 1 alpha hydroxycholecalciferol were studied in 10 kidney transplant recipients on chronic steroid therapy. Treatment resulted in a significant increase in intestinal calcium absorption, paralleled by a significant decrease of serum iPTH, whereas neither plasma calcium nor urinary calcium excretion rose significantly, suggesting a positive calcium balance throughout the study. It is therefore suggested that administration of active vitamin D metabolites is an effective protection against one of the pathogenic mechanisms of steroid induced osteopenia.

Calcium↗
PubMed1980

[Aluminum-balance during haemodialysis (author's transl)].

Aluminium kinetics in patients with endstage renal failure and chronic intermittent haemodialysis have been studied. All patients revealed elevated predialytic serum aluminum levels. Because of a significant correlation between daily intake of aluminiumhydroxyd and serum aluminium levels it is concluded that the intestinal aluminium absorption plays an etiological role in the development of hyperaluminaemia. Plasma aluminium levels at the end of a regular dialysis procedure are significant lower compared to predialytic values. Similarly a significant decrease of aluminium concentration was observed in the plasma after passage through the dialyzer. This is due to the fact that the aluminium content of the dialysate used in our unit (0.1-0.3 mumol/l) is lower than the ultrafiltrable fraction of the plasma aluminium measured in vivo. Therefore a negative aluminium-balance during haemodialysis has to be assumed in our patients. Extreme aluminium-accummulation seems to be avoided and we therefore never experienced aluminium intoxication and dialysis dementia in our center. To assess a negative aluminium balance during haemodialysis, because of high protein binding of aluminium, a dialysate with an extreme low aluminium content has to be recommended.

Adolescent↗
PubMed1980

[Interaction between blood platelets and capillary kidney in haemodialysis (author's transl)].

In haemodialysis an interaction between platelets and the dialysator membrane occurs, which is not prevented by heparin. This can be demonstrated by parietal depositions of platelets in the capillaries of the artificial kidney by scanning electron microscopy, as well as in a marked increase of reversible platelet microaggregates during the first phase of dialysis. Some patients are prone to develop thrombosis of the capillary kidneys in spite of a high-dose heparinization. In these cases the use of diclofenac, a cyclooxygenase inhibitor, prevents these adverse platelet reactions.

Adolescent↗
PubMed1980

[Determination of aluminium in blood-serum by inductively coupled plasma (ICP)-spectroscopy (author's transl)].

The application of ICP emission spectroscopy for the direct determination of aluminium in blood serum was investigated and the method with all important parameters is described. The well known matrix interferences in atomic absorption spectroscopy do not exist in ICP spectroscopy, due to the very high excitation temperature of the sample of about 8000 K. It is therefore possible to perform very sensitive and reproducible measurements.

Aluminum↗
PubMed1979

[Calcium and phosphorus metabolism in patients on chronic intermittent haemodialysis with different calcium concentrations in the dialysate (author's transl)].

A study was carried out in 25 patients on chronic intermittent haemodialysis on the effect of increasing the dialysate calcium concentration from 1.5 to 1.75 mMol/l on calcium and phosphorus metabolism. In 16 patients the increase in the dialysate calcium resulted in a sufficiently large increase in the plasma Ca level to suppress the parathyroid glands. The calcium influx during dialysis in these patients was sufficient to abolish the effects of diminished calcium absorption from the intestine due to loss of endocrine renal function. The remaining 9 patients showed no suppression of parathyroid gland activity and could be separated into two different groups, one requiring calcium supplementation and the other group manifesting signs of autonomic hyperparathyroidism. The five patients showing a higher calcium requirement were started on active vitamin D metabolites. In the remaining 4 patients parathyroidectomy will probably be inevitable if progression of the clinical manifestations of hyperparathyroidism occurs. Close control of plasma phosphorus levels is mandatory to avoid an increase in the calcium phosphate product or the danger of hypophosphataemic osteomalacia.

Adolescent↗
PubMed1979

[Circulating platelet aggregates during haemodialysis].

In eight chronically haemodialysed patients a significant increase of circulating platelet aggregates (method of Wu and Hoak) was observed immediately after starting haemodialysis. The number of aggregates decreased at the end of haemodialysis reaching the starting values after 360 min. The platelet interaction with the dialysis membrane surface might cause this phenomenon. Anticoagulation with heparin alone was insufficient in preventing aggregate formation during haemodialysis.

Adolescent↗
PubMed1979

[Renal failure and carbon monoxide diffusing capacity of the lung (author's transl)].

Reduced carbon monoxide diffusing capacity of the lung (DLCO) is reported in patients with impaired renal function. Since DLCO also depends on the pulmonary capillary blood volume the role of renal anaemia was evaluated. Measurements were carried out in 43 azotaemic patients [serum creatinine (SKr) 1.5 to 14.0 mg/100 ml], without evidence of cardiovascular or pulmonary complications of uraemia, of SKr, haemoglobin concentration (Hb) and steady state DLCO. In the case of DLCO values allowance was made for body surface area and thoracic gas volume. The relation was studied of the corrected DLCO to SKr and to Hb. There was a higher statistical correlation between DLCO and Hb than between DLCO and SKr. After additional correction of DLCO for Hb, no correlation to SKr was found. It is concluded that the reduction in DLCO in uraemia is due largely to a low Hb and, hence, to renal anaemia rather than to uraemic damage of interstitial lung tissue.

Adolescent↗
PubMed1979

Reversible acute tubular necrosis following severe acute renal rejection.

The clinical observation of 6 out of 250 renal transplant patients showed that acute renal rejection may lead to reversible acute tubular necrosis (ATN) necessitating intermittent haemodialysis treatment. Despite missing early response to high-dose (methyl-) prednisolone therapy (during a mean period of 4.7 days) all 6 patients developed spontaneous diuresis 14.5 days on average after onset of rejection while on maintenance immunosuppressive therapy. From the clinical course the conclusion was drawn that in severe cases of renal rejection with arteriographic and histological findings consistent with acute tubular necrosis, prolonged therapy with high doses of (methyl-) prednisolone is not desirable, since after reversal of immunological rejection the onset of spontaneous diuresis will be determined mainly by the duration of the healing and recovery phase of acute tubular necrosis.

Acute Kidney Injury↗
PubMed1979

The [18F]fluorodeoxyglucose method for the measurement of local cerebral glucose utilization in man.

A method has been developed to measure local glucose consumption in the various structures of the brain in man with three-dimensional resolution. [18F]-2-deoxy-2-fluoro-D-glucose is used as a tracer for the exchange of glucose between plasma and brain and its phosphorylation by hexokinase in the tissue. A mathematical model and derived operational equation are used which enable local cerebral glucose consumption to be calculated in terms of the following measurable variables. An intravenous bolus of [18F]-2-deoxy-2-fluoro-D-glucose is given and the arterial specific activity monitored for a predetermined period of from 30 to 120 minutes. Starting at 30 minutes, the activity in a series of sections through the brain is determined with three-dimensional resolution by an emission tomographic scanner. The method was used to measure local cerebral glucose consumption in two normal volunteers. The values in gray matter structures range from 5.79 mg/100 g per minute in the cerebellar cortex to 10.27 in the visual cortex, whereas, in white matter structures, the values range from 3.64 mg/100 g per minute in the corpus callosum to 4.22 in the occipital lobe. Average values for gray matter, white matter, and whole brain metabolic rates, calculated as a weighted average based on the approximate volume of each structure, are 8.05, 3.80, and 5.90 mg/100 g per minute, respectively. The value of 5.9 mg/100 g per minute compares favorably with values previously reported.

Adult↗
PubMed1979

[Alterations of the plasma ribonuclease activity in female wistar rats under the conditions of combined therapy of the ovary carcinoma (author's transl)].

The authors have analysed the influence exercised by the combined therapy of the ovary carcinoma on the plasma ribonuclease activity in Wistar rats. The medicaments "Proresid", "VM-26", and "Methotrexat" together with a percutaneous irradiation of the abdomen did not alterate perceptibly the enzyme activity during the experiment, but there was a considerable reduction of the enzyme activity after an application of "Endoxan", "Adriblastin" and "Methotrexat" with subsequent administration of "Leukovorin". The most violent ribonuclease suppression, however, was obtained by an intraperitoneal instillation of radiogold and a fractioned percutaneous irradiation of the abdomen with intercalated administration of "Endoxan".

Animals↗
PubMed1979

An analysis of corneal transplantation: I--graft clarity.

A retrospective review has been undertaken of the clarity results of 378 keratoplasties performed by 6 Toronto corneal surgeons between January 1970 and December 1974. Lamellar keratoplasties were included in the data related to herpes simplex only. In herpes simplex penetrating grafts gave better vision than lamellar grafts. The following factors were statistically important with respect to graft clarity: age of recipient, type of corneal disease, peroperative corneal vessels, first or subsequent graft, pre- and/or postoperative glaucoma, postoperative anterior synechiae, combined procedure, vitreous loss, previous cataract surgery, and follow-up time. The following factors were statistically unimportant with respect to graft clarity: donor age, time from death to enucleation (median 2.8 hours), time from enucleation to use (median 24 hours), sex of donor and recipient, interrupted or running suture, use of microscope, penetrating or lamellar graft in herpes simplex, postoperative astigmatism, and division of postoperative anterior synechiae. Silk (compared with nylon), larger grafts and combined procedures all increased the incidence of graft rejection. Repeat grafts were associated with more preoperative corneal vascularization.

Adolescent↗
PubMed1979

An analysis of corneal transplantation: II--postoperative astigmatism.

An analysis of 153 penetrating keratoplasties was undertaken. The same surgical technique was used in all cases. Three factors had a statistically significant effect on postoperative astigmatism, as measured by keratometry. (1) Astigmatism decreased with increasing follow-up time (P less than 0.05). (2) Vitreous loss at the time of the keratoplasty increased the amount of postoperative astigmatism (P less than 0.05). (3) Females had more postoperative astigmatism than males (P less than 0.05), but this was probably related to a tendency for females to have a greater incidence of postoperative anterior synechiae (P just greater than 0.05), and the fact that all 6 cases of vitreous loss were in females. There was an almost significant trend toward postoperative anterior synechiae being associated with increased astigmatism (P just greater than 0.05), and there was also a trend toward the division of these synechiae reducing the amount of astigmatism. Fifteen of the 153 penetrating grafts were done in cases of herpes simplex. These were compared with 11 lamellar grafts done for herpes simplex, and there was a statistically insignificant trend toward more postoperative astigmatism in penetrating grafts.

Astigmatism↗
PubMed1979

Handling of phosphate by the transplanted kidney.

Maximal tubular phosphate reabsorption capacity corrected for changes in glomerular filtration rate (TmP/GFR) was taken as a measure of renal phosphate handling in patients with good and stable functioning kidney allografts. TmP/GFR values were within the normal range in only one-fifth of the patients. Eighty per cent had an abnormally low renal phosphate threshold concentration. Persistent hyperparathyroidism was the causative factor of this diminished tubular reabsorption in less than half of these patients, the majority of them showing an iPTH independent phosphate leak. Although glucocorticoids, azathioprine and tubular damage of the graft in the perioperative phase may contribute to this iPTH independent phosphate wasting, no single causative factor could be identified. Cases with hypophosphataemia should be treated in order to avoid symptoms of phosphate depletion. Active Vitamin D metabolites would be the therapy of choice by suppressing the parathyroid glands ("chemical PTX") and by directly enhancing tubular phosphate reabsorption. In persistent hyperpathyroidism with hypercalcaemia, surgical parathyroidectomy must be considered. Therapy with phosphate salts is only symptomatic and should be used only as an adjunct.

Azathioprine↗
PubMed1979

[Determination of the plasma ribonuclease activity as a diagnostic aid in the diagnosis of ovarian cancer. Results of a double blind study (author's transl)].

The determination of the plasmaribonucleases was reported by Sheid and co-workers in 1977 for the diagnosis of carcinoma of the ovary. The authors investigated the accuracy of this test with a modified method in a double blind study encompassing healthy controls. Blood samples from 62 patients with ovarian cancer were tested. The results were accurate in 56 cases. In 6 cases the test results were doubtful. The difference in the ribonuclease activity was significant between patients with ovarian cancer and healthy patients or patients in remission from ovarian cancer. The results were not dependant upon the FIGO staging of the disease. Our results encourage the recommendation to use this test as a diagnostic aid in carcinoma of the ovary.

Clinical Enzyme Tests↗
PubMed1978

[Spontaneous rupture of renal allografts (author's transl)].

Spontaneous rupture of an allografted kidney is not such a rare complication of kidney transplantation. In our series 5.2% of the transplanted kidneys ruptured spontaneously. The condition is an acute emergency characterized by the triad, acute abdomen, swelling in the region of the transplant and haemorrhagic shock. The aetiology of transplant rupture seems to be multifactorial, but the superimposition of an acute rejection episode on ischaemic tubular damage with acute renal failure was found to be the most important combination of events leading to transplant rupture in our patients. Exceptionally precise immunological monitoring in the early phases following transplantation and early aggressive therapy of an acute rejection crisis associated with acute renal failure should prevent allograft rupture.

Abdomen, Acute↗