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Biomedical subjects

H Köhler

Publications and source records attributed to H Köhler.

At least 343 records · Page 19Linked to original sources
PubMed1984

[Angiomyolipoma of the kidneys in Bourneville-Pringle disease].

Three cases with renal angiomyolipoma in Bourneville's disease are reported. In two patients advanced renal insufficiency developed, one being treated by chronic intermittent hemodialysis. In the third patient rupture of angiomyolipoma with severe retroperitoneal bleeding occurred. In one patient, tumorous enlargement initially was diagnosed only in the right kidney and preceded angiomyolipoma of the left kidney for several years. In this patient nephrectomy was performed because malignancy was assumed before diagnosis of Bourneville's disease was established. Occasionally, histology may suggest sarcomatous changes. However, the absence of distant metastasis and the overall long survival of patients with renal angiomyolipoma in Bourneville's disease underline the benign character of the tumor. Treatment should be conservative because surgical intervention with loss of kidney parenchyma may enhance progression to end-stage renal failure.

Adult↗
PubMed1984

[Development of collateral circulation in arterial occlusions in advanced age].

Plethysmographic course controls in 15 male patients at the age between 70 and 76.5 years showed that the maximum of the collateral blood supply in arteriosclerosis in the femoral region is reached 1-2 years at the latest after vascular occlusion. The peak-flow-values measured confirm the possibility of efficient collaterals also at older age. When there is a bad early compensation of the artery occlusions, we intended to test in time, whether or not a percutaneous transluminal angioplasty or a local thrombolysis are possible. Furthermore, in 100 male patients with arteriosclerotic disturbances of the blood supply of the legs the plethysmographic measurement of the reactive blood supply showed that the internationally usual haemodynamic subdivision into degrees of severity also concerns the age group between 60 and 75 years. With progressing Fontaine-stage a decrease of the reactive blood supply (first-flow, peak-flow) and an increase of the peak-flow-time were found.

Aged↗
PubMed1984

Nitrocellulose-enzyme-linked immunosorbent assay (NC-ELISA) - a sensitive technique for the rapid visual detection of both viral antigens and antibodies.

A modification of the enzyme-linked immunosorbent assay (ELISA) is described for sensitive and rapid direct visual detection of antigens of four adenoviruses (Ad) and anti-Ad antibodies using nitrocellulose (NC) membrane discs as high-capacity solid phase. The NC-ELISA was performed in microtitre plates containing NC-discs. Small amounts of crude supernatants from Ad-infected cells as antigen were bound to the discs. Additional binding capacity was blocked with an excess of bovine serum albumin. The subsequent reaction of virus antigen with specific rabbit antibody was visualized using alkaline phosphatase-conjugated anti-rabbit IgG and histochemical substrates. The sensitivity of the NC-ELISA for the detection of Ad-antigens was found to be 8-10-fold higher than a conventional ELISA using polystyrene solid phase supports. The sensitivity levels were estimated to be similar comparing NC-ELISA and tissue culture assay results. The quantitative determination of anti-Ad antibodies by NC-ELISA showed 8-fold higher sensitivity compared to microneutralization test. The NC-ELISA could detect purified immunoglobulin at a level of 1 ng using a direct test procedure and 10 ng using the indirect method. The detection limits are good compared to other highly sensitive assays. The use of crude antigen combined with high sensitivity and easy technical performance makes the NC-ELISA useful as a tool for rapid viral diagnosis.

Adenoviridae Infections↗
PubMed1984

Active hepatitis B vaccination of dialysis patients and medical staff.

One hundred six patients with terminal renal insufficiency and 29 medical personnel were given three doses of hepatitis B vaccine at an interval of 0, 1, and 6 months (Merck, Sharp and Dohme, West Point, Pennsylvania, part of a joint study no. 649). Chronic hemodialysis patients (N = 99) received 40 micrograms vaccine (V) i.m. Uremic patients, who were just about to start chronic dialysis treatment (N = 7), were given 40 micrograms V, and at the first vaccination 3 ml hyperimmune globulin (HBIG) in addition. The medical personnel was alternately vaccinated with 20 micrograms V (N = 8), 40 micrograms (N = 11), 40 micrograms V, and 3 ml HBIG at the first vaccination (N = 10). After 12 months, 50% of the male dialysis patients, 66% of the female dialysis patients, and 95% of the medical staff developed anti-HBs antibodies. The anti-HBs titer of the dialysis patients was ten times lower than in the medical staff. The simultaneous passive immunization did not lead to any impairment of the anti-HBs titer in the dialysis patients and staff. The type of renal disease, length of time on dialysis, hematocrit, and immunoglobulin concentration did not influence the rate of immunization. After 12 months, 43 patients without antibody response were vaccinated a fourth time. Sixteen of these patients then developed anti-HBs, improving the immunization rate from 56.5 to 71.7%. A fifth vaccination only led to seroconversion, when brief or borderline anti-HBs could already be demonstrated previously. In dialysis patients who fail to develop anti-HBs after three doses of vaccine, a fourth vaccination is recommended after 12 months.

Antibodies, Viral↗
PubMed1984

Hemoglobin binds to the amino-terminal 23-residue fragment of human erythrocyte band 3 protein.

Hemoglobin, aldolase and glyceraldehyde 3-phosphate dehydrogenase are known to bind to the cytoplasmic domain of band 3 protein. Binding of glycolytic enzymes to band 3 protein is inhibited by its amino-terminal fragments. To precisely localize the sequence portion of band 3 protein to which hemoglobin binds and to see whether the same region of amino-acid sequence binds both hemoglobin and glycolytic enzymes, a simple, direct solid-phase binding assay was developed. Peptides generated from the 23-kDa fragment by trypsin, cyanogen bromide and mild acid hydrolysis were used as inhibitors to determine the minimal sequence structure involved in the binding of the 23-kDa fragment to hemoglobin. The shortest peptide which inhibits the binding of the 23-kDa fragment is an acid cleavage peptide containing the sequence positions 1 to 23. This sequence is unusual as 14 of its residues are negatively charged, it contains no basic residues and has its amino terminus blocked. Using aldolase, glyceraldehyde-3-phosphate dehydrogenase and hemoglobin as competitive inhibitors in the binding of 23-kDa fragment, the affinity of hemoglobin to this fragment appears several-fold weaker than that of both the enzymes. These findings demonstrate that glycolytic enzymes and hemoglobin bind competitively to the same polyanionic sequence region of band 3 protein.

Amino Acid Sequence↗
PubMed1984

Sonography of arteriovenous fistulae in hemodialysis patients.

In 88 chronic hemodialysis patients with clinically presumed fistula or graft complications the vascular access was investigated by ultrasonography. In 18 patients stenoses of the fistulae, in 24 patients partial or complete thrombosis, in 7 patients aneurysms and in 4 patients perivascular hematomas could be demonstrated precisely by ultrasonographic images. In 17 patients the preoperative sonography corresponded well with intraoperative findings. No sufficient information was obtained in cases of intra-luminal vessel diameters smaller than 3 mm. In complications or malfunctions of the vascular access of hemodialysis patients, noninvasive ultrasonography is suggested as the initial imaging procedure.

Aneurysm↗
PubMed1984

[In vitro electrically activated blood--an endogenous thrombogenic substance for the blocking of arteries supplying tumors and the microcirculation of tumor tissue--an experimental study].

Endovasal transcatheteral blockage of arteries supplying tumours is a clinically tested palliative measure and can also be used preoperatively to reduce intraoperative bleeding and the spread of tumour cells. In recent years several, mainly exogenic, substances have been used along with autologous muscle slurry and extracorporally produced autologous thromboses. Blood which has been exposed to the in-vitro effect of anodic direct current behaves like an endogenic thrombogenic substance. This can be used to block the microcirculation and the main artery of an organ, which results in its total dysfunction and loss of the parenchyma.

Animals↗
PubMed1983

Interaction of hemoglobin with band 3: a review.

The oxygen transport protein hemoglobin interacts specifically and reversibly with the red cell membrane. pH and ionic strength dependence of these interactions indicate their electrostatic nature. The anion transport protein band 3 has been implicated as the protein to which hemoglobin binds. Hemoglobin, aldolase and glyceraldehyde 3-phosphate dehydrogenase have a similar pH and ionic strength dependence in binding to 23K fragment. The three compete for the same amino-terminal 23 residue sequence region of band 3. The binding site is a highly acidic segment without any positive charge. We have recently determined the sequence of amino-terminal 23K fragment of band 3. There is a remarkable internal sequence homology between the first eleven and next eleven residues in this sequence region. Biophysical measurements in this sequence region. Biophysical measurements have revealed that 23K is a tetramer under physiological conditions. The implications of this structure of 23K is discussed with respect to the interaction of band 3 with the red cell cytoskeleton.

Amino Acid Sequence↗
PubMed1983

[Sonographic findings in analgesic nephropathy].

Demonstration of circular papillary calcifications in renal sonography, frequently combined with urinary retention and reduction of kidney size, can be used as evidence of analgesic nephropathy. This previously not described sonomorphologic pattern was observed in 8 out of 10 patients on dialysis treatment with previously known abuse of analgesics and in 5 out of 8 patients with compensated reduction of renal function and established abuse of analgesics. In addition, this sonographic pattern was also reported in 6 patients with increased serum creatinine concentration of unknown origin. This resulted in detection of a previously unknown abuse of analgesics.

Analgesics↗
PubMed1983

Transport of the precursor to neurospora ATPase subunit 9 into yeast mitochondria. Implications on the diversity of the transport mechanism.

Isolated yeast mitochondria were able to take up Neurospora ATPase subunit 9 in vitro although the homologous yeast protein is synthesized within the mitochondria and inserted into the membrane from the matrix side (Tzagoloff, A., and Meagher, P. (1972) J. Biol. Chem. 247, 594-603). The transfer of the protein was dependent on an energized mitochondrial inner membrane. It was accompanied by proteolytic processing of the precursor to the mature protein with the correct NH2 terminus as determined by Edman degradation of the transferred protein. The possibility is discussed that there are common features in the uptake machinery neither specific for one species nor specific for individual precursor proteins in the same species.

Adenosine Triphosphatases↗
PubMed1983

Accumulation and adverse effects of metoprolol and propranolol after concurrent administration of cimetidine.

Pharmacokinetics of metoprolol, propranolol and atenolol were investigated in six healthy volunteers following 7 days of oral monotherapy with these drugs and after 7 days concurrent administration of each of these betareceptor antagonists with cimetidine. Application of cimetidine did not lead to any interaction with atenolol, whereas mean peak plasma levels of metoprolol were increased by 70%, and those of propranolol by 95% due to concurrent administration of cimetidine (p less than 0.05). The AUC of the two last mentioned beta blockers behaved similarly (p less than 0.05). Measurement of exercise-induced tachycardia on the 6th day of administration showed no differences between monotherapy with the beta blocker and combined treatment with each of them and cimetidine. Except for one volunteer who complained of anxiety, weakness and sweating on the 6th day of cimetidine/metoprolol administration, no adverse effects could be observed during the combination therapy with cimetidine and the beta blockers or in monotherapy with beta blockers.

Adult↗
PubMed1983

Atenolol interaction with aspirin, allopurinol, and ampicillin.

Atenolol kinetics were investigated in six healthy subjects after 100 mg orally, as monotherapy a 6-day treatment began 48 hr later. After a therapy-free interval of 4 wk, the same subjects received the same dose of atenolol with 1 gm ampicillin, 500 mg aspirin, and with 300 mg allopurinol. Allopurinol and aspirin did not substantially alter the kinetics of atenolol. After a single oral dose of 100 mg atenolol combined with 1 gm ampicillin, the bioavailability of atenolol was reduced to 36 +/- 5% compared to 60 +/- 8% after monotherapy. During long-term treatment with atenolol and ampicillin the bioavailability of atenolol fell to 24% (P less than 0.01). Mean peak plasma levels were lowered from 511 +/- 59 ng/ml on monotherapy to 344 +/- 33 ng/ml after the combination with ampicillin. The area under the plasma level-time curve, mean steady-state concentration, and urinary recovery were reduced, also. Twelve hours after 100 mg atenolol and 1 gm ampicillin, exercise tachycardia was significantly higher than after atenolol alone. During the 4-wk treatment in six hypertensive patients blood pressure levels of those on atenolol alone were not different from those on the combination therapy with ampicillin.

Adult↗