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Biomedical subjects

W Albrecht

Publications and source records attributed to W Albrecht.

At least 55 records · Page 3Linked to original sources
PubMed1992

Management of ureteric calculi (minimally invasive therapy of ureteric stones).

As documented with results obtained in 1685 patients the treatment of ureteric stones is today based on ESWL in situ and ureteroscopy with semirigid, ultrathin ureteroscopes and laser lithotripsy. All stones in the upper third of the ureter and larger stones in the distal third of the ureter are preferably treated with ESWL in situ whereas smaller stones in the distal ureter are better treated endoscopically. Midureteric stones remain the domain of primary ureteroscopy; with moderate obstruction in the asymptomatic patient it may also be acceptable to wait for the stone to pass into the distal ureter spontaneously to be treated by ESWL in situ there. Manipulating stones back into the kidney and treating them by ESWL there (pushback/ESWL) offers no advantage over ESWL in situ, as the results are similar, yet morbidity is higher. Blind instrumentation and open surgery have lost all justification.

Endoscopy↗
PubMed1991

Lord's procedure--the best operation for hydrocele?

A prospective study was carried out to compare Lord's hydrocele operation with traditional surgical procedures. The groups of patients investigated were comparable in terms of age, period of observation, number of previous aspirations and size of hydrocele. The incidence of isolated hydrocele of the spermatic cord, as well as epididymal cysts, was lower in the patients who underwent Lord's procedure (7.2 versus 15.8%), as was the percentage of patients reporting post-operative pain for more than 3 days (4.3 versus 15.8%, p less than 0.05).

Adolescent↗
PubMed1991

How effective is topical alpha-2b interferon in preventing recurrence of superficial bladder cancer?

A total of 44 patients with low and intermediate grade superficial urothelial bladder cancer Ta and T1 were randomised into a controlled, long-term, phase III trial on topical instillation therapy with high dose alpha-2b interferon (100 x 10(6) IU versus low dose alpha-2b interferon (10 x 10(6) IU) versus ethoglucid. Thirteen patients in the low dose group, 11 in the high dose group and 10 in the ethoglucid group completing the trial were evaluable (median follow-up 36.5 months) and were followed up for 3 years. They were treated weekly for 10 weeks and then monthly for a total of 1 year. The aim of the trial was to establish the prophylactic efficacy and the toxic side effects, if any, of alpha-2b interferon in the topical treatment of superficial bladder cancer. Recurrence rate and disease-free survival were chosen as study end-points. The recurrence rate was 4.4 in the low dose interferon group, 2.76 in the high dose interferon group and 3.08 in the ethoglucid group. In the low dose interferon group the time to the first recurrence was 22.23 months versus 22.36 in the high dose group and 21.76 months in the ethoglucid group. No differences of statistical significance were noted between the 3 groups. Progression occurred in 5 patients on interferon but was not seen in those on ethoglucid. Neither systemic nor local side effects were seen in the interferon groups, but 3 patients had to be taken off ethoglucid because of severe chemocystitis. In superficial bladder cancer, topical instillation therapy with interferon is as effective as conventional chemotherapy and has no side effects.

Administration, Intravesical↗
PubMed1990

Biomonitoring of aromatic amines. III: Hemoglobin binding of benzidine and some benzidine congeners.

Covalent binding of benzidine and some congeners to hemoglobin was studied in female Wistar rats after oral administration. Hemoglobin adducts were hydrolyzed under alkaline conditions, and the arylamines extracted and analysed by HPLC with electrochemical detector. With benzidine, three cleavage products were observed, the major component being monoacetylbenzidine. This indicates that 4-nitroso-4'-N-acetylaminobiphenyl is the major reactive metabolite in erythrocytes. In addition benzidine and 4-aminobiphenyl were identified. The latter indicates a hitherto unknown metabolic pathway of benzidine. With 3,3'-dichlorobenzidine-dihydrochloride, 3,3'-dimethoxybenzidine and 3,3'-dimethylbenzidine two cleavage products were observed, the parent diamines being present in excess to or in amounts comparable to the monoacetyl derivative. With 3,3',5,5'-tetramethylbenzidine a hemoglobin adduct could not be found. When the azo dye direct red 28 was administered to the animals, the three cleavage products typical for benzidine were found, indicating that benzidine became bioavailable after reductive cleavage of the azo compound. In this case the fraction of 4-aminobiphenyl was greater than after benzidine. It is proposed to use the analysis of hemoglobin adducts in human blood to control the exposure of individuals to these carcinogenic chemicals in the course of biochemical effect monitoring.

Administration, Oral↗
PubMed1990

Recurrent superficial transitional cell carcinoma of the bladder: adjuvant topical chemotherapy versus immunotherapy. A prospective randomized trial.

A multicenter, prospective, randomized controlled study was begun in 1985 on the effect of ethoglucid and keyhole-limpet hemocyanin in the prevention of recurrent superficial transitional cell carcinoma of the bladder (stages pTa to pT1, grades 1 to 3 according to the recommendation of the International Union Against Cancer and the World Health Organization). The study was performed on a selected group of patients at high risk for further recurrences. All of these patients were pre-treated with different chemotherapeutic agents (doxorubicin or mitomycin C) and still had recurrent superficial transitional cell carcinoma. All tumors were removed by transurethral resection and all patients were presumed to be free of tumor at initiation of the prophylactic instillations. Patients in the ethoglucid group received 0.565 gm. (solution of 1%) ethoglucid weekly for 6 weeks and then monthly for 1 year. Patients in the keyhole-limpet hemocyanin group were immunized with 1 mg. keyhole-limpet hemocyanin intracutaneously, and then weekly bladder instillations of 30 mg. were given for 6 weeks and then monthly for 1 year. The percentage of recurrences, recurrence rate, interval free of disease, tumor progression and effect on downstaging were evaluated for both therapeutic arms. The percentage of recurrences (60.9% in the ethoglucid group versus 55.3% in the keyhole-limpet hemocyanin group) and the comparison of interval to recurrence for all patients showed no statistical significant difference (p = 0.808, Mantel-Cox test). A comparison of the interval to recurrence in patients with recurrent tumors only showed a mean interval free of disease of 8.8 months for patients given ethoglucid versus 5.5 months for those given keyhole-limpet hemocyanin (p = 0.006, Wilcoxon test). Recurrence rate (4.8 versus 6.5, respectively) and tumor progression rate (21.7 versus 21.1%, respectively) showed no statistically significant difference (p greater than 0.1).

Administration, Intravesical↗
PubMed1990

ESWL and endourology on the same table: a feasible concept?

Within 26 months a total of 4,126 procedures were performed on the ESWL multipurpose table. Forty percent of the procedures were comprised of endourology, 25% functional urinary tract radiology, and 37% ESWL therapy. Biplane fluoroscopy is an extraordinary help for percutaneous interventions. A further advantage is the possibility to perform endourology and ESWL in one session without having to transport the patient. This has facilitated pre- and post-operative ancillary measures in a total of 35.3%. Seventy-six percent of stones greater than 15 mm were managed via indwelling stents. In situ ESWL for ureteral stones has become the therapy of choice in more than 80% of patients due to the availability of radiological localization systems and a complication and failure rate of 20% for the push-and-smash procedure. The multipurpose table is equally successful as the piezoelectric system for ESWL therapy. Drawbacks include operational inconvenience with percutaneous interventions and the necessity to change patient position during ureterorenoscopy and retrograde pyelography. The multipurpose unit used is a valid compromise for ESWL and percutaneous endourology. For purely diagnostic interventions, a standard x-ray table is preferred.

Adolescent↗
PubMed1985

Biomonitoring of aniline and nitrobenzene. Hemoglobin binding in rats and analysis of adducts.

Covalent binding to hemoglobin was studied to further substantiate the proposal that it may be used for biomonitoring N-substituted aryl compounds. (14C)-Labeled acetanilide and nitrobenzene were orally administered to female Wistar rats and binding indices [Binding(mmol/mol Hb)/Dose(mmol/kg)] determined; these were 12 +/- 1 and 73 +/- 10, respectively. After mild acidic or alkaline hydrolysis, 90% of the bound material was released and identified as aniline by radio thin layer chromatography. This supports the hypothesis that nitroso aryl derivatives, common intermediates in the metabolism of N-substituted aryl compounds, react with SH-groups of hemoglobin to yield sulfinic acid amides. Aniline was furthermore identified and quantified by capillary gas chromatography, using hemoglobin from animals treated with unlabeled aniline and nitrobenzene. Binding indices in this case were 30 +/- 3 and 85 +/- 19, respectively. With this method human blood samples may also be analysed. Although nitrobenzene is known to produce less methemoglobin than aniline, hemoglobin binding is higher. This indicates that hemoglobin binding may be a better index of body burden than methemoglobin levels in biomonitoring N-substituted aryl compounds.

Acetanilides↗
PubMed1984

Role of the adrenals in the development of streptozotocin (STR)-induced diabetes in male albino rats.

Diabetes induced by streptozotocin (STR) (55 mg/kg i.v.) in non-fasting, male albino rats is considerably mitigated by adrenalectomy. The timing of the operation is important for the effect of blood glucose. The later the adrenalectomy, the lesser the protection against STR. Plasma insulin in intact, STR-treated rats is significantly lower than in rats that have also been adrenalectomized. Pancreatic insulin in both groups is 10 times lower than in normal controls and adrenalectomized rats. Plasma FFA are distinctly elevated in intact, STR-treated rats. Adrenalectomy in these diabetic animals reduces plasma FFA to levels below those of normal controls. The changes in the glycogen contents of the diaphragm and myocardium of STR-treated rats are reversed by adrenalectomy. The rate of pancreatic insulin degradation might be retarded or the rate of secretion increased. In addition, sensitivity to insulin is exaggerated after adrenalectomy, as is evident from the changes in blood sugar and the glycogen contents of the organs. These changes in the effects of insulin are ascribed to deprivation of adrenal steroids and in particular glucocorticoids. Loss of the adrenal medulla is presumably one of the causes of the changes in plasma FFA.

Adrenal Glands↗
PubMed1983

[Determination of the optimal L-thyroxine dosage for treating nontoxic goiter].

303 patients with non-toxic goitre (aged 14-85 years) were studied to determine the extent to which the level of thyroid-hormone dosage until a negative TRH test is reached can be defined in terms of age, body surface area and goitre size. In all instances detailed examination had determined regular hormone intake. The required L-thyroxine dose (until negative TRH test) was 100 micrograms/d in 75.6% of cases, 125 micrograms/d in 9.2% and 150 micrograms/d in 8.6% of cases. In 2.6% of cases was a satisfactory suppression reached at 50 microgram/d and in 4% at 75 micrograms/d. There was no correlation of the level of L-thyroxine dose to body surface area, age, T3 level, delta-TSH or goitre size. There was a slight correlation between T4 level and optimal L-thyroxine dose, but not significant because of the wide range of normal. The results indicate that the only way to obtain optimal L-thyroxine dosage in the treatment of goitre is by doing a TRH test in the given patient.

Adolescent↗
PubMed1983

Sulfonyliminoimidazolidines, a new class of oral hypoglycemic agents. 3. Hypoglycemic activity and mode of action of 1-[p-[2-(crotonylamino)-ethyl]-phenylsulfonyl]-3-cyclohexyl-2-imino- imidazolidine (CGP 11 112).

1-[p-[2-(Crotonylamino)-ethyl]-phenylsulfonyl]-3-cyclohexyl-2-imino- imidazolidine (CGP 11 112) is a representative of a new class of oral hypoglycemic agents. It lowers blood glucose in normal animals and in streptozocin (streptozotocin)-diabetic rats. In normal mice, rats and dogs the hypoglycemic effect is more potent (range 3-30 times) and has a shorter duration than that of tolbutamide. CGP 11 112 increases plasma insulin after oral administration in normal animals and stimulates release of insulin in perifused rat islets in vitro (sulfonylurea-like effect). In streptozocin-diabetic rats CGP 11 112 decreases blood glucose with a potency comparable to that of phenformin. In contrast to phenformin, CGP 11 112 does not increase blood lactate in diabetic rats or inhibit intestinal absorption of glucose. An effect of CGP 11 112 on gluconeogenesis and glycogenolysis could not be demonstrated. It is suggested that the hypoglycemic activity in streptozocin-diabetic rats may be due to stimulation of glucose efflux from the circulation. In vitro, CGP 11 112 inhibits glucose oxidation and lipolysis in isolated rat fat cells.

Adipose Tissue↗
PubMed1979

[Effect of dermatocorticoids on the activity of hepatic tryptophane pyrrolase in the guinea pig (author's transl)].

The enzyme activity of tryptophane pyrrolase in guinea pig liver can be measurably increased--as in other mammalian species--by systemic administration of corticoids, but this effect is short-lived and achieved only with high s.c. doses of, e.g., prednisolone (Ultracorten-H-hydrosoluble). In contradistinction and rather surprisingly the enzyme activity is variably but markedly reduced by high-dosed and protracted epicutaneous application (10 times within 2 weeks) of the well-known dermatocorticoids: hydrocortisone, fluocinolone acetonide, and clobetasol propionate. This reaction must be explained by the capacity of these corticoids to inhibit, after their percutaneous absorption, the functional axis pituitary--adrenal cortex--liver, the stimulatory role of which is mandatory for the endogenous basic activity of hepatic tryptophane pyrrolase.

Administration, Topical↗
PubMed1977

Biological activity of synthetic human insulin.

The biological activity of human insulin, prepared by total chemical synthesis, was compared in various tests in vivo and in vitro with that of natural human or pork insulin. The potencies of the synthetic and natural hormone, as determined by the mouse convulsion assay, by hypoglycaemic effect and diaphragm glycogen increase in fasted rats in vivo, or by stimulation of 14C-glucose metabolism in fat cells and binding to anti-insulin serum in vitro, did not differ significantly. It is concluded that this synthetic human insulin is biologically equivalent to the natural hormone.

Adipose Tissue↗