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Biomedical subjects

C Graf

Publications and source records attributed to C Graf.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Current information on the composition and breed distribution of urinary stones in dogs].

5706 canine urinary stones were analyzed by means of infrared spectroscopy from 1984-1996. The stones were sent in together with epidemiologic data (breed, age, sex, localisation of the stones, type of stone removal, stone frequency etc.) by more than 800 veterinarians from Germany, the Netherlands, Austria, and Switzerland. Irrespective of stone type, urinary stones were observed in almost all breeds, but small breeds like dachshound, poodle, terrier, schnauzer, and pekingese have a higher tendency to form stones. With 59.5% struvite is the most frequent stone type, followed by cystine with 15.5%. Cystine stones are becoming less frequent during the observation time, whereas the share of calcium oxalate (14.2%) and ammonium urate (6.0%) stones remains unchanged. The latter stone types are found predominantly in specific breeds. The stone formation appears predominantly at the age of 7. Male dogs form stones twice as often as female dogs. 98% of the stones were located in the lower urinary tract. About 90% of the urinary stones required surgical treatment.

Animals↗
PubMed1994

Pattern of gonadotrophin secretion in patients with hyperandrogenaemic amenorrhoea before and after ovarian wedge resection.

The follow-up of androgen and gonadotrophin concentrations after ovarian wedge resection is reported in two patients with hyperandrogenaemic amenorrhoea. Elevated testosterone concentrations decreased immediately and androstenedione after 3 months. In a patient with polycystic ovarian disease, luteinizing hormone (LH) amplitudes were reduced in the presence of unchanged pulse frequency. Small decreases in mean LH baseline values were accompanied by increases in follicle stimulating hormone concentrations. Our data provide evidence that reduction of elevated ovarian androgen concentrations leads (directly or indirectly) to a decrease of exaggerated LH pulse amplitude in patients with hyperandrogenaemic amenorrhoea.

Adult↗
PubMed1993

Sodium retention and hypertension after kidney transplantation in rats.

The present study was designed to investigate the development of blood pressure and renal sodium handling in recipients of renal grafts from adult stroke-prone spontaneously hypertensive rats (SHRSP), normotensive Wistar-Kyoto (WKY) rats, and borderline hypertensive F1 hybrids bred from SHRSP and WKY rats. Unilaterally nephrectomized F1 hybrids served as renal graft recipients. The second native kidney was removed 7 days after transplantation. Starting on the day of transplantation, renal graft recipients were put on a standard diet for 7 days followed by a low salt diet (0.18% salt) for 10 days and a high salt diet (1.8% salt) for another 14 days. In recipients of a renal graft from SHRSP donors, systolic blood pressure rose progressively from 140 +/- 4 mm Hg before to 190 +/- 7 mm Hg 4 weeks after transplantation. In contrast, in recipients of a renal graft from WKY rat donors, blood pressure fell during the same time from 139 +/- 7 mm Hg to 120 +/- 4 mm Hg. Blood pressure did not change significantly in recipients of a renal graft from F1 hybrid donors (132 +/- 4 versus 138 +/- 7 mm Hg). With transition from a low salt to high salt diet, all rats exhibited renal sodium retention. The accumulating amount of sodium retained by the renal graft was significantly higher in recipients of an SHRSP kidney than in recipients of a WKY rat kidney at all days on the high salt diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1992

[Dexamethasone does not normalize disordered LH pulsatility in hyperandrogenemic ovarian insufficiency].

Application of dexamethasone (DEX) is well accepted for treatment of hyperandrogenemic ovarian failure (HOI). In some cases of clomiphene resistance, additional DEX can induce ovulatory cycles. In this study, we evaluated the influence of adrenal androgen reduction on the gonadotroph during longterm therapy with 0.5 mg DEX daily in a larger group of patients (n = 25) in order to investigate subgroups of HOI. Women with elevated DHEA-sulfate levels only (DS-group); with elevated testosterone and/or androstenedione levels only (TA); with polycystic ovaries in ultrasound (PCO), with highest LH levels (LH); with secondary amenorrhea (SA); with oligomenorrhea (OL) and with elevated body mass index (BMI) were included. Blood samples were taken at 10 min intervals for 12 h sampling periods (8am-8pm) and analyzed by RIA. In amenorrhoeic patients, investigations took place at monthly intervals; in cycling women preferentially on day 5 of the cycle. LH and FSH profiles were evaluated by 3 different computerized peak identification programs ("pulsar", "ultra" and "modified Santen and Bardin"). DEX resulted in significant decreases in T, A, DS and progesterone serum levels in all subgroups. No significant alterations were found in estradiol levels and only small variations in few subgroups with estrone. Mean LH concentrations exhibited small decreases (p less than 0.05) in DS-, LH- and OL subgroups and no changes in the others. With the exception of a decrease in "pulsar" pulse frequency in the OL subgroup, no changes in pulse frequency or amplitude were found in any other group during DEX therapy. Mean FSH concentrations and pulsatility did not vary either.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

On the role of renal alpha-adrenergic receptors in spontaneously hypertensive rats.

We tested the hypothesis that a genetically determined increase in renal alpha-adrenergic receptor density might be a pathophysiologically important factor in the spontaneously hypertensive rat model of genetic hypertension. In a first study, we compared renal alpha 1 and alpha 2-adrenergic receptor density with systolic blood pressure in 45 rats of an F2 generation of Wistar-Kyoto x spontaneously hypertensive rat hybrids but were unable to detect significant cosegregation between either receptor density or blood pressure. In a second study, we determined renal alpha 1- and alpha 2-adrenergic receptor density in Wistar-Kyoto and spontaneously hypertensive rat kidneys that were transplanted into an F1 generation of Wistar-Kyoto x spontaneously hypertensive rat hybrids. Although Wistar-Kyoto kidneys lowered blood pressure in these animals and spontaneously hypertensive rat kidneys increased blood pressure, renal alpha-adrenergic receptor densities were similar in membranes from both types of kidneys. Since rat kidney coexpresses alpha 1A- and alpha 1B-adrenergic receptors, we also investigated whether differential regulation of these two subtypes might conceal ongoing alterations. The alpha 1A/alpha 1B-adrenergic receptor ratio, however, was similar in Wistar-Kyoto rats, spontaneously hypertensive rats, and F1 rats transplanted with a kidney from either strain. Taken together these data do not support the hypothesis that genetically determined alterations of renal alpha-adrenergic receptor numbers play an important role in the development of elevated blood pressure in the spontaneously hypertensive rat.

Animals↗
PubMed1991

Are renal mechanisms involved in primary hypertension? Evidence from kidney transplantation studies in rats.

Previous renal transplantation experiments in genetically hypertensive and normotensive rat strains indicated that a genetic defect in the kidney may be primarily involved in the pathogenesis of primary hypertension. In order to investigate whether this is also true for the most widely used animal model of primary hypertension, the spontaneously hypertensive rat (SHR), we performed renal transplantations using SHR and normotensive Wistar-Kyoto rats (WKY) as kidney donors and bilaterally nephrectomized F1 hybrids, bred from SHR x WKY parents as renal graft recipients. Our studies were also designed to differentiate between primary and secondary renal mechanisms as a possible cause of posttransplantation hypertension. Recipients of renal grafts from adult, naive SHR but not from adult normotensive WKY kidney donors developed posttransplantation hypertension. Permanent blood pressure normalization by antihypertensive treatment in adult SHR kidney donors and prehypertensive, young age of SHR kidney donors reduced, but did not prevent, posttransplantation hypertension. Increasing renal perfusion pressure in WKY kidney donors (2-kidney 1-clip hypertension) also resulted in posttransplantation hypertension in recipients of the non-clipped kidneys. Blood pressure remained normal in recipients of renal grafts from young WKY kidney donors. These data suggest that SHR kidneys carry a genetic defect which may be primarily involved in the pathogenesis of primary hypertension.

Animals↗
PubMed1991

Post-transplantation hypertension in recipients of renal grafts from hypertensive donor rats.

Renal transplantations were performed using stroke-prone spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) as kidney donors and bilaterally nephrectomized F1 hybrids, bred from SHR x WKY parents as renal graft recipients. Recipients of renal grafts from adult, naive SHR but not from adult normotensive WKY kidney donors developed post-transplantation hypertension. Permanent blood pressure normalization by antihypertensive treatment in adult SHR kidney donors, as well as the young, prehypertensive age of SHR kidney donors reduced but did not prevent the development of post-transplantation hypertension. Increasing renal perfusion pressure in WKY kidney donors (chronic 2-kidney 1-clip renovascular hypertension) also resulted in post-transplantation hypertension in recipients of the non-clipped kidneys. Blood pressure remained normal in recipients of renal grafts from young WKY kidney donors. These data suggest that SHR kidneys carry a genetic defect which can give rise to post-transplantation hypertension and which therefore may also play a role in the development of hypertension in naive SHR. In addition, secondary hypertension-induced renal damage may also contribute to post-transplantation hypertension in recipients of renal grafts from hypertensive donors.

Animals↗
PubMed1984

Thiamphenicol induced bone marrow suppression as a therapy of myeloproliferative diseases.

Sixteen patients, suffering from myeloproliferative diseases (9 polycythaemia vera, 7 primary thrombocythaemia) and 20 control subjects were treated for 14 days with 1 g of thiamphenicol per day. The effect of 40 treatment cycles was studied. The regimen resulted in lowering the haemoglobin values by 4.8% in controls (p greater than or equal to 0.001) and patients (p greater than or equal to 0.01); the reticulocyte count dropped 43% in the patient group (p greater than or equal to 0.01) and 32% in the controls (p greater than or equal to 0.05); the thrombocyte count was decreased 42% (p greater than or equal to 0.0001) vs 29% (p greater than or equal to 0.0001) in the control group. The administration of 1 g/day of thiamphenicol for a 14 day period reduced the myelopoietic activity by 40%. The decrease of all values was statistically significant. After discontinuation of thiamphenicol therapy the haematological parameters returned to the initial values within 1-2 months. The myelodepressant activity of thiamphenicol may therefore be applied to the therapy of the myeloproliferative diseases in order to reduce the risk of spontaneous haemorrhages and thrombosis.

Bone Marrow↗
PubMed1983

[Prevention of vascular complications in polycythemia vera and primary thrombocythemia treated with low doses of acetylsalicylic acid].

22 patients (13 with polycythaemia vera and 9 with primary thrombocythemia) were treated with 250 mg acetylsalicylic acid (ASA) daily for an average of 25 months. Before therapy was started, 3 patients had arterial thromboses, 3 had venous thromboses, 3 had spontaneous hemorrhage, 3 had acral circulatory disorders and 13 had dizziness, whereas under ASA treatment neither arterial nor venous thromboses occurred and only 4 mild spontaneous hemorrhages were recorded. Under ASA the circulatory disorders of the extremities disappeared completely in 11 patients and recurred intermittently in milder form in 2 patients. Dizziness was completely abolished in 12 of the 13 patients. Discontinuation of therapy was followed by prompt recurrence of symptoms. No correlation could be established between symptoms and extent of platelet disease either before or during ASA therapy. Low-dose salicylates are highly effective in the prevention and treatment of vascular complications in polycythaemia vera and primary thrombocythemia. Thanks to ASA, potentially leukemogenic cytostatic agents and radiophosphorus can be used more sparingly.

Aged↗
PubMed1983

[Idiopathic thrombocytopenic purpura: diagnosis and therapy in 46 patients].

The hematological and immunological data of 46 patients with idiopathic thrombozytopenic purpura (ITP) and their response to treatment are reported. The findings are as follows: (1) Antiplatelet antibodies (serum assays) cannot be recommended as a useful diagnostic approach in ITP. (2) Circulating immune complexes are demonstrable in 77% of our patients. (3) The bone marrow contains increased numbers of eosinophils and erythrocytes in about the half of the patients. (4) A "remission" is obtained in 50% of patients with corticosteroids and in 60-80% with splenectomy. Among the immunosuppressants, cyclophosphamide appears to be the most useful. (5) Fatal hemorrhages are very rarely seen in adults with ITP.

Adolescent↗
PubMed1983

[Non-Hodgkin lymphoma of the testis].

Non-Hodgkin's lymphomas of the testis comprise 25-50% of testicular tumors in men over 50 years of age. Using the Rappaport histologic terminology, most testicular lymphomas are of the diffuse histiocytic type. Concomitant involvement of Waldeyer's ring or of paranasal sinuses frequently occurs. Eight patients with primary non-Hodgkin's lymphoma of the testis and 2 patients with a lymphoma which arose in the paranasal sinuses and later involved the testis are reported. The median age of the 10 patients was 57 years. 5 of 8 patients with primary testicular lymphoma were in clinical stage IE. 8 of the 10 patients had diffuse histiocytic lymphoma. Using the Kiel histologic terminology, 4 of these 8 patients had diffuse centroblastic lymphoma and 4 had immunoblastic sarcoma. 5 of the 8 patients with primary testicular lymphoma had complete remission after orchiectomy followed by radio- and/or chemotherapy. The median survival of the 8 patients with primary testicular lymphoma was 30 months. The median survival of patients with complete remission was 44 months and in patients without remission 12 months. Careful staging of patients with testicular lymphoma is of decisive therapeutic and prognostic significance.

Humans↗
PubMed1982

[Clinical staging and course of chronic lymphatic leukemia].

77 patients with chronic lymphocytic leukemia were clinically staged according to a staging system recently proposed by Binet and limited to 3 stages. The 49 patients with stage A disease (not more than 2 areas of palpable nodes or organs) had a median survival time of 141 months; the 17 patients with stage B disease (three or more involved areas) had a median survival time of 71 months and the 11 patients with stage C disease (anemia and/or thrombopenia) had a median survival of 37 months. With this simple three-stage system statistically significant differences of survival between the three groups of patients have been observed. This staging system is useful for the prognostic evaluation of patients with chronic lymphocytic leukemia.

Adult↗