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Biomedical subjects

C Volz

Publications and source records attributed to C Volz.

10 recordsLinked to original sources
PubMed2006

Chain morphologies in semicrystalline polyfluorene: evidence from Raman scattering.

The beta phase in di-octyl substituted polyfluorene (PF8) exhibits a surprising level of conformational order at nanometer length scales compared to other phases. We present Raman scattering studies of PF8 as a function of thermal cycling, which establishes a connection between the conformational isomers and the side and main chain morphology. Density-functional calculations of the vibrational spectra of single chain oligomers in conjunction with the experimental results demonstrate the incompatibility of the beta phase with the overall alpha crystalline phase in PF8.

Journal Article↗
PubMed1996

The Dornier-Lithotripter U30. First clinical experience.

OBJECTIVE: It can be claimed that ESWL is an optimal alternative for ablation of calculi by external shock waves. The new developments in ESWL have focussed more on the economic aspects of treatment rather than enhancing its efficacy or reducing the side effects. Since August 1993, the prototype of the Dornier Lithotripter U-30 was used at the Department of Urology of the Katharinen hospital in Stuttgart. METHODS/RESULTS: In 16 months, 1092 stones were treated requiring 1533 sessions. Complete disintegration was achieved in 84%; after 3 months' follow-up, 85.5% of the patients were stone free. CONCLUSION: The Dornier Lithotripter U-30 provides easy handling and a short learning curve and a sufficient disintegration of the stones. The device is suitable for safe and effective treatment of all urinary calculi, with special respect to in situ treatment of ureteral stones.

Equipment Design↗
PubMed1995

The Dornier Lithotripter U 30: first clinical experience.

Since August 1993, the Dornier Lithotripter U 30 has been used at the Department of Urology of the Katharinenhospital in Stuttgart. The machine consists of an endourologic table with an X-ray unit mounted on a C-arm and an electromagnetic shockwave source equipped with an inline ultrasound scanner and oblique shockwave coupling with a water cushion. Stone location can be performed with fluoroscopy or simultaneous ultrasound scanning. Until December 1994, 1092 stones had been treated, requiring 1533 sessions: 497 stones (45.5%) were situated in a calix, 426 (39%) in the renal pelvis, 130 (11.9%) in the upper ureter, and 39 (3.6%) in the distal ureter. Auxiliary measures were necessary before SWL in 245 patients (16%): double-J stent placement in 184 patients (12%), percutaneous lithotripsy in 43 patients (2.8%), and percutaneous nephrostomy in 15 patients (1%). The mean number of shockwaves was 3018, ranging from 250 to 3750. The time needed for positioning ranged from 1 to 10 minutes (mean 3 minutes). The mean treatment time was 30.5 minutes (range 10-50 minutes). There were 26 treatments (1.7%) performed without analgetic medication. In 1359 cases (88.6%), analgetics were utilized, and in 108 cases (7.0%), a sedative was added. In 40 patients (2.6%), general anesthesia was necessary. Complete stone disintegration was achieved in 94%. Auxiliary measures after SWL were ureteroscopy in 8.4% and percutaneous nephrostomy in 1.3%. Perirenal hematomas were found in 10 patients (0.6%). Colic pain necessitating analgetic medication was reported by 247 patients (16.1%). Body temperature above 38 degrees C occurred after 20 treatments (1.3%). At 3 months' follow-up, 110 patients of 128 patients (85.9%) were stone free. The Dornier Lithotripter U 30 has proven highly effective for SWL of renal and ureteral stones, radiolucent and radiopaque, and can be used as a full endourologic work-station.

Follow-Up Studies↗
PubMed1995

Social variation in attitudes to obesity in children.

OBJECTIVE: To evaluate variations in children's attitudes to obesity in relation to age, gender and social class. DESIGN: Evaluation of sex, age and social class differences in judgements of figure drawings varying in body shape. SUBJECTS: 180 children aged from 4-11 from six schools, varying in the social background of their pupils. MEASUREMENTS: Self ratings of body shape, choices of ideal body shape now and in adulthood from a range of line drawings of figures varying in fatness, and behavioural and personality stereotype judgements of illustrations of thin, average and fat children. RESULTS: Few children in this age group were fat and few felt too fat; though a substantial minority felt too thin. Girls selected thinner ideal figures than boys. Children demonstrated strongly negative attitudes to obesity, which were less favourable among those who were older and from the higher social status schools. CONCLUSION: There are significant social variations in attitudes to obesity which might be important in understanding variations in the prevalence of obesity and weight control practices.

Aging↗
PubMed1995

[Magnetic resonance tomography of the scrotum. Experiences with 129 patients].

In our study 129 patients underwent MR imaging for evaluation of the scrotum with spin-echo pulse sequence (proton density and T2-weighted images). The final diagnosis was confirmed by surgery in 54 patients. Our findings show that MRI is a powerful supplementary technique for scrotal imaging when ultrasound findings are unclear or are inconsistent with the clinical history. MRI can reduce the number of unnecessary exploratory operations on the testis, though surgery is unavoidable if the findings are equivocal. Differentiation and specification of tumours cannot be achieved by MRI, nor does it allow accurate evaluation of subacute torsion of the testis. In these cases dynamic MRT following intravenous administration of Gd-DTPA may improve the diagnostic accuracy.

Adolescent↗
PubMed1989

Selective antagonists reveal different functions of M cholinoceptor subtypes in humans.

Effects of atropine and of the subtype selective mAChR antagonists pirenzepine (PZ) and AF-DX 116 were studied in humans. Dose- or time-response curves were established for heart rate and salivary flow. Plasma samples were drawn in parallel with the effect measurements and analysed for drug concentrations. Subtype-selective radioreceptor assays of the samples served to estimate the respective receptor occupancy in vivo. It is shown that low doses of PZ (M1-selective blockade) cause cholinomimetic effects indicated by bradycardia and increase in salivary flow. After high doses of PZ or atropine, tachycardia and inhibition of salivary flow are observed in parallel with occupancy of both the M2 and M3 subtypes. AF-DX 116 induces a tachycardia together with an increased salivary flow in agreement with its selectivity profile (M2 greater than M1 greater than M3). The diagnostic and therapeutic applications of M1- or M2-selective blockade by low dose PZ or AF-DX 116 respectively are discussed.

Humans↗
PubMed1984

Cytomorphological and histological studies on the urothelium during and after chemoimmune prophylaxis.

During and after chemoimmune prophylaxis with i.v. cyclophosphamide (CTX) and both intravesical and systemic BCG-treatment, the bladder mucosa is prone to morphological changes which might resemble tumor recurrences. Therefore, morphological parameters which can discriminate between treatment effects and tumor recurrences are of interest. In a prospective study, routine cytology, determination of granulocytes, lymphocytes, and macrophages in the urine sediment as well as flow-cytophotometry (FCM) for DNA analysis were performed before, during, and after chemoimmune prophylaxis. In addition, bladder biopsies and all recurrent tumors were histologically analysed. Our results show that FCM is the best method for monitoring the bladder mucosa for recurrent tumors during treatment. After termination of BCG, it takes at least 4 months for cytological normalization to take place. Urine excretion of granulocytes, lymphocytes, and macrophages does not correlate with this process. Histological alterations during treatment are demonstrated; their normalization requires at least 3 months. In 10% of the patients chronic inflammatory lesions ("pseudotumors") develop.

BCG Vaccine↗