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Biomedical subjects

A Schilling

Publications and source records attributed to A Schilling.

At least 73 records · Page 4Linked to original sources
PubMed1993

[Initial findings using dynamic magnetic resonance tomography in the diagnosis of inflammatory diseases of the sacroiliac joint].

Up to now 42 patients with clinically suspected diagnosis of sacroiliitis (including 19 patients with confirmed spondylitis ankylosans) and 12 healthy volunteers were examined via magnetic resonance tomography. In oblique sections parallel to the plane of the sacrum the signal intensity patterns from normal and pathological tissues of the sacroiliac articulations were evaluated by plain T1-weighted spin-echo sequences and T2*-weighted FLASH sequences. In addition we used a dynamic FLASH measurement following intravenous application of gadolinium-DTPA for quantitative calculation of signal-time courses. This method has proved to be capable of definitely differentiating normal findings of sacroiliac articulations from inflammatory changes (p = 0.0001) and also enables quantification of the inflammatory activity.

Adult↗
PubMed1993

Removal of the olfactory bulbs modifies the gonadal responses to photoperiod in the lesser mouse lemur (Microcebus murinus).

The sexual activity of the lesser mouse lemur, unlike that of most living primates, is clearly dependent on photoperiod. Males responded to long daylengths (> 12 h light/day) by rapid testicular development and an increase in testosterone levels reaching 65.8 +/- 1.5 ng/ml (n = 12) after 3 wk of inductive photoperiod. Levels were maintained unchanged until 14 wk of exposure to long photoperiod, when spontaneous gonadal regression was observed. Under short daylengths, intact males exhibited regressed gonadal function with low plasma concentrations of testosterone: 5.4 +/- 1 ng/ml. To investigate the effect of olfactory bulb deprivation on gonadal responses to photoperiod, 12 males were bulbectomized (BX) during exposure to either long (n = 8, BX1) or short (n = 4, BX2) daylengths. In both groups of BX males, responses to long or short daylengths were maintained. However, the timing and the amplitude of gonadal responses to photoperiod were modified; BX males underwent a significant delay in testis development and also had reduced testosterone levels (53.3 +/- 2.3 ng/ml and 37.3 +/- 0.9 ng/ml for BX1 and BX2 groups, respectively). Moreover, BX males did not exhibit spontaneous gonadal regression after 14 wk of exposure to long daylengths, indicating that the photorefractory state did not appear, at least under our experimental conditions. In this primate, olfactory bulbs exert an important effect on the neuroendocrinological control of reproductive responsiveness to photoperiod.

Animals↗
PubMed1993

Response to short photoperiod and spontaneous sexual recrudescence in the lesser mouse lemur: role of olfactory bulb removal.

The body weight and sexual activity of the male lesser mouse lemur, a prosimian primate, undergo cyclic changes that are photoperiod-dependent. Exposure to long daylength (LD; 14 h light/day) led to sustained sexual activity, fully developed testes and high plasma testosterone concentrations (228 +/- 25 nmol/l, n = 10). After 14 weeks under LD, a marked decrease in testosterone levels occurred. Gonadal regression was completed within 20 weeks under LD without concomitant changes in body weight. Exposure to short daylength (SD; 8 h light/day) reinforced the sexual quiescence and was associated with a high ponderal gain (from 60 to 110 g). However, independent of the date of gonadal arrest, the sexual activity of males spontaneously resumed at a fixed time after exposure to SD. The testes developed, testosterone concentrations increased to 155 nmol/l and the body weight decreased (from 110 to 80 g) within 20 weeks under SD exposure. The timing for refractoriness appeared very similar under inhibitory and stimulatory photoperiods. This is consistent with the hypothesis that the perception of a critical daylength is used to regulate the timing of the following sexual phase through a mechanism involving photorefractoriness. Contrary to cricetid rodents, a direct response to photoperiodic signals for both body weight and sexual activity were not prevented by olfactory bulb removal in male mouse lemurs. In bulbectomized males (n = 12), sexual activity was stimulated by LD and inhibited by SD. Their plasma testosterone levels, however, significantly differed from those of controls in both photoperiods. Likewise, ponderal cycles remained intact but the fattening phase was delayed and reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Detection and localization of perfluorodecalin in the human eye by fluorine 19 magnetic resonance.

Perfluorocarbons are applied as heavy liquids during vitreoretinal surgery. They are removed again intraoperatively because of possible harmful long-term effects. Following vitreoretinal surgery, residual perfluorodecalin (PFD) was detected in four eyes and localized in two others by fluorine 19 magnetic resonance (19F-MR). In vitro analysis of 19F-MR spectra shows that chemical shift artifacts can be avoided much better with PFD than with perfluorotributylamine and perfluoroctane. Therefore, PFD localization by 19F-MR imaging is superior to that of perfluorotributylamine and perfluoroctane. This examination can be performed on currently employed magnetic resonance imaging systems equipped with a fluorine channel. In the event of significant inadvertent residual quantities of PFD and obscured media, 19F-MR may specifically detect and localize PFD.

Aged↗
PubMed1992

[Recurrent renal colic with passing of horny lamellae. A rare differential diagnosis of renal calculi].

A 64-year-old man reported left-sided renal colics recurring regularly every 5-10 months for the past 25 years. After a typical colic urinary sediment was found to contain brownish, flaky elastic material which histologically consisted of nucleus-free keratoid lamellae. Calcium concentration in serum and urine was normal, as were the serum parathormone (215 pg/l) and inorganic phosphate levels. The intravenous pyelogram revealed a polycyclicly circumscribed filling defect (15 x 20 mm) in the left renal pelvis. At ureteroscopy a lamellar brown-grey tumour was identified which arose from the medial wall of the pelvis. Histological examination demonstrated hyper- and parakeratotic hornified squamous epithelium without malignant degeneration. This finding suggested a cholesteatoma originating from squamous epithelial metaplasia. The tumour was removed endoscopically and the renal wall coagulated by laser, a procedure repeated after 3 months. The patient has been free of symptoms for 3 years.

Cholesteatoma↗
PubMed1992

Liver tumors: follow-up with P-31 MR spectroscopy after local chemotherapy and chemoembolization.

The authors examined and quantified the changes observed in the phosphorus-31 magnetic resonance (MR) spectra of liver tumors after chemotherapy and chemoembolization to investigate the suitability of P-31 MR spectroscopy for follow-up. A 1.5-T unit was used before and at specific times during therapy to obtain spectra of liver tumors in 10 patients with liver metastases from colorectal carcinoma and two patients with hepatocellular carcinoma. A marked increase in inorganic phosphate and a decrease in the alpha- and beta-nucleotide phosphate portions of the spectra were observed during the first few hours after local chemotherapy or chemoembolization. Later, the phosphomonoester signals increased markedly and the phosphodiester signals decreased slightly. The effects of successful chemoembolization or local chemotherapy become apparent in the P-31 MR spectrum during the first few hours after the start of therapy. The results demonstrate that P-31 MR spectroscopy is a suitable method for follow-up. However, long-term studies are needed to determine whether it also yields prognostic information.

Carcinoma, Hepatocellular↗
PubMed1990

Vomeronasal activation by urine in the primate Microcebus murinus: a 2 DG study.

The vomeronasal system (VNS) seems to be functional in some primates and involved in the detection of urinary signals. Anterograde tracing (WGA-HRP) and evoked metabolic activity (2-DG method) were used in order to clarify the conditions under which the VNS is activated in the prosimian mouse lemur. After WGA-HRP deposition at one of the oral entries of the nasopalatine duct, reaction product was observed within the accessory bulb (AOB). 2-DG experiments show that urine in the volatile phase stimulates the main but not the accessory bulb (AOB). Liquid urine produced bilateral or unilateral activation of AOB depending on whether the stimulation was exclusively unilateral or not; under the same conditions distilled water could not produce 2-DG labelling. It is concluded that VNS is activated by urine in the liquid but not the volatile phase. The biological implications of these results are discussed.

Animals↗
PubMed1990

[The effect of nutritional status on the 31P MR spectrum of the normal liver].

Previous investigations in animal and human liver spectroscopy revealed a strong effect of metabolic activity on the 31P-spectra of the liver. This study examined the influence of a standardised meal on the liver spectra of healthy volunteers. The measurements were performed at 1.5 T (Magnetom, Siemens). The results show that the metabolic condition has a strong effect on the 31P MR liver spectra. The changes are of the same order of magnitude as those described in spectra of focal or diffuse liver diseases. This indicates that identical metabolic conditions are necessary for measuring liver spectra of volunteers and patients, especially in follow-ups.

Adult↗
PubMed1990

Transprostatic selective cystectomy with an ileal bladder.

Since 1987 we have changed our surgical approach to radical cystectomy and ileal neobladder in order to maintain erectile function and urinary continence. The routine diagnostic work-up includes a staging transurethral resection of the prostate in order not to miss any ductal involvement. The selective cystovesiculectomy is performed by cutting through the apex of the prostate, thus leaving a wide, funnel-shaped tunnel of the prostatic urethra for the anastamosis with the M- or W-shaped ileal reservoir. The preliminary results of 27 patients show excellent results concerning erectile function and continence, as requested by our predictive criteria. Especially the continence achieved after a training period of 3 months is reliable. Further observation will show whether the functional improvements and advantages in the operative technique are achieved at the cost of a higher relapse rate of urethral tumors.

Carcinoma, Transitional Cell↗
PubMed1990

[Prognosis and therapy of kidney carcinoma in a retrospective study in 624 patients].

624 patients, who were treated for carcinoma of the kidney between 1966 and 1987 were analysed in a retrospective study. Prognosis depended in tumor size, lymphatic metastases, and tumor grading. Tumor spread into the renal veins or into the vena cava without lymphatic metastases did not reduce life expectancy. Different symptoms are important as prognostic criteria. Small tumors without spread into the veins can be sufficiently operated from a lumbo costal incision. Preoperative radiation is no beneficial.

Humans↗
PubMed1989

[Magnetic resonance tomography in ophthalmology. II. Manifestations of edema of the optic nerve].

MRI findings specific for lesions of the optic nerve are reported in the present paper for the first time: a dilated subarachnoidal space during the acute phase and scars in the neural tissue several months later. For imaging, the authors used special pulse sequences and surface coils. Twenty of 37 patients presenting with these symptoms were suffering from retrobulbar neuritis. In at least 12 (60%) of them the neuritis was associated with multiple sclerosis. Patients with tumors of the sella region usually have bilateral edema in the subarachnoidal spaces of both nerves. The edema is always located distal to the nerve lesion. The subarachnoidal edema is only of limited significance as a sign of optic neuritis. On the other hand, the authors failed to find a single case of neuritis without such edema.

Adult↗
PubMed1989

[Septic sacroileitis].

Two cases of pyogenic sacroileitis, one in the late puerperium and the other in a patient caring out a term-pregnancy are reported. Epidemiology, clinical features, diagnostic measures, etiology and treatment are discussed.

Adult↗
PubMed1989

[Use and knowledge of contraceptive methods in female students of children education].

An inquire about contraception use and knowledge was applied to 292 female students. (Average of age = 21.3 years) An 88.4% of the woman with sexual activity had used contraceptive methods at least once. Principal reason for not going on using them, was not having sexual intercourse. In single women, the use of contraceptive methods was related with age, while the type selected was related with sexual intercourse's frequency. The most used contraceptive methods were rhythm and pill, which were not the best known ones.

Adult↗
PubMed1989

[Amelanotic melanoma and nuclear magnetic resonance tomography--case report].

In MRI choroidal melanoma shows a very short relaxation time (T2), shorter than that of any other intraocular tumor. This short T2 time is referred to the high concentration of paramagnetic melanine in this tumor. Therefore, it is of interest to measure the relaxation time in an amelanotic melanoma and compare it with the histological analysis. The duration of T2 for the amelanotic melanoma examined ranged from 130 to 160 ms. The small concentration of melanine is not a sufficient explanation, but it is possible that there are some precursors of melanine with paramagnetic characteristics.

Adult↗